[PATCH v3 0/4] PWM and keyboard backlight driver for ARM Macs

[PATCH v3 0/4] PWM and keyboard backlight driver for ARM Macs

[Sasha Finkelstein]

Hi,

This is the v3 of the patch series to add PWM and keyboard backlight
driver for ARM macs.

Changes in v1:
Addressing the review comments.

Changes in v2:
Added the reviewed-by and acked-by tags.
Addressing a review comment.

v1: https://www.spinics.net/lists/linux-pwm/msg19500.html
v2: https://www.spinics.net/lists/linux-pwm/msg19562.html

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

 .../bindings/pwm/apple,s5l-fpwm.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                       | 127 ++++++++++++++++++
 8 files changed, 242 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
 create mode 100644 drivers/pwm/pwm-apple.c

-- 
2.38.1

[PATCH v3 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>
Reviewed-by: Krzyszstof Kozlowski <krzyszstof.kozlowski@linaro.org>
Acked-by: Sven Peter <sven@svenpeter.dev>
---
 .../bindings/pwm/apple,s5l-fpwm.yaml          | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml

diff --git a/Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml b/Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
new file mode 100644
index 000000000000..142157bff0cd
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/apple,s5l-fpwm.yaml#
+$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@235044000 {
+      compatible = "apple,t8103-fpwm", "apple,s5l-fpwm";
+      reg = <0x35044000 0x4000>;
+      power-domains = <&ps_fpwm1>;
+      clocks = <&clkref>;
+      #pwm-cells = <2>;
+    };
-- 
2.38.1

[PATCH v3 2/4] pwm: Add Apple PWM controller

[Sasha Finkelstein]

Adds the Apple PWM controller driver.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Acked-by: Sven Peter <sven@svenpeter.dev>
---
 drivers/pwm/Kconfig     |  12 ++++
 drivers/pwm/Makefile    |   1 +
 drivers/pwm/pwm-apple.c | 127 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 140 insertions(+)
 create mode 100644 drivers/pwm/pwm-apple.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 60d13a949bc5..c3be11468414 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
+	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..b0c3f86fd578
--- /dev/null
+++ b/drivers/pwm/pwm-apple.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Driver for the Apple SoC PWM controller
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.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 = mul_u64_u64_div_u64(fpwm->clkrate,
+						state->duty_cycle, NSEC_PER_SEC);
+		off_cycles = mul_u64_u64_div_u64(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 = div_u64(on_cycles, fpwm->clkrate) * NSEC_PER_SEC;
+	state->period = div_u64(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");
-- 
2.38.1

[PATCH v3 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>
Acked-by: Sven Peter <sven@svenpeter.dev>
---
 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..0b4b7e8e0726 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";
 };
+
+/ {
+	led-controller {
+		compatible = "pwm-leds";
+		led-0 {
+			pwms = <&fpwm1 0 40000>;
+			pwm-names = "kbd-backlight";
+			label = "kbd_backlight";
+			function = LED_FUNCTION_KBD_BACKLIGHT;
+			color = <LED_COLOR_ID_WHITE>;
+			max-brightness = <255>;
+			default-state = "keep";
+		};
+	};
+};
+
+&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..0e0f57dee96b 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;
+
+/ {
+	led-controller {
+		compatible = "pwm-leds";
+		led-0 {
+			pwms = <&fpwm1 0 40000>;
+			pwm-names = "kbd-backlight";
+			label = "kbd_backlight";
+			function = LED_FUNCTION_KBD_BACKLIGHT;
+			color = <LED_COLOR_ID_WHITE>;
+			max-brightness = <255>;
+			default-state = "keep";
+		};
+	};
+};
+
+&fpwm1 {
+	status = "okay";
+};
diff --git a/arch/arm64/boot/dts/apple/t8103.dtsi b/arch/arm64/boot/dts/apple/t8103.dtsi
index 51a63b29d404..ccdb26ef6b22 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: pwm@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>;
-- 
2.38.1

[PATCH v3 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>
Acked-by: Sven Peter <sven@svenpeter.dev>
---
 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 046ff06ff97f..69f56f7cf907 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
-- 
2.38.1

Re: [PATCH v3 1/4] dt-bindings: pwm: Add Apple PWM controller

[Rob Herring]

On Fri, Nov 11, 2022 at 08:33:45PM +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>
> Reviewed-by: Krzyszstof Kozlowski <krzyszstof.kozlowski@linaro.org>

I assume you got a bounce on this as you got Krzysztof's name wrong 
(krzysztof.kozlowski@linaro.org). You should have either resent this or 
replied pointing out the typo.

> Acked-by: Sven Peter <sven@svenpeter.dev>
> ---
>  .../bindings/pwm/apple,s5l-fpwm.yaml          | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
> 
> diff --git a/Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml b/Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
> new file mode 100644
> index 000000000000..142157bff0cd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/pwm/apple,s5l-fpwm.yaml#
> +$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@235044000 {
> +      compatible = "apple,t8103-fpwm", "apple,s5l-fpwm";
> +      reg = <0x35044000 0x4000>;
> +      power-domains = <&ps_fpwm1>;
> +      clocks = <&clkref>;
> +      #pwm-cells = <2>;
> +    };
> -- 
> 2.38.1
> 
> 

Re: [PATCH v3 1/4] dt-bindings: pwm: Add Apple PWM controller

[Krzysztof Kozlowski]

On 16/11/2022 21:20, Rob Herring wrote:
> On Fri, Nov 11, 2022 at 08:33:45PM +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>
>> Reviewed-by: Krzyszstof Kozlowski <krzyszstof.kozlowski@linaro.org>
> 
> I assume you got a bounce on this as you got Krzysztof's name wrong 
> (krzysztof.kozlowski@linaro.org). You should have either resent this or 
> replied pointing out the typo.

Nice...

Please do not type my name. It's pretty impossible to get it right, so
instead copy-paste the tag entirely without changes and addons.

This actually applies to all other tags as well, even with easy-to-type
names.

Please resend.

Best regards,
Krzysztof