arch/arm/mach-omap2/serial.c

   1 /*
   2  * arch/arm/mach-omap2/serial.c
   3  *
   4  * OMAP2 serial support.
   5  *
   6  * Copyright (C) 2005-2008 Nokia Corporation
   7  * Author: Paul Mundt <paul.mundt@nokia.com>
   8  *
   9  * Major rework for PM support by Kevin Hilman
  10  *
  11  * Based off of arch/arm/mach-omap/omap1/serial.c
  12  *
  13  * Copyright (C) 2009 Texas Instruments
  14  * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com
  15  *
  16  * This file is subject to the terms and conditions of the GNU General Public
  17  * License. See the file "COPYING" in the main directory of this archive
  18  * for more details.
  19  */
  20 #include <linux/kernel.h>
  21 #include <linux/init.h>
  22 #include <linux/clk.h>
  23 #include <linux/io.h>
  24 #include <linux/delay.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/slab.h>
  27 #include <linux/pm_runtime.h>
  28 #include <linux/console.h>
  29 #include <linux/omap-dma.h>
  30
  31 #include <plat/omap-serial.h>
  32
  33 #include "common.h"
  34 #include "omap_hwmod.h"
  35 #include "omap_device.h"
  36 #include "omap-pm.h"
  37 #include "soc.h"
  38 #include "prm2xxx_3xxx.h"
  39 #include "pm.h"
  40 #include "cm2xxx_3xxx.h"
  41 #include "prm-regbits-34xx.h"
  42 #include "control.h"
  43 #include "mux.h"
  44 #include "serial.h"
  45
  46 /*
  47  * NOTE: By default the serial auto_suspend timeout is disabled as it causes
  48  * lost characters over the serial ports. This means that the UART clocks will
  49  * stay on until power/autosuspend_delay is set for the uart from sysfs.
  50  * This also causes that any deeper omap sleep states are blocked.
  51  */
  52 #define DEFAULT_AUTOSUSPEND_DELAY       -1
  53
  54 #define MAX_UART_HWMOD_NAME_LEN         16
  55
  56 struct omap_uart_state {
  57         int num;
  58
  59         struct list_head node;
  60         struct omap_hwmod *oh;
  61         struct omap_device_pad default_omap_uart_pads[2];
  62 };
  63
  64 static LIST_HEAD(uart_list);
  65 static u8 num_uarts;
  66 static u8 console_uart_id = -1;
  67 static u8 no_console_suspend;
  68 static u8 uart_debug;
  69
  70 #define DEFAULT_RXDMA_POLLRATE          1       /* RX DMA polling rate (us) */
  71 #define DEFAULT_RXDMA_BUFSIZE           4096    /* RX DMA buffer size */
  72 #define DEFAULT_RXDMA_TIMEOUT           (3 * HZ)/* RX DMA timeout (jiffies) */
  73
  74 static struct omap_uart_port_info omap_serial_default_info[] __initdata = {
  75         {
  76                 .dma_enabled    = false,
  77                 .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE,
  78                 .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE,
  79                 .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT,
  80                 .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY,
  81         },
  82 };
  83
  84 #ifdef CONFIG_PM
  85 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
  86 {
  87         struct platform_device *pdev = to_platform_device(dev);
  88         struct omap_device *od = to_omap_device(pdev);
  89
  90         if (!od)
  91                 return;
  92
  93         if (enable)
  94                 omap_hwmod_enable_wakeup(od->hwmods[0]);
  95         else
  96                 omap_hwmod_disable_wakeup(od->hwmods[0]);
  97 }
  98
  99 /*
 100  * Errata i291: [UART]:Cannot Acknowledge Idle Requests
 101  * in Smartidle Mode When Configured for DMA Operations.
 102  * WA: configure uart in force idle mode.
 103  */
 104 static void omap_uart_set_noidle(struct device *dev)
 105 {
 106         struct platform_device *pdev = to_platform_device(dev);
 107         struct omap_device *od = to_omap_device(pdev);
 108
 109         omap_hwmod_set_slave_idlemode(od->hwmods[0], HWMOD_IDLEMODE_NO);
 110 }
 111
 112 static void omap_uart_set_smartidle(struct device *dev)
 113 {
 114         struct platform_device *pdev = to_platform_device(dev);
 115         struct omap_device *od = to_omap_device(pdev);
 116         u8 idlemode;
 117
 118         if (od->hwmods[0]->class->sysc->idlemodes & SIDLE_SMART_WKUP)
 119                 idlemode = HWMOD_IDLEMODE_SMART_WKUP;
 120         else
 121                 idlemode = HWMOD_IDLEMODE_SMART;
 122
 123         omap_hwmod_set_slave_idlemode(od->hwmods[0], idlemode);
 124 }
 125
 126 #else
 127 static void omap_uart_enable_wakeup(struct device *dev, bool enable)
 128 {}
 129 static void omap_uart_set_noidle(struct device *dev) {}
 130 static void omap_uart_set_smartidle(struct device *dev) {}
 131 #endif /* CONFIG_PM */
 132
 133 #ifdef CONFIG_OMAP_MUX
 134
 135 #define OMAP_UART_DEFAULT_PAD_NAME_LEN  28
 136 static char rx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN],
 137                 tx_pad_name[OMAP_UART_DEFAULT_PAD_NAME_LEN] __initdata;
 138
 139 static void  __init
 140 omap_serial_fill_uart_tx_rx_pads(struct omap_board_data *bdata,
 141                                 struct omap_uart_state *uart)
 142 {
 143         uart->default_omap_uart_pads[0].name = rx_pad_name;
 144         uart->default_omap_uart_pads[0].flags = OMAP_DEVICE_PAD_REMUX |
 145                                                         OMAP_DEVICE_PAD_WAKEUP;
 146         uart->default_omap_uart_pads[0].enable = OMAP_PIN_INPUT |
 147                                                         OMAP_MUX_MODE0;
 148         uart->default_omap_uart_pads[0].idle = OMAP_PIN_INPUT | OMAP_MUX_MODE0;
 149         uart->default_omap_uart_pads[1].name = tx_pad_name;
 150         uart->default_omap_uart_pads[1].enable = OMAP_PIN_OUTPUT |
 151                                                         OMAP_MUX_MODE0;
 152         bdata->pads = uart->default_omap_uart_pads;
 153         bdata->pads_cnt = ARRAY_SIZE(uart->default_omap_uart_pads);
 154 }
 155
 156 static void  __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 157                                                 struct omap_uart_state *uart)
 158 {
 159         struct omap_mux_partition *tx_partition = NULL, *rx_partition = NULL;
 160         struct omap_mux *rx_mux = NULL, *tx_mux = NULL;
 161         char *rx_fmt, *tx_fmt;
 162         int uart_nr = bdata->id + 1;
 163
 164         if (bdata->id != 2) {
 165                 rx_fmt = "uart%d_rx.uart%d_rx";
 166                 tx_fmt = "uart%d_tx.uart%d_tx";
 167         } else {
 168                 rx_fmt = "uart%d_rx_irrx.uart%d_rx_irrx";
 169                 tx_fmt = "uart%d_tx_irtx.uart%d_tx_irtx";
 170         }
 171
 172         snprintf(rx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, rx_fmt,
 173                         uart_nr, uart_nr);
 174         snprintf(tx_pad_name, OMAP_UART_DEFAULT_PAD_NAME_LEN, tx_fmt,
 175                         uart_nr, uart_nr);
 176
 177         if (omap_mux_get_by_name(rx_pad_name, &rx_partition, &rx_mux) >= 0 &&
 178                         omap_mux_get_by_name
 179                                 (tx_pad_name, &tx_partition, &tx_mux) >= 0) {
 180                 u16 tx_mode, rx_mode;
 181
 182                 tx_mode = omap_mux_read(tx_partition, tx_mux->reg_offset);
 183                 rx_mode = omap_mux_read(rx_partition, rx_mux->reg_offset);
 184
 185                 /*
 186                  * Check if uart is used in default tx/rx mode i.e. in mux mode0
 187                  * if yes then configure rx pin for wake up capability
 188                  */
 189                 if (OMAP_MODE_UART(rx_mode) && OMAP_MODE_UART(tx_mode))
 190                         omap_serial_fill_uart_tx_rx_pads(bdata, uart);
 191         }
 192 }
 193 #else
 194 static void __init omap_serial_check_wakeup(struct omap_board_data *bdata,
 195                 struct omap_uart_state *uart)
 196 {
 197 }
 198 #endif
 199
 200 static char *cmdline_find_option(char *str)
 201 {
 202         extern char *saved_command_line;
 203
 204         return strstr(saved_command_line, str);
 205 }
 206
 207 static int __init omap_serial_early_init(void)
 208 {
 209         do {
 210                 char oh_name[MAX_UART_HWMOD_NAME_LEN];
 211                 struct omap_hwmod *oh;
 212                 struct omap_uart_state *uart;
 213                 char uart_name[MAX_UART_HWMOD_NAME_LEN];
 214
 215                 snprintf(oh_name, MAX_UART_HWMOD_NAME_LEN,
 216                          "uart%d", num_uarts + 1);
 217                 oh = omap_hwmod_lookup(oh_name);
 218                 if (!oh)
 219                         break;
 220
 221                 uart = kzalloc(sizeof(struct omap_uart_state), GFP_KERNEL);
 222                 if (WARN_ON(!uart))
 223                         return -ENODEV;
 224
 225                 uart->oh = oh;
 226                 uart->num = num_uarts++;
 227                 list_add_tail(&uart->node, &uart_list);
 228                 snprintf(uart_name, MAX_UART_HWMOD_NAME_LEN,
 229                                 "%s%d", OMAP_SERIAL_NAME, uart->num);
 230
 231                 if (cmdline_find_option(uart_name)) {
 232                         console_uart_id = uart->num;
 233
 234                         if (console_loglevel >= 10) {
 235                                 uart_debug = true;
 236                                 pr_info("%s used as console in debug mode: uart%d clocks will not be gated",
 237                                         uart_name, uart->num);
 238                         }
 239
 240                         if (cmdline_find_option("no_console_suspend"))
 241                                 no_console_suspend = true;
 242
 243                         /*
 244                          * omap-uart can be used for earlyprintk logs
 245                          * So if omap-uart is used as console then prevent
 246                          * uart reset and idle to get logs from omap-uart
 247                          * until uart console driver is available to take
 248                          * care for console messages.
 249                          * Idling or resetting omap-uart while printing logs
 250                          * early boot logs can stall the boot-up.
 251                          */
 252                         oh->flags |= HWMOD_INIT_NO_IDLE | HWMOD_INIT_NO_RESET;
 253                 }
 254         } while (1);
 255
 256         return 0;
 257 }
 258 core_initcall(omap_serial_early_init);
 259
 260 /**
 261  * omap_serial_init_port() - initialize single serial port
 262  * @bdata: port specific board data pointer
 263  * @info: platform specific data pointer
 264  *
 265  * This function initialies serial driver for given port only.
 266  * Platforms can call this function instead of omap_serial_init()
 267  * if they don't plan to use all available UARTs as serial ports.
 268  *
 269  * Don't mix calls to omap_serial_init_port() and omap_serial_init(),
 270  * use only one of the two.
 271  */
 272 void __init omap_serial_init_port(struct omap_board_data *bdata,
 273                         struct omap_uart_port_info *info)
 274 {
 275         struct omap_uart_state *uart;
 276         struct omap_hwmod *oh;
 277         struct platform_device *pdev;
 278         void *pdata = NULL;
 279         u32 pdata_size = 0;
 280         char *name;
 281         struct omap_uart_port_info omap_up;
 282
 283         if (WARN_ON(!bdata))
 284                 return;
 285         if (WARN_ON(bdata->id < 0))
 286                 return;
 287         if (WARN_ON(bdata->id >= num_uarts))
 288                 return;
 289
 290         list_for_each_entry(uart, &uart_list, node)
 291                 if (bdata->id == uart->num)
 292                         break;
 293         if (!info)
 294                 info = omap_serial_default_info;
 295
 296         oh = uart->oh;
 297         name = DRIVER_NAME;
 298
 299         omap_up.dma_enabled = info->dma_enabled;
 300         omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
 301         omap_up.flags = UPF_BOOT_AUTOCONF;
 302         omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
 303         omap_up.set_forceidle = omap_uart_set_smartidle;
 304         omap_up.set_noidle = omap_uart_set_noidle;
 305         omap_up.enable_wakeup = omap_uart_enable_wakeup;
 306         omap_up.dma_rx_buf_size = info->dma_rx_buf_size;
 307         omap_up.dma_rx_timeout = info->dma_rx_timeout;
 308         omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate;
 309         omap_up.autosuspend_timeout = info->autosuspend_timeout;
 310         omap_up.DTR_gpio = info->DTR_gpio;
 311         omap_up.DTR_inverted = info->DTR_inverted;
 312         omap_up.DTR_present = info->DTR_present;
 313
 314         pdata = &omap_up;
 315         pdata_size = sizeof(struct omap_uart_port_info);
 316
 317         if (WARN_ON(!oh))
 318                 return;
 319
 320         pdev = omap_device_build(name, uart->num, oh, pdata, pdata_size,
 321                                  NULL, 0, false);
 322         if (IS_ERR(pdev)) {
 323                 WARN(1, "Could not build omap_device for %s: %s.\n", name,
 324                      oh->name);
 325                 return;
 326         }
 327
 328         if ((console_uart_id == bdata->id) && no_console_suspend)
 329                 omap_device_disable_idle_on_suspend(pdev);
 330
 331         oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
 332
 333         if (console_uart_id == bdata->id) {
 334                 omap_device_enable(pdev);
 335                 pm_runtime_set_active(&pdev->dev);
 336         }
 337
 338         oh->dev_attr = uart;
 339
 340         if (((cpu_is_omap34xx() || cpu_is_omap44xx()) && bdata->pads)
 341                         && !uart_debug)
 342                 device_init_wakeup(&pdev->dev, true);
 343 }
 344
 345 /**
 346  * omap_serial_board_init() - initialize all supported serial ports
 347  * @info: platform specific data pointer
 348  *
 349  * Initializes all available UARTs as serial ports. Platforms
 350  * can call this function when they want to have default behaviour
 351  * for serial ports (e.g initialize them all as serial ports).
 352  */
 353 void __init omap_serial_board_init(struct omap_uart_port_info *info)
 354 {
 355         struct omap_uart_state *uart;
 356         struct omap_board_data bdata;
 357
 358         list_for_each_entry(uart, &uart_list, node) {
 359                 bdata.id = uart->num;
 360                 bdata.flags = 0;
 361                 bdata.pads = NULL;
 362                 bdata.pads_cnt = 0;
 363
 364                 omap_serial_check_wakeup(&bdata, uart);
 365
 366                 if (!info)
 367                         omap_serial_init_port(&bdata, NULL);
 368                 else
 369                         omap_serial_init_port(&bdata, &info[uart->num]);
 370         }
 371 }
 372
 373 /**
 374  * omap_serial_init() - initialize all supported serial ports
 375  *
 376  * Initializes all available UARTs.
 377  * Platforms can call this function when they want to have default behaviour
 378  * for serial ports (e.g initialize them all as serial ports).
 379  */
 380 void __init omap_serial_init(void)
 381 {
 382         omap_serial_board_init(NULL);
 383 }