watchdog: Add i.MX7ULP watchdog support (41b630f4) · Commits · 戴 / test

drivers/watchdog/Kconfig

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		@@ -724,6 +724,19 @@ config IMX_SC_WDT
		To compile this driver as a module, choose M here: the
		module will be called imx_sc_wdt.

		config IMX7ULP_WDT
		tristate "IMX7ULP Watchdog"
		depends on ARCH_MXC \|\| COMPILE_TEST
		select WATCHDOG_CORE
		help
		This is the driver for the hardware watchdog on the Freescale
		IMX7ULP and later processors. If you have one of these
		processors and wish to have watchdog support enabled,
		say Y, otherwise say N.

		To compile this driver as a module, choose M here: the
		module will be called imx7ulp_wdt.

		config UX500_WATCHDOG
		tristate "ST-Ericsson Ux500 watchdog"
		depends on MFD_DB8500_PRCMU

drivers/watchdog/Makefile

+1 −0

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		@@ -67,6 +67,7 @@ obj-$(CONFIG_TS4800_WATCHDOG) += ts4800_wdt.o
		obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
		obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
		obj-$(CONFIG_IMX_SC_WDT) += imx_sc_wdt.o
		obj-$(CONFIG_IMX7ULP_WDT) += imx7ulp_wdt.o
		obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
		obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
		obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o

drivers/watchdog/imx7ulp_wdt.c

0 → 100644

+243 −0

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		// SPDX-License-Identifier: GPL-2.0
		/*
		* Copyright 2019 NXP.
		*/

		#include <linux/clk.h>
		#include <linux/init.h>
		#include <linux/io.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/platform_device.h>
		#include <linux/reboot.h>
		#include <linux/watchdog.h>

		#define WDOG_CS 0x0
		#define WDOG_CS_CMD32EN BIT(13)
		#define WDOG_CS_ULK BIT(11)
		#define WDOG_CS_RCS BIT(10)
		#define WDOG_CS_EN BIT(7)
		#define WDOG_CS_UPDATE BIT(5)

		#define WDOG_CNT 0x4
		#define WDOG_TOVAL 0x8

		#define REFRESH_SEQ0 0xA602
		#define REFRESH_SEQ1 0xB480
		#define REFRESH ((REFRESH_SEQ1 << 16) \| REFRESH_SEQ0)

		#define UNLOCK_SEQ0 0xC520
		#define UNLOCK_SEQ1 0xD928
		#define UNLOCK ((UNLOCK_SEQ1 << 16) \| UNLOCK_SEQ0)

		#define DEFAULT_TIMEOUT 60
		#define MAX_TIMEOUT 128
		#define WDOG_CLOCK_RATE 1000

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

		struct imx7ulp_wdt_device {
		struct notifier_block restart_handler;
		struct watchdog_device wdd;
		void __iomem *base;
		struct clk *clk;
		};

		static inline void imx7ulp_wdt_enable(void __iomem *base, bool enable)
		{
		u32 val = readl(base + WDOG_CS);

		writel(UNLOCK, base + WDOG_CNT);
		if (enable)
		writel(val \| WDOG_CS_EN, base + WDOG_CS);
		else
		writel(val & ~WDOG_CS_EN, base + WDOG_CS);
		}

		static inline bool imx7ulp_wdt_is_enabled(void __iomem *base)
		{
		u32 val = readl(base + WDOG_CS);

		return val & WDOG_CS_EN;
		}

		static int imx7ulp_wdt_ping(struct watchdog_device *wdog)
		{
		struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);

		writel(REFRESH, wdt->base + WDOG_CNT);

		return 0;
		}

		static int imx7ulp_wdt_start(struct watchdog_device *wdog)
		{
		struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);

		imx7ulp_wdt_enable(wdt->base, true);

		return 0;
		}

		static int imx7ulp_wdt_stop(struct watchdog_device *wdog)
		{
		struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);

		imx7ulp_wdt_enable(wdt->base, false);

		return 0;
		}

		static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog,
		unsigned int timeout)
		{
		struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog);
		u32 val = WDOG_CLOCK_RATE * timeout;

		writel(UNLOCK, wdt->base + WDOG_CNT);
		writel(val, wdt->base + WDOG_TOVAL);

		wdog->timeout = timeout;

		return 0;
		}

		static const struct watchdog_ops imx7ulp_wdt_ops = {
		.owner = THIS_MODULE,
		.start = imx7ulp_wdt_start,
		.stop = imx7ulp_wdt_stop,
		.ping = imx7ulp_wdt_ping,
		.set_timeout = imx7ulp_wdt_set_timeout,
		};

		static const struct watchdog_info imx7ulp_wdt_info = {
		.identity = "i.MX7ULP watchdog timer",
		.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \|
		WDIOF_MAGICCLOSE,
		};

		static inline void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
		{
		u32 val;

		/* unlock the wdog for reconfiguration */
		writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
		writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);

		/* set an initial timeout value in TOVAL */
		writel(timeout, base + WDOG_TOVAL);
		/* enable 32bit command sequence and reconfigure */
		val = BIT(13) \| BIT(8) \| BIT(5);
		writel(val, base + WDOG_CS);
		}

		static void imx7ulp_wdt_action(void *data)
		{
		clk_disable_unprepare(data);
		}

		static int imx7ulp_wdt_probe(struct platform_device *pdev)
		{
		struct imx7ulp_wdt_device *imx7ulp_wdt;
		struct device *dev = &pdev->dev;
		struct watchdog_device *wdog;
		int ret;

		imx7ulp_wdt = devm_kzalloc(dev, sizeof(*imx7ulp_wdt), GFP_KERNEL);
		if (!imx7ulp_wdt)
		return -ENOMEM;

		platform_set_drvdata(pdev, imx7ulp_wdt);

		imx7ulp_wdt->base = devm_platform_ioremap_resource(pdev, 0);
		if (IS_ERR(imx7ulp_wdt->base))
		return PTR_ERR(imx7ulp_wdt->base);

		imx7ulp_wdt->clk = devm_clk_get(dev, NULL);
		if (IS_ERR(imx7ulp_wdt->clk)) {
		dev_err(dev, "Failed to get watchdog clock\n");
		return PTR_ERR(imx7ulp_wdt->clk);
		}

		ret = clk_prepare_enable(imx7ulp_wdt->clk);
		if (ret)
		return ret;

		ret = devm_add_action_or_reset(dev, imx7ulp_wdt_action, imx7ulp_wdt->clk);
		if (ret)
		return ret;

		wdog = &imx7ulp_wdt->wdd;
		wdog->info = &imx7ulp_wdt_info;
		wdog->ops = &imx7ulp_wdt_ops;
		wdog->min_timeout = 1;
		wdog->max_timeout = MAX_TIMEOUT;
		wdog->parent = dev;
		wdog->timeout = DEFAULT_TIMEOUT;

		watchdog_init_timeout(wdog, 0, dev);
		watchdog_stop_on_reboot(wdog);
		watchdog_stop_on_unregister(wdog);
		watchdog_set_drvdata(wdog, imx7ulp_wdt);
		imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE);

		return devm_watchdog_register_device(dev, wdog);
		}

		static int __maybe_unused imx7ulp_wdt_suspend(struct device *dev)
		{
		struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);

		if (watchdog_active(&imx7ulp_wdt->wdd))
		imx7ulp_wdt_stop(&imx7ulp_wdt->wdd);

		clk_disable_unprepare(imx7ulp_wdt->clk);

		return 0;
		}

		static int __maybe_unused imx7ulp_wdt_resume(struct device *dev)
		{
		struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev);
		u32 timeout = imx7ulp_wdt->wdd.timeout * WDOG_CLOCK_RATE;
		int ret;

		ret = clk_prepare_enable(imx7ulp_wdt->clk);
		if (ret)
		return ret;

		if (imx7ulp_wdt_is_enabled(imx7ulp_wdt->base))
		imx7ulp_wdt_init(imx7ulp_wdt->base, timeout);

		if (watchdog_active(&imx7ulp_wdt->wdd))
		imx7ulp_wdt_start(&imx7ulp_wdt->wdd);

		return 0;
		}

		static SIMPLE_DEV_PM_OPS(imx7ulp_wdt_pm_ops, imx7ulp_wdt_suspend,
		imx7ulp_wdt_resume);

		static const struct of_device_id imx7ulp_wdt_dt_ids[] = {
		{ .compatible = "fsl,imx7ulp-wdt", },
		{ /* sentinel */ }
		};
		MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids);

		static struct platform_driver imx7ulp_wdt_driver = {
		.probe = imx7ulp_wdt_probe,
		.driver = {
		.name = "imx7ulp-wdt",
		.pm = &imx7ulp_wdt_pm_ops,
		.of_match_table = imx7ulp_wdt_dt_ids,
		},
		};
		module_platform_driver(imx7ulp_wdt_driver);

		MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
		MODULE_DESCRIPTION("Freescale i.MX7ULP watchdog driver");
		MODULE_LICENSE("GPL v2");

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