1 /*
2  * linux/drivers/video/nvidia/nv_of.c
3  *
4  * Copyright 2004 Antonino A. Daplas <adaplas @pol.net>
5  *
6  * Based on rivafb-i2c.c
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file COPYING in the main directory of this archive
10  * for more details.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/gfp.h>
17 #include <linux/pci.h>
18 #include <linux/fb.h>
19 
20 #include <asm/io.h>
21 
22 #include "nv_type.h"
23 #include "nv_local.h"
24 #include "nv_proto.h"
25 
26 #include "../edid.h"
27 
nvidia_probe_of_connector(struct fb_info * info,int conn,u8 ** out_edid)28 int nvidia_probe_of_connector(struct fb_info *info, int conn, u8 **out_edid)
29 {
30 	struct nvidia_par *par = info->par;
31 	struct device_node *parent, *dp;
32 	const unsigned char *pedid = NULL;
33 	static char *propnames[] = {
34 		"DFP,EDID", "LCD,EDID", "EDID", "EDID1",
35 		"EDID,B", "EDID,A", NULL };
36 	int i;
37 
38 	parent = pci_device_to_OF_node(par->pci_dev);
39 	if (parent == NULL)
40 		return -1;
41 	if (par->twoHeads) {
42 		const char *pname;
43 		int len;
44 
45 		for (dp = NULL;
46 		     (dp = of_get_next_child(parent, dp)) != NULL;) {
47 			pname = of_get_property(dp, "name", NULL);
48 			if (!pname)
49 				continue;
50 			len = strlen(pname);
51 			if ((pname[len-1] == 'A' && conn == 1) ||
52 			    (pname[len-1] == 'B' && conn == 2)) {
53 				for (i = 0; propnames[i] != NULL; ++i) {
54 					pedid = of_get_property(dp,
55 							propnames[i], NULL);
56 					if (pedid != NULL)
57 						break;
58 				}
59 				of_node_put(dp);
60 				break;
61 			}
62 		}
63 	}
64 	if (pedid == NULL) {
65 		for (i = 0; propnames[i] != NULL; ++i) {
66 			pedid = of_get_property(parent, propnames[i], NULL);
67 			if (pedid != NULL)
68 				break;
69 		}
70 	}
71 	if (pedid) {
72 		*out_edid = kmemdup(pedid, EDID_LENGTH, GFP_KERNEL);
73 		if (*out_edid == NULL)
74 			return -1;
75 		printk(KERN_DEBUG "nvidiafb: Found OF EDID for head %d\n", conn);
76 		return 0;
77 	}
78 	return -1;
79 }
80