[go: nahoru, domu]
1/*
2 * Copyright (C) 2014 Texas Instruments
3 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 as published by
7 * the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program.  If not, see <http://www.gnu.org/licenses/>.
16 */
17
18/*
19 * As omapdss panel drivers are omapdss specific, but we want to define the
20 * DT-data in generic manner, we convert the compatible strings of the panel and
21 * encoder nodes from "panel-foo" to "omapdss,panel-foo". This way we can have
22 * both correct DT data and omapdss specific drivers.
23 *
24 * When we get generic panel drivers to the kernel, this file will be removed.
25 */
26
27#include <linux/kernel.h>
28#include <linux/of.h>
29#include <linux/of_graph.h>
30#include <linux/slab.h>
31#include <linux/list.h>
32
33static struct list_head dss_conv_list __initdata;
34
35static const char prefix[] __initconst = "omapdss,";
36
37struct dss_conv_node {
38	struct list_head list;
39	struct device_node *node;
40	bool root;
41};
42
43static int __init omapdss_count_strings(const struct property *prop)
44{
45	const char *p = prop->value;
46	int l = 0, total = 0;
47	int i;
48
49	for (i = 0; total < prop->length; total += l, p += l, i++)
50		l = strlen(p) + 1;
51
52	return i;
53}
54
55static void __init omapdss_update_prop(struct device_node *node, char *compat,
56	int len)
57{
58	struct property *prop;
59
60	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
61	if (!prop)
62		return;
63
64	prop->name = "compatible";
65	prop->value = compat;
66	prop->length = len;
67
68	of_update_property(node, prop);
69}
70
71static void __init omapdss_prefix_strcpy(char *dst, int dst_len,
72	const char *src, int src_len)
73{
74	size_t total = 0;
75
76	while (total < src_len) {
77		size_t l = strlen(src) + 1;
78
79		strcpy(dst, prefix);
80		dst += strlen(prefix);
81
82		strcpy(dst, src);
83		dst += l;
84
85		src += l;
86		total += l;
87	}
88}
89
90/* prepend compatible property strings with "omapdss," */
91static void __init omapdss_omapify_node(struct device_node *node)
92{
93	struct property *prop;
94	char *new_compat;
95	int num_strs;
96	int new_len;
97
98	prop = of_find_property(node, "compatible", NULL);
99
100	if (!prop || !prop->value)
101		return;
102
103	if (strnlen(prop->value, prop->length) >= prop->length)
104		return;
105
106	/* is it already prefixed? */
107	if (strncmp(prefix, prop->value, strlen(prefix)) == 0)
108		return;
109
110	num_strs = omapdss_count_strings(prop);
111
112	new_len = prop->length + strlen(prefix) * num_strs;
113	new_compat = kmalloc(new_len, GFP_KERNEL);
114
115	omapdss_prefix_strcpy(new_compat, new_len, prop->value, prop->length);
116
117	omapdss_update_prop(node, new_compat, new_len);
118}
119
120static void __init omapdss_add_to_list(struct device_node *node, bool root)
121{
122	struct dss_conv_node *n = kmalloc(sizeof(struct dss_conv_node),
123		GFP_KERNEL);
124	if (n) {
125		n->node = node;
126		n->root = root;
127		list_add(&n->list, &dss_conv_list);
128	}
129}
130
131static bool __init omapdss_list_contains(const struct device_node *node)
132{
133	struct dss_conv_node *n;
134
135	list_for_each_entry(n, &dss_conv_list, list) {
136		if (n->node == node)
137			return true;
138	}
139
140	return false;
141}
142
143static void __init omapdss_walk_device(struct device_node *node, bool root)
144{
145	struct device_node *n;
146
147	omapdss_add_to_list(node, root);
148
149	/*
150	 * of_graph_get_remote_port_parent() prints an error if there is no
151	 * port/ports node. To avoid that, check first that there's the node.
152	 */
153	n = of_get_child_by_name(node, "ports");
154	if (!n)
155		n = of_get_child_by_name(node, "port");
156	if (!n)
157		return;
158
159	of_node_put(n);
160
161	n = NULL;
162	while ((n = of_graph_get_next_endpoint(node, n)) != NULL) {
163		struct device_node *pn;
164
165		pn = of_graph_get_remote_port_parent(n);
166
167		if (!pn) {
168			of_node_put(n);
169			continue;
170		}
171
172		if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
173			of_node_put(pn);
174			of_node_put(n);
175			continue;
176		}
177
178		omapdss_walk_device(pn, false);
179
180		of_node_put(n);
181	}
182}
183
184static const struct of_device_id omapdss_of_match[] __initconst = {
185	{ .compatible = "ti,omap2-dss", },
186	{ .compatible = "ti,omap3-dss", },
187	{ .compatible = "ti,omap4-dss", },
188	{ .compatible = "ti,omap5-dss", },
189	{},
190};
191
192static int __init omapdss_boot_init(void)
193{
194	struct device_node *dss, *child;
195
196	INIT_LIST_HEAD(&dss_conv_list);
197
198	dss = of_find_matching_node(NULL, omapdss_of_match);
199
200	if (dss == NULL || !of_device_is_available(dss))
201		return 0;
202
203	omapdss_walk_device(dss, true);
204
205	for_each_available_child_of_node(dss, child) {
206		if (!of_find_property(child, "compatible", NULL)) {
207			of_node_put(child);
208			continue;
209		}
210
211		omapdss_walk_device(child, true);
212	}
213
214	while (!list_empty(&dss_conv_list)) {
215		struct dss_conv_node *n;
216
217		n = list_first_entry(&dss_conv_list, struct dss_conv_node,
218			list);
219
220		if (!n->root)
221			omapdss_omapify_node(n->node);
222
223		list_del(&n->list);
224		of_node_put(n->node);
225		kfree(n);
226	}
227
228	return 0;
229}
230
231subsys_initcall(omapdss_boot_init);
232