Re: [PATCH v4 12/12] watchdog: s3c2410: Add Exynos850 support

From: Sam Protsenko
Date: Mon Nov 22 2021 - 10:14:50 EST

On Sun, 21 Nov 2021 at 18:57, Sam Protsenko <semen.protsenko@xxxxxxxxxx> wrote:
>
> Exynos850 is a bit different from SoCs already supported in WDT driver:
> - AUTOMATIC_WDT_RESET_DISABLE register is removed, so its value is
> always 0; .disable_auto_reset callback is not set for that reason
> - MASK_WDT_RESET_REQUEST register is replaced with
> CLUSTERx_NONCPU_IN_EN register; instead of masking (disabling) WDT
> reset interrupt it's now enabled with the same value; .mask_reset
> callback is reused for that functionality though
> - To make WDT functional, WDT counter needs to be enabled in
> CLUSTERx_NONCPU_OUT register; it's done using .enable_counter
> callback
>
> Also Exynos850 has two CPU clusters, each has its own dedicated WDT
> instance. Different PMU registers and bits are used for each cluster. So
> driver data is now modified in probe, adding needed info depending on
> cluster index passed from device tree.
>
> Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---

Hi Guenter,

I've resent the whole series, but I can see you already applied my
previous series to your watchdog-next branch. So this patch is the
only one that actually changed in the whole series (with fixes for
0-day warning).

> Changes in v4:
> - Fixed build error when CONFIG_OF is disabled (found by 0-day):
> added #ifdef CONFIG_OF guard in s3c2410_get_wdt_drv_data()
> - Added R-b tag by Guenter Roeck
>
> Changes in v3:
> - Renamed "samsung,index" property to more descriptive
> "samsung,cluster-index"
> - Used pre-defined and completely set driver data for cluster0 and
> cluster1
>
> Changes in v2:
> - Used single compatible for Exynos850, populating missing driver data
> in probe
> - Added "index" property to specify CPU cluster index
>
> drivers/watchdog/s3c2410_wdt.c | 64 +++++++++++++++++++++++++++++++++-
> 1 file changed, 63 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 96aa5d9c6ed4..115a6fe7da57 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -56,6 +56,13 @@
> #define EXYNOS5_RST_STAT_REG_OFFSET 0x0404
> #define EXYNOS5_WDT_DISABLE_REG_OFFSET 0x0408
> #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET 0x040c
> +#define EXYNOS850_CLUSTER0_NONCPU_OUT 0x1220
> +#define EXYNOS850_CLUSTER0_NONCPU_INT_EN 0x1244
> +#define EXYNOS850_CLUSTER1_NONCPU_OUT 0x1620
> +#define EXYNOS850_CLUSTER1_NONCPU_INT_EN 0x1644
> +
> +#define EXYNOS850_CLUSTER0_WDTRESET_BIT 24
> +#define EXYNOS850_CLUSTER1_WDTRESET_BIT 23
>
> /**
> * Quirk flags for different Samsung watchdog IP-cores.
> @@ -205,6 +212,30 @@ static const struct s3c2410_wdt_variant drv_data_exynos7 = {
> QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_AUTO_DISABLE,
> };
>
> +static const struct s3c2410_wdt_variant drv_data_exynos850_cl0 = {
> + .mask_reset_reg = EXYNOS850_CLUSTER0_NONCPU_INT_EN,
> + .mask_bit = 2,
> + .mask_reset_inv = true,
> + .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
> + .rst_stat_bit = EXYNOS850_CLUSTER0_WDTRESET_BIT,
> + .cnt_en_reg = EXYNOS850_CLUSTER0_NONCPU_OUT,
> + .cnt_en_bit = 7,
> + .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
> + QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
> +};
> +
> +static const struct s3c2410_wdt_variant drv_data_exynos850_cl1 = {
> + .mask_reset_reg = EXYNOS850_CLUSTER1_NONCPU_INT_EN,
> + .mask_bit = 2,
> + .mask_reset_inv = true,
> + .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
> + .rst_stat_bit = EXYNOS850_CLUSTER1_WDTRESET_BIT,
> + .cnt_en_reg = EXYNOS850_CLUSTER1_NONCPU_OUT,
> + .cnt_en_bit = 7,
> + .quirks = QUIRK_HAS_WTCLRINT_REG | QUIRK_HAS_PMU_MASK_RESET | \
> + QUIRK_HAS_PMU_RST_STAT | QUIRK_HAS_PMU_CNT_EN,
> +};
> +
> static const struct of_device_id s3c2410_wdt_match[] = {
> { .compatible = "samsung,s3c2410-wdt",
> .data = &drv_data_s3c2410 },
> @@ -216,6 +247,8 @@ static const struct of_device_id s3c2410_wdt_match[] = {
> .data = &drv_data_exynos5420 },
> { .compatible = "samsung,exynos7-wdt",
> .data = &drv_data_exynos7 },
> + { .compatible = "samsung,exynos850-wdt",
> + .data = &drv_data_exynos850_cl0 },
> {},
> };
> MODULE_DEVICE_TABLE(of, s3c2410_wdt_match);
> @@ -587,14 +620,40 @@ static inline const struct s3c2410_wdt_variant *
> s3c2410_get_wdt_drv_data(struct platform_device *pdev)
> {
> const struct s3c2410_wdt_variant *variant;
> + struct device *dev = &pdev->dev;
>
> - variant = of_device_get_match_data(&pdev->dev);
> + variant = of_device_get_match_data(dev);
> if (!variant) {
> /* Device matched by platform_device_id */
> variant = (struct s3c2410_wdt_variant *)
> platform_get_device_id(pdev)->driver_data;
> }
>
> +#ifdef CONFIG_OF
> + /* Choose Exynos850 driver data w.r.t. cluster index */
> + if (variant == &drv_data_exynos850_cl0) {
> + u32 index;
> + int err;
> +
> + err = of_property_read_u32(dev->of_node,
> + "samsung,cluster-index", &index);
> + if (err) {
> + dev_err(dev, "failed to get cluster index\n");
> + return NULL;
> + }
> +
> + switch (index) {
> + case 0:
> + return &drv_data_exynos850_cl0;
> + case 1:
> + return &drv_data_exynos850_cl1;
> + default:
> + dev_err(dev, "wrong cluster index: %u\n", index);
> + return NULL;
> + }
> + }
> +#endif
> +
> return variant;
> }
>
> @@ -615,6 +674,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
> wdt->wdt_device = s3c2410_wdd;
>
> wdt->drv_data = s3c2410_get_wdt_drv_data(pdev);
> + if (!wdt->drv_data)
> + return -EINVAL;
> +
> if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
> wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
> "samsung,syscon-phandle");
> --
> 2.30.2
>