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

Guenter Roeck
2025-09-25T14:34:18Z

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

Guenter