Re: [PATCH v7 0/2] pwm: Add GPIO PWM driver

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Hello,

On Tue, Jun 04, 2024 at 11:00:39PM +0200, Linus Walleij wrote:
> Add a software PWM which toggles a GPIO from a high-resolution timer.
> 
> Recent discussions in the Raspberry Pi community revealt that a lot
> of users still use MMIO userspace tools for GPIO access. One argument
> for this approach is the lack of a GPIO PWM kernel driver. So this
> series tries to fill this gap.
> 
> This continues the work of Vincent Whitchurch [1], which is easier
> to read and more consequent by rejecting sleeping GPIOs than Nicola's
> approach [2]. It further takes over where Stefan Wahren left off.
> 
> I have not looked into the interrupt storm problem mentioned in [3]
> but instead focused on some real-life tests:
> 
> The IXP4xx NSLU2 has a speaker connected directly to a GPIO, and I
> wanted to use this patch to provide a proper beeper for the machine
> and not have to rely on custom hacks.
> 
> I added a DTS patch like this:
> 
> gpio_pwm: pwm {
>         #pwm-cells = <3>;
>         compatible = "pwm-gpio";
>         gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
> };
> 
> beeper {
>         compatible = "pwm-beeper";
>         pwms = <&gpio_pwm 0 1 0>;
>         beeper-hz = <1000>;
> };

Applied both patches to 
https://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux.git pwm/for-next

Thanks
Uwe

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