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Date: Tue, 12 Nov 2019 11:22:44 -0800
From: Bjorn Andersson <bjorn.andersson@...aro.org>
To: Amit Kucheria <amit.kucheria@...aro.org>
Cc: linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
edubezval@...il.com, swboyd@...omium.org, sivaa@...eaurora.org,
Andy Gross <agross@...nel.org>,
Daniel Lezcano <daniel.lezcano@...aro.org>,
Amit Kucheria <amit.kucheria@...durent.com>,
linux-pm@...r.kernel.org
Subject: Re: [PATCH 2/3] drivers: thermal: tsens: Add watchdog support
On Mon 11 Nov 11:21 PST 2019, Amit Kucheria wrote:
> TSENS IP v2.3 onwards adds support for a watchdog to detect if the TSENS
> HW FSM is frozen. Add support to detect and restart the FSM in the
> driver. The watchdog is configured by the bootloader, we just enable the
> feature in the kernel.
>
> Signed-off-by: Amit Kucheria <amit.kucheria@...aro.org>
> ---
> drivers/thermal/qcom/tsens-common.c | 41 +++++++++++++++++++++++++++++
> drivers/thermal/qcom/tsens-v2.c | 10 +++++++
> drivers/thermal/qcom/tsens.h | 12 +++++++++
> 3 files changed, 63 insertions(+)
>
> diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c
> index 2989cb952cdb..9432518502a7 100644
> --- a/drivers/thermal/qcom/tsens-common.c
> +++ b/drivers/thermal/qcom/tsens-common.c
> @@ -378,6 +378,28 @@ irqreturn_t tsens_critical_irq_thread(int irq, void *data)
> bool enable = true, disable = false;
> unsigned long flags;
> int temp, ret, i;
> + u32 wdog_status, wdog_count, ver_minor;
> +
> + ret = regmap_field_read(priv->rf[VER_MINOR], &ver_minor);
The version is unlikely to change from one interrupt to the next, so I
suggest that you add a boolean "has_watchdog" to your context that you
populate in init_common.
> + if (ret)
> + return ret;
> +
> + if (tsens_version(priv) > VER_1_X && ver_minor > 2) {
> + /* Watchdog is present only on v2.3+ */
> + ret = regmap_field_read(priv->rf[WDOG_BARK_STATUS], &wdog_status);
> + if (ret)
> + return ret;
> +
> + /* Clear WDOG interrupt */
> + regmap_field_write(priv->rf[WDOG_BARK_CLEAR], 1);
> + regmap_field_write(priv->rf[WDOG_BARK_CLEAR], 0);
> +
> + ret = regmap_field_read(priv->rf[WDOG_BARK_COUNT], &wdog_count);
> + if (ret)
> + return ret;
> + if (wdog_count)
> + dev_err(priv->dev, "%s: watchdog count: %d\n", __func__, wdog_count);
What's the benefit of reading wdog_count and who's the audience for this
print? What do I do when this goes to 11?
Regards,
Bjorn
> + }
>
> for (i = 0; i < priv->num_sensors; i++) {
> struct tsens_sensor *s = &priv->sensor[i];
> @@ -685,6 +707,7 @@ int __init init_common(struct tsens_priv *priv)
> {
> void __iomem *tm_base, *srot_base;
> struct device *dev = priv->dev;
> + u32 ver_minor;
> struct resource *res;
> u32 enabled;
> int ret, i, j;
> @@ -734,6 +757,9 @@ int __init init_common(struct tsens_priv *priv)
> if (IS_ERR(priv->rf[i]))
> return PTR_ERR(priv->rf[i]);
> }
> + ret = regmap_field_read(priv->rf[VER_MINOR], &ver_minor);
> + if (ret)
> + goto err_put_device;
> }
>
> priv->rf[TSENS_EN] = devm_regmap_field_alloc(dev, priv->srot_map,
> @@ -794,6 +820,21 @@ int __init init_common(struct tsens_priv *priv)
> }
> }
>
> + if (tsens_version(priv) > VER_1_X && ver_minor > 2) {
> + /* Watchdog is present only on v2.3+ */
> + for (i = 0, j = WDOG_BARK_STATUS; j <= CC_MON_MASK; i++, j++) {
> + priv->rf[j] = devm_regmap_field_alloc(dev, priv->tm_map,
> + priv->fields[j]);
> + if (IS_ERR(priv->rf[j])) {
> + ret = PTR_ERR(priv->rf[j]);
> + goto err_put_device;
> + }
> + }
> + /* Enable WDOG and disable cycle completion monitoring */
> + regmap_field_write(priv->rf[WDOG_BARK_MASK], 0);
> + regmap_field_write(priv->rf[CC_MON_MASK], 1);
> + }
> +
> spin_lock_init(&priv->ul_lock);
> tsens_enable_irq(priv);
> tsens_debug_init(op);
> diff --git a/drivers/thermal/qcom/tsens-v2.c b/drivers/thermal/qcom/tsens-v2.c
> index 47d831df0803..4184850d1e42 100644
> --- a/drivers/thermal/qcom/tsens-v2.c
> +++ b/drivers/thermal/qcom/tsens-v2.c
> @@ -24,6 +24,7 @@
> #define TM_Sn_CRITICAL_THRESHOLD_OFF 0x0060
> #define TM_Sn_STATUS_OFF 0x00a0
> #define TM_TRDY_OFF 0x00e4
> +#define TM_WDOG_LOG_OFF 0x013c
>
> /* v2.x: 8996, 8998, sdm845 */
>
> @@ -66,6 +67,15 @@ static const struct reg_field tsens_v2_regfields[MAX_REGFIELDS] = {
> REG_FIELD_SPLIT_BITS_0_15(CRIT_INT_CLEAR, TM_CRITICAL_INT_CLEAR_OFF),
> REG_FIELD_SPLIT_BITS_0_15(CRIT_INT_MASK, TM_CRITICAL_INT_MASK_OFF),
>
> + /* WATCHDOG on v2.3 or later */
> + [WDOG_BARK_STATUS] = REG_FIELD(TM_CRITICAL_INT_STATUS_OFF, 31, 31),
> + [WDOG_BARK_CLEAR] = REG_FIELD(TM_CRITICAL_INT_CLEAR_OFF, 31, 31),
> + [WDOG_BARK_MASK] = REG_FIELD(TM_CRITICAL_INT_MASK_OFF, 31, 31),
> + [CC_MON_STATUS] = REG_FIELD(TM_CRITICAL_INT_STATUS_OFF, 30, 30),
> + [CC_MON_CLEAR] = REG_FIELD(TM_CRITICAL_INT_CLEAR_OFF, 30, 30),
> + [CC_MON_MASK] = REG_FIELD(TM_CRITICAL_INT_MASK_OFF, 30, 30),
> + [WDOG_BARK_COUNT] = REG_FIELD(TM_WDOG_LOG_OFF, 0, 7),
> +
> /* Sn_STATUS */
> REG_FIELD_FOR_EACH_SENSOR16(LAST_TEMP, TM_Sn_STATUS_OFF, 0, 11),
> REG_FIELD_FOR_EACH_SENSOR16(VALID, TM_Sn_STATUS_OFF, 21, 21),
> diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
> index 9b5a30533c52..7608e7877a7b 100644
> --- a/drivers/thermal/qcom/tsens.h
> +++ b/drivers/thermal/qcom/tsens.h
> @@ -440,6 +440,18 @@ enum regfield_ids {
> CRIT_THRESH_13,
> CRIT_THRESH_14,
> CRIT_THRESH_15,
> +
> + /* WATCHDOG */
> + WDOG_BARK_STATUS,
> + WDOG_BARK_CLEAR,
> + WDOG_BARK_MASK,
> + WDOG_BARK_COUNT,
> +
> + /* CYCLE COMPLETION MONITOR */
> + CC_MON_STATUS,
> + CC_MON_CLEAR,
> + CC_MON_MASK,
> +
> MIN_STATUS_0, /* MIN threshold violated */
> MIN_STATUS_1,
> MIN_STATUS_2,
> --
> 2.17.1
>
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