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?
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.
>
> 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.
> + 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.
> +};
> +
> +#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.
> +}
> +
> 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.
> +}
> +
> 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.
> +
> + 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.
Best regards,
Tomasz
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