intel_ddi.c

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/* SPDX-License-Identifier: MIT */
 
#include <types.h>
#include <console/console.h>
#include <drivers/intel/gma/i915.h>
 
/* HDMI/DVI modes ignore everything but the last 2 items. So we share
 * them for both DP and FDI transports, allowing those ports to
 * automatically adapt to HDMI connections as well.
 */
static  u32 hsw_ddi_translations_dp[] = {
        0x00FFFFFF, 0x0006000E,         /* DP parameters */
        0x00D75FFF, 0x0005000A,
        0x00C30FFF, 0x00040006,
        0x80AAAFFF, 0x000B0000,
        0x00FFFFFF, 0x0005000A,
        0x00D75FFF, 0x000C0004,
        0x80C30FFF, 0x000B0000,
        0x00FFFFFF, 0x00040006,
        0x80D75FFF, 0x000B0000,
        0x00FFFFFF, 0x00040006          /* HDMI parameters */
};
 
static  u32 hsw_ddi_translations_fdi[] = {
        0x00FFFFFF, 0x0007000E,         /* FDI parameters */
        0x00D75FFF, 0x000F000A,
        0x00C30FFF, 0x00060006,
        0x00AAAFFF, 0x001E0000,
        0x00FFFFFF, 0x000F000A,
        0x00D75FFF, 0x00160004,
        0x00C30FFF, 0x001E0000,
        0x00FFFFFF, 0x00060006,
        0x00D75FFF, 0x001E0000,
        0x00FFFFFF, 0x00040006          /* HDMI parameters */
};
 
/* On Haswell, DDI port buffers must be programmed with correct values
 * in advance. The buffer values are different for FDI and DP modes,
 * but the HDMI/DVI fields are shared among those. So we program the DDI
 * in either FDI or DP modes only, as HDMI connections will work with both
 * of those.
 */
static void intel_prepare_ddi_buffers(int port, int use_fdi_mode)
{
        u32 reg;
        int i;
        u32 *ddi_translations = ((use_fdi_mode) ?
                                 hsw_ddi_translations_fdi :
                                 hsw_ddi_translations_dp);
 
        printk(BIOS_SPEW,  "Initializing DDI buffers for port %d in %s mode\n",
               port,
               use_fdi_mode ? "FDI" : "DP");
 
        for (i=0,reg=DDI_BUF_TRANS(port);i < ARRAY_SIZE(hsw_ddi_translations_fdi);i++) {
                gtt_write(reg,ddi_translations[i]);
                reg += 4;
        }
}
 
void intel_prepare_ddi(void)
{
        int port;
        u32 use_fdi = 1;
 
        for (port = PORT_A; port < PORT_E; port++)
                intel_prepare_ddi_buffers(port, !use_fdi);
 
        intel_prepare_ddi_buffers(PORT_E, use_fdi);
}