Commit bb28f3d5 authored by Pali Rohár's avatar Pali Rohár Committed by Darren Hart

thinkpad_acpi: Add support for keyboard backlight

This patch adds support for controlling keyboard backlight via standard
linux led class interface (::kbd_backlight). It uses ACPI HKEY device with
MLCG and MLCS methods.
Signed-off-by: default avatarPali Rohár <pali.rohar@gmail.com>
Tested-by: default avatarFabio D'Urso <fabiodurso@hotmail.it>
Acked-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
parent 481fe5be
......@@ -303,6 +303,7 @@ static struct {
u32 hotkey_mask:1;
u32 hotkey_wlsw:1;
u32 hotkey_tablet:1;
u32 kbdlight:1;
u32 light:1;
u32 light_status:1;
u32 bright_acpimode:1;
......@@ -4985,6 +4986,207 @@ static struct ibm_struct video_driver_data = {
#endif /* CONFIG_THINKPAD_ACPI_VIDEO */
/*************************************************************************
* Keyboard backlight subdriver
*/
static int kbdlight_set_level(int level)
{
if (!hkey_handle)
return -ENXIO;
if (!acpi_evalf(hkey_handle, NULL, "MLCS", "dd", level))
return -EIO;
return 0;
}
static int kbdlight_get_level(void)
{
int status = 0;
if (!hkey_handle)
return -ENXIO;
if (!acpi_evalf(hkey_handle, &status, "MLCG", "dd", 0))
return -EIO;
if (status < 0)
return status;
return status & 0x3;
}
static bool kbdlight_is_supported(void)
{
int status = 0;
if (!hkey_handle)
return false;
if (!acpi_has_method(hkey_handle, "MLCG")) {
vdbg_printk(TPACPI_DBG_INIT, "kbdlight MLCG is unavailable\n");
return false;
}
if (!acpi_evalf(hkey_handle, &status, "MLCG", "qdd", 0)) {
vdbg_printk(TPACPI_DBG_INIT, "kbdlight MLCG failed\n");
return false;
}
if (status < 0) {
vdbg_printk(TPACPI_DBG_INIT, "kbdlight MLCG err: %d\n", status);
return false;
}
vdbg_printk(TPACPI_DBG_INIT, "kbdlight MLCG returned 0x%x\n", status);
/*
* Guessed test for keyboard backlight:
*
* Machines with backlight keyboard return:
* b010100000010000000XX - ThinkPad X1 Carbon 3rd
* b110100010010000000XX - ThinkPad x230
* b010100000010000000XX - ThinkPad x240
* b010100000010000000XX - ThinkPad W541
* (XX is current backlight level)
*
* Machines without backlight keyboard return:
* b10100001000000000000 - ThinkPad x230
* b10110001000000000000 - ThinkPad E430
* b00000000000000000000 - ThinkPad E450
*
* Candidate BITs for detection test (XOR):
* b01000000001000000000
* ^
*/
return status & BIT(9);
}
static void kbdlight_set_worker(struct work_struct *work)
{
struct tpacpi_led_classdev *data =
container_of(work, struct tpacpi_led_classdev, work);
if (likely(tpacpi_lifecycle == TPACPI_LIFE_RUNNING))
kbdlight_set_level(data->new_state);
}
static void kbdlight_sysfs_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct tpacpi_led_classdev *data =
container_of(led_cdev,
struct tpacpi_led_classdev,
led_classdev);
data->new_state = brightness;
queue_work(tpacpi_wq, &data->work);
}
static enum led_brightness kbdlight_sysfs_get(struct led_classdev *led_cdev)
{
int level;
level = kbdlight_get_level();
if (level < 0)
return 0;
return level;
}
static struct tpacpi_led_classdev tpacpi_led_kbdlight = {
.led_classdev = {
.name = "tpacpi::kbd_backlight",
.max_brightness = 2,
.brightness_set = &kbdlight_sysfs_set,
.brightness_get = &kbdlight_sysfs_get,
.flags = LED_CORE_SUSPENDRESUME,
}
};
static int __init kbdlight_init(struct ibm_init_struct *iibm)
{
int rc;
vdbg_printk(TPACPI_DBG_INIT, "initializing kbdlight subdriver\n");
TPACPI_ACPIHANDLE_INIT(hkey);
INIT_WORK(&tpacpi_led_kbdlight.work, kbdlight_set_worker);
if (!kbdlight_is_supported()) {
tp_features.kbdlight = 0;
vdbg_printk(TPACPI_DBG_INIT, "kbdlight is unsupported\n");
return 1;
}
tp_features.kbdlight = 1;
rc = led_classdev_register(&tpacpi_pdev->dev,
&tpacpi_led_kbdlight.led_classdev);
if (rc < 0) {
tp_features.kbdlight = 0;
return rc;
}
return 0;
}
static void kbdlight_exit(void)
{
if (tp_features.kbdlight)
led_classdev_unregister(&tpacpi_led_kbdlight.led_classdev);
flush_workqueue(tpacpi_wq);
}
static int kbdlight_read(struct seq_file *m)
{
int level;
if (!tp_features.kbdlight) {
seq_printf(m, "status:\t\tnot supported\n");
} else {
level = kbdlight_get_level();
if (level < 0)
seq_printf(m, "status:\t\terror %d\n", level);
else
seq_printf(m, "status:\t\t%d\n", level);
seq_printf(m, "commands:\t0, 1, 2\n");
}
return 0;
}
static int kbdlight_write(char *buf)
{
char *cmd;
int level = -1;
if (!tp_features.kbdlight)
return -ENODEV;
while ((cmd = next_cmd(&buf))) {
if (strlencmp(cmd, "0") == 0)
level = 0;
else if (strlencmp(cmd, "1") == 0)
level = 1;
else if (strlencmp(cmd, "2") == 0)
level = 2;
else
return -EINVAL;
}
if (level == -1)
return -EINVAL;
return kbdlight_set_level(level);
}
static struct ibm_struct kbdlight_driver_data = {
.name = "kbdlight",
.read = kbdlight_read,
.write = kbdlight_write,
.exit = kbdlight_exit,
};
/*************************************************************************
* Light (thinklight) subdriver
*/
......@@ -9206,6 +9408,10 @@ static struct ibm_init_struct ibms_init[] __initdata = {
.data = &video_driver_data,
},
#endif
{
.init = kbdlight_init,
.data = &kbdlight_driver_data,
},
{
.init = light_init,
.data = &light_driver_data,
......
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