* [PATCH 0/2 v3 ] watchdog: driver for BCM7038 and newer chips. @ 2015-09-08 17:45 ` Justin Chen 0 siblings, 0 replies; 7+ messages in thread From: Justin Chen @ 2015-09-08 17:45 UTC (permalink / raw) To: linux-kernel Cc: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, justinpopo6, linux, devicetree, wim, linux-watchdog, bcm-kernel-feedback-list This driver is for a watchdog block contained in all Broadcom Set-top Box chips since BCM7038. BCM7038 was made public during the 2004 CES, and since then, many chips use this watchdog block including some cable modem chips. Changes since v2: Added clk_disable_unprepare if watchdog fails to register. Changes since v1: Removed clock-frequency because it brought unnecessary complexity to the driver. Renamed a few variables. Patch 1: watchdog device tree binding documentation Patch 2: watchdog driver Justin Chen (2): watchdog: bcm7038: add device tree binding documentation watchdog: Watchdog driver for Broadcom Set-Top Box .../bindings/watchdog/brcm,bcm7038-wdt.txt | 19 ++ drivers/watchdog/Kconfig | 8 + drivers/watchdog/Makefile | 1 + drivers/watchdog/bcm7038_wdt.c | 237 +++++++++++++++++++++ 4 files changed, 265 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt create mode 100644 drivers/watchdog/bcm7038_wdt.c -- 2.1.0 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 0/2 v3 ] watchdog: driver for BCM7038 and newer chips. @ 2015-09-08 17:45 ` Justin Chen 0 siblings, 0 replies; 7+ messages in thread From: Justin Chen @ 2015-09-08 17:45 UTC (permalink / raw) To: linux-kernel-u79uwXL29TY76Z2rM5mHXA Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A, pawel.moll-5wv7dgnIgG8, mark.rutland-5wv7dgnIgG8, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg, galak-sgV2jX0FEOL9JmXXK+q4OQ, justinpopo6-Re5JQEeQqe8AvxtiuMwx3w, linux-0h96xk9xTtrk1uMJSBkQmQ, devicetree-u79uwXL29TY76Z2rM5mHXA, wim-IQzOog9fTRqzQB+pC5nmwQ, linux-watchdog-u79uwXL29TY76Z2rM5mHXA, bcm-kernel-feedback-list-dY08KVG/lbp8UrSeD/g0lQ This driver is for a watchdog block contained in all Broadcom Set-top Box chips since BCM7038. BCM7038 was made public during the 2004 CES, and since then, many chips use this watchdog block including some cable modem chips. Changes since v2: Added clk_disable_unprepare if watchdog fails to register. Changes since v1: Removed clock-frequency because it brought unnecessary complexity to the driver. Renamed a few variables. Patch 1: watchdog device tree binding documentation Patch 2: watchdog driver Justin Chen (2): watchdog: bcm7038: add device tree binding documentation watchdog: Watchdog driver for Broadcom Set-Top Box .../bindings/watchdog/brcm,bcm7038-wdt.txt | 19 ++ drivers/watchdog/Kconfig | 8 + drivers/watchdog/Makefile | 1 + drivers/watchdog/bcm7038_wdt.c | 237 +++++++++++++++++++++ 4 files changed, 265 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt create mode 100644 drivers/watchdog/bcm7038_wdt.c -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/2 v3] watchdog: bcm7038: add device tree binding documentation @ 2015-09-08 17:45 ` Justin Chen 0 siblings, 0 replies; 7+ messages in thread From: Justin Chen @ 2015-09-08 17:45 UTC (permalink / raw) To: linux-kernel Cc: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, justinpopo6, linux, devicetree, wim, linux-watchdog, bcm-kernel-feedback-list Add device tree binding documentation for the watchdog hardware block on bcm7038 and newer SoCs. Signed-off-by: Justin Chen <justinpopo6@gmail.com> Acked-by: Guenter Roeck <linux@roeck-us.net> --- .../devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt diff --git a/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt new file mode 100644 index 0000000..39e5cf5 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt @@ -0,0 +1,19 @@ +BCM7038 Watchdog timer + +Required properties: + +- compatible : should be "brcm,bcm7038-wdt" +- reg : Specifies base physical address and size of the registers. + +Optional properties: + +- clocks: The clock running the watchdog. If no clock is found the + driver will default to 27000000 HZ. + +Example: + +watchdog { + compatible = "brcm,bcm7038-wdt"; + clocks = <&upg_fixed>; + reg = <0xf040a7e8 0x16>; +}; -- 2.1.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 1/2 v3] watchdog: bcm7038: add device tree binding documentation @ 2015-09-08 17:45 ` Justin Chen 0 siblings, 0 replies; 7+ messages in thread From: Justin Chen @ 2015-09-08 17:45 UTC (permalink / raw) To: linux-kernel-u79uwXL29TY76Z2rM5mHXA Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A, pawel.moll-5wv7dgnIgG8, mark.rutland-5wv7dgnIgG8, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg, galak-sgV2jX0FEOL9JmXXK+q4OQ, justinpopo6-Re5JQEeQqe8AvxtiuMwx3w, linux-0h96xk9xTtrk1uMJSBkQmQ, devicetree-u79uwXL29TY76Z2rM5mHXA, wim-IQzOog9fTRqzQB+pC5nmwQ, linux-watchdog-u79uwXL29TY76Z2rM5mHXA, bcm-kernel-feedback-list-dY08KVG/lbp8UrSeD/g0lQ Add device tree binding documentation for the watchdog hardware block on bcm7038 and newer SoCs. Signed-off-by: Justin Chen <justinpopo6-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Acked-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> --- .../devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt diff --git a/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt new file mode 100644 index 0000000..39e5cf5 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt @@ -0,0 +1,19 @@ +BCM7038 Watchdog timer + +Required properties: + +- compatible : should be "brcm,bcm7038-wdt" +- reg : Specifies base physical address and size of the registers. + +Optional properties: + +- clocks: The clock running the watchdog. If no clock is found the + driver will default to 27000000 HZ. + +Example: + +watchdog { + compatible = "brcm,bcm7038-wdt"; + clocks = <&upg_fixed>; + reg = <0xf040a7e8 0x16>; +}; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2 v3] watchdog: bcm7038: add device tree binding documentation 2015-09-08 17:45 ` Justin Chen (?) @ 2015-09-08 23:03 ` Rob Herring -1 siblings, 0 replies; 7+ messages in thread From: Rob Herring @ 2015-09-08 23:03 UTC (permalink / raw) To: Justin Chen, linux-kernel Cc: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, linux, devicetree, wim, linux-watchdog, bcm-kernel-feedback-list On 09/08/2015 12:45 PM, Justin Chen wrote: > Add device tree binding documentation for the watchdog hardware block > on bcm7038 and newer SoCs. > > Signed-off-by: Justin Chen <justinpopo6@gmail.com> > Acked-by: Guenter Roeck <linux@roeck-us.net> Some minor comments, otherwise: Acked-by: Rob Herring <robh@kernel.org> > --- > .../devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > create mode 100644 Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt > > diff --git a/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt > new file mode 100644 > index 0000000..39e5cf5 > --- /dev/null > +++ b/Documentation/devicetree/bindings/watchdog/brcm,bcm7038-wdt.txt > @@ -0,0 +1,19 @@ > +BCM7038 Watchdog timer > + > +Required properties: > + > +- compatible : should be "brcm,bcm7038-wdt" > +- reg : Specifies base physical address and size of the registers. > + > +Optional properties: > + > +- clocks: The clock running the watchdog. If no clock is found the > + driver will default to 27000000 HZ. s/HZ/Hz/ > + > +Example: > + > +watchdog { This should have a unit address (watchdog@f040a7e8). > + compatible = "brcm,bcm7038-wdt"; > + clocks = <&upg_fixed>; > + reg = <0xf040a7e8 0x16>; > +}; > ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 2/2 v3] watchdog: Watchdog driver for Broadcom Set-Top Box 2015-09-08 17:45 ` Justin Chen @ 2015-09-08 17:45 ` Justin Chen -1 siblings, 0 replies; 7+ messages in thread From: Justin Chen @ 2015-09-08 17:45 UTC (permalink / raw) To: linux-kernel Cc: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, justinpopo6, linux, devicetree, wim, linux-watchdog, bcm-kernel-feedback-list Watchdog driver for Broadcom 7038 and newer chips. Signed-off-by: Justin Chen <justinpopo6@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> --- drivers/watchdog/Kconfig | 8 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/bcm7038_wdt.c | 237 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 246 insertions(+) create mode 100644 drivers/watchdog/bcm7038_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 55c4b5b..b92222b 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1292,6 +1292,14 @@ config BCM_KONA_WDT_DEBUG If in doubt, say 'N'. +config BCM7038_WDT + tristate "BCM7038 Watchdog" + select WATCHDOG_CORE + help + Watchdog driver for the built-in hardware in Broadcom 7038 SoCs. + + Say 'Y or 'M' here to enable the driver. + config IMGPDC_WDT tristate "Imagination Technologies PDC Watchdog Timer" depends on HAS_IOMEM diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 59ea9a1..65d4169 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -66,6 +66,7 @@ obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o +obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/bcm7038_wdt.c b/drivers/watchdog/bcm7038_wdt.c new file mode 100644 index 0000000..4245b65 --- /dev/null +++ b/drivers/watchdog/bcm7038_wdt.c @@ -0,0 +1,237 @@ +/* + * Copyright (C) 2015 Broadcom Corporation + * + * 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. + * + * 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/init.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/watchdog.h> + +#define WDT_START_1 0xff00 +#define WDT_START_2 0x00ff +#define WDT_STOP_1 0xee00 +#define WDT_STOP_2 0x00ee + +#define WDT_TIMEOUT_REG 0x0 +#define WDT_CMD_REG 0x4 + +#define WDT_MIN_TIMEOUT 1 /* seconds */ +#define WDT_DEFAULT_TIMEOUT 30 /* seconds */ +#define WDT_DEFAULT_RATE 27000000 + +struct bcm7038_watchdog { + void __iomem *base; + struct watchdog_device wdd; + u32 rate; + struct clk *clk; +}; + +static bool nowayout = WATCHDOG_NOWAYOUT; + +static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + u32 timeout; + + timeout = wdt->rate * wdog->timeout; + + writel(timeout, wdt->base + WDT_TIMEOUT_REG); +} + +static int bcm7038_wdt_ping(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + + writel(WDT_START_1, wdt->base + WDT_CMD_REG); + writel(WDT_START_2, wdt->base + WDT_CMD_REG); + + return 0; +} + +static int bcm7038_wdt_start(struct watchdog_device *wdog) +{ + bcm7038_wdt_set_timeout_reg(wdog); + bcm7038_wdt_ping(wdog); + + return 0; +} + +static int bcm7038_wdt_stop(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + + writel(WDT_STOP_1, wdt->base + WDT_CMD_REG); + writel(WDT_STOP_2, wdt->base + WDT_CMD_REG); + + return 0; +} + +static int bcm7038_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int t) +{ + /* Can't modify timeout value if watchdog timer is running */ + bcm7038_wdt_stop(wdog); + wdog->timeout = t; + bcm7038_wdt_start(wdog); + + return 0; +} + +static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + u32 time_left; + + time_left = readl(wdt->base + WDT_CMD_REG); + + return time_left / wdt->rate; +} + +static struct watchdog_info bcm7038_wdt_info = { + .identity = "Broadcom BCM7038 Watchdog Timer", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE +}; + +static struct watchdog_ops bcm7038_wdt_ops = { + .owner = THIS_MODULE, + .start = bcm7038_wdt_start, + .stop = bcm7038_wdt_stop, + .set_timeout = bcm7038_wdt_set_timeout, + .get_timeleft = bcm7038_wdt_get_timeleft, +}; + +static int bcm7038_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bcm7038_watchdog *wdt; + struct resource *res; + int err; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + platform_set_drvdata(pdev, wdt); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + wdt->base = devm_ioremap_resource(dev, res); + if (IS_ERR(wdt->base)) + return PTR_ERR(wdt->base); + + wdt->clk = devm_clk_get(dev, NULL); + /* If unable to get clock, use default frequency */ + if (!IS_ERR(wdt->clk)) { + clk_prepare_enable(wdt->clk); + wdt->rate = clk_get_rate(wdt->clk); + /* Prevent divide-by-zero exception */ + if (!wdt->rate) + wdt->rate = WDT_DEFAULT_RATE; + } else { + wdt->rate = WDT_DEFAULT_RATE; + wdt->clk = NULL; + } + + wdt->wdd.info = &bcm7038_wdt_info; + wdt->wdd.ops = &bcm7038_wdt_ops; + wdt->wdd.min_timeout = WDT_MIN_TIMEOUT; + wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT; + wdt->wdd.max_timeout = 0xffffffff / wdt->rate; + wdt->wdd.parent = dev; + watchdog_set_drvdata(&wdt->wdd, wdt); + + err = watchdog_register_device(&wdt->wdd); + if (err) { + dev_err(dev, "Failed to register watchdog device\n"); + clk_disable_unprepare(wdt->clk); + return err; + } + + dev_info(dev, "Registered BCM7038 Watchdog\n"); + + return 0; +} + +static int bcm7038_wdt_remove(struct platform_device *pdev) +{ + struct bcm7038_watchdog *wdt = platform_get_drvdata(pdev); + + if (!nowayout) + bcm7038_wdt_stop(&wdt->wdd); + + watchdog_unregister_device(&wdt->wdd); + clk_disable_unprepare(wdt->clk); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int bcm7038_wdt_suspend(struct device *dev) +{ + struct bcm7038_watchdog *wdt = dev_get_drvdata(dev); + + if (watchdog_active(&wdt->wdd)) + return bcm7038_wdt_stop(&wdt->wdd); + + return 0; +} + +static int bcm7038_wdt_resume(struct device *dev) +{ + struct bcm7038_watchdog *wdt = dev_get_drvdata(dev); + + if (watchdog_active(&wdt->wdd)) + return bcm7038_wdt_start(&wdt->wdd); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(bcm7038_wdt_pm_ops, bcm7038_wdt_suspend, + bcm7038_wdt_resume); + +static void bcm7038_wdt_shutdown(struct platform_device *pdev) +{ + struct bcm7038_watchdog *wdt = platform_get_drvdata(pdev); + + if (watchdog_active(&wdt->wdd)) + bcm7038_wdt_stop(&wdt->wdd); +} + +static const struct of_device_id bcm7038_wdt_match[] = { + { .compatible = "brcm,bcm7038-wdt" }, + {}, +}; + +static struct platform_driver bcm7038_wdt_driver = { + .probe = bcm7038_wdt_probe, + .remove = bcm7038_wdt_remove, + .shutdown = bcm7038_wdt_shutdown, + .driver = { + .name = "bcm7038-wdt", + .of_match_table = bcm7038_wdt_match, + .pm = &bcm7038_wdt_pm_ops, + } +}; +module_platform_driver(bcm7038_wdt_driver); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Driver for Broadcom 7038 SoCs Watchdog"); +MODULE_AUTHOR("Justin Chen"); -- 2.1.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 2/2 v3] watchdog: Watchdog driver for Broadcom Set-Top Box @ 2015-09-08 17:45 ` Justin Chen 0 siblings, 0 replies; 7+ messages in thread From: Justin Chen @ 2015-09-08 17:45 UTC (permalink / raw) To: linux-kernel Cc: robh+dt, pawel.moll, mark.rutland, ijc+devicetree, galak, justinpopo6, linux, devicetree, wim, linux-watchdog, bcm-kernel-feedback-list Watchdog driver for Broadcom 7038 and newer chips. Signed-off-by: Justin Chen <justinpopo6@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> --- drivers/watchdog/Kconfig | 8 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/bcm7038_wdt.c | 237 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 246 insertions(+) create mode 100644 drivers/watchdog/bcm7038_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 55c4b5b..b92222b 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1292,6 +1292,14 @@ config BCM_KONA_WDT_DEBUG If in doubt, say 'N'. +config BCM7038_WDT + tristate "BCM7038 Watchdog" + select WATCHDOG_CORE + help + Watchdog driver for the built-in hardware in Broadcom 7038 SoCs. + + Say 'Y or 'M' here to enable the driver. + config IMGPDC_WDT tristate "Imagination Technologies PDC Watchdog Timer" depends on HAS_IOMEM diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 59ea9a1..65d4169 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -66,6 +66,7 @@ obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o obj-$(CONFIG_DIGICOLOR_WATCHDOG) += digicolor_wdt.o +obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/bcm7038_wdt.c b/drivers/watchdog/bcm7038_wdt.c new file mode 100644 index 0000000..4245b65 --- /dev/null +++ b/drivers/watchdog/bcm7038_wdt.c @@ -0,0 +1,237 @@ +/* + * Copyright (C) 2015 Broadcom Corporation + * + * 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. + * + * 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/init.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/watchdog.h> + +#define WDT_START_1 0xff00 +#define WDT_START_2 0x00ff +#define WDT_STOP_1 0xee00 +#define WDT_STOP_2 0x00ee + +#define WDT_TIMEOUT_REG 0x0 +#define WDT_CMD_REG 0x4 + +#define WDT_MIN_TIMEOUT 1 /* seconds */ +#define WDT_DEFAULT_TIMEOUT 30 /* seconds */ +#define WDT_DEFAULT_RATE 27000000 + +struct bcm7038_watchdog { + void __iomem *base; + struct watchdog_device wdd; + u32 rate; + struct clk *clk; +}; + +static bool nowayout = WATCHDOG_NOWAYOUT; + +static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + u32 timeout; + + timeout = wdt->rate * wdog->timeout; + + writel(timeout, wdt->base + WDT_TIMEOUT_REG); +} + +static int bcm7038_wdt_ping(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + + writel(WDT_START_1, wdt->base + WDT_CMD_REG); + writel(WDT_START_2, wdt->base + WDT_CMD_REG); + + return 0; +} + +static int bcm7038_wdt_start(struct watchdog_device *wdog) +{ + bcm7038_wdt_set_timeout_reg(wdog); + bcm7038_wdt_ping(wdog); + + return 0; +} + +static int bcm7038_wdt_stop(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + + writel(WDT_STOP_1, wdt->base + WDT_CMD_REG); + writel(WDT_STOP_2, wdt->base + WDT_CMD_REG); + + return 0; +} + +static int bcm7038_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int t) +{ + /* Can't modify timeout value if watchdog timer is running */ + bcm7038_wdt_stop(wdog); + wdog->timeout = t; + bcm7038_wdt_start(wdog); + + return 0; +} + +static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); + u32 time_left; + + time_left = readl(wdt->base + WDT_CMD_REG); + + return time_left / wdt->rate; +} + +static struct watchdog_info bcm7038_wdt_info = { + .identity = "Broadcom BCM7038 Watchdog Timer", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE +}; + +static struct watchdog_ops bcm7038_wdt_ops = { + .owner = THIS_MODULE, + .start = bcm7038_wdt_start, + .stop = bcm7038_wdt_stop, + .set_timeout = bcm7038_wdt_set_timeout, + .get_timeleft = bcm7038_wdt_get_timeleft, +}; + +static int bcm7038_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bcm7038_watchdog *wdt; + struct resource *res; + int err; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + platform_set_drvdata(pdev, wdt); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + wdt->base = devm_ioremap_resource(dev, res); + if (IS_ERR(wdt->base)) + return PTR_ERR(wdt->base); + + wdt->clk = devm_clk_get(dev, NULL); + /* If unable to get clock, use default frequency */ + if (!IS_ERR(wdt->clk)) { + clk_prepare_enable(wdt->clk); + wdt->rate = clk_get_rate(wdt->clk); + /* Prevent divide-by-zero exception */ + if (!wdt->rate) + wdt->rate = WDT_DEFAULT_RATE; + } else { + wdt->rate = WDT_DEFAULT_RATE; + wdt->clk = NULL; + } + + wdt->wdd.info = &bcm7038_wdt_info; + wdt->wdd.ops = &bcm7038_wdt_ops; + wdt->wdd.min_timeout = WDT_MIN_TIMEOUT; + wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT; + wdt->wdd.max_timeout = 0xffffffff / wdt->rate; + wdt->wdd.parent = dev; + watchdog_set_drvdata(&wdt->wdd, wdt); + + err = watchdog_register_device(&wdt->wdd); + if (err) { + dev_err(dev, "Failed to register watchdog device\n"); + clk_disable_unprepare(wdt->clk); + return err; + } + + dev_info(dev, "Registered BCM7038 Watchdog\n"); + + return 0; +} + +static int bcm7038_wdt_remove(struct platform_device *pdev) +{ + struct bcm7038_watchdog *wdt = platform_get_drvdata(pdev); + + if (!nowayout) + bcm7038_wdt_stop(&wdt->wdd); + + watchdog_unregister_device(&wdt->wdd); + clk_disable_unprepare(wdt->clk); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int bcm7038_wdt_suspend(struct device *dev) +{ + struct bcm7038_watchdog *wdt = dev_get_drvdata(dev); + + if (watchdog_active(&wdt->wdd)) + return bcm7038_wdt_stop(&wdt->wdd); + + return 0; +} + +static int bcm7038_wdt_resume(struct device *dev) +{ + struct bcm7038_watchdog *wdt = dev_get_drvdata(dev); + + if (watchdog_active(&wdt->wdd)) + return bcm7038_wdt_start(&wdt->wdd); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(bcm7038_wdt_pm_ops, bcm7038_wdt_suspend, + bcm7038_wdt_resume); + +static void bcm7038_wdt_shutdown(struct platform_device *pdev) +{ + struct bcm7038_watchdog *wdt = platform_get_drvdata(pdev); + + if (watchdog_active(&wdt->wdd)) + bcm7038_wdt_stop(&wdt->wdd); +} + +static const struct of_device_id bcm7038_wdt_match[] = { + { .compatible = "brcm,bcm7038-wdt" }, + {}, +}; + +static struct platform_driver bcm7038_wdt_driver = { + .probe = bcm7038_wdt_probe, + .remove = bcm7038_wdt_remove, + .shutdown = bcm7038_wdt_shutdown, + .driver = { + .name = "bcm7038-wdt", + .of_match_table = bcm7038_wdt_match, + .pm = &bcm7038_wdt_pm_ops, + } +}; +module_platform_driver(bcm7038_wdt_driver); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Driver for Broadcom 7038 SoCs Watchdog"); +MODULE_AUTHOR("Justin Chen"); -- 2.1.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
end of thread, other threads:[~2015-09-08 23:03 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-09-08 17:45 [PATCH 0/2 v3 ] watchdog: driver for BCM7038 and newer chips Justin Chen 2015-09-08 17:45 ` Justin Chen 2015-09-08 17:45 ` [PATCH 1/2 v3] watchdog: bcm7038: add device tree binding documentation Justin Chen 2015-09-08 17:45 ` Justin Chen 2015-09-08 23:03 ` Rob Herring 2015-09-08 17:45 ` [PATCH 2/2 v3] watchdog: Watchdog driver for Broadcom Set-Top Box Justin Chen 2015-09-08 17:45 ` Justin Chen
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