1 /*
2 * Copyright (c) 2015 Rimvydas Jasinskas
3 *
4 * Simple EDID firmware handling routines derived from
5 * drm_edid.c:drm_do_get_edid()
6 *
7 * Copyright (c) 2007-2008 Intel Corporation
8 * Jesse Barnes <jesse.barnes@intel.com>
9 * Copyright 2010 Red Hat, Inc.
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a
12 * copy of this software and associated documentation files (the "Software"),
13 * to deal in the Software without restriction, including without limitation
14 * the rights to use, copy, modify, merge, publish, distribute, sub license,
15 * and/or sell copies of the Software, and to permit persons to whom the
16 * Software is furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice (including the
19 * next paragraph) shall be included in all copies or substantial portions
20 * of the Software.
21 *
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
25 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
28 * DEALINGS IN THE SOFTWARE.
29 */
30
31 #include <drm/drmP.h>
32 #include <drm/drm_edid.h>
33 #include <sys/bus.h>
34 #include <sys/firmware.h>
35
36 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
37 static u8 *do_edid_fw_load(struct drm_connector *connector, const char *fwname,
38 const char *connector_name);
39
40 static char edidfw_tun[256];
41 TUNABLE_STR("drm.edid_firmware", edidfw_tun, sizeof(edidfw_tun));
42
drm_load_edid_firmware(struct drm_connector * connector)43 struct edid *drm_load_edid_firmware(struct drm_connector *connector)
44 {
45 const char *connector_name = connector->name;
46 char *cp, *fwname = edidfw_tun;
47 struct edid *fwedid;
48
49 if (*fwname == '\0')
50 return ERR_PTR(-ENOENT);
51
52 /* Check for connector specifier presence */
53 if ((cp = strchr(fwname, ':')) != NULL) {
54 /* if connector name doesn't match, we're done */
55 if (strncmp(connector_name, fwname, cp - fwname))
56 return ERR_PTR(-ENOENT);
57 fwname = cp + 1;
58 if (*fwname == '\0')
59 return ERR_PTR(-ENOENT);
60 }
61
62 fwedid = (struct edid *)do_edid_fw_load(connector, fwname, connector_name);
63
64 return fwedid;
65 }
66
67 static u8 *
do_edid_fw_load(struct drm_connector * connector,const char * fwname,const char * connector_name)68 do_edid_fw_load(struct drm_connector *connector, const char *fwname,
69 const char *connector_name)
70 {
71 const struct firmware *fw = NULL;
72 const u8 *fwdata;
73 u8 *block = NULL, *new = NULL;
74 int fwsize, expected;
75 int j, valid_extensions = 0;
76 bool print_bad_edid = !connector->bad_edid_counter || (drm_debug & DRM_UT_KMS);
77
78 fw = firmware_get(fwname);
79
80 if (fw == NULL) {
81 DRM_ERROR("Requesting EDID firmware %s failed\n", fwname);
82 return (NULL);
83 }
84
85 fwdata = fw->data;
86 fwsize = fw->datasize;
87
88 if (fwsize < EDID_LENGTH)
89 goto fw_out;
90
91 expected = (fwdata[0x7e] + 1) * EDID_LENGTH;
92 if (expected != fwsize) {
93 DRM_ERROR("Size of EDID firmware %s is invalid: %d vs %d(got)\n",
94 fwname, expected, fwsize);
95 goto fw_out;
96 }
97
98 block = kmalloc(fwsize, M_DRM, GFP_KERNEL);
99 if (block == NULL) {
100 goto fw_out;
101 }
102 memcpy(block, fwdata, fwsize);
103
104 /* now it is safe to release the firmware */
105 fw_out:
106 fwdata = NULL;
107 if (fw != NULL) {
108 /*
109 * Don't release edid fw right away, useful if / is
110 * still not mounted and/or we performing early kms
111 */
112 firmware_put(fw, 0);
113 }
114
115 if (block == NULL)
116 return (NULL);
117
118 /* first check the base block */
119 if (!drm_edid_block_valid(block, 0, print_bad_edid, NULL)) {
120 connector->bad_edid_counter++;
121 DRM_ERROR("EDID firmware %s base block is invalid ", fwname);
122 goto out;
123 }
124
125 DRM_INFO("Got EDID base block from %s for connector %s\n", fwname, connector_name);
126
127 /* if there's no extensions, we're done */
128 if (block[0x7e] == 0)
129 return block;
130
131 /* XXX then extension blocks */
132 WARN(1, "Loading EDID firmware with extensions is untested!\n");
133
134 for (j = 1; j <= block[0x7e]; j++) {
135 /* if we skiped any extension block we have to shuffle good ones */
136 if (j != valid_extensions + 1) {
137 memcpy(block + (valid_extensions + 1) * EDID_LENGTH,
138 block + (j * EDID_LENGTH), EDID_LENGTH);
139 }
140 if (drm_edid_block_valid(block + j * EDID_LENGTH, j, print_bad_edid, NULL)) {
141 valid_extensions++;
142 }
143 }
144
145 if (valid_extensions != block[0x7e]) {
146 block[EDID_LENGTH-1] += block[0x7e] - valid_extensions;
147 block[0x7e] = valid_extensions;
148 new = krealloc(block, (valid_extensions + 1) * EDID_LENGTH, M_DRM, M_WAITOK);
149 if (new == NULL)
150 goto out;
151 block = new;
152 }
153
154 if (valid_extensions > 0) {
155 DRM_INFO("Got %d extensions in EDID firmware from %s for connector %s\n",
156 valid_extensions, fwname, connector_name);
157 }
158
159 /* if got to here return edid block */
160 return block;
161
162 out:
163 kfree(block);
164 return (NULL);
165 }
166
167 #endif /* CONFIG_DRM_LOAD_EDID_FIRMWARE */
168