apple-pwm.patch

diff --git a/arch/arm64/boot/dts/apple/t600x-die0.dtsi b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
index 4c203778aa89..c24f0afabe14 100644
--- a/arch/arm64/boot/dts/apple/t600x-die0.dtsi
+++ b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
@@ -513,3 +513,11 @@ mca: mca@9b600000 {
 		#sound-dai-cells = <1>;
 		apple,nclusters = <4>;
 	};
+
+	fpwm0: pwm@0x39b030000 {
+		compatible = "apple,t6000-fpwm", "apple,fpwm";
+		reg = <0x3 0x9b030000 0x0 0x4000>;
+		clocks = <&clkref>;
+		#pwm-cells = <2>;
+		power-domains = <&ps_fpwm0>;
+	};
\ No newline at end of file
diff --git a/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi b/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi
index bbe66ea64f09..e41633e0480e 100644
--- a/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi
+++ b/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi
@@ -9,6 +9,8 @@
  * Copyright The Asahi Linux Contributors
  */
 
+#include <dt-bindings/leds/common.h>
+
 / {
 	aliases {
 		serial0 = &serial0;
@@ -309,6 +311,21 @@ backlight: gpio-bl {
 		default-on;
 	};
 
+	pwmleds {
+		compatible = "pwm-leds";
+
+		kbd-backlight {
+			label = "kbd_backlight";
+			function = LED_FUNCTION_KBD_BACKLIGHT;
+			color = <LED_COLOR_ID_WHITE>;
+			pwm-names = "kbd_backlight";
+			pwms = <&fpwm0 0 40000>;
+			max-brightness = <255>;
+			default-state = "keep";
+		};
+	};
+
+
 	sound {
 		compatible = "apple,j314-macaudio", "apple,macaudio";
 		model = "MacBook Pro J314/6 integrated audio";
diff --git a/arch/arm64/boot/dts/apple/t8103-j313.dts b/arch/arm64/boot/dts/apple/t8103-j313.dts
index b51f651d2326..e2598bdba06b 100644
--- a/arch/arm64/boot/dts/apple/t8103-j313.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j313.dts
@@ -11,10 +11,25 @@
 
 #include "t8103.dtsi"
 #include "t8103-jxxx.dtsi"
+#include <dt-bindings/leds/common.h>
 
 / {
 	compatible = "apple,j313", "apple,t8103", "apple,arm-platform";
 	model = "Apple MacBook Air (M1, 2020)";
+
+	pwmleds {
+		compatible = "pwm-leds";
+
+		kbd-backlight {
+			label = "kbd_backlight";
+			function = LED_FUNCTION_KBD_BACKLIGHT;
+			color = <LED_COLOR_ID_WHITE>;
+			pwm-names = "kbd_backlight";
+			pwms = <&fpwm1 0 40000>;
+			max-brightness = <255>;
+			default-state = "keep";
+		};
+	};
 };
 
 &wifi0 {
diff --git a/arch/arm64/boot/dts/apple/t8103.dtsi b/arch/arm64/boot/dts/apple/t8103.dtsi
index afb0688cb1c2..cc5668fb68fe 100644
--- a/arch/arm64/boot/dts/apple/t8103.dtsi
+++ b/arch/arm64/boot/dts/apple/t8103.dtsi
@@ -315,6 +315,14 @@ cpufreq_hw: cpufreq@210e20000 {
 			#freq-domain-cells = <1>;
 		};
 
+		fpwm1: pwm@235044000 {
+			compatible = "apple-fpwm";
+			reg = <0x2 0x35044000 0x0 0x4000>;
+			clocks = <&clkref>;
+			#pwm-cells = <2>;
+			power-domains = <&ps_fpwm1>;
+		};
+
 		i2c0: i2c@235010000 {
 			compatible = "apple,t8103-i2c", "apple,i2c";
 			reg = <0x2 0x35010000 0x0 0x4000>;
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 904de8d61828..c2c8180176d6 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -51,6 +51,16 @@ 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 PWM support"
+	depends on ARCH_APPLE || COMPILE_TEST
+	help
+	  Generic PWM framework driver for Apple FPWM.
+	  Found in Apple Silicon SoCs.
+
+	  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 5c08bdb817b4..bf0c04ce704e 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..bc3f78147bb4
--- /dev/null
+++ b/drivers/pwm/pwm-apple.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Apple FPWM driver
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define FPWM_CTRL 0x00
+
+#define CTRL_ENABLE BIT(0)
+/* Setting this bit to 1 changes mode from PWM to single-pulse mode. */
+#define CTRL_MODE BIT(2)
+/* Setting this bit to 1 to this causes changes in the TICKS_* registers to
+ * take effect at the end of the current period. Only for PWM mode. */
+#define CTRL_UPDATE BIT(5)
+/* Setting this bit to one generates a pulse in single-pulse mode.
+ * HW clears this at the end of the pulse. */
+#define CTRL_TRIGGER BIT(9)
+/* Configures single-pulse polarity: 0 means positive. Length is TICKS_ON.
+ * 1 means negative. Length is TICKS_OFF. */
+#define CTRL_INVERT BIT(10)
+#define CTRL_OUTPUT_ENABLE BIT(14)
+
+#define FPWM_STATUS 0x08
+
+/* Set at the end of the OFF period. Write 1 to clear. */
+#define STATUS_END_OF_OFF BIT(0)
+/* Set at the end of the ON period. Write 1 to clear. */
+#define STATUS_END_OF_ON BIT(1)
+
+#define FPWM_TICKS_OFF 0x18
+#define FPWM_TICKS_ON 0x1c
+
+struct apple_fpwm {
+	struct pwm_chip chip;
+	void __iomem *base;
+	struct clk *clk;
+};
+
+static inline struct apple_fpwm *to_fpwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct apple_fpwm, chip);
+}
+
+#define NSEC_PER_SEC 1000000000L
+
+static u64 ns_to_ticks(u64 ns, u64 rate)
+{
+	return mul_u64_u64_div_u64(ns, rate, NSEC_PER_SEC);
+}
+
+static u64 ticks_to_ns(u64 ticks, u64 rate)
+{
+	return mul_u64_u64_div_u64(ticks, NSEC_PER_SEC, rate);
+}
+
+static int apple_fpwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct apple_fpwm *fpwm = to_fpwm(chip);
+	u64 rate = clk_get_rate(fpwm->clk);
+	u64 duty_ticks = ns_to_ticks(state->duty_cycle, rate);
+	u64 period_ticks = ns_to_ticks(state->period, rate);
+	u64 off_ticks = period_ticks - duty_ticks;
+
+	writel(duty_ticks, fpwm->base + FPWM_TICKS_ON);
+	writel(off_ticks, fpwm->base + FPWM_TICKS_OFF);
+	writel(CTRL_ENABLE | CTRL_OUTPUT_ENABLE | CTRL_UPDATE,
+	       fpwm->base + FPWM_CTRL);
+
+	return 0;
+}
+
+static void apple_fpwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				 struct pwm_state *state)
+{
+	struct apple_fpwm *fpwm = to_fpwm(chip);
+	u64 rate = clk_get_rate(fpwm->clk);
+	u32 ctrl = readl(fpwm->base + FPWM_CTRL);
+	u32 ticks_off = readl(fpwm->base + FPWM_TICKS_OFF);
+	u32 ticks_on = readl(fpwm->base + FPWM_TICKS_ON);
+
+	state->period = ticks_to_ns(ticks_on + ticks_off, rate);
+	state->duty_cycle = ticks_to_ns(ticks_on, rate);
+	state->polarity = PWM_POLARITY_NORMAL;
+	state->enabled = (ctrl == (CTRL_ENABLE | CTRL_OUTPUT_ENABLE));
+	state->usage_power = false;
+}
+
+static const struct pwm_ops apple_fpwm_ops = {
+	.apply = apple_fpwm_apply,
+	.get_state = apple_fpwm_get_state,
+};
+
+static int apple_fpwm_probe(struct platform_device *pdev)
+{
+	struct apple_fpwm *fpwm;
+	int ret;
+
+	fpwm = devm_kzalloc(&pdev->dev, sizeof(*fpwm), GFP_KERNEL);
+	if (!fpwm)
+		return -ENOMEM;
+
+	fpwm->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(fpwm->base)) {
+		return PTR_ERR(fpwm->base);
+	}
+
+	fpwm->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(fpwm->clk))
+		return PTR_ERR(fpwm->clk);
+
+	ret = clk_prepare_enable(fpwm->clk);
+	if (ret)
+		return ret;
+
+	fpwm->chip.dev = &pdev->dev;
+	fpwm->chip.ops = &apple_fpwm_ops;
+	fpwm->chip.npwm = 1;
+
+	ret = devm_pwmchip_add(&pdev->dev, &fpwm->chip);
+	if (ret < 0) {
+		clk_disable_unprepare(fpwm->clk);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, fpwm);
+
+	return 0;
+}
+
+static int apple_fpwm_remove(struct platform_device *pdev)
+{
+	struct apple_fpwm *fpwm = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(fpwm->clk);
+
+	return 0;
+}
+
+static const struct of_device_id apple_fpwm_of_match[] = {
+	{ .compatible = "apple,fpwm" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, apple_fpwm_of_match);
+
+static struct platform_driver apple_fpwm_driver = {
+	.probe = apple_fpwm_probe,
+	.remove = apple_fpwm_remove,
+	.driver = {
+		.name = "apple-fpwm",
+		.of_match_table = apple_fpwm_of_match,
+	},
+};
+module_platform_driver(apple_fpwm_driver);