diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt | 5 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/pwm-sifive.txt | 33 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt | 9 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/pwm/pwm-stm32.txt | 3 | ||||
| -rw-r--r-- | Documentation/pwm.txt | 7 |
5 files changed, 50 insertions, 7 deletions
diff --git a/Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt b/Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt index 7d9d3f90641b..493bec80d59b 100644 --- a/Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt +++ b/Documentation/devicetree/bindings/pwm/ingenic,jz47xx-pwm.txt @@ -2,10 +2,7 @@ Ingenic JZ47xx PWM Controller ============================= Required properties: -- compatible: One of: - * "ingenic,jz4740-pwm" - * "ingenic,jz4770-pwm" - * "ingenic,jz4780-pwm" +- compatible: Should be "ingenic,jz4740-pwm" - #pwm-cells: Should be 3. See pwm.txt in this directory for a description of the cells format. - clocks : phandle to the external clock. diff --git a/Documentation/devicetree/bindings/pwm/pwm-sifive.txt b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt new file mode 100644 index 000000000000..36447e3c9378 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/pwm-sifive.txt @@ -0,0 +1,33 @@ +SiFive PWM controller + +Unlike most other PWM controllers, the SiFive PWM controller currently only +supports one period for all channels in the PWM. All PWMs need to run at +the same period. The period also has significant restrictions on the values +it can achieve, which the driver rounds to the nearest achievable period. +PWM RTL that corresponds to the IP block version numbers can be found +here: + +https://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/pwm + +Required properties: +- compatible: Should be "sifive,<chip>-pwm" and "sifive,pwm<version>". + Supported compatible strings are: "sifive,fu540-c000-pwm" for the SiFive + PWM v0 as integrated onto the SiFive FU540 chip, and "sifive,pwm0" for the + SiFive PWM v0 IP block with no chip integration tweaks. + Please refer to sifive-blocks-ip-versioning.txt for details. +- reg: physical base address and length of the controller's registers +- clocks: Should contain a clock identifier for the PWM's parent clock. +- #pwm-cells: Should be 3. See pwm.txt in this directory + for a description of the cell format. +- interrupts: one interrupt per PWM channel + +Examples: + +pwm: pwm@10020000 { + compatible = "sifive,fu540-c000-pwm", "sifive,pwm0"; + reg = <0x0 0x10020000 0x0 0x1000>; + clocks = <&tlclk>; + interrupt-parent = <&plic>; + interrupts = <42 43 44 45>; + #pwm-cells = <3>; +}; diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt index bd23302e84be..6521bc44a74e 100644 --- a/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32-lp.txt @@ -11,8 +11,10 @@ Required parameters: bindings defined in pwm.txt. Optional properties: -- pinctrl-names: Set to "default". -- pinctrl-0: Phandle pointing to pin configuration node for PWM. +- pinctrl-names: Set to "default". An additional "sleep" state can be + defined to set pins in sleep state when in low power. +- pinctrl-n: Phandle(s) pointing to pin configuration node for PWM, + respectively for "default" and "sleep" states. Example: timer@40002400 { @@ -21,7 +23,8 @@ Example: pwm { compatible = "st,stm32-pwm-lp"; #pwm-cells = <3>; - pinctrl-names = "default"; + pinctrl-names = "default", "sleep"; pinctrl-0 = <&lppwm1_pins>; + pinctrl-1 = <&lppwm1_sleep_pins>; }; }; diff --git a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt index 3e6d55018d7a..a8690bfa5e1f 100644 --- a/Documentation/devicetree/bindings/pwm/pwm-stm32.txt +++ b/Documentation/devicetree/bindings/pwm/pwm-stm32.txt @@ -8,6 +8,8 @@ Required parameters: - pinctrl-names: Set to "default". - pinctrl-0: List of phandles pointing to pin configuration nodes for PWM module. For Pinctrl properties see ../pinctrl/pinctrl-bindings.txt +- #pwm-cells: Should be set to 3. This PWM chip uses the default 3 cells + bindings defined in pwm.txt. Optional parameters: - st,breakinput: One or two <index level filter> to describe break input configurations. @@ -28,6 +30,7 @@ Example: pwm { compatible = "st,stm32-pwm"; + #pwm-cells = <3>; pinctrl-0 = <&pwm1_pins>; pinctrl-names = "default"; st,breakinput = <0 1 5>; diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index 8fbf0aa3ba2d..ab62f1bb0366 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt @@ -65,6 +65,10 @@ period). struct pwm_args contains 2 fields (period and polarity) and should be used to set the initial PWM config (usually done in the probe function of the PWM user). PWM arguments are retrieved with pwm_get_args(). +All consumers should really be reconfiguring the PWM upon resume as +appropriate. This is the only way to ensure that everything is resumed in +the proper order. + Using PWMs with the sysfs interface ----------------------------------- @@ -141,6 +145,9 @@ The implementation of ->get_state() (a method used to retrieve initial PWM state) is also encouraged for the same reason: letting the PWM user know about the current PWM state would allow him to avoid glitches. +Drivers should not implement any power management. In other words, +consumers should implement it as described in the "Using PWMs" section. + Locking ------- |