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 int cw1200_spi_irq_unsubscribe(struct hwbus_priv *self)
 272 {
 273         int ret = 0;
 274
 275         pr_debug("SW IRQ unsubscribe\n");
 276         disable_irq_wake(self->func->irq);
 277         free_irq(self->func->irq, self);
 278
 279         return ret;
 280 }
 281
 282 static int cw1200_spi_off(const struct cw1200_platform_data_spi *pdata)
 283 {
 284         if (pdata->reset) {
 285                 gpio_set_value(pdata->reset, 0);
 286                 msleep(30); /* Min is 2 * CLK32K cycles */
 287                 gpio_free(pdata->reset);
 288         }
 289
 290         if (pdata->power_ctrl)
 291                 pdata->power_ctrl(pdata, false);
 292         if (pdata->clk_ctrl)
 293                 pdata->clk_ctrl(pdata, false);
 294
 295         return 0;
 296 }
 297
 298 static int cw1200_spi_on(const struct cw1200_platform_data_spi *pdata)
 299 {
 300         /* Ensure I/Os are pulled low */
 301         if (pdata->reset) {
 302                 gpio_request(pdata->reset, "cw1200_wlan_reset");
 303                 gpio_direction_output(pdata->reset, 0);
 304         }
 305         if (pdata->powerup) {
 306                 gpio_request(pdata->powerup, "cw1200_wlan_powerup");
 307                 gpio_direction_output(pdata->powerup, 0);
 308         }
 309         if (pdata->reset || pdata->powerup)
 310                 msleep(10); /* Settle time? */
 311
 312         /* Enable 3v3 and 1v8 to hardware */
 313         if (pdata->power_ctrl) {
 314                 if (pdata->power_ctrl(pdata, true)) {
 315                         pr_err("power_ctrl() failed!\n");
 316                         return -1;
 317                 }
 318         }
 319
 320         /* Enable CLK32K */
 321         if (pdata->clk_ctrl) {
 322                 if (pdata->clk_ctrl(pdata, true)) {
 323                         pr_err("clk_ctrl() failed!\n");
 324                         return -1;
 325                 }
 326                 msleep(10); /* Delay until clock is stable for 2 cycles */
 327         }
 328
 329         /* Enable POWERUP signal */
 330         if (pdata->powerup) {
 331                 gpio_set_value(pdata->powerup, 1);
 332                 msleep(250); /* or more..? */
 333         }
 334         /* Enable RSTn signal */
 335         if (pdata->reset) {
 336                 gpio_set_value(pdata->reset, 1);
 337                 msleep(50); /* Or more..? */
 338         }
 339         return 0;
 340 }
 341
 342 static size_t cw1200_spi_align_size(struct hwbus_priv *self, size_t size)
 343 {
 344         return size & 1 ? size + 1 : size;
 345 }
 346
 347 static int cw1200_spi_pm(struct hwbus_priv *self, bool suspend)
 348 {
 349         return irq_set_irq_wake(self->func->irq, suspend);
 350 }
 351
 352 static const struct hwbus_ops cw1200_spi_hwbus_ops = {
 353         .hwbus_memcpy_fromio    = cw1200_spi_memcpy_fromio,
 354         .hwbus_memcpy_toio      = cw1200_spi_memcpy_toio,
 355         .lock                   = cw1200_spi_lock,
 356         .unlock                 = cw1200_spi_unlock,
 357         .align_size             = cw1200_spi_align_size,
 358         .power_mgmt             = cw1200_spi_pm,
 359 };
 360
 361 /* Probe Function to be called by SPI stack when device is discovered */
 362 static int cw1200_spi_probe(struct spi_device *func)
 363 {
 364         const struct cw1200_platform_data_spi *plat_data =
 365                 dev_get_platdata(&func->dev);
 366         struct hwbus_priv *self;
 367         int status;
 368
 369         /* Sanity check speed */
 370         if (func->max_speed_hz > 52000000)
 371                 func->max_speed_hz = 52000000;
 372         if (func->max_speed_hz < 1000000)
 373                 func->max_speed_hz = 1000000;
 374
 375         /* Fix up transfer size */
 376         if (plat_data->spi_bits_per_word)
 377                 func->bits_per_word = plat_data->spi_bits_per_word;
 378         if (!func->bits_per_word)
 379                 func->bits_per_word = 16;
 380
 381         /* And finally.. */
 382         func->mode = SPI_MODE_0;
 383
 384         pr_info("cw1200_wlan_spi: Probe called (CS %d M %d BPW %d CLK %d)\n",
 385                 func->chip_select, func->mode, func->bits_per_word,
 386                 func->max_speed_hz);
 387
 388         if (cw1200_spi_on(plat_data)) {
 389                 pr_err("spi_on() failed!\n");
 390                 return -1;
 391         }
 392
 393         if (spi_setup(func)) {
 394                 pr_err("spi_setup() failed!\n");
 395                 return -1;
 396         }
 397
 398         self = devm_kzalloc(&func->dev, sizeof(*self), GFP_KERNEL);
 399         if (!self) {
 400                 pr_err("Can't allocate SPI hwbus_priv.");
 401                 return -ENOMEM;
 402         }
 403
 404         self->pdata = plat_data;
 405         self->func = func;
 406         spin_lock_init(&self->lock);
 407
 408         spi_set_drvdata(func, self);
 409
 410         init_waitqueue_head(&self->wq);
 411
 412         status = cw1200_spi_irq_subscribe(self);
 413
 414         status = cw1200_core_probe(&cw1200_spi_hwbus_ops,
 415                                    self, &func->dev, &self->core,
 416                                    self->pdata->ref_clk,
 417                                    self->pdata->macaddr,
 418                                    self->pdata->sdd_file,
 419                                    self->pdata->have_5ghz);
 420
 421         if (status) {
 422                 cw1200_spi_irq_unsubscribe(self);
 423                 cw1200_spi_off(plat_data);
 424         }
 425
 426         return status;
 427 }
 428
 429 /* Disconnect Function to be called by SPI stack when device is disconnected */
 430 static int cw1200_spi_disconnect(struct spi_device *func)
 431 {
 432         struct hwbus_priv *self = spi_get_drvdata(func);
 433
 434         if (self) {
 435                 cw1200_spi_irq_unsubscribe(self);
 436                 if (self->core) {
 437                         cw1200_core_release(self->core);
 438                         self->core = NULL;
 439                 }
 440         }
 441         cw1200_spi_off(dev_get_platdata(&func->dev));
 442
 443         return 0;
 444 }
 445
 446 static int __maybe_unused cw1200_spi_suspend(struct device *dev)
 447 {
 448         struct hwbus_priv *self = spi_get_drvdata(to_spi_device(dev));
 449
 450         if (!cw1200_can_suspend(self->core))
 451                 return -EAGAIN;
 452
 453         /* XXX notify host that we have to keep CW1200 powered on? */
 454         return 0;
 455 }
 456
 457 static SIMPLE_DEV_PM_OPS(cw1200_pm_ops, cw1200_spi_suspend, NULL);
 458
 459 static struct spi_driver spi_driver = {
 460         .probe          = cw1200_spi_probe,
 461         .remove         = cw1200_spi_disconnect,
 462         .driver = {
 463                 .name           = "cw1200_wlan_spi",
 464                 .pm             = IS_ENABLED(CONFIG_PM) ? &cw1200_pm_ops : NULL,
 465         },
 466 };
 467
 468 module_spi_driver(spi_driver);