1/*
  2 * Copyright (C) 2009 Nokia Corporation
  3 * Author: Tomi Valkeinen <tomi.valkeinen@nokia.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
 31static void omapdss_default_get_timings(struct omap_dss_device *dssdev,
 32					struct videomode *vm)
 33{
 34	*vm = dssdev->panel.vm;
 35}
 36
 37static LIST_HEAD(panel_list);
 38static DEFINE_MUTEX(panel_list_mutex);
 39static int disp_num_counter;
 40
 41int 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}
 78EXPORT_SYMBOL(omapdss_register_display);
 79
 80void 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}
 86EXPORT_SYMBOL(omapdss_unregister_display);
 87
 88bool 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	}
100out:
101	mutex_unlock(&panel_list_mutex);
102	return found;
103}
104EXPORT_SYMBOL(omapdss_component_is_display);
105
106struct 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}
118EXPORT_SYMBOL(omap_dss_get_device);
119
120void omap_dss_put_device(struct omap_dss_device *dssdev)
121{
122	put_device(dssdev->dev);
123	module_put(dssdev->owner);
124}
125EXPORT_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 */
131struct 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;
170out:
171	mutex_unlock(&panel_list_mutex);
172	return dssdev;
173}
174EXPORT_SYMBOL(omap_dss_get_next_device);