[PATCH v2] watchdog: sirf: add watchdog driver of CSR SiRFprimaII and SiRFatlasVI
Barry Song
21cnbao at gmail.com
Thu Sep 12 09:41:43 EDT 2013
2013/9/12 Romain Izard <romain.izard.pro at gmail.com>:
> On 2013-09-12, Barry Song <21cnbao at gmail.com> wrote:
>> From: Xianglong Du <Xianglong.Du at csr.com>
>>
>> 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 at csr.com>
>> Signed-off-by: Barry Song <Baohua.Song at csr.com>
>> ---
>> -v2: select WATCHDOG_CORE;
>> module parameter name is timeout;
>> fix coding style;
>> define a local variable first that get's the value of watchdog_get_drvdata(wdd);
>> drop redundant watchdog_timeout_invalid check;
>> MODULE_ALIAS_MISCDEV is removed as we have the platform alias.
>>
>> arch/arm/boot/dts/atlas6.dtsi | 2 +-
>> arch/arm/boot/dts/prima2.dtsi | 2 +-
>> arch/arm/configs/prima2_defconfig | 6 +-
>> drivers/watchdog/Kconfig | 9 ++
>> drivers/watchdog/Makefile | 1 +
>> drivers/watchdog/sirfsoc_wdt.c | 251 ++++++++++++++++++++++++++++++++++++++
>> 6 files changed, 266 insertions(+), 5 deletions(-)
>> create mode 100644 drivers/watchdog/sirfsoc_wdt.c
>>
>> diff --git a/arch/arm/boot/dts/atlas6.dtsi b/arch/arm/boot/dts/atlas6.dtsi
>> index 8678e0c..afee4a1 100644
>> --- a/arch/arm/boot/dts/atlas6.dtsi
>> +++ b/arch/arm/boot/dts/atlas6.dtsi
>> @@ -155,7 +155,7 @@
>> <0x56000000 0x56000000 0x1b00000>;
>>
>> timer at b0020000 {
>> - compatible = "sirf,prima2-tick";
>> + compatible = "sirf,prima2-tick", "sirf,prima2-wdt";
>
> Does this really mean that both drivers will be loaded? From what I
> understand of device tree, this means to use the "sirf,prima2-tick"
> driver, and then if not available, the "sirf-prima2-wdt" driver.
> It would be necessary to either add the watchdog support in the
> clocksource driver, or create a separate node in the device tree
> (with the same address?) to respect the compatible rules.
that means both. the 6th timer can act as a watchdog timer when the
Watchdog mode is enabled. all 6 timers have been controlled by timer
driver, here it is a more-functionality for timer6.
>
>
>> reg = <0xb0020000 0x1000>;
>> interrupts = <0>;
>> };
>> diff --git a/arch/arm/boot/dts/prima2.dtsi b/arch/arm/boot/dts/prima2.dtsi
>> index bbeb623..d41ab98e 100644
>> --- a/arch/arm/boot/dts/prima2.dtsi
>> +++ b/arch/arm/boot/dts/prima2.dtsi
>> @@ -174,7 +174,7 @@
>> ranges = <0xb0000000 0xb0000000 0x180000>;
>>
>> timer at b0020000 {
>> - compatible = "sirf,prima2-tick";
>> + compatible = "sirf,prima2-tick", "sirf,prima2-wdt";
>
> See previous comment.
>
>> reg = <0xb0020000 0x1000>;
>> interrupts = <0>;
>> };
>> diff --git a/arch/arm/configs/prima2_defconfig b/arch/arm/configs/prima2_defconfig
>> index 002a1ce..eec56e8 100644
>> --- a/arch/arm/configs/prima2_defconfig
>> +++ b/arch/arm/configs/prima2_defconfig
>> @@ -1,4 +1,3 @@
>> -CONFIG_EXPERIMENTAL=y
>
> CONFIG_EXPERIMENTAL is not related to this change.
i think it is just due to kernel upgrade. here just make menuconfig
with enabling watchdog and save defconfig, then there are some minor
differences here.
>
>> CONFIG_NO_HZ=y
>> CONFIG_HIGH_RES_TIMERS=y
>> CONFIG_RELAY=y
>> @@ -39,6 +38,7 @@ 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
>> @@ -59,12 +59,12 @@ CONFIG_ROMFS_FS=y
>> CONFIG_NLS_CODEPAGE_437=y
>> CONFIG_NLS_ASCII=y
>> CONFIG_NLS_ISO8859_1=y
>> -CONFIG_MAGIC_SYSRQ=y
>> +CONFIG_DEBUG_INFO=y
>> CONFIG_DEBUG_SECTION_MISMATCH=y
>> +CONFIG_MAGIC_SYSRQ=y
>
> Both CONFIG_MAGIC_SYSRQ & CONFIG_DEBUG_INFO are not related to this change.
>
>> CONFIG_DEBUG_KERNEL=y
>> # CONFIG_DEBUG_PREEMPT is not set
>> CONFIG_DEBUG_RT_MUTEXES=y
>> CONFIG_DEBUG_SPINLOCK=y
>> CONFIG_DEBUG_MUTEXES=y
>> -CONFIG_DEBUG_INFO=y
>
> CONFIG_DEBUG_INFO is not related to this change.
>
>> CONFIG_CRC_CCITT=y
>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>> index 362085d..c76cb61 100644
>> --- a/drivers/watchdog/Kconfig
>> +++ b/drivers/watchdog/Kconfig
>> @@ -382,6 +382,15 @@ 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 2f26a0b..b917ae6 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-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
>>
>> # AVR32 Architecture
>> obj-$(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..0542a4d
>> --- /dev/null
>> +++ b/drivers/watchdog/sirfsoc_wdt.c
>> @@ -0,0 +1,251 @@
>> +/*
>> + * 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 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));
>> +
>> + if (match >= counter)
>> + time_left = match-counter;
>> + else
>> + /* rollover */
>> + time_left = (0xffffffffUL - counter) + match;
>
> As u32 is a modulo 2^32 type, those values are almost the same (off by one).
> time_left = match - counter; will be valid in all cases.
>
>> +
>> + 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);
>> +
>> + if ((0xffffffffUL - counter) >= timeout_ticks)
>> + counter += timeout_ticks;
>> + else
>> + /* Rollover */
>> + counter = timeout_ticks - (0xffffffffUL - counter);
>
> modulo 2^32 arithmetic, no need for two cases.
you mean just "counter += timeout_ticks" is ok?
>
>> +
>> + 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 (!base) {
>> + dev_err(&pdev->dev, "sirfsoc wdt: could not remap the mem\n");
>> + ret = -EADDRNOTAVAIL;
>> + goto out;
>> + }
>> + 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)
>> + 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 at csr.com>");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_ALIAS("platform:sirfsoc-wdt");
>
>
> --
> Romain Izard
-barry
More information about the linux-arm-kernel
mailing list