141 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| // Copyright (C) STMicroelectronics 2018
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| // Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics.
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| 
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| #include <linux/kernel.h>
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| #include <linux/mfd/stpmic1.h>
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| #include <linux/module.h>
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| #include <linux/platform_device.h>
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| #include <linux/of.h>
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| #include <linux/regmap.h>
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| #include <linux/slab.h>
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| #include <linux/watchdog.h>
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| 
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| /* WATCHDOG CONTROL REGISTER bit */
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| #define WDT_START		BIT(0)
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| #define WDT_PING		BIT(1)
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| #define WDT_START_MASK		BIT(0)
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| #define WDT_PING_MASK		BIT(1)
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| #define WDT_STOP		0
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| 
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| #define PMIC_WDT_MIN_TIMEOUT 1
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| #define PMIC_WDT_MAX_TIMEOUT 256
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| #define PMIC_WDT_DEFAULT_TIMEOUT 30
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| 
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| static bool nowayout = WATCHDOG_NOWAYOUT;
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| module_param(nowayout, bool, 0);
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| MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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| 		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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| 
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| struct stpmic1_wdt {
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| 	struct stpmic1 *pmic;
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| 	struct watchdog_device wdtdev;
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| };
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| 
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| static int pmic_wdt_start(struct watchdog_device *wdd)
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| {
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| 	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
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| 
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| 	return regmap_update_bits(wdt->pmic->regmap,
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| 				  WCHDG_CR, WDT_START_MASK, WDT_START);
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| }
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| 
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| static int pmic_wdt_stop(struct watchdog_device *wdd)
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| {
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| 	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
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| 
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| 	return regmap_update_bits(wdt->pmic->regmap,
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| 				  WCHDG_CR, WDT_START_MASK, WDT_STOP);
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| }
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| 
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| static int pmic_wdt_ping(struct watchdog_device *wdd)
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| {
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| 	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
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| 
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| 	return regmap_update_bits(wdt->pmic->regmap,
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| 				  WCHDG_CR, WDT_PING_MASK, WDT_PING);
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| }
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| 
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| static int pmic_wdt_set_timeout(struct watchdog_device *wdd,
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| 				unsigned int timeout)
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| {
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| 	struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd);
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| 
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| 	wdd->timeout = timeout;
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| 	/* timeout is equal to register value + 1 */
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| 	return regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout - 1);
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| }
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| 
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| static const struct watchdog_info pmic_watchdog_info = {
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| 	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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| 	.identity = "STPMIC1 PMIC Watchdog",
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| };
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| 
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| static const struct watchdog_ops pmic_watchdog_ops = {
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| 	.owner = THIS_MODULE,
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| 	.start = pmic_wdt_start,
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| 	.stop = pmic_wdt_stop,
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| 	.ping = pmic_wdt_ping,
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| 	.set_timeout = pmic_wdt_set_timeout,
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| };
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| 
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| static int pmic_wdt_probe(struct platform_device *pdev)
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| {
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| 	struct device *dev = &pdev->dev;
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| 	int ret;
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| 	struct stpmic1 *pmic;
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| 	struct stpmic1_wdt *wdt;
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| 
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| 	if (!dev->parent)
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| 		return -EINVAL;
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| 
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| 	pmic = dev_get_drvdata(dev->parent);
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| 	if (!pmic)
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| 		return -EINVAL;
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| 
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| 	wdt = devm_kzalloc(dev, sizeof(struct stpmic1_wdt), GFP_KERNEL);
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| 	if (!wdt)
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| 		return -ENOMEM;
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| 
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| 	wdt->pmic = pmic;
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| 
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| 	wdt->wdtdev.info = &pmic_watchdog_info;
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| 	wdt->wdtdev.ops = &pmic_watchdog_ops;
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| 	wdt->wdtdev.min_timeout = PMIC_WDT_MIN_TIMEOUT;
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| 	wdt->wdtdev.max_timeout = PMIC_WDT_MAX_TIMEOUT;
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| 	wdt->wdtdev.parent = dev;
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| 
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| 	wdt->wdtdev.timeout = PMIC_WDT_DEFAULT_TIMEOUT;
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| 	watchdog_init_timeout(&wdt->wdtdev, 0, dev);
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| 
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| 	watchdog_set_nowayout(&wdt->wdtdev, nowayout);
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| 	watchdog_set_drvdata(&wdt->wdtdev, wdt);
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| 
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| 	ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
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| 	if (ret)
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| 		return ret;
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| 
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| 	dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n");
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| 	return 0;
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| }
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| 
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| static const struct of_device_id of_pmic_wdt_match[] = {
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| 	{ .compatible = "st,stpmic1-wdt" },
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| 	{ },
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| };
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| 
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| MODULE_DEVICE_TABLE(of, of_pmic_wdt_match);
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| 
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| static struct platform_driver stpmic1_wdt_driver = {
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| 	.probe = pmic_wdt_probe,
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| 	.driver = {
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| 		.name = "stpmic1-wdt",
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| 		.of_match_table = of_pmic_wdt_match,
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| 	},
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| };
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| module_platform_driver(stpmic1_wdt_driver);
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| 
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| MODULE_DESCRIPTION("Watchdog driver for STPMIC1 device");
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| MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>");
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| MODULE_LICENSE("GPL v2");
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