| Message ID | 1374053091-5907-1-git-send-email-jonas.jensen@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 17, 2013 at 11:24:51AM +0200, Jonas Jensen wrote: > Add watchdog driver for MOXA ART SoCs. > > Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com> > --- > > Notes: > Changes since v2: > > 1. add devicetree bindings document > > Applies to next-20130716 > > .../bindings/watchdog/moxa,moxart-watchdog.txt | 15 ++ > drivers/watchdog/Kconfig | 10 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/moxart_wdt.c | 171 +++++++++++++++++++++ > 4 files changed, 197 insertions(+) > create mode 100644 Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt > create mode 100644 drivers/watchdog/moxart_wdt.c > > diff --git a/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt b/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt > new file mode 100644 > index 0000000..fb99e50 > --- /dev/null > +++ b/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt > @@ -0,0 +1,15 @@ > +MOXA ART Watchdog timer > + > +Required properties: > + > +- compatible : Should be "moxa,moxart-watchdog" > +- reg : Should contain registers location and length > +- clocks : Should contain phandle for APB clock "clkapb" > + > +Example: > + > + watchdog: watchdog@98500000 { > + compatible = "moxa,moxart-watchdog"; > + reg = <0x98500000 0x10>; > + clocks = <&clkapb>; > + }; > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 362085d..6883aab 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -382,6 +382,16 @@ config RETU_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called retu_wdt. > > +config MOXART_WDT > + tristate "MOXART watchdog" > + depends on ARCH_MOXART > + help > + Say Y here to include Watchdog timer support for the watchdog > + existing on the MOXA ART SoC series platforms. > + > + To compile this driver as a module, choose M here: the > + module will be called moxart_wdt. > + > # AVR32 Architecture > > config AT32AP700X_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 2f26a0b..7cab53a 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -54,6 +54,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o > obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o > obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o > obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o > +obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/moxart_wdt.c b/drivers/watchdog/moxart_wdt.c > new file mode 100644 > index 0000000..966855d > --- /dev/null > +++ b/drivers/watchdog/moxart_wdt.c > @@ -0,0 +1,171 @@ > +/* > + * MOXA ART SoCs watchdog driver. > + * > + * Copyright (C) 2013 Jonas Jensen > + * > + * Jonas Jensen <jonas.jensen@gmail.com> > + * > + * This file is licensed under the terms of the GNU General Public > + * License version 2. This program is licensed "as is" without any > + * warranty of any kind, whether express or implied. > + */ > + > +#include <linux/clk.h> > +#include <linux/err.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/moduleparam.h> > +#include <linux/of.h> > +#include <linux/of_address.h> Do you need the above two includes ? > +#include <linux/platform_device.h> > +#include <linux/types.h> > +#include <linux/watchdog.h> > + > +#include <asm/system_misc.h> > + > +#define REG_COUNT 0x4 > +#define REG_MODE 0x8 > +#define REG_ENABLE 0xC > + > +struct moxart_wdt_dev { > + struct watchdog_device wdt_dev; > + void __iomem *wdt_base; > +}; > + > +static struct moxart_wdt_dev *moxart_wdt; I don't think this variable is really needed as static variable; you should be able to use platform_get_drvdata() to get it whereever needed. In fact, you sometimes use the static variable and sometimes a local variable with the same name. I find this confusing. > +static bool nowayout = WATCHDOG_NOWAYOUT; Only used in probe function and should be declared there. > +static int heartbeat; > +static unsigned int clock_frequency; Curious - why did you declare this variable as static variable, but wdt_base is part of moxart_wdt_dev. > +static unsigned int max_timeout; This variable is only used in the probe function and should thus be declared there. > +static int moxart_wdt_stop(struct watchdog_device *wdt_dev) > +{ > + struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); > + void __iomem *wdt_base = moxart_wdt->wdt_base; > + > + writel(0, wdt_base + REG_ENABLE); > + > + return 0; > +} > + > +static int moxart_wdt_start(struct watchdog_device *wdt_dev) > +{ > + struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); > + void __iomem *wdt_base = moxart_wdt->wdt_base; > + > + writel(clock_frequency * moxart_wdt->wdt_dev.timeout, > + wdt_base + REG_COUNT); > + writel(0x5ab9, wdt_base + REG_MODE); > + writel(0x03, wdt_base + REG_ENABLE); > + > + return 0; > +} > + > +static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev, > + unsigned int timeout) > +{ > + dev_dbg(wdt_dev->dev, "%s: timeout=%u\n", __func__, timeout); > + > + moxart_wdt->wdt_dev.timeout = timeout; > + > + return 0; > +} > + > +static const struct watchdog_info moxart_wdt_info = { > + .identity = "moxart-wdt", > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | > + WDIOF_MAGICCLOSE, > +}; > + > +static const struct watchdog_ops moxart_wdt_ops = { > + .owner = THIS_MODULE, > + .start = moxart_wdt_start, > + .stop = moxart_wdt_stop, > + .set_timeout = moxart_wdt_set_timeout, > +}; > + > +static int moxart_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *node = dev->of_node; > + struct resource *res; > + struct clk *clk; > + int err; > + > + moxart_wdt = devm_kzalloc(&pdev->dev, sizeof(*moxart_wdt), GFP_KERNEL); > + if (!moxart_wdt) > + return -EINVAL; > + > + platform_set_drvdata(pdev, moxart_wdt); > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + moxart_wdt->wdt_base = devm_ioremap_resource(dev, res); > + if (IS_ERR(moxart_wdt->wdt_base)) > + return PTR_ERR(moxart_wdt->wdt_base); > + > + clk = of_clk_get(node, 0); > + if (IS_ERR(clk)) { > + pr_err("%s: of_clk_get failed\n", __func__); > + return PTR_ERR(clk); > + } > + > + clock_frequency = clk_get_rate(clk); Other callers of this function check the return value. Maybe the error can not happen here, but I am a bit concerned that the function may return 0, in which case you would have a problem with division by zero below. Is it guaranteed that this can never happen ? > + > + max_timeout = UINT_MAX / clock_frequency; > + > + moxart_wdt->wdt_dev.info = &moxart_wdt_info; > + moxart_wdt->wdt_dev.ops = &moxart_wdt_ops; > + moxart_wdt->wdt_dev.timeout = max_timeout; > + moxart_wdt->wdt_dev.min_timeout = 1; > + moxart_wdt->wdt_dev.max_timeout = max_timeout; > + moxart_wdt->wdt_dev.parent = &pdev->dev; > + > + watchdog_init_timeout(&moxart_wdt->wdt_dev, heartbeat, &pdev->dev); > + watchdog_set_nowayout(&moxart_wdt->wdt_dev, nowayout); > + > + watchdog_set_drvdata(&moxart_wdt->wdt_dev, moxart_wdt); > + > + err = watchdog_register_device(&moxart_wdt->wdt_dev); > + if (unlikely(err)) > + return err; > + > + dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n", > + moxart_wdt->wdt_dev.timeout, nowayout); > + > + return 0; > +} > + > +static int moxart_wdt_remove(struct platform_device *pdev) > +{ > + struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev); > + > + moxart_wdt_stop(&moxart_wdt->wdt_dev); > + watchdog_unregister_device(&moxart_wdt->wdt_dev); > + > + return 0; > +} > + > +static const struct of_device_id moxart_watchdog_match[] = { > + { .compatible = "moxa,moxart-watchdog" }, > + { }, > +}; > + > +static struct platform_driver moxart_wdt_driver = { > + .probe = moxart_wdt_probe, > + .remove = moxart_wdt_remove, > + .driver = { > + .name = "moxart-watchdog", > + .owner = THIS_MODULE, > + .of_match_table = moxart_watchdog_match, > + }, > +}; > +module_platform_driver(moxart_wdt_driver); > + > +module_param(heartbeat, int, 0); > +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds"); > + > +MODULE_DESCRIPTION("MOXART watchdog driver"); > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>"); > -- > 1.8.2.1 > >
diff --git a/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt b/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt new file mode 100644 index 0000000..fb99e50 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt @@ -0,0 +1,15 @@ +MOXA ART Watchdog timer + +Required properties: + +- compatible : Should be "moxa,moxart-watchdog" +- reg : Should contain registers location and length +- clocks : Should contain phandle for APB clock "clkapb" + +Example: + + watchdog: watchdog@98500000 { + compatible = "moxa,moxart-watchdog"; + reg = <0x98500000 0x10>; + clocks = <&clkapb>; + }; diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 362085d..6883aab 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -382,6 +382,16 @@ config RETU_WATCHDOG To compile this driver as a module, choose M here: the module will be called retu_wdt. +config MOXART_WDT + tristate "MOXART watchdog" + depends on ARCH_MOXART + help + Say Y here to include Watchdog timer support for the watchdog + existing on the MOXA ART SoC series platforms. + + To compile this driver as a module, choose M here: the + module will be called moxart_wdt. + # AVR32 Architecture config AT32AP700X_WDT diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2f26a0b..7cab53a 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -54,6 +54,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o +obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/moxart_wdt.c b/drivers/watchdog/moxart_wdt.c new file mode 100644 index 0000000..966855d --- /dev/null +++ b/drivers/watchdog/moxart_wdt.c @@ -0,0 +1,171 @@ +/* + * MOXA ART SoCs watchdog driver. + * + * Copyright (C) 2013 Jonas Jensen + * + * Jonas Jensen <jonas.jensen@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/types.h> +#include <linux/watchdog.h> + +#include <asm/system_misc.h> + +#define REG_COUNT 0x4 +#define REG_MODE 0x8 +#define REG_ENABLE 0xC + +struct moxart_wdt_dev { + struct watchdog_device wdt_dev; + void __iomem *wdt_base; +}; + +static struct moxart_wdt_dev *moxart_wdt; +static bool nowayout = WATCHDOG_NOWAYOUT; +static int heartbeat; +static unsigned int clock_frequency; +static unsigned int max_timeout; + +static int moxart_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); + void __iomem *wdt_base = moxart_wdt->wdt_base; + + writel(0, wdt_base + REG_ENABLE); + + return 0; +} + +static int moxart_wdt_start(struct watchdog_device *wdt_dev) +{ + struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); + void __iomem *wdt_base = moxart_wdt->wdt_base; + + writel(clock_frequency * moxart_wdt->wdt_dev.timeout, + wdt_base + REG_COUNT); + writel(0x5ab9, wdt_base + REG_MODE); + writel(0x03, wdt_base + REG_ENABLE); + + return 0; +} + +static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int timeout) +{ + dev_dbg(wdt_dev->dev, "%s: timeout=%u\n", __func__, timeout); + + moxart_wdt->wdt_dev.timeout = timeout; + + return 0; +} + +static const struct watchdog_info moxart_wdt_info = { + .identity = "moxart-wdt", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops moxart_wdt_ops = { + .owner = THIS_MODULE, + .start = moxart_wdt_start, + .stop = moxart_wdt_stop, + .set_timeout = moxart_wdt_set_timeout, +}; + +static int moxart_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *node = dev->of_node; + struct resource *res; + struct clk *clk; + int err; + + moxart_wdt = devm_kzalloc(&pdev->dev, sizeof(*moxart_wdt), GFP_KERNEL); + if (!moxart_wdt) + return -EINVAL; + + platform_set_drvdata(pdev, moxart_wdt); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + moxart_wdt->wdt_base = devm_ioremap_resource(dev, res); + if (IS_ERR(moxart_wdt->wdt_base)) + return PTR_ERR(moxart_wdt->wdt_base); + + clk = of_clk_get(node, 0); + if (IS_ERR(clk)) { + pr_err("%s: of_clk_get failed\n", __func__); + return PTR_ERR(clk); + } + + clock_frequency = clk_get_rate(clk); + + max_timeout = UINT_MAX / clock_frequency; + + moxart_wdt->wdt_dev.info = &moxart_wdt_info; + moxart_wdt->wdt_dev.ops = &moxart_wdt_ops; + moxart_wdt->wdt_dev.timeout = max_timeout; + moxart_wdt->wdt_dev.min_timeout = 1; + moxart_wdt->wdt_dev.max_timeout = max_timeout; + moxart_wdt->wdt_dev.parent = &pdev->dev; + + watchdog_init_timeout(&moxart_wdt->wdt_dev, heartbeat, &pdev->dev); + watchdog_set_nowayout(&moxart_wdt->wdt_dev, nowayout); + + watchdog_set_drvdata(&moxart_wdt->wdt_dev, moxart_wdt); + + err = watchdog_register_device(&moxart_wdt->wdt_dev); + if (unlikely(err)) + return err; + + dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n", + moxart_wdt->wdt_dev.timeout, nowayout); + + return 0; +} + +static int moxart_wdt_remove(struct platform_device *pdev) +{ + struct moxart_wdt_dev *moxart_wdt = platform_get_drvdata(pdev); + + moxart_wdt_stop(&moxart_wdt->wdt_dev); + watchdog_unregister_device(&moxart_wdt->wdt_dev); + + return 0; +} + +static const struct of_device_id moxart_watchdog_match[] = { + { .compatible = "moxa,moxart-watchdog" }, + { }, +}; + +static struct platform_driver moxart_wdt_driver = { + .probe = moxart_wdt_probe, + .remove = moxart_wdt_remove, + .driver = { + .name = "moxart-watchdog", + .owner = THIS_MODULE, + .of_match_table = moxart_watchdog_match, + }, +}; +module_platform_driver(moxart_wdt_driver); + +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds"); + +MODULE_DESCRIPTION("MOXART watchdog driver"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
Add watchdog driver for MOXA ART SoCs. Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com> --- Notes: Changes since v2: 1. add devicetree bindings document Applies to next-20130716 .../bindings/watchdog/moxa,moxart-watchdog.txt | 15 ++ drivers/watchdog/Kconfig | 10 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/moxart_wdt.c | 171 +++++++++++++++++++++ 4 files changed, 197 insertions(+) create mode 100644 Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt create mode 100644 drivers/watchdog/moxart_wdt.c