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Steffen Trumtrarcc3f4142012-10-04 15:32:52 +02001/*
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 **/
Steffen Trumtrarf5836622013-05-27 12:33:05 +000026static int parse_timing_property(const struct device_node *np, const char *name,
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020027 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/**
Tomi Valkeinenffa3fd22013-05-16 15:36:38 +030056 * of_parse_display_timing - parse display_timing entry from device_node
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020057 * @np: device_node with the properties
58 **/
Linus Torvalds2e17c5a2013-07-09 16:04:31 -070059static int of_parse_display_timing(const struct device_node *np,
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +030060 struct display_timing *dt)
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020061{
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020062 u32 val = 0;
63 int ret = 0;
64
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +030065 memset(dt, 0, sizeof(*dt));
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020066
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
Tomi Valkeinen06a33072013-03-12 10:26:45 +020077 dt->flags = 0;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020078 if (!of_property_read_u32(np, "vsync-active", &val))
Tomi Valkeinen06a33072013-03-12 10:26:45 +020079 dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH :
80 DISPLAY_FLAGS_VSYNC_LOW;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020081 if (!of_property_read_u32(np, "hsync-active", &val))
Tomi Valkeinen06a33072013-03-12 10:26:45 +020082 dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH :
83 DISPLAY_FLAGS_HSYNC_LOW;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020084 if (!of_property_read_u32(np, "de-active", &val))
Tomi Valkeinen06a33072013-03-12 10:26:45 +020085 dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH :
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020086 DISPLAY_FLAGS_DE_LOW;
87 if (!of_property_read_u32(np, "pixelclk-active", &val))
Tomi Valkeinen06a33072013-03-12 10:26:45 +020088 dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020089 DISPLAY_FLAGS_PIXDATA_NEGEDGE;
90
91 if (of_property_read_bool(np, "interlaced"))
Tomi Valkeinen06a33072013-03-12 10:26:45 +020092 dt->flags |= DISPLAY_FLAGS_INTERLACED;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020093 if (of_property_read_bool(np, "doublescan"))
Tomi Valkeinen06a33072013-03-12 10:26:45 +020094 dt->flags |= DISPLAY_FLAGS_DOUBLESCAN;
Steffen Trumtrar2d178a42013-05-27 12:33:34 +000095 if (of_property_read_bool(np, "doubleclk"))
96 dt->flags |= DISPLAY_FLAGS_DOUBLECLK;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +020097
98 if (ret) {
99 pr_err("%s: error reading timing properties\n",
100 of_node_full_name(np));
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +0300101 return -EINVAL;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200102 }
103
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +0300104 return 0;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200105}
106
107/**
Tomi Valkeinenffa3fd22013-05-16 15:36:38 +0300108 * of_get_display_timing - parse a display_timing entry
109 * @np: device_node with the timing subnode
110 * @name: name of the timing node
111 * @dt: display_timing struct to fill
112 **/
113int of_get_display_timing(struct device_node *np, const char *name,
114 struct display_timing *dt)
115{
116 struct device_node *timing_np;
117
Lucas Stachdc427152014-05-13 14:58:21 +0200118 if (!np)
Tomi Valkeinenffa3fd22013-05-16 15:36:38 +0300119 return -EINVAL;
Tomi Valkeinenffa3fd22013-05-16 15:36:38 +0300120
Andrzej Hajda60119a12013-09-25 13:51:31 +0200121 timing_np = of_get_child_by_name(np, name);
Tomi Valkeinenffa3fd22013-05-16 15:36:38 +0300122 if (!timing_np) {
123 pr_err("%s: could not find node '%s'\n",
124 of_node_full_name(np), name);
125 return -ENOENT;
126 }
127
128 return of_parse_display_timing(timing_np, dt);
129}
130EXPORT_SYMBOL_GPL(of_get_display_timing);
131
132/**
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200133 * of_get_display_timings - parse all display_timing entries from a device_node
134 * @np: device_node with the subnodes
135 **/
136struct display_timings *of_get_display_timings(struct device_node *np)
137{
138 struct device_node *timings_np;
139 struct device_node *entry;
140 struct device_node *native_mode;
141 struct display_timings *disp;
142
Lucas Stachdc427152014-05-13 14:58:21 +0200143 if (!np)
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200144 return NULL;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200145
Andrzej Hajda60119a12013-09-25 13:51:31 +0200146 timings_np = of_get_child_by_name(np, "display-timings");
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200147 if (!timings_np) {
148 pr_err("%s: could not find display-timings node\n",
149 of_node_full_name(np));
150 return NULL;
151 }
152
153 disp = kzalloc(sizeof(*disp), GFP_KERNEL);
154 if (!disp) {
155 pr_err("%s: could not allocate struct disp'\n",
156 of_node_full_name(np));
157 goto dispfail;
158 }
159
160 entry = of_parse_phandle(timings_np, "native-mode", 0);
161 /* assume first child as native mode if none provided */
162 if (!entry)
Boris BREZILLON80c68c12014-05-09 15:53:12 +0200163 entry = of_get_next_child(timings_np, NULL);
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200164 /* if there is no child, it is useless to go on */
165 if (!entry) {
166 pr_err("%s: no timing specifications given\n",
167 of_node_full_name(np));
168 goto entryfail;
169 }
170
171 pr_debug("%s: using %s as default timing\n",
172 of_node_full_name(np), entry->name);
173
174 native_mode = entry;
175
176 disp->num_timings = of_get_child_count(timings_np);
177 if (disp->num_timings == 0) {
178 /* should never happen, as entry was already found above */
179 pr_err("%s: no timings specified\n", of_node_full_name(np));
180 goto entryfail;
181 }
182
183 disp->timings = kzalloc(sizeof(struct display_timing *) *
184 disp->num_timings, GFP_KERNEL);
185 if (!disp->timings) {
186 pr_err("%s: could not allocate timings array\n",
187 of_node_full_name(np));
188 goto entryfail;
189 }
190
191 disp->num_timings = 0;
192 disp->native_mode = 0;
193
194 for_each_child_of_node(timings_np, entry) {
195 struct display_timing *dt;
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +0300196 int r;
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200197
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +0300198 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200199 if (!dt) {
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +0300200 pr_err("%s: could not allocate display_timing struct\n",
201 of_node_full_name(np));
202 goto timingfail;
203 }
204
Tomi Valkeinenffa3fd22013-05-16 15:36:38 +0300205 r = of_parse_display_timing(entry, dt);
Tomi Valkeinenfcf7e6e2013-05-16 15:29:06 +0300206 if (r) {
Steffen Trumtrarcc3f4142012-10-04 15:32:52 +0200207 /*
208 * to not encourage wrong devicetrees, fail in case of
209 * an error
210 */
211 pr_err("%s: error in timing %d\n",
212 of_node_full_name(np), disp->num_timings + 1);
213 goto timingfail;
214 }
215
216 if (native_mode == entry)
217 disp->native_mode = disp->num_timings;
218
219 disp->timings[disp->num_timings] = dt;
220 disp->num_timings++;
221 }
222 of_node_put(timings_np);
223 /*
224 * native_mode points to the device_node returned by of_parse_phandle
225 * therefore call of_node_put on it
226 */
227 of_node_put(native_mode);
228
229 pr_debug("%s: got %d timings. Using timing #%d as default\n",
230 of_node_full_name(np), disp->num_timings,
231 disp->native_mode + 1);
232
233 return disp;
234
235timingfail:
236 if (native_mode)
237 of_node_put(native_mode);
238 display_timings_release(disp);
239entryfail:
240 kfree(disp);
241dispfail:
242 of_node_put(timings_np);
243 return NULL;
244}
245EXPORT_SYMBOL_GPL(of_get_display_timings);
246
247/**
248 * of_display_timings_exist - check if a display-timings node is provided
249 * @np: device_node with the timing
250 **/
251int of_display_timings_exist(struct device_node *np)
252{
253 struct device_node *timings_np;
254
255 if (!np)
256 return -EINVAL;
257
258 timings_np = of_parse_phandle(np, "display-timings", 0);
259 if (!timings_np)
260 return -EINVAL;
261
262 of_node_put(timings_np);
263 return 1;
264}
265EXPORT_SYMBOL_GPL(of_display_timings_exist);