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 <addy.ke@rock-chips.com>
   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_SOI_OFFSET                          23
 111
 112 #define CR0_MTM_OFFSET                          0x21
 113
 114 /* Bit fields in SER, 2bit */
 115 #define SER_MASK                                        0x3
 116
 117 /* Bit fields in BAUDR */
 118 #define BAUDR_SCKDV_MIN                         2
 119 #define BAUDR_SCKDV_MAX                         65534
 120
 121 /* Bit fields in SR, 6bit */
 122 #define SR_MASK                                         0x3f
 123 #define SR_BUSY                                         (1 << 0)
 124 #define SR_TF_FULL                                      (1 << 1)
 125 #define SR_TF_EMPTY                                     (1 << 2)
 126 #define SR_RF_EMPTY                                     (1 << 3)
 127 #define SR_RF_FULL                                      (1 << 4)
 128 #define SR_SLAVE_TX_BUSY                                (1 << 5)
 129
 130 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
 131 #define INT_MASK                                        0x1f
 132 #define INT_TF_EMPTY                            (1 << 0)
 133 #define INT_TF_OVERFLOW                         (1 << 1)
 134 #define INT_RF_UNDERFLOW                        (1 << 2)
 135 #define INT_RF_OVERFLOW                         (1 << 3)
 136 #define INT_RF_FULL                             (1 << 4)
 137 #define INT_CS_INACTIVE                         (1 << 6)
 138
 139 /* Bit fields in ICR, 4bit */
 140 #define ICR_MASK                                        0x0f
 141 #define ICR_ALL                                         (1 << 0)
 142 #define ICR_RF_UNDERFLOW                        (1 << 1)
 143 #define ICR_RF_OVERFLOW                         (1 << 2)
 144 #define ICR_TF_OVERFLOW                         (1 << 3)
 145
 146 /* Bit fields in DMACR */
 147 #define RF_DMA_EN                                       (1 << 0)
 148 #define TF_DMA_EN                                       (1 << 1)
 149
 150 /* Driver state flags */
 151 #define RXDMA                                   (1 << 0)
 152 #define TXDMA                                   (1 << 1)
 153
 154 /* sclk_out: spi master internal logic in rk3x can support 50Mhz */
 155 #define MAX_SCLK_OUT                            50000000U
 156
 157 /*
 158  * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
 159  * the controller seems to hang when given 0x10000, so stick with this for now.
 160  */
 161 #define ROCKCHIP_SPI_MAX_TRANLEN                0xffff
 162
 163 /* 2 for native cs, 2 for cs-gpio */
 164 #define ROCKCHIP_SPI_MAX_CS_NUM                 4
 165 #define ROCKCHIP_SPI_VER2_TYPE1                 0x05EC0002
 166 #define ROCKCHIP_SPI_VER2_TYPE2                 0x00110002
 167
 168 #define ROCKCHIP_AUTOSUSPEND_TIMEOUT            2000
 169
 170 struct rockchip_spi {
 171         struct device *dev;
 172
 173         struct clk *spiclk;
 174         struct clk *apb_pclk;
 175
 176         void __iomem *regs;
 177         dma_addr_t dma_addr_rx;
 178         dma_addr_t dma_addr_tx;
 179
 180         const void *tx;
 181         void *rx;
 182         unsigned int tx_left;
 183         unsigned int rx_left;
 184
 185         atomic_t state;
 186
 187         /*depth of the FIFO buffer */
 188         u32 fifo_len;
 189         /* frequency of spiclk */
 190         u32 freq;
 191
 192         u8 n_bytes;
 193         u8 rsd;
 194
 195         bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
 196
 197         bool slave_abort;
 198         bool cs_inactive; /* spi slave tansmition stop when cs inactive */
 199         bool cs_high_supported; /* native CS supports active-high polarity */
 200
 201         struct spi_transfer *xfer; /* Store xfer temporarily */
 202 };
 203
 204 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
 205 {
 206         writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
 207 }
 208
 209 static inline void wait_for_tx_idle(struct rockchip_spi *rs, bool slave_mode)
 210 {
 211         unsigned long timeout = jiffies + msecs_to_jiffies(5);
 212
 213         do {
 214                 if (slave_mode) {
 215                         if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_SLAVE_TX_BUSY) &&
 216                             !((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY)))
 217                                 return;
 218                 } else {
 219                         if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
 220                                 return;
 221                 }
 222         } while (!time_after(jiffies, timeout));
 223
 224         dev_warn(rs->dev, "spi controller is in busy state!\n");
 225 }
 226
 227 static u32 get_fifo_len(struct rockchip_spi *rs)
 228 {
 229         u32 ver;
 230
 231         ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
 232
 233         switch (ver) {
 234         case ROCKCHIP_SPI_VER2_TYPE1:
 235         case ROCKCHIP_SPI_VER2_TYPE2:
 236                 return 64;
 237         default:
 238                 return 32;
 239         }
 240 }
 241
 242 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 243 {
 244         struct spi_controller *ctlr = spi->controller;
 245         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 246         bool cs_asserted = spi->mode & SPI_CS_HIGH ? enable : !enable;
 247
 248         /* Return immediately for no-op */
 249         if (cs_asserted == rs->cs_asserted[spi->chip_select])
 250                 return;
 251
 252         if (cs_asserted) {
 253                 /* Keep things powered as long as CS is asserted */
 254                 pm_runtime_get_sync(rs->dev);
 255
 256                 if (spi->cs_gpiod)
 257                         ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
 258                 else
 259                         ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));
 260         } else {
 261                 if (spi->cs_gpiod)
 262                         ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
 263                 else
 264                         ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));
 265
 266                 /* Drop reference from when we first asserted CS */
 267                 pm_runtime_put(rs->dev);
 268         }
 269
 270         rs->cs_asserted[spi->chip_select] = cs_asserted;
 271 }
 272
 273 static void rockchip_spi_handle_err(struct spi_controller *ctlr,
 274                                     struct spi_message *msg)
 275 {
 276         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 277
 278         /* stop running spi transfer
 279          * this also flushes both rx and tx fifos
 280          */
 281         spi_enable_chip(rs, false);
 282
 283         /* make sure all interrupts are masked and status cleared */
 284         writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 285         writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
 286
 287         if (atomic_read(&rs->state) & TXDMA)
 288                 dmaengine_terminate_async(ctlr->dma_tx);
 289
 290         if (atomic_read(&rs->state) & RXDMA)
 291                 dmaengine_terminate_async(ctlr->dma_rx);
 292 }
 293
 294 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
 295 {
 296         u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
 297         u32 words = min(rs->tx_left, tx_free);
 298
 299         rs->tx_left -= words;
 300         for (; words; words--) {
 301                 u32 txw;
 302
 303                 if (rs->n_bytes == 1)
 304                         txw = *(u8 *)rs->tx;
 305                 else
 306                         txw = *(u16 *)rs->tx;
 307
 308                 writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
 309                 rs->tx += rs->n_bytes;
 310         }
 311 }
 312
 313 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
 314 {
 315         u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
 316         u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
 317
 318         /* the hardware doesn't allow us to change fifo threshold
 319          * level while spi is enabled, so instead make sure to leave
 320          * enough words in the rx fifo to get the last interrupt
 321          * exactly when all words have been received
 322          */
 323         if (rx_left) {
 324                 u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
 325
 326                 if (rx_left < ftl) {
 327                         rx_left = ftl;
 328                         words = rs->rx_left - rx_left;
 329                 }
 330         }
 331
 332         rs->rx_left = rx_left;
 333         for (; words; words--) {
 334                 u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 335
 336                 if (!rs->rx)
 337                         continue;
 338
 339                 if (rs->n_bytes == 1)
 340                         *(u8 *)rs->rx = (u8)rxw;
 341                 else
 342                         *(u16 *)rs->rx = (u16)rxw;
 343                 rs->rx += rs->n_bytes;
 344         }
 345 }
 346
 347 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
 348 {
 349         struct spi_controller *ctlr = dev_id;
 350         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 351
 352         /* When int_cs_inactive comes, spi slave abort */
 353         if (rs->cs_inactive && readl_relaxed(rs->regs + ROCKCHIP_SPI_IMR) & INT_CS_INACTIVE) {
 354                 ctlr->slave_abort(ctlr);
 355                 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 356                 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
 357
 358                 return IRQ_HANDLED;
 359         }
 360
 361         if (rs->tx_left)
 362                 rockchip_spi_pio_writer(rs);
 363
 364         rockchip_spi_pio_reader(rs);
 365         if (!rs->rx_left) {
 366                 spi_enable_chip(rs, false);
 367                 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 368                 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
 369                 spi_finalize_current_transfer(ctlr);
 370         }
 371
 372         return IRQ_HANDLED;
 373 }
 374
 375 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
 376                                     struct spi_controller *ctlr,
 377                                     struct spi_transfer *xfer)
 378 {
 379         rs->tx = xfer->tx_buf;
 380         rs->rx = xfer->rx_buf;
 381         rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
 382         rs->rx_left = xfer->len / rs->n_bytes;
 383
 384         if (rs->cs_inactive)
 385                 writel_relaxed(INT_RF_FULL | INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
 386         else
 387                 writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
 388         spi_enable_chip(rs, true);
 389
 390         if (rs->tx_left)
 391                 rockchip_spi_pio_writer(rs);
 392
 393         /* 1 means the transfer is in progress */
 394         return 1;
 395 }
 396
 397 static void rockchip_spi_dma_rxcb(void *data)
 398 {
 399         struct spi_controller *ctlr = data;
 400         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 401         int state = atomic_fetch_andnot(RXDMA, &rs->state);
 402
 403         if (state & TXDMA && !rs->slave_abort)
 404                 return;
 405
 406         if (rs->cs_inactive)
 407                 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
 408
 409         spi_enable_chip(rs, false);
 410         spi_finalize_current_transfer(ctlr);
 411 }
 412
 413 static void rockchip_spi_dma_txcb(void *data)
 414 {
 415         struct spi_controller *ctlr = data;
 416         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 417         int state = atomic_fetch_andnot(TXDMA, &rs->state);
 418
 419         if (state & RXDMA && !rs->slave_abort)
 420                 return;
 421
 422         /* Wait until the FIFO data completely. */
 423         wait_for_tx_idle(rs, ctlr->slave);
 424
 425         spi_enable_chip(rs, false);
 426         spi_finalize_current_transfer(ctlr);
 427 }
 428
 429 static u32 rockchip_spi_calc_burst_size(u32 data_len)
 430 {
 431         u32 i;
 432
 433         /* burst size: 1, 2, 4, 8 */
 434         for (i = 1; i < 8; i <<= 1) {
 435                 if (data_len & i)
 436                         break;
 437         }
 438
 439         return i;
 440 }
 441
 442 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
 443                 struct spi_controller *ctlr, struct spi_transfer *xfer)
 444 {
 445         struct dma_async_tx_descriptor *rxdesc, *txdesc;
 446
 447         atomic_set(&rs->state, 0);
 448
 449         rs->tx = xfer->tx_buf;
 450         rs->rx = xfer->rx_buf;
 451
 452         rxdesc = NULL;
 453         if (xfer->rx_buf) {
 454                 struct dma_slave_config rxconf = {
 455                         .direction = DMA_DEV_TO_MEM,
 456                         .src_addr = rs->dma_addr_rx,
 457                         .src_addr_width = rs->n_bytes,
 458                         .src_maxburst = rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes),
 459                 };
 460
 461                 dmaengine_slave_config(ctlr->dma_rx, &rxconf);
 462
 463                 rxdesc = dmaengine_prep_slave_sg(
 464                                 ctlr->dma_rx,
 465                                 xfer->rx_sg.sgl, xfer->rx_sg.nents,
 466                                 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
 467                 if (!rxdesc)
 468                         return -EINVAL;
 469
 470                 rxdesc->callback = rockchip_spi_dma_rxcb;
 471                 rxdesc->callback_param = ctlr;
 472         }
 473
 474         txdesc = NULL;
 475         if (xfer->tx_buf) {
 476                 struct dma_slave_config txconf = {
 477                         .direction = DMA_MEM_TO_DEV,
 478                         .dst_addr = rs->dma_addr_tx,
 479                         .dst_addr_width = rs->n_bytes,
 480                         .dst_maxburst = rs->fifo_len / 4,
 481                 };
 482
 483                 dmaengine_slave_config(ctlr->dma_tx, &txconf);
 484
 485                 txdesc = dmaengine_prep_slave_sg(
 486                                 ctlr->dma_tx,
 487                                 xfer->tx_sg.sgl, xfer->tx_sg.nents,
 488                                 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
 489                 if (!txdesc) {
 490                         if (rxdesc)
 491                                 dmaengine_terminate_sync(ctlr->dma_rx);
 492                         return -EINVAL;
 493                 }
 494
 495                 txdesc->callback = rockchip_spi_dma_txcb;
 496                 txdesc->callback_param = ctlr;
 497         }
 498
 499         /* rx must be started before tx due to spi instinct */
 500         if (rxdesc) {
 501                 atomic_or(RXDMA, &rs->state);
 502                 ctlr->dma_rx->cookie = dmaengine_submit(rxdesc);
 503                 dma_async_issue_pending(ctlr->dma_rx);
 504         }
 505
 506         if (rs->cs_inactive)
 507                 writel_relaxed(INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
 508
 509         spi_enable_chip(rs, true);
 510
 511         if (txdesc) {
 512                 atomic_or(TXDMA, &rs->state);
 513                 dmaengine_submit(txdesc);
 514                 dma_async_issue_pending(ctlr->dma_tx);
 515         }
 516
 517         /* 1 means the transfer is in progress */
 518         return 1;
 519 }
 520
 521 static int rockchip_spi_config(struct rockchip_spi *rs,
 522                 struct spi_device *spi, struct spi_transfer *xfer,
 523                 bool use_dma, bool slave_mode)
 524 {
 525         u32 cr0 = CR0_FRF_SPI  << CR0_FRF_OFFSET
 526                 | CR0_BHT_8BIT << CR0_BHT_OFFSET
 527                 | CR0_SSD_ONE  << CR0_SSD_OFFSET
 528                 | CR0_EM_BIG   << CR0_EM_OFFSET;
 529         u32 cr1;
 530         u32 dmacr = 0;
 531
 532         if (slave_mode)
 533                 cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
 534         rs->slave_abort = false;
 535
 536         cr0 |= rs->rsd << CR0_RSD_OFFSET;
 537         cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
 538         if (spi->mode & SPI_LSB_FIRST)
 539                 cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
 540         if (spi->mode & SPI_CS_HIGH)
 541                 cr0 |= BIT(spi->chip_select) << CR0_SOI_OFFSET;
 542
 543         if (xfer->rx_buf && xfer->tx_buf)
 544                 cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
 545         else if (xfer->rx_buf)
 546                 cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
 547         else if (use_dma)
 548                 cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
 549
 550         switch (xfer->bits_per_word) {
 551         case 4:
 552                 cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
 553                 cr1 = xfer->len - 1;
 554                 break;
 555         case 8:
 556                 cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
 557                 cr1 = xfer->len - 1;
 558                 break;
 559         case 16:
 560                 cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
 561                 cr1 = xfer->len / 2 - 1;
 562                 break;
 563         default:
 564                 /* we only whitelist 4, 8 and 16 bit words in
 565                  * ctlr->bits_per_word_mask, so this shouldn't
 566                  * happen
 567                  */
 568                 dev_err(rs->dev, "unknown bits per word: %d\n",
 569                         xfer->bits_per_word);
 570                 return -EINVAL;
 571         }
 572
 573         if (use_dma) {
 574                 if (xfer->tx_buf)
 575                         dmacr |= TF_DMA_EN;
 576                 if (xfer->rx_buf)
 577                         dmacr |= RF_DMA_EN;
 578         }
 579
 580         writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
 581         writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
 582
 583         /* unfortunately setting the fifo threshold level to generate an
 584          * interrupt exactly when the fifo is full doesn't seem to work,
 585          * so we need the strict inequality here
 586          */
 587         if ((xfer->len / rs->n_bytes) < rs->fifo_len)
 588                 writel_relaxed(xfer->len / rs->n_bytes - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 589         else
 590                 writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 591
 592         writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
 593         writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
 594                        rs->regs + ROCKCHIP_SPI_DMARDLR);
 595         writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
 596
 597         /* the hardware only supports an even clock divisor, so
 598          * round divisor = spiclk / speed up to nearest even number
 599          * so that the resulting speed is <= the requested speed
 600          */
 601         writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
 602                         rs->regs + ROCKCHIP_SPI_BAUDR);
 603
 604         return 0;
 605 }
 606
 607 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
 608 {
 609         return ROCKCHIP_SPI_MAX_TRANLEN;
 610 }
 611
 612 static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
 613 {
 614         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 615         u32 rx_fifo_left;
 616         struct dma_tx_state state;
 617         enum dma_status status;
 618
 619         /* Get current dma rx point */
 620         if (atomic_read(&rs->state) & RXDMA) {
 621                 dmaengine_pause(ctlr->dma_rx);
 622                 status = dmaengine_tx_status(ctlr->dma_rx, ctlr->dma_rx->cookie, &state);
 623                 if (status == DMA_ERROR) {
 624                         rs->rx = rs->xfer->rx_buf;
 625                         rs->xfer->len = 0;
 626                         rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
 627                         for (; rx_fifo_left; rx_fifo_left--)
 628                                 readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 629                         goto out;
 630                 } else {
 631                         rs->rx += rs->xfer->len - rs->n_bytes * state.residue;
 632                 }
 633         }
 634
 635         /* Get the valid data left in rx fifo and set rs->xfer->len real rx size */
 636         if (rs->rx) {
 637                 rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
 638                 for (; rx_fifo_left; rx_fifo_left--) {
 639                         u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
 640
 641                         if (rs->n_bytes == 1)
 642                                 *(u8 *)rs->rx = (u8)rxw;
 643                         else
 644                                 *(u16 *)rs->rx = (u16)rxw;
 645                         rs->rx += rs->n_bytes;
 646                 }
 647                 rs->xfer->len = (unsigned int)(rs->rx - rs->xfer->rx_buf);
 648         }
 649
 650 out:
 651         if (atomic_read(&rs->state) & RXDMA)
 652                 dmaengine_terminate_sync(ctlr->dma_rx);
 653         if (atomic_read(&rs->state) & TXDMA)
 654                 dmaengine_terminate_sync(ctlr->dma_tx);
 655         atomic_set(&rs->state, 0);
 656         spi_enable_chip(rs, false);
 657         rs->slave_abort = true;
 658         spi_finalize_current_transfer(ctlr);
 659
 660         return 0;
 661 }
 662
 663 static int rockchip_spi_transfer_one(
 664                 struct spi_controller *ctlr,
 665                 struct spi_device *spi,
 666                 struct spi_transfer *xfer)
 667 {
 668         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 669         int ret;
 670         bool use_dma;
 671
 672         /* Zero length transfers won't trigger an interrupt on completion */
 673         if (!xfer->len) {
 674                 spi_finalize_current_transfer(ctlr);
 675                 return 1;
 676         }
 677
 678         WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
 679                 (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
 680
 681         if (!xfer->tx_buf && !xfer->rx_buf) {
 682                 dev_err(rs->dev, "No buffer for transfer\n");
 683                 return -EINVAL;
 684         }
 685
 686         if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
 687                 dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
 688                 return -EINVAL;
 689         }
 690
 691         rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
 692         rs->xfer = xfer;
 693         use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
 694
 695         ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
 696         if (ret)
 697                 return ret;
 698
 699         if (use_dma)
 700                 return rockchip_spi_prepare_dma(rs, ctlr, xfer);
 701
 702         return rockchip_spi_prepare_irq(rs, ctlr, xfer);
 703 }
 704
 705 static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
 706                                  struct spi_device *spi,
 707                                  struct spi_transfer *xfer)
 708 {
 709         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 710         unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
 711
 712         /* if the numbor of spi words to transfer is less than the fifo
 713          * length we can just fill the fifo and wait for a single irq,
 714          * so don't bother setting up dma
 715          */
 716         return xfer->len / bytes_per_word >= rs->fifo_len;
 717 }
 718
 719 static int rockchip_spi_setup(struct spi_device *spi)
 720 {
 721         struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
 722         u32 cr0;
 723
 724         if (!spi->cs_gpiod && (spi->mode & SPI_CS_HIGH) && !rs->cs_high_supported) {
 725                 dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
 726                 return -EINVAL;
 727         }
 728
 729         pm_runtime_get_sync(rs->dev);
 730
 731         cr0 = readl_relaxed(rs->regs + ROCKCHIP_SPI_CTRLR0);
 732
 733         cr0 &= ~(0x3 << CR0_SCPH_OFFSET);
 734         cr0 |= ((spi->mode & 0x3) << CR0_SCPH_OFFSET);
 735         if (spi->mode & SPI_CS_HIGH && spi->chip_select <= 1)
 736                 cr0 |= BIT(spi->chip_select) << CR0_SOI_OFFSET;
 737         else if (spi->chip_select <= 1)
 738                 cr0 &= ~(BIT(spi->chip_select) << CR0_SOI_OFFSET);
 739
 740         writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
 741
 742         pm_runtime_put(rs->dev);
 743
 744         return 0;
 745 }
 746
 747 static int rockchip_spi_probe(struct platform_device *pdev)
 748 {
 749         int ret;
 750         struct rockchip_spi *rs;
 751         struct spi_controller *ctlr;
 752         struct resource *mem;
 753         struct device_node *np = pdev->dev.of_node;
 754         u32 rsd_nsecs, num_cs;
 755         bool slave_mode;
 756
 757         slave_mode = of_property_read_bool(np, "spi-slave");
 758
 759         if (slave_mode)
 760                 ctlr = spi_alloc_slave(&pdev->dev,
 761                                 sizeof(struct rockchip_spi));
 762         else
 763                 ctlr = spi_alloc_master(&pdev->dev,
 764                                 sizeof(struct rockchip_spi));
 765
 766         if (!ctlr)
 767                 return -ENOMEM;
 768
 769         platform_set_drvdata(pdev, ctlr);
 770
 771         rs = spi_controller_get_devdata(ctlr);
 772         ctlr->slave = slave_mode;
 773
 774         /* Get basic io resource and map it */
 775         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 776         rs->regs = devm_ioremap_resource(&pdev->dev, mem);
 777         if (IS_ERR(rs->regs)) {
 778                 ret =  PTR_ERR(rs->regs);
 779                 goto err_put_ctlr;
 780         }
 781
 782         rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
 783         if (IS_ERR(rs->apb_pclk)) {
 784                 dev_err(&pdev->dev, "Failed to get apb_pclk\n");
 785                 ret = PTR_ERR(rs->apb_pclk);
 786                 goto err_put_ctlr;
 787         }
 788
 789         rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
 790         if (IS_ERR(rs->spiclk)) {
 791                 dev_err(&pdev->dev, "Failed to get spi_pclk\n");
 792                 ret = PTR_ERR(rs->spiclk);
 793                 goto err_put_ctlr;
 794         }
 795
 796         ret = clk_prepare_enable(rs->apb_pclk);
 797         if (ret < 0) {
 798                 dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
 799                 goto err_put_ctlr;
 800         }
 801
 802         ret = clk_prepare_enable(rs->spiclk);
 803         if (ret < 0) {
 804                 dev_err(&pdev->dev, "Failed to enable spi_clk\n");
 805                 goto err_disable_apbclk;
 806         }
 807
 808         spi_enable_chip(rs, false);
 809
 810         ret = platform_get_irq(pdev, 0);
 811         if (ret < 0)
 812                 goto err_disable_spiclk;
 813
 814         ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
 815                         IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
 816         if (ret)
 817                 goto err_disable_spiclk;
 818
 819         rs->dev = &pdev->dev;
 820         rs->freq = clk_get_rate(rs->spiclk);
 821
 822         if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
 823                                   &rsd_nsecs)) {
 824                 /* rx sample delay is expressed in parent clock cycles (max 3) */
 825                 u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
 826                                 1000000000 >> 8);
 827                 if (!rsd) {
 828                         dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
 829                                         rs->freq, rsd_nsecs);
 830                 } else if (rsd > CR0_RSD_MAX) {
 831                         rsd = CR0_RSD_MAX;
 832                         dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
 833                                         rs->freq, rsd_nsecs,
 834                                         CR0_RSD_MAX * 1000000000U / rs->freq);
 835                 }
 836                 rs->rsd = rsd;
 837         }
 838
 839         rs->fifo_len = get_fifo_len(rs);
 840         if (!rs->fifo_len) {
 841                 dev_err(&pdev->dev, "Failed to get fifo length\n");
 842                 ret = -EINVAL;
 843                 goto err_disable_spiclk;
 844         }
 845
 846         pm_runtime_set_autosuspend_delay(&pdev->dev, ROCKCHIP_AUTOSUSPEND_TIMEOUT);
 847         pm_runtime_use_autosuspend(&pdev->dev);
 848         pm_runtime_set_active(&pdev->dev);
 849         pm_runtime_enable(&pdev->dev);
 850
 851         ctlr->auto_runtime_pm = true;
 852         ctlr->bus_num = pdev->id;
 853         ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
 854         if (slave_mode) {
 855                 ctlr->mode_bits |= SPI_NO_CS;
 856                 ctlr->slave_abort = rockchip_spi_slave_abort;
 857         } else {
 858                 ctlr->flags = SPI_MASTER_GPIO_SS;
 859                 ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
 860                 /*
 861                  * rk spi0 has two native cs, spi1..5 one cs only
 862                  * if num-cs is missing in the dts, default to 1
 863                  */
 864                 if (of_property_read_u32(np, "num-cs", &num_cs))
 865                         num_cs = 1;
 866                 ctlr->num_chipselect = num_cs;
 867                 ctlr->use_gpio_descriptors = true;
 868         }
 869         ctlr->dev.of_node = pdev->dev.of_node;
 870         ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
 871         ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
 872         ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
 873
 874         ctlr->setup = rockchip_spi_setup;
 875         ctlr->set_cs = rockchip_spi_set_cs;
 876         ctlr->transfer_one = rockchip_spi_transfer_one;
 877         ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
 878         ctlr->handle_err = rockchip_spi_handle_err;
 879
 880         ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
 881         if (IS_ERR(ctlr->dma_tx)) {
 882                 /* Check tx to see if we need defer probing driver */
 883                 if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
 884                         ret = -EPROBE_DEFER;
 885                         goto err_disable_pm_runtime;
 886                 }
 887                 dev_warn(rs->dev, "Failed to request TX DMA channel\n");
 888                 ctlr->dma_tx = NULL;
 889         }
 890
 891         ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
 892         if (IS_ERR(ctlr->dma_rx)) {
 893                 if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
 894                         ret = -EPROBE_DEFER;
 895                         goto err_free_dma_tx;
 896                 }
 897                 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
 898                 ctlr->dma_rx = NULL;
 899         }
 900
 901         if (ctlr->dma_tx && ctlr->dma_rx) {
 902                 rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
 903                 rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
 904                 ctlr->can_dma = rockchip_spi_can_dma;
 905         }
 906
 907         switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
 908         case ROCKCHIP_SPI_VER2_TYPE2:
 909                 rs->cs_high_supported = true;
 910                 ctlr->mode_bits |= SPI_CS_HIGH;
 911                 if (ctlr->can_dma && slave_mode)
 912                         rs->cs_inactive = true;
 913                 else
 914                         rs->cs_inactive = false;
 915                 break;
 916         default:
 917                 rs->cs_inactive = false;
 918                 break;
 919         }
 920
 921         ret = devm_spi_register_controller(&pdev->dev, ctlr);
 922         if (ret < 0) {
 923                 dev_err(&pdev->dev, "Failed to register controller\n");
 924                 goto err_free_dma_rx;
 925         }
 926
 927         return 0;
 928
 929 err_free_dma_rx:
 930         if (ctlr->dma_rx)
 931                 dma_release_channel(ctlr->dma_rx);
 932 err_free_dma_tx:
 933         if (ctlr->dma_tx)
 934                 dma_release_channel(ctlr->dma_tx);
 935 err_disable_pm_runtime:
 936         pm_runtime_disable(&pdev->dev);
 937 err_disable_spiclk:
 938         clk_disable_unprepare(rs->spiclk);
 939 err_disable_apbclk:
 940         clk_disable_unprepare(rs->apb_pclk);
 941 err_put_ctlr:
 942         spi_controller_put(ctlr);
 943
 944         return ret;
 945 }
 946
 947 static int rockchip_spi_remove(struct platform_device *pdev)
 948 {
 949         struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
 950         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 951
 952         pm_runtime_get_sync(&pdev->dev);
 953
 954         clk_disable_unprepare(rs->spiclk);
 955         clk_disable_unprepare(rs->apb_pclk);
 956
 957         pm_runtime_put_noidle(&pdev->dev);
 958         pm_runtime_disable(&pdev->dev);
 959         pm_runtime_set_suspended(&pdev->dev);
 960
 961         if (ctlr->dma_tx)
 962                 dma_release_channel(ctlr->dma_tx);
 963         if (ctlr->dma_rx)
 964                 dma_release_channel(ctlr->dma_rx);
 965
 966         spi_controller_put(ctlr);
 967
 968         return 0;
 969 }
 970
 971 #ifdef CONFIG_PM_SLEEP
 972 static int rockchip_spi_suspend(struct device *dev)
 973 {
 974         int ret;
 975         struct spi_controller *ctlr = dev_get_drvdata(dev);
 976         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 977
 978         ret = spi_controller_suspend(ctlr);
 979         if (ret < 0)
 980                 return ret;
 981
 982         clk_disable_unprepare(rs->spiclk);
 983         clk_disable_unprepare(rs->apb_pclk);
 984
 985         pinctrl_pm_select_sleep_state(dev);
 986
 987         return 0;
 988 }
 989
 990 static int rockchip_spi_resume(struct device *dev)
 991 {
 992         int ret;
 993         struct spi_controller *ctlr = dev_get_drvdata(dev);
 994         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
 995
 996         pinctrl_pm_select_default_state(dev);
 997
 998         ret = clk_prepare_enable(rs->apb_pclk);
 999         if (ret < 0)
1000                 return ret;
1001
1002         ret = clk_prepare_enable(rs->spiclk);
1003         if (ret < 0)
1004                 clk_disable_unprepare(rs->apb_pclk);
1005
1006         ret = spi_controller_resume(ctlr);
1007         if (ret < 0) {
1008                 clk_disable_unprepare(rs->spiclk);
1009                 clk_disable_unprepare(rs->apb_pclk);
1010         }
1011
1012         return 0;
1013 }
1014 #endif /* CONFIG_PM_SLEEP */
1015
1016 #ifdef CONFIG_PM
1017 static int rockchip_spi_runtime_suspend(struct device *dev)
1018 {
1019         struct spi_controller *ctlr = dev_get_drvdata(dev);
1020         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
1021
1022         clk_disable_unprepare(rs->spiclk);
1023         clk_disable_unprepare(rs->apb_pclk);
1024
1025         return 0;
1026 }
1027
1028 static int rockchip_spi_runtime_resume(struct device *dev)
1029 {
1030         int ret;
1031         struct spi_controller *ctlr = dev_get_drvdata(dev);
1032         struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
1033
1034         ret = clk_prepare_enable(rs->apb_pclk);
1035         if (ret < 0)
1036                 return ret;
1037
1038         ret = clk_prepare_enable(rs->spiclk);
1039         if (ret < 0)
1040                 clk_disable_unprepare(rs->apb_pclk);
1041
1042         return 0;
1043 }
1044 #endif /* CONFIG_PM */
1045
1046 static const struct dev_pm_ops rockchip_spi_pm = {
1047         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
1048         SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
1049                            rockchip_spi_runtime_resume, NULL)
1050 };
1051
1052 static const struct of_device_id rockchip_spi_dt_match[] = {
1053         { .compatible = "rockchip,px30-spi", },
1054         { .compatible = "rockchip,rk3036-spi", },
1055         { .compatible = "rockchip,rk3066-spi", },
1056         { .compatible = "rockchip,rk3188-spi", },
1057         { .compatible = "rockchip,rk3228-spi", },
1058         { .compatible = "rockchip,rk3288-spi", },
1059         { .compatible = "rockchip,rk3308-spi", },
1060         { .compatible = "rockchip,rk3328-spi", },
1061         { .compatible = "rockchip,rk3368-spi", },
1062         { .compatible = "rockchip,rk3399-spi", },
1063         { .compatible = "rockchip,rv1108-spi", },
1064         { .compatible = "rockchip,rv1126-spi", },
1065         { },
1066 };
1067 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
1068
1069 static struct platform_driver rockchip_spi_driver = {
1070         .driver = {
1071                 .name   = DRIVER_NAME,
1072                 .pm = &rockchip_spi_pm,
1073                 .of_match_table = of_match_ptr(rockchip_spi_dt_match),
1074         },
1075         .probe = rockchip_spi_probe,
1076         .remove = rockchip_spi_remove,
1077 };
1078
1079 module_platform_driver(rockchip_spi_driver);
1080
1081 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
1082 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
1083 MODULE_LICENSE("GPL v2");