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Commit d00680ed authored by Carlo Caione's avatar Carlo Caione Committed by Wim Van Sebroeck
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watchdog: sunxi: New watchdog driver for Allwinner A10/A13 



This patch adds the driver for the watchdog found in the Allwinner A10 and
A13 SoCs. It has DT-support and uses the new watchdog framework.

Signed-off-by: default avatarCarlo Caione <carlo.caione@gmail.com>
Acked-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent af4ea631

drivers/watchdog/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -290,6 +290,16 @@ config ORION_WATCHDOG 
	  To compile this driver as a module, choose M here: the

	  module will be called orion_wdt.



config SUNXI_WATCHDOG

	tristate "Allwinner SoCs watchdog support"

	depends on ARCH_SUNXI

	select WATCHDOG_CORE

	help

	  Say Y here to include support for the watchdog timer

	  in Allwinner SoCs.

	  To compile this driver as a module, choose M here: the

	  module will be called sunxi_wdt.



config COH901327_WATCHDOG

	bool "ST-Ericsson COH 901 327 watchdog"

	depends on ARCH_U300

drivers/watchdog/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o 
obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o

obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o

obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o

obj-$(CONFIG_SUNXI_WATCHDOG) += sunxi_wdt.o

obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o

obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o

obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o

drivers/watchdog/sunxi_wdt.c

0 → 100644
+237 −0
Original line number Diff line number Diff line 
/*

 *      sunxi Watchdog Driver

 *

 *      Copyright (c) 2013 Carlo Caione

 *                    2012 Henrik Nordstrom

 *

 *      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.

 *

 *      Based on xen_wdt.c

 *      (c) Copyright 2010 Novell, Inc.

 */



#include <linux/clk.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/types.h>

#include <linux/watchdog.h>



#define WDT_MAX_TIMEOUT         16

#define WDT_MIN_TIMEOUT         1

#define WDT_MODE_TIMEOUT(n)     ((n) << 3)

#define WDT_TIMEOUT_MASK        WDT_MODE_TIMEOUT(0x0F)



#define WDT_CTRL                0x00

#define WDT_CTRL_RELOAD         ((1 << 0) | (0x0a57 << 1))



#define WDT_MODE                0x04

#define WDT_MODE_EN             (1 << 0)

#define WDT_MODE_RST_EN         (1 << 1)



#define DRV_NAME		"sunxi-wdt"

#define DRV_VERSION		"1.0"



static bool nowayout = WATCHDOG_NOWAYOUT;

static unsigned int timeout = WDT_MAX_TIMEOUT;



struct sunxi_wdt_dev {

	struct watchdog_device wdt_dev;

	void __iomem *wdt_base;

};



/*

 * wdt_timeout_map maps the watchdog timer interval value in seconds to

 * the value of the register WDT_MODE bit 3:6

 *

 * [timeout seconds] = register value

 *

 */



static const int wdt_timeout_map[] = {

	[1] = 0b0001,  /* 1s  */

	[2] = 0b0010,  /* 2s  */

	[3] = 0b0011,  /* 3s  */

	[4] = 0b0100,  /* 4s  */

	[5] = 0b0101,  /* 5s  */

	[6] = 0b0110,  /* 6s  */

	[8] = 0b0111,  /* 8s  */

	[10] = 0b1000, /* 10s */

	[12] = 0b1001, /* 12s */

	[14] = 0b1010, /* 14s */

	[16] = 0b1011, /* 16s */

};



static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)

{

	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);

	void __iomem *wdt_base = sunxi_wdt->wdt_base;



	iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL);



	return 0;

}



static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,

		unsigned int timeout)

{

	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);

	void __iomem *wdt_base = sunxi_wdt->wdt_base;

	u32 reg;



	if (wdt_timeout_map[timeout] == 0)

		timeout++;



	sunxi_wdt->wdt_dev.timeout = timeout;



	reg = ioread32(wdt_base + WDT_MODE);

	reg &= ~WDT_TIMEOUT_MASK;

	reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]);

	iowrite32(reg, wdt_base + WDT_MODE);



	sunxi_wdt_ping(wdt_dev);



	return 0;

}



static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)

{

	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);

	void __iomem *wdt_base = sunxi_wdt->wdt_base;



	iowrite32(0, wdt_base + WDT_MODE);



	return 0;

}



static int sunxi_wdt_start(struct watchdog_device *wdt_dev)

{

	u32 reg;

	struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);

	void __iomem *wdt_base = sunxi_wdt->wdt_base;

	int ret;



	ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,

			sunxi_wdt->wdt_dev.timeout);

	if (ret < 0)

		return ret;



	reg = ioread32(wdt_base + WDT_MODE);

	reg |= (WDT_MODE_RST_EN | WDT_MODE_EN);

	iowrite32(reg, wdt_base + WDT_MODE);



	return 0;

}



static const struct watchdog_info sunxi_wdt_info = {

	.identity	= DRV_NAME,

	.options	= WDIOF_SETTIMEOUT |

			  WDIOF_KEEPALIVEPING |

			  WDIOF_MAGICCLOSE,

};



static const struct watchdog_ops sunxi_wdt_ops = {

	.owner		= THIS_MODULE,

	.start		= sunxi_wdt_start,

	.stop		= sunxi_wdt_stop,

	.ping		= sunxi_wdt_ping,

	.set_timeout	= sunxi_wdt_set_timeout,

};



static int __init sunxi_wdt_probe(struct platform_device *pdev)

{

	struct sunxi_wdt_dev *sunxi_wdt;

	struct resource *res;

	int err;



	sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);

	if (!sunxi_wdt)

		return -EINVAL;



	platform_set_drvdata(pdev, sunxi_wdt);



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(sunxi_wdt->wdt_base))

		return PTR_ERR(sunxi_wdt->wdt_base);



	sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;

	sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;

	sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;

	sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;

	sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;

	sunxi_wdt->wdt_dev.parent = &pdev->dev;



	watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev);

	watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);



	watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);



	sunxi_wdt_stop(&sunxi_wdt->wdt_dev);



	err = watchdog_register_device(&sunxi_wdt->wdt_dev);

	if (unlikely(err))

		return err;



	dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",

			sunxi_wdt->wdt_dev.timeout, nowayout);



	return 0;

}



static int __exit sunxi_wdt_remove(struct platform_device *pdev)

{

	struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);



	watchdog_unregister_device(&sunxi_wdt->wdt_dev);

	watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL);



	return 0;

}



static void sunxi_wdt_shutdown(struct platform_device *pdev)

{

	struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev);



	sunxi_wdt_stop(&sunxi_wdt->wdt_dev);

}



static const struct of_device_id sunxi_wdt_dt_ids[] = {

	{ .compatible = "allwinner,sun4i-wdt" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);



static struct platform_driver sunxi_wdt_driver = {

	.probe		= sunxi_wdt_probe,

	.remove		= sunxi_wdt_remove,

	.shutdown	= sunxi_wdt_shutdown,

	.driver		= {

		.owner		= THIS_MODULE,

		.name		= DRV_NAME,

		.of_match_table	= of_match_ptr(sunxi_wdt_dt_ids)

	},

};



module_platform_driver(sunxi_wdt_driver);



module_param(timeout, uint, 0);

MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");



module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "

		"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");

MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");

MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");

MODULE_VERSION(DRV_VERSION);