2013/9/23 Guenter Roeck <linux@xxxxxxxxxxxx>:
> On Mon, Sep 23, 2013 at 10:33:09PM +0800, Barry Song wrote:
>> 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
>> pre-set, when this event occurs, the effect is the same as the system
>> software reset.
>>
>> Signed-off-by: Xianglong Du <Xianglong.Du@xxxxxxx>
>> Signed-off-by: Barry Song <Baohua.Song@xxxxxxx>
>> Cc: Romain Izard <romain.izard.pro@xxxxxxxxx>
>> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
>> ---
>> -v4: cleanup according to Guenter's comments
>>
>> .../devicetree/bindings/watchdog/sirfsoc_wdt.txt | 15 ++
>> arch/arm/configs/prima2_defconfig | 1 +
>> drivers/watchdog/Kconfig | 9 +
>> drivers/watchdog/Makefile | 1 +
>> drivers/watchdog/sirfsoc_wdt.c | 232 +++++++++++++++++++++
>> 5 files changed, 258 insertions(+)
>> 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..7d11960
>> --- /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"
>> +- reg: Address range of tick timer/WDT register set
>> +- interrupts: interrupt number to the cpu
>> +
>> +Example:
>> +
>> +timer@b0020000 {
>> + compatible = "sirf,prima2-tick";
>> + reg = <0xb0020000 0x1000>;
>> + interrupts = <0>;
>> +};
>> +
>> diff --git a/arch/arm/configs/prima2_defconfig b/arch/arm/configs/prima2_defconfig
>> index 002a1ce..23591db 100644
>> --- a/arch/arm/configs/prima2_defconfig
>> +++ b/arch/arm/configs/prima2_defconfig
>> @@ -39,6 +39,7 @@ CONFIG_SPI=y
>> CONFIG_SPI_SIRF=y
>> CONFIG_SPI_SPIDEV=y
>> # CONFIG_HWMON is not set
>> +CONFIG_WATCHDOG=y
>> CONFIG_USB_GADGET=y
>> CONFIG_USB_MASS_STORAGE=m
>> CONFIG_MMC=y
>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>> index d1d53f3..98fb560 100644
>> --- a/drivers/watchdog/Kconfig
>> +++ b/drivers/watchdog/Kconfig
>> @@ -392,6 +392,15 @@ 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
>> + select WATCHDOG_CORE
>> + 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 6c5bb27..1a1300d 100644
>> --- a/drivers/watchdog/Makefile
>> +++ b/drivers/watchdog/Makefile
>> @@ -55,6 +55,7 @@ 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-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
>>
>> # AVR32 Architecture
>> obj-$(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..8ae5294
>> --- /dev/null
>> +++ b/drivers/watchdog/sirfsoc_wdt.c
>> @@ -0,0 +1,232 @@
>> +/*
>> + * 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/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 timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT;
>> +static bool nowayout = WATCHDOG_NOWAYOUT;
>> +
>> +module_param(timeout, uint, 0);
>> +module_param(nowayout, bool, 0);
>> +
>> +MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
>> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
>> + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>> +
>> +static unsigned int sirfsoc_wdt_gettimeleft(struct watchdog_device *wdd)
>> +{
>> + u32 counter, match;
>> + void __iomem *wdt_base;
>> + int time_left;
>> +
>> + wdt_base = watchdog_get_drvdata(wdd);
>> + counter = readl(wdt_base + SIRFSOC_TIMER_COUNTER_LO);
>> + match = readl(wdt_base +
>> + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
>> +
>> + time_left = match - counter;
>> +
>> + return time_left / CLOCK_TICK_RATE;
>> +}
>> +
>> +static int sirfsoc_wdt_updatetimeout(struct watchdog_device *wdd)
>> +{
>> + u32 counter, timeout_ticks;
>> + void __iomem *wdt_base;
>> +
>> + timeout_ticks = wdd->timeout * CLOCK_TICK_RATE;
>> + wdt_base = watchdog_get_drvdata(wdd);
>> +
>> + /* Enable the latch before reading the LATCH_LO register */
>> + writel(1, wdt_base + SIRFSOC_TIMER_LATCH);
>> +
>> + /* Set the TO value */
>> + counter = readl(wdt_base + SIRFSOC_TIMER_LATCHED_LO);
>> +
>> + counter += timeout_ticks;
>> +
>> + writel(counter, wdt_base +
>> + SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
>> +
>> + return 0;
>> +}
>> +
>> +static int sirfsoc_wdt_enable(struct watchdog_device *wdd)
>> +{
>> + void __iomem *wdt_base = watchdog_get_drvdata(wdd);
>> + sirfsoc_wdt_updatetimeout(wdd);
>> +
>> + /*
>> + * NOTE: If interrupt is not enabled
>> + * then WD-Reset doesn't get generated at all.
>> + */
>> + writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN)
>> + | (1 << SIRFSOC_TIMER_WDT_INDEX),
>> + wdt_base + SIRFSOC_TIMER_INT_EN);
>> + writel(1, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN);
>> +
>> + return 0;
>> +}
>> +
>> +static int sirfsoc_wdt_disable(struct watchdog_device *wdd)
>> +{
>> + void __iomem *wdt_base = watchdog_get_drvdata(wdd);
>> +
>> + writel(0, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN);
>> + writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN)
>> + & (~(1 << SIRFSOC_TIMER_WDT_INDEX)),
>> + wdt_base + SIRFSOC_TIMER_INT_EN);
>> +
>> + return 0;
>> +}
>> +
>> +static int sirfsoc_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
>> +{
>> + 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;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(base)) {
>> + dev_err(&pdev->dev, "sirfsoc wdt: could not remap the mem\n");
>
> As mentioned earlier, devm_ioremap_resource() already displays an error message.
> Displaying another one doesn't add value. On a side note, the point of using
> dev_err is to display the device name so you don't have to do it yourself.
> So you have a double redundancy in this error message - first the message
> itself, then the driver name.
ok.
>
>> + return PTR_ERR(base);
>> + }
>> +
>> + watchdog_set_drvdata(&sirfsoc_wdd, base);
>> +
>> + watchdog_init_timeout(&sirfsoc_wdd, timeout, &pdev->dev);
>> + watchdog_set_nowayout(&sirfsoc_wdd, nowayout);
>> +
>> + ret = watchdog_register_device(&sirfsoc_wdd);
>> + if (ret)
>> + return ret;
>> +
>> + platform_set_drvdata(pdev, &sirfsoc_wdd);
>> +
>> + return 0;
>> +}
>> +
>> +static void sirfsoc_wdt_shutdown(struct platform_device *pdev)
>> +{
>> + struct watchdog_device *wdd = platform_get_drvdata(pdev);
>> +
>> + sirfsoc_wdt_disable(wdd);
>
> I just noticed that platform_set_drvdata() and platform_get_drvdata()
> are quite unnecessary here.
>
> sirfsoc_wdt_disable(&sirfsoc_wdd);
>
> would accomplish the same.
no.
i think the current codes are in the best practice for both generic c
and linux drivers as we always use private data to consider the
possibility of the driver will have multiple instances.
>
>> +}
>> +
>> +static int sirfsoc_wdt_remove(struct platform_device *pdev)
>> +{
>> + sirfsoc_wdt_shutdown(pdev);
>> + return 0;
>> +}
>> +
> Ah, that kind of defeats the idea of having just one function.
> I had not noticed the int vs. void return types.
> Might as well call sirfsoc_wdt_disable() directly here.
>
>> +#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 SIMPLE_DEV_PM_OPS(sirfsoc_wdt_pm_ops,
>> + sirfsoc_wdt_suspend, sirfsoc_wdt_resume);
>> +
>> +static const struct of_device_id sirfsoc_wdt_of_match[] = {
>> + { .compatible = "sirf,prima2-tick"},
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, sirfsoc_wdt_of_match);
>> +
>> +static struct platform_driver sirfsoc_wdt_driver = {
>> + .driver = {
>> + .name = "sirfsoc-wdt",
>> + .owner = THIS_MODULE,
>> + .pm = &sirfsoc_wdt_pm_ops,
>> + .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("platform:sirfsoc-wdt");
>> --
>> 1.8.2.3
>>
>>
-barry
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