sys/dev/drm/drm_edid_load.c

   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
  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 *
  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 */