target/linux/ramips/patches-3.18/0061-SPI-ralink-add-mt7621-SoC-spi-driver.patch

   1 --- a/drivers/spi/Kconfig
   2 +++ b/drivers/spi/Kconfig
   3 @@ -439,6 +439,12 @@ config SPI_RT2880
   4         help
   5           This selects a driver for the Ralink RT288x/RT305x SPI Controller.
   6
   7 +config SPI_MT7621
   8 +       tristate "MediaTek MT7621 SPI Controller"
   9 +       depends on RALINK
  10 +       help
  11 +         This selects a driver for the MediaTek MT7621 SPI Controller.
  12 +
  13  config SPI_S3C24XX
  14         tristate "Samsung S3C24XX series SPI"
  15         depends on ARCH_S3C24XX
  16 --- a/drivers/spi/Makefile
  17 +++ b/drivers/spi/Makefile
  18 @@ -46,6 +46,7 @@ obj-$(CONFIG_SPI_LM70_LLP)            += spi-lm70l
  19  obj-$(CONFIG_SPI_MPC512x_PSC)          += spi-mpc512x-psc.o
  20  obj-$(CONFIG_SPI_MPC52xx_PSC)          += spi-mpc52xx-psc.o
  21  obj-$(CONFIG_SPI_MPC52xx)              += spi-mpc52xx.o
  22 +obj-$(CONFIG_SPI_MT7621)               += spi-mt7621.o
  23  obj-$(CONFIG_SPI_MXS)                  += spi-mxs.o
  24  obj-$(CONFIG_SPI_NUC900)               += spi-nuc900.o
  25  obj-$(CONFIG_SPI_OC_TINY)              += spi-oc-tiny.o
  26 --- /dev/null
  27 +++ b/drivers/spi/spi-mt7621.c
  28 @@ -0,0 +1,315 @@
  29 +/*
  30 + * spi-mt7621.c -- MediaTek MT7621 SPI controller driver
  31 + *
  32 + * Copyright (C) 2011 Sergiy <piratfm@gmail.com>
  33 + * Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
  34 + * Copyright (C) 2014-2015 Felix Fietkau <nbd@openwrt.org>
  35 + *
  36 + * Some parts are based on spi-orion.c:
  37 + *   Author: Shadi Ammouri <shadi@marvell.com>
  38 + *   Copyright (C) 2007-2008 Marvell Ltd.
  39 + *
  40 + * This program is free software; you can redistribute it and/or modify
  41 + * it under the terms of the GNU General Public License version 2 as
  42 + * published by the Free Software Foundation.
  43 + */
  44 +
  45 +#include <linux/init.h>
  46 +#include <linux/module.h>
  47 +#include <linux/clk.h>
  48 +#include <linux/err.h>
  49 +#include <linux/delay.h>
  50 +#include <linux/io.h>
  51 +#include <linux/reset.h>
  52 +#include <linux/spi/spi.h>
  53 +#include <linux/of_device.h>
  54 +#include <linux/platform_device.h>
  55 +#include <linux/swab.h>
  56 +
  57 +#include <ralink_regs.h>
  58 +
  59 +#define SPI_BPW_MASK(bits) BIT((bits) - 1)
  60 +
  61 +#define DRIVER_NAME                    "spi-mt7621"
  62 +/* in usec */
  63 +#define RALINK_SPI_WAIT_MAX_LOOP       2000
  64 +
  65 +/* SPISTAT register bit field */
  66 +#define SPISTAT_BUSY                   BIT(0)
  67 +
  68 +#define MT7621_SPI_TRANS       0x00
  69 +#define SPITRANS_BUSY          BIT(16)
  70 +
  71 +#define MT7621_SPI_OPCODE      0x04
  72 +#define MT7621_SPI_DATA0       0x08
  73 +#define SPI_CTL_TX_RX_CNT_MASK 0xff
  74 +#define SPI_CTL_START          BIT(8)
  75 +
  76 +#define MT7621_SPI_POLAR       0x38
  77 +#define MT7621_SPI_MASTER      0x28
  78 +#define MT7621_SPI_MOREBUF     0x2c
  79 +#define MT7621_SPI_SPACE       0x3c
  80 +
  81 +#define RT2880_SPI_MODE_BITS   (SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH)
  82 +
  83 +struct mt7621_spi;
  84 +
  85 +struct mt7621_spi {
  86 +       struct spi_master       *master;
  87 +       void __iomem            *base;
  88 +       unsigned int            sys_freq;
  89 +       unsigned int            speed;
  90 +       struct clk              *clk;
  91 +       spinlock_t              lock;
  92 +
  93 +       struct mt7621_spi_ops   *ops;
  94 +};
  95 +
  96 +static inline struct mt7621_spi *spidev_to_mt7621_spi(struct spi_device *spi)
  97 +{
  98 +       return spi_master_get_devdata(spi->master);
  99 +}
 100 +
 101 +static inline u32 mt7621_spi_read(struct mt7621_spi *rs, u32 reg)
 102 +{
 103 +       return ioread32(rs->base + reg);
 104 +}
 105 +
 106 +static inline void mt7621_spi_write(struct mt7621_spi *rs, u32 reg, u32 val)
 107 +{
 108 +       iowrite32(val, rs->base + reg);
 109 +}
 110 +
 111 +static void mt7621_spi_set_cs(struct spi_device *spi, int enable)
 112 +{
 113 +       struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
 114 +       u32 polar = mt7621_spi_read(rs, MT7621_SPI_POLAR);
 115 +
 116 +       if (enable)
 117 +               polar |= 1;
 118 +       else
 119 +               polar &= ~1;
 120 +       mt7621_spi_write(rs, MT7621_SPI_POLAR, polar);
 121 +}
 122 +
 123 +static inline int mt7621_spi_wait_till_ready(struct spi_device *spi)
 124 +{
 125 +       struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
 126 +       int i;
 127 +
 128 +       for (i = 0; i < RALINK_SPI_WAIT_MAX_LOOP; i++) {
 129 +               u32 status;
 130 +
 131 +               status = mt7621_spi_read(rs, MT7621_SPI_TRANS);
 132 +               if ((status & SPITRANS_BUSY) == 0) {
 133 +                       return 0;
 134 +               }
 135 +               cpu_relax();
 136 +               udelay(1);
 137 +       }
 138 +
 139 +       return -ETIMEDOUT;
 140 +}
 141 +
 142 +static int mt7621_spi_transfer_one_message(struct spi_master *master,
 143 +                                          struct spi_message *m)
 144 +{
 145 +       struct mt7621_spi *rs = spi_master_get_devdata(master);
 146 +       struct spi_device *spi = m->spi;
 147 +       struct spi_transfer *t = NULL;
 148 +       int status = 0;
 149 +       int i, len = 0;
 150 +       int rx_len = 0;
 151 +       u32 data[9] = { 0 };
 152 +       u32 val;
 153 +
 154 +       mt7621_spi_wait_till_ready(spi);
 155 +
 156 +       list_for_each_entry(t, &m->transfers, transfer_list) {
 157 +               const u8 *buf = t->tx_buf;
 158 +
 159 +               if (t->rx_buf)
 160 +                       rx_len += t->len;
 161 +
 162 +               if (!buf)
 163 +                       continue;
 164 +
 165 +               if (WARN_ON(len + t->len > 36)) {
 166 +                       status = -EIO;
 167 +                       goto msg_done;
 168 +               }
 169 +
 170 +               for (i = 0; i < t->len; i++, len++)
 171 +                       data[len / 4] |= buf[i] << (8 * (len & 3));
 172 +       }
 173 +
 174 +       if (WARN_ON(rx_len > 32)) {
 175 +               status = -EIO;
 176 +               goto msg_done;
 177 +       }
 178 +
 179 +       data[0] = swab32(data[0]);
 180 +       if (len < 4)
 181 +               data[0] >>= (4 - len) * 8;
 182 +
 183 +       for (i = 0; i < len; i += 4)
 184 +               mt7621_spi_write(rs, MT7621_SPI_OPCODE + i, data[i / 4]);
 185 +
 186 +       val = (min_t(int, len, 4) * 8) << 24;
 187 +       if (len > 4)
 188 +               val |= (len - 4) * 8;
 189 +       val |= (rx_len * 8) << 12;
 190 +       mt7621_spi_write(rs, MT7621_SPI_MOREBUF, val);
 191 +
 192 +       mt7621_spi_set_cs(spi, 1);
 193 +
 194 +       val = mt7621_spi_read(rs, MT7621_SPI_TRANS);
 195 +       val |= SPI_CTL_START;
 196 +       mt7621_spi_write(rs, MT7621_SPI_TRANS, val);
 197 +
 198 +       mt7621_spi_wait_till_ready(spi);
 199 +
 200 +       mt7621_spi_set_cs(spi, 0);
 201 +
 202 +       for (i = 0; i < rx_len; i += 4)
 203 +               data[i / 4] = mt7621_spi_read(rs, MT7621_SPI_DATA0 + i);
 204 +
 205 +       m->actual_length = len + rx_len;
 206 +
 207 +       len = 0;
 208 +       list_for_each_entry(t, &m->transfers, transfer_list) {
 209 +               u8 *buf = t->rx_buf;
 210 +
 211 +               if (!buf)
 212 +                       continue;
 213 +
 214 +               for (i = 0; i < t->len; i++, len++)
 215 +                       buf[i] = data[len / 4] >> (8 * (len & 3));
 216 +       }
 217 +
 218 +msg_done:
 219 +       m->status = status;
 220 +       spi_finalize_current_message(master);
 221 +
 222 +       return 0;
 223 +}
 224 +
 225 +static int mt7621_spi_setup(struct spi_device *spi)
 226 +{
 227 +       return 0;
 228 +}
 229 +
 230 +static void mt7621_spi_reset(struct mt7621_spi *rs)
 231 +{
 232 +       u32 master = mt7621_spi_read(rs, MT7621_SPI_MASTER);
 233 +
 234 +       master &= ~(0xfff << 16);
 235 +       master |= 13 << 16;
 236 +       master |= 7 << 29;
 237 +       master |= 1 << 2;
 238 +
 239 +       mt7621_spi_write(rs, MT7621_SPI_MASTER, master);
 240 +}
 241 +
 242 +static const struct of_device_id mt7621_spi_match[] = {
 243 +       { .compatible = "ralink,mt7621-spi" },
 244 +       {},
 245 +};
 246 +MODULE_DEVICE_TABLE(of, mt7621_spi_match);
 247 +
 248 +static int mt7621_spi_probe(struct platform_device *pdev)
 249 +{
 250 +       const struct of_device_id *match;
 251 +       struct spi_master *master;
 252 +       struct mt7621_spi *rs;
 253 +       unsigned long flags;
 254 +       void __iomem *base;
 255 +       struct resource *r;
 256 +       int status = 0;
 257 +       struct clk *clk;
 258 +       struct mt7621_spi_ops *ops;
 259 +
 260 +       match = of_match_device(mt7621_spi_match, &pdev->dev);
 261 +       if (!match)
 262 +               return -EINVAL;
 263 +       ops = (struct mt7621_spi_ops *)match->data;
 264 +
 265 +       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 266 +       base = devm_ioremap_resource(&pdev->dev, r);
 267 +       if (IS_ERR(base))
 268 +               return PTR_ERR(base);
 269 +
 270 +       clk = devm_clk_get(&pdev->dev, NULL);
 271 +       if (IS_ERR(clk)) {
 272 +               dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
 273 +                       status);
 274 +               return PTR_ERR(clk);
 275 +       }
 276 +
 277 +       status = clk_prepare_enable(clk);
 278 +       if (status)
 279 +               return status;
 280 +
 281 +       master = spi_alloc_master(&pdev->dev, sizeof(*rs));
 282 +       if (master == NULL) {
 283 +               dev_dbg(&pdev->dev, "master allocation failed\n");
 284 +               return -ENOMEM;
 285 +       }
 286 +
 287 +       master->mode_bits = RT2880_SPI_MODE_BITS;
 288 +
 289 +       master->setup = mt7621_spi_setup;
 290 +       master->transfer_one_message = mt7621_spi_transfer_one_message;
 291 +       master->bits_per_word_mask = SPI_BPW_MASK(8);
 292 +       master->dev.of_node = pdev->dev.of_node;
 293 +       master->num_chipselect = 1;
 294 +
 295 +       dev_set_drvdata(&pdev->dev, master);
 296 +
 297 +       rs = spi_master_get_devdata(master);
 298 +       rs->base = base;
 299 +       rs->clk = clk;
 300 +       rs->master = master;
 301 +       rs->sys_freq = clk_get_rate(rs->clk);
 302 +       rs->ops = ops;
 303 +       dev_dbg(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
 304 +       spin_lock_irqsave(&rs->lock, flags);
 305 +
 306 +       device_reset(&pdev->dev);
 307 +
 308 +       mt7621_spi_reset(rs);
 309 +
 310 +       return spi_register_master(master);
 311 +}
 312 +
 313 +static int mt7621_spi_remove(struct platform_device *pdev)
 314 +{
 315 +       struct spi_master *master;
 316 +       struct mt7621_spi *rs;
 317 +
 318 +       master = dev_get_drvdata(&pdev->dev);
 319 +       rs = spi_master_get_devdata(master);
 320 +
 321 +       clk_disable(rs->clk);
 322 +       spi_unregister_master(master);
 323 +
 324 +       return 0;
 325 +}
 326 +
 327 +MODULE_ALIAS("platform:" DRIVER_NAME);
 328 +
 329 +static struct platform_driver mt7621_spi_driver = {
 330 +       .driver = {
 331 +               .name = DRIVER_NAME,
 332 +               .owner = THIS_MODULE,
 333 +               .of_match_table = mt7621_spi_match,
 334 +       },
 335 +       .probe = mt7621_spi_probe,
 336 +       .remove = mt7621_spi_remove,
 337 +};
 338 +
 339 +module_platform_driver(mt7621_spi_driver);
 340 +
 341 +MODULE_DESCRIPTION("MT7621 SPI driver");
 342 +MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
 343 +MODULE_LICENSE("GPL");