drivers/tty/serial/imx.c

   1 /*
   2  * Driver for Motorola/Freescale IMX serial ports
   3  *
   4  * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   5  *
   6  * Author: Sascha Hauer <sascha@saschahauer.de>
   7  * Copyright (C) 2004 Pengutronix
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  */
  19
  20 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  21 #define SUPPORT_SYSRQ
  22 #endif
  23
  24 #include <linux/module.h>
  25 #include <linux/ioport.h>
  26 #include <linux/init.h>
  27 #include <linux/console.h>
  28 #include <linux/sysrq.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/tty.h>
  31 #include <linux/tty_flip.h>
  32 #include <linux/serial_core.h>
  33 #include <linux/serial.h>
  34 #include <linux/clk.h>
  35 #include <linux/delay.h>
  36 #include <linux/rational.h>
  37 #include <linux/slab.h>
  38 #include <linux/of.h>
  39 #include <linux/of_device.h>
  40 #include <linux/io.h>
  41 #include <linux/dma-mapping.h>
  42
  43 #include <asm/irq.h>
  44 #include <linux/platform_data/serial-imx.h>
  45 #include <linux/platform_data/dma-imx.h>
  46
  47 #include "serial_mctrl_gpio.h"
  48
  49 /* Register definitions */
  50 #define URXD0 0x0  /* Receiver Register */
  51 #define URTX0 0x40 /* Transmitter Register */
  52 #define UCR1  0x80 /* Control Register 1 */
  53 #define UCR2  0x84 /* Control Register 2 */
  54 #define UCR3  0x88 /* Control Register 3 */
  55 #define UCR4  0x8c /* Control Register 4 */
  56 #define UFCR  0x90 /* FIFO Control Register */
  57 #define USR1  0x94 /* Status Register 1 */
  58 #define USR2  0x98 /* Status Register 2 */
  59 #define UESC  0x9c /* Escape Character Register */
  60 #define UTIM  0xa0 /* Escape Timer Register */
  61 #define UBIR  0xa4 /* BRM Incremental Register */
  62 #define UBMR  0xa8 /* BRM Modulator Register */
  63 #define UBRC  0xac /* Baud Rate Count Register */
  64 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
  65 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
  66 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
  67
  68 /* UART Control Register Bit Fields.*/
  69 #define URXD_DUMMY_READ (1<<16)
  70 #define URXD_CHARRDY    (1<<15)
  71 #define URXD_ERR        (1<<14)
  72 #define URXD_OVRRUN     (1<<13)
  73 #define URXD_FRMERR     (1<<12)
  74 #define URXD_BRK        (1<<11)
  75 #define URXD_PRERR      (1<<10)
  76 #define URXD_RX_DATA    (0xFF<<0)
  77 #define UCR1_ADEN       (1<<15) /* Auto detect interrupt */
  78 #define UCR1_ADBR       (1<<14) /* Auto detect baud rate */
  79 #define UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
  80 #define UCR1_IDEN       (1<<12) /* Idle condition interrupt */
  81 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
  82 #define UCR1_RRDYEN     (1<<9)  /* Recv ready interrupt enable */
  83 #define UCR1_RDMAEN     (1<<8)  /* Recv ready DMA enable */
  84 #define UCR1_IREN       (1<<7)  /* Infrared interface enable */
  85 #define UCR1_TXMPTYEN   (1<<6)  /* Transimitter empty interrupt enable */
  86 #define UCR1_RTSDEN     (1<<5)  /* RTS delta interrupt enable */
  87 #define UCR1_SNDBRK     (1<<4)  /* Send break */
  88 #define UCR1_TDMAEN     (1<<3)  /* Transmitter ready DMA enable */
  89 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
  90 #define UCR1_ATDMAEN    (1<<2)  /* Aging DMA Timer Enable */
  91 #define UCR1_DOZE       (1<<1)  /* Doze */
  92 #define UCR1_UARTEN     (1<<0)  /* UART enabled */
  93 #define UCR2_ESCI       (1<<15) /* Escape seq interrupt enable */
  94 #define UCR2_IRTS       (1<<14) /* Ignore RTS pin */
  95 #define UCR2_CTSC       (1<<13) /* CTS pin control */
  96 #define UCR2_CTS        (1<<12) /* Clear to send */
  97 #define UCR2_ESCEN      (1<<11) /* Escape enable */
  98 #define UCR2_PREN       (1<<8)  /* Parity enable */
  99 #define UCR2_PROE       (1<<7)  /* Parity odd/even */
 100 #define UCR2_STPB       (1<<6)  /* Stop */
 101 #define UCR2_WS         (1<<5)  /* Word size */
 102 #define UCR2_RTSEN      (1<<4)  /* Request to send interrupt enable */
 103 #define UCR2_ATEN       (1<<3)  /* Aging Timer Enable */
 104 #define UCR2_TXEN       (1<<2)  /* Transmitter enabled */
 105 #define UCR2_RXEN       (1<<1)  /* Receiver enabled */
 106 #define UCR2_SRST       (1<<0)  /* SW reset */
 107 #define UCR3_DTREN      (1<<13) /* DTR interrupt enable */
 108 #define UCR3_PARERREN   (1<<12) /* Parity enable */
 109 #define UCR3_FRAERREN   (1<<11) /* Frame error interrupt enable */
 110 #define UCR3_DSR        (1<<10) /* Data set ready */
 111 #define UCR3_DCD        (1<<9)  /* Data carrier detect */
 112 #define UCR3_RI         (1<<8)  /* Ring indicator */
 113 #define UCR3_ADNIMP     (1<<7)  /* Autobaud Detection Not Improved */
 114 #define UCR3_RXDSEN     (1<<6)  /* Receive status interrupt enable */
 115 #define UCR3_AIRINTEN   (1<<5)  /* Async IR wake interrupt enable */
 116 #define UCR3_AWAKEN     (1<<4)  /* Async wake interrupt enable */
 117 #define UCR3_DTRDEN     (1<<3)  /* Data Terminal Ready Delta Enable. */
 118 #define IMX21_UCR3_RXDMUXSEL    (1<<2)  /* RXD Muxed Input Select */
 119 #define UCR3_INVT       (1<<1)  /* Inverted Infrared transmission */
 120 #define UCR3_BPEN       (1<<0)  /* Preset registers enable */
 121 #define UCR4_CTSTL_SHF  10      /* CTS trigger level shift */
 122 #define UCR4_CTSTL_MASK 0x3F    /* CTS trigger is 6 bits wide */
 123 #define UCR4_INVR       (1<<9)  /* Inverted infrared reception */
 124 #define UCR4_ENIRI      (1<<8)  /* Serial infrared interrupt enable */
 125 #define UCR4_WKEN       (1<<7)  /* Wake interrupt enable */
 126 #define UCR4_REF16      (1<<6)  /* Ref freq 16 MHz */
 127 #define UCR4_IDDMAEN    (1<<6)  /* DMA IDLE Condition Detected */
 128 #define UCR4_IRSC       (1<<5)  /* IR special case */
 129 #define UCR4_TCEN       (1<<3)  /* Transmit complete interrupt enable */
 130 #define UCR4_BKEN       (1<<2)  /* Break condition interrupt enable */
 131 #define UCR4_OREN       (1<<1)  /* Receiver overrun interrupt enable */
 132 #define UCR4_DREN       (1<<0)  /* Recv data ready interrupt enable */
 133 #define UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
 134 #define UFCR_DCEDTE     (1<<6)  /* DCE/DTE mode select */
 135 #define UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
 136 #define UFCR_RFDIV_REG(x)       (((x) < 7 ? 6 - (x) : 6) << 7)
 137 #define UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
 138 #define USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
 139 #define USR1_RTSS       (1<<14) /* RTS pin status */
 140 #define USR1_TRDY       (1<<13) /* Transmitter ready interrupt/dma flag */
 141 #define USR1_RTSD       (1<<12) /* RTS delta */
 142 #define USR1_ESCF       (1<<11) /* Escape seq interrupt flag */
 143 #define USR1_FRAMERR    (1<<10) /* Frame error interrupt flag */
 144 #define USR1_RRDY       (1<<9)   /* Receiver ready interrupt/dma flag */
 145 #define USR1_AGTIM      (1<<8)   /* Ageing timer interrupt flag */
 146 #define USR1_DTRD       (1<<7)   /* DTR Delta */
 147 #define USR1_RXDS        (1<<6)  /* Receiver idle interrupt flag */
 148 #define USR1_AIRINT      (1<<5)  /* Async IR wake interrupt flag */
 149 #define USR1_AWAKE       (1<<4)  /* Aysnc wake interrupt flag */
 150 #define USR2_ADET        (1<<15) /* Auto baud rate detect complete */
 151 #define USR2_TXFE        (1<<14) /* Transmit buffer FIFO empty */
 152 #define USR2_DTRF        (1<<13) /* DTR edge interrupt flag */
 153 #define USR2_IDLE        (1<<12) /* Idle condition */
 154 #define USR2_RIDELT      (1<<10) /* Ring Interrupt Delta */
 155 #define USR2_RIIN        (1<<9)  /* Ring Indicator Input */
 156 #define USR2_IRINT       (1<<8)  /* Serial infrared interrupt flag */
 157 #define USR2_WAKE        (1<<7)  /* Wake */
 158 #define USR2_DCDIN       (1<<5)  /* Data Carrier Detect Input */
 159 #define USR2_RTSF        (1<<4)  /* RTS edge interrupt flag */
 160 #define USR2_TXDC        (1<<3)  /* Transmitter complete */
 161 #define USR2_BRCD        (1<<2)  /* Break condition */
 162 #define USR2_ORE        (1<<1)   /* Overrun error */
 163 #define USR2_RDR        (1<<0)   /* Recv data ready */
 164 #define UTS_FRCPERR     (1<<13) /* Force parity error */
 165 #define UTS_LOOP        (1<<12)  /* Loop tx and rx */
 166 #define UTS_TXEMPTY      (1<<6)  /* TxFIFO empty */
 167 #define UTS_RXEMPTY      (1<<5)  /* RxFIFO empty */
 168 #define UTS_TXFULL       (1<<4)  /* TxFIFO full */
 169 #define UTS_RXFULL       (1<<3)  /* RxFIFO full */
 170 #define UTS_SOFTRST      (1<<0)  /* Software reset */
 171
 172 /* We've been assigned a range on the "Low-density serial ports" major */
 173 #define SERIAL_IMX_MAJOR        207
 174 #define MINOR_START             16
 175 #define DEV_NAME                "ttymxc"
 176
 177 /*
 178  * This determines how often we check the modem status signals
 179  * for any change.  They generally aren't connected to an IRQ
 180  * so we have to poll them.  We also check immediately before
 181  * filling the TX fifo incase CTS has been dropped.
 182  */
 183 #define MCTRL_TIMEOUT   (250*HZ/1000)
 184
 185 #define DRIVER_NAME "IMX-uart"
 186
 187 #define UART_NR 8
 188
 189 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
 190 enum imx_uart_type {
 191         IMX1_UART,
 192         IMX21_UART,
 193         IMX53_UART,
 194         IMX6Q_UART,
 195 };
 196
 197 /* device type dependent stuff */
 198 struct imx_uart_data {
 199         unsigned uts_reg;
 200         enum imx_uart_type devtype;
 201 };
 202
 203 struct imx_port {
 204         struct uart_port        port;
 205         struct timer_list       timer;
 206         unsigned int            old_status;
 207         unsigned int            have_rtscts:1;
 208         unsigned int            have_rtsgpio:1;
 209         unsigned int            dte_mode:1;
 210         unsigned int            irda_inv_rx:1;
 211         unsigned int            irda_inv_tx:1;
 212         unsigned short          trcv_delay; /* transceiver delay */
 213         struct clk              *clk_ipg;
 214         struct clk              *clk_per;
 215         const struct imx_uart_data *devdata;
 216
 217         struct mctrl_gpios *gpios;
 218
 219         /* DMA fields */
 220         unsigned int            dma_is_inited:1;
 221         unsigned int            dma_is_enabled:1;
 222         unsigned int            dma_is_rxing:1;
 223         unsigned int            dma_is_txing:1;
 224         struct dma_chan         *dma_chan_rx, *dma_chan_tx;
 225         struct scatterlist      rx_sgl, tx_sgl[2];
 226         void                    *rx_buf;
 227         struct circ_buf         rx_ring;
 228         unsigned int            rx_periods;
 229         dma_cookie_t            rx_cookie;
 230         unsigned int            tx_bytes;
 231         unsigned int            dma_tx_nents;
 232         wait_queue_head_t       dma_wait;
 233         unsigned int            saved_reg[10];
 234         bool                    context_saved;
 235 };
 236
 237 struct imx_port_ucrs {
 238         unsigned int    ucr1;
 239         unsigned int    ucr2;
 240         unsigned int    ucr3;
 241 };
 242
 243 static struct imx_uart_data imx_uart_devdata[] = {
 244         [IMX1_UART] = {
 245                 .uts_reg = IMX1_UTS,
 246                 .devtype = IMX1_UART,
 247         },
 248         [IMX21_UART] = {
 249                 .uts_reg = IMX21_UTS,
 250                 .devtype = IMX21_UART,
 251         },
 252         [IMX53_UART] = {
 253                 .uts_reg = IMX21_UTS,
 254                 .devtype = IMX53_UART,
 255         },
 256         [IMX6Q_UART] = {
 257                 .uts_reg = IMX21_UTS,
 258                 .devtype = IMX6Q_UART,
 259         },
 260 };
 261
 262 static const struct platform_device_id imx_uart_devtype[] = {
 263         {
 264                 .name = "imx1-uart",
 265                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
 266         }, {
 267                 .name = "imx21-uart",
 268                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
 269         }, {
 270                 .name = "imx53-uart",
 271                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
 272         }, {
 273                 .name = "imx6q-uart",
 274                 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
 275         }, {
 276                 /* sentinel */
 277         }
 278 };
 279 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
 280
 281 static const struct of_device_id imx_uart_dt_ids[] = {
 282         { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
 283         { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
 284         { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
 285         { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
 286         { /* sentinel */ }
 287 };
 288 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
 289
 290 static inline unsigned uts_reg(struct imx_port *sport)
 291 {
 292         return sport->devdata->uts_reg;
 293 }
 294
 295 static inline int is_imx1_uart(struct imx_port *sport)
 296 {
 297         return sport->devdata->devtype == IMX1_UART;
 298 }
 299
 300 static inline int is_imx21_uart(struct imx_port *sport)
 301 {
 302         return sport->devdata->devtype == IMX21_UART;
 303 }
 304
 305 static inline int is_imx53_uart(struct imx_port *sport)
 306 {
 307         return sport->devdata->devtype == IMX53_UART;
 308 }
 309
 310 static inline int is_imx6q_uart(struct imx_port *sport)
 311 {
 312         return sport->devdata->devtype == IMX6Q_UART;
 313 }
 314 /*
 315  * Save and restore functions for UCR1, UCR2 and UCR3 registers
 316  */
 317 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
 318 static void imx_port_ucrs_save(struct uart_port *port,
 319                                struct imx_port_ucrs *ucr)
 320 {
 321         /* save control registers */
 322         ucr->ucr1 = readl(port->membase + UCR1);
 323         ucr->ucr2 = readl(port->membase + UCR2);
 324         ucr->ucr3 = readl(port->membase + UCR3);
 325 }
 326
 327 static void imx_port_ucrs_restore(struct uart_port *port,
 328                                   struct imx_port_ucrs *ucr)
 329 {
 330         /* restore control registers */
 331         writel(ucr->ucr1, port->membase + UCR1);
 332         writel(ucr->ucr2, port->membase + UCR2);
 333         writel(ucr->ucr3, port->membase + UCR3);
 334 }
 335 #endif
 336
 337 static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2)
 338 {
 339         *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
 340
 341         mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
 342 }
 343
 344 static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
 345 {
 346         *ucr2 &= ~UCR2_CTSC;
 347         *ucr2 |= UCR2_CTS;
 348
 349         mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
 350 }
 351
 352 static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
 353 {
 354         *ucr2 |= UCR2_CTSC;
 355 }
 356
 357 /*
 358  * interrupts disabled on entry
 359  */
 360 static void imx_stop_tx(struct uart_port *port)
 361 {
 362         struct imx_port *sport = (struct imx_port *)port;
 363         unsigned long temp;
 364
 365         /*
 366          * We are maybe in the SMP context, so if the DMA TX thread is running
 367          * on other cpu, we have to wait for it to finish.
 368          */
 369         if (sport->dma_is_enabled && sport->dma_is_txing)
 370                 return;
 371
 372         temp = readl(port->membase + UCR1);
 373         writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
 374
 375         /* in rs485 mode disable transmitter if shifter is empty */
 376         if (port->rs485.flags & SER_RS485_ENABLED &&
 377             readl(port->membase + USR2) & USR2_TXDC) {
 378                 temp = readl(port->membase + UCR2);
 379                 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
 380                         imx_port_rts_active(sport, &temp);
 381                 else
 382                         imx_port_rts_inactive(sport, &temp);
 383                 temp |= UCR2_RXEN;
 384                 writel(temp, port->membase + UCR2);
 385
 386                 temp = readl(port->membase + UCR4);
 387                 temp &= ~UCR4_TCEN;
 388                 writel(temp, port->membase + UCR4);
 389         }
 390 }
 391
 392 /*
 393  * interrupts disabled on entry
 394  */
 395 static void imx_stop_rx(struct uart_port *port)
 396 {
 397         struct imx_port *sport = (struct imx_port *)port;
 398         unsigned long temp;
 399
 400         if (sport->dma_is_enabled && sport->dma_is_rxing) {
 401                 if (sport->port.suspended) {
 402                         dmaengine_terminate_all(sport->dma_chan_rx);
 403                         sport->dma_is_rxing = 0;
 404                 } else {
 405                         return;
 406                 }
 407         }
 408
 409         temp = readl(sport->port.membase + UCR2);
 410         writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
 411
 412         /* disable the `Receiver Ready Interrrupt` */
 413         temp = readl(sport->port.membase + UCR1);
 414         writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
 415 }
 416
 417 /*
 418  * Set the modem control timer to fire immediately.
 419  */
 420 static void imx_enable_ms(struct uart_port *port)
 421 {
 422         struct imx_port *sport = (struct imx_port *)port;
 423
 424         mod_timer(&sport->timer, jiffies);
 425
 426         mctrl_gpio_enable_ms(sport->gpios);
 427 }
 428
 429 static void imx_dma_tx(struct imx_port *sport);
 430 static inline void imx_transmit_buffer(struct imx_port *sport)
 431 {
 432         struct circ_buf *xmit = &sport->port.state->xmit;
 433         unsigned long temp;
 434
 435         if (sport->port.x_char) {
 436                 /* Send next char */
 437                 writel(sport->port.x_char, sport->port.membase + URTX0);
 438                 sport->port.icount.tx++;
 439                 sport->port.x_char = 0;
 440                 return;
 441         }
 442
 443         if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
 444                 imx_stop_tx(&sport->port);
 445                 return;
 446         }
 447
 448         if (sport->dma_is_enabled) {
 449                 /*
 450                  * We've just sent a X-char Ensure the TX DMA is enabled
 451                  * and the TX IRQ is disabled.
 452                  **/
 453                 temp = readl(sport->port.membase + UCR1);
 454                 temp &= ~UCR1_TXMPTYEN;
 455                 if (sport->dma_is_txing) {
 456                         temp |= UCR1_TDMAEN;
 457                         writel(temp, sport->port.membase + UCR1);
 458                 } else {
 459                         writel(temp, sport->port.membase + UCR1);
 460                         imx_dma_tx(sport);
 461                 }
 462         }
 463
 464         while (!uart_circ_empty(xmit) &&
 465                !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
 466                 /* send xmit->buf[xmit->tail]
 467                  * out the port here */
 468                 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
 469                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 470                 sport->port.icount.tx++;
 471         }
 472
 473         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 474                 uart_write_wakeup(&sport->port);
 475
 476         if (uart_circ_empty(xmit))
 477                 imx_stop_tx(&sport->port);
 478 }
 479
 480 static void dma_tx_callback(void *data)
 481 {
 482         struct imx_port *sport = data;
 483         struct scatterlist *sgl = &sport->tx_sgl[0];
 484         struct circ_buf *xmit = &sport->port.state->xmit;
 485         unsigned long flags;
 486         unsigned long temp;
 487
 488         spin_lock_irqsave(&sport->port.lock, flags);
 489
 490         dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 491
 492         temp = readl(sport->port.membase + UCR1);
 493         temp &= ~UCR1_TDMAEN;
 494         writel(temp, sport->port.membase + UCR1);
 495
 496         /* update the stat */
 497         xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
 498         sport->port.icount.tx += sport->tx_bytes;
 499
 500         dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
 501
 502         sport->dma_is_txing = 0;
 503
 504         spin_unlock_irqrestore(&sport->port.lock, flags);
 505
 506         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 507                 uart_write_wakeup(&sport->port);
 508
 509         if (waitqueue_active(&sport->dma_wait)) {
 510                 wake_up(&sport->dma_wait);
 511                 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
 512                 return;
 513         }
 514
 515         spin_lock_irqsave(&sport->port.lock, flags);
 516         if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
 517                 imx_dma_tx(sport);
 518         spin_unlock_irqrestore(&sport->port.lock, flags);
 519 }
 520
 521 static void imx_dma_tx(struct imx_port *sport)
 522 {
 523         struct circ_buf *xmit = &sport->port.state->xmit;
 524         struct scatterlist *sgl = sport->tx_sgl;
 525         struct dma_async_tx_descriptor *desc;
 526         struct dma_chan *chan = sport->dma_chan_tx;
 527         struct device *dev = sport->port.dev;
 528         unsigned long temp;
 529         int ret;
 530
 531         if (sport->dma_is_txing)
 532                 return;
 533
 534         sport->tx_bytes = uart_circ_chars_pending(xmit);
 535
 536         if (xmit->tail < xmit->head) {
 537                 sport->dma_tx_nents = 1;
 538                 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
 539         } else {
 540                 sport->dma_tx_nents = 2;
 541                 sg_init_table(sgl, 2);
 542                 sg_set_buf(sgl, xmit->buf + xmit->tail,
 543                                 UART_XMIT_SIZE - xmit->tail);
 544                 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
 545         }
 546
 547         ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
 548         if (ret == 0) {
 549                 dev_err(dev, "DMA mapping error for TX.\n");
 550                 return;
 551         }
 552         desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
 553                                         DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 554         if (!desc) {
 555                 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
 556                              DMA_TO_DEVICE);
 557                 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
 558                 return;
 559         }
 560         desc->callback = dma_tx_callback;
 561         desc->callback_param = sport;
 562
 563         dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
 564                         uart_circ_chars_pending(xmit));
 565
 566         temp = readl(sport->port.membase + UCR1);
 567         temp |= UCR1_TDMAEN;
 568         writel(temp, sport->port.membase + UCR1);
 569
 570         /* fire it */
 571         sport->dma_is_txing = 1;
 572         dmaengine_submit(desc);
 573         dma_async_issue_pending(chan);
 574         return;
 575 }
 576
 577 /*
 578  * interrupts disabled on entry
 579  */
 580 static void imx_start_tx(struct uart_port *port)
 581 {
 582         struct imx_port *sport = (struct imx_port *)port;
 583         unsigned long temp;
 584
 585         if (port->rs485.flags & SER_RS485_ENABLED) {
 586                 temp = readl(port->membase + UCR2);
 587                 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
 588                         imx_port_rts_active(sport, &temp);
 589                 else
 590                         imx_port_rts_inactive(sport, &temp);
 591                 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
 592                         temp &= ~UCR2_RXEN;
 593                 writel(temp, port->membase + UCR2);
 594
 595                 /* enable transmitter and shifter empty irq */
 596                 temp = readl(port->membase + UCR4);
 597                 temp |= UCR4_TCEN;
 598                 writel(temp, port->membase + UCR4);
 599         }
 600
 601         if (!sport->dma_is_enabled) {
 602                 temp = readl(sport->port.membase + UCR1);
 603                 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
 604         }
 605
 606         if (sport->dma_is_enabled) {
 607                 if (sport->port.x_char) {
 608                         /* We have X-char to send, so enable TX IRQ and
 609                          * disable TX DMA to let TX interrupt to send X-char */
 610                         temp = readl(sport->port.membase + UCR1);
 611                         temp &= ~UCR1_TDMAEN;
 612                         temp |= UCR1_TXMPTYEN;
 613                         writel(temp, sport->port.membase + UCR1);
 614                         return;
 615                 }
 616
 617                 if (!uart_circ_empty(&port->state->xmit) &&
 618                     !uart_tx_stopped(port))
 619                         imx_dma_tx(sport);
 620                 return;
 621         }
 622 }
 623
 624 static irqreturn_t imx_rtsint(int irq, void *dev_id)
 625 {
 626         struct imx_port *sport = dev_id;
 627         unsigned int val;
 628         unsigned long flags;
 629
 630         spin_lock_irqsave(&sport->port.lock, flags);
 631
 632         writel(USR1_RTSD, sport->port.membase + USR1);
 633         val = readl(sport->port.membase + USR1) & USR1_RTSS;
 634         uart_handle_cts_change(&sport->port, !!val);
 635         wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 636
 637         spin_unlock_irqrestore(&sport->port.lock, flags);
 638         return IRQ_HANDLED;
 639 }
 640
 641 static irqreturn_t imx_txint(int irq, void *dev_id)
 642 {
 643         struct imx_port *sport = dev_id;
 644         unsigned long flags;
 645
 646         spin_lock_irqsave(&sport->port.lock, flags);
 647         imx_transmit_buffer(sport);
 648         spin_unlock_irqrestore(&sport->port.lock, flags);
 649         return IRQ_HANDLED;
 650 }
 651
 652 static irqreturn_t imx_rxint(int irq, void *dev_id)
 653 {
 654         struct imx_port *sport = dev_id;
 655         unsigned int rx, flg, ignored = 0;
 656         struct tty_port *port = &sport->port.state->port;
 657         unsigned long flags, temp;
 658
 659         spin_lock_irqsave(&sport->port.lock, flags);
 660
 661         while (readl(sport->port.membase + USR2) & USR2_RDR) {
 662                 flg = TTY_NORMAL;
 663                 sport->port.icount.rx++;
 664
 665                 rx = readl(sport->port.membase + URXD0);
 666
 667                 temp = readl(sport->port.membase + USR2);
 668                 if (temp & USR2_BRCD) {
 669                         writel(USR2_BRCD, sport->port.membase + USR2);
 670                         if (uart_handle_break(&sport->port))
 671                                 continue;
 672                 }
 673
 674                 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
 675                         continue;
 676
 677                 if (unlikely(rx & URXD_ERR)) {
 678                         if (rx & URXD_BRK)
 679                                 sport->port.icount.brk++;
 680                         else if (rx & URXD_PRERR)
 681                                 sport->port.icount.parity++;
 682                         else if (rx & URXD_FRMERR)
 683                                 sport->port.icount.frame++;
 684                         if (rx & URXD_OVRRUN)
 685                                 sport->port.icount.overrun++;
 686
 687                         if (rx & sport->port.ignore_status_mask) {
 688                                 if (++ignored > 100)
 689                                         goto out;
 690                                 continue;
 691                         }
 692
 693                         rx &= (sport->port.read_status_mask | 0xFF);
 694
 695                         if (rx & URXD_BRK)
 696                                 flg = TTY_BREAK;
 697                         else if (rx & URXD_PRERR)
 698                                 flg = TTY_PARITY;
 699                         else if (rx & URXD_FRMERR)
 700                                 flg = TTY_FRAME;
 701                         if (rx & URXD_OVRRUN)
 702                                 flg = TTY_OVERRUN;
 703
 704 #ifdef SUPPORT_SYSRQ
 705                         sport->port.sysrq = 0;
 706 #endif
 707                 }
 708
 709                 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
 710                         goto out;
 711
 712                 if (tty_insert_flip_char(port, rx, flg) == 0)
 713                         sport->port.icount.buf_overrun++;
 714         }
 715
 716 out:
 717         spin_unlock_irqrestore(&sport->port.lock, flags);
 718         tty_flip_buffer_push(port);
 719         return IRQ_HANDLED;
 720 }
 721
 722 static void imx_disable_rx_int(struct imx_port *sport)
 723 {
 724         unsigned long temp;
 725
 726         sport->dma_is_rxing = 1;
 727
 728         /* disable the receiver ready and aging timer interrupts */
 729         temp = readl(sport->port.membase + UCR1);
 730         temp &= ~(UCR1_RRDYEN);
 731         writel(temp, sport->port.membase + UCR1);
 732
 733         temp = readl(sport->port.membase + UCR2);
 734         temp &= ~(UCR2_ATEN);
 735         writel(temp, sport->port.membase + UCR2);
 736
 737         /* disable the rx errors interrupts */
 738         temp = readl(sport->port.membase + UCR4);
 739         temp &= ~UCR4_OREN;
 740         writel(temp, sport->port.membase + UCR4);
 741 }
 742
 743 static void clear_rx_errors(struct imx_port *sport);
 744 static int start_rx_dma(struct imx_port *sport);
 745 /*
 746  * If the RXFIFO is filled with some data, and then we
 747  * arise a DMA operation to receive them.
 748  */
 749 static void imx_dma_rxint(struct imx_port *sport)
 750 {
 751         unsigned long temp;
 752         unsigned long flags;
 753
 754         spin_lock_irqsave(&sport->port.lock, flags);
 755
 756         temp = readl(sport->port.membase + USR2);
 757         if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
 758
 759                 imx_disable_rx_int(sport);
 760
 761                 /* tell the DMA to receive the data. */
 762                 start_rx_dma(sport);
 763         }
 764
 765         spin_unlock_irqrestore(&sport->port.lock, flags);
 766 }
 767
 768 /*
 769  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
 770  */
 771 static unsigned int imx_get_hwmctrl(struct imx_port *sport)
 772 {
 773         unsigned int tmp = TIOCM_DSR;
 774         unsigned usr1 = readl(sport->port.membase + USR1);
 775         unsigned usr2 = readl(sport->port.membase + USR2);
 776
 777         if (usr1 & USR1_RTSS)
 778                 tmp |= TIOCM_CTS;
 779
 780         /* in DCE mode DCDIN is always 0 */
 781         if (!(usr2 & USR2_DCDIN))
 782                 tmp |= TIOCM_CAR;
 783
 784         if (sport->dte_mode)
 785                 if (!(readl(sport->port.membase + USR2) & USR2_RIIN))
 786                         tmp |= TIOCM_RI;
 787
 788         return tmp;
 789 }
 790
 791 /*
 792  * Handle any change of modem status signal since we were last called.
 793  */
 794 static void imx_mctrl_check(struct imx_port *sport)
 795 {
 796         unsigned int status, changed;
 797
 798         status = imx_get_hwmctrl(sport);
 799         changed = status ^ sport->old_status;
 800
 801         if (changed == 0)
 802                 return;
 803
 804         sport->old_status = status;
 805
 806         if (changed & TIOCM_RI && status & TIOCM_RI)
 807                 sport->port.icount.rng++;
 808         if (changed & TIOCM_DSR)
 809                 sport->port.icount.dsr++;
 810         if (changed & TIOCM_CAR)
 811                 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
 812         if (changed & TIOCM_CTS)
 813                 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
 814
 815         wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
 816 }
 817
 818 static irqreturn_t imx_int(int irq, void *dev_id)
 819 {
 820         struct imx_port *sport = dev_id;
 821         unsigned int sts;
 822         unsigned int sts2;
 823         irqreturn_t ret = IRQ_NONE;
 824
 825         sts = readl(sport->port.membase + USR1);
 826         sts2 = readl(sport->port.membase + USR2);
 827
 828         if (sts & (USR1_RRDY | USR1_AGTIM)) {
 829                 if (sport->dma_is_enabled)
 830                         imx_dma_rxint(sport);
 831                 else
 832                         imx_rxint(irq, dev_id);
 833                 ret = IRQ_HANDLED;
 834         }
 835
 836         if ((sts & USR1_TRDY &&
 837              readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) ||
 838             (sts2 & USR2_TXDC &&
 839              readl(sport->port.membase + UCR4) & UCR4_TCEN)) {
 840                 imx_txint(irq, dev_id);
 841                 ret = IRQ_HANDLED;
 842         }
 843
 844         if (sts & USR1_DTRD) {
 845                 unsigned long flags;
 846
 847                 if (sts & USR1_DTRD)
 848                         writel(USR1_DTRD, sport->port.membase + USR1);
 849
 850                 spin_lock_irqsave(&sport->port.lock, flags);
 851                 imx_mctrl_check(sport);
 852                 spin_unlock_irqrestore(&sport->port.lock, flags);
 853
 854                 ret = IRQ_HANDLED;
 855         }
 856
 857         if (sts & USR1_RTSD) {
 858                 imx_rtsint(irq, dev_id);
 859                 ret = IRQ_HANDLED;
 860         }
 861
 862         if (sts & USR1_AWAKE) {
 863                 writel(USR1_AWAKE, sport->port.membase + USR1);
 864                 ret = IRQ_HANDLED;
 865         }
 866
 867         if (sts2 & USR2_ORE) {
 868                 sport->port.icount.overrun++;
 869                 writel(USR2_ORE, sport->port.membase + USR2);
 870                 ret = IRQ_HANDLED;
 871         }
 872
 873         return ret;
 874 }
 875
 876 /*
 877  * Return TIOCSER_TEMT when transmitter is not busy.
 878  */
 879 static unsigned int imx_tx_empty(struct uart_port *port)
 880 {
 881         struct imx_port *sport = (struct imx_port *)port;
 882         unsigned int ret;
 883
 884         ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
 885
 886         /* If the TX DMA is working, return 0. */
 887         if (sport->dma_is_enabled && sport->dma_is_txing)
 888                 ret = 0;
 889
 890         return ret;
 891 }
 892
 893 static unsigned int imx_get_mctrl(struct uart_port *port)
 894 {
 895         struct imx_port *sport = (struct imx_port *)port;
 896         unsigned int ret = imx_get_hwmctrl(sport);
 897
 898         mctrl_gpio_get(sport->gpios, &ret);
 899
 900         return ret;
 901 }
 902
 903 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
 904 {
 905         struct imx_port *sport = (struct imx_port *)port;
 906         unsigned long temp;
 907
 908         if (!(port->rs485.flags & SER_RS485_ENABLED)) {
 909                 temp = readl(sport->port.membase + UCR2);
 910                 temp &= ~(UCR2_CTS | UCR2_CTSC);
 911                 if (mctrl & TIOCM_RTS)
 912                         temp |= UCR2_CTS | UCR2_CTSC;
 913                 writel(temp, sport->port.membase + UCR2);
 914         }
 915
 916         temp = readl(sport->port.membase + UCR3) & ~UCR3_DSR;
 917         if (!(mctrl & TIOCM_DTR))
 918                 temp |= UCR3_DSR;
 919         writel(temp, sport->port.membase + UCR3);
 920
 921         temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
 922         if (mctrl & TIOCM_LOOP)
 923                 temp |= UTS_LOOP;
 924         writel(temp, sport->port.membase + uts_reg(sport));
 925
 926         mctrl_gpio_set(sport->gpios, mctrl);
 927 }
 928
 929 /*
 930  * Interrupts always disabled.
 931  */
 932 static void imx_break_ctl(struct uart_port *port, int break_state)
 933 {
 934         struct imx_port *sport = (struct imx_port *)port;
 935         unsigned long flags, temp;
 936
 937         spin_lock_irqsave(&sport->port.lock, flags);
 938
 939         temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
 940
 941         if (break_state != 0)
 942                 temp |= UCR1_SNDBRK;
 943
 944         writel(temp, sport->port.membase + UCR1);
 945
 946         spin_unlock_irqrestore(&sport->port.lock, flags);
 947 }
 948
 949 /*
 950  * This is our per-port timeout handler, for checking the
 951  * modem status signals.
 952  */
 953 static void imx_timeout(unsigned long data)
 954 {
 955         struct imx_port *sport = (struct imx_port *)data;
 956         unsigned long flags;
 957
 958         if (sport->port.state) {
 959                 spin_lock_irqsave(&sport->port.lock, flags);
 960                 imx_mctrl_check(sport);
 961                 spin_unlock_irqrestore(&sport->port.lock, flags);
 962
 963                 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
 964         }
 965 }
 966
 967 #define RX_BUF_SIZE     (PAGE_SIZE)
 968
 969 /*
 970  * There are two kinds of RX DMA interrupts(such as in the MX6Q):
 971  *   [1] the RX DMA buffer is full.
 972  *   [2] the aging timer expires
 973  *
 974  * Condition [2] is triggered when a character has been sitting in the FIFO
 975  * for at least 8 byte durations.
 976  */
 977 static void dma_rx_callback(void *data)
 978 {
 979         struct imx_port *sport = data;
 980         struct dma_chan *chan = sport->dma_chan_rx;
 981         struct scatterlist *sgl = &sport->rx_sgl;
 982         struct tty_port *port = &sport->port.state->port;
 983         struct dma_tx_state state;
 984         struct circ_buf *rx_ring = &sport->rx_ring;
 985         enum dma_status status;
 986         unsigned int w_bytes = 0;
 987         unsigned int r_bytes;
 988         unsigned int bd_size;
 989
 990         status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
 991
 992         if (status == DMA_ERROR) {
 993                 dev_err(sport->port.dev, "DMA transaction error.\n");
 994                 clear_rx_errors(sport);
 995                 return;
 996         }
 997
 998         if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
 999
1000                 /*
1001                  * The state-residue variable represents the empty space
1002                  * relative to the entire buffer. Taking this in consideration
1003                  * the head is always calculated base on the buffer total
1004                  * length - DMA transaction residue. The UART script from the
1005                  * SDMA firmware will jump to the next buffer descriptor,
1006                  * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1007                  * Taking this in consideration the tail is always at the
1008                  * beginning of the buffer descriptor that contains the head.
1009                  */
1010
1011                 /* Calculate the head */
1012                 rx_ring->head = sg_dma_len(sgl) - state.residue;
1013
1014                 /* Calculate the tail. */
1015                 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1016                 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1017
1018                 if (rx_ring->head <= sg_dma_len(sgl) &&
1019                     rx_ring->head > rx_ring->tail) {
1020
1021                         /* Move data from tail to head */
1022                         r_bytes = rx_ring->head - rx_ring->tail;
1023
1024                         /* CPU claims ownership of RX DMA buffer */
1025                         dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1026                                 DMA_FROM_DEVICE);
1027
1028                         w_bytes = tty_insert_flip_string(port,
1029                                 sport->rx_buf + rx_ring->tail, r_bytes);
1030
1031                         /* UART retrieves ownership of RX DMA buffer */
1032                         dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1033                                 DMA_FROM_DEVICE);
1034
1035                         if (w_bytes != r_bytes)
1036                                 sport->port.icount.buf_overrun++;
1037
1038                         sport->port.icount.rx += w_bytes;
1039                 } else  {
1040                         WARN_ON(rx_ring->head > sg_dma_len(sgl));
1041                         WARN_ON(rx_ring->head <= rx_ring->tail);
1042                 }
1043         }
1044
1045         if (w_bytes) {
1046                 tty_flip_buffer_push(port);
1047                 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1048         }
1049 }
1050
1051 /* RX DMA buffer periods */
1052 #define RX_DMA_PERIODS 4
1053
1054 static int start_rx_dma(struct imx_port *sport)
1055 {
1056         struct scatterlist *sgl = &sport->rx_sgl;
1057         struct dma_chan *chan = sport->dma_chan_rx;
1058         struct device *dev = sport->port.dev;
1059         struct dma_async_tx_descriptor *desc;
1060         int ret;
1061
1062         sport->rx_ring.head = 0;
1063         sport->rx_ring.tail = 0;
1064         sport->rx_periods = RX_DMA_PERIODS;
1065
1066         sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1067         ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1068         if (ret == 0) {
1069                 dev_err(dev, "DMA mapping error for RX.\n");
1070                 return -EINVAL;
1071         }
1072
1073         desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1074                 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1075                 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1076
1077         if (!desc) {
1078                 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1079                 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1080                 return -EINVAL;
1081         }
1082         desc->callback = dma_rx_callback;
1083         desc->callback_param = sport;
1084
1085         dev_dbg(dev, "RX: prepare for the DMA.\n");
1086         sport->rx_cookie = dmaengine_submit(desc);
1087         dma_async_issue_pending(chan);
1088         return 0;
1089 }
1090
1091 static void clear_rx_errors(struct imx_port *sport)
1092 {
1093         unsigned int status_usr1, status_usr2;
1094
1095         status_usr1 = readl(sport->port.membase + USR1);
1096         status_usr2 = readl(sport->port.membase + USR2);
1097
1098         if (status_usr2 & USR2_BRCD) {
1099                 sport->port.icount.brk++;
1100                 writel(USR2_BRCD, sport->port.membase + USR2);
1101         } else if (status_usr1 & USR1_FRAMERR) {
1102                 sport->port.icount.frame++;
1103                 writel(USR1_FRAMERR, sport->port.membase + USR1);
1104         } else if (status_usr1 & USR1_PARITYERR) {
1105                 sport->port.icount.parity++;
1106                 writel(USR1_PARITYERR, sport->port.membase + USR1);
1107         }
1108
1109         if (status_usr2 & USR2_ORE) {
1110                 sport->port.icount.overrun++;
1111                 writel(USR2_ORE, sport->port.membase + USR2);
1112         }
1113
1114 }
1115
1116 #define TXTL_DEFAULT 2 /* reset default */
1117 #define RXTL_DEFAULT 1 /* reset default */
1118 #define TXTL_DMA 8 /* DMA burst setting */
1119 #define RXTL_DMA 9 /* DMA burst setting */
1120
1121 static void imx_setup_ufcr(struct imx_port *sport,
1122                           unsigned char txwl, unsigned char rxwl)
1123 {
1124         unsigned int val;
1125
1126         /* set receiver / transmitter trigger level */
1127         val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1128         val |= txwl << UFCR_TXTL_SHF | rxwl;
1129         writel(val, sport->port.membase + UFCR);
1130 }
1131
1132 static void imx_uart_dma_exit(struct imx_port *sport)
1133 {
1134         if (sport->dma_chan_rx) {
1135                 dmaengine_terminate_sync(sport->dma_chan_rx);
1136                 dma_release_channel(sport->dma_chan_rx);
1137                 sport->dma_chan_rx = NULL;
1138                 sport->rx_cookie = -EINVAL;
1139                 kfree(sport->rx_buf);
1140                 sport->rx_buf = NULL;
1141         }
1142
1143         if (sport->dma_chan_tx) {
1144                 dmaengine_terminate_sync(sport->dma_chan_tx);
1145                 dma_release_channel(sport->dma_chan_tx);
1146                 sport->dma_chan_tx = NULL;
1147         }
1148
1149         sport->dma_is_inited = 0;
1150 }
1151
1152 static int imx_uart_dma_init(struct imx_port *sport)
1153 {
1154         struct dma_slave_config slave_config = {};
1155         struct device *dev = sport->port.dev;
1156         int ret;
1157
1158         /* Prepare for RX : */
1159         sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1160         if (!sport->dma_chan_rx) {
1161                 dev_dbg(dev, "cannot get the DMA channel.\n");
1162                 ret = -EINVAL;
1163                 goto err;
1164         }
1165
1166         slave_config.direction = DMA_DEV_TO_MEM;
1167         slave_config.src_addr = sport->port.mapbase + URXD0;
1168         slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1169         /* one byte less than the watermark level to enable the aging timer */
1170         slave_config.src_maxburst = RXTL_DMA - 1;
1171         ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1172         if (ret) {
1173                 dev_err(dev, "error in RX dma configuration.\n");
1174                 goto err;
1175         }
1176
1177         sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1178         if (!sport->rx_buf) {
1179                 ret = -ENOMEM;
1180                 goto err;
1181         }
1182         sport->rx_ring.buf = sport->rx_buf;
1183
1184         /* Prepare for TX : */
1185         sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1186         if (!sport->dma_chan_tx) {
1187                 dev_err(dev, "cannot get the TX DMA channel!\n");
1188                 ret = -EINVAL;
1189                 goto err;
1190         }
1191
1192         slave_config.direction = DMA_MEM_TO_DEV;
1193         slave_config.dst_addr = sport->port.mapbase + URTX0;
1194         slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1195         slave_config.dst_maxburst = TXTL_DMA;
1196         ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1197         if (ret) {
1198                 dev_err(dev, "error in TX dma configuration.");
1199                 goto err;
1200         }
1201
1202         sport->dma_is_inited = 1;
1203
1204         return 0;
1205 err:
1206         imx_uart_dma_exit(sport);
1207         return ret;
1208 }
1209
1210 static void imx_enable_dma(struct imx_port *sport)
1211 {
1212         unsigned long temp;
1213
1214         init_waitqueue_head(&sport->dma_wait);
1215
1216         /* set UCR1 */
1217         temp = readl(sport->port.membase + UCR1);
1218         temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN;
1219         writel(temp, sport->port.membase + UCR1);
1220
1221         temp = readl(sport->port.membase + UCR2);
1222         temp |= UCR2_ATEN;
1223         writel(temp, sport->port.membase + UCR2);
1224
1225         imx_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1226
1227         sport->dma_is_enabled = 1;
1228 }
1229
1230 static void imx_disable_dma(struct imx_port *sport)
1231 {
1232         unsigned long temp;
1233
1234         /* clear UCR1 */
1235         temp = readl(sport->port.membase + UCR1);
1236         temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1237         writel(temp, sport->port.membase + UCR1);
1238
1239         /* clear UCR2 */
1240         temp = readl(sport->port.membase + UCR2);
1241         temp &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
1242         writel(temp, sport->port.membase + UCR2);
1243
1244         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1245
1246         sport->dma_is_enabled = 0;
1247 }
1248
1249 /* half the RX buffer size */
1250 #define CTSTL 16
1251
1252 static int imx_startup(struct uart_port *port)
1253 {
1254         struct imx_port *sport = (struct imx_port *)port;
1255         int retval, i;
1256         unsigned long flags, temp;
1257
1258         retval = clk_prepare_enable(sport->clk_per);
1259         if (retval)
1260                 return retval;
1261         retval = clk_prepare_enable(sport->clk_ipg);
1262         if (retval) {
1263                 clk_disable_unprepare(sport->clk_per);
1264                 return retval;
1265         }
1266
1267         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1268
1269         /* disable the DREN bit (Data Ready interrupt enable) before
1270          * requesting IRQs
1271          */
1272         temp = readl(sport->port.membase + UCR4);
1273
1274         /* set the trigger level for CTS */
1275         temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1276         temp |= CTSTL << UCR4_CTSTL_SHF;
1277
1278         writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1279
1280         /* Can we enable the DMA support? */
1281         if (!uart_console(port) && !sport->dma_is_inited)
1282                 imx_uart_dma_init(sport);
1283
1284         spin_lock_irqsave(&sport->port.lock, flags);
1285         /* Reset fifo's and state machines */
1286         i = 100;
1287
1288         temp = readl(sport->port.membase + UCR2);
1289         temp &= ~UCR2_SRST;
1290         writel(temp, sport->port.membase + UCR2);
1291
1292         while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1293                 udelay(1);
1294
1295         /*
1296          * Finally, clear and enable interrupts
1297          */
1298         writel(USR1_RTSD | USR1_DTRD, sport->port.membase + USR1);
1299         writel(USR2_ORE, sport->port.membase + USR2);
1300
1301         if (sport->dma_is_inited && !sport->dma_is_enabled)
1302                 imx_enable_dma(sport);
1303
1304         temp = readl(sport->port.membase + UCR1);
1305         temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1306
1307         writel(temp, sport->port.membase + UCR1);
1308
1309         temp = readl(sport->port.membase + UCR4);
1310         temp |= UCR4_OREN;
1311         writel(temp, sport->port.membase + UCR4);
1312
1313         temp = readl(sport->port.membase + UCR2);
1314         temp |= (UCR2_RXEN | UCR2_TXEN);
1315         if (!sport->have_rtscts)
1316                 temp |= UCR2_IRTS;
1317         /*
1318          * make sure the edge sensitive RTS-irq is disabled,
1319          * we're using RTSD instead.
1320          */
1321         if (!is_imx1_uart(sport))
1322                 temp &= ~UCR2_RTSEN;
1323         writel(temp, sport->port.membase + UCR2);
1324
1325         if (!is_imx1_uart(sport)) {
1326                 temp = readl(sport->port.membase + UCR3);
1327
1328                 temp |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1329
1330                 if (sport->dte_mode)
1331                         /* disable broken interrupts */
1332                         temp &= ~(UCR3_RI | UCR3_DCD);
1333
1334                 writel(temp, sport->port.membase + UCR3);
1335         }
1336
1337         /*
1338          * Enable modem status interrupts
1339          */
1340         imx_enable_ms(&sport->port);
1341
1342         /*
1343          * Start RX DMA immediately instead of waiting for RX FIFO interrupts.
1344          * In our iMX53 the average delay for the first reception dropped from
1345          * approximately 35000 microseconds to 1000 microseconds.
1346          */
1347         if (sport->dma_is_enabled) {
1348                 imx_disable_rx_int(sport);
1349                 start_rx_dma(sport);
1350         }
1351
1352         spin_unlock_irqrestore(&sport->port.lock, flags);
1353
1354         return 0;
1355 }
1356
1357 static void imx_shutdown(struct uart_port *port)
1358 {
1359         struct imx_port *sport = (struct imx_port *)port;
1360         unsigned long temp;
1361         unsigned long flags;
1362
1363         if (sport->dma_is_enabled) {
1364                 sport->dma_is_rxing = 0;
1365                 sport->dma_is_txing = 0;
1366                 dmaengine_terminate_sync(sport->dma_chan_tx);
1367                 dmaengine_terminate_sync(sport->dma_chan_rx);
1368
1369                 spin_lock_irqsave(&sport->port.lock, flags);
1370                 imx_stop_tx(port);
1371                 imx_stop_rx(port);
1372                 imx_disable_dma(sport);
1373                 spin_unlock_irqrestore(&sport->port.lock, flags);
1374                 imx_uart_dma_exit(sport);
1375         }
1376
1377         mctrl_gpio_disable_ms(sport->gpios);
1378
1379         spin_lock_irqsave(&sport->port.lock, flags);
1380         temp = readl(sport->port.membase + UCR2);
1381         temp &= ~(UCR2_TXEN);
1382         writel(temp, sport->port.membase + UCR2);
1383         spin_unlock_irqrestore(&sport->port.lock, flags);
1384
1385         /*
1386          * Stop our timer.
1387          */
1388         del_timer_sync(&sport->timer);
1389
1390         /*
1391          * Disable all interrupts, port and break condition.
1392          */
1393
1394         spin_lock_irqsave(&sport->port.lock, flags);
1395         temp = readl(sport->port.membase + UCR1);
1396         temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1397
1398         writel(temp, sport->port.membase + UCR1);
1399         spin_unlock_irqrestore(&sport->port.lock, flags);
1400
1401         clk_disable_unprepare(sport->clk_per);
1402         clk_disable_unprepare(sport->clk_ipg);
1403 }
1404
1405 static void imx_flush_buffer(struct uart_port *port)
1406 {
1407         struct imx_port *sport = (struct imx_port *)port;
1408         struct scatterlist *sgl = &sport->tx_sgl[0];
1409         unsigned long temp;
1410         int i = 100, ubir, ubmr, uts;
1411
1412         if (!sport->dma_chan_tx)
1413                 return;
1414
1415         sport->tx_bytes = 0;
1416         dmaengine_terminate_all(sport->dma_chan_tx);
1417         if (sport->dma_is_txing) {
1418                 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1419                              DMA_TO_DEVICE);
1420                 temp = readl(sport->port.membase + UCR1);
1421                 temp &= ~UCR1_TDMAEN;
1422                 writel(temp, sport->port.membase + UCR1);
1423                 sport->dma_is_txing = false;
1424         }
1425
1426         /*
1427          * According to the Reference Manual description of the UART SRST bit:
1428          * "Reset the transmit and receive state machines,
1429          * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1430          * and UTS[6-3]". As we don't need to restore the old values from
1431          * USR1, USR2, URXD, UTXD, only save/restore the other four registers
1432          */
1433         ubir = readl(sport->port.membase + UBIR);
1434         ubmr = readl(sport->port.membase + UBMR);
1435         uts = readl(sport->port.membase + IMX21_UTS);
1436
1437         temp = readl(sport->port.membase + UCR2);
1438         temp &= ~UCR2_SRST;
1439         writel(temp, sport->port.membase + UCR2);
1440
1441         while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1442                 udelay(1);
1443
1444         /* Restore the registers */
1445         writel(ubir, sport->port.membase + UBIR);
1446         writel(ubmr, sport->port.membase + UBMR);
1447         writel(uts, sport->port.membase + IMX21_UTS);
1448 }
1449
1450 static void
1451 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1452                    struct ktermios *old)
1453 {
1454         struct imx_port *sport = (struct imx_port *)port;
1455         unsigned long flags;
1456         unsigned long ucr2, old_ucr1, old_ucr2;
1457         unsigned int baud, quot;
1458         unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1459         unsigned long div, ufcr;
1460         unsigned long num, denom;
1461         uint64_t tdiv64;
1462
1463         /*
1464          * We only support CS7 and CS8.
1465          */
1466         while ((termios->c_cflag & CSIZE) != CS7 &&
1467                (termios->c_cflag & CSIZE) != CS8) {
1468                 termios->c_cflag &= ~CSIZE;
1469                 termios->c_cflag |= old_csize;
1470                 old_csize = CS8;
1471         }
1472
1473         if ((termios->c_cflag & CSIZE) == CS8)
1474                 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1475         else
1476                 ucr2 = UCR2_SRST | UCR2_IRTS;
1477
1478         if (termios->c_cflag & CRTSCTS) {
1479                 if (sport->have_rtscts) {
1480                         ucr2 &= ~UCR2_IRTS;
1481
1482                         if (port->rs485.flags & SER_RS485_ENABLED) {
1483                                 /*
1484                                  * RTS is mandatory for rs485 operation, so keep
1485                                  * it under manual control and keep transmitter
1486                                  * disabled.
1487                                  */
1488                                 if (port->rs485.flags &
1489                                     SER_RS485_RTS_AFTER_SEND)
1490                                         imx_port_rts_active(sport, &ucr2);
1491                                 else
1492                                         imx_port_rts_inactive(sport, &ucr2);
1493                         } else {
1494                                 imx_port_rts_auto(sport, &ucr2);
1495                         }
1496                 } else {
1497                         termios->c_cflag &= ~CRTSCTS;
1498                 }
1499         } else if (port->rs485.flags & SER_RS485_ENABLED) {
1500                 /* disable transmitter */
1501                 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1502                         imx_port_rts_active(sport, &ucr2);
1503                 else
1504                         imx_port_rts_inactive(sport, &ucr2);
1505         }
1506
1507
1508         if (termios->c_cflag & CSTOPB)
1509                 ucr2 |= UCR2_STPB;
1510         if (termios->c_cflag & PARENB) {
1511                 ucr2 |= UCR2_PREN;
1512                 if (termios->c_cflag & PARODD)
1513                         ucr2 |= UCR2_PROE;
1514         }
1515
1516         del_timer_sync(&sport->timer);
1517
1518         /*
1519          * Ask the core to calculate the divisor for us.
1520          */
1521         baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1522         quot = uart_get_divisor(port, baud);
1523
1524         spin_lock_irqsave(&sport->port.lock, flags);
1525
1526         sport->port.read_status_mask = 0;
1527         if (termios->c_iflag & INPCK)
1528                 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1529         if (termios->c_iflag & (BRKINT | PARMRK))
1530                 sport->port.read_status_mask |= URXD_BRK;
1531
1532         /*
1533          * Characters to ignore
1534          */
1535         sport->port.ignore_status_mask = 0;
1536         if (termios->c_iflag & IGNPAR)
1537                 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1538         if (termios->c_iflag & IGNBRK) {
1539                 sport->port.ignore_status_mask |= URXD_BRK;
1540                 /*
1541                  * If we're ignoring parity and break indicators,
1542                  * ignore overruns too (for real raw support).
1543                  */
1544                 if (termios->c_iflag & IGNPAR)
1545                         sport->port.ignore_status_mask |= URXD_OVRRUN;
1546         }
1547
1548         if ((termios->c_cflag & CREAD) == 0)
1549                 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1550
1551         /*
1552          * Update the per-port timeout.
1553          */
1554         uart_update_timeout(port, termios->c_cflag, baud);
1555
1556         /*
1557          * disable interrupts and drain transmitter
1558          */
1559         old_ucr1 = readl(sport->port.membase + UCR1);
1560         writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1561                         sport->port.membase + UCR1);
1562
1563         while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1564                 barrier();
1565
1566         /* then, disable everything */
1567         old_ucr2 = readl(sport->port.membase + UCR2);
1568         writel(old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN),
1569                         sport->port.membase + UCR2);
1570         old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
1571
1572         /* custom-baudrate handling */
1573         div = sport->port.uartclk / (baud * 16);
1574         if (baud == 38400 && quot != div)
1575                 baud = sport->port.uartclk / (quot * 16);
1576
1577         div = sport->port.uartclk / (baud * 16);
1578         if (div > 7)
1579                 div = 7;
1580         if (!div)
1581                 div = 1;
1582
1583         rational_best_approximation(16 * div * baud, sport->port.uartclk,
1584                 1 << 16, 1 << 16, &num, &denom);
1585
1586         tdiv64 = sport->port.uartclk;
1587         tdiv64 *= num;
1588         do_div(tdiv64, denom * 16 * div);
1589         tty_termios_encode_baud_rate(termios,
1590                                 (speed_t)tdiv64, (speed_t)tdiv64);
1591
1592         num -= 1;
1593         denom -= 1;
1594
1595         ufcr = readl(sport->port.membase + UFCR);
1596         ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1597         writel(ufcr, sport->port.membase + UFCR);
1598
1599         writel(num, sport->port.membase + UBIR);
1600         writel(denom, sport->port.membase + UBMR);
1601
1602         if (!is_imx1_uart(sport))
1603                 writel(sport->port.uartclk / div / 1000,
1604                                 sport->port.membase + IMX21_ONEMS);
1605
1606         writel(old_ucr1, sport->port.membase + UCR1);
1607
1608         /* set the parity, stop bits and data size */
1609         writel(ucr2 | old_ucr2, sport->port.membase + UCR2);
1610
1611         if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1612                 imx_enable_ms(&sport->port);
1613
1614         spin_unlock_irqrestore(&sport->port.lock, flags);
1615 }
1616
1617 static const char *imx_type(struct uart_port *port)
1618 {
1619         struct imx_port *sport = (struct imx_port *)port;
1620
1621         return sport->port.type == PORT_IMX ? "IMX" : NULL;
1622 }
1623
1624 /*
1625  * Configure/autoconfigure the port.
1626  */
1627 static void imx_config_port(struct uart_port *port, int flags)
1628 {
1629         struct imx_port *sport = (struct imx_port *)port;
1630
1631         if (flags & UART_CONFIG_TYPE)
1632                 sport->port.type = PORT_IMX;
1633 }
1634
1635 /*
1636  * Verify the new serial_struct (for TIOCSSERIAL).
1637  * The only change we allow are to the flags and type, and
1638  * even then only between PORT_IMX and PORT_UNKNOWN
1639  */
1640 static int
1641 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1642 {
1643         struct imx_port *sport = (struct imx_port *)port;
1644         int ret = 0;
1645
1646         if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1647                 ret = -EINVAL;
1648         if (sport->port.irq != ser->irq)
1649                 ret = -EINVAL;
1650         if (ser->io_type != UPIO_MEM)
1651                 ret = -EINVAL;
1652         if (sport->port.uartclk / 16 != ser->baud_base)
1653                 ret = -EINVAL;
1654         if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1655                 ret = -EINVAL;
1656         if (sport->port.iobase != ser->port)
1657                 ret = -EINVAL;
1658         if (ser->hub6 != 0)
1659                 ret = -EINVAL;
1660         return ret;
1661 }
1662
1663 #if defined(CONFIG_CONSOLE_POLL)
1664
1665 static int imx_poll_init(struct uart_port *port)
1666 {
1667         struct imx_port *sport = (struct imx_port *)port;
1668         unsigned long flags;
1669         unsigned long temp;
1670         int retval;
1671
1672         retval = clk_prepare_enable(sport->clk_ipg);
1673         if (retval)
1674                 return retval;
1675         retval = clk_prepare_enable(sport->clk_per);
1676         if (retval)
1677                 clk_disable_unprepare(sport->clk_ipg);
1678
1679         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1680
1681         spin_lock_irqsave(&sport->port.lock, flags);
1682
1683         temp = readl(sport->port.membase + UCR1);
1684         if (is_imx1_uart(sport))
1685                 temp |= IMX1_UCR1_UARTCLKEN;
1686         temp |= UCR1_UARTEN | UCR1_RRDYEN;
1687         temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN);
1688         writel(temp, sport->port.membase + UCR1);
1689
1690         temp = readl(sport->port.membase + UCR2);
1691         temp |= UCR2_RXEN;
1692         writel(temp, sport->port.membase + UCR2);
1693
1694         spin_unlock_irqrestore(&sport->port.lock, flags);
1695
1696         return 0;
1697 }
1698
1699 static int imx_poll_get_char(struct uart_port *port)
1700 {
1701         if (!(readl_relaxed(port->membase + USR2) & USR2_RDR))
1702                 return NO_POLL_CHAR;
1703
1704         return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA;
1705 }
1706
1707 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1708 {
1709         unsigned int status;
1710
1711         /* drain */
1712         do {
1713                 status = readl_relaxed(port->membase + USR1);
1714         } while (~status & USR1_TRDY);
1715
1716         /* write */
1717         writel_relaxed(c, port->membase + URTX0);
1718
1719         /* flush */
1720         do {
1721                 status = readl_relaxed(port->membase + USR2);
1722         } while (~status & USR2_TXDC);
1723 }
1724 #endif
1725
1726 static int imx_rs485_config(struct uart_port *port,
1727                             struct serial_rs485 *rs485conf)
1728 {
1729         struct imx_port *sport = (struct imx_port *)port;
1730         unsigned long temp;
1731
1732         /* unimplemented */
1733         rs485conf->delay_rts_before_send = 0;
1734         rs485conf->delay_rts_after_send = 0;
1735
1736         /* RTS is required to control the transmitter */
1737         if (!sport->have_rtscts && !sport->have_rtsgpio)
1738                 rs485conf->flags &= ~SER_RS485_ENABLED;
1739
1740         if (rs485conf->flags & SER_RS485_ENABLED) {
1741                 /* disable transmitter */
1742                 temp = readl(sport->port.membase + UCR2);
1743                 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1744                         imx_port_rts_active(sport, &temp);
1745                 else
1746                         imx_port_rts_inactive(sport, &temp);
1747                 writel(temp, sport->port.membase + UCR2);
1748         }
1749
1750         /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1751         if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1752             rs485conf->flags & SER_RS485_RX_DURING_TX) {
1753                 temp = readl(sport->port.membase + UCR2);
1754                 temp |= UCR2_RXEN;
1755                 writel(temp, sport->port.membase + UCR2);
1756         }
1757
1758         port->rs485 = *rs485conf;
1759
1760         return 0;
1761 }
1762
1763 static const struct uart_ops imx_pops = {
1764         .tx_empty       = imx_tx_empty,
1765         .set_mctrl      = imx_set_mctrl,
1766         .get_mctrl      = imx_get_mctrl,
1767         .stop_tx        = imx_stop_tx,
1768         .start_tx       = imx_start_tx,
1769         .stop_rx        = imx_stop_rx,
1770         .enable_ms      = imx_enable_ms,
1771         .break_ctl      = imx_break_ctl,
1772         .startup        = imx_startup,
1773         .shutdown       = imx_shutdown,
1774         .flush_buffer   = imx_flush_buffer,
1775         .set_termios    = imx_set_termios,
1776         .type           = imx_type,
1777         .config_port    = imx_config_port,
1778         .verify_port    = imx_verify_port,
1779 #if defined(CONFIG_CONSOLE_POLL)
1780         .poll_init      = imx_poll_init,
1781         .poll_get_char  = imx_poll_get_char,
1782         .poll_put_char  = imx_poll_put_char,
1783 #endif
1784 };
1785
1786 static struct imx_port *imx_ports[UART_NR];
1787
1788 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1789 static void imx_console_putchar(struct uart_port *port, int ch)
1790 {
1791         struct imx_port *sport = (struct imx_port *)port;
1792
1793         while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1794                 barrier();
1795
1796         writel(ch, sport->port.membase + URTX0);
1797 }
1798
1799 /*
1800  * Interrupts are disabled on entering
1801  */
1802 static void
1803 imx_console_write(struct console *co, const char *s, unsigned int count)
1804 {
1805         struct imx_port *sport = imx_ports[co->index];
1806         struct imx_port_ucrs old_ucr;
1807         unsigned int ucr1;
1808         unsigned long flags = 0;
1809         int locked = 1;
1810         int retval;
1811
1812         retval = clk_enable(sport->clk_per);
1813         if (retval)
1814                 return;
1815         retval = clk_enable(sport->clk_ipg);
1816         if (retval) {
1817                 clk_disable(sport->clk_per);
1818                 return;
1819         }
1820
1821         if (sport->port.sysrq)
1822                 locked = 0;
1823         else if (oops_in_progress)
1824                 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1825         else
1826                 spin_lock_irqsave(&sport->port.lock, flags);
1827
1828         /*
1829          *      First, save UCR1/2/3 and then disable interrupts
1830          */
1831         imx_port_ucrs_save(&sport->port, &old_ucr);
1832         ucr1 = old_ucr.ucr1;
1833
1834         if (is_imx1_uart(sport))
1835                 ucr1 |= IMX1_UCR1_UARTCLKEN;
1836         ucr1 |= UCR1_UARTEN;
1837         ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1838
1839         writel(ucr1, sport->port.membase + UCR1);
1840
1841         writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1842
1843         uart_console_write(&sport->port, s, count, imx_console_putchar);
1844
1845         /*
1846          *      Finally, wait for transmitter to become empty
1847          *      and restore UCR1/2/3
1848          */
1849         while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1850
1851         imx_port_ucrs_restore(&sport->port, &old_ucr);
1852
1853         if (locked)
1854                 spin_unlock_irqrestore(&sport->port.lock, flags);
1855
1856         clk_disable(sport->clk_ipg);
1857         clk_disable(sport->clk_per);
1858 }
1859
1860 /*
1861  * If the port was already initialised (eg, by a boot loader),
1862  * try to determine the current setup.
1863  */
1864 static void __init
1865 imx_console_get_options(struct imx_port *sport, int *baud,
1866                            int *parity, int *bits)
1867 {
1868
1869         if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1870                 /* ok, the port was enabled */
1871                 unsigned int ucr2, ubir, ubmr, uartclk;
1872                 unsigned int baud_raw;
1873                 unsigned int ucfr_rfdiv;
1874
1875                 ucr2 = readl(sport->port.membase + UCR2);
1876
1877                 *parity = 'n';
1878                 if (ucr2 & UCR2_PREN) {
1879                         if (ucr2 & UCR2_PROE)
1880                                 *parity = 'o';
1881                         else
1882                                 *parity = 'e';
1883                 }
1884
1885                 if (ucr2 & UCR2_WS)
1886                         *bits = 8;
1887                 else
1888                         *bits = 7;
1889
1890                 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1891                 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1892
1893                 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1894                 if (ucfr_rfdiv == 6)
1895                         ucfr_rfdiv = 7;
1896                 else
1897                         ucfr_rfdiv = 6 - ucfr_rfdiv;
1898
1899                 uartclk = clk_get_rate(sport->clk_per);
1900                 uartclk /= ucfr_rfdiv;
1901
1902                 {       /*
1903                          * The next code provides exact computation of
1904                          *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1905                          * without need of float support or long long division,
1906                          * which would be required to prevent 32bit arithmetic overflow
1907                          */
1908                         unsigned int mul = ubir + 1;
1909                         unsigned int div = 16 * (ubmr + 1);
1910                         unsigned int rem = uartclk % div;
1911
1912                         baud_raw = (uartclk / div) * mul;
1913                         baud_raw += (rem * mul + div / 2) / div;
1914                         *baud = (baud_raw + 50) / 100 * 100;
1915                 }
1916
1917                 if (*baud != baud_raw)
1918                         pr_info("Console IMX rounded baud rate from %d to %d\n",
1919                                 baud_raw, *baud);
1920         }
1921 }
1922
1923 static int __init
1924 imx_console_setup(struct console *co, char *options)
1925 {
1926         struct imx_port *sport;
1927         int baud = 9600;
1928         int bits = 8;
1929         int parity = 'n';
1930         int flow = 'n';
1931         int retval;
1932
1933         /*
1934          * Check whether an invalid uart number has been specified, and
1935          * if so, search for the first available port that does have
1936          * console support.
1937          */
1938         if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1939                 co->index = 0;
1940         sport = imx_ports[co->index];
1941         if (sport == NULL)
1942                 return -ENODEV;
1943
1944         /* For setting the registers, we only need to enable the ipg clock. */
1945         retval = clk_prepare_enable(sport->clk_ipg);
1946         if (retval)
1947                 goto error_console;
1948
1949         if (options)
1950                 uart_parse_options(options, &baud, &parity, &bits, &flow);
1951         else
1952                 imx_console_get_options(sport, &baud, &parity, &bits);
1953
1954         imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1955
1956         retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1957
1958         clk_disable(sport->clk_ipg);
1959         if (retval) {
1960                 clk_unprepare(sport->clk_ipg);
1961                 goto error_console;
1962         }
1963
1964         retval = clk_prepare(sport->clk_per);
1965         if (retval)
1966                 clk_disable_unprepare(sport->clk_ipg);
1967
1968 error_console:
1969         return retval;
1970 }
1971
1972 static struct uart_driver imx_reg;
1973 static struct console imx_console = {
1974         .name           = DEV_NAME,
1975         .write          = imx_console_write,
1976         .device         = uart_console_device,
1977         .setup          = imx_console_setup,
1978         .flags          = CON_PRINTBUFFER,
1979         .index          = -1,
1980         .data           = &imx_reg,
1981 };
1982
1983 #define IMX_CONSOLE     &imx_console
1984
1985 #ifdef CONFIG_OF
1986 static void imx_console_early_putchar(struct uart_port *port, int ch)
1987 {
1988         while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
1989                 cpu_relax();
1990
1991         writel_relaxed(ch, port->membase + URTX0);
1992 }
1993
1994 static void imx_console_early_write(struct console *con, const char *s,
1995                                     unsigned count)
1996 {
1997         struct earlycon_device *dev = con->data;
1998
1999         uart_console_write(&dev->port, s, count, imx_console_early_putchar);
2000 }
2001
2002 static int __init
2003 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
2004 {
2005         if (!dev->port.membase)
2006                 return -ENODEV;
2007
2008         dev->con->write = imx_console_early_write;
2009
2010         return 0;
2011 }
2012 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2013 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2014 #endif
2015
2016 #else
2017 #define IMX_CONSOLE     NULL
2018 #endif
2019
2020 static struct uart_driver imx_reg = {
2021         .owner          = THIS_MODULE,
2022         .driver_name    = DRIVER_NAME,
2023         .dev_name       = DEV_NAME,
2024         .major          = SERIAL_IMX_MAJOR,
2025         .minor          = MINOR_START,
2026         .nr             = ARRAY_SIZE(imx_ports),
2027         .cons           = IMX_CONSOLE,
2028 };
2029
2030 #ifdef CONFIG_OF
2031 /*
2032  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2033  * could successfully get all information from dt or a negative errno.
2034  */
2035 static int serial_imx_probe_dt(struct imx_port *sport,
2036                 struct platform_device *pdev)
2037 {
2038         struct device_node *np = pdev->dev.of_node;
2039         int ret;
2040
2041         sport->devdata = of_device_get_match_data(&pdev->dev);
2042         if (!sport->devdata)
2043                 /* no device tree device */
2044                 return 1;
2045
2046         ret = of_alias_get_id(np, "serial");
2047         if (ret < 0) {
2048                 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2049                 return ret;
2050         }
2051         sport->port.line = ret;
2052
2053         if (of_get_property(np, "uart-has-rtscts", NULL) ||
2054             of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2055                 sport->have_rtscts = 1;
2056
2057         if (of_get_property(np, "fsl,dte-mode", NULL))
2058                 sport->dte_mode = 1;
2059
2060         if (of_get_property(np, "rts-gpios", NULL))
2061                 sport->have_rtsgpio = 1;
2062
2063         return 0;
2064 }
2065 #else
2066 static inline int serial_imx_probe_dt(struct imx_port *sport,
2067                 struct platform_device *pdev)
2068 {
2069         return 1;
2070 }
2071 #endif
2072
2073 static void serial_imx_probe_pdata(struct imx_port *sport,
2074                 struct platform_device *pdev)
2075 {
2076         struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2077
2078         sport->port.line = pdev->id;
2079         sport->devdata = (struct imx_uart_data  *) pdev->id_entry->driver_data;
2080
2081         if (!pdata)
2082                 return;
2083
2084         if (pdata->flags & IMXUART_HAVE_RTSCTS)
2085                 sport->have_rtscts = 1;
2086 }
2087
2088 static int serial_imx_probe(struct platform_device *pdev)
2089 {
2090         struct imx_port *sport;
2091         void __iomem *base;
2092         int ret = 0, reg;
2093         struct resource *res;
2094         int txirq, rxirq, rtsirq;
2095
2096         sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2097         if (!sport)
2098                 return -ENOMEM;
2099
2100         ret = serial_imx_probe_dt(sport, pdev);
2101         if (ret > 0)
2102                 serial_imx_probe_pdata(sport, pdev);
2103         else if (ret < 0)
2104                 return ret;
2105
2106         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2107         base = devm_ioremap_resource(&pdev->dev, res);
2108         if (IS_ERR(base))
2109                 return PTR_ERR(base);
2110
2111         rxirq = platform_get_irq(pdev, 0);
2112         txirq = platform_get_irq(pdev, 1);
2113         rtsirq = platform_get_irq(pdev, 2);
2114
2115         sport->port.dev = &pdev->dev;
2116         sport->port.mapbase = res->start;
2117         sport->port.membase = base;
2118         sport->port.type = PORT_IMX,
2119         sport->port.iotype = UPIO_MEM;
2120         sport->port.irq = rxirq;
2121         sport->port.fifosize = 32;
2122         sport->port.ops = &imx_pops;
2123         sport->port.rs485_config = imx_rs485_config;
2124         sport->port.rs485.flags =
2125                 SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX;
2126         sport->port.flags = UPF_BOOT_AUTOCONF;
2127         init_timer(&sport->timer);
2128         sport->timer.function = imx_timeout;
2129         sport->timer.data     = (unsigned long)sport;
2130
2131         sport->gpios = mctrl_gpio_init(&sport->port, 0);
2132         if (IS_ERR(sport->gpios))
2133                 return PTR_ERR(sport->gpios);
2134
2135         sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2136         if (IS_ERR(sport->clk_ipg)) {
2137                 ret = PTR_ERR(sport->clk_ipg);
2138                 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2139                 return ret;
2140         }
2141
2142         sport->clk_per = devm_clk_get(&pdev->dev, "per");
2143         if (IS_ERR(sport->clk_per)) {
2144                 ret = PTR_ERR(sport->clk_per);
2145                 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2146                 return ret;
2147         }
2148
2149         sport->port.uartclk = clk_get_rate(sport->clk_per);
2150
2151         /* For register access, we only need to enable the ipg clock. */
2152         ret = clk_prepare_enable(sport->clk_ipg);
2153         if (ret) {
2154                 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2155                 return ret;
2156         }
2157
2158         /* Disable interrupts before requesting them */
2159         reg = readl_relaxed(sport->port.membase + UCR1);
2160         reg &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2161                  UCR1_TXMPTYEN | UCR1_RTSDEN);
2162         writel_relaxed(reg, sport->port.membase + UCR1);
2163
2164         if (!is_imx1_uart(sport) && sport->dte_mode) {
2165                 /*
2166                  * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2167                  * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2168                  * and DCD (when they are outputs) or enables the respective
2169                  * irqs. So set this bit early, i.e. before requesting irqs.
2170                  */
2171                 reg = readl(sport->port.membase + UFCR);
2172                 if (!(reg & UFCR_DCEDTE))
2173                         writel(reg | UFCR_DCEDTE, sport->port.membase + UFCR);
2174
2175                 /*
2176                  * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2177                  * enabled later because they cannot be cleared
2178                  * (confirmed on i.MX25) which makes them unusable.
2179                  */
2180                 writel(IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2181                        sport->port.membase + UCR3);
2182
2183         } else {
2184                 unsigned long ucr3 = UCR3_DSR;
2185
2186                 reg = readl(sport->port.membase + UFCR);
2187                 if (reg & UFCR_DCEDTE)
2188                         writel(reg & ~UFCR_DCEDTE, sport->port.membase + UFCR);
2189
2190                 if (!is_imx1_uart(sport))
2191                         ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2192                 writel(ucr3, sport->port.membase + UCR3);
2193         }
2194
2195         clk_disable_unprepare(sport->clk_ipg);
2196
2197         /*
2198          * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2199          * chips only have one interrupt.
2200          */
2201         if (txirq > 0) {
2202                 ret = devm_request_irq(&pdev->dev, rxirq, imx_rxint, 0,
2203                                        dev_name(&pdev->dev), sport);
2204                 if (ret) {
2205                         dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2206                                 ret);
2207                         return ret;
2208                 }
2209
2210                 ret = devm_request_irq(&pdev->dev, txirq, imx_txint, 0,
2211                                        dev_name(&pdev->dev), sport);
2212                 if (ret) {
2213                         dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2214                                 ret);
2215                         return ret;
2216                 }
2217         } else {
2218                 ret = devm_request_irq(&pdev->dev, rxirq, imx_int, 0,
2219                                        dev_name(&pdev->dev), sport);
2220                 if (ret) {
2221                         dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2222                         return ret;
2223                 }
2224         }
2225
2226         imx_ports[sport->port.line] = sport;
2227
2228         platform_set_drvdata(pdev, sport);
2229
2230         return uart_add_one_port(&imx_reg, &sport->port);
2231 }
2232
2233 static int serial_imx_remove(struct platform_device *pdev)
2234 {
2235         struct imx_port *sport = platform_get_drvdata(pdev);
2236
2237         return uart_remove_one_port(&imx_reg, &sport->port);
2238 }
2239
2240 static void serial_imx_restore_context(struct imx_port *sport)
2241 {
2242         if (!sport->context_saved)
2243                 return;
2244
2245         writel(sport->saved_reg[4], sport->port.membase + UFCR);
2246         writel(sport->saved_reg[5], sport->port.membase + UESC);
2247         writel(sport->saved_reg[6], sport->port.membase + UTIM);
2248         writel(sport->saved_reg[7], sport->port.membase + UBIR);
2249         writel(sport->saved_reg[8], sport->port.membase + UBMR);
2250         writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS);
2251         writel(sport->saved_reg[0], sport->port.membase + UCR1);
2252         writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2);
2253         writel(sport->saved_reg[2], sport->port.membase + UCR3);
2254         writel(sport->saved_reg[3], sport->port.membase + UCR4);
2255         sport->context_saved = false;
2256 }
2257
2258 static void serial_imx_save_context(struct imx_port *sport)
2259 {
2260         /* Save necessary regs */
2261         sport->saved_reg[0] = readl(sport->port.membase + UCR1);
2262         sport->saved_reg[1] = readl(sport->port.membase + UCR2);
2263         sport->saved_reg[2] = readl(sport->port.membase + UCR3);
2264         sport->saved_reg[3] = readl(sport->port.membase + UCR4);
2265         sport->saved_reg[4] = readl(sport->port.membase + UFCR);
2266         sport->saved_reg[5] = readl(sport->port.membase + UESC);
2267         sport->saved_reg[6] = readl(sport->port.membase + UTIM);
2268         sport->saved_reg[7] = readl(sport->port.membase + UBIR);
2269         sport->saved_reg[8] = readl(sport->port.membase + UBMR);
2270         sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS);
2271         sport->context_saved = true;
2272 }
2273
2274 static void serial_imx_enable_wakeup(struct imx_port *sport, bool on)
2275 {
2276         unsigned int val;
2277
2278         val = readl(sport->port.membase + UCR3);
2279         if (on)
2280                 val |= UCR3_AWAKEN;
2281         else
2282                 val &= ~UCR3_AWAKEN;
2283         writel(val, sport->port.membase + UCR3);
2284
2285         val = readl(sport->port.membase + UCR1);
2286         if (on)
2287                 val |= UCR1_RTSDEN;
2288         else
2289                 val &= ~UCR1_RTSDEN;
2290         writel(val, sport->port.membase + UCR1);
2291 }
2292
2293 static int imx_serial_port_suspend_noirq(struct device *dev)
2294 {
2295         struct platform_device *pdev = to_platform_device(dev);
2296         struct imx_port *sport = platform_get_drvdata(pdev);
2297         int ret;
2298
2299         ret = clk_enable(sport->clk_ipg);
2300         if (ret)
2301                 return ret;
2302
2303         serial_imx_save_context(sport);
2304
2305         clk_disable(sport->clk_ipg);
2306
2307         return 0;
2308 }
2309
2310 static int imx_serial_port_resume_noirq(struct device *dev)
2311 {
2312         struct platform_device *pdev = to_platform_device(dev);
2313         struct imx_port *sport = platform_get_drvdata(pdev);
2314         int ret;
2315
2316         ret = clk_enable(sport->clk_ipg);
2317         if (ret)
2318                 return ret;
2319
2320         serial_imx_restore_context(sport);
2321
2322         clk_disable(sport->clk_ipg);
2323
2324         return 0;
2325 }
2326
2327 static int imx_serial_port_suspend(struct device *dev)
2328 {
2329         struct platform_device *pdev = to_platform_device(dev);
2330         struct imx_port *sport = platform_get_drvdata(pdev);
2331
2332         /* enable wakeup from i.MX UART */
2333         serial_imx_enable_wakeup(sport, true);
2334
2335         uart_suspend_port(&imx_reg, &sport->port);
2336
2337         /* Needed to enable clock in suspend_noirq */
2338         return clk_prepare(sport->clk_ipg);
2339 }
2340
2341 static int imx_serial_port_resume(struct device *dev)
2342 {
2343         struct platform_device *pdev = to_platform_device(dev);
2344         struct imx_port *sport = platform_get_drvdata(pdev);
2345
2346         /* disable wakeup from i.MX UART */
2347         serial_imx_enable_wakeup(sport, false);
2348
2349         uart_resume_port(&imx_reg, &sport->port);
2350
2351         clk_unprepare(sport->clk_ipg);
2352
2353         return 0;
2354 }
2355
2356 static const struct dev_pm_ops imx_serial_port_pm_ops = {
2357         .suspend_noirq = imx_serial_port_suspend_noirq,
2358         .resume_noirq = imx_serial_port_resume_noirq,
2359         .suspend = imx_serial_port_suspend,
2360         .resume = imx_serial_port_resume,
2361 };
2362
2363 static struct platform_driver serial_imx_driver = {
2364         .probe          = serial_imx_probe,
2365         .remove         = serial_imx_remove,
2366
2367         .id_table       = imx_uart_devtype,
2368         .driver         = {
2369                 .name   = "imx-uart",
2370                 .of_match_table = imx_uart_dt_ids,
2371                 .pm     = &imx_serial_port_pm_ops,
2372         },
2373 };
2374
2375 static int __init imx_serial_init(void)
2376 {
2377         int ret = uart_register_driver(&imx_reg);
2378
2379         if (ret)
2380                 return ret;
2381
2382         ret = platform_driver_register(&serial_imx_driver);
2383         if (ret != 0)
2384                 uart_unregister_driver(&imx_reg);
2385
2386         return ret;
2387 }
2388
2389 static void __exit imx_serial_exit(void)
2390 {
2391         platform_driver_unregister(&serial_imx_driver);
2392         uart_unregister_driver(&imx_reg);
2393 }
2394
2395 module_init(imx_serial_init);
2396 module_exit(imx_serial_exit);
2397
2398 MODULE_AUTHOR("Sascha Hauer");
2399 MODULE_DESCRIPTION("IMX generic serial port driver");
2400 MODULE_LICENSE("GPL");
2401 MODULE_ALIAS("platform:imx-uart");