Subject: [PATCH v9 0/5] PWM and keyboard backlight driver for ARM Macs

Hi,

This is the v9 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.

Changes in v3 and v4:
Addressing the review comments.

Changes in v5:
Added t600x device tree changes

Changes in v8:
Changed the overflow handling to clamp instead of erroring.

Changes in v9:
Missed a spot where clamping should be applied. Fixed that.

v1: https://www.spinics.net/lists/linux-pwm/msg19500.html
v2: https://www.spinics.net/lists/linux-pwm/msg19562.html
v3: https://www.spinics.net/lists/linux-pwm/msg19901.html
v4: https://www.spinics.net/lists/linux-pwm/msg20093.html
v5: https://www.spinics.net/lists/linux-pwm/msg20150.html
v6: https://www.spinics.net/lists/linux-pwm/msg20190.html
v7: https://lore.kernel.org/r/[email protected]
v8: https://lore.kernel.org/r/[email protected]

---
Sasha Finkelstein (5):
dt-bindings: pwm: Add Apple PWM controller
pwm: Add Apple PWM controller
arm64: dts: apple: t8103: Add PWM controller
arm64: dts: apple: t600x: Add PWM controller
MAINTAINERS: Add entries for Apple PWM driver

.../devicetree/bindings/pwm/apple,s5l-fpwm.yaml | 51 +++++++
MAINTAINERS | 2 +
arch/arm64/boot/dts/apple/t600x-die0.dtsi | 9 ++
arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi | 18 +++
arch/arm64/boot/dts/apple/t8103-j293.dts | 17 +++
arch/arm64/boot/dts/apple/t8103-j313.dts | 17 +++
arch/arm64/boot/dts/apple/t8103.dtsi | 9 ++
drivers/pwm/Kconfig | 12 ++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-apple.c | 159 +++++++++++++++++++++
10 files changed, 295 insertions(+)
---
base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6
change-id: 20230214-fpwm-d8f76bc8ddc1

Best regards,
--
Sasha Finkelstein <[email protected]>



Subject: [PATCH v9 3/5] arm64: dts: apple: t8103: Add PWM controller

From: Sasha Finkelstein <[email protected]>

Adds PWM controller and keyboard backlight bindings for M1 MacBooks

Signed-off-by: Sasha Finkelstein <[email protected]>
Acked-by: Sven Peter <[email protected]>
---
arch/arm64/boot/dts/apple/t8103-j293.dts | 17 +++++++++++++++++
arch/arm64/boot/dts/apple/t8103-j313.dts | 17 +++++++++++++++++
arch/arm64/boot/dts/apple/t8103.dtsi | 9 +++++++++
3 files changed, 43 insertions(+)

diff --git a/arch/arm64/boot/dts/apple/t8103-j293.dts b/arch/arm64/boot/dts/apple/t8103-j293.dts
index 151074109a11..fc55ce0fa40d 100644
--- a/arch/arm64/boot/dts/apple/t8103-j293.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j293.dts
@@ -11,10 +11,23 @@

#include "t8103.dtsi"
#include "t8103-jxxx.dtsi"
+#include <dt-bindings/leds/common.h>

/ {
compatible = "apple,j293", "apple,t8103", "apple,arm-platform";
model = "Apple MacBook Pro (13-inch, M1, 2020)";
+
+ led-controller {
+ compatible = "pwm-leds";
+ led-0 {
+ pwms = <&fpwm1 0 40000>;
+ label = "kbd_backlight";
+ function = LED_FUNCTION_KBD_BACKLIGHT;
+ color = <LED_COLOR_ID_WHITE>;
+ max-brightness = <255>;
+ default-state = "keep";
+ };
+ };
};

&bluetooth0 {
@@ -47,3 +60,7 @@ &i2c2 {
&i2c4 {
status = "okay";
};
+
+&fpwm1 {
+ status = "okay";
+};
diff --git a/arch/arm64/boot/dts/apple/t8103-j313.dts b/arch/arm64/boot/dts/apple/t8103-j313.dts
index bc1f865aa790..1e26aa1ef525 100644
--- a/arch/arm64/boot/dts/apple/t8103-j313.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j313.dts
@@ -11,10 +11,23 @@

#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)";
+
+ led-controller {
+ compatible = "pwm-leds";
+ led-0 {
+ pwms = <&fpwm1 0 40000>;
+ label = "kbd_backlight";
+ function = LED_FUNCTION_KBD_BACKLIGHT;
+ color = <LED_COLOR_ID_WHITE>;
+ max-brightness = <255>;
+ default-state = "keep";
+ };
+ };
};

&bluetooth0 {
@@ -39,3 +52,7 @@ &pcie0_dart_2 {

/delete-node/ &port01;
/delete-node/ &port02;
+
+&fpwm1 {
+ status = "okay";
+};
diff --git a/arch/arm64/boot/dts/apple/t8103.dtsi b/arch/arm64/boot/dts/apple/t8103.dtsi
index 9859219699f4..5300fd115561 100644
--- a/arch/arm64/boot/dts/apple/t8103.dtsi
+++ b/arch/arm64/boot/dts/apple/t8103.dtsi
@@ -432,6 +432,15 @@ 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>;

--
Git-137.1)


Subject: [PATCH v9 5/5] MAINTAINERS: Add entries for Apple PWM driver

From: Sasha Finkelstein <[email protected]>

Add the MAINTAINERS entries for the driver

Signed-off-by: Sasha Finkelstein <[email protected]>
Acked-by: Sven Peter <[email protected]>
---
MAINTAINERS | 2 ++
1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 8d5bc223f305..7c0b7c2bb55f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1955,6 +1955,7 @@ 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/bluetooth/hci_bcm4377.c
@@ -1970,6 +1971,7 @@ 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

--
Git-137.1)


Subject: [PATCH v9 2/5] pwm: Add Apple PWM controller

From: Sasha Finkelstein <[email protected]>

Adds the Apple PWM controller driver.

Signed-off-by: Sasha Finkelstein <[email protected]>
Acked-by: Sven Peter <[email protected]>
Reviewed-by: Uwe Kleine-König <[email protected]>
---
drivers/pwm/Kconfig | 12 ++++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-apple.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 172 insertions(+)

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index dae023d783a2..8df861b1f4a3 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..a38a62edd713
--- /dev/null
+++ b/drivers/pwm/pwm-apple.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Driver for the Apple SoC PWM controller
+ *
+ * Copyright The Asahi Linux Contributors
+ *
+ * Limitations:
+ * - The writes to cycle registers are shadowed until a write to
+ * the control register.
+ * - If both OFF_CYCLES and ON_CYCLES are set to 0, the output
+ * is a constant off signal.
+ * - When APPLE_PWM_CTRL is set to 0, the output is constant low
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/math64.h>
+
+#define APPLE_PWM_CTRL 0x00
+#define APPLE_PWM_ON_CYCLES 0x1c
+#define APPLE_PWM_OFF_CYCLES 0x18
+
+#define APPLE_PWM_CTRL_ENABLE BIT(0)
+#define APPLE_PWM_CTRL_MODE BIT(2)
+#define APPLE_PWM_CTRL_UPDATE BIT(5)
+#define APPLE_PWM_CTRL_TRIGGER BIT(9)
+#define APPLE_PWM_CTRL_INVERT BIT(10)
+#define APPLE_PWM_CTRL_OUTPUT_ENABLE BIT(14)
+
+struct apple_pwm {
+ struct pwm_chip chip;
+ void __iomem *base;
+ u64 clkrate;
+};
+
+static inline struct apple_pwm *to_apple_pwm(struct pwm_chip *chip)
+{
+ return container_of(chip, struct apple_pwm, chip);
+}
+
+static int apple_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct apple_pwm *fpwm;
+
+ if (state->polarity == PWM_POLARITY_INVERSED)
+ return -EINVAL;
+
+ fpwm = to_apple_pwm(chip);
+ if (state->enabled) {
+ u64 on_cycles, off_cycles;
+
+ on_cycles = mul_u64_u64_div_u64(fpwm->clkrate,
+ state->duty_cycle, NSEC_PER_SEC);
+ if (on_cycles > 0xFFFFFFFF)
+ on_cycles = 0xFFFFFFFF;
+
+ off_cycles = mul_u64_u64_div_u64(fpwm->clkrate,
+ state->period, NSEC_PER_SEC) - on_cycles;
+ if (off_cycles > 0xFFFFFFFF)
+ off_cycles = 0xFFFFFFFF;
+
+ writel(on_cycles, fpwm->base + APPLE_PWM_ON_CYCLES);
+ writel(off_cycles, fpwm->base + APPLE_PWM_OFF_CYCLES);
+ writel(APPLE_PWM_CTRL_ENABLE | APPLE_PWM_CTRL_OUTPUT_ENABLE | APPLE_PWM_CTRL_UPDATE,
+ fpwm->base + APPLE_PWM_CTRL);
+ } else {
+ writel(0, fpwm->base + APPLE_PWM_CTRL);
+ }
+ return 0;
+}
+
+static int 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 = to_apple_pwm(chip);
+
+ ctrl = readl(fpwm->base + APPLE_PWM_CTRL);
+ on_cycles = readl(fpwm->base + APPLE_PWM_ON_CYCLES);
+ off_cycles = readl(fpwm->base + APPLE_PWM_OFF_CYCLES);
+
+ state->enabled = (ctrl & APPLE_PWM_CTRL_ENABLE) && (ctrl & APPLE_PWM_CTRL_OUTPUT_ENABLE);
+ state->polarity = PWM_POLARITY_NORMAL;
+ // on_cycles + off_cycles is 33 bits, NSEC_PER_SEC is 30, there is no overflow
+ state->duty_cycle = DIV64_U64_ROUND_UP((u64)on_cycles * NSEC_PER_SEC, fpwm->clkrate);
+ state->period = DIV64_U64_ROUND_UP(((u64)off_cycles + (u64)on_cycles) *
+ NSEC_PER_SEC, fpwm->clkrate);
+
+ return 0;
+}
+
+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 *fpwm;
+ struct clk *clk;
+ 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);
+
+ clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (IS_ERR(clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(clk), "unable to get the clock");
+
+ /*
+ * Uses the 24MHz system clock on all existing devices, can only
+ * happen if the device tree is broken
+ *
+ * This check is done to prevent an overflow in .apply
+ */
+ fpwm->clkrate = clk_get_rate(clk);
+ if (fpwm->clkrate > NSEC_PER_SEC)
+ return dev_err_probe(&pdev->dev, -EINVAL, "pwm clock out of range");
+
+ fpwm->chip.dev = &pdev->dev;
+ fpwm->chip.npwm = 1;
+ fpwm->chip.ops = &apple_pwm_ops;
+
+ ret = devm_pwmchip_add(&pdev->dev, &fpwm->chip);
+ if (ret < 0)
+ return dev_err_probe(&pdev->dev, ret, "unable to add pwm chip");
+
+ return 0;
+}
+
+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",
+ .of_match_table = apple_pwm_of_match,
+ },
+};
+module_platform_driver(apple_pwm_driver);
+
+MODULE_DESCRIPTION("Apple SoC PWM driver");
+MODULE_LICENSE("Dual MIT/GPL");

--
Git-137.1)


Subject: [PATCH v9 4/5] arm64: dts: apple: t600x: Add PWM controller

From: Sasha Finkelstein <[email protected]>

Adds PWM controller and keyboard backlight bindings for M1 Pro/Max MacBook Pros

Signed-off-by: Sasha Finkelstein <[email protected]>
Acked-by: Hector Martin <[email protected]>
---
arch/arm64/boot/dts/apple/t600x-die0.dtsi | 9 +++++++++
arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi | 18 ++++++++++++++++++
2 files changed, 27 insertions(+)

diff --git a/arch/arm64/boot/dts/apple/t600x-die0.dtsi b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
index 1c41954e3899..9157ae2a9f7f 100644
--- a/arch/arm64/boot/dts/apple/t600x-die0.dtsi
+++ b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
@@ -71,6 +71,15 @@ sio_dart_1: iommu@39b008000 {
power-domains = <&ps_sio_cpu>;
};

+ fpwm0: pwm@39b030000 {
+ compatible = "apple,t6000-fpwm", "apple,s5l-fpwm";
+ reg = <0x3 0x9b030000 0x0 0x4000>;
+ power-domains = <&ps_fpwm0>;
+ clocks = <&clkref>;
+ #pwm-cells = <2>;
+ status = "disabled";
+ };
+
i2c0: i2c@39b040000 {
compatible = "apple,t6000-i2c", "apple,i2c";
reg = <0x3 0x9b040000 0x0 0x4000>;
diff --git a/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi b/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi
index 34906d522f0a..96de7165df6d 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;
@@ -34,6 +36,18 @@ memory@10000000000 {
device_type = "memory";
reg = <0x100 0 0x2 0>; /* To be filled by loader */
};
+
+ led-controller {
+ compatible = "pwm-leds";
+ led-0 {
+ pwms = <&fpwm0 0 40000>;
+ label = "kbd_backlight";
+ function = LED_FUNCTION_KBD_BACKLIGHT;
+ color = <LED_COLOR_ID_WHITE>;
+ max-brightness = <255>;
+ default-state = "keep";
+ };
+ };
};

&serial0 {
@@ -110,5 +124,9 @@ &pcie0_dart_3 {
status = "disabled";
};

+&fpwm0 {
+ status = "okay";
+};
+
/delete-node/ &port02;
/delete-node/ &port03;

--
Git-137.1)