summaryrefslogtreecommitdiffstats
path: root/drivers/pinctrl/devicetree.c
blob: 2969ff3162c35b17fdce2b516f927b558543e497 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
/*
 * Device tree integration for the pin control subsystem
 *
 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/device.h>
#include <linux/of.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/slab.h>

#include "core.h"
#include "devicetree.h"

/**
 * struct pinctrl_dt_map - mapping table chunk parsed from device tree
 * @node: list node for struct pinctrl's @dt_maps field
 * @pctldev: the pin controller that allocated this struct, and will free it
 * @maps: the mapping table entries
 */
struct pinctrl_dt_map {
	struct list_head node;
	struct pinctrl_dev *pctldev;
	struct pinctrl_map *map;
	unsigned num_maps;
};

static void dt_free_map(struct pinctrl_dev *pctldev,
		     struct pinctrl_map *map, unsigned num_maps)
{
	if (pctldev) {
		const struct pinctrl_ops *ops = pctldev->desc->pctlops;
		if (ops->dt_free_map)
			ops->dt_free_map(pctldev, map, num_maps);
	} else {
		/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
		kfree(map);
	}
}

void pinctrl_dt_free_maps(struct pinctrl *p)
{
	struct pinctrl_dt_map *dt_map, *n1;

	list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
		pinctrl_unregister_map(dt_map->map);
		list_del(&dt_map->node);
		dt_free_map(dt_map->pctldev, dt_map->map,
			    dt_map->num_maps);
		kfree(dt_map);
	}

	of_node_put(p->dev->of_node);
}

static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
				   struct pinctrl_dev *pctldev,
				   struct pinctrl_map *map, unsigned num_maps)
{
	int i;
	struct pinctrl_dt_map *dt_map;

	/* Initialize common mapping table entry fields */
	for (i = 0; i < num_maps; i++) {
		map[i].dev_name = dev_name(p->dev);
		map[i].name = statename;
		if (pctldev)
			map[i].ctrl_dev_name = dev_name(pctldev->dev);
	}

	/* Remember the converted mapping table entries */
	dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
	if (!dt_map) {
		dt_free_map(pctldev, map, num_maps);
		return -ENOMEM;
	}

	dt_map->pctldev = pctldev;
	dt_map->map = map;
	dt_map->num_maps = num_maps;
	list_add_tail(&dt_map->node, &p->dt_maps);

	return pinctrl_register_map(map, num_maps, false);
}

struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
{
	return get_pinctrl_dev_from_of_node(np);
}

static int dt_to_map_one_config(struct pinctrl *p,
				struct pinctrl_dev *hog_pctldev,
				const char *statename,
				struct device_node *np_config)
{
	struct pinctrl_dev *pctldev = NULL;
	struct device_node *np_pctldev;
	const struct pinctrl_ops *ops;
	int ret;
	struct pinctrl_map *map;
	unsigned num_maps;
	bool allow_default = false;

	/* Find the pin controller containing np_config */
	np_pctldev = of_node_get(np_config);
	for (;;) {
		if (!allow_default)
			allow_default = of_property_read_bool(np_pctldev,
							      "pinctrl-use-default");

		np_pctldev = of_get_next_parent(np_pctldev);
		if (!np_pctldev || of_node_is_root(np_pctldev)) {
			of_node_put(np_pctldev);
			ret = driver_deferred_probe_check_state(p->dev);
			/* keep deferring if modules are enabled unless we've timed out */
			if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret == -ENODEV)
				ret = -EPROBE_DEFER;

			return ret;
		}
		/* If we're creating a hog we can use the passed pctldev */
		if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
			pctldev = hog_pctldev;
			break;
		}
		pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
		if (pctldev)
			break;
		/* Do not defer probing of hogs (circular loop) */
		if (np_pctldev == p->dev->of_node) {
			of_node_put(np_pctldev);
			return -ENODEV;
		}
	}
	of_node_put(np_pctldev);

	/*
	 * Call pinctrl driver to parse device tree node, and
	 * generate mapping table entries
	 */
	ops = pctldev->desc->pctlops;
	if (!ops->dt_node_to_map) {
		dev_err(p->dev, "pctldev %s doesn't support DT\n",
			dev_name(pctldev->dev));
		return -ENODEV;
	}
	ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
	if (ret < 0)
		return ret;

	/* Stash the mapping table chunk away for later use */
	return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
}

static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
{
	struct pinctrl_map *map;

	map = kzalloc(sizeof(*map), GFP_KERNEL);
	if (!map)
		return -ENOMEM;

	/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
	map->type = PIN_MAP_TYPE_DUMMY_STATE;

	return dt_remember_or_free_map(p, statename, NULL, map, 1);
}

bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
{
	struct device_node *np;
	struct property *prop;
	int size;

	np = pctldev->dev->of_node;
	if (!np)
		return false;

	prop = of_find_property(np, "pinctrl-0", &size);

	return prop ? true : false;
}

int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
{
	struct device_node *np = p->dev->of_node;
	int state, ret;
	char *propname;
	struct property *prop;
	const char *statename;
	const __be32 *list;
	int size, config;
	phandle phandle;
	struct device_node *np_config;

	/* CONFIG_OF enabled, p->dev not instantiated from DT */
	if (!np) {
		if (of_have_populated_dt())
			dev_dbg(p->dev,
				"no of_node; not parsing pinctrl DT\n");
		return 0;
	}

	/* We may store pointers to property names within the node */
	of_node_get(np);

	/* For each defined state ID */
	for (state = 0; ; state++) {
		/* Retrieve the pinctrl-* property */
		propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
		prop = of_find_property(np, propname, &size);
		kfree(propname);
		if (!prop) {
			if (state == 0) {
				of_node_put(np);
				return -ENODEV;
			}
			break;
		}
		list = prop->value;
		size /= sizeof(*list);

		/* Determine whether pinctrl-names property names the state */
		ret = of_property_read_string_index(np, "pinctrl-names",
						    state, &statename);
		/*
		 * If not, statename is just the integer state ID. But rather
		 * than dynamically allocate it and have to free it later,
		 * just point part way into the property name for the string.
		 */
		if (ret < 0) {
			/* strlen("pinctrl-") == 8 */
			statename = prop->name + 8;
		}

		/* For every referenced pin configuration node in it */
		for (config = 0; config < size; config++) {
			phandle = be32_to_cpup(list++);

			/* Look up the pin configuration node */
			np_config = of_find_node_by_phandle(phandle);
			if (!np_config) {
				dev_err(p->dev,
					"prop %s index %i invalid phandle\n",
					prop->name, config);
				ret = -EINVAL;
				goto err;
			}

			/* Parse the node */
			ret = dt_to_map_one_config(p, pctldev, statename,
						   np_config);
			of_node_put(np_config);
			if (ret < 0)
				goto err;
		}

		/* No entries in DT? Generate a dummy state table entry */
		if (!size) {
			ret = dt_remember_dummy_state(p, statename);
			if (ret < 0)
				goto err;
		}
	}

	return 0;

err:
	pinctrl_dt_free_maps(p);
	return ret;
}

/*
 * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 * device, so either parent or grandparent. See pinctrl-bindings.txt.
 */
static int pinctrl_find_cells_size(const struct device_node *np)
{
	const char *cells_name = "#pinctrl-cells";
	int cells_size, error;

	error = of_property_read_u32(np->parent, cells_name, &cells_size);
	if (error) {
		error = of_property_read_u32(np->parent->parent,
					     cells_name, &cells_size);
		if (error)
			return -ENOENT;
	}

	return cells_size;
}

/**
 * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 * @np: pointer to device node with the property
 * @list_name: property that contains the list
 * @list: pointer for the list found
 * @cells_size: pointer for the cell size found
 * @nr_elements: pointer for the number of elements found
 *
 * Typically np is a single pinctrl entry containing the list.
 */
static int pinctrl_get_list_and_count(const struct device_node *np,
				      const char *list_name,
				      const __be32 **list,
				      int *cells_size,
				      int *nr_elements)
{
	int size;

	*cells_size = 0;
	*nr_elements = 0;

	*list = of_get_property(np, list_name, &size);
	if (!*list)
		return -ENOENT;

	*cells_size = pinctrl_find_cells_size(np);
	if (*cells_size < 0)
		return -ENOENT;

	/* First element is always the index within the pinctrl device */
	*nr_elements = (size / sizeof(**list)) / (*cells_size + 1);

	return 0;
}

/**
 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 * @np: pointer to device node with the property
 * @list_name: property that contains the list
 *
 * Counts the number of elements in a pinctrl array consisting of an index
 * within the controller and a number of u32 entries specified for each
 * entry. Note that device_node is always for the parent pin controller device.
 */
int pinctrl_count_index_with_args(const struct device_node *np,
				  const char *list_name)
{
	const __be32 *list;
	int size, nr_cells, error;

	error = pinctrl_get_list_and_count(np, list_name, &list,
					   &nr_cells, &size);
	if (error)
		return error;

	return size;
}
EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);

/**
 * pinctrl_copy_args - Populates of_phandle_args based on index
 * @np: pointer to device node with the property
 * @list: pointer to a list with the elements
 * @index: entry within the list of elements
 * @nr_cells: number of cells in the list
 * @nr_elem: number of elements for each entry in the list
 * @out_args: returned values
 *
 * Populates the of_phandle_args based on the index in the list.
 */
static int pinctrl_copy_args(const struct device_node *np,
			     const __be32 *list,
			     int index, int nr_cells, int nr_elem,
			     struct of_phandle_args *out_args)
{
	int i;

	memset(out_args, 0, sizeof(*out_args));
	out_args->np = (struct device_node *)np;
	out_args->args_count = nr_cells + 1;

	if (index >= nr_elem)
		return -EINVAL;

	list += index * (nr_cells + 1);

	for (i = 0; i < nr_cells + 1; i++)
		out_args->args[i] = be32_to_cpup(list++);

	return 0;
}

/**
 * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 * @np: pointer to device node with the property
 * @list_name: property that contains the list
 * @index: index within the list
 * @out_arts: entries in the list pointed by index
 *
 * Finds the selected element in a pinctrl array consisting of an index
 * within the controller and a number of u32 entries specified for each
 * entry. Note that device_node is always for the parent pin controller device.
 */
int pinctrl_parse_index_with_args(const struct device_node *np,
				  const char *list_name, int index,
				  struct of_phandle_args *out_args)
{
	const __be32 *list;
	int nr_elem, nr_cells, error;

	error = pinctrl_get_list_and_count(np, list_name, &list,
					   &nr_cells, &nr_elem);
	if (error || !nr_cells)
		return error;

	error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
				  out_args);
	if (error)
		return error;

	return 0;
}
EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);