diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-30 09:22:37 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-30 09:22:37 -0700 |
commit | 9ec97169e7d6afe2f8206d694d1411fb3bb49853 (patch) | |
tree | 9d24c8cd440a312f96b70db5cdaaef1136787003 /Documentation/devicetree | |
parent | a410963ba4c0c768302f0298e258b1ee940e8316 (diff) | |
parent | 19891b20e7c275feb92d669f4b1879861f7e8c25 (diff) |
Merge branch 'for-3.6' of git://gitorious.org/linux-pwm/linux-pwm
Pull PWM subsystem from Thierry Reding:
"The new PWM subsystem aims at collecting all implementations of the
legacy PWM API and to eventually replace it completely.
The subsystem has been in development for over half a year now and
many drivers have already been converted. It has been in linux-next
for a couple of weeks and there have been no major issues so I think
it is ready for inclusion in your tree."
Arnd Bergmann <arnd@arndb.de>:
"Very much Ack on the new subsystem. It uses the interface
declarations as the previously separate pwm drivers, so nothing
changes for now in the drivers using it, although it enables us to
change those more easily in the future if we want to.
This work is also one of the missing pieces that are required to
eventually build ARM kernels for multiple platforms, which is
currently prohibited (amongs other things) by the fact that you cannot
have more than one driver exporting the pwm functions."
Tested-and-acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Philip, Avinash <avinashphilip@ti.com> # TI's AM33xx platforms
Acked-By: Alexandre Pereira da Silva <aletes.xgr@gmail.com> # LPC32XX
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sachin Kamat <sachin.kamat@linaro.org>
Fix up trivial conflicts with other cleanups and DT updates.
* 'for-3.6' of git://gitorious.org/linux-pwm/linux-pwm: (36 commits)
pwm: pwm-tiehrpwm: PWM driver support for EHRPWM
pwm: pwm-tiecap: PWM driver support for ECAP APWM
pwm: fix used-uninitialized warning in pwm_get()
pwm: add lpc32xx PWM support
pwm_backlight: pass correct brightness to callback
pwm: Use pr_* functions in pwm-samsung.c file
pwm: Convert pwm-samsung to use devm_* APIs
pwm: Convert pwm-tegra to use devm_clk_get()
pwm: pwm-mxs: Return proper error if pwmchip_remove() fails
pwm: pwm-bfin: Return proper error if pwmchip_remove() fails
pwm: pxa: Propagate pwmchip_remove() error
pwm: Convert pwm-pxa to use devm_* APIs
pwm: Convert pwm-vt8500 to use devm_* APIs
pwm: Convert pwm-imx to use devm_* APIs
pwm: Conflict with legacy PWM API
pwm: pwm-mxs: add pinctrl support
pwm: pwm-mxs: use devm_* managed functions
pwm: pwm-mxs: use global reset function stmp_reset_block
pwm: pwm-mxs: encode soc name in compatible string
pwm: Take over maintainership of the PWM subsystem
...
Diffstat (limited to 'Documentation/devicetree')
5 files changed, 132 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt b/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt new file mode 100644 index 000000000000..cfe1db3bb6e9 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/lpc32xx-pwm.txt @@ -0,0 +1,12 @@ +LPC32XX PWM controller + +Required properties: +- compatible: should be "nxp,lpc3220-pwm" +- reg: physical base address and length of the controller's registers + +Examples: + +pwm@0x4005C000 { + compatible = "nxp,lpc3220-pwm"; + reg = <0x4005C000 0x8>; +}; diff --git a/Documentation/devicetree/bindings/pwm/mxs-pwm.txt b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt new file mode 100644 index 000000000000..b16f4a57d111 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/mxs-pwm.txt @@ -0,0 +1,17 @@ +Freescale MXS PWM controller + +Required properties: +- compatible: should be "fsl,imx23-pwm" +- reg: physical base address and length of the controller's registers +- #pwm-cells: should be 2. The first cell specifies the per-chip index + of the PWM to use and the second cell is the duty cycle in nanoseconds. +- fsl,pwm-number: the number of PWM devices + +Example: + +pwm: pwm@80064000 { + compatible = "fsl,imx28-pwm", "fsl,imx23-pwm"; + reg = <0x80064000 2000>; + #pwm-cells = <2>; + fsl,pwm-number = <8>; +}; diff --git a/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt new file mode 100644 index 000000000000..bbbeedb4ec05 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt @@ -0,0 +1,18 @@ +Tegra SoC PWFM controller + +Required properties: +- compatible: should be one of: + - "nvidia,tegra20-pwm" + - "nvidia,tegra30-pwm" +- reg: physical base address and length of the controller's registers +- #pwm-cells: On Tegra the number of cells used to specify a PWM is 2. The + first cell specifies the per-chip index of the PWM to use and the second + cell is the duty cycle in nanoseconds. + +Example: + + pwm: pwm@7000a000 { + compatible = "nvidia,tegra20-pwm"; + reg = <0x7000a000 0x100>; + #pwm-cells = <2>; + }; diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt new file mode 100644 index 000000000000..73ec962bfe8c --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pwm.txt @@ -0,0 +1,57 @@ +Specifying PWM information for devices +====================================== + +1) PWM user nodes +----------------- + +PWM users should specify a list of PWM devices that they want to use +with a property containing a 'pwm-list': + + pwm-list ::= <single-pwm> [pwm-list] + single-pwm ::= <pwm-phandle> <pwm-specifier> + pwm-phandle : phandle to PWM controller node + pwm-specifier : array of #pwm-cells specifying the given PWM + (controller specific) + +PWM properties should be named "pwms". The exact meaning of each pwms +property must be documented in the device tree binding for each device. +An optional property "pwm-names" may contain a list of strings to label +each of the PWM devices listed in the "pwms" property. If no "pwm-names" +property is given, the name of the user node will be used as fallback. + +Drivers for devices that use more than a single PWM device can use the +"pwm-names" property to map the name of the PWM device requested by the +pwm_get() call to an index into the list given by the "pwms" property. + +The following example could be used to describe a PWM-based backlight +device: + + pwm: pwm { + #pwm-cells = <2>; + }; + + [...] + + bl: backlight { + pwms = <&pwm 0 5000000>; + pwm-names = "backlight"; + }; + +pwm-specifier typically encodes the chip-relative PWM number and the PWM +period in nanoseconds. Note that in the example above, specifying the +"pwm-names" is redundant because the name "backlight" would be used as +fallback anyway. + +2) PWM controller nodes +----------------------- + +PWM controller nodes must specify the number of cells used for the +specifier using the '#pwm-cells' property. + +An example PWM controller might look like this: + + pwm: pwm@7000a000 { + compatible = "nvidia,tegra20-pwm"; + reg = <0x7000a000 0x100>; + #pwm-cells = <2>; + }; diff --git a/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt new file mode 100644 index 000000000000..1e4fc727f3b1 --- /dev/null +++ b/Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt @@ -0,0 +1,28 @@ +pwm-backlight bindings + +Required properties: + - compatible: "pwm-backlight" + - pwms: OF device-tree PWM specification (see PWM binding[0]) + - brightness-levels: Array of distinct brightness levels. Typically these + are in the range from 0 to 255, but any range starting at 0 will do. + The actual brightness level (PWM duty cycle) will be interpolated + from these values. 0 means a 0% duty cycle (darkest/off), while the + last value in the array represents a 100% duty cycle (brightest). + - default-brightness-level: the default brightness level (index into the + array defined by the "brightness-levels" property) + +Optional properties: + - pwm-names: a list of names for the PWM devices specified in the + "pwms" property (see PWM binding[0]) + +[0]: Documentation/devicetree/bindings/pwm/pwm.txt + +Example: + + backlight { + compatible = "pwm-backlight"; + pwms = <&pwm 0 5000000>; + + brightness-levels = <0 4 8 16 32 64 128 255>; + default-brightness-level = <6>; + }; |