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Commit 1d8565ee authored by Yang Ling's avatar Yang Ling Committed by Guenter Roeck
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watchdog: loongson1: Add Loongson1 SoC watchdog driver 



Add watchdog timer specific driver for Loongson1 SoC.

Signed-off-by: default avatarYang Ling <gnaygnil@gmail.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent b6621df5

drivers/watchdog/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -1514,6 +1514,13 @@ config LANTIQ_WDT 
	help

	  Hardware driver for the Lantiq SoC Watchdog Timer.



config LOONGSON1_WDT

	tristate "Loongson1 SoC hardware watchdog"

	depends on MACH_LOONGSON32

	select WATCHDOG_CORE

	help

	  Hardware driver for the Loongson1 SoC Watchdog Timer.



config RALINK_WDT

	tristate "Ralink SoC watchdog"

	select WATCHDOG_CORE

drivers/watchdog/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ obj-$(CONFIG_TXX9_WDT) += txx9wdt.o 
obj-$(CONFIG_OCTEON_WDT) += octeon-wdt.o

octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o

obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o

obj-$(CONFIG_LOONGSON1_WDT) += loongson1_wdt.o

obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o

obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o

obj-$(CONFIG_MT7621_WDT) += mt7621_wdt.o

drivers/watchdog/loongson1_wdt.c

0 → 100644
+170 −0
Original line number Diff line number Diff line 
/*

 * 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");