Commit | Line | Data |
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57291ce2 SW |
1 | /* |
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 | */ | |
33 | struct pinctrl_dt_map { | |
34 | struct list_head node; | |
35 | struct pinctrl_dev *pctldev; | |
36 | struct pinctrl_map *map; | |
37 | unsigned num_maps; | |
38 | }; | |
39 | ||
40 | static void dt_free_map(struct pinctrl_dev *pctldev, | |
41 | struct pinctrl_map *map, unsigned num_maps) | |
42 | { | |
43 | if (pctldev) { | |
022ab148 | 44 | const struct pinctrl_ops *ops = pctldev->desc->pctlops; |
57291ce2 SW |
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 | ||
52 | void 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 | ||
67 | static 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 | ||
c5272a28 | 95 | return pinctrl_register_map(map, num_maps, false); |
57291ce2 SW |
96 | } |
97 | ||
1e63d7b9 | 98 | struct pinctrl_dev *of_pinctrl_get(struct device_node *np) |
f23f1516 | 99 | { |
fb00de77 | 100 | return get_pinctrl_dev_from_of_node(np); |
f23f1516 SH |
101 | } |
102 | ||
57291ce2 SW |
103 | static int dt_to_map_one_config(struct pinctrl *p, const char *statename, |
104 | struct device_node *np_config) | |
105 | { | |
106 | struct device_node *np_pctldev; | |
107 | struct pinctrl_dev *pctldev; | |
022ab148 | 108 | const struct pinctrl_ops *ops; |
57291ce2 SW |
109 | int ret; |
110 | struct pinctrl_map *map; | |
111 | unsigned num_maps; | |
112 | ||
113 | /* Find the pin controller containing np_config */ | |
114 | np_pctldev = of_node_get(np_config); | |
115 | for (;;) { | |
116 | np_pctldev = of_get_next_parent(np_pctldev); | |
117 | if (!np_pctldev || of_node_is_root(np_pctldev)) { | |
c05127c4 | 118 | dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n", |
57291ce2 SW |
119 | np_config->full_name); |
120 | of_node_put(np_pctldev); | |
c05127c4 LW |
121 | /* OK let's just assume this will appear later then */ |
122 | return -EPROBE_DEFER; | |
57291ce2 | 123 | } |
42fed7ba | 124 | pctldev = get_pinctrl_dev_from_of_node(np_pctldev); |
57291ce2 SW |
125 | if (pctldev) |
126 | break; | |
b2083062 LW |
127 | /* Do not defer probing of hogs (circular loop) */ |
128 | if (np_pctldev == p->dev->of_node) { | |
129 | of_node_put(np_pctldev); | |
130 | return -ENODEV; | |
131 | } | |
57291ce2 SW |
132 | } |
133 | of_node_put(np_pctldev); | |
134 | ||
135 | /* | |
136 | * Call pinctrl driver to parse device tree node, and | |
137 | * generate mapping table entries | |
138 | */ | |
139 | ops = pctldev->desc->pctlops; | |
140 | if (!ops->dt_node_to_map) { | |
141 | dev_err(p->dev, "pctldev %s doesn't support DT\n", | |
142 | dev_name(pctldev->dev)); | |
143 | return -ENODEV; | |
144 | } | |
145 | ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); | |
146 | if (ret < 0) | |
147 | return ret; | |
148 | ||
149 | /* Stash the mapping table chunk away for later use */ | |
150 | return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); | |
151 | } | |
152 | ||
153 | static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) | |
154 | { | |
155 | struct pinctrl_map *map; | |
156 | ||
157 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
158 | if (!map) { | |
159 | dev_err(p->dev, "failed to alloc struct pinctrl_map\n"); | |
160 | return -ENOMEM; | |
161 | } | |
162 | ||
163 | /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ | |
164 | map->type = PIN_MAP_TYPE_DUMMY_STATE; | |
165 | ||
166 | return dt_remember_or_free_map(p, statename, NULL, map, 1); | |
167 | } | |
168 | ||
169 | int pinctrl_dt_to_map(struct pinctrl *p) | |
170 | { | |
171 | struct device_node *np = p->dev->of_node; | |
172 | int state, ret; | |
173 | char *propname; | |
174 | struct property *prop; | |
175 | const char *statename; | |
176 | const __be32 *list; | |
177 | int size, config; | |
178 | phandle phandle; | |
179 | struct device_node *np_config; | |
180 | ||
181 | /* CONFIG_OF enabled, p->dev not instantiated from DT */ | |
182 | if (!np) { | |
5d88dcea MB |
183 | if (of_have_populated_dt()) |
184 | dev_dbg(p->dev, | |
185 | "no of_node; not parsing pinctrl DT\n"); | |
57291ce2 SW |
186 | return 0; |
187 | } | |
188 | ||
189 | /* We may store pointers to property names within the node */ | |
190 | of_node_get(np); | |
191 | ||
192 | /* For each defined state ID */ | |
193 | for (state = 0; ; state++) { | |
194 | /* Retrieve the pinctrl-* property */ | |
195 | propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); | |
196 | prop = of_find_property(np, propname, &size); | |
197 | kfree(propname); | |
198 | if (!prop) | |
199 | break; | |
200 | list = prop->value; | |
201 | size /= sizeof(*list); | |
202 | ||
203 | /* Determine whether pinctrl-names property names the state */ | |
204 | ret = of_property_read_string_index(np, "pinctrl-names", | |
205 | state, &statename); | |
206 | /* | |
207 | * If not, statename is just the integer state ID. But rather | |
208 | * than dynamically allocate it and have to free it later, | |
209 | * just point part way into the property name for the string. | |
210 | */ | |
211 | if (ret < 0) { | |
212 | /* strlen("pinctrl-") == 8 */ | |
213 | statename = prop->name + 8; | |
214 | } | |
215 | ||
216 | /* For every referenced pin configuration node in it */ | |
217 | for (config = 0; config < size; config++) { | |
218 | phandle = be32_to_cpup(list++); | |
219 | ||
220 | /* Look up the pin configuration node */ | |
221 | np_config = of_find_node_by_phandle(phandle); | |
222 | if (!np_config) { | |
223 | dev_err(p->dev, | |
224 | "prop %s index %i invalid phandle\n", | |
225 | prop->name, config); | |
226 | ret = -EINVAL; | |
227 | goto err; | |
228 | } | |
229 | ||
230 | /* Parse the node */ | |
231 | ret = dt_to_map_one_config(p, statename, np_config); | |
232 | of_node_put(np_config); | |
233 | if (ret < 0) | |
234 | goto err; | |
235 | } | |
236 | ||
237 | /* No entries in DT? Generate a dummy state table entry */ | |
238 | if (!size) { | |
239 | ret = dt_remember_dummy_state(p, statename); | |
240 | if (ret < 0) | |
241 | goto err; | |
242 | } | |
243 | } | |
244 | ||
245 | return 0; | |
246 | ||
247 | err: | |
248 | pinctrl_dt_free_maps(p); | |
249 | return ret; | |
250 | } |