From d635711daa98be86d4c7fd01499c34f566b54ccb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Fri, 10 Jun 2016 05:30:17 -0300 Subject: Linux-libre 4.6.2-gnu --- drivers/watchdog/dw_wdt.c | 323 +++++++++++++++++----------------------------- 1 file changed, 116 insertions(+), 207 deletions(-) (limited to 'drivers/watchdog/dw_wdt.c') diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index 8fefa4ad4..2acb51cf5 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -12,9 +12,8 @@ * and these are a function of the input clock frequency. * * The DesignWare watchdog cannot be stopped once it has been started so we - * use a software timer to implement a ping that will keep the watchdog alive. - * If we receive an expected close for the watchdog then we keep the timer - * running, otherwise the timer is stopped and the watchdog will expire. + * do not implement a stop function. The watchdog core will continue to send + * heartbeat requests after the watchdog device has been closed. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -22,12 +21,9 @@ #include #include #include -#include #include -#include #include #include -#include #include #include #include @@ -35,8 +31,6 @@ #include #include #include -#include -#include #include #define WDOG_CONTROL_REG_OFFSET 0x00 @@ -57,53 +51,50 @@ module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); -#define WDT_TIMEOUT (HZ / 2) - -static struct { +struct dw_wdt { void __iomem *regs; struct clk *clk; - unsigned long in_use; - unsigned long next_heartbeat; - struct timer_list timer; - int expect_close; struct notifier_block restart_handler; -} dw_wdt; + struct watchdog_device wdd; +}; + +#define to_dw_wdt(wdd) container_of(wdd, struct dw_wdt, wdd) -static inline int dw_wdt_is_enabled(void) +static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt) { - return readl(dw_wdt.regs + WDOG_CONTROL_REG_OFFSET) & + return readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET) & WDOG_CONTROL_REG_WDT_EN_MASK; } -static inline int dw_wdt_top_in_seconds(unsigned top) +static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top) { /* * There are 16 possible timeout values in 0..15 where the number of * cycles is 2 ^ (16 + i) and the watchdog counts down. */ - return (1U << (16 + top)) / clk_get_rate(dw_wdt.clk); + return (1U << (16 + top)) / clk_get_rate(dw_wdt->clk); } -static int dw_wdt_get_top(void) +static int dw_wdt_get_top(struct dw_wdt *dw_wdt) { - int top = readl(dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF; + int top = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF; - return dw_wdt_top_in_seconds(top); + return dw_wdt_top_in_seconds(dw_wdt, top); } -static inline void dw_wdt_set_next_heartbeat(void) +static int dw_wdt_ping(struct watchdog_device *wdd) { - dw_wdt.next_heartbeat = jiffies + dw_wdt_get_top() * HZ; -} + struct dw_wdt *dw_wdt = to_dw_wdt(wdd); -static void dw_wdt_keepalive(void) -{ - writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs + + writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET); + + return 0; } -static int dw_wdt_set_top(unsigned top_s) +static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s) { + struct dw_wdt *dw_wdt = to_dw_wdt(wdd); int i, top_val = DW_WDT_MAX_TOP; /* @@ -111,7 +102,7 @@ static int dw_wdt_set_top(unsigned top_s) * always look for >=. */ for (i = 0; i <= DW_WDT_MAX_TOP; ++i) - if (dw_wdt_top_in_seconds(i) >= top_s) { + if (dw_wdt_top_in_seconds(dw_wdt, i) >= top_s) { top_val = i; break; } @@ -123,33 +114,43 @@ static int dw_wdt_set_top(unsigned top_s) * effectively get a pat of the watchdog right here. */ writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT, - dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); + dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); - /* - * Add an explicit pat to handle versions of the watchdog that - * don't have TOPINIT. This won't hurt on versions that have - * it. - */ - dw_wdt_keepalive(); + wdd->timeout = dw_wdt_top_in_seconds(dw_wdt, top_val); - dw_wdt_set_next_heartbeat(); + return 0; +} + +static int dw_wdt_start(struct watchdog_device *wdd) +{ + struct dw_wdt *dw_wdt = to_dw_wdt(wdd); + + dw_wdt_set_timeout(wdd, wdd->timeout); - return dw_wdt_top_in_seconds(top_val); + set_bit(WDOG_HW_RUNNING, &wdd->status); + + writel(WDOG_CONTROL_REG_WDT_EN_MASK, + dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); + + return 0; } static int dw_wdt_restart_handle(struct notifier_block *this, - unsigned long mode, void *cmd) + unsigned long mode, void *cmd) { + struct dw_wdt *dw_wdt; u32 val; - writel(0, dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); - val = readl(dw_wdt.regs + WDOG_CONTROL_REG_OFFSET); + dw_wdt = container_of(this, struct dw_wdt, restart_handler); + + writel(0, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); + val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); if (val & WDOG_CONTROL_REG_WDT_EN_MASK) - writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs + - WDOG_COUNTER_RESTART_REG_OFFSET); + writel(WDOG_COUNTER_RESTART_KICK_VALUE, + dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET); else writel(WDOG_CONTROL_REG_WDT_EN_MASK, - dw_wdt.regs + WDOG_CONTROL_REG_OFFSET); + dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); /* wait for reset to assert... */ mdelay(500); @@ -157,74 +158,12 @@ static int dw_wdt_restart_handle(struct notifier_block *this, return NOTIFY_DONE; } -static void dw_wdt_ping(unsigned long data) +static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd) { - if (time_before(jiffies, dw_wdt.next_heartbeat) || - (!nowayout && !dw_wdt.in_use)) { - dw_wdt_keepalive(); - mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT); - } else - pr_crit("keepalive missed, machine will reset\n"); -} - -static int dw_wdt_open(struct inode *inode, struct file *filp) -{ - if (test_and_set_bit(0, &dw_wdt.in_use)) - return -EBUSY; - - /* Make sure we don't get unloaded. */ - __module_get(THIS_MODULE); - - if (!dw_wdt_is_enabled()) { - /* - * The watchdog is not currently enabled. Set the timeout to - * something reasonable and then start it. - */ - dw_wdt_set_top(DW_WDT_DEFAULT_SECONDS); - writel(WDOG_CONTROL_REG_WDT_EN_MASK, - dw_wdt.regs + WDOG_CONTROL_REG_OFFSET); - } - - dw_wdt_set_next_heartbeat(); - - return nonseekable_open(inode, filp); -} - -static ssize_t dw_wdt_write(struct file *filp, const char __user *buf, - size_t len, loff_t *offset) -{ - if (!len) - return 0; - - if (!nowayout) { - size_t i; - - dw_wdt.expect_close = 0; - - for (i = 0; i < len; ++i) { - char c; - - if (get_user(c, buf + i)) - return -EFAULT; - - if (c == 'V') { - dw_wdt.expect_close = 1; - break; - } - } - } + struct dw_wdt *dw_wdt = to_dw_wdt(wdd); - dw_wdt_set_next_heartbeat(); - dw_wdt_keepalive(); - mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT); - - return len; -} - -static u32 dw_wdt_time_left(void) -{ - return readl(dw_wdt.regs + WDOG_CURRENT_COUNT_REG_OFFSET) / - clk_get_rate(dw_wdt.clk); + return readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET) / + clk_get_rate(dw_wdt->clk); } static const struct watchdog_info dw_wdt_ident = { @@ -233,78 +172,33 @@ static const struct watchdog_info dw_wdt_ident = { .identity = "Synopsys DesignWare Watchdog", }; -static long dw_wdt_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) -{ - unsigned long val; - int timeout; - - switch (cmd) { - case WDIOC_GETSUPPORT: - return copy_to_user((void __user *)arg, &dw_wdt_ident, - sizeof(dw_wdt_ident)) ? -EFAULT : 0; - - case WDIOC_GETSTATUS: - case WDIOC_GETBOOTSTATUS: - return put_user(0, (int __user *)arg); - - case WDIOC_KEEPALIVE: - dw_wdt_set_next_heartbeat(); - return 0; - - case WDIOC_SETTIMEOUT: - if (get_user(val, (int __user *)arg)) - return -EFAULT; - timeout = dw_wdt_set_top(val); - return put_user(timeout , (int __user *)arg); - - case WDIOC_GETTIMEOUT: - return put_user(dw_wdt_get_top(), (int __user *)arg); - - case WDIOC_GETTIMELEFT: - /* Get the time left until expiry. */ - if (get_user(val, (int __user *)arg)) - return -EFAULT; - return put_user(dw_wdt_time_left(), (int __user *)arg); - - default: - return -ENOTTY; - } -} - -static int dw_wdt_release(struct inode *inode, struct file *filp) -{ - clear_bit(0, &dw_wdt.in_use); - - if (!dw_wdt.expect_close) { - del_timer(&dw_wdt.timer); - - if (!nowayout) - pr_crit("unexpected close, system will reboot soon\n"); - else - pr_crit("watchdog cannot be disabled, system will reboot soon\n"); - } - - dw_wdt.expect_close = 0; - - return 0; -} +static const struct watchdog_ops dw_wdt_ops = { + .owner = THIS_MODULE, + .start = dw_wdt_start, + .ping = dw_wdt_ping, + .set_timeout = dw_wdt_set_timeout, + .get_timeleft = dw_wdt_get_timeleft, +}; #ifdef CONFIG_PM_SLEEP static int dw_wdt_suspend(struct device *dev) { - clk_disable_unprepare(dw_wdt.clk); + struct dw_wdt *dw_wdt = dev_get_drvdata(dev); + + clk_disable_unprepare(dw_wdt->clk); return 0; } static int dw_wdt_resume(struct device *dev) { - int err = clk_prepare_enable(dw_wdt.clk); + struct dw_wdt *dw_wdt = dev_get_drvdata(dev); + int err = clk_prepare_enable(dw_wdt->clk); if (err) return err; - dw_wdt_keepalive(); + dw_wdt_ping(&dw_wdt->wdd); return 0; } @@ -312,67 +206,82 @@ static int dw_wdt_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume); -static const struct file_operations wdt_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .open = dw_wdt_open, - .write = dw_wdt_write, - .unlocked_ioctl = dw_wdt_ioctl, - .release = dw_wdt_release -}; - -static struct miscdevice dw_wdt_miscdev = { - .fops = &wdt_fops, - .name = "watchdog", - .minor = WATCHDOG_MINOR, -}; - static int dw_wdt_drv_probe(struct platform_device *pdev) { + struct device *dev = &pdev->dev; + struct watchdog_device *wdd; + struct dw_wdt *dw_wdt; + struct resource *mem; int ret; - struct resource *mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); - dw_wdt.regs = devm_ioremap_resource(&pdev->dev, mem); - if (IS_ERR(dw_wdt.regs)) - return PTR_ERR(dw_wdt.regs); + dw_wdt = devm_kzalloc(dev, sizeof(*dw_wdt), GFP_KERNEL); + if (!dw_wdt) + return -ENOMEM; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dw_wdt->regs = devm_ioremap_resource(dev, mem); + if (IS_ERR(dw_wdt->regs)) + return PTR_ERR(dw_wdt->regs); - dw_wdt.clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(dw_wdt.clk)) - return PTR_ERR(dw_wdt.clk); + dw_wdt->clk = devm_clk_get(dev, NULL); + if (IS_ERR(dw_wdt->clk)) + return PTR_ERR(dw_wdt->clk); - ret = clk_prepare_enable(dw_wdt.clk); + ret = clk_prepare_enable(dw_wdt->clk); if (ret) return ret; - ret = misc_register(&dw_wdt_miscdev); + wdd = &dw_wdt->wdd; + wdd->info = &dw_wdt_ident; + wdd->ops = &dw_wdt_ops; + wdd->min_timeout = 1; + wdd->max_hw_heartbeat_ms = + dw_wdt_top_in_seconds(dw_wdt, DW_WDT_MAX_TOP) * 1000; + wdd->parent = dev; + + watchdog_set_drvdata(wdd, dw_wdt); + watchdog_set_nowayout(wdd, nowayout); + watchdog_init_timeout(wdd, 0, dev); + + /* + * If the watchdog is already running, use its already configured + * timeout. Otherwise use the default or the value provided through + * devicetree. + */ + if (dw_wdt_is_enabled(dw_wdt)) { + wdd->timeout = dw_wdt_get_top(dw_wdt); + set_bit(WDOG_HW_RUNNING, &wdd->status); + } else { + wdd->timeout = DW_WDT_DEFAULT_SECONDS; + watchdog_init_timeout(wdd, 0, dev); + } + + platform_set_drvdata(pdev, dw_wdt); + + ret = watchdog_register_device(wdd); if (ret) goto out_disable_clk; - dw_wdt.restart_handler.notifier_call = dw_wdt_restart_handle; - dw_wdt.restart_handler.priority = 128; - ret = register_restart_handler(&dw_wdt.restart_handler); + dw_wdt->restart_handler.notifier_call = dw_wdt_restart_handle; + dw_wdt->restart_handler.priority = 128; + ret = register_restart_handler(&dw_wdt->restart_handler); if (ret) pr_warn("cannot register restart handler\n"); - dw_wdt_set_next_heartbeat(); - setup_timer(&dw_wdt.timer, dw_wdt_ping, 0); - mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT); - return 0; out_disable_clk: - clk_disable_unprepare(dw_wdt.clk); - + clk_disable_unprepare(dw_wdt->clk); return ret; } static int dw_wdt_drv_remove(struct platform_device *pdev) { - unregister_restart_handler(&dw_wdt.restart_handler); - - misc_deregister(&dw_wdt_miscdev); + struct dw_wdt *dw_wdt = platform_get_drvdata(pdev); - clk_disable_unprepare(dw_wdt.clk); + unregister_restart_handler(&dw_wdt->restart_handler); + watchdog_unregister_device(&dw_wdt->wdd); + clk_disable_unprepare(dw_wdt->clk); return 0; } -- cgit v1.2.3