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authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-08 12:18:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-08 12:18:04 -0700
commit8c1bfd746030a14435c9b60d08a81af61332089b (patch)
tree91f3cf34eac8b319342dd54c600d3adf8cf3e0b3 /Documentation
parentb0dfd9af28b60d7ec42c359ae84c1ba97e093100 (diff)
parentbebedf2bb4a9e0cb4ffa72cbc960728051b338a4 (diff)
downloadlwn-8c1bfd746030a14435c9b60d08a81af61332089b.tar.gz
lwn-8c1bfd746030a14435c9b60d08a81af61332089b.zip
Merge tag 'pwm/for-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding: "This contains mostly various fixes, cleanups and some conversions to the atomic API. One noteworthy change is that PWM consumers can now pass a hint to the PWM core about the PWM usage, enabling PWM providers to implement various optimizations. There's also a fair bit of simplification here with the addition of some device-managed helpers as well as unification between the DT and ACPI firmware interfaces" * tag 'pwm/for-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (50 commits) pwm: Remove redundant assignment to pointer pwm pwm: ep93xx: Fix read of uninitialized variable ret pwm: ep93xx: Prepare clock before using it pwm: ep93xx: Unfold legacy callbacks into ep93xx_pwm_apply() pwm: ep93xx: Implement .apply callback pwm: vt8500: Only unprepare the clock after the pwmchip was removed pwm: vt8500: Drop if with an always false condition pwm: tegra: Assert reset only after the PWM was unregistered pwm: tegra: Don't needlessly enable and disable the clock in .remove() pwm: tegra: Don't modify HW state in .remove callback pwm: tegra: Drop an if block with an always false condition pwm: core: Simplify some devm_*pwm*() functions pwm: core: Remove unused devm_pwm_put() pwm: core: Unify fwnode checks in the module pwm: core: Reuse fwnode_to_pwmchip() in ACPI case pwm: core: Convert to use fwnode for matching docs: firmware-guide: ACPI: Add a PWM example dt-bindings: pwm: pwm-tiecap: Add compatible string for AM64 SoC dt-bindings: pwm: pwm-tiecap: Convert to json schema pwm: sprd: Don't check the return code of pwmchip_remove() ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/pwm/pwm-tiecap.txt51
-rw-r--r--Documentation/devicetree/bindings/pwm/pwm-tiecap.yaml64
-rw-r--r--Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt50
-rw-r--r--Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.yaml65
-rw-r--r--Documentation/driver-api/driver-model/devres.rst3
-rw-r--r--Documentation/driver-api/pwm.rst7
-rw-r--r--Documentation/firmware-guide/acpi/enumeration.rst32
7 files changed, 169 insertions, 103 deletions
diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt b/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
deleted file mode 100644
index c7c4347a769a..000000000000
--- a/Documentation/devicetree/bindings/pwm/pwm-tiecap.txt
+++ /dev/null
@@ -1,51 +0,0 @@
-TI SOC ECAP based APWM controller
-
-Required properties:
-- compatible: Must be "ti,<soc>-ecap".
- for am33xx - compatible = "ti,am3352-ecap", "ti,am33xx-ecap";
- for am4372 - compatible = "ti,am4372-ecap", "ti,am3352-ecap", "ti,am33xx-ecap";
- for da850 - compatible = "ti,da850-ecap", "ti,am3352-ecap", "ti,am33xx-ecap";
- for dra746 - compatible = "ti,dra746-ecap", "ti,am3352-ecap";
- for 66ak2g - compatible = "ti,k2g-ecap", "ti,am3352-ecap";
- for am654 - compatible = "ti,am654-ecap", "ti,am3352-ecap";
-- #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
- the cells format. The PWM channel index ranges from 0 to 4. The only third
- cell flag supported by this binding is PWM_POLARITY_INVERTED.
-- reg: physical base address and size of the registers map.
-
-Optional properties:
-- clocks: Handle to the ECAP's functional clock.
-- clock-names: Must be set to "fck".
-
-Example:
-
-ecap0: ecap@48300100 { /* ECAP on am33xx */
- compatible = "ti,am3352-ecap", "ti,am33xx-ecap";
- #pwm-cells = <3>;
- reg = <0x48300100 0x80>;
- clocks = <&l4ls_gclk>;
- clock-names = "fck";
-};
-
-ecap0: ecap@48300100 { /* ECAP on am4372 */
- compatible = "ti,am4372-ecap", "ti,am3352-ecap", "ti,am33xx-ecap";
- #pwm-cells = <3>;
- reg = <0x48300100 0x80>;
- ti,hwmods = "ecap0";
- clocks = <&l4ls_gclk>;
- clock-names = "fck";
-};
-
-ecap0: ecap@1f06000 { /* ECAP on da850 */
- compatible = "ti,da850-ecap", "ti,am3352-ecap", "ti,am33xx-ecap";
- #pwm-cells = <3>;
- reg = <0x1f06000 0x80>;
-};
-
-ecap0: ecap@4843e100 {
- compatible = "ti,dra746-ecap", "ti,am3352-ecap";
- #pwm-cells = <3>;
- reg = <0x4843e100 0x80>;
- clocks = <&l4_root_clk_div>;
- clock-names = "fck";
-};
diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiecap.yaml b/Documentation/devicetree/bindings/pwm/pwm-tiecap.yaml
new file mode 100644
index 000000000000..ed35b6cc48d5
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-tiecap.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-tiecap.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI SOC ECAP based APWM controller
+
+maintainers:
+ - Vignesh R <vigneshr@ti.com>
+
+allOf:
+ - $ref: pwm.yaml#
+
+properties:
+ compatible:
+ oneOf:
+ - const: ti,am3352-ecap
+ - items:
+ - enum:
+ - ti,da850-ecap
+ - ti,am4372-ecap
+ - ti,dra746-ecap
+ - ti,k2g-ecap
+ - ti,am654-ecap
+ - ti,am64-ecap
+ - const: ti,am3352-ecap
+
+ reg:
+ maxItems: 1
+
+ "#pwm-cells":
+ const: 3
+ description: |
+ See pwm.yaml in this directory for a description of the cells format.
+ The only third cell flag supported by this binding is PWM_POLARITY_INVERTED.
+
+ clock-names:
+ const: fck
+
+ clocks:
+ maxItems: 1
+
+ power-domains:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - "#pwm-cells"
+ - clocks
+ - clock-names
+
+additionalProperties: false
+
+examples:
+ - |
+ ecap0: pwm@48300100 { /* ECAP on am33xx */
+ compatible = "ti,am3352-ecap";
+ #pwm-cells = <3>;
+ reg = <0x48300100 0x80>;
+ clocks = <&l4ls_gclk>;
+ clock-names = "fck";
+ };
diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt b/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
deleted file mode 100644
index c7e28f6d28be..000000000000
--- a/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt
+++ /dev/null
@@ -1,50 +0,0 @@
-TI SOC EHRPWM based PWM controller
-
-Required properties:
-- compatible: Must be "ti,<soc>-ehrpwm".
- for am33xx - compatible = "ti,am3352-ehrpwm", "ti,am33xx-ehrpwm";
- for am4372 - compatible = "ti,am4372-ehrpwm", "ti-am3352-ehrpwm", "ti,am33xx-ehrpwm";
- for am654 - compatible = "ti,am654-ehrpwm", "ti-am3352-ehrpwm";
- for da850 - compatible = "ti,da850-ehrpwm", "ti-am3352-ehrpwm", "ti,am33xx-ehrpwm";
- for dra746 - compatible = "ti,dra746-ehrpwm", "ti-am3352-ehrpwm";
-- #pwm-cells: should be 3. See pwm.yaml in this directory for a description of
- the cells format. The only third cell flag supported by this binding is
- PWM_POLARITY_INVERTED.
-- reg: physical base address and size of the registers map.
-
-Optional properties:
-- clocks: Handle to the PWM's time-base and functional clock.
-- clock-names: Must be set to "tbclk" and "fck".
-
-Example:
-
-ehrpwm0: pwm@48300200 { /* EHRPWM on am33xx */
- compatible = "ti,am3352-ehrpwm", "ti,am33xx-ehrpwm";
- #pwm-cells = <3>;
- reg = <0x48300200 0x100>;
- clocks = <&ehrpwm0_tbclk>, <&l4ls_gclk>;
- clock-names = "tbclk", "fck";
-};
-
-ehrpwm0: pwm@48300200 { /* EHRPWM on am4372 */
- compatible = "ti,am4372-ehrpwm", "ti,am3352-ehrpwm", "ti,am33xx-ehrpwm";
- #pwm-cells = <3>;
- reg = <0x48300200 0x80>;
- clocks = <&ehrpwm0_tbclk>, <&l4ls_gclk>;
- clock-names = "tbclk", "fck";
- ti,hwmods = "ehrpwm0";
-};
-
-ehrpwm0: pwm@1f00000 { /* EHRPWM on da850 */
- compatible = "ti,da850-ehrpwm", "ti,am3352-ehrpwm", "ti,am33xx-ehrpwm";
- #pwm-cells = <3>;
- reg = <0x1f00000 0x2000>;
-};
-
-ehrpwm0: pwm@4843e200 { /* EHRPWM on dra746 */
- compatible = "ti,dra746-ehrpwm", "ti,am3352-ehrpwm";
- #pwm-cells = <3>;
- reg = <0x4843e200 0x80>;
- clocks = <&ehrpwm0_tbclk>, <&l4_root_clk_div>;
- clock-names = "tbclk", "fck";
-};
diff --git a/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.yaml b/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.yaml
new file mode 100644
index 000000000000..ee312cb210e6
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-tiehrpwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI SOC EHRPWM based PWM controller
+
+maintainers:
+ - Vignesh R <vigneshr@ti.com>
+
+allOf:
+ - $ref: pwm.yaml#
+
+properties:
+ compatible:
+ oneOf:
+ - const: ti,am3352-ehrpwm
+ - items:
+ - enum:
+ - ti,da850-ehrpwm
+ - ti,am4372-ehrpwm
+ - ti,dra746-ehrpwm
+ - ti,am654-ehrpwm
+ - ti,am64-epwm
+ - const: ti,am3352-ehrpwm
+
+ reg:
+ maxItems: 1
+
+ "#pwm-cells":
+ const: 3
+ description: |
+ See pwm.yaml in this directory for a description of the cells format.
+ The only third cell flag supported by this binding is PWM_POLARITY_INVERTED.
+
+ clock-names:
+ items:
+ - const: tbclk
+ - const: fck
+
+ clocks:
+ maxItems: 2
+
+ power-domains:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - "#pwm-cells"
+ - clocks
+ - clock-names
+
+additionalProperties: false
+
+examples:
+ - |
+ ehrpwm0: pwm@48300200 { /* EHRPWM on am33xx */
+ compatible = "ti,am3352-ehrpwm";
+ #pwm-cells = <3>;
+ reg = <0x48300200 0x100>;
+ clocks = <&ehrpwm0_tbclk>, <&l4ls_gclk>;
+ clock-names = "tbclk", "fck";
+ };
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index 0fe1fffa295e..650096523f4f 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -400,7 +400,8 @@ POWER
PWM
devm_pwm_get()
- devm_pwm_put()
+ devm_of_pwm_get()
+ devm_fwnode_pwm_get()
REGULATOR
devm_regulator_bulk_get()
diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst
index a7ca4f58305a..ccb06e485756 100644
--- a/Documentation/driver-api/pwm.rst
+++ b/Documentation/driver-api/pwm.rst
@@ -40,7 +40,8 @@ after usage with pwm_free().
New users should use the pwm_get() function and pass to it the consumer
device or a consumer name. pwm_put() is used to free the PWM device. Managed
-variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist.
+variants of the getter, devm_pwm_get(), devm_of_pwm_get(),
+devm_fwnode_pwm_get(), also exist.
After being requested, a PWM has to be configured using::
@@ -48,6 +49,10 @@ After being requested, a PWM has to be configured using::
This API controls both the PWM period/duty_cycle config and the
enable/disable state.
+There is also a usage_power setting: If set, the PWM driver is only required to
+maintain the power output but has more freedom regarding signal form.
+If supported by the driver, the signal can be optimized, for example to improve
+EMI by phase shifting the individual channels of a chip.
The pwm_config(), pwm_enable() and pwm_disable() functions are just wrappers
around pwm_apply_state() and should not be used if the user wants to change
diff --git a/Documentation/firmware-guide/acpi/enumeration.rst b/Documentation/firmware-guide/acpi/enumeration.rst
index 18074eb71860..74b830b2fd59 100644
--- a/Documentation/firmware-guide/acpi/enumeration.rst
+++ b/Documentation/firmware-guide/acpi/enumeration.rst
@@ -258,6 +258,38 @@ input driver::
.id_table = mpu3050_ids,
};
+Reference to PWM device
+=======================
+
+Sometimes a device can be a consumer of PWM channel. Obviously OS would like
+to know which one. To provide this mapping the special property has been
+introduced, i.e.::
+
+ Device (DEV)
+ {
+ Name (_DSD, Package ()
+ {
+ ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
+ Package () {
+ Package () { "compatible", Package () { "pwm-leds" } },
+ Package () { "label", "alarm-led" },
+ Package () { "pwms",
+ Package () {
+ "\\_SB.PCI0.PWM", // <PWM device reference>
+ 0, // <PWM index>
+ 600000000, // <PWM period>
+ 0, // <PWM flags>
+ }
+ }
+ }
+
+ })
+ ...
+
+In the above example the PWM-based LED driver references to the PWM channel 0
+of \_SB.PCI0.PWM device with initial period setting equal to 600 ms (note that
+value is given in nanoseconds).
+
GPIO support
============