Re: [PATCH v3 0/3] Add RP1 PWM controller support

[Florian Fainelli <florian.fainelli@broadcom.com>]

On 5/8/26 01:15, Andrea della Porta wrote:
> Hi Uwe,
> 
> On 10:30 Thu 23 Apr     , Andrea della Porta wrote:
>> This patchset adds support for the PWM controller found on the
>> Raspberry Pi RP1 southbridge. This is necessary to operate the
>> cooling fan connected to one of the PWM channels.
>>
>> The tachometer pin for the fan speed is managed by the firmware
>> running on the RP1's M-core. It uses the PHASE2 register
>> to report the RPM, which is then exported by this driver via
>> syscon registers. A subsequent patch will add a new device
>> and driver to read the RPM and export this value via hwmon.
>>   
>> Subsequent patches will also add the CPU thermal zone, which
>> acts as a consumer of the PWM device.
>>
>> Best regards,
>> Andrea
>>
>> CHANGES in V3:
>>
>> - Refactored all the register macros. They now have RP1_PWM_ prefix
>>    and follow the register name.
>> - Dropped the tab alignment in front of struct declarations (use a space
>>    instead).
>> - Added a check in tohw() to test (and bail out quickly) in case that
>>    period_length_ns is zero.
>> - Probing now returns an error if clk_rate > 1 GHz.
>> - Added a check on minimum period ticks. Return 1 to signal round-up.
>> - Fixed inverted polarity detection on edge cases.
>> - Fixed rounding errors (in both tohwi() and fromhw()) in inverted
>>    polarity calculations.
>> - Dropped a redundant check on period >= duty.
>> - Replaced memset by inline struct init.
>> - Disabling a channel now is faster, skipping the duty/period/polarity
>>    setup.
>> - Fixed an error string (s/Fail/Failed)
>> - Used %pe to signal error string instead of an integer.
>> - Added several new sections to the Limitations paragraph to better
>>    explain what will happen on edge cases.
>> - Maximum period is now U32_MAX-1 to allow 100% duty cycle on all
>>    selectable periods.
>> - The hw period register now takes into account for the extra tick at
>>    the end of the period (subtracted one to wfhw->period_ticks in tohw
>>    and added 1 in fromhw).
>> - Added .remove() callback to free resources even if the driver is
>>    not unbindable/unloadable, to avoid accumulating tech debt.
>>
>>
>> Naushir Patuck (2):
>>    dt-bindings: pwm: Add Raspberry Pi RP1 PWM controller
>>    pwm: rp1: Add RP1 PWM controller driver
>>
>> Stanimir Varbanov (1):
>>    arm64: dts: broadcom: rpi-5: Add RP1 PWM node
>>
>>   .../bindings/pwm/raspberrypi,rp1-pwm.yaml     |  54 +++
>>   .../boot/dts/broadcom/bcm2712-rpi-5-b.dts     |  12 +
>>   arch/arm64/boot/dts/broadcom/rp1-common.dtsi  |  10 +
>>   drivers/pwm/Kconfig                           |   9 +
>>   drivers/pwm/Makefile                          |   1 +
>>   drivers/pwm/pwm-rp1.c                         | 414 ++++++++++++++++++
>>   6 files changed, 500 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/pwm/raspberrypi,rp1-pwm.yaml
>>   create mode 100644 drivers/pwm/pwm-rp1.c
>>
>> -- 
>> 2.35.3
>>
> 
> A gentle reminder about this patchset :)

Hi Uwe,

I would prefer to take the DTS changes through the Broadcom ARM SoC tree 
to minimize conflicts on my end, are you going to take the PWM patches 
for 7.2? Thanks!
-- 
Florian