watchdog: uniphier: add UniPhier watchdog driver (e7bf0289) · Commits · e / devices / android_kernel_fairphone_FP4

Documentation/watchdog/watchdog-parameters.txt

+6 −0

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		@@ -369,6 +369,12 @@ timeout: Watchdog timeout in seconds. (0<timeout<N, default=60)
		nowayout: Watchdog cannot be stopped once started
		(default=kernel config parameter)
		-------------------------------------------------
		uniphier_wdt:
		timeout: Watchdog timeout in power of two seconds.
		(1 <= timeout <= 128, default=64)
		nowayout: Watchdog cannot be stopped once started
		(default=kernel config parameter)
		-------------------------------------------------
		w83627hf_wdt:
		wdt_io: w83627hf/thf WDT io port (default 0x2E)
		timeout: Watchdog timeout in seconds. 1 <= timeout <= 255, default=60.

drivers/watchdog/Kconfig

+12 −0

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		@@ -775,6 +775,18 @@ config STM32_WATCHDOG
		To compile this driver as a module, choose M here: the
		module will be called stm32_iwdg.

		config UNIPHIER_WATCHDOG
		tristate "UniPhier watchdog support"
		depends on ARCH_UNIPHIER \|\| COMPILE_TEST
		depends on OF && MFD_SYSCON
		select WATCHDOG_CORE
		help
		Say Y here to include support watchdog timer embedded
		into the UniPhier system.

		To compile this driver as a module, choose M here: the
		module will be called uniphier_wdt.

		# AVR32 Architecture

		config AT32AP700X_WDT

drivers/watchdog/Makefile

+1 −0

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		@@ -86,6 +86,7 @@ obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o
		obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o
		obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o
		obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o
		obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o

		# AVR32 Architecture
		obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o

drivers/watchdog/uniphier_wdt.c

0 → 100644

+268 −0

Original line number	Diff line number	Diff line
		/*
		* Watchdog driver for the UniPhier watchdog timer
		*
		* (c) Copyright 2014 Panasonic Corporation
		* (c) Copyright 2016 Socionext Inc.
		* All rights reserved.
		*
		* 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.
		*
		* 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/bitops.h>
		#include <linux/mfd/syscon.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/platform_device.h>
		#include <linux/regmap.h>
		#include <linux/watchdog.h>

		/* WDT timer setting register */
		#define WDTTIMSET 0x3004
		#define WDTTIMSET_PERIOD_MASK (0xf << 0)
		#define WDTTIMSET_PERIOD_1_SEC (0x3 << 0)

		/* WDT reset selection register */
		#define WDTRSTSEL 0x3008
		#define WDTRSTSEL_RSTSEL_MASK (0x3 << 0)
		#define WDTRSTSEL_RSTSEL_BOTH (0x0 << 0)
		#define WDTRSTSEL_RSTSEL_IRQ_ONLY (0x2 << 0)

		/* WDT control register */
		#define WDTCTRL 0x300c
		#define WDTCTRL_STATUS BIT(8)
		#define WDTCTRL_CLEAR BIT(1)
		#define WDTCTRL_ENABLE BIT(0)

		#define SEC_TO_WDTTIMSET_PRD(sec) \
		(ilog2(sec) + WDTTIMSET_PERIOD_1_SEC)

		#define WDTST_TIMEOUT 1000 /* usec */

		#define WDT_DEFAULT_TIMEOUT 64 /* Default is 64 seconds */
		#define WDT_PERIOD_MIN 1
		#define WDT_PERIOD_MAX 128

		static unsigned int timeout = 0;
		static bool nowayout = WATCHDOG_NOWAYOUT;

		struct uniphier_wdt_dev {
		struct watchdog_device wdt_dev;
		struct regmap *regmap;
		};

		/*
		* UniPhier Watchdog operations
		*/
		static int uniphier_watchdog_ping(struct watchdog_device *w)
		{
		struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
		unsigned int val;
		int ret;

		/* Clear counter */
		ret = regmap_write_bits(wdev->regmap, WDTCTRL,
		WDTCTRL_CLEAR, WDTCTRL_CLEAR);
		if (!ret)
		/*
		* As SoC specification, after clear counter,
		* it needs to wait until counter status is 1.
		*/
		ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val,
		(val & WDTCTRL_STATUS),
		0, WDTST_TIMEOUT);

		return ret;
		}

		static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec)
		{
		unsigned int val;
		int ret;

		ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
		!(val & WDTCTRL_STATUS),
		0, WDTST_TIMEOUT);
		if (ret)
		return ret;

		/* Setup period */
		ret = regmap_write(regmap, WDTTIMSET,
		SEC_TO_WDTTIMSET_PRD(sec));
		if (ret)
		return ret;

		/* Enable and clear watchdog */
		ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE \| WDTCTRL_CLEAR);
		if (!ret)
		/*
		* As SoC specification, after clear counter,
		* it needs to wait until counter status is 1.
		*/
		ret = regmap_read_poll_timeout(regmap, WDTCTRL, val,
		(val & WDTCTRL_STATUS),
		0, WDTST_TIMEOUT);

		return ret;
		}

		static int __uniphier_watchdog_stop(struct regmap *regmap)
		{
		/* Disable and stop watchdog */
		return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0);
		}

		static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec)
		{
		int ret;

		ret = __uniphier_watchdog_stop(regmap);
		if (ret)
		return ret;

		return __uniphier_watchdog_start(regmap, sec);
		}

		static int uniphier_watchdog_start(struct watchdog_device *w)
		{
		struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
		unsigned int tmp_timeout;

		tmp_timeout = roundup_pow_of_two(w->timeout);

		return __uniphier_watchdog_start(wdev->regmap, tmp_timeout);
		}

		static int uniphier_watchdog_stop(struct watchdog_device *w)
		{
		struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);

		return __uniphier_watchdog_stop(wdev->regmap);
		}

		static int uniphier_watchdog_set_timeout(struct watchdog_device *w,
		unsigned int t)
		{
		struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w);
		unsigned int tmp_timeout;
		int ret;

		tmp_timeout = roundup_pow_of_two(t);
		if (tmp_timeout == w->timeout)
		return 0;

		if (watchdog_active(w)) {
		ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout);
		if (ret)
		return ret;
		}

		w->timeout = tmp_timeout;

		return 0;
		}

		/*
		* Kernel Interfaces
		*/
		static const struct watchdog_info uniphier_wdt_info = {
		.identity = "uniphier-wdt",
		.options = WDIOF_SETTIMEOUT \|
		WDIOF_KEEPALIVEPING \|
		WDIOF_MAGICCLOSE \|
		WDIOF_OVERHEAT,
		};

		static const struct watchdog_ops uniphier_wdt_ops = {
		.owner = THIS_MODULE,
		.start = uniphier_watchdog_start,
		.stop = uniphier_watchdog_stop,
		.ping = uniphier_watchdog_ping,
		.set_timeout = uniphier_watchdog_set_timeout,
		};

		static int uniphier_wdt_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct uniphier_wdt_dev *wdev;
		struct regmap *regmap;
		struct device_node *parent;
		int ret;

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

		platform_set_drvdata(pdev, wdev);

		parent = of_get_parent(dev->of_node); /* parent should be syscon node */
		regmap = syscon_node_to_regmap(parent);
		of_node_put(parent);
		if (IS_ERR(regmap))
		return PTR_ERR(regmap);

		wdev->regmap = regmap;
		wdev->wdt_dev.info = &uniphier_wdt_info;
		wdev->wdt_dev.ops = &uniphier_wdt_ops;
		wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX;
		wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN;
		wdev->wdt_dev.parent = dev;

		if (watchdog_init_timeout(&wdev->wdt_dev, timeout, dev) < 0) {
		wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT;
		}
		watchdog_set_nowayout(&wdev->wdt_dev, nowayout);
		watchdog_stop_on_reboot(&wdev->wdt_dev);

		watchdog_set_drvdata(&wdev->wdt_dev, wdev);

		uniphier_watchdog_stop(&wdev->wdt_dev);
		ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH);
		if (ret)
		return ret;

		ret = devm_watchdog_register_device(dev, &wdev->wdt_dev);
		if (ret)
		return ret;

		dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n",
		wdev->wdt_dev.timeout, nowayout);

		return 0;
		}

		static const struct of_device_id uniphier_wdt_dt_ids[] = {
		{ .compatible = "socionext,uniphier-wdt" },
		{ /* sentinel */ }
		};
		MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids);

		static struct platform_driver uniphier_wdt_driver = {
		.probe = uniphier_wdt_probe,
		.driver = {
		.name = "uniphier-wdt",
		.of_match_table = uniphier_wdt_dt_ids,
		},
		};

		module_platform_driver(uniphier_wdt_driver);

		module_param(timeout, uint, 0000);
		MODULE_PARM_DESC(timeout,
		"Watchdog timeout seconds in power of 2. (0 < timeout < 128, default="
		__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");

		module_param(nowayout, bool, 0000);
		MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

		MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>");
		MODULE_DESCRIPTION("UniPhier Watchdog Device Driver");
		MODULE_LICENSE("GPL v2");