Re: [PATCH 3/3] platform/x86: int3472/discrete: Add support for sensor-drivers which expect clken + pled GPIOs

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 11/25/22 17:07, Dan Scally wrote:
> Hi Hans
> 
> On 24/11/2022 20:00, Hans de Goede wrote:
>> The hm11b1 and ov01a1s sensor drivers shipped with the out of tree IPU6
>> driver, expect the clk_en GPIO to be modelled as a "clken" GPIO rather
>> then using the clk framework; and the hm11b1, ov01a1s and ov2740 driver
>> all 3 expect the privacy-led to be modelled as a "pled" GPIO, rather then
>> it being turned on/off at the same time as the clk.
>>
>> Adjust how we handle the GPIOs on these sensors accordingly, for now at
>> least, so that the out of tree driver can work with standard distro kernels
>> through e.g. dkms. Otherwise users need to run a patched kernel just for
>> this small difference.
>>
>> This of course needs to be revisited when we mainline these sensor drivers,
>> I can imagine the drivers getting clk-framework support when they are
>> mainlined and then at that same time their acpi HID can be dropped from
>> the use_gpio_for_clk_acpi_ids[] array.
>>
>> Note there already is a mainline driver for the ov2740, but that is not
>> impacted by this change since atm it uses neither the clk framework nor
>> a "clken" GPIO.
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>> Maybe we should patch the sensor drivers for sensors supported with
>> the IPU3 to also expect the privacy-led to always be a separate GPIO?
>>
>> This way we can also avoid the camera LED briefly going on at boot,
>> when the driver is powering things up to read the sensor's ID register.
>>
>> And I have also put looking at making the mainline ov2740 driver suitable
>> for use with the (out of tree) IPU6 driver on my TODO list.
>> ---
>>   drivers/platform/x86/intel/int3472/common.h   |  2 +-
>>   drivers/platform/x86/intel/int3472/discrete.c | 37 +++++++++++++++----
>>   2 files changed, 31 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/platform/x86/intel/int3472/common.h b/drivers/platform/x86/intel/int3472/common.h
>> index 53270d19c73a..58647d3084b9 100644
>> --- a/drivers/platform/x86/intel/int3472/common.h
>> +++ b/drivers/platform/x86/intel/int3472/common.h
>> @@ -23,7 +23,7 @@
>>   #define INT3472_GPIO_TYPE_PRIVACY_LED                0x0d
>>     #define INT3472_PDEV_MAX_NAME_LEN                23
>> -#define INT3472_MAX_SENSOR_GPIOS                3
>> +#define INT3472_MAX_SENSOR_GPIOS                4
>>     #define GPIO_REGULATOR_NAME_LENGTH                21
>>   #define GPIO_REGULATOR_SUPPLY_NAME_LENGTH            9
>> diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
>> index 9159291be28a..bfcf8184db16 100644
>> --- a/drivers/platform/x86/intel/int3472/discrete.c
>> +++ b/drivers/platform/x86/intel/int3472/discrete.c
>> @@ -216,6 +216,26 @@ static const char *int3472_dsm_type_to_func(u8 type)
>>       return "unknown";
>>   }
>>   +/*
>> + * The hm11b1 and ov01a1s sensor drivers shipped with the out of tree IPU6 driver,
>> + * expect the clk_en GPIO to be modelled as a "clken" GPIO rather then as a clk and
>> + * the hm11b1, ov01a1s and ov2740 driver all 3 expect the privacy-led to be modelled
>> + * as a "pled" GPIO, rather then it being turned on/off at the same time as the clk.
>> + *
>> + * Note there also is a mainline driver for the ov2740, but that does not use
>> + * the clk framework atm either.
>> + *
>> + * Adjust how we handle the GPIOs on these sensors accordingly, for now at least.
>> + * This needs to be revisited when we mainline these sensor drivers / when we merge
>> + * the necessary changes in the ov2740 sensor driver so that it can work on the IPU6.
>> + */
> 
> 
> I'm not really sure about this one though; wouldn't it be better to alter those sensor drivers to use the clock framework properly?

Yes, Laurent more or less said the same thing; and I was already starting
to think in this direction myself when typing the cover letter.

So yes I agree with you and Laurent. That still leaves the question of what to do
with devices with just a privacy LED without a clk-en though.

Dan, do you have a list of sensors which currently are known to work / be used
together with the IPU3 (and the int3472 discrete code) ?

I know I will need to modifi the ov5693 code, but I wonder what other drivers
I will need to modify ?

I think I might just move those sensor-drivers over to using a GPIO
for the privacy LED and just always register a GPIO for the privacy LED
pin, does that sound like a good idea to you ?

Anyways it is weekend now and I've already worked too many hours this week,
so I'll take a look at this on Monday.

Regards,

Hans



>> +static const struct acpi_device_id use_gpio_for_clk_acpi_ids[] = {
>> +    { "HIMX11B1" }, /* hm11b1 */
>> +    { "OVTI01AS" }, /* ov01a1s */
>> +    { "INT3474" },  /* ov2740 */
>> +    {}
>> +};
>> +
>>   /**
>>    * skl_int3472_handle_gpio_resources: Map PMIC resources to consuming sensor
>>    * @ares: A pointer to a &struct acpi_resource
>> @@ -293,19 +313,22 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
>>           (polarity == GPIO_ACTIVE_HIGH) ? "high" : "low");
>>         switch (type) {
>> +    case INT3472_GPIO_TYPE_CLK_ENABLE:
>> +    case INT3472_GPIO_TYPE_PRIVACY_LED:
>> +        if (!acpi_match_device_ids(int3472->adev, use_gpio_for_clk_acpi_ids)) {
>> +            ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
>> +            if (ret)
>> +                err_msg = "Failed to map GPIO to clock\n";
>> +
>> +            break;
>> +        }
>> +        fallthrough;
>>       case INT3472_GPIO_TYPE_RESET:
>>       case INT3472_GPIO_TYPE_POWERDOWN:
>>           ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, func, polarity);
>>           if (ret)
>>               err_msg = "Failed to map GPIO pin to sensor\n";
>>   -        break;
>> -    case INT3472_GPIO_TYPE_CLK_ENABLE:
>> -    case INT3472_GPIO_TYPE_PRIVACY_LED:
>> -        ret = skl_int3472_map_gpio_to_clk(int3472, agpio, type);
>> -        if (ret)
>> -            err_msg = "Failed to map GPIO to clock\n";
>> -
>>           break;
>>       case INT3472_GPIO_TYPE_POWER_ENABLE:
>>           ret = skl_int3472_register_regulator(int3472, agpio);
>