xref: /openbmc/linux/drivers/video/fbdev/mmp/core.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * linux/drivers/video/mmp/common.c
4  * This driver is a common framework for Marvell Display Controller
5  *
6  * Copyright (C) 2012 Marvell Technology Group Ltd.
7  * Authors: Zhou Zhu <zzhu3@marvell.com>
8  */
9 
10 #include <linux/slab.h>
11 #include <linux/dma-mapping.h>
12 #include <linux/export.h>
13 #include <linux/module.h>
14 #include <video/mmp_disp.h>
15 
16 static struct mmp_overlay *path_get_overlay(struct mmp_path *path,
17 		int overlay_id)
18 {
19 	if (path && overlay_id < path->overlay_num)
20 		return &path->overlays[overlay_id];
21 	return NULL;
22 }
23 
24 static int path_check_status(struct mmp_path *path)
25 {
26 	int i;
27 	for (i = 0; i < path->overlay_num; i++)
28 		if (path->overlays[i].status)
29 			return 1;
30 
31 	return 0;
32 }
33 
34 /*
35  * Get modelist write pointer of modelist.
36  * It also returns modelist number
37  * this function fetches modelist from phy/panel:
38  *   for HDMI/parallel or dsi to hdmi cases, get from phy
39  *   or get from panel
40  */
41 static int path_get_modelist(struct mmp_path *path,
42 		struct mmp_mode **modelist)
43 {
44 	BUG_ON(!path || !modelist);
45 
46 	if (path->panel && path->panel->get_modelist)
47 		return path->panel->get_modelist(path->panel, modelist);
48 
49 	return 0;
50 }
51 
52 /*
53  * panel list is used to pair panel/path when path/panel registered
54  * path list is used for both buffer driver and platdriver
55  * plat driver do path register/unregister
56  * panel driver do panel register/unregister
57  * buffer driver get registered path
58  */
59 static LIST_HEAD(panel_list);
60 static LIST_HEAD(path_list);
61 static DEFINE_MUTEX(disp_lock);
62 
63 /*
64  * mmp_register_panel - register panel to panel_list and connect to path
65  * @p: panel to be registered
66  *
67  * this function provides interface for panel drivers to register panel
68  * to panel_list and connect to path which matchs panel->plat_path_name.
69  * no error returns when no matching path is found as path register after
70  * panel register is permitted.
71  */
72 void mmp_register_panel(struct mmp_panel *panel)
73 {
74 	struct mmp_path *path;
75 
76 	mutex_lock(&disp_lock);
77 
78 	/* add */
79 	list_add_tail(&panel->node, &panel_list);
80 
81 	/* try to register to path */
82 	list_for_each_entry(path, &path_list, node) {
83 		if (!strcmp(panel->plat_path_name, path->name)) {
84 			dev_info(panel->dev, "connect to path %s\n",
85 				path->name);
86 			path->panel = panel;
87 			break;
88 		}
89 	}
90 
91 	mutex_unlock(&disp_lock);
92 }
93 EXPORT_SYMBOL_GPL(mmp_register_panel);
94 
95 /*
96  * mmp_unregister_panel - unregister panel from panel_list and disconnect
97  * @p: panel to be unregistered
98  *
99  * this function provides interface for panel drivers to unregister panel
100  * from panel_list and disconnect from path.
101  */
102 void mmp_unregister_panel(struct mmp_panel *panel)
103 {
104 	struct mmp_path *path;
105 
106 	mutex_lock(&disp_lock);
107 	list_del(&panel->node);
108 
109 	list_for_each_entry(path, &path_list, node) {
110 		if (path->panel && path->panel == panel) {
111 			dev_info(panel->dev, "disconnect from path %s\n",
112 				path->name);
113 			path->panel = NULL;
114 			break;
115 		}
116 	}
117 	mutex_unlock(&disp_lock);
118 }
119 EXPORT_SYMBOL_GPL(mmp_unregister_panel);
120 
121 /*
122  * mmp_get_path - get path by name
123  * @p: path name
124  *
125  * this function checks path name in path_list and return matching path
126  * return NULL if no matching path
127  */
128 struct mmp_path *mmp_get_path(const char *name)
129 {
130 	struct mmp_path *path;
131 	int found = 0;
132 
133 	mutex_lock(&disp_lock);
134 	list_for_each_entry(path, &path_list, node) {
135 		if (!strcmp(name, path->name)) {
136 			found = 1;
137 			break;
138 		}
139 	}
140 	mutex_unlock(&disp_lock);
141 
142 	return found ? path : NULL;
143 }
144 EXPORT_SYMBOL_GPL(mmp_get_path);
145 
146 /*
147  * mmp_register_path - init and register path by path_info
148  * @p: path info provided by display controller
149  *
150  * this function init by path info and register path to path_list
151  * this function also try to connect path with panel by name
152  */
153 struct mmp_path *mmp_register_path(struct mmp_path_info *info)
154 {
155 	int i;
156 	size_t size;
157 	struct mmp_path *path = NULL;
158 	struct mmp_panel *panel;
159 
160 	size = sizeof(struct mmp_path)
161 		+ sizeof(struct mmp_overlay) * info->overlay_num;
162 	path = kzalloc(size, GFP_KERNEL);
163 	if (!path)
164 		return NULL;
165 
166 	/* path set */
167 	mutex_init(&path->access_ok);
168 	path->dev = info->dev;
169 	path->id = info->id;
170 	path->name = info->name;
171 	path->output_type = info->output_type;
172 	path->overlay_num = info->overlay_num;
173 	path->plat_data = info->plat_data;
174 	path->ops.set_mode = info->set_mode;
175 
176 	mutex_lock(&disp_lock);
177 	/* get panel */
178 	list_for_each_entry(panel, &panel_list, node) {
179 		if (!strcmp(info->name, panel->plat_path_name)) {
180 			dev_info(path->dev, "get panel %s\n", panel->name);
181 			path->panel = panel;
182 			break;
183 		}
184 	}
185 
186 	dev_info(path->dev, "register %s, overlay_num %d\n",
187 			path->name, path->overlay_num);
188 
189 	/* default op set: if already set by driver, never cover it */
190 	if (!path->ops.check_status)
191 		path->ops.check_status = path_check_status;
192 	if (!path->ops.get_overlay)
193 		path->ops.get_overlay = path_get_overlay;
194 	if (!path->ops.get_modelist)
195 		path->ops.get_modelist = path_get_modelist;
196 
197 	/* step3: init overlays */
198 	for (i = 0; i < path->overlay_num; i++) {
199 		path->overlays[i].path = path;
200 		path->overlays[i].id = i;
201 		mutex_init(&path->overlays[i].access_ok);
202 		path->overlays[i].ops = info->overlay_ops;
203 	}
204 
205 	/* add to pathlist */
206 	list_add_tail(&path->node, &path_list);
207 
208 	mutex_unlock(&disp_lock);
209 	return path;
210 }
211 EXPORT_SYMBOL_GPL(mmp_register_path);
212 
213 /*
214  * mmp_unregister_path - unregister and destroy path
215  * @p: path to be destroyed.
216  *
217  * this function registers path and destroys it.
218  */
219 void mmp_unregister_path(struct mmp_path *path)
220 {
221 	int i;
222 
223 	if (!path)
224 		return;
225 
226 	mutex_lock(&disp_lock);
227 	/* del from pathlist */
228 	list_del(&path->node);
229 
230 	/* deinit overlays */
231 	for (i = 0; i < path->overlay_num; i++)
232 		mutex_destroy(&path->overlays[i].access_ok);
233 
234 	mutex_destroy(&path->access_ok);
235 
236 	kfree(path);
237 	mutex_unlock(&disp_lock);
238 }
239 EXPORT_SYMBOL_GPL(mmp_unregister_path);
240 
241 MODULE_AUTHOR("Zhou Zhu <zzhu3@marvell.com>");
242 MODULE_DESCRIPTION("Marvell MMP display framework");
243 MODULE_LICENSE("GPL");
244