[linux-block.git] / drivers / watchdog / mena21_wdt.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Watchdog driver for the A21 VME CPU Boards
 *
 * Copyright (C) 2013 MEN Mikro Elektronik Nuernberg GmbH
 *
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/delay.h>
#include <linux/bitops.h>

#define NUM_GPIOS 6

enum a21_wdt_gpios {
	GPIO_WD_ENAB,
	GPIO_WD_FAST,
	GPIO_WD_TRIG,
	GPIO_WD_RST0,
	GPIO_WD_RST1,
	GPIO_WD_RST2,
};

struct a21_wdt_drv {
	struct watchdog_device wdt;
	struct mutex lock;
	unsigned gpios[NUM_GPIOS];
};

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 int a21_wdt_get_bootstatus(struct a21_wdt_drv *drv)
{
	int reset = 0;

	reset |= gpio_get_value(drv->gpios[GPIO_WD_RST0]) ? (1 << 0) : 0;
	reset |= gpio_get_value(drv->gpios[GPIO_WD_RST1]) ? (1 << 1) : 0;
	reset |= gpio_get_value(drv->gpios[GPIO_WD_RST2]) ? (1 << 2) : 0;

	return reset;
}

static int a21_wdt_start(struct watchdog_device *wdt)
{
	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);

	mutex_lock(&drv->lock);

	gpio_set_value(drv->gpios[GPIO_WD_ENAB], 1);

	mutex_unlock(&drv->lock);

	return 0;
}

static int a21_wdt_stop(struct watchdog_device *wdt)
{
	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);

	mutex_lock(&drv->lock);

	gpio_set_value(drv->gpios[GPIO_WD_ENAB], 0);

	mutex_unlock(&drv->lock);

	return 0;
}

static int a21_wdt_ping(struct watchdog_device *wdt)
{
	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);

	mutex_lock(&drv->lock);

	gpio_set_value(drv->gpios[GPIO_WD_TRIG], 0);
	ndelay(10);
	gpio_set_value(drv->gpios[GPIO_WD_TRIG], 1);

	mutex_unlock(&drv->lock);

	return 0;
}

static int a21_wdt_set_timeout(struct watchdog_device *wdt,
			       unsigned int timeout)
{
	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);

	if (timeout != 1 && timeout != 30) {
		dev_err(wdt->parent, "Only 1 and 30 allowed as timeout\n");
		return -EINVAL;
	}

	if (timeout == 30 && wdt->timeout == 1) {
		dev_err(wdt->parent,
			"Transition from fast to slow mode not allowed\n");
		return -EINVAL;
	}

	mutex_lock(&drv->lock);

	if (timeout == 1)
		gpio_set_value(drv->gpios[GPIO_WD_FAST], 1);
	else
		gpio_set_value(drv->gpios[GPIO_WD_FAST], 0);

	wdt->timeout = timeout;

	mutex_unlock(&drv->lock);

	return 0;
}

static const struct watchdog_info a21_wdt_info = {
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
	.identity = "MEN A21 Watchdog",
};

static const struct watchdog_ops a21_wdt_ops = {
	.owner = THIS_MODULE,
	.start = a21_wdt_start,
	.stop = a21_wdt_stop,
	.ping = a21_wdt_ping,
	.set_timeout = a21_wdt_set_timeout,
};

static struct watchdog_device a21_wdt = {
	.info = &a21_wdt_info,
	.ops = &a21_wdt_ops,
	.min_timeout = 1,
	.max_timeout = 30,
};

static int a21_wdt_probe(struct platform_device *pdev)
{
	struct device_node *node;
	struct a21_wdt_drv *drv;
	unsigned int reset = 0;
	int num_gpios;
	int ret;
	int i;

	drv = devm_kzalloc(&pdev->dev, sizeof(struct a21_wdt_drv), GFP_KERNEL);
	if (!drv)
		return -ENOMEM;

	/* Fill GPIO pin array */
	node = pdev->dev.of_node;

	num_gpios = of_gpio_count(node);
	if (num_gpios != NUM_GPIOS) {
		dev_err(&pdev->dev, "gpios DT property wrong, got %d want %d",
			num_gpios, NUM_GPIOS);
		return -ENODEV;
	}

	for (i = 0; i < num_gpios; i++) {
		int val;

		val = of_get_gpio(node, i);
		if (val < 0)
			return val;

		drv->gpios[i] = val;
	}

	/* Request the used GPIOs */
	for (i = 0; i < num_gpios; i++) {
		ret = devm_gpio_request(&pdev->dev, drv->gpios[i],
					"MEN A21 Watchdog");
		if (ret)
			return ret;

		if (i < GPIO_WD_RST0)
			ret = gpio_direction_output(drv->gpios[i],
						gpio_get_value(drv->gpios[i]));
		else		/* GPIO_WD_RST[0..2] are inputs */
			ret = gpio_direction_input(drv->gpios[i]);
		if (ret)
			return ret;
	}

	mutex_init(&drv->lock);
	watchdog_init_timeout(&a21_wdt, 30, &pdev->dev);
	watchdog_set_nowayout(&a21_wdt, nowayout);
	watchdog_set_drvdata(&a21_wdt, drv);
	a21_wdt.parent = &pdev->dev;

	reset = a21_wdt_get_bootstatus(drv);
	if (reset == 2)
		a21_wdt.bootstatus |= WDIOF_EXTERN1;
	else if (reset == 4)
		a21_wdt.bootstatus |= WDIOF_CARDRESET;
	else if (reset == 5)
		a21_wdt.bootstatus |= WDIOF_POWERUNDER;
	else if (reset == 7)
		a21_wdt.bootstatus |= WDIOF_EXTERN2;

	drv->wdt = a21_wdt;
	dev_set_drvdata(&pdev->dev, drv);

	ret = devm_watchdog_register_device(&pdev->dev, &a21_wdt);
	if (ret) {
		dev_err(&pdev->dev, "Cannot register watchdog device\n");
		return ret;
	}

	dev_info(&pdev->dev, "MEN A21 watchdog timer driver enabled\n");

	return 0;
}

static void a21_wdt_shutdown(struct platform_device *pdev)
{
	struct a21_wdt_drv *drv = dev_get_drvdata(&pdev->dev);

	gpio_set_value(drv->gpios[GPIO_WD_ENAB], 0);
}

static const struct of_device_id a21_wdt_ids[] = {
	{ .compatible = "men,a021-wdt" },
	{ },
};
MODULE_DEVICE_TABLE(of, a21_wdt_ids);

static struct platform_driver a21_wdt_driver = {
	.probe = a21_wdt_probe,
	.shutdown = a21_wdt_shutdown,
	.driver = {
		.name = "a21-watchdog",
		.of_match_table = a21_wdt_ids,
	},
};

module_platform_driver(a21_wdt_driver);

MODULE_AUTHOR("MEN Mikro Elektronik");
MODULE_DESCRIPTION("MEN A21 Watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:a21-watchdog");
Commit	Line	Data
2e62c498	1	// SPDX-License-Identifier: GPL-2.0+
26c57ef1 JT	2	/*
	3	* Watchdog driver for the A21 VME CPU Boards
	4	*
	5	* Copyright (C) 2013 MEN Mikro Elektronik Nuernberg GmbH
	6	*
26c57ef1 JT	7	*/
	8	#include <linux/module.h>
	9	#include <linux/moduleparam.h>
	10	#include <linux/types.h>
	11	#include <linux/kernel.h>
	12	#include <linux/slab.h>
	13	#include <linux/platform_device.h>
	14	#include <linux/watchdog.h>
	15	#include <linux/uaccess.h>
	16	#include <linux/gpio.h>
	17	#include <linux/of_gpio.h>
	18	#include <linux/delay.h>
	19	#include <linux/bitops.h>
	20
	21	#define NUM_GPIOS 6
	22
	23	enum a21_wdt_gpios {
	24	GPIO_WD_ENAB,
	25	GPIO_WD_FAST,
	26	GPIO_WD_TRIG,
	27	GPIO_WD_RST0,
	28	GPIO_WD_RST1,
	29	GPIO_WD_RST2,
	30	};
	31
	32	struct a21_wdt_drv {
	33	struct watchdog_device wdt;
	34	struct mutex lock;
	35	unsigned gpios[NUM_GPIOS];
	36	};
	37
	38	static bool nowayout = WATCHDOG_NOWAYOUT;
	39	module_param(nowayout, bool, 0);
	40	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
	41	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	42
	43	static unsigned int a21_wdt_get_bootstatus(struct a21_wdt_drv *drv)
	44	{
	45	int reset = 0;
	46
	47	reset \|= gpio_get_value(drv->gpios[GPIO_WD_RST0]) ? (1 << 0) : 0;
	48	reset \|= gpio_get_value(drv->gpios[GPIO_WD_RST1]) ? (1 << 1) : 0;
	49	reset \|= gpio_get_value(drv->gpios[GPIO_WD_RST2]) ? (1 << 2) : 0;
	50
	51	return reset;
	52	}
	53
	54	static int a21_wdt_start(struct watchdog_device *wdt)
	55	{
	56	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
	57
	58	mutex_lock(&drv->lock);
	59
	60	gpio_set_value(drv->gpios[GPIO_WD_ENAB], 1);
	61
	62	mutex_unlock(&drv->lock);
	63
	64	return 0;
	65	}
	66
	67	static int a21_wdt_stop(struct watchdog_device *wdt)
	68	{
	69	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
	70
71	mutex_lock(&drv->lock);
72
73	gpio_set_value(drv->gpios[GPIO_WD_ENAB], 0);
74
75	mutex_unlock(&drv->lock);
76
77	return 0;
78	}
79
80	static int a21_wdt_ping(struct watchdog_device *wdt)
81	{
82	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
83
84	mutex_lock(&drv->lock);
85
86	gpio_set_value(drv->gpios[GPIO_WD_TRIG], 0);
87	ndelay(10);
88	gpio_set_value(drv->gpios[GPIO_WD_TRIG], 1);
89
90	mutex_unlock(&drv->lock);
91
92	return 0;
93	}
94
95	static int a21_wdt_set_timeout(struct watchdog_device *wdt,
96	unsigned int timeout)
97	{
98	struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt);
99
100	if (timeout != 1 && timeout != 30) {
07352366	101	dev_err(wdt->parent, "Only 1 and 30 allowed as timeout\n");
26c57ef1 JT	102	return -EINVAL;
	103	}
	104
	105	if (timeout == 30 && wdt->timeout == 1) {
07352366	106	dev_err(wdt->parent,
26c57ef1 JT	107	"Transition from fast to slow mode not allowed\n");
	108	return -EINVAL;
	109	}
	110
	111	mutex_lock(&drv->lock);
	112
	113	if (timeout == 1)
	114	gpio_set_value(drv->gpios[GPIO_WD_FAST], 1);
	115	else
	116	gpio_set_value(drv->gpios[GPIO_WD_FAST], 0);
	117
	118	wdt->timeout = timeout;
	119
	120	mutex_unlock(&drv->lock);
	121
	122	return 0;
	123	}
	124
	125	static const struct watchdog_info a21_wdt_info = {
	126	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	127	.identity = "MEN A21 Watchdog",
	128	};
	129
	130	static const struct watchdog_ops a21_wdt_ops = {
	131	.owner = THIS_MODULE,
	132	.start = a21_wdt_start,
	133	.stop = a21_wdt_stop,
	134	.ping = a21_wdt_ping,
	135	.set_timeout = a21_wdt_set_timeout,
	136	};
	137
	138	static struct watchdog_device a21_wdt = {
	139	.info = &a21_wdt_info,
	140	.ops = &a21_wdt_ops,
	141	.min_timeout = 1,
	142	.max_timeout = 30,
	143	};
	144
	145	static int a21_wdt_probe(struct platform_device *pdev)
	146	{
	147	struct device_node *node;
	148	struct a21_wdt_drv *drv;
	149	unsigned int reset = 0;
	150	int num_gpios;
	151	int ret;
	152	int i;
	153
	154	drv = devm_kzalloc(&pdev->dev, sizeof(struct a21_wdt_drv), GFP_KERNEL);
	155	if (!drv)
	156	return -ENOMEM;
	157
	158	/* Fill GPIO pin array */
	159	node = pdev->dev.of_node;
	160
	161	num_gpios = of_gpio_count(node);
	162	if (num_gpios != NUM_GPIOS) {
	163	dev_err(&pdev->dev, "gpios DT property wrong, got %d want %d",
	164	num_gpios, NUM_GPIOS);
	165	return -ENODEV;
	166	}
	167
	168	for (i = 0; i < num_gpios; i++) {
	169	int val;
	170
171	val = of_get_gpio(node, i);
172	if (val < 0)
173	return val;
174
175	drv->gpios[i] = val;
176	}
177
178	/* Request the used GPIOs */
179	for (i = 0; i < num_gpios; i++) {
180	ret = devm_gpio_request(&pdev->dev, drv->gpios[i],
181	"MEN A21 Watchdog");
182	if (ret)
183	return ret;
184
185	if (i < GPIO_WD_RST0)
186	ret = gpio_direction_output(drv->gpios[i],
187	gpio_get_value(drv->gpios[i]));
188	else /* GPIO_WD_RST[0..2] are inputs */
189	ret = gpio_direction_input(drv->gpios[i]);
190	if (ret)
191	return ret;
192	}
193
194	mutex_init(&drv->lock);
195	watchdog_init_timeout(&a21_wdt, 30, &pdev->dev);
196	watchdog_set_nowayout(&a21_wdt, nowayout);
197	watchdog_set_drvdata(&a21_wdt, drv);
6551881c	198	a21_wdt.parent = &pdev->dev;
26c57ef1 JT	199
	200	reset = a21_wdt_get_bootstatus(drv);
	201	if (reset == 2)
	202	a21_wdt.bootstatus \|= WDIOF_EXTERN1;
	203	else if (reset == 4)
	204	a21_wdt.bootstatus \|= WDIOF_CARDRESET;
	205	else if (reset == 5)
	206	a21_wdt.bootstatus \|= WDIOF_POWERUNDER;
	207	else if (reset == 7)
	208	a21_wdt.bootstatus \|= WDIOF_EXTERN2;
	209
57337db1 JT	210	drv->wdt = a21_wdt;
	211	dev_set_drvdata(&pdev->dev, drv);
	212
cb5c14ea	213	ret = devm_watchdog_register_device(&pdev->dev, &a21_wdt);
26c57ef1 JT	214	if (ret) {
26c57ef1 JT	215	dev_err(&pdev->dev, "Cannot register watchdog device\n");
cb5c14ea	216	return ret;
26c57ef1 JT	217	}
26c57ef1 JT	218
26c57ef1 JT	219	dev_info(&pdev->dev, "MEN A21 watchdog timer driver enabled\n");
26c57ef1 JT	220
26c57ef1 JT	221	return 0;
	222	}
	223
	224	static void a21_wdt_shutdown(struct platform_device *pdev)
	225	{
	226	struct a21_wdt_drv *drv = dev_get_drvdata(&pdev->dev);
	227
	228	gpio_set_value(drv->gpios[GPIO_WD_ENAB], 0);
	229	}
	230
	231	static const struct of_device_id a21_wdt_ids[] = {
	232	{ .compatible = "men,a021-wdt" },
	233	{ },
	234	};
c73318f4	235	MODULE_DEVICE_TABLE(of, a21_wdt_ids);
26c57ef1 JT	236
	237	static struct platform_driver a21_wdt_driver = {
	238	.probe = a21_wdt_probe,
26c57ef1 JT	239	.shutdown = a21_wdt_shutdown,
	240	.driver = {
	241	.name = "a21-watchdog",
	242	.of_match_table = a21_wdt_ids,
	243	},
	244	};
	245
	246	module_platform_driver(a21_wdt_driver);
	247
	248	MODULE_AUTHOR("MEN Mikro Elektronik");
	249	MODULE_DESCRIPTION("MEN A21 Watchdog");
	250	MODULE_LICENSE("GPL");
	251	MODULE_ALIAS("platform:a21-watchdog");