Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 1 | /* |
| 2 | * drivers/watchdog/orion5x_wdt.c |
| 3 | * |
| 4 | * Watchdog driver for Orion5x processors |
| 5 | * |
| 6 | * Author: Sylver Bruneau <sylver.bruneau@googlemail.com> |
| 7 | * |
| 8 | * This file is licensed under the terms of the GNU General Public |
| 9 | * License version 2. This program is licensed "as is" without any |
| 10 | * warranty of any kind, whether express or implied. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/moduleparam.h> |
| 15 | #include <linux/types.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/miscdevice.h> |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 19 | #include <linux/platform_device.h> |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 20 | #include <linux/watchdog.h> |
| 21 | #include <linux/init.h> |
| 22 | #include <linux/uaccess.h> |
| 23 | #include <linux/io.h> |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 24 | #include <linux/spinlock.h> |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 25 | #include <plat/orion5x_wdt.h> |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 26 | |
| 27 | /* |
| 28 | * Watchdog timer block registers. |
| 29 | */ |
| 30 | #define TIMER_CTRL (TIMER_VIRT_BASE + 0x0000) |
| 31 | #define WDT_EN 0x0010 |
| 32 | #define WDT_VAL (TIMER_VIRT_BASE + 0x0024) |
| 33 | |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 34 | #define WDT_MAX_CYCLE_COUNT 0xffffffff |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 35 | #define WDT_IN_USE 0 |
| 36 | #define WDT_OK_TO_CLOSE 1 |
| 37 | |
| 38 | static int nowayout = WATCHDOG_NOWAYOUT; |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 39 | static int heartbeat = -1; /* module parameter (seconds) */ |
| 40 | static unsigned int wdt_max_duration; /* (seconds) */ |
| 41 | static unsigned int wdt_tclk; |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 42 | static unsigned long wdt_status; |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 43 | static spinlock_t wdt_lock; |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 44 | |
| 45 | static void wdt_enable(void) |
| 46 | { |
| 47 | u32 reg; |
| 48 | |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 49 | spin_lock(&wdt_lock); |
| 50 | |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 51 | /* Set watchdog duration */ |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 52 | writel(wdt_tclk * heartbeat, WDT_VAL); |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 53 | |
| 54 | /* Clear watchdog timer interrupt */ |
| 55 | reg = readl(BRIDGE_CAUSE); |
| 56 | reg &= ~WDT_INT_REQ; |
| 57 | writel(reg, BRIDGE_CAUSE); |
| 58 | |
| 59 | /* Enable watchdog timer */ |
| 60 | reg = readl(TIMER_CTRL); |
| 61 | reg |= WDT_EN; |
| 62 | writel(reg, TIMER_CTRL); |
| 63 | |
| 64 | /* Enable reset on watchdog */ |
| 65 | reg = readl(CPU_RESET_MASK); |
| 66 | reg |= WDT_RESET; |
| 67 | writel(reg, CPU_RESET_MASK); |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 68 | |
| 69 | spin_unlock(&wdt_lock); |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 70 | } |
| 71 | |
| 72 | static void wdt_disable(void) |
| 73 | { |
| 74 | u32 reg; |
| 75 | |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 76 | spin_lock(&wdt_lock); |
| 77 | |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 78 | /* Disable reset on watchdog */ |
| 79 | reg = readl(CPU_RESET_MASK); |
| 80 | reg &= ~WDT_RESET; |
| 81 | writel(reg, CPU_RESET_MASK); |
| 82 | |
| 83 | /* Disable watchdog timer */ |
| 84 | reg = readl(TIMER_CTRL); |
| 85 | reg &= ~WDT_EN; |
| 86 | writel(reg, TIMER_CTRL); |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 87 | |
| 88 | spin_unlock(&wdt_lock); |
| 89 | } |
| 90 | |
| 91 | static int orion5x_wdt_get_timeleft(int *time_left) |
| 92 | { |
| 93 | spin_lock(&wdt_lock); |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 94 | *time_left = readl(WDT_VAL) / wdt_tclk; |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 95 | spin_unlock(&wdt_lock); |
| 96 | return 0; |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 97 | } |
| 98 | |
| 99 | static int orion5x_wdt_open(struct inode *inode, struct file *file) |
| 100 | { |
| 101 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) |
| 102 | return -EBUSY; |
| 103 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 104 | wdt_enable(); |
| 105 | return nonseekable_open(inode, file); |
| 106 | } |
| 107 | |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 108 | static ssize_t orion5x_wdt_write(struct file *file, const char *data, |
| 109 | size_t len, loff_t *ppos) |
| 110 | { |
| 111 | if (len) { |
| 112 | if (!nowayout) { |
| 113 | size_t i; |
| 114 | |
| 115 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 116 | for (i = 0; i != len; i++) { |
| 117 | char c; |
| 118 | |
| 119 | if (get_user(c, data + i)) |
| 120 | return -EFAULT; |
| 121 | if (c == 'V') |
| 122 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 123 | } |
| 124 | } |
| 125 | wdt_enable(); |
| 126 | } |
| 127 | return len; |
| 128 | } |
| 129 | |
| 130 | static struct watchdog_info ident = { |
| 131 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | |
| 132 | WDIOF_KEEPALIVEPING, |
| 133 | .identity = "Orion5x Watchdog", |
| 134 | }; |
| 135 | |
| 136 | |
| 137 | static long orion5x_wdt_ioctl(struct file *file, unsigned int cmd, |
| 138 | unsigned long arg) |
| 139 | { |
| 140 | int ret = -ENOTTY; |
| 141 | int time; |
| 142 | |
| 143 | switch (cmd) { |
| 144 | case WDIOC_GETSUPPORT: |
| 145 | ret = copy_to_user((struct watchdog_info *)arg, &ident, |
| 146 | sizeof(ident)) ? -EFAULT : 0; |
| 147 | break; |
| 148 | |
| 149 | case WDIOC_GETSTATUS: |
| 150 | case WDIOC_GETBOOTSTATUS: |
| 151 | ret = put_user(0, (int *)arg); |
| 152 | break; |
| 153 | |
| 154 | case WDIOC_KEEPALIVE: |
| 155 | wdt_enable(); |
| 156 | ret = 0; |
| 157 | break; |
| 158 | |
| 159 | case WDIOC_SETTIMEOUT: |
| 160 | ret = get_user(time, (int *)arg); |
| 161 | if (ret) |
| 162 | break; |
| 163 | |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 164 | if (time <= 0 || time > wdt_max_duration) { |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 165 | ret = -EINVAL; |
| 166 | break; |
| 167 | } |
| 168 | heartbeat = time; |
| 169 | wdt_enable(); |
| 170 | /* Fall through */ |
| 171 | |
| 172 | case WDIOC_GETTIMEOUT: |
| 173 | ret = put_user(heartbeat, (int *)arg); |
| 174 | break; |
| 175 | |
| 176 | case WDIOC_GETTIMELEFT: |
| 177 | if (orion5x_wdt_get_timeleft(&time)) { |
| 178 | ret = -EINVAL; |
| 179 | break; |
| 180 | } |
| 181 | ret = put_user(time, (int *)arg); |
| 182 | break; |
| 183 | } |
| 184 | return ret; |
| 185 | } |
| 186 | |
| 187 | static int orion5x_wdt_release(struct inode *inode, struct file *file) |
| 188 | { |
| 189 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) |
| 190 | wdt_disable(); |
| 191 | else |
| 192 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " |
| 193 | "timer will not stop\n"); |
| 194 | clear_bit(WDT_IN_USE, &wdt_status); |
| 195 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | |
| 201 | static const struct file_operations orion5x_wdt_fops = { |
| 202 | .owner = THIS_MODULE, |
| 203 | .llseek = no_llseek, |
| 204 | .write = orion5x_wdt_write, |
| 205 | .unlocked_ioctl = orion5x_wdt_ioctl, |
| 206 | .open = orion5x_wdt_open, |
| 207 | .release = orion5x_wdt_release, |
| 208 | }; |
| 209 | |
| 210 | static struct miscdevice orion5x_wdt_miscdev = { |
| 211 | .minor = WATCHDOG_MINOR, |
| 212 | .name = "watchdog", |
| 213 | .fops = &orion5x_wdt_fops, |
| 214 | }; |
| 215 | |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 216 | static int __devinit orion5x_wdt_probe(struct platform_device *pdev) |
| 217 | { |
| 218 | struct orion5x_wdt_platform_data *pdata = pdev->dev.platform_data; |
| 219 | int ret; |
| 220 | |
| 221 | if (pdata) { |
| 222 | wdt_tclk = pdata->tclk; |
| 223 | } else { |
| 224 | printk(KERN_ERR "Orion5x Watchdog misses platform data\n"); |
| 225 | return -ENODEV; |
| 226 | } |
| 227 | |
| 228 | if (orion5x_wdt_miscdev.parent) |
| 229 | return -EBUSY; |
| 230 | orion5x_wdt_miscdev.parent = &pdev->dev; |
| 231 | |
| 232 | wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk; |
| 233 | if (heartbeat <= 0 || heartbeat > wdt_max_duration) |
| 234 | heartbeat = wdt_max_duration; |
| 235 | |
| 236 | ret = misc_register(&orion5x_wdt_miscdev); |
| 237 | if (ret) |
| 238 | return ret; |
| 239 | |
| 240 | printk(KERN_INFO "Orion5x Watchdog Timer: Initial timeout %d sec%s\n", |
| 241 | heartbeat, nowayout ? ", nowayout" : ""); |
| 242 | return 0; |
| 243 | } |
| 244 | |
| 245 | static int __devexit orion5x_wdt_remove(struct platform_device *pdev) |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 246 | { |
| 247 | int ret; |
| 248 | |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 249 | if (test_bit(WDT_IN_USE, &wdt_status)) { |
| 250 | wdt_disable(); |
| 251 | clear_bit(WDT_IN_USE, &wdt_status); |
| 252 | } |
Wim Van Sebroeck | 6d0f0df | 2008-10-02 09:32:45 +0000 | [diff] [blame] | 253 | |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 254 | ret = misc_deregister(&orion5x_wdt_miscdev); |
| 255 | if (!ret) |
| 256 | orion5x_wdt_miscdev.parent = NULL; |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 257 | |
| 258 | return ret; |
| 259 | } |
| 260 | |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 261 | static struct platform_driver orion5x_wdt_driver = { |
| 262 | .probe = orion5x_wdt_probe, |
| 263 | .remove = __devexit_p(orion5x_wdt_remove), |
| 264 | .driver = { |
| 265 | .owner = THIS_MODULE, |
| 266 | .name = "orion5x_wdt", |
| 267 | }, |
| 268 | }; |
| 269 | |
| 270 | static int __init orion5x_wdt_init(void) |
| 271 | { |
| 272 | spin_lock_init(&wdt_lock); |
| 273 | return platform_driver_register(&orion5x_wdt_driver); |
| 274 | } |
| 275 | |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 276 | static void __exit orion5x_wdt_exit(void) |
| 277 | { |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 278 | platform_driver_unregister(&orion5x_wdt_driver); |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 279 | } |
| 280 | |
| 281 | module_init(orion5x_wdt_init); |
| 282 | module_exit(orion5x_wdt_exit); |
| 283 | |
| 284 | MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>"); |
| 285 | MODULE_DESCRIPTION("Orion5x Processor Watchdog"); |
| 286 | |
| 287 | module_param(heartbeat, int, 0); |
Thomas Reitmayr | 9e058d4 | 2009-02-24 14:59:22 -0800 | [diff] [blame] | 288 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds"); |
Sylver Bruneau | 22ac923 | 2008-06-26 10:47:45 +0200 | [diff] [blame] | 289 | |
| 290 | module_param(nowayout, int, 0); |
| 291 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
| 292 | |
| 293 | MODULE_LICENSE("GPL"); |
| 294 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |