drivers/spi/spi-orion.c

   1 /*
   2  * Marvell Orion SPI controller driver
   3  *
   4  * Author: Shadi Ammouri <shadi@marvell.com>
   5  * Copyright (C) 2007-2008 Marvell Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/interrupt.h>
  13 #include <linux/delay.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/err.h>
  16 #include <linux/io.h>
  17 #include <linux/spi/spi.h>
  18 #include <linux/module.h>
  19 #include <linux/pm_runtime.h>
  20 #include <linux/of.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_device.h>
  23 #include <linux/of_gpio.h>
  24 #include <linux/clk.h>
  25 #include <linux/sizes.h>
  26 #include <linux/gpio.h>
  27 #include <asm/unaligned.h>
  28
  29 #define DRIVER_NAME                     "orion_spi"
  30
  31 /* Runtime PM autosuspend timeout: PM is fairly light on this driver */
  32 #define SPI_AUTOSUSPEND_TIMEOUT         200
  33
  34 /* Some SoCs using this driver support up to 8 chip selects.
  35  * It is up to the implementer to only use the chip selects
  36  * that are available.
  37  */
  38 #define ORION_NUM_CHIPSELECTS           8
  39
  40 #define ORION_SPI_WAIT_RDY_MAX_LOOP     2000 /* in usec */
  41
  42 #define ORION_SPI_IF_CTRL_REG           0x00
  43 #define ORION_SPI_IF_CONFIG_REG         0x04
  44 #define ORION_SPI_IF_RXLSBF             BIT(14)
  45 #define ORION_SPI_IF_TXLSBF             BIT(13)
  46 #define ORION_SPI_DATA_OUT_REG          0x08
  47 #define ORION_SPI_DATA_IN_REG           0x0c
  48 #define ORION_SPI_INT_CAUSE_REG         0x10
  49 #define ORION_SPI_TIMING_PARAMS_REG     0x18
  50
  51 /* Register for the "Direct Mode" */
  52 #define SPI_DIRECT_WRITE_CONFIG_REG     0x20
  53
  54 #define ORION_SPI_TMISO_SAMPLE_MASK     (0x3 << 6)
  55 #define ORION_SPI_TMISO_SAMPLE_1        (1 << 6)
  56 #define ORION_SPI_TMISO_SAMPLE_2        (2 << 6)
  57
  58 #define ORION_SPI_MODE_CPOL             (1 << 11)
  59 #define ORION_SPI_MODE_CPHA             (1 << 12)
  60 #define ORION_SPI_IF_8_16_BIT_MODE      (1 << 5)
  61 #define ORION_SPI_CLK_PRESCALE_MASK     0x1F
  62 #define ARMADA_SPI_CLK_PRESCALE_MASK    0xDF
  63 #define ORION_SPI_MODE_MASK             (ORION_SPI_MODE_CPOL | \
  64                                          ORION_SPI_MODE_CPHA)
  65 #define ORION_SPI_CS_MASK       0x1C
  66 #define ORION_SPI_CS_SHIFT      2
  67 #define ORION_SPI_CS(cs)        ((cs << ORION_SPI_CS_SHIFT) & \
  68                                         ORION_SPI_CS_MASK)
  69
  70 enum orion_spi_type {
  71         ORION_SPI,
  72         ARMADA_SPI,
  73 };
  74
  75 struct orion_spi_dev {
  76         enum orion_spi_type     typ;
  77         /*
  78          * min_divisor and max_hz should be exclusive, the only we can
  79          * have both is for managing the armada-370-spi case with old
  80          * device tree
  81          */
  82         unsigned long           max_hz;
  83         unsigned int            min_divisor;
  84         unsigned int            max_divisor;
  85         u32                     prescale_mask;
  86         bool                    is_errata_50mhz_ac;
  87 };
  88
  89 struct orion_direct_acc {
  90         void __iomem            *vaddr;
  91         u32                     size;
  92 };
  93
  94 struct orion_child_options {
  95         struct orion_direct_acc direct_access;
  96 };
  97
  98 struct orion_spi {
  99         struct spi_master       *master;
 100         void __iomem            *base;
 101         struct clk              *clk;
 102         struct clk              *axi_clk;
 103         const struct orion_spi_dev *devdata;
 104         int                     unused_hw_gpio;
 105
 106         struct orion_child_options      child[ORION_NUM_CHIPSELECTS];
 107 };
 108
 109 static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg)
 110 {
 111         return orion_spi->base + reg;
 112 }
 113
 114 static inline void
 115 orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
 116 {
 117         void __iomem *reg_addr = spi_reg(orion_spi, reg);
 118         u32 val;
 119
 120         val = readl(reg_addr);
 121         val |= mask;
 122         writel(val, reg_addr);
 123 }
 124
 125 static inline void
 126 orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask)
 127 {
 128         void __iomem *reg_addr = spi_reg(orion_spi, reg);
 129         u32 val;
 130
 131         val = readl(reg_addr);
 132         val &= ~mask;
 133         writel(val, reg_addr);
 134 }
 135
 136 static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
 137 {
 138         u32 tclk_hz;
 139         u32 rate;
 140         u32 prescale;
 141         u32 reg;
 142         struct orion_spi *orion_spi;
 143         const struct orion_spi_dev *devdata;
 144
 145         orion_spi = spi_master_get_devdata(spi->master);
 146         devdata = orion_spi->devdata;
 147
 148         tclk_hz = clk_get_rate(orion_spi->clk);
 149
 150         if (devdata->typ == ARMADA_SPI) {
 151                 /*
 152                  * Given the core_clk (tclk_hz) and the target rate (speed) we
 153                  * determine the best values for SPR (in [0 .. 15]) and SPPR (in
 154                  * [0..7]) such that
 155                  *
 156                  *      core_clk / (SPR * 2 ** SPPR)
 157                  *
 158                  * is as big as possible but not bigger than speed.
 159                  */
 160
 161                 /* best integer divider: */
 162                 unsigned divider = DIV_ROUND_UP(tclk_hz, speed);
 163                 unsigned spr, sppr;
 164
 165                 if (divider < 16) {
 166                         /* This is the easy case, divider is less than 16 */
 167                         spr = divider;
 168                         sppr = 0;
 169
 170                 } else {
 171                         unsigned two_pow_sppr;
 172                         /*
 173                          * Find the highest bit set in divider. This and the
 174                          * three next bits define SPR (apart from rounding).
 175                          * SPPR is then the number of zero bits that must be
 176                          * appended:
 177                          */
 178                         sppr = fls(divider) - 4;
 179
 180                         /*
 181                          * As SPR only has 4 bits, we have to round divider up
 182                          * to the next multiple of 2 ** sppr.
 183                          */
 184                         two_pow_sppr = 1 << sppr;
 185                         divider = (divider + two_pow_sppr - 1) & -two_pow_sppr;
 186
 187                         /*
 188                          * recalculate sppr as rounding up divider might have
 189                          * increased it enough to change the position of the
 190                          * highest set bit. In this case the bit that now
 191                          * doesn't make it into SPR is 0, so there is no need to
 192                          * round again.
 193                          */
 194                         sppr = fls(divider) - 4;
 195                         spr = divider >> sppr;
 196
 197                         /*
 198                          * Now do range checking. SPR is constructed to have a
 199                          * width of 4 bits, so this is fine for sure. So we
 200                          * still need to check for sppr to fit into 3 bits:
 201                          */
 202                         if (sppr > 7)
 203                                 return -EINVAL;
 204                 }
 205
 206                 prescale = ((sppr & 0x6) << 5) | ((sppr & 0x1) << 4) | spr;
 207         } else {
 208                 /*
 209                  * the supported rates are: 4,6,8...30
 210                  * round up as we look for equal or less speed
 211                  */
 212                 rate = DIV_ROUND_UP(tclk_hz, speed);
 213                 rate = roundup(rate, 2);
 214
 215                 /* check if requested speed is too small */
 216                 if (rate > 30)
 217                         return -EINVAL;
 218
 219                 if (rate < 4)
 220                         rate = 4;
 221
 222                 /* Convert the rate to SPI clock divisor value. */
 223                 prescale = 0x10 + rate/2;
 224         }
 225
 226         reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
 227         reg = ((reg & ~devdata->prescale_mask) | prescale);
 228         writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
 229
 230         return 0;
 231 }
 232
 233 static void
 234 orion_spi_mode_set(struct spi_device *spi)
 235 {
 236         u32 reg;
 237         struct orion_spi *orion_spi;
 238
 239         orion_spi = spi_master_get_devdata(spi->master);
 240
 241         reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
 242         reg &= ~ORION_SPI_MODE_MASK;
 243         if (spi->mode & SPI_CPOL)
 244                 reg |= ORION_SPI_MODE_CPOL;
 245         if (spi->mode & SPI_CPHA)
 246                 reg |= ORION_SPI_MODE_CPHA;
 247         if (spi->mode & SPI_LSB_FIRST)
 248                 reg |= ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF;
 249         else
 250                 reg &= ~(ORION_SPI_IF_RXLSBF | ORION_SPI_IF_TXLSBF);
 251
 252         writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG));
 253 }
 254
 255 static void
 256 orion_spi_50mhz_ac_timing_erratum(struct spi_device *spi, unsigned int speed)
 257 {
 258         u32 reg;
 259         struct orion_spi *orion_spi;
 260
 261         orion_spi = spi_master_get_devdata(spi->master);
 262
 263         /*
 264          * Erratum description: (Erratum NO. FE-9144572) The device
 265          * SPI interface supports frequencies of up to 50 MHz.
 266          * However, due to this erratum, when the device core clock is
 267          * 250 MHz and the SPI interfaces is configured for 50MHz SPI
 268          * clock and CPOL=CPHA=1 there might occur data corruption on
 269          * reads from the SPI device.
 270          * Erratum Workaround:
 271          * Work in one of the following configurations:
 272          * 1. Set CPOL=CPHA=0 in "SPI Interface Configuration
 273          * Register".
 274          * 2. Set TMISO_SAMPLE value to 0x2 in "SPI Timing Parameters 1
 275          * Register" before setting the interface.
 276          */
 277         reg = readl(spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
 278         reg &= ~ORION_SPI_TMISO_SAMPLE_MASK;
 279
 280         if (clk_get_rate(orion_spi->clk) == 250000000 &&
 281                         speed == 50000000 && spi->mode & SPI_CPOL &&
 282                         spi->mode & SPI_CPHA)
 283                 reg |= ORION_SPI_TMISO_SAMPLE_2;
 284         else
 285                 reg |= ORION_SPI_TMISO_SAMPLE_1; /* This is the default value */
 286
 287         writel(reg, spi_reg(orion_spi, ORION_SPI_TIMING_PARAMS_REG));
 288 }
 289
 290 /*
 291  * called only when no transfer is active on the bus
 292  */
 293 static int
 294 orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 295 {
 296         struct orion_spi *orion_spi;
 297         unsigned int speed = spi->max_speed_hz;
 298         unsigned int bits_per_word = spi->bits_per_word;
 299         int     rc;
 300
 301         orion_spi = spi_master_get_devdata(spi->master);
 302
 303         if ((t != NULL) && t->speed_hz)
 304                 speed = t->speed_hz;
 305
 306         if ((t != NULL) && t->bits_per_word)
 307                 bits_per_word = t->bits_per_word;
 308
 309         orion_spi_mode_set(spi);
 310
 311         if (orion_spi->devdata->is_errata_50mhz_ac)
 312                 orion_spi_50mhz_ac_timing_erratum(spi, speed);
 313
 314         rc = orion_spi_baudrate_set(spi, speed);
 315         if (rc)
 316                 return rc;
 317
 318         if (bits_per_word == 16)
 319                 orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
 320                                   ORION_SPI_IF_8_16_BIT_MODE);
 321         else
 322                 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG,
 323                                   ORION_SPI_IF_8_16_BIT_MODE);
 324
 325         return 0;
 326 }
 327
 328 static void orion_spi_set_cs(struct spi_device *spi, bool enable)
 329 {
 330         struct orion_spi *orion_spi;
 331         int cs;
 332
 333         orion_spi = spi_master_get_devdata(spi->master);
 334
 335         if (gpio_is_valid(spi->cs_gpio))
 336                 cs = orion_spi->unused_hw_gpio;
 337         else
 338                 cs = spi->chip_select;
 339
 340         orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
 341         orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
 342                                 ORION_SPI_CS(cs));
 343
 344         /* Chip select logic is inverted from spi_set_cs */
 345         if (!enable)
 346                 orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
 347         else
 348                 orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
 349 }
 350
 351 static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)
 352 {
 353         int i;
 354
 355         for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) {
 356                 if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG)))
 357                         return 1;
 358
 359                 udelay(1);
 360         }
 361
 362         return -1;
 363 }
 364
 365 static inline int
 366 orion_spi_write_read_8bit(struct spi_device *spi,
 367                           const u8 **tx_buf, u8 **rx_buf)
 368 {
 369         void __iomem *tx_reg, *rx_reg, *int_reg;
 370         struct orion_spi *orion_spi;
 371
 372         orion_spi = spi_master_get_devdata(spi->master);
 373         tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
 374         rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
 375         int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
 376
 377         /* clear the interrupt cause register */
 378         writel(0x0, int_reg);
 379
 380         if (tx_buf && *tx_buf)
 381                 writel(*(*tx_buf)++, tx_reg);
 382         else
 383                 writel(0, tx_reg);
 384
 385         if (orion_spi_wait_till_ready(orion_spi) < 0) {
 386                 dev_err(&spi->dev, "TXS timed out\n");
 387                 return -1;
 388         }
 389
 390         if (rx_buf && *rx_buf)
 391                 *(*rx_buf)++ = readl(rx_reg);
 392
 393         return 1;
 394 }
 395
 396 static inline int
 397 orion_spi_write_read_16bit(struct spi_device *spi,
 398                            const u16 **tx_buf, u16 **rx_buf)
 399 {
 400         void __iomem *tx_reg, *rx_reg, *int_reg;
 401         struct orion_spi *orion_spi;
 402
 403         orion_spi = spi_master_get_devdata(spi->master);
 404         tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG);
 405         rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG);
 406         int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG);
 407
 408         /* clear the interrupt cause register */
 409         writel(0x0, int_reg);
 410
 411         if (tx_buf && *tx_buf)
 412                 writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg);
 413         else
 414                 writel(0, tx_reg);
 415
 416         if (orion_spi_wait_till_ready(orion_spi) < 0) {
 417                 dev_err(&spi->dev, "TXS timed out\n");
 418                 return -1;
 419         }
 420
 421         if (rx_buf && *rx_buf)
 422                 put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++);
 423
 424         return 1;
 425 }
 426
 427 static unsigned int
 428 orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
 429 {
 430         unsigned int count;
 431         int word_len;
 432         struct orion_spi *orion_spi;
 433         int cs = spi->chip_select;
 434         void __iomem *vaddr;
 435
 436         word_len = spi->bits_per_word;
 437         count = xfer->len;
 438
 439         orion_spi = spi_master_get_devdata(spi->master);
 440
 441         /*
 442          * Use SPI direct write mode if base address is available. Otherwise
 443          * fall back to PIO mode for this transfer.
 444          */
 445         vaddr = orion_spi->child[cs].direct_access.vaddr;
 446
 447         if (vaddr && xfer->tx_buf && word_len == 8) {
 448                 unsigned int cnt = count / 4;
 449                 unsigned int rem = count % 4;
 450
 451                 /*
 452                  * Send the TX-data to the SPI device via the direct
 453                  * mapped address window
 454                  */
 455                 iowrite32_rep(vaddr, xfer->tx_buf, cnt);
 456                 if (rem) {
 457                         u32 *buf = (u32 *)xfer->tx_buf;
 458
 459                         iowrite8_rep(vaddr, &buf[cnt], rem);
 460                 }
 461
 462                 return count;
 463         }
 464
 465         if (word_len == 8) {
 466                 const u8 *tx = xfer->tx_buf;
 467                 u8 *rx = xfer->rx_buf;
 468
 469                 do {
 470                         if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0)
 471                                 goto out;
 472                         count--;
 473                         if (xfer->word_delay_usecs)
 474                                 udelay(xfer->word_delay_usecs);
 475                 } while (count);
 476         } else if (word_len == 16) {
 477                 const u16 *tx = xfer->tx_buf;
 478                 u16 *rx = xfer->rx_buf;
 479
 480                 do {
 481                         if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0)
 482                                 goto out;
 483                         count -= 2;
 484                         if (xfer->word_delay_usecs)
 485                                 udelay(xfer->word_delay_usecs);
 486                 } while (count);
 487         }
 488
 489 out:
 490         return xfer->len - count;
 491 }
 492
 493 static int orion_spi_transfer_one(struct spi_master *master,
 494                                         struct spi_device *spi,
 495                                         struct spi_transfer *t)
 496 {
 497         int status = 0;
 498
 499         status = orion_spi_setup_transfer(spi, t);
 500         if (status < 0)
 501                 return status;
 502
 503         if (t->len)
 504                 orion_spi_write_read(spi, t);
 505
 506         return status;
 507 }
 508
 509 static int orion_spi_setup(struct spi_device *spi)
 510 {
 511         if (gpio_is_valid(spi->cs_gpio)) {
 512                 gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
 513         }
 514         return orion_spi_setup_transfer(spi, NULL);
 515 }
 516
 517 static int orion_spi_reset(struct orion_spi *orion_spi)
 518 {
 519         /* Verify that the CS is deasserted */
 520         orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
 521
 522         /* Don't deassert CS between the direct mapped SPI transfers */
 523         writel(0, spi_reg(orion_spi, SPI_DIRECT_WRITE_CONFIG_REG));
 524
 525         return 0;
 526 }
 527
 528 static const struct orion_spi_dev orion_spi_dev_data = {
 529         .typ = ORION_SPI,
 530         .min_divisor = 4,
 531         .max_divisor = 30,
 532         .prescale_mask = ORION_SPI_CLK_PRESCALE_MASK,
 533 };
 534
 535 static const struct orion_spi_dev armada_370_spi_dev_data = {
 536         .typ = ARMADA_SPI,
 537         .min_divisor = 4,
 538         .max_divisor = 1920,
 539         .max_hz = 50000000,
 540         .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
 541 };
 542
 543 static const struct orion_spi_dev armada_xp_spi_dev_data = {
 544         .typ = ARMADA_SPI,
 545         .max_hz = 50000000,
 546         .max_divisor = 1920,
 547         .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
 548 };
 549
 550 static const struct orion_spi_dev armada_375_spi_dev_data = {
 551         .typ = ARMADA_SPI,
 552         .min_divisor = 15,
 553         .max_divisor = 1920,
 554         .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
 555 };
 556
 557 static const struct orion_spi_dev armada_380_spi_dev_data = {
 558         .typ = ARMADA_SPI,
 559         .max_hz = 50000000,
 560         .max_divisor = 1920,
 561         .prescale_mask = ARMADA_SPI_CLK_PRESCALE_MASK,
 562         .is_errata_50mhz_ac = true,
 563 };
 564
 565 static const struct of_device_id orion_spi_of_match_table[] = {
 566         {
 567                 .compatible = "marvell,orion-spi",
 568                 .data = &orion_spi_dev_data,
 569         },
 570         {
 571                 .compatible = "marvell,armada-370-spi",
 572                 .data = &armada_370_spi_dev_data,
 573         },
 574         {
 575                 .compatible = "marvell,armada-375-spi",
 576                 .data = &armada_375_spi_dev_data,
 577         },
 578         {
 579                 .compatible = "marvell,armada-380-spi",
 580                 .data = &armada_380_spi_dev_data,
 581         },
 582         {
 583                 .compatible = "marvell,armada-390-spi",
 584                 .data = &armada_xp_spi_dev_data,
 585         },
 586         {
 587                 .compatible = "marvell,armada-xp-spi",
 588                 .data = &armada_xp_spi_dev_data,
 589         },
 590
 591         {}
 592 };
 593 MODULE_DEVICE_TABLE(of, orion_spi_of_match_table);
 594
 595 static int orion_spi_probe(struct platform_device *pdev)
 596 {
 597         const struct of_device_id *of_id;
 598         const struct orion_spi_dev *devdata;
 599         struct spi_master *master;
 600         struct orion_spi *spi;
 601         struct resource *r;
 602         unsigned long tclk_hz;
 603         int status = 0;
 604         struct device_node *np;
 605
 606         master = spi_alloc_master(&pdev->dev, sizeof(*spi));
 607         if (master == NULL) {
 608                 dev_dbg(&pdev->dev, "master allocation failed\n");
 609                 return -ENOMEM;
 610         }
 611
 612         if (pdev->id != -1)
 613                 master->bus_num = pdev->id;
 614         if (pdev->dev.of_node) {
 615                 u32 cell_index;
 616
 617                 if (!of_property_read_u32(pdev->dev.of_node, "cell-index",
 618                                           &cell_index))
 619                         master->bus_num = cell_index;
 620         }
 621
 622         /* we support all 4 SPI modes and LSB first option */
 623         master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
 624         master->set_cs = orion_spi_set_cs;
 625         master->transfer_one = orion_spi_transfer_one;
 626         master->num_chipselect = ORION_NUM_CHIPSELECTS;
 627         master->setup = orion_spi_setup;
 628         master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16);
 629         master->auto_runtime_pm = true;
 630         master->flags = SPI_MASTER_GPIO_SS;
 631
 632         platform_set_drvdata(pdev, master);
 633
 634         spi = spi_master_get_devdata(master);
 635         spi->master = master;
 636         spi->unused_hw_gpio = -1;
 637
 638         of_id = of_match_device(orion_spi_of_match_table, &pdev->dev);
 639         devdata = (of_id) ? of_id->data : &orion_spi_dev_data;
 640         spi->devdata = devdata;
 641
 642         spi->clk = devm_clk_get(&pdev->dev, NULL);
 643         if (IS_ERR(spi->clk)) {
 644                 status = PTR_ERR(spi->clk);
 645                 goto out;
 646         }
 647
 648         status = clk_prepare_enable(spi->clk);
 649         if (status)
 650                 goto out;
 651
 652         /* The following clock is only used by some SoCs */
 653         spi->axi_clk = devm_clk_get(&pdev->dev, "axi");
 654         if (IS_ERR(spi->axi_clk) &&
 655             PTR_ERR(spi->axi_clk) == -EPROBE_DEFER) {
 656                 status = -EPROBE_DEFER;
 657                 goto out_rel_clk;
 658         }
 659         if (!IS_ERR(spi->axi_clk))
 660                 clk_prepare_enable(spi->axi_clk);
 661
 662         tclk_hz = clk_get_rate(spi->clk);
 663
 664         /*
 665          * With old device tree, armada-370-spi could be used with
 666          * Armada XP, however for this SoC the maximum frequency is
 667          * 50MHz instead of tclk/4. On Armada 370, tclk cannot be
 668          * higher than 200MHz. So, in order to be able to handle both
 669          * SoCs, we can take the minimum of 50MHz and tclk/4.
 670          */
 671         if (of_device_is_compatible(pdev->dev.of_node,
 672                                         "marvell,armada-370-spi"))
 673                 master->max_speed_hz = min(devdata->max_hz,
 674                                 DIV_ROUND_UP(tclk_hz, devdata->min_divisor));
 675         else if (devdata->min_divisor)
 676                 master->max_speed_hz =
 677                         DIV_ROUND_UP(tclk_hz, devdata->min_divisor);
 678         else
 679                 master->max_speed_hz = devdata->max_hz;
 680         master->min_speed_hz = DIV_ROUND_UP(tclk_hz, devdata->max_divisor);
 681
 682         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 683         spi->base = devm_ioremap_resource(&pdev->dev, r);
 684         if (IS_ERR(spi->base)) {
 685                 status = PTR_ERR(spi->base);
 686                 goto out_rel_axi_clk;
 687         }
 688
 689         for_each_available_child_of_node(pdev->dev.of_node, np) {
 690                 struct orion_direct_acc *dir_acc;
 691                 u32 cs;
 692                 int cs_gpio;
 693
 694                 /* Get chip-select number from the "reg" property */
 695                 status = of_property_read_u32(np, "reg", &cs);
 696                 if (status) {
 697                         dev_err(&pdev->dev,
 698                                 "%pOF has no valid 'reg' property (%d)\n",
 699                                 np, status);
 700                         continue;
 701                 }
 702
 703                 /*
 704                  * Initialize the CS GPIO:
 705                  * - properly request the actual GPIO signal
 706                  * - de-assert the logical signal so that all GPIO CS lines
 707                  *   are inactive when probing for slaves
 708                  * - find an unused physical CS which will be driven for any
 709                  *   slave which uses a CS GPIO
 710                  */
 711                 cs_gpio = of_get_named_gpio(pdev->dev.of_node, "cs-gpios", cs);
 712                 if (cs_gpio > 0) {
 713                         char *gpio_name;
 714                         int cs_flags;
 715
 716                         if (spi->unused_hw_gpio == -1) {
 717                                 dev_info(&pdev->dev,
 718                                         "Selected unused HW CS#%d for any GPIO CSes\n",
 719                                         cs);
 720                                 spi->unused_hw_gpio = cs;
 721                         }
 722
 723                         gpio_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
 724                                         "%s-CS%d", dev_name(&pdev->dev), cs);
 725                         if (!gpio_name) {
 726                                 status = -ENOMEM;
 727                                 goto out_rel_axi_clk;
 728                         }
 729
 730                         cs_flags = of_property_read_bool(np, "spi-cs-high") ?
 731                                 GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH;
 732                         status = devm_gpio_request_one(&pdev->dev, cs_gpio,
 733                                         cs_flags, gpio_name);
 734                         if (status) {
 735                                 dev_err(&pdev->dev,
 736                                         "Can't request GPIO for CS %d\n", cs);
 737                                 goto out_rel_axi_clk;
 738                         }
 739                 }
 740
 741                 /*
 742                  * Check if an address is configured for this SPI device. If
 743                  * not, the MBus mapping via the 'ranges' property in the 'soc'
 744                  * node is not configured and this device should not use the
 745                  * direct mode. In this case, just continue with the next
 746                  * device.
 747                  */
 748                 status = of_address_to_resource(pdev->dev.of_node, cs + 1, r);
 749                 if (status)
 750                         continue;
 751
 752                 /*
 753                  * Only map one page for direct access. This is enough for the
 754                  * simple TX transfer which only writes to the first word.
 755                  * This needs to get extended for the direct SPI-NOR / SPI-NAND
 756                  * support, once this gets implemented.
 757                  */
 758                 dir_acc = &spi->child[cs].direct_access;
 759                 dir_acc->vaddr = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
 760                 if (!dir_acc->vaddr) {
 761                         status = -ENOMEM;
 762                         goto out_rel_axi_clk;
 763                 }
 764                 dir_acc->size = PAGE_SIZE;
 765
 766                 dev_info(&pdev->dev, "CS%d configured for direct access\n", cs);
 767         }
 768
 769         pm_runtime_set_active(&pdev->dev);
 770         pm_runtime_use_autosuspend(&pdev->dev);
 771         pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
 772         pm_runtime_enable(&pdev->dev);
 773
 774         status = orion_spi_reset(spi);
 775         if (status < 0)
 776                 goto out_rel_pm;
 777
 778         pm_runtime_mark_last_busy(&pdev->dev);
 779         pm_runtime_put_autosuspend(&pdev->dev);
 780
 781         master->dev.of_node = pdev->dev.of_node;
 782         status = spi_register_master(master);
 783         if (status < 0)
 784                 goto out_rel_pm;
 785
 786         return status;
 787
 788 out_rel_pm:
 789         pm_runtime_disable(&pdev->dev);
 790 out_rel_axi_clk:
 791         clk_disable_unprepare(spi->axi_clk);
 792 out_rel_clk:
 793         clk_disable_unprepare(spi->clk);
 794 out:
 795         spi_master_put(master);
 796         return status;
 797 }
 798
 799
 800 static int orion_spi_remove(struct platform_device *pdev)
 801 {
 802         struct spi_master *master = platform_get_drvdata(pdev);
 803         struct orion_spi *spi = spi_master_get_devdata(master);
 804
 805         pm_runtime_get_sync(&pdev->dev);
 806         clk_disable_unprepare(spi->axi_clk);
 807         clk_disable_unprepare(spi->clk);
 808
 809         spi_unregister_master(master);
 810         pm_runtime_disable(&pdev->dev);
 811
 812         return 0;
 813 }
 814
 815 MODULE_ALIAS("platform:" DRIVER_NAME);
 816
 817 #ifdef CONFIG_PM
 818 static int orion_spi_runtime_suspend(struct device *dev)
 819 {
 820         struct spi_master *master = dev_get_drvdata(dev);
 821         struct orion_spi *spi = spi_master_get_devdata(master);
 822
 823         clk_disable_unprepare(spi->axi_clk);
 824         clk_disable_unprepare(spi->clk);
 825         return 0;
 826 }
 827
 828 static int orion_spi_runtime_resume(struct device *dev)
 829 {
 830         struct spi_master *master = dev_get_drvdata(dev);
 831         struct orion_spi *spi = spi_master_get_devdata(master);
 832
 833         if (!IS_ERR(spi->axi_clk))
 834                 clk_prepare_enable(spi->axi_clk);
 835         return clk_prepare_enable(spi->clk);
 836 }
 837 #endif
 838
 839 static const struct dev_pm_ops orion_spi_pm_ops = {
 840         SET_RUNTIME_PM_OPS(orion_spi_runtime_suspend,
 841                            orion_spi_runtime_resume,
 842                            NULL)
 843 };
 844
 845 static struct platform_driver orion_spi_driver = {
 846         .driver = {
 847                 .name   = DRIVER_NAME,
 848                 .pm     = &orion_spi_pm_ops,
 849                 .of_match_table = of_match_ptr(orion_spi_of_match_table),
 850         },
 851         .probe          = orion_spi_probe,
 852         .remove         = orion_spi_remove,
 853 };
 854
 855 module_platform_driver(orion_spi_driver);
 856
 857 MODULE_DESCRIPTION("Orion SPI driver");
 858 MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>");
 859 MODULE_LICENSE("GPL");