video: ARM CLCD: support pads connected in reverse order
There are CLCDs connected with the pads in BGR rather than RGB
order. It really doesn't matter since the CLCD has a flag and
a bit to switch the position of the RGB and BGR components.
This is needed to put something logical into the
arm,pl11x,tft-r0g0b0-pads property of the device tree on the
Nomadik which will then be <16 8 0>.
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/fbdev/amba-clcd.c b/drivers/video/fbdev/amba-clcd.c
index 5bd20e8..080e8a2 100644
--- a/drivers/video/fbdev/amba-clcd.c
+++ b/drivers/video/fbdev/amba-clcd.c
@@ -675,6 +675,7 @@
} panels[] = {
{ 0x110, 1, 7, 13, CLCD_CAP_5551 },
{ 0x110, 0, 8, 16, CLCD_CAP_888 },
+ { 0x110, 16, 8, 0, CLCD_CAP_888 },
{ 0x111, 4, 14, 20, CLCD_CAP_444 },
{ 0x111, 3, 11, 19, CLCD_CAP_444 | CLCD_CAP_5551 },
{ 0x111, 3, 10, 19, CLCD_CAP_444 | CLCD_CAP_5551 |
@@ -702,6 +703,13 @@
fb->panel->caps = panels[i].caps;
}
+ /*
+ * If we actually physically connected the R lines to B and
+ * vice versa
+ */
+ if (r0 != 0 && b0 == 0)
+ fb->panel->bgr_connection = true;
+
return fb->panel->caps ? 0 : -EINVAL;
}
diff --git a/include/linux/amba/clcd.h b/include/linux/amba/clcd.h
index e64c1cc..8b64ec0 100644
--- a/include/linux/amba/clcd.h
+++ b/include/linux/amba/clcd.h
@@ -108,6 +108,12 @@
grayscale:1;
unsigned int connector;
struct backlight_device *backlight;
+ /*
+ * If the B/R lines are switched between the CLCD
+ * and the panel we need to know this and not try to
+ * compensate with the BGR bit in the control register.
+ */
+ bool bgr_connection;
};
struct clcd_regs {
@@ -234,16 +240,22 @@
if (var->grayscale)
val |= CNTL_LCDBW;
- if (fb->panel->caps && fb->board->caps &&
- var->bits_per_pixel >= 16) {
+ if (fb->panel->caps && fb->board->caps && var->bits_per_pixel >= 16) {
/*
* if board and panel supply capabilities, we can support
- * changing BGR/RGB depending on supplied parameters
+ * changing BGR/RGB depending on supplied parameters. Here
+ * we switch to what the framebuffer is providing if need
+ * be, so if the framebuffer is BGR but the display connection
+ * is RGB (first case) we switch it around. Vice versa mutatis
+ * mutandis if the framebuffer is RGB but the display connection
+ * is BGR, we flip it around.
*/
if (var->red.offset == 0)
val &= ~CNTL_BGR;
else
val |= CNTL_BGR;
+ if (fb->panel->bgr_connection)
+ val ^= CNTL_BGR;
}
switch (var->bits_per_pixel) {