|From:||Thierry Reding <thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org>|
|Subject:||[PATCH v4 00/10] Add PWM framework and device tree support.|
|Date:||Wed, 14 Mar 2012 16:56:23 +0100|
|Cc:||linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>, Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>, Matthias Kaehlcke <matthias-RprLehDfhQ3k1uMJSBkQmQ@public.gmane.org>, Kurt Van Dijck <kurt.van.dijck-/BeEPy95v10@public.gmane.org>, Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>, Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>, Colin Cross <ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>, Olof Johansson <olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org>, Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>, Richard Purdie <rpurdie-Fm38FmjxZ/leoWH0uzbU5w@public.gmane.org>, Mark Brown <broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>, Mitch Bradley <wmb-D5eQfiDGL7eakBO8gow8eQ@public.gmane.org>, Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>, Eric Miao <eric.y.miao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Lars-Peter Clausen <lars-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>, Ryan Mallon <rmallon-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>|
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 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 adds an API to request a PWM device given the PWM chip or the struct device associated with a PWM chip. 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 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 4 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 5 because a subsequent patch will instantiate one PWFM controller device instead of four. Patch 6 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 7. Patches 8 and 9 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. They are meant as test-bed for the framework. Sascha already has patches that port all in-tree drivers to the framework and will rebase them on top of this series when it is ready. Patch 10 implements DT-based probing in the pwm-backlight driver. Note that this code only handles the "pwm" 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. The whole series is based on the linux-next tree from 20120314. I think I've addressed all of the concerns raised in the first three versions. Thierry : http://git.pengutronix.de/?p=imx/linux-2.6.git;a=shortlog;... Sascha Hauer (1): PWM: add pwm framework support Simon Que (1): ARM: tegra: Fix PWM clock programming Thierry Reding (8): pwm: Allow chips to support multiple PWMs. 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: Add Blackfin support pwm: Add PXA support pwm-backlight: Add rudimentary device tree support Documentation/devicetree/bindings/pwm/pwm.txt | 48 ++ .../devicetree/bindings/pwm/tegra-pwm.txt | 18 + .../bindings/video/backlight/pwm-backlight | 19 + Documentation/pwm.txt | 56 ++ MAINTAINERS | 6 + arch/arm/boot/dts/tegra20.dtsi | 6 + arch/arm/boot/dts/tegra30.dtsi | 6 + arch/arm/mach-tegra/board-dt-tegra20.c | 1 + arch/arm/mach-tegra/board-dt-tegra30.c | 3 + arch/arm/mach-tegra/tegra2_clocks.c | 37 +- arch/arm/plat-pxa/Makefile | 1 - arch/arm/plat-pxa/pwm.c | 304 ----------- arch/blackfin/Kconfig | 10 - arch/blackfin/kernel/Makefile | 1 - arch/blackfin/kernel/pwm.c | 100 ---- drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/of/Kconfig | 6 + drivers/pwm/Kconfig | 40 ++ drivers/pwm/Makefile | 4 + drivers/pwm/core.c | 557 ++++++++++++++++++++ drivers/pwm/pwm-bfin.c | 164 ++++++ drivers/pwm/pwm-pxa.c | 244 +++++++++ drivers/pwm/pwm-tegra.c | 267 ++++++++++ drivers/video/backlight/Kconfig | 2 +- drivers/video/backlight/pwm_bl.c | 136 ++++- include/linux/of_pwm.h | 36 ++ include/linux/pwm.h | 97 ++++ include/linux/pwm_backlight.h | 2 + 29 files changed, 1732 insertions(+), 442 deletions(-) create mode 100644 Documentation/devicetree/bindings/pwm/pwm.txt create mode 100644 Documentation/devicetree/bindings/pwm/tegra-pwm.txt create mode 100644 Documentation/devicetree/bindings/video/backlight/pwm-backlight create mode 100644 Documentation/pwm.txt delete mode 100644 arch/arm/plat-pxa/pwm.c delete mode 100644 arch/blackfin/kernel/pwm.c create mode 100644 drivers/pwm/Kconfig create mode 100644 drivers/pwm/Makefile create mode 100644 drivers/pwm/core.c create mode 100644 drivers/pwm/pwm-bfin.c create mode 100644 drivers/pwm/pwm-pxa.c create mode 100644 drivers/pwm/pwm-tegra.c create mode 100644 include/linux/of_pwm.h -- 22.214.171.124
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