1 /* linux/drivers/watchdog/rk29_wdt.c
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3 * Copyright (C) 2011 ROCKCHIP, Inc.
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6 * This program is free software; you can redistribute it and/or modify
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7 * it under the terms of the GNU General Public License as published by
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8 * the Free Software Foundation; either version 2 of the License, or
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9 * (at your option) any later version.
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11 * This program is distributed in the hope that it will be useful,
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 * GNU General Public License for more details.
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16 * You should have received a copy of the GNU General Public License
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17 * along with this program; if not, write to the Free Software
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18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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22 #include <linux/module.h>
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23 #include <linux/moduleparam.h>
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24 #include <linux/types.h>
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25 #include <linux/timer.h>
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26 #include <linux/miscdevice.h>
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27 #include <linux/watchdog.h>
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28 #include <linux/fs.h>
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29 #include <linux/init.h>
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30 #include <linux/platform_device.h>
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31 #include <linux/interrupt.h>
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32 #include <linux/clk.h>
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33 #include <linux/uaccess.h>
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34 #include <linux/io.h>
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36 #include <asm/mach/map.h>
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39 /* RK29 registers define */
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40 #define RK29_WDT_CR 0X00
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41 #define RK29_WDT_TORR 0X04
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42 #define RK29_WDT_CCVR 0X08
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43 #define RK29_WDT_CRR 0X0C
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44 #define RK29_WDT_STAT 0X10
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45 #define RK29_WDT_EOI 0X14
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47 #define RK29_WDT_EN 1
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48 #define RK29_RESPONSE_MODE 1
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49 #define RK29_RESET_PULSE 4
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51 //THAT wdt's clock is 24MHZ
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52 #define RK29_WDT_2730US 0
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53 #define RK29_WDT_5460US 1
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54 #define RK29_WDT_10920US 2
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55 #define RK29_WDT_21840US 3
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56 #define RK29_WDT_43680US 4
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57 #define RK29_WDT_87360US 5
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58 #define RK29_WDT_174720US 6
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59 #define RK29_WDT_349440US 7
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60 #define RK29_WDT_698880US 8
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61 #define RK29_WDT_1397760US 9
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62 #define RK29_WDT_2795520US 10
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63 #define RK29_WDT_5591040US 11
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64 #define RK29_WDT_11182080US 12
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65 #define RK29_WDT_22364160US 13
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66 #define RK29_WDT_44728320US 14
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67 #define RK29_WDT_89456640US 15
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70 #define CONFIG_RK29_WATCHDOG_ATBOOT (1)
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71 #define CONFIG_RK29_WATCHDOG_DEFAULT_TIME 10 //unit second
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72 #define CONFIG_RK29_WATCHDOG_DEBUG 1
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75 static int nowayout = WATCHDOG_NOWAYOUT;
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76 static int tmr_margin = CONFIG_RK29_WATCHDOG_DEFAULT_TIME;
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77 #ifdef CONFIG_RK29_WATCHDOG_ATBOOT
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78 static int tmr_atboot = 1;
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80 static int tmr_atboot = 0;
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83 static int soft_noboot;
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85 #ifdef CONFIG_RK29_WATCHDOG_DEBUG
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86 static int debug = 1;
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88 static int debug = 0;
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91 module_param(tmr_margin, int, 0);
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92 module_param(tmr_atboot, int, 0);
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93 module_param(nowayout, int, 0);
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94 module_param(soft_noboot, int, 0);
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95 module_param(debug, int, 0);
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97 MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. default="
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98 __MODULE_STRING(CONFIG_RK29_WATCHDOG_DEFAULT_TIME) ")");
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99 MODULE_PARM_DESC(tmr_atboot,
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100 "Watchdog is started at boot time if set to 1, default="
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101 __MODULE_STRING(CONFIG_RK29_WATCHDOG_ATBOOT));
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102 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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103 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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104 MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
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105 "0 to reboot (default depends on ONLY_TESTING)");
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106 MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug, (default 0)");
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109 static unsigned long open_lock;
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110 static struct device *wdt_dev; /* platform device attached to */
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111 static struct resource *wdt_mem;
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112 static struct resource *wdt_irq;
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113 static struct clk *wdt_clock;
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114 static void __iomem *wdt_base;
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115 static char expect_close;
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118 /* watchdog control routines */
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120 #define DBG(msg...) do { \
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122 printk(KERN_INFO msg); \
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125 #define wdt_writel(v, offset) do { writel_relaxed(v, wdt_base + offset); dsb(); } while (0)
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128 void rk29_wdt_keepalive(void)
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131 wdt_writel(0x76, RK29_WDT_CRR);
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134 static void __rk29_wdt_stop(void)
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136 rk29_wdt_keepalive(); //feed dog
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137 wdt_writel(0x0a, RK29_WDT_CR);
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140 static void rk29_wdt_stop(void)
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143 clk_disable(wdt_clock);
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146 /* timeout unit us */
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147 static int rk29_wdt_set_heartbeat(int timeout)
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149 unsigned int freq = clk_get_rate(wdt_clock);
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150 unsigned int count;
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151 unsigned int torr = 0;
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152 unsigned int acc = 1;
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157 // freq /= 1000000;
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158 count = timeout * freq;
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161 while(acc < count){
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168 DBG("%s:%d\n", __func__, torr);
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169 wdt_writel(torr, RK29_WDT_TORR);
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173 static void rk29_wdt_start(void)
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175 unsigned long wtcon;
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176 clk_enable(wdt_clock);
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177 rk29_wdt_set_heartbeat(tmr_margin);
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178 wtcon = (RK29_WDT_EN << 0) | (RK29_RESPONSE_MODE << 1) | (RK29_RESET_PULSE << 2);
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179 wdt_writel(wtcon, RK29_WDT_CR);
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183 * /dev/watchdog handling
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186 static int rk29_wdt_open(struct inode *inode, struct file *file)
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188 DBG("%s\n", __func__);
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189 if (test_and_set_bit(0, &open_lock))
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193 __module_get(THIS_MODULE);
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197 /* start the timer */
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199 return nonseekable_open(inode, file);
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202 static int rk29_wdt_release(struct inode *inode, struct file *file)
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205 * Shut off the timer.
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206 * Lock it in if it's a module and we set nowayout
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208 DBG("%s\n", __func__);
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209 if (expect_close == 42)
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212 dev_err(wdt_dev, "Unexpected close, not stopping watchdog\n");
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213 rk29_wdt_keepalive();
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216 clear_bit(0, &open_lock);
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220 static ssize_t rk29_wdt_write(struct file *file, const char __user *data,
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221 size_t len, loff_t *ppos)
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224 * Refresh the timer.
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226 DBG("%s\n", __func__);
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231 /* In case it was set long ago */
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234 for (i = 0; i != len; i++) {
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237 if (get_user(c, data + i))
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243 rk29_wdt_keepalive();
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248 #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
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250 static const struct watchdog_info rk29_wdt_ident = {
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251 .options = OPTIONS,
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252 .firmware_version = 0,
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253 .identity = "rk29 Watchdog",
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257 static long rk29_wdt_ioctl(struct file *file, unsigned int cmd,
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260 void __user *argp = (void __user *)arg;
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261 int __user *p = argp;
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263 DBG("%s\n", __func__);
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265 case WDIOC_GETSUPPORT:
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266 return copy_to_user(argp, &rk29_wdt_ident,
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267 sizeof(rk29_wdt_ident)) ? -EFAULT : 0;
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268 case WDIOC_GETSTATUS:
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269 case WDIOC_GETBOOTSTATUS:
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270 return put_user(0, p);
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271 case WDIOC_KEEPALIVE:
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272 DBG("%s:rk29_wdt_keepalive\n", __func__);
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273 rk29_wdt_keepalive();
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275 case WDIOC_SETTIMEOUT:
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276 if (get_user(new_margin, p))
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278 if (rk29_wdt_set_heartbeat(new_margin))
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280 rk29_wdt_keepalive();
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281 return put_user(tmr_margin, p);
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282 case WDIOC_GETTIMEOUT:
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283 return put_user(tmr_margin, p);
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291 /* kernel interface */
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293 static const struct file_operations rk29_wdt_fops = {
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294 .owner = THIS_MODULE,
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295 .llseek = no_llseek,
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296 .write = rk29_wdt_write,
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297 .unlocked_ioctl = rk29_wdt_ioctl,
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298 .open = rk29_wdt_open,
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299 .release = rk29_wdt_release,
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302 static struct miscdevice rk29_wdt_miscdev = {
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303 .minor = WATCHDOG_MINOR,
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304 .name = "watchdog",
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305 .fops = &rk29_wdt_fops,
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309 /* interrupt handler code */
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311 static irqreturn_t rk29_wdt_irq_handler(int irqno, void *param)
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313 DBG("RK29_wdt:watchdog timer expired (irq)\n");
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314 rk29_wdt_keepalive();
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315 return IRQ_HANDLED;
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319 /* device interface */
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321 static int __devinit rk29_wdt_probe(struct platform_device *pdev)
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323 struct resource *res;
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324 struct device *dev;
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330 wdt_dev = &pdev->dev;
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332 /* get the memory region for the watchdog timer */
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334 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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336 dev_err(dev, "no memory resource specified\n");
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340 size = (res->end - res->start) + 1;
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341 wdt_mem = request_mem_region(res->start, size, pdev->name);
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342 if (wdt_mem == NULL) {
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343 dev_err(dev, "failed to get memory region\n");
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348 wdt_base = ioremap(res->start, size);
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349 if (wdt_base == NULL) {
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350 dev_err(dev, "failed to ioremap() region\n");
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355 DBG("probe: mapped wdt_base=%p\n", wdt_base);
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358 #ifdef CONFIG_RK29_FEED_DOG_BY_INTE
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360 wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
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361 if (wdt_irq == NULL) {
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362 dev_err(dev, "no irq resource specified\n");
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367 ret = request_irq(wdt_irq->start, rk29_wdt_irq_handler, 0, pdev->name, pdev);
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370 dev_err(dev, "failed to install irq (%d)\n", ret);
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376 wdt_clock = clk_get(&pdev->dev, "wdt");
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377 if (IS_ERR(wdt_clock)) {
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378 dev_err(dev, "failed to find watchdog clock source\n");
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379 ret = PTR_ERR(wdt_clock);
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383 ret = misc_register(&rk29_wdt_miscdev);
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385 dev_err(dev, "cannot register miscdev on minor=%d (%d)\n",
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386 WATCHDOG_MINOR, ret);
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389 if (tmr_atboot && started == 0) {
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390 dev_info(dev, "starting watchdog timer\n");
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392 } else if (!tmr_atboot) {
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393 /* if we're not enabling the watchdog, then ensure it is
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394 * disabled if it has been left running from the bootloader
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395 * or other source */
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403 clk_disable(wdt_clock);
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404 clk_put(wdt_clock);
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407 free_irq(wdt_irq->start, pdev);
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413 release_resource(wdt_mem);
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419 static int __devexit rk29_wdt_remove(struct platform_device *dev)
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421 release_resource(wdt_mem);
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425 free_irq(wdt_irq->start, dev);
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428 clk_disable(wdt_clock);
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429 clk_put(wdt_clock);
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433 misc_deregister(&rk29_wdt_miscdev);
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438 static void rk29_wdt_shutdown(struct platform_device *dev)
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445 static int rk29_wdt_suspend(struct platform_device *dev, pm_message_t state)
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451 static int rk29_wdt_resume(struct platform_device *dev)
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458 #define rk29_wdt_suspend NULL
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459 #define rk29_wdt_resume NULL
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460 #endif /* CONFIG_PM */
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463 static struct platform_driver rk29_wdt_driver = {
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464 .probe = rk29_wdt_probe,
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465 .remove = __devexit_p(rk29_wdt_remove),
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466 .shutdown = rk29_wdt_shutdown,
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467 .suspend = rk29_wdt_suspend,
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468 .resume = rk29_wdt_resume,
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470 .owner = THIS_MODULE,
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471 .name = "rk29-wdt",
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476 static char banner[] __initdata =
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477 KERN_INFO "RK29 Watchdog Timer, (c) 2011 Rockchip Electronics\n";
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479 static int __init watchdog_init(void)
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482 return platform_driver_register(&rk29_wdt_driver);
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485 static void __exit watchdog_exit(void)
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487 platform_driver_unregister(&rk29_wdt_driver);
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490 subsys_initcall(watchdog_init);
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491 module_exit(watchdog_exit);
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493 MODULE_AUTHOR("hhb@rock-chips.com");
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494 MODULE_DESCRIPTION("RK29 Watchdog Device Driver");
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495 MODULE_LICENSE("GPL");
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496 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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497 MODULE_ALIAS("platform:rk29-wdt");
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