blob: fd40a11ad645a38e9a82739c9d0aaa58124db0d0 [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;
Linus Walleijb2083062013-01-11 21:22:36 +0100144 /* Do not defer probing of hogs (circular loop) */
145 if (np_pctldev == p->dev->of_node) {
146 of_node_put(np_pctldev);
147 return -ENODEV;
148 }
Stephen Warren57291ce2012-03-23 10:29:46 -0600149 }
150 of_node_put(np_pctldev);
151
152 /*
153 * Call pinctrl driver to parse device tree node, and
154 * generate mapping table entries
155 */
156 ops = pctldev->desc->pctlops;
157 if (!ops->dt_node_to_map) {
158 dev_err(p->dev, "pctldev %s doesn't support DT\n",
159 dev_name(pctldev->dev));
160 return -ENODEV;
161 }
162 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
163 if (ret < 0)
164 return ret;
165
166 /* Stash the mapping table chunk away for later use */
167 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
168}
169
170static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
171{
172 struct pinctrl_map *map;
173
174 map = kzalloc(sizeof(*map), GFP_KERNEL);
175 if (!map) {
176 dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
177 return -ENOMEM;
178 }
179
180 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
181 map->type = PIN_MAP_TYPE_DUMMY_STATE;
182
183 return dt_remember_or_free_map(p, statename, NULL, map, 1);
184}
185
186int pinctrl_dt_to_map(struct pinctrl *p)
187{
188 struct device_node *np = p->dev->of_node;
189 int state, ret;
190 char *propname;
191 struct property *prop;
192 const char *statename;
193 const __be32 *list;
194 int size, config;
195 phandle phandle;
196 struct device_node *np_config;
197
198 /* CONFIG_OF enabled, p->dev not instantiated from DT */
199 if (!np) {
200 dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n");
201 return 0;
202 }
203
204 /* We may store pointers to property names within the node */
205 of_node_get(np);
206
207 /* For each defined state ID */
208 for (state = 0; ; state++) {
209 /* Retrieve the pinctrl-* property */
210 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
211 prop = of_find_property(np, propname, &size);
212 kfree(propname);
213 if (!prop)
214 break;
215 list = prop->value;
216 size /= sizeof(*list);
217
218 /* Determine whether pinctrl-names property names the state */
219 ret = of_property_read_string_index(np, "pinctrl-names",
220 state, &statename);
221 /*
222 * If not, statename is just the integer state ID. But rather
223 * than dynamically allocate it and have to free it later,
224 * just point part way into the property name for the string.
225 */
226 if (ret < 0) {
227 /* strlen("pinctrl-") == 8 */
228 statename = prop->name + 8;
229 }
230
231 /* For every referenced pin configuration node in it */
232 for (config = 0; config < size; config++) {
233 phandle = be32_to_cpup(list++);
234
235 /* Look up the pin configuration node */
236 np_config = of_find_node_by_phandle(phandle);
237 if (!np_config) {
238 dev_err(p->dev,
239 "prop %s index %i invalid phandle\n",
240 prop->name, config);
241 ret = -EINVAL;
242 goto err;
243 }
244
245 /* Parse the node */
246 ret = dt_to_map_one_config(p, statename, np_config);
247 of_node_put(np_config);
248 if (ret < 0)
249 goto err;
250 }
251
252 /* No entries in DT? Generate a dummy state table entry */
253 if (!size) {
254 ret = dt_remember_dummy_state(p, statename);
255 if (ret < 0)
256 goto err;
257 }
258 }
259
260 return 0;
261
262err:
263 pinctrl_dt_free_maps(p);
264 return ret;
265}