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
>>>>
>>>>
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