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

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