target/linux/bcm53xx/patches-3.14/180-spi-bcm53xx-driver-for-SPI-controller-on-Broadcom-bc.patch

   1 From a59f3fa1dd4cb284171a53cb7a614ad947c544f6 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
   3 Date: Wed, 13 Aug 2014 14:11:39 +0200
   4 Subject: [PATCH V2] spi: bcm53xx: driver for SPI controller on Broadcom bcma
   5  SoC
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 Broadcom 53xx ARM SoCs use bcma bus that contains various cores (AKA
  11 devices). If board has a serial flash, it's connected over SPI and the
  12 bcma bus includes a SPI controller. Example log from such a board:
  13 bus0: Found chip with id 53010, rev 0x00 and package 0x02
  14 (...)
  15 bus0: Core 18 found: SPI flash controller (manuf 0x4BF, id 0x50A, rev 0x01, class 0x0)
  16
  17 This patch adds a bcma driver for SPI core, it registers SPI master
  18 controller and "bcm53xxspiflash" SPI device.
  19
  20 Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
  21 ---
  22 Since RFC: Add Signed-off-by
  23            Update to compile on top of for-next
  24 V2: Use wait timeout
  25     Describe bcm53xxspi_calc_timeout a bit
  26     Use devm_spi_register_master
  27
  28 Thanks Mark for your comments!
  29 ---
  30  drivers/spi/Kconfig       |   6 +
  31  drivers/spi/Makefile      |   1 +
  32  drivers/spi/spi-bcm53xx.c | 295 ++++++++++++++++++++++++++++++++++++++++++++++
  33  drivers/spi/spi-bcm53xx.h |  72 +++++++++++
  34  4 files changed, 374 insertions(+)
  35  create mode 100644 drivers/spi/spi-bcm53xx.c
  36  create mode 100644 drivers/spi/spi-bcm53xx.h
  37
  38 --- a/drivers/spi/Kconfig
  39 +++ b/drivers/spi/Kconfig
  40 @@ -112,6 +112,12 @@ config SPI_AU1550
  41           If you say yes to this option, support will be included for the
  42           PSC SPI controller found on Au1550, Au1200 and Au1300 series.
  43
  44 +config SPI_BCM53XX
  45 +       tristate "Broadcom BCM53xx SPI controller"
  46 +       depends on ARCH_BCM_5301X
  47 +       help
  48 +          Enable support for the SPI controller on Broadcom BCM53xx ARM SoCs.
  49 +
  50  config SPI_BCM63XX
  51         tristate "Broadcom BCM63xx SPI controller"
  52         depends on BCM63XX
  53 --- a/drivers/spi/Makefile
  54 +++ b/drivers/spi/Makefile
  55 @@ -15,6 +15,7 @@ obj-$(CONFIG_SPI_ATMEL)                       += spi-atmel.o
  56  obj-$(CONFIG_SPI_ATH79)                        += spi-ath79.o
  57  obj-$(CONFIG_SPI_AU1550)               += spi-au1550.o
  58  obj-$(CONFIG_SPI_BCM2835)              += spi-bcm2835.o
  59 +obj-$(CONFIG_SPI_BCM53XX)              += spi-bcm53xx.o
  60  obj-$(CONFIG_SPI_BCM63XX)              += spi-bcm63xx.o
  61  obj-$(CONFIG_SPI_BCM63XX_HSSPI)                += spi-bcm63xx-hsspi.o
  62  obj-$(CONFIG_SPI_BFIN5XX)              += spi-bfin5xx.o
  63 --- /dev/null
  64 +++ b/drivers/spi/spi-bcm53xx.c
  65 @@ -0,0 +1,295 @@
  66 +#define pr_fmt(fmt)            KBUILD_MODNAME ": " fmt
  67 +
  68 +#include <linux/kernel.h>
  69 +#include <linux/module.h>
  70 +#include <linux/slab.h>
  71 +#include <linux/delay.h>
  72 +#include <linux/bcma/bcma.h>
  73 +#include <linux/spi/spi.h>
  74 +
  75 +#include "spi-bcm53xx.h"
  76 +
  77 +#define BCM53XXSPI_MAX_SPI_BAUD        13500000        /* 216 MHz? */
  78 +
  79 +/* The longest observed required wait was 19 ms */
  80 +#define BCM53XXSPI_SPE_TIMEOUT_MS      80
  81 +
  82 +struct bcm53xxspi {
  83 +       struct bcma_device *core;
  84 +       struct spi_master *master;
  85 +
  86 +       size_t read_offset;
  87 +};
  88 +
  89 +static inline u32 bcm53xxspi_read(struct bcm53xxspi *b53spi, u16 offset)
  90 +{
  91 +       return bcma_read32(b53spi->core, offset);
  92 +}
  93 +
  94 +static inline void bcm53xxspi_write(struct bcm53xxspi *b53spi, u16 offset,
  95 +                                   u32 value)
  96 +{
  97 +       bcma_write32(b53spi->core, offset, value);
  98 +}
  99 +
 100 +static inline unsigned int bcm53xxspi_calc_timeout(size_t len)
 101 +{
 102 +       /* Do some magic calculation based on length and buad. Add 10% and 1. */
 103 +       return (len * 9000 / BCM53XXSPI_MAX_SPI_BAUD * 110 / 100) + 1;
 104 +}
 105 +
 106 +static int bcm53xxspi_wait(struct bcm53xxspi *b53spi, unsigned int timeout_ms)
 107 +{
 108 +       unsigned long deadline;
 109 +       u32 tmp;
 110 +
 111 +       /* SPE bit has to be 0 before we read MSPI STATUS */
 112 +       deadline = jiffies + BCM53XXSPI_SPE_TIMEOUT_MS * HZ / 1000;
 113 +       do {
 114 +               tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
 115 +               if (!(tmp & B53SPI_MSPI_SPCR2_SPE))
 116 +                       break;
 117 +               udelay(5);
 118 +       } while (!time_after_eq(jiffies, deadline));
 119 +
 120 +       if (tmp & B53SPI_MSPI_SPCR2_SPE)
 121 +               goto spi_timeout;
 122 +
 123 +       /* Check status */
 124 +       deadline = jiffies + timeout_ms * HZ / 1000;
 125 +       do {
 126 +               tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_MSPI_STATUS);
 127 +               if (tmp & B53SPI_MSPI_MSPI_STATUS_SPIF) {
 128 +                       bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0);
 129 +                       return 0;
 130 +               }
 131 +
 132 +               cpu_relax();
 133 +               udelay(100);
 134 +       } while (!time_after_eq(jiffies, deadline));
 135 +
 136 +spi_timeout:
 137 +       bcm53xxspi_write(b53spi, B53SPI_MSPI_MSPI_STATUS, 0);
 138 +
 139 +       pr_err("Timeout waiting for SPI to be ready!\n");
 140 +
 141 +       return -EBUSY;
 142 +}
 143 +
 144 +static void bcm53xxspi_buf_write(struct bcm53xxspi *b53spi, u8 *w_buf,
 145 +                                size_t len, bool cont)
 146 +{
 147 +       u32 tmp;
 148 +       int i;
 149 +
 150 +       for (i = 0; i < len; i++) {
 151 +               /* Transmit Register File MSB */
 152 +               bcm53xxspi_write(b53spi, B53SPI_MSPI_TXRAM + 4 * (i * 2),
 153 +                                (unsigned int)w_buf[i]);
 154 +       }
 155 +
 156 +       for (i = 0; i < len; i++) {
 157 +               tmp = B53SPI_CDRAM_CONT | B53SPI_CDRAM_PCS_DISABLE_ALL |
 158 +                     B53SPI_CDRAM_PCS_DSCK;
 159 +               if (!cont && i == len - 1)
 160 +                       tmp &= ~B53SPI_CDRAM_CONT;
 161 +               tmp &= ~0x1;
 162 +               /* Command Register File */
 163 +               bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp);
 164 +       }
 165 +
 166 +       /* Set queue pointers */
 167 +       bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0);
 168 +       bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP, len - 1);
 169 +
 170 +       if (cont)
 171 +               bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1);
 172 +
 173 +       /* Start SPI transfer */
 174 +       tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
 175 +       tmp |= B53SPI_MSPI_SPCR2_SPE;
 176 +       if (cont)
 177 +               tmp |= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD;
 178 +       bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp);
 179 +
 180 +       /* Wait for SPI to finish */
 181 +       bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len));
 182 +
 183 +       if (!cont)
 184 +               bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);
 185 +
 186 +       b53spi->read_offset = len;
 187 +}
 188 +
 189 +static void bcm53xxspi_buf_read(struct bcm53xxspi *b53spi, u8 *r_buf,
 190 +                               size_t len, bool cont)
 191 +{
 192 +       u32 tmp;
 193 +       int i;
 194 +
 195 +       for (i = 0; i < b53spi->read_offset + len; i++) {
 196 +               tmp = B53SPI_CDRAM_CONT | B53SPI_CDRAM_PCS_DISABLE_ALL |
 197 +                     B53SPI_CDRAM_PCS_DSCK;
 198 +               if (!cont && i == b53spi->read_offset + len - 1)
 199 +                       tmp &= ~B53SPI_CDRAM_CONT;
 200 +               tmp &= ~0x1;
 201 +               /* Command Register File */
 202 +               bcm53xxspi_write(b53spi, B53SPI_MSPI_CDRAM + 4 * i, tmp);
 203 +       }
 204 +
 205 +       /* Set queue pointers */
 206 +       bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0);
 207 +       bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP,
 208 +                        b53spi->read_offset + len - 1);
 209 +
 210 +       if (cont)
 211 +               bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1);
 212 +
 213 +       /* Start SPI transfer */
 214 +       tmp = bcm53xxspi_read(b53spi, B53SPI_MSPI_SPCR2);
 215 +       tmp |= B53SPI_MSPI_SPCR2_SPE;
 216 +       if (cont)
 217 +               tmp |= B53SPI_MSPI_SPCR2_CONT_AFTER_CMD;
 218 +       bcm53xxspi_write(b53spi, B53SPI_MSPI_SPCR2, tmp);
 219 +
 220 +       /* Wait for SPI to finish */
 221 +       bcm53xxspi_wait(b53spi, bcm53xxspi_calc_timeout(len));
 222 +
 223 +       if (!cont)
 224 +               bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);
 225 +
 226 +       for (i = 0; i < len; ++i) {
 227 +               int offset = b53spi->read_offset + i;
 228 +
 229 +               /* Data stored in the transmit register file LSB */
 230 +               r_buf[i] = (u8)bcm53xxspi_read(b53spi, B53SPI_MSPI_RXRAM + 4 * (1 + offset * 2));
 231 +       }
 232 +
 233 +       b53spi->read_offset = 0;
 234 +}
 235 +
 236 +static int bcm53xxspi_transfer_one(struct spi_master *master,
 237 +                                  struct spi_device *spi,
 238 +                                  struct spi_transfer *t)
 239 +{
 240 +       struct bcm53xxspi *b53spi = spi_master_get_devdata(master);
 241 +       u8 *buf;
 242 +       size_t left;
 243 +
 244 +       if (t->tx_buf) {
 245 +               buf = (u8 *)t->tx_buf;
 246 +               left = t->len;
 247 +               while (left) {
 248 +                       size_t to_write = min_t(size_t, 16, left);
 249 +                       bool cont = left - to_write > 0;
 250 +
 251 +                       bcm53xxspi_buf_write(b53spi, buf, to_write, cont);
 252 +                       left -= to_write;
 253 +                       buf += to_write;
 254 +               }
 255 +       }
 256 +
 257 +       if (t->rx_buf) {
 258 +               buf = (u8 *)t->rx_buf;
 259 +               left = t->len;
 260 +               while (left) {
 261 +                       size_t to_read = min_t(size_t, 16 - b53spi->read_offset,
 262 +                                              left);
 263 +                       bool cont = left - to_read > 0;
 264 +
 265 +                       bcm53xxspi_buf_read(b53spi, buf, to_read, cont);
 266 +                       left -= to_read;
 267 +                       buf += to_read;
 268 +               }
 269 +       }
 270 +
 271 +       return 0;
 272 +}
 273 +
 274 +/**************************************************
 275 + * BCMA
 276 + **************************************************/
 277 +
 278 +struct spi_board_info bcm53xx_info = {
 279 +       .modalias       = "bcm53xxspiflash",
 280 +};
 281 +
 282 +static const struct bcma_device_id bcm53xxspi_bcma_tbl[] = {
 283 +       BCMA_CORE(BCMA_MANUF_BCM, BCMA_CORE_NS_QSPI, BCMA_ANY_REV, BCMA_ANY_CLASS),
 284 +       BCMA_CORETABLE_END
 285 +};
 286 +MODULE_DEVICE_TABLE(bcma, bcm53xxspi_bcma_tbl);
 287 +
 288 +static int bcm53xxspi_bcma_probe(struct bcma_device *core)
 289 +{
 290 +       struct bcm53xxspi *b53spi;
 291 +       struct spi_master *master;
 292 +       int err;
 293 +
 294 +       if (core->bus->drv_cc.core->id.rev != 42) {
 295 +               pr_err("SPI on SoC with unsupported ChipCommon rev\n");
 296 +               return -ENOTSUPP;
 297 +       }
 298 +
 299 +       master = spi_alloc_master(&core->dev, sizeof(*b53spi));
 300 +       if (!master)
 301 +               return -ENOMEM;
 302 +
 303 +       b53spi = spi_master_get_devdata(master);
 304 +       b53spi->master = master;
 305 +       b53spi->core = core;
 306 +
 307 +       master->transfer_one = bcm53xxspi_transfer_one;
 308 +
 309 +       bcma_set_drvdata(core, b53spi);
 310 +
 311 +       err = devm_spi_register_master(&core->dev, master);
 312 +       if (err) {
 313 +               spi_master_put(master);
 314 +               bcma_set_drvdata(core, NULL);
 315 +               goto out;
 316 +       }
 317 +
 318 +       /* Broadcom SoCs (at least with the CC rev 42) use SPI for flash only */
 319 +       spi_new_device(master, &bcm53xx_info);
 320 +
 321 +out:
 322 +       return err;
 323 +}
 324 +
 325 +static void bcm53xxspi_bcma_remove(struct bcma_device *core)
 326 +{
 327 +       struct bcm53xxspi *b53spi = bcma_get_drvdata(core);
 328 +
 329 +       spi_unregister_master(b53spi->master);
 330 +}
 331 +
 332 +static struct bcma_driver bcm53xxspi_bcma_driver = {
 333 +       .name           = KBUILD_MODNAME,
 334 +       .id_table       = bcm53xxspi_bcma_tbl,
 335 +       .probe          = bcm53xxspi_bcma_probe,
 336 +       .remove         = bcm53xxspi_bcma_remove,
 337 +};
 338 +
 339 +/**************************************************
 340 + * Init & exit
 341 + **************************************************/
 342 +
 343 +static int __init bcm53xxspi_module_init(void)
 344 +{
 345 +       int err = 0;
 346 +
 347 +       err = bcma_driver_register(&bcm53xxspi_bcma_driver);
 348 +       if (err)
 349 +               pr_err("Failed to register bcma driver: %d\n", err);
 350 +
 351 +       return err;
 352 +}
 353 +
 354 +static void __exit bcm53xxspi_module_exit(void)
 355 +{
 356 +       bcma_driver_unregister(&bcm53xxspi_bcma_driver);
 357 +}
 358 +
 359 +module_init(bcm53xxspi_module_init);
 360 +module_exit(bcm53xxspi_module_exit);
 361 --- /dev/null
 362 +++ b/drivers/spi/spi-bcm53xx.h
 363 @@ -0,0 +1,72 @@
 364 +#ifndef SPI_BCM53XX_H
 365 +#define SPI_BCM53XX_H
 366 +
 367 +#define B53SPI_BSPI_REVISION_ID                        0x000
 368 +#define B53SPI_BSPI_SCRATCH                    0x004
 369 +#define B53SPI_BSPI_MAST_N_BOOT_CTRL           0x008
 370 +#define B53SPI_BSPI_BUSY_STATUS                        0x00c
 371 +#define B53SPI_BSPI_INTR_STATUS                        0x010
 372 +#define B53SPI_BSPI_B0_STATUS                  0x014
 373 +#define B53SPI_BSPI_B0_CTRL                    0x018
 374 +#define B53SPI_BSPI_B1_STATUS                  0x01c
 375 +#define B53SPI_BSPI_B1_CTRL                    0x020
 376 +#define B53SPI_BSPI_STRAP_OVERRIDE_CTRL                0x024
 377 +#define B53SPI_BSPI_FLEX_MODE_ENABLE           0x028
 378 +#define B53SPI_BSPI_BITS_PER_CYCLE             0x02c
 379 +#define B53SPI_BSPI_BITS_PER_PHASE             0x030
 380 +#define B53SPI_BSPI_CMD_AND_MODE_BYTE          0x034
 381 +#define B53SPI_BSPI_BSPI_FLASH_UPPER_ADDR_BYTE 0x038
 382 +#define B53SPI_BSPI_BSPI_XOR_VALUE             0x03c
 383 +#define B53SPI_BSPI_BSPI_XOR_ENABLE            0x040
 384 +#define B53SPI_BSPI_BSPI_PIO_MODE_ENABLE       0x044
 385 +#define B53SPI_BSPI_BSPI_PIO_IODIR             0x048
 386 +#define B53SPI_BSPI_BSPI_PIO_DATA              0x04c
 387 +
 388 +/* RAF */
 389 +#define B53SPI_RAF_START_ADDR                  0x100
 390 +#define B53SPI_RAF_NUM_WORDS                   0x104
 391 +#define B53SPI_RAF_CTRL                                0x108
 392 +#define B53SPI_RAF_FULLNESS                    0x10c
 393 +#define B53SPI_RAF_WATERMARK                   0x110
 394 +#define B53SPI_RAF_STATUS                      0x114
 395 +#define B53SPI_RAF_READ_DATA                   0x118
 396 +#define B53SPI_RAF_WORD_CNT                    0x11c
 397 +#define B53SPI_RAF_CURR_ADDR                   0x120
 398 +
 399 +/* MSPI */
 400 +#define B53SPI_MSPI_SPCR0_LSB                  0x200
 401 +#define B53SPI_MSPI_SPCR0_MSB                  0x204
 402 +#define B53SPI_MSPI_SPCR1_LSB                  0x208
 403 +#define B53SPI_MSPI_SPCR1_MSB                  0x20c
 404 +#define B53SPI_MSPI_NEWQP                      0x210
 405 +#define B53SPI_MSPI_ENDQP                      0x214
 406 +#define B53SPI_MSPI_SPCR2                      0x218
 407 +#define  B53SPI_MSPI_SPCR2_SPE                 0x00000040
 408 +#define  B53SPI_MSPI_SPCR2_CONT_AFTER_CMD      0x00000080
 409 +#define B53SPI_MSPI_MSPI_STATUS                        0x220
 410 +#define  B53SPI_MSPI_MSPI_STATUS_SPIF          0x00000001
 411 +#define B53SPI_MSPI_CPTQP                      0x224
 412 +#define B53SPI_MSPI_TXRAM                      0x240 /* 32 registers, up to 0x2b8 */
 413 +#define B53SPI_MSPI_RXRAM                      0x2c0 /* 32 registers, up to 0x33c */
 414 +#define B53SPI_MSPI_CDRAM                      0x340 /* 16 registers, up to 0x37c */
 415 +#define  B53SPI_CDRAM_PCS_PCS0                 0x00000001
 416 +#define  B53SPI_CDRAM_PCS_PCS1                 0x00000002
 417 +#define  B53SPI_CDRAM_PCS_PCS2                 0x00000004
 418 +#define  B53SPI_CDRAM_PCS_PCS3                 0x00000008
 419 +#define  B53SPI_CDRAM_PCS_DISABLE_ALL          0x0000000f
 420 +#define  B53SPI_CDRAM_PCS_DSCK                 0x00000010
 421 +#define  B53SPI_CDRAM_BITSE                    0x00000040
 422 +#define  B53SPI_CDRAM_CONT                     0x00000080
 423 +#define B53SPI_MSPI_WRITE_LOCK                 0x380
 424 +#define B53SPI_MSPI_DISABLE_FLUSH_GEN          0x384
 425 +
 426 +/* Interrupt */
 427 +#define B53SPI_INTR_RAF_LR_FULLNESS_REACHED    0x3a0
 428 +#define B53SPI_INTR_RAF_LR_TRUNCATED           0x3a4
 429 +#define B53SPI_INTR_RAF_LR_IMPATIENT           0x3a8
 430 +#define B53SPI_INTR_RAF_LR_SESSION_DONE                0x3ac
 431 +#define B53SPI_INTR_RAF_LR_OVERREAD            0x3b0
 432 +#define B53SPI_INTR_MSPI_DONE                  0x3b4
 433 +#define B53SPI_INTR_MSPI_HALT_SET_TRANSACTION_DONE     0x3b8
 434 +
 435 +#endif /* SPI_BCM53XX_H */