diff options
| -rw-r--r-- | drivers/watchdog/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/qcom-wdt.c | 186 |
3 files changed, 200 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 786f8c8338fb..17b39b8a2520 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -461,6 +461,19 @@ config TEGRA_WATCHDOG To compile this driver as a module, choose M here: the module will be called tegra_wdt. +config QCOM_WDT + tristate "QCOM watchdog" + depends on HAS_IOMEM + depends on ARCH_QCOM + select WATCHDOG_CORE + help + Say Y here to include Watchdog timer support for the watchdog found + on QCOM chipsets. Currently supported targets are the MSM8960, + APQ8064, and IPQ8064. + + To compile this driver as a module, choose M here: the + module will be called qcom_wdt. + # AVR32 Architecture config AT32AP700X_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 82af9956f96a..44f5d6842fc6 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -58,6 +58,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o +obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o diff --git a/drivers/watchdog/qcom-wdt.c b/drivers/watchdog/qcom-wdt.c new file mode 100644 index 000000000000..68db322341bc --- /dev/null +++ b/drivers/watchdog/qcom-wdt.c @@ -0,0 +1,186 @@ +/* Copyright (c) 2014, The Linux Foundation. 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 and + * only 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/clk.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> + +#define WDT_RST 0x0 +#define WDT_EN 0x8 +#define WDT_BITE_TIME 0x24 + +struct qcom_wdt { + struct watchdog_device wdd; + struct clk *clk; + unsigned long rate; + void __iomem *base; +}; + +static inline +struct qcom_wdt *to_qcom_wdt(struct watchdog_device *wdd) +{ + return container_of(wdd, struct qcom_wdt, wdd); +} + +static int qcom_wdt_start(struct watchdog_device *wdd) +{ + struct qcom_wdt *wdt = to_qcom_wdt(wdd); + + writel(0, wdt->base + WDT_EN); + writel(1, wdt->base + WDT_RST); + writel(wdd->timeout * wdt->rate, wdt->base + WDT_BITE_TIME); + writel(1, wdt->base + WDT_EN); + return 0; +} + +static int qcom_wdt_stop(struct watchdog_device *wdd) +{ + struct qcom_wdt *wdt = to_qcom_wdt(wdd); + + writel(0, wdt->base + WDT_EN); + return 0; +} + +static int qcom_wdt_ping(struct watchdog_device *wdd) +{ + struct qcom_wdt *wdt = to_qcom_wdt(wdd); + + writel(1, wdt->base + WDT_RST); + return 0; +} + +static int qcom_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + wdd->timeout = timeout; + return qcom_wdt_start(wdd); +} + +static const struct watchdog_ops qcom_wdt_ops = { + .start = qcom_wdt_start, + .stop = qcom_wdt_stop, + .ping = qcom_wdt_ping, + .set_timeout = qcom_wdt_set_timeout, + .owner = THIS_MODULE, +}; + +static const struct watchdog_info qcom_wdt_info = { + .options = WDIOF_KEEPALIVEPING + | WDIOF_MAGICCLOSE + | WDIOF_SETTIMEOUT, + .identity = KBUILD_MODNAME, +}; + +static int qcom_wdt_probe(struct platform_device *pdev) +{ + struct qcom_wdt *wdt; + struct resource *res; + 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); + + wdt->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(wdt->clk)) { + dev_err(&pdev->dev, "failed to get input clock\n"); + return PTR_ERR(wdt->clk); + } + + ret = clk_prepare_enable(wdt->clk); + if (ret) { + dev_err(&pdev->dev, "failed to setup clock\n"); + return ret; + } + + /* + * We use the clock rate to calculate the max timeout, so ensure it's + * not zero to avoid a divide-by-zero exception. + * + * WATCHDOG_CORE assumes units of seconds, if the WDT is clocked such + * that it would bite before a second elapses it's usefulness is + * limited. Bail if this is the case. + */ + wdt->rate = clk_get_rate(wdt->clk); + if (wdt->rate == 0 || + wdt->rate > 0x10000000U) { + dev_err(&pdev->dev, "invalid clock rate\n"); + ret = -EINVAL; + goto err_clk_unprepare; + } + + wdt->wdd.dev = &pdev->dev; + wdt->wdd.info = &qcom_wdt_info; + wdt->wdd.ops = &qcom_wdt_ops; + wdt->wdd.min_timeout = 1; + wdt->wdd.max_timeout = 0x10000000U / wdt->rate; + + /* + * If 'timeout-sec' unspecified in devicetree, assume a 30 second + * default, unless the max timeout is less than 30 seconds, then use + * the max instead. + */ + wdt->wdd.timeout = min(wdt->wdd.max_timeout, 30U); + watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev); + + ret = watchdog_register_device(&wdt->wdd); + if (ret) { + dev_err(&pdev->dev, "failed to register watchdog\n"); + goto err_clk_unprepare; + } + + platform_set_drvdata(pdev, wdt); + return 0; + +err_clk_unprepare: + clk_disable_unprepare(wdt->clk); + return ret; +} + +static int qcom_wdt_remove(struct platform_device *pdev) +{ + struct qcom_wdt *wdt = platform_get_drvdata(pdev); + + watchdog_unregister_device(&wdt->wdd); + clk_disable_unprepare(wdt->clk); + return 0; +} + +static const struct of_device_id qcom_wdt_of_table[] = { + { .compatible = "qcom,kpss-wdt-msm8960", }, + { .compatible = "qcom,kpss-wdt-apq8064", }, + { .compatible = "qcom,kpss-wdt-ipq8064", }, + { }, +}; +MODULE_DEVICE_TABLE(of, qcom_wdt_of_table); + +static struct platform_driver qcom_watchdog_driver = { + .probe = qcom_wdt_probe, + .remove = qcom_wdt_remove, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = qcom_wdt_of_table, + }, +}; +module_platform_driver(qcom_watchdog_driver); + +MODULE_DESCRIPTION("QCOM KPSS Watchdog Driver"); +MODULE_LICENSE("GPL v2"); |