Re: [PATCH 2/4] hwmon: adc: rp1: Add Raspberry Pi's RP1 ADC driver

Stanimir Varbanov
2025-09-29T21:50:54Z

Hi,

On 9/25/25 5:34 PM, Guenter Roeck wrote:
> On Thu, Sep 25, 2025 at 07:26:10AM +0200, Stefan Wahren wrote:
>> Hi Guenter,
>>
>> Am 25.09.25 um 04:42 schrieb Guenter Roeck:
>>> On Thu, Sep 25, 2025 at 03:04:14AM +0300, Stanimir Varbanov wrote:
>>>> A five-input successive-approximation analogue-to-digital converter
>>>> with 12-bit (effective number of 9.5 bits) resolution at 500kSPS.
>>>> The ADC has four external inputs and one internal temperature sensor.
>>>>
>>>> Signed-off-by: Phil Elwell <phil@raspberrypi.com>
>>>> Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
>>>> Signed-off-by: Stanimir Varbanov <svarbanov@suse.de>
>>> I just realized that there is already a hwmon driver for
>>> Rasperri Pi - drivers/hwmon/raspberrypi-hwmon.c.
>>>
>>> Please add this code to that driver.
>> could you please explain the reason for this?
>>
>> Yes, both drivers are for Raspberry Pi boards, but they don't share any code
>> base. The raspberrypi-hwmon uses a mailbox interfaces to get the sensor data
>> and works for the board generation 1 - 4. This driver works completely
>> differently ( MMIO ), doesn't depend on the mailbox interface and applies
>> only for board generation 5. Actually I don't see a benefit of merging them.

Thank you Stefan for the explanation.

>>
> Ok. Please make sure to add this explanation to the patch description.

Sure, I will extend the description in next version.

~Stan