blob: fcb1de45473cd2f7f6df93cbe28542b774f59ab3 [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
109static int dt_to_map_one_config(struct pinctrl *p, const char *statename,
110 struct device_node *np_config)
111{
112 struct device_node *np_pctldev;
113 struct pinctrl_dev *pctldev;
114 struct pinctrl_ops *ops;
115 int ret;
116 struct pinctrl_map *map;
117 unsigned num_maps;
118
119 /* Find the pin controller containing np_config */
120 np_pctldev = of_node_get(np_config);
121 for (;;) {
122 np_pctldev = of_get_next_parent(np_pctldev);
123 if (!np_pctldev || of_node_is_root(np_pctldev)) {
Linus Walleijc05127c2012-04-10 10:00:38 +0200124 dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n",
Stephen Warren57291ce2012-03-23 10:29:46 -0600125 np_config->full_name);
126 of_node_put(np_pctldev);
Linus Walleijc05127c2012-04-10 10:00:38 +0200127 /* OK let's just assume this will appear later then */
128 return -EPROBE_DEFER;
Stephen Warren57291ce2012-03-23 10:29:46 -0600129 }
130 pctldev = find_pinctrl_by_of_node(np_pctldev);
131 if (pctldev)
132 break;
133 }
134 of_node_put(np_pctldev);
135
136 /*
137 * Call pinctrl driver to parse device tree node, and
138 * generate mapping table entries
139 */
140 ops = pctldev->desc->pctlops;
141 if (!ops->dt_node_to_map) {
142 dev_err(p->dev, "pctldev %s doesn't support DT\n",
143 dev_name(pctldev->dev));
144 return -ENODEV;
145 }
146 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
147 if (ret < 0)
148 return ret;
149
150 /* Stash the mapping table chunk away for later use */
151 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
152}
153
154static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
155{
156 struct pinctrl_map *map;
157
158 map = kzalloc(sizeof(*map), GFP_KERNEL);
159 if (!map) {
160 dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
161 return -ENOMEM;
162 }
163
164 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
165 map->type = PIN_MAP_TYPE_DUMMY_STATE;
166
167 return dt_remember_or_free_map(p, statename, NULL, map, 1);
168}
169
170int pinctrl_dt_to_map(struct pinctrl *p)
171{
172 struct device_node *np = p->dev->of_node;
173 int state, ret;
174 char *propname;
175 struct property *prop;
176 const char *statename;
177 const __be32 *list;
178 int size, config;
179 phandle phandle;
180 struct device_node *np_config;
181
182 /* CONFIG_OF enabled, p->dev not instantiated from DT */
183 if (!np) {
184 dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n");
185 return 0;
186 }
187
188 /* We may store pointers to property names within the node */
189 of_node_get(np);
190
191 /* For each defined state ID */
192 for (state = 0; ; state++) {
193 /* Retrieve the pinctrl-* property */
194 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
195 prop = of_find_property(np, propname, &size);
196 kfree(propname);
197 if (!prop)
198 break;
199 list = prop->value;
200 size /= sizeof(*list);
201
202 /* Determine whether pinctrl-names property names the state */
203 ret = of_property_read_string_index(np, "pinctrl-names",
204 state, &statename);
205 /*
206 * If not, statename is just the integer state ID. But rather
207 * than dynamically allocate it and have to free it later,
208 * just point part way into the property name for the string.
209 */
210 if (ret < 0) {
211 /* strlen("pinctrl-") == 8 */
212 statename = prop->name + 8;
213 }
214
215 /* For every referenced pin configuration node in it */
216 for (config = 0; config < size; config++) {
217 phandle = be32_to_cpup(list++);
218
219 /* Look up the pin configuration node */
220 np_config = of_find_node_by_phandle(phandle);
221 if (!np_config) {
222 dev_err(p->dev,
223 "prop %s index %i invalid phandle\n",
224 prop->name, config);
225 ret = -EINVAL;
226 goto err;
227 }
228
229 /* Parse the node */
230 ret = dt_to_map_one_config(p, statename, np_config);
231 of_node_put(np_config);
232 if (ret < 0)
233 goto err;
234 }
235
236 /* No entries in DT? Generate a dummy state table entry */
237 if (!size) {
238 ret = dt_remember_dummy_state(p, statename);
239 if (ret < 0)
240 goto err;
241 }
242 }
243
244 return 0;
245
246err:
247 pinctrl_dt_free_maps(p);
248 return ret;
249}