omapdss-boot-init.c

  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
 22static struct list_head dss_conv_list __initdata;
 23
 24static const char prefix[] __initconst = "omapdss,";
 25
 26struct dss_conv_node {
 27	struct list_head list;
 28	struct device_node *node;
 29	bool root;
 30};
 31
 32static 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
 44static void __init omapdss_update_prop(struct device_node *node, char *compat,
 45	int len)
 46{
 47	struct property *prop;
 48
 49	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
 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
 60static 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," */
 80static 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
111static void __init omapdss_add_to_list(struct device_node *node, bool root)
112{
113	struct dss_conv_node *n = kmalloc(sizeof(struct dss_conv_node),
114		GFP_KERNEL);
115	if (n) {
116		n->node = node;
117		n->root = root;
118		list_add(&n->list, &dss_conv_list);
119	}
120}
121
122static bool __init omapdss_list_contains(const struct device_node *node)
123{
124	struct dss_conv_node *n;
125
126	list_for_each_entry(n, &dss_conv_list, list) {
127		if (n->node == node)
128			return true;
129	}
130
131	return false;
132}
133
134static void __init omapdss_walk_device(struct device_node *node, bool root)
135{
136	struct device_node *n;
137
138	omapdss_add_to_list(node, root);
139
140	/*
141	 * of_graph_get_remote_port_parent() prints an error if there is no
142	 * port/ports node. To avoid that, check first that there's the node.
143	 */
144	n = of_get_child_by_name(node, "ports");
145	if (!n)
146		n = of_get_child_by_name(node, "port");
147	if (!n)
148		return;
149
150	of_node_put(n);
151
152	for_each_endpoint_of_node(node, n) {
153		struct device_node *pn;
154
155		pn = of_graph_get_remote_port_parent(n);
156
157		if (!pn)
158			continue;
159
160		if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
161			of_node_put(pn);
162			continue;
163		}
164
165		omapdss_walk_device(pn, false);
166	}
167}
168
169static const struct of_device_id omapdss_of_match[] __initconst = {
170	{ .compatible = "ti,omap2-dss", },
171	{ .compatible = "ti,omap3-dss", },
172	{ .compatible = "ti,omap4-dss", },
173	{ .compatible = "ti,omap5-dss", },
174	{ .compatible = "ti,dra7-dss", },
175	{},
176};
177
178static int __init omapdss_boot_init(void)
179{
180	struct device_node *dss, *child;
181
182	INIT_LIST_HEAD(&dss_conv_list);
183
184	dss = of_find_matching_node(NULL, omapdss_of_match);
185
186	if (dss == NULL || !of_device_is_available(dss)) {
187		of_node_put(dss);
188		return 0;
189	}
190
191	omapdss_walk_device(dss, true);
192
193	for_each_available_child_of_node(dss, child) {
194		if (!of_property_present(child, "compatible"))
195			continue;
196
197		omapdss_walk_device(child, true);
198	}
199
200	while (!list_empty(&dss_conv_list)) {
201		struct dss_conv_node *n;
202
203		n = list_first_entry(&dss_conv_list, struct dss_conv_node,
204			list);
205
206		if (!n->root)
207			omapdss_omapify_node(n->node);
208
209		list_del(&n->list);
210		of_node_put(n->node);
211		kfree(n);
212	}
213
214	return 0;
215}
216
217subsys_initcall(omapdss_boot_init);