linux-kernel - [PATCH 1/2] platform/chrome: cros_kbd_led_backlight: Automatically enable keyboard backlight control if feature present in EC

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Date: Fri, 22 Mar 2024 20:27:58 +1000
From: Stephen Horvath <s.horvath@...look.com.au>
To: Lee Jones <lee@...nel.org>,
	Benson Leung <bleung@...omium.org>,
	Guenter Roeck <groeck@...omium.org>,
	Tzung-Bi Shih <tzungbi@...nel.org>,
	chrome-platform@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Cc: Stephen Horvath <s.horvath@...look.com.au>
Subject: [PATCH 1/2] platform/chrome: cros_kbd_led_backlight: Automatically enable keyboard backlight control if feature present in EC

The keyboard backlight control is not enabled by default on all devices
with a Chromium EC, e.g. my Framework 13.
This patch adds a check for the feature and enables backlight control if
it is present.

I also fixed a bug that seemed like there was some confusion between
`cros_ec_dev` and `cros_ec_device`, so I'm not sure if this module even
worked until now.

Signed-off-by: Stephen Horvath <s.horvath@...look.com.au>
---
 drivers/mfd/cros_ec_dev.c                     |  9 +++++++
 .../platform/chrome/cros_kbd_led_backlight.c  | 24 +++++++------------
 2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index a52d59cc2b1e..29b85ed5fece 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -99,6 +99,10 @@ static const struct mfd_cell cros_ec_wdt_cells[] = {
 	{ .name = "cros-ec-wdt", }
 };
 
+static const struct mfd_cell cros_ec_pwm_kbd_cells[] = {
+	{ .name = "chromeos-keyboard-leds", }
+};
+
 static const struct cros_feature_to_cells cros_subdevices[] = {
 	{
 		.id		= EC_FEATURE_CEC,
@@ -125,6 +129,11 @@ static const struct cros_feature_to_cells cros_subdevices[] = {
 		.mfd_cells	= cros_ec_wdt_cells,
 		.num_cells	= ARRAY_SIZE(cros_ec_wdt_cells),
 	},
+	{
+		.id		= EC_FEATURE_PWM_KEYB,
+		.mfd_cells	= cros_ec_pwm_kbd_cells,
+		.num_cells	= ARRAY_SIZE(cros_ec_pwm_kbd_cells),
+	},
 };
 
 static const struct mfd_cell cros_ec_platform_cells[] = {
diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
index 793fd3f1015d..06e9a57536af 100644
--- a/drivers/platform/chrome/cros_kbd_led_backlight.c
+++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
@@ -171,12 +171,15 @@ static int keyboard_led_init_ec_pwm(struct platform_device *pdev)
 {
 	struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);
 
-	keyboard_led->ec = dev_get_drvdata(pdev->dev.parent);
-	if (!keyboard_led->ec) {
+	struct cros_ec_dev *parent_ec = dev_get_drvdata(pdev->dev.parent);
+
+	if (!parent_ec) {
 		dev_err(&pdev->dev, "no parent EC device\n");
 		return -EINVAL;
 	}
 
+	keyboard_led->ec = parent_ec->ec_dev;
+
 	return 0;
 }
 
@@ -200,8 +203,10 @@ static int keyboard_led_probe(struct platform_device *pdev)
 	int error;
 
 	drvdata = device_get_match_data(&pdev->dev);
-	if (!drvdata)
-		return -EINVAL;
+	if (!drvdata) {
+		/* Assume EC if no match data is provided */
+		drvdata = &keyboard_led_drvdata_ec_pwm;
+	}
 
 	keyboard_led = devm_kzalloc(&pdev->dev, sizeof(*keyboard_led), GFP_KERNEL);
 	if (!keyboard_led)
@@ -236,22 +241,10 @@ static const struct acpi_device_id keyboard_led_acpi_match[] = {
 MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
 #endif
 
-#ifdef CONFIG_OF
-static const struct of_device_id keyboard_led_of_match[] = {
-	{
-		.compatible = "google,cros-kbd-led-backlight",
-		.data = &keyboard_led_drvdata_ec_pwm,
-	},
-	{}
-};
-MODULE_DEVICE_TABLE(of, keyboard_led_of_match);
-#endif
-
 static struct platform_driver keyboard_led_driver = {
 	.driver		= {
 		.name	= "chromeos-keyboard-leds",
 		.acpi_match_table = ACPI_PTR(keyboard_led_acpi_match),
-		.of_match_table = of_match_ptr(keyboard_led_of_match),
 	},
 	.probe		= keyboard_led_probe,
 };
-- 
2.43.0