On 09/17/2013 02:36 AM, Sascha Hauer wrote: > Hi Mike, > > On Thu, Sep 12, 2013 at 11:35:52AM -0700, Mike Dunn wrote: >> Currently the driver assumes that the values specified in the >> brightness-levels >> device tree property increase as they are parsed from left to right. But >> boards >> that invert the signal between the PWM output and the backlight will need to >> specify decreasing brightness-levels. This patch removes the assumption that >> the last element of the array is the max value, and instead searches the >> array >> for the max value and uses that as the normalizing value when determining the >> duty cycle. > > Note there's also support for inverted PWMs in the PWM framework > provided your hardware supports this.
Yes, and in fact my first solution was to implement simulated polarity inversion in the pwm driver, but that was shot down because polarity inversion is not actually supported by the pwm hardware. My inverter is external in the path between the pwm output and the backlight. Not sure of the reason for its presence. Thanks, Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
