diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/thinkpad_acpi.c | 64 |
1 files changed, 49 insertions, 15 deletions
diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c index 7dc6b73e8f5..5e25abc5400 100644 --- a/drivers/misc/thinkpad_acpi.c +++ b/drivers/misc/thinkpad_acpi.c @@ -4295,8 +4295,16 @@ static struct ibm_struct ecdump_driver_data = { #define TPACPI_BACKLIGHT_DEV_NAME "thinkpad_screen" +enum { + TP_EC_BACKLIGHT = 0x31, + + /* TP_EC_BACKLIGHT bitmasks */ + TP_EC_BACKLIGHT_LVLMSK = 0x1F, + TP_EC_BACKLIGHT_CMDMSK = 0xE0, + TP_EC_BACKLIGHT_MAPSW = 0x20, +}; + static struct backlight_device *ibm_backlight_device; -static int brightness_offset = 0x31; static int brightness_mode; static unsigned int brightness_enable = 2; /* 2 = auto, 0 = no, 1 = yes */ @@ -4305,16 +4313,24 @@ static struct mutex brightness_mutex; /* * ThinkPads can read brightness from two places: EC 0x31, or * CMOS NVRAM byte 0x5E, bits 0-3. + * + * EC 0x31 has the following layout + * Bit 7: unknown function + * Bit 6: unknown function + * Bit 5: Z: honour scale changes, NZ: ignore scale changes + * Bit 4: must be set to zero to avoid problems + * Bit 3-0: backlight brightness level + * + * brightness_get_raw returns status data in the EC 0x31 layout */ -static int brightness_get(struct backlight_device *bd) +static int brightness_get_raw(int *status) { u8 lec = 0, lcmos = 0, level = 0; if (brightness_mode & 1) { - if (!acpi_ec_read(brightness_offset, &lec)) + if (!acpi_ec_read(TP_EC_BACKLIGHT, &lec)) return -EIO; - lec &= (tp_features.bright_16levels)? 0x0f : 0x07; - level = lec; + level = lec & TP_EC_BACKLIGHT_LVLMSK; }; if (brightness_mode & 2) { lcmos = (nvram_read_byte(TP_NVRAM_ADDR_BRIGHTNESS) @@ -4325,6 +4341,8 @@ static int brightness_get(struct backlight_device *bd) } if (brightness_mode == 3) { + *status = lec; /* Prefer EC, CMOS is just a backing store */ + lec &= TP_EC_BACKLIGHT_LVLMSK; if (lec == lcmos) tp_warned.bright_cmos_ec_unsync = 0; else { @@ -4338,9 +4356,11 @@ static int brightness_get(struct backlight_device *bd) } return -EIO; } + } else { + *status = level; } - return level; + return 0; } /* May return EINTR which can always be mapped to ERESTARTSYS */ @@ -4348,19 +4368,22 @@ static int brightness_set(int value) { int cmos_cmd, inc, i, res; int current_value; + int command_bits; - if (value > ((tp_features.bright_16levels)? 15 : 7)) + if (value > ((tp_features.bright_16levels)? 15 : 7) || + value < 0) return -EINVAL; res = mutex_lock_interruptible(&brightness_mutex); if (res < 0) return res; - current_value = brightness_get(NULL); - if (current_value < 0) { - res = current_value; + res = brightness_get_raw(¤t_value); + if (res < 0) goto errout; - } + + command_bits = current_value & TP_EC_BACKLIGHT_CMDMSK; + current_value &= TP_EC_BACKLIGHT_LVLMSK; cmos_cmd = value > current_value ? TP_CMOS_BRIGHTNESS_UP : @@ -4375,7 +4398,8 @@ static int brightness_set(int value) goto errout; } if ((brightness_mode & 1) && - !acpi_ec_write(brightness_offset, i + inc)) { + !acpi_ec_write(TP_EC_BACKLIGHT, + (i + inc) | command_bits)) { res = -EIO; goto errout;; } @@ -4398,6 +4422,17 @@ static int brightness_update_status(struct backlight_device *bd) bd->props.brightness : 0); } +static int brightness_get(struct backlight_device *bd) +{ + int status, res; + + res = brightness_get_raw(&status); + if (res < 0) + return 0; /* FIXME: teach backlight about error handling */ + + return status & TP_EC_BACKLIGHT_LVLMSK; +} + static struct backlight_ops ibm_backlight_data = { .get_brightness = brightness_get, .update_status = brightness_update_status, @@ -4462,8 +4497,7 @@ static int __init brightness_init(struct ibm_init_struct *iibm) if (brightness_mode > 3) return -EINVAL; - b = brightness_get(NULL); - if (b < 0) + if (brightness_get_raw(&b) < 0) return 1; if (tp_features.bright_16levels) @@ -4481,7 +4515,7 @@ static int __init brightness_init(struct ibm_init_struct *iibm) ibm_backlight_device->props.max_brightness = (tp_features.bright_16levels)? 15 : 7; - ibm_backlight_device->props.brightness = b; + ibm_backlight_device->props.brightness = b & TP_EC_BACKLIGHT_LVLMSK; backlight_update_status(ibm_backlight_device); return 0; |