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 #define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
  29                 writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
  30 #define ROCKCHIP_SPI_SET_BITS(reg, bits) \
  31                 writel_relaxed(readl_relaxed(reg) | (bits), reg)
  32
  33 /* SPI register offsets */
  34 #define ROCKCHIP_SPI_CTRLR0                     0x0000
  35 #define ROCKCHIP_SPI_CTRLR1                     0x0004
  36 #define ROCKCHIP_SPI_SSIENR                     0x0008
  37 #define ROCKCHIP_SPI_SER                        0x000c
  38 #define ROCKCHIP_SPI_BAUDR                      0x0010
  39 #define ROCKCHIP_SPI_TXFTLR                     0x0014
  40 #define ROCKCHIP_SPI_RXFTLR                     0x0018
  41 #define ROCKCHIP_SPI_TXFLR                      0x001c
  42 #define ROCKCHIP_SPI_RXFLR                      0x0020
  43 #define ROCKCHIP_SPI_SR                         0x0024
  44 #define ROCKCHIP_SPI_IPR                        0x0028
  45 #define ROCKCHIP_SPI_IMR                        0x002c
  46 #define ROCKCHIP_SPI_ISR                        0x0030
  47 #define ROCKCHIP_SPI_RISR                       0x0034
  48 #define ROCKCHIP_SPI_ICR                        0x0038
  49 #define ROCKCHIP_SPI_DMACR                      0x003c
  50 #define ROCKCHIP_SPI_DMATDLR            0x0040
  51 #define ROCKCHIP_SPI_DMARDLR            0x0044
  52 #define ROCKCHIP_SPI_TXDR                       0x0400
  53 #define ROCKCHIP_SPI_RXDR                       0x0800
  54
  55 /* Bit fields in CTRLR0 */
  56 #define CR0_DFS_OFFSET                          0
  57 #define CR0_DFS_4BIT                            0x0
  58 #define CR0_DFS_8BIT                            0x1
  59 #define CR0_DFS_16BIT                           0x2
  60
  61 #define CR0_CFS_OFFSET                          2
  62
  63 #define CR0_SCPH_OFFSET                         6
  64
  65 #define CR0_SCPOL_OFFSET                        7
  66
  67 #define CR0_CSM_OFFSET                          8
  68 #define CR0_CSM_KEEP                            0x0
  69 /* ss_n be high for half sclk_out cycles */
  70 #define CR0_CSM_HALF                            0X1
  71 /* ss_n be high for one sclk_out cycle */
  72 #define CR0_CSM_ONE                                     0x2
  73
  74 /* ss_n to sclk_out delay */
  75 #define CR0_SSD_OFFSET                          10
  76 /*
  77  * The period between ss_n active and
  78  * sclk_out active is half sclk_out cycles
  79  */
  80 #define CR0_SSD_HALF                            0x0
  81 /*
  82  * The period between ss_n active and
  83  * sclk_out active is one sclk_out cycle
  84  */
  85 #define CR0_SSD_ONE                                     0x1
  86
  87 #define CR0_EM_OFFSET                           11
  88 #define CR0_EM_LITTLE                           0x0
  89 #define CR0_EM_BIG                                      0x1
  90
  91 #define CR0_FBM_OFFSET                          12
  92 #define CR0_FBM_MSB                                     0x0
  93 #define CR0_FBM_LSB                                     0x1
  94
  95 #define CR0_BHT_OFFSET                          13
  96 #define CR0_BHT_16BIT                           0x0
  97 #define CR0_BHT_8BIT                            0x1
  98
  99 #define CR0_RSD_OFFSET                          14
 100 #define CR0_RSD_MAX                             0x3
 101
 102 #define CR0_FRF_OFFSET                          16
 103 #define CR0_FRF_SPI                                     0x0
 104 #define CR0_FRF_SSP                                     0x1
 105 #define CR0_FRF_MICROWIRE                       0x2
 106
 107 #define CR0_XFM_OFFSET                          18
 108 #define CR0_XFM_MASK                            (0x03 << SPI_XFM_OFFSET)
 109 #define CR0_XFM_TR                                      0x0
 110 #define CR0_XFM_TO                                      0x1
 111 #define CR0_XFM_RO                                      0x2
 112
 113 #define CR0_OPM_OFFSET                          20
 114 #define CR0_OPM_MASTER                          0x0
 115 #define CR0_OPM_SLAVE                           0x1
 116
 117 #define CR0_MTM_OFFSET                          0x21
 118
 119 /* Bit fields in SER, 2bit */
 120 #define SER_MASK                                        0x3
 121
 122 /* Bit fields in BAUDR */
 123 #define BAUDR_SCKDV_MIN                         2
 124 #define BAUDR_SCKDV_MAX                         65534
 125
 126 /* Bit fields in SR, 5bit */
 127 #define SR_MASK                                         0x1f
 128 #define SR_BUSY                                         (1 << 0)
 129 #define SR_TF_FULL                                      (1 << 1)
 130 #define SR_TF_EMPTY                                     (1 << 2)
 131 #define SR_RF_EMPTY                                     (1 << 3)
 132 #define SR_RF_FULL                                      (1 << 4)
 133
 134 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
 135 #define INT_MASK                                        0x1f
 136 #define INT_TF_EMPTY                            (1 << 0)
 137 #define INT_TF_OVERFLOW                         (1 << 1)
 138 #define INT_RF_UNDERFLOW                        (1 << 2)
 139 #define INT_RF_OVERFLOW                         (1 << 3)
 140 #define INT_RF_FULL                                     (1 << 4)
 141
 142 /* Bit fields in ICR, 4bit */
 143 #define ICR_MASK                                        0x0f
 144 #define ICR_ALL                                         (1 << 0)
 145 #define ICR_RF_UNDERFLOW                        (1 << 1)
 146 #define ICR_RF_OVERFLOW                         (1 << 2)
 147 #define ICR_TF_OVERFLOW                         (1 << 3)
 148
 149 /* Bit fields in DMACR */
 150 #define RF_DMA_EN                                       (1 << 0)
 151 #define TF_DMA_EN                                       (1 << 1)
 152
 153 /* Driver state flags */
 154 #define RXDMA                                   (1 << 0)
 155 #define TXDMA                                   (1 << 1)
 156
 157 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
 158 #define MAX_SCLK_OUT                            50000000U
 159
 160 /*
 161  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
 162  * the controller seems to hang when given 0x10000, so stick with this for now.
 163  */
 164 #define ROCKCHIP_SPI_MAX_TRANLEN                0xffff
 165
 166 #define ROCKCHIP_SPI_MAX_CS_NUM                 2
 167
 168 struct rockchip_spi {
 169         struct device *dev;
 170
 171         struct clk *spiclk;
 172         struct clk *apb_pclk;
 173
 174         void __iomem *regs;
 175         dma_addr_t dma_addr_rx;
 176         dma_addr_t dma_addr_tx;
 177
 178         const void *tx;
 179         void *rx;
 180         unsigned int tx_left;
 181         unsigned int rx_left;
 182
 183         atomic_t state;
 184
 185         /*depth of the FIFO buffer */
 186         u32 fifo_len;
 187         /* frequency of spiclk */
 188         u32 freq;
 189
 190         u8 n_bytes;
 191         u8 rsd;
 192
 193         bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
 194 };
 195
 196 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
 197 {
 198         writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
 199 }
 200
 201 static inline void wait_for_idle(struct rockchip_spi *rs)
 202 {
 203         unsigned long timeout = jiffies + msecs_to_jiffies(5);
 204
 205         do {
 206                 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
 207                         return;
 208         } while (!time_after(jiffies, timeout));
 209
 210         dev_warn(rs->dev, "spi controller is in busy state!\n");
 211 }
 212
 213 static u32 get_fifo_len(struct rockchip_spi *rs)
 214 {
 215         u32 fifo;
 216
 217         for (fifo = 2; fifo < 32; fifo++) {
 218                 writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
 219                 if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
 220                         break;
 221         }
 222
 223         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
 224
 225         return (fifo == 31) ? 0 : fifo;
 226 }
 227
 228 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 229 {
 230         struct spi_master *master = spi->master;
 231         struct rockchip_spi *rs = spi_master_get_devdata(master);
 232         bool cs_asserted = !enable;
 233
 234         /* Return immediately for no-op */
 235         if (cs_asserted == rs->cs_asserted[spi->chip_select])
 236                 return;
 237
 238         if (cs_asserted) {
 239                 /* Keep things powered as long as CS is asserted */
 240                 pm_runtime_get_sync(rs->dev);
 241
 242                 ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
 243                                       BIT(spi->chip_select));
 244         } else {
 245                 ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
 246                                       BIT(spi->chip_select));
 247
 248                 /* Drop reference from when we first asserted CS */
 249                 pm_runtime_put(rs->dev);
 250         }
 251
 252         rs->cs_asserted[spi->chip_select] = cs_asserted;
 253 }
 254
 255 static void rockchip_spi_handle_err(struct spi_master *master,
 256                                     struct spi_message *msg)
 257 {
 258         struct rockchip_spi *rs = spi_master_get_devdata(master);
 259
 260         /* stop running spi transfer
 261          * this also flushes both rx and tx fifos
 262          */
 263         spi_enable_chip(rs, false);
 264
 265         /* make sure all interrupts are masked */
 266         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 267
 268         if (atomic_read(&rs->state) & TXDMA)
 269                 dmaengine_terminate_async(master->dma_tx);
 270
 271         if (atomic_read(&rs->state) & RXDMA)
 272                 dmaengine_terminate_async(master->dma_rx);
 273 }
 274
 275 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
 276 {
 277         u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
 278         u32 words = min(rs->tx_left, tx_free);
 279
 280         rs->tx_left -= words;
 281         for (; words; words--) {
 282                 u32 txw;
 283
 284                 if (rs->n_bytes == 1)
 285                         txw = *(u8 *)rs->tx;
 286                 else
 287                         txw = *(u16 *)rs->tx;
 288
 289                 writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
 290                 rs->tx += rs->n_bytes;
 291         }
 292 }
 293
 294 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
 295 {
 296         u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
 297         u32 rx_left = rs->rx_left - words;
 298
 299         /* the hardware doesn't allow us to change fifo threshold
 300          * level while spi is enabled, so instead make sure to leave
 301          * enough words in the rx fifo to get the last interrupt
 302          * exactly when all words have been received
 303          */
 304         if (rx_left) {
 305                 u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
 306
 307                 if (rx_left < ftl) {
 308                         rx_left = ftl;
 309                         words = rs->rx_left - rx_left;
 310                 }
 311         }
 312
 313         rs->rx_left = rx_left;
 314         for (; words; words--) {
 315                 u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 316
 317                 if (!rs->rx)
 318                         continue;
 319
 320                 if (rs->n_bytes == 1)
 321                         *(u8 *)rs->rx = (u8)rxw;
 322                 else
 323                         *(u16 *)rs->rx = (u16)rxw;
 324                 rs->rx += rs->n_bytes;
 325         }
 326 }
 327
 328 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
 329 {
 330         struct spi_master *master = dev_id;
 331         struct rockchip_spi *rs = spi_master_get_devdata(master);
 332
 333         if (rs->tx_left)
 334                 rockchip_spi_pio_writer(rs);
 335
 336         rockchip_spi_pio_reader(rs);
 337         if (!rs->rx_left) {
 338                 spi_enable_chip(rs, false);
 339                 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 340                 spi_finalize_current_transfer(master);
 341         }
 342
 343         return IRQ_HANDLED;
 344 }
 345
 346 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
 347                 struct spi_transfer *xfer)
 348 {
 349         rs->tx = xfer->tx_buf;
 350         rs->rx = xfer->rx_buf;
 351         rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
 352         rs->rx_left = xfer->len / rs->n_bytes;
 353
 354         writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
 355         spi_enable_chip(rs, true);
 356
 357         if (rs->tx_left)
 358                 rockchip_spi_pio_writer(rs);
 359
 360         /* 1 means the transfer is in progress */
 361         return 1;
 362 }
 363
 364 static void rockchip_spi_dma_rxcb(void *data)
 365 {
 366         struct spi_master *master = data;
 367         struct rockchip_spi *rs = spi_master_get_devdata(master);
 368         int state = atomic_fetch_andnot(RXDMA, &rs->state);
 369
 370         if (state & TXDMA)
 371                 return;
 372
 373         spi_enable_chip(rs, false);
 374         spi_finalize_current_transfer(master);
 375 }
 376
 377 static void rockchip_spi_dma_txcb(void *data)
 378 {
 379         struct spi_master *master = data;
 380         struct rockchip_spi *rs = spi_master_get_devdata(master);
 381         int state = atomic_fetch_andnot(TXDMA, &rs->state);
 382
 383         if (state & RXDMA)
 384                 return;
 385
 386         /* Wait until the FIFO data completely. */
 387         wait_for_idle(rs);
 388
 389         spi_enable_chip(rs, false);
 390         spi_finalize_current_transfer(master);
 391 }
 392
 393 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
 394                 struct spi_master *master, struct spi_transfer *xfer)
 395 {
 396         struct dma_async_tx_descriptor *rxdesc, *txdesc;
 397
 398         atomic_set(&rs->state, 0);
 399
 400         rxdesc = NULL;
 401         if (xfer->rx_buf) {
 402                 struct dma_slave_config rxconf = {
 403                         .direction = DMA_DEV_TO_MEM,
 404                         .src_addr = rs->dma_addr_rx,
 405                         .src_addr_width = rs->n_bytes,
 406                         .src_maxburst = 1,
 407                 };
 408
 409                 dmaengine_slave_config(master->dma_rx, &rxconf);
 410
 411                 rxdesc = dmaengine_prep_slave_sg(
 412                                 master->dma_rx,
 413                                 xfer->rx_sg.sgl, xfer->rx_sg.nents,
 414                                 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
 415                 if (!rxdesc)
 416                         return -EINVAL;
 417
 418                 rxdesc->callback = rockchip_spi_dma_rxcb;
 419                 rxdesc->callback_param = master;
 420         }
 421
 422         txdesc = NULL;
 423         if (xfer->tx_buf) {
 424                 struct dma_slave_config txconf = {
 425                         .direction = DMA_MEM_TO_DEV,
 426                         .dst_addr = rs->dma_addr_tx,
 427                         .dst_addr_width = rs->n_bytes,
 428                         .dst_maxburst = rs->fifo_len / 2,
 429                 };
 430
 431                 dmaengine_slave_config(master->dma_tx, &txconf);
 432
 433                 txdesc = dmaengine_prep_slave_sg(
 434                                 master->dma_tx,
 435                                 xfer->tx_sg.sgl, xfer->tx_sg.nents,
 436                                 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 437                 if (!txdesc) {
 438                         if (rxdesc)
 439                                 dmaengine_terminate_sync(master->dma_rx);
 440                         return -EINVAL;
 441                 }
 442
 443                 txdesc->callback = rockchip_spi_dma_txcb;
 444                 txdesc->callback_param = master;
 445         }
 446
 447         /* rx must be started before tx due to spi instinct */
 448         if (rxdesc) {
 449                 atomic_or(RXDMA, &rs->state);
 450                 dmaengine_submit(rxdesc);
 451                 dma_async_issue_pending(master->dma_rx);
 452         }
 453
 454         spi_enable_chip(rs, true);
 455
 456         if (txdesc) {
 457                 atomic_or(TXDMA, &rs->state);
 458                 dmaengine_submit(txdesc);
 459                 dma_async_issue_pending(master->dma_tx);
 460         }
 461
 462         /* 1 means the transfer is in progress */
 463         return 1;
 464 }
 465
 466 static void rockchip_spi_config(struct rockchip_spi *rs,
 467                 struct spi_device *spi, struct spi_transfer *xfer,
 468                 bool use_dma)
 469 {
 470         u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
 471                 | CR0_BHT_8BIT << CR0_BHT_OFFSET
 472                 | CR0_SSD_ONE  << CR0_SSD_OFFSET
 473                 | CR0_EM_BIG   << CR0_EM_OFFSET;
 474         u32 cr1;
 475         u32 dmacr = 0;
 476
 477         cr0 |= rs->rsd << CR0_RSD_OFFSET;
 478         cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
 479         if (spi->mode & SPI_LSB_FIRST)
 480                 cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
 481
 482         if (xfer->rx_buf && xfer->tx_buf)
 483                 cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
 484         else if (xfer->rx_buf)
 485                 cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
 486         else if (use_dma)
 487                 cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
 488
 489         switch (xfer->bits_per_word) {
 490         case 4:
 491                 cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
 492                 cr1 = xfer->len - 1;
 493                 break;
 494         case 8:
 495                 cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
 496                 cr1 = xfer->len - 1;
 497                 break;
 498         case 16:
 499                 cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
 500                 cr1 = xfer->len / 2 - 1;
 501                 break;
 502         default:
 503                 /* we only whitelist 4, 8 and 16 bit words in
 504                  * master->bits_per_word_mask, so this shouldn't
 505                  * happen
 506                  */
 507                 unreachable();
 508         }
 509
 510         if (use_dma) {
 511                 if (xfer->tx_buf)
 512                         dmacr |= TF_DMA_EN;
 513                 if (xfer->rx_buf)
 514                         dmacr |= RF_DMA_EN;
 515         }
 516
 517         writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
 518         writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
 519
 520         /* unfortunately setting the fifo threshold level to generate an
 521          * interrupt exactly when the fifo is full doesn't seem to work,
 522          * so we need the strict inequality here
 523          */
 524         if (xfer->len < rs->fifo_len)
 525                 writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 526         else
 527                 writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 528
 529         writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
 530         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
 531         writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
 532
 533         /* the hardware only supports an even clock divisor, so
 534          * round divisor = spiclk / speed up to nearest even number
 535          * so that the resulting speed is <= the requested speed
 536          */
 537         writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
 538                         rs->regs + ROCKCHIP_SPI_BAUDR);
 539 }
 540
 541 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
 542 {
 543         return ROCKCHIP_SPI_MAX_TRANLEN;
 544 }
 545
 546 static int rockchip_spi_transfer_one(
 547                 struct spi_master *master,
 548                 struct spi_device *spi,
 549                 struct spi_transfer *xfer)
 550 {
 551         struct rockchip_spi *rs = spi_master_get_devdata(master);
 552         bool use_dma;
 553
 554         WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
 555                 (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
 556
 557         if (!xfer->tx_buf && !xfer->rx_buf) {
 558                 dev_err(rs->dev, "No buffer for transfer\n");
 559                 return -EINVAL;
 560         }
 561
 562         if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
 563                 dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
 564                 return -EINVAL;
 565         }
 566
 567         rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
 568
 569         use_dma = master->can_dma ? master->can_dma(master, spi, xfer) : false;
 570
 571         rockchip_spi_config(rs, spi, xfer, use_dma);
 572
 573         if (use_dma)
 574                 return rockchip_spi_prepare_dma(rs, master, xfer);
 575
 576         return rockchip_spi_prepare_irq(rs, xfer);
 577 }
 578
 579 static bool rockchip_spi_can_dma(struct spi_master *master,
 580                                  struct spi_device *spi,
 581                                  struct spi_transfer *xfer)
 582 {
 583         struct rockchip_spi *rs = spi_master_get_devdata(master);
 584         unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
 585
 586         /* if the numbor of spi words to transfer is less than the fifo
 587          * length we can just fill the fifo and wait for a single irq,
 588          * so don't bother setting up dma
 589          */
 590         return xfer->len / bytes_per_word >= rs->fifo_len;
 591 }
 592
 593 static int rockchip_spi_probe(struct platform_device *pdev)
 594 {
 595         int ret;
 596         struct rockchip_spi *rs;
 597         struct spi_master *master;
 598         struct resource *mem;
 599         u32 rsd_nsecs;
 600
 601         master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
 602         if (!master)
 603                 return -ENOMEM;
 604
 605         platform_set_drvdata(pdev, master);
 606
 607         rs = spi_master_get_devdata(master);
 608
 609         /* Get basic io resource and map it */
 610         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 611         rs->regs = devm_ioremap_resource(&pdev->dev, mem);
 612         if (IS_ERR(rs->regs)) {
 613                 ret =  PTR_ERR(rs->regs);
 614                 goto err_put_master;
 615         }
 616
 617         rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
 618         if (IS_ERR(rs->apb_pclk)) {
 619                 dev_err(&pdev->dev, "Failed to get apb_pclk\n");
 620                 ret = PTR_ERR(rs->apb_pclk);
 621                 goto err_put_master;
 622         }
 623
 624         rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
 625         if (IS_ERR(rs->spiclk)) {
 626                 dev_err(&pdev->dev, "Failed to get spi_pclk\n");
 627                 ret = PTR_ERR(rs->spiclk);
 628                 goto err_put_master;
 629         }
 630
 631         ret = clk_prepare_enable(rs->apb_pclk);
 632         if (ret < 0) {
 633                 dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
 634                 goto err_put_master;
 635         }
 636
 637         ret = clk_prepare_enable(rs->spiclk);
 638         if (ret < 0) {
 639                 dev_err(&pdev->dev, "Failed to enable spi_clk\n");
 640                 goto err_disable_apbclk;
 641         }
 642
 643         spi_enable_chip(rs, false);
 644
 645         ret = platform_get_irq(pdev, 0);
 646         if (ret < 0)
 647                 goto err_disable_spiclk;
 648
 649         ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
 650                         IRQF_ONESHOT, dev_name(&pdev->dev), master);
 651         if (ret)
 652                 goto err_disable_spiclk;
 653
 654         rs->dev = &pdev->dev;
 655         rs->freq = clk_get_rate(rs->spiclk);
 656
 657         if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
 658                                   &rsd_nsecs)) {
 659                 /* rx sample delay is expressed in parent clock cycles (max 3) */
 660                 u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
 661                                 1000000000 >> 8);
 662                 if (!rsd) {
 663                         dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
 664                                         rs->freq, rsd_nsecs);
 665                 } else if (rsd > CR0_RSD_MAX) {
 666                         rsd = CR0_RSD_MAX;
 667                         dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
 668                                         rs->freq, rsd_nsecs,
 669                                         CR0_RSD_MAX * 1000000000U / rs->freq);
 670                 }
 671                 rs->rsd = rsd;
 672         }
 673
 674         rs->fifo_len = get_fifo_len(rs);
 675         if (!rs->fifo_len) {
 676                 dev_err(&pdev->dev, "Failed to get fifo length\n");
 677                 ret = -EINVAL;
 678                 goto err_disable_spiclk;
 679         }
 680
 681         pm_runtime_set_active(&pdev->dev);
 682         pm_runtime_enable(&pdev->dev);
 683
 684         master->auto_runtime_pm = true;
 685         master->bus_num = pdev->id;
 686         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
 687         master->num_chipselect = ROCKCHIP_SPI_MAX_CS_NUM;
 688         master->dev.of_node = pdev->dev.of_node;
 689         master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
 690         master->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
 691         master->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
 692
 693         master->set_cs = rockchip_spi_set_cs;
 694         master->transfer_one = rockchip_spi_transfer_one;
 695         master->max_transfer_size = rockchip_spi_max_transfer_size;
 696         master->handle_err = rockchip_spi_handle_err;
 697         master->flags = SPI_MASTER_GPIO_SS;
 698
 699         master->dma_tx = dma_request_chan(rs->dev, "tx");
 700         if (IS_ERR(master->dma_tx)) {
 701                 /* Check tx to see if we need defer probing driver */
 702                 if (PTR_ERR(master->dma_tx) == -EPROBE_DEFER) {
 703                         ret = -EPROBE_DEFER;
 704                         goto err_disable_pm_runtime;
 705                 }
 706                 dev_warn(rs->dev, "Failed to request TX DMA channel\n");
 707                 master->dma_tx = NULL;
 708         }
 709
 710         master->dma_rx = dma_request_chan(rs->dev, "rx");
 711         if (IS_ERR(master->dma_rx)) {
 712                 if (PTR_ERR(master->dma_rx) == -EPROBE_DEFER) {
 713                         ret = -EPROBE_DEFER;
 714                         goto err_free_dma_tx;
 715                 }
 716                 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
 717                 master->dma_rx = NULL;
 718         }
 719
 720         if (master->dma_tx && master->dma_rx) {
 721                 rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
 722                 rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
 723                 master->can_dma = rockchip_spi_can_dma;
 724         }
 725
 726         ret = devm_spi_register_master(&pdev->dev, master);
 727         if (ret < 0) {
 728                 dev_err(&pdev->dev, "Failed to register master\n");
 729                 goto err_free_dma_rx;
 730         }
 731
 732         return 0;
 733
 734 err_free_dma_rx:
 735         if (master->dma_rx)
 736                 dma_release_channel(master->dma_rx);
 737 err_free_dma_tx:
 738         if (master->dma_tx)
 739                 dma_release_channel(master->dma_tx);
 740 err_disable_pm_runtime:
 741         pm_runtime_disable(&pdev->dev);
 742 err_disable_spiclk:
 743         clk_disable_unprepare(rs->spiclk);
 744 err_disable_apbclk:
 745         clk_disable_unprepare(rs->apb_pclk);
 746 err_put_master:
 747         spi_master_put(master);
 748
 749         return ret;
 750 }
 751
 752 static int rockchip_spi_remove(struct platform_device *pdev)
 753 {
 754         struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
 755         struct rockchip_spi *rs = spi_master_get_devdata(master);
 756
 757         pm_runtime_get_sync(&pdev->dev);
 758
 759         clk_disable_unprepare(rs->spiclk);
 760         clk_disable_unprepare(rs->apb_pclk);
 761
 762         pm_runtime_put_noidle(&pdev->dev);
 763         pm_runtime_disable(&pdev->dev);
 764         pm_runtime_set_suspended(&pdev->dev);
 765
 766         if (master->dma_tx)
 767                 dma_release_channel(master->dma_tx);
 768         if (master->dma_rx)
 769                 dma_release_channel(master->dma_rx);
 770
 771         spi_master_put(master);
 772
 773         return 0;
 774 }
 775
 776 #ifdef CONFIG_PM_SLEEP
 777 static int rockchip_spi_suspend(struct device *dev)
 778 {
 779         int ret;
 780         struct spi_master *master = dev_get_drvdata(dev);
 781
 782         ret = spi_master_suspend(master);
 783         if (ret < 0)
 784                 return ret;
 785
 786         ret = pm_runtime_force_suspend(dev);
 787         if (ret < 0)
 788                 return ret;
 789
 790         pinctrl_pm_select_sleep_state(dev);
 791
 792         return 0;
 793 }
 794
 795 static int rockchip_spi_resume(struct device *dev)
 796 {
 797         int ret;
 798         struct spi_master *master = dev_get_drvdata(dev);
 799         struct rockchip_spi *rs = spi_master_get_devdata(master);
 800
 801         pinctrl_pm_select_default_state(dev);
 802
 803         ret = pm_runtime_force_resume(dev);
 804         if (ret < 0)
 805                 return ret;
 806
 807         ret = spi_master_resume(master);
 808         if (ret < 0) {
 809                 clk_disable_unprepare(rs->spiclk);
 810                 clk_disable_unprepare(rs->apb_pclk);
 811         }
 812
 813         return 0;
 814 }
 815 #endif /* CONFIG_PM_SLEEP */
 816
 817 #ifdef CONFIG_PM
 818 static int rockchip_spi_runtime_suspend(struct device *dev)
 819 {
 820         struct spi_master *master = dev_get_drvdata(dev);
 821         struct rockchip_spi *rs = spi_master_get_devdata(master);
 822
 823         clk_disable_unprepare(rs->spiclk);
 824         clk_disable_unprepare(rs->apb_pclk);
 825
 826         return 0;
 827 }
 828
 829 static int rockchip_spi_runtime_resume(struct device *dev)
 830 {
 831         int ret;
 832         struct spi_master *master = dev_get_drvdata(dev);
 833         struct rockchip_spi *rs = spi_master_get_devdata(master);
 834
 835         ret = clk_prepare_enable(rs->apb_pclk);
 836         if (ret < 0)
 837                 return ret;
 838
 839         ret = clk_prepare_enable(rs->spiclk);
 840         if (ret < 0)
 841                 clk_disable_unprepare(rs->apb_pclk);
 842
 843         return 0;
 844 }
 845 #endif /* CONFIG_PM */
 846
 847 static const struct dev_pm_ops rockchip_spi_pm = {
 848         SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
 849         SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
 850                            rockchip_spi_runtime_resume, NULL)
 851 };
 852
 853 static const struct of_device_id rockchip_spi_dt_match[] = {
 854         { .compatible = "rockchip,rv1108-spi", },
 855         { .compatible = "rockchip,rk3036-spi", },
 856         { .compatible = "rockchip,rk3066-spi", },
 857         { .compatible = "rockchip,rk3188-spi", },
 858         { .compatible = "rockchip,rk3228-spi", },
 859         { .compatible = "rockchip,rk3288-spi", },
 860         { .compatible = "rockchip,rk3368-spi", },
 861         { .compatible = "rockchip,rk3399-spi", },
 862         { },
 863 };
 864 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
 865
 866 static struct platform_driver rockchip_spi_driver = {
 867         .driver = {
 868                 .name   = DRIVER_NAME,
 869                 .pm = &rockchip_spi_pm,
 870                 .of_match_table = of_match_ptr(rockchip_spi_dt_match),
 871         },
 872         .probe = rockchip_spi_probe,
 873         .remove = rockchip_spi_remove,
 874 };
 875
 876 module_platform_driver(rockchip_spi_driver);
 877
 878 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
 879 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
 880 MODULE_LICENSE("GPL v2");