2017-12-05 04:45:37

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH V1 3/4] qcom: spmi-wled: Add support for OVP interrupt handling

On Thu 16 Nov 04:18 PST 2017, Kiran Gunda wrote:

> WLED peripheral has over voltage protection(OVP) circuitry and the OVP
> fault is notified through an interrupt. Though this fault condition rising
> is due to an incorrect hardware configuration is mitigated in the hardware,
> it still needs to be detected and handled. Add support for it.
>
> When WLED module is enabled, keep OVP fault interrupt disabled for 10 ms to
> account for soft start delay.
>
> Signed-off-by: Kiran Gunda <[email protected]>
> ---
> .../bindings/leds/backlight/qcom-spmi-wled.txt | 7 +-
> drivers/video/backlight/qcom-spmi-wled.c | 83 ++++++++++++++++++++++
> 2 files changed, 87 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt b/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt
> index 768608c..d39ee93 100644
> --- a/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt
> +++ b/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt
> @@ -92,7 +92,7 @@ The PMIC is connected to the host processor via SPMI bus.
> Usage: optional
> Value type: <string>
> Definition: Interrupt names associated with the interrupts.
> - Must be "sc-irq".
> + Currently supported interrupts are "sc-irq" and "ovp-irq".
>

As before, we know this is an IRQ, so omit the -irq from the name.

[..]
> diff --git a/drivers/video/backlight/qcom-spmi-wled.c b/drivers/video/backlight/qcom-spmi-wled.c
[..]
> @@ -115,6 +123,28 @@ static int qcom_wled_module_enable(struct qcom_wled *wled, int val)
> rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
> QCOM_WLED_CTRL_MOD_ENABLE, QCOM_WLED_CTRL_MOD_EN_MASK,
> val << QCOM_WLED_CTRL_MODULE_EN_SHIFT);
> + if (rc < 0)
> + return rc;
> + /*
> + * Wait for at least 10ms before enabling OVP fault interrupt after
> + * enabling the module so that soft start is completed. Keep the OVP
> + * interrupt disabled when the module is disabled.
> + */
> + if (val) {
> + usleep_range(QCOM_WLED_SOFT_START_DLY_US,
> + QCOM_WLED_SOFT_START_DLY_US + 1000);

This is sleeping in the brightness/enable code path, can you
schedule_delayed_work() instead to not block this code path
unnecessarily?

> +
> + if (wled->cfg.ovp_irq > 0 && wled->ovp_irq_disabled) {
> + enable_irq(wled->cfg.ovp_irq);
> + wled->ovp_irq_disabled = false;
> + }
> + } else {
> + if (wled->cfg.ovp_irq > 0 && !wled->ovp_irq_disabled) {
> + disable_irq(wled->cfg.ovp_irq);
> + wled->ovp_irq_disabled = true;
> + }
> + }
> +
> return rc;
> }
>
> @@ -264,12 +294,42 @@ static irqreturn_t qcom_wled_sc_irq_handler(int irq, void *_wled)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t qcom_wled_ovp_irq_handler(int irq, void *_wled)
> +{
> + struct qcom_wled *wled = _wled;
> + int rc;
> + u32 int_sts, fault_sts;
> +
> + rc = regmap_read(wled->regmap,
> + wled->ctrl_addr + QCOM_WLED_CTRL_INT_RT_STS, &int_sts);
> + if (rc < 0) {
> + pr_err("Error in reading WLED_INT_RT_STS rc=%d\n", rc);
> + return IRQ_HANDLED;
> + }
> +
> + rc = regmap_read(wled->regmap, wled->ctrl_addr +
> + QCOM_WLED_CTRL_FAULT_STATUS, &fault_sts);
> + if (rc < 0) {
> + pr_err("Error in reading WLED_FAULT_STATUS rc=%d\n", rc);
> + return IRQ_HANDLED;
> + }
> +
> + if (fault_sts &
> + (QCOM_WLED_CTRL_OVP_FAULT_BIT | QCOM_WLED_CTRL_ILIM_FAULT_BIT))
> + pr_err("WLED OVP fault detected, int_sts=%x fault_sts= %x\n",
> + int_sts, fault_sts);

All this function does is print things to the log. When is this
information consumed and by whom? dev_dbg() instead?

> +
> + return IRQ_HANDLED;
> +}
> +
> static int qcom_wled_setup(struct qcom_wled *wled)
> {
> int rc, temp, i;
> u8 sink_en = 0;
> + u32 val;
> u8 string_cfg = wled->cfg.string_cfg;
> int sc_irq = wled->cfg.sc_irq;
> + int ovp_irq = wled->cfg.ovp_irq;
>
> rc = regmap_update_bits(wled->regmap,
> wled->ctrl_addr + QCOM_WLED_CTRL_OVP,
> @@ -367,6 +427,25 @@ static int qcom_wled_setup(struct qcom_wled *wled)
> }
> }
>
> + if (ovp_irq >= 0) {

As with the previous patch.

[..]
> @@ -539,6 +618,10 @@ static int qcom_wled_configure(struct qcom_wled *wled, struct device *dev)
[..]
> + wled->cfg.ovp_irq = platform_get_irq_byname(wled->pdev, "ovp-irq");
> + if (wled->cfg.ovp_irq < 0)
> + dev_dbg(&wled->pdev->dev, "ovp irq is not used\n");
> +

Regards,
Bjorn


2017-12-11 09:31:45

by Kiran Gunda

[permalink] [raw]
Subject: Re: [PATCH V1 3/4] qcom: spmi-wled: Add support for OVP interrupt handling

On 2017-12-05 10:15, Bjorn Andersson wrote:
> On Thu 16 Nov 04:18 PST 2017, Kiran Gunda wrote:
>
>> WLED peripheral has over voltage protection(OVP) circuitry and the OVP
>> fault is notified through an interrupt. Though this fault condition
>> rising
>> is due to an incorrect hardware configuration is mitigated in the
>> hardware,
>> it still needs to be detected and handled. Add support for it.
>>
>> When WLED module is enabled, keep OVP fault interrupt disabled for 10
>> ms to
>> account for soft start delay.
>>
>> Signed-off-by: Kiran Gunda <[email protected]>
>> ---
>> .../bindings/leds/backlight/qcom-spmi-wled.txt | 7 +-
>> drivers/video/backlight/qcom-spmi-wled.c | 83
>> ++++++++++++++++++++++
>> 2 files changed, 87 insertions(+), 3 deletions(-)
>>
>> diff --git
>> a/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt
>> b/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt
>> index 768608c..d39ee93 100644
>> ---
>> a/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt
>> +++
>> b/Documentation/devicetree/bindings/leds/backlight/qcom-spmi-wled.txt
>> @@ -92,7 +92,7 @@ The PMIC is connected to the host processor via SPMI
>> bus.
>> Usage: optional
>> Value type: <string>
>> Definition: Interrupt names associated with the interrupts.
>> - Must be "sc-irq".
>> + Currently supported interrupts are "sc-irq" and "ovp-irq".
>>
>
> As before, we know this is an IRQ, so omit the -irq from the name.
>
> [..]
Sure. Will change it in the next series.
>> diff --git a/drivers/video/backlight/qcom-spmi-wled.c
>> b/drivers/video/backlight/qcom-spmi-wled.c
> [..]
>> @@ -115,6 +123,28 @@ static int qcom_wled_module_enable(struct
>> qcom_wled *wled, int val)
>> rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
>> QCOM_WLED_CTRL_MOD_ENABLE, QCOM_WLED_CTRL_MOD_EN_MASK,
>> val << QCOM_WLED_CTRL_MODULE_EN_SHIFT);
>> + if (rc < 0)
>> + return rc;
>> + /*
>> + * Wait for at least 10ms before enabling OVP fault interrupt after
>> + * enabling the module so that soft start is completed. Keep the OVP
>> + * interrupt disabled when the module is disabled.
>> + */
>> + if (val) {
>> + usleep_range(QCOM_WLED_SOFT_START_DLY_US,
>> + QCOM_WLED_SOFT_START_DLY_US + 1000);
>
> This is sleeping in the brightness/enable code path, can you
> schedule_delayed_work() instead to not block this code path
> unnecessarily?
>
Sure. Will change it in the next series.
>> +
>> + if (wled->cfg.ovp_irq > 0 && wled->ovp_irq_disabled) {
>> + enable_irq(wled->cfg.ovp_irq);
>> + wled->ovp_irq_disabled = false;
>> + }
>> + } else {
>> + if (wled->cfg.ovp_irq > 0 && !wled->ovp_irq_disabled) {
>> + disable_irq(wled->cfg.ovp_irq);
>> + wled->ovp_irq_disabled = true;
>> + }
>> + }
>> +
>> return rc;
>> }
>>
>> @@ -264,12 +294,42 @@ static irqreturn_t qcom_wled_sc_irq_handler(int
>> irq, void *_wled)
>> return IRQ_HANDLED;
>> }
>>
>> +static irqreturn_t qcom_wled_ovp_irq_handler(int irq, void *_wled)
>> +{
>> + struct qcom_wled *wled = _wled;
>> + int rc;
>> + u32 int_sts, fault_sts;
>> +
>> + rc = regmap_read(wled->regmap,
>> + wled->ctrl_addr + QCOM_WLED_CTRL_INT_RT_STS, &int_sts);
>> + if (rc < 0) {
>> + pr_err("Error in reading WLED_INT_RT_STS rc=%d\n", rc);
>> + return IRQ_HANDLED;
>> + }
>> +
>> + rc = regmap_read(wled->regmap, wled->ctrl_addr +
>> + QCOM_WLED_CTRL_FAULT_STATUS, &fault_sts);
>> + if (rc < 0) {
>> + pr_err("Error in reading WLED_FAULT_STATUS rc=%d\n", rc);
>> + return IRQ_HANDLED;
>> + }
>> +
>> + if (fault_sts &
>> + (QCOM_WLED_CTRL_OVP_FAULT_BIT | QCOM_WLED_CTRL_ILIM_FAULT_BIT))
>> + pr_err("WLED OVP fault detected, int_sts=%x fault_sts= %x\n",
>> + int_sts, fault_sts);
>
> All this function does is print things to the log. When is this
> information consumed and by whom? dev_dbg() instead?
>
Sure. Will change it in the next series.
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> static int qcom_wled_setup(struct qcom_wled *wled)
>> {
>> int rc, temp, i;
>> u8 sink_en = 0;
>> + u32 val;
>> u8 string_cfg = wled->cfg.string_cfg;
>> int sc_irq = wled->cfg.sc_irq;
>> + int ovp_irq = wled->cfg.ovp_irq;
>>
>> rc = regmap_update_bits(wled->regmap,
>> wled->ctrl_addr + QCOM_WLED_CTRL_OVP,
>> @@ -367,6 +427,25 @@ static int qcom_wled_setup(struct qcom_wled
>> *wled)
>> }
>> }
>>
>> + if (ovp_irq >= 0) {
>
> As with the previous patch.
>
> [..]
Sure. Will change it in the next series.
>> @@ -539,6 +618,10 @@ static int qcom_wled_configure(struct qcom_wled
>> *wled, struct device *dev)
> [..]
>> + wled->cfg.ovp_irq = platform_get_irq_byname(wled->pdev, "ovp-irq");
>> + if (wled->cfg.ovp_irq < 0)
>> + dev_dbg(&wled->pdev->dev, "ovp irq is not used\n");
>> +
>
> Regards,
> Bjorn