diff options
Diffstat (limited to 'drivers/watchdog/sirfsoc_wdt.c')
| -rw-r--r-- | drivers/watchdog/sirfsoc_wdt.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/drivers/watchdog/sirfsoc_wdt.c b/drivers/watchdog/sirfsoc_wdt.c new file mode 100644 index 000000000000..ced3edc95957 --- /dev/null +++ b/drivers/watchdog/sirfsoc_wdt.c @@ -0,0 +1,226 @@ +/* + * Watchdog driver for CSR SiRFprimaII and SiRFatlasVI + * + * Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company. + * + * Licensed under GPLv2 or later. + */ + +#include <linux/module.h> +#include <linux/watchdog.h> +#include <linux/platform_device.h> +#include <linux/moduleparam.h> +#include <linux/of.h> +#include <linux/io.h> +#include <linux/uaccess.h> + +#define CLOCK_FREQ 1000000 + +#define SIRFSOC_TIMER_COUNTER_LO 0x0000 +#define SIRFSOC_TIMER_MATCH_0 0x0008 +#define SIRFSOC_TIMER_INT_EN 0x0024 +#define SIRFSOC_TIMER_WATCHDOG_EN 0x0028 +#define SIRFSOC_TIMER_LATCH 0x0030 +#define SIRFSOC_TIMER_LATCHED_LO 0x0034 + +#define SIRFSOC_TIMER_WDT_INDEX 5 + +#define SIRFSOC_WDT_MIN_TIMEOUT 30 /* 30 secs */ +#define SIRFSOC_WDT_MAX_TIMEOUT (10 * 60) /* 10 mins */ +#define SIRFSOC_WDT_DEFAULT_TIMEOUT 30 /* 30 secs */ + +static unsigned int timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT; +static bool nowayout = WATCHDOG_NOWAYOUT; + +module_param(timeout, uint, 0); +module_param(nowayout, bool, 0); + +MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)"); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +static unsigned int sirfsoc_wdt_gettimeleft(struct watchdog_device *wdd) +{ + u32 counter, match; + void __iomem *wdt_base; + int time_left; + + wdt_base = watchdog_get_drvdata(wdd); + counter = readl(wdt_base + SIRFSOC_TIMER_COUNTER_LO); + match = readl(wdt_base + + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2)); + + time_left = match - counter; + + return time_left / CLOCK_FREQ; +} + +static int sirfsoc_wdt_updatetimeout(struct watchdog_device *wdd) +{ + u32 counter, timeout_ticks; + void __iomem *wdt_base; + + timeout_ticks = wdd->timeout * CLOCK_FREQ; + wdt_base = watchdog_get_drvdata(wdd); + + /* Enable the latch before reading the LATCH_LO register */ + writel(1, wdt_base + SIRFSOC_TIMER_LATCH); + + /* Set the TO value */ + counter = readl(wdt_base + SIRFSOC_TIMER_LATCHED_LO); + + counter += timeout_ticks; + + writel(counter, wdt_base + + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2)); + + return 0; +} + +static int sirfsoc_wdt_enable(struct watchdog_device *wdd) +{ + void __iomem *wdt_base = watchdog_get_drvdata(wdd); + sirfsoc_wdt_updatetimeout(wdd); + + /* + * NOTE: If interrupt is not enabled + * then WD-Reset doesn't get generated at all. + */ + writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN) + | (1 << SIRFSOC_TIMER_WDT_INDEX), + wdt_base + SIRFSOC_TIMER_INT_EN); + writel(1, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN); + + return 0; +} + +static int sirfsoc_wdt_disable(struct watchdog_device *wdd) +{ + void __iomem *wdt_base = watchdog_get_drvdata(wdd); + + writel(0, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN); + writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN) + & (~(1 << SIRFSOC_TIMER_WDT_INDEX)), + wdt_base + SIRFSOC_TIMER_INT_EN); + + return 0; +} + +static int sirfsoc_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) +{ + wdd->timeout = to; + sirfsoc_wdt_updatetimeout(wdd); + + return 0; +} + +#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) + +static const struct watchdog_info sirfsoc_wdt_ident = { + .options = OPTIONS, + .firmware_version = 0, + .identity = "SiRFSOC Watchdog", +}; + +static struct watchdog_ops sirfsoc_wdt_ops = { + .owner = THIS_MODULE, + .start = sirfsoc_wdt_enable, + .stop = sirfsoc_wdt_disable, + .get_timeleft = sirfsoc_wdt_gettimeleft, + .ping = sirfsoc_wdt_updatetimeout, + .set_timeout = sirfsoc_wdt_settimeout, +}; + +static struct watchdog_device sirfsoc_wdd = { + .info = &sirfsoc_wdt_ident, + .ops = &sirfsoc_wdt_ops, + .timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT, + .min_timeout = SIRFSOC_WDT_MIN_TIMEOUT, + .max_timeout = SIRFSOC_WDT_MAX_TIMEOUT, +}; + +static int sirfsoc_wdt_probe(struct platform_device *pdev) +{ + struct resource *res; + int ret; + void __iomem *base; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + watchdog_set_drvdata(&sirfsoc_wdd, base); + + watchdog_init_timeout(&sirfsoc_wdd, timeout, &pdev->dev); + watchdog_set_nowayout(&sirfsoc_wdd, nowayout); + + ret = watchdog_register_device(&sirfsoc_wdd); + if (ret) + return ret; + + platform_set_drvdata(pdev, &sirfsoc_wdd); + + return 0; +} + +static void sirfsoc_wdt_shutdown(struct platform_device *pdev) +{ + struct watchdog_device *wdd = platform_get_drvdata(pdev); + + sirfsoc_wdt_disable(wdd); +} + +static int sirfsoc_wdt_remove(struct platform_device *pdev) +{ + sirfsoc_wdt_shutdown(pdev); + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int sirfsoc_wdt_suspend(struct device *dev) +{ + return 0; +} + +static int sirfsoc_wdt_resume(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + /* + * NOTE: Since timer controller registers settings are saved + * and restored back by the timer-prima2.c, so we need not + * update WD settings except refreshing timeout. + */ + sirfsoc_wdt_updatetimeout(wdd); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(sirfsoc_wdt_pm_ops, + sirfsoc_wdt_suspend, sirfsoc_wdt_resume); + +static const struct of_device_id sirfsoc_wdt_of_match[] = { + { .compatible = "sirf,prima2-tick"}, + {}, +}; +MODULE_DEVICE_TABLE(of, sirfsoc_wdt_of_match); + +static struct platform_driver sirfsoc_wdt_driver = { + .driver = { + .name = "sirfsoc-wdt", + .owner = THIS_MODULE, + .pm = &sirfsoc_wdt_pm_ops, + .of_match_table = of_match_ptr(sirfsoc_wdt_of_match), + }, + .probe = sirfsoc_wdt_probe, + .remove = sirfsoc_wdt_remove, + .shutdown = sirfsoc_wdt_shutdown, +}; +module_platform_driver(sirfsoc_wdt_driver); + +MODULE_DESCRIPTION("SiRF SoC watchdog driver"); +MODULE_AUTHOR("Xianglong Du <Xianglong.Du@csr.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:sirfsoc-wdt"); |