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         int claimed;
  44 };
  45
  46 #define SDIO_TO_SPI_ADDR(addr) ((addr & 0x1f)>>2)
  47 #define SET_WRITE 0x7FFF /* usage: and operation */
  48 #define SET_READ 0x8000  /* usage: or operation */
  49
  50 /* Notes on byte ordering:
  51    LE:  B0 B1 B2 B3
  52    BE:  B3 B2 B1 B0
  53
  54    Hardware expects 32-bit data to be written as 16-bit BE words:
  55
  56    B1 B0 B3 B2
  57 */
  58
  59 static int cw1200_spi_memcpy_fromio(struct hwbus_priv *self,
  60                                      unsigned int addr,
  61                                      void *dst, int count)
  62 {
  63         int ret, i;
  64         u16 regaddr;
  65         struct spi_message      m;
  66
  67         struct spi_transfer     t_addr = {
  68                 .tx_buf         = &regaddr,
  69                 .len            = sizeof(regaddr),
  70         };
  71         struct spi_transfer     t_msg = {
  72                 .rx_buf         = dst,
  73                 .len            = count,
  74         };
  75
  76         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
  77         regaddr |= SET_READ;
  78         regaddr |= (count>>1);
  79
  80 #ifdef SPI_DEBUG
  81         pr_info("READ : %04d from 0x%02x (%04x)\n", count, addr, regaddr);
  82 #endif
  83
  84         /* Header is LE16 */
  85         regaddr = cpu_to_le16(regaddr);
  86
  87         /* We have to byteswap if the SPI bus is limited to 8b operation
  88            or we are running on a Big Endian system
  89         */
  90 #if defined(__LITTLE_ENDIAN)
  91         if (self->func->bits_per_word == 8)
  92 #endif
  93                 regaddr = swab16(regaddr);
  94
  95         spi_message_init(&m);
  96         spi_message_add_tail(&t_addr, &m);
  97         spi_message_add_tail(&t_msg, &m);
  98         ret = spi_sync(self->func, &m);
  99
 100 #ifdef SPI_DEBUG
 101         pr_info("READ : ");
 102         for (i = 0; i < t_addr.len; i++)
 103                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 104         printk(" : ");
 105         for (i = 0; i < t_msg.len; i++)
 106                 printk("%02x ", ((u8 *)t_msg.rx_buf)[i]);
 107         printk("\n");
 108 #endif
 109
 110         /* We have to byteswap if the SPI bus is limited to 8b operation
 111            or we are running on a Big Endian system
 112         */
 113 #if defined(__LITTLE_ENDIAN)
 114         if (self->func->bits_per_word == 8)
 115 #endif
 116         {
 117                 uint16_t *buf = (uint16_t *)dst;
 118                 for (i = 0; i < ((count + 1) >> 1); i++)
 119                         buf[i] = swab16(buf[i]);
 120         }
 121
 122         return ret;
 123 }
 124
 125 static int cw1200_spi_memcpy_toio(struct hwbus_priv *self,
 126                                    unsigned int addr,
 127                                    const void *src, int count)
 128 {
 129         int rval, i;
 130         u16 regaddr;
 131         struct spi_transfer     t_addr = {
 132                 .tx_buf         = &regaddr,
 133                 .len            = sizeof(regaddr),
 134         };
 135         struct spi_transfer     t_msg = {
 136                 .tx_buf         = src,
 137                 .len            = count,
 138         };
 139         struct spi_message      m;
 140
 141         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
 142         regaddr &= SET_WRITE;
 143         regaddr |= (count>>1);
 144
 145 #ifdef SPI_DEBUG
 146         pr_info("WRITE: %04d  to  0x%02x (%04x)\n", count, addr, regaddr);
 147 #endif
 148
 149         /* Header is LE16 */
 150         regaddr = cpu_to_le16(regaddr);
 151
 152         /* We have to byteswap if the SPI bus is limited to 8b operation
 153            or we are running on a Big Endian system
 154         */
 155 #if defined(__LITTLE_ENDIAN)
 156         if (self->func->bits_per_word == 8)
 157 #endif
 158         {
 159                 uint16_t *buf = (uint16_t *)src;
 160                 regaddr = swab16(regaddr);
 161                 for (i = 0; i < ((count + 1) >> 1); i++)
 162                         buf[i] = swab16(buf[i]);
 163         }
 164
 165 #ifdef SPI_DEBUG
 166         pr_info("WRITE: ");
 167         for (i = 0; i < t_addr.len; i++)
 168                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 169         printk(" : ");
 170         for (i = 0; i < t_msg.len; i++)
 171                 printk("%02x ", ((u8 *)t_msg.tx_buf)[i]);
 172         printk("\n");
 173 #endif
 174
 175         spi_message_init(&m);
 176         spi_message_add_tail(&t_addr, &m);
 177         spi_message_add_tail(&t_msg, &m);
 178         rval = spi_sync(self->func, &m);
 179
 180 #ifdef SPI_DEBUG
 181         pr_info("WROTE: %d\n", m.actual_length);
 182 #endif
 183
 184 #if defined(__LITTLE_ENDIAN)
 185         /* We have to byteswap if the SPI bus is limited to 8b operation */
 186         if (self->func->bits_per_word == 8)
 187 #endif
 188         {
 189                 uint16_t *buf = (uint16_t *)src;
 190                 for (i = 0; i < ((count + 1) >> 1); i++)
 191                         buf[i] = swab16(buf[i]);
 192         }
 193         return rval;
 194 }
 195
 196 static void cw1200_spi_lock(struct hwbus_priv *self)
 197 {
 198         unsigned long flags;
 199
 200         might_sleep();
 201
 202         spin_lock_irqsave(&self->lock, flags);
 203         while (1) {
 204                 set_current_state(TASK_UNINTERRUPTIBLE);
 205                 if (!self->claimed)
 206                         break;
 207                 spin_unlock_irqrestore(&self->lock, flags);
 208                 schedule();
 209                 spin_lock_irqsave(&self->lock, flags);
 210         }
 211         set_current_state(TASK_RUNNING);
 212         self->claimed = 1;
 213         spin_unlock_irqrestore(&self->lock, flags);
 214
 215         return;
 216 }
 217
 218 static void cw1200_spi_unlock(struct hwbus_priv *self)
 219 {
 220         unsigned long flags;
 221
 222         spin_lock_irqsave(&self->lock, flags);
 223         self->claimed = 0;
 224         spin_unlock_irqrestore(&self->lock, flags);
 225         return;
 226 }
 227
 228 static irqreturn_t cw1200_spi_irq_handler(int irq, void *dev_id)
 229 {
 230         struct hwbus_priv *self = dev_id;
 231
 232         if (self->core) {
 233                 cw1200_irq_handler(self->core);
 234                 return IRQ_HANDLED;
 235         } else {
 236                 return IRQ_NONE;
 237         }
 238 }
 239
 240 static int cw1200_spi_irq_subscribe(struct hwbus_priv *self)
 241 {
 242         int ret;
 243
 244         pr_debug("SW IRQ subscribe\n");
 245
 246         ret = request_any_context_irq(self->func->irq, cw1200_spi_irq_handler,
 247                                       IRQF_TRIGGER_HIGH,
 248                                       "cw1200_wlan_irq", self);
 249         if (WARN_ON(ret < 0))
 250                 goto exit;
 251
 252         ret = enable_irq_wake(self->func->irq);
 253         if (WARN_ON(ret))
 254                 goto free_irq;
 255
 256         return 0;
 257
 258 free_irq:
 259         free_irq(self->func->irq, self);
 260 exit:
 261         return ret;
 262 }
 263
 264 static int cw1200_spi_irq_unsubscribe(struct hwbus_priv *self)
 265 {
 266         int ret = 0;
 267
 268         pr_debug("SW IRQ unsubscribe\n");
 269         disable_irq_wake(self->func->irq);
 270         free_irq(self->func->irq, self);
 271
 272         return ret;
 273 }
 274
 275 static int cw1200_spi_off(const struct cw1200_platform_data_spi *pdata)
 276 {
 277         if (pdata->reset) {
 278                 gpio_set_value(pdata->reset, 0);
 279                 msleep(30); /* Min is 2 * CLK32K cycles */
 280                 gpio_free(pdata->reset);
 281         }
 282
 283         if (pdata->power_ctrl)
 284                 pdata->power_ctrl(pdata, false);
 285         if (pdata->clk_ctrl)
 286                 pdata->clk_ctrl(pdata, false);
 287
 288         return 0;
 289 }
 290
 291 static int cw1200_spi_on(const struct cw1200_platform_data_spi *pdata)
 292 {
 293         /* Ensure I/Os are pulled low */
 294         if (pdata->reset) {
 295                 gpio_request(pdata->reset, "cw1200_wlan_reset");
 296                 gpio_direction_output(pdata->reset, 0);
 297         }
 298         if (pdata->powerup) {
 299                 gpio_request(pdata->powerup, "cw1200_wlan_powerup");
 300                 gpio_direction_output(pdata->powerup, 0);
 301         }
 302         if (pdata->reset || pdata->powerup)
 303                 msleep(10); /* Settle time? */
 304
 305         /* Enable 3v3 and 1v8 to hardware */
 306         if (pdata->power_ctrl) {
 307                 if (pdata->power_ctrl(pdata, true)) {
 308                         pr_err("power_ctrl() failed!\n");
 309                         return -1;
 310                 }
 311         }
 312
 313         /* Enable CLK32K */
 314         if (pdata->clk_ctrl) {
 315                 if (pdata->clk_ctrl(pdata, true)) {
 316                         pr_err("clk_ctrl() failed!\n");
 317                         return -1;
 318                 }
 319                 msleep(10); /* Delay until clock is stable for 2 cycles */
 320         }
 321
 322         /* Enable POWERUP signal */
 323         if (pdata->powerup) {
 324                 gpio_set_value(pdata->powerup, 1);
 325                 msleep(250); /* or more..? */
 326         }
 327         /* Enable RSTn signal */
 328         if (pdata->reset) {
 329                 gpio_set_value(pdata->reset, 1);
 330                 msleep(50); /* Or more..? */
 331         }
 332         return 0;
 333 }
 334
 335 static size_t cw1200_spi_align_size(struct hwbus_priv *self, size_t size)
 336 {
 337         return size & 1 ? size + 1 : size;
 338 }
 339
 340 static int cw1200_spi_pm(struct hwbus_priv *self, bool suspend)
 341 {
 342         return irq_set_irq_wake(self->func->irq, suspend);
 343 }
 344
 345 static struct hwbus_ops cw1200_spi_hwbus_ops = {
 346         .hwbus_memcpy_fromio    = cw1200_spi_memcpy_fromio,
 347         .hwbus_memcpy_toio      = cw1200_spi_memcpy_toio,
 348         .lock                   = cw1200_spi_lock,
 349         .unlock                 = cw1200_spi_unlock,
 350         .align_size             = cw1200_spi_align_size,
 351         .power_mgmt             = cw1200_spi_pm,
 352 };
 353
 354 /* Probe Function to be called by SPI stack when device is discovered */
 355 static int cw1200_spi_probe(struct spi_device *func)
 356 {
 357         const struct cw1200_platform_data_spi *plat_data =
 358                 func->dev.platform_data;
 359         struct hwbus_priv *self;
 360         int status;
 361
 362         /* Sanity check speed */
 363         if (func->max_speed_hz > 52000000)
 364                 func->max_speed_hz = 52000000;
 365         if (func->max_speed_hz < 1000000)
 366                 func->max_speed_hz = 1000000;
 367
 368         /* Fix up transfer size */
 369         if (plat_data->spi_bits_per_word)
 370                 func->bits_per_word = plat_data->spi_bits_per_word;
 371         if (!func->bits_per_word)
 372                 func->bits_per_word = 16;
 373
 374         /* And finally.. */
 375         func->mode = SPI_MODE_0;
 376
 377         pr_info("cw1200_wlan_spi: Probe called (CS %d M %d BPW %d CLK %d)\n",
 378                 func->chip_select, func->mode, func->bits_per_word,
 379                 func->max_speed_hz);
 380
 381         if (cw1200_spi_on(plat_data)) {
 382                 pr_err("spi_on() failed!\n");
 383                 return -1;
 384         }
 385
 386         if (spi_setup(func)) {
 387                 pr_err("spi_setup() failed!\n");
 388                 return -1;
 389         }
 390
 391         self = kzalloc(sizeof(*self), GFP_KERNEL);
 392         if (!self) {
 393                 pr_err("Can't allocate SPI hwbus_priv.");
 394                 return -ENOMEM;
 395         }
 396
 397         self->pdata = plat_data;
 398         self->func = func;
 399         spin_lock_init(&self->lock);
 400
 401         spi_set_drvdata(func, self);
 402
 403         status = cw1200_spi_irq_subscribe(self);
 404
 405         status = cw1200_core_probe(&cw1200_spi_hwbus_ops,
 406                                    self, &func->dev, &self->core,
 407                                    self->pdata->ref_clk,
 408                                    self->pdata->macaddr,
 409                                    self->pdata->sdd_file,
 410                                    self->pdata->have_5ghz);
 411
 412         if (status) {
 413                 cw1200_spi_irq_unsubscribe(self);
 414                 cw1200_spi_off(plat_data);
 415                 kfree(self);
 416         }
 417
 418         return status;
 419 }
 420
 421 /* Disconnect Function to be called by SPI stack when device is disconnected */
 422 static int cw1200_spi_disconnect(struct spi_device *func)
 423 {
 424         struct hwbus_priv *self = spi_get_drvdata(func);
 425
 426         if (self) {
 427                 cw1200_spi_irq_unsubscribe(self);
 428                 if (self->core) {
 429                         cw1200_core_release(self->core);
 430                         self->core = NULL;
 431                 }
 432                 kfree(self);
 433         }
 434         cw1200_spi_off(func->dev.platform_data);
 435
 436         return 0;
 437 }
 438
 439 #ifdef CONFIG_PM
 440 static int cw1200_spi_suspend(struct device *dev, pm_message_t state)
 441 {
 442         struct hwbus_priv *self = spi_get_drvdata(to_spi_device(dev));
 443
 444         if (!cw1200_can_suspend(self->core))
 445                 return -EAGAIN;
 446
 447         /* XXX notify host that we have to keep CW1200 powered on? */
 448         return 0;
 449 }
 450
 451 static int cw1200_spi_resume(struct device *dev)
 452 {
 453         return 0;
 454 }
 455 #endif
 456
 457 static struct spi_driver spi_driver = {
 458         .probe          = cw1200_spi_probe,
 459         .remove         = cw1200_spi_disconnect,
 460         .driver = {
 461                 .name           = "cw1200_wlan_spi",
 462                 .bus            = &spi_bus_type,
 463                 .owner          = THIS_MODULE,
 464 #ifdef CONFIG_PM
 465                 .suspend        = cw1200_spi_suspend,
 466                 .resume         = cw1200_spi_resume,
 467 #endif
 468         },
 469 };
 470
 471 module_spi_driver(spi_driver);