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author | Yang Ling <gnaygnil@gmail.com> | 2016-12-08 00:10:58 +0800 |
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committer | Guenter Roeck <linux@roeck-us.net> | 2016-12-16 06:53:55 -0800 |
commit | 1d8565ee4f5bd9fccb738e53d6b9fc7a559f7d2b (patch) | |
tree | 85a2c31f943e2e578d248b0dfc4dc674a65cbd57 /drivers/watchdog/loongson1_wdt.c | |
parent | b6621df5c87603310c3f94903bb30adbfeb9aa69 (diff) | |
download | blackbird-op-linux-1d8565ee4f5bd9fccb738e53d6b9fc7a559f7d2b.tar.gz blackbird-op-linux-1d8565ee4f5bd9fccb738e53d6b9fc7a559f7d2b.zip |
watchdog: loongson1: Add Loongson1 SoC watchdog driver
Add watchdog timer specific driver for Loongson1 SoC.
Signed-off-by: Yang Ling <gnaygnil@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
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 000000000000..3aee50c64a36 --- /dev/null +++ b/drivers/watchdog/loongson1_wdt.c @@ -0,0 +1,170 @@ +/* + * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> +#include <loongson1.h> + +#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 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, +}; + +static int ls1x_wdt_probe(struct platform_device *pdev) +{ + struct ls1x_wdt_drvdata *drvdata; + struct watchdog_device *ls1x_wdt; + unsigned long clk_rate; + struct resource *res; + int err; + + drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + drvdata->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(drvdata->base)) + return PTR_ERR(drvdata->base); + + drvdata->clk = devm_clk_get(&pdev->dev, pdev->name); + if (IS_ERR(drvdata->clk)) + return PTR_ERR(drvdata->clk); + + err = clk_prepare_enable(drvdata->clk); + if (err) { + dev_err(&pdev->dev, "clk enable failed\n"); + return err; + } + + clk_rate = clk_get_rate(drvdata->clk); + if (!clk_rate) { + err = -EINVAL; + goto err0; + } + 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 = &pdev->dev; + + watchdog_init_timeout(ls1x_wdt, heartbeat, &pdev->dev); + watchdog_set_nowayout(ls1x_wdt, nowayout); + watchdog_set_drvdata(ls1x_wdt, drvdata); + + err = watchdog_register_device(&drvdata->wdt); + if (err) { + dev_err(&pdev->dev, "failed to register watchdog device\n"); + goto err0; + } + + platform_set_drvdata(pdev, drvdata); + + dev_info(&pdev->dev, "Loongson1 Watchdog driver registered\n"); + + return 0; +err0: + clk_disable_unprepare(drvdata->clk); + return err; +} + +static int ls1x_wdt_remove(struct platform_device *pdev) +{ + struct ls1x_wdt_drvdata *drvdata = platform_get_drvdata(pdev); + + watchdog_unregister_device(&drvdata->wdt); + clk_disable_unprepare(drvdata->clk); + + return 0; +} + +static struct platform_driver ls1x_wdt_driver = { + .probe = ls1x_wdt_probe, + .remove = ls1x_wdt_remove, + .driver = { + .name = "ls1x-wdt", + }, +}; + +module_platform_driver(ls1x_wdt_driver); + +MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>"); +MODULE_DESCRIPTION("Loongson1 Watchdog Driver"); +MODULE_LICENSE("GPL"); |