[PATCH v3 0/4] Add channel type support to pwm-cros-ec

[PATCH v3 0/4] Add channel type support to pwm-cros-ec

[Fabio Baltieri]

Hi,

The ChromiumOS EC PWM host command protocol supports specifying the
requested PWM by type rather than channel. [1]

This series adds support for specifying PWM by type rather than channel
number in the pwm-cros-ec driver, which abstracts the node definitions
from the actual hardware configuration from the kernel perspective,
aligns the API with the one used by the bootloader, and allows removing
some dtsi overrides.

Tested on a sc7180-trogdor board.

Changes from v2:
(https://patchwork.kernel.org/project/chrome-platform/list/?series=627837)
- reworded patch 2 commit description
- reworked the driver and dt documentation to use a new compatible rather than
  boolean property
- dropped the comment about build test only, tested on actual hardware
  (trogdor), build test on x86 (with CONFIG_OF=n).

Changes from v1:
(https://patchwork.kernel.org/project/chrome-platform/list/?series=625182)
- fixed the dt include file license
- fixed the property name (s/_/-/)
- rebased on current linus tree (few dts files changed from a soc tree
  pull, so patch 4 needs a recent base to apply correctly)

[1] https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/ec/common/pwm.c;l=24
[2] https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/depthcharge/src/drivers/ec/cros/ec.c;l=1271-1273

Fabio Baltieri (4):
  dt-bindings: add mfd/cros_ec definitions
  drivers: pwm: pwm-cros-ec: add channel type support
  dt-bindings: update google,cros-ec-pwm documentation
  arm64: dts: address cros-ec-pwm channels by type

 .../bindings/pwm/google,cros-ec-pwm.yaml      |   9 +-
 .../mt8183-kukui-jacuzzi-fennel-sku1.dts      |   4 +-
 .../dts/mediatek/mt8183-kukui-jacuzzi.dtsi    |   4 +-
 .../arm64/boot/dts/mediatek/mt8183-kukui.dtsi |   1 +
 .../boot/dts/qcom/sc7180-trogdor-coachz.dtsi  |   4 -
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi  |   9 +-
 .../qcom/sc7280-herobrine-herobrine-r0.dts    |   7 +-
 .../arm64/boot/dts/qcom/sc7280-herobrine.dtsi |   7 +-
 .../arm64/boot/dts/qcom/sc7280-idp-ec-h1.dtsi |   4 +-
 arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi    |   7 +-
 .../boot/dts/rockchip/rk3399-gru-bob.dts      |   4 -
 .../dts/rockchip/rk3399-gru-chromebook.dtsi   |   5 +-
 .../boot/dts/rockchip/rk3399-gru-kevin.dts    |   4 -
 arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi  |   1 +
 drivers/pwm/pwm-cros-ec.c                     | 109 ++++++++++++++----
 include/dt-bindings/mfd/cros_ec.h             |  18 +++
 16 files changed, 140 insertions(+), 57 deletions(-)
 create mode 100644 include/dt-bindings/mfd/cros_ec.h

-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 1/4] dt-bindings: add mfd/cros_ec definitions

[Fabio Baltieri]

Add a dt-bindings include file for cros_ec devicetree definition, define
a pair of special purpose PWM channels in it.

Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org>
---
 include/dt-bindings/mfd/cros_ec.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 include/dt-bindings/mfd/cros_ec.h

diff --git a/include/dt-bindings/mfd/cros_ec.h b/include/dt-bindings/mfd/cros_ec.h
new file mode 100644
index 000000000000..3b29cd049578
--- /dev/null
+++ b/include/dt-bindings/mfd/cros_ec.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/*
+ * DTS binding definitions used for the Chromium OS Embedded Controller.
+ *
+ * Copyright (c) 2022 The Chromium OS Authors. All rights reserved.
+ */
+
+#ifndef _DT_BINDINGS_MFD_CROS_EC_H
+#define _DT_BINDINGS_MFD_CROS_EC_H
+
+/* Typed channel for keyboard backlight. */
+#define CROS_EC_PWM_DT_KB_LIGHT		0
+/* Typed channel for display backlight. */
+#define CROS_EC_PWM_DT_DISPLAY_LIGHT	1
+/* Number of typed channels. */
+#define CROS_EC_PWM_DT_COUNT		2
+
+#endif
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 2/4] drivers: pwm: pwm-cros-ec: add channel type support

[Fabio Baltieri]

Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm
types to the PWM cros_ec_pwm driver. This allows specifying one of these
PWM channel by functionality, and let the EC firmware pick the correct
channel, thus abstracting the hardware implementation from the kernel
driver.

To use it, define the node with the "google,cros-ec-pwm-type"
compatible.

Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org>
---
 drivers/pwm/pwm-cros-ec.c | 109 ++++++++++++++++++++++++++++++--------
 1 file changed, 86 insertions(+), 23 deletions(-)

diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 5e29d9c682c3..83c33958d52b 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -6,23 +6,30 @@
  */
 
 #include <linux/module.h>
+#include <linux/of_device.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
 
+#include <dt-bindings/mfd/cros_ec.h>
+
+#define OF_CROS_EC_PWM_TYPE ((void *)1)
+
 /**
  * struct cros_ec_pwm_device - Driver data for EC PWM
  *
  * @dev: Device node
  * @ec: Pointer to EC device
  * @chip: PWM controller chip
+ * @use_pwm_type: Use PWM types instead of generic channels
  */
 struct cros_ec_pwm_device {
 	struct device *dev;
 	struct cros_ec_device *ec;
 	struct pwm_chip chip;
+	bool use_pwm_type;
 };
 
 /**
@@ -58,14 +65,31 @@ static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 	kfree(channel);
 }
 
-static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty)
+static int cros_ec_dt_type_to_pwm_type(u8 dt_index, u8 *pwm_type)
 {
+	switch (dt_index) {
+	case CROS_EC_PWM_DT_KB_LIGHT:
+		*pwm_type = EC_PWM_TYPE_KB_LIGHT;
+		return 0;
+	case CROS_EC_PWM_DT_DISPLAY_LIGHT:
+		*pwm_type = EC_PWM_TYPE_DISPLAY_LIGHT;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int cros_ec_pwm_set_duty(struct cros_ec_pwm_device *ec_pwm, u8 index,
+				u16 duty)
+{
+	struct cros_ec_device *ec = ec_pwm->ec;
 	struct {
 		struct cros_ec_command msg;
 		struct ec_params_pwm_set_duty params;
 	} __packed buf;
 	struct ec_params_pwm_set_duty *params = &buf.params;
 	struct cros_ec_command *msg = &buf.msg;
+	int ret;
 
 	memset(&buf, 0, sizeof(buf));
 
@@ -75,14 +99,25 @@ static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty)
 	msg->outsize = sizeof(*params);
 
 	params->duty = duty;
-	params->pwm_type = EC_PWM_TYPE_GENERIC;
-	params->index = index;
+
+	if (ec_pwm->use_pwm_type) {
+		ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);
+		if (ret) {
+			dev_err(ec->dev, "Invalid PWM type index: %d\n", index);
+			return ret;
+		}
+		params->index = 0;
+	} else {
+		params->pwm_type = EC_PWM_TYPE_GENERIC;
+		params->index = index;
+	}
 
 	return cros_ec_cmd_xfer_status(ec, msg);
 }
 
-static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
+static int cros_ec_pwm_get_duty(struct cros_ec_pwm_device *ec_pwm, u8 index)
 {
+	struct cros_ec_device *ec = ec_pwm->ec;
 	struct {
 		struct cros_ec_command msg;
 		union {
@@ -102,8 +137,17 @@ static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
 	msg->insize = sizeof(*resp);
 	msg->outsize = sizeof(*params);
 
-	params->pwm_type = EC_PWM_TYPE_GENERIC;
-	params->index = index;
+	if (ec_pwm->use_pwm_type) {
+		ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);
+		if (ret) {
+			dev_err(ec->dev, "Invalid PWM type index: %d\n", index);
+			return ret;
+		}
+		params->index = 0;
+	} else {
+		params->pwm_type = EC_PWM_TYPE_GENERIC;
+		params->index = index;
+	}
 
 	ret = cros_ec_cmd_xfer_status(ec, msg);
 	if (ret < 0)
@@ -133,7 +177,7 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	 */
 	duty_cycle = state->enabled ? state->duty_cycle : 0;
 
-	ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);
+	ret = cros_ec_pwm_set_duty(ec_pwm, pwm->hwpwm, duty_cycle);
 	if (ret < 0)
 		return ret;
 
@@ -149,7 +193,7 @@ static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
 	int ret;
 
-	ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm);
+	ret = cros_ec_pwm_get_duty(ec_pwm, pwm->hwpwm);
 	if (ret < 0) {
 		dev_err(chip->dev, "error getting initial duty: %d\n", ret);
 		return;
@@ -204,13 +248,13 @@ static const struct pwm_ops cros_ec_pwm_ops = {
  * of PWMs it supports directly, so we have to read the pwm duty cycle for
  * subsequent channels until we get an error.
  */
-static int cros_ec_num_pwms(struct cros_ec_device *ec)
+static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
 {
 	int i, ret;
 
 	/* The index field is only 8 bits */
 	for (i = 0; i <= U8_MAX; i++) {
-		ret = cros_ec_pwm_get_duty(ec, i);
+		ret = cros_ec_pwm_get_duty(ec_pwm, i);
 		/*
 		 * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM
 		 * responses; everything else is treated as an error.
@@ -232,10 +276,27 @@ static int cros_ec_num_pwms(struct cros_ec_device *ec)
 	return U8_MAX;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id cros_ec_pwm_of_match[] = {
+	{
+		.compatible = "google,cros-ec-pwm",
+	},
+	{
+		.compatible = "google,cros-ec-pwm-type",
+		.data = OF_CROS_EC_PWM_TYPE,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
+#else
+#define cros_ec_pwm_of_match NULL
+#endif
+
 static int cros_ec_pwm_probe(struct platform_device *pdev)
 {
 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
 	struct device *dev = &pdev->dev;
+	const struct of_device_id *id;
 	struct cros_ec_pwm_device *ec_pwm;
 	struct pwm_chip *chip;
 	int ret;
@@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
 	chip = &ec_pwm->chip;
 	ec_pwm->ec = ec;
 
+	id = of_match_device(cros_ec_pwm_of_match, dev);
+	if (id && id->data == OF_CROS_EC_PWM_TYPE)
+		ec_pwm->use_pwm_type = true;
+
 	/* PWM chip */
 	chip->dev = dev;
 	chip->ops = &cros_ec_pwm_ops;
 	chip->of_xlate = cros_ec_pwm_xlate;
 	chip->of_pwm_n_cells = 1;
-	ret = cros_ec_num_pwms(ec);
-	if (ret < 0) {
-		dev_err(dev, "Couldn't find PWMs: %d\n", ret);
-		return ret;
+
+	if (ec_pwm->use_pwm_type) {
+		chip->npwm = CROS_EC_PWM_DT_COUNT;
+	} else {
+		ret = cros_ec_num_pwms(ec_pwm);
+		if (ret < 0) {
+			dev_err(dev, "Couldn't find PWMs: %d\n", ret);
+			return ret;
+		}
+		chip->npwm = ret;
 	}
-	chip->npwm = ret;
+
 	dev_dbg(dev, "Probed %u PWMs\n", chip->npwm);
 
 	ret = pwmchip_add(chip);
@@ -285,14 +356,6 @@ static int cros_ec_pwm_remove(struct platform_device *dev)
 	return 0;
 }
 
-#ifdef CONFIG_OF
-static const struct of_device_id cros_ec_pwm_of_match[] = {
-	{ .compatible = "google,cros-ec-pwm" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
-#endif
-
 static struct platform_driver cros_ec_pwm_driver = {
 	.probe = cros_ec_pwm_probe,
 	.remove = cros_ec_pwm_remove,
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 3/4] dt-bindings: update google,cros-ec-pwm documentation

[Fabio Baltieri]

Update google,cros-ec-pwm node documentation to mention the
google,cros-ec-pwm-type compatible.

Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org>
---
 .../devicetree/bindings/pwm/google,cros-ec-pwm.yaml      | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml
index 7ab6912a845f..deb9e4488773 100644
--- a/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/google,cros-ec-pwm.yaml
@@ -21,7 +21,14 @@ allOf:
 
 properties:
   compatible:
-    const: google,cros-ec-pwm
+    oneOf:
+      - description: PWM controlled using EC_PWM_TYPE_GENERIC channels.
+        items:
+        - const: google,cros-ec-pwm
+      - description: PWM controlled using CROS_EC_PWM_DT_<...> types.
+        items:
+        - const: google,cros-ec-pwm-type
+
   "#pwm-cells":
     description: The cell specifies the PWM index.
     const: 1
-- 
2.35.1.1178.g4f1659d476-goog

[PATCH v3 4/4] arm64: dts: address cros-ec-pwm channels by type

[Fabio Baltieri]

Update various cros-ec-pwm board definitions to address the keyboard and
screen backlight PWM channels by type rather than channel number. This
makes the instance independent by the actual hardware configuration,
relying on the EC firmware to pick the right channel, and allows
dropping few dtsi overrides as a consequence.

Changed the node label used to cros_ec_pwm_type to avoid ambiguity about
the pwm cell meaning.

Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org>
---
 .../dts/mediatek/mt8183-kukui-jacuzzi-fennel-sku1.dts    | 4 ++--
 arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi.dtsi   | 4 ++--
 arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi           | 1 +
 arch/arm64/boot/dts/qcom/sc7180-trogdor-coachz.dtsi      | 4 ----
 arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi             | 9 +++++----
 .../boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts      | 7 ++++---
 arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi           | 7 ++++---
 arch/arm64/boot/dts/qcom/sc7280-idp-ec-h1.dtsi           | 4 ++--
 arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi               | 7 ++++---
 arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts          | 4 ----
 arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi  | 5 +++--
 arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts        | 4 ----
 arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi             | 1 +
 13 files changed, 28 insertions(+), 33 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi-fennel-sku1.dts b/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi-fennel-sku1.dts
index dec11a4eb59e..e2554a313deb 100644
--- a/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi-fennel-sku1.dts
+++ b/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi-fennel-sku1.dts
@@ -15,13 +15,13 @@ pwmleds {
 		compatible = "pwm-leds";
 		keyboard_backlight: keyboard-backlight {
 			label = "cros_ec::kbd_backlight";
-			pwms = <&cros_ec_pwm 0>;
+			pwms = <&cros_ec_pwm_type CROS_EC_PWM_DT_KB_LIGHT>;
 			max-brightness = <1023>;
 		};
 	};
 };
 
-&cros_ec_pwm {
+&cros_ec_pwm_type {
 	status = "okay";
 };
 
diff --git a/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi.dtsi b/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi.dtsi
index 8f7bf33f607d..8474bd3af6eb 100644
--- a/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8183-kukui-jacuzzi.dtsi
@@ -92,8 +92,8 @@ volume_up {
 };
 
 &cros_ec {
-	cros_ec_pwm: ec-pwm {
-		compatible = "google,cros-ec-pwm";
+	cros_ec_pwm_type: ec-pwm {
+		compatible = "google,cros-ec-pwm-type";
 		#pwm-cells = <1>;
 		status = "disabled";
 	};
diff --git a/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi b/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi
index 0f9480f91261..ff54687ab8bf 100644
--- a/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8183-kukui.dtsi
@@ -7,6 +7,7 @@
 
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/mfd/cros_ec.h>
 #include "mt8183.dtsi"
 #include "mt6358.dtsi"
 
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor-coachz.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor-coachz.dtsi
index c81805ef2250..aea7c66d95e0 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor-coachz.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor-coachz.dtsi
@@ -77,10 +77,6 @@ &ap_spi_fp {
 	status = "okay";
 };
 
-&backlight {
-	pwms = <&cros_ec_pwm 0>;
-};
-
 &camcc {
 	status = "okay";
 };
diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
index 732e1181af48..6552e0025f84 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
@@ -8,6 +8,7 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/input/gpio-keys.h>
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/mfd/cros_ec.h>
 #include <dt-bindings/regulator/qcom,rpmh-regulator.h>
 #include <dt-bindings/sound/sc7180-lpass.h>
 
@@ -316,7 +317,7 @@ backlight: backlight {
 		num-interpolated-steps = <64>;
 		default-brightness-level = <951>;
 
-		pwms = <&cros_ec_pwm 1>;
+		pwms = <&cros_ec_pwm_type CROS_EC_PWM_DT_DISPLAY_LIGHT>;
 		enable-gpios = <&tlmm 12 GPIO_ACTIVE_HIGH>;
 		power-supply = <&ppvar_sys>;
 		pinctrl-names = "default";
@@ -354,7 +355,7 @@ pwmleds {
 		keyboard_backlight: keyboard-backlight {
 			status = "disabled";
 			label = "cros_ec::kbd_backlight";
-			pwms = <&cros_ec_pwm 0>;
+			pwms = <&cros_ec_pwm_type CROS_EC_PWM_DT_KB_LIGHT>;
 			max-brightness = <1023>;
 		};
 	};
@@ -637,8 +638,8 @@ cros_ec: ec@0 {
 		pinctrl-0 = <&ap_ec_int_l>;
 		spi-max-frequency = <3000000>;
 
-		cros_ec_pwm: pwm {
-			compatible = "google,cros-ec-pwm";
+		cros_ec_pwm_type: pwm {
+			compatible = "google,cros-ec-pwm-type";
 			#pwm-cells = <1>;
 		};
 
diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts b/arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts
index 1779d96c30f6..628ef990433b 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts
+++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine-herobrine-r0.dts
@@ -11,6 +11,7 @@
 #include <dt-bindings/iio/qcom,spmi-adc7-pmr735a.h>
 #include <dt-bindings/input/gpio-keys.h>
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/mfd/cros_ec.h>
 #include <dt-bindings/pinctrl/qcom,pmic-gpio.h>
 #include <dt-bindings/regulator/qcom,rpmh-regulator.h>
 
@@ -336,7 +337,7 @@ pwmleds {
 		keyboard_backlight: keyboard-backlight {
 			status = "disabled";
 			label = "cros_ec::kbd_backlight";
-			pwms = <&cros_ec_pwm 0>;
+			pwms = <&cros_ec_pwm_type CROS_EC_PWM_DT_KB_LIGHT>;
 			max-brightness = <1023>;
 		};
 	};
@@ -705,8 +706,8 @@ cros_ec: ec@0 {
 		pinctrl-0 = <&ap_ec_int_l>;
 		spi-max-frequency = <3000000>;
 
-		cros_ec_pwm: pwm {
-			compatible = "google,cros-ec-pwm";
+		cros_ec_pwm_type: pwm {
+			compatible = "google,cros-ec-pwm-type";
 			#pwm-cells = <1>;
 		};
 
diff --git a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
index dc17f2079695..eb4b0e17adec 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-herobrine.dtsi
@@ -15,6 +15,7 @@
 
 #include <dt-bindings/input/gpio-keys.h>
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/mfd/cros_ec.h>
 
 #include "sc7280-qcard.dtsi"
 #include "sc7280-chrome-common.dtsi"
@@ -288,7 +289,7 @@ pwmleds {
 		keyboard_backlight: keyboard-backlight {
 			status = "disabled";
 			label = "cros_ec::kbd_backlight";
-			pwms = <&cros_ec_pwm 0>;
+			pwms = <&cros_ec_pwm_type CROS_EC_PWM_DT_KB_LIGHT>;
 			max-brightness = <1023>;
 		};
 	};
@@ -421,8 +422,8 @@ cros_ec: ec@0 {
 		pinctrl-0 = <&ap_ec_int_l>;
 		spi-max-frequency = <3000000>;
 
-		cros_ec_pwm: pwm {
-			compatible = "google,cros-ec-pwm";
+		cros_ec_pwm_type: pwm {
+			compatible = "google,cros-ec-pwm-type";
 			#pwm-cells = <1>;
 		};
 
diff --git a/arch/arm64/boot/dts/qcom/sc7280-idp-ec-h1.dtsi b/arch/arm64/boot/dts/qcom/sc7280-idp-ec-h1.dtsi
index a7c346aa3b02..a797f09e1328 100644
--- a/arch/arm64/boot/dts/qcom/sc7280-idp-ec-h1.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280-idp-ec-h1.dtsi
@@ -20,8 +20,8 @@ cros_ec: ec@0 {
 		pinctrl-0 = <&ap_ec_int_l>;
 		spi-max-frequency = <3000000>;
 
-		cros_ec_pwm: pwm {
-			compatible = "google,cros-ec-pwm";
+		cros_ec_pwm_type: pwm {
+			compatible = "google,cros-ec-pwm-type";
 			#pwm-cells = <1>;
 		};
 
diff --git a/arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi b/arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi
index e7e4cc5936aa..a57951a50cd6 100644
--- a/arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi
+++ b/arch/arm64/boot/dts/qcom/sdm845-cheza.dtsi
@@ -6,6 +6,7 @@
  */
 
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/mfd/cros_ec.h>
 #include <dt-bindings/regulator/qcom,rpmh-regulator.h>
 #include "sdm845.dtsi"
 
@@ -27,7 +28,7 @@ chosen {
 
 	backlight: backlight {
 		compatible = "pwm-backlight";
-		pwms = <&cros_ec_pwm 0>;
+		pwms = <&cros_ec_pwm_type CROS_EC_PWM_DT_DISPLAY_LIGHT>;
 		enable-gpios = <&tlmm 37 GPIO_ACTIVE_HIGH>;
 		power-supply = <&ppvar_sys>;
 		pinctrl-names = "default";
@@ -708,8 +709,8 @@ cros_ec: ec@0 {
 		pinctrl-0 = <&ec_ap_int_l>;
 		spi-max-frequency = <3000000>;
 
-		cros_ec_pwm: pwm {
-			compatible = "google,cros-ec-pwm";
+		cros_ec_pwm_type: pwm {
+			compatible = "google,cros-ec-pwm-type";
 			#pwm-cells = <1>;
 		};
 
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts b/arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts
index 31ebb4e5fd33..5a076c2564f6 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts
@@ -55,10 +55,6 @@ trackpad: trackpad@15 {
 	};
 };
 
-&backlight {
-	pwms = <&cros_ec_pwm 0>;
-};
-
 &cpu_alert0 {
 	temperature = <65000>;
 };
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi
index 3355fb90fa54..28eda361dfe1 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi
@@ -198,6 +198,7 @@ backlight: backlight {
 		power-supply = <&pp3300_disp>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&bl_en>;
+		pwms = <&cros_ec_pwm_type CROS_EC_PWM_DT_DISPLAY_LIGHT>;
 		pwm-delay-us = <10000>;
 	};
 
@@ -462,8 +463,8 @@ ap_i2c_tp: &i2c5 {
 };
 
 &cros_ec {
-	cros_ec_pwm: pwm {
-		compatible = "google,cros-ec-pwm";
+	cros_ec_pwm_type: pwm {
+		compatible = "google,cros-ec-pwm-type";
 		#pwm-cells = <1>;
 	};
 
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts b/arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts
index 6863689df06f..e959a33af34b 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts
@@ -84,10 +84,6 @@ thermistor_ppvar_litcpu: thermistor-ppvar-litcpu {
 	};
 };
 
-&backlight {
-	pwms = <&cros_ec_pwm 1>;
-};
-
 &gpio_keys {
 	pinctrl-names = "default";
 	pinctrl-0 = <&bt_host_wake_l>, <&cpu1_pen_eject>;
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
index 162f08bca0d4..181159e9982d 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi
@@ -6,6 +6,7 @@
  */
 
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/mfd/cros_ec.h>
 #include "rk3399.dtsi"
 #include "rk3399-op1-opp.dtsi"
 
-- 
2.35.1.1178.g4f1659d476-goog

Re: [PATCH v3 2/4] drivers: pwm: pwm-cros-ec: add channel type support

[Fabio Baltieri]

On Mon, Apr 11, 2022 at 03:21:12PM +0000, Fabio Baltieri wrote:
> Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm
> types to the PWM cros_ec_pwm driver. This allows specifying one of these
> PWM channel by functionality, and let the EC firmware pick the correct
> channel, thus abstracting the hardware implementation from the kernel
> driver.
> 
> To use it, define the node with the "google,cros-ec-pwm-type"
> compatible.
> 
> Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org>

Hey Tzung-Bi, ended up not adding your "Reviewed-by" tag since I changed
a chunk of this patch after Rob's comment and there's few options for
handling the DT compatibles, feel free to take another look.

Thanks
Fabio

> ---
>  drivers/pwm/pwm-cros-ec.c | 109 ++++++++++++++++++++++++++++++--------
>  1 file changed, 86 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
> index 5e29d9c682c3..83c33958d52b 100644
> --- a/drivers/pwm/pwm-cros-ec.c
> +++ b/drivers/pwm/pwm-cros-ec.c
> @@ -6,23 +6,30 @@
>   */
>  
>  #include <linux/module.h>
> +#include <linux/of_device.h>
>  #include <linux/platform_data/cros_ec_commands.h>
>  #include <linux/platform_data/cros_ec_proto.h>
>  #include <linux/platform_device.h>
>  #include <linux/pwm.h>
>  #include <linux/slab.h>
>  
> +#include <dt-bindings/mfd/cros_ec.h>
> +
> +#define OF_CROS_EC_PWM_TYPE ((void *)1)
> +
>  /**
>   * struct cros_ec_pwm_device - Driver data for EC PWM
>   *
>   * @dev: Device node
>   * @ec: Pointer to EC device
>   * @chip: PWM controller chip
> + * @use_pwm_type: Use PWM types instead of generic channels
>   */
>  struct cros_ec_pwm_device {
>  	struct device *dev;
>  	struct cros_ec_device *ec;
>  	struct pwm_chip chip;
> +	bool use_pwm_type;
>  };
>  
>  /**
> @@ -58,14 +65,31 @@ static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
>  	kfree(channel);
>  }
>  
> -static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty)
> +static int cros_ec_dt_type_to_pwm_type(u8 dt_index, u8 *pwm_type)
>  {
> +	switch (dt_index) {
> +	case CROS_EC_PWM_DT_KB_LIGHT:
> +		*pwm_type = EC_PWM_TYPE_KB_LIGHT;
> +		return 0;
> +	case CROS_EC_PWM_DT_DISPLAY_LIGHT:
> +		*pwm_type = EC_PWM_TYPE_DISPLAY_LIGHT;
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int cros_ec_pwm_set_duty(struct cros_ec_pwm_device *ec_pwm, u8 index,
> +				u16 duty)
> +{
> +	struct cros_ec_device *ec = ec_pwm->ec;
>  	struct {
>  		struct cros_ec_command msg;
>  		struct ec_params_pwm_set_duty params;
>  	} __packed buf;
>  	struct ec_params_pwm_set_duty *params = &buf.params;
>  	struct cros_ec_command *msg = &buf.msg;
> +	int ret;
>  
>  	memset(&buf, 0, sizeof(buf));
>  
> @@ -75,14 +99,25 @@ static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty)
>  	msg->outsize = sizeof(*params);
>  
>  	params->duty = duty;
> -	params->pwm_type = EC_PWM_TYPE_GENERIC;
> -	params->index = index;
> +
> +	if (ec_pwm->use_pwm_type) {
> +		ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);
> +		if (ret) {
> +			dev_err(ec->dev, "Invalid PWM type index: %d\n", index);
> +			return ret;
> +		}
> +		params->index = 0;
> +	} else {
> +		params->pwm_type = EC_PWM_TYPE_GENERIC;
> +		params->index = index;
> +	}
>  
>  	return cros_ec_cmd_xfer_status(ec, msg);
>  }
>  
> -static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
> +static int cros_ec_pwm_get_duty(struct cros_ec_pwm_device *ec_pwm, u8 index)
>  {
> +	struct cros_ec_device *ec = ec_pwm->ec;
>  	struct {
>  		struct cros_ec_command msg;
>  		union {
> @@ -102,8 +137,17 @@ static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index)
>  	msg->insize = sizeof(*resp);
>  	msg->outsize = sizeof(*params);
>  
> -	params->pwm_type = EC_PWM_TYPE_GENERIC;
> -	params->index = index;
> +	if (ec_pwm->use_pwm_type) {
> +		ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);
> +		if (ret) {
> +			dev_err(ec->dev, "Invalid PWM type index: %d\n", index);
> +			return ret;
> +		}
> +		params->index = 0;
> +	} else {
> +		params->pwm_type = EC_PWM_TYPE_GENERIC;
> +		params->index = index;
> +	}
>  
>  	ret = cros_ec_cmd_xfer_status(ec, msg);
>  	if (ret < 0)
> @@ -133,7 +177,7 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
>  	 */
>  	duty_cycle = state->enabled ? state->duty_cycle : 0;
>  
> -	ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);
> +	ret = cros_ec_pwm_set_duty(ec_pwm, pwm->hwpwm, duty_cycle);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -149,7 +193,7 @@ static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
>  	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);
>  	int ret;
>  
> -	ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm);
> +	ret = cros_ec_pwm_get_duty(ec_pwm, pwm->hwpwm);
>  	if (ret < 0) {
>  		dev_err(chip->dev, "error getting initial duty: %d\n", ret);
>  		return;
> @@ -204,13 +248,13 @@ static const struct pwm_ops cros_ec_pwm_ops = {
>   * of PWMs it supports directly, so we have to read the pwm duty cycle for
>   * subsequent channels until we get an error.
>   */
> -static int cros_ec_num_pwms(struct cros_ec_device *ec)
> +static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
>  {
>  	int i, ret;
>  
>  	/* The index field is only 8 bits */
>  	for (i = 0; i <= U8_MAX; i++) {
> -		ret = cros_ec_pwm_get_duty(ec, i);
> +		ret = cros_ec_pwm_get_duty(ec_pwm, i);
>  		/*
>  		 * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM
>  		 * responses; everything else is treated as an error.
> @@ -232,10 +276,27 @@ static int cros_ec_num_pwms(struct cros_ec_device *ec)
>  	return U8_MAX;
>  }
>  
> +#ifdef CONFIG_OF
> +static const struct of_device_id cros_ec_pwm_of_match[] = {
> +	{
> +		.compatible = "google,cros-ec-pwm",
> +	},
> +	{
> +		.compatible = "google,cros-ec-pwm-type",
> +		.data = OF_CROS_EC_PWM_TYPE,
> +	},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
> +#else
> +#define cros_ec_pwm_of_match NULL
> +#endif
> +
>  static int cros_ec_pwm_probe(struct platform_device *pdev)
>  {
>  	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
>  	struct device *dev = &pdev->dev;
> +	const struct of_device_id *id;
>  	struct cros_ec_pwm_device *ec_pwm;
>  	struct pwm_chip *chip;
>  	int ret;
> @@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
>  	chip = &ec_pwm->chip;
>  	ec_pwm->ec = ec;
>  
> +	id = of_match_device(cros_ec_pwm_of_match, dev);
> +	if (id && id->data == OF_CROS_EC_PWM_TYPE)
> +		ec_pwm->use_pwm_type = true;
> +
>  	/* PWM chip */
>  	chip->dev = dev;
>  	chip->ops = &cros_ec_pwm_ops;
>  	chip->of_xlate = cros_ec_pwm_xlate;
>  	chip->of_pwm_n_cells = 1;
> -	ret = cros_ec_num_pwms(ec);
> -	if (ret < 0) {
> -		dev_err(dev, "Couldn't find PWMs: %d\n", ret);
> -		return ret;
> +
> +	if (ec_pwm->use_pwm_type) {
> +		chip->npwm = CROS_EC_PWM_DT_COUNT;
> +	} else {
> +		ret = cros_ec_num_pwms(ec_pwm);
> +		if (ret < 0) {
> +			dev_err(dev, "Couldn't find PWMs: %d\n", ret);
> +			return ret;
> +		}
> +		chip->npwm = ret;
>  	}
> -	chip->npwm = ret;
> +
>  	dev_dbg(dev, "Probed %u PWMs\n", chip->npwm);
>  
>  	ret = pwmchip_add(chip);
> @@ -285,14 +356,6 @@ static int cros_ec_pwm_remove(struct platform_device *dev)
>  	return 0;
>  }
>  
> -#ifdef CONFIG_OF
> -static const struct of_device_id cros_ec_pwm_of_match[] = {
> -	{ .compatible = "google,cros-ec-pwm" },
> -	{},
> -};
> -MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
> -#endif
> -
>  static struct platform_driver cros_ec_pwm_driver = {
>  	.probe = cros_ec_pwm_probe,
>  	.remove = cros_ec_pwm_remove,
> -- 
> 2.35.1.1178.g4f1659d476-goog
> 

-- 
Fabio Baltieri

Re: [PATCH v3 2/4] drivers: pwm: pwm-cros-ec: add channel type support

[Tzung-Bi Shih]

On Mon, Apr 11, 2022 at 03:21:12PM +0000, Fabio Baltieri wrote:
> Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm
> types to the PWM cros_ec_pwm driver. This allows specifying one of these
> PWM channel by functionality, and let the EC firmware pick the correct
> channel, thus abstracting the hardware implementation from the kernel
> driver.
> 
> To use it, define the node with the "google,cros-ec-pwm-type"
> compatible.

Not sure whether you decide to leave the prefix as is or not[1], just another
reminder: to be neat, suggest to remove "drivers: " prefix from the commit
title.

[1]: https://patchwork.kernel.org/project/chrome-platform/patch/20220331125818.3776912-3-fabiobaltieri@chromium.org/

> +#ifdef CONFIG_OF
> +static const struct of_device_id cros_ec_pwm_of_match[] = {
> +	{
> +		.compatible = "google,cros-ec-pwm",
> +	},
> +	{
> +		.compatible = "google,cros-ec-pwm-type",
> +		.data = OF_CROS_EC_PWM_TYPE,
> +	},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
> +#else
> +#define cros_ec_pwm_of_match NULL
> +#endif
> +
>  static int cros_ec_pwm_probe(struct platform_device *pdev)
>  {
>  	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
>  	struct device *dev = &pdev->dev;
> +	const struct of_device_id *id;
>  	struct cros_ec_pwm_device *ec_pwm;
>  	struct pwm_chip *chip;
>  	int ret;
> @@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
>  	chip = &ec_pwm->chip;
>  	ec_pwm->ec = ec;
>  
> +	id = of_match_device(cros_ec_pwm_of_match, dev);
> +	if (id && id->data == OF_CROS_EC_PWM_TYPE)
> +		ec_pwm->use_pwm_type = true;
> +
[...]
> -#ifdef CONFIG_OF
> -static const struct of_device_id cros_ec_pwm_of_match[] = {
> -	{ .compatible = "google,cros-ec-pwm" },
> -	{},
> -};
> -MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
> -#endif
> -

Use dev->driver->of_match_table to access the table so that the table
declaration doesn't actually need a move.  Instead, the helper function
of_device_get_match_data() is preferred.

Alternatively, it could use
of_device_is_compatible(..."google,cros-ec-pwm-type") so that it doesn't
need to introduce OF_CROS_EC_PWM_TYPE and reduce some bits.  I would prefer
this way.

Re: [PATCH v3 2/4] drivers: pwm: pwm-cros-ec: add channel type support

[Fabio Baltieri]

Hi Tzung-Bi,

On Tue, Apr 12, 2022 at 03:32:01PM +0800, Tzung-Bi Shih wrote:
> On Mon, Apr 11, 2022 at 03:21:12PM +0000, Fabio Baltieri wrote:
> > Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm
> > types to the PWM cros_ec_pwm driver. This allows specifying one of these
> > PWM channel by functionality, and let the EC firmware pick the correct
> > channel, thus abstracting the hardware implementation from the kernel
> > driver.
> > 
> > To use it, define the node with the "google,cros-ec-pwm-type"
> > compatible.
> 
> Not sure whether you decide to leave the prefix as is or not[1], just another
> reminder: to be neat, suggest to remove "drivers: " prefix from the commit
> title.

Sorry I messed up there, fixed in on the wrong branch and then forgot to
re-fix it once I moved to the wrong one -- I'll make sure to get that
right now, thanks for your patience.

> 
> [1]: https://patchwork.kernel.org/project/chrome-platform/patch/20220331125818.3776912-3-fabiobaltieri@chromium.org/
> 
> > +#ifdef CONFIG_OF
> > +static const struct of_device_id cros_ec_pwm_of_match[] = {
> > +	{
> > +		.compatible = "google,cros-ec-pwm",
> > +	},
> > +	{
> > +		.compatible = "google,cros-ec-pwm-type",
> > +		.data = OF_CROS_EC_PWM_TYPE,
> > +	},
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
> > +#else
> > +#define cros_ec_pwm_of_match NULL
> > +#endif
> > +
> >  static int cros_ec_pwm_probe(struct platform_device *pdev)
> >  {
> >  	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
> >  	struct device *dev = &pdev->dev;
> > +	const struct of_device_id *id;
> >  	struct cros_ec_pwm_device *ec_pwm;
> >  	struct pwm_chip *chip;
> >  	int ret;
> > @@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
> >  	chip = &ec_pwm->chip;
> >  	ec_pwm->ec = ec;
> >  
> > +	id = of_match_device(cros_ec_pwm_of_match, dev);
> > +	if (id && id->data == OF_CROS_EC_PWM_TYPE)
> > +		ec_pwm->use_pwm_type = true;
> > +
> [...]
> > -#ifdef CONFIG_OF
> > -static const struct of_device_id cros_ec_pwm_of_match[] = {
> > -	{ .compatible = "google,cros-ec-pwm" },
> > -	{},
> > -};
> > -MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match);
> > -#endif
> > -
> 
> Use dev->driver->of_match_table to access the table so that the table
> declaration doesn't actually need a move.  Instead, the helper function
> of_device_get_match_data() is preferred.
> 
> Alternatively, it could use
> of_device_is_compatible(..."google,cros-ec-pwm-type") so that it doesn't
> need to introduce OF_CROS_EC_PWM_TYPE and reduce some bits.  I would prefer
> this way.

That's a very good point, should simplify things a fair bit, did not
realize of_device_is_compatible() was an option somehow, will rework it
for that and send a v4 soon. Thanks for the pointer.

Fabio

-- 
Fabio Baltieri