diff options
Diffstat (limited to 'drivers/platform/chrome/cros_kbd_led_backlight.c')
-rw-r--r-- | drivers/platform/chrome/cros_kbd_led_backlight.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_kbd_led_backlight.c b/drivers/platform/chrome/cros_kbd_led_backlight.c new file mode 100644 index 0000000000..793fd3f101 --- /dev/null +++ b/drivers/platform/chrome/cros_kbd_led_backlight.c @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Keyboard backlight LED driver for ChromeOS +// +// Copyright (C) 2012 Google, Inc. + +#include <linux/acpi.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/slab.h> + +struct keyboard_led { + struct led_classdev cdev; + struct cros_ec_device *ec; +}; + +/** + * 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; +}; + +#define KEYBOARD_BACKLIGHT_MAX 100 + +#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" +#define ACPI_KEYBOARD_BACKLIGHT_WRITE ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM" + +static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev, + enum led_brightness brightness) +{ + union acpi_object param; + struct acpi_object_list input; + acpi_status status; + + param.type = ACPI_TYPE_INTEGER; + param.integer.value = brightness; + input.count = 1; + input.pointer = ¶m; + + status = acpi_evaluate_object(NULL, ACPI_KEYBOARD_BACKLIGHT_WRITE, + &input, NULL); + if (ACPI_FAILURE(status)) + dev_err(cdev->dev, "Error setting keyboard LED value: %d\n", + status); +} + +static enum led_brightness +keyboard_led_get_brightness_acpi(struct led_classdev *cdev) +{ + unsigned long long brightness; + acpi_status status; + + status = acpi_evaluate_integer(NULL, ACPI_KEYBOARD_BACKLIGHT_READ, + NULL, &brightness); + if (ACPI_FAILURE(status)) { + dev_err(cdev->dev, "Error getting keyboard LED value: %d\n", + status); + return -EIO; + } + + return brightness; +} + +static int keyboard_led_init_acpi(struct platform_device *pdev) +{ + acpi_handle handle; + acpi_status status; + + /* Look for the keyboard LED ACPI Device */ + status = acpi_get_handle(ACPI_ROOT_OBJECT, + ACPI_KEYBOARD_BACKLIGHT_DEVICE, + &handle); + if (ACPI_FAILURE(status)) { + dev_err(&pdev->dev, "Unable to find ACPI device %s: %d\n", + ACPI_KEYBOARD_BACKLIGHT_DEVICE, status); + 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 = KEYBOARD_BACKLIGHT_MAX, +}; + +#endif /* CONFIG_ACPI */ + +#if IS_ENABLED(CONFIG_CROS_EC) + +static int +keyboard_led_set_brightness_ec_pwm(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct { + struct cros_ec_command msg; + struct ec_params_pwm_set_keyboard_backlight params; + } __packed buf; + struct ec_params_pwm_set_keyboard_backlight *params = &buf.params; + struct cros_ec_command *msg = &buf.msg; + struct keyboard_led *keyboard_led = container_of(cdev, struct keyboard_led, cdev); + + memset(&buf, 0, sizeof(buf)); + + msg->command = EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT; + msg->outsize = sizeof(*params); + + params->percent = brightness; + + return cros_ec_cmd_xfer_status(keyboard_led->ec, msg); +} + +static enum led_brightness +keyboard_led_get_brightness_ec_pwm(struct led_classdev *cdev) +{ + struct { + struct cros_ec_command msg; + struct ec_response_pwm_get_keyboard_backlight resp; + } __packed buf; + struct ec_response_pwm_get_keyboard_backlight *resp = &buf.resp; + struct cros_ec_command *msg = &buf.msg; + struct keyboard_led *keyboard_led = container_of(cdev, struct keyboard_led, cdev); + int ret; + + memset(&buf, 0, sizeof(buf)); + + msg->command = EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT; + msg->insize = sizeof(*resp); + + ret = cros_ec_cmd_xfer_status(keyboard_led->ec, msg); + if (ret < 0) + return ret; + + return resp->percent; +} + +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) { + dev_err(&pdev->dev, "no parent EC device\n"); + return -EINVAL; + } + + return 0; +} + +static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = { + .init = keyboard_led_init_ec_pwm, + .brightness_set_blocking = keyboard_led_set_brightness_ec_pwm, + .brightness_get = keyboard_led_get_brightness_ec_pwm, + .max_brightness = KEYBOARD_BACKLIGHT_MAX, +}; + +#else /* IS_ENABLED(CONFIG_CROS_EC) */ + +static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {}; + +#endif /* IS_ENABLED(CONFIG_CROS_EC) */ + +static int keyboard_led_probe(struct platform_device *pdev) +{ + const struct keyboard_led_drvdata *drvdata; + struct keyboard_led *keyboard_led; + int error; + + drvdata = device_get_match_data(&pdev->dev); + if (!drvdata) + return -EINVAL; + + keyboard_led = devm_kzalloc(&pdev->dev, sizeof(*keyboard_led), GFP_KERNEL); + if (!keyboard_led) + return -ENOMEM; + platform_set_drvdata(pdev, keyboard_led); + + if (drvdata->init) { + error = drvdata->init(pdev); + if (error) + return error; + } + + keyboard_led->cdev.name = "chromeos::kbd_backlight"; + keyboard_led->cdev.flags |= LED_CORE_SUSPENDRESUME; + keyboard_led->cdev.max_brightness = drvdata->max_brightness; + keyboard_led->cdev.brightness_set = drvdata->brightness_set; + keyboard_led->cdev.brightness_set_blocking = drvdata->brightness_set_blocking; + keyboard_led->cdev.brightness_get = drvdata->brightness_get; + + error = devm_led_classdev_register(&pdev->dev, &keyboard_led->cdev); + if (error) + return error; + + return 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_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, +}; +module_platform_driver(keyboard_led_driver); + +MODULE_AUTHOR("Simon Que <sque@chromium.org>"); +MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:chromeos-keyboard-leds"); |