Ways to enable and drive Dual Display independently!!

Hello Viks,

There are some tutorials for displays on omappedia and processors wiki:

http://omappedia.org/wiki/Bootargs_for_enabling_display

http://omappedia.org/wiki/Display_Drivers_Domain_Wiki

http://processors.wiki.ti.com/index.php/UserGuideDisplayDrivers_PSP_04.02.00.07

Hope this helps.

Best Regards,

Yordan

Hi Yordan,

Thanks for the reply. I have gone through the links you mentioned and yes it helped in understanding OMAP DSS. However it is based on OMAP3 and OMAP4 not OMAP5. Also I think it is based on omapfb driver. Does all the information remains valid for OMAP5 with omapdrm driver?

I am using custom board based on OMAP5432evm and wants to connect a display on DPI interface. What all things I need to change to add support for DPI interface? or Enabling the DPI support and generic DPI panel in kernel config will make it working? My omap_dss_device structure lists only one device (i.e. hdmi_device @ arch/arm/mach-omap2/board-omap5.c)

Thanks once again.

Regards,
Vikash

Hi,

I am referring to the configurations in GLP1.6.8 source files and OMAP5 uEVM board.

Here the default omap_dss device structure lists  &omap5evm_lcd_device and &omap5evm_hdmi_device connected for dsi and hdmi interface respectively.

In order to make your DPI interface work you need to:

Enable DPI panel in kernel config.

Add your dpi interface in the omap_dss_device structure (you should have a generic dpi driver in your sources).

Add a structure for your dpi interface, which holds its parameters, something like:

struct omap_dss_device omap4_panda_dvi_device = {
    .type            = OMAP_DISPLAY_TYPE_DPI,
    .name            = "dvi",
    .driver_name        = "tfp410",
    .data            = &omap4_dvi_panel,
    .phy.dpi.data_lines    = 24,
    .reset_gpio        = PANDA_DVI_TFP410_POWER_DOWN_GPIO,
    .channel        = OMAP_DSS_CHANNEL_LCD2,
    .clocks.fck_div        = 9,
    .clocks.dispc.channel.lcd_clk_src = OMAP_DSS_CLK_SRC_DSI2_PLL_HSDIV_DISPC,
    .clocks.dispc.dispc_fclk_src = OMAP_DSS_CLK_SRC_DSI2_PLL_HSDIV_DISPC,
};

Regards,

Yordan

Thanks Yordan.

From where can I get GLP1.6.8 release source?

Thanks & Regards,

Vikash

Hi Vikash,

I was using the release as a reference, it is not the latest linux supporting OMAP5. Here is what is available for OMAP5:

http://processors.wiki.ti.com/index.php/OMAP5_GLSDK_Software_Developers_Guide

http://software-dl.ti.com/dsps/dsps_public_sw/glsdk/latest/index_FDS.html

Best Regards,

Yordan

Hi Yordan,

Thanks for the reply.
I want to use LCD channel with DPI interface. I want to use panel-generic-dpi.c driver from video/omap2/displays. For this I have added the following structure and code to my board-omap5evm.c and also set this to the default DSS device. Does this looks the sufficient code or I am missing something?

static void omap5evm_lcd_init(void)
{
    pr_info("omap5evm_lcd_init\n");
}

static int omap5evm_panel_enable_lcd(struct omap_dss_device *dssdev)
{
    pr_info("omap5evm_panel_enable_lcd\n");
    return 0;
}

static void omap5evm_panel_disable_lcd(struct omap_dss_device *dssdev)
{
    pr_info("omap5evm_panel_disable_lcd\n");

}

static struct panel_generic_dpi_data omap5evm_dpi_data = {
    .name = "generic_dpi_panel",
    .platform_enable  = omap5evm_panel_enable_lcd,
    .platform_disable = omap5evm_panel_disable_lcd,
};

static struct omap_dss_device omap5evm_lcd_device = {
    .name = "lcd",
    .driver_name = "generic_dpi_panel",
    .type = OMAP_DISPLAY_TYPE_DPI,
    .channel = OMAP_DSS_CHANNEL_LCD,
    .data = &omap5evm_dpi_data,
};


static struct omap_dss_device *omap5evm_dss_devices[] = {
    &omap5evm_hdmi_device,
    &omap5evm_lcd_device,
};

Thanks & Regards,

Viks

Hi,

I am getting following errror on kernel boot. Does DPI LCD panel needs to be connected ? or later we can connect once generic_dpi_driver initialized?

[    1.478393] omapdss CORE error: driver probe failed: -22
[    1.483978] generic_dpi_panel: probe of display0 failed with error -22

Thanks & Regards,

Viks

Hi,

I am getting following error on kernel boot. Does DPI LCD panel needs to be connected ? or later we can connect once generic_dpi_driver initialized?

[    1.478393] omapdss CORE error: driver probe failed: -22
[    1.483978] generic_dpi_panel: probe of display0 failed with error -22

Thanks & Regards,

Viks