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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Mac80211 SPI driver for ST-Ericsson CW1200 device
   4  *
   5  * Copyright (c) 2011, Sagrad Inc.
   6  * Author:  Solomon Peachy <speachy@sagrad.com>
   7  *
   8  * Based on cw1200_sdio.c
   9  * Copyright (c) 2010, ST-Ericsson
  10  * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/gpio.h>
  15 #include <linux/delay.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/interrupt.h>
  18 #include <net/mac80211.h>
  19
  20 #include <linux/spi/spi.h>
  21 #include <linux/device.h>
  22
  23 #include "cw1200.h"
  24 #include "hwbus.h"
  25 #include <linux/platform_data/net-cw1200.h>
  26 #include "hwio.h"
  27
  28 MODULE_AUTHOR("Solomon Peachy <speachy@sagrad.com>");
  29 MODULE_DESCRIPTION("mac80211 ST-Ericsson CW1200 SPI driver");
  30 MODULE_LICENSE("GPL");
  31 MODULE_ALIAS("spi:cw1200_wlan_spi");
  32
  33 /* #define SPI_DEBUG */
  34
  35 struct hwbus_priv {
  36         struct spi_device       *func;
  37         struct cw1200_common    *core;
  38         const struct cw1200_platform_data_spi *pdata;
  39         spinlock_t              lock; /* Serialize all bus operations */
  40         wait_queue_head_t       wq;
  41         int claimed;
  42 };
  43
  44 #define SDIO_TO_SPI_ADDR(addr) ((addr & 0x1f)>>2)
  45 #define SET_WRITE 0x7FFF /* usage: and operation */
  46 #define SET_READ 0x8000  /* usage: or operation */
  47
  48 /* Notes on byte ordering:
  49    LE:  B0 B1 B2 B3
  50    BE:  B3 B2 B1 B0
  51
  52    Hardware expects 32-bit data to be written as 16-bit BE words:
  53
  54    B1 B0 B3 B2
  55 */
  56
  57 static int cw1200_spi_memcpy_fromio(struct hwbus_priv *self,
  58                                      unsigned int addr,
  59                                      void *dst, int count)
  60 {
  61         int ret, i;
  62         u16 regaddr;
  63         struct spi_message      m;
  64
  65         struct spi_transfer     t_addr = {
  66                 .tx_buf         = &regaddr,
  67                 .len            = sizeof(regaddr),
  68         };
  69         struct spi_transfer     t_msg = {
  70                 .rx_buf         = dst,
  71                 .len            = count,
  72         };
  73
  74         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
  75         regaddr |= SET_READ;
  76         regaddr |= (count>>1);
  77
  78 #ifdef SPI_DEBUG
  79         pr_info("READ : %04d from 0x%02x (%04x)\n", count, addr, regaddr);
  80 #endif
  81
  82         /* Header is LE16 */
  83         regaddr = cpu_to_le16(regaddr);
  84
  85         /* We have to byteswap if the SPI bus is limited to 8b operation
  86            or we are running on a Big Endian system
  87         */
  88 #if defined(__LITTLE_ENDIAN)
  89         if (self->func->bits_per_word == 8)
  90 #endif
  91                 regaddr = swab16(regaddr);
  92
  93         spi_message_init(&m);
  94         spi_message_add_tail(&t_addr, &m);
  95         spi_message_add_tail(&t_msg, &m);
  96         ret = spi_sync(self->func, &m);
  97
  98 #ifdef SPI_DEBUG
  99         pr_info("READ : ");
 100         for (i = 0; i < t_addr.len; i++)
 101                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 102         printk(" : ");
 103         for (i = 0; i < t_msg.len; i++)
 104                 printk("%02x ", ((u8 *)t_msg.rx_buf)[i]);
 105         printk("\n");
 106 #endif
 107
 108         /* We have to byteswap if the SPI bus is limited to 8b operation
 109            or we are running on a Big Endian system
 110         */
 111 #if defined(__LITTLE_ENDIAN)
 112         if (self->func->bits_per_word == 8)
 113 #endif
 114         {
 115                 uint16_t *buf = (uint16_t *)dst;
 116                 for (i = 0; i < ((count + 1) >> 1); i++)
 117                         buf[i] = swab16(buf[i]);
 118         }
 119
 120         return ret;
 121 }
 122
 123 static int cw1200_spi_memcpy_toio(struct hwbus_priv *self,
 124                                    unsigned int addr,
 125                                    const void *src, int count)
 126 {
 127         int rval, i;
 128         u16 regaddr;
 129         struct spi_transfer     t_addr = {
 130                 .tx_buf         = &regaddr,
 131                 .len            = sizeof(regaddr),
 132         };
 133         struct spi_transfer     t_msg = {
 134                 .tx_buf         = src,
 135                 .len            = count,
 136         };
 137         struct spi_message      m;
 138
 139         regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
 140         regaddr &= SET_WRITE;
 141         regaddr |= (count>>1);
 142
 143 #ifdef SPI_DEBUG
 144         pr_info("WRITE: %04d  to  0x%02x (%04x)\n", count, addr, regaddr);
 145 #endif
 146
 147         /* Header is LE16 */
 148         regaddr = cpu_to_le16(regaddr);
 149
 150         /* We have to byteswap if the SPI bus is limited to 8b operation
 151            or we are running on a Big Endian system
 152         */
 153 #if defined(__LITTLE_ENDIAN)
 154         if (self->func->bits_per_word == 8)
 155 #endif
 156         {
 157                 uint16_t *buf = (uint16_t *)src;
 158                 regaddr = swab16(regaddr);
 159                 for (i = 0; i < ((count + 1) >> 1); i++)
 160                         buf[i] = swab16(buf[i]);
 161         }
 162
 163 #ifdef SPI_DEBUG
 164         pr_info("WRITE: ");
 165         for (i = 0; i < t_addr.len; i++)
 166                 printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
 167         printk(" : ");
 168         for (i = 0; i < t_msg.len; i++)
 169                 printk("%02x ", ((u8 *)t_msg.tx_buf)[i]);
 170         printk("\n");
 171 #endif
 172
 173         spi_message_init(&m);
 174         spi_message_add_tail(&t_addr, &m);
 175         spi_message_add_tail(&t_msg, &m);
 176         rval = spi_sync(self->func, &m);
 177
 178 #ifdef SPI_DEBUG
 179         pr_info("WROTE: %d\n", m.actual_length);
 180 #endif
 181
 182 #if defined(__LITTLE_ENDIAN)
 183         /* We have to byteswap if the SPI bus is limited to 8b operation */
 184         if (self->func->bits_per_word == 8)
 185 #endif
 186         {
 187                 uint16_t *buf = (uint16_t *)src;
 188                 for (i = 0; i < ((count + 1) >> 1); i++)
 189                         buf[i] = swab16(buf[i]);
 190         }
 191         return rval;
 192 }
 193
 194 static void cw1200_spi_lock(struct hwbus_priv *self)
 195 {
 196         unsigned long flags;
 197
 198         DECLARE_WAITQUEUE(wait, current);
 199
 200         might_sleep();
 201
 202         add_wait_queue(&self->wq, &wait);
 203         spin_lock_irqsave(&self->lock, flags);
 204         while (1) {
 205                 set_current_state(TASK_UNINTERRUPTIBLE);
 206                 if (!self->claimed)
 207                         break;
 208                 spin_unlock_irqrestore(&self->lock, flags);
 209                 schedule();
 210                 spin_lock_irqsave(&self->lock, flags);
 211         }
 212         set_current_state(TASK_RUNNING);
 213         self->claimed = 1;
 214         spin_unlock_irqrestore(&self->lock, flags);
 215         remove_wait_queue(&self->wq, &wait);
 216
 217         return;
 218 }
 219
 220 static void cw1200_spi_unlock(struct hwbus_priv *self)
 221 {
 222         unsigned long flags;
 223
 224         spin_lock_irqsave(&self->lock, flags);
 225         self->claimed = 0;
 226         spin_unlock_irqrestore(&self->lock, flags);
 227         wake_up(&self->wq);
 228
 229         return;
 230 }
 231
 232 static irqreturn_t cw1200_spi_irq_handler(int irq, void *dev_id)
 233 {
 234         struct hwbus_priv *self = dev_id;
 235
 236         if (self->core) {
 237                 cw1200_spi_lock(self);
 238                 cw1200_irq_handler(self->core);
 239                 cw1200_spi_unlock(self);
 240                 return IRQ_HANDLED;
 241         } else {
 242                 return IRQ_NONE;
 243         }
 244 }
 245
 246 static int cw1200_spi_irq_subscribe(struct hwbus_priv *self)
 247 {
 248         int ret;
 249
 250         pr_debug("SW IRQ subscribe\n");
 251
 252         ret = request_threaded_irq(self->func->irq, NULL,
 253                                    cw1200_spi_irq_handler,
 254                                    IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
 255                                    "cw1200_wlan_irq", self);
 256         if (WARN_ON(ret < 0))
 257                 goto exit;
 258
 259         ret = enable_irq_wake(self->func->irq);
 260         if (WARN_ON(ret))
 261                 goto free_irq;
 262
 263         return 0;
 264
 265 free_irq:
 266         free_irq(self->func->irq, self);
 267 exit:
 268         return ret;
 269 }
 270
 271 static void cw1200_spi_irq_unsubscribe(struct hwbus_priv *self)
 272 {
 273         pr_debug("SW IRQ unsubscribe\n");
 274         disable_irq_wake(self->func->irq);
 275         free_irq(self->func->irq, self);
 276 }
 277
 278 static int cw1200_spi_off(const struct cw1200_platform_data_spi *pdata)
 279 {
 280         if (pdata->reset) {
 281                 gpio_set_value(pdata->reset, 0);
 282                 msleep(30); /* Min is 2 * CLK32K cycles */
 283                 gpio_free(pdata->reset);
 284         }
 285
 286         if (pdata->power_ctrl)
 287                 pdata->power_ctrl(pdata, false);
 288         if (pdata->clk_ctrl)
 289                 pdata->clk_ctrl(pdata, false);
 290
 291         return 0;
 292 }
 293
 294 static int cw1200_spi_on(const struct cw1200_platform_data_spi *pdata)
 295 {
 296         /* Ensure I/Os are pulled low */
 297         if (pdata->reset) {
 298                 gpio_request(pdata->reset, "cw1200_wlan_reset");
 299                 gpio_direction_output(pdata->reset, 0);
 300         }
 301         if (pdata->powerup) {
 302                 gpio_request(pdata->powerup, "cw1200_wlan_powerup");
 303                 gpio_direction_output(pdata->powerup, 0);
 304         }
 305         if (pdata->reset || pdata->powerup)
 306                 msleep(10); /* Settle time? */
 307
 308         /* Enable 3v3 and 1v8 to hardware */
 309         if (pdata->power_ctrl) {
 310                 if (pdata->power_ctrl(pdata, true)) {
 311                         pr_err("power_ctrl() failed!\n");
 312                         return -1;
 313                 }
 314         }
 315
 316         /* Enable CLK32K */
 317         if (pdata->clk_ctrl) {
 318                 if (pdata->clk_ctrl(pdata, true)) {
 319                         pr_err("clk_ctrl() failed!\n");
 320                         return -1;
 321                 }
 322                 msleep(10); /* Delay until clock is stable for 2 cycles */
 323         }
 324
 325         /* Enable POWERUP signal */
 326         if (pdata->powerup) {
 327                 gpio_set_value(pdata->powerup, 1);
 328                 msleep(250); /* or more..? */
 329         }
 330         /* Enable RSTn signal */
 331         if (pdata->reset) {
 332                 gpio_set_value(pdata->reset, 1);
 333                 msleep(50); /* Or more..? */
 334         }
 335         return 0;
 336 }
 337
 338 static size_t cw1200_spi_align_size(struct hwbus_priv *self, size_t size)
 339 {
 340         return size & 1 ? size + 1 : size;
 341 }
 342
 343 static int cw1200_spi_pm(struct hwbus_priv *self, bool suspend)
 344 {
 345         return irq_set_irq_wake(self->func->irq, suspend);
 346 }
 347
 348 static const struct hwbus_ops cw1200_spi_hwbus_ops = {
 349         .hwbus_memcpy_fromio    = cw1200_spi_memcpy_fromio,
 350         .hwbus_memcpy_toio      = cw1200_spi_memcpy_toio,
 351         .lock                   = cw1200_spi_lock,
 352         .unlock                 = cw1200_spi_unlock,
 353         .align_size             = cw1200_spi_align_size,
 354         .power_mgmt             = cw1200_spi_pm,
 355 };
 356
 357 /* Probe Function to be called by SPI stack when device is discovered */
 358 static int cw1200_spi_probe(struct spi_device *func)
 359 {
 360         const struct cw1200_platform_data_spi *plat_data =
 361                 dev_get_platdata(&func->dev);
 362         struct hwbus_priv *self;
 363         int status;
 364
 365         /* Sanity check speed */
 366         if (func->max_speed_hz > 52000000)
 367                 func->max_speed_hz = 52000000;
 368         if (func->max_speed_hz < 1000000)
 369                 func->max_speed_hz = 1000000;
 370
 371         /* Fix up transfer size */
 372         if (plat_data->spi_bits_per_word)
 373                 func->bits_per_word = plat_data->spi_bits_per_word;
 374         if (!func->bits_per_word)
 375                 func->bits_per_word = 16;
 376
 377         /* And finally.. */
 378         func->mode = SPI_MODE_0;
 379
 380         pr_info("cw1200_wlan_spi: Probe called (CS %d M %d BPW %d CLK %d)\n",
 381                 spi_get_chipselect(func, 0), func->mode, func->bits_per_word,
 382                 func->max_speed_hz);
 383
 384         if (cw1200_spi_on(plat_data)) {
 385                 pr_err("spi_on() failed!\n");
 386                 return -1;
 387         }
 388
 389         if (spi_setup(func)) {
 390                 pr_err("spi_setup() failed!\n");
 391                 return -1;
 392         }
 393
 394         self = devm_kzalloc(&func->dev, sizeof(*self), GFP_KERNEL);
 395         if (!self) {
 396                 pr_err("Can't allocate SPI hwbus_priv.");
 397                 return -ENOMEM;
 398         }
 399
 400         self->pdata = plat_data;
 401         self->func = func;
 402         spin_lock_init(&self->lock);
 403
 404         spi_set_drvdata(func, self);
 405
 406         init_waitqueue_head(&self->wq);
 407
 408         status = cw1200_spi_irq_subscribe(self);
 409
 410         status = cw1200_core_probe(&cw1200_spi_hwbus_ops,
 411                                    self, &func->dev, &self->core,
 412                                    self->pdata->ref_clk,
 413                                    self->pdata->macaddr,
 414                                    self->pdata->sdd_file,
 415                                    self->pdata->have_5ghz);
 416
 417         if (status) {
 418                 cw1200_spi_irq_unsubscribe(self);
 419                 cw1200_spi_off(plat_data);
 420         }
 421
 422         return status;
 423 }
 424
 425 /* Disconnect Function to be called by SPI stack when device is disconnected */
 426 static void cw1200_spi_disconnect(struct spi_device *func)
 427 {
 428         struct hwbus_priv *self = spi_get_drvdata(func);
 429
 430         if (self) {
 431                 cw1200_spi_irq_unsubscribe(self);
 432                 if (self->core) {
 433                         cw1200_core_release(self->core);
 434                         self->core = NULL;
 435                 }
 436         }
 437         cw1200_spi_off(dev_get_platdata(&func->dev));
 438 }
 439
 440 static int __maybe_unused cw1200_spi_suspend(struct device *dev)
 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 SIMPLE_DEV_PM_OPS(cw1200_pm_ops, cw1200_spi_suspend, NULL);
 452
 453 static struct spi_driver spi_driver = {
 454         .probe          = cw1200_spi_probe,
 455         .remove         = cw1200_spi_disconnect,
 456         .driver = {
 457                 .name           = "cw1200_wlan_spi",
 458                 .pm             = IS_ENABLED(CONFIG_PM) ? &cw1200_pm_ops : NULL,
 459         },
 460 };
 461
 462 module_spi_driver(spi_driver);