xref: /openbmc/linux/drivers/video/fbdev/mmp/core.c (revision be709d48)
1 /*
2  * linux/drivers/video/mmp/common.c
3  * This driver is a common framework for Marvell Display Controller
4  *
5  * Copyright (C) 2012 Marvell Technology Group Ltd.
6  * Authors: Zhou Zhu <zzhu3@marvell.com>
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 as published by the
10  * Free Software Foundation; either version 2 of the License, or (at your
11  * option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  *
18  * You should have received a copy of the GNU General Public License along with
19  * this program.  If not, see <http://www.gnu.org/licenses/>.
20  *
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/dma-mapping.h>
25 #include <linux/export.h>
26 #include <linux/module.h>
27 #include <video/mmp_disp.h>
28 
29 static struct mmp_overlay *path_get_overlay(struct mmp_path *path,
30 		int overlay_id)
31 {
32 	if (path && overlay_id < path->overlay_num)
33 		return &path->overlays[overlay_id];
34 	return NULL;
35 }
36 
37 static int path_check_status(struct mmp_path *path)
38 {
39 	int i;
40 	for (i = 0; i < path->overlay_num; i++)
41 		if (path->overlays[i].status)
42 			return 1;
43 
44 	return 0;
45 }
46 
47 /*
48  * Get modelist write pointer of modelist.
49  * It also returns modelist number
50  * this function fetches modelist from phy/panel:
51  *   for HDMI/parallel or dsi to hdmi cases, get from phy
52  *   or get from panel
53  */
54 static int path_get_modelist(struct mmp_path *path,
55 		struct mmp_mode **modelist)
56 {
57 	BUG_ON(!path || !modelist);
58 
59 	if (path->panel && path->panel->get_modelist)
60 		return path->panel->get_modelist(path->panel, modelist);
61 
62 	return 0;
63 }
64 
65 /*
66  * panel list is used to pair panel/path when path/panel registered
67  * path list is used for both buffer driver and platdriver
68  * plat driver do path register/unregister
69  * panel driver do panel register/unregister
70  * buffer driver get registered path
71  */
72 static LIST_HEAD(panel_list);
73 static LIST_HEAD(path_list);
74 static DEFINE_MUTEX(disp_lock);
75 
76 /*
77  * mmp_register_panel - register panel to panel_list and connect to path
78  * @p: panel to be registered
79  *
80  * this function provides interface for panel drivers to register panel
81  * to panel_list and connect to path which matchs panel->plat_path_name.
82  * no error returns when no matching path is found as path register after
83  * panel register is permitted.
84  */
85 void mmp_register_panel(struct mmp_panel *panel)
86 {
87 	struct mmp_path *path;
88 
89 	mutex_lock(&disp_lock);
90 
91 	/* add */
92 	list_add_tail(&panel->node, &panel_list);
93 
94 	/* try to register to path */
95 	list_for_each_entry(path, &path_list, node) {
96 		if (!strcmp(panel->plat_path_name, path->name)) {
97 			dev_info(panel->dev, "connect to path %s\n",
98 				path->name);
99 			path->panel = panel;
100 			break;
101 		}
102 	}
103 
104 	mutex_unlock(&disp_lock);
105 }
106 EXPORT_SYMBOL_GPL(mmp_register_panel);
107 
108 /*
109  * mmp_unregister_panel - unregister panel from panel_list and disconnect
110  * @p: panel to be unregistered
111  *
112  * this function provides interface for panel drivers to unregister panel
113  * from panel_list and disconnect from path.
114  */
115 void mmp_unregister_panel(struct mmp_panel *panel)
116 {
117 	struct mmp_path *path;
118 
119 	mutex_lock(&disp_lock);
120 	list_del(&panel->node);
121 
122 	list_for_each_entry(path, &path_list, node) {
123 		if (path->panel && path->panel == panel) {
124 			dev_info(panel->dev, "disconnect from path %s\n",
125 				path->name);
126 			path->panel = NULL;
127 			break;
128 		}
129 	}
130 	mutex_unlock(&disp_lock);
131 }
132 EXPORT_SYMBOL_GPL(mmp_unregister_panel);
133 
134 /*
135  * mmp_get_path - get path by name
136  * @p: path name
137  *
138  * this function checks path name in path_list and return matching path
139  * return NULL if no matching path
140  */
141 struct mmp_path *mmp_get_path(const char *name)
142 {
143 	struct mmp_path *path;
144 	int found = 0;
145 
146 	mutex_lock(&disp_lock);
147 	list_for_each_entry(path, &path_list, node) {
148 		if (!strcmp(name, path->name)) {
149 			found = 1;
150 			break;
151 		}
152 	}
153 	mutex_unlock(&disp_lock);
154 
155 	return found ? path : NULL;
156 }
157 EXPORT_SYMBOL_GPL(mmp_get_path);
158 
159 /*
160  * mmp_register_path - init and register path by path_info
161  * @p: path info provided by display controller
162  *
163  * this function init by path info and register path to path_list
164  * this function also try to connect path with panel by name
165  */
166 struct mmp_path *mmp_register_path(struct mmp_path_info *info)
167 {
168 	int i;
169 	size_t size;
170 	struct mmp_path *path = NULL;
171 	struct mmp_panel *panel;
172 
173 	size = sizeof(struct mmp_path)
174 		+ sizeof(struct mmp_overlay) * info->overlay_num;
175 	path = kzalloc(size, GFP_KERNEL);
176 	if (!path)
177 		return NULL;
178 
179 	/* path set */
180 	mutex_init(&path->access_ok);
181 	path->dev = info->dev;
182 	path->id = info->id;
183 	path->name = info->name;
184 	path->output_type = info->output_type;
185 	path->overlay_num = info->overlay_num;
186 	path->plat_data = info->plat_data;
187 	path->ops.set_mode = info->set_mode;
188 
189 	mutex_lock(&disp_lock);
190 	/* get panel */
191 	list_for_each_entry(panel, &panel_list, node) {
192 		if (!strcmp(info->name, panel->plat_path_name)) {
193 			dev_info(path->dev, "get panel %s\n", panel->name);
194 			path->panel = panel;
195 			break;
196 		}
197 	}
198 
199 	dev_info(path->dev, "register %s, overlay_num %d\n",
200 			path->name, path->overlay_num);
201 
202 	/* default op set: if already set by driver, never cover it */
203 	if (!path->ops.check_status)
204 		path->ops.check_status = path_check_status;
205 	if (!path->ops.get_overlay)
206 		path->ops.get_overlay = path_get_overlay;
207 	if (!path->ops.get_modelist)
208 		path->ops.get_modelist = path_get_modelist;
209 
210 	/* step3: init overlays */
211 	for (i = 0; i < path->overlay_num; i++) {
212 		path->overlays[i].path = path;
213 		path->overlays[i].id = i;
214 		mutex_init(&path->overlays[i].access_ok);
215 		path->overlays[i].ops = info->overlay_ops;
216 	}
217 
218 	/* add to pathlist */
219 	list_add_tail(&path->node, &path_list);
220 
221 	mutex_unlock(&disp_lock);
222 	return path;
223 }
224 EXPORT_SYMBOL_GPL(mmp_register_path);
225 
226 /*
227  * mmp_unregister_path - unregister and destroy path
228  * @p: path to be destroyed.
229  *
230  * this function registers path and destroys it.
231  */
232 void mmp_unregister_path(struct mmp_path *path)
233 {
234 	int i;
235 
236 	if (!path)
237 		return;
238 
239 	mutex_lock(&disp_lock);
240 	/* del from pathlist */
241 	list_del(&path->node);
242 
243 	/* deinit overlays */
244 	for (i = 0; i < path->overlay_num; i++)
245 		mutex_destroy(&path->overlays[i].access_ok);
246 
247 	mutex_destroy(&path->access_ok);
248 
249 	kfree(path);
250 	mutex_unlock(&disp_lock);
251 }
252 EXPORT_SYMBOL_GPL(mmp_unregister_path);
253 
254 MODULE_AUTHOR("Zhou Zhu <zzhu3@marvell.com>");
255 MODULE_DESCRIPTION("Marvell MMP display framework");
256 MODULE_LICENSE("GPL");
257