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 Petermaier<oe5...@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
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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