diff options
Diffstat (limited to 'drivers/watchdog/bcm63xx_wdt.c')
| -rw-r--r-- | drivers/watchdog/bcm63xx_wdt.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c new file mode 100644 index 000000000..d3c1113e7 --- /dev/null +++ b/drivers/watchdog/bcm63xx_wdt.c @@ -0,0 +1,314 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Broadcom BCM63xx SoC watchdog driver + * + * Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com> + * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org> + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/bitops.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/uaccess.h> +#include <linux/watchdog.h> +#include <linux/timer.h> +#include <linux/jiffies.h> +#include <linux/interrupt.h> +#include <linux/ptrace.h> +#include <linux/resource.h> +#include <linux/platform_device.h> + +#include <bcm63xx_cpu.h> +#include <bcm63xx_io.h> +#include <bcm63xx_regs.h> +#include <bcm63xx_timer.h> + +#define PFX KBUILD_MODNAME + +#define WDT_HZ 50000000 /* Fclk */ +#define WDT_DEFAULT_TIME 30 /* seconds */ +#define WDT_MAX_TIME 256 /* seconds */ + +static struct { + void __iomem *regs; + struct timer_list timer; + unsigned long inuse; + atomic_t ticks; +} bcm63xx_wdt_device; + +static int expect_close; + +static int wdt_time = WDT_DEFAULT_TIME; +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) ")"); + +/* HW functions */ +static void bcm63xx_wdt_hw_start(void) +{ + bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG); + bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); + bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); +} + +static void bcm63xx_wdt_hw_stop(void) +{ + bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG); + bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG); +} + +static void bcm63xx_wdt_isr(void *data) +{ + struct pt_regs *regs = get_irq_regs(); + + die(PFX " fire", regs); +} + +static void bcm63xx_timer_tick(struct timer_list *unused) +{ + if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) { + bcm63xx_wdt_hw_start(); + mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ); + } else + pr_crit("watchdog will restart system\n"); +} + +static void bcm63xx_wdt_pet(void) +{ + atomic_set(&bcm63xx_wdt_device.ticks, wdt_time); +} + +static void bcm63xx_wdt_start(void) +{ + bcm63xx_wdt_pet(); + bcm63xx_timer_tick(0); +} + +static void bcm63xx_wdt_pause(void) +{ + del_timer_sync(&bcm63xx_wdt_device.timer); + bcm63xx_wdt_hw_stop(); +} + +static int bcm63xx_wdt_settimeout(int new_time) +{ + if ((new_time <= 0) || (new_time > WDT_MAX_TIME)) + return -EINVAL; + + wdt_time = new_time; + + return 0; +} + +static int bcm63xx_wdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse)) + return -EBUSY; + + bcm63xx_wdt_start(); + return nonseekable_open(inode, file); +} + +static int bcm63xx_wdt_release(struct inode *inode, struct file *file) +{ + if (expect_close == 42) + bcm63xx_wdt_pause(); + else { + pr_crit("Unexpected close, not stopping watchdog!\n"); + bcm63xx_wdt_start(); + } + clear_bit(0, &bcm63xx_wdt_device.inuse); + expect_close = 0; + return 0; +} + +static ssize_t bcm63xx_wdt_write(struct file *file, const char *data, + size_t len, loff_t *ppos) +{ + if (len) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + for (i = 0; i != len; i++) { + char c; + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } + bcm63xx_wdt_pet(); + } + return len; +} + +static struct watchdog_info bcm63xx_wdt_info = { + .identity = PFX, + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + + +static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + int new_value, retval = -EINVAL; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(argp, &bcm63xx_wdt_info, + sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, p); + + case WDIOC_SETOPTIONS: + if (get_user(new_value, p)) + return -EFAULT; + + if (new_value & WDIOS_DISABLECARD) { + bcm63xx_wdt_pause(); + retval = 0; + } + if (new_value & WDIOS_ENABLECARD) { + bcm63xx_wdt_start(); + retval = 0; + } + + return retval; + + case WDIOC_KEEPALIVE: + bcm63xx_wdt_pet(); + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(new_value, p)) + return -EFAULT; + + if (bcm63xx_wdt_settimeout(new_value)) + return -EINVAL; + + bcm63xx_wdt_pet(); + + case WDIOC_GETTIMEOUT: + return put_user(wdt_time, p); + + default: + return -ENOTTY; + + } +} + +static const struct file_operations bcm63xx_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = bcm63xx_wdt_write, + .unlocked_ioctl = bcm63xx_wdt_ioctl, + .open = bcm63xx_wdt_open, + .release = bcm63xx_wdt_release, +}; + +static struct miscdevice bcm63xx_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &bcm63xx_wdt_fops, +}; + + +static int bcm63xx_wdt_probe(struct platform_device *pdev) +{ + int ret; + struct resource *r; + + timer_setup(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!r) { + dev_err(&pdev->dev, "failed to get resources\n"); + return -ENODEV; + } + + bcm63xx_wdt_device.regs = devm_ioremap_nocache(&pdev->dev, r->start, + resource_size(r)); + if (!bcm63xx_wdt_device.regs) { + dev_err(&pdev->dev, "failed to remap I/O resources\n"); + return -ENXIO; + } + + ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL); + if (ret < 0) { + dev_err(&pdev->dev, "failed to register wdt timer isr\n"); + return ret; + } + + if (bcm63xx_wdt_settimeout(wdt_time)) { + bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME); + dev_info(&pdev->dev, + ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n", + wdt_time); + } + + ret = misc_register(&bcm63xx_wdt_miscdev); + if (ret < 0) { + dev_err(&pdev->dev, "failed to register watchdog device\n"); + goto unregister_timer; + } + + dev_info(&pdev->dev, " started, timer margin: %d sec\n", + WDT_DEFAULT_TIME); + + return 0; + +unregister_timer: + bcm63xx_timer_unregister(TIMER_WDT_ID); + return ret; +} + +static int bcm63xx_wdt_remove(struct platform_device *pdev) +{ + if (!nowayout) + bcm63xx_wdt_pause(); + + misc_deregister(&bcm63xx_wdt_miscdev); + bcm63xx_timer_unregister(TIMER_WDT_ID); + return 0; +} + +static void bcm63xx_wdt_shutdown(struct platform_device *pdev) +{ + bcm63xx_wdt_pause(); +} + +static struct platform_driver bcm63xx_wdt_driver = { + .probe = bcm63xx_wdt_probe, + .remove = bcm63xx_wdt_remove, + .shutdown = bcm63xx_wdt_shutdown, + .driver = { + .name = "bcm63xx-wdt", + } +}; + +module_platform_driver(bcm63xx_wdt_driver); + +MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>"); +MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); +MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:bcm63xx-wdt"); |