target/linux/gemini/patches/110-watchdog-add-gemini_wdt-driver.patch

   1 --- /dev/null
   2 +++ b/drivers/watchdog/gemini_wdt.c
   3 @@ -0,0 +1,378 @@
   4 +/*
   5 + *  Watchdog driver for Cortina Systems Gemini SoC
   6 + *
   7 + *  Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
   8 + *
   9 + * This program is free software; you can redistribute it and/or modify
  10 + * it under the terms of the GNU General Public License version 2 as
  11 + * published by the Free Software Foundation.
  12 + */
  13 +
  14 +#include <linux/kernel.h>
  15 +#include <linux/init.h>
  16 +#include <linux/module.h>
  17 +#include <linux/io.h>
  18 +#include <linux/fs.h>
  19 +#include <linux/uaccess.h>
  20 +#include <linux/miscdevice.h>
  21 +#include <linux/platform_device.h>
  22 +#include <linux/watchdog.h>
  23 +#include <linux/slab.h>
  24 +
  25 +#define GEMINI_WDCOUNTER       0x0
  26 +#define GEMINI_WDLOAD          0x4
  27 +#define GEMINI_WDRESTART       0x8
  28 +
  29 +#define WDRESTART_MAGIC                0x5AB9
  30 +
  31 +#define GEMINI_WDCR            0xC
  32 +
  33 +#define WDCR_CLOCK_5MHZ                (1 << 4)
  34 +#define WDCR_SYS_RST           (1 << 1)
  35 +#define WDCR_ENABLE            (1 << 0)
  36 +
  37 +#define WDT_CLOCK              5000000         /* 5 MHz */
  38 +#define WDT_DEFAULT_TIMEOUT    13
  39 +#define WDT_MAX_TIMEOUT                (0xFFFFFFFF / WDT_CLOCK)
  40 +
  41 +/* status bits */
  42 +#define WDT_ACTIVE             0
  43 +#define WDT_OK_TO_CLOSE                1
  44 +
  45 +static unsigned int timeout = WDT_DEFAULT_TIMEOUT;
  46 +static int nowayout = WATCHDOG_NOWAYOUT;
  47 +
  48 +static DEFINE_SPINLOCK(gemini_wdt_lock);
  49 +
  50 +static struct platform_device *gemini_wdt_dev;
  51 +
  52 +struct gemini_wdt_struct {
  53 +       struct resource         *res;
  54 +       struct device           *dev;
  55 +       void __iomem            *base;
  56 +       unsigned long           status;
  57 +};
  58 +
  59 +static struct watchdog_info gemini_wdt_info = {
  60 +       .identity       = "Gemini watchdog",
  61 +       .options        = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
  62 +                         WDIOF_SETTIMEOUT,
  63 +};
  64 +
  65 +/* Disable the watchdog. */
  66 +static void gemini_wdt_stop(struct gemini_wdt_struct *gemini_wdt)
  67 +{
  68 +       spin_lock(&gemini_wdt_lock);
  69 +
  70 +       __raw_writel(0, gemini_wdt->base + GEMINI_WDCR);
  71 +
  72 +       clear_bit(WDT_ACTIVE, &gemini_wdt->status);
  73 +
  74 +       spin_unlock(&gemini_wdt_lock);
  75 +}
  76 +
  77 +/* Service the watchdog */
  78 +static void gemini_wdt_service(struct gemini_wdt_struct *gemini_wdt)
  79 +{
  80 +       __raw_writel(WDRESTART_MAGIC, gemini_wdt->base + GEMINI_WDRESTART);
  81 +}
  82 +
  83 +/* Enable and reset the watchdog. */
  84 +static void gemini_wdt_start(struct gemini_wdt_struct *gemini_wdt)
  85 +{
  86 +       spin_lock(&gemini_wdt_lock);
  87 +
  88 +       __raw_writel(timeout * WDT_CLOCK, gemini_wdt->base + GEMINI_WDLOAD);
  89 +
  90 +       gemini_wdt_service(gemini_wdt);
  91 +
  92 +       /* set clock before enabling */
  93 +       __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST,
  94 +                       gemini_wdt->base + GEMINI_WDCR);
  95 +
  96 +       __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST | WDCR_ENABLE,
  97 +                       gemini_wdt->base + GEMINI_WDCR);
  98 +
  99 +       set_bit(WDT_ACTIVE, &gemini_wdt->status);
 100 +
 101 +       spin_unlock(&gemini_wdt_lock);
 102 +}
 103 +
 104 +/* Watchdog device is opened, and watchdog starts running. */
 105 +static int gemini_wdt_open(struct inode *inode, struct file *file)
 106 +{
 107 +       struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(gemini_wdt_dev);
 108 +
 109 +       if (test_bit(WDT_ACTIVE, &gemini_wdt->status))
 110 +               return -EBUSY;
 111 +
 112 +       file->private_data = gemini_wdt;
 113 +
 114 +       gemini_wdt_start(gemini_wdt);
 115 +
 116 +       return nonseekable_open(inode, file);
 117 +}
 118 +
 119 +/* Close the watchdog device. */
 120 +static int gemini_wdt_close(struct inode *inode, struct file *file)
 121 +{
 122 +       struct gemini_wdt_struct *gemini_wdt = file->private_data;
 123 +
 124 +       /* Disable the watchdog if possible */
 125 +       if (test_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status))
 126 +               gemini_wdt_stop(gemini_wdt);
 127 +       else
 128 +               dev_warn(gemini_wdt->dev, "Device closed unexpectedly - timer will not stop\n");
 129 +
 130 +       return 0;
 131 +}
 132 +
 133 +/* Handle commands from user-space. */
 134 +static long gemini_wdt_ioctl(struct file *file, unsigned int cmd,
 135 +                            unsigned long arg)
 136 +{
 137 +       struct gemini_wdt_struct *gemini_wdt = file->private_data;
 138 +
 139 +       int value;
 140 +
 141 +       switch (cmd) {
 142 +       case WDIOC_KEEPALIVE:
 143 +               gemini_wdt_service(gemini_wdt);
 144 +               return 0;
 145 +
 146 +       case WDIOC_GETSUPPORT:
 147 +               return copy_to_user((struct watchdog_info *)arg, &gemini_wdt_info,
 148 +                       sizeof(gemini_wdt_info)) ? -EFAULT : 0;
 149 +
 150 +       case WDIOC_SETTIMEOUT:
 151 +               if (get_user(value, (int *)arg))
 152 +                       return -EFAULT;
 153 +
 154 +               if ((value < 1) || (value > WDT_MAX_TIMEOUT))
 155 +                       return -EINVAL;
 156 +
 157 +               timeout = value;
 158 +
 159 +               /* restart wdt to use new timeout */
 160 +               gemini_wdt_stop(gemini_wdt);
 161 +               gemini_wdt_start(gemini_wdt);
 162 +
 163 +               /* Fall through */
 164 +       case WDIOC_GETTIMEOUT:
 165 +               return put_user(timeout, (int *)arg);
 166 +
 167 +       case WDIOC_GETTIMELEFT:
 168 +               value = __raw_readl(gemini_wdt->base + GEMINI_WDCOUNTER);
 169 +               return put_user(value / WDT_CLOCK, (int *)arg);
 170 +
 171 +       default:
 172 +               return -ENOTTY;
 173 +       }
 174 +}
 175 +
 176 +/* Refresh the watchdog whenever device is written to. */
 177 +static ssize_t gemini_wdt_write(struct file *file, const char *data,
 178 +                                               size_t len, loff_t *ppos)
 179 +{
 180 +       struct gemini_wdt_struct *gemini_wdt = file->private_data;
 181 +
 182 +       if (len) {
 183 +               if (!nowayout) {
 184 +                       size_t i;
 185 +
 186 +                       clear_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status);
 187 +                       for (i = 0; i != len; i++) {
 188 +                               char c;
 189 +
 190 +                               if (get_user(c, data + i))
 191 +                                       return -EFAULT;
 192 +                               if (c == 'V')
 193 +                                       set_bit(WDT_OK_TO_CLOSE,
 194 +                                               &gemini_wdt->status);
 195 +                       }
 196 +               }
 197 +               gemini_wdt_service(gemini_wdt);
 198 +       }
 199 +
 200 +       return len;
 201 +}
 202 +
 203 +static const struct file_operations gemini_wdt_fops = {
 204 +       .owner          = THIS_MODULE,
 205 +       .llseek         = no_llseek,
 206 +       .unlocked_ioctl = gemini_wdt_ioctl,
 207 +       .open           = gemini_wdt_open,
 208 +       .release        = gemini_wdt_close,
 209 +       .write          = gemini_wdt_write,
 210 +};
 211 +
 212 +static struct miscdevice gemini_wdt_miscdev = {
 213 +       .minor          = WATCHDOG_MINOR,
 214 +       .name           = "watchdog",
 215 +       .fops           = &gemini_wdt_fops,
 216 +};
 217 +
 218 +static void gemini_wdt_shutdown(struct platform_device *pdev)
 219 +{
 220 +       struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
 221 +
 222 +       gemini_wdt_stop(gemini_wdt);
 223 +}
 224 +
 225 +static int gemini_wdt_probe(struct platform_device *pdev)
 226 +{
 227 +       int ret;
 228 +       int res_size;
 229 +       struct resource *res;
 230 +       void __iomem *base;
 231 +       struct gemini_wdt_struct *gemini_wdt;
 232 +       unsigned int reg;
 233 +
 234 +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 235 +       if (!res) {
 236 +               dev_err(&pdev->dev, "can't get device resources\n");
 237 +               return -ENODEV;
 238 +       }
 239 +
 240 +       res_size = resource_size(res);
 241 +       if (!request_mem_region(res->start, res_size, res->name)) {
 242 +               dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n",
 243 +                       res_size, res->start);
 244 +               return -ENOMEM;
 245 +       }
 246 +
 247 +       base = ioremap(res->start, res_size);
 248 +       if (!base) {
 249 +               dev_err(&pdev->dev, "ioremap failed\n");
 250 +               ret = -EIO;
 251 +               goto fail0;
 252 +       }
 253 +
 254 +       gemini_wdt = kzalloc(sizeof(struct gemini_wdt_struct), GFP_KERNEL);
 255 +       if (!gemini_wdt) {
 256 +               dev_err(&pdev->dev, "can't allocate interface\n");
 257 +               ret = -ENOMEM;
 258 +               goto fail1;
 259 +       }
 260 +
 261 +       /* Setup gemini_wdt driver structure */
 262 +       gemini_wdt->base = base;
 263 +       gemini_wdt->res = res;
 264 +
 265 +       /* Set up platform driver data */
 266 +       platform_set_drvdata(pdev, gemini_wdt);
 267 +       gemini_wdt_dev = pdev;
 268 +
 269 +       if (gemini_wdt_miscdev.parent) {
 270 +               ret = -EBUSY;
 271 +               goto fail2;
 272 +       }
 273 +
 274 +       gemini_wdt_miscdev.parent = &pdev->dev;
 275 +
 276 +       reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
 277 +       if (reg & WDCR_ENABLE) {
 278 +               /* Watchdog was enabled by the bootloader, disable it. */
 279 +               reg &= ~(WDCR_ENABLE);
 280 +               __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
 281 +       }
 282 +
 283 +       ret = misc_register(&gemini_wdt_miscdev);
 284 +       if (ret)
 285 +               goto fail2;
 286 +
 287 +       return 0;
 288 +
 289 +fail2:
 290 +       platform_set_drvdata(pdev, NULL);
 291 +       kfree(gemini_wdt);
 292 +fail1:
 293 +       iounmap(base);
 294 +fail0:
 295 +       release_mem_region(res->start, res_size);
 296 +
 297 +       return ret;
 298 +}
 299 +
 300 +static int gemini_wdt_remove(struct platform_device *pdev)
 301 +{
 302 +       struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
 303 +
 304 +       platform_set_drvdata(pdev, NULL);
 305 +       misc_deregister(&gemini_wdt_miscdev);
 306 +       gemini_wdt_dev = NULL;
 307 +       iounmap(gemini_wdt->base);
 308 +       release_mem_region(gemini_wdt->res->start, resource_size(gemini_wdt->res));
 309 +
 310 +       kfree(gemini_wdt);
 311 +
 312 +       return 0;
 313 +}
 314 +
 315 +#ifdef CONFIG_PM
 316 +static int gemini_wdt_suspend(struct platform_device *pdev, pm_message_t message)
 317 +{
 318 +       struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
 319 +       unsigned int reg;
 320 +
 321 +       reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
 322 +       reg &= ~(WDCR_WDENABLE);
 323 +       __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
 324 +
 325 +       return 0;
 326 +}
 327 +
 328 +static int gemini_wdt_resume(struct platform_device *pdev)
 329 +{
 330 +       struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
 331 +       unsigned int reg;
 332 +
 333 +       if (gemini_wdt->status) {
 334 +               reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
 335 +               reg |= WDCR_WDENABLE;
 336 +               __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
 337 +       }
 338 +
 339 +       return 0;
 340 +}
 341 +#else
 342 +#define gemini_wdt_suspend     NULL
 343 +#define gemini_wdt_resume      NULL
 344 +#endif
 345 +
 346 +static struct platform_driver gemini_wdt_driver = {
 347 +       .probe          = gemini_wdt_probe,
 348 +       .remove         = gemini_wdt_remove,
 349 +       .shutdown       = gemini_wdt_shutdown,
 350 +       .suspend        = gemini_wdt_suspend,
 351 +       .resume         = gemini_wdt_resume,
 352 +       .driver         = {
 353 +               .name   = "gemini-wdt",
 354 +               .owner  = THIS_MODULE,
 355 +       },
 356 +};
 357 +
 358 +static int __init gemini_wdt_init(void)
 359 +{
 360 +       return platform_driver_probe(&gemini_wdt_driver, gemini_wdt_probe);
 361 +}
 362 +
 363 +static void __exit gemini_wdt_exit(void)
 364 +{
 365 +       platform_driver_unregister(&gemini_wdt_driver);
 366 +}
 367 +
 368 +module_init(gemini_wdt_init);
 369 +module_exit(gemini_wdt_exit);
 370 +
 371 +module_param(timeout, uint, 0);
 372 +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
 373 +
 374 +module_param(nowayout, int, 0);
 375 +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
 376 +
 377 +MODULE_AUTHOR("Paulius Zaleckas");
 378 +MODULE_DESCRIPTION("Watchdog driver for Gemini");
 379 +MODULE_LICENSE("GPL");
 380 +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 381 +MODULE_ALIAS("platform:gemini-wdt");
 382 --- a/drivers/watchdog/Kconfig
 383 +++ b/drivers/watchdog/Kconfig
 384 @@ -154,6 +154,16 @@ config 977_WATCHDOG
 385
 386           Not sure? It's safe to say N.
 387
 388 +config GEMINI_WATCHDOG
 389 +       tristate "Gemini watchdog"
 390 +       depends on ARCH_GEMINI
 391 +       help
 392 +         Say Y here if to include support for the watchdog timer
 393 +         embedded in the Cortina Systems Gemini family of devices.
 394 +
 395 +         To compile this driver as a module, choose M here: the
 396 +         module will be called gemini_wdt.
 397 +
 398  config IXP4XX_WATCHDOG
 399         tristate "IXP4xx Watchdog"
 400         depends on ARCH_IXP4XX
 401 --- a/drivers/watchdog/Makefile
 402 +++ b/drivers/watchdog/Makefile
 403 @@ -36,6 +36,7 @@ obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.
 404  obj-$(CONFIG_TWL4030_WATCHDOG) += twl4030_wdt.o
 405  obj-$(CONFIG_21285_WATCHDOG) += wdt285.o
 406  obj-$(CONFIG_977_WATCHDOG) += wdt977.o
 407 +obj-$(CONFIG_GEMINI_WATCHDOG) += gemini_wdt.o
 408  obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
 409  obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
 410  obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o