On Wed, 01 Jul 2015 23:57:57 +0200 Heiko Stübner <heiko@xxxxxxxxx> wrote: > Hi Boris, > > Am Mittwoch, 1. Juli 2015, 10:21:46 schrieb Boris Brezillon: > > Hello Thierry, > > > > This series adds support for atomic PWM update, or ITO, the capability > > to update all the parameters of a PWM device (enabled/disabled, period, > > duty and polarity) in one go. > > > > This implementation is still experimental, and I may have missed some key > > aspect, so any feedback are welcome. > > > > Also note that I haven't protected the state update with any locking. > > That's because the existing config does not protect against concurrent > > access to a requested PWM device (see the pwm_config implementation). > > I guess the PWM framework assume the user will implement the proper locking > > scheme if it has to concurrently access the device. > > > > The 5 first patches prepare the addition of the pwm_state concept, which > > will be used to allow atomic updates. > > The following patches introduce the pwm_state struct, initial state > > retrieval and atomic update concepts. > > > > Patches 12 and 13 are showing how one can implement the initial state > > retrieval and atomic update features in a PWM driver (in this specific > > case I implemented it in the rockchip driver). > > > > The last 2 patches are making use of those changes to improve the > > pwm-regulator driver (initializing the regulator state based on the > > initial PWM state). > > at first I got very strange readings (very wrong values and wrong polarity), > which resulted from the issues I pointed out in the replies to individual > patches. After fixing these, the pwm read-back now returns exactly the expected > values :-) . Sorry about that, as I said I only compile tested the series :-/. Anyway, thanks for providing fixes for these bugs, they'll be applied in the next version. > > And with the original voltage table from the Chromeos-devicetrees, the pwm- > regulator also returns the expected 1.2V that coreboot initially set. Great! And thanks for testing the patches. Best Regards, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
