linux/drivers/net/wireless/ti/wlcore/spi.c
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   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/crc7.h>
  28#include <linux/spi/spi.h>
  29#include <linux/wl12xx.h>
  30#include <linux/platform_device.h>
  31#include <linux/slab.h>
  32
  33#include "wlcore.h"
  34#include "wl12xx_80211.h"
  35#include "io.h"
  36
  37#define WSPI_CMD_READ                 0x40000000
  38#define WSPI_CMD_WRITE                0x00000000
  39#define WSPI_CMD_FIXED                0x20000000
  40#define WSPI_CMD_BYTE_LENGTH          0x1FFE0000
  41#define WSPI_CMD_BYTE_LENGTH_OFFSET   17
  42#define WSPI_CMD_BYTE_ADDR            0x0001FFFF
  43
  44#define WSPI_INIT_CMD_CRC_LEN       5
  45
  46#define WSPI_INIT_CMD_START         0x00
  47#define WSPI_INIT_CMD_TX            0x40
  48/* the extra bypass bit is sampled by the TNET as '1' */
  49#define WSPI_INIT_CMD_BYPASS_BIT    0x80
  50#define WSPI_INIT_CMD_FIXEDBUSY_LEN 0x07
  51#define WSPI_INIT_CMD_EN_FIXEDBUSY  0x80
  52#define WSPI_INIT_CMD_DIS_FIXEDBUSY 0x00
  53#define WSPI_INIT_CMD_IOD           0x40
  54#define WSPI_INIT_CMD_IP            0x20
  55#define WSPI_INIT_CMD_CS            0x10
  56#define WSPI_INIT_CMD_WS            0x08
  57#define WSPI_INIT_CMD_WSPI          0x01
  58#define WSPI_INIT_CMD_END           0x01
  59
  60#define WSPI_INIT_CMD_LEN           8
  61
  62#define HW_ACCESS_WSPI_FIXED_BUSY_LEN \
  63                ((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
  64#define HW_ACCESS_WSPI_INIT_CMD_MASK  0
  65
  66/* HW limitation: maximum possible chunk size is 4095 bytes */
  67#define WSPI_MAX_CHUNK_SIZE    4092
  68
  69/*
  70 * only support SPI for 12xx - this code should be reworked when 18xx
  71 * support is introduced
  72 */
  73#define SPI_AGGR_BUFFER_SIZE (4 * PAGE_SIZE)
  74
  75#define WSPI_MAX_NUM_OF_CHUNKS (SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE)
  76
  77struct wl12xx_spi_glue {
  78        struct device *dev;
  79        struct platform_device *core;
  80};
  81
  82static void wl12xx_spi_reset(struct device *child)
  83{
  84        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
  85        u8 *cmd;
  86        struct spi_transfer t;
  87        struct spi_message m;
  88
  89        cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
  90        if (!cmd) {
  91                dev_err(child->parent,
  92                        "could not allocate cmd for spi reset\n");
  93                return;
  94        }
  95
  96        memset(&t, 0, sizeof(t));
  97        spi_message_init(&m);
  98
  99        memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
 100
 101        t.tx_buf = cmd;
 102        t.len = WSPI_INIT_CMD_LEN;
 103        spi_message_add_tail(&t, &m);
 104
 105        spi_sync(to_spi_device(glue->dev), &m);
 106
 107        kfree(cmd);
 108}
 109
 110static void wl12xx_spi_init(struct device *child)
 111{
 112        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 113        u8 crc[WSPI_INIT_CMD_CRC_LEN], *cmd;
 114        struct spi_transfer t;
 115        struct spi_message m;
 116
 117        cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
 118        if (!cmd) {
 119                dev_err(child->parent,
 120                        "could not allocate cmd for spi init\n");
 121                return;
 122        }
 123
 124        memset(crc, 0, sizeof(crc));
 125        memset(&t, 0, sizeof(t));
 126        spi_message_init(&m);
 127
 128        /*
 129         * Set WSPI_INIT_COMMAND
 130         * the data is being send from the MSB to LSB
 131         */
 132        cmd[2] = 0xff;
 133        cmd[3] = 0xff;
 134        cmd[1] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
 135        cmd[0] = 0;
 136        cmd[7] = 0;
 137        cmd[6] |= HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
 138        cmd[6] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
 139
 140        if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
 141                cmd[5] |=  WSPI_INIT_CMD_DIS_FIXEDBUSY;
 142        else
 143                cmd[5] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
 144
 145        cmd[5] |= WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
 146                | WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
 147
 148        crc[0] = cmd[1];
 149        crc[1] = cmd[0];
 150        crc[2] = cmd[7];
 151        crc[3] = cmd[6];
 152        crc[4] = cmd[5];
 153
 154        cmd[4] |= crc7(0, crc, WSPI_INIT_CMD_CRC_LEN) << 1;
 155        cmd[4] |= WSPI_INIT_CMD_END;
 156
 157        t.tx_buf = cmd;
 158        t.len = WSPI_INIT_CMD_LEN;
 159        spi_message_add_tail(&t, &m);
 160
 161        spi_sync(to_spi_device(glue->dev), &m);
 162        kfree(cmd);
 163}
 164
 165#define WL1271_BUSY_WORD_TIMEOUT 1000
 166
 167static int wl12xx_spi_read_busy(struct device *child)
 168{
 169        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 170        struct wl1271 *wl = dev_get_drvdata(child);
 171        struct spi_transfer t[1];
 172        struct spi_message m;
 173        u32 *busy_buf;
 174        int num_busy_bytes = 0;
 175
 176        /*
 177         * Read further busy words from SPI until a non-busy word is
 178         * encountered, then read the data itself into the buffer.
 179         */
 180
 181        num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
 182        busy_buf = wl->buffer_busyword;
 183        while (num_busy_bytes) {
 184                num_busy_bytes--;
 185                spi_message_init(&m);
 186                memset(t, 0, sizeof(t));
 187                t[0].rx_buf = busy_buf;
 188                t[0].len = sizeof(u32);
 189                t[0].cs_change = true;
 190                spi_message_add_tail(&t[0], &m);
 191                spi_sync(to_spi_device(glue->dev), &m);
 192
 193                if (*busy_buf & 0x1)
 194                        return 0;
 195        }
 196
 197        /* The SPI bus is unresponsive, the read failed. */
 198        dev_err(child->parent, "SPI read busy-word timeout!\n");
 199        return -ETIMEDOUT;
 200}
 201
 202static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
 203                                            void *buf, size_t len, bool fixed)
 204{
 205        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 206        struct wl1271 *wl = dev_get_drvdata(child);
 207        struct spi_transfer t[2];
 208        struct spi_message m;
 209        u32 *busy_buf;
 210        u32 *cmd;
 211        u32 chunk_len;
 212
 213        while (len > 0) {
 214                chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
 215
 216                cmd = &wl->buffer_cmd;
 217                busy_buf = wl->buffer_busyword;
 218
 219                *cmd = 0;
 220                *cmd |= WSPI_CMD_READ;
 221                *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
 222                        WSPI_CMD_BYTE_LENGTH;
 223                *cmd |= addr & WSPI_CMD_BYTE_ADDR;
 224
 225                if (fixed)
 226                        *cmd |= WSPI_CMD_FIXED;
 227
 228                spi_message_init(&m);
 229                memset(t, 0, sizeof(t));
 230
 231                t[0].tx_buf = cmd;
 232                t[0].len = 4;
 233                t[0].cs_change = true;
 234                spi_message_add_tail(&t[0], &m);
 235
 236                /* Busy and non busy words read */
 237                t[1].rx_buf = busy_buf;
 238                t[1].len = WL1271_BUSY_WORD_LEN;
 239                t[1].cs_change = true;
 240                spi_message_add_tail(&t[1], &m);
 241
 242                spi_sync(to_spi_device(glue->dev), &m);
 243
 244                if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
 245                    wl12xx_spi_read_busy(child)) {
 246                        memset(buf, 0, chunk_len);
 247                        return 0;
 248                }
 249
 250                spi_message_init(&m);
 251                memset(t, 0, sizeof(t));
 252
 253                t[0].rx_buf = buf;
 254                t[0].len = chunk_len;
 255                t[0].cs_change = true;
 256                spi_message_add_tail(&t[0], &m);
 257
 258                spi_sync(to_spi_device(glue->dev), &m);
 259
 260                if (!fixed)
 261                        addr += chunk_len;
 262                buf += chunk_len;
 263                len -= chunk_len;
 264        }
 265
 266        return 0;
 267}
 268
 269static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
 270                                             void *buf, size_t len, bool fixed)
 271{
 272        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
 273        struct spi_transfer t[2 * (WSPI_MAX_NUM_OF_CHUNKS + 1)];
 274        struct spi_message m;
 275        u32 commands[WSPI_MAX_NUM_OF_CHUNKS];
 276        u32 *cmd;
 277        u32 chunk_len;
 278        int i;
 279
 280        WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
 281
 282        spi_message_init(&m);
 283        memset(t, 0, sizeof(t));
 284
 285        cmd = &commands[0];
 286        i = 0;
 287        while (len > 0) {
 288                chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
 289
 290                *cmd = 0;
 291                *cmd |= WSPI_CMD_WRITE;
 292                *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
 293                        WSPI_CMD_BYTE_LENGTH;
 294                *cmd |= addr & WSPI_CMD_BYTE_ADDR;
 295
 296                if (fixed)
 297                        *cmd |= WSPI_CMD_FIXED;
 298
 299                t[i].tx_buf = cmd;
 300                t[i].len = sizeof(*cmd);
 301                spi_message_add_tail(&t[i++], &m);
 302
 303                t[i].tx_buf = buf;
 304                t[i].len = chunk_len;
 305                spi_message_add_tail(&t[i++], &m);
 306
 307                if (!fixed)
 308                        addr += chunk_len;
 309                buf += chunk_len;
 310                len -= chunk_len;
 311                cmd++;
 312        }
 313
 314        spi_sync(to_spi_device(glue->dev), &m);
 315
 316        return 0;
 317}
 318
 319static struct wl1271_if_operations spi_ops = {
 320        .read           = wl12xx_spi_raw_read,
 321        .write          = wl12xx_spi_raw_write,
 322        .reset          = wl12xx_spi_reset,
 323        .init           = wl12xx_spi_init,
 324        .set_block_size = NULL,
 325};
 326
 327static int wl1271_probe(struct spi_device *spi)
 328{
 329        struct wl12xx_spi_glue *glue;
 330        struct wlcore_platdev_data *pdev_data;
 331        struct resource res[1];
 332        int ret = -ENOMEM;
 333
 334        pdev_data = kzalloc(sizeof(*pdev_data), GFP_KERNEL);
 335        if (!pdev_data)
 336                goto out;
 337
 338        pdev_data->pdata = spi->dev.platform_data;
 339        if (!pdev_data->pdata) {
 340                dev_err(&spi->dev, "no platform data\n");
 341                ret = -ENODEV;
 342                goto out_free_pdev_data;
 343        }
 344
 345        pdev_data->if_ops = &spi_ops;
 346
 347        glue = kzalloc(sizeof(*glue), GFP_KERNEL);
 348        if (!glue) {
 349                dev_err(&spi->dev, "can't allocate glue\n");
 350                goto out_free_pdev_data;
 351        }
 352
 353        glue->dev = &spi->dev;
 354
 355        spi_set_drvdata(spi, glue);
 356
 357        /* This is the only SPI value that we need to set here, the rest
 358         * comes from the board-peripherals file */
 359        spi->bits_per_word = 32;
 360
 361        ret = spi_setup(spi);
 362        if (ret < 0) {
 363                dev_err(glue->dev, "spi_setup failed\n");
 364                goto out_free_glue;
 365        }
 366
 367        glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
 368        if (!glue->core) {
 369                dev_err(glue->dev, "can't allocate platform_device\n");
 370                ret = -ENOMEM;
 371                goto out_free_glue;
 372        }
 373
 374        glue->core->dev.parent = &spi->dev;
 375
 376        memset(res, 0x00, sizeof(res));
 377
 378        res[0].start = spi->irq;
 379        res[0].flags = IORESOURCE_IRQ;
 380        res[0].name = "irq";
 381
 382        ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
 383        if (ret) {
 384                dev_err(glue->dev, "can't add resources\n");
 385                goto out_dev_put;
 386        }
 387
 388        ret = platform_device_add_data(glue->core, pdev_data,
 389                                       sizeof(*pdev_data));
 390        if (ret) {
 391                dev_err(glue->dev, "can't add platform data\n");
 392                goto out_dev_put;
 393        }
 394
 395        ret = platform_device_add(glue->core);
 396        if (ret) {
 397                dev_err(glue->dev, "can't register platform device\n");
 398                goto out_dev_put;
 399        }
 400
 401        return 0;
 402
 403out_dev_put:
 404        platform_device_put(glue->core);
 405
 406out_free_glue:
 407        kfree(glue);
 408
 409out_free_pdev_data:
 410        kfree(pdev_data);
 411
 412out:
 413        return ret;
 414}
 415
 416static int wl1271_remove(struct spi_device *spi)
 417{
 418        struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
 419
 420        platform_device_unregister(glue->core);
 421        kfree(glue);
 422
 423        return 0;
 424}
 425
 426
 427static struct spi_driver wl1271_spi_driver = {
 428        .driver = {
 429                .name           = "wl1271_spi",
 430                .owner          = THIS_MODULE,
 431        },
 432
 433        .probe          = wl1271_probe,
 434        .remove         = wl1271_remove,
 435};
 436
 437static int __init wl1271_init(void)
 438{
 439        return spi_register_driver(&wl1271_spi_driver);
 440}
 441
 442static void __exit wl1271_exit(void)
 443{
 444        spi_unregister_driver(&wl1271_spi_driver);
 445}
 446
 447module_init(wl1271_init);
 448module_exit(wl1271_exit);
 449
 450MODULE_LICENSE("GPL");
 451MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
 452MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
 453MODULE_ALIAS("spi:wl1271");
 454