Hi Boris, Am Mittwoch, 8. Juni 2016, 18:34:35 schrieb Boris Brezillon: > This patch series series aims at adding two important features to the > pwm-regulator driver. > > The first one is the support for 'smooth handover' between the > bootloader and the kernel. This is mainly solving problems we have when > the PWM is controlling a critical regulator (like the one powering the > DDR chip). Currently, when the PWM regulator acquire the PWM device it > assumes it was off and it's safe to change the configuration before > enabling it, which can generate glitches on the PWM signal which in turn > generated glitches on the output voltage. > To solve that we've introduced support for hardware readout to the > PWM framework, so that the PWM regulator driver can adjust the PWM > a probe time and avoid glitches. > Atomic update is also helping in this regard. [...] > The second feature we add to the driver is the capability of using > a sub duty_cycle range in continuous mode. By default the regulator > is assuming that min_uV is achieved with a 0% dutycyle and max_uV > with a 100% dutycycle, but this is not necessarily true. > Moreover, in some cases (when the PWM device does not support > polarity inversion), we might have min_uV at 100% and max_uV at 0%. > Hence the addition of new properties to the existing DT bindings. > The feature is added in patch 12 and 13. I've tested this series on a rk3288-veyron chromebook and both the backlight- pwm as well as the pwm-regulator still work as expected, so for everything except the STI parts: Tested-by: Heiko Stuebner <heiko at sntech.de>
