Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1418548

Re: [PATCH v2 00/13] regulator: pwm: various improvements

Show all headers | View raw

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@sntech.de>

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH v2 00/13] regulator: pwm: various improvements Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-08 18:40 +0200
  [PATCH v2 06/13] pwm: sti: Add support for hardware readout Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-08 18:40 +0200
  [PATCH v2 08/13] regulator: pwm: Adjust PWM config at probe time Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-06-08 18:40 +0200
  Re: [PATCH v2 00/13] regulator: pwm: various improvements Heiko Stübner <heiko@sntech.de> - 2016-06-09 20:10 +0200

csiph-web