Re: [PATCH v1 4/4] watchdog: npcm: sets card ext1 and ext2 bootstatus during probe

Guenter Roeck
2020-03-01T10:48:16Z

On 3/1/20 1:40 AM, Tomer Maimon wrote:
> During probe NPCM watchdog sets the following bootstatus flags:
> - WDIOF_CARDRESET represent power and core reset.
> - WDIOF_EXTERN1 represent watchdog 0-2 reset.
> - WDIOF_EXTERN2 represent software 1-4 reset.
>
> Each flag is representing a group of bootstatus.
> The user can configure through the device treethe exact reset
> to each flag group.
>

Sorry, this doesn't make sense to me. I could understand reporting
the above, but it looks to me like devicetree is used to associate
a reset bit from the controller with one of the above.
Devicetree only seems to be used to associate reset status bits
from the controller with WDIOF_CARDRESET, WDIOF_EXTERN1, or
WDIOF_EXTERN2. That adds a lot of complexity for little if any
gain.

It would make sense to set the bootstatus bits as suggested above,
but that doesn't require devicetree properties.

More comments inline.

Guenter

> Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
> ---
> drivers/watchdog/npcm_wdt.c | 132 ++++++++++++++++++++++++++++++++----
> 1 file changed, 119 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/watchdog/npcm_wdt.c b/drivers/watchdog/npcm_wdt.c
> index 8609c7acf17d..dba9a73249c9 100644
> --- a/drivers/watchdog/npcm_wdt.c
> +++ b/drivers/watchdog/npcm_wdt.c
> @@ -11,7 +11,24 @@
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> #include <linux/watchdog.h>
> -
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +
New include files in alphabetic order merged with existing ones, please.

> +/* NPCM7xx GCR module */
> +#define NPCM7XX_RESSR_OFFSET 0x6C
> +#define NPCM7XX_INTCR2_OFFSET 0x60
> +
> +#define NPCM7XX_PORST BIT(31)
> +#define NPCM7XX_CORST BIT(30)
> +#define NPCM7XX_WD0RST BIT(29)
> +#define NPCM7XX_WD1RST BIT(24)
> +#define NPCM7XX_WD2RST BIT(23)
> +#define NPCM7XX_SWR1RST BIT(28)
> +#define NPCM7XX_SWR2RST BIT(27)
> +#define NPCM7XX_SWR3RST BIT(26)
> +#define NPCM7XX_SWR4RST BIT(25)
> +
> + /* WD register */
> #define NPCM_WTCR 0x1C
>
> #define NPCM_WTCLK (BIT(10) | BIT(11)) /* Clock divider */
> @@ -43,6 +60,9 @@
> struct npcm_wdt {
> struct watchdog_device wdd;
> void __iomem *reg;
> + u32 card_reset;
> + u32 ext1_reset;
> + u32 ext2_reset;
> };
>
> static inline struct npcm_wdt *to_npcm_wdt(struct watchdog_device *wdd)
> @@ -103,30 +123,29 @@ static int npcm_wdt_stop(struct watchdog_device *wdd)
> return 0;
> }
>
> -
> static int npcm_wdt_set_timeout(struct watchdog_device *wdd,
> unsigned int timeout)
> {
> if (timeout < 2)
> wdd->timeout = 1;
> else if (timeout < 3)
> - wdd->timeout = 2;
> + wdd->timeout = 2;
> else if (timeout < 6)
> - wdd->timeout = 5;
> + wdd->timeout = 5;
> else if (timeout < 11)
> - wdd->timeout = 10;
> + wdd->timeout = 10;
> else if (timeout < 22)
> - wdd->timeout = 21;
> + wdd->timeout = 21;
> else if (timeout < 44)
> - wdd->timeout = 43;
> + wdd->timeout = 43;
> else if (timeout < 87)
> - wdd->timeout = 86;
> + wdd->timeout = 86;
> else if (timeout < 173)
> - wdd->timeout = 172;
> + wdd->timeout = 172;
> else if (timeout < 688)
> - wdd->timeout = 687;
> + wdd->timeout = 687;
> else
> - wdd->timeout = 2750;
> + wdd->timeout = 2750;
>

Whitespace changes in a separate patch, please.

> if (watchdog_active(wdd))
> npcm_wdt_start(wdd);
> @@ -177,9 +196,61 @@ static const struct watchdog_ops npcm_wdt_ops = {
> .restart = npcm_wdt_restart,
> };
>
> +static void npcm_get_reset_status(struct npcm_wdt *wdt, struct device *dev)
> +{
> + struct regmap *gcr_regmap;
> + u32 rstval;
> +
> + if (of_device_is_compatible(dev->of_node, "nuvoton,npcm750-wdt")) {
> + gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
> + if (IS_ERR(gcr_regmap))
> + dev_warn(dev, "Failed to find nuvoton,npcm750-gcr WD reset status not supported\n");
> +
> + regmap_read(gcr_regmap, NPCM7XX_RESSR_OFFSET, &rstval);
> + if (!rstval) {
> + regmap_read(gcr_regmap, NPCM7XX_INTCR2_OFFSET, &rstval);
> + rstval = ~rstval;
> + }

The second register reports the same as the first only negated if
bits in the first register are not set ? That seems unlikely.
Please point to the datasheet, or at least provide a reference to the
two registers.

> +
> + if (rstval & wdt->card_reset)
> + wdt->wdd.bootstatus |= WDIOF_CARDRESET;
> + if (rstval & wdt->ext1_reset)
> + wdt->wdd.bootstatus |= WDIOF_EXTERN1;
> + if (rstval & wdt->ext2_reset)
> + wdt->wdd.bootstatus |= WDIOF_EXTERN2;
> + }
> +}
> +
> +static u32 npcm_wdt_reset_type(const char *reset_type)
> +{
> + if (!strcmp(reset_type, "porst"))
> + return NPCM7XX_PORST;
> + else if (!strcmp(reset_type, "corst"))
> + return NPCM7XX_CORST;
> + else if (!strcmp(reset_type, "wd0"))
> + return NPCM7XX_WD0RST;
> + else if (!strcmp(reset_type, "wd1"))
> + return NPCM7XX_WD1RST;
> + else if (!strcmp(reset_type, "wd2"))
> + return NPCM7XX_WD2RST;
> + else if (!strcmp(reset_type, "sw1"))
> + return NPCM7XX_SWR1RST;
> + else if (!strcmp(reset_type, "sw2"))
> + return NPCM7XX_SWR2RST;
> + else if (!strcmp(reset_type, "sw3"))
> + return NPCM7XX_SWR3RST;
> + else if (!strcmp(reset_type, "sw4"))
> + return NPCM7XX_SWR4RST;
> +
> + return 0;
> +}
> +
> static int npcm_wdt_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> + const char *card_reset_type;
> + const char *ext1_reset_type;
> + const char *ext2_reset_type;
> struct npcm_wdt *wdt;
> u32 priority;
> int irq;
> @@ -202,6 +273,39 @@ static int npcm_wdt_probe(struct platform_device *pdev)
> else
> watchdog_set_restart_priority(&wdt->wdd, priority);
>
> + ret = of_property_read_string(pdev->dev.of_node,
> + "nuvoton,card-reset-type",
> + &card_reset_type);
> + if (ret) {
> + wdt->card_reset = NPCM7XX_PORST;
> + } else {
> + wdt->card_reset = npcm_wdt_reset_type(card_reset_type);
> + if (!wdt->card_reset)
> + wdt->card_reset = NPCM7XX_PORST;
> + }
> +
> + ret = of_property_read_string(pdev->dev.of_node,
> + "nuvoton,ext1-reset-type",
> + &ext1_reset_type);
> + if (ret) {
> + wdt->ext1_reset = NPCM7XX_WD0RST;
> + } else {
> + wdt->ext1_reset = npcm_wdt_reset_type(ext1_reset_type);
> + if (!wdt->ext1_reset)
> + wdt->ext1_reset = NPCM7XX_WD0RST;
> + }
> +
> + ret = of_property_read_string(pdev->dev.of_node,
> + "nuvoton,ext2-reset-type",
> + &ext2_reset_type);
> + if (ret) {
> + wdt->ext2_reset = NPCM7XX_SWR1RST;
> + } else {
> + wdt->ext2_reset = npcm_wdt_reset_type(ext2_reset_type);
> + if (!wdt->ext2_reset)
> + wdt->ext2_reset = NPCM7XX_SWR1RST;
> + }
> +
> wdt->wdd.info = &npcm_wdt_info;
> wdt->wdd.ops = &npcm_wdt_ops;
> wdt->wdd.min_timeout = 1;
> @@ -220,8 +324,10 @@ static int npcm_wdt_probe(struct platform_device *pdev)
> set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
> }
>
> - ret = devm_request_irq(dev, irq, npcm_wdt_interrupt, 0, "watchdog",
> - wdt);
> + npcm_get_reset_status(wdt, dev);
> +
> + ret = devm_request_irq(dev, irq, npcm_wdt_interrupt, 0,
> + "watchdog", wdt);
> if (ret)
> return ret;
>
>