Hi Gareth, > From: Gareth Williams, Sent: Monday, September 16, 2019 10:56 PM > > Hi Laurent/Kieran, > > I need to upstream a driver for a display controller that within its > registers memory region contains registers related > to a PWM device. The PWM device is for controlling the backlight of the > display. > Ideally, I would like to create a separated driver for the PWM, so that I can > re-use "pwm-backlight", but since the registers > for the PWM are right in the middle of the registers for the display > controller I would need to ioremap the memory region > for the PWM registers region twice, once from the display controller driver, > and once from the PWM driver. > Do you think that the double ioremap would be acceptable upstream?
I think that an MFD driver can support such hardware. I checked Documentation/devicetree/bindings/mfd roughly, and then atmel-hlcdc.txt seems to have a display controller and a PWM device. Best regards, Yoshihiro Shimoda
