[mirror_ubuntu-hirsute-kernel.git] / drivers / watchdog / meson_wdt.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *      Meson Watchdog Driver
 *
 *      Copyright (c) 2014 Carlo Caione
 */

#include <linux/clk.h>
#include <linux/delay.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/of_device.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/watchdog.h>

#define DRV_NAME		"meson_wdt"

#define MESON_WDT_TC		0x00
#define MESON_WDT_DC_RESET	(3 << 24)

#define MESON_WDT_RESET		0x04

#define MESON_WDT_TIMEOUT	30
#define MESON_WDT_MIN_TIMEOUT	1

#define MESON_SEC_TO_TC(s, c)	((s) * (c))

static bool nowayout = WATCHDOG_NOWAYOUT;
static unsigned int timeout;

struct meson_wdt_data {
	unsigned int enable;
	unsigned int terminal_count_mask;
	unsigned int count_unit;
};

static struct meson_wdt_data meson6_wdt_data = {
	.enable			= BIT(22),
	.terminal_count_mask	= 0x3fffff,
	.count_unit		= 100000, /* 10 us */
};

static struct meson_wdt_data meson8b_wdt_data = {
	.enable			= BIT(19),
	.terminal_count_mask	= 0xffff,
	.count_unit		= 7812, /* 128 us */
};

struct meson_wdt_dev {
	struct watchdog_device wdt_dev;
	void __iomem *wdt_base;
	const struct meson_wdt_data *data;
};

static int meson_wdt_restart(struct watchdog_device *wdt_dev,
			     unsigned long action, void *data)
{
	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	u32 tc_reboot = MESON_WDT_DC_RESET;

	tc_reboot |= meson_wdt->data->enable;

	while (1) {
		writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
		mdelay(5);
	}

	return 0;
}

static int meson_wdt_ping(struct watchdog_device *wdt_dev)
{
	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);

	writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);

	return 0;
}

static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
				     unsigned int timeout)
{
	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	u32 reg;

	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
	reg &= ~meson_wdt->data->terminal_count_mask;
	reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
}

static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
				 unsigned int timeout)
{
	wdt_dev->timeout = timeout;

	meson_wdt_change_timeout(wdt_dev, timeout);
	meson_wdt_ping(wdt_dev);

	return 0;
}

static int meson_wdt_stop(struct watchdog_device *wdt_dev)
{
	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	u32 reg;

	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
	reg &= ~meson_wdt->data->enable;
	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);

	return 0;
}

static int meson_wdt_start(struct watchdog_device *wdt_dev)
{
	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	u32 reg;

	meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
	meson_wdt_ping(wdt_dev);

	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
	reg |= meson_wdt->data->enable;
	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);

	return 0;
}

static const struct watchdog_info meson_wdt_info = {
	.identity	= DRV_NAME,
	.options	= WDIOF_SETTIMEOUT |
			  WDIOF_KEEPALIVEPING |
			  WDIOF_MAGICCLOSE,
};

static const struct watchdog_ops meson_wdt_ops = {
	.owner		= THIS_MODULE,
	.start		= meson_wdt_start,
	.stop		= meson_wdt_stop,
	.ping		= meson_wdt_ping,
	.set_timeout	= meson_wdt_set_timeout,
	.restart        = meson_wdt_restart,
};

static const struct of_device_id meson_wdt_dt_ids[] = {
	{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
	{ .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data },
	{ .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
	{ .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);

static int meson_wdt_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct meson_wdt_dev *meson_wdt;
	const struct of_device_id *of_id;
	int err;

	meson_wdt = devm_kzalloc(dev, sizeof(*meson_wdt), GFP_KERNEL);
	if (!meson_wdt)
		return -ENOMEM;

	meson_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(meson_wdt->wdt_base))
		return PTR_ERR(meson_wdt->wdt_base);

	of_id = of_match_device(meson_wdt_dt_ids, dev);
	if (!of_id) {
		dev_err(dev, "Unable to initialize WDT data\n");
		return -ENODEV;
	}
	meson_wdt->data = of_id->data;

	meson_wdt->wdt_dev.parent = dev;
	meson_wdt->wdt_dev.info = &meson_wdt_info;
	meson_wdt->wdt_dev.ops = &meson_wdt_ops;
	meson_wdt->wdt_dev.max_timeout =
		meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
	meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
	meson_wdt->wdt_dev.timeout = min_t(unsigned int,
					   MESON_WDT_TIMEOUT,
					   meson_wdt->wdt_dev.max_timeout);

	watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);

	watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, dev);
	watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
	watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);

	meson_wdt_stop(&meson_wdt->wdt_dev);

	watchdog_stop_on_reboot(&meson_wdt->wdt_dev);
	err = devm_watchdog_register_device(dev, &meson_wdt->wdt_dev);
	if (err)
		return err;

	dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
		 meson_wdt->wdt_dev.timeout, nowayout);

	return 0;
}

static struct platform_driver meson_wdt_driver = {
	.probe		= meson_wdt_probe,
	.driver		= {
		.name		= DRV_NAME,
		.of_match_table	= meson_wdt_dt_ids,
	},
};

module_platform_driver(meson_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.org>");
MODULE_DESCRIPTION("Meson Watchdog Timer Driver");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
22e1b8f6 CC	2	/*
	3	* Meson Watchdog Driver
	4	*
	5	* Copyright (c) 2014 Carlo Caione
22e1b8f6 CC	6	*/
	7
	8	#include <linux/clk.h>
	9	#include <linux/delay.h>
	10	#include <linux/err.h>
	11	#include <linux/init.h>
	12	#include <linux/io.h>
	13	#include <linux/kernel.h>
	14	#include <linux/module.h>
	15	#include <linux/moduleparam.h>
22e1b8f6	16	#include <linux/of.h>
943bf1f6	17	#include <linux/of_device.h>
22e1b8f6	18	#include <linux/platform_device.h>
22e1b8f6 CC	19	#include <linux/types.h>
	20	#include <linux/watchdog.h>
	21
	22	#define DRV_NAME "meson_wdt"
	23
	24	#define MESON_WDT_TC 0x00
22e1b8f6 CC	25	#define MESON_WDT_DC_RESET (3 << 24)
	26
	27	#define MESON_WDT_RESET 0x04
	28
	29	#define MESON_WDT_TIMEOUT 30
	30	#define MESON_WDT_MIN_TIMEOUT 1
22e1b8f6	31
943bf1f6	32	#define MESON_SEC_TO_TC(s, c) ((s) * (c))
22e1b8f6 CC	33
22e1b8f6 CC	34	static bool nowayout = WATCHDOG_NOWAYOUT;
4590d62c	35	static unsigned int timeout;
22e1b8f6	36
943bf1f6 CC	37	struct meson_wdt_data {
	38	unsigned int enable;
	39	unsigned int terminal_count_mask;
	40	unsigned int count_unit;
	41	};
	42
	43	static struct meson_wdt_data meson6_wdt_data = {
	44	.enable = BIT(22),
	45	.terminal_count_mask = 0x3fffff,
	46	.count_unit = 100000, /* 10 us */
	47	};
	48
71388840 CC	49	static struct meson_wdt_data meson8b_wdt_data = {
	50	.enable = BIT(19),
	51	.terminal_count_mask = 0xffff,
	52	.count_unit = 7812, /* 128 us */
	53	};
	54
22e1b8f6 CC	55	struct meson_wdt_dev {
	56	struct watchdog_device wdt_dev;
	57	void __iomem *wdt_base;
943bf1f6	58	const struct meson_wdt_data *data;
22e1b8f6 CC	59	};
22e1b8f6 CC	60
4d8b229d GR	61	static int meson_wdt_restart(struct watchdog_device *wdt_dev,
4d8b229d GR	62	unsigned long action, void *data)
22e1b8f6	63	{
1b6fd59a	64	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
943bf1f6 CC	65	u32 tc_reboot = MESON_WDT_DC_RESET;
	66
	67	tc_reboot \|= meson_wdt->data->enable;
22e1b8f6 CC	68
	69	while (1) {
	70	writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
	71	mdelay(5);
	72	}
	73
1b6fd59a	74	return 0;
22e1b8f6 CC	75	}
	76
	77	static int meson_wdt_ping(struct watchdog_device *wdt_dev)
	78	{
	79	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	80
	81	writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);
	82
	83	return 0;
	84	}
	85
	86	static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
	87	unsigned int timeout)
	88	{
	89	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	90	u32 reg;
	91
	92	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
943bf1f6 CC	93	reg &= ~meson_wdt->data->terminal_count_mask;
943bf1f6 CC	94	reg \|= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
22e1b8f6 CC	95	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
	96	}
	97
	98	static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
	99	unsigned int timeout)
	100	{
	101	wdt_dev->timeout = timeout;
	102
	103	meson_wdt_change_timeout(wdt_dev, timeout);
	104	meson_wdt_ping(wdt_dev);
	105
	106	return 0;
	107	}
	108
	109	static int meson_wdt_stop(struct watchdog_device *wdt_dev)
	110	{
	111	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	112	u32 reg;
	113
	114	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
943bf1f6	115	reg &= ~meson_wdt->data->enable;
22e1b8f6 CC	116	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
	117
	118	return 0;
	119	}
	120
	121	static int meson_wdt_start(struct watchdog_device *wdt_dev)
	122	{
	123	struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
	124	u32 reg;
	125
	126	meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
	127	meson_wdt_ping(wdt_dev);
	128
	129	reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
943bf1f6	130	reg \|= meson_wdt->data->enable;
22e1b8f6 CC	131	writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
	132
	133	return 0;
	134	}
	135
	136	static const struct watchdog_info meson_wdt_info = {
	137	.identity = DRV_NAME,
	138	.options = WDIOF_SETTIMEOUT \|
	139	WDIOF_KEEPALIVEPING \|
	140	WDIOF_MAGICCLOSE,
	141	};
	142
	143	static const struct watchdog_ops meson_wdt_ops = {
	144	.owner = THIS_MODULE,
	145	.start = meson_wdt_start,
	146	.stop = meson_wdt_stop,
	147	.ping = meson_wdt_ping,
	148	.set_timeout = meson_wdt_set_timeout,
1b6fd59a	149	.restart = meson_wdt_restart,
22e1b8f6 CC	150	};
22e1b8f6 CC	151
943bf1f6 CC	152	static const struct of_device_id meson_wdt_dt_ids[] = {
943bf1f6 CC	153	{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
43a64e81	154	{ .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data },
71388840	155	{ .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
43a64e81	156	{ .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data },
943bf1f6 CC	157	{ /* sentinel */ }
	158	};
	159	MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
	160
22e1b8f6 CC	161	static int meson_wdt_probe(struct platform_device *pdev)
22e1b8f6 CC	162	{
dd1c66e2	163	struct device *dev = &pdev->dev;
22e1b8f6	164	struct meson_wdt_dev *meson_wdt;
943bf1f6	165	const struct of_device_id *of_id;
22e1b8f6 CC	166	int err;
22e1b8f6 CC	167
dd1c66e2	168	meson_wdt = devm_kzalloc(dev, sizeof(*meson_wdt), GFP_KERNEL);
22e1b8f6 CC	169	if (!meson_wdt)
	170	return -ENOMEM;
	171
0f0a6a28	172	meson_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
22e1b8f6 CC	173	if (IS_ERR(meson_wdt->wdt_base))
	174	return PTR_ERR(meson_wdt->wdt_base);
	175
dd1c66e2	176	of_id = of_match_device(meson_wdt_dt_ids, dev);
943bf1f6	177	if (!of_id) {
dd1c66e2	178	dev_err(dev, "Unable to initialize WDT data\n");
943bf1f6 CC	179	return -ENODEV;
	180	}
	181	meson_wdt->data = of_id->data;
	182
dd1c66e2	183	meson_wdt->wdt_dev.parent = dev;
22e1b8f6 CC	184	meson_wdt->wdt_dev.info = &meson_wdt_info;
22e1b8f6 CC	185	meson_wdt->wdt_dev.ops = &meson_wdt_ops;
943bf1f6 CC	186	meson_wdt->wdt_dev.max_timeout =
943bf1f6 CC	187	meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
22e1b8f6	188	meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
943bf1f6 CC	189	meson_wdt->wdt_dev.timeout = min_t(unsigned int,
	190	MESON_WDT_TIMEOUT,
	191	meson_wdt->wdt_dev.max_timeout);
22e1b8f6 CC	192
	193	watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
	194
dd1c66e2	195	watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, dev);
22e1b8f6	196	watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
1b6fd59a	197	watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
22e1b8f6 CC	198
	199	meson_wdt_stop(&meson_wdt->wdt_dev);
	200
c8841a60	201	watchdog_stop_on_reboot(&meson_wdt->wdt_dev);
dd1c66e2	202	err = devm_watchdog_register_device(dev, &meson_wdt->wdt_dev);
22e1b8f6 CC	203	if (err)
	204	return err;
	205
dd1c66e2	206	dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
22e1b8f6 CC	207	meson_wdt->wdt_dev.timeout, nowayout);
	208
	209	return 0;
	210	}
	211
22e1b8f6 CC	212	static struct platform_driver meson_wdt_driver = {
22e1b8f6 CC	213	.probe = meson_wdt_probe,
22e1b8f6	214	.driver = {
22e1b8f6 CC	215	.name = DRV_NAME,
	216	.of_match_table = meson_wdt_dt_ids,
	217	},
	218	};
	219
	220	module_platform_driver(meson_wdt_driver);
	221
	222	module_param(timeout, uint, 0);
	223	MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
	224
	225	module_param(nowayout, bool, 0);
	226	MODULE_PARM_DESC(nowayout,
	227	"Watchdog cannot be stopped once started (default="
	228	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	229
	230	MODULE_LICENSE("GPL");
	231	MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
	232	MODULE_DESCRIPTION("Meson Watchdog Timer Driver");