drivers/watchdog/da9062_wdt.c - arm/linux - Git at Google

 /*
  * Watchdog device driver for DA9062 and DA9061 PMICs
  * Copyright (C) 2015  Dialog Semiconductor Ltd.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version 2
  * of the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #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 void da9062_apply_window_protection(struct da9062_watchdog *wdt)
 {
 	unsigned long delay = msecs_to_jiffies(DA9062_RESET_PROTECTION_MS);
 	unsigned long timeout = wdt->j_time_stamp + delay;
 	unsigned long now = jiffies;
 	unsigned int diff_ms;

 	/* if time-limit has not elapsed then wait for remainder */
 	if (time_before(now, timeout)) {
 		diff_ms = jiffies_to_msecs(timeout-now);
 		dev_dbg(wdt->hw->dev,
 			"Kicked too quickly. Delaying %u msecs\n", diff_ms);
 		msleep(diff_ms);
 	}
 }

 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;

 	da9062_apply_window_protection(wdt);

 	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;

 	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 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,
 };

 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.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
 	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
 	wdt->wdtdev.parent = &pdev->dev;

 	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");
	/*
	* Watchdog device driver for DA9062 and DA9061 PMICs
	* Copyright (C) 2015 Dialog Semiconductor Ltd.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version 2
	* of the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#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 void da9062_apply_window_protection(struct da9062_watchdog *wdt)
	{
	unsigned long delay = msecs_to_jiffies(DA9062_RESET_PROTECTION_MS);
	unsigned long timeout = wdt->j_time_stamp + delay;
	unsigned long now = jiffies;
	unsigned int diff_ms;

	/* if time-limit has not elapsed then wait for remainder */
	if (time_before(now, timeout)) {
	diff_ms = jiffies_to_msecs(timeout-now);
	dev_dbg(wdt->hw->dev,
	"Kicked too quickly. Delaying %u msecs\n", diff_ms);
	msleep(diff_ms);
	}
	}

	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;

	da9062_apply_window_protection(wdt);

	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;

	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 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,
	};

	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.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
	wdt->wdtdev.parent = &pdev->dev;

	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");