From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/watchdog/dw_wdt.c | 408 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 408 insertions(+) create mode 100644 kernel/drivers/watchdog/dw_wdt.c (limited to 'kernel/drivers/watchdog/dw_wdt.c') diff --git a/kernel/drivers/watchdog/dw_wdt.c b/kernel/drivers/watchdog/dw_wdt.c new file mode 100644 index 000000000..d0bb9499d --- /dev/null +++ b/kernel/drivers/watchdog/dw_wdt.c @@ -0,0 +1,408 @@ +/* + * Copyright 2010-2011 Picochip Ltd., Jamie Iles + * http://www.picochip.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * This file implements a driver for the Synopsys DesignWare watchdog device + * in the many subsystems. The watchdog has 16 different timeout periods + * 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define WDOG_CONTROL_REG_OFFSET 0x00 +#define WDOG_CONTROL_REG_WDT_EN_MASK 0x01 +#define WDOG_TIMEOUT_RANGE_REG_OFFSET 0x04 +#define WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT 4 +#define WDOG_CURRENT_COUNT_REG_OFFSET 0x08 +#define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c +#define WDOG_COUNTER_RESTART_KICK_VALUE 0x76 + +/* The maximum TOP (timeout period) value that can be set in the watchdog. */ +#define DW_WDT_MAX_TOP 15 + +#define DW_WDT_DEFAULT_SECONDS 30 + +static bool nowayout = WATCHDOG_NOWAYOUT; +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 { + spinlock_t lock; + 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; + +static inline int dw_wdt_is_enabled(void) +{ + 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) +{ + /* + * There are 16 possible timeout values in 0..15 where the number of + * cycles is 2 ^ (16 + i) and the watchdog counts down. + */ + return (1 << (16 + top)) / clk_get_rate(dw_wdt.clk); +} + +static int dw_wdt_get_top(void) +{ + int top = readl(dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF; + + return dw_wdt_top_in_seconds(top); +} + +static inline void dw_wdt_set_next_heartbeat(void) +{ + dw_wdt.next_heartbeat = jiffies + dw_wdt_get_top() * HZ; +} + +static void dw_wdt_keepalive(void) +{ + writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs + + WDOG_COUNTER_RESTART_REG_OFFSET); +} + +static int dw_wdt_set_top(unsigned top_s) +{ + int i, top_val = DW_WDT_MAX_TOP; + + /* + * Iterate over the timeout values until we find the closest match. We + * always look for >=. + */ + for (i = 0; i <= DW_WDT_MAX_TOP; ++i) + if (dw_wdt_top_in_seconds(i) >= top_s) { + top_val = i; + break; + } + + /* + * Set the new value in the watchdog. Some versions of dw_wdt + * have have TOPINIT in the TIMEOUT_RANGE register (as per + * CP_WDT_DUAL_TOP in WDT_COMP_PARAMS_1). On those we + * 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); + + /* + * 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(); + + dw_wdt_set_next_heartbeat(); + + return dw_wdt_top_in_seconds(top_val); +} + +static int dw_wdt_restart_handle(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + u32 val; + + 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); + else + writel(WDOG_CONTROL_REG_WDT_EN_MASK, + dw_wdt.regs + WDOG_CONTROL_REG_OFFSET); + + /* wait for reset to assert... */ + mdelay(500); + + return NOTIFY_DONE; +} + +static void dw_wdt_ping(unsigned long data) +{ + 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); + + spin_lock(&dw_wdt.lock); + 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(); + + spin_unlock(&dw_wdt.lock); + + 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; + } + } + } + + dw_wdt_set_next_heartbeat(); + 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); +} + +static const struct watchdog_info dw_wdt_ident = { + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE, + .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; +} + +#ifdef CONFIG_PM_SLEEP +static int dw_wdt_suspend(struct device *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); + + if (err) + return err; + + dw_wdt_keepalive(); + + return 0; +} +#endif /* CONFIG_PM_SLEEP */ + +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) +{ + 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.clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(dw_wdt.clk)) + return PTR_ERR(dw_wdt.clk); + + ret = clk_prepare_enable(dw_wdt.clk); + if (ret) + return ret; + + spin_lock_init(&dw_wdt.lock); + + ret = misc_register(&dw_wdt_miscdev); + 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); + 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); + + return ret; +} + +static int dw_wdt_drv_remove(struct platform_device *pdev) +{ + unregister_restart_handler(&dw_wdt.restart_handler); + + misc_deregister(&dw_wdt_miscdev); + + clk_disable_unprepare(dw_wdt.clk); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id dw_wdt_of_match[] = { + { .compatible = "snps,dw-wdt", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, dw_wdt_of_match); +#endif + +static struct platform_driver dw_wdt_driver = { + .probe = dw_wdt_drv_probe, + .remove = dw_wdt_drv_remove, + .driver = { + .name = "dw_wdt", + .of_match_table = of_match_ptr(dw_wdt_of_match), + .pm = &dw_wdt_pm_ops, + }, +}; + +module_platform_driver(dw_wdt_driver); + +MODULE_AUTHOR("Jamie Iles"); +MODULE_DESCRIPTION("Synopsys DesignWare Watchdog Driver"); +MODULE_LICENSE("GPL"); -- cgit 1.2.3-korg