On Mon, Sep 8, 2014 at 9:19 AM, Ran Shalit <ranshalit@gmail.com> wrote:

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The control on led brightness value is done as part of dedicated character device which was written for the purpose of brightness control (which uses i2c bus) I wander if this is possible using the linux PM capabilities, and how this should be done. In either case it should be possible as per my understanding. You need to implement it in the appropriate PM handlers. case1 ----> write the appropriate code in driver->pm->suspend case2 ----> write the appropriate code in driver->pm->runtime_idle

Where should be the command to change brightness to minimum through i2c ? In runtime_suspend ?

If you want to reduce brightness to minimum when the character device goes in a runtime-suspend mode, then Yes. (Please include kernelnewbies, as others will also be able to respond to your query and rectify if I am mistaken)