[v4,04/11] watchdog: add support for sl28cpld watchdog

Message ID	20200604211039.12689-5-michael@walle.cc (mailing list archive)
State	Not Applicable
Headers	show Return-Path: <SRS0=Agb6=7R=vger.kernel.org=linux-hwmon-owner@kernel.org> From: Michael Walle <michael@walle.cc> To: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-pwm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Linus Walleij <linus.walleij@linaro.org>, Bartosz Golaszewski <bgolaszewski@baylibre.com>, Rob Herring <robh+dt@kernel.org>, Jean Delvare <jdelvare@suse.com>, Guenter Roeck <linux@roeck-us.net>, Lee Jones <lee.jones@linaro.org>, Thierry Reding <thierry.reding@gmail.com>, =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>, Wim Van Sebroeck <wim@linux-watchdog.org>, Shawn Guo <shawnguo@kernel.org>, Li Yang <leoyang.li@nxp.com>, Thomas Gleixner <tglx@linutronix.de>, Jason Cooper <jason@lakedaemon.net>, Marc Zyngier <maz@kernel.org>, Mark Brown <broonie@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Michael Walle <michael@walle.cc> Subject: [PATCH v4 04/11] watchdog: add support for sl28cpld watchdog Date: Thu, 4 Jun 2020 23:10:32 +0200 Message-Id: <20200604211039.12689-5-michael@walle.cc> In-Reply-To: <20200604211039.12689-1-michael@walle.cc> References: <20200604211039.12689-1-michael@walle.cc> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk
Series	Add support for Kontron sl28cpld \| expand [v4,00/11] Add support for Kontron sl28cpld [v4,01/11] dt-bindings: mfd: Add bindings for sl28cpld [v4,02/11] mfd: Add support for Kontron sl28cpld management controller [v4,03/11] irqchip: add sl28cpld interrupt controller support [v4,04/11] watchdog: add support for sl28cpld watchdog [v4,05/11] pwm: add support for sl28cpld PWM controller [v4,06/11] gpio: add support for the sl28cpld GPIO controller [v4,07/11] hwmon: add support for the sl28cpld hardware monitoring controller [v4,08/11] arm64: dts: freescale: sl28: enable sl28cpld [v4,09/11] arm64: dts: freescale: sl28: map GPIOs to input events [v4,10/11] arm64: dts: freescale: sl28: enable LED support [v4,11/11] arm64: dts: freescale: sl28: enable fan support

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 55b910c453da..2c7b0f10151e 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -340,6 +340,17 @@ config MLX_WDT To compile this driver as a module, choose M here: the module will be called mlx-wdt. +config SL28CPLD_WATCHDOG + tristate "Kontron sl28 watchdog" + depends on MFD_SL28CPLD + select WATCHDOG_CORE + help + Say Y here to include support for the watchdog timer + on the Kontron sl28 CPLD. + + To compile this driver as a module, choose M here: the + module will be called sl28cpld_wdt. + # ALPHA Architecture # ARM Architecture diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 97bed1d3d97c..aa6e41126901 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -225,3 +225,4 @@ obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o obj-$(CONFIG_MENZ069_WATCHDOG) += menz69_wdt.o obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.o +obj-$(CONFIG_SL28CPLD_WATCHDOG) += sl28cpld_wdt.o diff --git a/drivers/watchdog/sl28cpld_wdt.c b/drivers/watchdog/sl28cpld_wdt.c new file mode 100644 index 000000000000..6c9518dc454a --- /dev/null +++ b/drivers/watchdog/sl28cpld_wdt.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sl28cpld watchdog driver. + * + * Copyright 2019 Kontron Europe GmbH + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/watchdog.h> + +/* + * Watchdog timer block registers. + */ +#define WDT_CTRL 0x00 +#define WDT_CTRL_EN BIT(0) +#define WDT_CTRL_LOCK BIT(2) +#define WDT_CTRL_ASSERT_SYS_RESET BIT(6) +#define WDT_CTRL_ASSERT_WDT_TIMEOUT BIT(7) +#define WDT_TIMEOUT 0x01 +#define WDT_KICK 0x02 +#define WDT_KICK_VALUE 0x6b +#define WDT_COUNT 0x03 + +#define WDT_DEFAULT_TIMEOUT 10 + +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 int timeout; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds"); + +struct sl28cpld_wdt { + struct watchdog_device wdd; + struct regmap *regmap; + u32 offset; + bool assert_wdt_timeout; +}; + +static int sl28cpld_wdt_ping(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_write(wdt->regmap, wdt->offset + WDT_KICK, + WDT_KICK_VALUE); +} + +static int sl28cpld_wdt_start(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + unsigned int val; + + val = WDT_CTRL_EN | WDT_CTRL_ASSERT_SYS_RESET; + if (wdt->assert_wdt_timeout) + val |= WDT_CTRL_ASSERT_WDT_TIMEOUT; + if (nowayout) + val |= WDT_CTRL_LOCK; + + return regmap_update_bits(wdt->regmap, wdt->offset + WDT_CTRL, + val, val); +} + +static int sl28cpld_wdt_stop(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->regmap, wdt->offset + WDT_CTRL, + WDT_CTRL_EN, 0); +} + +static unsigned int sl28cpld_wdt_get_timeleft(struct watchdog_device *wdd) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + unsigned int val; + int ret; + + ret = regmap_read(wdt->regmap, wdt->offset + WDT_COUNT, &val); + + return (ret < 0) ? 0 : val; +} + +static int sl28cpld_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); + int ret; + + ret = regmap_write(wdt->regmap, wdt->offset + WDT_TIMEOUT, timeout); + if (!ret) + wdd->timeout = timeout; + + return ret; +} + +static const struct watchdog_info sl28cpld_wdt_info = { + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "sl28cpld watchdog", +}; + +static struct watchdog_ops sl28cpld_wdt_ops = { + .owner = THIS_MODULE, + .start = sl28cpld_wdt_start, + .stop = sl28cpld_wdt_stop, + .ping = sl28cpld_wdt_ping, + .set_timeout = sl28cpld_wdt_set_timeout, + .get_timeleft = sl28cpld_wdt_get_timeleft, +}; + +static int sl28cpld_wdt_probe(struct platform_device *pdev) +{ + struct watchdog_device *wdd; + struct sl28cpld_wdt *wdt; + unsigned int status; + unsigned int val; + int ret; + + if (!pdev->dev.parent) + return -ENODEV; + + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!wdt->regmap) + return -ENODEV; + + ret = device_property_read_u32(&pdev->dev, "reg", &wdt->offset); + if (ret) + return -EINVAL; + + wdt->assert_wdt_timeout = device_property_read_bool(&pdev->dev, + "kontron,assert-wdt-timeout-pin"); + + /* initialize struct watchdog_device */ + wdd = &wdt->wdd; + wdd->parent = &pdev->dev; + wdd->info = &sl28cpld_wdt_info; + wdd->ops = &sl28cpld_wdt_ops; + wdd->min_timeout = 1; + wdd->max_timeout = 255; + + watchdog_set_drvdata(wdd, wdt); + watchdog_stop_on_reboot(wdd); + + /* + * Read the status early, in case of an error, we haven't modified the + * hardware. + */ + ret = regmap_read(wdt->regmap, wdt->offset + WDT_CTRL, &status); + if (ret < 0) + return ret; + + /* + * Initial timeout value, may be overwritten by device tree or module + * parmeter in watchdog_init_timeout(). + * + * Reading a zero here means that either the hardware has a default + * value of zero (which is very unlikely and definitely a hardware + * bug) or the bootloader set it to zero. In any case, we handle + * this case gracefully and set out own timeout. + */ + ret = regmap_read(wdt->regmap, wdt->offset + WDT_TIMEOUT, &val); + if (ret < 0) + return ret; + + if (val) + wdd->timeout = val; + else + wdd->timeout = WDT_DEFAULT_TIMEOUT; + + watchdog_init_timeout(wdd, timeout, &pdev->dev); + sl28cpld_wdt_set_timeout(wdd, wdd->timeout); + + /* if the watchdog is locked, we set nowayout */ + if (status & WDT_CTRL_LOCK) + nowayout = true; + watchdog_set_nowayout(wdd, nowayout); + + /* + * If watchdog is already running, keep it enabled, but make + * sure its mode is set correctly. + */ + if (status & WDT_CTRL_EN) { + sl28cpld_wdt_start(wdd); + set_bit(WDOG_HW_RUNNING, &wdd->status); + } + + ret = devm_watchdog_register_device(&pdev->dev, wdd); + if (ret < 0) { + dev_err(&pdev->dev, "failed to register watchdog device\n"); + return ret; + } + + dev_info(&pdev->dev, "initial timeout %d sec%s\n", + wdd->timeout, nowayout ? ", nowayout" : ""); + + return 0; +} + +static const struct of_device_id sl28cpld_wdt_of_match[] = { + { .compatible = "kontron,sl28cpld-wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(of, sl28cpld_wdt_of_match); + +static const struct platform_device_id sl28cpld_wdt_id_table[] = { + { "sl28cpld-wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(platform, sl28cpld_wdt_id_table); + +static struct platform_driver sl28cpld_wdt_driver = { + .probe = sl28cpld_wdt_probe, + .id_table = sl28cpld_wdt_id_table, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = sl28cpld_wdt_of_match, + }, +}; +module_platform_driver(sl28cpld_wdt_driver); + +MODULE_DESCRIPTION("sl28cpld Watchdog Driver"); +MODULE_AUTHOR("Michael Walle <michael@walle.cc>"); +MODULE_LICENSE("GPL");

[v4,04/11] watchdog: add support for sl28cpld watchdog

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