Use of the pwm-names DT property

From: Alex Courbot
Date: Wed Jul 04 2012 - 02:51:29 EST

Hi Thierry,

Looking at your PWM/DT integration patches for linux-next, I was wondering what is the rationale behind using the pwm-names property. If I got it correctly, its purpose is to be able to reference different PWMs by name, e.g. by having

pwms = <&pwm 0 5000000>, <&pwm 1 5000000>;
pwm-names = "backlight", "flash";

You could get the first PWM in the driver code by calling pwm_get(dev, "backlight") and the second through pwm_get(dev, "flash").

While I am ok with this way of doing, why not having the form that is already used by the regulator and gpio frameworks, in which the consumer is part of the property name?

vdd-supply = <&vdd_reg>;
core-supply = <&core_reg>;

Both regulators are then accessed using regulator_get(dev, "vdd") and regulator_get(dev, "core").

Wouldn't it make more sense to follow the same scheme that has been popularized by other frameworks? It also has the advantage that you do not need to maintain two different properties which must be the same size.

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