On 04/27/2016 01:21 AM, Martin Pietryka wrote:
To support 16bpp we just need to change the raster_ctrl register accordingly. Also 32bpp mode should work as well, but was not tested. According to the TRM the uppermost byte will be ignored when LCD_TFT_24BPP_UNPACK is set.
The switch logic is based on the Liunx kernel tilcdc driver: drivers/gpu/drm/tilcdc/tilcdc_crtc.c: lines 407 through 419 (kernel was checked out at commit: bcc981e9ed8)
Signed-off-by: Martin Pietryka martin.pietryka@chello.at
drivers/video/am335x-fb.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/drivers/video/am335x-fb.c b/drivers/video/am335x-fb.c index 0ec843f..f2b4c78 100644 --- a/drivers/video/am335x-fb.c +++ b/drivers/video/am335x-fb.c @@ -5,7 +5,7 @@
- minimal framebuffer driver for TI's AM335x SoC to be compatible with
- Wolfgang Denk's LCD-Framework (CONFIG_LCD, common/lcd.c)
- supporting only 24bit RGB/TFT raster Mode (not using palette)
- supporting 16/24/32bit RGB/TFT raster Mode (not using palette)
- sets up LCD controller as in 'am335x_lcdpanel' struct given
- starts output DMA from gd->fb_base buffer
@@ -106,6 +106,8 @@ int lcd_get_size(int *line_length)
int am335xfb_init(struct am335x_lcdpanel *panel) {
- u32 raster_ctrl = 0;
- if (0 == gd->fb_base) { printf("ERROR: no valid fb_base stored in GLOBAL_DATA_PTR!\n"); return -1;
@@ -157,11 +159,26 @@ int am335xfb_init(struct am335x_lcdpanel *panel) LCD_HBPMSB(panel->hbp) | LCD_HFPMSB(panel->hfp) | 0x0000FF00; /* clk cycles for ac-bias */
- lcdhw->raster_ctrl = LCD_TFT_24BPP_MODE |
LCD_TFT_24BPP_UNPACK |LCD_PALMODE_RAWDATA |LCD_TFT_MODE |LCD_RASTER_ENABLE;
- raster_ctrl = LCD_PALMODE_RAWDATA |
LCD_TFT_MODE |LCD_RASTER_ENABLE;- switch (panel->bpp) {
- case 16:
break;- case 32:
raster_ctrl |= LCD_TFT_24BPP_UNPACK;/* fallthrough */- case 24:
raster_ctrl |= LCD_TFT_24BPP_MODE;break;- default:
error("am335x-fb: invalid bpp value: %d\n", panel->bpp);return 1;
please return -1 on error; I would also suggest to put this switch case above the first hw-access or doing anything on lcd, so the controller and display leaves untouched on wrong parameters.
}
lcdhw->raster_ctrl = raster_ctrl;
gd->fb_base += 0x20; /* point fb behind palette */
best regards, Hannes