[mirror_ubuntu-artful-kernel.git] / drivers / video / of_display_timing.c

/*
 * OF helpers for parsing display timings
 *
 * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
 *
 * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de>
 *
 * This file is released under the GPLv2
 */
#include <linux/export.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <video/display_timing.h>
#include <video/of_display_timing.h>

/**
 * parse_timing_property - parse timing_entry from device_node
 * @np: device_node with the property
 * @name: name of the property
 * @result: will be set to the return value
 *
 * DESCRIPTION:
 * Every display_timing can be specified with either just the typical value or
 * a range consisting of min/typ/max. This function helps handling this
 **/
static int parse_timing_property(struct device_node *np, const char *name,
			  struct timing_entry *result)
{
	struct property *prop;
	int length, cells, ret;

	prop = of_find_property(np, name, &length);
	if (!prop) {
		pr_err("%s: could not find property %s\n",
			of_node_full_name(np), name);
		return -EINVAL;
	}

	cells = length / sizeof(u32);
	if (cells == 1) {
		ret = of_property_read_u32(np, name, &result->typ);
		result->min = result->typ;
		result->max = result->typ;
	} else if (cells == 3) {
		ret = of_property_read_u32_array(np, name, &result->min, cells);
	} else {
		pr_err("%s: illegal timing specification in %s\n",
			of_node_full_name(np), name);
		return -EINVAL;
	}

	return ret;
}

/**
 * of_get_display_timing - parse display_timing entry from device_node
 * @np: device_node with the properties
 **/
static struct display_timing *of_get_display_timing(struct device_node *np)
{
	struct display_timing *dt;
	u32 val = 0;
	int ret = 0;

	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
	if (!dt) {
		pr_err("%s: could not allocate display_timing struct\n",
			of_node_full_name(np));
		return NULL;
	}

	ret |= parse_timing_property(np, "hback-porch", &dt->hback_porch);
	ret |= parse_timing_property(np, "hfront-porch", &dt->hfront_porch);
	ret |= parse_timing_property(np, "hactive", &dt->hactive);
	ret |= parse_timing_property(np, "hsync-len", &dt->hsync_len);
	ret |= parse_timing_property(np, "vback-porch", &dt->vback_porch);
	ret |= parse_timing_property(np, "vfront-porch", &dt->vfront_porch);
	ret |= parse_timing_property(np, "vactive", &dt->vactive);
	ret |= parse_timing_property(np, "vsync-len", &dt->vsync_len);
	ret |= parse_timing_property(np, "clock-frequency", &dt->pixelclock);

	dt->dmt_flags = 0;
	dt->data_flags = 0;
	if (!of_property_read_u32(np, "vsync-active", &val))
		dt->dmt_flags |= val ? VESA_DMT_VSYNC_HIGH :
				VESA_DMT_VSYNC_LOW;
	if (!of_property_read_u32(np, "hsync-active", &val))
		dt->dmt_flags |= val ? VESA_DMT_HSYNC_HIGH :
				VESA_DMT_HSYNC_LOW;
	if (!of_property_read_u32(np, "de-active", &val))
		dt->data_flags |= val ? DISPLAY_FLAGS_DE_HIGH :
				DISPLAY_FLAGS_DE_LOW;
	if (!of_property_read_u32(np, "pixelclk-active", &val))
		dt->data_flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
				DISPLAY_FLAGS_PIXDATA_NEGEDGE;

	if (of_property_read_bool(np, "interlaced"))
		dt->data_flags |= DISPLAY_FLAGS_INTERLACED;
	if (of_property_read_bool(np, "doublescan"))
		dt->data_flags |= DISPLAY_FLAGS_DOUBLESCAN;

	if (ret) {
		pr_err("%s: error reading timing properties\n",
			of_node_full_name(np));
		kfree(dt);
		return NULL;
	}

	return dt;
}

/**
 * of_get_display_timings - parse all display_timing entries from a device_node
 * @np: device_node with the subnodes
 **/
struct display_timings *of_get_display_timings(struct device_node *np)
{
	struct device_node *timings_np;
	struct device_node *entry;
	struct device_node *native_mode;
	struct display_timings *disp;

	if (!np) {
		pr_err("%s: no devicenode given\n", of_node_full_name(np));
		return NULL;
	}

	timings_np = of_find_node_by_name(np, "display-timings");
	if (!timings_np) {
		pr_err("%s: could not find display-timings node\n",
			of_node_full_name(np));
		return NULL;
	}

	disp = kzalloc(sizeof(*disp), GFP_KERNEL);
	if (!disp) {
		pr_err("%s: could not allocate struct disp'\n",
			of_node_full_name(np));
		goto dispfail;
	}

	entry = of_parse_phandle(timings_np, "native-mode", 0);
	/* assume first child as native mode if none provided */
	if (!entry)
		entry = of_get_next_child(np, NULL);
	/* if there is no child, it is useless to go on */
	if (!entry) {
		pr_err("%s: no timing specifications given\n",
			of_node_full_name(np));
		goto entryfail;
	}

	pr_debug("%s: using %s as default timing\n",
		of_node_full_name(np), entry->name);

	native_mode = entry;

	disp->num_timings = of_get_child_count(timings_np);
	if (disp->num_timings == 0) {
		/* should never happen, as entry was already found above */
		pr_err("%s: no timings specified\n", of_node_full_name(np));
		goto entryfail;
	}

	disp->timings = kzalloc(sizeof(struct display_timing *) *
				disp->num_timings, GFP_KERNEL);
	if (!disp->timings) {
		pr_err("%s: could not allocate timings array\n",
			of_node_full_name(np));
		goto entryfail;
	}

	disp->num_timings = 0;
	disp->native_mode = 0;

	for_each_child_of_node(timings_np, entry) {
		struct display_timing *dt;

		dt = of_get_display_timing(entry);
		if (!dt) {
			/*
			 * to not encourage wrong devicetrees, fail in case of
			 * an error
			 */
			pr_err("%s: error in timing %d\n",
				of_node_full_name(np), disp->num_timings + 1);
			goto timingfail;
		}

		if (native_mode == entry)
			disp->native_mode = disp->num_timings;

		disp->timings[disp->num_timings] = dt;
		disp->num_timings++;
	}
	of_node_put(timings_np);
	/*
	 * native_mode points to the device_node returned by of_parse_phandle
	 * therefore call of_node_put on it
	 */
	of_node_put(native_mode);

	pr_debug("%s: got %d timings. Using timing #%d as default\n",
		of_node_full_name(np), disp->num_timings,
		disp->native_mode + 1);

	return disp;

timingfail:
	if (native_mode)
		of_node_put(native_mode);
	display_timings_release(disp);
entryfail:
	kfree(disp);
dispfail:
	of_node_put(timings_np);
	return NULL;
}
EXPORT_SYMBOL_GPL(of_get_display_timings);

/**
 * of_display_timings_exist - check if a display-timings node is provided
 * @np: device_node with the timing
 **/
int of_display_timings_exist(struct device_node *np)
{
	struct device_node *timings_np;

	if (!np)
		return -EINVAL;

	timings_np = of_parse_phandle(np, "display-timings", 0);
	if (!timings_np)
		return -EINVAL;

	of_node_put(timings_np);
	return 1;
}
EXPORT_SYMBOL_GPL(of_display_timings_exist);
Commit	Line	Data
cc3f414c ST	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(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_get_display_timing - parse display_timing entry from device_node
	57	* @np: device_node with the properties
	58	**/
	59	static struct display_timing of_get_display_timing(struct device_node np)
	60	{
	61	struct display_timing *dt;
	62	u32 val = 0;
	63	int ret = 0;
	64
65	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
66	if (!dt) {
67	pr_err("%s: could not allocate display_timing struct\n",
68	of_node_full_name(np));
69	return NULL;
70	}
71
72	ret \|= parse_timing_property(np, "hback-porch", &dt->hback_porch);
73	ret \|= parse_timing_property(np, "hfront-porch", &dt->hfront_porch);
74	ret \|= parse_timing_property(np, "hactive", &dt->hactive);
75	ret \|= parse_timing_property(np, "hsync-len", &dt->hsync_len);
76	ret \|= parse_timing_property(np, "vback-porch", &dt->vback_porch);
77	ret \|= parse_timing_property(np, "vfront-porch", &dt->vfront_porch);
78	ret \|= parse_timing_property(np, "vactive", &dt->vactive);
79	ret \|= parse_timing_property(np, "vsync-len", &dt->vsync_len);
80	ret \|= parse_timing_property(np, "clock-frequency", &dt->pixelclock);
81
82	dt->dmt_flags = 0;
83	dt->data_flags = 0;
84	if (!of_property_read_u32(np, "vsync-active", &val))
85	dt->dmt_flags \|= val ? VESA_DMT_VSYNC_HIGH :
86	VESA_DMT_VSYNC_LOW;
87	if (!of_property_read_u32(np, "hsync-active", &val))
88	dt->dmt_flags \|= val ? VESA_DMT_HSYNC_HIGH :
89	VESA_DMT_HSYNC_LOW;
90	if (!of_property_read_u32(np, "de-active", &val))
91	dt->data_flags \|= val ? DISPLAY_FLAGS_DE_HIGH :
92	DISPLAY_FLAGS_DE_LOW;
93	if (!of_property_read_u32(np, "pixelclk-active", &val))
94	dt->data_flags \|= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
95	DISPLAY_FLAGS_PIXDATA_NEGEDGE;
96
97	if (of_property_read_bool(np, "interlaced"))
98	dt->data_flags \|= DISPLAY_FLAGS_INTERLACED;
99	if (of_property_read_bool(np, "doublescan"))
100	dt->data_flags \|= DISPLAY_FLAGS_DOUBLESCAN;
101
102	if (ret) {
103	pr_err("%s: error reading timing properties\n",
104	of_node_full_name(np));
105	kfree(dt);
106	return NULL;
107	}
108
109	return dt;
110	}
111
112	/**
113	* of_get_display_timings - parse all display_timing entries from a device_node
114	* @np: device_node with the subnodes
115	**/
116	struct display_timings of_get_display_timings(struct device_node np)
117	{
118	struct device_node *timings_np;
119	struct device_node *entry;
120	struct device_node *native_mode;
121	struct display_timings *disp;
122
123	if (!np) {
124	pr_err("%s: no devicenode given\n", of_node_full_name(np));
125	return NULL;
126	}
127
128	timings_np = of_find_node_by_name(np, "display-timings");
129	if (!timings_np) {
130	pr_err("%s: could not find display-timings node\n",
131	of_node_full_name(np));
132	return NULL;
133	}
134
135	disp = kzalloc(sizeof(*disp), GFP_KERNEL);
136	if (!disp) {
137	pr_err("%s: could not allocate struct disp'\n",
138	of_node_full_name(np));
139	goto dispfail;
140	}
141
142	entry = of_parse_phandle(timings_np, "native-mode", 0);
143	/* assume first child as native mode if none provided */
144	if (!entry)
145	entry = of_get_next_child(np, NULL);
146	/* if there is no child, it is useless to go on */
147	if (!entry) {
148	pr_err("%s: no timing specifications given\n",
149	of_node_full_name(np));
150	goto entryfail;
151	}
152
153	pr_debug("%s: using %s as default timing\n",
154	of_node_full_name(np), entry->name);
155
156	native_mode = entry;
157
158	disp->num_timings = of_get_child_count(timings_np);
159	if (disp->num_timings == 0) {
160	/* should never happen, as entry was already found above */
161	pr_err("%s: no timings specified\n", of_node_full_name(np));
162	goto entryfail;
163	}
164
165	disp->timings = kzalloc(sizeof(struct display_timing )
166	disp->num_timings, GFP_KERNEL);
167	if (!disp->timings) {
168	pr_err("%s: could not allocate timings array\n",
169	of_node_full_name(np));
170	goto entryfail;
171	}
172
173	disp->num_timings = 0;
174	disp->native_mode = 0;
175
176	for_each_child_of_node(timings_np, entry) {
177	struct display_timing *dt;
178
179	dt = of_get_display_timing(entry);
180	if (!dt) {
181	/*
182	* to not encourage wrong devicetrees, fail in case of
183	* an error
184	*/
185	pr_err("%s: error in timing %d\n",
186	of_node_full_name(np), disp->num_timings + 1);
187	goto timingfail;
188	}
189
190	if (native_mode == entry)
191	disp->native_mode = disp->num_timings;
192
193	disp->timings[disp->num_timings] = dt;
194	disp->num_timings++;
195	}
196	of_node_put(timings_np);
197	/*
198	* native_mode points to the device_node returned by of_parse_phandle
199	* therefore call of_node_put on it
200	*/
201	of_node_put(native_mode);
202
203	pr_debug("%s: got %d timings. Using timing #%d as default\n",
204	of_node_full_name(np), disp->num_timings,
205	disp->native_mode + 1);
206
207	return disp;
208
209	timingfail:
210	if (native_mode)
211	of_node_put(native_mode);
212	display_timings_release(disp);
213	entryfail:
214	kfree(disp);
215	dispfail:
216	of_node_put(timings_np);
217	return NULL;
218	}
219	EXPORT_SYMBOL_GPL(of_get_display_timings);
220
221	/**
222	* of_display_timings_exist - check if a display-timings node is provided
223	* @np: device_node with the timing
224	**/
225	int of_display_timings_exist(struct device_node *np)
226	{
227	struct device_node *timings_np;
228
229	if (!np)
230	return -EINVAL;
231
232	timings_np = of_parse_phandle(np, "display-timings", 0);
233	if (!timings_np)
234	return -EINVAL;
235
236	of_node_put(timings_np);
237	return 1;
238	}
239	EXPORT_SYMBOL_GPL(of_display_timings_exist);