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
  90         if (ret)
  91                 return ret;
  92
  93         return b53_spi_set_page(spi, page);
  94 }
  95
  96 static int b53_spi_prepare_reg_read(struct spi_device *spi, u8 reg)
  97 {
  98         u8 rxbuf;
  99         int retry_count;
 100         int ret;
 101
 102         ret = b53_spi_read_reg(spi, reg, &rxbuf, 1);
 103         if (ret)
 104                 return ret;
 105
 106         for (retry_count = 0; retry_count < 10; retry_count++) {
 107                 ret = b53_spi_read_reg(spi, B53_SPI_STATUS, &rxbuf, 1);
 108                 if (ret)
 109                         return ret;
 110
 111                 if (rxbuf & B53_SPI_CMD_RACK)
 112                         break;
 113
 114                 mdelay(1);
 115         }
 116
 117         if (retry_count == 10)
 118                 return -EIO;
 119
 120         return 0;
 121 }
 122
 123 static int b53_spi_read(struct b53_device *dev, u8 page, u8 reg, u8 *data,
 124                         unsigned len)
 125 {
 126         struct spi_device *spi = dev->priv;
 127         int ret;
 128
 129         ret = b53_prepare_reg_access(spi, page);
 130         if (ret)
 131                 return ret;
 132
 133         ret = b53_spi_prepare_reg_read(spi, reg);
 134         if (ret)
 135                 return ret;
 136
 137         return b53_spi_read_reg(spi, B53_SPI_DATA, data, len);
 138 }
 139
 140 static int b53_spi_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
 141 {
 142         return b53_spi_read(dev, page, reg, val, 1);
 143 }
 144
 145 static int b53_spi_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
 146 {
 147         int ret = b53_spi_read(dev, page, reg, (u8 *)val, 2);
 148
 149         if (!ret)
 150                 *val = le16_to_cpu(*val);
 151
 152         return ret;
 153 }
 154
 155 static int b53_spi_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
 156 {
 157         int ret = b53_spi_read(dev, page, reg, (u8 *)val, 4);
 158
 159         if (!ret)
 160                 *val = le32_to_cpu(*val);
 161
 162         return ret;
 163 }
 164
 165 static int b53_spi_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 166 {
 167         int ret;
 168
 169         *val = 0;
 170         ret = b53_spi_read(dev, page, reg, (u8 *)val, 6);
 171         if (!ret)
 172                 *val = le64_to_cpu(*val);
 173
 174         return ret;
 175 }
 176
 177 static int b53_spi_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
 178 {
 179         int ret = b53_spi_read(dev, page, reg, (u8 *)val, 8);
 180
 181         if (!ret)
 182                 *val = le64_to_cpu(*val);
 183
 184         return ret;
 185 }
 186
 187 static int b53_spi_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
 188 {
 189         struct spi_device *spi = dev->priv;
 190         int ret;
 191         u8 txbuf[3];
 192
 193         ret = b53_prepare_reg_access(spi, page);
 194         if (ret)
 195                 return ret;
 196
 197         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 198         txbuf[1] = reg;
 199         txbuf[2] = value;
 200
 201         return spi_write(spi, txbuf, sizeof(txbuf));
 202 }
 203
 204 static int b53_spi_write16(struct b53_device *dev, u8 page, u8 reg, u16 value)
 205 {
 206         struct spi_device *spi = dev->priv;
 207         int ret;
 208         u8 txbuf[4];
 209
 210         ret = b53_prepare_reg_access(spi, page);
 211         if (ret)
 212                 return ret;
 213
 214         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 215         txbuf[1] = reg;
 216         put_unaligned_le16(value, &txbuf[2]);
 217
 218         return spi_write(spi, txbuf, sizeof(txbuf));
 219 }
 220
 221 static int b53_spi_write32(struct b53_device *dev, u8 page, u8 reg, u32 value)
 222 {
 223         struct spi_device *spi = dev->priv;
 224         int ret;
 225         u8 txbuf[6];
 226
 227         ret = b53_prepare_reg_access(spi, page);
 228         if (ret)
 229                 return ret;
 230
 231         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 232         txbuf[1] = reg;
 233         put_unaligned_le32(value, &txbuf[2]);
 234
 235         return spi_write(spi, txbuf, sizeof(txbuf));
 236 }
 237
 238 static int b53_spi_write48(struct b53_device *dev, u8 page, u8 reg, u64 value)
 239 {
 240         struct spi_device *spi = dev->priv;
 241         int ret;
 242         u8 txbuf[10];
 243
 244         ret = b53_prepare_reg_access(spi, page);
 245         if (ret)
 246                 return ret;
 247
 248         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 249         txbuf[1] = reg;
 250         put_unaligned_le64(value, &txbuf[2]);
 251
 252         return spi_write(spi, txbuf, sizeof(txbuf) - 2);
 253 }
 254
 255 static int b53_spi_write64(struct b53_device *dev, u8 page, u8 reg, u64 value)
 256 {
 257         struct spi_device *spi = dev->priv;
 258         int ret;
 259         u8 txbuf[10];
 260
 261         ret = b53_prepare_reg_access(spi, page);
 262         if (ret)
 263                 return ret;
 264
 265         txbuf[0] = B53_SPI_CMD_NORMAL | B53_SPI_CMD_WRITE;
 266         txbuf[1] = reg;
 267         put_unaligned_le64(value, &txbuf[2]);
 268
 269         return spi_write(spi, txbuf, sizeof(txbuf));
 270 }
 271
 272 static struct b53_io_ops b53_spi_ops = {
 273         .read8 = b53_spi_read8,
 274         .read16 = b53_spi_read16,
 275         .read32 = b53_spi_read32,
 276         .read48 = b53_spi_read48,
 277         .read64 = b53_spi_read64,
 278         .write8 = b53_spi_write8,
 279         .write16 = b53_spi_write16,
 280         .write32 = b53_spi_write32,
 281         .write48 = b53_spi_write48,
 282         .write64 = b53_spi_write64,
 283 };
 284
 285 static int b53_spi_probe(struct spi_device *spi)
 286 {
 287         struct b53_device *dev;
 288         int ret;
 289
 290         dev = b53_switch_alloc(&spi->dev, &b53_spi_ops, spi);
 291         if (!dev)
 292                 return -ENOMEM;
 293
 294         if (spi->dev.platform_data)
 295                 dev->pdata = spi->dev.platform_data;
 296
 297         ret = b53_switch_register(dev);
 298         if (ret)
 299                 return ret;
 300
 301         spi_set_drvdata(spi, dev);
 302
 303         return 0;
 304 }
 305
 306 static int b53_spi_remove(struct spi_device *spi)
 307 {
 308         struct b53_device *dev = spi_get_drvdata(spi);
 309
 310         if (dev)
 311                 b53_switch_remove(dev);
 312
 313         return 0;
 314 }
 315
 316 static struct spi_driver b53_spi_driver = {
 317         .driver = {
 318                 .name   = "b53-switch",
 319                 .bus    = &spi_bus_type,
 320                 .owner  = THIS_MODULE,
 321         },
 322         .probe  = b53_spi_probe,
 323         .remove = b53_spi_remove,
 324 };
 325
 326 module_spi_driver(b53_spi_driver);
 327
 328 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
 329 MODULE_DESCRIPTION("B53 SPI access driver");
 330 MODULE_LICENSE("Dual BSD/GPL");