watchdog: atlas7: add watchdog driver of CSRatlas7 (b466ee89) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/watchdog/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -585,6 +585,16 @@ config LPC18XX_WATCHDOG
		To compile this driver as a module, choose M here: the
		module will be called lpc18xx_wdt.

		config ATLAS7_WATCHDOG
		tristate "CSRatlas7 watchdog"
		depends on ARCH_ATLAS7
		help
		Say Y here to include Watchdog timer support for the watchdog
		existing on the CSRatlas7 series platforms.

		To compile this driver as a module, choose M here: the
		module will be called atlas7_wdt.

		# AVR32 Architecture

		config AT32AP700X_WDT

drivers/watchdog/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -69,6 +69,7 @@ obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o
		obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o
		obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o
		obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o
		obj-$(CONFIG_ATLAS7_WATCHDOG) += atlas7_wdt.o

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

drivers/watchdog/atlas7_wdt.c

0 → 100644

+242 −0

Original line number	Diff line number	Diff line
		/*
		* Watchdog driver for CSR Atlas7
		*
		* Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
		*
		* Licensed under GPLv2.
		*/

		#include <linux/clk.h>
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/moduleparam.h>
		#include <linux/of.h>
		#include <linux/platform_device.h>
		#include <linux/watchdog.h>

		#define ATLAS7_TIMER_WDT_INDEX 5
		#define ATLAS7_WDT_DEFAULT_TIMEOUT 20

		#define ATLAS7_WDT_CNT_CTRL (0 + 4 * ATLAS7_TIMER_WDT_INDEX)
		#define ATLAS7_WDT_CNT_MATCH (0x18 + 4 * ATLAS7_TIMER_WDT_INDEX)
		#define ATLAS7_WDT_CNT (0x48 + 4 * ATLAS7_TIMER_WDT_INDEX)
		#define ATLAS7_WDT_CNT_EN (BIT(0) \| BIT(1))
		#define ATLAS7_WDT_EN 0x64

		static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT;
		static bool nowayout = WATCHDOG_NOWAYOUT;

		module_param(timeout, uint, 0);
		module_param(nowayout, bool, 0);

		MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
		MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

		struct atlas7_wdog {
		struct device *dev;
		void __iomem *base;
		unsigned long tick_rate;
		struct clk *clk;
		};

		static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd)
		{
		struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
		u32 counter, match, delta;

		counter = readl(wdt->base + ATLAS7_WDT_CNT);
		match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH);
		delta = match - counter;

		return delta / wdt->tick_rate;
		}

		static int atlas7_wdt_ping(struct watchdog_device *wdd)
		{
		struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
		u32 counter, match, delta;

		counter = readl(wdt->base + ATLAS7_WDT_CNT);
		delta = wdd->timeout * wdt->tick_rate;
		match = counter + delta;

		writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH);

		return 0;
		}

		static int atlas7_wdt_enable(struct watchdog_device *wdd)
		{
		struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

		atlas7_wdt_ping(wdd);

		writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) \| ATLAS7_WDT_CNT_EN,
		wdt->base + ATLAS7_WDT_CNT_CTRL);
		writel(1, wdt->base + ATLAS7_WDT_EN);

		return 0;
		}

		static int atlas7_wdt_disable(struct watchdog_device *wdd)
		{
		struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

		writel(0, wdt->base + ATLAS7_WDT_EN);
		writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN,
		wdt->base + ATLAS7_WDT_CNT_CTRL);

		return 0;
		}

		static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
		{
		wdd->timeout = to;

		return 0;
		}

		#define OPTIONS (WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE)

		static const struct watchdog_info atlas7_wdt_ident = {
		.options = OPTIONS,
		.firmware_version = 0,
		.identity = "atlas7 Watchdog",
		};

		static struct watchdog_ops atlas7_wdt_ops = {
		.owner = THIS_MODULE,
		.start = atlas7_wdt_enable,
		.stop = atlas7_wdt_disable,
		.get_timeleft = atlas7_wdt_gettimeleft,
		.ping = atlas7_wdt_ping,
		.set_timeout = atlas7_wdt_settimeout,
		};

		static struct watchdog_device atlas7_wdd = {
		.info = &atlas7_wdt_ident,
		.ops = &atlas7_wdt_ops,
		.timeout = ATLAS7_WDT_DEFAULT_TIMEOUT,
		};

		static const struct of_device_id atlas7_wdt_ids[] = {
		{ .compatible = "sirf,atlas7-tick"},
		{}
		};

		static int atlas7_wdt_probe(struct platform_device *pdev)
		{
		struct device_node *np = pdev->dev.of_node;
		struct atlas7_wdog *wdt;
		struct resource *res;
		struct clk *clk;
		int ret;

		wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
		if (!wdt)
		return -ENOMEM;
		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		wdt->base = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(wdt->base))
		return PTR_ERR(wdt->base);

		clk = of_clk_get(np, 0);
		if (IS_ERR(clk))
		return PTR_ERR(clk);
		ret = clk_prepare_enable(clk);
		if (ret) {
		dev_err(&pdev->dev, "clk enable failed\n");
		goto err;
		}

		/* disable watchdog hardware */
		writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);

		wdt->tick_rate = clk_get_rate(clk);
		wdt->clk = clk;
		atlas7_wdd.min_timeout = 1;
		atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;

		watchdog_init_timeout(&atlas7_wdd, 0, &pdev->dev);
		watchdog_set_nowayout(&atlas7_wdd, nowayout);

		watchdog_set_drvdata(&atlas7_wdd, wdt);
		platform_set_drvdata(pdev, &atlas7_wdd);

		ret = watchdog_register_device(&atlas7_wdd);
		if (ret)
		goto err1;

		return 0;

		err1:
		clk_disable_unprepare(clk);
		err:
		clk_put(clk);
		return ret;
		}

		static void atlas7_wdt_shutdown(struct platform_device *pdev)
		{
		struct watchdog_device *wdd = platform_get_drvdata(pdev);
		struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

		atlas7_wdt_disable(wdd);
		clk_disable_unprepare(wdt->clk);
		}

		static int atlas7_wdt_remove(struct platform_device *pdev)
		{
		struct watchdog_device *wdd = platform_get_drvdata(pdev);
		struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);

		atlas7_wdt_shutdown(pdev);
		clk_put(wdt->clk);
		return 0;
		}

		static int __maybe_unused atlas7_wdt_suspend(struct device *dev)
		{
		/*
		* NOTE:timer controller registers settings are saved
		* and restored back by the timer-atlas7.c
		*/
		return 0;
		}

		static int __maybe_unused atlas7_wdt_resume(struct device *dev)
		{
		struct watchdog_device *wdd = dev_get_drvdata(dev);

		/*
		* NOTE: Since timer controller registers settings are saved
		* and restored back by the timer-atlas7.c, so we need not
		* update WD settings except refreshing timeout.
		*/
		atlas7_wdt_ping(wdd);

		return 0;
		}

		static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops,
		atlas7_wdt_suspend, atlas7_wdt_resume);

		MODULE_DEVICE_TABLE(of, atlas7_wdt_ids);

		static struct platform_driver atlas7_wdt_driver = {
		.driver = {
		.name = "atlas7-wdt",
		.pm = &atlas7_wdt_pm_ops,
		.of_match_table = atlas7_wdt_ids,
		},
		.probe = atlas7_wdt_probe,
		.remove = atlas7_wdt_remove,
		.shutdown = atlas7_wdt_shutdown,
		};
		module_platform_driver(atlas7_wdt_driver);

		MODULE_DESCRIPTION("CSRatlas7 watchdog driver");
		MODULE_AUTHOR("Guo Zeng <Guo.Zeng@csr.com>");
		MODULE_LICENSE("GPL v2");
		MODULE_ALIAS("platform:atlas7-wdt");