Re: [PATCH 2/2] media: hi556: Support full range of power rails

[Hans de Goede <hansg@kernel.org>]

Hi Sakari,

On 6-Jun-25 9:17 AM, Sakari Ailus wrote:
> Hi Hans,
> 
> On Sat, May 31, 2025 at 09:05:34PM +0200, Hans de Goede wrote:
>> From: Hans de Goede <hdegoede@redhat.com>
>>
>> Use regulator_bulk_* to get the array of potential power rails for
>> the hi556.
>>
>> Previously the driver only supported avdd as only avdd is used on IPU6
>> designs. But other designs may also need the driver to control the other
>> power rails and the new INT3472 handshake support also makes use of
>> dvdd on IPU6 designs.
>>
>> Link: https://bugzilla.redhat.com/show_bug.cgi?id=2368506
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>  drivers/media/i2c/hi556.c | 40 +++++++++++++++++++++------------------
>>  1 file changed, 22 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/media/i2c/hi556.c b/drivers/media/i2c/hi556.c
>> index d3cc65b67855..110dd00c51ae 100644
>> --- a/drivers/media/i2c/hi556.c
>> +++ b/drivers/media/i2c/hi556.c
>> @@ -624,6 +624,12 @@ static const struct hi556_mode supported_modes[] = {
>>  	},
>>  };
>>  
>> +static const char * const hi556_supply_names[] = {
>> +	"dovdd",	/* Digital I/O power */
>> +	"avdd",		/* Analog power */
>> +	"dvdd",		/* Digital core power */
>> +};
> 
> As the need to have these regulators is not related to a proper firmware
> API, I think we should have at least DT bindings that document them.

The hi556 driver does not support DT binding atm, only ACPI binding
and the DT maintainers have been very clear in the past that they
do NOT want any DT bindings for things which are not actually used
by DT platforms.

I've checked a HI556 datasheet I found on the net and the HI556
has the usual 3 power rails, called VDDD + VDDIO + VDDA in the datasheet,
so I believe that this patch is correct.

Regards,

Hans