1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2014 Texas Instruments
4 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
5 */
6
7 /*
8 * As omapdss panel drivers are omapdss specific, but we want to define the
9 * DT-data in generic manner, we convert the compatible strings of the panel and
10 * encoder nodes from "panel-foo" to "omapdss,panel-foo". This way we can have
11 * both correct DT data and omapdss specific drivers.
12 *
13 * When we get generic panel drivers to the kernel, this file will be removed.
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/of.h>
18 #include <linux/of_graph.h>
19 #include <linux/slab.h>
20 #include <linux/list.h>
21
22 static struct list_head dss_conv_list __initdata;
23
24 static const char prefix[] __initconst = "omapdss,";
25
26 struct dss_conv_node {
27 struct list_head list;
28 struct device_node *node;
29 bool root;
30 };
31
omapdss_count_strings(const struct property * prop)32 static int __init omapdss_count_strings(const struct property *prop)
33 {
34 const char *p = prop->value;
35 int l = 0, total = 0;
36 int i;
37
38 for (i = 0; total < prop->length; total += l, p += l, i++)
39 l = strlen(p) + 1;
40
41 return i;
42 }
43
omapdss_update_prop(struct device_node * node,char * compat,int len)44 static void __init omapdss_update_prop(struct device_node *node, char *compat,
45 int len)
46 {
47 struct property *prop;
48
49 prop = kzalloc_obj(*prop);
50 if (!prop)
51 return;
52
53 prop->name = "compatible";
54 prop->value = compat;
55 prop->length = len;
56
57 of_update_property(node, prop);
58 }
59
omapdss_prefix_strcpy(char * dst,int dst_len,const char * src,int src_len)60 static void __init omapdss_prefix_strcpy(char *dst, int dst_len,
61 const char *src, int src_len)
62 {
63 size_t total = 0;
64
65 while (total < src_len) {
66 size_t l = strlen(src) + 1;
67
68 strcpy(dst, prefix);
69 dst += strlen(prefix);
70
71 strcpy(dst, src);
72 dst += l;
73
74 src += l;
75 total += l;
76 }
77 }
78
79 /* prepend compatible property strings with "omapdss," */
omapdss_omapify_node(struct device_node * node)80 static void __init omapdss_omapify_node(struct device_node *node)
81 {
82 struct property *prop;
83 char *new_compat;
84 int num_strs;
85 int new_len;
86
87 prop = of_find_property(node, "compatible", NULL);
88
89 if (!prop || !prop->value)
90 return;
91
92 if (strnlen(prop->value, prop->length) >= prop->length)
93 return;
94
95 /* is it already prefixed? */
96 if (strncmp(prefix, prop->value, strlen(prefix)) == 0)
97 return;
98
99 num_strs = omapdss_count_strings(prop);
100
101 new_len = prop->length + strlen(prefix) * num_strs;
102 new_compat = kmalloc(new_len, GFP_KERNEL);
103 if (!new_compat)
104 return;
105
106 omapdss_prefix_strcpy(new_compat, new_len, prop->value, prop->length);
107
108 omapdss_update_prop(node, new_compat, new_len);
109 }
110
omapdss_add_to_list(struct device_node * node,bool root)111 static void __init omapdss_add_to_list(struct device_node *node, bool root)
112 {
113 struct dss_conv_node *n = kmalloc_obj(struct dss_conv_node);
114 if (n) {
115 n->node = node;
116 n->root = root;
117 list_add(&n->list, &dss_conv_list);
118 }
119 }
120
omapdss_list_contains(const struct device_node * node)121 static bool __init omapdss_list_contains(const struct device_node *node)
122 {
123 struct dss_conv_node *n;
124
125 list_for_each_entry(n, &dss_conv_list, list) {
126 if (n->node == node)
127 return true;
128 }
129
130 return false;
131 }
132
omapdss_walk_device(struct device_node * node,bool root)133 static void __init omapdss_walk_device(struct device_node *node, bool root)
134 {
135 struct device_node *n;
136
137 omapdss_add_to_list(node, root);
138
139 /*
140 * of_graph_get_remote_port_parent() prints an error if there is no
141 * port/ports node. To avoid that, check first that there's the node.
142 */
143 n = of_get_child_by_name(node, "ports");
144 if (!n)
145 n = of_get_child_by_name(node, "port");
146 if (!n)
147 return;
148
149 of_node_put(n);
150
151 for_each_endpoint_of_node(node, n) {
152 struct device_node *pn;
153
154 pn = of_graph_get_remote_port_parent(n);
155
156 if (!pn)
157 continue;
158
159 if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
160 of_node_put(pn);
161 continue;
162 }
163
164 omapdss_walk_device(pn, false);
165 }
166 }
167
168 static const struct of_device_id omapdss_of_match[] __initconst = {
169 { .compatible = "ti,omap2-dss", },
170 { .compatible = "ti,omap3-dss", },
171 { .compatible = "ti,omap4-dss", },
172 { .compatible = "ti,omap5-dss", },
173 { .compatible = "ti,dra7-dss", },
174 {},
175 };
176
omapdss_boot_init(void)177 static int __init omapdss_boot_init(void)
178 {
179 struct device_node *dss, *child;
180
181 INIT_LIST_HEAD(&dss_conv_list);
182
183 dss = of_find_matching_node(NULL, omapdss_of_match);
184
185 if (dss == NULL || !of_device_is_available(dss)) {
186 of_node_put(dss);
187 return 0;
188 }
189
190 omapdss_walk_device(dss, true);
191
192 for_each_available_child_of_node(dss, child) {
193 if (!of_property_present(child, "compatible"))
194 continue;
195
196 omapdss_walk_device(child, true);
197 }
198
199 while (!list_empty(&dss_conv_list)) {
200 struct dss_conv_node *n;
201
202 n = list_first_entry(&dss_conv_list, struct dss_conv_node,
203 list);
204
205 if (!n->root)
206 omapdss_omapify_node(n->node);
207
208 list_del(&n->list);
209 of_node_put(n->node);
210 kfree(n);
211 }
212
213 return 0;
214 }
215
216 subsys_initcall(omapdss_boot_init);
217