Hello Hannes,
Am 07.03.2014 11:28, schrieb Hannes Petermaier:
Hi Heiko,
Heiko Schocher wrote:
Hello Hannes,
Am 06.03.2014 15:24, schrieb Hannes Petermaier:
On 2014-03-06 14:58, Heiko Schocher wrote:
Hello Hannes,
Am 06.03.2014 14:39, schrieb Hannes Petermaier:
- Adds support for a minimal framebuffer driver of TI's AM335x SoC
to be compatible with Wolfgang Denk's LCD-Framework (CONFIG_LCD, common/lcd.c)
Signed-off-by: Hannes Petermaieroe5hpm@oevsv.at
drivers/video/Makefile | 1 + drivers/video/am335x-fb.c | 169 +++++++++++++++++++++++++++++++++++++++++++++ drivers/video/am335x-fb.h | 67 ++++++++++++++++++ 3 files changed, 237 insertions(+) create mode 100644 drivers/video/am335x-fb.c create mode 100644 drivers/video/am335x-fb.h
Why you cannot use:
u-boot:drivers/video/da8xx-fb.c ?
bye, Heiko
Hi Heiko,
for my opinion this clone of the linux-driver is very overloaded and difficult to use/configure. With the words 'small-is-beautiful' and 'keep-it-simple' i've wrote a few lines which do the minimum:
- configure raster-controller
- setup DMA
- powerON Display
maybe we can use the small-version in other projects too.
Why is it difficult to use/configure the existing driver?
Look for example into the board/siemens/pxm2/board.c board, which uses this driver. You have to define:
static struct da8xx_panel lcd_panels[] static const struct display_panel disp_panel static const struct lcd_ctrl_config lcd_cfg
and call "da8xx_video_init(&lcd_panels[0],&lcd_cfg, lcd_cfg.bpp);"
Thats all ...
i've looked around again for using the da8xx-fb driver and found another detail which motivated me for writing a new instance.
-- par->vram_virt = malloc(par->vram_size);
par->vram_phys = (dma_addr_t) par->vram_virt; debug("Requesting 0x%x bytes for framebuffer at 0x%x\n", (unsigned int)par->vram_size, (unsigned int)par->vram_virt); if (!par->vram_virt) { printf("GLCD: malloc for frame buffer failed\n"); goto err_release_fb; } gd->fb_base = (int)par->vram_virt; --
da8xx-fb.c does allocate a new framebuffer by itself. But in my case lcd-framework allready has reserved memory (on top of ram) for framebuffer usage and i want use this memory from lcd-framework for two reasons:
- don't waste memory
- have this memory really on top of ram to give the following OS (in my
case vxWorks) a pointer where it have to write Video-data.
maybe there are other possibilites to achieve this. any ideas ?
Maybe you can introduce a common function like this? :
void *get_vram(size_t size) { if (gd->fb_base) { if (gd->fb_size == size) return gd->fb_base; printf("fb size does not match\n"); } else { void *ret = malloc(size); if (ret) { gd->fb_base = ret; gd->fb_size = size; } return ret } return NULL; }
(gd->fb_size is a new variable ...)
and use in your driver only:
par->vram_virt = get_vram(par->vram_size);
or, just only check in the driver, if "gd->fb_base" has a value, and if so, do not malloc the vram ...
bye, Heiko