target/linux/generic/files/drivers/net/phy/b53/b53_spi.c

   1 /*
   2  * B53 register access through SPI
   3  *
   4  * Copyright (C) 2011-2013 Jonas Gorski <jogo@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <asm/unaligned.h>
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/spi/spi.h>
  24 #include <linux/platform_data/b53.h>
  25
  26 #include "b53_priv.h"
  27
  28 #define B53_SPI_DATA            0xf0
  29
  30 #define B53_SPI_STATUS          0xfe
  31 #define B53_SPI_CMD_SPIF        BIT(7)
  32 #define B53_SPI_CMD_RACK        BIT(5)
  33
  34 #define B53_SPI_CMD_READ        0x00
  35 #define B53_SPI_CMD_WRITE       0x01
  36 #define B53_SPI_CMD_NORMAL      0x60
  37 #define B53_SPI_CMD_FAST        0x10
  38
  39 #define B53_SPI_PAGE_SELECT     0xff
  40
  41 static inline int b53_spi_read_reg(struct spi_device *spi, u8 reg, u8 *val,
  42                                      unsigned len)
  43 {
  44         u8 txbuf[2];
  45
  46         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_READ;
  47         txbuf[1] = reg;
  48
  49         return spi_write_then_read(spi, txbuf, 2, val, len);
  50 }
  51
  52 static inline int b53_spi_clear_status(struct spi_device *spi)
  53 {
  54         unsigned int i;
  55         u8 rxbuf;
  56         int ret;
  57
  58         for (i = 0; i < 10; i++) {
  59                 ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
  60                 if (ret)
  61                         return ret;
  62
  63                 if (!(rxbuf & B53_SPI_CMD_SPIF))
  64                         break;
  65
  66                 mdelay(1);
  67         }
  68
  69         if (i == 10)
  70                 return -EIO;
  71
  72         return 0;
  73 }
  74
  75 static inline int b53_spi_set_page(struct spi_device *spi, u8 page)
  76 {
  77         u8 txbuf[3];
  78
  79         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
  80         txbuf[1] = B53_SPI_PAGE_SELECT;
  81         txbuf[2] = page;
  82
  83         return spi_write(spi, txbuf, sizeof(txbuf));
  84 }
  85
  86 static inline int b53_prepare_reg_access(struct spi_device *spi, u8 page)
  87 {
  88         int ret = b53_spi_clear_status(spi);
  89         if (ret)
  90                 return ret;
  91
  92         return b53_spi_set_page(spi, page);
  93 }
  94
  95 static int b53_spi_prepare_reg_read(struct spi_device *spi, u8 reg)
  96 {
  97         u8 rxbuf;
  98         int retry_count;
  99         int ret;
 100
 101         ret = b53_spi_read_reg(spi, reg, &rxbuf, 1);
 102         if (ret)
 103                 return ret;
 104
 105         for (retry_count = 0; retry_count < 10; retry_count++) {
 106                 ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
 107                 if (ret)
 108                         return ret;
 109
 110                 if (rxbuf & B53_SPI_CMD_RACK)
 111                         break;
 112
 113                 mdelay(1);
 114         }
 115
 116         if (retry_count == 10)
 117                 return -EIO;
 118
 119         return 0;
 120 }
 121
 122 static int b53_spi_read(struct b53_device *dev, u8 page, u8 reg, u8 *data,
 123                         unsigned len)
 124 {
 125         struct spi_device *spi = dev->priv;
 126         int ret;
 127
 128         ret = b53_prepare_reg_access(spi, page);
 129         if (ret)
 130                 return ret;
 131
 132         ret = b53_spi_prepare_reg_read(spi, reg);
 133         if (ret)
 134                 return ret;
 135
 136         return b53_spi_read_reg(spi, B53_SPI_DATA, data, len);
 137 }
 138
 139 static int b53_spi_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
 140 {
 141         return b53_spi_read(dev, page, reg, val, 1);
 142 }
 143
 144 static int b53_spi_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
 145 {
 146         int ret = b53_spi_read(dev, page, reg, (u8 *)val, 2);
 147         if (!ret)
 148                 *val = le16_to_cpu(*val);
 149
 150         return ret;
 151 }
 152
 153 static int b53_spi_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
 154 {
 155         int ret = b53_spi_read(dev, page, reg, (u8 *)val, 4);
 156         if (!ret)
 157                 *val = le32_to_cpu(*val);
 158
 159         return ret;
 160 }
 161
 162 static int b53_spi_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 163 {
 164         int ret;
 165
 166         *val = 0;
 167         ret = b53_spi_read(dev, page, reg, (u8 *)val, 6);
 168         if (!ret)
 169                 *val = le64_to_cpu(*val);
 170
 171         return ret;
 172 }
 173
 174 static int b53_spi_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 175 {
 176         int ret = b53_spi_read(dev, page, reg, (u8 *)val, 8);
 177         if (!ret)
 178                 *val = le64_to_cpu(*val);
 179
 180         return ret;
 181 }
 182
 183 static int b53_spi_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
 184 {
 185         struct spi_device *spi = dev->priv;
 186         int ret;
 187         u8 txbuf[3];
 188
 189         ret = b53_prepare_reg_access(spi, page);
 190         if (ret)
 191                 return ret;
 192
 193         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 194         txbuf[1] = reg;
 195         txbuf[2] = value;
 196
 197         return spi_write(spi, txbuf, sizeof(txbuf));
 198 }
 199
 200 static int b53_spi_write16(struct b53_device *dev, u8 page, u8 reg, u16 value)
 201 {
 202         struct spi_device *spi = dev->priv;
 203         int ret;
 204         u8 txbuf[4];
 205
 206         ret = b53_prepare_reg_access(spi, page);
 207         if (ret)
 208                 return ret;
 209
 210         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 211         txbuf[1] = reg;
 212         put_unaligned_le16(value, &txbuf[2]);
 213
 214         return spi_write(spi, txbuf, sizeof(txbuf));
 215 }
 216
 217 static int b53_spi_write32(struct b53_device *dev, u8 page, u8 reg, u32 value)
 218 {
 219         struct spi_device *spi = dev->priv;
 220         int ret;
 221         u8 txbuf[6];
 222
 223         ret = b53_prepare_reg_access(spi, page);
 224         if (ret)
 225                 return ret;
 226
 227         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 228         txbuf[1] = reg;
 229         put_unaligned_le32(value, &txbuf[2]);
 230
 231         return spi_write(spi, txbuf, sizeof(txbuf));
 232 }
 233
 234 static int b53_spi_write48(struct b53_device *dev, u8 page, u8 reg, u64 value)
 235 {
 236         struct spi_device *spi = dev->priv;
 237         int ret;
 238         u8 txbuf[10];
 239
 240         ret = b53_prepare_reg_access(spi, page);
 241         if (ret)
 242                 return ret;
 243
 244         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 245         txbuf[1] = reg;
 246         put_unaligned_le64(value, &txbuf[2]);
 247
 248         return spi_write(spi, txbuf, sizeof(txbuf) - 2);
 249 }
 250
 251 static int b53_spi_write64(struct b53_device *dev, u8 page, u8 reg, u64 value)
 252 {
 253         struct spi_device *spi = dev->priv;
 254         int ret;
 255         u8 txbuf[10];
 256
 257         ret = b53_prepare_reg_access(spi, page);
 258         if (ret)
 259                 return ret;
 260
 261         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 262         txbuf[1] = reg;
 263         put_unaligned_le64(value, &txbuf[2]);
 264
 265         return spi_write(spi, txbuf, sizeof(txbuf));
 266 }
 267
 268 static struct b53_io_ops b53_spi_ops = {
 269         .read8 = b53_spi_read8,
 270         .read16 = b53_spi_read16,
 271         .read32 = b53_spi_read32,
 272         .read48 = b53_spi_read48,
 273         .read64 = b53_spi_read64,
 274         .write8 = b53_spi_write8,
 275         .write16 = b53_spi_write16,
 276         .write32 = b53_spi_write32,
 277         .write48 = b53_spi_write48,
 278         .write64 = b53_spi_write64,
 279 };
 280
 281 static int __devinit b53_spi_probe(struct spi_device *spi)
 282 {
 283         struct b53_device *dev;
 284         int ret;
 285
 286         dev = b53_switch_alloc(&spi->dev, &b53_spi_ops, spi);
 287         if (!dev)
 288                 return -ENOMEM;
 289
 290         if (spi->dev.platform_data)
 291                 dev->pdata = spi->dev.platform_data;
 292
 293         ret = b53_switch_register(dev);
 294         if (ret)
 295                 return ret;
 296
 297         spi->dev.platform_data = dev;
 298
 299         return 0;
 300 }
 301
 302 static int __devexit b53_spi_remove(struct spi_device *spi)
 303 {
 304         struct b53_device *dev = spi->dev.platform_data;
 305
 306         if (dev) {
 307                 struct b53_platform_data *pdata = dev->pdata;
 308                 b53_switch_remove(dev);
 309                 spi->dev.platform_data = pdata;
 310         }
 311
 312         return 0;
 313 }
 314
 315 static struct spi_driver b53_spi_driver = {
 316         .driver = {
 317                 .name   = "b53-switch",
 318                 .bus    = &spi_bus_type,
 319                 .owner  = THIS_MODULE,
 320         },
 321         .probe  = b53_spi_probe,
 322         .remove = __devexit_p(b53_spi_remove),
 323 };
 324
 325 module_spi_driver(b53_spi_driver);
 326
 327 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
 328 MODULE_DESCRIPTION("B53 SPI access driver");
 329 MODULE_LICENSE("Dual BSD/GPL");