rt2880_wdt.rar_rt288x

/* * Ralink RT288x/RT3xxx/MT76xx built-in hardware watchdog timer */ #include <linux/clk.h> #include <linux/reset.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/watchdog.h> #include <linux/moduleparam.h> #include <linux/platform_device.h> #include <asm/mach-ralink/ralink_regs.h> #define SYSC_RSTSTAT 0x38 #define WDT_RST_CAUSE BIT(1) #define RALINK_WDT_TIMEOUT 30 #define RALINK_WDT_PRESCALE 65536 #define TIMER_REG_TMR1LOAD 0x00 #define TIMER_REG_TMR1CTL 0x08 #define TMRSTAT_TMR1RST BIT(5) #define TMR1CTL_ENABLE BIT(7) #define TMR1CTL_MODE_SHIFT 4 #define TMR1CTL_MODE_MASK 0x3 #define TMR1CTL_MODE_FREE_RUNNING 0x0 #define TMR1CTL_MODE_PERIODIC 0x1 #define TMR1CTL_MODE_TIMEOUT 0x2 #define TMR1CTL_MODE_WDT 0x3 #define TMR1CTL_PRESCALE_MASK 0xf #define TMR1CTL_PRESCALE_65536 0xf static struct clk *rt288x_wdt_clk; static unsigned long rt288x_wdt_freq; static void __iomem *rt288x_wdt_base; 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) ")"); static inline void rt_wdt_w32(unsigned reg, u32 val) { iowrite32(val, rt288x_wdt_base + reg); } static inline u32 rt_wdt_r32(unsigned reg) { return ioread32(rt288x_wdt_base + reg); } static int rt288x_wdt_ping(struct watchdog_device *w) { rt_wdt_w32(TIMER_REG_TMR1LOAD, w->timeout * rt288x_wdt_freq); return 0; } static int rt288x_wdt_start(struct watchdog_device *w) { u32 t; t = rt_wdt_r32(TIMER_REG_TMR1CTL); t &= ~(TMR1CTL_MODE_MASK << TMR1CTL_MODE_SHIFT | TMR1CTL_PRESCALE_MASK); t |= (TMR1CTL_MODE_WDT << TMR1CTL_MODE_SHIFT | TMR1CTL_PRESCALE_65536); rt_wdt_w32(TIMER_REG_TMR1CTL, t); rt288x_wdt_ping(w); t = rt_wdt_r32(TIMER_REG_TMR1CTL); t |= TMR1CTL_ENABLE; rt_wdt_w32(TIMER_REG_TMR1CTL, t); return 0; } static int rt288x_wdt_stop(struct watchdog_device *w) { u32 t; rt288x_wdt_ping(w); t = rt_wdt_r32(TIMER_REG_TMR1CTL); t &= ~TMR1CTL_ENABLE; rt_wdt_w32(TIMER_REG_TMR1CTL, t); return 0; } static int rt288x_wdt_set_timeout(struct watchdog_device *w, unsigned int t) { w->timeout = t; rt288x_wdt_ping(w); return 0; } static int rt288x_wdt_bootcause(void) { if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) return WDIOF_CARDRESET; return 0; } static struct watchdog_info rt288x_wdt_info = { .identity = "Ralink Watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static struct watchdog_ops rt288x_wdt_ops = { .owner = THIS_MODULE, .start = rt288x_wdt_start, .stop = rt288x_wdt_stop, .ping = rt288x_wdt_ping, .set_timeout = rt288x_wdt_set_timeout, }; static struct watchdog_device rt288x_wdt_dev = { .info = &rt288x_wdt_info, .ops = &rt288x_wdt_ops, .min_timeout = 1, }; static int rt288x_wdt_probe(struct platform_device *pdev) { struct resource *res; int ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); rt288x_wdt_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(rt288x_wdt_base)) return PTR_ERR(rt288x_wdt_base); rt288x_wdt_clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(rt288x_wdt_clk)) return PTR_ERR(rt288x_wdt_clk); device_reset(&pdev->dev); rt288x_wdt_freq = clk_get_rate(rt288x_wdt_clk) / RALINK_WDT_PRESCALE; rt288x_wdt_dev.dev = &pdev->dev; rt288x_wdt_dev.bootstatus = rt288x_wdt_bootcause(); rt288x_wdt_dev.max_timeout = (0xfffful / rt288x_wdt_freq); rt288x_wdt_dev.timeout = rt288x_wdt_dev.max_timeout; watchdog_set_nowayout(&rt288x_wdt_dev, nowayout); ret = watchdog_register_device(&rt288x_wdt_dev); if (!ret) dev_info(&pdev->dev, "Initialized\n"); return 0; } static int rt288x_wdt_remove(struct platform_device *pdev) { watchdog_unregister_device(&rt288x_wdt_dev); return 0; } static void rt288x_wdt_shutdown(struct platform_device *pdev) { rt288x_wdt_stop(&rt288x_wdt_dev); } static const struct of_device_id rt288x_wdt_match[] = { { .compatible = "ralink,rt2880-wdt" }, {}, }; MODULE_DEVICE_TABLE(of, rt288x_wdt_match); static struct platform_driver rt288x_wdt_driver = { .probe = rt288x_wdt_probe, .remove = rt288x_wdt_remove, .shutdown = rt288x_wdt_shutdown, .driver = { .name = KBUILD_MODNAME, .owner = THIS_MODULE, .of_match_table = rt288x_wdt_match, }, }; module_platform_driver(rt288x_wdt_driver); MODULE_DESCRIPTION("MediaTek/Ralink RT288x/RT3xxx hardware watchdog driver"); MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org"); MODULE_LICENSE("GPL v2");