drivers/gpu/drm/omapdrm/dss/display.c

   1 /*
   2  * linux/drivers/video/omap2/dss/display.c
   3  *
   4  * Copyright (C) 2009 Nokia Corporation
   5  * Author: Tomi Valkeinen <tomi.valkeinen@nokia.com>
   6  *
   7  * Some code and ideas taken from drivers/video/omap/ driver
   8  * by Imre Deak.
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License version 2 as published by
  12  * the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but WITHOUT
  15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17  * more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along with
  20  * this program.  If not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #define DSS_SUBSYS_NAME "DISPLAY"
  24
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/of.h>
  30
  31 #include "omapdss.h"
  32
  33 void omapdss_default_get_timings(struct omap_dss_device *dssdev,
  34                                  struct videomode *vm)
  35 {
  36         *vm = dssdev->panel.vm;
  37 }
  38 EXPORT_SYMBOL(omapdss_default_get_timings);
  39
  40 static LIST_HEAD(panel_list);
  41 static DEFINE_MUTEX(panel_list_mutex);
  42 static int disp_num_counter;
  43
  44 int omapdss_register_display(struct omap_dss_device *dssdev)
  45 {
  46         struct omap_dss_driver *drv = dssdev->driver;
  47         struct list_head *cur;
  48         int id;
  49
  50         /*
  51          * Note: this presumes that all displays either have an DT alias, or
  52          * none has.
  53          */
  54         id = of_alias_get_id(dssdev->dev->of_node, "display");
  55         if (id < 0)
  56                 id = disp_num_counter++;
  57
  58         snprintf(dssdev->alias, sizeof(dssdev->alias), "display%d", id);
  59
  60         /* Use 'label' property for name, if it exists */
  61         of_property_read_string(dssdev->dev->of_node, "label", &dssdev->name);
  62
  63         if (dssdev->name == NULL)
  64                 dssdev->name = dssdev->alias;
  65
  66         if (drv && drv->get_timings == NULL)
  67                 drv->get_timings = omapdss_default_get_timings;
  68
  69         mutex_lock(&panel_list_mutex);
  70         list_for_each(cur, &panel_list) {
  71                 struct omap_dss_device *ldev = list_entry(cur,
  72                                                          struct omap_dss_device,
  73                                                          panel_list);
  74                 if (strcmp(ldev->alias, dssdev->alias) > 0)
  75                         break;
  76         }
  77         list_add_tail(&dssdev->panel_list, cur);
  78         mutex_unlock(&panel_list_mutex);
  79         return 0;
  80 }
  81 EXPORT_SYMBOL(omapdss_register_display);
  82
  83 void omapdss_unregister_display(struct omap_dss_device *dssdev)
  84 {
  85         mutex_lock(&panel_list_mutex);
  86         list_del(&dssdev->panel_list);
  87         mutex_unlock(&panel_list_mutex);
  88 }
  89 EXPORT_SYMBOL(omapdss_unregister_display);
  90
  91 bool omapdss_component_is_display(struct device_node *node)
  92 {
  93         struct omap_dss_device *dssdev;
  94         bool found = false;
  95
  96         mutex_lock(&panel_list_mutex);
  97         list_for_each_entry(dssdev, &panel_list, panel_list) {
  98                 if (dssdev->dev->of_node == node) {
  99                         found = true;
 100                         goto out;
 101                 }
 102         }
 103 out:
 104         mutex_unlock(&panel_list_mutex);
 105         return found;
 106 }
 107 EXPORT_SYMBOL(omapdss_component_is_display);
 108
 109 struct omap_dss_device *omap_dss_get_device(struct omap_dss_device *dssdev)
 110 {
 111         if (!try_module_get(dssdev->owner))
 112                 return NULL;
 113
 114         if (get_device(dssdev->dev) == NULL) {
 115                 module_put(dssdev->owner);
 116                 return NULL;
 117         }
 118
 119         return dssdev;
 120 }
 121 EXPORT_SYMBOL(omap_dss_get_device);
 122
 123 void omap_dss_put_device(struct omap_dss_device *dssdev)
 124 {
 125         put_device(dssdev->dev);
 126         module_put(dssdev->owner);
 127 }
 128 EXPORT_SYMBOL(omap_dss_put_device);
 129
 130 /*
 131  * ref count of the found device is incremented.
 132  * ref count of from-device is decremented.
 133  */
 134 struct omap_dss_device *omap_dss_get_next_device(struct omap_dss_device *from)
 135 {
 136         struct list_head *l;
 137         struct omap_dss_device *dssdev;
 138
 139         mutex_lock(&panel_list_mutex);
 140
 141         if (list_empty(&panel_list)) {
 142                 dssdev = NULL;
 143                 goto out;
 144         }
 145
 146         if (from == NULL) {
 147                 dssdev = list_first_entry(&panel_list, struct omap_dss_device,
 148                                 panel_list);
 149                 omap_dss_get_device(dssdev);
 150                 goto out;
 151         }
 152
 153         omap_dss_put_device(from);
 154
 155         list_for_each(l, &panel_list) {
 156                 dssdev = list_entry(l, struct omap_dss_device, panel_list);
 157                 if (dssdev == from) {
 158                         if (list_is_last(l, &panel_list)) {
 159                                 dssdev = NULL;
 160                                 goto out;
 161                         }
 162
 163                         dssdev = list_entry(l->next, struct omap_dss_device,
 164                                         panel_list);
 165                         omap_dss_get_device(dssdev);
 166                         goto out;
 167                 }
 168         }
 169
 170         WARN(1, "'from' dssdev not found\n");
 171
 172         dssdev = NULL;
 173 out:
 174         mutex_unlock(&panel_list_mutex);
 175         return dssdev;
 176 }
 177 EXPORT_SYMBOL(omap_dss_get_next_device);
 178
 179 struct omap_dss_device *omap_dss_find_device(void *data,
 180                 int (*match)(struct omap_dss_device *dssdev, void *data))
 181 {
 182         struct omap_dss_device *dssdev = NULL;
 183
 184         while ((dssdev = omap_dss_get_next_device(dssdev)) != NULL) {
 185                 if (match(dssdev, data))
 186                         return dssdev;
 187         }
 188
 189         return NULL;
 190 }
 191 EXPORT_SYMBOL(omap_dss_find_device);