LXR linux/drivers/video/via/via_aux

   1/*
   2 * Copyright 2011 Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public
   6 * License as published by the Free Software Foundation;
   7 * either version 2, or (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTIES OR REPRESENTATIONS; without even
  11 * the implied warranty of MERCHANTABILITY or FITNESS FOR
  12 * A PARTICULAR PURPOSE.See the GNU General Public License
  13 * for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc.,
  18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 */
  20/*
  21 * generic EDID driver
  22 */
  23
  24#include <linux/slab.h>
  25#include <linux/fb.h>
  26#include "via_aux.h"
  27#include "../edid.h"
  28
  29
  30static const char *name = "EDID";
  31
  32
  33static void query_edid(struct via_aux_drv *drv)
  34{
  35        struct fb_monspecs *spec = drv->data;
  36        unsigned char edid[EDID_LENGTH];
  37        bool valid = false;
  38
  39        if (spec) {
  40                fb_destroy_modedb(spec->modedb);
  41        } else {
  42                spec = kmalloc(sizeof(*spec), GFP_KERNEL);
  43                if (!spec)
  44                        return;
  45        }
  46
  47        spec->version = spec->revision = 0;
  48        if (via_aux_read(drv, 0x00, edid, EDID_LENGTH)) {
  49                fb_edid_to_monspecs(edid, spec);
  50                valid = spec->version || spec->revision;
  51        }
  52
  53        if (!valid) {
  54                kfree(spec);
  55                spec = NULL;
  56        } else
  57                printk(KERN_DEBUG "EDID: %s %s\n", spec->manufacturer, spec->monitor);
  58
  59        drv->data = spec;
  60}
  61
  62static const struct fb_videomode *get_preferred_mode(struct via_aux_drv *drv)
  63{
  64        struct fb_monspecs *spec = drv->data;
  65        int i;
  66
  67        if (!spec || !spec->modedb || !(spec->misc & FB_MISC_1ST_DETAIL))
  68                return NULL;
  69
  70        for (i = 0; i < spec->modedb_len; i++) {
  71                if (spec->modedb[i].flag & FB_MODE_IS_FIRST &&
  72                        spec->modedb[i].flag & FB_MODE_IS_DETAILED)
  73                        return &spec->modedb[i];
  74        }
  75
  76        return NULL;
  77}
  78
  79static void cleanup(struct via_aux_drv *drv)
  80{
  81        struct fb_monspecs *spec = drv->data;
  82
  83        if (spec)
  84                fb_destroy_modedb(spec->modedb);
  85}
  86
  87void via_aux_edid_probe(struct via_aux_bus *bus)
  88{
  89        struct via_aux_drv drv = {
  90                .bus    =       bus,
  91                .addr   =       0x50,
  92                .name   =       name,
  93                .cleanup        =       cleanup,
  94                .get_preferred_mode     =       get_preferred_mode};
  95
  96        query_edid(&drv);
  97
  98        /* as EDID devices can be connected/disconnected just add the driver */
  99        via_aux_add(&drv);
 100}
 101