Hi Barry,
> From: Xianglong Du <Xianglong.Du@xxxxxxx>
>
> On CSR SiRFprimaII and SiRFatlasVI, the 6th timer can act as a Watchdog timer
> when the Watchdog mode is enabled.
>
> watchdog occur when TIMER watchdog counter matches the value software set, when
> this event occur, the effect is the same as system software reset.
>
> Signed-off-by: Xianglong Du <Xianglong.Du@xxxxxxx>
> Signed-off-by: Barry Song <Baohua.Song@xxxxxxx>
> ---
> .../devicetree/bindings/watchdog/sirfsoc_wdt.txt | 15 ++
> arch/arm/boot/dts/atlas6.dtsi | 2 +-
> arch/arm/boot/dts/prima2.dtsi | 2 +-
> arch/arm/configs/prima2_defconfig | 3 +-
> drivers/watchdog/Kconfig | 8 +
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/sirfsoc_wdt.c | 250 ++++++++++++++++++++
> 7 files changed, 278 insertions(+), 3 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/watchdog/sirfsoc_wdt.txt
> create mode 100644 drivers/watchdog/sirfsoc_wdt.c
>
> diff --git a/Documentation/devicetree/bindings/watchdog/sirfsoc_wdt.txt b/Documentation/devicetree/bindings/watchdog/sirfsoc_wdt.txt
> new file mode 100644
> index 0000000..b2af5fb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/watchdog/sirfsoc_wdt.txt
> @@ -0,0 +1,15 @@
> +SiRFSoC Timer and Watchdog Timer(WDT) Controller
> +
> +Required properties:
> +- compatible: "sirf,prima2-tick", "sirf,prima2-wdt"
> +- reg: Address range of tick timer/WDT register set
> +- interrupts: interrupt number to the cpu
> +
> +Example:
> +
> +timer@b0020000 {
> + compatible = "sirf,prima2-tick", "sirf,prima2-wdt";
> + reg = <0xb0020000 0x1000>;
> + interrupts = <0>;
> +};
> +
> diff --git a/arch/arm/boot/dts/atlas6.dtsi b/arch/arm/boot/dts/atlas6.dtsi
> index 7d1a279..c101f3e 100644
> --- a/arch/arm/boot/dts/atlas6.dtsi
> +++ b/arch/arm/boot/dts/atlas6.dtsi
> @@ -155,7 +155,7 @@
> <0x56000000 0x56000000 0x1b00000>;
>
> timer@b0020000 {
> - compatible = "sirf,prima2-tick";
> + compatible = "sirf,prima2-tick", "sirf,prima2-wdt";
> reg = <0xb0020000 0x1000>;
> interrupts = <0>;
> };
> diff --git a/arch/arm/boot/dts/prima2.dtsi b/arch/arm/boot/dts/prima2.dtsi
> index 3329719..3c76dc2 100644
> --- a/arch/arm/boot/dts/prima2.dtsi
> +++ b/arch/arm/boot/dts/prima2.dtsi
> @@ -172,7 +172,7 @@
> ranges = <0xb0000000 0xb0000000 0x180000>;
>
> timer@b0020000 {
> - compatible = "sirf,prima2-tick";
> + compatible = "sirf,prima2-tick", "sirf,prima2-wdt";
> reg = <0xb0020000 0x1000>;
> interrupts = <0>;
> };
> diff --git a/arch/arm/configs/prima2_defconfig b/arch/arm/configs/prima2_defconfig
> index 002a1ce..a1d7c67 100644
> --- a/arch/arm/configs/prima2_defconfig
> +++ b/arch/arm/configs/prima2_defconfig
> @@ -1,4 +1,3 @@
> -CONFIG_EXPERIMENTAL=y
> CONFIG_NO_HZ=y
> CONFIG_HIGH_RES_TIMERS=y
> CONFIG_RELAY=y
> @@ -39,6 +38,8 @@ CONFIG_SPI=y
> CONFIG_SPI_SIRF=y
> CONFIG_SPI_SPIDEV=y
> # CONFIG_HWMON is not set
> +CONFIG_WATCHDOG=y
> +CONFIG_WATCHDOG_CORE=y
> CONFIG_USB_GADGET=y
> CONFIG_USB_MASS_STORAGE=m
> CONFIG_MMC=y
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index e89fc31..fe005a8 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -391,6 +391,14 @@ config RETU_WATCHDOG
> To compile this driver as a module, choose M here: the
> module will be called retu_wdt.
>
> +config SIRFSOC_WATCHDOG
> + tristate "SiRFSOC watchdog"
> + depends on ARCH_SIRF
You are missing a:
select WATCHDOG_CORE
here.
> + default y
> + help
> + Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When
> + the watchdog triggers the system will be reset.
> +
> # AVR32 Architecture
>
> config AT32AP700X_WDT
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index a300b94..9064f6a 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -54,6 +54,7 @@ obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
> obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
> obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
> obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
> +obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
>
> # AVR32 Architecture
> obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
> diff --git a/drivers/watchdog/sirfsoc_wdt.c b/drivers/watchdog/sirfsoc_wdt.c
> new file mode 100644
> index 0000000..ab3dd42
> --- /dev/null
> +++ b/drivers/watchdog/sirfsoc_wdt.c
> @@ -0,0 +1,250 @@
> +/*
> + * Watchdog driver for CSR SiRFprimaII and SiRFatlasVI
> + *
> + * Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company.
> + *
> + * Licensed under GPLv2 or later.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/miscdevice.h>
> +#include <linux/watchdog.h>
> +#include <linux/platform_device.h>
> +#include <linux/moduleparam.h>
> +#include <linux/of.h>
> +#include <linux/io.h>
> +#include <linux/uaccess.h>
> +
> +#define SIRFSOC_TIMER_COUNTER_LO 0x0000
> +#define SIRFSOC_TIMER_MATCH_0 0x0008
> +#define SIRFSOC_TIMER_INT_EN 0x0024
> +#define SIRFSOC_TIMER_WATCHDOG_EN 0x0028
> +#define SIRFSOC_TIMER_LATCH 0x0030
> +#define SIRFSOC_TIMER_LATCHED_LO 0x0034
> +
> +#define SIRFSOC_TIMER_WDT_INDEX 5
> +
> +#define SIRFSOC_WDT_MIN_TIMEOUT 30 /* 30 secs */
> +#define SIRFSOC_WDT_MAX_TIMEOUT (10 * 60) /* 10 mins */
> +#define SIRFSOC_WDT_DEFAULT_TIMEOUT 30 /* 30 secs */
> +
> +
> +static unsigned int default_timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT;
> +module_param(default_timeout, uint, 0);
> +MODULE_PARM_DESC(default_timeout, "Default watchdog timeout (in seconds)");
Preferred module parameter name is timeout .
> +static unsigned int sirfsoc_wdt_gettimeleft(struct watchdog_device *wdd)
> +{
> + u32 counter, match;
> + int time_left;
> +
> + counter = readl(watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_COUNTER_LO);
> + match = readl(watchdog_get_drvdata(wdd) +
> + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
> +
> + if (match >= counter) {
> + time_left = match-counter;
> + } else {
> + /* rollover */
> + time_left = (0xffffffffUL - counter) + match;
> + }
should be:
if (match >= counter)
time_left = match-counter;
else
/* rollover */
time_left = (0xffffffffUL - counter) + match;
according to coding style.
> +
> + return time_left / CLOCK_TICK_RATE;
> +}
> +
> +static int sirfsoc_wdt_updatetimeout(struct watchdog_device *wdd)
> +{
> + u32 counter, timeout_ticks;
> +
> + timeout_ticks = wdd->timeout * CLOCK_TICK_RATE;
> +
> + /* Enable the latch before reading the LATCH_LO register */
> + writel(1, watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_LATCH);
> +
> + /* Set the TO value */
> + counter = readl(watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_LATCHED_LO);
> +
> + if ((0xffffffffUL - counter) >= timeout_ticks) {
> + counter += timeout_ticks;
> + } else {
> + /* Rollover */
> + counter = timeout_ticks - (0xffffffffUL - counter);
> + }
Same here (coding style).
> + writel(counter, watchdog_get_drvdata(wdd) +
> + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
> +
> + return 0;
> +}
> +
> +static int sirfsoc_wdt_enable(struct watchdog_device *wdd)
> +{
> + sirfsoc_wdt_updatetimeout(wdd);
> +
> + /*
> + * NOTE: If interrupt is not enabled
> + * then WD-Reset doesn't get generated at all.
> + */
> + writel(readl(watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_INT_EN)
> + | (1 << SIRFSOC_TIMER_WDT_INDEX),
> + watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_INT_EN);
> + writel(1, watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_WATCHDOG_EN);
Wouldn't it be better to define a local variable first that get's the value
of watchdog_get_drvdata(wdd)? This would definitely improve readability.
Goes also for other functions (like sirfsoc_wdt_gettimeleft and
sirfsoc_wdt_disable).
> +
> + return 0;
> +}
> +
> +static int sirfsoc_wdt_disable(struct watchdog_device *wdd)
> +{
> + writel(0, watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_WATCHDOG_EN);
> + writel(readl(watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_INT_EN)
> + & (~(1 << SIRFSOC_TIMER_WDT_INDEX)),
> + watchdog_get_drvdata(wdd) + SIRFSOC_TIMER_INT_EN);
> +
> + return 0;
> +}
> +
> +static int sirfsoc_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
> +{
> + if (to < SIRFSOC_WDT_MIN_TIMEOUT)
> + to = SIRFSOC_WDT_MIN_TIMEOUT;
> + if (to > SIRFSOC_WDT_MAX_TIMEOUT)
> + to = SIRFSOC_WDT_MAX_TIMEOUT;
Hmm, since SIRFSOC_WDT_MIN_TIMEOUT and SIRFSOC_WDT_MAX_TIMEOUT are defined:
setting the timeout will call watchdog_set_timeout and that function will do a:
if (watchdog_timeout_invalid(wddev, timeout))
return -EINVAL;
with watchdog_timeout_invalid returning:
((wdd->max_timeout != 0) && (t < wdd->min_timeout || t > wdd->max_timeout));
So this will never happen...
> + wdd->timeout = to;
> + sirfsoc_wdt_updatetimeout(wdd);
> +
> + return 0;
> +}
> +
> +#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
> +
> +static const struct watchdog_info sirfsoc_wdt_ident = {
> + .options = OPTIONS,
> + .firmware_version = 0,
> + .identity = "SiRFSOC Watchdog",
> +};
> +
> +static struct watchdog_ops sirfsoc_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = sirfsoc_wdt_enable,
> + .stop = sirfsoc_wdt_disable,
> + .get_timeleft = sirfsoc_wdt_gettimeleft,
> + .ping = sirfsoc_wdt_updatetimeout,
> + .set_timeout = sirfsoc_wdt_settimeout,
> +};
> +
> +static struct watchdog_device sirfsoc_wdd = {
> + .info = &sirfsoc_wdt_ident,
> + .ops = &sirfsoc_wdt_ops,
> + .timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT,
> + .min_timeout = SIRFSOC_WDT_MIN_TIMEOUT,
> + .max_timeout = SIRFSOC_WDT_MAX_TIMEOUT,
> +};
> +
> +static int sirfsoc_wdt_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + int ret;
> + void __iomem *base;
> +
> + /* reserve static register mappings */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "sirfsoc wdt: could not get mem resources\n");
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + base = devm_ioremap_resource(&pdev->dev, res);
> + if (!base) {
> + dev_err(&pdev->dev, "sirfsoc wdt: could not remap the mem\n");
> + ret = -EADDRNOTAVAIL;
> + goto out;
> + }
> + watchdog_set_drvdata(&sirfsoc_wdd, base);
> +
> + sirfsoc_wdd.timeout = default_timeout;
You can consider using watchdog_init_timeout here.
I would also advice to add watchdog_set_nowayout and use the nowayout functionality.
> +
> + ret = watchdog_register_device(&sirfsoc_wdd);
> + if (!!ret)
> + goto out;
> +
> + platform_set_drvdata(pdev, &sirfsoc_wdd);
> +
> + return 0;
> +
> +out:
> + return ret;
> +}
> +
> +static int sirfsoc_wdt_remove(struct platform_device *pdev)
> +{
> + struct watchdog_device *wdd = platform_get_drvdata(pdev);
> +
> + sirfsoc_wdt_disable(wdd);
> +
> + return 0;
> +}
> +
> +static void sirfsoc_wdt_shutdown(struct platform_device *pdev)
> +{
> + struct watchdog_device *wdd = platform_get_drvdata(pdev);
> +
> + sirfsoc_wdt_disable(wdd);
> +}
> +
> +#ifdef CONFIG_PM
> +
> +static int sirfsoc_wdt_suspend(struct device *dev)
> +{
> + return 0;
> +}
> +
> +static int sirfsoc_wdt_resume(struct device *dev)
> +{
> + struct watchdog_device *wdd = dev_get_drvdata(dev);
> +
> + /*
> + * NOTE: Since timer controller registers settings are saved
> + * and restored back by the timer-prima2.c, so we need not
> + * update WD settings except refreshing timeout.
> + */
> + sirfsoc_wdt_updatetimeout(wdd);
> +
> + return 0;
> +}
> +
> +#else
> +#define sirfsoc_wdt_suspend NULL
> +#define sirfsoc_wdt_resume NULL
> +#endif
> +
> +static const struct dev_pm_ops sirfsoc_wdt_pm_ops = {
> + .suspend = sirfsoc_wdt_suspend,
> + .resume = sirfsoc_wdt_resume,
> +};
> +
> +static const struct of_device_id sirfsoc_wdt_of_match[] = {
> + { .compatible = "sirf,prima2-wdt"},
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, sirfsoc_wdt_of_match);
> +
> +static struct platform_driver sirfsoc_wdt_driver = {
> + .driver = {
> + .name = "sirfsoc-wdt",
> + .owner = THIS_MODULE,
> +#ifdef CONFIG_PM
> + .pm = &sirfsoc_wdt_pm_ops,
> +#endif
> + .of_match_table = of_match_ptr(sirfsoc_wdt_of_match),
> + },
> + .probe = sirfsoc_wdt_probe,
> + .remove = sirfsoc_wdt_remove,
> + .shutdown = sirfsoc_wdt_shutdown,
> +};
> +module_platform_driver(sirfsoc_wdt_driver);
> +
> +MODULE_DESCRIPTION("SiRF SoC watchdog driver");
> +MODULE_AUTHOR("Xianglong Du <Xianglong.Du@xxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
This alias can be removed if you have the platform alias (like listed in the following line).
> +MODULE_ALIAS("platform:sirfsoc-wdt");
> --
> 1.7.4.1
Kind regards,
Wim.
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