gmux: Add generic write32 function

Move the special-cased backlight update function to a generic gmux_write32
function.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
This commit is contained in:
Matthew Garrett 2012-08-09 12:47:00 -04:00
parent 846b99964a
commit 7e30ed6bdd

View file

@ -75,6 +75,18 @@ static inline u32 gmux_read32(struct apple_gmux_data *gmux_data, int port)
return inl(gmux_data->iostart + port);
}
static inline u32 gmux_write32(struct apple_gmux_data *gmux_data, int port,
u32 val)
{
int i;
u8 tmpval;
for (i = 0; i < 4; i++) {
tmpval = (val >> (i * 8)) & 0xff;
outb(tmpval, port + i);
}
}
static int gmux_get_brightness(struct backlight_device *bd)
{
struct apple_gmux_data *gmux_data = bl_get_data(bd);
@ -90,16 +102,7 @@ static int gmux_update_status(struct backlight_device *bd)
if (bd->props.state & BL_CORE_SUSPENDED)
return 0;
/*
* Older gmux versions require writing out lower bytes first then
* setting the upper byte to 0 to flush the values. Newer versions
* accept a single u32 write, but the old method also works, so we
* just use the old method for all gmux versions.
*/
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 1, brightness >> 8);
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 2, brightness >> 16);
gmux_write8(gmux_data, GMUX_PORT_BRIGHTNESS + 3, 0);
gmux_write32(gmux_data, GMUX_PORT_BRIGHTNESS, brightness);
return 0;
}