diff options
Diffstat (limited to 'drivers/watchdog/loongson1_wdt.c')
| -rw-r--r-- | drivers/watchdog/loongson1_wdt.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/watchdog/loongson1_wdt.c b/drivers/watchdog/loongson1_wdt.c new file mode 100644 index 0000000000..0587ff44d3 --- /dev/null +++ b/drivers/watchdog/loongson1_wdt.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com> + */ + +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> + +/* Loongson 1 Watchdog Register Definitions */ +#define WDT_EN 0x0 +#define WDT_TIMER 0x4 +#define WDT_SET 0x8 + +#define DEFAULT_HEARTBEAT 30 + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0444); + +static unsigned int heartbeat; +module_param(heartbeat, uint, 0444); + +struct ls1x_wdt_drvdata { + void __iomem *base; + struct clk *clk; + unsigned long clk_rate; + struct watchdog_device wdt; +}; + +static int ls1x_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + + writel(0x1, drvdata->base + WDT_SET); + + return 0; +} + +static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int timeout) +{ + struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000; + unsigned int counts; + + wdt_dev->timeout = timeout; + + counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat); + writel(counts, drvdata->base + WDT_TIMER); + + return 0; +} + +static int ls1x_wdt_start(struct watchdog_device *wdt_dev) +{ + struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + + writel(0x1, drvdata->base + WDT_EN); + + return 0; +} + +static int ls1x_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + + writel(0x0, drvdata->base + WDT_EN); + + return 0; +} + +static int ls1x_wdt_restart(struct watchdog_device *wdt_dev, + unsigned long action, void *data) +{ + struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev); + + writel(0x1, drvdata->base + WDT_EN); + writel(0x1, drvdata->base + WDT_TIMER); + writel(0x1, drvdata->base + WDT_SET); + + return 0; +} + +static const struct watchdog_info ls1x_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "Loongson1 Watchdog", +}; + +static const struct watchdog_ops ls1x_wdt_ops = { + .owner = THIS_MODULE, + .start = ls1x_wdt_start, + .stop = ls1x_wdt_stop, + .ping = ls1x_wdt_ping, + .set_timeout = ls1x_wdt_set_timeout, + .restart = ls1x_wdt_restart, +}; + +static int ls1x_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct ls1x_wdt_drvdata *drvdata; + struct watchdog_device *ls1x_wdt; + unsigned long clk_rate; + int err; + + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + drvdata->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(drvdata->base)) + return PTR_ERR(drvdata->base); + + drvdata->clk = devm_clk_get_enabled(dev, NULL); + if (IS_ERR(drvdata->clk)) + return PTR_ERR(drvdata->clk); + + clk_rate = clk_get_rate(drvdata->clk); + if (!clk_rate) + return -EINVAL; + drvdata->clk_rate = clk_rate; + + ls1x_wdt = &drvdata->wdt; + ls1x_wdt->info = &ls1x_wdt_info; + ls1x_wdt->ops = &ls1x_wdt_ops; + ls1x_wdt->timeout = DEFAULT_HEARTBEAT; + ls1x_wdt->min_timeout = 1; + ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000; + ls1x_wdt->parent = dev; + + watchdog_init_timeout(ls1x_wdt, heartbeat, dev); + watchdog_set_nowayout(ls1x_wdt, nowayout); + watchdog_set_drvdata(ls1x_wdt, drvdata); + + err = devm_watchdog_register_device(dev, &drvdata->wdt); + if (err) + return err; + + platform_set_drvdata(pdev, drvdata); + + dev_info(dev, "Loongson1 Watchdog driver registered\n"); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id ls1x_wdt_dt_ids[] = { + { .compatible = "loongson,ls1b-wdt", }, + { .compatible = "loongson,ls1c-wdt", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, ls1x_wdt_dt_ids); +#endif + +static struct platform_driver ls1x_wdt_driver = { + .probe = ls1x_wdt_probe, + .driver = { + .name = "ls1x-wdt", + .of_match_table = of_match_ptr(ls1x_wdt_dt_ids), + }, +}; + +module_platform_driver(ls1x_wdt_driver); + +MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>"); +MODULE_DESCRIPTION("Loongson1 Watchdog Driver"); +MODULE_LICENSE("GPL"); |