[linux-block.git] / drivers / watchdog / da9062_wdt.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Watchdog device driver for DA9062 and DA9061 PMICs
 * Copyright (C) 2015  Dialog Semiconductor Ltd.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/mfd/da9062/registers.h>
#include <linux/mfd/da9062/core.h>
#include <linux/regmap.h>
#include <linux/of.h>

static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
#define DA9062_TWDSCALE_DISABLE		0
#define DA9062_TWDSCALE_MIN		1
#define DA9062_TWDSCALE_MAX		(ARRAY_SIZE(wdt_timeout) - 1)
#define DA9062_WDT_MIN_TIMEOUT		wdt_timeout[DA9062_TWDSCALE_MIN]
#define DA9062_WDT_MAX_TIMEOUT		wdt_timeout[DA9062_TWDSCALE_MAX]
#define DA9062_WDG_DEFAULT_TIMEOUT	wdt_timeout[DA9062_TWDSCALE_MAX-1]
#define DA9062_RESET_PROTECTION_MS	300

struct da9062_watchdog {
	struct da9062 *hw;
	struct watchdog_device wdtdev;
	unsigned long j_time_stamp;
};

static void da9062_set_window_start(struct da9062_watchdog *wdt)
{
	wdt->j_time_stamp = jiffies;
}

static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
{
	unsigned int i;

	for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
		if (wdt_timeout[i] >= secs)
			return i;
	}

	return DA9062_TWDSCALE_MAX;
}

static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
{
	int ret;

	ret = regmap_update_bits(wdt->hw->regmap,
			   DA9062AA_CONTROL_F,
			   DA9062AA_WATCHDOG_MASK,
			   DA9062AA_WATCHDOG_MASK);

	da9062_set_window_start(wdt);

	return ret;
}

static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
					      unsigned int regval)
{
	struct da9062 *chip = wdt->hw;
	int ret;

	ret = da9062_reset_watchdog_timer(wdt);
	if (ret)
		return ret;

	regmap_update_bits(chip->regmap,
				  DA9062AA_CONTROL_D,
				  DA9062AA_TWDSCALE_MASK,
				  DA9062_TWDSCALE_DISABLE);

	usleep_range(150, 300);

	return regmap_update_bits(chip->regmap,
				  DA9062AA_CONTROL_D,
				  DA9062AA_TWDSCALE_MASK,
				  regval);
}

static int da9062_wdt_start(struct watchdog_device *wdd)
{
	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	unsigned int selector;
	int ret;

	selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
	ret = da9062_wdt_update_timeout_register(wdt, selector);
	if (ret)
		dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
			ret);

	return ret;
}

static int da9062_wdt_stop(struct watchdog_device *wdd)
{
	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	int ret;

	ret = da9062_reset_watchdog_timer(wdt);
	if (ret) {
		dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
			ret);
		return ret;
	}

	ret = regmap_update_bits(wdt->hw->regmap,
				 DA9062AA_CONTROL_D,
				 DA9062AA_TWDSCALE_MASK,
				 DA9062_TWDSCALE_DISABLE);
	if (ret)
		dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
			ret);

	return ret;
}

static int da9062_wdt_ping(struct watchdog_device *wdd)
{
	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	int ret;

	ret = da9062_reset_watchdog_timer(wdt);
	if (ret)
		dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
			ret);

	return ret;
}

static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
				  unsigned int timeout)
{
	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	unsigned int selector;
	int ret;

	selector = da9062_wdt_timeout_to_sel(timeout);
	ret = da9062_wdt_update_timeout_register(wdt, selector);
	if (ret)
		dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
			ret);
	else
		wdd->timeout = wdt_timeout[selector];

	return ret;
}

static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
			      void *data)
{
	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	int ret;

	ret = regmap_write(wdt->hw->regmap,
			   DA9062AA_CONTROL_F,
			   DA9062AA_SHUTDOWN_MASK);
	if (ret)
		dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
			  ret);

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

	return ret;
}

static const struct watchdog_info da9062_watchdog_info = {
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
	.identity = "DA9062 WDT",
};

static const struct watchdog_ops da9062_watchdog_ops = {
	.owner = THIS_MODULE,
	.start = da9062_wdt_start,
	.stop = da9062_wdt_stop,
	.ping = da9062_wdt_ping,
	.set_timeout = da9062_wdt_set_timeout,
	.restart = da9062_wdt_restart,
};

static const struct of_device_id da9062_compatible_id_table[] = {
	{ .compatible = "dlg,da9062-watchdog", },
	{ },
};

MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);

static int da9062_wdt_probe(struct platform_device *pdev)
{
	int ret;
	struct da9062 *chip;
	struct da9062_watchdog *wdt;

	chip = dev_get_drvdata(pdev->dev.parent);
	if (!chip)
		return -EINVAL;

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

	wdt->hw = chip;

	wdt->wdtdev.info = &da9062_watchdog_info;
	wdt->wdtdev.ops = &da9062_watchdog_ops;
	wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
	wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
	wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
	wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
	wdt->wdtdev.parent = &pdev->dev;

	watchdog_set_restart_priority(&wdt->wdtdev, 128);

	watchdog_set_drvdata(&wdt->wdtdev, wdt);

	ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);
	if (ret < 0) {
		dev_err(wdt->hw->dev,
			"watchdog registration failed (%d)\n", ret);
		return ret;
	}

	da9062_set_window_start(wdt);

	return da9062_wdt_ping(&wdt->wdtdev);
}

static struct platform_driver da9062_wdt_driver = {
	.probe = da9062_wdt_probe,
	.driver = {
		.name = "da9062-watchdog",
		.of_match_table = da9062_compatible_id_table,
	},
};
module_platform_driver(da9062_wdt_driver);

MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9062-watchdog");
Commit	Line	Data
2e62c498	1	// SPDX-License-Identifier: GPL-2.0+
7a7cb009	2	/*
72106c18	3	* Watchdog device driver for DA9062 and DA9061 PMICs
7a7cb009 T	4	* Copyright (C) 2015 Dialog Semiconductor Ltd.
7a7cb009 T	5	*
7a7cb009 T	6	*/
	7
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/watchdog.h>
	11	#include <linux/platform_device.h>
	12	#include <linux/uaccess.h>
	13	#include <linux/slab.h>
	14	#include <linux/delay.h>
	15	#include <linux/jiffies.h>
	16	#include <linux/mfd/da9062/registers.h>
	17	#include <linux/mfd/da9062/core.h>
	18	#include <linux/regmap.h>
	19	#include <linux/of.h>
	20
	21	static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
	22	#define DA9062_TWDSCALE_DISABLE 0
	23	#define DA9062_TWDSCALE_MIN 1
	24	#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
	25	#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
	26	#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
	27	#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
	28	#define DA9062_RESET_PROTECTION_MS 300
	29
	30	struct da9062_watchdog {
	31	struct da9062 *hw;
	32	struct watchdog_device wdtdev;
	33	unsigned long j_time_stamp;
	34	};
	35
	36	static void da9062_set_window_start(struct da9062_watchdog *wdt)
	37	{
	38	wdt->j_time_stamp = jiffies;
	39	}
	40
7a7cb009 T	41	static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
	42	{
	43	unsigned int i;
	44
	45	for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
	46	if (wdt_timeout[i] >= secs)
	47	return i;
	48	}
	49
	50	return DA9062_TWDSCALE_MAX;
	51	}
	52
	53	static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
	54	{
	55	int ret;
	56
7a7cb009 T	57	ret = regmap_update_bits(wdt->hw->regmap,
	58	DA9062AA_CONTROL_F,
	59	DA9062AA_WATCHDOG_MASK,
	60	DA9062AA_WATCHDOG_MASK);
	61
	62	da9062_set_window_start(wdt);
	63
	64	return ret;
	65	}
	66
	67	static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
	68	unsigned int regval)
	69	{
	70	struct da9062 *chip = wdt->hw;
	71	int ret;
	72
	73	ret = da9062_reset_watchdog_timer(wdt);
	74	if (ret)
	75	return ret;
	76
f31b2a9b MG	77	regmap_update_bits(chip->regmap,
	78	DA9062AA_CONTROL_D,
	79	DA9062AA_TWDSCALE_MASK,
	80	DA9062_TWDSCALE_DISABLE);
	81
	82	usleep_range(150, 300);
	83
7a7cb009 T	84	return regmap_update_bits(chip->regmap,
	85	DA9062AA_CONTROL_D,
	86	DA9062AA_TWDSCALE_MASK,
	87	regval);
	88	}
	89
	90	static int da9062_wdt_start(struct watchdog_device *wdd)
	91	{
	92	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	93	unsigned int selector;
	94	int ret;
	95
	96	selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
	97	ret = da9062_wdt_update_timeout_register(wdt, selector);
	98	if (ret)
	99	dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
	100	ret);
	101
	102	return ret;
	103	}
	104
	105	static int da9062_wdt_stop(struct watchdog_device *wdd)
	106	{
	107	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	108	int ret;
	109
	110	ret = da9062_reset_watchdog_timer(wdt);
	111	if (ret) {
	112	dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
	113	ret);
	114	return ret;
	115	}
	116
	117	ret = regmap_update_bits(wdt->hw->regmap,
	118	DA9062AA_CONTROL_D,
	119	DA9062AA_TWDSCALE_MASK,
	120	DA9062_TWDSCALE_DISABLE);
	121	if (ret)
	122	dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
	123	ret);
	124
	125	return ret;
	126	}
	127
	128	static int da9062_wdt_ping(struct watchdog_device *wdd)
	129	{
	130	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	131	int ret;
	132
	133	ret = da9062_reset_watchdog_timer(wdt);
	134	if (ret)
	135	dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
	136	ret);
	137
	138	return ret;
	139	}
	140
	141	static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
	142	unsigned int timeout)
	143	{
	144	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	145	unsigned int selector;
	146	int ret;
	147
148	selector = da9062_wdt_timeout_to_sel(timeout);
149	ret = da9062_wdt_update_timeout_register(wdt, selector);
150	if (ret)
151	dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
152	ret);
153	else
154	wdd->timeout = wdt_timeout[selector];
155
156	return ret;
157	}
158
540f6351 MG	159	static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
	160	void *data)
	161	{
	162	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	163	int ret;
	164
	165	ret = regmap_write(wdt->hw->regmap,
	166	DA9062AA_CONTROL_F,
	167	DA9062AA_SHUTDOWN_MASK);
	168	if (ret)
	169	dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
	170	ret);
	171
	172	/* wait for reset to assert... */
	173	mdelay(500);
	174
	175	return ret;
	176	}
	177
7a7cb009 T	178	static const struct watchdog_info da9062_watchdog_info = {
	179	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	180	.identity = "DA9062 WDT",
	181	};
	182
	183	static const struct watchdog_ops da9062_watchdog_ops = {
	184	.owner = THIS_MODULE,
	185	.start = da9062_wdt_start,
	186	.stop = da9062_wdt_stop,
	187	.ping = da9062_wdt_ping,
	188	.set_timeout = da9062_wdt_set_timeout,
540f6351	189	.restart = da9062_wdt_restart,
7a7cb009 T	190	};
7a7cb009 T	191
72106c18 ST	192	static const struct of_device_id da9062_compatible_id_table[] = {
	193	{ .compatible = "dlg,da9062-watchdog", },
	194	{ },
	195	};
	196
	197	MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
	198
7a7cb009 T	199	static int da9062_wdt_probe(struct platform_device *pdev)
	200	{
	201	int ret;
	202	struct da9062 *chip;
	203	struct da9062_watchdog *wdt;
	204
	205	chip = dev_get_drvdata(pdev->dev.parent);
	206	if (!chip)
	207	return -EINVAL;
	208
	209	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	210	if (!wdt)
	211	return -ENOMEM;
	212
	213	wdt->hw = chip;
	214
	215	wdt->wdtdev.info = &da9062_watchdog_info;
	216	wdt->wdtdev.ops = &da9062_watchdog_ops;
	217	wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
	218	wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
fb484262	219	wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
7a7cb009 T	220	wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
7a7cb009 T	221	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
6551881c	222	wdt->wdtdev.parent = &pdev->dev;
7a7cb009	223
540f6351 MG	224	watchdog_set_restart_priority(&wdt->wdtdev, 128);
540f6351 MG	225
7a7cb009	226	watchdog_set_drvdata(&wdt->wdtdev, wdt);
7a7cb009	227
528eff34	228	ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);
7a7cb009 T	229	if (ret < 0) {
	230	dev_err(wdt->hw->dev,
	231	"watchdog registration failed (%d)\n", ret);
	232	return ret;
	233	}
	234
	235	da9062_set_window_start(wdt);
	236
528eff34	237	return da9062_wdt_ping(&wdt->wdtdev);
7a7cb009 T	238	}
	239
	240	static struct platform_driver da9062_wdt_driver = {
	241	.probe = da9062_wdt_probe,
7a7cb009 T	242	.driver = {
7a7cb009 T	243	.name = "da9062-watchdog",
72106c18	244	.of_match_table = da9062_compatible_id_table,
7a7cb009 T	245	},
	246	};
	247	module_platform_driver(da9062_wdt_driver);
	248
	249	MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
72106c18	250	MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
7a7cb009 T	251	MODULE_LICENSE("GPL");
7a7cb009 T	252	MODULE_ALIAS("platform:da9062-watchdog");