target/linux/ramips/patches-4.14/0043-spi-add-mt7621-support.patch

   1 From 87a5fcd57c577cd94b5b080deb98885077c13a42 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 27 Jul 2014 09:49:07 +0100
   4 Subject: [PATCH 43/53] spi: add mt7621 support
   5
   6 Signed-off-by: John Crispin <blogic@openwrt.org>
   7 ---
   8  drivers/spi/Kconfig      |    6 +
   9  drivers/spi/Makefile     |    1 +
  10  drivers/spi/spi-mt7621.c |  480 ++++++++++++++++++++++++++++++++++++++++++++++
  11  3 files changed, 487 insertions(+)
  12  create mode 100644 drivers/spi/spi-mt7621.c
  13
  14 --- a/drivers/spi/Kconfig
  15 +++ b/drivers/spi/Kconfig
  16 @@ -569,6 +569,12 @@ config SPI_RT2880
  17         help
  18           This selects a driver for the Ralink RT288x/RT305x SPI Controller.
  19
  20 +config SPI_MT7621
  21 +       tristate "MediaTek MT7621 SPI Controller"
  22 +       depends on RALINK
  23 +       help
  24 +         This selects a driver for the MediaTek MT7621 SPI Controller.
  25 +
  26  config SPI_S3C24XX
  27         tristate "Samsung S3C24XX series SPI"
  28         depends on ARCH_S3C24XX
  29 --- a/drivers/spi/Makefile
  30 +++ b/drivers/spi/Makefile
  31 @@ -60,6 +60,7 @@ obj-$(CONFIG_SPI_MPC512x_PSC)         += spi-mp
  32  obj-$(CONFIG_SPI_MPC52xx_PSC)          += spi-mpc52xx-psc.o
  33  obj-$(CONFIG_SPI_MPC52xx)              += spi-mpc52xx.o
  34  obj-$(CONFIG_SPI_MT65XX)                += spi-mt65xx.o
  35 +obj-$(CONFIG_SPI_MT7621)               += spi-mt7621.o
  36  obj-$(CONFIG_SPI_MXS)                  += spi-mxs.o
  37  obj-$(CONFIG_SPI_NUC900)               += spi-nuc900.o
  38  obj-$(CONFIG_SPI_OC_TINY)              += spi-oc-tiny.o
  39 --- /dev/null
  40 +++ b/drivers/spi/spi-mt7621.c
  41 @@ -0,0 +1,488 @@
  42 +/*
  43 + * spi-mt7621.c -- MediaTek MT7621 SPI controller driver
  44 + *
  45 + * Copyright (C) 2011 Sergiy <piratfm@gmail.com>
  46 + * Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
  47 + * Copyright (C) 2014-2015 Felix Fietkau <nbd@nbd.name>
  48 + *
  49 + * Some parts are based on spi-orion.c:
  50 + *   Author: Shadi Ammouri <shadi@marvell.com>
  51 + *   Copyright (C) 2007-2008 Marvell Ltd.
  52 + *
  53 + * This program is free software; you can redistribute it and/or modify
  54 + * it under the terms of the GNU General Public License version 2 as
  55 + * published by the Free Software Foundation.
  56 + */
  57 +
  58 +#include <linux/init.h>
  59 +#include <linux/module.h>
  60 +#include <linux/clk.h>
  61 +#include <linux/err.h>
  62 +#include <linux/delay.h>
  63 +#include <linux/io.h>
  64 +#include <linux/reset.h>
  65 +#include <linux/spi/spi.h>
  66 +#include <linux/of_device.h>
  67 +#include <linux/platform_device.h>
  68 +#include <linux/swab.h>
  69 +
  70 +#include <ralink_regs.h>
  71 +
  72 +#define SPI_BPW_MASK(bits) BIT((bits) - 1)
  73 +
  74 +#define DRIVER_NAME                    "spi-mt7621"
  75 +/* in usec */
  76 +#define RALINK_SPI_WAIT_MAX_LOOP       2000
  77 +
  78 +/* SPISTAT register bit field */
  79 +#define SPISTAT_BUSY                   BIT(0)
  80 +
  81 +#define MT7621_SPI_TRANS       0x00
  82 +#define SPITRANS_BUSY          BIT(16)
  83 +
  84 +#define MT7621_SPI_OPCODE      0x04
  85 +#define MT7621_SPI_DATA0       0x08
  86 +#define MT7621_SPI_DATA4       0x18
  87 +#define SPI_CTL_TX_RX_CNT_MASK 0xff
  88 +#define SPI_CTL_START          BIT(8)
  89 +
  90 +#define MT7621_SPI_POLAR       0x38
  91 +#define MT7621_SPI_MASTER      0x28
  92 +#define MT7621_SPI_MOREBUF     0x2c
  93 +#define MT7621_SPI_SPACE       0x3c
  94 +
  95 +#define MT7621_CPHA            BIT(5)
  96 +#define MT7621_CPOL            BIT(4)
  97 +#define MT7621_LSB_FIRST       BIT(3)
  98 +
  99 +#define RT2880_SPI_MODE_BITS   (SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH)
 100 +
 101 +struct mt7621_spi;
 102 +
 103 +struct mt7621_spi {
 104 +       struct spi_master       *master;
 105 +       void __iomem            *base;
 106 +       unsigned int            sys_freq;
 107 +       unsigned int            speed;
 108 +       struct clk              *clk;
 109 +
 110 +       struct mt7621_spi_ops   *ops;
 111 +};
 112 +
 113 +static inline struct mt7621_spi *spidev_to_mt7621_spi(struct spi_device *spi)
 114 +{
 115 +       return spi_master_get_devdata(spi->master);
 116 +}
 117 +
 118 +static inline u32 mt7621_spi_read(struct mt7621_spi *rs, u32 reg)
 119 +{
 120 +       return ioread32(rs->base + reg);
 121 +}
 122 +
 123 +static inline void mt7621_spi_write(struct mt7621_spi *rs, u32 reg, u32 val)
 124 +{
 125 +       iowrite32(val, rs->base + reg);
 126 +}
 127 +
 128 +static void mt7621_spi_reset(struct mt7621_spi *rs, int duplex)
 129 +{
 130 +       u32 master = mt7621_spi_read(rs, MT7621_SPI_MASTER);
 131 +
 132 +       master |= 7 << 29;
 133 +       master |= 1 << 2;
 134 +       if (duplex)
 135 +               master |= 1 << 10;
 136 +       else
 137 +               master &= ~(1 << 10);
 138 +
 139 +       mt7621_spi_write(rs, MT7621_SPI_MASTER, master);
 140 +}
 141 +
 142 +static void mt7621_spi_set_cs(struct spi_device *spi, int enable)
 143 +{
 144 +       struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
 145 +       int cs = spi->chip_select;
 146 +       u32 polar = 0;
 147 +
 148 +        mt7621_spi_reset(rs, cs);
 149 +       if (enable)
 150 +               polar = BIT(cs);
 151 +       mt7621_spi_write(rs, MT7621_SPI_POLAR, polar);
 152 +}
 153 +
 154 +static int mt7621_spi_prepare(struct spi_device *spi, unsigned int speed)
 155 +{
 156 +       struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
 157 +       u32 rate;
 158 +       u32 reg;
 159 +
 160 +       dev_dbg(&spi->dev, "speed:%u\n", speed);
 161 +
 162 +       rate = DIV_ROUND_UP(rs->sys_freq, speed);
 163 +       dev_dbg(&spi->dev, "rate-1:%u\n", rate);
 164 +
 165 +       if (rate > 4097)
 166 +               return -EINVAL;
 167 +
 168 +       if (rate < 2)
 169 +               rate = 2;
 170 +
 171 +       reg = mt7621_spi_read(rs, MT7621_SPI_MASTER);
 172 +       reg &= ~(0xfff << 16);
 173 +       reg |= (rate - 2) << 16;
 174 +       rs->speed = speed;
 175 +
 176 +       reg &= ~MT7621_LSB_FIRST;
 177 +       if (spi->mode & SPI_LSB_FIRST)
 178 +               reg |= MT7621_LSB_FIRST;
 179 +
 180 +       reg &= ~(MT7621_CPHA | MT7621_CPOL);
 181 +       switch(spi->mode & (SPI_CPOL | SPI_CPHA)) {
 182 +               case SPI_MODE_0:
 183 +                       break;
 184 +               case SPI_MODE_1:
 185 +                       reg |= MT7621_CPHA;
 186 +                       break;
 187 +               case SPI_MODE_2:
 188 +                       reg |= MT7621_CPOL;
 189 +                       break;
 190 +               case SPI_MODE_3:
 191 +                       reg |= MT7621_CPOL | MT7621_CPHA;
 192 +                       break;
 193 +       }
 194 +       mt7621_spi_write(rs, MT7621_SPI_MASTER, reg);
 195 +
 196 +       return 0;
 197 +}
 198 +
 199 +static inline int mt7621_spi_wait_till_ready(struct spi_device *spi)
 200 +{
 201 +       struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
 202 +       int i;
 203 +
 204 +       for (i = 0; i < RALINK_SPI_WAIT_MAX_LOOP; i++) {
 205 +               u32 status;
 206 +
 207 +               status = mt7621_spi_read(rs, MT7621_SPI_TRANS);
 208 +               if ((status & SPITRANS_BUSY) == 0) {
 209 +                       return 0;
 210 +               }
 211 +               cpu_relax();
 212 +               udelay(1);
 213 +       }
 214 +
 215 +       return -ETIMEDOUT;
 216 +}
 217 +
 218 +static int mt7621_spi_transfer_half_duplex(struct spi_master *master,
 219 +                                          struct spi_message *m)
 220 +{
 221 +       struct mt7621_spi *rs = spi_master_get_devdata(master);
 222 +       struct spi_device *spi = m->spi;
 223 +       unsigned int speed = spi->max_speed_hz;
 224 +       struct spi_transfer *t = NULL;
 225 +       int status = 0;
 226 +       int i, len = 0;
 227 +       int rx_len = 0;
 228 +       u32 data[9] = { 0 };
 229 +       u32 val;
 230 +
 231 +       mt7621_spi_wait_till_ready(spi);
 232 +
 233 +       list_for_each_entry(t, &m->transfers, transfer_list) {
 234 +               const u8 *buf = t->tx_buf;
 235 +
 236 +               if (t->rx_buf)
 237 +                       rx_len += t->len;
 238 +
 239 +               if (!buf)
 240 +                       continue;
 241 +
 242 +               if (t->speed_hz < speed)
 243 +                       speed = t->speed_hz;
 244 +
 245 +               /*
 246 +                * m25p80 might attempt to write more data than we can handle.
 247 +                * truncate the message to what we can fit into the registers
 248 +                */
 249 +               if (len + t->len > 36)
 250 +                       t->len = 36 - len;
 251 +
 252 +               for (i = 0; i < t->len; i++, len++)
 253 +                       data[len / 4] |= buf[i] << (8 * (len & 3));
 254 +       }
 255 +
 256 +       if (WARN_ON(rx_len > 32)) {
 257 +               status = -EIO;
 258 +               goto msg_done;
 259 +       }
 260 +
 261 +       if (mt7621_spi_prepare(spi, speed)) {
 262 +               status = -EIO;
 263 +               goto msg_done;
 264 +       }
 265 +       data[0] = swab32(data[0]);
 266 +       if (len < 4)
 267 +               data[0] >>= (4 - len) * 8;
 268 +
 269 +       for (i = 0; i < len; i += 4)
 270 +               mt7621_spi_write(rs, MT7621_SPI_OPCODE + i, data[i / 4]);
 271 +
 272 +       val = (min_t(int, len, 4) * 8) << 24;
 273 +       if (len > 4)
 274 +               val |= (len - 4) * 8;
 275 +       val |= (rx_len * 8) << 12;
 276 +       mt7621_spi_write(rs, MT7621_SPI_MOREBUF, val);
 277 +
 278 +       mt7621_spi_set_cs(spi, 1);
 279 +
 280 +       val = mt7621_spi_read(rs, MT7621_SPI_TRANS);
 281 +       val |= SPI_CTL_START;
 282 +       mt7621_spi_write(rs, MT7621_SPI_TRANS, val);
 283 +
 284 +       mt7621_spi_wait_till_ready(spi);
 285 +
 286 +       mt7621_spi_set_cs(spi, 0);
 287 +
 288 +       for (i = 0; i < rx_len; i += 4)
 289 +               data[i / 4] = mt7621_spi_read(rs, MT7621_SPI_DATA0 + i);
 290 +
 291 +       m->actual_length = len + rx_len;
 292 +
 293 +       len = 0;
 294 +       list_for_each_entry(t, &m->transfers, transfer_list) {
 295 +               u8 *buf = t->rx_buf;
 296 +
 297 +               if (!buf)
 298 +                       continue;
 299 +
 300 +               for (i = 0; i < t->len; i++, len++)
 301 +                       buf[i] = data[len / 4] >> (8 * (len & 3));
 302 +       }
 303 +
 304 +msg_done:
 305 +       m->status = status;
 306 +       spi_finalize_current_message(master);
 307 +
 308 +       return 0;
 309 +}
 310 +
 311 +static int mt7621_spi_transfer_full_duplex(struct spi_master *master,
 312 +                                          struct spi_message *m)
 313 +{
 314 +       struct mt7621_spi *rs = spi_master_get_devdata(master);
 315 +       struct spi_device *spi = m->spi;
 316 +       unsigned int speed = spi->max_speed_hz;
 317 +       struct spi_transfer *t = NULL;
 318 +       int status = 0;
 319 +       int i, len = 0;
 320 +       int rx_len = 0;
 321 +       u32 data[9] = { 0 };
 322 +       u32 val = 0;
 323 +
 324 +       mt7621_spi_wait_till_ready(spi);
 325 +
 326 +       list_for_each_entry(t, &m->transfers, transfer_list) {
 327 +               const u8 *buf = t->tx_buf;
 328 +
 329 +               if (t->rx_buf)
 330 +                       rx_len += t->len;
 331 +
 332 +               if (!buf)
 333 +                       continue;
 334 +
 335 +               if (WARN_ON(len + t->len > 16)) {
 336 +                       status = -EIO;
 337 +                       goto msg_done;
 338 +               }
 339 +
 340 +               for (i = 0; i < t->len; i++, len++)
 341 +                       data[len / 4] |= buf[i] << (8 * (len & 3));
 342 +               if (speed > t->speed_hz)
 343 +                       speed = t->speed_hz;
 344 +       }
 345 +
 346 +       if (WARN_ON(rx_len > 16)) {
 347 +               status = -EIO;
 348 +               goto msg_done;
 349 +       }
 350 +
 351 +       if (mt7621_spi_prepare(spi, speed)) {
 352 +               status = -EIO;
 353 +               goto msg_done;
 354 +       }
 355 +
 356 +       for (i = 0; i < len; i += 4)
 357 +               mt7621_spi_write(rs, MT7621_SPI_DATA0 + i, data[i / 4]);
 358 +
 359 +       val |= len * 8;
 360 +       val |= (rx_len * 8) << 12;
 361 +       mt7621_spi_write(rs, MT7621_SPI_MOREBUF, val);
 362 +
 363 +       mt7621_spi_set_cs(spi, 1);
 364 +
 365 +       val = mt7621_spi_read(rs, MT7621_SPI_TRANS);
 366 +       val |= SPI_CTL_START;
 367 +       mt7621_spi_write(rs, MT7621_SPI_TRANS, val);
 368 +
 369 +       mt7621_spi_wait_till_ready(spi);
 370 +
 371 +       mt7621_spi_set_cs(spi, 0);
 372 +
 373 +       for (i = 0; i < rx_len; i += 4)
 374 +               data[i / 4] = mt7621_spi_read(rs, MT7621_SPI_DATA4 + i);
 375 +
 376 +       m->actual_length = rx_len;
 377 +
 378 +       len = 0;
 379 +       list_for_each_entry(t, &m->transfers, transfer_list) {
 380 +               u8 *buf = t->rx_buf;
 381 +
 382 +               if (!buf)
 383 +                       continue;
 384 +
 385 +               for (i = 0; i < t->len; i++, len++)
 386 +                       buf[i] = data[len / 4] >> (8 * (len & 3));
 387 +       }
 388 +
 389 +msg_done:
 390 +       m->status = status;
 391 +       spi_finalize_current_message(master);
 392 +
 393 +       return 0;
 394 +}
 395 +
 396 +static int mt7621_spi_transfer_one_message(struct spi_master *master,
 397 +                                          struct spi_message *m)
 398 +{
 399 +       struct spi_device *spi = m->spi;
 400 +       int cs = spi->chip_select;
 401 +
 402 +       if (cs)
 403 +               return mt7621_spi_transfer_full_duplex(master, m);
 404 +       return mt7621_spi_transfer_half_duplex(master, m);
 405 +}
 406 +
 407 +static int mt7621_spi_setup(struct spi_device *spi)
 408 +{
 409 +       struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
 410 +
 411 +       if ((spi->max_speed_hz == 0) ||
 412 +               (spi->max_speed_hz > (rs->sys_freq / 2)))
 413 +               spi->max_speed_hz = (rs->sys_freq / 2);
 414 +
 415 +       if (spi->max_speed_hz < (rs->sys_freq / 4097)) {
 416 +               dev_err(&spi->dev, "setup: requested speed is too low %d Hz\n",
 417 +                       spi->max_speed_hz);
 418 +               return -EINVAL;
 419 +       }
 420 +
 421 +       return 0;
 422 +}
 423 +
 424 +static const struct of_device_id mt7621_spi_match[] = {
 425 +       { .compatible = "ralink,mt7621-spi" },
 426 +       {},
 427 +};
 428 +MODULE_DEVICE_TABLE(of, mt7621_spi_match);
 429 +
 430 +static size_t mt7621_max_transfer_size(struct spi_device *spi)
 431 +{
 432 +       return 32;
 433 +}
 434 +
 435 +static int mt7621_spi_probe(struct platform_device *pdev)
 436 +{
 437 +       const struct of_device_id *match;
 438 +       struct spi_master *master;
 439 +       struct mt7621_spi *rs;
 440 +       void __iomem *base;
 441 +       struct resource *r;
 442 +       int status = 0;
 443 +       struct clk *clk;
 444 +       struct mt7621_spi_ops *ops;
 445 +
 446 +       match = of_match_device(mt7621_spi_match, &pdev->dev);
 447 +       if (!match)
 448 +               return -EINVAL;
 449 +       ops = (struct mt7621_spi_ops *)match->data;
 450 +
 451 +       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 452 +       base = devm_ioremap_resource(&pdev->dev, r);
 453 +       if (IS_ERR(base))
 454 +               return PTR_ERR(base);
 455 +
 456 +       clk = devm_clk_get(&pdev->dev, NULL);
 457 +       if (IS_ERR(clk)) {
 458 +               dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
 459 +                       status);
 460 +               return PTR_ERR(clk);
 461 +       }
 462 +
 463 +       status = clk_prepare_enable(clk);
 464 +       if (status)
 465 +               return status;
 466 +
 467 +       master = spi_alloc_master(&pdev->dev, sizeof(*rs));
 468 +       if (master == NULL) {
 469 +               dev_info(&pdev->dev, "master allocation failed\n");
 470 +               return -ENOMEM;
 471 +       }
 472 +
 473 +       master->mode_bits = RT2880_SPI_MODE_BITS;
 474 +
 475 +       master->setup = mt7621_spi_setup;
 476 +       master->transfer_one_message = mt7621_spi_transfer_one_message;
 477 +       master->bits_per_word_mask = SPI_BPW_MASK(8);
 478 +       master->dev.of_node = pdev->dev.of_node;
 479 +       master->num_chipselect = 2;
 480 +       master->max_transfer_size = mt7621_max_transfer_size;
 481 +
 482 +       dev_set_drvdata(&pdev->dev, master);
 483 +
 484 +       rs = spi_master_get_devdata(master);
 485 +       rs->base = base;
 486 +       rs->clk = clk;
 487 +       rs->master = master;
 488 +       rs->sys_freq = clk_get_rate(rs->clk);
 489 +       rs->ops = ops;
 490 +       dev_info(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
 491 +
 492 +       device_reset(&pdev->dev);
 493 +
 494 +       mt7621_spi_reset(rs, 0);
 495 +
 496 +       return spi_register_master(master);
 497 +}
 498 +
 499 +static int mt7621_spi_remove(struct platform_device *pdev)
 500 +{
 501 +       struct spi_master *master;
 502 +       struct mt7621_spi *rs;
 503 +
 504 +       master = dev_get_drvdata(&pdev->dev);
 505 +       rs = spi_master_get_devdata(master);
 506 +
 507 +       clk_disable(rs->clk);
 508 +       spi_unregister_master(master);
 509 +
 510 +       return 0;
 511 +}
 512 +
 513 +MODULE_ALIAS("platform:" DRIVER_NAME);
 514 +
 515 +static struct platform_driver mt7621_spi_driver = {
 516 +       .driver = {
 517 +               .name = DRIVER_NAME,
 518 +               .owner = THIS_MODULE,
 519 +               .of_match_table = mt7621_spi_match,
 520 +       },
 521 +       .probe = mt7621_spi_probe,
 522 +       .remove = mt7621_spi_remove,
 523 +};
 524 +
 525 +module_platform_driver(mt7621_spi_driver);
 526 +
 527 +MODULE_DESCRIPTION("MT7621 SPI driver");
 528 +MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
 529 +MODULE_LICENSE("GPL");