dmitry pervushin | accde16 | 2009-06-03 20:21:21 +0400 | [diff] [blame] | 1 | /* |
| 2 | * Watchdog driver for Freescale STMP37XX/STMP378X |
| 3 | * |
| 4 | * Author: Vitaly Wool <vital@embeddedalley.com> |
| 5 | * |
| 6 | * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved. |
| 7 | * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. |
| 8 | */ |
| 9 | #include <linux/init.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/fs.h> |
| 12 | #include <linux/miscdevice.h> |
| 13 | #include <linux/watchdog.h> |
| 14 | #include <linux/platform_device.h> |
| 15 | #include <linux/spinlock.h> |
| 16 | #include <linux/uaccess.h> |
Paul Gortmaker | e7455b7a | 2011-08-29 10:58:55 -0400 | [diff] [blame^] | 17 | #include <linux/module.h> |
dmitry pervushin | accde16 | 2009-06-03 20:21:21 +0400 | [diff] [blame] | 18 | |
| 19 | #include <mach/platform.h> |
| 20 | #include <mach/regs-rtc.h> |
| 21 | |
| 22 | #define DEFAULT_HEARTBEAT 19 |
| 23 | #define MAX_HEARTBEAT (0x10000000 >> 6) |
| 24 | |
| 25 | /* missing bitmask in headers */ |
| 26 | #define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER 0x80000000 |
| 27 | |
| 28 | #define WDT_IN_USE 0 |
| 29 | #define WDT_OK_TO_CLOSE 1 |
| 30 | |
| 31 | #define WDOG_COUNTER_RATE 1000 /* 1 kHz clock */ |
| 32 | |
| 33 | static DEFINE_SPINLOCK(stmp3xxx_wdt_io_lock); |
| 34 | static unsigned long wdt_status; |
| 35 | static const int nowayout = WATCHDOG_NOWAYOUT; |
| 36 | static int heartbeat = DEFAULT_HEARTBEAT; |
| 37 | static unsigned long boot_status; |
| 38 | |
| 39 | static void wdt_enable(u32 value) |
| 40 | { |
| 41 | spin_lock(&stmp3xxx_wdt_io_lock); |
| 42 | __raw_writel(value, REGS_RTC_BASE + HW_RTC_WATCHDOG); |
| 43 | stmp3xxx_setl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL); |
| 44 | stmp3xxx_setl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER, |
| 45 | REGS_RTC_BASE + HW_RTC_PERSISTENT1); |
| 46 | spin_unlock(&stmp3xxx_wdt_io_lock); |
| 47 | } |
| 48 | |
| 49 | static void wdt_disable(void) |
| 50 | { |
| 51 | spin_lock(&stmp3xxx_wdt_io_lock); |
| 52 | stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER, |
| 53 | REGS_RTC_BASE + HW_RTC_PERSISTENT1); |
| 54 | stmp3xxx_clearl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL); |
| 55 | spin_unlock(&stmp3xxx_wdt_io_lock); |
| 56 | } |
| 57 | |
| 58 | static void wdt_ping(void) |
| 59 | { |
| 60 | wdt_enable(heartbeat * WDOG_COUNTER_RATE); |
| 61 | } |
| 62 | |
| 63 | static int stmp3xxx_wdt_open(struct inode *inode, struct file *file) |
| 64 | { |
| 65 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) |
| 66 | return -EBUSY; |
| 67 | |
| 68 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 69 | wdt_ping(); |
| 70 | |
| 71 | return nonseekable_open(inode, file); |
| 72 | } |
| 73 | |
| 74 | static ssize_t stmp3xxx_wdt_write(struct file *file, const char __user *data, |
| 75 | size_t len, loff_t *ppos) |
| 76 | { |
| 77 | if (len) { |
| 78 | if (!nowayout) { |
| 79 | size_t i; |
| 80 | |
| 81 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 82 | |
| 83 | for (i = 0; i != len; i++) { |
| 84 | char c; |
| 85 | |
| 86 | if (get_user(c, data + i)) |
| 87 | return -EFAULT; |
| 88 | if (c == 'V') |
| 89 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 90 | } |
| 91 | } |
| 92 | wdt_ping(); |
| 93 | } |
| 94 | |
| 95 | return len; |
| 96 | } |
| 97 | |
Wim Van Sebroeck | 42747d7 | 2009-12-26 18:55:22 +0000 | [diff] [blame] | 98 | static const struct watchdog_info ident = { |
dmitry pervushin | accde16 | 2009-06-03 20:21:21 +0400 | [diff] [blame] | 99 | .options = WDIOF_CARDRESET | |
| 100 | WDIOF_MAGICCLOSE | |
| 101 | WDIOF_SETTIMEOUT | |
| 102 | WDIOF_KEEPALIVEPING, |
| 103 | .identity = "STMP3XXX Watchdog", |
| 104 | }; |
| 105 | |
| 106 | static long stmp3xxx_wdt_ioctl(struct file *file, unsigned int cmd, |
| 107 | unsigned long arg) |
| 108 | { |
| 109 | void __user *argp = (void __user *)arg; |
| 110 | int __user *p = argp; |
| 111 | int new_heartbeat, opts; |
| 112 | int ret = -ENOTTY; |
| 113 | |
| 114 | switch (cmd) { |
| 115 | case WDIOC_GETSUPPORT: |
| 116 | ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; |
| 117 | break; |
| 118 | |
| 119 | case WDIOC_GETSTATUS: |
| 120 | ret = put_user(0, p); |
| 121 | break; |
| 122 | |
| 123 | case WDIOC_GETBOOTSTATUS: |
| 124 | ret = put_user(boot_status, p); |
| 125 | break; |
| 126 | |
| 127 | case WDIOC_SETOPTIONS: |
| 128 | if (get_user(opts, p)) { |
| 129 | ret = -EFAULT; |
| 130 | break; |
| 131 | } |
| 132 | if (opts & WDIOS_DISABLECARD) |
| 133 | wdt_disable(); |
| 134 | else if (opts & WDIOS_ENABLECARD) |
| 135 | wdt_ping(); |
| 136 | else { |
| 137 | pr_debug("%s: unknown option 0x%x\n", __func__, opts); |
| 138 | ret = -EINVAL; |
| 139 | break; |
| 140 | } |
| 141 | ret = 0; |
| 142 | break; |
| 143 | |
| 144 | case WDIOC_KEEPALIVE: |
| 145 | wdt_ping(); |
| 146 | ret = 0; |
| 147 | break; |
| 148 | |
| 149 | case WDIOC_SETTIMEOUT: |
| 150 | if (get_user(new_heartbeat, p)) { |
| 151 | ret = -EFAULT; |
| 152 | break; |
| 153 | } |
| 154 | if (new_heartbeat <= 0 || new_heartbeat > MAX_HEARTBEAT) { |
| 155 | ret = -EINVAL; |
| 156 | break; |
| 157 | } |
| 158 | |
| 159 | heartbeat = new_heartbeat; |
| 160 | wdt_ping(); |
| 161 | /* Fall through */ |
| 162 | |
| 163 | case WDIOC_GETTIMEOUT: |
| 164 | ret = put_user(heartbeat, p); |
| 165 | break; |
| 166 | } |
| 167 | return ret; |
| 168 | } |
| 169 | |
| 170 | static int stmp3xxx_wdt_release(struct inode *inode, struct file *file) |
| 171 | { |
| 172 | int ret = 0; |
| 173 | |
| 174 | if (!nowayout) { |
| 175 | if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { |
| 176 | wdt_ping(); |
| 177 | pr_debug("%s: Device closed unexpectdly\n", __func__); |
| 178 | ret = -EINVAL; |
| 179 | } else { |
| 180 | wdt_disable(); |
| 181 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 182 | } |
| 183 | } |
| 184 | clear_bit(WDT_IN_USE, &wdt_status); |
| 185 | |
| 186 | return ret; |
| 187 | } |
| 188 | |
| 189 | static const struct file_operations stmp3xxx_wdt_fops = { |
| 190 | .owner = THIS_MODULE, |
| 191 | .llseek = no_llseek, |
| 192 | .write = stmp3xxx_wdt_write, |
| 193 | .unlocked_ioctl = stmp3xxx_wdt_ioctl, |
| 194 | .open = stmp3xxx_wdt_open, |
| 195 | .release = stmp3xxx_wdt_release, |
| 196 | }; |
| 197 | |
| 198 | static struct miscdevice stmp3xxx_wdt_miscdev = { |
| 199 | .minor = WATCHDOG_MINOR, |
| 200 | .name = "watchdog", |
| 201 | .fops = &stmp3xxx_wdt_fops, |
| 202 | }; |
| 203 | |
| 204 | static int __devinit stmp3xxx_wdt_probe(struct platform_device *pdev) |
| 205 | { |
| 206 | int ret = 0; |
| 207 | |
| 208 | if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) |
| 209 | heartbeat = DEFAULT_HEARTBEAT; |
| 210 | |
| 211 | boot_status = __raw_readl(REGS_RTC_BASE + HW_RTC_PERSISTENT1) & |
| 212 | BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER; |
| 213 | boot_status = !!boot_status; |
| 214 | stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER, |
| 215 | REGS_RTC_BASE + HW_RTC_PERSISTENT1); |
| 216 | wdt_disable(); /* disable for now */ |
| 217 | |
| 218 | ret = misc_register(&stmp3xxx_wdt_miscdev); |
| 219 | if (ret < 0) { |
| 220 | dev_err(&pdev->dev, "cannot register misc device\n"); |
| 221 | return ret; |
| 222 | } |
| 223 | |
| 224 | printk(KERN_INFO "stmp3xxx watchdog: initialized, heartbeat %d sec\n", |
| 225 | heartbeat); |
| 226 | |
| 227 | return ret; |
| 228 | } |
| 229 | |
| 230 | static int __devexit stmp3xxx_wdt_remove(struct platform_device *pdev) |
| 231 | { |
| 232 | misc_deregister(&stmp3xxx_wdt_miscdev); |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | #ifdef CONFIG_PM |
| 237 | static int wdt_suspended; |
| 238 | static u32 wdt_saved_time; |
| 239 | |
| 240 | static int stmp3xxx_wdt_suspend(struct platform_device *pdev, |
| 241 | pm_message_t state) |
| 242 | { |
| 243 | if (__raw_readl(REGS_RTC_BASE + HW_RTC_CTRL) & |
| 244 | BM_RTC_CTRL_WATCHDOGEN) { |
| 245 | wdt_suspended = 1; |
| 246 | wdt_saved_time = __raw_readl(REGS_RTC_BASE + HW_RTC_WATCHDOG); |
| 247 | wdt_disable(); |
| 248 | } |
| 249 | return 0; |
| 250 | } |
| 251 | |
| 252 | static int stmp3xxx_wdt_resume(struct platform_device *pdev) |
| 253 | { |
| 254 | if (wdt_suspended) { |
| 255 | wdt_enable(wdt_saved_time); |
| 256 | wdt_suspended = 0; |
| 257 | } |
| 258 | return 0; |
| 259 | } |
| 260 | #else |
| 261 | #define stmp3xxx_wdt_suspend NULL |
| 262 | #define stmp3xxx_wdt_resume NULL |
| 263 | #endif |
| 264 | |
| 265 | static struct platform_driver platform_wdt_driver = { |
| 266 | .driver = { |
| 267 | .name = "stmp3xxx_wdt", |
| 268 | }, |
| 269 | .probe = stmp3xxx_wdt_probe, |
| 270 | .remove = __devexit_p(stmp3xxx_wdt_remove), |
| 271 | .suspend = stmp3xxx_wdt_suspend, |
| 272 | .resume = stmp3xxx_wdt_resume, |
| 273 | }; |
| 274 | |
| 275 | static int __init stmp3xxx_wdt_init(void) |
| 276 | { |
| 277 | return platform_driver_register(&platform_wdt_driver); |
| 278 | } |
| 279 | |
| 280 | static void __exit stmp3xxx_wdt_exit(void) |
| 281 | { |
| 282 | return platform_driver_unregister(&platform_wdt_driver); |
| 283 | } |
| 284 | |
| 285 | module_init(stmp3xxx_wdt_init); |
| 286 | module_exit(stmp3xxx_wdt_exit); |
| 287 | |
| 288 | MODULE_DESCRIPTION("STMP3XXX Watchdog Driver"); |
| 289 | MODULE_LICENSE("GPL"); |
| 290 | |
| 291 | module_param(heartbeat, int, 0); |
| 292 | MODULE_PARM_DESC(heartbeat, |
| 293 | "Watchdog heartbeat period in seconds from 1 to " |
| 294 | __MODULE_STRING(MAX_HEARTBEAT) ", default " |
| 295 | __MODULE_STRING(DEFAULT_HEARTBEAT)); |
| 296 | |
| 297 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |