// 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/mfd/core.h>
#include <linux/mod_devicetable.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) */
#if IS_ENABLED(CONFIG_MFD_CROS_EC_DEV)
static int keyboard_led_init_ec_pwm_mfd(struct platform_device *pdev)
{
struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent);
struct cros_ec_device *cros_ec = ec_dev->ec_dev;
struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);
keyboard_led->ec = cros_ec;
return 0;
}
static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {
.init = keyboard_led_init_ec_pwm_mfd,
.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_MFD_CROS_EC_DEV) */
static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {};
#endif /* IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) */
static int keyboard_led_is_mfd_device(struct platform_device *pdev)
{
return IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) && mfd_get_cell(pdev);
}
static int keyboard_led_probe(struct platform_device *pdev)
{
const struct keyboard_led_drvdata *drvdata;
struct keyboard_led *keyboard_led;
int error;
if (keyboard_led_is_mfd_device(pdev))
drvdata = &keyboard_led_drvdata_ec_pwm_mfd;
else
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 | LED_REJECT_NAME_CONFLICT;
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 == -EEXIST) /* Already bound via other mechanism */
return -ENODEV;
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 const struct platform_device_id keyboard_led_id[] = {
{ "cros-keyboard-leds", 0 },
{}
};
MODULE_DEVICE_TABLE(platform, keyboard_led_id);
static struct platform_driver keyboard_led_driver = {
.driver = {
.name = "cros-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,
.id_table = keyboard_led_id,
};
module_platform_driver(keyboard_led_driver);
MODULE_AUTHOR("Simon Que <[email protected]>");
MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver");
MODULE_LICENSE("GPL");
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