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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-08 12:18:04 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-08 12:18:04 -0700 |
commit | 8c1bfd746030a14435c9b60d08a81af61332089b (patch) | |
tree | 91f3cf34eac8b319342dd54c600d3adf8cf3e0b3 /Documentation | |
parent | b0dfd9af28b60d7ec42c359ae84c1ba97e093100 (diff) | |
parent | bebedf2bb4a9e0cb4ffa72cbc960728051b338a4 (diff) | |
download | lwn-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.txt | 51 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/pwm/pwm-tiecap.yaml | 64 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.txt | 50 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/pwm/pwm-tiehrpwm.yaml | 65 | ||||
-rw-r--r-- | Documentation/driver-api/driver-model/devres.rst | 3 | ||||
-rw-r--r-- | Documentation/driver-api/pwm.rst | 7 | ||||
-rw-r--r-- | Documentation/firmware-guide/acpi/enumeration.rst | 32 |
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 ============ |