drivers/watchdog/imgpdc_wdt.c - kernel/msm-4.9 - Gitiles

 /*
  * Imagination Technologies PowerDown Controller Watchdog Timer.
  *
  * Copyright (c) 2014 Imagination Technologies Ltd.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  *
  * Based on drivers/watchdog/sunxi_wdt.c Copyright (c) 2013 Carlo Caione
  *                                                     2012 Henrik Nordstrom
  */

 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/log2.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/watchdog.h>

 /* registers */
 #define PDC_WDT_SOFT_RESET		0x00
 #define PDC_WDT_CONFIG			0x04
   #define PDC_WDT_CONFIG_ENABLE		BIT(31)
   #define PDC_WDT_CONFIG_DELAY_MASK	0x1f

 #define PDC_WDT_TICKLE1			0x08
 #define PDC_WDT_TICKLE1_MAGIC		0xabcd1234
 #define PDC_WDT_TICKLE2			0x0c
 #define PDC_WDT_TICKLE2_MAGIC		0x4321dcba

 #define PDC_WDT_TICKLE_STATUS_MASK	0x7
 #define PDC_WDT_TICKLE_STATUS_SHIFT	0
 #define PDC_WDT_TICKLE_STATUS_HRESET	0x0  /* Hard reset */
 #define PDC_WDT_TICKLE_STATUS_TIMEOUT	0x1  /* Timeout */
 #define PDC_WDT_TICKLE_STATUS_TICKLE	0x2  /* Tickled incorrectly */
 #define PDC_WDT_TICKLE_STATUS_SRESET	0x3  /* Soft reset */
 #define PDC_WDT_TICKLE_STATUS_USER	0x4  /* User reset */

 /* Timeout values are in seconds */
 #define PDC_WDT_MIN_TIMEOUT		1
 #define PDC_WDT_DEF_TIMEOUT		64

 static int heartbeat;
 module_param(heartbeat, int, 0);
 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
 	"(default = " __MODULE_STRING(PDC_WDT_DEF_TIMEOUT) ")");

 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
 	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

 struct pdc_wdt_dev {
 	struct watchdog_device wdt_dev;
 	struct clk *wdt_clk;
 	struct clk *sys_clk;
 	void __iomem *base;
 };

 static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev)
 {
 	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

 	writel(PDC_WDT_TICKLE1_MAGIC, wdt->base + PDC_WDT_TICKLE1);
 	writel(PDC_WDT_TICKLE2_MAGIC, wdt->base + PDC_WDT_TICKLE2);

 	return 0;
 }

 static int pdc_wdt_stop(struct watchdog_device *wdt_dev)
 {
 	unsigned int val;
 	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

 	val = readl(wdt->base + PDC_WDT_CONFIG);
 	val &= ~PDC_WDT_CONFIG_ENABLE;
 	writel(val, wdt->base + PDC_WDT_CONFIG);

 	/* Must tickle to finish the stop */
 	pdc_wdt_keepalive(wdt_dev);

 	return 0;
 }

 static int pdc_wdt_set_timeout(struct watchdog_device *wdt_dev,
 			       unsigned int new_timeout)
 {
 	unsigned int val;
 	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);
 	unsigned long clk_rate = clk_get_rate(wdt->wdt_clk);

 	wdt->wdt_dev.timeout = new_timeout;

 	val = readl(wdt->base + PDC_WDT_CONFIG) & ~PDC_WDT_CONFIG_DELAY_MASK;
 	val |= order_base_2(new_timeout * clk_rate) - 1;
 	writel(val, wdt->base + PDC_WDT_CONFIG);

 	return 0;
 }

 /* Start the watchdog timer (delay should already be set) */
 static int pdc_wdt_start(struct watchdog_device *wdt_dev)
 {
 	unsigned int val;
 	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

 	val = readl(wdt->base + PDC_WDT_CONFIG);
 	val |= PDC_WDT_CONFIG_ENABLE;
 	writel(val, wdt->base + PDC_WDT_CONFIG);

 	return 0;
 }

 static struct watchdog_info pdc_wdt_info = {
 	.identity	= "IMG PDC Watchdog",
 	.options	= WDIOF_SETTIMEOUT |
 			  WDIOF_KEEPALIVEPING |
 			  WDIOF_MAGICCLOSE,
 };

 static const struct watchdog_ops pdc_wdt_ops = {
 	.owner		= THIS_MODULE,
 	.start		= pdc_wdt_start,
 	.stop		= pdc_wdt_stop,
 	.ping		= pdc_wdt_keepalive,
 	.set_timeout	= pdc_wdt_set_timeout,
 };

 static int pdc_wdt_probe(struct platform_device *pdev)
 {
 	int ret, val;
 	unsigned long clk_rate;
 	struct resource *res;
 	struct pdc_wdt_dev *pdc_wdt;

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

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pdc_wdt->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(pdc_wdt->base))
 		return PTR_ERR(pdc_wdt->base);

 	pdc_wdt->sys_clk = devm_clk_get(&pdev->dev, "sys");
 	if (IS_ERR(pdc_wdt->sys_clk)) {
 		dev_err(&pdev->dev, "failed to get the sys clock\n");
 		return PTR_ERR(pdc_wdt->sys_clk);
 	}

 	pdc_wdt->wdt_clk = devm_clk_get(&pdev->dev, "wdt");
 	if (IS_ERR(pdc_wdt->wdt_clk)) {
 		dev_err(&pdev->dev, "failed to get the wdt clock\n");
 		return PTR_ERR(pdc_wdt->wdt_clk);
 	}

 	ret = clk_prepare_enable(pdc_wdt->sys_clk);
 	if (ret) {
 		dev_err(&pdev->dev, "could not prepare or enable sys clock\n");
 		return ret;
 	}

 	ret = clk_prepare_enable(pdc_wdt->wdt_clk);
 	if (ret) {
 		dev_err(&pdev->dev, "could not prepare or enable wdt clock\n");
 		goto disable_sys_clk;
 	}

 	/* We use the clock rate to calculate the max timeout */
 	clk_rate = clk_get_rate(pdc_wdt->wdt_clk);
 	if (clk_rate == 0) {
 		dev_err(&pdev->dev, "failed to get clock rate\n");
 		ret = -EINVAL;
 		goto disable_wdt_clk;
 	}

 	if (order_base_2(clk_rate) > PDC_WDT_CONFIG_DELAY_MASK + 1) {
 		dev_err(&pdev->dev, "invalid clock rate\n");
 		ret = -EINVAL;
 		goto disable_wdt_clk;
 	}

 	if (order_base_2(clk_rate) == 0)
 		pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT + 1;
 	else
 		pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT;

 	pdc_wdt->wdt_dev.info = &pdc_wdt_info;
 	pdc_wdt->wdt_dev.ops = &pdc_wdt_ops;
 	pdc_wdt->wdt_dev.max_timeout = 1 << PDC_WDT_CONFIG_DELAY_MASK;
 	pdc_wdt->wdt_dev.parent = &pdev->dev;

 	ret = watchdog_init_timeout(&pdc_wdt->wdt_dev, heartbeat, &pdev->dev);
 	if (ret < 0) {
 		pdc_wdt->wdt_dev.timeout = pdc_wdt->wdt_dev.max_timeout;
 		dev_warn(&pdev->dev,
 			 "Initial timeout out of range! setting max timeout\n");
 	}

 	pdc_wdt_stop(&pdc_wdt->wdt_dev);

 	/* Find what caused the last reset */
 	val = readl(pdc_wdt->base + PDC_WDT_TICKLE1);
 	val = (val & PDC_WDT_TICKLE_STATUS_MASK) >> PDC_WDT_TICKLE_STATUS_SHIFT;
 	switch (val) {
 	case PDC_WDT_TICKLE_STATUS_TICKLE:
 	case PDC_WDT_TICKLE_STATUS_TIMEOUT:
 		pdc_wdt->wdt_dev.bootstatus |= WDIOF_CARDRESET;
 		dev_info(&pdev->dev,
 			 "watchdog module last reset due to timeout\n");
 		break;
 	case PDC_WDT_TICKLE_STATUS_HRESET:
 		dev_info(&pdev->dev,
 			 "watchdog module last reset due to hard reset\n");
 		break;
 	case PDC_WDT_TICKLE_STATUS_SRESET:
 		dev_info(&pdev->dev,
 			 "watchdog module last reset due to soft reset\n");
 		break;
 	case PDC_WDT_TICKLE_STATUS_USER:
 		dev_info(&pdev->dev,
 			 "watchdog module last reset due to user reset\n");
 		break;
 	default:
 		dev_info(&pdev->dev,
 			 "contains an illegal status code (%08x)\n", val);
 		break;
 	}

 	watchdog_set_nowayout(&pdc_wdt->wdt_dev, nowayout);

 	platform_set_drvdata(pdev, pdc_wdt);
 	watchdog_set_drvdata(&pdc_wdt->wdt_dev, pdc_wdt);

 	ret = watchdog_register_device(&pdc_wdt->wdt_dev);
 	if (ret)
 		goto disable_wdt_clk;

 	return 0;

 disable_wdt_clk:
 	clk_disable_unprepare(pdc_wdt->wdt_clk);
 disable_sys_clk:
 	clk_disable_unprepare(pdc_wdt->sys_clk);
 	return ret;
 }

 static void pdc_wdt_shutdown(struct platform_device *pdev)
 {
 	struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev);

 	pdc_wdt_stop(&pdc_wdt->wdt_dev);
 }

 static int pdc_wdt_remove(struct platform_device *pdev)
 {
 	struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev);

 	pdc_wdt_stop(&pdc_wdt->wdt_dev);
 	watchdog_unregister_device(&pdc_wdt->wdt_dev);
 	clk_disable_unprepare(pdc_wdt->wdt_clk);
 	clk_disable_unprepare(pdc_wdt->sys_clk);

 	return 0;
 }

 static const struct of_device_id pdc_wdt_match[] = {
 	{ .compatible = "img,pdc-wdt" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, pdc_wdt_match);

 static struct platform_driver pdc_wdt_driver = {
 	.driver = {
 		.name = "imgpdc-wdt",
 		.of_match_table	= pdc_wdt_match,
 	},
 	.probe = pdc_wdt_probe,
 	.remove = pdc_wdt_remove,
 	.shutdown = pdc_wdt_shutdown,
 };
 module_platform_driver(pdc_wdt_driver);

 MODULE_AUTHOR("Jude Abraham <Jude.Abraham@imgtec.com>");
 MODULE_AUTHOR("Naidu Tellapati <Naidu.Tellapati@imgtec.com>");
 MODULE_DESCRIPTION("Imagination Technologies PDC Watchdog Timer Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Imagination Technologies PowerDown Controller Watchdog Timer.
	*
	* Copyright (c) 2014 Imagination Technologies Ltd.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*
	* Based on drivers/watchdog/sunxi_wdt.c Copyright (c) 2013 Carlo Caione
	* 2012 Henrik Nordstrom
	*/

	#include <linux/clk.h>
	#include <linux/io.h>
	#include <linux/log2.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/watchdog.h>

	/* registers */
	#define PDC_WDT_SOFT_RESET 0x00
	#define PDC_WDT_CONFIG 0x04
	#define PDC_WDT_CONFIG_ENABLE BIT(31)
	#define PDC_WDT_CONFIG_DELAY_MASK 0x1f

	#define PDC_WDT_TICKLE1 0x08
	#define PDC_WDT_TICKLE1_MAGIC 0xabcd1234
	#define PDC_WDT_TICKLE2 0x0c
	#define PDC_WDT_TICKLE2_MAGIC 0x4321dcba

	#define PDC_WDT_TICKLE_STATUS_MASK 0x7
	#define PDC_WDT_TICKLE_STATUS_SHIFT 0
	#define PDC_WDT_TICKLE_STATUS_HRESET 0x0 /* Hard reset */
	#define PDC_WDT_TICKLE_STATUS_TIMEOUT 0x1 /* Timeout */
	#define PDC_WDT_TICKLE_STATUS_TICKLE 0x2 /* Tickled incorrectly */
	#define PDC_WDT_TICKLE_STATUS_SRESET 0x3 /* Soft reset */
	#define PDC_WDT_TICKLE_STATUS_USER 0x4 /* User reset */

	/* Timeout values are in seconds */
	#define PDC_WDT_MIN_TIMEOUT 1
	#define PDC_WDT_DEF_TIMEOUT 64

	static int heartbeat;
	module_param(heartbeat, int, 0);
	MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
	"(default = " __MODULE_STRING(PDC_WDT_DEF_TIMEOUT) ")");

	static bool nowayout = WATCHDOG_NOWAYOUT;
	module_param(nowayout, bool, 0);
	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

	struct pdc_wdt_dev {
	struct watchdog_device wdt_dev;
	struct clk *wdt_clk;
	struct clk *sys_clk;
	void __iomem *base;
	};

	static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev)
	{
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	writel(PDC_WDT_TICKLE1_MAGIC, wdt->base + PDC_WDT_TICKLE1);
	writel(PDC_WDT_TICKLE2_MAGIC, wdt->base + PDC_WDT_TICKLE2);

	return 0;
	}

	static int pdc_wdt_stop(struct watchdog_device *wdt_dev)
	{
	unsigned int val;
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	val = readl(wdt->base + PDC_WDT_CONFIG);
	val &= ~PDC_WDT_CONFIG_ENABLE;
	writel(val, wdt->base + PDC_WDT_CONFIG);

	/* Must tickle to finish the stop */
	pdc_wdt_keepalive(wdt_dev);

	return 0;
	}

	static int pdc_wdt_set_timeout(struct watchdog_device *wdt_dev,
	unsigned int new_timeout)
	{
	unsigned int val;
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);
	unsigned long clk_rate = clk_get_rate(wdt->wdt_clk);

	wdt->wdt_dev.timeout = new_timeout;

	val = readl(wdt->base + PDC_WDT_CONFIG) & ~PDC_WDT_CONFIG_DELAY_MASK;
	val \|= order_base_2(new_timeout * clk_rate) - 1;
	writel(val, wdt->base + PDC_WDT_CONFIG);

	return 0;
	}

	/* Start the watchdog timer (delay should already be set) */
	static int pdc_wdt_start(struct watchdog_device *wdt_dev)
	{
	unsigned int val;
	struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);

	val = readl(wdt->base + PDC_WDT_CONFIG);
	val \|= PDC_WDT_CONFIG_ENABLE;
	writel(val, wdt->base + PDC_WDT_CONFIG);

	return 0;
	}

	static struct watchdog_info pdc_wdt_info = {
	.identity = "IMG PDC Watchdog",
	.options = WDIOF_SETTIMEOUT \|
	WDIOF_KEEPALIVEPING \|
	WDIOF_MAGICCLOSE,
	};

	static const struct watchdog_ops pdc_wdt_ops = {
	.owner = THIS_MODULE,
	.start = pdc_wdt_start,
	.stop = pdc_wdt_stop,
	.ping = pdc_wdt_keepalive,
	.set_timeout = pdc_wdt_set_timeout,
	};

	static int pdc_wdt_probe(struct platform_device *pdev)
	{
	int ret, val;
	unsigned long clk_rate;
	struct resource *res;
	struct pdc_wdt_dev *pdc_wdt;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	pdc_wdt->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(pdc_wdt->base))
	return PTR_ERR(pdc_wdt->base);

	pdc_wdt->sys_clk = devm_clk_get(&pdev->dev, "sys");
	if (IS_ERR(pdc_wdt->sys_clk)) {
	dev_err(&pdev->dev, "failed to get the sys clock\n");
	return PTR_ERR(pdc_wdt->sys_clk);
	}

	pdc_wdt->wdt_clk = devm_clk_get(&pdev->dev, "wdt");
	if (IS_ERR(pdc_wdt->wdt_clk)) {
	dev_err(&pdev->dev, "failed to get the wdt clock\n");
	return PTR_ERR(pdc_wdt->wdt_clk);
	}

	ret = clk_prepare_enable(pdc_wdt->sys_clk);
	if (ret) {
	dev_err(&pdev->dev, "could not prepare or enable sys clock\n");
	return ret;
	}

	ret = clk_prepare_enable(pdc_wdt->wdt_clk);
	if (ret) {
	dev_err(&pdev->dev, "could not prepare or enable wdt clock\n");
	goto disable_sys_clk;
	}

	/* We use the clock rate to calculate the max timeout */
	clk_rate = clk_get_rate(pdc_wdt->wdt_clk);
	if (clk_rate == 0) {
	dev_err(&pdev->dev, "failed to get clock rate\n");
	ret = -EINVAL;
	goto disable_wdt_clk;
	}

	if (order_base_2(clk_rate) > PDC_WDT_CONFIG_DELAY_MASK + 1) {
	dev_err(&pdev->dev, "invalid clock rate\n");
	ret = -EINVAL;
	goto disable_wdt_clk;
	}

	if (order_base_2(clk_rate) == 0)
	pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT + 1;
	else
	pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT;

	pdc_wdt->wdt_dev.info = &pdc_wdt_info;
	pdc_wdt->wdt_dev.ops = &pdc_wdt_ops;
	pdc_wdt->wdt_dev.max_timeout = 1 << PDC_WDT_CONFIG_DELAY_MASK;
	pdc_wdt->wdt_dev.parent = &pdev->dev;

	ret = watchdog_init_timeout(&pdc_wdt->wdt_dev, heartbeat, &pdev->dev);
	if (ret < 0) {
	pdc_wdt->wdt_dev.timeout = pdc_wdt->wdt_dev.max_timeout;
	dev_warn(&pdev->dev,
	"Initial timeout out of range! setting max timeout\n");
	}

	pdc_wdt_stop(&pdc_wdt->wdt_dev);

	/* Find what caused the last reset */
	val = readl(pdc_wdt->base + PDC_WDT_TICKLE1);
	val = (val & PDC_WDT_TICKLE_STATUS_MASK) >> PDC_WDT_TICKLE_STATUS_SHIFT;
	switch (val) {
	case PDC_WDT_TICKLE_STATUS_TICKLE:
	case PDC_WDT_TICKLE_STATUS_TIMEOUT:
	pdc_wdt->wdt_dev.bootstatus \|= WDIOF_CARDRESET;
	dev_info(&pdev->dev,
	"watchdog module last reset due to timeout\n");
	break;
	case PDC_WDT_TICKLE_STATUS_HRESET:
	dev_info(&pdev->dev,
	"watchdog module last reset due to hard reset\n");
	break;
	case PDC_WDT_TICKLE_STATUS_SRESET:
	dev_info(&pdev->dev,
	"watchdog module last reset due to soft reset\n");
	break;
	case PDC_WDT_TICKLE_STATUS_USER:
	dev_info(&pdev->dev,
	"watchdog module last reset due to user reset\n");
	break;
	default:
	dev_info(&pdev->dev,
	"contains an illegal status code (%08x)\n", val);
	break;
	}

	watchdog_set_nowayout(&pdc_wdt->wdt_dev, nowayout);

	platform_set_drvdata(pdev, pdc_wdt);
	watchdog_set_drvdata(&pdc_wdt->wdt_dev, pdc_wdt);

	ret = watchdog_register_device(&pdc_wdt->wdt_dev);
	if (ret)
	goto disable_wdt_clk;

	return 0;

	disable_wdt_clk:
	clk_disable_unprepare(pdc_wdt->wdt_clk);
	disable_sys_clk:
	clk_disable_unprepare(pdc_wdt->sys_clk);
	return ret;
	}

	static void pdc_wdt_shutdown(struct platform_device *pdev)
	{
	struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev);

	pdc_wdt_stop(&pdc_wdt->wdt_dev);
	}

	static int pdc_wdt_remove(struct platform_device *pdev)
	{
	struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev);

	pdc_wdt_stop(&pdc_wdt->wdt_dev);
	watchdog_unregister_device(&pdc_wdt->wdt_dev);
	clk_disable_unprepare(pdc_wdt->wdt_clk);
	clk_disable_unprepare(pdc_wdt->sys_clk);

	return 0;
	}

	static const struct of_device_id pdc_wdt_match[] = {
	{ .compatible = "img,pdc-wdt" },
	{}
	};
	MODULE_DEVICE_TABLE(of, pdc_wdt_match);

	static struct platform_driver pdc_wdt_driver = {
	.driver = {
	.name = "imgpdc-wdt",
	.of_match_table = pdc_wdt_match,
	},
	.probe = pdc_wdt_probe,
	.remove = pdc_wdt_remove,
	.shutdown = pdc_wdt_shutdown,
	};
	module_platform_driver(pdc_wdt_driver);

	MODULE_AUTHOR("Jude Abraham <Jude.Abraham@imgtec.com>");
	MODULE_AUTHOR("Naidu Tellapati <Naidu.Tellapati@imgtec.com>");
	MODULE_DESCRIPTION("Imagination Technologies PDC Watchdog Timer Driver");
	MODULE_LICENSE("GPL v2");