linux/drivers/spi/spi-fsl-lpspi.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2//
   3// Freescale i.MX7ULP LPSPI driver
   4//
   5// Copyright 2016 Freescale Semiconductor, Inc.
   6// Copyright 2018 NXP Semiconductors
   7
   8#include <linux/clk.h>
   9#include <linux/completion.h>
  10#include <linux/delay.h>
  11#include <linux/dmaengine.h>
  12#include <linux/dma-mapping.h>
  13#include <linux/err.h>
  14#include <linux/interrupt.h>
  15#include <linux/io.h>
  16#include <linux/irq.h>
  17#include <linux/kernel.h>
  18#include <linux/module.h>
  19#include <linux/of.h>
  20#include <linux/of_device.h>
  21#include <linux/pinctrl/consumer.h>
  22#include <linux/platform_device.h>
  23#include <linux/platform_data/dma-imx.h>
  24#include <linux/pm_runtime.h>
  25#include <linux/slab.h>
  26#include <linux/spi/spi.h>
  27#include <linux/spi/spi_bitbang.h>
  28#include <linux/types.h>
  29
  30#define DRIVER_NAME "fsl_lpspi"
  31
  32#define FSL_LPSPI_RPM_TIMEOUT 50 /* 50ms */
  33
  34/* The maximum bytes that edma can transfer once.*/
  35#define FSL_LPSPI_MAX_EDMA_BYTES  ((1 << 15) - 1)
  36
  37/* i.MX7ULP LPSPI registers */
  38#define IMX7ULP_VERID   0x0
  39#define IMX7ULP_PARAM   0x4
  40#define IMX7ULP_CR      0x10
  41#define IMX7ULP_SR      0x14
  42#define IMX7ULP_IER     0x18
  43#define IMX7ULP_DER     0x1c
  44#define IMX7ULP_CFGR0   0x20
  45#define IMX7ULP_CFGR1   0x24
  46#define IMX7ULP_DMR0    0x30
  47#define IMX7ULP_DMR1    0x34
  48#define IMX7ULP_CCR     0x40
  49#define IMX7ULP_FCR     0x58
  50#define IMX7ULP_FSR     0x5c
  51#define IMX7ULP_TCR     0x60
  52#define IMX7ULP_TDR     0x64
  53#define IMX7ULP_RSR     0x70
  54#define IMX7ULP_RDR     0x74
  55
  56/* General control register field define */
  57#define CR_RRF          BIT(9)
  58#define CR_RTF          BIT(8)
  59#define CR_RST          BIT(1)
  60#define CR_MEN          BIT(0)
  61#define SR_MBF          BIT(24)
  62#define SR_TCF          BIT(10)
  63#define SR_FCF          BIT(9)
  64#define SR_RDF          BIT(1)
  65#define SR_TDF          BIT(0)
  66#define IER_TCIE        BIT(10)
  67#define IER_FCIE        BIT(9)
  68#define IER_RDIE        BIT(1)
  69#define IER_TDIE        BIT(0)
  70#define DER_RDDE        BIT(1)
  71#define DER_TDDE        BIT(0)
  72#define CFGR1_PCSCFG    BIT(27)
  73#define CFGR1_PINCFG    (BIT(24)|BIT(25))
  74#define CFGR1_PCSPOL    BIT(8)
  75#define CFGR1_NOSTALL   BIT(3)
  76#define CFGR1_MASTER    BIT(0)
  77#define FSR_TXCOUNT     (0xFF)
  78#define RSR_RXEMPTY     BIT(1)
  79#define TCR_CPOL        BIT(31)
  80#define TCR_CPHA        BIT(30)
  81#define TCR_CONT        BIT(21)
  82#define TCR_CONTC       BIT(20)
  83#define TCR_RXMSK       BIT(19)
  84#define TCR_TXMSK       BIT(18)
  85
  86struct lpspi_config {
  87        u8 bpw;
  88        u8 chip_select;
  89        u8 prescale;
  90        u16 mode;
  91        u32 speed_hz;
  92};
  93
  94struct fsl_lpspi_data {
  95        struct device *dev;
  96        void __iomem *base;
  97        unsigned long base_phys;
  98        struct clk *clk_ipg;
  99        struct clk *clk_per;
 100        bool is_slave;
 101        bool is_only_cs1;
 102        bool is_first_byte;
 103
 104        void *rx_buf;
 105        const void *tx_buf;
 106        void (*tx)(struct fsl_lpspi_data *);
 107        void (*rx)(struct fsl_lpspi_data *);
 108
 109        u32 remain;
 110        u8 watermark;
 111        u8 txfifosize;
 112        u8 rxfifosize;
 113
 114        struct lpspi_config config;
 115        struct completion xfer_done;
 116
 117        bool slave_aborted;
 118
 119        /* DMA */
 120        bool usedma;
 121        struct completion dma_rx_completion;
 122        struct completion dma_tx_completion;
 123};
 124
 125static const struct of_device_id fsl_lpspi_dt_ids[] = {
 126        { .compatible = "fsl,imx7ulp-spi", },
 127        { /* sentinel */ }
 128};
 129MODULE_DEVICE_TABLE(of, fsl_lpspi_dt_ids);
 130
 131#define LPSPI_BUF_RX(type)                                              \
 132static void fsl_lpspi_buf_rx_##type(struct fsl_lpspi_data *fsl_lpspi)   \
 133{                                                                       \
 134        unsigned int val = readl(fsl_lpspi->base + IMX7ULP_RDR);        \
 135                                                                        \
 136        if (fsl_lpspi->rx_buf) {                                        \
 137                *(type *)fsl_lpspi->rx_buf = val;                       \
 138                fsl_lpspi->rx_buf += sizeof(type);                      \
 139        }                                                               \
 140}
 141
 142#define LPSPI_BUF_TX(type)                                              \
 143static void fsl_lpspi_buf_tx_##type(struct fsl_lpspi_data *fsl_lpspi)   \
 144{                                                                       \
 145        type val = 0;                                                   \
 146                                                                        \
 147        if (fsl_lpspi->tx_buf) {                                        \
 148                val = *(type *)fsl_lpspi->tx_buf;                       \
 149                fsl_lpspi->tx_buf += sizeof(type);                      \
 150        }                                                               \
 151                                                                        \
 152        fsl_lpspi->remain -= sizeof(type);                              \
 153        writel(val, fsl_lpspi->base + IMX7ULP_TDR);                     \
 154}
 155
 156LPSPI_BUF_RX(u8)
 157LPSPI_BUF_TX(u8)
 158LPSPI_BUF_RX(u16)
 159LPSPI_BUF_TX(u16)
 160LPSPI_BUF_RX(u32)
 161LPSPI_BUF_TX(u32)
 162
 163static void fsl_lpspi_intctrl(struct fsl_lpspi_data *fsl_lpspi,
 164                              unsigned int enable)
 165{
 166        writel(enable, fsl_lpspi->base + IMX7ULP_IER);
 167}
 168
 169static int fsl_lpspi_bytes_per_word(const int bpw)
 170{
 171        return DIV_ROUND_UP(bpw, BITS_PER_BYTE);
 172}
 173
 174static bool fsl_lpspi_can_dma(struct spi_controller *controller,
 175                              struct spi_device *spi,
 176                              struct spi_transfer *transfer)
 177{
 178        unsigned int bytes_per_word;
 179
 180        if (!controller->dma_rx)
 181                return false;
 182
 183        bytes_per_word = fsl_lpspi_bytes_per_word(transfer->bits_per_word);
 184
 185        switch (bytes_per_word) {
 186        case 1:
 187        case 2:
 188        case 4:
 189                break;
 190        default:
 191                return false;
 192        }
 193
 194        return true;
 195}
 196
 197static int lpspi_prepare_xfer_hardware(struct spi_controller *controller)
 198{
 199        struct fsl_lpspi_data *fsl_lpspi =
 200                                spi_controller_get_devdata(controller);
 201        int ret;
 202
 203        ret = pm_runtime_resume_and_get(fsl_lpspi->dev);
 204        if (ret < 0) {
 205                dev_err(fsl_lpspi->dev, "failed to enable clock\n");
 206                return ret;
 207        }
 208
 209        return 0;
 210}
 211
 212static int lpspi_unprepare_xfer_hardware(struct spi_controller *controller)
 213{
 214        struct fsl_lpspi_data *fsl_lpspi =
 215                                spi_controller_get_devdata(controller);
 216
 217        pm_runtime_mark_last_busy(fsl_lpspi->dev);
 218        pm_runtime_put_autosuspend(fsl_lpspi->dev);
 219
 220        return 0;
 221}
 222
 223static void fsl_lpspi_write_tx_fifo(struct fsl_lpspi_data *fsl_lpspi)
 224{
 225        u8 txfifo_cnt;
 226        u32 temp;
 227
 228        txfifo_cnt = readl(fsl_lpspi->base + IMX7ULP_FSR) & 0xff;
 229
 230        while (txfifo_cnt < fsl_lpspi->txfifosize) {
 231                if (!fsl_lpspi->remain)
 232                        break;
 233                fsl_lpspi->tx(fsl_lpspi);
 234                txfifo_cnt++;
 235        }
 236
 237        if (txfifo_cnt < fsl_lpspi->txfifosize) {
 238                if (!fsl_lpspi->is_slave) {
 239                        temp = readl(fsl_lpspi->base + IMX7ULP_TCR);
 240                        temp &= ~TCR_CONTC;
 241                        writel(temp, fsl_lpspi->base + IMX7ULP_TCR);
 242                }
 243
 244                fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE);
 245        } else
 246                fsl_lpspi_intctrl(fsl_lpspi, IER_TDIE);
 247}
 248
 249static void fsl_lpspi_read_rx_fifo(struct fsl_lpspi_data *fsl_lpspi)
 250{
 251        while (!(readl(fsl_lpspi->base + IMX7ULP_RSR) & RSR_RXEMPTY))
 252                fsl_lpspi->rx(fsl_lpspi);
 253}
 254
 255static void fsl_lpspi_set_cmd(struct fsl_lpspi_data *fsl_lpspi)
 256{
 257        u32 temp = 0;
 258
 259        temp |= fsl_lpspi->config.bpw - 1;
 260        temp |= (fsl_lpspi->config.mode & 0x3) << 30;
 261        temp |= (fsl_lpspi->config.chip_select & 0x3) << 24;
 262        if (!fsl_lpspi->is_slave) {
 263                temp |= fsl_lpspi->config.prescale << 27;
 264                /*
 265                 * Set TCR_CONT will keep SS asserted after current transfer.
 266                 * For the first transfer, clear TCR_CONTC to assert SS.
 267                 * For subsequent transfer, set TCR_CONTC to keep SS asserted.
 268                 */
 269                if (!fsl_lpspi->usedma) {
 270                        temp |= TCR_CONT;
 271                        if (fsl_lpspi->is_first_byte)
 272                                temp &= ~TCR_CONTC;
 273                        else
 274                                temp |= TCR_CONTC;
 275                }
 276        }
 277        writel(temp, fsl_lpspi->base + IMX7ULP_TCR);
 278
 279        dev_dbg(fsl_lpspi->dev, "TCR=0x%x\n", temp);
 280}
 281
 282static void fsl_lpspi_set_watermark(struct fsl_lpspi_data *fsl_lpspi)
 283{
 284        u32 temp;
 285
 286        if (!fsl_lpspi->usedma)
 287                temp = fsl_lpspi->watermark >> 1 |
 288                       (fsl_lpspi->watermark >> 1) << 16;
 289        else
 290                temp = fsl_lpspi->watermark >> 1;
 291
 292        writel(temp, fsl_lpspi->base + IMX7ULP_FCR);
 293
 294        dev_dbg(fsl_lpspi->dev, "FCR=0x%x\n", temp);
 295}
 296
 297static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi)
 298{
 299        struct lpspi_config config = fsl_lpspi->config;
 300        unsigned int perclk_rate, scldiv;
 301        u8 prescale;
 302
 303        perclk_rate = clk_get_rate(fsl_lpspi->clk_per);
 304
 305        if (config.speed_hz > perclk_rate / 2) {
 306                dev_err(fsl_lpspi->dev,
 307                      "per-clk should be at least two times of transfer speed");
 308                return -EINVAL;
 309        }
 310
 311        for (prescale = 0; prescale < 8; prescale++) {
 312                scldiv = perclk_rate / config.speed_hz / (1 << prescale) - 2;
 313                if (scldiv < 256) {
 314                        fsl_lpspi->config.prescale = prescale;
 315                        break;
 316                }
 317        }
 318
 319        if (scldiv >= 256)
 320                return -EINVAL;
 321
 322        writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16),
 323                                        fsl_lpspi->base + IMX7ULP_CCR);
 324
 325        dev_dbg(fsl_lpspi->dev, "perclk=%d, speed=%d, prescale=%d, scldiv=%d\n",
 326                perclk_rate, config.speed_hz, prescale, scldiv);
 327
 328        return 0;
 329}
 330
 331static int fsl_lpspi_dma_configure(struct spi_controller *controller)
 332{
 333        int ret;
 334        enum dma_slave_buswidth buswidth;
 335        struct dma_slave_config rx = {}, tx = {};
 336        struct fsl_lpspi_data *fsl_lpspi =
 337                                spi_controller_get_devdata(controller);
 338
 339        switch (fsl_lpspi_bytes_per_word(fsl_lpspi->config.bpw)) {
 340        case 4:
 341                buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
 342                break;
 343        case 2:
 344                buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
 345                break;
 346        case 1:
 347                buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
 348                break;
 349        default:
 350                return -EINVAL;
 351        }
 352
 353        tx.direction = DMA_MEM_TO_DEV;
 354        tx.dst_addr = fsl_lpspi->base_phys + IMX7ULP_TDR;
 355        tx.dst_addr_width = buswidth;
 356        tx.dst_maxburst = 1;
 357        ret = dmaengine_slave_config(controller->dma_tx, &tx);
 358        if (ret) {
 359                dev_err(fsl_lpspi->dev, "TX dma configuration failed with %d\n",
 360                        ret);
 361                return ret;
 362        }
 363
 364        rx.direction = DMA_DEV_TO_MEM;
 365        rx.src_addr = fsl_lpspi->base_phys + IMX7ULP_RDR;
 366        rx.src_addr_width = buswidth;
 367        rx.src_maxburst = 1;
 368        ret = dmaengine_slave_config(controller->dma_rx, &rx);
 369        if (ret) {
 370                dev_err(fsl_lpspi->dev, "RX dma configuration failed with %d\n",
 371                        ret);
 372                return ret;
 373        }
 374
 375        return 0;
 376}
 377
 378static int fsl_lpspi_config(struct fsl_lpspi_data *fsl_lpspi)
 379{
 380        u32 temp;
 381        int ret;
 382
 383        if (!fsl_lpspi->is_slave) {
 384                ret = fsl_lpspi_set_bitrate(fsl_lpspi);
 385                if (ret)
 386                        return ret;
 387        }
 388
 389        fsl_lpspi_set_watermark(fsl_lpspi);
 390
 391        if (!fsl_lpspi->is_slave)
 392                temp = CFGR1_MASTER;
 393        else
 394                temp = CFGR1_PINCFG;
 395        if (fsl_lpspi->config.mode & SPI_CS_HIGH)
 396                temp |= CFGR1_PCSPOL;
 397        writel(temp, fsl_lpspi->base + IMX7ULP_CFGR1);
 398
 399        temp = readl(fsl_lpspi->base + IMX7ULP_CR);
 400        temp |= CR_RRF | CR_RTF | CR_MEN;
 401        writel(temp, fsl_lpspi->base + IMX7ULP_CR);
 402
 403        temp = 0;
 404        if (fsl_lpspi->usedma)
 405                temp = DER_TDDE | DER_RDDE;
 406        writel(temp, fsl_lpspi->base + IMX7ULP_DER);
 407
 408        return 0;
 409}
 410
 411static int fsl_lpspi_setup_transfer(struct spi_controller *controller,
 412                                     struct spi_device *spi,
 413                                     struct spi_transfer *t)
 414{
 415        struct fsl_lpspi_data *fsl_lpspi =
 416                                spi_controller_get_devdata(spi->controller);
 417
 418        if (t == NULL)
 419                return -EINVAL;
 420
 421        fsl_lpspi->config.mode = spi->mode;
 422        fsl_lpspi->config.bpw = t->bits_per_word;
 423        fsl_lpspi->config.speed_hz = t->speed_hz;
 424        if (fsl_lpspi->is_only_cs1)
 425                fsl_lpspi->config.chip_select = 1;
 426        else
 427                fsl_lpspi->config.chip_select = spi->chip_select;
 428
 429        if (!fsl_lpspi->config.speed_hz)
 430                fsl_lpspi->config.speed_hz = spi->max_speed_hz;
 431        if (!fsl_lpspi->config.bpw)
 432                fsl_lpspi->config.bpw = spi->bits_per_word;
 433
 434        /* Initialize the functions for transfer */
 435        if (fsl_lpspi->config.bpw <= 8) {
 436                fsl_lpspi->rx = fsl_lpspi_buf_rx_u8;
 437                fsl_lpspi->tx = fsl_lpspi_buf_tx_u8;
 438        } else if (fsl_lpspi->config.bpw <= 16) {
 439                fsl_lpspi->rx = fsl_lpspi_buf_rx_u16;
 440                fsl_lpspi->tx = fsl_lpspi_buf_tx_u16;
 441        } else {
 442                fsl_lpspi->rx = fsl_lpspi_buf_rx_u32;
 443                fsl_lpspi->tx = fsl_lpspi_buf_tx_u32;
 444        }
 445
 446        if (t->len <= fsl_lpspi->txfifosize)
 447                fsl_lpspi->watermark = t->len;
 448        else
 449                fsl_lpspi->watermark = fsl_lpspi->txfifosize;
 450
 451        if (fsl_lpspi_can_dma(controller, spi, t))
 452                fsl_lpspi->usedma = true;
 453        else
 454                fsl_lpspi->usedma = false;
 455
 456        return fsl_lpspi_config(fsl_lpspi);
 457}
 458
 459static int fsl_lpspi_slave_abort(struct spi_controller *controller)
 460{
 461        struct fsl_lpspi_data *fsl_lpspi =
 462                                spi_controller_get_devdata(controller);
 463
 464        fsl_lpspi->slave_aborted = true;
 465        if (!fsl_lpspi->usedma)
 466                complete(&fsl_lpspi->xfer_done);
 467        else {
 468                complete(&fsl_lpspi->dma_tx_completion);
 469                complete(&fsl_lpspi->dma_rx_completion);
 470        }
 471
 472        return 0;
 473}
 474
 475static int fsl_lpspi_wait_for_completion(struct spi_controller *controller)
 476{
 477        struct fsl_lpspi_data *fsl_lpspi =
 478                                spi_controller_get_devdata(controller);
 479
 480        if (fsl_lpspi->is_slave) {
 481                if (wait_for_completion_interruptible(&fsl_lpspi->xfer_done) ||
 482                        fsl_lpspi->slave_aborted) {
 483                        dev_dbg(fsl_lpspi->dev, "interrupted\n");
 484                        return -EINTR;
 485                }
 486        } else {
 487                if (!wait_for_completion_timeout(&fsl_lpspi->xfer_done, HZ)) {
 488                        dev_dbg(fsl_lpspi->dev, "wait for completion timeout\n");
 489                        return -ETIMEDOUT;
 490                }
 491        }
 492
 493        return 0;
 494}
 495
 496static int fsl_lpspi_reset(struct fsl_lpspi_data *fsl_lpspi)
 497{
 498        u32 temp;
 499
 500        if (!fsl_lpspi->usedma) {
 501                /* Disable all interrupt */
 502                fsl_lpspi_intctrl(fsl_lpspi, 0);
 503        }
 504
 505        /* W1C for all flags in SR */
 506        temp = 0x3F << 8;
 507        writel(temp, fsl_lpspi->base + IMX7ULP_SR);
 508
 509        /* Clear FIFO and disable module */
 510        temp = CR_RRF | CR_RTF;
 511        writel(temp, fsl_lpspi->base + IMX7ULP_CR);
 512
 513        return 0;
 514}
 515
 516static void fsl_lpspi_dma_rx_callback(void *cookie)
 517{
 518        struct fsl_lpspi_data *fsl_lpspi = (struct fsl_lpspi_data *)cookie;
 519
 520        complete(&fsl_lpspi->dma_rx_completion);
 521}
 522
 523static void fsl_lpspi_dma_tx_callback(void *cookie)
 524{
 525        struct fsl_lpspi_data *fsl_lpspi = (struct fsl_lpspi_data *)cookie;
 526
 527        complete(&fsl_lpspi->dma_tx_completion);
 528}
 529
 530static int fsl_lpspi_calculate_timeout(struct fsl_lpspi_data *fsl_lpspi,
 531                                       int size)
 532{
 533        unsigned long timeout = 0;
 534
 535        /* Time with actual data transfer and CS change delay related to HW */
 536        timeout = (8 + 4) * size / fsl_lpspi->config.speed_hz;
 537
 538        /* Add extra second for scheduler related activities */
 539        timeout += 1;
 540
 541        /* Double calculated timeout */
 542        return msecs_to_jiffies(2 * timeout * MSEC_PER_SEC);
 543}
 544
 545static int fsl_lpspi_dma_transfer(struct spi_controller *controller,
 546                                struct fsl_lpspi_data *fsl_lpspi,
 547                                struct spi_transfer *transfer)
 548{
 549        struct dma_async_tx_descriptor *desc_tx, *desc_rx;
 550        unsigned long transfer_timeout;
 551        unsigned long timeout;
 552        struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
 553        int ret;
 554
 555        ret = fsl_lpspi_dma_configure(controller);
 556        if (ret)
 557                return ret;
 558
 559        desc_rx = dmaengine_prep_slave_sg(controller->dma_rx,
 560                                rx->sgl, rx->nents, DMA_DEV_TO_MEM,
 561                                DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 562        if (!desc_rx)
 563                return -EINVAL;
 564
 565        desc_rx->callback = fsl_lpspi_dma_rx_callback;
 566        desc_rx->callback_param = (void *)fsl_lpspi;
 567        dmaengine_submit(desc_rx);
 568        reinit_completion(&fsl_lpspi->dma_rx_completion);
 569        dma_async_issue_pending(controller->dma_rx);
 570
 571        desc_tx = dmaengine_prep_slave_sg(controller->dma_tx,
 572                                tx->sgl, tx->nents, DMA_MEM_TO_DEV,
 573                                DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 574        if (!desc_tx) {
 575                dmaengine_terminate_all(controller->dma_tx);
 576                return -EINVAL;
 577        }
 578
 579        desc_tx->callback = fsl_lpspi_dma_tx_callback;
 580        desc_tx->callback_param = (void *)fsl_lpspi;
 581        dmaengine_submit(desc_tx);
 582        reinit_completion(&fsl_lpspi->dma_tx_completion);
 583        dma_async_issue_pending(controller->dma_tx);
 584
 585        fsl_lpspi->slave_aborted = false;
 586
 587        if (!fsl_lpspi->is_slave) {
 588                transfer_timeout = fsl_lpspi_calculate_timeout(fsl_lpspi,
 589                                                               transfer->len);
 590
 591                /* Wait eDMA to finish the data transfer.*/
 592                timeout = wait_for_completion_timeout(&fsl_lpspi->dma_tx_completion,
 593                                                      transfer_timeout);
 594                if (!timeout) {
 595                        dev_err(fsl_lpspi->dev, "I/O Error in DMA TX\n");
 596                        dmaengine_terminate_all(controller->dma_tx);
 597                        dmaengine_terminate_all(controller->dma_rx);
 598                        fsl_lpspi_reset(fsl_lpspi);
 599                        return -ETIMEDOUT;
 600                }
 601
 602                timeout = wait_for_completion_timeout(&fsl_lpspi->dma_rx_completion,
 603                                                      transfer_timeout);
 604                if (!timeout) {
 605                        dev_err(fsl_lpspi->dev, "I/O Error in DMA RX\n");
 606                        dmaengine_terminate_all(controller->dma_tx);
 607                        dmaengine_terminate_all(controller->dma_rx);
 608                        fsl_lpspi_reset(fsl_lpspi);
 609                        return -ETIMEDOUT;
 610                }
 611        } else {
 612                if (wait_for_completion_interruptible(&fsl_lpspi->dma_tx_completion) ||
 613                        fsl_lpspi->slave_aborted) {
 614                        dev_dbg(fsl_lpspi->dev,
 615                                "I/O Error in DMA TX interrupted\n");
 616                        dmaengine_terminate_all(controller->dma_tx);
 617                        dmaengine_terminate_all(controller->dma_rx);
 618                        fsl_lpspi_reset(fsl_lpspi);
 619                        return -EINTR;
 620                }
 621
 622                if (wait_for_completion_interruptible(&fsl_lpspi->dma_rx_completion) ||
 623                        fsl_lpspi->slave_aborted) {
 624                        dev_dbg(fsl_lpspi->dev,
 625                                "I/O Error in DMA RX interrupted\n");
 626                        dmaengine_terminate_all(controller->dma_tx);
 627                        dmaengine_terminate_all(controller->dma_rx);
 628                        fsl_lpspi_reset(fsl_lpspi);
 629                        return -EINTR;
 630                }
 631        }
 632
 633        fsl_lpspi_reset(fsl_lpspi);
 634
 635        return 0;
 636}
 637
 638static void fsl_lpspi_dma_exit(struct spi_controller *controller)
 639{
 640        if (controller->dma_rx) {
 641                dma_release_channel(controller->dma_rx);
 642                controller->dma_rx = NULL;
 643        }
 644
 645        if (controller->dma_tx) {
 646                dma_release_channel(controller->dma_tx);
 647                controller->dma_tx = NULL;
 648        }
 649}
 650
 651static int fsl_lpspi_dma_init(struct device *dev,
 652                              struct fsl_lpspi_data *fsl_lpspi,
 653                              struct spi_controller *controller)
 654{
 655        int ret;
 656
 657        /* Prepare for TX DMA: */
 658        controller->dma_tx = dma_request_chan(dev, "tx");
 659        if (IS_ERR(controller->dma_tx)) {
 660                ret = PTR_ERR(controller->dma_tx);
 661                dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret);
 662                controller->dma_tx = NULL;
 663                goto err;
 664        }
 665
 666        /* Prepare for RX DMA: */
 667        controller->dma_rx = dma_request_chan(dev, "rx");
 668        if (IS_ERR(controller->dma_rx)) {
 669                ret = PTR_ERR(controller->dma_rx);
 670                dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret);
 671                controller->dma_rx = NULL;
 672                goto err;
 673        }
 674
 675        init_completion(&fsl_lpspi->dma_rx_completion);
 676        init_completion(&fsl_lpspi->dma_tx_completion);
 677        controller->can_dma = fsl_lpspi_can_dma;
 678        controller->max_dma_len = FSL_LPSPI_MAX_EDMA_BYTES;
 679
 680        return 0;
 681err:
 682        fsl_lpspi_dma_exit(controller);
 683        return ret;
 684}
 685
 686static int fsl_lpspi_pio_transfer(struct spi_controller *controller,
 687                                  struct spi_transfer *t)
 688{
 689        struct fsl_lpspi_data *fsl_lpspi =
 690                                spi_controller_get_devdata(controller);
 691        int ret;
 692
 693        fsl_lpspi->tx_buf = t->tx_buf;
 694        fsl_lpspi->rx_buf = t->rx_buf;
 695        fsl_lpspi->remain = t->len;
 696
 697        reinit_completion(&fsl_lpspi->xfer_done);
 698        fsl_lpspi->slave_aborted = false;
 699
 700        fsl_lpspi_write_tx_fifo(fsl_lpspi);
 701
 702        ret = fsl_lpspi_wait_for_completion(controller);
 703        if (ret)
 704                return ret;
 705
 706        fsl_lpspi_reset(fsl_lpspi);
 707
 708        return 0;
 709}
 710
 711static int fsl_lpspi_transfer_one(struct spi_controller *controller,
 712                                  struct spi_device *spi,
 713                                  struct spi_transfer *t)
 714{
 715        struct fsl_lpspi_data *fsl_lpspi =
 716                                        spi_controller_get_devdata(controller);
 717        int ret;
 718
 719        fsl_lpspi->is_first_byte = true;
 720        ret = fsl_lpspi_setup_transfer(controller, spi, t);
 721        if (ret < 0)
 722                return ret;
 723
 724        fsl_lpspi_set_cmd(fsl_lpspi);
 725        fsl_lpspi->is_first_byte = false;
 726
 727        if (fsl_lpspi->usedma)
 728                ret = fsl_lpspi_dma_transfer(controller, fsl_lpspi, t);
 729        else
 730                ret = fsl_lpspi_pio_transfer(controller, t);
 731        if (ret < 0)
 732                return ret;
 733
 734        return 0;
 735}
 736
 737static irqreturn_t fsl_lpspi_isr(int irq, void *dev_id)
 738{
 739        u32 temp_SR, temp_IER;
 740        struct fsl_lpspi_data *fsl_lpspi = dev_id;
 741
 742        temp_IER = readl(fsl_lpspi->base + IMX7ULP_IER);
 743        fsl_lpspi_intctrl(fsl_lpspi, 0);
 744        temp_SR = readl(fsl_lpspi->base + IMX7ULP_SR);
 745
 746        fsl_lpspi_read_rx_fifo(fsl_lpspi);
 747
 748        if ((temp_SR & SR_TDF) && (temp_IER & IER_TDIE)) {
 749                fsl_lpspi_write_tx_fifo(fsl_lpspi);
 750                return IRQ_HANDLED;
 751        }
 752
 753        if (temp_SR & SR_MBF ||
 754            readl(fsl_lpspi->base + IMX7ULP_FSR) & FSR_TXCOUNT) {
 755                writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR);
 756                fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE);
 757                return IRQ_HANDLED;
 758        }
 759
 760        if (temp_SR & SR_FCF && (temp_IER & IER_FCIE)) {
 761                writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR);
 762                complete(&fsl_lpspi->xfer_done);
 763                return IRQ_HANDLED;
 764        }
 765
 766        return IRQ_NONE;
 767}
 768
 769#ifdef CONFIG_PM
 770static int fsl_lpspi_runtime_resume(struct device *dev)
 771{
 772        struct spi_controller *controller = dev_get_drvdata(dev);
 773        struct fsl_lpspi_data *fsl_lpspi;
 774        int ret;
 775
 776        fsl_lpspi = spi_controller_get_devdata(controller);
 777
 778        ret = clk_prepare_enable(fsl_lpspi->clk_per);
 779        if (ret)
 780                return ret;
 781
 782        ret = clk_prepare_enable(fsl_lpspi->clk_ipg);
 783        if (ret) {
 784                clk_disable_unprepare(fsl_lpspi->clk_per);
 785                return ret;
 786        }
 787
 788        return 0;
 789}
 790
 791static int fsl_lpspi_runtime_suspend(struct device *dev)
 792{
 793        struct spi_controller *controller = dev_get_drvdata(dev);
 794        struct fsl_lpspi_data *fsl_lpspi;
 795
 796        fsl_lpspi = spi_controller_get_devdata(controller);
 797
 798        clk_disable_unprepare(fsl_lpspi->clk_per);
 799        clk_disable_unprepare(fsl_lpspi->clk_ipg);
 800
 801        return 0;
 802}
 803#endif
 804
 805static int fsl_lpspi_init_rpm(struct fsl_lpspi_data *fsl_lpspi)
 806{
 807        struct device *dev = fsl_lpspi->dev;
 808
 809        pm_runtime_enable(dev);
 810        pm_runtime_set_autosuspend_delay(dev, FSL_LPSPI_RPM_TIMEOUT);
 811        pm_runtime_use_autosuspend(dev);
 812
 813        return 0;
 814}
 815
 816static int fsl_lpspi_probe(struct platform_device *pdev)
 817{
 818        struct fsl_lpspi_data *fsl_lpspi;
 819        struct spi_controller *controller;
 820        struct resource *res;
 821        int ret, irq;
 822        u32 temp;
 823        bool is_slave;
 824
 825        is_slave = of_property_read_bool((&pdev->dev)->of_node, "spi-slave");
 826        if (is_slave)
 827                controller = spi_alloc_slave(&pdev->dev,
 828                                        sizeof(struct fsl_lpspi_data));
 829        else
 830                controller = spi_alloc_master(&pdev->dev,
 831                                        sizeof(struct fsl_lpspi_data));
 832
 833        if (!controller)
 834                return -ENOMEM;
 835
 836        platform_set_drvdata(pdev, controller);
 837
 838        fsl_lpspi = spi_controller_get_devdata(controller);
 839        fsl_lpspi->dev = &pdev->dev;
 840        fsl_lpspi->is_slave = is_slave;
 841        fsl_lpspi->is_only_cs1 = of_property_read_bool((&pdev->dev)->of_node,
 842                                                "fsl,spi-only-use-cs1-sel");
 843
 844        controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32);
 845        controller->transfer_one = fsl_lpspi_transfer_one;
 846        controller->prepare_transfer_hardware = lpspi_prepare_xfer_hardware;
 847        controller->unprepare_transfer_hardware = lpspi_unprepare_xfer_hardware;
 848        controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 849        controller->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
 850        controller->dev.of_node = pdev->dev.of_node;
 851        controller->bus_num = pdev->id;
 852        controller->slave_abort = fsl_lpspi_slave_abort;
 853        if (!fsl_lpspi->is_slave)
 854                controller->use_gpio_descriptors = true;
 855
 856        init_completion(&fsl_lpspi->xfer_done);
 857
 858        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 859        fsl_lpspi->base = devm_ioremap_resource(&pdev->dev, res);
 860        if (IS_ERR(fsl_lpspi->base)) {
 861                ret = PTR_ERR(fsl_lpspi->base);
 862                goto out_controller_put;
 863        }
 864        fsl_lpspi->base_phys = res->start;
 865
 866        irq = platform_get_irq(pdev, 0);
 867        if (irq < 0) {
 868                ret = irq;
 869                goto out_controller_put;
 870        }
 871
 872        ret = devm_request_irq(&pdev->dev, irq, fsl_lpspi_isr, 0,
 873                               dev_name(&pdev->dev), fsl_lpspi);
 874        if (ret) {
 875                dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
 876                goto out_controller_put;
 877        }
 878
 879        fsl_lpspi->clk_per = devm_clk_get(&pdev->dev, "per");
 880        if (IS_ERR(fsl_lpspi->clk_per)) {
 881                ret = PTR_ERR(fsl_lpspi->clk_per);
 882                goto out_controller_put;
 883        }
 884
 885        fsl_lpspi->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
 886        if (IS_ERR(fsl_lpspi->clk_ipg)) {
 887                ret = PTR_ERR(fsl_lpspi->clk_ipg);
 888                goto out_controller_put;
 889        }
 890
 891        /* enable the clock */
 892        ret = fsl_lpspi_init_rpm(fsl_lpspi);
 893        if (ret)
 894                goto out_controller_put;
 895
 896        ret = pm_runtime_get_sync(fsl_lpspi->dev);
 897        if (ret < 0) {
 898                dev_err(fsl_lpspi->dev, "failed to enable clock\n");
 899                goto out_pm_get;
 900        }
 901
 902        temp = readl(fsl_lpspi->base + IMX7ULP_PARAM);
 903        fsl_lpspi->txfifosize = 1 << (temp & 0x0f);
 904        fsl_lpspi->rxfifosize = 1 << ((temp >> 8) & 0x0f);
 905
 906        ret = fsl_lpspi_dma_init(&pdev->dev, fsl_lpspi, controller);
 907        if (ret == -EPROBE_DEFER)
 908                goto out_pm_get;
 909
 910        if (ret < 0)
 911                dev_err(&pdev->dev, "dma setup error %d, use pio\n", ret);
 912
 913        ret = devm_spi_register_controller(&pdev->dev, controller);
 914        if (ret < 0) {
 915                dev_err(&pdev->dev, "spi_register_controller error.\n");
 916                goto out_pm_get;
 917        }
 918
 919        pm_runtime_mark_last_busy(fsl_lpspi->dev);
 920        pm_runtime_put_autosuspend(fsl_lpspi->dev);
 921
 922        return 0;
 923
 924out_pm_get:
 925        pm_runtime_dont_use_autosuspend(fsl_lpspi->dev);
 926        pm_runtime_put_sync(fsl_lpspi->dev);
 927        pm_runtime_disable(fsl_lpspi->dev);
 928out_controller_put:
 929        spi_controller_put(controller);
 930
 931        return ret;
 932}
 933
 934static int fsl_lpspi_remove(struct platform_device *pdev)
 935{
 936        struct spi_controller *controller = platform_get_drvdata(pdev);
 937        struct fsl_lpspi_data *fsl_lpspi =
 938                                spi_controller_get_devdata(controller);
 939
 940        pm_runtime_disable(fsl_lpspi->dev);
 941        return 0;
 942}
 943
 944static int __maybe_unused fsl_lpspi_suspend(struct device *dev)
 945{
 946        int ret;
 947
 948        pinctrl_pm_select_sleep_state(dev);
 949        ret = pm_runtime_force_suspend(dev);
 950        return ret;
 951}
 952
 953static int __maybe_unused fsl_lpspi_resume(struct device *dev)
 954{
 955        int ret;
 956
 957        ret = pm_runtime_force_resume(dev);
 958        if (ret) {
 959                dev_err(dev, "Error in resume: %d\n", ret);
 960                return ret;
 961        }
 962
 963        pinctrl_pm_select_default_state(dev);
 964
 965        return 0;
 966}
 967
 968static const struct dev_pm_ops fsl_lpspi_pm_ops = {
 969        SET_RUNTIME_PM_OPS(fsl_lpspi_runtime_suspend,
 970                                fsl_lpspi_runtime_resume, NULL)
 971        SET_SYSTEM_SLEEP_PM_OPS(fsl_lpspi_suspend, fsl_lpspi_resume)
 972};
 973
 974static struct platform_driver fsl_lpspi_driver = {
 975        .driver = {
 976                .name = DRIVER_NAME,
 977                .of_match_table = fsl_lpspi_dt_ids,
 978                .pm = &fsl_lpspi_pm_ops,
 979        },
 980        .probe = fsl_lpspi_probe,
 981        .remove = fsl_lpspi_remove,
 982};
 983module_platform_driver(fsl_lpspi_driver);
 984
 985MODULE_DESCRIPTION("LPSPI Controller driver");
 986MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
 987MODULE_LICENSE("GPL");
 988