--- zzzz-none-000/linux-3.10.107/drivers/watchdog/imx2_wdt.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/drivers/watchdog/imx2_wdt.c 2021-02-04 17:41:59.000000000 +0000 @@ -2,6 +2,7 @@ * Watchdog driver for IMX2 and later processors * * Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de> + * Copyright (C) 2014 Freescale Semiconductor, Inc. * * some parts adapted by similar drivers from Darius Augulis and Vladimir * Zapolskiy, additional improvements by Wim Van Sebroeck. @@ -20,19 +21,21 @@ * Halt on suspend: Manual Can be automatic */ +#include <linux/clk.h> +#include <linux/delay.h> #include <linux/init.h> +#include <linux/io.h> +#include <linux/jiffies.h> #include <linux/kernel.h> -#include <linux/miscdevice.h> #include <linux/module.h> #include <linux/moduleparam.h> +#include <linux/notifier.h> +#include <linux/of_address.h> #include <linux/platform_device.h> -#include <linux/watchdog.h> -#include <linux/clk.h> -#include <linux/fs.h> -#include <linux/io.h> -#include <linux/uaccess.h> +#include <linux/reboot.h> +#include <linux/regmap.h> #include <linux/timer.h> -#include <linux/jiffies.h> +#include <linux/watchdog.h> #define DRIVER_NAME "imx2-wdt" @@ -40,6 +43,7 @@ #define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */ #define IMX2_WDT_WCR_WRE (1 << 3) /* -> WDOG Reset Enable */ #define IMX2_WDT_WCR_WDE (1 << 2) /* -> Watchdog Enable */ +#define IMX2_WDT_WCR_WDZST (1 << 0) /* -> Watchdog timer Suspend */ #define IMX2_WDT_WSR 0x02 /* Service Register */ #define IMX2_WDT_SEQ1 0x5555 /* -> service sequence 1 */ @@ -48,24 +52,20 @@ #define IMX2_WDT_WRSR 0x04 /* Reset Status Register */ #define IMX2_WDT_WRSR_TOUT (1 << 1) /* -> Reset due to Timeout */ +#define IMX2_WDT_WMCR 0x08 /* Misc Register */ + #define IMX2_WDT_MAX_TIME 128 #define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */ #define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8) -#define IMX2_WDT_STATUS_OPEN 0 -#define IMX2_WDT_STATUS_STARTED 1 -#define IMX2_WDT_EXPECT_CLOSE 2 - -static struct { +struct imx2_wdt_device { struct clk *clk; - void __iomem *base; - unsigned timeout; - unsigned long status; + struct regmap *regmap; struct timer_list timer; /* Pings the watchdog when closed */ -} imx2_wdt; - -static struct miscdevice imx2_wdt_miscdev; + struct watchdog_device wdog; + struct notifier_block restart_handler; +}; static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); @@ -83,10 +83,40 @@ .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, }; -static inline void imx2_wdt_setup(void) +static int imx2_restart_handler(struct notifier_block *this, unsigned long mode, + void *cmd) { - u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR); + unsigned int wcr_enable = IMX2_WDT_WCR_WDE; + struct imx2_wdt_device *wdev = container_of(this, + struct imx2_wdt_device, + restart_handler); + /* Assert SRS signal */ + regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable); + /* + * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be + * written twice), we add another two writes to ensure there must be at + * least two writes happen in the same one 32kHz clock period. We save + * the target check here, since the writes shouldn't be a huge burden + * for other platforms. + */ + regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable); + regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable); + + /* wait for reset to assert... */ + mdelay(500); + + return NOTIFY_DONE; +} + +static inline void imx2_wdt_setup(struct watchdog_device *wdog) +{ + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); + u32 val; + + regmap_read(wdev->regmap, IMX2_WDT_WCR, &val); + /* Suspend timer in low power mode, write once-only */ + val |= IMX2_WDT_WCR_WDZST; /* Strip the old watchdog Time-Out value */ val &= ~IMX2_WDT_WCR_WT; /* Generate reset if WDOG times out */ @@ -94,243 +124,300 @@ /* Keep Watchdog Disabled */ val &= ~IMX2_WDT_WCR_WDE; /* Set the watchdog's Time-Out value */ - val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout); + val |= WDOG_SEC_TO_COUNT(wdog->timeout); - __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR); + regmap_write(wdev->regmap, IMX2_WDT_WCR, val); /* enable the watchdog */ val |= IMX2_WDT_WCR_WDE; - __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR); + regmap_write(wdev->regmap, IMX2_WDT_WCR, val); } -static inline void imx2_wdt_ping(void) +static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev) { - __raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR); - __raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR); -} + u32 val; -static void imx2_wdt_timer_ping(unsigned long arg) -{ - /* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */ - imx2_wdt_ping(); - mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2); -} - -static void imx2_wdt_start(void) -{ - if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) { - /* at our first start we enable clock and do initialisations */ - clk_prepare_enable(imx2_wdt.clk); + regmap_read(wdev->regmap, IMX2_WDT_WCR, &val); - imx2_wdt_setup(); - } else /* delete the timer that pings the watchdog after close */ - del_timer_sync(&imx2_wdt.timer); - - /* Watchdog is enabled - time to reload the timeout value */ - imx2_wdt_ping(); -} - -static void imx2_wdt_stop(void) -{ - /* we don't need a clk_disable, it cannot be disabled once started. - * We use a timer to ping the watchdog while /dev/watchdog is closed */ - imx2_wdt_timer_ping(0); + return val & IMX2_WDT_WCR_WDE; } -static void imx2_wdt_set_timeout(int new_timeout) +static int imx2_wdt_ping(struct watchdog_device *wdog) { - u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR); + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - /* set the new timeout value in the WSR */ - val &= ~IMX2_WDT_WCR_WT; - val |= WDOG_SEC_TO_COUNT(new_timeout); - __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR); + regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1); + regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2); + return 0; } -static int imx2_wdt_open(struct inode *inode, struct file *file) +static void imx2_wdt_timer_ping(unsigned long arg) { - if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status)) - return -EBUSY; + struct watchdog_device *wdog = (struct watchdog_device *)arg; + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - imx2_wdt_start(); - return nonseekable_open(inode, file); + /* ping it every wdog->timeout / 2 seconds to prevent reboot */ + imx2_wdt_ping(wdog); + mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2); } -static int imx2_wdt_close(struct inode *inode, struct file *file) +static int imx2_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int new_timeout) { - if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout) - imx2_wdt_stop(); - else { - dev_crit(imx2_wdt_miscdev.parent, - "Unexpected close: Expect reboot!\n"); - imx2_wdt_ping(); - } + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status); - clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status); + wdog->timeout = new_timeout; + + regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT, + WDOG_SEC_TO_COUNT(new_timeout)); return 0; } -static long imx2_wdt_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) +static int imx2_wdt_start(struct watchdog_device *wdog) { - void __user *argp = (void __user *)arg; - int __user *p = argp; - int new_value; - u16 val; - - switch (cmd) { - case WDIOC_GETSUPPORT: - return copy_to_user(argp, &imx2_wdt_info, - sizeof(struct watchdog_info)) ? -EFAULT : 0; - - case WDIOC_GETSTATUS: - return put_user(0, p); - - case WDIOC_GETBOOTSTATUS: - val = __raw_readw(imx2_wdt.base + IMX2_WDT_WRSR); - new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0; - return put_user(new_value, p); - - case WDIOC_KEEPALIVE: - imx2_wdt_ping(); - return 0; - - case WDIOC_SETTIMEOUT: - if (get_user(new_value, p)) - return -EFAULT; - if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME)) - return -EINVAL; - imx2_wdt_set_timeout(new_value); - imx2_wdt.timeout = new_value; - imx2_wdt_ping(); - - /* Fallthrough to return current value */ - case WDIOC_GETTIMEOUT: - return put_user(imx2_wdt.timeout, p); + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - default: - return -ENOTTY; - } + if (imx2_wdt_is_running(wdev)) { + /* delete the timer that pings the watchdog after close */ + del_timer_sync(&wdev->timer); + imx2_wdt_set_timeout(wdog, wdog->timeout); + } else + imx2_wdt_setup(wdog); + + return imx2_wdt_ping(wdog); } -static ssize_t imx2_wdt_write(struct file *file, const char __user *data, - size_t len, loff_t *ppos) +static int imx2_wdt_stop(struct watchdog_device *wdog) { - size_t i; - char c; + /* + * We don't need a clk_disable, it cannot be disabled once started. + * We use a timer to ping the watchdog while /dev/watchdog is closed + */ + imx2_wdt_timer_ping((unsigned long)wdog); + return 0; +} - if (len == 0) /* Can we see this even ? */ - return 0; +static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog) +{ + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status); - /* scan to see whether or not we got the magic character */ - for (i = 0; i != len; i++) { - if (get_user(c, data + i)) - return -EFAULT; - if (c == 'V') - set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status); + if (imx2_wdt_is_running(wdev)) { + imx2_wdt_set_timeout(wdog, wdog->timeout); + imx2_wdt_timer_ping((unsigned long)wdog); } - - imx2_wdt_ping(); - return len; } -static const struct file_operations imx2_wdt_fops = { +static const struct watchdog_ops imx2_wdt_ops = { .owner = THIS_MODULE, - .llseek = no_llseek, - .unlocked_ioctl = imx2_wdt_ioctl, - .open = imx2_wdt_open, - .release = imx2_wdt_close, - .write = imx2_wdt_write, + .start = imx2_wdt_start, + .stop = imx2_wdt_stop, + .ping = imx2_wdt_ping, + .set_timeout = imx2_wdt_set_timeout, }; -static struct miscdevice imx2_wdt_miscdev = { - .minor = WATCHDOG_MINOR, - .name = "watchdog", - .fops = &imx2_wdt_fops, +static const struct regmap_config imx2_wdt_regmap_config = { + .reg_bits = 16, + .reg_stride = 2, + .val_bits = 16, + .max_register = 0x8, }; static int __init imx2_wdt_probe(struct platform_device *pdev) { - int ret; + struct imx2_wdt_device *wdev; + struct watchdog_device *wdog; struct resource *res; + void __iomem *base; + int ret; + u32 val; + + wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL); + if (!wdev) + return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - imx2_wdt.base = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(imx2_wdt.base)) - return PTR_ERR(imx2_wdt.base); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + wdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base, + &imx2_wdt_regmap_config); + if (IS_ERR(wdev->regmap)) { + dev_err(&pdev->dev, "regmap init failed\n"); + return PTR_ERR(wdev->regmap); + } - imx2_wdt.clk = clk_get(&pdev->dev, NULL); - if (IS_ERR(imx2_wdt.clk)) { + wdev->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(wdev->clk)) { dev_err(&pdev->dev, "can't get Watchdog clock\n"); - return PTR_ERR(imx2_wdt.clk); + return PTR_ERR(wdev->clk); } - imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME); - if (imx2_wdt.timeout != timeout) - dev_warn(&pdev->dev, "Initial timeout out of range! " - "Clamped from %u to %u\n", timeout, imx2_wdt.timeout); + wdog = &wdev->wdog; + wdog->info = &imx2_wdt_info; + wdog->ops = &imx2_wdt_ops; + wdog->min_timeout = 1; + wdog->max_timeout = IMX2_WDT_MAX_TIME; + wdog->parent = &pdev->dev; - setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0); + ret = clk_prepare_enable(wdev->clk); + if (ret) + return ret; + + regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val); + wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0; + + wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME); + if (wdog->timeout != timeout) + dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n", + timeout, wdog->timeout); + + platform_set_drvdata(pdev, wdog); + watchdog_set_drvdata(wdog, wdev); + watchdog_set_nowayout(wdog, nowayout); + watchdog_init_timeout(wdog, timeout, &pdev->dev); + + setup_timer(&wdev->timer, imx2_wdt_timer_ping, (unsigned long)wdog); + + imx2_wdt_ping_if_active(wdog); + + /* + * Disable the watchdog power down counter at boot. Otherwise the power + * down counter will pull down the #WDOG interrupt line for one clock + * cycle. + */ + regmap_write(wdev->regmap, IMX2_WDT_WMCR, 0); + + ret = watchdog_register_device(wdog); + if (ret) { + dev_err(&pdev->dev, "cannot register watchdog device\n"); + goto disable_clk; + } - imx2_wdt_miscdev.parent = &pdev->dev; - ret = misc_register(&imx2_wdt_miscdev); + wdev->restart_handler.notifier_call = imx2_restart_handler; + wdev->restart_handler.priority = 128; + ret = register_restart_handler(&wdev->restart_handler); if (ret) - goto fail; + dev_err(&pdev->dev, "cannot register restart handler\n"); + + dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n", + wdog->timeout, nowayout); - dev_info(&pdev->dev, - "IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n", - imx2_wdt.timeout, nowayout); return 0; -fail: - imx2_wdt_miscdev.parent = NULL; - clk_put(imx2_wdt.clk); +disable_clk: + clk_disable_unprepare(wdev->clk); return ret; } static int __exit imx2_wdt_remove(struct platform_device *pdev) { - misc_deregister(&imx2_wdt_miscdev); + struct watchdog_device *wdog = platform_get_drvdata(pdev); + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) { - del_timer_sync(&imx2_wdt.timer); + unregister_restart_handler(&wdev->restart_handler); - dev_crit(imx2_wdt_miscdev.parent, - "Device removed: Expect reboot!\n"); - } else - clk_put(imx2_wdt.clk); + watchdog_unregister_device(wdog); - imx2_wdt_miscdev.parent = NULL; + if (imx2_wdt_is_running(wdev)) { + del_timer_sync(&wdev->timer); + imx2_wdt_ping(wdog); + dev_crit(&pdev->dev, "Device removed: Expect reboot!\n"); + } return 0; } static void imx2_wdt_shutdown(struct platform_device *pdev) { - if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) { - /* we are running, we need to delete the timer but will give - * max timeout before reboot will take place */ - del_timer_sync(&imx2_wdt.timer); - imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME); - imx2_wdt_ping(); + struct watchdog_device *wdog = platform_get_drvdata(pdev); + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); - dev_crit(imx2_wdt_miscdev.parent, - "Device shutdown: Expect reboot!\n"); + if (imx2_wdt_is_running(wdev)) { + /* + * We are running, we need to delete the timer but will + * give max timeout before reboot will take place + */ + del_timer_sync(&wdev->timer); + imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); + imx2_wdt_ping(wdog); + dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n"); } } +#ifdef CONFIG_PM_SLEEP +/* Disable watchdog if it is active or non-active but still running */ +static int imx2_wdt_suspend(struct device *dev) +{ + struct watchdog_device *wdog = dev_get_drvdata(dev); + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); + + /* The watchdog IP block is running */ + if (imx2_wdt_is_running(wdev)) { + imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); + imx2_wdt_ping(wdog); + + /* The watchdog is not active */ + if (!watchdog_active(wdog)) + del_timer_sync(&wdev->timer); + } + + clk_disable_unprepare(wdev->clk); + + return 0; +} + +/* Enable watchdog and configure it if necessary */ +static int imx2_wdt_resume(struct device *dev) +{ + struct watchdog_device *wdog = dev_get_drvdata(dev); + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog); + int ret; + + ret = clk_prepare_enable(wdev->clk); + if (ret) + return ret; + + if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) { + /* + * If the watchdog is still active and resumes + * from deep sleep state, need to restart the + * watchdog again. + */ + imx2_wdt_setup(wdog); + imx2_wdt_set_timeout(wdog, wdog->timeout); + imx2_wdt_ping(wdog); + } else if (imx2_wdt_is_running(wdev)) { + /* Resuming from non-deep sleep state. */ + imx2_wdt_set_timeout(wdog, wdog->timeout); + imx2_wdt_ping(wdog); + /* + * But the watchdog is not active, then start + * the timer again. + */ + if (!watchdog_active(wdog)) + mod_timer(&wdev->timer, + jiffies + wdog->timeout * HZ / 2); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend, + imx2_wdt_resume); + static const struct of_device_id imx2_wdt_dt_ids[] = { { .compatible = "fsl,imx21-wdt", }, { /* sentinel */ } }; +MODULE_DEVICE_TABLE(of, imx2_wdt_dt_ids); static struct platform_driver imx2_wdt_driver = { .remove = __exit_p(imx2_wdt_remove), .shutdown = imx2_wdt_shutdown, .driver = { .name = DRIVER_NAME, - .owner = THIS_MODULE, + .pm = &imx2_wdt_pm_ops, .of_match_table = imx2_wdt_dt_ids, }, }; @@ -340,5 +427,4 @@ MODULE_AUTHOR("Wolfram Sang"); MODULE_DESCRIPTION("Watchdog driver for IMX2 and later"); MODULE_LICENSE("GPL v2"); -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); MODULE_ALIAS("platform:" DRIVER_NAME);