drivers/spi/spi-meson-spicc.c

   1 /*
   2  * Driver for Amlogic Meson SPI communication controller (SPICC)
   3  *
   4  * Copyright (C) BayLibre, SAS
   5  * Author: Neil Armstrong <narmstrong@baylibre.com>
   6  *
   7  * SPDX-License-Identifier: GPL-2.0+
   8  */
   9
  10 #include <linux/bitfield.h>
  11 #include <linux/clk.h>
  12 #include <linux/clk-provider.h>
  13 #include <linux/device.h>
  14 #include <linux/io.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/of.h>
  18 #include <linux/of_device.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/spi/spi.h>
  21 #include <linux/types.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/reset.h>
  24
  25 /*
  26  * The Meson SPICC controller could support DMA based transfers, but is not
  27  * implemented by the vendor code, and while having the registers documentation
  28  * it has never worked on the GXL Hardware.
  29  * The PIO mode is the only mode implemented, and due to badly designed HW :
  30  * - all transfers are cutted in 16 words burst because the FIFO hangs on
  31  *   TX underflow, and there is no TX "Half-Empty" interrupt, so we go by
  32  *   FIFO max size chunk only
  33  * - CS management is dumb, and goes UP between every burst, so is really a
  34  *   "Data Valid" signal than a Chip Select, GPIO link should be used instead
  35  *   to have a CS go down over the full transfer
  36  */
  37
  38 #define SPICC_MAX_BURST 128
  39
  40 /* Register Map */
  41 #define SPICC_RXDATA    0x00
  42
  43 #define SPICC_TXDATA    0x04
  44
  45 #define SPICC_CONREG    0x08
  46 #define SPICC_ENABLE            BIT(0)
  47 #define SPICC_MODE_MASTER       BIT(1)
  48 #define SPICC_XCH               BIT(2)
  49 #define SPICC_SMC               BIT(3)
  50 #define SPICC_POL               BIT(4)
  51 #define SPICC_PHA               BIT(5)
  52 #define SPICC_SSCTL             BIT(6)
  53 #define SPICC_SSPOL             BIT(7)
  54 #define SPICC_DRCTL_MASK        GENMASK(9, 8)
  55 #define SPICC_DRCTL_IGNORE      0
  56 #define SPICC_DRCTL_FALLING     1
  57 #define SPICC_DRCTL_LOWLEVEL    2
  58 #define SPICC_CS_MASK           GENMASK(13, 12)
  59 #define SPICC_DATARATE_MASK     GENMASK(18, 16)
  60 #define SPICC_DATARATE_DIV4     0
  61 #define SPICC_DATARATE_DIV8     1
  62 #define SPICC_DATARATE_DIV16    2
  63 #define SPICC_DATARATE_DIV32    3
  64 #define SPICC_BITLENGTH_MASK    GENMASK(24, 19)
  65 #define SPICC_BURSTLENGTH_MASK  GENMASK(31, 25)
  66
  67 #define SPICC_INTREG    0x0c
  68 #define SPICC_TE_EN     BIT(0) /* TX FIFO Empty Interrupt */
  69 #define SPICC_TH_EN     BIT(1) /* TX FIFO Half-Full Interrupt */
  70 #define SPICC_TF_EN     BIT(2) /* TX FIFO Full Interrupt */
  71 #define SPICC_RR_EN     BIT(3) /* RX FIFO Ready Interrupt */
  72 #define SPICC_RH_EN     BIT(4) /* RX FIFO Half-Full Interrupt */
  73 #define SPICC_RF_EN     BIT(5) /* RX FIFO Full Interrupt */
  74 #define SPICC_RO_EN     BIT(6) /* RX FIFO Overflow Interrupt */
  75 #define SPICC_TC_EN     BIT(7) /* Transfert Complete Interrupt */
  76
  77 #define SPICC_DMAREG    0x10
  78 #define SPICC_DMA_ENABLE                BIT(0)
  79 #define SPICC_TXFIFO_THRESHOLD_MASK     GENMASK(5, 1)
  80 #define SPICC_RXFIFO_THRESHOLD_MASK     GENMASK(10, 6)
  81 #define SPICC_READ_BURST_MASK           GENMASK(14, 11)
  82 #define SPICC_WRITE_BURST_MASK          GENMASK(18, 15)
  83 #define SPICC_DMA_URGENT                BIT(19)
  84 #define SPICC_DMA_THREADID_MASK         GENMASK(25, 20)
  85 #define SPICC_DMA_BURSTNUM_MASK         GENMASK(31, 26)
  86
  87 #define SPICC_STATREG   0x14
  88 #define SPICC_TE        BIT(0) /* TX FIFO Empty Interrupt */
  89 #define SPICC_TH        BIT(1) /* TX FIFO Half-Full Interrupt */
  90 #define SPICC_TF        BIT(2) /* TX FIFO Full Interrupt */
  91 #define SPICC_RR        BIT(3) /* RX FIFO Ready Interrupt */
  92 #define SPICC_RH        BIT(4) /* RX FIFO Half-Full Interrupt */
  93 #define SPICC_RF        BIT(5) /* RX FIFO Full Interrupt */
  94 #define SPICC_RO        BIT(6) /* RX FIFO Overflow Interrupt */
  95 #define SPICC_TC        BIT(7) /* Transfert Complete Interrupt */
  96
  97 #define SPICC_PERIODREG 0x18
  98 #define SPICC_PERIOD    GENMASK(14, 0)  /* Wait cycles */
  99
 100 #define SPICC_TESTREG   0x1c
 101 #define SPICC_TXCNT_MASK        GENMASK(4, 0)   /* TX FIFO Counter */
 102 #define SPICC_RXCNT_MASK        GENMASK(9, 5)   /* RX FIFO Counter */
 103 #define SPICC_SMSTATUS_MASK     GENMASK(12, 10) /* State Machine Status */
 104 #define SPICC_LBC_RO            BIT(13) /* Loop Back Control Read-Only */
 105 #define SPICC_LBC_W1            BIT(14) /* Loop Back Control Write-Only */
 106 #define SPICC_SWAP_RO           BIT(14) /* RX FIFO Data Swap Read-Only */
 107 #define SPICC_SWAP_W1           BIT(15) /* RX FIFO Data Swap Write-Only */
 108 #define SPICC_DLYCTL_RO_MASK    GENMASK(20, 15) /* Delay Control Read-Only */
 109 #define SPICC_MO_DELAY_MASK     GENMASK(17, 16) /* Master Output Delay */
 110 #define SPICC_MO_NO_DELAY       0
 111 #define SPICC_MO_DELAY_1_CYCLE  1
 112 #define SPICC_MO_DELAY_2_CYCLE  2
 113 #define SPICC_MO_DELAY_3_CYCLE  3
 114 #define SPICC_MI_DELAY_MASK     GENMASK(19, 18) /* Master Input Delay */
 115 #define SPICC_MI_NO_DELAY       0
 116 #define SPICC_MI_DELAY_1_CYCLE  1
 117 #define SPICC_MI_DELAY_2_CYCLE  2
 118 #define SPICC_MI_DELAY_3_CYCLE  3
 119 #define SPICC_MI_CAP_DELAY_MASK GENMASK(21, 20) /* Master Capture Delay */
 120 #define SPICC_CAP_AHEAD_2_CYCLE 0
 121 #define SPICC_CAP_AHEAD_1_CYCLE 1
 122 #define SPICC_CAP_NO_DELAY      2
 123 #define SPICC_CAP_DELAY_1_CYCLE 3
 124 #define SPICC_FIFORST_RO_MASK   GENMASK(22, 21) /* FIFO Softreset Read-Only */
 125 #define SPICC_FIFORST_W1_MASK   GENMASK(23, 22) /* FIFO Softreset Write-Only */
 126
 127 #define SPICC_DRADDR    0x20    /* Read Address of DMA */
 128
 129 #define SPICC_DWADDR    0x24    /* Write Address of DMA */
 130
 131 #define SPICC_ENH_CTL0  0x38    /* Enhanced Feature */
 132 #define SPICC_ENH_CLK_CS_DELAY_MASK     GENMASK(15, 0)
 133 #define SPICC_ENH_DATARATE_MASK         GENMASK(23, 16)
 134 #define SPICC_ENH_DATARATE_EN           BIT(24)
 135 #define SPICC_ENH_MOSI_OEN              BIT(25)
 136 #define SPICC_ENH_CLK_OEN               BIT(26)
 137 #define SPICC_ENH_CS_OEN                BIT(27)
 138 #define SPICC_ENH_CLK_CS_DELAY_EN       BIT(28)
 139 #define SPICC_ENH_MAIN_CLK_AO           BIT(29)
 140
 141 #define writel_bits_relaxed(mask, val, addr) \
 142         writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr)
 143
 144 struct meson_spicc_data {
 145         unsigned int                    max_speed_hz;
 146         unsigned int                    min_speed_hz;
 147         unsigned int                    fifo_size;
 148         bool                            has_oen;
 149         bool                            has_enhance_clk_div;
 150         bool                            has_pclk;
 151 };
 152
 153 struct meson_spicc_device {
 154         struct spi_master               *master;
 155         struct platform_device          *pdev;
 156         void __iomem                    *base;
 157         struct clk                      *core;
 158         struct clk                      *pclk;
 159         struct clk                      *clk;
 160         struct spi_message              *message;
 161         struct spi_transfer             *xfer;
 162         const struct meson_spicc_data   *data;
 163         u8                              *tx_buf;
 164         u8                              *rx_buf;
 165         unsigned int                    bytes_per_word;
 166         unsigned long                   tx_remain;
 167         unsigned long                   rx_remain;
 168         unsigned long                   xfer_remain;
 169 };
 170
 171 static void meson_spicc_oen_enable(struct meson_spicc_device *spicc)
 172 {
 173         u32 conf;
 174
 175         if (!spicc->data->has_oen)
 176                 return;
 177
 178         conf = readl_relaxed(spicc->base + SPICC_ENH_CTL0) |
 179                 SPICC_ENH_MOSI_OEN | SPICC_ENH_CLK_OEN | SPICC_ENH_CS_OEN;
 180
 181         writel_relaxed(conf, spicc->base + SPICC_ENH_CTL0);
 182 }
 183
 184 static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc)
 185 {
 186         return !!FIELD_GET(SPICC_TF,
 187                            readl_relaxed(spicc->base + SPICC_STATREG));
 188 }
 189
 190 static inline bool meson_spicc_rxready(struct meson_spicc_device *spicc)
 191 {
 192         return FIELD_GET(SPICC_RH | SPICC_RR | SPICC_RF,
 193                          readl_relaxed(spicc->base + SPICC_STATREG));
 194 }
 195
 196 static inline u32 meson_spicc_pull_data(struct meson_spicc_device *spicc)
 197 {
 198         unsigned int bytes = spicc->bytes_per_word;
 199         unsigned int byte_shift = 0;
 200         u32 data = 0;
 201         u8 byte;
 202
 203         while (bytes--) {
 204                 byte = *spicc->tx_buf++;
 205                 data |= (byte & 0xff) << byte_shift;
 206                 byte_shift += 8;
 207         }
 208
 209         spicc->tx_remain--;
 210         return data;
 211 }
 212
 213 static inline void meson_spicc_push_data(struct meson_spicc_device *spicc,
 214                                          u32 data)
 215 {
 216         unsigned int bytes = spicc->bytes_per_word;
 217         unsigned int byte_shift = 0;
 218         u8 byte;
 219
 220         while (bytes--) {
 221                 byte = (data >> byte_shift) & 0xff;
 222                 *spicc->rx_buf++ = byte;
 223                 byte_shift += 8;
 224         }
 225
 226         spicc->rx_remain--;
 227 }
 228
 229 static inline void meson_spicc_rx(struct meson_spicc_device *spicc)
 230 {
 231         /* Empty RX FIFO */
 232         while (spicc->rx_remain &&
 233                meson_spicc_rxready(spicc))
 234                 meson_spicc_push_data(spicc,
 235                                 readl_relaxed(spicc->base + SPICC_RXDATA));
 236 }
 237
 238 static inline void meson_spicc_tx(struct meson_spicc_device *spicc)
 239 {
 240         /* Fill Up TX FIFO */
 241         while (spicc->tx_remain &&
 242                !meson_spicc_txfull(spicc))
 243                 writel_relaxed(meson_spicc_pull_data(spicc),
 244                                spicc->base + SPICC_TXDATA);
 245 }
 246
 247 static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc)
 248 {
 249
 250         unsigned int burst_len = min_t(unsigned int,
 251                                        spicc->xfer_remain /
 252                                        spicc->bytes_per_word,
 253                                        spicc->data->fifo_size);
 254         /* Setup Xfer variables */
 255         spicc->tx_remain = burst_len;
 256         spicc->rx_remain = burst_len;
 257         spicc->xfer_remain -= burst_len * spicc->bytes_per_word;
 258
 259         /* Setup burst length */
 260         writel_bits_relaxed(SPICC_BURSTLENGTH_MASK,
 261                         FIELD_PREP(SPICC_BURSTLENGTH_MASK,
 262                                 burst_len - 1),
 263                         spicc->base + SPICC_CONREG);
 264
 265         /* Fill TX FIFO */
 266         meson_spicc_tx(spicc);
 267 }
 268
 269 static irqreturn_t meson_spicc_irq(int irq, void *data)
 270 {
 271         struct meson_spicc_device *spicc = (void *) data;
 272
 273         writel_bits_relaxed(SPICC_TC, SPICC_TC, spicc->base + SPICC_STATREG);
 274
 275         /* Empty RX FIFO */
 276         meson_spicc_rx(spicc);
 277
 278         if (!spicc->xfer_remain) {
 279                 /* Disable all IRQs */
 280                 writel(0, spicc->base + SPICC_INTREG);
 281
 282                 spi_finalize_current_transfer(spicc->master);
 283
 284                 return IRQ_HANDLED;
 285         }
 286
 287         /* Setup burst */
 288         meson_spicc_setup_burst(spicc);
 289
 290         /* Start burst */
 291         writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
 292
 293         return IRQ_HANDLED;
 294 }
 295
 296 static void meson_spicc_auto_io_delay(struct meson_spicc_device *spicc)
 297 {
 298         u32 div, hz;
 299         u32 mi_delay, cap_delay;
 300         u32 conf;
 301
 302         if (spicc->data->has_enhance_clk_div) {
 303                 div = FIELD_GET(SPICC_ENH_DATARATE_MASK,
 304                                 readl_relaxed(spicc->base + SPICC_ENH_CTL0));
 305                 div++;
 306                 div <<= 1;
 307         } else {
 308                 div = FIELD_GET(SPICC_DATARATE_MASK,
 309                                 readl_relaxed(spicc->base + SPICC_CONREG));
 310                 div += 2;
 311                 div = 1 << div;
 312         }
 313
 314         mi_delay = SPICC_MI_NO_DELAY;
 315         cap_delay = SPICC_CAP_AHEAD_2_CYCLE;
 316         hz = clk_get_rate(spicc->clk);
 317
 318         if (hz >= 100000000)
 319                 cap_delay = SPICC_CAP_DELAY_1_CYCLE;
 320         else if (hz >= 80000000)
 321                 cap_delay = SPICC_CAP_NO_DELAY;
 322         else if (hz >= 40000000)
 323                 cap_delay = SPICC_CAP_AHEAD_1_CYCLE;
 324         else if (div >= 16)
 325                 mi_delay = SPICC_MI_DELAY_3_CYCLE;
 326         else if (div >= 8)
 327                 mi_delay = SPICC_MI_DELAY_2_CYCLE;
 328         else if (div >= 6)
 329                 mi_delay = SPICC_MI_DELAY_1_CYCLE;
 330
 331         conf = readl_relaxed(spicc->base + SPICC_TESTREG);
 332         conf &= ~(SPICC_MO_DELAY_MASK | SPICC_MI_DELAY_MASK
 333                   | SPICC_MI_CAP_DELAY_MASK);
 334         conf |= FIELD_PREP(SPICC_MI_DELAY_MASK, mi_delay);
 335         conf |= FIELD_PREP(SPICC_MI_CAP_DELAY_MASK, cap_delay);
 336         writel_relaxed(conf, spicc->base + SPICC_TESTREG);
 337 }
 338
 339 static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc,
 340                                    struct spi_transfer *xfer)
 341 {
 342         u32 conf, conf_orig;
 343
 344         /* Read original configuration */
 345         conf = conf_orig = readl_relaxed(spicc->base + SPICC_CONREG);
 346
 347         /* Setup word width */
 348         conf &= ~SPICC_BITLENGTH_MASK;
 349         conf |= FIELD_PREP(SPICC_BITLENGTH_MASK,
 350                            (spicc->bytes_per_word << 3) - 1);
 351
 352         /* Ignore if unchanged */
 353         if (conf != conf_orig)
 354                 writel_relaxed(conf, spicc->base + SPICC_CONREG);
 355
 356         clk_set_rate(spicc->clk, xfer->speed_hz);
 357
 358         meson_spicc_auto_io_delay(spicc);
 359
 360         writel_relaxed(0, spicc->base + SPICC_DMAREG);
 361 }
 362
 363 static void meson_spicc_reset_fifo(struct meson_spicc_device *spicc)
 364 {
 365         if (spicc->data->has_oen)
 366                 writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO,
 367                                     SPICC_ENH_MAIN_CLK_AO,
 368                                     spicc->base + SPICC_ENH_CTL0);
 369
 370         writel_bits_relaxed(SPICC_FIFORST_W1_MASK, SPICC_FIFORST_W1_MASK,
 371                             spicc->base + SPICC_TESTREG);
 372
 373         while (meson_spicc_rxready(spicc))
 374                 readl_relaxed(spicc->base + SPICC_RXDATA);
 375
 376         if (spicc->data->has_oen)
 377                 writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO, 0,
 378                                     spicc->base + SPICC_ENH_CTL0);
 379 }
 380
 381 static int meson_spicc_transfer_one(struct spi_master *master,
 382                                     struct spi_device *spi,
 383                                     struct spi_transfer *xfer)
 384 {
 385         struct meson_spicc_device *spicc = spi_master_get_devdata(master);
 386
 387         /* Store current transfer */
 388         spicc->xfer = xfer;
 389
 390         /* Setup transfer parameters */
 391         spicc->tx_buf = (u8 *)xfer->tx_buf;
 392         spicc->rx_buf = (u8 *)xfer->rx_buf;
 393         spicc->xfer_remain = xfer->len;
 394
 395         /* Pre-calculate word size */
 396         spicc->bytes_per_word =
 397            DIV_ROUND_UP(spicc->xfer->bits_per_word, 8);
 398
 399         if (xfer->len % spicc->bytes_per_word)
 400                 return -EINVAL;
 401
 402         /* Setup transfer parameters */
 403         meson_spicc_setup_xfer(spicc, xfer);
 404
 405         meson_spicc_reset_fifo(spicc);
 406
 407         /* Setup burst */
 408         meson_spicc_setup_burst(spicc);
 409
 410         /* Start burst */
 411         writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
 412
 413         /* Enable interrupts */
 414         writel_relaxed(SPICC_TC_EN, spicc->base + SPICC_INTREG);
 415
 416         return 1;
 417 }
 418
 419 static int meson_spicc_prepare_message(struct spi_master *master,
 420                                        struct spi_message *message)
 421 {
 422         struct meson_spicc_device *spicc = spi_master_get_devdata(master);
 423         struct spi_device *spi = message->spi;
 424         u32 conf = 0;
 425
 426         /* Store current message */
 427         spicc->message = message;
 428
 429         /* Enable Master */
 430         conf |= SPICC_ENABLE;
 431         conf |= SPICC_MODE_MASTER;
 432
 433         /* SMC = 0 */
 434
 435         /* Setup transfer mode */
 436         if (spi->mode & SPI_CPOL)
 437                 conf |= SPICC_POL;
 438         else
 439                 conf &= ~SPICC_POL;
 440
 441         if (spi->mode & SPI_CPHA)
 442                 conf |= SPICC_PHA;
 443         else
 444                 conf &= ~SPICC_PHA;
 445
 446         /* SSCTL = 0 */
 447
 448         if (spi->mode & SPI_CS_HIGH)
 449                 conf |= SPICC_SSPOL;
 450         else
 451                 conf &= ~SPICC_SSPOL;
 452
 453         if (spi->mode & SPI_READY)
 454                 conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_LOWLEVEL);
 455         else
 456                 conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_IGNORE);
 457
 458         /* Select CS */
 459         conf |= FIELD_PREP(SPICC_CS_MASK, spi->chip_select);
 460
 461         /* Default Clock rate core/4 */
 462
 463         /* Default 8bit word */
 464         conf |= FIELD_PREP(SPICC_BITLENGTH_MASK, 8 - 1);
 465
 466         writel_relaxed(conf, spicc->base + SPICC_CONREG);
 467
 468         /* Setup no wait cycles by default */
 469         writel_relaxed(0, spicc->base + SPICC_PERIODREG);
 470
 471         writel_bits_relaxed(SPICC_LBC_W1, 0, spicc->base + SPICC_TESTREG);
 472
 473         return 0;
 474 }
 475
 476 static int meson_spicc_unprepare_transfer(struct spi_master *master)
 477 {
 478         struct meson_spicc_device *spicc = spi_master_get_devdata(master);
 479
 480         /* Disable all IRQs */
 481         writel(0, spicc->base + SPICC_INTREG);
 482
 483         device_reset_optional(&spicc->pdev->dev);
 484
 485         return 0;
 486 }
 487
 488 static int meson_spicc_setup(struct spi_device *spi)
 489 {
 490         if (!spi->controller_state)
 491                 spi->controller_state = spi_master_get_devdata(spi->master);
 492
 493         return 0;
 494 }
 495
 496 static void meson_spicc_cleanup(struct spi_device *spi)
 497 {
 498         spi->controller_state = NULL;
 499 }
 500
 501 /*
 502  * The Clock Mux
 503  *            x-----------------x   x------------x    x------\
 504  *        |---| pow2 fixed div  |---| pow2 div   |----|      |
 505  *        |   x-----------------x   x------------x    |      |
 506  * src ---|                                           | mux  |-- out
 507  *        |   x-----------------x   x------------x    |      |
 508  *        |---| enh fixed div   |---| enh div    |0---|      |
 509  *            x-----------------x   x------------x    x------/
 510  *
 511  * Clk path for GX series:
 512  *    src -> pow2 fixed div -> pow2 div -> out
 513  *
 514  * Clk path for AXG series:
 515  *    src -> pow2 fixed div -> pow2 div -> mux -> out
 516  *    src -> enh fixed div -> enh div -> mux -> out
 517  *
 518  * Clk path for G12A series:
 519  *    pclk -> pow2 fixed div -> pow2 div -> mux -> out
 520  *    pclk -> enh fixed div -> enh div -> mux -> out
 521  */
 522
 523 static int meson_spicc_clk_init(struct meson_spicc_device *spicc)
 524 {
 525         struct device *dev = &spicc->pdev->dev;
 526         struct clk_fixed_factor *pow2_fixed_div, *enh_fixed_div;
 527         struct clk_divider *pow2_div, *enh_div;
 528         struct clk_mux *mux;
 529         struct clk_init_data init;
 530         struct clk *clk;
 531         struct clk_parent_data parent_data[2];
 532         char name[64];
 533
 534         memset(&init, 0, sizeof(init));
 535         memset(&parent_data, 0, sizeof(parent_data));
 536
 537         init.parent_data = parent_data;
 538
 539         /* algorithm for pow2 div: rate = freq / 4 / (2 ^ N) */
 540
 541         pow2_fixed_div = devm_kzalloc(dev, sizeof(*pow2_fixed_div), GFP_KERNEL);
 542         if (!pow2_fixed_div)
 543                 return -ENOMEM;
 544
 545         snprintf(name, sizeof(name), "%s#pow2_fixed_div", dev_name(dev));
 546         init.name = name;
 547         init.ops = &clk_fixed_factor_ops;
 548         init.flags = 0;
 549         if (spicc->data->has_pclk)
 550                 parent_data[0].hw = __clk_get_hw(spicc->pclk);
 551         else
 552                 parent_data[0].hw = __clk_get_hw(spicc->core);
 553         init.num_parents = 1;
 554
 555         pow2_fixed_div->mult = 1,
 556         pow2_fixed_div->div = 4,
 557         pow2_fixed_div->hw.init = &init;
 558
 559         clk = devm_clk_register(dev, &pow2_fixed_div->hw);
 560         if (WARN_ON(IS_ERR(clk)))
 561                 return PTR_ERR(clk);
 562
 563         pow2_div = devm_kzalloc(dev, sizeof(*pow2_div), GFP_KERNEL);
 564         if (!pow2_div)
 565                 return -ENOMEM;
 566
 567         snprintf(name, sizeof(name), "%s#pow2_div", dev_name(dev));
 568         init.name = name;
 569         init.ops = &clk_divider_ops;
 570         init.flags = CLK_SET_RATE_PARENT;
 571         parent_data[0].hw = &pow2_fixed_div->hw;
 572         init.num_parents = 1;
 573
 574         pow2_div->shift = 16,
 575         pow2_div->width = 3,
 576         pow2_div->flags = CLK_DIVIDER_POWER_OF_TWO,
 577         pow2_div->reg = spicc->base + SPICC_CONREG;
 578         pow2_div->hw.init = &init;
 579
 580         clk = devm_clk_register(dev, &pow2_div->hw);
 581         if (WARN_ON(IS_ERR(clk)))
 582                 return PTR_ERR(clk);
 583
 584         if (!spicc->data->has_enhance_clk_div) {
 585                 spicc->clk = clk;
 586                 return 0;
 587         }
 588
 589         /* algorithm for enh div: rate = freq / 2 / (N + 1) */
 590
 591         enh_fixed_div = devm_kzalloc(dev, sizeof(*enh_fixed_div), GFP_KERNEL);
 592         if (!enh_fixed_div)
 593                 return -ENOMEM;
 594
 595         snprintf(name, sizeof(name), "%s#enh_fixed_div", dev_name(dev));
 596         init.name = name;
 597         init.ops = &clk_fixed_factor_ops;
 598         init.flags = 0;
 599         if (spicc->data->has_pclk)
 600                 parent_data[0].hw = __clk_get_hw(spicc->pclk);
 601         else
 602                 parent_data[0].hw = __clk_get_hw(spicc->core);
 603         init.num_parents = 1;
 604
 605         enh_fixed_div->mult = 1,
 606         enh_fixed_div->div = 2,
 607         enh_fixed_div->hw.init = &init;
 608
 609         clk = devm_clk_register(dev, &enh_fixed_div->hw);
 610         if (WARN_ON(IS_ERR(clk)))
 611                 return PTR_ERR(clk);
 612
 613         enh_div = devm_kzalloc(dev, sizeof(*enh_div), GFP_KERNEL);
 614         if (!enh_div)
 615                 return -ENOMEM;
 616
 617         snprintf(name, sizeof(name), "%s#enh_div", dev_name(dev));
 618         init.name = name;
 619         init.ops = &clk_divider_ops;
 620         init.flags = CLK_SET_RATE_PARENT;
 621         parent_data[0].hw = &enh_fixed_div->hw;
 622         init.num_parents = 1;
 623
 624         enh_div->shift  = 16,
 625         enh_div->width  = 8,
 626         enh_div->reg = spicc->base + SPICC_ENH_CTL0;
 627         enh_div->hw.init = &init;
 628
 629         clk = devm_clk_register(dev, &enh_div->hw);
 630         if (WARN_ON(IS_ERR(clk)))
 631                 return PTR_ERR(clk);
 632
 633         mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
 634         if (!mux)
 635                 return -ENOMEM;
 636
 637         snprintf(name, sizeof(name), "%s#sel", dev_name(dev));
 638         init.name = name;
 639         init.ops = &clk_mux_ops;
 640         parent_data[0].hw = &pow2_div->hw;
 641         parent_data[1].hw = &enh_div->hw;
 642         init.num_parents = 2;
 643         init.flags = CLK_SET_RATE_PARENT;
 644
 645         mux->mask = 0x1,
 646         mux->shift = 24,
 647         mux->reg = spicc->base + SPICC_ENH_CTL0;
 648         mux->hw.init = &init;
 649
 650         spicc->clk = devm_clk_register(dev, &mux->hw);
 651         if (WARN_ON(IS_ERR(spicc->clk)))
 652                 return PTR_ERR(spicc->clk);
 653
 654         return 0;
 655 }
 656
 657 static int meson_spicc_probe(struct platform_device *pdev)
 658 {
 659         struct spi_master *master;
 660         struct meson_spicc_device *spicc;
 661         int ret, irq;
 662
 663         master = spi_alloc_master(&pdev->dev, sizeof(*spicc));
 664         if (!master) {
 665                 dev_err(&pdev->dev, "master allocation failed\n");
 666                 return -ENOMEM;
 667         }
 668         spicc = spi_master_get_devdata(master);
 669         spicc->master = master;
 670
 671         spicc->data = of_device_get_match_data(&pdev->dev);
 672         if (!spicc->data) {
 673                 dev_err(&pdev->dev, "failed to get match data\n");
 674                 ret = -EINVAL;
 675                 goto out_master;
 676         }
 677
 678         spicc->pdev = pdev;
 679         platform_set_drvdata(pdev, spicc);
 680
 681         spicc->base = devm_platform_ioremap_resource(pdev, 0);
 682         if (IS_ERR(spicc->base)) {
 683                 dev_err(&pdev->dev, "io resource mapping failed\n");
 684                 ret = PTR_ERR(spicc->base);
 685                 goto out_master;
 686         }
 687
 688         /* Set master mode and enable controller */
 689         writel_relaxed(SPICC_ENABLE | SPICC_MODE_MASTER,
 690                        spicc->base + SPICC_CONREG);
 691
 692         /* Disable all IRQs */
 693         writel_relaxed(0, spicc->base + SPICC_INTREG);
 694
 695         irq = platform_get_irq(pdev, 0);
 696         ret = devm_request_irq(&pdev->dev, irq, meson_spicc_irq,
 697                                0, NULL, spicc);
 698         if (ret) {
 699                 dev_err(&pdev->dev, "irq request failed\n");
 700                 goto out_master;
 701         }
 702
 703         spicc->core = devm_clk_get(&pdev->dev, "core");
 704         if (IS_ERR(spicc->core)) {
 705                 dev_err(&pdev->dev, "core clock request failed\n");
 706                 ret = PTR_ERR(spicc->core);
 707                 goto out_master;
 708         }
 709
 710         if (spicc->data->has_pclk) {
 711                 spicc->pclk = devm_clk_get(&pdev->dev, "pclk");
 712                 if (IS_ERR(spicc->pclk)) {
 713                         dev_err(&pdev->dev, "pclk clock request failed\n");
 714                         ret = PTR_ERR(spicc->pclk);
 715                         goto out_master;
 716                 }
 717         }
 718
 719         ret = clk_prepare_enable(spicc->core);
 720         if (ret) {
 721                 dev_err(&pdev->dev, "core clock enable failed\n");
 722                 goto out_master;
 723         }
 724
 725         ret = clk_prepare_enable(spicc->pclk);
 726         if (ret) {
 727                 dev_err(&pdev->dev, "pclk clock enable failed\n");
 728                 goto out_master;
 729         }
 730
 731         device_reset_optional(&pdev->dev);
 732
 733         master->num_chipselect = 4;
 734         master->dev.of_node = pdev->dev.of_node;
 735         master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH;
 736         master->bits_per_word_mask = SPI_BPW_MASK(32) |
 737                                      SPI_BPW_MASK(24) |
 738                                      SPI_BPW_MASK(16) |
 739                                      SPI_BPW_MASK(8);
 740         master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
 741         master->min_speed_hz = spicc->data->min_speed_hz;
 742         master->max_speed_hz = spicc->data->max_speed_hz;
 743         master->setup = meson_spicc_setup;
 744         master->cleanup = meson_spicc_cleanup;
 745         master->prepare_message = meson_spicc_prepare_message;
 746         master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
 747         master->transfer_one = meson_spicc_transfer_one;
 748         master->use_gpio_descriptors = true;
 749
 750         meson_spicc_oen_enable(spicc);
 751
 752         ret = meson_spicc_clk_init(spicc);
 753         if (ret) {
 754                 dev_err(&pdev->dev, "clock registration failed\n");
 755                 goto out_master;
 756         }
 757
 758         ret = devm_spi_register_master(&pdev->dev, master);
 759         if (ret) {
 760                 dev_err(&pdev->dev, "spi master registration failed\n");
 761                 goto out_clk;
 762         }
 763
 764         return 0;
 765
 766 out_clk:
 767         clk_disable_unprepare(spicc->core);
 768         clk_disable_unprepare(spicc->pclk);
 769
 770 out_master:
 771         spi_master_put(master);
 772
 773         return ret;
 774 }
 775
 776 static int meson_spicc_remove(struct platform_device *pdev)
 777 {
 778         struct meson_spicc_device *spicc = platform_get_drvdata(pdev);
 779
 780         /* Disable SPI */
 781         writel(0, spicc->base + SPICC_CONREG);
 782
 783         clk_disable_unprepare(spicc->core);
 784         clk_disable_unprepare(spicc->pclk);
 785
 786         return 0;
 787 }
 788
 789 static const struct meson_spicc_data meson_spicc_gx_data = {
 790         .max_speed_hz           = 30000000,
 791         .min_speed_hz           = 325000,
 792         .fifo_size              = 16,
 793 };
 794
 795 static const struct meson_spicc_data meson_spicc_axg_data = {
 796         .max_speed_hz           = 80000000,
 797         .min_speed_hz           = 325000,
 798         .fifo_size              = 16,
 799         .has_oen                = true,
 800         .has_enhance_clk_div    = true,
 801 };
 802
 803 static const struct meson_spicc_data meson_spicc_g12a_data = {
 804         .max_speed_hz           = 166666666,
 805         .min_speed_hz           = 50000,
 806         .fifo_size              = 15,
 807         .has_oen                = true,
 808         .has_enhance_clk_div    = true,
 809         .has_pclk               = true,
 810 };
 811
 812 static const struct of_device_id meson_spicc_of_match[] = {
 813         {
 814                 .compatible     = "amlogic,meson-gx-spicc",
 815                 .data           = &meson_spicc_gx_data,
 816         },
 817         {
 818                 .compatible = "amlogic,meson-axg-spicc",
 819                 .data           = &meson_spicc_axg_data,
 820         },
 821         {
 822                 .compatible = "amlogic,meson-g12a-spicc",
 823                 .data           = &meson_spicc_g12a_data,
 824         },
 825         { /* sentinel */ }
 826 };
 827 MODULE_DEVICE_TABLE(of, meson_spicc_of_match);
 828
 829 static struct platform_driver meson_spicc_driver = {
 830         .probe   = meson_spicc_probe,
 831         .remove  = meson_spicc_remove,
 832         .driver  = {
 833                 .name = "meson-spicc",
 834                 .of_match_table = of_match_ptr(meson_spicc_of_match),
 835         },
 836 };
 837
 838 module_platform_driver(meson_spicc_driver);
 839
 840 MODULE_DESCRIPTION("Meson SPI Communication Controller driver");
 841 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
 842 MODULE_LICENSE("GPL");