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1 | /* | |
2 | * OF helpers for parsing display timings | |
3 | * | |
4 | * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix | |
5 | * | |
6 | * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de> | |
7 | * | |
8 | * This file is released under the GPLv2 | |
9 | */ | |
10 | #include <linux/export.h> | |
11 | #include <linux/of.h> | |
12 | #include <linux/slab.h> | |
13 | #include <video/display_timing.h> | |
14 | #include <video/of_display_timing.h> | |
15 | ||
16 | /** | |
17 | * parse_timing_property - parse timing_entry from device_node | |
18 | * @np: device_node with the property | |
19 | * @name: name of the property | |
20 | * @result: will be set to the return value | |
21 | * | |
22 | * DESCRIPTION: | |
23 | * Every display_timing can be specified with either just the typical value or | |
24 | * a range consisting of min/typ/max. This function helps handling this | |
25 | **/ | |
26 | static int parse_timing_property(const struct device_node *np, const char *name, | |
27 | struct timing_entry *result) | |
28 | { | |
29 | struct property *prop; | |
30 | int length, cells, ret; | |
31 | ||
32 | prop = of_find_property(np, name, &length); | |
33 | if (!prop) { | |
34 | pr_err("%s: could not find property %s\n", | |
35 | of_node_full_name(np), name); | |
36 | return -EINVAL; | |
37 | } | |
38 | ||
39 | cells = length / sizeof(u32); | |
40 | if (cells == 1) { | |
41 | ret = of_property_read_u32(np, name, &result->typ); | |
42 | result->min = result->typ; | |
43 | result->max = result->typ; | |
44 | } else if (cells == 3) { | |
45 | ret = of_property_read_u32_array(np, name, &result->min, cells); | |
46 | } else { | |
47 | pr_err("%s: illegal timing specification in %s\n", | |
48 | of_node_full_name(np), name); | |
49 | return -EINVAL; | |
50 | } | |
51 | ||
52 | return ret; | |
53 | } | |
54 | ||
55 | /** | |
56 | * of_parse_display_timing - parse display_timing entry from device_node | |
57 | * @np: device_node with the properties | |
58 | **/ | |
59 | static int of_parse_display_timing(const struct device_node *np, | |
60 | struct display_timing *dt) | |
61 | { | |
62 | u32 val = 0; | |
63 | int ret = 0; | |
64 | ||
65 | memset(dt, 0, sizeof(*dt)); | |
66 | ||
67 | ret |= parse_timing_property(np, "hback-porch", &dt->hback_porch); | |
68 | ret |= parse_timing_property(np, "hfront-porch", &dt->hfront_porch); | |
69 | ret |= parse_timing_property(np, "hactive", &dt->hactive); | |
70 | ret |= parse_timing_property(np, "hsync-len", &dt->hsync_len); | |
71 | ret |= parse_timing_property(np, "vback-porch", &dt->vback_porch); | |
72 | ret |= parse_timing_property(np, "vfront-porch", &dt->vfront_porch); | |
73 | ret |= parse_timing_property(np, "vactive", &dt->vactive); | |
74 | ret |= parse_timing_property(np, "vsync-len", &dt->vsync_len); | |
75 | ret |= parse_timing_property(np, "clock-frequency", &dt->pixelclock); | |
76 | ||
77 | dt->flags = 0; | |
78 | if (!of_property_read_u32(np, "vsync-active", &val)) | |
79 | dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH : | |
80 | DISPLAY_FLAGS_VSYNC_LOW; | |
81 | if (!of_property_read_u32(np, "hsync-active", &val)) | |
82 | dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH : | |
83 | DISPLAY_FLAGS_HSYNC_LOW; | |
84 | if (!of_property_read_u32(np, "de-active", &val)) | |
85 | dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH : | |
86 | DISPLAY_FLAGS_DE_LOW; | |
87 | if (!of_property_read_u32(np, "pixelclk-active", &val)) | |
88 | dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE : | |
89 | DISPLAY_FLAGS_PIXDATA_NEGEDGE; | |
90 | ||
91 | if (!of_property_read_u32(np, "syncclk-active", &val)) | |
92 | dt->flags |= val ? DISPLAY_FLAGS_SYNC_POSEDGE : | |
93 | DISPLAY_FLAGS_SYNC_NEGEDGE; | |
94 | else if (dt->flags & (DISPLAY_FLAGS_PIXDATA_POSEDGE | | |
95 | DISPLAY_FLAGS_PIXDATA_NEGEDGE)) | |
96 | dt->flags |= dt->flags & DISPLAY_FLAGS_PIXDATA_POSEDGE ? | |
97 | DISPLAY_FLAGS_SYNC_POSEDGE : | |
98 | DISPLAY_FLAGS_SYNC_NEGEDGE; | |
99 | ||
100 | if (of_property_read_bool(np, "interlaced")) | |
101 | dt->flags |= DISPLAY_FLAGS_INTERLACED; | |
102 | if (of_property_read_bool(np, "doublescan")) | |
103 | dt->flags |= DISPLAY_FLAGS_DOUBLESCAN; | |
104 | if (of_property_read_bool(np, "doubleclk")) | |
105 | dt->flags |= DISPLAY_FLAGS_DOUBLECLK; | |
106 | ||
107 | if (ret) { | |
108 | pr_err("%s: error reading timing properties\n", | |
109 | of_node_full_name(np)); | |
110 | return -EINVAL; | |
111 | } | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | /** | |
117 | * of_get_display_timing - parse a display_timing entry | |
118 | * @np: device_node with the timing subnode | |
119 | * @name: name of the timing node | |
120 | * @dt: display_timing struct to fill | |
121 | **/ | |
122 | int of_get_display_timing(const struct device_node *np, const char *name, | |
123 | struct display_timing *dt) | |
124 | { | |
125 | struct device_node *timing_np; | |
126 | ||
127 | if (!np) | |
128 | return -EINVAL; | |
129 | ||
130 | timing_np = of_get_child_by_name(np, name); | |
131 | if (!timing_np) { | |
132 | pr_err("%s: could not find node '%s'\n", | |
133 | of_node_full_name(np), name); | |
134 | return -ENOENT; | |
135 | } | |
136 | ||
137 | return of_parse_display_timing(timing_np, dt); | |
138 | } | |
139 | EXPORT_SYMBOL_GPL(of_get_display_timing); | |
140 | ||
141 | /** | |
142 | * of_get_display_timings - parse all display_timing entries from a device_node | |
143 | * @np: device_node with the subnodes | |
144 | **/ | |
145 | struct display_timings *of_get_display_timings(const struct device_node *np) | |
146 | { | |
147 | struct device_node *timings_np; | |
148 | struct device_node *entry; | |
149 | struct device_node *native_mode; | |
150 | struct display_timings *disp; | |
151 | ||
152 | if (!np) | |
153 | return NULL; | |
154 | ||
155 | timings_np = of_get_child_by_name(np, "display-timings"); | |
156 | if (!timings_np) { | |
157 | pr_err("%s: could not find display-timings node\n", | |
158 | of_node_full_name(np)); | |
159 | return NULL; | |
160 | } | |
161 | ||
162 | disp = kzalloc(sizeof(*disp), GFP_KERNEL); | |
163 | if (!disp) { | |
164 | pr_err("%s: could not allocate struct disp'\n", | |
165 | of_node_full_name(np)); | |
166 | goto dispfail; | |
167 | } | |
168 | ||
169 | entry = of_parse_phandle(timings_np, "native-mode", 0); | |
170 | /* assume first child as native mode if none provided */ | |
171 | if (!entry) | |
172 | entry = of_get_next_child(timings_np, NULL); | |
173 | /* if there is no child, it is useless to go on */ | |
174 | if (!entry) { | |
175 | pr_err("%s: no timing specifications given\n", | |
176 | of_node_full_name(np)); | |
177 | goto entryfail; | |
178 | } | |
179 | ||
180 | pr_debug("%s: using %s as default timing\n", | |
181 | of_node_full_name(np), entry->name); | |
182 | ||
183 | native_mode = entry; | |
184 | ||
185 | disp->num_timings = of_get_child_count(timings_np); | |
186 | if (disp->num_timings == 0) { | |
187 | /* should never happen, as entry was already found above */ | |
188 | pr_err("%s: no timings specified\n", of_node_full_name(np)); | |
189 | goto entryfail; | |
190 | } | |
191 | ||
192 | disp->timings = kzalloc(sizeof(struct display_timing *) * | |
193 | disp->num_timings, GFP_KERNEL); | |
194 | if (!disp->timings) { | |
195 | pr_err("%s: could not allocate timings array\n", | |
196 | of_node_full_name(np)); | |
197 | goto entryfail; | |
198 | } | |
199 | ||
200 | disp->num_timings = 0; | |
201 | disp->native_mode = 0; | |
202 | ||
203 | for_each_child_of_node(timings_np, entry) { | |
204 | struct display_timing *dt; | |
205 | int r; | |
206 | ||
207 | dt = kzalloc(sizeof(*dt), GFP_KERNEL); | |
208 | if (!dt) { | |
209 | pr_err("%s: could not allocate display_timing struct\n", | |
210 | of_node_full_name(np)); | |
211 | goto timingfail; | |
212 | } | |
213 | ||
214 | r = of_parse_display_timing(entry, dt); | |
215 | if (r) { | |
216 | /* | |
217 | * to not encourage wrong devicetrees, fail in case of | |
218 | * an error | |
219 | */ | |
220 | pr_err("%s: error in timing %d\n", | |
221 | of_node_full_name(np), disp->num_timings + 1); | |
222 | kfree(dt); | |
223 | goto timingfail; | |
224 | } | |
225 | ||
226 | if (native_mode == entry) | |
227 | disp->native_mode = disp->num_timings; | |
228 | ||
229 | disp->timings[disp->num_timings] = dt; | |
230 | disp->num_timings++; | |
231 | } | |
232 | of_node_put(timings_np); | |
233 | /* | |
234 | * native_mode points to the device_node returned by of_parse_phandle | |
235 | * therefore call of_node_put on it | |
236 | */ | |
237 | of_node_put(native_mode); | |
238 | ||
239 | pr_debug("%s: got %d timings. Using timing #%d as default\n", | |
240 | of_node_full_name(np), disp->num_timings, | |
241 | disp->native_mode + 1); | |
242 | ||
243 | return disp; | |
244 | ||
245 | timingfail: | |
246 | of_node_put(native_mode); | |
247 | display_timings_release(disp); | |
248 | disp = NULL; | |
249 | entryfail: | |
250 | kfree(disp); | |
251 | dispfail: | |
252 | of_node_put(timings_np); | |
253 | return NULL; | |
254 | } | |
255 | EXPORT_SYMBOL_GPL(of_get_display_timings); | |
256 | ||
257 | /** | |
258 | * of_display_timings_exist - check if a display-timings node is provided | |
259 | * @np: device_node with the timing | |
260 | **/ | |
261 | int of_display_timings_exist(const struct device_node *np) | |
262 | { | |
263 | struct device_node *timings_np; | |
264 | ||
265 | if (!np) | |
266 | return -EINVAL; | |
267 | ||
268 | timings_np = of_parse_phandle(np, "display-timings", 0); | |
269 | if (!timings_np) | |
270 | return -EINVAL; | |
271 | ||
272 | of_node_put(timings_np); | |
273 | return 1; | |
274 | } | |
275 | EXPORT_SYMBOL_GPL(of_display_timings_exist); |