Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 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) { |
Laurent Pinchart | 022ab14 | 2013-02-16 10:25:07 +0100 | [diff] [blame] | 44 | const struct pinctrl_ops *ops = pctldev->desc->pctlops; |
Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 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 | |
| 95 | return pinctrl_register_map(map, num_maps, false, true); |
| 96 | } |
| 97 | |
Linus Walleij | 1e63d7b | 2012-11-06 16:03:35 +0100 | [diff] [blame] | 98 | struct pinctrl_dev *of_pinctrl_get(struct device_node *np) |
Shiraz Hashim | f23f151 | 2012-10-27 15:21:36 +0530 | [diff] [blame] | 99 | { |
| 100 | struct pinctrl_dev *pctldev; |
| 101 | |
Patrice Chotard | 42fed7b | 2013-04-11 11:01:27 +0200 | [diff] [blame] | 102 | pctldev = get_pinctrl_dev_from_of_node(np); |
Shiraz Hashim | f23f151 | 2012-10-27 15:21:36 +0530 | [diff] [blame] | 103 | if (!pctldev) |
| 104 | return NULL; |
| 105 | |
Shiraz Hashim | f23f151 | 2012-10-27 15:21:36 +0530 | [diff] [blame] | 106 | return pctldev; |
| 107 | } |
| 108 | |
Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 109 | static 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; |
Laurent Pinchart | 022ab14 | 2013-02-16 10:25:07 +0100 | [diff] [blame] | 114 | const struct pinctrl_ops *ops; |
Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 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 Walleij | c05127c | 2012-04-10 10:00:38 +0200 | [diff] [blame] | 124 | dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n", |
Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 125 | np_config->full_name); |
| 126 | of_node_put(np_pctldev); |
Linus Walleij | c05127c | 2012-04-10 10:00:38 +0200 | [diff] [blame] | 127 | /* OK let's just assume this will appear later then */ |
| 128 | return -EPROBE_DEFER; |
Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 129 | } |
Patrice Chotard | 42fed7b | 2013-04-11 11:01:27 +0200 | [diff] [blame] | 130 | pctldev = get_pinctrl_dev_from_of_node(np_pctldev); |
Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 131 | if (pctldev) |
| 132 | break; |
Linus Walleij | b208306 | 2013-01-11 21:22:36 +0100 | [diff] [blame] | 133 | /* Do not defer probing of hogs (circular loop) */ |
| 134 | if (np_pctldev == p->dev->of_node) { |
| 135 | of_node_put(np_pctldev); |
| 136 | return -ENODEV; |
| 137 | } |
Stephen Warren | 57291ce | 2012-03-23 10:29:46 -0600 | [diff] [blame] | 138 | } |
| 139 | of_node_put(np_pctldev); |
| 140 | |
| 141 | /* |
| 142 | * Call pinctrl driver to parse device tree node, and |
| 143 | * generate mapping table entries |
| 144 | */ |
| 145 | ops = pctldev->desc->pctlops; |
| 146 | if (!ops->dt_node_to_map) { |
| 147 | dev_err(p->dev, "pctldev %s doesn't support DT\n", |
| 148 | dev_name(pctldev->dev)); |
| 149 | return -ENODEV; |
| 150 | } |
| 151 | ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); |
| 152 | if (ret < 0) |
| 153 | return ret; |
| 154 | |
| 155 | /* Stash the mapping table chunk away for later use */ |
| 156 | return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); |
| 157 | } |
| 158 | |
| 159 | static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) |
| 160 | { |
| 161 | struct pinctrl_map *map; |
| 162 | |
| 163 | map = kzalloc(sizeof(*map), GFP_KERNEL); |
| 164 | if (!map) { |
| 165 | dev_err(p->dev, "failed to alloc struct pinctrl_map\n"); |
| 166 | return -ENOMEM; |
| 167 | } |
| 168 | |
| 169 | /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ |
| 170 | map->type = PIN_MAP_TYPE_DUMMY_STATE; |
| 171 | |
| 172 | return dt_remember_or_free_map(p, statename, NULL, map, 1); |
| 173 | } |
| 174 | |
| 175 | int pinctrl_dt_to_map(struct pinctrl *p) |
| 176 | { |
| 177 | struct device_node *np = p->dev->of_node; |
| 178 | int state, ret; |
| 179 | char *propname; |
| 180 | struct property *prop; |
| 181 | const char *statename; |
| 182 | const __be32 *list; |
| 183 | int size, config; |
| 184 | phandle phandle; |
| 185 | struct device_node *np_config; |
| 186 | |
| 187 | /* CONFIG_OF enabled, p->dev not instantiated from DT */ |
| 188 | if (!np) { |
| 189 | dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n"); |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | /* We may store pointers to property names within the node */ |
| 194 | of_node_get(np); |
| 195 | |
| 196 | /* For each defined state ID */ |
| 197 | for (state = 0; ; state++) { |
| 198 | /* Retrieve the pinctrl-* property */ |
| 199 | propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); |
| 200 | prop = of_find_property(np, propname, &size); |
| 201 | kfree(propname); |
| 202 | if (!prop) |
| 203 | break; |
| 204 | list = prop->value; |
| 205 | size /= sizeof(*list); |
| 206 | |
| 207 | /* Determine whether pinctrl-names property names the state */ |
| 208 | ret = of_property_read_string_index(np, "pinctrl-names", |
| 209 | state, &statename); |
| 210 | /* |
| 211 | * If not, statename is just the integer state ID. But rather |
| 212 | * than dynamically allocate it and have to free it later, |
| 213 | * just point part way into the property name for the string. |
| 214 | */ |
| 215 | if (ret < 0) { |
| 216 | /* strlen("pinctrl-") == 8 */ |
| 217 | statename = prop->name + 8; |
| 218 | } |
| 219 | |
| 220 | /* For every referenced pin configuration node in it */ |
| 221 | for (config = 0; config < size; config++) { |
| 222 | phandle = be32_to_cpup(list++); |
| 223 | |
| 224 | /* Look up the pin configuration node */ |
| 225 | np_config = of_find_node_by_phandle(phandle); |
| 226 | if (!np_config) { |
| 227 | dev_err(p->dev, |
| 228 | "prop %s index %i invalid phandle\n", |
| 229 | prop->name, config); |
| 230 | ret = -EINVAL; |
| 231 | goto err; |
| 232 | } |
| 233 | |
| 234 | /* Parse the node */ |
| 235 | ret = dt_to_map_one_config(p, statename, np_config); |
| 236 | of_node_put(np_config); |
| 237 | if (ret < 0) |
| 238 | goto err; |
| 239 | } |
| 240 | |
| 241 | /* No entries in DT? Generate a dummy state table entry */ |
| 242 | if (!size) { |
| 243 | ret = dt_remember_dummy_state(p, statename); |
| 244 | if (ret < 0) |
| 245 | goto err; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | return 0; |
| 250 | |
| 251 | err: |
| 252 | pinctrl_dt_free_maps(p); |
| 253 | return ret; |
| 254 | } |