diff options
| author | Matthew Garrett <mjg@redhat.com> | 2011-03-22 16:30:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-22 17:43:59 -0700 |
| commit | bb7ca747f8d6243b3943c5b133048652020f4a50 (patch) | |
| tree | b40e879a7b26e3763aea2af2d4dd9079483de11e /drivers/video/backlight/backlight.c | |
| parent | ccd7510fd8dea5b4b2af87fb2aef2ebd6b23b76b (diff) | |
backlight: add backlight type
There may be multiple ways of controlling the backlight on a given
machine. Allow drivers to expose the type of interface they are
providing, making it possible for userspace to make appropriate policy
decisions.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Airlie <airlied@linux.ie>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/backlight/backlight.c')
| -rw-r--r-- | drivers/video/backlight/backlight.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 08703299ef61..80d292fb92d8 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -19,6 +19,12 @@ #include <asm/backlight.h> #endif +static const char const *backlight_types[] = { + [BACKLIGHT_RAW] = "raw", + [BACKLIGHT_PLATFORM] = "platform", + [BACKLIGHT_FIRMWARE] = "firmware", +}; + #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \ defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)) /* This callback gets called when something important happens inside a @@ -169,6 +175,14 @@ static ssize_t backlight_store_brightness(struct device *dev, return rc; } +static ssize_t backlight_show_type(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct backlight_device *bd = to_backlight_device(dev); + + return sprintf(buf, "%s\n", backlight_types[bd->props.type]); +} + static ssize_t backlight_show_max_brightness(struct device *dev, struct device_attribute *attr, char *buf) { @@ -234,6 +248,7 @@ static struct device_attribute bl_device_attributes[] = { __ATTR(actual_brightness, 0444, backlight_show_actual_brightness, NULL), __ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL), + __ATTR(type, 0444, backlight_show_type, NULL), __ATTR_NULL, }; @@ -292,9 +307,16 @@ struct backlight_device *backlight_device_register(const char *name, dev_set_drvdata(&new_bd->dev, devdata); /* Set default properties */ - if (props) + if (props) { memcpy(&new_bd->props, props, sizeof(struct backlight_properties)); + if (props->type <= 0 || props->type >= BACKLIGHT_TYPE_MAX) { + WARN(1, "%s: invalid backlight type", name); + new_bd->props.type = BACKLIGHT_RAW; + } + } else { + new_bd->props.type = BACKLIGHT_RAW; + } rc = device_register(&new_bd->dev); if (rc) { |