[PATCH 0/4] PWM and keyboard backlight driver for ARM Macs

[PATCH 0/4] PWM and keyboard backlight driver for ARM Macs

[Sasha Finkelstein]

Hi,

This series adds support for the PWM controller present on ARM Macs and used
among other things for the keyboard backlight on those laptops.

The included device tree patch also hooks up the keyboard backlight using
the pwm-leds binding.

Best Regards.

Sasha Finkelstein (4):
 dt-bindings: pwm: Add Apple PWM controller
 pwm: Add Apple PWM controller
 arm64: dts: apple: t8103: Add PWM controller
 MAINTAINERS: Add entries for Apple PWM driver

 Documentation/devicetree/bindings/pwm/pwm-apple.yaml |  51 +++++++++++++
 MAINTAINERS                                          |   2 ++
 arch/arm64/boot/dts/apple/t8103-j293.dts             |  20 ++++++++
 arch/arm64/boot/dts/apple/t8103-j313.dts             |  20 ++++++++
 arch/arm64/boot/dts/apple/t8103.dtsi                 |   9 ++++
 drivers/pwm/Kconfig                                  |  12 ++++
 drivers/pwm/Makefile                                 |   1 +
 drivers/pwm/pwm-apple.c                              | 124 +++++++++++++++++++
 8 files changed, 239 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-apple.yaml
 create mode 100644 drivers/pwm/pwm-apple.c

[PATCH 1/4] dt-bindings: pwm: Add Apple PWM controller

[Sasha Finkelstein]

Apple SoCs such as the M1 contain a PWM controller used
among other things to control the keyboard backlight.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 .../devicetree/bindings/pwm/pwm-apple.yaml    | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-apple.yaml

diff --git a/Documentation/devicetree/bindings/pwm/pwm-apple.yaml b/Documentation/devicetree/bindings/pwm/pwm-apple.yaml
new file mode 100644
index 000000000000..39dc32e00a3f
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-apple.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-apple.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple FPWM controller
+
+maintainers:
+  - asahi@lists.linux.dev
+  - Sasha Finkelstein <fnkl.kernel@gmail.com>
+
+description: |+
+  PWM controller used for keyboard backlight on ARM Macs
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - apple,t8103-fpwm
+          - apple,t6000-fpwm
+          - apple,t8112-fpwm
+      - const: apple,s5l-fpwm
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - clocks
+
+additionalProperties: false
+
+examples:
+  - |
+    pwm: fpwm@235044000 {
+      compatible = "apple,s5l-fpwm";
+      reg = <0x2 0x35044000 0x0 0x4000>;
+      power-domains = <&ps_fpwm1>;
+      clocks = <&clkref>;
+      #pwm-cells = <2>;
+    };
-- 
2.37.3

Re: [PATCH 1/4] dt-bindings: pwm: Add Apple PWM controller

[Krzysztof Kozlowski]

On 28/10/2022 12:52, Sasha Finkelstein wrote:
> Apple SoCs such as the M1 contain a PWM controller used
> among other things to control the keyboard backlight.
> 
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> ---
>  .../devicetree/bindings/pwm/pwm-apple.yaml    | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-apple.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-apple.yaml b/Documentation/devicetree/bindings/pwm/pwm-apple.yaml
> new file mode 100644
> index 000000000000..39dc32e00a3f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/pwm-apple.yaml

Filename matching compatible, so apple,s5l-fpwm.yaml

> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/pwm-apple.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Apple FPWM controller
> +
> +maintainers:
> +  - asahi@lists.linux.dev
> +  - Sasha Finkelstein <fnkl.kernel@gmail.com>
> +
> +description: |+

Drop |+

> +  PWM controller used for keyboard backlight on ARM Macs
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - apple,t8103-fpwm
> +          - apple,t6000-fpwm
> +          - apple,t8112-fpwm
> +      - const: apple,s5l-fpwm

Is it then derived from Samsung platform? If yes, it is candidate for
merging.

> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 2
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    pwm: fpwm@235044000 {

Generic node name, so just "pwm". Drop also label - it's not used in the
example.


Best regards,
Krzysztof

Re: [PATCH 1/4] dt-bindings: pwm: Add Apple PWM controller

[Sasha Finkelstein]

On Fri, 28 Oct 2022 at 20:53, Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> On 28/10/2022 12:52, Sasha Finkelstein wrote:
> > +  PWM controller used for keyboard backlight on ARM Macs
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - enum:
> > +          - apple,t8103-fpwm
> > +          - apple,t6000-fpwm
> > +          - apple,t8112-fpwm
> > +      - const: apple,s5l-fpwm
>
> Is it then derived from Samsung platform? If yes, it is candidate for
> merging.
Apple calls it the 'AppleS5L8920XFPWM' which suggests some samsung
lineage, but the register interface is different from the one in
pwm-samsung driver.

Re: [PATCH 1/4] dt-bindings: pwm: Add Apple PWM controller

[Rob Herring]

On Fri, 28 Oct 2022 19:52:13 +0300, Sasha Finkelstein wrote:
> Apple SoCs such as the M1 contain a PWM controller used
> among other things to control the keyboard backlight.
> 
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> ---
>  .../devicetree/bindings/pwm/pwm-apple.yaml    | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-apple.yaml
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pwm/pwm-apple.example.dtb: fpwm@235044000: compatible:0: 'apple,s5l-fpwm' is not one of ['apple,t8103-fpwm', 'apple,t6000-fpwm', 'apple,t8112-fpwm']
	From schema: /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pwm/pwm-apple.yaml
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pwm/pwm-apple.example.dtb: fpwm@235044000: compatible: ['apple,s5l-fpwm'] is too short
	From schema: /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pwm/pwm-apple.yaml
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pwm/pwm-apple.example.dtb: fpwm@235044000: reg: [[2, 889470976], [0, 16384]] is too long
	From schema: /builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pwm/pwm-apple.yaml

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/patch/

This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit.

Re: [PATCH 1/4] dt-bindings: pwm: Add Apple PWM controller

[Krzysztof Kozlowski]

On 28/10/2022 12:52, Sasha Finkelstein wrote:
> Apple SoCs such as the M1 contain a PWM controller used
> among other things to control the keyboard backlight.
> 
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> ---
>  .../devicetree/bindings/pwm/pwm-apple.yaml    | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/pwm-apple.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/pwm-apple.yaml b/Documentation/devicetree/bindings/pwm/pwm-apple.yaml
> new file mode 100644
> index 000000000000..39dc32e00a3f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/pwm-apple.yaml
> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/pwm-apple.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Apple FPWM controller
> +
> +maintainers:
> +  - asahi@lists.linux.dev
> +  - Sasha Finkelstein <fnkl.kernel@gmail.com>
> +
> +description: |+
> +  PWM controller used for keyboard backlight on ARM Macs
> +
> +properties:
> +  compatible:
> +    items:
> +      - enum:
> +          - apple,t8103-fpwm
> +          - apple,t6000-fpwm
> +          - apple,t8112-fpwm
> +      - const: apple,s5l-fpwm

Missing blank line.

> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  power-domains:
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 2
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    pwm: fpwm@235044000 {
> +      compatible = "apple,s5l-fpwm";

As Rob's bot pointed out, this does not match the bindings so you did
not test them before sending :(

Best regards,
Krzysztof

[PATCH 2/4] pwm: Add Apple PWM controller

[Sasha Finkelstein]

Adds the Apple PWM controller driver.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 drivers/pwm/Kconfig     |  12 ++++
 drivers/pwm/Makefile    |   1 +
 drivers/pwm/pwm-apple.c | 124 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 137 insertions(+)
 create mode 100644 drivers/pwm/pwm-apple.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 60d13a949bc5..ec6acb368073 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -51,6 +51,18 @@ config PWM_AB8500
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-ab8500.
 
+config PWM_APPLE
+	tristate "Apple SoC PWM support"
+	depends on ARCH_APPLE || (COMPILE_TEST && 64BIT)
+	help
+	  Generic PWM framework driver for PWM controller present on
+	  Apple SoCs
+
+	  Say Y here if you have an ARM Apple laptop, otherwise say N
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-apple.
+
 config PWM_ATMEL
 	tristate "Atmel PWM support"
 	depends on ARCH_AT91 || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index 7bf1a29f02b8..19899b912e00 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -2,6 +2,7 @@
 obj-$(CONFIG_PWM)		+= core.o
 obj-$(CONFIG_PWM_SYSFS)		+= sysfs.o
 obj-$(CONFIG_PWM_AB8500)	+= pwm-ab8500.o
+obj-$(CONFIG_PWM_APPLE)		+= pwm-apple.o
 obj-$(CONFIG_PWM_ATMEL)		+= pwm-atmel.o
 obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM)	+= pwm-atmel-hlcdc.o
 obj-$(CONFIG_PWM_ATMEL_TCB)	+= pwm-atmel-tcb.o
diff --git a/drivers/pwm/pwm-apple.c b/drivers/pwm/pwm-apple.c
new file mode 100644
index 000000000000..4cfa9bf435dc
--- /dev/null
+++ b/drivers/pwm/pwm-apple.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Driver for the Apple SoC PWM controller
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
+
+#define PWM_CONTROL     0x00
+#define PWM_ON_CYCLES   0x1c
+#define PWM_OFF_CYCLES  0x18
+
+#define CTRL_ENABLE        BIT(0)
+#define CTRL_MODE          BIT(2)
+#define CTRL_UPDATE        BIT(5)
+#define CTRL_TRIGGER       BIT(9)
+#define CTRL_INVERT        BIT(10)
+#define CTRL_OUTPUT_ENABLE BIT(14)
+
+struct apple_pwm {
+	struct pwm_chip chip;
+	void __iomem *base;
+	u64 clkrate;
+};
+
+static int apple_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			   const struct pwm_state *state)
+{
+	struct apple_pwm *fpwm;
+	u64 on_cycles, off_cycles;
+
+	fpwm = container_of(chip, struct apple_pwm, chip);
+	if (state->enabled) {
+		on_cycles = fpwm->clkrate * state->duty_cycle / NSEC_PER_SEC;
+		off_cycles = (fpwm->clkrate * state->period / NSEC_PER_SEC) - on_cycles;
+		writel(on_cycles, fpwm->base + PWM_ON_CYCLES);
+		writel(off_cycles, fpwm->base + PWM_OFF_CYCLES);
+		writel(CTRL_ENABLE | CTRL_OUTPUT_ENABLE | CTRL_UPDATE,
+		       fpwm->base + PWM_CONTROL);
+	} else {
+		writel(0, fpwm->base + PWM_CONTROL);
+	}
+	return 0;
+}
+
+static void apple_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+			   struct pwm_state *state)
+{
+	struct apple_pwm *fpwm;
+	u32 on_cycles, off_cycles, ctrl;
+
+	fpwm = container_of(chip, struct apple_pwm, chip);
+
+	ctrl = readl(fpwm->base + PWM_CONTROL);
+	on_cycles = readl(fpwm->base + PWM_ON_CYCLES);
+	off_cycles = readl(fpwm->base + PWM_OFF_CYCLES);
+
+	state->enabled = (ctrl & CTRL_ENABLE) && (ctrl & CTRL_OUTPUT_ENABLE);
+	state->polarity = PWM_POLARITY_NORMAL;
+	state->duty_cycle = on_cycles / fpwm->clkrate * NSEC_PER_SEC;
+	state->period = (off_cycles + on_cycles) / fpwm->clkrate * NSEC_PER_SEC;
+}
+
+static const struct pwm_ops apple_pwm_ops = {
+	.apply = apple_pwm_apply,
+	.get_state = apple_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static int apple_pwm_probe(struct platform_device *pdev)
+{
+	struct apple_pwm *pwm;
+	struct clk *clk;
+	int ret;
+
+	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	pwm->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pwm->base))
+		return PTR_ERR(pwm->base);
+
+	platform_set_drvdata(pdev, pwm);
+
+	clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	pwm->clkrate = clk_get_rate(clk);
+	pwm->chip.dev = &pdev->dev;
+	pwm->chip.npwm = 1;
+	pwm->chip.ops = &apple_pwm_ops;
+
+	ret = devm_pwmchip_add(&pdev->dev, &pwm->chip);
+	return ret;
+}
+
+static const struct of_device_id apple_pwm_of_match[] = {
+	{ .compatible = "apple,s5l-fpwm" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, apple_pwm_of_match);
+
+static struct platform_driver apple_pwm_driver = {
+	.probe = apple_pwm_probe,
+	.driver = {
+		.name = "apple-pwm",
+		.owner = THIS_MODULE,
+		.of_match_table = apple_pwm_of_match,
+	},
+};
+module_platform_driver(apple_pwm_driver);
+
+MODULE_DESCRIPTION("Apple SoC PWM driver");
+MODULE_LICENSE("Dual MIT/GPL");
-- 
2.37.3

Re: [PATCH 2/4] pwm: Add Apple PWM controller

[Krzysztof Kozlowski]

On 28/10/2022 12:52, Sasha Finkelstein wrote:
> Adds the Apple PWM controller driver.
> 
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> ---
>  drivers/pwm/Kconfig     |  12 ++++
>  drivers/pwm/Makefile    |   1 +
>  drivers/pwm/pwm-apple.c | 124 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 137 insertions(+)
>  create mode 100644 drivers/pwm/pwm-apple.c
> 
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index 60d13a949bc5..ec6acb368073 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -51,6 +51,18 @@ config PWM_AB8500
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called pwm-ab8500.
>  
> +config PWM_APPLE
> +	tristate "Apple SoC PWM support"
> +	depends on ARCH_APPLE || (COMPILE_TEST && 64BIT)

Why this code cannot be build on 32-bit?

> +	help
> +	  Generic PWM framework driver for PWM controller present on
> +	  Apple SoCs
> +

Best regards,
Krzysztof

Re: [PATCH 2/4] pwm: Add Apple PWM controller

[Sasha Finkelstein]

On Fri, 28 Oct 2022 at 20:54, Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:
>
> On 28/10/2022 12:52, Sasha Finkelstein wrote:
> > +config PWM_APPLE
> > +     tristate "Apple SoC PWM support"
> > +     depends on ARCH_APPLE || (COMPILE_TEST && 64BIT)
>
> Why this code cannot be build on 32-bit?
It uses 64-bit divisions, which causes it to fail to build on 32-bit
mips. It should not be a
problem, since this hardware is only present on 64-bit SoCs.

Re: [PATCH 2/4] pwm: Add Apple PWM controller

[Krzysztof Kozlowski]

On 28/10/2022 14:51, Sasha Finkelstein wrote:
> On Fri, 28 Oct 2022 at 20:54, Krzysztof Kozlowski
> <krzysztof.kozlowski@linaro.org> wrote:
>>
>> On 28/10/2022 12:52, Sasha Finkelstein wrote:
>>> +config PWM_APPLE
>>> +     tristate "Apple SoC PWM support"
>>> +     depends on ARCH_APPLE || (COMPILE_TEST && 64BIT)
>>
>> Why this code cannot be build on 32-bit?
> It uses 64-bit divisions, which causes it to fail to build on 32-bit
> mips. It should not be a
> problem, since this hardware is only present on 64-bit SoCs.

Does not matter, code should be portable and buildable on 32-bit. If it
does not build then your code is not correct.

You need to investigate the failure. Maybe using do_div would solve (or
other macros from div64.h)

Best regards,
Krzysztof

Re: [PATCH 2/4] pwm: Add Apple PWM controller

[Hector Martin]

On 29/10/2022 04.49, Krzysztof Kozlowski wrote:
> On 28/10/2022 14:51, Sasha Finkelstein wrote:
>> On Fri, 28 Oct 2022 at 20:54, Krzysztof Kozlowski
>> <krzysztof.kozlowski@linaro.org> wrote:
>>>
>>> On 28/10/2022 12:52, Sasha Finkelstein wrote:
>>>> +config PWM_APPLE
>>>> +     tristate "Apple SoC PWM support"
>>>> +     depends on ARCH_APPLE || (COMPILE_TEST && 64BIT)
>>>
>>> Why this code cannot be build on 32-bit?
>> It uses 64-bit divisions, which causes it to fail to build on 32-bit
>> mips. It should not be a
>> problem, since this hardware is only present on 64-bit SoCs.
> 
> Does not matter, code should be portable and buildable on 32-bit. If it
> does not build then your code is not correct.

This statement does not apply in general. There are plenty of drivers
which cannot reasonably build for 32-bit, and make no sense because no
32-bit hardware exists that could use them. Examples include anything
that accesses 64-bit registers on 64-bit SoCs the normal way, and
further anything that touches CPU stuff like system registers.

In *this* case, if the only issue is some 64-bit math, then yes, it
should be made to build on 32-bit (especially since this is likely to
also work for older 32-bit Apple SoCs). But the (COMPILE_TEST && 64BIT)
pattern is definitely valid in other cases, and I've been adding it
lately to shut up the kernel test bot since it makes no sense to compile
test a whole pile of our drivers on 32-bit architectures - they
fundamentally can't compile without adding pointless hypothetical broken
fluff to the driver like split MMIO accesses (which often can't work on
real hardware), and it serves no purpose.


- Hector

[PATCH 3/4] arm64: dts: apple: t8103: Add PWM controller

[Sasha Finkelstein]

Adds PWM controller and keyboard backlight bindings for M1 MacBooks

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 arch/arm64/boot/dts/apple/t8103-j293.dts | 20 ++++++++++++++++++++
 arch/arm64/boot/dts/apple/t8103-j313.dts | 20 ++++++++++++++++++++
 arch/arm64/boot/dts/apple/t8103.dtsi     |  9 +++++++++
 3 files changed, 49 insertions(+)

diff --git a/arch/arm64/boot/dts/apple/t8103-j293.dts b/arch/arm64/boot/dts/apple/t8103-j293.dts
index ecb10d237a05..5652cd41730a 100644
--- a/arch/arm64/boot/dts/apple/t8103-j293.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j293.dts
@@ -11,6 +11,7 @@
 
 #include "t8103.dtsi"
 #include "t8103-jxxx.dtsi"
+#include <dt-bindings/leds/common.h>
 
 / {
 	compatible = "apple,j293", "apple,t8103", "apple,arm-platform";
@@ -43,3 +44,22 @@ &i2c2 {
 &i2c4 {
 	status = "okay";
 };
+
+/ {
+	pwmleds {
+		compatible = "pwm-leds";
+		kbd-backlight {
+			pwms = <&fpwm1 0 40000>;
+			label = "kbd_backlight";
+			function = LED_FUNCTION_KBD_BACKLIGHT;
+			color = <LED_COLOR_ID_WHITE>;
+			max-brightness = <255>;
+			default-state = "keep";
+			pwm-names = "kbd-backlight";
+		};
+	};
+};
+
+&fpwm1 {
+	status = "okay";
+};
diff --git a/arch/arm64/boot/dts/apple/t8103-j313.dts b/arch/arm64/boot/dts/apple/t8103-j313.dts
index df741737b8e6..cff53f8770f3 100644
--- a/arch/arm64/boot/dts/apple/t8103-j313.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j313.dts
@@ -11,6 +11,7 @@
 
 #include "t8103.dtsi"
 #include "t8103-jxxx.dtsi"
+#include <dt-bindings/leds/common.h>
 
 / {
 	compatible = "apple,j313", "apple,t8103", "apple,arm-platform";
@@ -35,3 +36,22 @@ &pcie0_dart_2 {
 
 /delete-node/ &port01;
 /delete-node/ &port02;
+
+/ {
+	pwmleds {
+		compatible = "pwm-leds";
+		kbd-backlight {
+			pwms = <&fpwm1 0 40000>;
+			label = "kbd_backlight";
+			function = LED_FUNCTION_KBD_BACKLIGHT;
+			color = <LED_COLOR_ID_WHITE>;
+			max-brightness = <255>;
+			default-state = "keep";
+			pwm-names = "kbd-backlight";
+		};
+	};
+};
+
+&fpwm1 {
+	status = "okay";
+};
diff --git a/arch/arm64/boot/dts/apple/t8103.dtsi b/arch/arm64/boot/dts/apple/t8103.dtsi
index 51a63b29d404..a95dc482102e 100644
--- a/arch/arm64/boot/dts/apple/t8103.dtsi
+++ b/arch/arm64/boot/dts/apple/t8103.dtsi
@@ -191,6 +191,15 @@ i2c4: i2c@235020000 {
 			status = "disabled"; /* only used in J293 */
 		};
 
+		fpwm1: fpwm@235044000 {
+			compatible = "apple,t8103-fpwm", "apple,s5l-fpwm";
+			reg = <0x2 0x35044000 0x0 0x4000>;
+			power-domains = <&ps_fpwm1>;
+			clocks = <&clkref>;
+			#pwm-cells = <2>;
+			status = "disabled";
+		};
+
 		serial0: serial@235200000 {
 			compatible = "apple,s5l-uart";
 			reg = <0x2 0x35200000 0x0 0x1000>;
-- 
2.37.3

Re: [PATCH 3/4] arm64: dts: apple: t8103: Add PWM controller

[Krzysztof Kozlowski]

On 28/10/2022 12:52, Sasha Finkelstein wrote:
> Adds PWM controller and keyboard backlight bindings for M1 MacBooks
> 
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> ---
>  arch/arm64/boot/dts/apple/t8103-j293.dts | 20 ++++++++++++++++++++
>  arch/arm64/boot/dts/apple/t8103-j313.dts | 20 ++++++++++++++++++++
>  arch/arm64/boot/dts/apple/t8103.dtsi     |  9 +++++++++
>  3 files changed, 49 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/apple/t8103-j293.dts b/arch/arm64/boot/dts/apple/t8103-j293.dts
> index ecb10d237a05..5652cd41730a 100644
> --- a/arch/arm64/boot/dts/apple/t8103-j293.dts
> +++ b/arch/arm64/boot/dts/apple/t8103-j293.dts
> @@ -11,6 +11,7 @@
>  
>  #include "t8103.dtsi"
>  #include "t8103-jxxx.dtsi"
> +#include <dt-bindings/leds/common.h>
>  
>  / {
>  	compatible = "apple,j293", "apple,t8103", "apple,arm-platform";
> @@ -43,3 +44,22 @@ &i2c2 {
>  &i2c4 {
>  	status = "okay";
>  };
> +
> +/ {
> +	pwmleds {

Node names should be generic: led-controller
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation


> +		compatible = "pwm-leds";
> +		kbd-backlight {

Does not look like you tested the DTS against bindings. Please run `make
dtbs_check` (see Documentation/devicetree/bindings/writing-schema.rst
for instructions).

> +			pwms = <&fpwm1 0 40000>;
> +			label = "kbd_backlight";
> +			function = LED_FUNCTION_KBD_BACKLIGHT;
> +			color = <LED_COLOR_ID_WHITE>;
> +			max-brightness = <255>;
> +			default-state = "keep";
> +			pwm-names = "kbd-backlight";

This goes just after pwms.

> +		};
> +	};
> +};
> +
> +&fpwm1 {
> +	status = "okay";
> +};
> diff --git a/arch/arm64/boot/dts/apple/t8103-j313.dts b/arch/arm64/boot/dts/apple/t8103-j313.dts
> index df741737b8e6..cff53f8770f3 100644
> --- a/arch/arm64/boot/dts/apple/t8103-j313.dts
> +++ b/arch/arm64/boot/dts/apple/t8103-j313.dts
> @@ -11,6 +11,7 @@
>  
>  #include "t8103.dtsi"
>  #include "t8103-jxxx.dtsi"
> +#include <dt-bindings/leds/common.h>
>  
>  / {
>  	compatible = "apple,j313", "apple,t8103", "apple,arm-platform";
> @@ -35,3 +36,22 @@ &pcie0_dart_2 {
>  
>  /delete-node/ &port01;
>  /delete-node/ &port02;
> +
> +/ {
> +	pwmleds {

Same comments

> +		compatible = "pwm-leds";
> +		kbd-backlight {
> +			pwms = <&fpwm1 0 40000>;
> +			label = "kbd_backlight";
> +			function = LED_FUNCTION_KBD_BACKLIGHT;
> +			color = <LED_COLOR_ID_WHITE>;
> +			max-brightness = <255>;
> +			default-state = "keep";
> +			pwm-names = "kbd-backlight";
> +		};
> +	};
> +};
> +
> +&fpwm1 {
> +	status = "okay";
> +};
> diff --git a/arch/arm64/boot/dts/apple/t8103.dtsi b/arch/arm64/boot/dts/apple/t8103.dtsi
> index 51a63b29d404..a95dc482102e 100644
> --- a/arch/arm64/boot/dts/apple/t8103.dtsi
> +++ b/arch/arm64/boot/dts/apple/t8103.dtsi
> @@ -191,6 +191,15 @@ i2c4: i2c@235020000 {
>  			status = "disabled"; /* only used in J293 */
>  		};
>  
> +		fpwm1: fpwm@235044000 {

Node names should be generic, so pwm.
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

> +			compatible = "apple,t8103-fpwm", "apple,s5l-fpwm";
> +			reg = <0x2 0x35044000 0x0 0x4000>;

Best regards,
Krzysztof

[PATCH 4/4] MAINTAINERS: Add entries for Apple PWM driver

[Sasha Finkelstein]

Add the MAINTAINERS entries for the driver

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index e04d944005ba..4c9719a2439a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1908,6 +1908,7 @@ F:	Documentation/devicetree/bindings/nvmem/apple,efuses.yaml
 F:	Documentation/devicetree/bindings/pci/apple,pcie.yaml
 F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
 F:	Documentation/devicetree/bindings/power/apple*
+F:	Documentation/devicetree/bindings/pwm/pwm-apple.yaml
 F:	Documentation/devicetree/bindings/watchdog/apple,wdt.yaml
 F:	arch/arm64/boot/dts/apple/
 F:	drivers/clk/clk-apple-nco.c
@@ -1921,6 +1922,7 @@ F:	drivers/mailbox/apple-mailbox.c
 F:	drivers/nvme/host/apple.c
 F:	drivers/nvmem/apple-efuses.c
 F:	drivers/pinctrl/pinctrl-apple-gpio.c
+F:	drivers/pwm/pwm-apple.c
 F:	drivers/soc/apple/*
 F:	drivers/watchdog/apple_wdt.c
 F:	include/dt-bindings/interrupt-controller/apple-aic.h
-- 
2.37.3