[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/i2c.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/mfd/da9062/registers.h>
#include <linux/mfd/da9062/core.h>
#include <linux/property.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;
	bool use_sw_pm;
};

static unsigned int da9062_wdt_read_timeout(struct da9062_watchdog *wdt)
{
	unsigned int val;

	regmap_read(wdt->hw->regmap, DA9062AA_CONTROL_D, &val);

	return wdt_timeout[val & DA9062AA_TWDSCALE_MASK];
}

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)
{
	return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
				  DA9062AA_WATCHDOG_MASK,
				  DA9062AA_WATCHDOG_MASK);
}

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

	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 = 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;

	/*
	 * Prevent pings from occurring late in system poweroff/reboot sequence
	 * and possibly locking out restart handler from accessing i2c bus.
	 */
	if (system_state > SYSTEM_RUNNING)
		return 0;

	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);
	struct i2c_client *client = to_i2c_client(wdt->hw->dev);
	int ret;

	/* Don't use regmap because it is not atomic safe */
	ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
					DA9062AA_SHUTDOWN_MASK);
	if (ret < 0)
		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)
{
	struct device *dev = &pdev->dev;
	unsigned int timeout;
	struct da9062 *chip;
	struct da9062_watchdog *wdt;

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

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

	wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");

	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 = dev;

	watchdog_set_restart_priority(&wdt->wdtdev, 128);

	watchdog_set_drvdata(&wdt->wdtdev, wdt);
	dev_set_drvdata(dev, &wdt->wdtdev);

	timeout = da9062_wdt_read_timeout(wdt);
	if (timeout)
		wdt->wdtdev.timeout = timeout;

	/* Set timeout from DT value if available */
	watchdog_init_timeout(&wdt->wdtdev, 0, dev);

	if (timeout) {
		da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout);
		set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
	}

	return devm_watchdog_register_device(dev, &wdt->wdtdev);
}

static int __maybe_unused da9062_wdt_suspend(struct device *dev)
{
	struct watchdog_device *wdd = dev_get_drvdata(dev);
	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);

	if (!wdt->use_sw_pm)
		return 0;

	if (watchdog_active(wdd))
		return da9062_wdt_stop(wdd);

	return 0;
}

static int __maybe_unused da9062_wdt_resume(struct device *dev)
{
	struct watchdog_device *wdd = dev_get_drvdata(dev);
	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);

	if (!wdt->use_sw_pm)
		return 0;

	if (watchdog_active(wdd))
		return da9062_wdt_start(wdd);

	return 0;
}

static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
			 da9062_wdt_suspend, da9062_wdt_resume);

static struct platform_driver da9062_wdt_driver = {
	.probe = da9062_wdt_probe,
	.driver = {
		.name = "da9062-watchdog",
		.pm = &da9062_wdt_pm_ops,
		.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>
057b52b4	14	#include <linux/i2c.h>
7a7cb009 T	15	#include <linux/delay.h>
	16	#include <linux/jiffies.h>
	17	#include <linux/mfd/da9062/registers.h>
	18	#include <linux/mfd/da9062/core.h>
8541673d	19	#include <linux/property.h>
7a7cb009 T	20	#include <linux/regmap.h>
	21	#include <linux/of.h>
	22
	23	static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
	24	#define DA9062_TWDSCALE_DISABLE 0
	25	#define DA9062_TWDSCALE_MIN 1
	26	#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
	27	#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
	28	#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
	29	#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
	30	#define DA9062_RESET_PROTECTION_MS 300
	31
	32	struct da9062_watchdog {
	33	struct da9062 *hw;
	34	struct watchdog_device wdtdev;
8541673d	35	bool use_sw_pm;
7a7cb009 T	36	};
7a7cb009 T	37
e8799ce8 SR	38	static unsigned int da9062_wdt_read_timeout(struct da9062_watchdog *wdt)
	39	{
	40	unsigned int val;
	41
	42	regmap_read(wdt->hw->regmap, DA9062AA_CONTROL_D, &val);
	43
	44	return wdt_timeout[val & DA9062AA_TWDSCALE_MASK];
	45	}
	46
7a7cb009 T	47	static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
	48	{
	49	unsigned int i;
	50
	51	for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
	52	if (wdt_timeout[i] >= secs)
	53	return i;
	54	}
	55
	56	return DA9062_TWDSCALE_MAX;
	57	}
	58
	59	static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
	60	{
6e8a7c75 GR	61	return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
	62	DA9062AA_WATCHDOG_MASK,
	63	DA9062AA_WATCHDOG_MASK);
7a7cb009 T	64	}
	65
	66	static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
	67	unsigned int regval)
	68	{
	69	struct da9062 *chip = wdt->hw;
7a7cb009	70
f31b2a9b MG	71	regmap_update_bits(chip->regmap,
	72	DA9062AA_CONTROL_D,
	73	DA9062AA_TWDSCALE_MASK,
	74	DA9062_TWDSCALE_DISABLE);
	75
	76	usleep_range(150, 300);
	77
7a7cb009 T	78	return regmap_update_bits(chip->regmap,
	79	DA9062AA_CONTROL_D,
	80	DA9062AA_TWDSCALE_MASK,
	81	regval);
	82	}
	83
	84	static int da9062_wdt_start(struct watchdog_device *wdd)
	85	{
	86	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	87	unsigned int selector;
	88	int ret;
	89
	90	selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
	91	ret = da9062_wdt_update_timeout_register(wdt, selector);
	92	if (ret)
	93	dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
	94	ret);
	95
	96	return ret;
	97	}
	98
	99	static int da9062_wdt_stop(struct watchdog_device *wdd)
	100	{
	101	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	102	int ret;
	103
7a7cb009 T	104	ret = regmap_update_bits(wdt->hw->regmap,
	105	DA9062AA_CONTROL_D,
	106	DA9062AA_TWDSCALE_MASK,
	107	DA9062_TWDSCALE_DISABLE);
	108	if (ret)
	109	dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
	110	ret);
	111
	112	return ret;
	113	}
	114
	115	static int da9062_wdt_ping(struct watchdog_device *wdd)
	116	{
	117	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	118	int ret;
	119
2f61b3a7 PF	120	/*
	121	* Prevent pings from occurring late in system poweroff/reboot sequence
	122	* and possibly locking out restart handler from accessing i2c bus.
	123	*/
	124	if (system_state > SYSTEM_RUNNING)
	125	return 0;
	126
7a7cb009 T	127	ret = da9062_reset_watchdog_timer(wdt);
	128	if (ret)
	129	dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
	130	ret);
	131
	132	return ret;
	133	}
	134
	135	static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
	136	unsigned int timeout)
	137	{
	138	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	139	unsigned int selector;
	140	int ret;
	141
	142	selector = da9062_wdt_timeout_to_sel(timeout);
	143	ret = da9062_wdt_update_timeout_register(wdt, selector);
	144	if (ret)
	145	dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
	146	ret);
	147	else
	148	wdd->timeout = wdt_timeout[selector];
	149
	150	return ret;
	151	}
	152
540f6351 MG	153	static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
	154	void *data)
	155	{
	156	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
057b52b4	157	struct i2c_client *client = to_i2c_client(wdt->hw->dev);
540f6351 MG	158	int ret;
540f6351 MG	159
057b52b4 MF	160	/* Don't use regmap because it is not atomic safe */
	161	ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
	162	DA9062AA_SHUTDOWN_MASK);
	163	if (ret < 0)
540f6351 MG	164	dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
	165	ret);
	166
	167	/* wait for reset to assert... */
	168	mdelay(500);
	169
	170	return ret;
	171	}
	172
7a7cb009 T	173	static const struct watchdog_info da9062_watchdog_info = {
	174	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	175	.identity = "DA9062 WDT",
	176	};
	177
	178	static const struct watchdog_ops da9062_watchdog_ops = {
	179	.owner = THIS_MODULE,
	180	.start = da9062_wdt_start,
	181	.stop = da9062_wdt_stop,
	182	.ping = da9062_wdt_ping,
	183	.set_timeout = da9062_wdt_set_timeout,
540f6351	184	.restart = da9062_wdt_restart,
7a7cb009 T	185	};
7a7cb009 T	186
72106c18 ST	187	static const struct of_device_id da9062_compatible_id_table[] = {
	188	{ .compatible = "dlg,da9062-watchdog", },
	189	{ },
	190	};
	191
	192	MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
	193
7a7cb009 T	194	static int da9062_wdt_probe(struct platform_device *pdev)
7a7cb009 T	195	{
6e8a7c75	196	struct device *dev = &pdev->dev;
e8799ce8	197	unsigned int timeout;
7a7cb009 T	198	struct da9062 *chip;
	199	struct da9062_watchdog *wdt;
	200
6e8a7c75	201	chip = dev_get_drvdata(dev->parent);
7a7cb009 T	202	if (!chip)
	203	return -EINVAL;
	204
6e8a7c75	205	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
7a7cb009 T	206	if (!wdt)
	207	return -ENOMEM;
	208
8541673d MF	209	wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm");
8541673d MF	210
7a7cb009 T	211	wdt->hw = chip;
	212
	213	wdt->wdtdev.info = &da9062_watchdog_info;
	214	wdt->wdtdev.ops = &da9062_watchdog_ops;
	215	wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
	216	wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
fb484262	217	wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
7a7cb009 T	218	wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
7a7cb009 T	219	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
6e8a7c75	220	wdt->wdtdev.parent = dev;
7a7cb009	221
540f6351 MG	222	watchdog_set_restart_priority(&wdt->wdtdev, 128);
540f6351 MG	223
7a7cb009	224	watchdog_set_drvdata(&wdt->wdtdev, wdt);
f6c98b08	225	dev_set_drvdata(dev, &wdt->wdtdev);
7a7cb009	226
e8799ce8 SR	227	timeout = da9062_wdt_read_timeout(wdt);
	228	if (timeout)
	229	wdt->wdtdev.timeout = timeout;
	230
	231	/* Set timeout from DT value if available */
	232	watchdog_init_timeout(&wdt->wdtdev, 0, dev);
	233
	234	if (timeout) {
	235	da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout);
	236	set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
	237	}
7a7cb009	238
e8799ce8	239	return devm_watchdog_register_device(dev, &wdt->wdtdev);
7a7cb009 T	240	}
7a7cb009 T	241
f6c98b08 MF	242	static int __maybe_unused da9062_wdt_suspend(struct device *dev)
	243	{
	244	struct watchdog_device *wdd = dev_get_drvdata(dev);
8541673d MF	245	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	246
	247	if (!wdt->use_sw_pm)
	248	return 0;
f6c98b08 MF	249
	250	if (watchdog_active(wdd))
	251	return da9062_wdt_stop(wdd);
	252
	253	return 0;
	254	}
	255
	256	static int __maybe_unused da9062_wdt_resume(struct device *dev)
	257	{
	258	struct watchdog_device *wdd = dev_get_drvdata(dev);
8541673d MF	259	struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
	260
	261	if (!wdt->use_sw_pm)
	262	return 0;
f6c98b08 MF	263
	264	if (watchdog_active(wdd))
	265	return da9062_wdt_start(wdd);
	266
	267	return 0;
	268	}
	269
	270	static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
	271	da9062_wdt_suspend, da9062_wdt_resume);
	272
7a7cb009 T	273	static struct platform_driver da9062_wdt_driver = {
7a7cb009 T	274	.probe = da9062_wdt_probe,
7a7cb009 T	275	.driver = {
7a7cb009 T	276	.name = "da9062-watchdog",
f6c98b08	277	.pm = &da9062_wdt_pm_ops,
72106c18	278	.of_match_table = da9062_compatible_id_table,
7a7cb009 T	279	},
	280	};
	281	module_platform_driver(da9062_wdt_driver);
	282
	283	MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
72106c18	284	MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
7a7cb009 T	285	MODULE_LICENSE("GPL");
7a7cb009 T	286	MODULE_ALIAS("platform:da9062-watchdog");