Is driver available PWM channels on PMIC for Wi-i.MX53 with DigiEL_5.9 Linux

Question

I am looking to make use of the PWM channels connected to the PMIC device on the Wi-i.MX53 module. Is a Linux driver available for this on the Digi platform. So far I have been unable to locate one within the Linux distribution and have not located options in the kernel config.

Thanks

Answer 1

The i.MX53 SoC has a PWM module, and Digi’s ConnectCore for MX53 module has a Dialog’s DA9052 PMIC with a PWM WLED module. These have different characteristics which are described on their respective datasheets.

The Freescale BSP does include a PWM module for the i.MX53 onchip PWM [1] which we don’t support in DEL/DEY and we have not integrated. If required, this integration work can be done through Etherios design services.

On DEL and DEY only the PMIC’s PWM controller is supported [2]. This WLED module is ideal for driving display backlights, and that is what it is being used for in Dig’s BSP. It is also what it seems the customer needs.

As you say, there is no PWM support in u-boot, although we provide a “pmic” command which allows to access the PMIC’s registers, including those controlling the WLED PWM. This command could be used to script u-boot so that it configures the WLED at startup.



[1] arch/arm/plat-mxc/pwm.c
[2] drivers/video/backlight/da9052_bl.c

Comments

Thanks you for responding to this. After posting I continued to dig a bit further and found the LED driver which you suggested  and as you say this performs the required PWM function. This will be suitable for what I need and it is good to have confirmation that this is the supported route for PWM.
For now we do not need it supported within u-boot but it is a consideration for the future.