On Mon, Jul 29, 2013 at 01:33:48PM +0100, Jonas Jensen wrote: > Add watchdog driver for MOXA ART SoCs. > It would be nice to have a fuller description here. > Signed-off-by: Jonas Jensen <jonas.jensen@xxxxxxxxx> > --- > > Notes: > Changes since v6: > > 1. use local struct device *dev pointer, replace "&pdev->dev" with "dev" > > Applies to next-20130729 > > .../bindings/watchdog/moxa,moxart-watchdog.txt | 15 ++ > drivers/watchdog/Kconfig | 10 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/moxart_wdt.c | 165 +++++++++++++++++++++ > 4 files changed, 191 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..1169857 > --- /dev/null > +++ b/Documentation/devicetree/bindings/watchdog/moxa,moxart-watchdog.txt > @@ -0,0 +1,15 @@ > +MOXA ART Watchdog timer > + > +Required properties: > + > +- compatible : Must be "moxa,moxart-watchdog" > +- reg : Should contain registers location and length > +- clocks : Should contain phandle for the clock that drives the counter > + > +Example: > + > + watchdog: watchdog@98500000 { > + compatible = "moxa,moxart-watchdog"; > + reg = <0x98500000 0x10>; > + clocks = <&coreclk>; > + }; This seems sensible to me. I assume the watchdog is a standalone unit, and not part of some larger piece of IP? > 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..48dc334 > --- /dev/null > +++ b/drivers/watchdog/moxart_wdt.c > @@ -0,0 +1,165 @@ > +/* > + * MOXA ART SoCs watchdog driver. > + * > + * Copyright (C) 2013 Jonas Jensen > + * > + * Jonas Jensen <jonas.jensen@xxxxxxxxx> > + * > + * 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/io.h> > +#include <linux/module.h> > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/platform_device.h> > +#include <linux/watchdog.h> > +#include <linux/moduleparam.h> > + > +#define REG_COUNT 0x4 > +#define REG_MODE 0x8 > +#define REG_ENABLE 0xC > + > +struct moxart_wdt_dev { > + struct watchdog_device dev; > + void __iomem *base; > + unsigned int clock_frequency; > +}; > + > +static int heartbeat; > + > +static int moxart_wdt_stop(struct watchdog_device *wdt_dev) > +{ > + struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); > + > + writel(0, moxart_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); > + > + writel(moxart_wdt->clock_frequency * wdt_dev->timeout, > + moxart_wdt->base + REG_COUNT); > + writel(0x5ab9, moxart_wdt->base + REG_MODE); > + writel(0x03, moxart_wdt->base + REG_ENABLE); > + > + return 0; > +} > + > +static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev, > + unsigned int timeout) > +{ > + 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 moxart_wdt_dev *moxart_wdt; > + struct device *dev = &pdev->dev; > + struct device_node *node = dev->of_node; > + struct resource *res; > + struct clk *clk; > + int err; > + unsigned int max_timeout; > + bool nowayout = WATCHDOG_NOWAYOUT; > + > + moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL); > + if (!moxart_wdt) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, moxart_wdt); > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + moxart_wdt->base = devm_ioremap_resource(dev, res); > + if (IS_ERR(moxart_wdt->base)) > + return PTR_ERR(moxart_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); > + } > + > + moxart_wdt->clock_frequency = clk_get_rate(clk); > + if (moxart_wdt->clock_frequency == 0) { > + pr_err("%s: incorrect clock frequency\n", __func__); > + return -EINVAL; > + } > + > + max_timeout = UINT_MAX / moxart_wdt->clock_frequency; > + > + moxart_wdt->dev.info = &moxart_wdt_info; > + moxart_wdt->dev.ops = &moxart_wdt_ops; > + moxart_wdt->dev.timeout = max_timeout; > + moxart_wdt->dev.min_timeout = 1; > + moxart_wdt->dev.max_timeout = max_timeout; > + moxart_wdt->dev.parent = dev; > + > + watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev); > + watchdog_set_nowayout(&moxart_wdt->dev, nowayout); > + > + watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt); > + > + err = watchdog_register_device(&moxart_wdt->dev); > + if (unlikely(err)) > + return err; This is a probe path. Is the use of unlikely() really appropriate here? I suspect it doesn't make any appreciable difference, and should go. > + > + dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n", > + moxart_wdt->dev.timeout, nowayout); > + > + return 0; > +} Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html