| 1 | /* linux/drivers/char/watchdog/s3c2410_wdt.c |
| 2 | * |
| 3 | * Copyright (c) 2004 Simtec Electronics |
| 4 | * Ben Dooks <ben@simtec.co.uk> |
| 5 | * |
| 6 | * S3C2410 Watchdog Timer Support |
| 7 | * |
| 8 | * Based on, softdog.c by Alan Cox, |
| 9 | * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk> |
| 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 as published by |
| 13 | * the Free Software Foundation; either version 2 of the License, or |
| 14 | * (at your option) any later version. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | * GNU General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU General Public License |
| 22 | * along with this program; if not, write to the Free Software |
| 23 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 24 | */ |
| 25 | |
| 26 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 27 | |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/moduleparam.h> |
| 30 | #include <linux/types.h> |
| 31 | #include <linux/timer.h> |
| 32 | #include <linux/watchdog.h> |
| 33 | #include <linux/platform_device.h> |
| 34 | #include <linux/interrupt.h> |
| 35 | #include <linux/clk.h> |
| 36 | #include <linux/uaccess.h> |
| 37 | #include <linux/io.h> |
| 38 | #include <linux/cpufreq.h> |
| 39 | #include <linux/slab.h> |
| 40 | #include <linux/err.h> |
| 41 | #include <linux/of.h> |
| 42 | #include <linux/mfd/syscon.h> |
| 43 | #include <linux/regmap.h> |
| 44 | #include <linux/delay.h> |
| 45 | |
| 46 | #define S3C2410_WTCON 0x00 |
| 47 | #define S3C2410_WTDAT 0x04 |
| 48 | #define S3C2410_WTCNT 0x08 |
| 49 | |
| 50 | #define S3C2410_WTCNT_MAXCNT 0xffff |
| 51 | |
| 52 | #define S3C2410_WTCON_RSTEN (1 << 0) |
| 53 | #define S3C2410_WTCON_INTEN (1 << 2) |
| 54 | #define S3C2410_WTCON_ENABLE (1 << 5) |
| 55 | |
| 56 | #define S3C2410_WTCON_DIV16 (0 << 3) |
| 57 | #define S3C2410_WTCON_DIV32 (1 << 3) |
| 58 | #define S3C2410_WTCON_DIV64 (2 << 3) |
| 59 | #define S3C2410_WTCON_DIV128 (3 << 3) |
| 60 | |
| 61 | #define S3C2410_WTCON_MAXDIV 0x80 |
| 62 | |
| 63 | #define S3C2410_WTCON_PRESCALE(x) ((x) << 8) |
| 64 | #define S3C2410_WTCON_PRESCALE_MASK (0xff << 8) |
| 65 | #define S3C2410_WTCON_PRESCALE_MAX 0xff |
| 66 | |
| 67 | #define CONFIG_S3C2410_WATCHDOG_ATBOOT (0) |
| 68 | #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15) |
| 69 | |
| 70 | #define EXYNOS5_RST_STAT_REG_OFFSET 0x0404 |
| 71 | #define EXYNOS5_WDT_DISABLE_REG_OFFSET 0x0408 |
| 72 | #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET 0x040c |
| 73 | #define QUIRK_HAS_PMU_CONFIG (1 << 0) |
| 74 | #define QUIRK_HAS_RST_STAT (1 << 1) |
| 75 | |
| 76 | /* These quirks require that we have a PMU register map */ |
| 77 | #define QUIRKS_HAVE_PMUREG (QUIRK_HAS_PMU_CONFIG | \ |
| 78 | QUIRK_HAS_RST_STAT) |
| 79 | |
| 80 | static bool nowayout = WATCHDOG_NOWAYOUT; |
| 81 | static int tmr_margin; |
| 82 | static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT; |
| 83 | static int soft_noboot; |
| 84 | static int debug; |
| 85 | |
| 86 | module_param(tmr_margin, int, 0); |
| 87 | module_param(tmr_atboot, int, 0); |
| 88 | module_param(nowayout, bool, 0); |
| 89 | module_param(soft_noboot, int, 0); |
| 90 | module_param(debug, int, 0); |
| 91 | |
| 92 | MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. (default=" |
| 93 | __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")"); |
| 94 | MODULE_PARM_DESC(tmr_atboot, |
| 95 | "Watchdog is started at boot time if set to 1, default=" |
| 96 | __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT)); |
| 97 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
| 98 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| 99 | MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, " |
| 100 | "0 to reboot (default 0)"); |
| 101 | MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)"); |
| 102 | |
| 103 | /** |
| 104 | * struct s3c2410_wdt_variant - Per-variant config data |
| 105 | * |
| 106 | * @disable_reg: Offset in pmureg for the register that disables the watchdog |
| 107 | * timer reset functionality. |
| 108 | * @mask_reset_reg: Offset in pmureg for the register that masks the watchdog |
| 109 | * timer reset functionality. |
| 110 | * @mask_bit: Bit number for the watchdog timer in the disable register and the |
| 111 | * mask reset register. |
| 112 | * @rst_stat_reg: Offset in pmureg for the register that has the reset status. |
| 113 | * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog |
| 114 | * reset. |
| 115 | * @quirks: A bitfield of quirks. |
| 116 | */ |
| 117 | |
| 118 | struct s3c2410_wdt_variant { |
| 119 | int disable_reg; |
| 120 | int mask_reset_reg; |
| 121 | int mask_bit; |
| 122 | int rst_stat_reg; |
| 123 | int rst_stat_bit; |
| 124 | u32 quirks; |
| 125 | }; |
| 126 | |
| 127 | struct s3c2410_wdt { |
| 128 | struct device *dev; |
| 129 | struct clk *clock; |
| 130 | void __iomem *reg_base; |
| 131 | unsigned int count; |
| 132 | spinlock_t lock; |
| 133 | unsigned long wtcon_save; |
| 134 | unsigned long wtdat_save; |
| 135 | struct watchdog_device wdt_device; |
| 136 | struct notifier_block freq_transition; |
| 137 | struct s3c2410_wdt_variant *drv_data; |
| 138 | struct regmap *pmureg; |
| 139 | }; |
| 140 | |
| 141 | static const struct s3c2410_wdt_variant drv_data_s3c2410 = { |
| 142 | .quirks = 0 |
| 143 | }; |
| 144 | |
| 145 | #ifdef CONFIG_OF |
| 146 | static const struct s3c2410_wdt_variant drv_data_exynos5250 = { |
| 147 | .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET, |
| 148 | .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET, |
| 149 | .mask_bit = 20, |
| 150 | .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET, |
| 151 | .rst_stat_bit = 20, |
| 152 | .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT, |
| 153 | }; |
| 154 | |
| 155 | static const struct s3c2410_wdt_variant drv_data_exynos5420 = { |
| 156 | .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET, |
| 157 | .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET, |
| 158 | .mask_bit = 0, |
| 159 | .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET, |
| 160 | .rst_stat_bit = 9, |
| 161 | .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT, |
| 162 | }; |
| 163 | |
| 164 | static const struct s3c2410_wdt_variant drv_data_exynos7 = { |
| 165 | .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET, |
| 166 | .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET, |
| 167 | .mask_bit = 23, |
| 168 | .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET, |
| 169 | .rst_stat_bit = 23, /* A57 WDTRESET */ |
| 170 | .quirks = QUIRK_HAS_PMU_CONFIG | QUIRK_HAS_RST_STAT, |
| 171 | }; |
| 172 | |
| 173 | static const struct of_device_id s3c2410_wdt_match[] = { |
| 174 | { .compatible = "samsung,s3c2410-wdt", |
| 175 | .data = &drv_data_s3c2410 }, |
| 176 | { .compatible = "samsung,exynos5250-wdt", |
| 177 | .data = &drv_data_exynos5250 }, |
| 178 | { .compatible = "samsung,exynos5420-wdt", |
| 179 | .data = &drv_data_exynos5420 }, |
| 180 | { .compatible = "samsung,exynos7-wdt", |
| 181 | .data = &drv_data_exynos7 }, |
| 182 | {}, |
| 183 | }; |
| 184 | MODULE_DEVICE_TABLE(of, s3c2410_wdt_match); |
| 185 | #endif |
| 186 | |
| 187 | static const struct platform_device_id s3c2410_wdt_ids[] = { |
| 188 | { |
| 189 | .name = "s3c2410-wdt", |
| 190 | .driver_data = (unsigned long)&drv_data_s3c2410, |
| 191 | }, |
| 192 | {} |
| 193 | }; |
| 194 | MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids); |
| 195 | |
| 196 | /* watchdog control routines */ |
| 197 | |
| 198 | #define DBG(fmt, ...) \ |
| 199 | do { \ |
| 200 | if (debug) \ |
| 201 | pr_info(fmt, ##__VA_ARGS__); \ |
| 202 | } while (0) |
| 203 | |
| 204 | /* functions */ |
| 205 | |
| 206 | static inline unsigned int s3c2410wdt_max_timeout(struct clk *clock) |
| 207 | { |
| 208 | unsigned long freq = clk_get_rate(clock); |
| 209 | |
| 210 | return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1) |
| 211 | / S3C2410_WTCON_MAXDIV); |
| 212 | } |
| 213 | |
| 214 | static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb) |
| 215 | { |
| 216 | return container_of(nb, struct s3c2410_wdt, freq_transition); |
| 217 | } |
| 218 | |
| 219 | static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask) |
| 220 | { |
| 221 | int ret; |
| 222 | u32 mask_val = 1 << wdt->drv_data->mask_bit; |
| 223 | u32 val = 0; |
| 224 | |
| 225 | /* No need to do anything if no PMU CONFIG needed */ |
| 226 | if (!(wdt->drv_data->quirks & QUIRK_HAS_PMU_CONFIG)) |
| 227 | return 0; |
| 228 | |
| 229 | if (mask) |
| 230 | val = mask_val; |
| 231 | |
| 232 | ret = regmap_update_bits(wdt->pmureg, |
| 233 | wdt->drv_data->disable_reg, |
| 234 | mask_val, val); |
| 235 | if (ret < 0) |
| 236 | goto error; |
| 237 | |
| 238 | ret = regmap_update_bits(wdt->pmureg, |
| 239 | wdt->drv_data->mask_reset_reg, |
| 240 | mask_val, val); |
| 241 | error: |
| 242 | if (ret < 0) |
| 243 | dev_err(wdt->dev, "failed to update reg(%d)\n", ret); |
| 244 | |
| 245 | return ret; |
| 246 | } |
| 247 | |
| 248 | static int s3c2410wdt_keepalive(struct watchdog_device *wdd) |
| 249 | { |
| 250 | struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); |
| 251 | |
| 252 | spin_lock(&wdt->lock); |
| 253 | writel(wdt->count, wdt->reg_base + S3C2410_WTCNT); |
| 254 | spin_unlock(&wdt->lock); |
| 255 | |
| 256 | return 0; |
| 257 | } |
| 258 | |
| 259 | static void __s3c2410wdt_stop(struct s3c2410_wdt *wdt) |
| 260 | { |
| 261 | unsigned long wtcon; |
| 262 | |
| 263 | wtcon = readl(wdt->reg_base + S3C2410_WTCON); |
| 264 | wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN); |
| 265 | writel(wtcon, wdt->reg_base + S3C2410_WTCON); |
| 266 | } |
| 267 | |
| 268 | static int s3c2410wdt_stop(struct watchdog_device *wdd) |
| 269 | { |
| 270 | struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); |
| 271 | |
| 272 | spin_lock(&wdt->lock); |
| 273 | __s3c2410wdt_stop(wdt); |
| 274 | spin_unlock(&wdt->lock); |
| 275 | |
| 276 | return 0; |
| 277 | } |
| 278 | |
| 279 | static int s3c2410wdt_start(struct watchdog_device *wdd) |
| 280 | { |
| 281 | unsigned long wtcon; |
| 282 | struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); |
| 283 | |
| 284 | spin_lock(&wdt->lock); |
| 285 | |
| 286 | __s3c2410wdt_stop(wdt); |
| 287 | |
| 288 | wtcon = readl(wdt->reg_base + S3C2410_WTCON); |
| 289 | wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128; |
| 290 | |
| 291 | if (soft_noboot) { |
| 292 | wtcon |= S3C2410_WTCON_INTEN; |
| 293 | wtcon &= ~S3C2410_WTCON_RSTEN; |
| 294 | } else { |
| 295 | wtcon &= ~S3C2410_WTCON_INTEN; |
| 296 | wtcon |= S3C2410_WTCON_RSTEN; |
| 297 | } |
| 298 | |
| 299 | DBG("%s: count=0x%08x, wtcon=%08lx\n", |
| 300 | __func__, wdt->count, wtcon); |
| 301 | |
| 302 | writel(wdt->count, wdt->reg_base + S3C2410_WTDAT); |
| 303 | writel(wdt->count, wdt->reg_base + S3C2410_WTCNT); |
| 304 | writel(wtcon, wdt->reg_base + S3C2410_WTCON); |
| 305 | spin_unlock(&wdt->lock); |
| 306 | |
| 307 | return 0; |
| 308 | } |
| 309 | |
| 310 | static inline int s3c2410wdt_is_running(struct s3c2410_wdt *wdt) |
| 311 | { |
| 312 | return readl(wdt->reg_base + S3C2410_WTCON) & S3C2410_WTCON_ENABLE; |
| 313 | } |
| 314 | |
| 315 | static int s3c2410wdt_set_heartbeat(struct watchdog_device *wdd, unsigned timeout) |
| 316 | { |
| 317 | struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); |
| 318 | unsigned long freq = clk_get_rate(wdt->clock); |
| 319 | unsigned int count; |
| 320 | unsigned int divisor = 1; |
| 321 | unsigned long wtcon; |
| 322 | |
| 323 | if (timeout < 1) |
| 324 | return -EINVAL; |
| 325 | |
| 326 | freq = DIV_ROUND_UP(freq, 128); |
| 327 | count = timeout * freq; |
| 328 | |
| 329 | DBG("%s: count=%d, timeout=%d, freq=%lu\n", |
| 330 | __func__, count, timeout, freq); |
| 331 | |
| 332 | /* if the count is bigger than the watchdog register, |
| 333 | then work out what we need to do (and if) we can |
| 334 | actually make this value |
| 335 | */ |
| 336 | |
| 337 | if (count >= 0x10000) { |
| 338 | divisor = DIV_ROUND_UP(count, 0xffff); |
| 339 | |
| 340 | if (divisor > 0x100) { |
| 341 | dev_err(wdt->dev, "timeout %d too big\n", timeout); |
| 342 | return -EINVAL; |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n", |
| 347 | __func__, timeout, divisor, count, DIV_ROUND_UP(count, divisor)); |
| 348 | |
| 349 | count = DIV_ROUND_UP(count, divisor); |
| 350 | wdt->count = count; |
| 351 | |
| 352 | /* update the pre-scaler */ |
| 353 | wtcon = readl(wdt->reg_base + S3C2410_WTCON); |
| 354 | wtcon &= ~S3C2410_WTCON_PRESCALE_MASK; |
| 355 | wtcon |= S3C2410_WTCON_PRESCALE(divisor-1); |
| 356 | |
| 357 | writel(count, wdt->reg_base + S3C2410_WTDAT); |
| 358 | writel(wtcon, wdt->reg_base + S3C2410_WTCON); |
| 359 | |
| 360 | wdd->timeout = (count * divisor) / freq; |
| 361 | |
| 362 | return 0; |
| 363 | } |
| 364 | |
| 365 | static int s3c2410wdt_restart(struct watchdog_device *wdd, unsigned long action, |
| 366 | void *data) |
| 367 | { |
| 368 | struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); |
| 369 | void __iomem *wdt_base = wdt->reg_base; |
| 370 | |
| 371 | /* disable watchdog, to be safe */ |
| 372 | writel(0, wdt_base + S3C2410_WTCON); |
| 373 | |
| 374 | /* put initial values into count and data */ |
| 375 | writel(0x80, wdt_base + S3C2410_WTCNT); |
| 376 | writel(0x80, wdt_base + S3C2410_WTDAT); |
| 377 | |
| 378 | /* set the watchdog to go and reset... */ |
| 379 | writel(S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV16 | |
| 380 | S3C2410_WTCON_RSTEN | S3C2410_WTCON_PRESCALE(0x20), |
| 381 | wdt_base + S3C2410_WTCON); |
| 382 | |
| 383 | /* wait for reset to assert... */ |
| 384 | mdelay(500); |
| 385 | |
| 386 | return 0; |
| 387 | } |
| 388 | |
| 389 | #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) |
| 390 | |
| 391 | static const struct watchdog_info s3c2410_wdt_ident = { |
| 392 | .options = OPTIONS, |
| 393 | .firmware_version = 0, |
| 394 | .identity = "S3C2410 Watchdog", |
| 395 | }; |
| 396 | |
| 397 | static struct watchdog_ops s3c2410wdt_ops = { |
| 398 | .owner = THIS_MODULE, |
| 399 | .start = s3c2410wdt_start, |
| 400 | .stop = s3c2410wdt_stop, |
| 401 | .ping = s3c2410wdt_keepalive, |
| 402 | .set_timeout = s3c2410wdt_set_heartbeat, |
| 403 | .restart = s3c2410wdt_restart, |
| 404 | }; |
| 405 | |
| 406 | static struct watchdog_device s3c2410_wdd = { |
| 407 | .info = &s3c2410_wdt_ident, |
| 408 | .ops = &s3c2410wdt_ops, |
| 409 | .timeout = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME, |
| 410 | }; |
| 411 | |
| 412 | /* interrupt handler code */ |
| 413 | |
| 414 | static irqreturn_t s3c2410wdt_irq(int irqno, void *param) |
| 415 | { |
| 416 | struct s3c2410_wdt *wdt = platform_get_drvdata(param); |
| 417 | |
| 418 | dev_info(wdt->dev, "watchdog timer expired (irq)\n"); |
| 419 | |
| 420 | s3c2410wdt_keepalive(&wdt->wdt_device); |
| 421 | return IRQ_HANDLED; |
| 422 | } |
| 423 | |
| 424 | #ifdef CONFIG_ARM_S3C24XX_CPUFREQ |
| 425 | |
| 426 | static int s3c2410wdt_cpufreq_transition(struct notifier_block *nb, |
| 427 | unsigned long val, void *data) |
| 428 | { |
| 429 | int ret; |
| 430 | struct s3c2410_wdt *wdt = freq_to_wdt(nb); |
| 431 | |
| 432 | if (!s3c2410wdt_is_running(wdt)) |
| 433 | goto done; |
| 434 | |
| 435 | if (val == CPUFREQ_PRECHANGE) { |
| 436 | /* To ensure that over the change we don't cause the |
| 437 | * watchdog to trigger, we perform an keep-alive if |
| 438 | * the watchdog is running. |
| 439 | */ |
| 440 | |
| 441 | s3c2410wdt_keepalive(&wdt->wdt_device); |
| 442 | } else if (val == CPUFREQ_POSTCHANGE) { |
| 443 | s3c2410wdt_stop(&wdt->wdt_device); |
| 444 | |
| 445 | ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device, |
| 446 | wdt->wdt_device.timeout); |
| 447 | |
| 448 | if (ret >= 0) |
| 449 | s3c2410wdt_start(&wdt->wdt_device); |
| 450 | else |
| 451 | goto err; |
| 452 | } |
| 453 | |
| 454 | done: |
| 455 | return 0; |
| 456 | |
| 457 | err: |
| 458 | dev_err(wdt->dev, "cannot set new value for timeout %d\n", |
| 459 | wdt->wdt_device.timeout); |
| 460 | return ret; |
| 461 | } |
| 462 | |
| 463 | static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt) |
| 464 | { |
| 465 | wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition; |
| 466 | |
| 467 | return cpufreq_register_notifier(&wdt->freq_transition, |
| 468 | CPUFREQ_TRANSITION_NOTIFIER); |
| 469 | } |
| 470 | |
| 471 | static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) |
| 472 | { |
| 473 | wdt->freq_transition.notifier_call = s3c2410wdt_cpufreq_transition; |
| 474 | |
| 475 | cpufreq_unregister_notifier(&wdt->freq_transition, |
| 476 | CPUFREQ_TRANSITION_NOTIFIER); |
| 477 | } |
| 478 | |
| 479 | #else |
| 480 | |
| 481 | static inline int s3c2410wdt_cpufreq_register(struct s3c2410_wdt *wdt) |
| 482 | { |
| 483 | return 0; |
| 484 | } |
| 485 | |
| 486 | static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) |
| 487 | { |
| 488 | } |
| 489 | #endif |
| 490 | |
| 491 | static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt) |
| 492 | { |
| 493 | unsigned int rst_stat; |
| 494 | int ret; |
| 495 | |
| 496 | if (!(wdt->drv_data->quirks & QUIRK_HAS_RST_STAT)) |
| 497 | return 0; |
| 498 | |
| 499 | ret = regmap_read(wdt->pmureg, wdt->drv_data->rst_stat_reg, &rst_stat); |
| 500 | if (ret) |
| 501 | dev_warn(wdt->dev, "Couldn't get RST_STAT register\n"); |
| 502 | else if (rst_stat & BIT(wdt->drv_data->rst_stat_bit)) |
| 503 | return WDIOF_CARDRESET; |
| 504 | |
| 505 | return 0; |
| 506 | } |
| 507 | |
| 508 | /* s3c2410_get_wdt_driver_data */ |
| 509 | static inline struct s3c2410_wdt_variant * |
| 510 | get_wdt_drv_data(struct platform_device *pdev) |
| 511 | { |
| 512 | if (pdev->dev.of_node) { |
| 513 | const struct of_device_id *match; |
| 514 | match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node); |
| 515 | return (struct s3c2410_wdt_variant *)match->data; |
| 516 | } else { |
| 517 | return (struct s3c2410_wdt_variant *) |
| 518 | platform_get_device_id(pdev)->driver_data; |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | static int s3c2410wdt_probe(struct platform_device *pdev) |
| 523 | { |
| 524 | struct device *dev; |
| 525 | struct s3c2410_wdt *wdt; |
| 526 | struct resource *wdt_mem; |
| 527 | struct resource *wdt_irq; |
| 528 | unsigned int wtcon; |
| 529 | int started = 0; |
| 530 | int ret; |
| 531 | |
| 532 | DBG("%s: probe=%p\n", __func__, pdev); |
| 533 | |
| 534 | dev = &pdev->dev; |
| 535 | |
| 536 | wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); |
| 537 | if (!wdt) |
| 538 | return -ENOMEM; |
| 539 | |
| 540 | wdt->dev = &pdev->dev; |
| 541 | spin_lock_init(&wdt->lock); |
| 542 | wdt->wdt_device = s3c2410_wdd; |
| 543 | |
| 544 | wdt->drv_data = get_wdt_drv_data(pdev); |
| 545 | if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) { |
| 546 | wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node, |
| 547 | "samsung,syscon-phandle"); |
| 548 | if (IS_ERR(wdt->pmureg)) { |
| 549 | dev_err(dev, "syscon regmap lookup failed.\n"); |
| 550 | return PTR_ERR(wdt->pmureg); |
| 551 | } |
| 552 | } |
| 553 | |
| 554 | wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
| 555 | if (wdt_irq == NULL) { |
| 556 | dev_err(dev, "no irq resource specified\n"); |
| 557 | ret = -ENOENT; |
| 558 | goto err; |
| 559 | } |
| 560 | |
| 561 | /* get the memory region for the watchdog timer */ |
| 562 | wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 563 | wdt->reg_base = devm_ioremap_resource(dev, wdt_mem); |
| 564 | if (IS_ERR(wdt->reg_base)) { |
| 565 | ret = PTR_ERR(wdt->reg_base); |
| 566 | goto err; |
| 567 | } |
| 568 | |
| 569 | DBG("probe: mapped reg_base=%p\n", wdt->reg_base); |
| 570 | |
| 571 | wdt->clock = devm_clk_get(dev, "watchdog"); |
| 572 | if (IS_ERR(wdt->clock)) { |
| 573 | dev_err(dev, "failed to find watchdog clock source\n"); |
| 574 | ret = PTR_ERR(wdt->clock); |
| 575 | goto err; |
| 576 | } |
| 577 | |
| 578 | ret = clk_prepare_enable(wdt->clock); |
| 579 | if (ret < 0) { |
| 580 | dev_err(dev, "failed to enable clock\n"); |
| 581 | return ret; |
| 582 | } |
| 583 | |
| 584 | wdt->wdt_device.min_timeout = 1; |
| 585 | wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt->clock); |
| 586 | |
| 587 | ret = s3c2410wdt_cpufreq_register(wdt); |
| 588 | if (ret < 0) { |
| 589 | dev_err(dev, "failed to register cpufreq\n"); |
| 590 | goto err_clk; |
| 591 | } |
| 592 | |
| 593 | watchdog_set_drvdata(&wdt->wdt_device, wdt); |
| 594 | |
| 595 | /* see if we can actually set the requested timer margin, and if |
| 596 | * not, try the default value */ |
| 597 | |
| 598 | watchdog_init_timeout(&wdt->wdt_device, tmr_margin, &pdev->dev); |
| 599 | ret = s3c2410wdt_set_heartbeat(&wdt->wdt_device, |
| 600 | wdt->wdt_device.timeout); |
| 601 | if (ret) { |
| 602 | started = s3c2410wdt_set_heartbeat(&wdt->wdt_device, |
| 603 | CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME); |
| 604 | |
| 605 | if (started == 0) |
| 606 | dev_info(dev, |
| 607 | "tmr_margin value out of range, default %d used\n", |
| 608 | CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME); |
| 609 | else |
| 610 | dev_info(dev, "default timer value is out of range, " |
| 611 | "cannot start\n"); |
| 612 | } |
| 613 | |
| 614 | ret = devm_request_irq(dev, wdt_irq->start, s3c2410wdt_irq, 0, |
| 615 | pdev->name, pdev); |
| 616 | if (ret != 0) { |
| 617 | dev_err(dev, "failed to install irq (%d)\n", ret); |
| 618 | goto err_cpufreq; |
| 619 | } |
| 620 | |
| 621 | watchdog_set_nowayout(&wdt->wdt_device, nowayout); |
| 622 | watchdog_set_restart_priority(&wdt->wdt_device, 128); |
| 623 | |
| 624 | wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt); |
| 625 | wdt->wdt_device.parent = &pdev->dev; |
| 626 | |
| 627 | ret = watchdog_register_device(&wdt->wdt_device); |
| 628 | if (ret) { |
| 629 | dev_err(dev, "cannot register watchdog (%d)\n", ret); |
| 630 | goto err_cpufreq; |
| 631 | } |
| 632 | |
| 633 | ret = s3c2410wdt_mask_and_disable_reset(wdt, false); |
| 634 | if (ret < 0) |
| 635 | goto err_unregister; |
| 636 | |
| 637 | if (tmr_atboot && started == 0) { |
| 638 | dev_info(dev, "starting watchdog timer\n"); |
| 639 | s3c2410wdt_start(&wdt->wdt_device); |
| 640 | } else if (!tmr_atboot) { |
| 641 | /* if we're not enabling the watchdog, then ensure it is |
| 642 | * disabled if it has been left running from the bootloader |
| 643 | * or other source */ |
| 644 | |
| 645 | s3c2410wdt_stop(&wdt->wdt_device); |
| 646 | } |
| 647 | |
| 648 | platform_set_drvdata(pdev, wdt); |
| 649 | |
| 650 | /* print out a statement of readiness */ |
| 651 | |
| 652 | wtcon = readl(wdt->reg_base + S3C2410_WTCON); |
| 653 | |
| 654 | dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n", |
| 655 | (wtcon & S3C2410_WTCON_ENABLE) ? "" : "in", |
| 656 | (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis", |
| 657 | (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis"); |
| 658 | |
| 659 | return 0; |
| 660 | |
| 661 | err_unregister: |
| 662 | watchdog_unregister_device(&wdt->wdt_device); |
| 663 | |
| 664 | err_cpufreq: |
| 665 | s3c2410wdt_cpufreq_deregister(wdt); |
| 666 | |
| 667 | err_clk: |
| 668 | clk_disable_unprepare(wdt->clock); |
| 669 | |
| 670 | err: |
| 671 | return ret; |
| 672 | } |
| 673 | |
| 674 | static int s3c2410wdt_remove(struct platform_device *dev) |
| 675 | { |
| 676 | int ret; |
| 677 | struct s3c2410_wdt *wdt = platform_get_drvdata(dev); |
| 678 | |
| 679 | ret = s3c2410wdt_mask_and_disable_reset(wdt, true); |
| 680 | if (ret < 0) |
| 681 | return ret; |
| 682 | |
| 683 | watchdog_unregister_device(&wdt->wdt_device); |
| 684 | |
| 685 | s3c2410wdt_cpufreq_deregister(wdt); |
| 686 | |
| 687 | clk_disable_unprepare(wdt->clock); |
| 688 | |
| 689 | return 0; |
| 690 | } |
| 691 | |
| 692 | static void s3c2410wdt_shutdown(struct platform_device *dev) |
| 693 | { |
| 694 | struct s3c2410_wdt *wdt = platform_get_drvdata(dev); |
| 695 | |
| 696 | s3c2410wdt_mask_and_disable_reset(wdt, true); |
| 697 | |
| 698 | s3c2410wdt_stop(&wdt->wdt_device); |
| 699 | } |
| 700 | |
| 701 | #ifdef CONFIG_PM_SLEEP |
| 702 | |
| 703 | static int s3c2410wdt_suspend(struct device *dev) |
| 704 | { |
| 705 | int ret; |
| 706 | struct s3c2410_wdt *wdt = dev_get_drvdata(dev); |
| 707 | |
| 708 | /* Save watchdog state, and turn it off. */ |
| 709 | wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON); |
| 710 | wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT); |
| 711 | |
| 712 | ret = s3c2410wdt_mask_and_disable_reset(wdt, true); |
| 713 | if (ret < 0) |
| 714 | return ret; |
| 715 | |
| 716 | /* Note that WTCNT doesn't need to be saved. */ |
| 717 | s3c2410wdt_stop(&wdt->wdt_device); |
| 718 | |
| 719 | return 0; |
| 720 | } |
| 721 | |
| 722 | static int s3c2410wdt_resume(struct device *dev) |
| 723 | { |
| 724 | int ret; |
| 725 | struct s3c2410_wdt *wdt = dev_get_drvdata(dev); |
| 726 | |
| 727 | /* Restore watchdog state. */ |
| 728 | writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTDAT); |
| 729 | writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset count */ |
| 730 | writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON); |
| 731 | |
| 732 | ret = s3c2410wdt_mask_and_disable_reset(wdt, false); |
| 733 | if (ret < 0) |
| 734 | return ret; |
| 735 | |
| 736 | dev_info(dev, "watchdog %sabled\n", |
| 737 | (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis"); |
| 738 | |
| 739 | return 0; |
| 740 | } |
| 741 | #endif |
| 742 | |
| 743 | static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend, |
| 744 | s3c2410wdt_resume); |
| 745 | |
| 746 | static struct platform_driver s3c2410wdt_driver = { |
| 747 | .probe = s3c2410wdt_probe, |
| 748 | .remove = s3c2410wdt_remove, |
| 749 | .shutdown = s3c2410wdt_shutdown, |
| 750 | .id_table = s3c2410_wdt_ids, |
| 751 | .driver = { |
| 752 | .name = "s3c2410-wdt", |
| 753 | .pm = &s3c2410wdt_pm_ops, |
| 754 | .of_match_table = of_match_ptr(s3c2410_wdt_match), |
| 755 | }, |
| 756 | }; |
| 757 | |
| 758 | module_platform_driver(s3c2410wdt_driver); |
| 759 | |
| 760 | MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, " |
| 761 | "Dimitry Andric <dimitry.andric@tomtom.com>"); |
| 762 | MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver"); |
| 763 | MODULE_LICENSE("GPL"); |