Merge tag 'pwm/for-5.14-rc1' of git://git.kernel.org/pub/scm/linux/ke…

…rnel/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()
  ...

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 <[email protected]>
+
+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";
+    };

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 <[email protected]>
+
+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";
+    };

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()

Documentation/driver-api/pwm.rst

@@ -40,14 +40,19 @@ 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::
 
 	int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state);
 
 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

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
 ============