blob: fe2d1af7cfa0d0bce2eeb8a8391a4567da70bdd8 [file] [log] [blame]
Stephen Warren57291ce2012-03-23 10:29:46 -06001/*
2 * Device tree integration for the pin control subsystem
3 *
4 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 */
18
19#include <linux/device.h>
20#include <linux/of.h>
21#include <linux/pinctrl/pinctrl.h>
22#include <linux/slab.h>
23
24#include "core.h"
25#include "devicetree.h"
26
27/**
28 * struct pinctrl_dt_map - mapping table chunk parsed from device tree
29 * @node: list node for struct pinctrl's @dt_maps field
30 * @pctldev: the pin controller that allocated this struct, and will free it
31 * @maps: the mapping table entries
32 */
33struct pinctrl_dt_map {
34 struct list_head node;
35 struct pinctrl_dev *pctldev;
36 struct pinctrl_map *map;
37 unsigned num_maps;
38};
39
40static void dt_free_map(struct pinctrl_dev *pctldev,
41 struct pinctrl_map *map, unsigned num_maps)
42{
43 if (pctldev) {
44 struct pinctrl_ops *ops = pctldev->desc->pctlops;
45 ops->dt_free_map(pctldev, map, num_maps);
46 } else {
47 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
48 kfree(map);
49 }
50}
51
52void pinctrl_dt_free_maps(struct pinctrl *p)
53{
54 struct pinctrl_dt_map *dt_map, *n1;
55
56 list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
57 pinctrl_unregister_map(dt_map->map);
58 list_del(&dt_map->node);
59 dt_free_map(dt_map->pctldev, dt_map->map,
60 dt_map->num_maps);
61 kfree(dt_map);
62 }
63
64 of_node_put(p->dev->of_node);
65}
66
67static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
68 struct pinctrl_dev *pctldev,
69 struct pinctrl_map *map, unsigned num_maps)
70{
71 int i;
72 struct pinctrl_dt_map *dt_map;
73
74 /* Initialize common mapping table entry fields */
75 for (i = 0; i < num_maps; i++) {
76 map[i].dev_name = dev_name(p->dev);
77 map[i].name = statename;
78 if (pctldev)
79 map[i].ctrl_dev_name = dev_name(pctldev->dev);
80 }
81
82 /* Remember the converted mapping table entries */
83 dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
84 if (!dt_map) {
85 dev_err(p->dev, "failed to alloc struct pinctrl_dt_map\n");
86 dt_free_map(pctldev, map, num_maps);
87 return -ENOMEM;
88 }
89
90 dt_map->pctldev = pctldev;
91 dt_map->map = map;
92 dt_map->num_maps = num_maps;
93 list_add_tail(&dt_map->node, &p->dt_maps);
94
95 return pinctrl_register_map(map, num_maps, false, true);
96}
97
98static struct pinctrl_dev *find_pinctrl_by_of_node(struct device_node *np)
99{
100 struct pinctrl_dev *pctldev;
101
102 list_for_each_entry(pctldev, &pinctrldev_list, node)
103 if (pctldev->dev->of_node == np)
104 return pctldev;
105
106 return NULL;
107}
108
Linus Walleij1e63d7b2012-11-06 16:03:35 +0100109struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
Shiraz Hashimf23f1512012-10-27 15:21:36 +0530110{
111 struct pinctrl_dev *pctldev;
112
113 pctldev = find_pinctrl_by_of_node(np);
114 if (!pctldev)
115 return NULL;
116
Shiraz Hashimf23f1512012-10-27 15:21:36 +0530117 return pctldev;
118}
119
Stephen Warren57291ce2012-03-23 10:29:46 -0600120static int dt_to_map_one_config(struct pinctrl *p, const char *statename,
121 struct device_node *np_config)
122{
123 struct device_node *np_pctldev;
124 struct pinctrl_dev *pctldev;
125 struct pinctrl_ops *ops;
126 int ret;
127 struct pinctrl_map *map;
128 unsigned num_maps;
129
130 /* Find the pin controller containing np_config */
131 np_pctldev = of_node_get(np_config);
132 for (;;) {
133 np_pctldev = of_get_next_parent(np_pctldev);
134 if (!np_pctldev || of_node_is_root(np_pctldev)) {
Linus Walleijc05127c2012-04-10 10:00:38 +0200135 dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n",
Stephen Warren57291ce2012-03-23 10:29:46 -0600136 np_config->full_name);
137 of_node_put(np_pctldev);
Linus Walleijc05127c2012-04-10 10:00:38 +0200138 /* OK let's just assume this will appear later then */
139 return -EPROBE_DEFER;
Stephen Warren57291ce2012-03-23 10:29:46 -0600140 }
141 pctldev = find_pinctrl_by_of_node(np_pctldev);
142 if (pctldev)
143 break;
144 }
145 of_node_put(np_pctldev);
146
147 /*
148 * Call pinctrl driver to parse device tree node, and
149 * generate mapping table entries
150 */
151 ops = pctldev->desc->pctlops;
152 if (!ops->dt_node_to_map) {
153 dev_err(p->dev, "pctldev %s doesn't support DT\n",
154 dev_name(pctldev->dev));
155 return -ENODEV;
156 }
157 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
158 if (ret < 0)
159 return ret;
160
161 /* Stash the mapping table chunk away for later use */
162 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
163}
164
165static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
166{
167 struct pinctrl_map *map;
168
169 map = kzalloc(sizeof(*map), GFP_KERNEL);
170 if (!map) {
171 dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
172 return -ENOMEM;
173 }
174
175 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
176 map->type = PIN_MAP_TYPE_DUMMY_STATE;
177
178 return dt_remember_or_free_map(p, statename, NULL, map, 1);
179}
180
181int pinctrl_dt_to_map(struct pinctrl *p)
182{
183 struct device_node *np = p->dev->of_node;
184 int state, ret;
185 char *propname;
186 struct property *prop;
187 const char *statename;
188 const __be32 *list;
189 int size, config;
190 phandle phandle;
191 struct device_node *np_config;
192
193 /* CONFIG_OF enabled, p->dev not instantiated from DT */
194 if (!np) {
195 dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n");
196 return 0;
197 }
198
199 /* We may store pointers to property names within the node */
200 of_node_get(np);
201
202 /* For each defined state ID */
203 for (state = 0; ; state++) {
204 /* Retrieve the pinctrl-* property */
205 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
206 prop = of_find_property(np, propname, &size);
207 kfree(propname);
208 if (!prop)
209 break;
210 list = prop->value;
211 size /= sizeof(*list);
212
213 /* Determine whether pinctrl-names property names the state */
214 ret = of_property_read_string_index(np, "pinctrl-names",
215 state, &statename);
216 /*
217 * If not, statename is just the integer state ID. But rather
218 * than dynamically allocate it and have to free it later,
219 * just point part way into the property name for the string.
220 */
221 if (ret < 0) {
222 /* strlen("pinctrl-") == 8 */
223 statename = prop->name + 8;
224 }
225
226 /* For every referenced pin configuration node in it */
227 for (config = 0; config < size; config++) {
228 phandle = be32_to_cpup(list++);
229
230 /* Look up the pin configuration node */
231 np_config = of_find_node_by_phandle(phandle);
232 if (!np_config) {
233 dev_err(p->dev,
234 "prop %s index %i invalid phandle\n",
235 prop->name, config);
236 ret = -EINVAL;
237 goto err;
238 }
239
240 /* Parse the node */
241 ret = dt_to_map_one_config(p, statename, np_config);
242 of_node_put(np_config);
243 if (ret < 0)
244 goto err;
245 }
246
247 /* No entries in DT? Generate a dummy state table entry */
248 if (!size) {
249 ret = dt_remember_dummy_state(p, statename);
250 if (ret < 0)
251 goto err;
252 }
253 }
254
255 return 0;
256
257err:
258 pinctrl_dt_free_maps(p);
259 return ret;
260}