drivers/spi/spi-rockchip.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
   4  * Author: Addy Ke <[email protected]>
   5  */
   6
   7 #include <linux/clk.h>
   8 #include <linux/dmaengine.h>
   9 #include <linux/interrupt.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/pinctrl/consumer.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/scatterlist.h>
  17
  18 #define DRIVER_NAME "rockchip-spi"
  19
  20 #define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
  21                 writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
  22 #define ROCKCHIP_SPI_SET_BITS(reg, bits) \
  23                 writel_relaxed(readl_relaxed(reg) | (bits), reg)
  24
  25 /* SPI register offsets */
  26 #define ROCKCHIP_SPI_CTRLR0                     0x0000
  27 #define ROCKCHIP_SPI_CTRLR1                     0x0004
  28 #define ROCKCHIP_SPI_SSIENR                     0x0008
  29 #define ROCKCHIP_SPI_SER                        0x000c
  30 #define ROCKCHIP_SPI_BAUDR                      0x0010
  31 #define ROCKCHIP_SPI_TXFTLR                     0x0014
  32 #define ROCKCHIP_SPI_RXFTLR                     0x0018
  33 #define ROCKCHIP_SPI_TXFLR                      0x001c
  34 #define ROCKCHIP_SPI_RXFLR                      0x0020
  35 #define ROCKCHIP_SPI_SR                         0x0024
  36 #define ROCKCHIP_SPI_IPR                        0x0028
  37 #define ROCKCHIP_SPI_IMR                        0x002c
  38 #define ROCKCHIP_SPI_ISR                        0x0030
  39 #define ROCKCHIP_SPI_RISR                       0x0034
  40 #define ROCKCHIP_SPI_ICR                        0x0038
  41 #define ROCKCHIP_SPI_DMACR                      0x003c
  42 #define ROCKCHIP_SPI_DMATDLR                    0x0040
  43 #define ROCKCHIP_SPI_DMARDLR                    0x0044
  44 #define ROCKCHIP_SPI_VERSION                    0x0048
  45 #define ROCKCHIP_SPI_TXDR                       0x0400
  46 #define ROCKCHIP_SPI_RXDR                       0x0800
  47
  48 /* Bit fields in CTRLR0 */
  49 #define CR0_DFS_OFFSET                          0
  50 #define CR0_DFS_4BIT                            0x0
  51 #define CR0_DFS_8BIT                            0x1
  52 #define CR0_DFS_16BIT                           0x2
  53
  54 #define CR0_CFS_OFFSET                          2
  55
  56 #define CR0_SCPH_OFFSET                         6
  57
  58 #define CR0_SCPOL_OFFSET                        7
  59
  60 #define CR0_CSM_OFFSET                          8
  61 #define CR0_CSM_KEEP                            0x0
  62 /* ss_n be high for half sclk_out cycles */
  63 #define CR0_CSM_HALF                            0X1
  64 /* ss_n be high for one sclk_out cycle */
  65 #define CR0_CSM_ONE                                     0x2
  66
  67 /* ss_n to sclk_out delay */
  68 #define CR0_SSD_OFFSET                          10
  69 /*
  70  * The period between ss_n active and
  71  * sclk_out active is half sclk_out cycles
  72  */
  73 #define CR0_SSD_HALF                            0x0
  74 /*
  75  * The period between ss_n active and
  76  * sclk_out active is one sclk_out cycle
  77  */
  78 #define CR0_SSD_ONE                                     0x1
  79
  80 #define CR0_EM_OFFSET                           11
  81 #define CR0_EM_LITTLE                           0x0
  82 #define CR0_EM_BIG                                      0x1
  83
  84 #define CR0_FBM_OFFSET                          12
  85 #define CR0_FBM_MSB                                     0x0
  86 #define CR0_FBM_LSB                                     0x1
  87
  88 #define CR0_BHT_OFFSET                          13
  89 #define CR0_BHT_16BIT                           0x0
  90 #define CR0_BHT_8BIT                            0x1
  91
  92 #define CR0_RSD_OFFSET                          14
  93 #define CR0_RSD_MAX                             0x3
  94
  95 #define CR0_FRF_OFFSET                          16
  96 #define CR0_FRF_SPI                                     0x0
  97 #define CR0_FRF_SSP                                     0x1
  98 #define CR0_FRF_MICROWIRE                       0x2
  99
 100 #define CR0_XFM_OFFSET                          18
 101 #define CR0_XFM_MASK                            (0x03 << SPI_XFM_OFFSET)
 102 #define CR0_XFM_TR                                      0x0
 103 #define CR0_XFM_TO                                      0x1
 104 #define CR0_XFM_RO                                      0x2
 105
 106 #define CR0_OPM_OFFSET                          20
 107 #define CR0_OPM_MASTER                          0x0
 108 #define CR0_OPM_SLAVE                           0x1
 109
 110 #define CR0_MTM_OFFSET                          0x21
 111
 112 /* Bit fields in SER, 2bit */
 113 #define SER_MASK                                        0x3
 114
 115 /* Bit fields in BAUDR */
 116 #define BAUDR_SCKDV_MIN                         2
 117 #define BAUDR_SCKDV_MAX                         65534
 118
 119 /* Bit fields in SR, 5bit */
 120 #define SR_MASK                                         0x1f
 121 #define SR_BUSY                                         (1 << 0)
 122 #define SR_TF_FULL                                      (1 << 1)
 123 #define SR_TF_EMPTY                                     (1 << 2)
 124 #define SR_RF_EMPTY                                     (1 << 3)
 125 #define SR_RF_FULL                                      (1 << 4)
 126
 127 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
 128 #define INT_MASK                                        0x1f
 129 #define INT_TF_EMPTY                            (1 << 0)
 130 #define INT_TF_OVERFLOW                         (1 << 1)
 131 #define INT_RF_UNDERFLOW                        (1 << 2)
 132 #define INT_RF_OVERFLOW                         (1 << 3)
 133 #define INT_RF_FULL                                     (1 << 4)
 134
 135 /* Bit fields in ICR, 4bit */
 136 #define ICR_MASK                                        0x0f
 137 #define ICR_ALL                                         (1 << 0)
 138 #define ICR_RF_UNDERFLOW                        (1 << 1)
 139 #define ICR_RF_OVERFLOW                         (1 << 2)
 140 #define ICR_TF_OVERFLOW                         (1 << 3)
 141
 142 /* Bit fields in DMACR */
 143 #define RF_DMA_EN                                       (1 << 0)
 144 #define TF_DMA_EN                                       (1 << 1)
 145
 146 /* Driver state flags */
 147 #define RXDMA                                   (1 << 0)
 148 #define TXDMA                                   (1 << 1)
 149
 150 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
 151 #define MAX_SCLK_OUT                            50000000U
 152
 153 /*
 154  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
 155  * the controller seems to hang when given 0x10000, so stick with this for now.
 156  */
 157 #define ROCKCHIP_SPI_MAX_TRANLEN                0xffff
 158
 159 #define ROCKCHIP_SPI_MAX_CS_NUM                 2
 160 #define ROCKCHIP_SPI_VER2_TYPE1                 0x05EC0002
 161 #define ROCKCHIP_SPI_VER2_TYPE2                 0x00110002
 162
 163 struct rockchip_spi {
 164         struct device *dev;
 165
 166         struct clk *spiclk;
 167         struct clk *apb_pclk;
 168
 169         void __iomem *regs;
 170         dma_addr_t dma_addr_rx;
 171         dma_addr_t dma_addr_tx;
 172
 173         const void *tx;
 174         void *rx;
 175         unsigned int tx_left;
 176         unsigned int rx_left;
 177
 178         atomic_t state;
 179
 180         /*depth of the FIFO buffer */
 181         u32 fifo_len;
 182         /* frequency of spiclk */
 183         u32 freq;
 184
 185         u8 n_bytes;
 186         u8 rsd;
 187
 188         bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
 189
 190         bool slave_abort;
 191 };
 192
 193 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
 194 {
 195         writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
 196 }
 197
 198 static inline void wait_for_idle(struct rockchip_spi *rs)
 199 {
 200         unsigned long timeout = jiffies + msecs_to_jiffies(5);
 201
 202         do {
 203                 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
 204                         return;
 205         } while (!time_after(jiffies, timeout));
 206
 207         dev_warn(rs->dev, "spi controller is in busy state!\n");
 208 }
 209
 210 static u32 get_fifo_len(struct rockchip_spi *rs)
 211 {
 212         u32 ver;
 213
 214         ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
 215
 216         switch (ver) {
 217         case ROCKCHIP_SPI_VER2_TYPE1:
 218         case ROCKCHIP_SPI_VER2_TYPE2:
 219                 return 64;
 220         default:
 221                 return 32;
 222         }
 223 }
 224
 225 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 226 {
 227         struct spi_controller *ctlr = spi->controller;
 228         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 229         bool cs_asserted = !enable;
 230
 231         /* Return immediately for no-op */
 232         if (cs_asserted == rs->cs_asserted[spi->chip_select])
 233                 return;
 234
 235         if (cs_asserted) {
 236                 /* Keep things powered as long as CS is asserted */
 237                 pm_runtime_get_sync(rs->dev);
 238
 239                 ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
 240                                       BIT(spi->chip_select));
 241         } else {
 242                 ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
 243                                       BIT(spi->chip_select));
 244
 245                 /* Drop reference from when we first asserted CS */
 246                 pm_runtime_put(rs->dev);
 247         }
 248
 249         rs->cs_asserted[spi->chip_select] = cs_asserted;
 250 }
 251
 252 static void rockchip_spi_handle_err(struct spi_controller *ctlr,
 253                                     struct spi_message *msg)
 254 {
 255         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 256
 257         /* stop running spi transfer
 258          * this also flushes both rx and tx fifos
 259          */
 260         spi_enable_chip(rs, false);
 261
 262         /* make sure all interrupts are masked */
 263         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 264
 265         if (atomic_read(&rs->state) & TXDMA)
 266                 dmaengine_terminate_async(ctlr->dma_tx);
 267
 268         if (atomic_read(&rs->state) & RXDMA)
 269                 dmaengine_terminate_async(ctlr->dma_rx);
 270 }
 271
 272 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
 273 {
 274         u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
 275         u32 words = min(rs->tx_left, tx_free);
 276
 277         rs->tx_left -= words;
 278         for (; words; words--) {
 279                 u32 txw;
 280
 281                 if (rs->n_bytes == 1)
 282                         txw = *(u8 *)rs->tx;
 283                 else
 284                         txw = *(u16 *)rs->tx;
 285
 286                 writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
 287                 rs->tx += rs->n_bytes;
 288         }
 289 }
 290
 291 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
 292 {
 293         u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
 294         u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
 295
 296         /* the hardware doesn't allow us to change fifo threshold
 297          * level while spi is enabled, so instead make sure to leave
 298          * enough words in the rx fifo to get the last interrupt
 299          * exactly when all words have been received
 300          */
 301         if (rx_left) {
 302                 u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
 303
 304                 if (rx_left < ftl) {
 305                         rx_left = ftl;
 306                         words = rs->rx_left - rx_left;
 307                 }
 308         }
 309
 310         rs->rx_left = rx_left;
 311         for (; words; words--) {
 312                 u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 313
 314                 if (!rs->rx)
 315                         continue;
 316
 317                 if (rs->n_bytes == 1)
 318                         *(u8 *)rs->rx = (u8)rxw;
 319                 else
 320                         *(u16 *)rs->rx = (u16)rxw;
 321                 rs->rx += rs->n_bytes;
 322         }
 323 }
 324
 325 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
 326 {
 327         struct spi_controller *ctlr = dev_id;
 328         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 329
 330         if (rs->tx_left)
 331                 rockchip_spi_pio_writer(rs);
 332
 333         rockchip_spi_pio_reader(rs);
 334         if (!rs->rx_left) {
 335                 spi_enable_chip(rs, false);
 336                 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 337                 spi_finalize_current_transfer(ctlr);
 338         }
 339
 340         return IRQ_HANDLED;
 341 }
 342
 343 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
 344                 struct spi_transfer *xfer)
 345 {
 346         rs->tx = xfer->tx_buf;
 347         rs->rx = xfer->rx_buf;
 348         rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
 349         rs->rx_left = xfer->len / rs->n_bytes;
 350
 351         writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
 352         spi_enable_chip(rs, true);
 353
 354         if (rs->tx_left)
 355                 rockchip_spi_pio_writer(rs);
 356
 357         /* 1 means the transfer is in progress */
 358         return 1;
 359 }
 360
 361 static void rockchip_spi_dma_rxcb(void *data)
 362 {
 363         struct spi_controller *ctlr = data;
 364         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 365         int state = atomic_fetch_andnot(RXDMA, &rs->state);
 366
 367         if (state & TXDMA && !rs->slave_abort)
 368                 return;
 369
 370         spi_enable_chip(rs, false);
 371         spi_finalize_current_transfer(ctlr);
 372 }
 373
 374 static void rockchip_spi_dma_txcb(void *data)
 375 {
 376         struct spi_controller *ctlr = data;
 377         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 378         int state = atomic_fetch_andnot(TXDMA, &rs->state);
 379
 380         if (state & RXDMA && !rs->slave_abort)
 381                 return;
 382
 383         /* Wait until the FIFO data completely. */
 384         wait_for_idle(rs);
 385
 386         spi_enable_chip(rs, false);
 387         spi_finalize_current_transfer(ctlr);
 388 }
 389
 390 static u32 rockchip_spi_calc_burst_size(u32 data_len)
 391 {
 392         u32 i;
 393
 394         /* burst size: 1, 2, 4, 8 */
 395         for (i = 1; i < 8; i <<= 1) {
 396                 if (data_len & i)
 397                         break;
 398         }
 399
 400         return i;
 401 }
 402
 403 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
 404                 struct spi_controller *ctlr, struct spi_transfer *xfer)
 405 {
 406         struct dma_async_tx_descriptor *rxdesc, *txdesc;
 407
 408         atomic_set(&rs->state, 0);
 409
 410         rxdesc = NULL;
 411         if (xfer->rx_buf) {
 412                 struct dma_slave_config rxconf = {
 413                         .direction = DMA_DEV_TO_MEM,
 414                         .src_addr = rs->dma_addr_rx,
 415                         .src_addr_width = rs->n_bytes,
 416                         .src_maxburst = rockchip_spi_calc_burst_size(xfer->len /
 417                                                                      rs->n_bytes),
 418                 };
 419
 420                 dmaengine_slave_config(ctlr->dma_rx, &rxconf);
 421
 422                 rxdesc = dmaengine_prep_slave_sg(
 423                                 ctlr->dma_rx,
 424                                 xfer->rx_sg.sgl, xfer->rx_sg.nents,
 425                                 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
 426                 if (!rxdesc)
 427                         return -EINVAL;
 428
 429                 rxdesc->callback = rockchip_spi_dma_rxcb;
 430                 rxdesc->callback_param = ctlr;
 431         }
 432
 433         txdesc = NULL;
 434         if (xfer->tx_buf) {
 435                 struct dma_slave_config txconf = {
 436                         .direction = DMA_MEM_TO_DEV,
 437                         .dst_addr = rs->dma_addr_tx,
 438                         .dst_addr_width = rs->n_bytes,
 439                         .dst_maxburst = rs->fifo_len / 4,
 440                 };
 441
 442                 dmaengine_slave_config(ctlr->dma_tx, &txconf);
 443
 444                 txdesc = dmaengine_prep_slave_sg(
 445                                 ctlr->dma_tx,
 446                                 xfer->tx_sg.sgl, xfer->tx_sg.nents,
 447                                 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 448                 if (!txdesc) {
 449                         if (rxdesc)
 450                                 dmaengine_terminate_sync(ctlr->dma_rx);
 451                         return -EINVAL;
 452                 }
 453
 454                 txdesc->callback = rockchip_spi_dma_txcb;
 455                 txdesc->callback_param = ctlr;
 456         }
 457
 458         /* rx must be started before tx due to spi instinct */
 459         if (rxdesc) {
 460                 atomic_or(RXDMA, &rs->state);
 461                 dmaengine_submit(rxdesc);
 462                 dma_async_issue_pending(ctlr->dma_rx);
 463         }
 464
 465         spi_enable_chip(rs, true);
 466
 467         if (txdesc) {
 468                 atomic_or(TXDMA, &rs->state);
 469                 dmaengine_submit(txdesc);
 470                 dma_async_issue_pending(ctlr->dma_tx);
 471         }
 472
 473         /* 1 means the transfer is in progress */
 474         return 1;
 475 }
 476
 477 static void rockchip_spi_config(struct rockchip_spi *rs,
 478                 struct spi_device *spi, struct spi_transfer *xfer,
 479                 bool use_dma, bool slave_mode)
 480 {
 481         u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
 482                 | CR0_BHT_8BIT << CR0_BHT_OFFSET
 483                 | CR0_SSD_ONE  << CR0_SSD_OFFSET
 484                 | CR0_EM_BIG   << CR0_EM_OFFSET;
 485         u32 cr1;
 486         u32 dmacr = 0;
 487
 488         if (slave_mode)
 489                 cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
 490         rs->slave_abort = false;
 491
 492         cr0 |= rs->rsd << CR0_RSD_OFFSET;
 493         cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
 494         if (spi->mode & SPI_LSB_FIRST)
 495                 cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
 496
 497         if (xfer->rx_buf && xfer->tx_buf)
 498                 cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
 499         else if (xfer->rx_buf)
 500                 cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
 501         else if (use_dma)
 502                 cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
 503
 504         switch (xfer->bits_per_word) {
 505         case 4:
 506                 cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
 507                 cr1 = xfer->len - 1;
 508                 break;
 509         case 8:
 510                 cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
 511                 cr1 = xfer->len - 1;
 512                 break;
 513         case 16:
 514                 cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
 515                 cr1 = xfer->len / 2 - 1;
 516                 break;
 517         default:
 518                 /* we only whitelist 4, 8 and 16 bit words in
 519                  * ctlr->bits_per_word_mask, so this shouldn't
 520                  * happen
 521                  */
 522                 unreachable();
 523         }
 524
 525         if (use_dma) {
 526                 if (xfer->tx_buf)
 527                         dmacr |= TF_DMA_EN;
 528                 if (xfer->rx_buf)
 529                         dmacr |= RF_DMA_EN;
 530         }
 531
 532         writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
 533         writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
 534
 535         /* unfortunately setting the fifo threshold level to generate an
 536          * interrupt exactly when the fifo is full doesn't seem to work,
 537          * so we need the strict inequality here
 538          */
 539         if (xfer->len < rs->fifo_len)
 540                 writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 541         else
 542                 writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 543
 544         writel_relaxed(rs->fifo_len / 2, rs->regs + ROCKCHIP_SPI_DMATDLR);
 545         writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
 546                        rs->regs + ROCKCHIP_SPI_DMARDLR);
 547         writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
 548
 549         /* the hardware only supports an even clock divisor, so
 550          * round divisor = spiclk / speed up to nearest even number
 551          * so that the resulting speed is <= the requested speed
 552          */
 553         writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
 554                         rs->regs + ROCKCHIP_SPI_BAUDR);
 555 }
 556
 557 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
 558 {
 559         return ROCKCHIP_SPI_MAX_TRANLEN;
 560 }
 561
 562 static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
 563 {
 564         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 565
 566         rs->slave_abort = true;
 567         complete(&ctlr->xfer_completion);
 568
 569         return 0;
 570 }
 571
 572 static int rockchip_spi_transfer_one(
 573                 struct spi_controller *ctlr,
 574                 struct spi_device *spi,
 575                 struct spi_transfer *xfer)
 576 {
 577         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 578         bool use_dma;
 579
 580         WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
 581                 (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
 582
 583         if (!xfer->tx_buf && !xfer->rx_buf) {
 584                 dev_err(rs->dev, "No buffer for transfer\n");
 585                 return -EINVAL;
 586         }
 587
 588         if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
 589                 dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
 590                 return -EINVAL;
 591         }
 592
 593         rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
 594
 595         use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
 596
 597         rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
 598
 599         if (use_dma)
 600                 return rockchip_spi_prepare_dma(rs, ctlr, xfer);
 601
 602         return rockchip_spi_prepare_irq(rs, xfer);
 603 }
 604
 605 static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
 606                                  struct spi_device *spi,
 607                                  struct spi_transfer *xfer)
 608 {
 609         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 610         unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
 611
 612         /* if the numbor of spi words to transfer is less than the fifo
 613          * length we can just fill the fifo and wait for a single irq,
 614          * so don't bother setting up dma
 615          */
 616         return xfer->len / bytes_per_word >= rs->fifo_len;
 617 }
 618
 619 static int rockchip_spi_probe(struct platform_device *pdev)
 620 {
 621         int ret;
 622         struct rockchip_spi *rs;
 623         struct spi_controller *ctlr;
 624         struct resource *mem;
 625         struct device_node *np = pdev->dev.of_node;
 626         u32 rsd_nsecs;
 627         bool slave_mode;
 628
 629         slave_mode = of_property_read_bool(np, "spi-slave");
 630
 631         if (slave_mode)
 632                 ctlr = spi_alloc_slave(&pdev->dev,
 633                                 sizeof(struct rockchip_spi));
 634         else
 635                 ctlr = spi_alloc_master(&pdev->dev,
 636                                 sizeof(struct rockchip_spi));
 637
 638         if (!ctlr)
 639                 return -ENOMEM;
 640
 641         platform_set_drvdata(pdev, ctlr);
 642
 643         rs = spi_controller_get_devdata(ctlr);
 644         ctlr->slave = slave_mode;
 645
 646         /* Get basic io resource and map it */
 647         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 648         rs->regs = devm_ioremap_resource(&pdev->dev, mem);
 649         if (IS_ERR(rs->regs)) {
 650                 ret =  PTR_ERR(rs->regs);
 651                 goto err_put_ctlr;
 652         }
 653
 654         rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
 655         if (IS_ERR(rs->apb_pclk)) {
 656                 dev_err(&pdev->dev, "Failed to get apb_pclk\n");
 657                 ret = PTR_ERR(rs->apb_pclk);
 658                 goto err_put_ctlr;
 659         }
 660
 661         rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
 662         if (IS_ERR(rs->spiclk)) {
 663                 dev_err(&pdev->dev, "Failed to get spi_pclk\n");
 664                 ret = PTR_ERR(rs->spiclk);
 665                 goto err_put_ctlr;
 666         }
 667
 668         ret = clk_prepare_enable(rs->apb_pclk);
 669         if (ret < 0) {
 670                 dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
 671                 goto err_put_ctlr;
 672         }
 673
 674         ret = clk_prepare_enable(rs->spiclk);
 675         if (ret < 0) {
 676                 dev_err(&pdev->dev, "Failed to enable spi_clk\n");
 677                 goto err_disable_apbclk;
 678         }
 679
 680         spi_enable_chip(rs, false);
 681
 682         ret = platform_get_irq(pdev, 0);
 683         if (ret < 0)
 684                 goto err_disable_spiclk;
 685
 686         ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
 687                         IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
 688         if (ret)
 689                 goto err_disable_spiclk;
 690
 691         rs->dev = &pdev->dev;
 692         rs->freq = clk_get_rate(rs->spiclk);
 693
 694         if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
 695                                   &rsd_nsecs)) {
 696                 /* rx sample delay is expressed in parent clock cycles (max 3) */
 697                 u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
 698                                 1000000000 >> 8);
 699                 if (!rsd) {
 700                         dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
 701                                         rs->freq, rsd_nsecs);
 702                 } else if (rsd > CR0_RSD_MAX) {
 703                         rsd = CR0_RSD_MAX;
 704                         dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
 705                                         rs->freq, rsd_nsecs,
 706                                         CR0_RSD_MAX * 1000000000U / rs->freq);
 707                 }
 708                 rs->rsd = rsd;
 709         }
 710
 711         rs->fifo_len = get_fifo_len(rs);
 712         if (!rs->fifo_len) {
 713                 dev_err(&pdev->dev, "Failed to get fifo length\n");
 714                 ret = -EINVAL;
 715                 goto err_disable_spiclk;
 716         }
 717
 718         pm_runtime_set_active(&pdev->dev);
 719         pm_runtime_enable(&pdev->dev);
 720
 721         ctlr->auto_runtime_pm = true;
 722         ctlr->bus_num = pdev->id;
 723         ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
 724         if (slave_mode) {
 725                 ctlr->mode_bits |= SPI_NO_CS;
 726                 ctlr->slave_abort = rockchip_spi_slave_abort;
 727         } else {
 728                 ctlr->flags = SPI_MASTER_GPIO_SS;
 729                 ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
 730                 /*
 731                  * rk spi0 has two native cs, spi1..5 one cs only
 732                  * if num-cs is missing in the dts, default to 1
 733                  */
 734                 if (of_property_read_u16(np, "num-cs", &ctlr->num_chipselect))
 735                         ctlr->num_chipselect = 1;
 736                 ctlr->use_gpio_descriptors = true;
 737         }
 738         ctlr->dev.of_node = pdev->dev.of_node;
 739         ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
 740         ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
 741         ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
 742
 743         ctlr->set_cs = rockchip_spi_set_cs;
 744         ctlr->transfer_one = rockchip_spi_transfer_one;
 745         ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
 746         ctlr->handle_err = rockchip_spi_handle_err;
 747
 748         ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
 749         if (IS_ERR(ctlr->dma_tx)) {
 750                 /* Check tx to see if we need defer probing driver */
 751                 if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
 752                         ret = -EPROBE_DEFER;
 753                         goto err_disable_pm_runtime;
 754                 }
 755                 dev_warn(rs->dev, "Failed to request TX DMA channel\n");
 756                 ctlr->dma_tx = NULL;
 757         }
 758
 759         ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
 760         if (IS_ERR(ctlr->dma_rx)) {
 761                 if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
 762                         ret = -EPROBE_DEFER;
 763                         goto err_free_dma_tx;
 764                 }
 765                 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
 766                 ctlr->dma_rx = NULL;
 767         }
 768
 769         if (ctlr->dma_tx && ctlr->dma_rx) {
 770                 rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
 771                 rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
 772                 ctlr->can_dma = rockchip_spi_can_dma;
 773         }
 774
 775         ret = devm_spi_register_controller(&pdev->dev, ctlr);
 776         if (ret < 0) {
 777                 dev_err(&pdev->dev, "Failed to register controller\n");
 778                 goto err_free_dma_rx;
 779         }
 780
 781         return 0;
 782
 783 err_free_dma_rx:
 784         if (ctlr->dma_rx)
 785                 dma_release_channel(ctlr->dma_rx);
 786 err_free_dma_tx:
 787         if (ctlr->dma_tx)
 788                 dma_release_channel(ctlr->dma_tx);
 789 err_disable_pm_runtime:
 790         pm_runtime_disable(&pdev->dev);
 791 err_disable_spiclk:
 792         clk_disable_unprepare(rs->spiclk);
 793 err_disable_apbclk:
 794         clk_disable_unprepare(rs->apb_pclk);
 795 err_put_ctlr:
 796         spi_controller_put(ctlr);
 797
 798         return ret;
 799 }
 800
 801 static int rockchip_spi_remove(struct platform_device *pdev)
 802 {
 803         struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
 804         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 805
 806         pm_runtime_get_sync(&pdev->dev);
 807
 808         clk_disable_unprepare(rs->spiclk);
 809         clk_disable_unprepare(rs->apb_pclk);
 810
 811         pm_runtime_put_noidle(&pdev->dev);
 812         pm_runtime_disable(&pdev->dev);
 813         pm_runtime_set_suspended(&pdev->dev);
 814
 815         if (ctlr->dma_tx)
 816                 dma_release_channel(ctlr->dma_tx);
 817         if (ctlr->dma_rx)
 818                 dma_release_channel(ctlr->dma_rx);
 819
 820         spi_controller_put(ctlr);
 821
 822         return 0;
 823 }
 824
 825 #ifdef CONFIG_PM_SLEEP
 826 static int rockchip_spi_suspend(struct device *dev)
 827 {
 828         int ret;
 829         struct spi_controller *ctlr = dev_get_drvdata(dev);
 830
 831         ret = spi_controller_suspend(ctlr);
 832         if (ret < 0)
 833                 return ret;
 834
 835         ret = pm_runtime_force_suspend(dev);
 836         if (ret < 0)
 837                 return ret;
 838
 839         pinctrl_pm_select_sleep_state(dev);
 840
 841         return 0;
 842 }
 843
 844 static int rockchip_spi_resume(struct device *dev)
 845 {
 846         int ret;
 847         struct spi_controller *ctlr = dev_get_drvdata(dev);
 848         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 849
 850         pinctrl_pm_select_default_state(dev);
 851
 852         ret = pm_runtime_force_resume(dev);
 853         if (ret < 0)
 854                 return ret;
 855
 856         ret = spi_controller_resume(ctlr);
 857         if (ret < 0) {
 858                 clk_disable_unprepare(rs->spiclk);
 859                 clk_disable_unprepare(rs->apb_pclk);
 860         }
 861
 862         return 0;
 863 }
 864 #endif /* CONFIG_PM_SLEEP */
 865
 866 #ifdef CONFIG_PM
 867 static int rockchip_spi_runtime_suspend(struct device *dev)
 868 {
 869         struct spi_controller *ctlr = dev_get_drvdata(dev);
 870         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 871
 872         clk_disable_unprepare(rs->spiclk);
 873         clk_disable_unprepare(rs->apb_pclk);
 874
 875         return 0;
 876 }
 877
 878 static int rockchip_spi_runtime_resume(struct device *dev)
 879 {
 880         int ret;
 881         struct spi_controller *ctlr = dev_get_drvdata(dev);
 882         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 883
 884         ret = clk_prepare_enable(rs->apb_pclk);
 885         if (ret < 0)
 886                 return ret;
 887
 888         ret = clk_prepare_enable(rs->spiclk);
 889         if (ret < 0)
 890                 clk_disable_unprepare(rs->apb_pclk);
 891
 892         return 0;
 893 }
 894 #endif /* CONFIG_PM */
 895
 896 static const struct dev_pm_ops rockchip_spi_pm = {
 897         SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
 898         SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
 899                            rockchip_spi_runtime_resume, NULL)
 900 };
 901
 902 static const struct of_device_id rockchip_spi_dt_match[] = {
 903         { .compatible = "rockchip,px30-spi", },
 904         { .compatible = "rockchip,rk3036-spi", },
 905         { .compatible = "rockchip,rk3066-spi", },
 906         { .compatible = "rockchip,rk3188-spi", },
 907         { .compatible = "rockchip,rk3228-spi", },
 908         { .compatible = "rockchip,rk3288-spi", },
 909         { .compatible = "rockchip,rk3308-spi", },
 910         { .compatible = "rockchip,rk3328-spi", },
 911         { .compatible = "rockchip,rk3368-spi", },
 912         { .compatible = "rockchip,rk3399-spi", },
 913         { .compatible = "rockchip,rv1108-spi", },
 914         { },
 915 };
 916 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
 917
 918 static struct platform_driver rockchip_spi_driver = {
 919         .driver = {
 920                 .name   = DRIVER_NAME,
 921                 .pm = &rockchip_spi_pm,
 922                 .of_match_table = of_match_ptr(rockchip_spi_dt_match),
 923         },
 924         .probe = rockchip_spi_probe,
 925         .remove = rockchip_spi_remove,
 926 };
 927
 928 module_platform_driver(rockchip_spi_driver);
 929
 930 MODULE_AUTHOR("Addy Ke <[email protected]>");
 931 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
 932 MODULE_LICENSE("GPL v2");