kernel/drivers/net/wireless/ti/wlcore/spi.c

   1 /*
   2  * This file is part of wl1271
   3  *
   4  * Copyright (C) 2008-2009 Nokia Corporation
   5  *
   6  * Contact: Luciano Coelho <luciano.coelho@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  *
  22  */
  23
  24 #include <linux/interrupt.h>
  25 #include <linux/irq.h>
  26 #include <linux/module.h>
  27 #include <linux/slab.h>
  28 #include <linux/swab.h>
  29 #include <linux/crc7.h>
  30 #include <linux/spi/spi.h>
  31 #include <linux/wl12xx.h>
  32 #include <linux/platform_device.h>
  33
  34 #include "wlcore.h"
  35 #include "wl12xx_80211.h"
  36 #include "io.h"
  37
  38 #define WSPI_CMD_READ                 0x40000000
  39 #define WSPI_CMD_WRITE                0x00000000
  40 #define WSPI_CMD_FIXED                0x20000000
  41 #define WSPI_CMD_BYTE_LENGTH          0x1FFE0000
  42 #define WSPI_CMD_BYTE_LENGTH_OFFSET   17
  43 #define WSPI_CMD_BYTE_ADDR            0x0001FFFF
  44
  45 #define WSPI_INIT_CMD_CRC_LEN       5
  46
  47 #define WSPI_INIT_CMD_START         0x00
  48 #define WSPI_INIT_CMD_TX            0x40
  49 /* the extra bypass bit is sampled by the TNET as '1' */
  50 #define WSPI_INIT_CMD_BYPASS_BIT    0x80
  51 #define WSPI_INIT_CMD_FIXEDBUSY_LEN 0x07
  52 #define WSPI_INIT_CMD_EN_FIXEDBUSY  0x80
  53 #define WSPI_INIT_CMD_DIS_FIXEDBUSY 0x00
  54 #define WSPI_INIT_CMD_IOD           0x40
  55 #define WSPI_INIT_CMD_IP            0x20
  56 #define WSPI_INIT_CMD_CS            0x10
  57 #define WSPI_INIT_CMD_WS            0x08
  58 #define WSPI_INIT_CMD_WSPI          0x01
  59 #define WSPI_INIT_CMD_END           0x01
  60
  61 #define WSPI_INIT_CMD_LEN           8
  62
  63 #define HW_ACCESS_WSPI_FIXED_BUSY_LEN \
  64                 ((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
  65 #define HW_ACCESS_WSPI_INIT_CMD_MASK  0
  66
  67 /* HW limitation: maximum possible chunk size is 4095 bytes */
  68 #define WSPI_MAX_CHUNK_SIZE    4092
  69
  70 /*
  71  * only support SPI for 12xx - this code should be reworked when 18xx
  72  * support is introduced
  73  */
  74 #define SPI_AGGR_BUFFER_SIZE (4 * PAGE_SIZE)
  75
  76 /* Maximum number of SPI write chunks */
  77 #define WSPI_MAX_NUM_OF_CHUNKS \
  78         ((SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE) + 1)
  79
  80
  81 struct wl12xx_spi_glue {
  82         struct device *dev;
  83         struct platform_device *core;
  84 };
  85
  86 static void wl12xx_spi_reset(struct device *child)
  87 {
  88         struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
  89         u8 *cmd;
  90         struct spi_transfer t;
  91         struct spi_message m;
  92
  93         cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
  94         if (!cmd) {
  95                 dev_err(child->parent,
  96                         "could not allocate cmd for spi reset\n");
  97                 return;
  98         }
  99
 100         memset(&t, 0, sizeof(t));
 101         spi_message_init(&m);
 102
 103         memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
 104
 105         t.tx_buf = cmd;
 106         t.len = WSPI_INIT_CMD_LEN;
 107         spi_message_add_tail(&t, &m);
 108
 109         spi_sync(to_spi_device(glue->dev), &m);
 110
 111         kfree(cmd);
 112 }
 113
 114 static void wl12xx_spi_init(struct device *child)
 115 {
 116         struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 117         struct spi_transfer t;
 118         struct spi_message m;
 119         u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
 120
 121         if (!cmd) {
 122                 dev_err(child->parent,
 123                         "could not allocate cmd for spi init\n");
 124                 return;
 125         }
 126
 127         memset(&t, 0, sizeof(t));
 128         spi_message_init(&m);
 129
 130         /*
 131          * Set WSPI_INIT_COMMAND
 132          * the data is being send from the MSB to LSB
 133          */
 134         cmd[0] = 0xff;
 135         cmd[1] = 0xff;
 136         cmd[2] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
 137         cmd[3] = 0;
 138         cmd[4] = 0;
 139         cmd[5] = HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
 140         cmd[5] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
 141
 142         cmd[6] = WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
 143                 | WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
 144
 145         if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
 146                 cmd[6] |= WSPI_INIT_CMD_DIS_FIXEDBUSY;
 147         else
 148                 cmd[6] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
 149
 150         cmd[7] = crc7_be(0, cmd+2, WSPI_INIT_CMD_CRC_LEN) | WSPI_INIT_CMD_END;
 151         /*
 152          * The above is the logical order; it must actually be stored
 153          * in the buffer byte-swapped.
 154          */
 155         __swab32s((u32 *)cmd);
 156         __swab32s((u32 *)cmd+1);
 157
 158         t.tx_buf = cmd;
 159         t.len = WSPI_INIT_CMD_LEN;
 160         spi_message_add_tail(&t, &m);
 161
 162         spi_sync(to_spi_device(glue->dev), &m);
 163         kfree(cmd);
 164 }
 165
 166 #define WL1271_BUSY_WORD_TIMEOUT 1000
 167
 168 static int wl12xx_spi_read_busy(struct device *child)
 169 {
 170         struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 171         struct wl1271 *wl = dev_get_drvdata(child);
 172         struct spi_transfer t[1];
 173         struct spi_message m;
 174         u32 *busy_buf;
 175         int num_busy_bytes = 0;
 176
 177         /*
 178          * Read further busy words from SPI until a non-busy word is
 179          * encountered, then read the data itself into the buffer.
 180          */
 181
 182         num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
 183         busy_buf = wl->buffer_busyword;
 184         while (num_busy_bytes) {
 185                 num_busy_bytes--;
 186                 spi_message_init(&m);
 187                 memset(t, 0, sizeof(t));
 188                 t[0].rx_buf = busy_buf;
 189                 t[0].len = sizeof(u32);
 190                 t[0].cs_change = true;
 191                 spi_message_add_tail(&t[0], &m);
 192                 spi_sync(to_spi_device(glue->dev), &m);
 193
 194                 if (*busy_buf & 0x1)
 195                         return 0;
 196         }
 197
 198         /* The SPI bus is unresponsive, the read failed. */
 199         dev_err(child->parent, "SPI read busy-word timeout!\n");
 200         return -ETIMEDOUT;
 201 }
 202
 203 static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
 204                                             void *buf, size_t len, bool fixed)
 205 {
 206         struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 207         struct wl1271 *wl = dev_get_drvdata(child);
 208         struct spi_transfer t[2];
 209         struct spi_message m;
 210         u32 *busy_buf;
 211         u32 *cmd;
 212         u32 chunk_len;
 213
 214         while (len > 0) {
 215                 chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
 216
 217                 cmd = &wl->buffer_cmd;
 218                 busy_buf = wl->buffer_busyword;
 219
 220                 *cmd = 0;
 221                 *cmd |= WSPI_CMD_READ;
 222                 *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
 223                         WSPI_CMD_BYTE_LENGTH;
 224                 *cmd |= addr & WSPI_CMD_BYTE_ADDR;
 225
 226                 if (fixed)
 227                         *cmd |= WSPI_CMD_FIXED;
 228
 229                 spi_message_init(&m);
 230                 memset(t, 0, sizeof(t));
 231
 232                 t[0].tx_buf = cmd;
 233                 t[0].len = 4;
 234                 t[0].cs_change = true;
 235                 spi_message_add_tail(&t[0], &m);
 236
 237                 /* Busy and non busy words read */
 238                 t[1].rx_buf = busy_buf;
 239                 t[1].len = WL1271_BUSY_WORD_LEN;
 240                 t[1].cs_change = true;
 241                 spi_message_add_tail(&t[1], &m);
 242
 243                 spi_sync(to_spi_device(glue->dev), &m);
 244
 245                 if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
 246                     wl12xx_spi_read_busy(child)) {
 247                         memset(buf, 0, chunk_len);
 248                         return 0;
 249                 }
 250
 251                 spi_message_init(&m);
 252                 memset(t, 0, sizeof(t));
 253
 254                 t[0].rx_buf = buf;
 255                 t[0].len = chunk_len;
 256                 t[0].cs_change = true;
 257                 spi_message_add_tail(&t[0], &m);
 258
 259                 spi_sync(to_spi_device(glue->dev), &m);
 260
 261                 if (!fixed)
 262                         addr += chunk_len;
 263                 buf += chunk_len;
 264                 len -= chunk_len;
 265         }
 266
 267         return 0;
 268 }
 269
 270 static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
 271                                              void *buf, size_t len, bool fixed)
 272 {
 273         struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 274         /* SPI write buffers - 2 for each chunk */
 275         struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
 276         struct spi_message m;
 277         u32 commands[WSPI_MAX_NUM_OF_CHUNKS]; /* 1 command per chunk */
 278         u32 *cmd;
 279         u32 chunk_len;
 280         int i;
 281
 282         WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
 283
 284         spi_message_init(&m);
 285         memset(t, 0, sizeof(t));
 286
 287         cmd = &commands[0];
 288         i = 0;
 289         while (len > 0) {
 290                 chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
 291
 292                 *cmd = 0;
 293                 *cmd |= WSPI_CMD_WRITE;
 294                 *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
 295                         WSPI_CMD_BYTE_LENGTH;
 296                 *cmd |= addr & WSPI_CMD_BYTE_ADDR;
 297
 298                 if (fixed)
 299                         *cmd |= WSPI_CMD_FIXED;
 300
 301                 t[i].tx_buf = cmd;
 302                 t[i].len = sizeof(*cmd);
 303                 spi_message_add_tail(&t[i++], &m);
 304
 305                 t[i].tx_buf = buf;
 306                 t[i].len = chunk_len;
 307                 spi_message_add_tail(&t[i++], &m);
 308
 309                 if (!fixed)
 310                         addr += chunk_len;
 311                 buf += chunk_len;
 312                 len -= chunk_len;
 313                 cmd++;
 314         }
 315
 316         spi_sync(to_spi_device(glue->dev), &m);
 317
 318         return 0;
 319 }
 320
 321 static struct wl1271_if_operations spi_ops = {
 322         .read           = wl12xx_spi_raw_read,
 323         .write          = wl12xx_spi_raw_write,
 324         .reset          = wl12xx_spi_reset,
 325         .init           = wl12xx_spi_init,
 326         .set_block_size = NULL,
 327 };
 328
 329 static int wl1271_probe(struct spi_device *spi)
 330 {
 331         struct wl12xx_spi_glue *glue;
 332         struct wlcore_platdev_data pdev_data;
 333         struct resource res[1];
 334         int ret;
 335
 336         memset(&pdev_data, 0x00, sizeof(pdev_data));
 337
 338         /* TODO: add DT parsing when needed */
 339
 340         pdev_data.if_ops = &spi_ops;
 341
 342         glue = devm_kzalloc(&spi->dev, sizeof(*glue), GFP_KERNEL);
 343         if (!glue) {
 344                 dev_err(&spi->dev, "can't allocate glue\n");
 345                 return -ENOMEM;
 346         }
 347
 348         glue->dev = &spi->dev;
 349
 350         spi_set_drvdata(spi, glue);
 351
 352         /* This is the only SPI value that we need to set here, the rest
 353          * comes from the board-peripherals file */
 354         spi->bits_per_word = 32;
 355
 356         ret = spi_setup(spi);
 357         if (ret < 0) {
 358                 dev_err(glue->dev, "spi_setup failed\n");
 359                 return ret;
 360         }
 361
 362         glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
 363         if (!glue->core) {
 364                 dev_err(glue->dev, "can't allocate platform_device\n");
 365                 return -ENOMEM;
 366         }
 367
 368         glue->core->dev.parent = &spi->dev;
 369
 370         memset(res, 0x00, sizeof(res));
 371
 372         res[0].start = spi->irq;
 373         res[0].flags = IORESOURCE_IRQ;
 374         res[0].name = "irq";
 375
 376         ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
 377         if (ret) {
 378                 dev_err(glue->dev, "can't add resources\n");
 379                 goto out_dev_put;
 380         }
 381
 382         ret = platform_device_add_data(glue->core, &pdev_data,
 383                                        sizeof(pdev_data));
 384         if (ret) {
 385                 dev_err(glue->dev, "can't add platform data\n");
 386                 goto out_dev_put;
 387         }
 388
 389         ret = platform_device_add(glue->core);
 390         if (ret) {
 391                 dev_err(glue->dev, "can't register platform device\n");
 392                 goto out_dev_put;
 393         }
 394
 395         return 0;
 396
 397 out_dev_put:
 398         platform_device_put(glue->core);
 399         return ret;
 400 }
 401
 402 static int wl1271_remove(struct spi_device *spi)
 403 {
 404         struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
 405
 406         platform_device_unregister(glue->core);
 407
 408         return 0;
 409 }
 410
 411
 412 static struct spi_driver wl1271_spi_driver = {
 413         .driver = {
 414                 .name           = "wl1271_spi",
 415         },
 416
 417         .probe          = wl1271_probe,
 418         .remove         = wl1271_remove,
 419 };
 420
 421 module_spi_driver(wl1271_spi_driver);
 422 MODULE_LICENSE("GPL");
 423 MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
 424 MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
 425 MODULE_ALIAS("spi:wl1271");