| // 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 stream_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, |
| .compat_ioctl = compat_ptr_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"); |