Hi Guenter Roeck, On Tue, Nov 19, 2013 at 10:30 AM, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > On 11/18/2013 08:36 PM, Leela Krishna Amudala wrote: >> >> Hi Guenter Roeck, >> >> Thanks for reviewing the patch. >> >> >> On Mon, Nov 18, 2013 at 10:12 PM, Guenter Roeck <linux@xxxxxxxxxxxx> >> wrote: >>> >>> On Mon, Nov 18, 2013 at 03:19:48PM +0530, Leela Krishna Amudala wrote: >>>> >>>> Add device tree support for exynos5250 and 5420 SoCs and use syscon >>>> regmap interface >>>> to configure AUTOMATIC_WDT_RESET_DISABLE and MASK_WDT_RESET_REQUEST >>>> registers of PMU >>>> to mask/unmask enable/disable of watchdog in probe and s2r scenarios. >>>> >>>> Signed-off-by: Leela Krishna Amudala <l.krishna@xxxxxxxxxxx> >>>> --- >>>> .../devicetree/bindings/watchdog/samsung-wdt.txt | 21 ++- >>>> drivers/watchdog/Kconfig | 1 + >>>> drivers/watchdog/s3c2410_wdt.c | 145 >>>> ++++++++++++++++++-- >>>> 3 files changed, 157 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt >>>> b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt >>>> index 2aa486c..5dea363 100644 >>>> --- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt >>>> +++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt >>>> @@ -5,10 +5,29 @@ after a preset amount of time during which the WDT >>>> reset event has not >>>> occurred. >>>> >>>> Required properties: >>>> -- compatible : should be "samsung,s3c2410-wdt" >>>> +- compatible : should be one among the following >>>> + (a) "samsung,s3c2410-wdt" for Exynos4 and previous SoCs >>>> + (b) "samsung,exynos5250-wdt" for Exynos5250 >>>> + (c) "samsung,exynos5420-wdt" for Exynos5420 >>>> + >>>> - reg : base physical address of the controller and length of memory >>>> mapped >>>> region. >>>> - interrupts : interrupt number to the cpu. >>>> +- samsung,syscon-phandle : reference to syscon node (This property >>>> required only >>>> + in case of compatible being "samsung,exynos5250-wdt" or >>>> "samsung,exynos5420-wdt". >>>> + In case of Exynos5250 and 5420 this property points to syscon node >>>> holding the PMU >>>> + base address) >>>> >>>> Optional properties: >>>> - timeout-sec : contains the watchdog timeout in seconds. >>>> + >>>> +Example: >>>> + >>>> +watchdog@101D0000 { >>>> + compatible = "samsung,exynos5250-wdt"; >>>> + reg = <0x101D0000 0x100>; >>>> + interrupts = <0 42 0>; >>>> + clocks = <&clock 336>; >>>> + clock-names = "watchdog"; >>>> + samsung,syscon-phandle = <&pmu_sys_reg>; >>>> +}; >>>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >>>> index d1d53f3..0d272ae 100644 >>>> --- a/drivers/watchdog/Kconfig >>>> +++ b/drivers/watchdog/Kconfig >>>> @@ -188,6 +188,7 @@ config S3C2410_WATCHDOG >>>> tristate "S3C2410 Watchdog" >>>> depends on HAVE_S3C2410_WATCHDOG >>>> select WATCHDOG_CORE >>>> + select MFD_SYSCON if ARCH_EXYNOS5 >>>> help >>>> Watchdog timer block in the Samsung SoCs. This will reboot >>>> the system when the timer expires with the watchdog enabled. >>>> diff --git a/drivers/watchdog/s3c2410_wdt.c >>>> b/drivers/watchdog/s3c2410_wdt.c >>>> index 23aad7c..42e0fd3 100644 >>>> --- a/drivers/watchdog/s3c2410_wdt.c >>>> +++ b/drivers/watchdog/s3c2410_wdt.c >>>> @@ -41,6 +41,8 @@ >>>> #include <linux/slab.h> >>>> #include <linux/err.h> >>>> #include <linux/of.h> >>>> +#include <linux/mfd/syscon.h> >>>> +#include <linux/regmap.h> >>>> >>>> #define S3C2410_WTCON 0x00 >>>> #define S3C2410_WTDAT 0x04 >>>> @@ -61,6 +63,10 @@ >>>> #define CONFIG_S3C2410_WATCHDOG_ATBOOT (0) >>>> #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15) >>>> >>>> +#define WDT_DISABLE_REG_OFFSET 0x0408 >>>> +#define WDT_MASK_RESET_REG_OFFSET 0x040c >>>> +#define QUIRK_NEEDS_PMU_CONFIG (1 << 0) >>>> + >>>> static bool nowayout = WATCHDOG_NOWAYOUT; >>>> static int tmr_margin; >>>> static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT; >>>> @@ -84,6 +90,13 @@ MODULE_PARM_DESC(soft_noboot, "Watchdog action, set >>>> to 1 to ignore reboots, " >>>> "0 to reboot (default 0)"); >>>> MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default >>>> 0)"); >>>> >>>> +struct s3c2410_wdt_variant { >>>> + int disable_reg; >>>> + int mask_reset_reg; >>>> + int mask_bit; >>>> + u32 quirks; >>>> +}; >>>> + >>>> struct s3c2410_wdt { >>>> struct device *dev; >>>> struct clk *clock; >>>> @@ -94,7 +107,49 @@ struct s3c2410_wdt { >>>> unsigned long wtdat_save; >>>> struct watchdog_device wdt_device; >>>> struct notifier_block freq_transition; >>>> + struct s3c2410_wdt_variant *drv_data; >>>> + struct regmap *pmureg; >>>> +}; >>>> + >>>> +static const struct s3c2410_wdt_variant drv_data_s3c2410 = { >>>> + .quirks = 0 >>>> +}; >>>> + >>>> +#ifdef CONFIG_OF >>>> +static const struct s3c2410_wdt_variant drv_data_exynos5250 = { >>>> + .disable_reg = WDT_DISABLE_REG_OFFSET, >>>> + .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET, >>>> + .mask_bit = 20, >>>> + .quirks = QUIRK_NEEDS_PMU_CONFIG >>>> +}; >>>> + >>>> +static const struct s3c2410_wdt_variant drv_data_exynos5420 = { >>>> + .disable_reg = WDT_DISABLE_REG_OFFSET, >>>> + .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET, >>>> + .mask_bit = 0, >>>> + .quirks = QUIRK_NEEDS_PMU_CONFIG >>>> +}; >>>> + >>>> +static const struct of_device_id s3c2410_wdt_match[] = { >>>> + { .compatible = "samsung,s3c2410-wdt", >>>> + .data = &drv_data_s3c2410 }, >>>> + { .compatible = "samsung,exynos5250-wdt", >>>> + .data = &drv_data_exynos5250 }, >>>> + { .compatible = "samsung,exynos5420-wdt", >>>> + .data = &drv_data_exynos5420 }, >>>> + {}, >>>> }; >>>> +MODULE_DEVICE_TABLE(of, s3c2410_wdt_match); >>>> +#endif >>>> + >>>> +static const struct platform_device_id s3c2410_wdt_ids[] = { >>>> + { >>>> + .name = "s3c2410-wdt", >>>> + .driver_data = (unsigned long)&drv_data_s3c2410, >>>> + }, >>>> + {} >>>> +}; >>>> +MODULE_DEVICE_TABLE(platform, s3c2410_wdt_ids); >>>> >>>> /* watchdog control routines */ >>>> >>>> @@ -111,6 +166,26 @@ static inline struct s3c2410_wdt >>>> *freq_to_wdt(struct notifier_block *nb) >>>> return container_of(nb, struct s3c2410_wdt, freq_transition); >>>> } >>>> >>>> +static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, >>>> bool mask) >>>> +{ >>>> + int ret; >>>> + u32 mask_val = 1 << wdt->drv_data->mask_bit; >>>> + u32 val = 0; >>>> + >>>> + if (mask) >>>> + val = mask_val; >>>> + >>>> + ret = regmap_update_bits(wdt->pmureg, >>>> + wdt->drv_data->disable_reg, >>>> + mask_val, val); >>>> + if (ret < 0) >>>> + return ret; >>>> + >>>> + return regmap_update_bits(wdt->pmureg, >>>> + wdt->drv_data->mask_reset_reg, >>>> + mask_val, val); >>>> +} >>>> + >>>> static int s3c2410wdt_keepalive(struct watchdog_device *wdd) >>>> { >>>> struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); >>>> @@ -332,6 +407,20 @@ static inline void >>>> s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) >>>> } >>>> #endif >>>> >>>> +/* s3c2410_get_wdt_driver_data */ >>>> +static inline struct s3c2410_wdt_variant * >>>> +get_wdt_drv_data(struct platform_device *pdev) >>>> +{ >>>> + if (pdev->dev.of_node) { >>>> + const struct of_device_id *match; >>>> + match = of_match_node(s3c2410_wdt_match, >>>> pdev->dev.of_node); >>>> + return (struct s3c2410_wdt_variant *)match->data; >>>> + } else { >>>> + return (struct s3c2410_wdt_variant *) >>>> + platform_get_device_id(pdev)->driver_data; >>>> + } >>>> +} >>>> + >>>> static int s3c2410wdt_probe(struct platform_device *pdev) >>>> { >>>> struct device *dev; >>>> @@ -354,6 +443,16 @@ static int s3c2410wdt_probe(struct platform_device >>>> *pdev) >>>> spin_lock_init(&wdt->lock); >>>> wdt->wdt_device = s3c2410_wdd; >>>> >>>> + wdt->drv_data = get_wdt_drv_data(pdev); >>>> + if (wdt->drv_data->quirks & QUIRK_NEEDS_PMU_CONFIG) { >>>> + wdt->pmureg = >>>> syscon_regmap_lookup_by_phandle(dev->of_node, >>>> + >>>> "samsung,syscon-phandle"); >>>> + if (IS_ERR(wdt->pmureg)) { >>>> + dev_err(dev, "syscon regmap lookup failed.\n"); >>>> + return PTR_ERR(wdt->pmureg); >>>> + } >>>> + } >>>> + >>>> wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); >>>> if (wdt_irq == NULL) { >>>> dev_err(dev, "no irq resource specified\n"); >>>> @@ -444,6 +543,14 @@ static int s3c2410wdt_probe(struct platform_device >>>> *pdev) >>>> (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis", >>>> (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis"); >>>> >>>> + if (wdt->drv_data->quirks & QUIRK_NEEDS_PMU_CONFIG) { >>>> + ret = s3c2410wdt_mask_and_disable_reset(wdt, false); >>>> + if (ret < 0) { >>>> + dev_err(wdt->dev, "failed to update pmu >>>> register"); >>> >>> >>> Hmm ... still not happy ;-). This message is the same for each call >>> to s3c2410wdt_mask_and_disable_reset(). Why not create it there ? >>> Sure, you'd have to decide if you want to use dev_warn() or dev_err(), >>> but that would still be better than repeating the same message (and code) >>> five times. >>> >>> The same is true for the if() statement. It might be worthwhile calling >>> s3c2410wdt_mask_and_disable_reset() unconditionally and adding something >>> like >>> >>> if (!(wdt->drv_data->quirks & QUIRK_NEEDS_PMU_CONFIG)) >>> return 0; >>> >>> to it. >>> >> >> As Tomasz Figa suggested I handled the error conditions here >> Please go through this link for your reference >> https://patchwork.kernel.org/patch/3118771/ >> > > His proposed function had the error message in the function, > so I am not entirely following your logic. > > He said you should _handle_ the error condition in the calling code. > Dumping an error message and doing nothing isn't really "handling" > the error condition. > I know printing an error message is not really "handling" the error condition. But apart from probe function I don't have anything to handle in remove, shutdown, suspend and resume functions. In remove, shutdown, suspend funtions I must do stop/deregister the device even if regmap_update_bits fails so I simply do dev_warn and continuing So I removed the error message prints in the s3c2410wdt_mask_and_disable_reset function and added it in the above mentioned functions as part of error handling. Best Wishes, Leela Krishna. > Guenter > >> Best Wishes, >> Leela Krishna. >> >>> Thanks, >>> Guenter >>> >>>> + goto err_cpufreq; >>>> + } >>>> + } >>>> + >>>> return 0; >>>> >>>> err_cpufreq: >>>> @@ -459,8 +566,15 @@ static int s3c2410wdt_probe(struct platform_device >>>> *pdev) >>>> >>>> static int s3c2410wdt_remove(struct platform_device *dev) >>>> { >>>> + int ret; >>>> struct s3c2410_wdt *wdt = platform_get_drvdata(dev); >>>> >>>> + if (wdt->drv_data->quirks & QUIRK_NEEDS_PMU_CONFIG) { >>>> + ret = s3c2410wdt_mask_and_disable_reset(wdt, true); >>>> + if (ret < 0) >>>> + dev_warn(wdt->dev, "failed to update pmu >>>> register"); >>>> + } >>>> + >>>> watchdog_unregister_device(&wdt->wdt_device); >>>> >>>> s3c2410wdt_cpufreq_deregister(wdt); >>>> @@ -473,8 +587,15 @@ static int s3c2410wdt_remove(struct platform_device >>>> *dev) >>>> >>>> static void s3c2410wdt_shutdown(struct platform_device *dev) >>>> { >>>> + int ret; >>>> struct s3c2410_wdt *wdt = platform_get_drvdata(dev); >>>> >>>> + if (wdt->drv_data->quirks & QUIRK_NEEDS_PMU_CONFIG) { >>>> + ret = s3c2410wdt_mask_and_disable_reset(wdt, true); >>>> + if (ret < 0) >>>> + dev_warn(wdt->dev, "failed to update pmu >>>> register"); >>>> + } >>>> + >>>> s3c2410wdt_stop(&wdt->wdt_device); >>>> } >>>> >>>> @@ -482,12 +603,19 @@ static void s3c2410wdt_shutdown(struct >>>> platform_device *dev) >>>> >>>> static int s3c2410wdt_suspend(struct device *dev) >>>> { >>>> + int ret; >>>> struct s3c2410_wdt *wdt = dev_get_drvdata(dev); >>>> >>>> /* Save watchdog state, and turn it off. */ >>>> wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON); >>>> wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT); >>>> >>>> + if (wdt->drv_data->quirks & QUIRK_NEEDS_PMU_CONFIG) { >>>> + ret = s3c2410wdt_mask_and_disable_reset(wdt, true); >>>> + if (ret < 0) >>>> + dev_warn(wdt->dev, "failed to update pmu >>>> register"); >>>> + } >>>> + >>>> /* Note that WTCNT doesn't need to be saved. */ >>>> s3c2410wdt_stop(&wdt->wdt_device); >>>> >>>> @@ -496,6 +624,7 @@ static int s3c2410wdt_suspend(struct device *dev) >>>> >>>> static int s3c2410wdt_resume(struct device *dev) >>>> { >>>> + int ret; >>>> struct s3c2410_wdt *wdt = dev_get_drvdata(dev); >>>> >>>> /* Restore watchdog state. */ >>>> @@ -503,6 +632,12 @@ static int s3c2410wdt_resume(struct device *dev) >>>> writel(wdt->wtdat_save, wdt->reg_base + S3C2410_WTCNT);/* Reset >>>> count */ >>>> writel(wdt->wtcon_save, wdt->reg_base + S3C2410_WTCON); >>>> >>>> + if (wdt->drv_data->quirks & QUIRK_NEEDS_PMU_CONFIG) { >>>> + ret = s3c2410wdt_mask_and_disable_reset(wdt, false); >>>> + if (ret < 0) >>>> + dev_warn(wdt->dev, "failed to update pmu >>>> register"); >>>> + } >>>> + >>>> dev_info(dev, "watchdog %sabled\n", >>>> (wdt->wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis"); >>>> >>>> @@ -513,18 +648,11 @@ static int s3c2410wdt_resume(struct device *dev) >>>> static SIMPLE_DEV_PM_OPS(s3c2410wdt_pm_ops, s3c2410wdt_suspend, >>>> s3c2410wdt_resume); >>>> >>>> -#ifdef CONFIG_OF >>>> -static const struct of_device_id s3c2410_wdt_match[] = { >>>> - { .compatible = "samsung,s3c2410-wdt" }, >>>> - {}, >>>> -}; >>>> -MODULE_DEVICE_TABLE(of, s3c2410_wdt_match); >>>> -#endif >>>> - >>>> static struct platform_driver s3c2410wdt_driver = { >>>> .probe = s3c2410wdt_probe, >>>> .remove = s3c2410wdt_remove, >>>> .shutdown = s3c2410wdt_shutdown, >>>> + .id_table = s3c2410_wdt_ids, >>>> .driver = { >>>> .owner = THIS_MODULE, >>>> .name = "s3c2410-wdt", >>>> @@ -540,4 +668,3 @@ MODULE_AUTHOR("Ben Dooks <ben@xxxxxxxxxxxx>, " >>>> MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver"); >>>> MODULE_LICENSE("GPL"); >>>> MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); >>>> -MODULE_ALIAS("platform:s3c2410-wdt"); >>>> -- >>>> 1.7.10.4 >>>> >>>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe >>> linux-samsung-soc" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> -- >> 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 >> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" > in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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