Am 27.06.24 um 08:52 schrieb Uwe Kleine-König:
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
\o/ Thanks
Thanks Uwe
