From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH V5 3/3] watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu register Date: Thu, 31 Oct 2013 06:29:03 -0700 Message-ID: <52725B1F.4040107@roeck-us.net> References: <1383199250-15405-1-git-send-email-l.krishna@samsung.com> <1383199250-15405-4-git-send-email-l.krishna@samsung.com> <2427917.T2x6X1TJ2k@amdc1227> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <2427917.T2x6X1TJ2k@amdc1227> Sender: linux-samsung-soc-owner@vger.kernel.org To: Tomasz Figa , Leela Krishna Amudala Cc: linux-samsung-soc@vger.kernel.org, kgene.kim@samsung.com, wim@iguana.be, devicetree@vger.kernel.org, dianders@chromium.org, linux-watchdog@vger.kernel.org, cpgs@samsung.com, sachin.kamat@linaro.org List-Id: devicetree@vger.kernel.org On 10/31/2013 05:29 AM, Tomasz Figa wrote: > Hi Leela, > > On Thursday 31 of October 2013 11:30:50 Leela Krishna Amudala wrote: >> The syscon regmap interface is used 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 | 22 ++- >> drivers/watchdog/s3c2410_wdt.c | 150 +++++++++++++++++--- >> 2 files changed, 154 insertions(+), 18 deletions(-) > > This patch looks better now, but there are still several issues remaining. > Please see my comments inline. > >> diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt >> index 2aa486c..0b8aa4b 100644 >> --- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt >> +++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt >> @@ -5,10 +5,30 @@ 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,sysreg = <&pmu_sys_reg>; > > Shouldn't it be samsung,syscon-phandle? > >> + status = "okay"; > > The status property is not a part of this binding, so can be dropped > from the example. > >> +}; >> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c >> index 23aad7c..235d160 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; >> @@ -84,18 +90,61 @@ 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; > > nit: To avoid the need of changing the indentation in future, if fields > with longer types gets added, I would simply separate type name from field > name using a single space. > >> +}; >> + >> struct s3c2410_wdt { >> - struct device *dev; >> - struct clk *clock; >> - void __iomem *reg_base; >> - unsigned int count; >> - spinlock_t lock; >> - unsigned long wtcon_save; >> - unsigned long wtdat_save; >> - struct watchdog_device wdt_device; >> - struct notifier_block freq_transition; >> + struct device *dev; >> + struct clk *clock; >> + void __iomem *reg_base; >> + unsigned int count; >> + spinlock_t lock; >> + unsigned long wtcon_save; >> + unsigned long wtdat_save; >> + struct watchdog_device wdt_device; >> + struct notifier_block freq_transition; >> + struct s3c2410_wdt_variant *pmu_config; >> + struct regmap *pmureg; > > And here's an example of such (unnecessary) change. I believe it would > be better to keep indendation of other fields as is, use single space for > the new field and then change remaining fields in a separate patch, > outside of this series. > >> +}; >> + >> +#ifdef CONFIG_OF >> +static struct s3c2410_wdt_variant pmu_config_s3c2410 = { > > static const struct > >> + .disable_reg = 0x0, >> + .mask_reset_reg = 0x0, >> + .mask_bit = 0, > > nit: I would simply omit the three fields above, since they are irrelevant > when QUIRK_NEEDS_PMU_CONFIG flag is not set. Not even saying that when > unspecified, they default to zero. > checkpatch used to complain about that ... in general, static variables should not be initialized to 0. That is just unnecessary extra code. Guenter >> + .quirks = 0 >> }; >> >> +static struct s3c2410_wdt_variant pmu_config_5250 = { > > static const struct > >> + .disable_reg = WDT_DISABLE_REG_OFFSET, >> + .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET, >> + .mask_bit = 20, >> + .quirks = QUIRK_NEEDS_PMU_CONFIG >> +}; >> + >> +static struct s3c2410_wdt_variant pmu_config_5420 = { > > static const struct > >> + .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 = (struct s3c2410_wdt_variant *) &pmu_config_s3c2410 }, > > No need for the cast. > >> + { .compatible = "samsung,exynos5250-wdt", >> + .data = (struct s3c2410_wdt_variant *) &pmu_config_5250 }, > > Ditto. > >> + { .compatible = "samsung,exynos5420-wdt", >> + .data = (struct s3c2410_wdt_variant *) &pmu_config_5420 }, > > Ditto. > >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, s3c2410_wdt_match); >> +#endif >> + >> /* watchdog control routines */ >> >> #define DBG(fmt, ...) \ >> @@ -111,6 +160,47 @@ static inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb) >> return container_of(nb, struct s3c2410_wdt, freq_transition); >> } >> >> +static void s3c2410wdt_mask_and_disable_reset(int mask, struct s3c2410_wdt *wdt) > > This function should return int and propagate possible errors to the caller. > > Also the order of arguments is rather strange. The main context structure > is usually passed as first argument. > > In addition, bool probably would make more sense for mask argument than int. > >> +{ >> + int ret; >> + >> + if (mask) { >> + ret = regmap_update_bits(wdt->pmureg, >> + wdt->pmu_config->disable_reg, >> + (1 << wdt->pmu_config->mask_bit), >> + (1 << wdt->pmu_config->mask_bit)); >> + if (ret < 0) { >> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret); >> + return; >> + } >> + ret = regmap_update_bits(wdt->pmureg, >> + wdt->pmu_config->mask_reset_reg, >> + (1 << wdt->pmu_config->mask_bit), >> + (1 << wdt->pmu_config->mask_bit)); >> + if (ret < 0) { >> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret); >> + return; >> + } >> + } else { >> + ret = regmap_update_bits(wdt->pmureg, >> + wdt->pmu_config->disable_reg, >> + (1 << wdt->pmu_config->mask_bit), >> + (0 << wdt->pmu_config->mask_bit)); >> + if (ret < 0) { >> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret); >> + return; >> + } >> + ret = regmap_update_bits(wdt->pmureg, >> + wdt->pmu_config->mask_reset_reg, >> + (1 << wdt->pmu_config->mask_bit), >> + (0 << wdt->pmu_config->mask_bit)); >> + if (ret < 0) { >> + dev_err(wdt->dev, "failed to update reg(%d)\n", ret); >> + return; >> + } >> + } > > This is not really what I imagined. You can greatly simplify this code > by refactoring it as follows: > > static int s3c2410wdt_mask_and_disable_reset(struct s3c2410_wdt *wdt, bool mask) > { > int ret; > u32 mask_val = 1 << wdt->pmu_config->mask_bit; > u32 val = 0; > > if (mask) > val = mask_val; > > ret = regmap_update_bits(wdt->pmureg, > wdt->pmu_config->disable_reg, > mask_val, val); > if (ret < 0) { > dev_err(wdt->dev, "failed to update reg(%d)\n", ret); > return ret; > } > > ret = regmap_update_bits(wdt->pmureg, > wdt->pmu_config->mask_reset_reg, > mask_val, val); > if (ret < 0) { > dev_err(wdt->dev, "failed to update reg(%d)\n", ret); > return ret; > } > > return 0; > } > >> +} >> + >> static int s3c2410wdt_keepalive(struct watchdog_device *wdd) >> { >> struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd); >> @@ -332,6 +422,15 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt) >> } >> #endif >> >> +/* s3c2410_get_wdt_driver_data */ >> +static inline struct s3c2410_wdt_variant * > > const struct > >> +get_wdt_drv_data(struct platform_device *pdev) >> +{ >> + const struct of_device_id *match; >> + match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node); >> + return (struct s3c2410_wdt_variant *)match->data; > > This function does not handle non-DT cases, which will cause a NULL pointer > dereference when the device is instantiated from a board file. > >> +} >> + >> static int s3c2410wdt_probe(struct platform_device *pdev) >> { >> struct device *dev; >> @@ -354,6 +453,16 @@ static int s3c2410wdt_probe(struct platform_device *pdev) >> spin_lock_init(&wdt->lock); >> wdt->wdt_device = s3c2410_wdd; >> >> + wdt->pmu_config = (struct s3c2410_wdt_variant *) get_wdt_drv_data(pdev); > > No need for type cast here. > >> + if (wdt->pmu_config->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 +553,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev) >> (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis", >> (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis"); >> >> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) >> + s3c2410wdt_mask_and_disable_reset(0, wdt); > > Error should be handled here. Also false would be better than 0 here. > >> + >> return 0; >> >> err_cpufreq: >> @@ -461,6 +573,9 @@ static int s3c2410wdt_remove(struct platform_device *dev) >> { >> struct s3c2410_wdt *wdt = platform_get_drvdata(dev); >> >> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) >> + s3c2410wdt_mask_and_disable_reset(1, wdt); > > Error should be handled here. Also true would be better than 1 here. > >> + >> watchdog_unregister_device(&wdt->wdt_device); >> >> s3c2410wdt_cpufreq_deregister(wdt); >> @@ -475,6 +590,9 @@ static void s3c2410wdt_shutdown(struct platform_device *dev) >> { >> struct s3c2410_wdt *wdt = platform_get_drvdata(dev); >> >> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) >> + s3c2410wdt_mask_and_disable_reset(1, wdt); > > Error should be handled here. Also true would be better than 1 here. > >> + >> s3c2410wdt_stop(&wdt->wdt_device); >> } >> >> @@ -488,6 +606,9 @@ static int s3c2410wdt_suspend(struct device *dev) >> wdt->wtcon_save = readl(wdt->reg_base + S3C2410_WTCON); >> wdt->wtdat_save = readl(wdt->reg_base + S3C2410_WTDAT); >> >> + if (wdt->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) >> + s3c2410wdt_mask_and_disable_reset(1, wdt); > > Error should be handled here. Also true would be better than 1 here. > >> + >> /* Note that WTCNT doesn't need to be saved. */ >> s3c2410wdt_stop(&wdt->wdt_device); >> >> @@ -503,6 +624,9 @@ 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->pmu_config->quirks & QUIRK_NEEDS_PMU_CONFIG) >> + s3c2410wdt_mask_and_disable_reset(0, wdt); > > Error should be handled here. Also false would be better than 0 here. > > Best regards, > Tomasz > > -- > 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 > >