Messages in this thread | | | Date | Wed, 6 Mar 2013 13:53:27 +0900 | From | Alex Courbot <> | Subject | Re: [PATCH 1/1 v3] pwm_bl: Add support for backlight enable regulator |
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On 03/06/2013 11:41 AM, Andrew Chew wrote: >>> struct pwm_bl_data { >>> struct pwm_device *pwm; >>> struct device *dev; >>> + struct regulator *en_supply; >>> + bool en_supply_enabled; >> >> Couldn't you use regulator_is_enabled() and get rid of en_supply_enabled? >> It would also ensure the driver performs correctly no matter what the initial >> state of the regulator is. > > Are you sure this works? I'm concerned about the (bizarre and unlikely) case > where this supply is shared with another driver, so I use en_supply_enabled > to track the state of the supply such that I can ignore that case.
You're right, consumers can share regulators and the calls to enable/disable need to be balanced. Also there is no way to check the intensity of the backlight prior to the change to detect a transition, so I guess your approach is indeed the most appropriate here.
Alex.
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