RE: [PATCH v3 0/3] Platform support for EHRPWM & ECAP devices inDAVINCI.

[Philip, Avinash]

On Thu, Apr 04, 2013 at 11:19:44, Nori, Sekhar wrote:
> On 4/4/2013 10:09 AM, Philip, Avinash wrote:
> > On Tue, Apr 02, 2013 at 14:05:09, Nori, Sekhar wrote:
> >> On 3/25/2013 1:19 PM, Philip Avinash wrote:
> >>> Add platform support for EHRPWM and ECAP by providing clock nodes and
> >>> device tree nodes.
> >>> This series depends on [1] and [2] and is available for testing at [3].
> >>> Tested for back light support in da850 EVM with EHRPWM PWM device.
> >>>
> >>> [1] http://gitorious.org/linux-davinci/linux-davinci/trees/davinci-for-v3.9/dt-2
> >>> [2] https://gitorious.org/linux-pwm/linux-pwm/trees/for-next
> >>> [3] https://github.com/avinashphilip/am335x_linux/tree/davinci-for-v3.9_soc_pwm
> >>>
> >>> Note:
> >>> DT support for EHRPWM backlight has not been added in da850-evm.dts as there is
> >>> conflicting pin-mux requirement with SPI flash.
> >>
> >> Can you check if this is really true even in newer boards (have a look
> >> at the latest schematics)? I remember this used to be a problem in very
> >> early versions but was fixed later.
> > 
> > On looking schematics, panel has three power controls LCD_BACKLIGHT_PWR, LCD_PANEL_PWR,
> > LCD_PWM0. On latest schematic, LCD_PWM0 is connected to ECAP instance 2. So backlight
> > can control through ECAP2 (not conflicting with SPI1 cs0). Still for controlling
> > backlight, require support for LCD_BACKLIGHT_PWR & LCD_PANEL_PWR. These signals
> 
> By controlling above you mean "switching on/off"? Otherwise this seems
> to be contradicting the statement just before.

Yes these lines should be switching on/off.

> 
> > to be controlled by GPIO 2[8] & GPIO 2[15]. In release platform callbacks used
> > to control GPIO functionality. But with DT support, I have to check how platform
> > callbacks can be used.
> 
> Platform callbacks are not possible with DT.

Ok.

> You can look at what freescale mxsfb.c does. Look for panel-enable-gpios DT binding.

I will use GPIO pin configuration info from DT nodes. From probe GPIO pin make active and
in remove disable GPIO pin.

Thanks
Avinash

> 
> Thanks,
> Sekhar
> 

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