diff options
Diffstat (limited to 'drivers/platform')
| -rw-r--r-- | drivers/platform/x86/x86-android-tablets/other.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/platform/x86/x86-android-tablets/other.c b/drivers/platform/x86/x86-android-tablets/other.c index ff7b1d0abaa3..eb0e55c69dfe 100644 --- a/drivers/platform/x86/x86-android-tablets/other.c +++ b/drivers/platform/x86/x86-android-tablets/other.c @@ -11,7 +11,9 @@ #include <linux/acpi.h> #include <linux/gpio/machine.h> #include <linux/input.h> +#include <linux/leds.h> #include <linux/platform_device.h> +#include <linux/pwm.h> #include <dt-bindings/leds/common.h> @@ -662,8 +664,53 @@ static const struct software_node *ktd2026_node_group[] = { NULL }; +/* + * For the LEDs which backlight the menu / home / back capacitive buttons on + * the bottom bezel. These are attached to a TPS61158 LED controller which + * is controlled by the "pwm_soc_lpss_2" PWM output. + */ +#define XIAOMI_MIPAD2_LED_PERIOD_NS 19200 +#define XIAOMI_MIPAD2_LED_DEFAULT_DUTY 6000 /* From Android kernel */ + +static struct pwm_device *xiaomi_mipad2_led_pwm; + +static int xiaomi_mipad2_brightness_set(struct led_classdev *led_cdev, + enum led_brightness val) +{ + struct pwm_state state = { + .period = XIAOMI_MIPAD2_LED_PERIOD_NS, + .duty_cycle = val, + /* Always set PWM enabled to avoid the pin floating */ + .enabled = true, + }; + + return pwm_apply_might_sleep(xiaomi_mipad2_led_pwm, &state); +} + static int __init xiaomi_mipad2_init(struct device *dev) { + struct led_classdev *led_cdev; + int ret; + + xiaomi_mipad2_led_pwm = devm_pwm_get(dev, "pwm_soc_lpss_2"); + if (IS_ERR(xiaomi_mipad2_led_pwm)) + return dev_err_probe(dev, PTR_ERR(xiaomi_mipad2_led_pwm), "getting pwm\n"); + + led_cdev = devm_kzalloc(dev, sizeof(*led_cdev), GFP_KERNEL); + if (!led_cdev) + return -ENOMEM; + + led_cdev->name = "mipad2:white:touch-buttons-backlight"; + led_cdev->max_brightness = XIAOMI_MIPAD2_LED_PERIOD_NS; + /* "input-events" trigger uses blink_brightness */ + led_cdev->blink_brightness = XIAOMI_MIPAD2_LED_DEFAULT_DUTY; + led_cdev->default_trigger = "input-events"; + led_cdev->brightness_set_blocking = xiaomi_mipad2_brightness_set; + + ret = devm_led_classdev_register(dev, led_cdev); + if (ret) + return dev_err_probe(dev, ret, "registering LED\n"); + return software_node_register_node_group(ktd2026_node_group); } |