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 #include <linux/pinctrl/consumer.h>
  25
  26 /*
  27  * The Meson SPICC controller could support DMA based transfers, but is not
  28  * implemented by the vendor code, and while having the registers documentation
  29  * it has never worked on the GXL Hardware.
  30  * The PIO mode is the only mode implemented, and due to badly designed HW :
  31  * - all transfers are cutted in 16 words burst because the FIFO hangs on
  32  *   TX underflow, and there is no TX "Half-Empty" interrupt, so we go by
  33  *   FIFO max size chunk only
  34  * - CS management is dumb, and goes UP between every burst, so is really a
  35  *   "Data Valid" signal than a Chip Select, GPIO link should be used instead
  36  *   to have a CS go down over the full transfer
  37  */
  38
  39 #define SPICC_MAX_BURST 128
  40
  41 /* Register Map */
  42 #define SPICC_RXDATA    0x00
  43
  44 #define SPICC_TXDATA    0x04
  45
  46 #define SPICC_CONREG    0x08
  47 #define SPICC_ENABLE            BIT(0)
  48 #define SPICC_MODE_MASTER       BIT(1)
  49 #define SPICC_XCH               BIT(2)
  50 #define SPICC_SMC               BIT(3)
  51 #define SPICC_POL               BIT(4)
  52 #define SPICC_PHA               BIT(5)
  53 #define SPICC_SSCTL             BIT(6)
  54 #define SPICC_SSPOL             BIT(7)
  55 #define SPICC_DRCTL_MASK        GENMASK(9, 8)
  56 #define SPICC_DRCTL_IGNORE      0
  57 #define SPICC_DRCTL_FALLING     1
  58 #define SPICC_DRCTL_LOWLEVEL    2
  59 #define SPICC_CS_MASK           GENMASK(13, 12)
  60 #define SPICC_DATARATE_MASK     GENMASK(18, 16)
  61 #define SPICC_DATARATE_DIV4     0
  62 #define SPICC_DATARATE_DIV8     1
  63 #define SPICC_DATARATE_DIV16    2
  64 #define SPICC_DATARATE_DIV32    3
  65 #define SPICC_BITLENGTH_MASK    GENMASK(24, 19)
  66 #define SPICC_BURSTLENGTH_MASK  GENMASK(31, 25)
  67
  68 #define SPICC_INTREG    0x0c
  69 #define SPICC_TE_EN     BIT(0) /* TX FIFO Empty Interrupt */
  70 #define SPICC_TH_EN     BIT(1) /* TX FIFO Half-Full Interrupt */
  71 #define SPICC_TF_EN     BIT(2) /* TX FIFO Full Interrupt */
  72 #define SPICC_RR_EN     BIT(3) /* RX FIFO Ready Interrupt */
  73 #define SPICC_RH_EN     BIT(4) /* RX FIFO Half-Full Interrupt */
  74 #define SPICC_RF_EN     BIT(5) /* RX FIFO Full Interrupt */
  75 #define SPICC_RO_EN     BIT(6) /* RX FIFO Overflow Interrupt */
  76 #define SPICC_TC_EN     BIT(7) /* Transfert Complete Interrupt */
  77
  78 #define SPICC_DMAREG    0x10
  79 #define SPICC_DMA_ENABLE                BIT(0)
  80 #define SPICC_TXFIFO_THRESHOLD_MASK     GENMASK(5, 1)
  81 #define SPICC_RXFIFO_THRESHOLD_MASK     GENMASK(10, 6)
  82 #define SPICC_READ_BURST_MASK           GENMASK(14, 11)
  83 #define SPICC_WRITE_BURST_MASK          GENMASK(18, 15)
  84 #define SPICC_DMA_URGENT                BIT(19)
  85 #define SPICC_DMA_THREADID_MASK         GENMASK(25, 20)
  86 #define SPICC_DMA_BURSTNUM_MASK         GENMASK(31, 26)
  87
  88 #define SPICC_STATREG   0x14
  89 #define SPICC_TE        BIT(0) /* TX FIFO Empty Interrupt */
  90 #define SPICC_TH        BIT(1) /* TX FIFO Half-Full Interrupt */
  91 #define SPICC_TF        BIT(2) /* TX FIFO Full Interrupt */
  92 #define SPICC_RR        BIT(3) /* RX FIFO Ready Interrupt */
  93 #define SPICC_RH        BIT(4) /* RX FIFO Half-Full Interrupt */
  94 #define SPICC_RF        BIT(5) /* RX FIFO Full Interrupt */
  95 #define SPICC_RO        BIT(6) /* RX FIFO Overflow Interrupt */
  96 #define SPICC_TC        BIT(7) /* Transfert Complete Interrupt */
  97
  98 #define SPICC_PERIODREG 0x18
  99 #define SPICC_PERIOD    GENMASK(14, 0)  /* Wait cycles */
 100
 101 #define SPICC_TESTREG   0x1c
 102 #define SPICC_TXCNT_MASK        GENMASK(4, 0)   /* TX FIFO Counter */
 103 #define SPICC_RXCNT_MASK        GENMASK(9, 5)   /* RX FIFO Counter */
 104 #define SPICC_SMSTATUS_MASK     GENMASK(12, 10) /* State Machine Status */
 105 #define SPICC_LBC_RO            BIT(13) /* Loop Back Control Read-Only */
 106 #define SPICC_LBC_W1            BIT(14) /* Loop Back Control Write-Only */
 107 #define SPICC_SWAP_RO           BIT(14) /* RX FIFO Data Swap Read-Only */
 108 #define SPICC_SWAP_W1           BIT(15) /* RX FIFO Data Swap Write-Only */
 109 #define SPICC_DLYCTL_RO_MASK    GENMASK(20, 15) /* Delay Control Read-Only */
 110 #define SPICC_MO_DELAY_MASK     GENMASK(17, 16) /* Master Output Delay */
 111 #define SPICC_MO_NO_DELAY       0
 112 #define SPICC_MO_DELAY_1_CYCLE  1
 113 #define SPICC_MO_DELAY_2_CYCLE  2
 114 #define SPICC_MO_DELAY_3_CYCLE  3
 115 #define SPICC_MI_DELAY_MASK     GENMASK(19, 18) /* Master Input Delay */
 116 #define SPICC_MI_NO_DELAY       0
 117 #define SPICC_MI_DELAY_1_CYCLE  1
 118 #define SPICC_MI_DELAY_2_CYCLE  2
 119 #define SPICC_MI_DELAY_3_CYCLE  3
 120 #define SPICC_MI_CAP_DELAY_MASK GENMASK(21, 20) /* Master Capture Delay */
 121 #define SPICC_CAP_AHEAD_2_CYCLE 0
 122 #define SPICC_CAP_AHEAD_1_CYCLE 1
 123 #define SPICC_CAP_NO_DELAY      2
 124 #define SPICC_CAP_DELAY_1_CYCLE 3
 125 #define SPICC_FIFORST_RO_MASK   GENMASK(22, 21) /* FIFO Softreset Read-Only */
 126 #define SPICC_FIFORST_W1_MASK   GENMASK(23, 22) /* FIFO Softreset Write-Only */
 127
 128 #define SPICC_DRADDR    0x20    /* Read Address of DMA */
 129
 130 #define SPICC_DWADDR    0x24    /* Write Address of DMA */
 131
 132 #define SPICC_ENH_CTL0  0x38    /* Enhanced Feature */
 133 #define SPICC_ENH_CLK_CS_DELAY_MASK     GENMASK(15, 0)
 134 #define SPICC_ENH_DATARATE_MASK         GENMASK(23, 16)
 135 #define SPICC_ENH_DATARATE_EN           BIT(24)
 136 #define SPICC_ENH_MOSI_OEN              BIT(25)
 137 #define SPICC_ENH_CLK_OEN               BIT(26)
 138 #define SPICC_ENH_CS_OEN                BIT(27)
 139 #define SPICC_ENH_CLK_CS_DELAY_EN       BIT(28)
 140 #define SPICC_ENH_MAIN_CLK_AO           BIT(29)
 141
 142 #define writel_bits_relaxed(mask, val, addr) \
 143         writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr)
 144
 145 struct meson_spicc_data {
 146         unsigned int                    max_speed_hz;
 147         unsigned int                    min_speed_hz;
 148         unsigned int                    fifo_size;
 149         bool                            has_oen;
 150         bool                            has_enhance_clk_div;
 151         bool                            has_pclk;
 152 };
 153
 154 struct meson_spicc_device {
 155         struct spi_master               *master;
 156         struct platform_device          *pdev;
 157         void __iomem                    *base;
 158         struct clk                      *core;
 159         struct clk                      *pclk;
 160         struct clk_divider              pow2_div;
 161         struct clk                      *clk;
 162         struct spi_message              *message;
 163         struct spi_transfer             *xfer;
 164         struct completion               done;
 165         const struct meson_spicc_data   *data;
 166         u8                              *tx_buf;
 167         u8                              *rx_buf;
 168         unsigned int                    bytes_per_word;
 169         unsigned long                   tx_remain;
 170         unsigned long                   rx_remain;
 171         unsigned long                   xfer_remain;
 172         struct pinctrl                  *pinctrl;
 173         struct pinctrl_state            *pins_idle_high;
 174         struct pinctrl_state            *pins_idle_low;
 175 };
 176
 177 #define pow2_clk_to_spicc(_div) container_of(_div, struct meson_spicc_device, pow2_div)
 178
 179 static void meson_spicc_oen_enable(struct meson_spicc_device *spicc)
 180 {
 181         u32 conf;
 182
 183         if (!spicc->data->has_oen) {
 184                 /* Try to get pinctrl states for idle high/low */
 185                 spicc->pins_idle_high = pinctrl_lookup_state(spicc->pinctrl,
 186                                                              "idle-high");
 187                 if (IS_ERR(spicc->pins_idle_high)) {
 188                         dev_warn(&spicc->pdev->dev, "can't get idle-high pinctrl\n");
 189                         spicc->pins_idle_high = NULL;
 190                 }
 191                 spicc->pins_idle_low = pinctrl_lookup_state(spicc->pinctrl,
 192                                                              "idle-low");
 193                 if (IS_ERR(spicc->pins_idle_low)) {
 194                         dev_warn(&spicc->pdev->dev, "can't get idle-low pinctrl\n");
 195                         spicc->pins_idle_low = NULL;
 196                 }
 197                 return;
 198         }
 199
 200         conf = readl_relaxed(spicc->base + SPICC_ENH_CTL0) |
 201                 SPICC_ENH_MOSI_OEN | SPICC_ENH_CLK_OEN | SPICC_ENH_CS_OEN;
 202
 203         writel_relaxed(conf, spicc->base + SPICC_ENH_CTL0);
 204 }
 205
 206 static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc)
 207 {
 208         return !!FIELD_GET(SPICC_TF,
 209                            readl_relaxed(spicc->base + SPICC_STATREG));
 210 }
 211
 212 static inline bool meson_spicc_rxready(struct meson_spicc_device *spicc)
 213 {
 214         return FIELD_GET(SPICC_RH | SPICC_RR | SPICC_RF,
 215                          readl_relaxed(spicc->base + SPICC_STATREG));
 216 }
 217
 218 static inline u32 meson_spicc_pull_data(struct meson_spicc_device *spicc)
 219 {
 220         unsigned int bytes = spicc->bytes_per_word;
 221         unsigned int byte_shift = 0;
 222         u32 data = 0;
 223         u8 byte;
 224
 225         while (bytes--) {
 226                 byte = *spicc->tx_buf++;
 227                 data |= (byte & 0xff) << byte_shift;
 228                 byte_shift += 8;
 229         }
 230
 231         spicc->tx_remain--;
 232         return data;
 233 }
 234
 235 static inline void meson_spicc_push_data(struct meson_spicc_device *spicc,
 236                                          u32 data)
 237 {
 238         unsigned int bytes = spicc->bytes_per_word;
 239         unsigned int byte_shift = 0;
 240         u8 byte;
 241
 242         while (bytes--) {
 243                 byte = (data >> byte_shift) & 0xff;
 244                 *spicc->rx_buf++ = byte;
 245                 byte_shift += 8;
 246         }
 247
 248         spicc->rx_remain--;
 249 }
 250
 251 static inline void meson_spicc_rx(struct meson_spicc_device *spicc)
 252 {
 253         /* Empty RX FIFO */
 254         while (spicc->rx_remain &&
 255                meson_spicc_rxready(spicc))
 256                 meson_spicc_push_data(spicc,
 257                                 readl_relaxed(spicc->base + SPICC_RXDATA));
 258 }
 259
 260 static inline void meson_spicc_tx(struct meson_spicc_device *spicc)
 261 {
 262         /* Fill Up TX FIFO */
 263         while (spicc->tx_remain &&
 264                !meson_spicc_txfull(spicc))
 265                 writel_relaxed(meson_spicc_pull_data(spicc),
 266                                spicc->base + SPICC_TXDATA);
 267 }
 268
 269 static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc)
 270 {
 271
 272         unsigned int burst_len = min_t(unsigned int,
 273                                        spicc->xfer_remain /
 274                                        spicc->bytes_per_word,
 275                                        spicc->data->fifo_size);
 276         /* Setup Xfer variables */
 277         spicc->tx_remain = burst_len;
 278         spicc->rx_remain = burst_len;
 279         spicc->xfer_remain -= burst_len * spicc->bytes_per_word;
 280
 281         /* Setup burst length */
 282         writel_bits_relaxed(SPICC_BURSTLENGTH_MASK,
 283                         FIELD_PREP(SPICC_BURSTLENGTH_MASK,
 284                                 burst_len - 1),
 285                         spicc->base + SPICC_CONREG);
 286
 287         /* Fill TX FIFO */
 288         meson_spicc_tx(spicc);
 289 }
 290
 291 static irqreturn_t meson_spicc_irq(int irq, void *data)
 292 {
 293         struct meson_spicc_device *spicc = (void *) data;
 294
 295         writel_bits_relaxed(SPICC_TC, SPICC_TC, spicc->base + SPICC_STATREG);
 296
 297         /* Empty RX FIFO */
 298         meson_spicc_rx(spicc);
 299
 300         if (!spicc->xfer_remain) {
 301                 /* Disable all IRQs */
 302                 writel(0, spicc->base + SPICC_INTREG);
 303
 304                 complete(&spicc->done);
 305
 306                 return IRQ_HANDLED;
 307         }
 308
 309         /* Setup burst */
 310         meson_spicc_setup_burst(spicc);
 311
 312         /* Start burst */
 313         writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
 314
 315         return IRQ_HANDLED;
 316 }
 317
 318 static void meson_spicc_auto_io_delay(struct meson_spicc_device *spicc)
 319 {
 320         u32 div, hz;
 321         u32 mi_delay, cap_delay;
 322         u32 conf;
 323
 324         if (spicc->data->has_enhance_clk_div) {
 325                 div = FIELD_GET(SPICC_ENH_DATARATE_MASK,
 326                                 readl_relaxed(spicc->base + SPICC_ENH_CTL0));
 327                 div++;
 328                 div <<= 1;
 329         } else {
 330                 div = FIELD_GET(SPICC_DATARATE_MASK,
 331                                 readl_relaxed(spicc->base + SPICC_CONREG));
 332                 div += 2;
 333                 div = 1 << div;
 334         }
 335
 336         mi_delay = SPICC_MI_NO_DELAY;
 337         cap_delay = SPICC_CAP_AHEAD_2_CYCLE;
 338         hz = clk_get_rate(spicc->clk);
 339
 340         if (hz >= 100000000)
 341                 cap_delay = SPICC_CAP_DELAY_1_CYCLE;
 342         else if (hz >= 80000000)
 343                 cap_delay = SPICC_CAP_NO_DELAY;
 344         else if (hz >= 40000000)
 345                 cap_delay = SPICC_CAP_AHEAD_1_CYCLE;
 346         else if (div >= 16)
 347                 mi_delay = SPICC_MI_DELAY_3_CYCLE;
 348         else if (div >= 8)
 349                 mi_delay = SPICC_MI_DELAY_2_CYCLE;
 350         else if (div >= 6)
 351                 mi_delay = SPICC_MI_DELAY_1_CYCLE;
 352
 353         conf = readl_relaxed(spicc->base + SPICC_TESTREG);
 354         conf &= ~(SPICC_MO_DELAY_MASK | SPICC_MI_DELAY_MASK
 355                   | SPICC_MI_CAP_DELAY_MASK);
 356         conf |= FIELD_PREP(SPICC_MI_DELAY_MASK, mi_delay);
 357         conf |= FIELD_PREP(SPICC_MI_CAP_DELAY_MASK, cap_delay);
 358         writel_relaxed(conf, spicc->base + SPICC_TESTREG);
 359 }
 360
 361 static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc,
 362                                    struct spi_transfer *xfer)
 363 {
 364         u32 conf, conf_orig;
 365
 366         /* Read original configuration */
 367         conf = conf_orig = readl_relaxed(spicc->base + SPICC_CONREG);
 368
 369         /* Setup word width */
 370         conf &= ~SPICC_BITLENGTH_MASK;
 371         conf |= FIELD_PREP(SPICC_BITLENGTH_MASK,
 372                            (spicc->bytes_per_word << 3) - 1);
 373
 374         /* Ignore if unchanged */
 375         if (conf != conf_orig)
 376                 writel_relaxed(conf, spicc->base + SPICC_CONREG);
 377
 378         clk_set_rate(spicc->clk, xfer->speed_hz);
 379
 380         meson_spicc_auto_io_delay(spicc);
 381
 382         writel_relaxed(0, spicc->base + SPICC_DMAREG);
 383 }
 384
 385 static void meson_spicc_reset_fifo(struct meson_spicc_device *spicc)
 386 {
 387         if (spicc->data->has_oen)
 388                 writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO,
 389                                     SPICC_ENH_MAIN_CLK_AO,
 390                                     spicc->base + SPICC_ENH_CTL0);
 391
 392         writel_bits_relaxed(SPICC_FIFORST_W1_MASK, SPICC_FIFORST_W1_MASK,
 393                             spicc->base + SPICC_TESTREG);
 394
 395         while (meson_spicc_rxready(spicc))
 396                 readl_relaxed(spicc->base + SPICC_RXDATA);
 397
 398         if (spicc->data->has_oen)
 399                 writel_bits_relaxed(SPICC_ENH_MAIN_CLK_AO, 0,
 400                                     spicc->base + SPICC_ENH_CTL0);
 401 }
 402
 403 static int meson_spicc_transfer_one(struct spi_master *master,
 404                                     struct spi_device *spi,
 405                                     struct spi_transfer *xfer)
 406 {
 407         struct meson_spicc_device *spicc = spi_master_get_devdata(master);
 408         uint64_t timeout;
 409
 410         /* Store current transfer */
 411         spicc->xfer = xfer;
 412
 413         /* Setup transfer parameters */
 414         spicc->tx_buf = (u8 *)xfer->tx_buf;
 415         spicc->rx_buf = (u8 *)xfer->rx_buf;
 416         spicc->xfer_remain = xfer->len;
 417
 418         /* Pre-calculate word size */
 419         spicc->bytes_per_word =
 420            DIV_ROUND_UP(spicc->xfer->bits_per_word, 8);
 421
 422         if (xfer->len % spicc->bytes_per_word)
 423                 return -EINVAL;
 424
 425         /* Setup transfer parameters */
 426         meson_spicc_setup_xfer(spicc, xfer);
 427
 428         meson_spicc_reset_fifo(spicc);
 429
 430         /* Setup burst */
 431         meson_spicc_setup_burst(spicc);
 432
 433         /* Setup wait for completion */
 434         reinit_completion(&spicc->done);
 435
 436         /* For each byte we wait for 8 cycles of the SPI clock */
 437         timeout = 8LL * MSEC_PER_SEC * xfer->len;
 438         do_div(timeout, xfer->speed_hz);
 439
 440         /* Add 10us delay between each fifo bursts */
 441         timeout += ((xfer->len >> 4) * 10) / MSEC_PER_SEC;
 442
 443         /* Increase it twice and add 200 ms tolerance */
 444         timeout += timeout + 200;
 445
 446         /* Start burst */
 447         writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
 448
 449         /* Enable interrupts */
 450         writel_relaxed(SPICC_TC_EN, spicc->base + SPICC_INTREG);
 451
 452         if (!wait_for_completion_timeout(&spicc->done, msecs_to_jiffies(timeout)))
 453                 return -ETIMEDOUT;
 454
 455         return 0;
 456 }
 457
 458 static int meson_spicc_prepare_message(struct spi_master *master,
 459                                        struct spi_message *message)
 460 {
 461         struct meson_spicc_device *spicc = spi_master_get_devdata(master);
 462         struct spi_device *spi = message->spi;
 463         u32 conf = readl_relaxed(spicc->base + SPICC_CONREG) & SPICC_DATARATE_MASK;
 464
 465         /* Store current message */
 466         spicc->message = message;
 467
 468         /* Enable Master */
 469         conf |= SPICC_ENABLE;
 470         conf |= SPICC_MODE_MASTER;
 471
 472         /* SMC = 0 */
 473
 474         /* Setup transfer mode */
 475         if (spi->mode & SPI_CPOL)
 476                 conf |= SPICC_POL;
 477         else
 478                 conf &= ~SPICC_POL;
 479
 480         if (!spicc->data->has_oen) {
 481                 if (spi->mode & SPI_CPOL) {
 482                         if (spicc->pins_idle_high)
 483                                 pinctrl_select_state(spicc->pinctrl, spicc->pins_idle_high);
 484                 } else {
 485                         if (spicc->pins_idle_low)
 486                                 pinctrl_select_state(spicc->pinctrl, spicc->pins_idle_low);
 487                 }
 488         }
 489
 490         if (spi->mode & SPI_CPHA)
 491                 conf |= SPICC_PHA;
 492         else
 493                 conf &= ~SPICC_PHA;
 494
 495         /* SSCTL = 0 */
 496
 497         if (spi->mode & SPI_CS_HIGH)
 498                 conf |= SPICC_SSPOL;
 499         else
 500                 conf &= ~SPICC_SSPOL;
 501
 502         if (spi->mode & SPI_READY)
 503                 conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_LOWLEVEL);
 504         else
 505                 conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_IGNORE);
 506
 507         /* Select CS */
 508         conf |= FIELD_PREP(SPICC_CS_MASK, spi->chip_select);
 509
 510         /* Default 8bit word */
 511         conf |= FIELD_PREP(SPICC_BITLENGTH_MASK, 8 - 1);
 512
 513         writel_relaxed(conf, spicc->base + SPICC_CONREG);
 514
 515         /* Setup no wait cycles by default */
 516         writel_relaxed(0, spicc->base + SPICC_PERIODREG);
 517
 518         writel_bits_relaxed(SPICC_LBC_W1, 0, spicc->base + SPICC_TESTREG);
 519
 520         return 0;
 521 }
 522
 523 static int meson_spicc_unprepare_transfer(struct spi_master *master)
 524 {
 525         struct meson_spicc_device *spicc = spi_master_get_devdata(master);
 526         u32 conf = readl_relaxed(spicc->base + SPICC_CONREG) & SPICC_DATARATE_MASK;
 527
 528         /* Disable all IRQs */
 529         writel(0, spicc->base + SPICC_INTREG);
 530
 531         device_reset_optional(&spicc->pdev->dev);
 532
 533         /* Set default configuration, keeping datarate field */
 534         writel_relaxed(conf, spicc->base + SPICC_CONREG);
 535
 536         if (!spicc->data->has_oen)
 537                 pinctrl_select_default_state(&spicc->pdev->dev);
 538
 539         return 0;
 540 }
 541
 542 static int meson_spicc_setup(struct spi_device *spi)
 543 {
 544         if (!spi->controller_state)
 545                 spi->controller_state = spi_master_get_devdata(spi->master);
 546
 547         return 0;
 548 }
 549
 550 static void meson_spicc_cleanup(struct spi_device *spi)
 551 {
 552         spi->controller_state = NULL;
 553 }
 554
 555 /*
 556  * The Clock Mux
 557  *            x-----------------x   x------------x    x------\
 558  *        |---| pow2 fixed div  |---| pow2 div   |----|      |
 559  *        |   x-----------------x   x------------x    |      |
 560  * src ---|                                           | mux  |-- out
 561  *        |   x-----------------x   x------------x    |      |
 562  *        |---| enh fixed div   |---| enh div    |0---|      |
 563  *            x-----------------x   x------------x    x------/
 564  *
 565  * Clk path for GX series:
 566  *    src -> pow2 fixed div -> pow2 div -> out
 567  *
 568  * Clk path for AXG series:
 569  *    src -> pow2 fixed div -> pow2 div -> mux -> out
 570  *    src -> enh fixed div -> enh div -> mux -> out
 571  *
 572  * Clk path for G12A series:
 573  *    pclk -> pow2 fixed div -> pow2 div -> mux -> out
 574  *    pclk -> enh fixed div -> enh div -> mux -> out
 575  *
 576  * The pow2 divider is tied to the controller HW state, and the
 577  * divider is only valid when the controller is initialized.
 578  *
 579  * A set of clock ops is added to make sure we don't read/set this
 580  * clock rate while the controller is in an unknown state.
 581  */
 582
 583 static unsigned long meson_spicc_pow2_recalc_rate(struct clk_hw *hw,
 584                                                   unsigned long parent_rate)
 585 {
 586         struct clk_divider *divider = to_clk_divider(hw);
 587         struct meson_spicc_device *spicc = pow2_clk_to_spicc(divider);
 588
 589         if (!spicc->master->cur_msg)
 590                 return 0;
 591
 592         return clk_divider_ops.recalc_rate(hw, parent_rate);
 593 }
 594
 595 static int meson_spicc_pow2_determine_rate(struct clk_hw *hw,
 596                                            struct clk_rate_request *req)
 597 {
 598         struct clk_divider *divider = to_clk_divider(hw);
 599         struct meson_spicc_device *spicc = pow2_clk_to_spicc(divider);
 600
 601         if (!spicc->master->cur_msg)
 602                 return -EINVAL;
 603
 604         return clk_divider_ops.determine_rate(hw, req);
 605 }
 606
 607 static int meson_spicc_pow2_set_rate(struct clk_hw *hw, unsigned long rate,
 608                                      unsigned long parent_rate)
 609 {
 610         struct clk_divider *divider = to_clk_divider(hw);
 611         struct meson_spicc_device *spicc = pow2_clk_to_spicc(divider);
 612
 613         if (!spicc->master->cur_msg)
 614                 return -EINVAL;
 615
 616         return clk_divider_ops.set_rate(hw, rate, parent_rate);
 617 }
 618
 619 static const struct clk_ops meson_spicc_pow2_clk_ops = {
 620         .recalc_rate = meson_spicc_pow2_recalc_rate,
 621         .determine_rate = meson_spicc_pow2_determine_rate,
 622         .set_rate = meson_spicc_pow2_set_rate,
 623 };
 624
 625 static int meson_spicc_pow2_clk_init(struct meson_spicc_device *spicc)
 626 {
 627         struct device *dev = &spicc->pdev->dev;
 628         struct clk_fixed_factor *pow2_fixed_div;
 629         struct clk_init_data init;
 630         struct clk *clk;
 631         struct clk_parent_data parent_data[2];
 632         char name[64];
 633
 634         memset(&init, 0, sizeof(init));
 635         memset(&parent_data, 0, sizeof(parent_data));
 636
 637         init.parent_data = parent_data;
 638
 639         /* algorithm for pow2 div: rate = freq / 4 / (2 ^ N) */
 640
 641         pow2_fixed_div = devm_kzalloc(dev, sizeof(*pow2_fixed_div), GFP_KERNEL);
 642         if (!pow2_fixed_div)
 643                 return -ENOMEM;
 644
 645         snprintf(name, sizeof(name), "%s#pow2_fixed_div", dev_name(dev));
 646         init.name = name;
 647         init.ops = &clk_fixed_factor_ops;
 648         init.flags = 0;
 649         if (spicc->data->has_pclk)
 650                 parent_data[0].hw = __clk_get_hw(spicc->pclk);
 651         else
 652                 parent_data[0].hw = __clk_get_hw(spicc->core);
 653         init.num_parents = 1;
 654
 655         pow2_fixed_div->mult = 1,
 656         pow2_fixed_div->div = 4,
 657         pow2_fixed_div->hw.init = &init;
 658
 659         clk = devm_clk_register(dev, &pow2_fixed_div->hw);
 660         if (WARN_ON(IS_ERR(clk)))
 661                 return PTR_ERR(clk);
 662
 663         snprintf(name, sizeof(name), "%s#pow2_div", dev_name(dev));
 664         init.name = name;
 665         init.ops = &meson_spicc_pow2_clk_ops;
 666         /*
 667          * Set NOCACHE here to make sure we read the actual HW value
 668          * since we reset the HW after each transfer.
 669          */
 670         init.flags = CLK_SET_RATE_PARENT | CLK_GET_RATE_NOCACHE;
 671         parent_data[0].hw = &pow2_fixed_div->hw;
 672         init.num_parents = 1;
 673
 674         spicc->pow2_div.shift = 16,
 675         spicc->pow2_div.width = 3,
 676         spicc->pow2_div.flags = CLK_DIVIDER_POWER_OF_TWO,
 677         spicc->pow2_div.reg = spicc->base + SPICC_CONREG;
 678         spicc->pow2_div.hw.init = &init;
 679
 680         spicc->clk = devm_clk_register(dev, &spicc->pow2_div.hw);
 681         if (WARN_ON(IS_ERR(spicc->clk)))
 682                 return PTR_ERR(spicc->clk);
 683
 684         return 0;
 685 }
 686
 687 static int meson_spicc_enh_clk_init(struct meson_spicc_device *spicc)
 688 {
 689         struct device *dev = &spicc->pdev->dev;
 690         struct clk_fixed_factor *enh_fixed_div;
 691         struct clk_divider *enh_div;
 692         struct clk_mux *mux;
 693         struct clk_init_data init;
 694         struct clk *clk;
 695         struct clk_parent_data parent_data[2];
 696         char name[64];
 697
 698         memset(&init, 0, sizeof(init));
 699         memset(&parent_data, 0, sizeof(parent_data));
 700
 701         init.parent_data = parent_data;
 702
 703         /* algorithm for enh div: rate = freq / 2 / (N + 1) */
 704
 705         enh_fixed_div = devm_kzalloc(dev, sizeof(*enh_fixed_div), GFP_KERNEL);
 706         if (!enh_fixed_div)
 707                 return -ENOMEM;
 708
 709         snprintf(name, sizeof(name), "%s#enh_fixed_div", dev_name(dev));
 710         init.name = name;
 711         init.ops = &clk_fixed_factor_ops;
 712         init.flags = 0;
 713         if (spicc->data->has_pclk)
 714                 parent_data[0].hw = __clk_get_hw(spicc->pclk);
 715         else
 716                 parent_data[0].hw = __clk_get_hw(spicc->core);
 717         init.num_parents = 1;
 718
 719         enh_fixed_div->mult = 1,
 720         enh_fixed_div->div = 2,
 721         enh_fixed_div->hw.init = &init;
 722
 723         clk = devm_clk_register(dev, &enh_fixed_div->hw);
 724         if (WARN_ON(IS_ERR(clk)))
 725                 return PTR_ERR(clk);
 726
 727         enh_div = devm_kzalloc(dev, sizeof(*enh_div), GFP_KERNEL);
 728         if (!enh_div)
 729                 return -ENOMEM;
 730
 731         snprintf(name, sizeof(name), "%s#enh_div", dev_name(dev));
 732         init.name = name;
 733         init.ops = &clk_divider_ops;
 734         init.flags = CLK_SET_RATE_PARENT;
 735         parent_data[0].hw = &enh_fixed_div->hw;
 736         init.num_parents = 1;
 737
 738         enh_div->shift  = 16,
 739         enh_div->width  = 8,
 740         enh_div->reg = spicc->base + SPICC_ENH_CTL0;
 741         enh_div->hw.init = &init;
 742
 743         clk = devm_clk_register(dev, &enh_div->hw);
 744         if (WARN_ON(IS_ERR(clk)))
 745                 return PTR_ERR(clk);
 746
 747         mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
 748         if (!mux)
 749                 return -ENOMEM;
 750
 751         snprintf(name, sizeof(name), "%s#sel", dev_name(dev));
 752         init.name = name;
 753         init.ops = &clk_mux_ops;
 754         parent_data[0].hw = &spicc->pow2_div.hw;
 755         parent_data[1].hw = &enh_div->hw;
 756         init.num_parents = 2;
 757         init.flags = CLK_SET_RATE_PARENT;
 758
 759         mux->mask = 0x1,
 760         mux->shift = 24,
 761         mux->reg = spicc->base + SPICC_ENH_CTL0;
 762         mux->hw.init = &init;
 763
 764         spicc->clk = devm_clk_register(dev, &mux->hw);
 765         if (WARN_ON(IS_ERR(spicc->clk)))
 766                 return PTR_ERR(spicc->clk);
 767
 768         return 0;
 769 }
 770
 771 static int meson_spicc_probe(struct platform_device *pdev)
 772 {
 773         struct spi_master *master;
 774         struct meson_spicc_device *spicc;
 775         int ret, irq;
 776
 777         master = spi_alloc_master(&pdev->dev, sizeof(*spicc));
 778         if (!master) {
 779                 dev_err(&pdev->dev, "master allocation failed\n");
 780                 return -ENOMEM;
 781         }
 782         spicc = spi_master_get_devdata(master);
 783         spicc->master = master;
 784
 785         spicc->data = of_device_get_match_data(&pdev->dev);
 786         if (!spicc->data) {
 787                 dev_err(&pdev->dev, "failed to get match data\n");
 788                 ret = -EINVAL;
 789                 goto out_master;
 790         }
 791
 792         spicc->pdev = pdev;
 793         platform_set_drvdata(pdev, spicc);
 794
 795         init_completion(&spicc->done);
 796
 797         spicc->base = devm_platform_ioremap_resource(pdev, 0);
 798         if (IS_ERR(spicc->base)) {
 799                 dev_err(&pdev->dev, "io resource mapping failed\n");
 800                 ret = PTR_ERR(spicc->base);
 801                 goto out_master;
 802         }
 803
 804         /* Set master mode and enable controller */
 805         writel_relaxed(SPICC_ENABLE | SPICC_MODE_MASTER,
 806                        spicc->base + SPICC_CONREG);
 807
 808         /* Disable all IRQs */
 809         writel_relaxed(0, spicc->base + SPICC_INTREG);
 810
 811         irq = platform_get_irq(pdev, 0);
 812         if (irq < 0) {
 813                 ret = irq;
 814                 goto out_master;
 815         }
 816
 817         ret = devm_request_irq(&pdev->dev, irq, meson_spicc_irq,
 818                                0, NULL, spicc);
 819         if (ret) {
 820                 dev_err(&pdev->dev, "irq request failed\n");
 821                 goto out_master;
 822         }
 823
 824         spicc->core = devm_clk_get(&pdev->dev, "core");
 825         if (IS_ERR(spicc->core)) {
 826                 dev_err(&pdev->dev, "core clock request failed\n");
 827                 ret = PTR_ERR(spicc->core);
 828                 goto out_master;
 829         }
 830
 831         if (spicc->data->has_pclk) {
 832                 spicc->pclk = devm_clk_get(&pdev->dev, "pclk");
 833                 if (IS_ERR(spicc->pclk)) {
 834                         dev_err(&pdev->dev, "pclk clock request failed\n");
 835                         ret = PTR_ERR(spicc->pclk);
 836                         goto out_master;
 837                 }
 838         }
 839
 840         ret = clk_prepare_enable(spicc->core);
 841         if (ret) {
 842                 dev_err(&pdev->dev, "core clock enable failed\n");
 843                 goto out_master;
 844         }
 845
 846         ret = clk_prepare_enable(spicc->pclk);
 847         if (ret) {
 848                 dev_err(&pdev->dev, "pclk clock enable failed\n");
 849                 goto out_core_clk;
 850         }
 851
 852         spicc->pinctrl = devm_pinctrl_get(&pdev->dev);
 853         if (IS_ERR(spicc->pinctrl)) {
 854                 ret = PTR_ERR(spicc->pinctrl);
 855                 goto out_clk;
 856         }
 857
 858         device_reset_optional(&pdev->dev);
 859
 860         master->num_chipselect = 4;
 861         master->dev.of_node = pdev->dev.of_node;
 862         master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH;
 863         master->bits_per_word_mask = SPI_BPW_MASK(32) |
 864                                      SPI_BPW_MASK(24) |
 865                                      SPI_BPW_MASK(16) |
 866                                      SPI_BPW_MASK(8);
 867         master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
 868         master->min_speed_hz = spicc->data->min_speed_hz;
 869         master->max_speed_hz = spicc->data->max_speed_hz;
 870         master->setup = meson_spicc_setup;
 871         master->cleanup = meson_spicc_cleanup;
 872         master->prepare_message = meson_spicc_prepare_message;
 873         master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
 874         master->transfer_one = meson_spicc_transfer_one;
 875         master->use_gpio_descriptors = true;
 876
 877         meson_spicc_oen_enable(spicc);
 878
 879         ret = meson_spicc_pow2_clk_init(spicc);
 880         if (ret) {
 881                 dev_err(&pdev->dev, "pow2 clock registration failed\n");
 882                 goto out_clk;
 883         }
 884
 885         if (spicc->data->has_enhance_clk_div) {
 886                 ret = meson_spicc_enh_clk_init(spicc);
 887                 if (ret) {
 888                         dev_err(&pdev->dev, "clock registration failed\n");
 889                         goto out_clk;
 890                 }
 891         }
 892
 893         ret = devm_spi_register_master(&pdev->dev, master);
 894         if (ret) {
 895                 dev_err(&pdev->dev, "spi master registration failed\n");
 896                 goto out_clk;
 897         }
 898
 899         return 0;
 900
 901 out_clk:
 902         clk_disable_unprepare(spicc->pclk);
 903
 904 out_core_clk:
 905         clk_disable_unprepare(spicc->core);
 906
 907 out_master:
 908         spi_master_put(master);
 909
 910         return ret;
 911 }
 912
 913 static int meson_spicc_remove(struct platform_device *pdev)
 914 {
 915         struct meson_spicc_device *spicc = platform_get_drvdata(pdev);
 916
 917         /* Disable SPI */
 918         writel(0, spicc->base + SPICC_CONREG);
 919
 920         clk_disable_unprepare(spicc->core);
 921         clk_disable_unprepare(spicc->pclk);
 922
 923         spi_master_put(spicc->master);
 924
 925         return 0;
 926 }
 927
 928 static const struct meson_spicc_data meson_spicc_gx_data = {
 929         .max_speed_hz           = 30000000,
 930         .min_speed_hz           = 325000,
 931         .fifo_size              = 16,
 932 };
 933
 934 static const struct meson_spicc_data meson_spicc_axg_data = {
 935         .max_speed_hz           = 80000000,
 936         .min_speed_hz           = 325000,
 937         .fifo_size              = 16,
 938         .has_oen                = true,
 939         .has_enhance_clk_div    = true,
 940 };
 941
 942 static const struct meson_spicc_data meson_spicc_g12a_data = {
 943         .max_speed_hz           = 166666666,
 944         .min_speed_hz           = 50000,
 945         .fifo_size              = 15,
 946         .has_oen                = true,
 947         .has_enhance_clk_div    = true,
 948         .has_pclk               = true,
 949 };
 950
 951 static const struct of_device_id meson_spicc_of_match[] = {
 952         {
 953                 .compatible     = "amlogic,meson-gx-spicc",
 954                 .data           = &meson_spicc_gx_data,
 955         },
 956         {
 957                 .compatible = "amlogic,meson-axg-spicc",
 958                 .data           = &meson_spicc_axg_data,
 959         },
 960         {
 961                 .compatible = "amlogic,meson-g12a-spicc",
 962                 .data           = &meson_spicc_g12a_data,
 963         },
 964         { /* sentinel */ }
 965 };
 966 MODULE_DEVICE_TABLE(of, meson_spicc_of_match);
 967
 968 static struct platform_driver meson_spicc_driver = {
 969         .probe   = meson_spicc_probe,
 970         .remove  = meson_spicc_remove,
 971         .driver  = {
 972                 .name = "meson-spicc",
 973                 .of_match_table = of_match_ptr(meson_spicc_of_match),
 974         },
 975 };
 976
 977 module_platform_driver(meson_spicc_driver);
 978
 979 MODULE_DESCRIPTION("Meson SPI Communication Controller driver");
 980 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
 981 MODULE_LICENSE("GPL");