1/*
  2 * Copyright (C) 2015 Texas Instruments
  3 * Author: Jyri Sarha <jsarha@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 */
 10
 11/*
 12 * To support the old "ti,tilcdc,slave" binding the binding has to be
 13 * transformed to the new external encoder binding.
 14 */
 15
 16#include <linux/kernel.h>
 17#include <linux/of.h>
 18#include <linux/of_graph.h>
 19#include <linux/of_fdt.h>
 20#include <linux/slab.h>
 21#include <linux/list.h>
 22
 23#include "tilcdc_slave_compat.h"
 24
 25struct kfree_table {
 26	int total;
 27	int num;
 28	void **table;
 29};
 30
 31static int __init kfree_table_init(struct kfree_table *kft)
 32{
 33	kft->total = 32;
 34	kft->num = 0;
 35	kft->table = kmalloc(kft->total * sizeof(*kft->table),
 36			     GFP_KERNEL);
 37	if (!kft->table)
 38		return -ENOMEM;
 39
 40	return 0;
 41}
 42
 43static int __init kfree_table_add(struct kfree_table *kft, void *p)
 44{
 45	if (kft->num == kft->total) {
 46		void **old = kft->table;
 47
 48		kft->total *= 2;
 49		kft->table = krealloc(old, kft->total * sizeof(*kft->table),
 50				      GFP_KERNEL);
 51		if (!kft->table) {
 52			kft->table = old;
 53			kfree(p);
 54			return -ENOMEM;
 55		}
 56	}
 57	kft->table[kft->num++] = p;
 58	return 0;
 59}
 60
 61static void __init kfree_table_free(struct kfree_table *kft)
 62{
 63	int i;
 64
 65	for (i = 0; i < kft->num; i++)
 66		kfree(kft->table[i]);
 67
 68	kfree(kft->table);
 69}
 70
 71static
 72struct property * __init tilcdc_prop_dup(const struct property *prop,
 73					 struct kfree_table *kft)
 74{
 75	struct property *nprop;
 76
 77	nprop = kzalloc(sizeof(*nprop), GFP_KERNEL);
 78	if (!nprop || kfree_table_add(kft, nprop))
 79		return NULL;
 80
 81	nprop->name = kstrdup(prop->name, GFP_KERNEL);
 82	if (!nprop->name || kfree_table_add(kft, nprop->name))
 83		return NULL;
 84
 85	nprop->value = kmemdup(prop->value, prop->length, GFP_KERNEL);
 86	if (!nprop->value || kfree_table_add(kft, nprop->value))
 87		return NULL;
 88
 89	nprop->length = prop->length;
 90
 91	return nprop;
 92}
 93
 94static void __init tilcdc_copy_props(struct device_node *from,
 95				     struct device_node *to,
 96				     const char * const props[],
 97				     struct kfree_table *kft)
 98{
 99	struct property *prop;
100	int i;
101
102	for (i = 0; props[i]; i++) {
103		prop = of_find_property(from, props[i], NULL);
104		if (!prop)
105			continue;
106
107		prop = tilcdc_prop_dup(prop, kft);
108		if (!prop)
109			continue;
110
111		prop->next = to->properties;
112		to->properties = prop;
113	}
114}
115
116static int __init tilcdc_prop_str_update(struct property *prop,
117					  const char *str,
118					  struct kfree_table *kft)
119{
120	prop->value = kstrdup(str, GFP_KERNEL);
121	if (kfree_table_add(kft, prop->value) || !prop->value)
122		return -ENOMEM;
123	prop->length = strlen(str)+1;
124	return 0;
125}
126
127static void __init tilcdc_node_disable(struct device_node *node)
128{
129	struct property *prop;
130
131	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
132	if (!prop)
133		return;
134
135	prop->name = "status";
136	prop->value = "disabled";
137	prop->length = strlen((char *)prop->value)+1;
138
139	of_update_property(node, prop);
140}
141
142struct device_node * __init tilcdc_get_overlay(struct kfree_table *kft)
143{
144	const int size = __dtb_tilcdc_slave_compat_end -
145		__dtb_tilcdc_slave_compat_begin;
146	static void *overlay_data;
147	struct device_node *overlay;
148	int ret;
149
150	if (!size) {
151		pr_warn("%s: No overlay data\n", __func__);
152		return NULL;
153	}
154
155	overlay_data = kmemdup(__dtb_tilcdc_slave_compat_begin,
156			       size, GFP_KERNEL);
157	if (!overlay_data || kfree_table_add(kft, overlay_data))
158		return NULL;
159
160	of_fdt_unflatten_tree(overlay_data, &overlay);
161	if (!overlay) {
162		pr_warn("%s: Unfattening overlay tree failed\n", __func__);
163		return NULL;
164	}
165
166	of_node_set_flag(overlay, OF_DETACHED);
167	ret = of_resolve_phandles(overlay);
168	if (ret) {
169		pr_err("%s: Failed to resolve phandles: %d\n", __func__, ret);
170		return NULL;
171	}
172
173	return overlay;
174}
175
176static const struct of_device_id tilcdc_slave_of_match[] __initconst = {
177	{ .compatible = "ti,tilcdc,slave", },
178	{},
179};
180
181static const struct of_device_id tilcdc_of_match[] __initconst = {
182	{ .compatible = "ti,am33xx-tilcdc", },
183	{},
184};
185
186static const struct of_device_id tilcdc_tda998x_of_match[] __initconst = {
187	{ .compatible = "nxp,tda998x", },
188	{},
189};
190
191static const char * const tilcdc_slave_props[] __initconst = {
192	"pinctrl-names",
193	"pinctrl-0",
194	"pinctrl-1",
195	NULL
196};
197
198void __init tilcdc_convert_slave_node(void)
199{
200	struct device_node *slave = NULL, *lcdc = NULL;
201	struct device_node *i2c = NULL, *fragment = NULL;
202	struct device_node *overlay, *encoder;
203	struct property *prop;
204	/* For all memory needed for the overlay tree. This memory can
205	   be freed after the overlay has been applied. */
206	struct kfree_table kft;
207	int ret;
208
209	if (kfree_table_init(&kft))
210		goto out;
211
212	lcdc = of_find_matching_node(NULL, tilcdc_of_match);
213	slave = of_find_matching_node(NULL, tilcdc_slave_of_match);
214
215	if (!slave || !of_device_is_available(lcdc))
216		goto out;
217
218	i2c = of_parse_phandle(slave, "i2c", 0);
219	if (!i2c) {
220		pr_err("%s: Can't find i2c node trough phandle\n", __func__);
221		goto out;
222	}
223
224	overlay = tilcdc_get_overlay(&kft);
225	if (!overlay)
226		goto out;
227
228	encoder = of_find_matching_node(overlay, tilcdc_tda998x_of_match);
229	if (!encoder) {
230		pr_err("%s: Failed to find tda998x node\n", __func__);
231		goto out;
232	}
233
234	tilcdc_copy_props(slave, encoder, tilcdc_slave_props, &kft);
235
236	for_each_child_of_node(overlay, fragment) {
237		prop = of_find_property(fragment, "target-path", NULL);
238		if (!prop)
239			continue;
240		if (!strncmp("i2c", (char *)prop->value, prop->length))
241			if (tilcdc_prop_str_update(prop, i2c->full_name, &kft))
242				goto out;
243		if (!strncmp("lcdc", (char *)prop->value, prop->length))
244			if (tilcdc_prop_str_update(prop, lcdc->full_name, &kft))
245				goto out;
246	}
247
248	tilcdc_node_disable(slave);
249
250	ret = of_overlay_create(overlay);
251	if (ret)
252		pr_err("%s: Creating overlay failed: %d\n", __func__, ret);
253	else
254		pr_info("%s: ti,tilcdc,slave node successfully converted\n",
255			__func__);
256out:
257	kfree_table_free(&kft);
258	of_node_put(i2c);
259	of_node_put(slave);
260	of_node_put(lcdc);
261	of_node_put(fragment);
262}
263
264int __init tilcdc_slave_compat_init(void)
265{
266	tilcdc_convert_slave_node();
267	return 0;
268}
269
270subsys_initcall(tilcdc_slave_compat_init);