drivers/net/wireless/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         int irq_disabled;
  46 };
  47
  48 #define SDIO_TO_SPI_ADDR(addr) ((addr & 0x1f)>>2)
  49 #define SET_WRITE 0x7FFF /* usage: and operation */
  50 #define SET_READ 0x8000  /* usage: or operation */
  51
  52 /* Notes on byte ordering:
  53    LE:  B0 B1 B2 B3
  54    BE:  B3 B2 B1 B0
  55
  56    Hardware expects 32-bit data to be written as 16-bit BE words:
  57
  58    B1 B0 B3 B2
  59 */
  60
  61 static int cw1200_spi_memcpy_fromio(struct hwbus_priv *self,
  62                                      unsigned int addr,
  63                                      void *dst, int count)
  64 {
  65         int ret, i;
  66         u16 regaddr;
  67         struct spi_message      m;
  68
  69         struct spi_transfer     t_addr = {
  70                 .tx_buf         = &regaddr,
  71                 .len            = sizeof(regaddr),
  72         };
  73         struct spi_transfer     t_msg = {
  74                 .rx_buf         = dst,
  75                 .len            = count,
  76         };
  77
  78         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
  79         regaddr |= SET_READ;
  80         regaddr |= (count>>1);
  81
  82 #ifdef SPI_DEBUG
  83         pr_info("READ : %04d from 0x%02x (%04x)\n", count, addr, regaddr);
  84 #endif
  85
  86         /* Header is LE16 */
  87         regaddr = cpu_to_le16(regaddr);
  88
  89         /* We have to byteswap if the SPI bus is limited to 8b operation
  90            or we are running on a Big Endian system
  91         */
  92 #if defined(__LITTLE_ENDIAN)
  93         if (self->func->bits_per_word == 8)
  94 #endif
  95                 regaddr = swab16(regaddr);
  96
  97         spi_message_init(&m);
  98         spi_message_add_tail(&t_addr, &m);
  99         spi_message_add_tail(&t_msg, &m);
 100         ret = spi_sync(self->func, &m);
 101
 102 #ifdef SPI_DEBUG
 103         pr_info("READ : ");
 104         for (i = 0; i < t_addr.len; i++)
 105                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 106         printk(" : ");
 107         for (i = 0; i < t_msg.len; i++)
 108                 printk("%02x ", ((u8 *)t_msg.rx_buf)[i]);
 109         printk("\n");
 110 #endif
 111
 112         /* We have to byteswap if the SPI bus is limited to 8b operation
 113            or we are running on a Big Endian system
 114         */
 115 #if defined(__LITTLE_ENDIAN)
 116         if (self->func->bits_per_word == 8)
 117 #endif
 118         {
 119                 uint16_t *buf = (uint16_t *)dst;
 120                 for (i = 0; i < ((count + 1) >> 1); i++)
 121                         buf[i] = swab16(buf[i]);
 122         }
 123
 124         return ret;
 125 }
 126
 127 static int cw1200_spi_memcpy_toio(struct hwbus_priv *self,
 128                                    unsigned int addr,
 129                                    const void *src, int count)
 130 {
 131         int rval, i;
 132         u16 regaddr;
 133         struct spi_transfer     t_addr = {
 134                 .tx_buf         = &regaddr,
 135                 .len            = sizeof(regaddr),
 136         };
 137         struct spi_transfer     t_msg = {
 138                 .tx_buf         = src,
 139                 .len            = count,
 140         };
 141         struct spi_message      m;
 142
 143         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
 144         regaddr &= SET_WRITE;
 145         regaddr |= (count>>1);
 146
 147 #ifdef SPI_DEBUG
 148         pr_info("WRITE: %04d  to  0x%02x (%04x)\n", count, addr, regaddr);
 149 #endif
 150
 151         /* Header is LE16 */
 152         regaddr = cpu_to_le16(regaddr);
 153
 154         /* We have to byteswap if the SPI bus is limited to 8b operation
 155            or we are running on a Big Endian system
 156         */
 157 #if defined(__LITTLE_ENDIAN)
 158         if (self->func->bits_per_word == 8)
 159 #endif
 160         {
 161                 uint16_t *buf = (uint16_t *)src;
 162                 regaddr = swab16(regaddr);
 163                 for (i = 0; i < ((count + 1) >> 1); i++)
 164                         buf[i] = swab16(buf[i]);
 165         }
 166
 167 #ifdef SPI_DEBUG
 168         pr_info("WRITE: ");
 169         for (i = 0; i < t_addr.len; i++)
 170                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 171         printk(" : ");
 172         for (i = 0; i < t_msg.len; i++)
 173                 printk("%02x ", ((u8 *)t_msg.tx_buf)[i]);
 174         printk("\n");
 175 #endif
 176
 177         spi_message_init(&m);
 178         spi_message_add_tail(&t_addr, &m);
 179         spi_message_add_tail(&t_msg, &m);
 180         rval = spi_sync(self->func, &m);
 181
 182 #ifdef SPI_DEBUG
 183         pr_info("WROTE: %d\n", m.actual_length);
 184 #endif
 185
 186 #if defined(__LITTLE_ENDIAN)
 187         /* We have to byteswap if the SPI bus is limited to 8b operation */
 188         if (self->func->bits_per_word == 8)
 189 #endif
 190         {
 191                 uint16_t *buf = (uint16_t *)src;
 192                 for (i = 0; i < ((count + 1) >> 1); i++)
 193                         buf[i] = swab16(buf[i]);
 194         }
 195         return rval;
 196 }
 197
 198 static void cw1200_spi_lock(struct hwbus_priv *self)
 199 {
 200         unsigned long flags;
 201
 202         DECLARE_WAITQUEUE(wait, current);
 203
 204         might_sleep();
 205
 206         add_wait_queue(&self->wq, &wait);
 207         spin_lock_irqsave(&self->lock, flags);
 208         while (1) {
 209                 set_current_state(TASK_UNINTERRUPTIBLE);
 210                 if (!self->claimed)
 211                         break;
 212                 spin_unlock_irqrestore(&self->lock, flags);
 213                 schedule();
 214                 spin_lock_irqsave(&self->lock, flags);
 215         }
 216         set_current_state(TASK_RUNNING);
 217         self->claimed = 1;
 218         spin_unlock_irqrestore(&self->lock, flags);
 219         remove_wait_queue(&self->wq, &wait);
 220
 221         return;
 222 }
 223
 224 static void cw1200_spi_unlock(struct hwbus_priv *self)
 225 {
 226         unsigned long flags;
 227
 228         spin_lock_irqsave(&self->lock, flags);
 229         self->claimed = 0;
 230         spin_unlock_irqrestore(&self->lock, flags);
 231         wake_up(&self->wq);
 232
 233         return;
 234 }
 235
 236 static irqreturn_t cw1200_spi_irq_handler(int irq, void *dev_id)
 237 {
 238         struct hwbus_priv *self = dev_id;
 239
 240         if (self->core) {
 241                 disable_irq_nosync(self->func->irq);
 242                 self->irq_disabled = 1;
 243                 cw1200_irq_handler(self->core);
 244                 return IRQ_HANDLED;
 245         } else {
 246                 return IRQ_NONE;
 247         }
 248 }
 249
 250 static int cw1200_spi_irq_subscribe(struct hwbus_priv *self)
 251 {
 252         int ret;
 253
 254         pr_debug("SW IRQ subscribe\n");
 255
 256         ret = request_any_context_irq(self->func->irq, cw1200_spi_irq_handler,
 257                                       IRQF_TRIGGER_HIGH,
 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         pr_debug("SW IRQ unsubscribe\n");
 277         disable_irq_wake(self->func->irq);
 278         free_irq(self->func->irq, self);
 279
 280         return 0;
 281 }
 282
 283 static int cw1200_spi_irq_enable(struct hwbus_priv *self, int enable)
 284 {
 285         /* Disables are handled by the interrupt handler */
 286         if (enable && self->irq_disabled) {
 287                 enable_irq(self->func->irq);
 288                 self->irq_disabled = 0;
 289         }
 290
 291         return 0;
 292 }
 293
 294 static int cw1200_spi_off(const struct cw1200_platform_data_spi *pdata)
 295 {
 296         if (pdata->reset) {
 297                 gpio_set_value(pdata->reset, 0);
 298                 msleep(30); /* Min is 2 * CLK32K cycles */
 299                 gpio_free(pdata->reset);
 300         }
 301
 302         if (pdata->power_ctrl)
 303                 pdata->power_ctrl(pdata, false);
 304         if (pdata->clk_ctrl)
 305                 pdata->clk_ctrl(pdata, false);
 306
 307         return 0;
 308 }
 309
 310 static int cw1200_spi_on(const struct cw1200_platform_data_spi *pdata)
 311 {
 312         /* Ensure I/Os are pulled low */
 313         if (pdata->reset) {
 314                 gpio_request(pdata->reset, "cw1200_wlan_reset");
 315                 gpio_direction_output(pdata->reset, 0);
 316         }
 317         if (pdata->powerup) {
 318                 gpio_request(pdata->powerup, "cw1200_wlan_powerup");
 319                 gpio_direction_output(pdata->powerup, 0);
 320         }
 321         if (pdata->reset || pdata->powerup)
 322                 msleep(10); /* Settle time? */
 323
 324         /* Enable 3v3 and 1v8 to hardware */
 325         if (pdata->power_ctrl) {
 326                 if (pdata->power_ctrl(pdata, true)) {
 327                         pr_err("power_ctrl() failed!\n");
 328                         return -1;
 329                 }
 330         }
 331
 332         /* Enable CLK32K */
 333         if (pdata->clk_ctrl) {
 334                 if (pdata->clk_ctrl(pdata, true)) {
 335                         pr_err("clk_ctrl() failed!\n");
 336                         return -1;
 337                 }
 338                 msleep(10); /* Delay until clock is stable for 2 cycles */
 339         }
 340
 341         /* Enable POWERUP signal */
 342         if (pdata->powerup) {
 343                 gpio_set_value(pdata->powerup, 1);
 344                 msleep(250); /* or more..? */
 345         }
 346         /* Enable RSTn signal */
 347         if (pdata->reset) {
 348                 gpio_set_value(pdata->reset, 1);
 349                 msleep(50); /* Or more..? */
 350         }
 351         return 0;
 352 }
 353
 354 static size_t cw1200_spi_align_size(struct hwbus_priv *self, size_t size)
 355 {
 356         return size & 1 ? size + 1 : size;
 357 }
 358
 359 static int cw1200_spi_pm(struct hwbus_priv *self, bool suspend)
 360 {
 361         return irq_set_irq_wake(self->func->irq, suspend);
 362 }
 363
 364 static struct hwbus_ops cw1200_spi_hwbus_ops = {
 365         .hwbus_memcpy_fromio    = cw1200_spi_memcpy_fromio,
 366         .hwbus_memcpy_toio      = cw1200_spi_memcpy_toio,
 367         .lock                   = cw1200_spi_lock,
 368         .unlock                 = cw1200_spi_unlock,
 369         .align_size             = cw1200_spi_align_size,
 370         .power_mgmt             = cw1200_spi_pm,
 371         .irq_enable             = cw1200_spi_irq_enable,
 372 };
 373
 374 /* Probe Function to be called by SPI stack when device is discovered */
 375 static int cw1200_spi_probe(struct spi_device *func)
 376 {
 377         const struct cw1200_platform_data_spi *plat_data =
 378                 func->dev.platform_data;
 379         struct hwbus_priv *self;
 380         int status;
 381
 382         /* Sanity check speed */
 383         if (func->max_speed_hz > 52000000)
 384                 func->max_speed_hz = 52000000;
 385         if (func->max_speed_hz < 1000000)
 386                 func->max_speed_hz = 1000000;
 387
 388         /* Fix up transfer size */
 389         if (plat_data->spi_bits_per_word)
 390                 func->bits_per_word = plat_data->spi_bits_per_word;
 391         if (!func->bits_per_word)
 392                 func->bits_per_word = 16;
 393
 394         /* And finally.. */
 395         func->mode = SPI_MODE_0;
 396
 397         pr_info("cw1200_wlan_spi: Probe called (CS %d M %d BPW %d CLK %d)\n",
 398                 func->chip_select, func->mode, func->bits_per_word,
 399                 func->max_speed_hz);
 400
 401         if (cw1200_spi_on(plat_data)) {
 402                 pr_err("spi_on() failed!\n");
 403                 return -1;
 404         }
 405
 406         if (spi_setup(func)) {
 407                 pr_err("spi_setup() failed!\n");
 408                 return -1;
 409         }
 410
 411         self = kzalloc(sizeof(*self), GFP_KERNEL);
 412         if (!self) {
 413                 pr_err("Can't allocate SPI hwbus_priv.");
 414                 return -ENOMEM;
 415         }
 416
 417         self->pdata = plat_data;
 418         self->func = func;
 419         spin_lock_init(&self->lock);
 420
 421         spi_set_drvdata(func, self);
 422
 423         init_waitqueue_head(&self->wq);
 424
 425         status = cw1200_spi_irq_subscribe(self);
 426
 427         status = cw1200_core_probe(&cw1200_spi_hwbus_ops,
 428                                    self, &func->dev, &self->core,
 429                                    self->pdata->ref_clk,
 430                                    self->pdata->macaddr,
 431                                    self->pdata->sdd_file,
 432                                    self->pdata->have_5ghz);
 433
 434         if (status) {
 435                 cw1200_spi_irq_unsubscribe(self);
 436                 cw1200_spi_off(plat_data);
 437                 kfree(self);
 438         }
 439
 440         return status;
 441 }
 442
 443 /* Disconnect Function to be called by SPI stack when device is disconnected */
 444 static int cw1200_spi_disconnect(struct spi_device *func)
 445 {
 446         struct hwbus_priv *self = spi_get_drvdata(func);
 447
 448         if (self) {
 449                 cw1200_spi_irq_unsubscribe(self);
 450                 if (self->core) {
 451                         cw1200_core_release(self->core);
 452                         self->core = NULL;
 453                 }
 454                 kfree(self);
 455         }
 456         cw1200_spi_off(func->dev.platform_data);
 457
 458         return 0;
 459 }
 460
 461 #ifdef CONFIG_PM
 462 static int cw1200_spi_suspend(struct device *dev, pm_message_t state)
 463 {
 464         struct hwbus_priv *self = spi_get_drvdata(to_spi_device(dev));
 465
 466         if (!cw1200_can_suspend(self->core))
 467                 return -EAGAIN;
 468
 469         /* XXX notify host that we have to keep CW1200 powered on? */
 470         return 0;
 471 }
 472
 473 static int cw1200_spi_resume(struct device *dev)
 474 {
 475         return 0;
 476 }
 477 #endif
 478
 479 static struct spi_driver spi_driver = {
 480         .probe          = cw1200_spi_probe,
 481         .remove         = cw1200_spi_disconnect,
 482         .driver = {
 483                 .name           = "cw1200_wlan_spi",
 484                 .bus            = &spi_bus_type,
 485                 .owner          = THIS_MODULE,
 486 #ifdef CONFIG_PM
 487                 .suspend        = cw1200_spi_suspend,
 488                 .resume         = cw1200_spi_resume,
 489 #endif
 490         },
 491 };
 492
 493 module_spi_driver(spi_driver);