On 5/4/21 8:32 AM, Michal Simek wrote: > > > On 5/4/21 10:51 AM, Uwe Kleine-König wrote: >> Hello, >> >> On Mon, May 03, 2021 at 05:44:13PM -0400, Sean Anderson wrote: >>> This adds PWM support for Xilinx LogiCORE IP AXI soft timers commonly >>> found on Xilinx FPGAs. There is another driver for this device located >>> at arch/microblaze/kernel/timer.c, but it is only used for timekeeping. >>> This driver was written with reference to Xilinx DS764 for v1.03.a [1]. >>> >>> [1] https://www.xilinx.com/support/documentation/ip_documentation/axi_timer/v1_03_a/axi_timer_ds764.pdf >>> >>> Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxx> >>> --- >>> >>> arch/arm64/configs/defconfig | 1 + >>> drivers/pwm/Kconfig | 11 ++ >>> drivers/pwm/Makefile | 1 + >>> drivers/pwm/pwm-xilinx.c | 322 +++++++++++++++++++++++++++++++++++ >>> 4 files changed, 335 insertions(+) >>> create mode 100644 drivers/pwm/pwm-xilinx.c >>> >>> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig >>> index 08c6f769df9a..81794209f287 100644 >>> --- a/arch/arm64/configs/defconfig >>> +++ b/arch/arm64/configs/defconfig >>> @@ -1083,6 +1083,7 @@ CONFIG_PWM_SAMSUNG=y >>> CONFIG_PWM_SL28CPLD=m >>> CONFIG_PWM_SUN4I=m >>> CONFIG_PWM_TEGRA=m >>> +CONFIG_PWM_XILINX=m >>> CONFIG_SL28CPLD_INTC=y >>> CONFIG_QCOM_PDC=y >>> CONFIG_RESET_IMX7=y >> >> I think this should go into a separate patch once this driver is >> accepted. This can then go via the ARM people. >> >>> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig >>> index d3371ac7b871..01e62928f4bf 100644 >>> --- a/drivers/pwm/Kconfig >>> +++ b/drivers/pwm/Kconfig >>> @@ -628,4 +628,15 @@ config PWM_VT8500 >>> To compile this driver as a module, choose M here: the module >>> will be called pwm-vt8500. >>> >>> +config PWM_XILINX >>> + tristate "Xilinx AXI Timer PWM support" >>> + depends on !MICROBLAZE >> >> I don't understand this dependency. > > The dependency is clear here because microblaze has already driver for > this timer here arch/microblaze/kernel/timer.c. > > And that's exactly pointing to the way how this should be done. > IP itself is single or dual timer and in case of dual timer you can > select if there is pwm output and use it for PWM generation. > > It means it is timer with PMW together. > I didn't have a time but Uwe likely knows this better how to design it. > > I see that gpio-mvebu driver instantiate pwm driver. Maybe that's the > way to go. I think drivers/clocksource/samsung_pwm_timer.c and drivers/pwm/pwm-samsung.c provide another example for how to go about this. > Step first is move axi timer driver from microblaze to generic location. Yes. However, I don't have a microblaze setup, so I have just added the PWM driver. > Figured it out how to add PWM (with DT flag) and then write support for it. I would really like to see a standard way of doing this. Many timers also have PWM support (e.g. samsung, and also DW). I think it's unusual that this problem has not already been addressed. --Sean > > Thanks, > Michal >
