platform/chrome: cros_kbd_led_backlight: separate ACPI backend

cros_kbd_led_backlight uses ACPI_KEYBOARD_BACKLIGHT_WRITE and
ACPI_KEYBOARD_BACKLIGHT_READ for setting and getting the brightness
respectively.

Separate ACPI operations for preparing the driver to support other
backends.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20220523090822.3035189-3-tzungbi@kernel.org

diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c
index f9587a562bb7b9e068a0f84ac11b51006517d6bd..a86d664854ae9fb721e32aceb402206e1b25f133 100644 (file)
--- a/drivers/platform/chrome/cros_kbd_led_backlight.c
+++ b/drivers/platform/chrome/cros_kbd_led_backlight.c
@@ -13,6 +13,33 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
+/**
+ * struct keyboard_led_drvdata - keyboard LED driver data.
+ * @init:                      Init function.
+ * @brightness_get:            Get LED brightness level.
+ * @brightness_set:            Set LED brightness level.  Must not sleep.
+ * @brightness_set_blocking:   Set LED brightness level.  It can block the
+ *                             caller for the time required for accessing a
+ *                             LED device register
+ * @max_brightness:            Maximum brightness.
+ *
+ * See struct led_classdev in include/linux/leds.h for more details.
+ */
+struct keyboard_led_drvdata {
+       int (*init)(struct platform_device *pdev);
+
+       enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
+
+       void (*brightness_set)(struct led_classdev *led_cdev,
+                              enum led_brightness brightness);
+       int (*brightness_set_blocking)(struct led_classdev *led_cdev,
+                                      enum led_brightness brightness);
+
+       enum led_brightness max_brightness;
+};
+
+#ifdef CONFIG_ACPI
+
 /* Keyboard LED ACPI Device must be defined in firmware */
 #define ACPI_KEYBOARD_BACKLIGHT_DEVICE "\\_SB.KBLT"
 #define ACPI_KEYBOARD_BACKLIGHT_READ   ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC"
@@ -20,8 +47,8 @@
 
 #define ACPI_KEYBOARD_BACKLIGHT_MAX            100
 
-static void keyboard_led_set_brightness(struct led_classdev *cdev,
-                                       enum led_brightness brightness)
+static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev,
+                                            enum led_brightness brightness)
 {
        union acpi_object param;
        struct acpi_object_list input;
@@ -40,7 +67,7 @@ static void keyboard_led_set_brightness(struct led_classdev *cdev,
 }
 
 static enum led_brightness
-keyboard_led_get_brightness(struct led_classdev *cdev)
+keyboard_led_get_brightness_acpi(struct led_classdev *cdev)
 {
        unsigned long long brightness;
        acpi_status status;
@@ -56,12 +83,10 @@ keyboard_led_get_brightness(struct led_classdev *cdev)
        return brightness;
 }
 
-static int keyboard_led_probe(struct platform_device *pdev)
+static int keyboard_led_init_acpi(struct platform_device *pdev)
 {
-       struct led_classdev *cdev;
        acpi_handle handle;
        acpi_status status;
-       int error;
 
        /* Look for the keyboard LED ACPI Device */
        status = acpi_get_handle(ACPI_ROOT_OBJECT,
@@ -73,15 +98,44 @@ static int keyboard_led_probe(struct platform_device *pdev)
                return -ENXIO;
        }
 
+       return 0;
+}
+
+static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {
+       .init = keyboard_led_init_acpi,
+       .brightness_set = keyboard_led_set_brightness_acpi,
+       .brightness_get = keyboard_led_get_brightness_acpi,
+       .max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX,
+};
+
+#endif /* CONFIG_ACPI */
+
+static int keyboard_led_probe(struct platform_device *pdev)
+{
+       struct led_classdev *cdev;
+       const struct keyboard_led_drvdata *drvdata;
+       int error;
+
+       drvdata = acpi_device_get_match_data(&pdev->dev);
+       if (!drvdata)
+               return -EINVAL;
+
+       if (drvdata->init) {
+               error = drvdata->init(pdev);
+               if (error)
+                       return error;
+       }
+
        cdev = devm_kzalloc(&pdev->dev, sizeof(*cdev), GFP_KERNEL);
        if (!cdev)
                return -ENOMEM;
 
        cdev->name = "chromeos::kbd_backlight";
-       cdev->max_brightness = ACPI_KEYBOARD_BACKLIGHT_MAX;
        cdev->flags |= LED_CORE_SUSPENDRESUME;
-       cdev->brightness_set = keyboard_led_set_brightness;
-       cdev->brightness_get = keyboard_led_get_brightness;
+       cdev->max_brightness = drvdata->max_brightness;
+       cdev->brightness_set = drvdata->brightness_set;
+       cdev->brightness_set_blocking = drvdata->brightness_set_blocking;
+       cdev->brightness_get = drvdata->brightness_get;
 
        error = devm_led_classdev_register(&pdev->dev, cdev);
        if (error)
@@ -90,16 +144,18 @@ static int keyboard_led_probe(struct platform_device *pdev)
        return 0;
 }
 
-static const struct acpi_device_id keyboard_led_id[] = {
-       { "GOOG0002", 0 },
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id keyboard_led_acpi_match[] = {
+       { "GOOG0002", (kernel_ulong_t)&keyboard_led_drvdata_acpi },
        { }
 };
-MODULE_DEVICE_TABLE(acpi, keyboard_led_id);
+MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);
+#endif
 
 static struct platform_driver keyboard_led_driver = {
        .driver         = {
                .name   = "chromeos-keyboard-leds",
-               .acpi_match_table = ACPI_PTR(keyboard_led_id),
+               .acpi_match_table = ACPI_PTR(keyboard_led_acpi_match),
        },
        .probe          = keyboard_led_probe,
 };