From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH V9 2/3] watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu register Date: Mon, 18 Nov 2013 21:00:39 -0800 Message-ID: <528AF077.8000307@roeck-us.net> References: <1384768189-2839-1-git-send-email-l.krishna@samsung.com> <1384768189-2839-3-git-send-email-l.krishna@samsung.com> <20131118164203.GA15902@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-samsung-soc-owner@vger.kernel.org To: Leela Krishna Amudala Cc: linux-samsung-soc , Kukjin Kim , Wim Van Sebroeck , Tomasz Figa , devicetree@vger.kernel.org, Douglas Anderson , linux-watchdog@vger.kernel.org, cpgs@samsung.com, Sachin Kamat List-Id: devicetree@vger.kernel.org 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 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 >>> --- >>> .../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 >>> #include >>> #include >>> +#include >>> +#include >>> >>> #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. 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 , " >>> 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@vger.kernel.org >> 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@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >