1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * OMAP Display Subsystem Base
  4 *
  5 * Copyright (C) 2015-2017 Texas Instruments Incorporated - https://www.ti.com/
  6 */
  7
  8#include <linux/kernel.h>
  9#include <linux/list.h>
 10#include <linux/module.h>
 11#include <linux/mutex.h>
 12#include <linux/of.h>
 13#include <linux/of_graph.h>
 14#include <linux/platform_device.h>
 15
 16#include "dss.h"
 17#include "omapdss.h"
 18
 19struct dispc_device *dispc_get_dispc(struct dss_device *dss)
 20{
 21	return dss->dispc;
 22}
 23
 24/* -----------------------------------------------------------------------------
 25 * OMAP DSS Devices Handling
 26 */
 27
 28static LIST_HEAD(omapdss_devices_list);
 29static DEFINE_MUTEX(omapdss_devices_lock);
 30
 31void omapdss_device_register(struct omap_dss_device *dssdev)
 32{
 33	mutex_lock(&omapdss_devices_lock);
 34	list_add_tail(&dssdev->list, &omapdss_devices_list);
 35	mutex_unlock(&omapdss_devices_lock);
 36}
 37
 38void omapdss_device_unregister(struct omap_dss_device *dssdev)
 39{
 40	mutex_lock(&omapdss_devices_lock);
 41	list_del(&dssdev->list);
 42	mutex_unlock(&omapdss_devices_lock);
 43}
 44
 45static bool omapdss_device_is_registered(struct device_node *node)
 46{
 47	struct omap_dss_device *dssdev;
 48	bool found = false;
 49
 50	mutex_lock(&omapdss_devices_lock);
 51
 52	list_for_each_entry(dssdev, &omapdss_devices_list, list) {
 53		if (dssdev->dev->of_node == node) {
 54			found = true;
 55			break;
 56		}
 57	}
 58
 59	mutex_unlock(&omapdss_devices_lock);
 60	return found;
 61}
 62
 63struct omap_dss_device *omapdss_device_get(struct omap_dss_device *dssdev)
 64{
 65	if (get_device(dssdev->dev) == NULL)
 66		return NULL;
 67
 68	return dssdev;
 69}
 70
 71void omapdss_device_put(struct omap_dss_device *dssdev)
 72{
 73	put_device(dssdev->dev);
 74}
 75
 76struct omap_dss_device *omapdss_find_device_by_node(struct device_node *node)
 77{
 78	struct omap_dss_device *dssdev;
 79
 80	list_for_each_entry(dssdev, &omapdss_devices_list, list) {
 81		if (dssdev->dev->of_node == node)
 82			return omapdss_device_get(dssdev);
 83	}
 84
 85	return NULL;
 86}
 87
 88/*
 89 * Search for the next output device starting at @from. Release the reference to
 90 * the @from device, and acquire a reference to the returned device if found.
 91 */
 92struct omap_dss_device *omapdss_device_next_output(struct omap_dss_device *from)
 93{
 94	struct omap_dss_device *dssdev;
 95	struct list_head *list;
 96
 97	mutex_lock(&omapdss_devices_lock);
 98
 99	if (list_empty(&omapdss_devices_list)) {
100		dssdev = NULL;
101		goto done;
102	}
103
104	/*
105	 * Start from the from entry if given or from omapdss_devices_list
106	 * otherwise.
107	 */
108	list = from ? &from->list : &omapdss_devices_list;
109
110	list_for_each_entry(dssdev, list, list) {
111		/*
112		 * Stop if we reach the omapdss_devices_list, that's the end of
113		 * the list.
114		 */
115		if (&dssdev->list == &omapdss_devices_list) {
116			dssdev = NULL;
117			goto done;
118		}
119
120		if (dssdev->id && dssdev->bridge)
121			goto done;
122	}
123
124	dssdev = NULL;
125
126done:
127	if (from)
128		omapdss_device_put(from);
129	if (dssdev)
130		omapdss_device_get(dssdev);
131
132	mutex_unlock(&omapdss_devices_lock);
133	return dssdev;
134}
135
136static bool omapdss_device_is_connected(struct omap_dss_device *dssdev)
137{
138	return dssdev->dss;
139}
140
141int omapdss_device_connect(struct dss_device *dss,
142			   struct omap_dss_device *dst)
143{
144	dev_dbg(&dss->pdev->dev, "connect(%s)\n",
145		dst ? dev_name(dst->dev) : "NULL");
146
147	if (!dst)
148		return -EINVAL;
149
150	if (omapdss_device_is_connected(dst))
151		return -EBUSY;
152
153	dst->dss = dss;
154
155	return 0;
156}
157
158void omapdss_device_disconnect(struct dss_device *dss,
159			       struct omap_dss_device *dst)
160{
161	dev_dbg(&dss->pdev->dev, "disconnect(%s)\n",
162		dst ? dev_name(dst->dev) : "NULL");
163
164	if (WARN_ON(!dst))
165		return;
166
167	if (!dst->id && !omapdss_device_is_connected(dst)) {
168		WARN_ON(1);
169		return;
170	}
171
172	dst->dss = NULL;
173}
174
175/* -----------------------------------------------------------------------------
176 * Components Handling
177 */
178
179static struct list_head omapdss_comp_list;
180
181struct omapdss_comp_node {
182	struct list_head list;
183	struct device_node *node;
184	bool dss_core_component;
185	const char *compat;
186};
187
188static bool omapdss_list_contains(const struct device_node *node)
189{
190	struct omapdss_comp_node *comp;
191
192	list_for_each_entry(comp, &omapdss_comp_list, list) {
193		if (comp->node == node)
194			return true;
195	}
196
197	return false;
198}
199
200static void omapdss_walk_device(struct device *dev, struct device_node *node,
201				bool dss_core)
202{
203	struct omapdss_comp_node *comp;
204	struct device_node *n;
205	const char *compat;
206	int ret;
207
208	ret = of_property_read_string(node, "compatible", &compat);
209	if (ret < 0)
210		return;
211
212	comp = devm_kzalloc(dev, sizeof(*comp), GFP_KERNEL);
213	if (comp) {
214		comp->node = node;
215		comp->dss_core_component = dss_core;
216		comp->compat = compat;
217		list_add(&comp->list, &omapdss_comp_list);
218	}
219
220	/*
221	 * of_graph_get_remote_port_parent() prints an error if there is no
222	 * port/ports node. To avoid that, check first that there's the node.
223	 */
224	n = of_get_child_by_name(node, "ports");
225	if (!n)
226		n = of_get_child_by_name(node, "port");
227	if (!n)
228		return;
229
230	of_node_put(n);
231
232	for_each_endpoint_of_node(node, n) {
233		struct device_node *pn = of_graph_get_remote_port_parent(n);
234
235		if (!pn)
236			continue;
237
238		if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
239			of_node_put(pn);
240			continue;
241		}
242
243		omapdss_walk_device(dev, pn, false);
244	}
245}
246
247void omapdss_gather_components(struct device *dev)
248{
249	struct device_node *child;
250
251	INIT_LIST_HEAD(&omapdss_comp_list);
252
253	omapdss_walk_device(dev, dev->of_node, true);
254
255	for_each_available_child_of_node(dev->of_node, child)
256		omapdss_walk_device(dev, child, true);
257}
258
259static bool omapdss_component_is_loaded(struct omapdss_comp_node *comp)
260{
261	if (comp->dss_core_component)
262		return true;
263	if (!strstarts(comp->compat, "omapdss,"))
264		return true;
265	if (omapdss_device_is_registered(comp->node))
266		return true;
267
268	return false;
269}
270
271bool omapdss_stack_is_ready(void)
272{
273	struct omapdss_comp_node *comp;
274
275	list_for_each_entry(comp, &omapdss_comp_list, list) {
276		if (!omapdss_component_is_loaded(comp))
277			return false;
278	}
279
280	return true;
281}