drivers/net/wireless/st/cw1200/cw1200_spi.c

   1 /*
   2  * Mac80211 SPI driver for ST-Ericsson CW1200 device
   3  *
   4  * Copyright (c) 2011, Sagrad Inc.
   5  * Author:  Solomon Peachy <speachy@sagrad.com>
   6  *
   7  * Based on cw1200_sdio.c
   8  * Copyright (c) 2010, ST-Ericsson
   9  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/gpio.h>
  18 #include <linux/delay.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/interrupt.h>
  21 #include <net/mac80211.h>
  22
  23 #include <linux/spi/spi.h>
  24 #include <linux/device.h>
  25
  26 #include "cw1200.h"
  27 #include "hwbus.h"
  28 #include <linux/platform_data/net-cw1200.h>
  29 #include "hwio.h"
  30
  31 MODULE_AUTHOR("Solomon Peachy <speachy@sagrad.com>");
  32 MODULE_DESCRIPTION("mac80211 ST-Ericsson CW1200 SPI driver");
  33 MODULE_LICENSE("GPL");
  34 MODULE_ALIAS("spi:cw1200_wlan_spi");
  35
  36 /* #define SPI_DEBUG */
  37
  38 struct hwbus_priv {
  39         struct spi_device       *func;
  40         struct cw1200_common    *core;
  41         const struct cw1200_platform_data_spi *pdata;
  42         spinlock_t              lock; /* Serialize all bus operations */
  43         wait_queue_head_t       wq;
  44         int claimed;
  45 };
  46
  47 #define SDIO_TO_SPI_ADDR(addr) ((addr & 0x1f)>>2)
  48 #define SET_WRITE 0x7FFF /* usage: and operation */
  49 #define SET_READ 0x8000  /* usage: or operation */
  50
  51 /* Notes on byte ordering:
  52    LE:  B0 B1 B2 B3
  53    BE:  B3 B2 B1 B0
  54
  55    Hardware expects 32-bit data to be written as 16-bit BE words:
  56
  57    B1 B0 B3 B2
  58 */
  59
  60 static int cw1200_spi_memcpy_fromio(struct hwbus_priv *self,
  61                                      unsigned int addr,
  62                                      void *dst, int count)
  63 {
  64         int ret, i;
  65         u16 regaddr;
  66         struct spi_message      m;
  67
  68         struct spi_transfer     t_addr = {
  69                 .tx_buf         = &regaddr,
  70                 .len            = sizeof(regaddr),
  71         };
  72         struct spi_transfer     t_msg = {
  73                 .rx_buf         = dst,
  74                 .len            = count,
  75         };
  76
  77         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
  78         regaddr |= SET_READ;
  79         regaddr |= (count>>1);
  80
  81 #ifdef SPI_DEBUG
  82         pr_info("READ : %04d from 0x%02x (%04x)\n", count, addr, regaddr);
  83 #endif
  84
  85         /* Header is LE16 */
  86         regaddr = cpu_to_le16(regaddr);
  87
  88         /* We have to byteswap if the SPI bus is limited to 8b operation
  89            or we are running on a Big Endian system
  90         */
  91 #if defined(__LITTLE_ENDIAN)
  92         if (self->func->bits_per_word == 8)
  93 #endif
  94                 regaddr = swab16(regaddr);
  95
  96         spi_message_init(&m);
  97         spi_message_add_tail(&t_addr, &m);
  98         spi_message_add_tail(&t_msg, &m);
  99         ret = spi_sync(self->func, &m);
 100
 101 #ifdef SPI_DEBUG
 102         pr_info("READ : ");
 103         for (i = 0; i < t_addr.len; i++)
 104                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 105         printk(" : ");
 106         for (i = 0; i < t_msg.len; i++)
 107                 printk("%02x ", ((u8 *)t_msg.rx_buf)[i]);
 108         printk("\n");
 109 #endif
 110
 111         /* We have to byteswap if the SPI bus is limited to 8b operation
 112            or we are running on a Big Endian system
 113         */
 114 #if defined(__LITTLE_ENDIAN)
 115         if (self->func->bits_per_word == 8)
 116 #endif
 117         {
 118                 uint16_t *buf = (uint16_t *)dst;
 119                 for (i = 0; i < ((count + 1) >> 1); i++)
 120                         buf[i] = swab16(buf[i]);
 121         }
 122
 123         return ret;
 124 }
 125
 126 static int cw1200_spi_memcpy_toio(struct hwbus_priv *self,
 127                                    unsigned int addr,
 128                                    const void *src, int count)
 129 {
 130         int rval, i;
 131         u16 regaddr;
 132         struct spi_transfer     t_addr = {
 133                 .tx_buf         = &regaddr,
 134                 .len            = sizeof(regaddr),
 135         };
 136         struct spi_transfer     t_msg = {
 137                 .tx_buf         = src,
 138                 .len            = count,
 139         };
 140         struct spi_message      m;
 141
 142         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
 143         regaddr &= SET_WRITE;
 144         regaddr |= (count>>1);
 145
 146 #ifdef SPI_DEBUG
 147         pr_info("WRITE: %04d  to  0x%02x (%04x)\n", count, addr, regaddr);
 148 #endif
 149
 150         /* Header is LE16 */
 151         regaddr = cpu_to_le16(regaddr);
 152
 153         /* We have to byteswap if the SPI bus is limited to 8b operation
 154            or we are running on a Big Endian system
 155         */
 156 #if defined(__LITTLE_ENDIAN)
 157         if (self->func->bits_per_word == 8)
 158 #endif
 159         {
 160                 uint16_t *buf = (uint16_t *)src;
 161                 regaddr = swab16(regaddr);
 162                 for (i = 0; i < ((count + 1) >> 1); i++)
 163                         buf[i] = swab16(buf[i]);
 164         }
 165
 166 #ifdef SPI_DEBUG
 167         pr_info("WRITE: ");
 168         for (i = 0; i < t_addr.len; i++)
 169                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 170         printk(" : ");
 171         for (i = 0; i < t_msg.len; i++)
 172                 printk("%02x ", ((u8 *)t_msg.tx_buf)[i]);
 173         printk("\n");
 174 #endif
 175
 176         spi_message_init(&m);
 177         spi_message_add_tail(&t_addr, &m);
 178         spi_message_add_tail(&t_msg, &m);
 179         rval = spi_sync(self->func, &m);
 180
 181 #ifdef SPI_DEBUG
 182         pr_info("WROTE: %d\n", m.actual_length);
 183 #endif
 184
 185 #if defined(__LITTLE_ENDIAN)
 186         /* We have to byteswap if the SPI bus is limited to 8b operation */
 187         if (self->func->bits_per_word == 8)
 188 #endif
 189         {
 190                 uint16_t *buf = (uint16_t *)src;
 191                 for (i = 0; i < ((count + 1) >> 1); i++)
 192                         buf[i] = swab16(buf[i]);
 193         }
 194         return rval;
 195 }
 196
 197 static void cw1200_spi_lock(struct hwbus_priv *self)
 198 {
 199         unsigned long flags;
 200
 201         DECLARE_WAITQUEUE(wait, current);
 202
 203         might_sleep();
 204
 205         add_wait_queue(&self->wq, &wait);
 206         spin_lock_irqsave(&self->lock, flags);
 207         while (1) {
 208                 set_current_state(TASK_UNINTERRUPTIBLE);
 209                 if (!self->claimed)
 210                         break;
 211                 spin_unlock_irqrestore(&self->lock, flags);
 212                 schedule();
 213                 spin_lock_irqsave(&self->lock, flags);
 214         }
 215         set_current_state(TASK_RUNNING);
 216         self->claimed = 1;
 217         spin_unlock_irqrestore(&self->lock, flags);
 218         remove_wait_queue(&self->wq, &wait);
 219
 220         return;
 221 }
 222
 223 static void cw1200_spi_unlock(struct hwbus_priv *self)
 224 {
 225         unsigned long flags;
 226
 227         spin_lock_irqsave(&self->lock, flags);
 228         self->claimed = 0;
 229         spin_unlock_irqrestore(&self->lock, flags);
 230         wake_up(&self->wq);
 231
 232         return;
 233 }
 234
 235 static irqreturn_t cw1200_spi_irq_handler(int irq, void *dev_id)
 236 {
 237         struct hwbus_priv *self = dev_id;
 238
 239         if (self->core) {
 240                 cw1200_spi_lock(self);
 241                 cw1200_irq_handler(self->core);
 242                 cw1200_spi_unlock(self);
 243                 return IRQ_HANDLED;
 244         } else {
 245                 return IRQ_NONE;
 246         }
 247 }
 248
 249 static int cw1200_spi_irq_subscribe(struct hwbus_priv *self)
 250 {
 251         int ret;
 252
 253         pr_debug("SW IRQ subscribe\n");
 254
 255         ret = request_threaded_irq(self->func->irq, NULL,
 256                                    cw1200_spi_irq_handler,
 257                                    IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
 258                                    "cw1200_wlan_irq", self);
 259         if (WARN_ON(ret < 0))
 260                 goto exit;
 261
 262         ret = enable_irq_wake(self->func->irq);
 263         if (WARN_ON(ret))
 264                 goto free_irq;
 265
 266         return 0;
 267
 268 free_irq:
 269         free_irq(self->func->irq, self);
 270 exit:
 271         return ret;
 272 }
 273
 274 static int cw1200_spi_irq_unsubscribe(struct hwbus_priv *self)
 275 {
 276         int ret = 0;
 277
 278         pr_debug("SW IRQ unsubscribe\n");
 279         disable_irq_wake(self->func->irq);
 280         free_irq(self->func->irq, self);
 281
 282         return ret;
 283 }
 284
 285 static int cw1200_spi_off(const struct cw1200_platform_data_spi *pdata)
 286 {
 287         if (pdata->reset) {
 288                 gpio_set_value(pdata->reset, 0);
 289                 msleep(30); /* Min is 2 * CLK32K cycles */
 290                 gpio_free(pdata->reset);
 291         }
 292
 293         if (pdata->power_ctrl)
 294                 pdata->power_ctrl(pdata, false);
 295         if (pdata->clk_ctrl)
 296                 pdata->clk_ctrl(pdata, false);
 297
 298         return 0;
 299 }
 300
 301 static int cw1200_spi_on(const struct cw1200_platform_data_spi *pdata)
 302 {
 303         /* Ensure I/Os are pulled low */
 304         if (pdata->reset) {
 305                 gpio_request(pdata->reset, "cw1200_wlan_reset");
 306                 gpio_direction_output(pdata->reset, 0);
 307         }
 308         if (pdata->powerup) {
 309                 gpio_request(pdata->powerup, "cw1200_wlan_powerup");
 310                 gpio_direction_output(pdata->powerup, 0);
 311         }
 312         if (pdata->reset || pdata->powerup)
 313                 msleep(10); /* Settle time? */
 314
 315         /* Enable 3v3 and 1v8 to hardware */
 316         if (pdata->power_ctrl) {
 317                 if (pdata->power_ctrl(pdata, true)) {
 318                         pr_err("power_ctrl() failed!\n");
 319                         return -1;
 320                 }
 321         }
 322
 323         /* Enable CLK32K */
 324         if (pdata->clk_ctrl) {
 325                 if (pdata->clk_ctrl(pdata, true)) {
 326                         pr_err("clk_ctrl() failed!\n");
 327                         return -1;
 328                 }
 329                 msleep(10); /* Delay until clock is stable for 2 cycles */
 330         }
 331
 332         /* Enable POWERUP signal */
 333         if (pdata->powerup) {
 334                 gpio_set_value(pdata->powerup, 1);
 335                 msleep(250); /* or more..? */
 336         }
 337         /* Enable RSTn signal */
 338         if (pdata->reset) {
 339                 gpio_set_value(pdata->reset, 1);
 340                 msleep(50); /* Or more..? */
 341         }
 342         return 0;
 343 }
 344
 345 static size_t cw1200_spi_align_size(struct hwbus_priv *self, size_t size)
 346 {
 347         return size & 1 ? size + 1 : size;
 348 }
 349
 350 static int cw1200_spi_pm(struct hwbus_priv *self, bool suspend)
 351 {
 352         return irq_set_irq_wake(self->func->irq, suspend);
 353 }
 354
 355 static struct hwbus_ops cw1200_spi_hwbus_ops = {
 356         .hwbus_memcpy_fromio    = cw1200_spi_memcpy_fromio,
 357         .hwbus_memcpy_toio      = cw1200_spi_memcpy_toio,
 358         .lock                   = cw1200_spi_lock,
 359         .unlock                 = cw1200_spi_unlock,
 360         .align_size             = cw1200_spi_align_size,
 361         .power_mgmt             = cw1200_spi_pm,
 362 };
 363
 364 /* Probe Function to be called by SPI stack when device is discovered */
 365 static int cw1200_spi_probe(struct spi_device *func)
 366 {
 367         const struct cw1200_platform_data_spi *plat_data =
 368                 dev_get_platdata(&func->dev);
 369         struct hwbus_priv *self;
 370         int status;
 371
 372         /* Sanity check speed */
 373         if (func->max_speed_hz > 52000000)
 374                 func->max_speed_hz = 52000000;
 375         if (func->max_speed_hz < 1000000)
 376                 func->max_speed_hz = 1000000;
 377
 378         /* Fix up transfer size */
 379         if (plat_data->spi_bits_per_word)
 380                 func->bits_per_word = plat_data->spi_bits_per_word;
 381         if (!func->bits_per_word)
 382                 func->bits_per_word = 16;
 383
 384         /* And finally.. */
 385         func->mode = SPI_MODE_0;
 386
 387         pr_info("cw1200_wlan_spi: Probe called (CS %d M %d BPW %d CLK %d)\n",
 388                 func->chip_select, func->mode, func->bits_per_word,
 389                 func->max_speed_hz);
 390
 391         if (cw1200_spi_on(plat_data)) {
 392                 pr_err("spi_on() failed!\n");
 393                 return -1;
 394         }
 395
 396         if (spi_setup(func)) {
 397                 pr_err("spi_setup() failed!\n");
 398                 return -1;
 399         }
 400
 401         self = devm_kzalloc(&func->dev, sizeof(*self), GFP_KERNEL);
 402         if (!self) {
 403                 pr_err("Can't allocate SPI hwbus_priv.");
 404                 return -ENOMEM;
 405         }
 406
 407         self->pdata = plat_data;
 408         self->func = func;
 409         spin_lock_init(&self->lock);
 410
 411         spi_set_drvdata(func, self);
 412
 413         init_waitqueue_head(&self->wq);
 414
 415         status = cw1200_spi_irq_subscribe(self);
 416
 417         status = cw1200_core_probe(&cw1200_spi_hwbus_ops,
 418                                    self, &func->dev, &self->core,
 419                                    self->pdata->ref_clk,
 420                                    self->pdata->macaddr,
 421                                    self->pdata->sdd_file,
 422                                    self->pdata->have_5ghz);
 423
 424         if (status) {
 425                 cw1200_spi_irq_unsubscribe(self);
 426                 cw1200_spi_off(plat_data);
 427         }
 428
 429         return status;
 430 }
 431
 432 /* Disconnect Function to be called by SPI stack when device is disconnected */
 433 static int cw1200_spi_disconnect(struct spi_device *func)
 434 {
 435         struct hwbus_priv *self = spi_get_drvdata(func);
 436
 437         if (self) {
 438                 cw1200_spi_irq_unsubscribe(self);
 439                 if (self->core) {
 440                         cw1200_core_release(self->core);
 441                         self->core = NULL;
 442                 }
 443         }
 444         cw1200_spi_off(dev_get_platdata(&func->dev));
 445
 446         return 0;
 447 }
 448
 449 static int __maybe_unused cw1200_spi_suspend(struct device *dev)
 450 {
 451         struct hwbus_priv *self = spi_get_drvdata(to_spi_device(dev));
 452
 453         if (!cw1200_can_suspend(self->core))
 454                 return -EAGAIN;
 455
 456         /* XXX notify host that we have to keep CW1200 powered on? */
 457         return 0;
 458 }
 459
 460 static SIMPLE_DEV_PM_OPS(cw1200_pm_ops, cw1200_spi_suspend, NULL);
 461
 462 static struct spi_driver spi_driver = {
 463         .probe          = cw1200_spi_probe,
 464         .remove         = cw1200_spi_disconnect,
 465         .driver = {
 466                 .name           = "cw1200_wlan_spi",
 467                 .pm             = IS_ENABLED(CONFIG_PM) ? &cw1200_pm_ops : NULL,
 468         },
 469 };
 470
 471 module_spi_driver(spi_driver);