Re: [PATCH fixes 2/2] extcon: max77693: Fix always masked MUIC interrupts

Chanwoo Choi
2014-10-10T10:05:51Z

On 10/10/2014 06:03 PM, Krzysztof Kozlowski wrote:
> On pią, 2014-10-10 at 17:45 +0900, Chanwoo Choi wrote:
>> On 10/10/2014 05:22 PM, Krzysztof Kozlowski wrote:
>>> All interrupts coming from MUIC were ignored because interrupt source
>>> register was masked.
>>>
>>> The Maxim 77693 has a "interrupt source" - a separate register and interrupts
>>> which give information about PMIC block triggering the individual
>>> interrupt (charger, topsys, MUIC, flash LED).
>>>
>>> By default bootloader could initialize this register to "mask all"
>>> value. In such case (observed on Trats2 board) MUIC interrupts won't be
>>> generated regardless of their mask status. Regmap irq chip was unmasking
>>> individual MUIC interrupts but the source was masked
>>>
>>> Before introducing regmap irq chip this interrupt source was unmasked,
>>> read and acked. Reading and acking is not necessary but unmasking is. Do
>>> it in extcon driver.
>>>
>>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>>> Cc: <stable@vger.kernel.org>
>>> Fixes: 342d669c1ee4 ("mfd: max77693: Handle IRQs using regmap")
>>> ---
>>> drivers/extcon/extcon-max77693.c | 16 ++++++++++++++++
>>> include/linux/mfd/max77693-private.h | 5 +++++
>>> 2 files changed, 21 insertions(+)
>>>
>>> diff --git a/drivers/extcon/extcon-max77693.c b/drivers/extcon/extcon-max77693.c
>>> index 490e27475bac..d3adacf3187f 100644
>>> --- a/drivers/extcon/extcon-max77693.c
>>> +++ b/drivers/extcon/extcon-max77693.c
>>> @@ -1176,6 +1176,22 @@ static int max77693_muic_probe(struct platform_device *pdev)
>>> }
>>> }
>>>
>>> + if (i) {
>>> + /*
>>> + * i>0, at least one MUIC interrupt requested so need to unmask
>>> + * MUIC interrupt in INTSRC register. Without that MUIC
>>> + * interrupts will not be reported.
>>> + */
>>> + ret = regmap_update_bits(max77693->regmap,
>>> + MAX77693_PMIC_REG_INTSRC_MASK, SRC_IRQ_MUIC,
>>> + ~SRC_IRQ_MUIC);
>>> + if (ret < 0) {
>>> + dev_err(&pdev->dev, "Could not unmask MUIC interrupt in INTSRC: %d\n",
>>> + ret);
>>> + return ret;
>>> + }
>>> + }
>>> +
>>
>> No,
>> The extcon-max77693 driver cannot enable IRQ_CHARGER/TOP/FLASH
>> because MAX77693_PMIC_REG_INTSRC_MASK register is common register of MAX77693.
>>
>> The IRQ_CHARGER/TOP/FLASH of MAX77693_PMIC_REG_INTSRC_MASK register should be enabled
>> in drivers/mfd/max77693.c.
>
> The code above unmasks only SRC_IRQ_MUIC. Other bits are not touched.
> Why do you think that other IRQs will be enabled?

I think that MAX77693_PMIC_REG_INTSRC_MASK common register better to be controlled
in drivers/mfd/max77693.c. I prefer that MAX77693 extcon driver would read/write only MUIC registers.

Also, MAX77693 extcon driver have to be always unmasked.
If IRQ_MUIC is masked, MAX77693 extcon driver could not detect any external cables.

For example,
The max77836 enable MUIC_IRQ by un-masking MUIC_IRQ.
You can check it on drivers/mfd/max14577.c (line 251~258)

Best Regards,
Chanwoo Choi

>
> Best regards,
> Krzysztof
>
>>
>>> /* Initialize extcon device */
>>> info->edev = devm_extcon_dev_allocate(&pdev->dev,
>>> max77693_extcon_cable);
>>> diff --git a/include/linux/mfd/max77693-private.h b/include/linux/mfd/max77693-private.h
>>> index e1b2b61285b9..4f1a80b66ecf 100644
>>> --- a/include/linux/mfd/max77693-private.h
>>> +++ b/include/linux/mfd/max77693-private.h
>>> @@ -438,6 +438,11 @@ enum max77693_irq_source {
>>> MAX77693_IRQ_GROUP_NR,
>>> };
>>>
>>> +#define SRC_IRQ_CHARGER BIT(0)
>>> +#define SRC_IRQ_TOP BIT(1)
>>> +#define SRC_IRQ_FLASH BIT(2)
>>> +#define SRC_IRQ_MUIC BIT(3)
>>> +
>>> #define LED_IRQ_FLED2_OPEN BIT(0)
>>> #define LED_IRQ_FLED2_SHORT BIT(1)
>>> #define LED_IRQ_FLED1_OPEN BIT(2)
>>>
>
>