Hi Tomasz,
On Wed, Oct 30, 2013 at 8:09 PM, Tomasz Figa <t.figa@xxxxxxxxxxx> wrote:
> Hi Leela,
>
> On Wednesday 30 of October 2013 15:21:13 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 <l.krishna@xxxxxxxxxxx>
>> ---
>> .../devicetree/bindings/watchdog/samsung-wdt.txt | 19 +++-
>> drivers/watchdog/s3c2410_wdt.c | 112 ++++++++++++++++++--
>> 2 files changed, 122 insertions(+), 9 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
>> index 2aa486c..5a9889b 100644
>> --- a/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
>> +++ b/Documentation/devicetree/bindings/watchdog/samsung-wdt.txt
>> @@ -5,10 +5,27 @@ 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,pmusysreg : reference node to pmu sysreg (required only in case of Exynos5250 and 5420)
>
> I don't really like the name of this property. Maybe
> samsung,syscon-phandle would be better?
>
Okay, changed.
> I'm not sure if this property should be tied to PMU, as on future SoCs
> those registers might be located in another syscon-style IP. The
> description should note that in case of Exynos 5250 and 5420 this should
> point to the PMU node, though.
>
Added
>>
>> 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>;
>> + status = "okay";
>> +};
>> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
>> index 23aad7c..d8aefef 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 +90,12 @@ 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 pmu_config {
>
> For the sake of future extensibility I'd rename this struct to
> s3c2410_wdt_variant and add an u32 quirks field, which would has
> the QUIRK_NEEDS_PMU_CONFIG set for 5250 and 5420 variants.
>
Modified
>> + int disable_reg;
>> + int mask_reset_reg;
>> + int mask_bit;
>> +};
>> +
>> struct s3c2410_wdt {
>> struct device *dev;
>> struct clk *clock;
>> @@ -94,7 +106,34 @@ struct s3c2410_wdt {
>> unsigned long wtdat_save;
>> struct watchdog_device wdt_device;
>> struct notifier_block freq_transition;
>> + struct pmu_config *wdt_pmu_config;
>> + struct regmap *pmureg;
>> + unsigned int quirks;
>
> Quirks should be a static per-variant property.
>
Taken care
>> +};
>> +
>> +#ifdef CONFIG_OF
>> +static struct pmu_config pmu_config_5250 = {
>> + .disable_reg = WDT_DISABLE_REG_OFFSET,
>> + .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
>> + .mask_bit = 20
>> +};
>> +
>> +static struct pmu_config pmu_config_5420 = {
>> + .disable_reg = WDT_DISABLE_REG_OFFSET,
>> + .mask_reset_reg = WDT_MASK_RESET_REG_OFFSET,
>> + .mask_bit = 0
>> +};
>> +
>> +static const struct of_device_id s3c2410_wdt_match[] = {
>> + { .compatible = "samsung,s3c2410-wdt" },
>
> If you follow what I suggested above, the basic variant would also have
> a variant struct associated with it, which would be more consistent.
>
>> + { .compatible = "samsung,exynos5250-wdt",
>> + .data = (struct pmu_config *) &pmu_config_5250 },
>> + { .compatible = "samsung,exynos5420-wdt",
>> + .data = (struct pmu_config *) &pmu_config_5420 },
>> + {},
>> };
>> +MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
>> +#endif
>>
>> /* watchdog control routines */
>>
>> @@ -111,6 +150,38 @@ 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)
>> +{
>> + unsigned int disable, mask_reset;
>> + int ret;
>> +
>> + ret = regmap_read(wdt->pmureg, wdt->wdt_pmu_config->disable_reg,
>> + &disable);
>> + if (ret < 0) {
>> + dev_err(wdt->dev, "failed to read disable reg(%d)\n", ret);
>> + return;
>> + }
>> +
>> + ret = regmap_read(wdt->pmureg, wdt->wdt_pmu_config->mask_reset_reg,
>> + &mask_reset);
>> + if (ret < 0) {
>> + dev_err(wdt->dev, "failed to read mask reset reg(%d)\n", ret);
>> + return;
>> + }
>> +
>> + if (mask) {
>> + disable |= (1 << wdt->wdt_pmu_config->mask_bit);
>> + mask_reset |= (1 << wdt->wdt_pmu_config->mask_bit);
>> + } else {
>> + disable &= ~(1 << wdt->wdt_pmu_config->mask_bit);
>> + mask_reset &= ~(1 << wdt->wdt_pmu_config->mask_bit);
>> + }
>> +
>> + regmap_write(wdt->pmureg, wdt->wdt_pmu_config->disable_reg, disable);
>> + regmap_write(wdt->pmureg, wdt->wdt_pmu_config->mask_reset_reg,
>> + mask_reset);
>
> I believe you can (and on some SoCs even have to, due to other bits in the
> registers being used for other purposes) use regmap_update_bits() for
> read-modify-write sequences above.
>
Okay, Modified
>> +}
>> +
>> static int s3c2410wdt_keepalive(struct watchdog_device *wdd)
>> {
>> struct s3c2410_wdt *wdt = watchdog_get_drvdata(wdd);
>> @@ -332,6 +403,14 @@ static inline void s3c2410wdt_cpufreq_deregister(struct s3c2410_wdt *wdt)
>> }
>> #endif
>>
>> +/* s3c2410_get_wdt_driver_data */
>> +static inline unsigned int get_wdt_driver_data(struct platform_device *pdev)
>> +{
>> + const struct of_device_id *match;
>> + match = of_match_node(s3c2410_wdt_match, pdev->dev.of_node);
>> + return (unsigned int)match->data;
>
> Why do you need this cast? I believe this function should simply return
> (const struct pmu_config *) or (const struct s3c2410_wdt_variant *) when
> my comments above get addressed.
>
My mistake, Changed
>> +}
>> +
>> static int s3c2410wdt_probe(struct platform_device *pdev)
>> {
>> struct device *dev;
>> @@ -354,6 +433,17 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>> spin_lock_init(&wdt->lock);
>> wdt->wdt_device = s3c2410_wdd;
>>
>> + wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
>> + "samsung,pmusysreg");
>> + if (IS_ERR(wdt->pmureg)) {
>> + dev_err(dev, "syscon regmap lookup failed.\n");
>> + return PTR_ERR(wdt->pmureg);
>> + }
>
> This should be performed only if given variant has the
> QUIRK_NEEDS_PMU_CONFIG flag set in its variant data. Otherwise you don't
> have any distinction between cases when PMU is not needed (and so
> unspecified) and PMU is needed, but unspecified.
>
Okay, Taken care
>> +
>> + wdt->wdt_pmu_config = (struct pmu_config *) get_wdt_driver_data(pdev);
>> + if (wdt->wdt_pmu_config)
>> + wdt->quirks = QUIRK_NEEDS_PMU_CONFIG;
>
> See my comment on quirks above.
>
>> +
>> wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
>> if (wdt_irq == NULL) {
>> dev_err(dev, "no irq resource specified\n");
>> @@ -444,6 +534,8 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>> (wtcon & S3C2410_WTCON_RSTEN) ? "en" : "dis",
>> (wtcon & S3C2410_WTCON_INTEN) ? "en" : "dis");
>>
>> + if (wdt->quirks & QUIRK_NEEDS_PMU_CONFIG)
>> + s3c2410wdt_mask_and_disable_reset(0, wdt);
>
> nit: Blank line here would be nice.
>
Done.
Best Wishes,
Leela Krishna
> Best regards,
> Tomasz
>
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