Messages in this thread | | | From | "Kim, Milo" <> | Subject | RE: [PATCH 0/3] LP3943 MFD driver for a GPIO expander and a PWM generator | Date | Mon, 22 Jul 2013 01:19:10 +0000 |
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Hi Linus, Thanks for your review.
> On Tue, Jul 16, 2013 at 4:38 AM, Kim, Milo <Milo.Kim@ti.com> wrote: > > > LP3943 is an integrated device capable of driving 16 output channels. > > It supports a GPIO expander and a PWM generator. > > But actually the data sheet describes it as a LED driver with PWM > chip. > > Do you have use cases not using it for LEDs but other thing or why > do you want to model the 16 LED lines as GPIO lines? > Why can't you just have a drivers/leds/* as for any other LED > chip?
We have two ways to provide LED functions.
(a) Creating LP3943 LED driver. This is what you mentioned. LP3943 MFD will consist of GPIO, LED and PWM drivers
(b) Using a LED PWM driver with the PWM generator With LP3943 PWM driver, we can control LEDs by using LED PWM driver under drivers/leds/leds-pwm.c Then, the MFD consists of just two drivers - GPIO and PWM. LP3943 PWM driver can be used as general usages - Not only simple LED drivers but also the PWM signal input for a backlight device. That's why I prefer to the second way.
> Atleast some good explanation of this needs to be found in the > patch text and also as comments in Kconfig and the code I think.
I should describe the usage of the 'leds-pwm' driver for LED lighting. Thanks for this guideline.
Regards, Milo
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