[PATCH 05/10] ARM: clcd: add method for describing display capabilities
Russell King - ARM Linux
linux at arm.linux.org.uk
Thu Jan 27 07:59:31 EST 2011
The ARM CLCD PL110 controller in TFT mode provides two output formats
based on whether the controller is in 24bpp mode or not - either 5551
or 888. PL111 augments this with a 444 and 565 modes.
Some implementations provide an external MUX on the PL110 output to
reassign the bits to achieve 565 mode.
Provide a system of capability flags to allow the CLCD driver to work
out what is supported by each panel and board, and therefore which
display formats are permitted.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
drivers/video/amba-clcd.c | 95 +++++++++++++++++++++++++++++++++++++++-----
include/linux/amba/clcd.h | 82 ++++++++++++++++++++++++++++++--------
2 files changed, 149 insertions(+), 28 deletions(-)
diff --git a/drivers/video/amba-clcd.c b/drivers/video/amba-clcd.c
index aedbb34..8bd3706 100644
--- a/drivers/video/amba-clcd.c
+++ b/drivers/video/amba-clcd.c
@@ -120,8 +120,23 @@ static void clcdfb_enable(struct clcd_fb *fb, u32 cntl)
static int
clcdfb_set_bitfields(struct clcd_fb *fb, struct fb_var_screeninfo *var)
{
+ u32 caps;
int ret = 0;
+ if (fb->panel->caps && fb->board->caps)
+ caps = fb->panel->caps & fb->board->caps;
+ else {
+ /* Old way of specifying what can be used */
+ caps = fb->panel->cntl & CNTL_BGR ?
+ CLCD_CAP_BGR : CLCD_CAP_RGB;
+ /* But mask out 444 modes as they weren't supported */
+ caps &= ~CLCD_CAP_444;
+ }
+
+ /* Only TFT panels can do RGB888/BGR888 */
+ if (!(fb->panel->cntl & CNTL_LCDTFT))
+ caps &= ~CLCD_CAP_888;
+
memset(&var->transp, 0, sizeof(var->transp));
var->red.msb_right = 0;
@@ -133,6 +148,13 @@ clcdfb_set_bitfields(struct clcd_fb *fb, struct fb_var_screeninfo *var)
case 2:
case 4:
case 8:
+ /* If we can't do 5551, reject */
+ caps &= CLCD_CAP_5551;
+ if (!caps) {
+ ret = -EINVAL;
+ break;
+ }
+
var->red.length = var->bits_per_pixel;
var->red.offset = 0;
var->green.length = var->bits_per_pixel;
@@ -140,23 +162,61 @@ clcdfb_set_bitfields(struct clcd_fb *fb, struct fb_var_screeninfo *var)
var->blue.length = var->bits_per_pixel;
var->blue.offset = 0;
break;
+
case 16:
- var->red.length = 5;
- var->blue.length = 5;
+ /* If we can't do 444, 5551 or 565, reject */
+ if (!(caps & (CLCD_CAP_444 | CLCD_CAP_5551 | CLCD_CAP_565))) {
+ ret = -EINVAL;
+ break;
+ }
+
/*
- * Green length can be 5 or 6 depending whether
- * we're operating in RGB555 or RGB565 mode.
+ * Green length can be 4, 5 or 6 depending whether
+ * we're operating in 444, 5551 or 565 mode.
*/
- if (var->green.length != 5 && var->green.length != 6)
- var->green.length = 6;
+ if (var->green.length == 4 && caps & CLCD_CAP_444)
+ caps &= CLCD_CAP_444;
+ if (var->green.length == 5 && caps & CLCD_CAP_5551)
+ caps &= CLCD_CAP_5551;
+ else if (var->green.length == 6 && caps & CLCD_CAP_565)
+ caps &= CLCD_CAP_565;
+ else {
+ /*
+ * PL110 officially only supports RGB555,
+ * but may be wired up to allow RGB565.
+ */
+ if (caps & CLCD_CAP_565) {
+ var->green.length = 6;
+ caps &= CLCD_CAP_565;
+ } else if (caps & CLCD_CAP_5551) {
+ var->green.length = 5;
+ caps &= CLCD_CAP_5551;
+ } else {
+ var->green.length = 4;
+ caps &= CLCD_CAP_444;
+ }
+ }
+
+ if (var->green.length >= 5) {
+ var->red.length = 5;
+ var->blue.length = 5;
+ } else {
+ var->red.length = 4;
+ var->blue.length = 4;
+ }
break;
case 32:
- if (fb->panel->cntl & CNTL_LCDTFT) {
- var->red.length = 8;
- var->green.length = 8;
- var->blue.length = 8;
+ /* If we can't do 888, reject */
+ caps &= CLCD_CAP_888;
+ if (!caps) {
+ ret = -EINVAL;
break;
}
+
+ var->red.length = 8;
+ var->green.length = 8;
+ var->blue.length = 8;
+ break;
default:
ret = -EINVAL;
break;
@@ -168,7 +228,20 @@ clcdfb_set_bitfields(struct clcd_fb *fb, struct fb_var_screeninfo *var)
* the bitfield length defined above.
*/
if (ret == 0 && var->bits_per_pixel >= 16) {
- if (fb->panel->cntl & CNTL_BGR) {
+ bool bgr, rgb;
+
+ bgr = caps & CLCD_CAP_BGR && var->blue.offset == 0;
+ rgb = caps & CLCD_CAP_RGB && var->red.offset == 0;
+
+ if (!bgr && !rgb)
+ /*
+ * The requested format was not possible, try just
+ * our capabilities. One of BGR or RGB must be
+ * supported.
+ */
+ bgr = caps & CLCD_CAP_BGR;
+
+ if (bgr) {
var->blue.offset = 0;
var->green.offset = var->blue.offset + var->blue.length;
var->red.offset = var->green.offset + var->green.length;
diff --git a/include/linux/amba/clcd.h b/include/linux/amba/clcd.h
index 2e51121..24d26ef 100644
--- a/include/linux/amba/clcd.h
+++ b/include/linux/amba/clcd.h
@@ -53,6 +53,7 @@
#define CNTL_LCDBPP8 (3 << 1)
#define CNTL_LCDBPP16 (4 << 1)
#define CNTL_LCDBPP16_565 (6 << 1)
+#define CNTL_LCDBPP16_444 (7 << 1)
#define CNTL_LCDBPP24 (5 << 1)
#define CNTL_LCDBW (1 << 4)
#define CNTL_LCDTFT (1 << 5)
@@ -66,6 +67,32 @@
#define CNTL_LDMAFIFOTIME (1 << 15)
#define CNTL_WATERMARK (1 << 16)
+enum {
+ /* individual formats */
+ CLCD_CAP_RGB444 = (1 << 0),
+ CLCD_CAP_RGB5551 = (1 << 1),
+ CLCD_CAP_RGB565 = (1 << 2),
+ CLCD_CAP_RGB888 = (1 << 3),
+ CLCD_CAP_BGR444 = (1 << 4),
+ CLCD_CAP_BGR5551 = (1 << 5),
+ CLCD_CAP_BGR565 = (1 << 6),
+ CLCD_CAP_BGR888 = (1 << 7),
+
+ /* connection layouts */
+ CLCD_CAP_444 = CLCD_CAP_RGB444 | CLCD_CAP_BGR444,
+ CLCD_CAP_5551 = CLCD_CAP_RGB5551 | CLCD_CAP_BGR5551,
+ CLCD_CAP_565 = CLCD_CAP_RGB565 | CLCD_CAP_BGR565,
+ CLCD_CAP_888 = CLCD_CAP_RGB888 | CLCD_CAP_BGR888,
+
+ /* red/blue ordering */
+ CLCD_CAP_RGB = CLCD_CAP_RGB444 | CLCD_CAP_RGB5551 |
+ CLCD_CAP_RGB565 | CLCD_CAP_RGB888,
+ CLCD_CAP_BGR = CLCD_CAP_BGR444 | CLCD_CAP_BGR5551 |
+ CLCD_CAP_BGR565 | CLCD_CAP_BGR888,
+
+ CLCD_CAP_ALL = CLCD_CAP_BGR | CLCD_CAP_RGB,
+};
+
struct clcd_panel {
struct fb_videomode mode;
signed short width; /* width in mm */
@@ -73,6 +100,7 @@ struct clcd_panel {
u32 tim2;
u32 tim3;
u32 cntl;
+ u32 caps;
unsigned int bpp:8,
fixedtimings:1,
grayscale:1;
@@ -97,6 +125,11 @@ struct clcd_board {
const char *name;
/*
+ * Optional. Hardware capability flags.
+ */
+ u32 caps;
+
+ /*
* Optional. Check whether the var structure is acceptable
* for this display.
*/
@@ -155,34 +188,35 @@ struct clcd_fb {
static inline void clcdfb_decode(struct clcd_fb *fb, struct clcd_regs *regs)
{
+ struct fb_var_screeninfo *var = &fb->fb.var;
u32 val, cpl;
/*
* Program the CLCD controller registers and start the CLCD
*/
- val = ((fb->fb.var.xres / 16) - 1) << 2;
- val |= (fb->fb.var.hsync_len - 1) << 8;
- val |= (fb->fb.var.right_margin - 1) << 16;
- val |= (fb->fb.var.left_margin - 1) << 24;
+ val = ((var->xres / 16) - 1) << 2;
+ val |= (var->hsync_len - 1) << 8;
+ val |= (var->right_margin - 1) << 16;
+ val |= (var->left_margin - 1) << 24;
regs->tim0 = val;
- val = fb->fb.var.yres;
+ val = var->yres;
if (fb->panel->cntl & CNTL_LCDDUAL)
val /= 2;
val -= 1;
- val |= (fb->fb.var.vsync_len - 1) << 10;
- val |= fb->fb.var.lower_margin << 16;
- val |= fb->fb.var.upper_margin << 24;
+ val |= (var->vsync_len - 1) << 10;
+ val |= var->lower_margin << 16;
+ val |= var->upper_margin << 24;
regs->tim1 = val;
val = fb->panel->tim2;
- val |= fb->fb.var.sync & FB_SYNC_HOR_HIGH_ACT ? 0 : TIM2_IHS;
- val |= fb->fb.var.sync & FB_SYNC_VERT_HIGH_ACT ? 0 : TIM2_IVS;
+ val |= var->sync & FB_SYNC_HOR_HIGH_ACT ? 0 : TIM2_IHS;
+ val |= var->sync & FB_SYNC_VERT_HIGH_ACT ? 0 : TIM2_IVS;
- cpl = fb->fb.var.xres_virtual;
+ cpl = var->xres_virtual;
if (fb->panel->cntl & CNTL_LCDTFT) /* TFT */
/* / 1 */;
- else if (!fb->fb.var.grayscale) /* STN color */
+ else if (!var->grayscale) /* STN color */
cpl = cpl * 8 / 3;
else if (fb->panel->cntl & CNTL_LCDMONO8) /* STN monochrome, 8bit */
cpl /= 8;
@@ -194,10 +228,22 @@ static inline void clcdfb_decode(struct clcd_fb *fb, struct clcd_regs *regs)
regs->tim3 = fb->panel->tim3;
val = fb->panel->cntl;
- if (fb->fb.var.grayscale)
+ if (var->grayscale)
val |= CNTL_LCDBW;
- switch (fb->fb.var.bits_per_pixel) {
+ 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
+ */
+ if (var->red.offset == 0)
+ val &= ~CNTL_BGR;
+ else
+ val |= CNTL_BGR;
+ }
+
+ switch (var->bits_per_pixel) {
case 1:
val |= CNTL_LCDBPP1;
break;
@@ -217,10 +263,12 @@ static inline void clcdfb_decode(struct clcd_fb *fb, struct clcd_regs *regs)
* custom external wiring.
*/
if (amba_part(fb->dev) == 0x110 ||
- fb->fb.var.green.length == 5)
+ var->green.length == 5)
val |= CNTL_LCDBPP16;
- else
+ else if (var->green.length == 6)
val |= CNTL_LCDBPP16_565;
+ else
+ val |= CNTL_LCDBPP16_444;
break;
case 32:
val |= CNTL_LCDBPP24;
@@ -228,7 +276,7 @@ static inline void clcdfb_decode(struct clcd_fb *fb, struct clcd_regs *regs)
}
regs->cntl = val;
- regs->pixclock = fb->fb.var.pixclock;
+ regs->pixclock = var->pixclock;
}
static inline int clcdfb_check(struct clcd_fb *fb, struct fb_var_screeninfo *var)
--
1.6.2.5
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