drivers/spi/spi-rockchip.c

   1 /*
   2  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
   3  * Author: Addy Ke <addy.ke@rock-chips.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  */
  15
  16 #include <linux/clk.h>
  17 #include <linux/dmaengine.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/pinctrl/consumer.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/spi/spi.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/scatterlist.h>
  25
  26 #define DRIVER_NAME "rockchip-spi"
  27
  28 /* SPI register offsets */
  29 #define ROCKCHIP_SPI_CTRLR0                     0x0000
  30 #define ROCKCHIP_SPI_CTRLR1                     0x0004
  31 #define ROCKCHIP_SPI_SSIENR                     0x0008
  32 #define ROCKCHIP_SPI_SER                        0x000c
  33 #define ROCKCHIP_SPI_BAUDR                      0x0010
  34 #define ROCKCHIP_SPI_TXFTLR                     0x0014
  35 #define ROCKCHIP_SPI_RXFTLR                     0x0018
  36 #define ROCKCHIP_SPI_TXFLR                      0x001c
  37 #define ROCKCHIP_SPI_RXFLR                      0x0020
  38 #define ROCKCHIP_SPI_SR                         0x0024
  39 #define ROCKCHIP_SPI_IPR                        0x0028
  40 #define ROCKCHIP_SPI_IMR                        0x002c
  41 #define ROCKCHIP_SPI_ISR                        0x0030
  42 #define ROCKCHIP_SPI_RISR                       0x0034
  43 #define ROCKCHIP_SPI_ICR                        0x0038
  44 #define ROCKCHIP_SPI_DMACR                      0x003c
  45 #define ROCKCHIP_SPI_DMATDLR            0x0040
  46 #define ROCKCHIP_SPI_DMARDLR            0x0044
  47 #define ROCKCHIP_SPI_TXDR                       0x0400
  48 #define ROCKCHIP_SPI_RXDR                       0x0800
  49
  50 /* Bit fields in CTRLR0 */
  51 #define CR0_DFS_OFFSET                          0
  52
  53 #define CR0_CFS_OFFSET                          2
  54
  55 #define CR0_SCPH_OFFSET                         6
  56
  57 #define CR0_SCPOL_OFFSET                        7
  58
  59 #define CR0_CSM_OFFSET                          8
  60 #define CR0_CSM_KEEP                            0x0
  61 /* ss_n be high for half sclk_out cycles */
  62 #define CR0_CSM_HALF                            0X1
  63 /* ss_n be high for one sclk_out cycle */
  64 #define CR0_CSM_ONE                                     0x2
  65
  66 /* ss_n to sclk_out delay */
  67 #define CR0_SSD_OFFSET                          10
  68 /*
  69  * The period between ss_n active and
  70  * sclk_out active is half sclk_out cycles
  71  */
  72 #define CR0_SSD_HALF                            0x0
  73 /*
  74  * The period between ss_n active and
  75  * sclk_out active is one sclk_out cycle
  76  */
  77 #define CR0_SSD_ONE                                     0x1
  78
  79 #define CR0_EM_OFFSET                           11
  80 #define CR0_EM_LITTLE                           0x0
  81 #define CR0_EM_BIG                                      0x1
  82
  83 #define CR0_FBM_OFFSET                          12
  84 #define CR0_FBM_MSB                                     0x0
  85 #define CR0_FBM_LSB                                     0x1
  86
  87 #define CR0_BHT_OFFSET                          13
  88 #define CR0_BHT_16BIT                           0x0
  89 #define CR0_BHT_8BIT                            0x1
  90
  91 #define CR0_RSD_OFFSET                          14
  92
  93 #define CR0_FRF_OFFSET                          16
  94 #define CR0_FRF_SPI                                     0x0
  95 #define CR0_FRF_SSP                                     0x1
  96 #define CR0_FRF_MICROWIRE                       0x2
  97
  98 #define CR0_XFM_OFFSET                          18
  99 #define CR0_XFM_MASK                            (0x03 << SPI_XFM_OFFSET)
 100 #define CR0_XFM_TR                                      0x0
 101 #define CR0_XFM_TO                                      0x1
 102 #define CR0_XFM_RO                                      0x2
 103
 104 #define CR0_OPM_OFFSET                          20
 105 #define CR0_OPM_MASTER                          0x0
 106 #define CR0_OPM_SLAVE                           0x1
 107
 108 #define CR0_MTM_OFFSET                          0x21
 109
 110 /* Bit fields in SER, 2bit */
 111 #define SER_MASK                                        0x3
 112
 113 /* Bit fields in SR, 5bit */
 114 #define SR_MASK                                         0x1f
 115 #define SR_BUSY                                         (1 << 0)
 116 #define SR_TF_FULL                                      (1 << 1)
 117 #define SR_TF_EMPTY                                     (1 << 2)
 118 #define SR_RF_EMPTY                                     (1 << 3)
 119 #define SR_RF_FULL                                      (1 << 4)
 120
 121 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
 122 #define INT_MASK                                        0x1f
 123 #define INT_TF_EMPTY                            (1 << 0)
 124 #define INT_TF_OVERFLOW                         (1 << 1)
 125 #define INT_RF_UNDERFLOW                        (1 << 2)
 126 #define INT_RF_OVERFLOW                         (1 << 3)
 127 #define INT_RF_FULL                                     (1 << 4)
 128
 129 /* Bit fields in ICR, 4bit */
 130 #define ICR_MASK                                        0x0f
 131 #define ICR_ALL                                         (1 << 0)
 132 #define ICR_RF_UNDERFLOW                        (1 << 1)
 133 #define ICR_RF_OVERFLOW                         (1 << 2)
 134 #define ICR_TF_OVERFLOW                         (1 << 3)
 135
 136 /* Bit fields in DMACR */
 137 #define RF_DMA_EN                                       (1 << 0)
 138 #define TF_DMA_EN                                       (1 << 1)
 139
 140 #define RXBUSY                                          (1 << 0)
 141 #define TXBUSY                                          (1 << 1)
 142
 143 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
 144 #define MAX_SCLK_OUT            50000000
 145
 146 /*
 147  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
 148  * the controller seems to hang when given 0x10000, so stick with this for now.
 149  */
 150 #define ROCKCHIP_SPI_MAX_TRANLEN                0xffff
 151
 152 enum rockchip_ssi_type {
 153         SSI_MOTO_SPI = 0,
 154         SSI_TI_SSP,
 155         SSI_NS_MICROWIRE,
 156 };
 157
 158 struct rockchip_spi_dma_data {
 159         struct dma_chan *ch;
 160         enum dma_transfer_direction direction;
 161         dma_addr_t addr;
 162 };
 163
 164 struct rockchip_spi {
 165         struct device *dev;
 166         struct spi_master *master;
 167
 168         struct clk *spiclk;
 169         struct clk *apb_pclk;
 170
 171         void __iomem *regs;
 172         /*depth of the FIFO buffer */
 173         u32 fifo_len;
 174         /* max bus freq supported */
 175         u32 max_freq;
 176         /* supported slave numbers */
 177         enum rockchip_ssi_type type;
 178
 179         u16 mode;
 180         u8 tmode;
 181         u8 bpw;
 182         u8 n_bytes;
 183         u32 rsd_nsecs;
 184         unsigned len;
 185         u32 speed;
 186
 187         const void *tx;
 188         const void *tx_end;
 189         void *rx;
 190         void *rx_end;
 191
 192         u32 state;
 193         /* protect state */
 194         spinlock_t lock;
 195
 196         u32 use_dma;
 197         struct sg_table tx_sg;
 198         struct sg_table rx_sg;
 199         struct rockchip_spi_dma_data dma_rx;
 200         struct rockchip_spi_dma_data dma_tx;
 201         struct dma_slave_caps dma_caps;
 202 };
 203
 204 static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
 205 {
 206         writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
 207 }
 208
 209 static inline void spi_set_clk(struct rockchip_spi *rs, u16 div)
 210 {
 211         writel_relaxed(div, rs->regs + ROCKCHIP_SPI_BAUDR);
 212 }
 213
 214 static inline void flush_fifo(struct rockchip_spi *rs)
 215 {
 216         while (readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR))
 217                 readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 218 }
 219
 220 static inline void wait_for_idle(struct rockchip_spi *rs)
 221 {
 222         unsigned long timeout = jiffies + msecs_to_jiffies(5);
 223
 224         do {
 225                 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
 226                         return;
 227         } while (!time_after(jiffies, timeout));
 228
 229         dev_warn(rs->dev, "spi controller is in busy state!\n");
 230 }
 231
 232 static u32 get_fifo_len(struct rockchip_spi *rs)
 233 {
 234         u32 fifo;
 235
 236         for (fifo = 2; fifo < 32; fifo++) {
 237                 writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
 238                 if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
 239                         break;
 240         }
 241
 242         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
 243
 244         return (fifo == 31) ? 0 : fifo;
 245 }
 246
 247 static inline u32 tx_max(struct rockchip_spi *rs)
 248 {
 249         u32 tx_left, tx_room;
 250
 251         tx_left = (rs->tx_end - rs->tx) / rs->n_bytes;
 252         tx_room = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
 253
 254         return min(tx_left, tx_room);
 255 }
 256
 257 static inline u32 rx_max(struct rockchip_spi *rs)
 258 {
 259         u32 rx_left = (rs->rx_end - rs->rx) / rs->n_bytes;
 260         u32 rx_room = (u32)readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
 261
 262         return min(rx_left, rx_room);
 263 }
 264
 265 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 266 {
 267         u32 ser;
 268         struct spi_master *master = spi->master;
 269         struct rockchip_spi *rs = spi_master_get_devdata(master);
 270
 271         pm_runtime_get_sync(rs->dev);
 272
 273         ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
 274
 275         /*
 276          * drivers/spi/spi.c:
 277          * static void spi_set_cs(struct spi_device *spi, bool enable)
 278          * {
 279          *              if (spi->mode & SPI_CS_HIGH)
 280          *                      enable = !enable;
 281          *
 282          *              if (spi->cs_gpio >= 0)
 283          *                      gpio_set_value(spi->cs_gpio, !enable);
 284          *              else if (spi->master->set_cs)
 285          *              spi->master->set_cs(spi, !enable);
 286          * }
 287          *
 288          * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
 289          */
 290         if (!enable)
 291                 ser |= 1 << spi->chip_select;
 292         else
 293                 ser &= ~(1 << spi->chip_select);
 294
 295         writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
 296
 297         pm_runtime_put_sync(rs->dev);
 298 }
 299
 300 static int rockchip_spi_prepare_message(struct spi_master *master,
 301                                         struct spi_message *msg)
 302 {
 303         struct rockchip_spi *rs = spi_master_get_devdata(master);
 304         struct spi_device *spi = msg->spi;
 305
 306         rs->mode = spi->mode;
 307
 308         return 0;
 309 }
 310
 311 static void rockchip_spi_handle_err(struct spi_master *master,
 312                                     struct spi_message *msg)
 313 {
 314         unsigned long flags;
 315         struct rockchip_spi *rs = spi_master_get_devdata(master);
 316
 317         spin_lock_irqsave(&rs->lock, flags);
 318
 319         /*
 320          * For DMA mode, we need terminate DMA channel and flush
 321          * fifo for the next transfer if DMA thansfer timeout.
 322          * handle_err() was called by core if transfer failed.
 323          * Maybe it is reasonable for error handling here.
 324          */
 325         if (rs->use_dma) {
 326                 if (rs->state & RXBUSY) {
 327                         dmaengine_terminate_async(rs->dma_rx.ch);
 328                         flush_fifo(rs);
 329                 }
 330
 331                 if (rs->state & TXBUSY)
 332                         dmaengine_terminate_async(rs->dma_tx.ch);
 333         }
 334
 335         spin_unlock_irqrestore(&rs->lock, flags);
 336 }
 337
 338 static int rockchip_spi_unprepare_message(struct spi_master *master,
 339                                           struct spi_message *msg)
 340 {
 341         struct rockchip_spi *rs = spi_master_get_devdata(master);
 342
 343         spi_enable_chip(rs, 0);
 344
 345         return 0;
 346 }
 347
 348 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
 349 {
 350         u32 max = tx_max(rs);
 351         u32 txw = 0;
 352
 353         while (max--) {
 354                 if (rs->n_bytes == 1)
 355                         txw = *(u8 *)(rs->tx);
 356                 else
 357                         txw = *(u16 *)(rs->tx);
 358
 359                 writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
 360                 rs->tx += rs->n_bytes;
 361         }
 362 }
 363
 364 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
 365 {
 366         u32 max = rx_max(rs);
 367         u32 rxw;
 368
 369         while (max--) {
 370                 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 371                 if (rs->n_bytes == 1)
 372                         *(u8 *)(rs->rx) = (u8)rxw;
 373                 else
 374                         *(u16 *)(rs->rx) = (u16)rxw;
 375                 rs->rx += rs->n_bytes;
 376         }
 377 }
 378
 379 static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
 380 {
 381         int remain = 0;
 382
 383         do {
 384                 if (rs->tx) {
 385                         remain = rs->tx_end - rs->tx;
 386                         rockchip_spi_pio_writer(rs);
 387                 }
 388
 389                 if (rs->rx) {
 390                         remain = rs->rx_end - rs->rx;
 391                         rockchip_spi_pio_reader(rs);
 392                 }
 393
 394                 cpu_relax();
 395         } while (remain);
 396
 397         /* If tx, wait until the FIFO data completely. */
 398         if (rs->tx)
 399                 wait_for_idle(rs);
 400
 401         spi_enable_chip(rs, 0);
 402
 403         return 0;
 404 }
 405
 406 static void rockchip_spi_dma_rxcb(void *data)
 407 {
 408         unsigned long flags;
 409         struct rockchip_spi *rs = data;
 410
 411         spin_lock_irqsave(&rs->lock, flags);
 412
 413         rs->state &= ~RXBUSY;
 414         if (!(rs->state & TXBUSY)) {
 415                 spi_enable_chip(rs, 0);
 416                 spi_finalize_current_transfer(rs->master);
 417         }
 418
 419         spin_unlock_irqrestore(&rs->lock, flags);
 420 }
 421
 422 static void rockchip_spi_dma_txcb(void *data)
 423 {
 424         unsigned long flags;
 425         struct rockchip_spi *rs = data;
 426
 427         /* Wait until the FIFO data completely. */
 428         wait_for_idle(rs);
 429
 430         spin_lock_irqsave(&rs->lock, flags);
 431
 432         rs->state &= ~TXBUSY;
 433         if (!(rs->state & RXBUSY)) {
 434                 spi_enable_chip(rs, 0);
 435                 spi_finalize_current_transfer(rs->master);
 436         }
 437
 438         spin_unlock_irqrestore(&rs->lock, flags);
 439 }
 440
 441 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 442 {
 443         unsigned long flags;
 444         struct dma_slave_config rxconf, txconf;
 445         struct dma_async_tx_descriptor *rxdesc, *txdesc;
 446
 447         spin_lock_irqsave(&rs->lock, flags);
 448         rs->state &= ~RXBUSY;
 449         rs->state &= ~TXBUSY;
 450         spin_unlock_irqrestore(&rs->lock, flags);
 451
 452         rxdesc = NULL;
 453         if (rs->rx) {
 454                 rxconf.direction = rs->dma_rx.direction;
 455                 rxconf.src_addr = rs->dma_rx.addr;
 456                 rxconf.src_addr_width = rs->n_bytes;
 457                 if (rs->dma_caps.max_burst > 4)
 458                         rxconf.src_maxburst = 4;
 459                 else
 460                         rxconf.src_maxburst = 1;
 461                 dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
 462
 463                 rxdesc = dmaengine_prep_slave_sg(
 464                                 rs->dma_rx.ch,
 465                                 rs->rx_sg.sgl, rs->rx_sg.nents,
 466                                 rs->dma_rx.direction, DMA_PREP_INTERRUPT);
 467                 if (!rxdesc)
 468                         return -EINVAL;
 469
 470                 rxdesc->callback = rockchip_spi_dma_rxcb;
 471                 rxdesc->callback_param = rs;
 472         }
 473
 474         txdesc = NULL;
 475         if (rs->tx) {
 476                 txconf.direction = rs->dma_tx.direction;
 477                 txconf.dst_addr = rs->dma_tx.addr;
 478                 txconf.dst_addr_width = rs->n_bytes;
 479                 if (rs->dma_caps.max_burst > 4)
 480                         txconf.dst_maxburst = 4;
 481                 else
 482                         txconf.dst_maxburst = 1;
 483                 dmaengine_slave_config(rs->dma_tx.ch, &txconf);
 484
 485                 txdesc = dmaengine_prep_slave_sg(
 486                                 rs->dma_tx.ch,
 487                                 rs->tx_sg.sgl, rs->tx_sg.nents,
 488                                 rs->dma_tx.direction, DMA_PREP_INTERRUPT);
 489                 if (!txdesc) {
 490                         if (rxdesc)
 491                                 dmaengine_terminate_sync(rs->dma_rx.ch);
 492                         return -EINVAL;
 493                 }
 494
 495                 txdesc->callback = rockchip_spi_dma_txcb;
 496                 txdesc->callback_param = rs;
 497         }
 498
 499         /* rx must be started before tx due to spi instinct */
 500         if (rxdesc) {
 501                 spin_lock_irqsave(&rs->lock, flags);
 502                 rs->state |= RXBUSY;
 503                 spin_unlock_irqrestore(&rs->lock, flags);
 504                 dmaengine_submit(rxdesc);
 505                 dma_async_issue_pending(rs->dma_rx.ch);
 506         }
 507
 508         if (txdesc) {
 509                 spin_lock_irqsave(&rs->lock, flags);
 510                 rs->state |= TXBUSY;
 511                 spin_unlock_irqrestore(&rs->lock, flags);
 512                 dmaengine_submit(txdesc);
 513                 dma_async_issue_pending(rs->dma_tx.ch);
 514         }
 515
 516         return 0;
 517 }
 518
 519 static void rockchip_spi_config(struct rockchip_spi *rs)
 520 {
 521         u32 div = 0;
 522         u32 dmacr = 0;
 523         int rsd = 0;
 524
 525         u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
 526                 | (CR0_SSD_ONE << CR0_SSD_OFFSET)
 527                 | (CR0_EM_BIG << CR0_EM_OFFSET);
 528
 529         cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
 530         cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
 531         cr0 |= (rs->tmode << CR0_XFM_OFFSET);
 532         cr0 |= (rs->type << CR0_FRF_OFFSET);
 533
 534         if (rs->use_dma) {
 535                 if (rs->tx)
 536                         dmacr |= TF_DMA_EN;
 537                 if (rs->rx)
 538                         dmacr |= RF_DMA_EN;
 539         }
 540
 541         if (WARN_ON(rs->speed > MAX_SCLK_OUT))
 542                 rs->speed = MAX_SCLK_OUT;
 543
 544         /* the minimum divisor is 2 */
 545         if (rs->max_freq < 2 * rs->speed) {
 546                 clk_set_rate(rs->spiclk, 2 * rs->speed);
 547                 rs->max_freq = clk_get_rate(rs->spiclk);
 548         }
 549
 550         /* div doesn't support odd number */
 551         div = DIV_ROUND_UP(rs->max_freq, rs->speed);
 552         div = (div + 1) & 0xfffe;
 553
 554         /* Rx sample delay is expressed in parent clock cycles (max 3) */
 555         rsd = DIV_ROUND_CLOSEST(rs->rsd_nsecs * (rs->max_freq >> 8),
 556                                 1000000000 >> 8);
 557         if (!rsd && rs->rsd_nsecs) {
 558                 pr_warn_once("rockchip-spi: %u Hz are too slow to express %u ns delay\n",
 559                              rs->max_freq, rs->rsd_nsecs);
 560         } else if (rsd > 3) {
 561                 rsd = 3;
 562                 pr_warn_once("rockchip-spi: %u Hz are too fast to express %u ns delay, clamping at %u ns\n",
 563                              rs->max_freq, rs->rsd_nsecs,
 564                              rsd * 1000000000U / rs->max_freq);
 565         }
 566         cr0 |= rsd << CR0_RSD_OFFSET;
 567
 568         writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
 569
 570         writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
 571         writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
 572         writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 573
 574         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
 575         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
 576         writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
 577
 578         spi_set_clk(rs, div);
 579
 580         dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
 581 }
 582
 583 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
 584 {
 585         return ROCKCHIP_SPI_MAX_TRANLEN;
 586 }
 587
 588 static int rockchip_spi_transfer_one(
 589                 struct spi_master *master,
 590                 struct spi_device *spi,
 591                 struct spi_transfer *xfer)
 592 {
 593         int ret = 0;
 594         struct rockchip_spi *rs = spi_master_get_devdata(master);
 595
 596         WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
 597                 (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
 598
 599         if (!xfer->tx_buf && !xfer->rx_buf) {
 600                 dev_err(rs->dev, "No buffer for transfer\n");
 601                 return -EINVAL;
 602         }
 603
 604         if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
 605                 dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
 606                 return -EINVAL;
 607         }
 608
 609         rs->speed = xfer->speed_hz;
 610         rs->bpw = xfer->bits_per_word;
 611         rs->n_bytes = rs->bpw >> 3;
 612
 613         rs->tx = xfer->tx_buf;
 614         rs->tx_end = rs->tx + xfer->len;
 615         rs->rx = xfer->rx_buf;
 616         rs->rx_end = rs->rx + xfer->len;
 617         rs->len = xfer->len;
 618
 619         rs->tx_sg = xfer->tx_sg;
 620         rs->rx_sg = xfer->rx_sg;
 621
 622         if (rs->tx && rs->rx)
 623                 rs->tmode = CR0_XFM_TR;
 624         else if (rs->tx)
 625                 rs->tmode = CR0_XFM_TO;
 626         else if (rs->rx)
 627                 rs->tmode = CR0_XFM_RO;
 628
 629         /* we need prepare dma before spi was enabled */
 630         if (master->can_dma && master->can_dma(master, spi, xfer))
 631                 rs->use_dma = 1;
 632         else
 633                 rs->use_dma = 0;
 634
 635         rockchip_spi_config(rs);
 636
 637         if (rs->use_dma) {
 638                 if (rs->tmode == CR0_XFM_RO) {
 639                         /* rx: dma must be prepared first */
 640                         ret = rockchip_spi_prepare_dma(rs);
 641                         spi_enable_chip(rs, 1);
 642                 } else {
 643                         /* tx or tr: spi must be enabled first */
 644                         spi_enable_chip(rs, 1);
 645                         ret = rockchip_spi_prepare_dma(rs);
 646                 }
 647                 /* successful DMA prepare means the transfer is in progress */
 648                 ret = ret ? ret : 1;
 649         } else {
 650                 spi_enable_chip(rs, 1);
 651                 ret = rockchip_spi_pio_transfer(rs);
 652         }
 653
 654         return ret;
 655 }
 656
 657 static bool rockchip_spi_can_dma(struct spi_master *master,
 658                                  struct spi_device *spi,
 659                                  struct spi_transfer *xfer)
 660 {
 661         struct rockchip_spi *rs = spi_master_get_devdata(master);
 662
 663         return (xfer->len > rs->fifo_len);
 664 }
 665
 666 static int rockchip_spi_probe(struct platform_device *pdev)
 667 {
 668         int ret = 0;
 669         struct rockchip_spi *rs;
 670         struct spi_master *master;
 671         struct resource *mem;
 672         u32 rsd_nsecs;
 673
 674         master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
 675         if (!master)
 676                 return -ENOMEM;
 677
 678         platform_set_drvdata(pdev, master);
 679
 680         rs = spi_master_get_devdata(master);
 681
 682         /* Get basic io resource and map it */
 683         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 684         rs->regs = devm_ioremap_resource(&pdev->dev, mem);
 685         if (IS_ERR(rs->regs)) {
 686                 ret =  PTR_ERR(rs->regs);
 687                 goto err_ioremap_resource;
 688         }
 689
 690         rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
 691         if (IS_ERR(rs->apb_pclk)) {
 692                 dev_err(&pdev->dev, "Failed to get apb_pclk\n");
 693                 ret = PTR_ERR(rs->apb_pclk);
 694                 goto err_ioremap_resource;
 695         }
 696
 697         rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
 698         if (IS_ERR(rs->spiclk)) {
 699                 dev_err(&pdev->dev, "Failed to get spi_pclk\n");
 700                 ret = PTR_ERR(rs->spiclk);
 701                 goto err_ioremap_resource;
 702         }
 703
 704         ret = clk_prepare_enable(rs->apb_pclk);
 705         if (ret) {
 706                 dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
 707                 goto err_ioremap_resource;
 708         }
 709
 710         ret = clk_prepare_enable(rs->spiclk);
 711         if (ret) {
 712                 dev_err(&pdev->dev, "Failed to enable spi_clk\n");
 713                 goto err_spiclk_enable;
 714         }
 715
 716         spi_enable_chip(rs, 0);
 717
 718         rs->type = SSI_MOTO_SPI;
 719         rs->master = master;
 720         rs->dev = &pdev->dev;
 721         rs->max_freq = clk_get_rate(rs->spiclk);
 722
 723         if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
 724                                   &rsd_nsecs))
 725                 rs->rsd_nsecs = rsd_nsecs;
 726
 727         rs->fifo_len = get_fifo_len(rs);
 728         if (!rs->fifo_len) {
 729                 dev_err(&pdev->dev, "Failed to get fifo length\n");
 730                 ret = -EINVAL;
 731                 goto err_get_fifo_len;
 732         }
 733
 734         spin_lock_init(&rs->lock);
 735
 736         pm_runtime_set_active(&pdev->dev);
 737         pm_runtime_enable(&pdev->dev);
 738
 739         master->auto_runtime_pm = true;
 740         master->bus_num = pdev->id;
 741         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
 742         master->num_chipselect = 2;
 743         master->dev.of_node = pdev->dev.of_node;
 744         master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
 745
 746         master->set_cs = rockchip_spi_set_cs;
 747         master->prepare_message = rockchip_spi_prepare_message;
 748         master->unprepare_message = rockchip_spi_unprepare_message;
 749         master->transfer_one = rockchip_spi_transfer_one;
 750         master->max_transfer_size = rockchip_spi_max_transfer_size;
 751         master->handle_err = rockchip_spi_handle_err;
 752
 753         rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
 754         if (IS_ERR(rs->dma_tx.ch)) {
 755                 /* Check tx to see if we need defer probing driver */
 756                 if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
 757                         ret = -EPROBE_DEFER;
 758                         goto err_get_fifo_len;
 759                 }
 760                 dev_warn(rs->dev, "Failed to request TX DMA channel\n");
 761                 rs->dma_tx.ch = NULL;
 762         }
 763
 764         rs->dma_rx.ch = dma_request_chan(rs->dev, "rx");
 765         if (IS_ERR(rs->dma_rx.ch)) {
 766                 if (PTR_ERR(rs->dma_rx.ch) == -EPROBE_DEFER) {
 767                         ret = -EPROBE_DEFER;
 768                         goto err_free_dma_tx;
 769                 }
 770                 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
 771                 rs->dma_rx.ch = NULL;
 772         }
 773
 774         if (rs->dma_tx.ch && rs->dma_rx.ch) {
 775                 dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps));
 776                 rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
 777                 rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
 778                 rs->dma_tx.direction = DMA_MEM_TO_DEV;
 779                 rs->dma_rx.direction = DMA_DEV_TO_MEM;
 780
 781                 master->can_dma = rockchip_spi_can_dma;
 782                 master->dma_tx = rs->dma_tx.ch;
 783                 master->dma_rx = rs->dma_rx.ch;
 784         }
 785
 786         ret = devm_spi_register_master(&pdev->dev, master);
 787         if (ret) {
 788                 dev_err(&pdev->dev, "Failed to register master\n");
 789                 goto err_register_master;
 790         }
 791
 792         return 0;
 793
 794 err_register_master:
 795         pm_runtime_disable(&pdev->dev);
 796         if (rs->dma_rx.ch)
 797                 dma_release_channel(rs->dma_rx.ch);
 798 err_free_dma_tx:
 799         if (rs->dma_tx.ch)
 800                 dma_release_channel(rs->dma_tx.ch);
 801 err_get_fifo_len:
 802         clk_disable_unprepare(rs->spiclk);
 803 err_spiclk_enable:
 804         clk_disable_unprepare(rs->apb_pclk);
 805 err_ioremap_resource:
 806         spi_master_put(master);
 807
 808         return ret;
 809 }
 810
 811 static int rockchip_spi_remove(struct platform_device *pdev)
 812 {
 813         struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
 814         struct rockchip_spi *rs = spi_master_get_devdata(master);
 815
 816         pm_runtime_disable(&pdev->dev);
 817
 818         clk_disable_unprepare(rs->spiclk);
 819         clk_disable_unprepare(rs->apb_pclk);
 820
 821         if (rs->dma_tx.ch)
 822                 dma_release_channel(rs->dma_tx.ch);
 823         if (rs->dma_rx.ch)
 824                 dma_release_channel(rs->dma_rx.ch);
 825
 826         spi_master_put(master);
 827
 828         return 0;
 829 }
 830
 831 #ifdef CONFIG_PM_SLEEP
 832 static int rockchip_spi_suspend(struct device *dev)
 833 {
 834         int ret = 0;
 835         struct spi_master *master = dev_get_drvdata(dev);
 836         struct rockchip_spi *rs = spi_master_get_devdata(master);
 837
 838         ret = spi_master_suspend(rs->master);
 839         if (ret)
 840                 return ret;
 841
 842         if (!pm_runtime_suspended(dev)) {
 843                 clk_disable_unprepare(rs->spiclk);
 844                 clk_disable_unprepare(rs->apb_pclk);
 845         }
 846
 847         pinctrl_pm_select_sleep_state(dev);
 848
 849         return ret;
 850 }
 851
 852 static int rockchip_spi_resume(struct device *dev)
 853 {
 854         int ret = 0;
 855         struct spi_master *master = dev_get_drvdata(dev);
 856         struct rockchip_spi *rs = spi_master_get_devdata(master);
 857
 858         pinctrl_pm_select_default_state(dev);
 859
 860         if (!pm_runtime_suspended(dev)) {
 861                 ret = clk_prepare_enable(rs->apb_pclk);
 862                 if (ret < 0)
 863                         return ret;
 864
 865                 ret = clk_prepare_enable(rs->spiclk);
 866                 if (ret < 0) {
 867                         clk_disable_unprepare(rs->apb_pclk);
 868                         return ret;
 869                 }
 870         }
 871
 872         ret = spi_master_resume(rs->master);
 873         if (ret < 0) {
 874                 clk_disable_unprepare(rs->spiclk);
 875                 clk_disable_unprepare(rs->apb_pclk);
 876         }
 877
 878         return ret;
 879 }
 880 #endif /* CONFIG_PM_SLEEP */
 881
 882 #ifdef CONFIG_PM
 883 static int rockchip_spi_runtime_suspend(struct device *dev)
 884 {
 885         struct spi_master *master = dev_get_drvdata(dev);
 886         struct rockchip_spi *rs = spi_master_get_devdata(master);
 887
 888         clk_disable_unprepare(rs->spiclk);
 889         clk_disable_unprepare(rs->apb_pclk);
 890
 891         return 0;
 892 }
 893
 894 static int rockchip_spi_runtime_resume(struct device *dev)
 895 {
 896         int ret;
 897         struct spi_master *master = dev_get_drvdata(dev);
 898         struct rockchip_spi *rs = spi_master_get_devdata(master);
 899
 900         ret = clk_prepare_enable(rs->apb_pclk);
 901         if (ret)
 902                 return ret;
 903
 904         ret = clk_prepare_enable(rs->spiclk);
 905         if (ret)
 906                 clk_disable_unprepare(rs->apb_pclk);
 907
 908         return ret;
 909 }
 910 #endif /* CONFIG_PM */
 911
 912 static const struct dev_pm_ops rockchip_spi_pm = {
 913         SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
 914         SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
 915                            rockchip_spi_runtime_resume, NULL)
 916 };
 917
 918 static const struct of_device_id rockchip_spi_dt_match[] = {
 919         { .compatible = "rockchip,rk3036-spi", },
 920         { .compatible = "rockchip,rk3066-spi", },
 921         { .compatible = "rockchip,rk3188-spi", },
 922         { .compatible = "rockchip,rk3228-spi", },
 923         { .compatible = "rockchip,rk3288-spi", },
 924         { .compatible = "rockchip,rk3368-spi", },
 925         { .compatible = "rockchip,rk3399-spi", },
 926         { },
 927 };
 928 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
 929
 930 static struct platform_driver rockchip_spi_driver = {
 931         .driver = {
 932                 .name   = DRIVER_NAME,
 933                 .pm = &rockchip_spi_pm,
 934                 .of_match_table = of_match_ptr(rockchip_spi_dt_match),
 935         },
 936         .probe = rockchip_spi_probe,
 937         .remove = rockchip_spi_remove,
 938 };
 939
 940 module_platform_driver(rockchip_spi_driver);
 941
 942 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
 943 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
 944 MODULE_LICENSE("GPL v2");