From dca536c433a20f916451d8318f4aa7158c0d811c Mon Sep 17 00:00:00 2001 From: Mans Rullgard Date: Thu, 19 Nov 2015 22:09:05 +0000 Subject: [PATCH] watchdog: add support for Sigma Designs SMP86xx/SMP87xx This adds support for the Sigma Designs SMP86xx/SMP87xx family built-in watchdog. Signed-off-by: Mans Rullgard Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/Kconfig | 10 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/tangox_wdt.c | 225 ++++++++++++++++++++++++++++++++++ 3 files changed, 236 insertions(+) create mode 100644 drivers/watchdog/tangox_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index ba2bf0ea2cf2..afb7f91795cb 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -142,6 +142,16 @@ config MENF21BMC_WATCHDOG This driver can also be built as a module. If so the module will be called menf21bmc_wdt. +config TANGOX_WATCHDOG + tristate "Sigma Designs SMP86xx/SMP87xx watchdog" + select WATCHDOG_CORE + depends on ARCH_TANGOX || COMPILE_TEST + help + Support for the watchdog in Sigma Designs SMP86xx (tango3) + and SMP87xx (tango4) family chips. + + This driver can be built as a module. The module name is tangox_wdt. + config WM831X_WATCHDOG tristate "WM831x watchdog" depends on MFD_WM831X diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 62b7fdb0a2ab..2d203fc3cfdb 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -190,6 +190,7 @@ obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o obj-$(CONFIG_GPIO_WATCHDOG) += gpio_wdt.o +obj-$(CONFIG_TANGOX_WATCHDOG) += tangox_wdt.o obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c new file mode 100644 index 000000000000..b9ee6246e7c2 --- /dev/null +++ b/drivers/watchdog/tangox_wdt.c @@ -0,0 +1,225 @@ +/* + * Copyright (C) 2015 Mans Rullgard + * SMP86xx/SMP87xx Watchdog driver + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DEFAULT_TIMEOUT 30 + +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) ")"); + +static unsigned int timeout; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout"); + +/* + * Counter counts down from programmed value. Reset asserts when + * the counter reaches 1. + */ +#define WD_COUNTER 0 + +#define WD_CONFIG 4 +#define WD_CONFIG_XTAL_IN BIT(0) +#define WD_CONFIG_DISABLE BIT(31) + +struct tangox_wdt_device { + struct watchdog_device wdt; + void __iomem *base; + unsigned long clk_rate; + struct clk *clk; + struct notifier_block restart; +}; + +static int tangox_wdt_set_timeout(struct watchdog_device *wdt, + unsigned int new_timeout) +{ + wdt->timeout = new_timeout; + + return 0; +} + +static int tangox_wdt_start(struct watchdog_device *wdt) +{ + struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt); + u32 ticks; + + ticks = 1 + wdt->timeout * dev->clk_rate; + writel(ticks, dev->base + WD_COUNTER); + + return 0; +} + +static int tangox_wdt_stop(struct watchdog_device *wdt) +{ + struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt); + + writel(0, dev->base + WD_COUNTER); + + return 0; +} + +static unsigned int tangox_wdt_get_timeleft(struct watchdog_device *wdt) +{ + struct tangox_wdt_device *dev = watchdog_get_drvdata(wdt); + u32 count; + + count = readl(dev->base + WD_COUNTER); + + if (!count) + return 0; + + return (count - 1) / dev->clk_rate; +} + +static const struct watchdog_info tangox_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "tangox watchdog", +}; + +static const struct watchdog_ops tangox_wdt_ops = { + .start = tangox_wdt_start, + .stop = tangox_wdt_stop, + .set_timeout = tangox_wdt_set_timeout, + .get_timeleft = tangox_wdt_get_timeleft, +}; + +static int tangox_wdt_restart(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct tangox_wdt_device *dev = + container_of(nb, struct tangox_wdt_device, restart); + + writel(1, dev->base + WD_COUNTER); + + return NOTIFY_DONE; +} + +static int tangox_wdt_probe(struct platform_device *pdev) +{ + struct tangox_wdt_device *dev; + struct resource *res; + u32 config; + int err; + + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dev->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dev->base)) + return PTR_ERR(dev->base); + + dev->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + + err = clk_prepare_enable(dev->clk); + if (err) + return err; + + dev->clk_rate = clk_get_rate(dev->clk); + + dev->wdt.parent = &pdev->dev; + dev->wdt.info = &tangox_wdt_info; + dev->wdt.ops = &tangox_wdt_ops; + dev->wdt.timeout = DEFAULT_TIMEOUT; + dev->wdt.min_timeout = 1; + dev->wdt.max_timeout = (U32_MAX - 1) / dev->clk_rate; + + watchdog_init_timeout(&dev->wdt, timeout, &pdev->dev); + watchdog_set_nowayout(&dev->wdt, nowayout); + watchdog_set_drvdata(&dev->wdt, dev); + + /* + * Deactivate counter if disable bit is set to avoid + * accidental reset. + */ + config = readl(dev->base + WD_CONFIG); + if (config & WD_CONFIG_DISABLE) + writel(0, dev->base + WD_COUNTER); + + writel(WD_CONFIG_XTAL_IN, dev->base + WD_CONFIG); + + /* + * Mark as active and restart with configured timeout if + * already running. + */ + if (readl(dev->base + WD_COUNTER)) { + set_bit(WDOG_ACTIVE, &dev->wdt.status); + tangox_wdt_start(&dev->wdt); + } + + err = watchdog_register_device(&dev->wdt); + if (err) { + clk_disable_unprepare(dev->clk); + return err; + } + + platform_set_drvdata(pdev, dev); + + dev->restart.notifier_call = tangox_wdt_restart; + dev->restart.priority = 128; + err = register_restart_handler(&dev->restart); + if (err) + dev_warn(&pdev->dev, "failed to register restart handler\n"); + + dev_info(dev->wdt.dev, "SMP86xx/SMP87xx watchdog registered\n"); + + return 0; +} + +static int tangox_wdt_remove(struct platform_device *pdev) +{ + struct tangox_wdt_device *dev = platform_get_drvdata(pdev); + + tangox_wdt_stop(&dev->wdt); + clk_disable_unprepare(dev->clk); + + unregister_restart_handler(&dev->restart); + watchdog_unregister_device(&dev->wdt); + + return 0; +} + +static const struct of_device_id tangox_wdt_dt_ids[] = { + { .compatible = "sigma,smp8642-wdt" }, + { .compatible = "sigma,smp8759-wdt" }, + { } +}; +MODULE_DEVICE_TABLE(of, tangox_wdt_dt_ids); + +static struct platform_driver tangox_wdt_driver = { + .probe = tangox_wdt_probe, + .remove = tangox_wdt_remove, + .driver = { + .name = "tangox-wdt", + .of_match_table = tangox_wdt_dt_ids, + }, +}; + +module_platform_driver(tangox_wdt_driver); + +MODULE_AUTHOR("Mans Rullgard "); +MODULE_DESCRIPTION("SMP86xx/SMP87xx Watchdog driver"); +MODULE_LICENSE("GPL"); -- 2.20.1