From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@roeck-us.net (Guenter Roeck) Date: Tue, 7 Oct 2014 10:23:22 -0700 Subject: [PATCH 4/4] watchdog: st_wdt: Add new driver for ST's LPC Watchdog In-Reply-To: <1412692572-14031-5-git-send-email-lee.jones@linaro.org> References: <1412692572-14031-1-git-send-email-lee.jones@linaro.org> <1412692572-14031-5-git-send-email-lee.jones@linaro.org> Message-ID: <20141007172322.GA28047@roeck-us.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Oct 07, 2014 at 03:36:12PM +0100, Lee Jones wrote: > Signed-off-by: David Paris > Signed-off-by: Lee Jones > --- > drivers/watchdog/Kconfig | 16 +++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/st_wdt.c | 325 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 342 insertions(+) > create mode 100644 drivers/watchdog/st_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index f57312f..c8abf57 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -432,6 +432,22 @@ config SIRFSOC_WATCHDOG > Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When > the watchdog triggers the system will be reset. > > +config ST_WATCHDOG > + tristate "STMicroelectronics LPC Watchdog" > + depends on ARCH_STI && OF > + depends on !RTC_DRV_ST_LPC > + select WATCHDOG_CORE > + help > + Say Y here to include Watchdog timer support for the watchdog > + existing in the LPC of STMicroelectronics SOCs. > + !!! BE CARREFUL !!! > + This driver shares hardware resources with RTC Alarm part of the > + LPC. Both LPC Watchdog driver and LPC RTC driver cannot be > + used together. > + > + To compile this driver as a module, choose M here: the > + module will be called st-wdt. > + > config TEGRA_WATCHDOG > tristate "Tegra watchdog" > depends on ARCH_TEGRA || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 468c320..eb19937 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -57,6 +57,7 @@ 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-$(CONFIG_ST_WATCHDOG) += st_wdt.o > obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o > obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o > > diff --git a/drivers/watchdog/st_wdt.c b/drivers/watchdog/st_wdt.c > new file mode 100644 > index 0000000..97ead2b > --- /dev/null > +++ b/drivers/watchdog/st_wdt.c > @@ -0,0 +1,325 @@ > +/* > + * st-wdt.c -- ST's LPC Watchdog > + * > + * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved > + * > + * Author: David Paris for STMicroelectronics > + * Contributor: Lee Jones for STMicroelectronics > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public Licence > + * as published by the Free Software Foundation; either version > + * 2 of the Licence, or (at your option) any later version. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* Low Power Alarm */ > +#define LPC_LPA_LSB_OFF 0x410 > +#define LPC_LPA_START_OFF 0x418 > + > +/* LPC as WDT */ > +#define LPC_WDT_OFF 0x510 > + > +#define WATCHDOG_MIN 1 > +#define WATCHDOG_MAX32 4294967 /* 32bit resolution */ > + > +#define WDT_ENABLE 1 > +#define WDT_DISABLE 0 Used as bool, so maybe should be true / false (though I am not sure if those defines are really needed) > + > +struct st_wdog_syscfg { > + struct regmap *regmap; > + unsigned int type_reg; > + unsigned int type_mask; > + unsigned int enable_reg; > + unsigned int enable_mask; > +}; > + > +struct st_wdog { > + void __iomem *base; > + struct device *dev; > + struct st_wdog_syscfg *syscfg; > + struct clk *clk; > + int warm_reset; > +}; > + > +static struct st_wdog_syscfg stid127_syscfg = { > + .type_mask = BIT(2), > + .enable_mask = BIT(2), > +}; > + > +static struct st_wdog_syscfg stih415_syscfg = { > + .type_mask = BIT(6), > + .enable_mask = BIT(7), > +}; > + > +static struct st_wdog_syscfg stih416_syscfg = { > + .type_mask = BIT(6), > + .enable_mask = BIT(7), > +}; > + > +static struct st_wdog_syscfg stih407_syscfg = { > + .enable_mask = BIT(19), > +}; > + > +static struct of_device_id st_wdog_match[] = { > + { > + .compatible = "st,stih407-watchdog", > + .data = (void *)&stih407_syscfg, > + }, > + { > + .compatible = "st,stih416-watchdog", > + .data = (void *)&stih416_syscfg, > + }, > + { > + .compatible = "st,stih415-watchdog", > + .data = (void *)&stih415_syscfg, > + }, > + { > + .compatible = "st,stid127-watchdog", > + .data = (void *)&stid127_syscfg, > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, st_wdog_match); > + > +static void st_wdog_setup(struct st_wdog *st_wdog, bool enable) > +{ > + /* Type of watchdog reset - 0: Cold 1: Warm */ > + if (st_wdog->syscfg->type_reg) > + regmap_update_bits(st_wdog->syscfg->regmap, > + st_wdog->syscfg->type_reg, > + st_wdog->syscfg->type_mask, > + st_wdog->warm_reset); > + > + /* Mask/unmask watchdog reset */ > + regmap_update_bits(st_wdog->syscfg->regmap, > + st_wdog->syscfg->enable_reg, > + st_wdog->syscfg->enable_mask, > + enable ? 0 : st_wdog->syscfg->enable_mask); > +} > + > +static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout) > +{ > + unsigned long clkrate = clk_get_rate(st_wdog->clk); > + int maxtimeout = 0xFFFFFFFF / clkrate; > + > + if (timeout > maxtimeout) { > + dev_warn(st_wdog->dev, > + "timer overrun detected at current freq (%dHz)\n" > + "wdog timeout set for %ds instead of requested %ds", > + clkrate, maxtimeout, timeout); > + timeout = maxtimeout; > + } > + timeout *= clkrate; > + > + writel_relaxed(timeout, st_wdog->base + LPC_LPA_LSB_OFF); > + writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF); > +} > + > +static int st_wdog_start(struct watchdog_device *wdd) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + writel_relaxed(1, st_wdog->base + LPC_WDT_OFF); > + > + return 0; > +} > + > +static int st_wdog_stop(struct watchdog_device *wdd) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + writel_relaxed(0, st_wdog->base + LPC_WDT_OFF); > + > + return 0; > +} > + > +static int st_wdog_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + wdd->timeout = timeout; > + st_wdog_load_timer(st_wdog, timeout); > + > + return 0; > +} > + > +static int st_wdog_keepalive(struct watchdog_device *wdd) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + st_wdog_load_timer(st_wdog, wdd->timeout); > + > + return 0; > +} > + > +static const struct watchdog_info st_wdog_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, > + .identity = "ST LPC WDT", > +}; > + > +static const struct watchdog_ops st_wdog_ops = { > + .owner = THIS_MODULE, > + .start = st_wdog_start, > + .stop = st_wdog_stop, > + .ping = st_wdog_keepalive, > + .set_timeout = st_wdog_set_timeout, > +}; > + > +static struct watchdog_device st_wdog_dev = { > + .info = &st_wdog_info, > + .ops = &st_wdog_ops, > + .min_timeout = WATCHDOG_MIN, > + .max_timeout = WATCHDOG_MAX32, > +}; > + > +static int st_wdog_probe(struct platform_device *pdev) > +{ > + const struct of_device_id *match; > + struct device_node *np = pdev->dev.of_node; > + struct st_wdog *st_wdog; > + struct regmap *regmap; > + struct resource *res; > + struct clk *clk; > + void __iomem *base; > + int ret; > + > + st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL); > + if (!st_wdog) > + return -ENOMEM; > + > + match = of_match_device(st_wdog_match, &pdev->dev); > + if (!match) { > + dev_err(&pdev->dev, "Couldn't match device\n"); > + return -ENODEV; > + } > + st_wdog->syscfg = (struct st_wdog_syscfg *)match->data; > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "base"); > + base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(base)) { > + dev_err(&pdev->dev, "Failed to ioremap base\n"); > + return PTR_ERR(base); > + } > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-en"); > + if (!res) { > + dev_err(&pdev->dev, "Failed to get enable register address\n"); > + return -EINVAL; > + } > + st_wdog->syscfg->enable_reg = res->start; > + > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "syscfg-type"); > + if (res) > + st_wdog->syscfg->type_reg = res->start; > + > + regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); > + if (IS_ERR(regmap)) { > + dev_err(&pdev->dev, "No syscfg phandle specified\n"); > + return PTR_ERR(regmap); > + } > + > + clk = of_clk_get_by_name(np, "st_wdog"); > + if (IS_ERR(clk)) { > + dev_err(&pdev->dev, "Unable to request clock\n"); > + return PTR_ERR(clk); > + } > + clk_prepare_enable(st_wdog->clk); > + > + st_wdog->dev = &pdev->dev; > + st_wdog->base = base; > + st_wdog->clk = clk; > + st_wdog->warm_reset = of_property_read_bool(np, "st,warm_reset"); > + st_wdog->syscfg->regmap = regmap; > + > + watchdog_set_drvdata(&st_wdog_dev, st_wdog); > + watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT); > + > + ret = watchdog_register_device(&st_wdog_dev); > + if (ret) { > + dev_err(&pdev->dev, "Unable to register watchdog\n"); > + clk_disable_unprepare(clk); > + return ret; > + } > + > + /* Init Watchdog timeout with value in DT */ > + ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev); > + if (ret) { > + dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n"); > + return ret; > + } You should make that call prior to calling watchdog_register_device, and clk_disable_unprepare is missing. > + > + st_wdog_setup(st_wdog, WDT_ENABLE); > + > + dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s", > + st_wdog->warm_reset ? "warm" : "cold"); > + > + return ret; > +} > + > +static int st_wdog_remove(struct platform_device *pdev) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); > + > + if (watchdog_active(&st_wdog_dev)) > + st_wdog_stop(&st_wdog_dev); > + I think this effectively defeats nowayout, since that is the only time where the function can return true at this point. Are you sure you want to do this here ? > + st_wdog_setup(st_wdog, WDT_DISABLE); > + > + watchdog_unregister_device(&st_wdog_dev); > + clk_disable_unprepare ? Thanks, Guenter > + return 0; > +} > + > +#ifdef CONFIG_PM > +static int st_wdog_suspend(struct device *dev) > +{ > + if (watchdog_active(&st_wdog_dev)) > + st_wdog_stop(&st_wdog_dev); > + > + return 0; > +} > + > +static int st_wdog_resume(struct device *dev) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); > + > + if (watchdog_active(&st_wdog_dev)) { > + st_wdog_load_timer(st_wdog, st_wdog_dev.timeout); > + st_wdog_start(&st_wdog_dev); > + } > + > + return 0; > +} > +#endif > + > +static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops, > + st_wdog_suspend, > + st_wdog_resume); > + > +static struct platform_driver st_wdog_driver = { > + .driver = { > + .name = "st-wdt", > + .pm = &st_wdog_pm_ops, > + .of_match_table = st_wdog_match, > + }, > + .probe = st_wdog_probe, > + .remove = st_wdog_remove, > +}; > +module_platform_driver(st_wdog_driver); > + > +MODULE_AUTHOR("David PARIS "); > +MODULE_DESCRIPTION("ST LPC Watchdog Driver"); > +MODULE_LICENSE("GPL v2"); > -- > 1.9.1 >