Re: [RFC PATCH] pinctrl-single: Use of pinctrl-single for external device over I2C
From: Vaibhav Hiremath <hidden>
Date: 2015-07-16 14:16:13
Also in:
linux-arm-kernel, linux-gpio, lkml
From: Vaibhav Hiremath <hidden>
Date: 2015-07-16 14:16:13
Also in:
linux-arm-kernel, linux-gpio, lkml
On Thursday 16 July 2015 06:28 PM, Linus Walleij wrote:
On Thu, Jul 2, 2015 at 6:53 PM, Vaibhav Hiremath [off-list ref] wrote:quoted
In some usecases, the external device (in my case it PMIC over I2C) does support pin in multiple configuration, we may need to control/configure them during boot or runtime.What is missing from this patch is an explanation why pinctrl-single should be used for this PMIC. Repeat: pinctrl-single: when you have exactly one register per pin, and the description of the pins is delivered in an opaque ASIC-specific format without developers knowing much about how the hardware actually works, just "set these magic values". I strongly prefer that this PMIC has its own pin controller using standard bindings with groups and functions, see eg. drivers/pinctrl/nomadik/pinctrl-ab* for a PMIC pinctrl driver.
Thanks for the reference, good to know this. Let me check this driver before commenting anything further on this. Thanks, Vaibhav
Yours, Linus Walleij