xref: /aosp_15_r20/external/coreboot/src/drivers/intel/gma/intel_ddi.c (revision b9411a12aaaa7e1e6a6fb7c5e057f44ee179a49c)
1 /* SPDX-License-Identifier: MIT */
2 
3 #include <types.h>
4 #include <console/console.h>
5 #include <drivers/intel/gma/i915.h>
6 
7 /* HDMI/DVI modes ignore everything but the last 2 items. So we share
8  * them for both DP and FDI transports, allowing those ports to
9  * automatically adapt to HDMI connections as well.
10  */
11 static  u32 hsw_ddi_translations_dp[] = {
12 	0x00FFFFFF, 0x0006000E,		/* DP parameters */
13 	0x00D75FFF, 0x0005000A,
14 	0x00C30FFF, 0x00040006,
15 	0x80AAAFFF, 0x000B0000,
16 	0x00FFFFFF, 0x0005000A,
17 	0x00D75FFF, 0x000C0004,
18 	0x80C30FFF, 0x000B0000,
19 	0x00FFFFFF, 0x00040006,
20 	0x80D75FFF, 0x000B0000,
21 	0x00FFFFFF, 0x00040006		/* HDMI parameters */
22 };
23 
24 static  u32 hsw_ddi_translations_fdi[] = {
25 	0x00FFFFFF, 0x0007000E,		/* FDI parameters */
26 	0x00D75FFF, 0x000F000A,
27 	0x00C30FFF, 0x00060006,
28 	0x00AAAFFF, 0x001E0000,
29 	0x00FFFFFF, 0x000F000A,
30 	0x00D75FFF, 0x00160004,
31 	0x00C30FFF, 0x001E0000,
32 	0x00FFFFFF, 0x00060006,
33 	0x00D75FFF, 0x001E0000,
34 	0x00FFFFFF, 0x00040006		/* HDMI parameters */
35 };
36 
37 /* On Haswell, DDI port buffers must be programmed with correct values
38  * in advance. The buffer values are different for FDI and DP modes,
39  * but the HDMI/DVI fields are shared among those. So we program the DDI
40  * in either FDI or DP modes only, as HDMI connections will work with both
41  * of those.
42  */
intel_prepare_ddi_buffers(int port,int use_fdi_mode)43 static void intel_prepare_ddi_buffers(int port, int use_fdi_mode)
44 {
45 	u32 reg;
46 	int i;
47 	u32 *ddi_translations = ((use_fdi_mode) ?
48 				 hsw_ddi_translations_fdi :
49 				 hsw_ddi_translations_dp);
50 
51 	printk(BIOS_SPEW, "Initializing DDI buffers for port %d in %s mode\n",
52 	       port,
53 	       use_fdi_mode ? "FDI" : "DP");
54 
55 	for (i=0,reg=DDI_BUF_TRANS(port);i < ARRAY_SIZE(hsw_ddi_translations_fdi);i++) {
56 		gtt_write(reg,ddi_translations[i]);
57 		reg += 4;
58 	}
59 }
60 
intel_prepare_ddi(void)61 void intel_prepare_ddi(void)
62 {
63 	int port;
64 	u32 use_fdi = 1;
65 
66 	for (port = PORT_A; port < PORT_E; port++)
67 		intel_prepare_ddi_buffers(port, !use_fdi);
68 
69 	intel_prepare_ddi_buffers(PORT_E, use_fdi);
70 }
71