[mirror_ubuntu-bionic-kernel.git] / drivers / watchdog / imx2_wdt.c

/*
 * Watchdog driver for IMX2 and later processors
 *
 *  Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
 *  Copyright (C) 2014 Freescale Semiconductor, Inc.
 *
 * some parts adapted by similar drivers from Darius Augulis and Vladimir
 * Zapolskiy, additional improvements by Wim Van Sebroeck.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * NOTE: MX1 has a slightly different Watchdog than MX2 and later:
 *
 *			MX1:		MX2+:
 *			----		-----
 * Registers:		32-bit		16-bit
 * Stopable timer:	Yes		No
 * Need to enable clk:	No		Yes
 * Halt on suspend:	Manual		Can be automatic
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/watchdog.h>

#define DRIVER_NAME "imx2-wdt"

#define IMX2_WDT_WCR		0x00		/* Control Register */
#define IMX2_WDT_WCR_WT		(0xFF << 8)	/* -> Watchdog Timeout Field */
#define IMX2_WDT_WCR_WRE	(1 << 3)	/* -> WDOG Reset Enable */
#define IMX2_WDT_WCR_WDE	(1 << 2)	/* -> Watchdog Enable */
#define IMX2_WDT_WCR_WDZST	(1 << 0)	/* -> Watchdog timer Suspend */

#define IMX2_WDT_WSR		0x02		/* Service Register */
#define IMX2_WDT_SEQ1		0x5555		/* -> service sequence 1 */
#define IMX2_WDT_SEQ2		0xAAAA		/* -> service sequence 2 */

#define IMX2_WDT_WRSR		0x04		/* Reset Status Register */
#define IMX2_WDT_WRSR_TOUT	(1 << 1)	/* -> Reset due to Timeout */

#define IMX2_WDT_WMCR		0x08		/* Misc Register */

#define IMX2_WDT_MAX_TIME	128
#define IMX2_WDT_DEFAULT_TIME	60		/* in seconds */

#define WDOG_SEC_TO_COUNT(s)	((s * 2 - 1) << 8)

struct imx2_wdt_device {
	struct clk *clk;
	struct regmap *regmap;
	struct watchdog_device wdog;
};

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


static unsigned timeout = IMX2_WDT_DEFAULT_TIME;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
				__MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");

static const struct watchdog_info imx2_wdt_info = {
	.identity = "imx2+ watchdog",
	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
};

static int imx2_wdt_restart(struct watchdog_device *wdog, unsigned long action,
			    void *data)
{
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
	unsigned int wcr_enable = IMX2_WDT_WCR_WDE;

	/* Assert SRS signal */
	regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
	/*
	 * Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be
	 * written twice), we add another two writes to ensure there must be at
	 * least two writes happen in the same one 32kHz clock period.  We save
	 * the target check here, since the writes shouldn't be a huge burden
	 * for other platforms.
	 */
	regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
	regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);

	/* wait for reset to assert... */
	mdelay(500);

	return 0;
}

static inline void imx2_wdt_setup(struct watchdog_device *wdog)
{
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
	u32 val;

	regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);

	/* Suspend timer in low power mode, write once-only */
	val |= IMX2_WDT_WCR_WDZST;
	/* Strip the old watchdog Time-Out value */
	val &= ~IMX2_WDT_WCR_WT;
	/* Generate reset if WDOG times out */
	val &= ~IMX2_WDT_WCR_WRE;
	/* Keep Watchdog Disabled */
	val &= ~IMX2_WDT_WCR_WDE;
	/* Set the watchdog's Time-Out value */
	val |= WDOG_SEC_TO_COUNT(wdog->timeout);

	regmap_write(wdev->regmap, IMX2_WDT_WCR, val);

	/* enable the watchdog */
	val |= IMX2_WDT_WCR_WDE;
	regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
}

static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev)
{
	u32 val;

	regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);

	return val & IMX2_WDT_WCR_WDE;
}

static int imx2_wdt_ping(struct watchdog_device *wdog)
{
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

	regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
	regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
	return 0;
}

static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
				unsigned int new_timeout)
{
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

	wdog->timeout = new_timeout;

	regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
			   WDOG_SEC_TO_COUNT(new_timeout));
	return 0;
}

static int imx2_wdt_start(struct watchdog_device *wdog)
{
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

	if (imx2_wdt_is_running(wdev))
		imx2_wdt_set_timeout(wdog, wdog->timeout);
	else
		imx2_wdt_setup(wdog);

	set_bit(WDOG_HW_RUNNING, &wdog->status);

	return imx2_wdt_ping(wdog);
}

static const struct watchdog_ops imx2_wdt_ops = {
	.owner = THIS_MODULE,
	.start = imx2_wdt_start,
	.ping = imx2_wdt_ping,
	.set_timeout = imx2_wdt_set_timeout,
	.restart = imx2_wdt_restart,
};

static const struct regmap_config imx2_wdt_regmap_config = {
	.reg_bits = 16,
	.reg_stride = 2,
	.val_bits = 16,
	.max_register = 0x8,
};

static int __init imx2_wdt_probe(struct platform_device *pdev)
{
	struct imx2_wdt_device *wdev;
	struct watchdog_device *wdog;
	struct resource *res;
	void __iomem *base;
	int ret;
	u32 val;

	wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
	if (!wdev)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	wdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
						 &imx2_wdt_regmap_config);
	if (IS_ERR(wdev->regmap)) {
		dev_err(&pdev->dev, "regmap init failed\n");
		return PTR_ERR(wdev->regmap);
	}

	wdev->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(wdev->clk)) {
		dev_err(&pdev->dev, "can't get Watchdog clock\n");
		return PTR_ERR(wdev->clk);
	}

	wdog			= &wdev->wdog;
	wdog->info		= &imx2_wdt_info;
	wdog->ops		= &imx2_wdt_ops;
	wdog->min_timeout	= 1;
	wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000;
	wdog->parent		= &pdev->dev;

	ret = clk_prepare_enable(wdev->clk);
	if (ret)
		return ret;

	regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);
	wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;

	wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
	if (wdog->timeout != timeout)
		dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n",
			 timeout, wdog->timeout);

	platform_set_drvdata(pdev, wdog);
	watchdog_set_drvdata(wdog, wdev);
	watchdog_set_nowayout(wdog, nowayout);
	watchdog_set_restart_priority(wdog, 128);
	watchdog_init_timeout(wdog, timeout, &pdev->dev);

	if (imx2_wdt_is_running(wdev)) {
		imx2_wdt_set_timeout(wdog, wdog->timeout);
		set_bit(WDOG_HW_RUNNING, &wdog->status);
	}

	/*
	 * Disable the watchdog power down counter at boot. Otherwise the power
	 * down counter will pull down the #WDOG interrupt line for one clock
	 * cycle.
	 */
	regmap_write(wdev->regmap, IMX2_WDT_WMCR, 0);

	ret = watchdog_register_device(wdog);
	if (ret) {
		dev_err(&pdev->dev, "cannot register watchdog device\n");
		goto disable_clk;
	}

	dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n",
		 wdog->timeout, nowayout);

	return 0;

disable_clk:
	clk_disable_unprepare(wdev->clk);
	return ret;
}

static int __exit imx2_wdt_remove(struct platform_device *pdev)
{
	struct watchdog_device *wdog = platform_get_drvdata(pdev);
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

	watchdog_unregister_device(wdog);

	if (imx2_wdt_is_running(wdev)) {
		imx2_wdt_ping(wdog);
		dev_crit(&pdev->dev, "Device removed: Expect reboot!\n");
	}
	return 0;
}

static void imx2_wdt_shutdown(struct platform_device *pdev)
{
	struct watchdog_device *wdog = platform_get_drvdata(pdev);
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

	if (imx2_wdt_is_running(wdev)) {
		/*
		 * We are running, configure max timeout before reboot
		 * will take place.
		 */
		imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
		imx2_wdt_ping(wdog);
		dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n");
	}
}

#ifdef CONFIG_PM_SLEEP
/* Disable watchdog if it is active or non-active but still running */
static int imx2_wdt_suspend(struct device *dev)
{
	struct watchdog_device *wdog = dev_get_drvdata(dev);
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);

	/* The watchdog IP block is running */
	if (imx2_wdt_is_running(wdev)) {
		imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
		imx2_wdt_ping(wdog);
	}

	clk_disable_unprepare(wdev->clk);

	return 0;
}

/* Enable watchdog and configure it if necessary */
static int imx2_wdt_resume(struct device *dev)
{
	struct watchdog_device *wdog = dev_get_drvdata(dev);
	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
	int ret;

	ret = clk_prepare_enable(wdev->clk);
	if (ret)
		return ret;

	if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) {
		/*
		 * If the watchdog is still active and resumes
		 * from deep sleep state, need to restart the
		 * watchdog again.
		 */
		imx2_wdt_setup(wdog);
	}
	if (imx2_wdt_is_running(wdev)) {
		imx2_wdt_set_timeout(wdog, wdog->timeout);
		imx2_wdt_ping(wdog);
	}

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend,
			 imx2_wdt_resume);

static const struct of_device_id imx2_wdt_dt_ids[] = {
	{ .compatible = "fsl,imx21-wdt", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx2_wdt_dt_ids);

static struct platform_driver imx2_wdt_driver = {
	.remove		= __exit_p(imx2_wdt_remove),
	.shutdown	= imx2_wdt_shutdown,
	.driver		= {
		.name	= DRIVER_NAME,
		.pm     = &imx2_wdt_pm_ops,
		.of_match_table = imx2_wdt_dt_ids,
	},
};

module_platform_driver_probe(imx2_wdt_driver, imx2_wdt_probe);

MODULE_AUTHOR("Wolfram Sang");
MODULE_DESCRIPTION("Watchdog driver for IMX2 and later");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);
Commit	Line	Data
bb2fd8a8 WS	1	/*
	2	* Watchdog driver for IMX2 and later processors
	3	*
	4	* Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
1a9c5efa	5	* Copyright (C) 2014 Freescale Semiconductor, Inc.
bb2fd8a8 WS	6	*
	7	* some parts adapted by similar drivers from Darius Augulis and Vladimir
	8	* Zapolskiy, additional improvements by Wim Van Sebroeck.
	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License version 2 as published by
	12	* the Free Software Foundation.
	13	*
	14	* NOTE: MX1 has a slightly different Watchdog than MX2 and later:
	15	*
	16	* MX1: MX2+:
	17	* ---- -----
	18	* Registers: 32-bit 16-bit
	19	* Stopable timer: Yes No
	20	* Need to enable clk: No Yes
	21	* Halt on suspend: Manual Can be automatic
	22	*/
	23
30cb042a	24	#include <linux/clk.h>
334a9d81	25	#include <linux/delay.h>
bb2fd8a8	26	#include <linux/init.h>
30cb042a	27	#include <linux/io.h>
bb2fd8a8	28	#include <linux/kernel.h>
bb2fd8a8 WS	29	#include <linux/module.h>
bb2fd8a8 WS	30	#include <linux/moduleparam.h>
f728f4bf	31	#include <linux/of_address.h>
bb2fd8a8	32	#include <linux/platform_device.h>
a7977003	33	#include <linux/regmap.h>
30cb042a	34	#include <linux/watchdog.h>
bb2fd8a8 WS	35
	36	#define DRIVER_NAME "imx2-wdt"
	37
	38	#define IMX2_WDT_WCR 0x00 /* Control Register */
	39	#define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */
	40	#define IMX2_WDT_WCR_WRE (1 << 3) /* -> WDOG Reset Enable */
	41	#define IMX2_WDT_WCR_WDE (1 << 2) /* -> Watchdog Enable */
1a9c5efa	42	#define IMX2_WDT_WCR_WDZST (1 << 0) /* -> Watchdog timer Suspend */
bb2fd8a8 WS	43
	44	#define IMX2_WDT_WSR 0x02 /* Service Register */
	45	#define IMX2_WDT_SEQ1 0x5555 /* -> service sequence 1 */
	46	#define IMX2_WDT_SEQ2 0xAAAA /* -> service sequence 2 */
	47
474ef121 OS	48	#define IMX2_WDT_WRSR 0x04 /* Reset Status Register */
	49	#define IMX2_WDT_WRSR_TOUT (1 << 1) /* -> Reset due to Timeout */
	50
5fe65ce7 MP	51	#define IMX2_WDT_WMCR 0x08 /* Misc Register */
5fe65ce7 MP	52
bb2fd8a8 WS	53	#define IMX2_WDT_MAX_TIME 128
	54	#define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */
	55
	56	#define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)
	57
faad5de0	58	struct imx2_wdt_device {
bb2fd8a8	59	struct clk *clk;
a7977003	60	struct regmap *regmap;
faad5de0 AG	61	struct watchdog_device wdog;
faad5de0 AG	62	};
bb2fd8a8	63
86a1e189 WVS	64	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	65	module_param(nowayout, bool, 0);
bb2fd8a8 WS	66	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	67	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	68
	69
	70	static unsigned timeout = IMX2_WDT_DEFAULT_TIME;
	71	module_param(timeout, uint, 0);
	72	MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
	73	__MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");
	74
	75	static const struct watchdog_info imx2_wdt_info = {
	76	.identity = "imx2+ watchdog",
	77	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
	78	};
	79
4d8b229d GR	80	static int imx2_wdt_restart(struct watchdog_device *wdog, unsigned long action,
4d8b229d GR	81	void *data)
334a9d81	82	{
2d9d2475	83	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
334a9d81	84	unsigned int wcr_enable = IMX2_WDT_WCR_WDE;
2d9d2475	85
334a9d81	86	/* Assert SRS signal */
9493c0d8	87	regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
334a9d81 JL	88	/*
	89	* Due to imx6q errata ERR004346 (WDOG: WDOG SRS bit requires to be
	90	* written twice), we add another two writes to ensure there must be at
	91	* least two writes happen in the same one 32kHz clock period. We save
	92	* the target check here, since the writes shouldn't be a huge burden
	93	* for other platforms.
	94	*/
9493c0d8 FE	95	regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
9493c0d8 FE	96	regmap_write(wdev->regmap, IMX2_WDT_WCR, wcr_enable);
334a9d81 JL	97
	98	/* wait for reset to assert... */
	99	mdelay(500);
	100
2d9d2475	101	return 0;
334a9d81 JL	102	}
334a9d81 JL	103
faad5de0	104	static inline void imx2_wdt_setup(struct watchdog_device *wdog)
bb2fd8a8	105	{
faad5de0	106	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
a7977003 XL	107	u32 val;
a7977003 XL	108
faad5de0	109	regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
bb2fd8a8	110
1a9c5efa AH	111	/* Suspend timer in low power mode, write once-only */
1a9c5efa AH	112	val \|= IMX2_WDT_WCR_WDZST;
bb2fd8a8 WS	113	/* Strip the old watchdog Time-Out value */
	114	val &= ~IMX2_WDT_WCR_WT;
	115	/* Generate reset if WDOG times out */
	116	val &= ~IMX2_WDT_WCR_WRE;
	117	/* Keep Watchdog Disabled */
	118	val &= ~IMX2_WDT_WCR_WDE;
	119	/* Set the watchdog's Time-Out value */
faad5de0	120	val \|= WDOG_SEC_TO_COUNT(wdog->timeout);
bb2fd8a8	121
faad5de0	122	regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
bb2fd8a8 WS	123
	124	/* enable the watchdog */
	125	val \|= IMX2_WDT_WCR_WDE;
faad5de0	126	regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
bb2fd8a8 WS	127	}
bb2fd8a8 WS	128
faad5de0	129	static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev)
bb2fd8a8	130	{
faad5de0	131	u32 val;
bb2fd8a8	132
faad5de0 AG	133	regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
	134
	135	return val & IMX2_WDT_WCR_WDE;
bb2fd8a8 WS	136	}
bb2fd8a8 WS	137
faad5de0	138	static int imx2_wdt_ping(struct watchdog_device *wdog)
bb2fd8a8	139	{
faad5de0	140	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
bb2fd8a8	141
faad5de0 AG	142	regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
	143	regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
	144	return 0;
bb2fd8a8 WS	145	}
bb2fd8a8 WS	146
faad5de0 AG	147	static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
faad5de0 AG	148	unsigned int new_timeout)
bb2fd8a8	149	{
faad5de0 AG	150	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
faad5de0 AG	151
30dd4a8f MG	152	wdog->timeout = new_timeout;
30dd4a8f MG	153
faad5de0	154	regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
a7977003	155	WDOG_SEC_TO_COUNT(new_timeout));
faad5de0	156	return 0;
bb2fd8a8 WS	157	}
bb2fd8a8 WS	158
faad5de0	159	static int imx2_wdt_start(struct watchdog_device *wdog)
bb2fd8a8	160	{
faad5de0	161	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
bb2fd8a8	162
11d7aba9	163	if (imx2_wdt_is_running(wdev))
faad5de0	164	imx2_wdt_set_timeout(wdog, wdog->timeout);
11d7aba9	165	else
faad5de0 AG	166	imx2_wdt_setup(wdog);
faad5de0 AG	167
11d7aba9	168	set_bit(WDOG_HW_RUNNING, &wdog->status);
bb2fd8a8	169
11d7aba9	170	return imx2_wdt_ping(wdog);
bb2fd8a8 WS	171	}
bb2fd8a8 WS	172
4bd8ce33	173	static const struct watchdog_ops imx2_wdt_ops = {
bb2fd8a8	174	.owner = THIS_MODULE,
faad5de0	175	.start = imx2_wdt_start,
faad5de0 AG	176	.ping = imx2_wdt_ping,
faad5de0 AG	177	.set_timeout = imx2_wdt_set_timeout,
2d9d2475	178	.restart = imx2_wdt_restart,
bb2fd8a8 WS	179	};
bb2fd8a8 WS	180
4bd8ce33	181	static const struct regmap_config imx2_wdt_regmap_config = {
a7977003 XL	182	.reg_bits = 16,
	183	.reg_stride = 2,
	184	.val_bits = 16,
	185	.max_register = 0x8,
	186	};
	187
bb2fd8a8 WS	188	static int __init imx2_wdt_probe(struct platform_device *pdev)
bb2fd8a8 WS	189	{
faad5de0 AG	190	struct imx2_wdt_device *wdev;
faad5de0 AG	191	struct watchdog_device *wdog;
bb2fd8a8	192	struct resource *res;
a7977003 XL	193	void __iomem *base;
a7977003 XL	194	int ret;
faad5de0 AG	195	u32 val;
	196
	197	wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
	198	if (!wdev)
	199	return -ENOMEM;
bb2fd8a8 WS	200
bb2fd8a8 WS	201	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
a7977003 XL	202	base = devm_ioremap_resource(&pdev->dev, res);
	203	if (IS_ERR(base))
	204	return PTR_ERR(base);
	205
faad5de0 AG	206	wdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
	207	&imx2_wdt_regmap_config);
	208	if (IS_ERR(wdev->regmap)) {
a7977003	209	dev_err(&pdev->dev, "regmap init failed\n");
faad5de0	210	return PTR_ERR(wdev->regmap);
a7977003	211	}
bb2fd8a8	212
faad5de0 AG	213	wdev->clk = devm_clk_get(&pdev->dev, NULL);
faad5de0 AG	214	if (IS_ERR(wdev->clk)) {
bb2fd8a8	215	dev_err(&pdev->dev, "can't get Watchdog clock\n");
faad5de0	216	return PTR_ERR(wdev->clk);
bb2fd8a8 WS	217	}
bb2fd8a8 WS	218
faad5de0 AG	219	wdog = &wdev->wdog;
	220	wdog->info = &imx2_wdt_info;
	221	wdog->ops = &imx2_wdt_ops;
	222	wdog->min_timeout = 1;
11d7aba9	223	wdog->max_hw_heartbeat_ms = IMX2_WDT_MAX_TIME * 1000;
8135193c	224	wdog->parent = &pdev->dev;
bb2fd8a8	225
aefb163c FE	226	ret = clk_prepare_enable(wdev->clk);
	227	if (ret)
	228	return ret;
bb2fd8a8	229
faad5de0 AG	230	regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);
faad5de0 AG	231	wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
bb2fd8a8	232
faad5de0 AG	233	wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
	234	if (wdog->timeout != timeout)
	235	dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n",
	236	timeout, wdog->timeout);
	237
	238	platform_set_drvdata(pdev, wdog);
	239	watchdog_set_drvdata(wdog, wdev);
	240	watchdog_set_nowayout(wdog, nowayout);
2d9d2475	241	watchdog_set_restart_priority(wdog, 128);
faad5de0 AG	242	watchdog_init_timeout(wdog, timeout, &pdev->dev);
faad5de0 AG	243
11d7aba9 GR	244	if (imx2_wdt_is_running(wdev)) {
	245	imx2_wdt_set_timeout(wdog, wdog->timeout);
	246	set_bit(WDOG_HW_RUNNING, &wdog->status);
	247	}
faad5de0	248
5fe65ce7 MP	249	/*
	250	* Disable the watchdog power down counter at boot. Otherwise the power
	251	* down counter will pull down the #WDOG interrupt line for one clock
	252	* cycle.
	253	*/
	254	regmap_write(wdev->regmap, IMX2_WDT_WMCR, 0);
	255
faad5de0 AG	256	ret = watchdog_register_device(wdog);
	257	if (ret) {
	258	dev_err(&pdev->dev, "cannot register watchdog device\n");
db11cba2	259	goto disable_clk;
faad5de0 AG	260	}
	261
	262	dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n",
	263	wdog->timeout, nowayout);
	264
	265	return 0;
db11cba2 FE	266
	267	disable_clk:
	268	clk_disable_unprepare(wdev->clk);
	269	return ret;
bb2fd8a8 WS	270	}
	271
	272	static int __exit imx2_wdt_remove(struct platform_device *pdev)
	273	{
faad5de0 AG	274	struct watchdog_device *wdog = platform_get_drvdata(pdev);
faad5de0 AG	275	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
bb2fd8a8	276
faad5de0	277	watchdog_unregister_device(wdog);
bb2fd8a8	278
faad5de0	279	if (imx2_wdt_is_running(wdev)) {
faad5de0 AG	280	imx2_wdt_ping(wdog);
faad5de0 AG	281	dev_crit(&pdev->dev, "Device removed: Expect reboot!\n");
bdf49574	282	}
bb2fd8a8 WS	283	return 0;
	284	}
	285
	286	static void imx2_wdt_shutdown(struct platform_device *pdev)
	287	{
faad5de0 AG	288	struct watchdog_device *wdog = platform_get_drvdata(pdev);
	289	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
	290
	291	if (imx2_wdt_is_running(wdev)) {
	292	/*
11d7aba9 GR	293	* We are running, configure max timeout before reboot
11d7aba9 GR	294	* will take place.
faad5de0	295	*/
faad5de0 AG	296	imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
	297	imx2_wdt_ping(wdog);
	298	dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n");
bb2fd8a8 WS	299	}
	300	}
	301
aefbaf3a	302	#ifdef CONFIG_PM_SLEEP
bbd59009	303	/* Disable watchdog if it is active or non-active but still running */
aefbaf3a XL	304	static int imx2_wdt_suspend(struct device *dev)
	305	{
	306	struct watchdog_device *wdog = dev_get_drvdata(dev);
	307	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
	308
bbd59009 XL	309	/* The watchdog IP block is running */
	310	if (imx2_wdt_is_running(wdev)) {
	311	imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
	312	imx2_wdt_ping(wdog);
bbd59009	313	}
aefbaf3a XL	314
	315	clk_disable_unprepare(wdev->clk);
	316
	317	return 0;
	318	}
	319
	320	/* Enable watchdog and configure it if necessary */
	321	static int imx2_wdt_resume(struct device *dev)
	322	{
	323	struct watchdog_device *wdog = dev_get_drvdata(dev);
	324	struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
aefb163c	325	int ret;
aefbaf3a	326
aefb163c FE	327	ret = clk_prepare_enable(wdev->clk);
	328	if (ret)
	329	return ret;
aefbaf3a XL	330
aefbaf3a XL	331	if (watchdog_active(wdog) && !imx2_wdt_is_running(wdev)) {
bbd59009 XL	332	/*
	333	* If the watchdog is still active and resumes
	334	* from deep sleep state, need to restart the
	335	* watchdog again.
aefbaf3a XL	336	*/
aefbaf3a XL	337	imx2_wdt_setup(wdog);
11d7aba9 GR	338	}
11d7aba9 GR	339	if (imx2_wdt_is_running(wdev)) {
aefbaf3a XL	340	imx2_wdt_set_timeout(wdog, wdog->timeout);
aefbaf3a XL	341	imx2_wdt_ping(wdog);
aefbaf3a XL	342	}
	343
	344	return 0;
	345	}
	346	#endif
	347
	348	static SIMPLE_DEV_PM_OPS(imx2_wdt_pm_ops, imx2_wdt_suspend,
	349	imx2_wdt_resume);
	350
f5a427ee SG	351	static const struct of_device_id imx2_wdt_dt_ids[] = {
	352	{ .compatible = "fsl,imx21-wdt", },
	353	{ /* sentinel */ }
	354	};
813296a1	355	MODULE_DEVICE_TABLE(of, imx2_wdt_dt_ids);
f5a427ee	356
bb2fd8a8	357	static struct platform_driver imx2_wdt_driver = {
bb2fd8a8 WS	358	.remove = __exit_p(imx2_wdt_remove),
	359	.shutdown = imx2_wdt_shutdown,
	360	.driver = {
	361	.name = DRIVER_NAME,
aefbaf3a	362	.pm = &imx2_wdt_pm_ops,
f5a427ee	363	.of_match_table = imx2_wdt_dt_ids,
bb2fd8a8 WS	364	},
	365	};
	366
1cb9204c	367	module_platform_driver_probe(imx2_wdt_driver, imx2_wdt_probe);
bb2fd8a8 WS	368
	369	MODULE_AUTHOR("Wolfram Sang");
	370	MODULE_DESCRIPTION("Watchdog driver for IMX2 and later");
	371	MODULE_LICENSE("GPL v2");
bb2fd8a8	372	MODULE_ALIAS("platform:" DRIVER_NAME);