Hi Thierry, Le Tue, 10 Apr 2012 17:06:23 +0200, Thierry Reding <thierry.reding@xxxxxxxxxxxxxxxxx> a écrit : > This patch series adds very rudimentary device-tree support for PWM > devices. With all of these patches applied (plus one board-specific > patch that is not included), I'm able to control the backlight on the > device I'm working on using the sysfs interface provided by the pwm-bl > driver and the backlight class. > > This series is based on Sascha Hauer's series of patches[0] to add a > generic PWM framework. The first patch in this series is taken from > Sascha's branch, while the second patch enables each PWM chip to provide > multiple PWM devices (the Blackfin and PXA drivers have been ported to > the framework for reference). Currently a global namespace is still > provided to keep backwards-compatibility with the legacy PWM API. In > order to achieve this, the number of global PWM devices is limited to > 1024. However, patch 2 introduces per-chip indexing of PWM devices in > the core and patch 4 adds an API to request a PWM device using a lookup > table registered by board setup code. They are supposed to eventually > replace pwm_request() and allow to get rid of the global namespace. The > device tree support code does not use the global namespace. > > Patch 3 adds a debugfs interface. > > Patch 5 adds some code to lookup a PWM chip given its device-tree > handle. This code will be used later on by the pwm-bl driver to find the > PWM device that it should be using. If the no corresponding PWM chip is > available yet, the code returns EPROBE_DEFER to have users automatically > probed again later when the PWM provider may have become available. > Device tree binding documentation is also provided. > > Patch 6 was taken from the Chromium tree and is required to provide > proper clocking of the Tegra2 PWFM controller. All Chromium-specific > tags have been removed from the commit message. Some cleanup of the > clock registration for Tegra is done in patch 7 because a subsequent > patch will instantiate one PWFM controller device instead of four. > > Patch 8 adds a generic PWM framework driver for the Tegra2 PWFM > controller. The code is taken from the Chromium tree with some > adjustments to integrate it with the PWM framework. Device tree based > probing of the driver is implemented in patch 9. > > Patches 10 and 11 are ports of the Blackfin PWM and the PXA PWM drivers > to the PWM framework. These are only compile-tested as I do not have any > hardware to test them on. > > Patches 12, 13 and 14 move the i.MX, Samsung and VT8500 drivers over to > the framework. These are originally by Sascha Hauer and were updated to > take advantage of the multiple PWM devices per chip feature. Patch 15 > adds support for Freescale MXS by Shawn Guo. > > Patch 16 implements DT-based probing in the pwm-backlight driver. Note > that this code only handles the "pwms" property (by looking up the PWM > device via the new PWM DT binding). Switching power to the backlight via > GPIOs is not supported yet. The DT binding also deviates from the > platform data in that it requires a list of brightness levels to be > specified instead of assuming a linearily spaced range from 0 to a given > maximum brightness. > > Finally, patch 17 makes me the new maintainer of the PWM subsystem. > > The whole series is based on the linux-next tree from 20120405. I think > I've addressed all of the concerns raised in the first five versions. I > have also pushed this version of the series to the PWM subsystem > repository[1]. > > Thierry > > [0]: http://git.pengutronix.de/?p=imx/linux-2.6.git;a=shortlog;h=refs/heads/pwmlib > [1]: http://gitorious.org/linux-pwm/linux-pwm/trees/pwm-v6 > > Sascha Hauer (4): > pwm: Add PWM framework support > ARM i.MX: Move i.MX pwm driver to pwm framework > ARM Samsung: Move s3c pwm driver to pwm framework > ARM vt8500: Move vt8500 pwm driver to pwm framework > > Shawn Guo (1): > pwm: add pwm-mxs support > > Simon Que (1): > ARM: tegra: Fix PWM clock programming > > Thierry Reding (11): > pwm: Allow chips to support multiple PWMs > pwm: Add debugfs interface > pwm: Add table-based lookup for static mappings > pwm: Add device tree support > ARM: tegra: Provide clock for only one PWM controller > pwm: Add NVIDIA Tegra SoC support > pwm: tegra: Add device tree support > pwm: Move Blackfin PWM driver to PWM framework > pwm: Move PXA PWM driver to PWM framework > pwm-backlight: Add rudimentary device tree support > pwm: Take over maintainership of the PWM subsystem > for pwm-core & pwm-imx (with the 3 patches I sent a few minutes ago) : Tested-by: Eric Bénard <eric@xxxxxxxxxx> Thanks ! Eric -- 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
