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  1/*
  2 * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
  3 *
  4 * Copyright (C) 2015, Intel Corp.
  5 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
  6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  7 *
  8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  9 *
 10 *  This program is free software; you can redistribute it and/or modify
 11 *  it under the terms of the GNU General Public License version 2 as published
 12 *  by the Free Software Foundation.
 13 *
 14 *  This program is distributed in the hope that it will be useful, but
 15 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 16 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 17 *  General Public License for more details.
 18 *
 19 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 20 */
 21
 22#include <linux/acpi.h>
 23#include <linux/device.h>
 24#include <linux/export.h>
 25#include <linux/nls.h>
 26
 27#include "internal.h"
 28
 29static ssize_t acpi_object_path(acpi_handle handle, char *buf)
 30{
 31	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 32	int result;
 33
 34	result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
 35	if (result)
 36		return result;
 37
 38	result = sprintf(buf, "%s\n", (char*)path.pointer);
 39	kfree(path.pointer);
 40	return result;
 41}
 42
 43struct acpi_data_node_attr {
 44	struct attribute attr;
 45	ssize_t (*show)(struct acpi_data_node *, char *);
 46	ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
 47};
 48
 49#define DATA_NODE_ATTR(_name)			\
 50	static struct acpi_data_node_attr data_node_##_name =	\
 51		__ATTR(_name, 0444, data_node_show_##_name, NULL)
 52
 53static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
 54{
 55	return acpi_object_path(dn->handle, buf);
 56}
 57
 58DATA_NODE_ATTR(path);
 59
 60static struct attribute *acpi_data_node_default_attrs[] = {
 61	&data_node_path.attr,
 62	NULL
 63};
 64
 65#define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
 66#define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
 67
 68static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
 69					struct attribute *attr, char *buf)
 70{
 71	struct acpi_data_node *dn = to_data_node(kobj);
 72	struct acpi_data_node_attr *dn_attr = to_attr(attr);
 73
 74	return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
 75}
 76
 77static const struct sysfs_ops acpi_data_node_sysfs_ops = {
 78	.show	= acpi_data_node_attr_show,
 79};
 80
 81static void acpi_data_node_release(struct kobject *kobj)
 82{
 83	struct acpi_data_node *dn = to_data_node(kobj);
 84	complete(&dn->kobj_done);
 85}
 86
 87static struct kobj_type acpi_data_node_ktype = {
 88	.sysfs_ops = &acpi_data_node_sysfs_ops,
 89	.default_attrs = acpi_data_node_default_attrs,
 90	.release = acpi_data_node_release,
 91};
 92
 93static void acpi_expose_nondev_subnodes(struct kobject *kobj,
 94					struct acpi_device_data *data)
 95{
 96	struct list_head *list = &data->subnodes;
 97	struct acpi_data_node *dn;
 98
 99	if (list_empty(list))
100		return;
101
102	list_for_each_entry(dn, list, sibling) {
103		int ret;
104
105		init_completion(&dn->kobj_done);
106		ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
107					   kobj, "%s", dn->name);
108		if (ret)
109			acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
110		else
111			acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
112	}
113}
114
115static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
116{
117	struct list_head *list = &data->subnodes;
118	struct acpi_data_node *dn;
119
120	if (list_empty(list))
121		return;
122
123	list_for_each_entry_reverse(dn, list, sibling) {
124		acpi_hide_nondev_subnodes(&dn->data);
125		kobject_put(&dn->kobj);
126	}
127}
128
129/**
130 * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
131 * @acpi_dev: ACPI device object.
132 * @modalias: Buffer to print into.
133 * @size: Size of the buffer.
134 *
135 * Creates hid/cid(s) string needed for modalias and uevent
136 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
137 * char *modalias: "acpi:IBM0001:ACPI0001"
138 * Return: 0: no _HID and no _CID
139 *         -EINVAL: output error
140 *         -ENOMEM: output is truncated
141*/
142static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
143			       int size)
144{
145	int len;
146	int count;
147	struct acpi_hardware_id *id;
148
149	/*
150	 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
151	 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
152	 * device's list.
153	 */
154	count = 0;
155	list_for_each_entry(id, &acpi_dev->pnp.ids, list)
156		if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
157			count++;
158
159	if (!count)
160		return 0;
161
162	len = snprintf(modalias, size, "acpi:");
163	if (len <= 0)
164		return len;
165
166	size -= len;
167
168	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
169		if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
170			continue;
171
172		count = snprintf(&modalias[len], size, "%s:", id->id);
173		if (count < 0)
174			return -EINVAL;
175
176		if (count >= size)
177			return -ENOMEM;
178
179		len += count;
180		size -= count;
181	}
182	modalias[len] = '\0';
183	return len;
184}
185
186/**
187 * create_of_modalias - Creates DT compatible string for modalias and uevent
188 * @acpi_dev: ACPI device object.
189 * @modalias: Buffer to print into.
190 * @size: Size of the buffer.
191 *
192 * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
193 * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
194 * ACPI/PNP IDs.
195 */
196static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
197			      int size)
198{
199	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
200	const union acpi_object *of_compatible, *obj;
201	int len, count;
202	int i, nval;
203	char *c;
204
205	acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
206	/* DT strings are all in lower case */
207	for (c = buf.pointer; *c != '\0'; c++)
208		*c = tolower(*c);
209
210	len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
211	ACPI_FREE(buf.pointer);
212
213	if (len <= 0)
214		return len;
215
216	of_compatible = acpi_dev->data.of_compatible;
217	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
218		nval = of_compatible->package.count;
219		obj = of_compatible->package.elements;
220	} else { /* Must be ACPI_TYPE_STRING. */
221		nval = 1;
222		obj = of_compatible;
223	}
224	for (i = 0; i < nval; i++, obj++) {
225		count = snprintf(&modalias[len], size, "C%s",
226				 obj->string.pointer);
227		if (count < 0)
228			return -EINVAL;
229
230		if (count >= size)
231			return -ENOMEM;
232
233		len += count;
234		size -= count;
235	}
236	modalias[len] = '\0';
237	return len;
238}
239
240int __acpi_device_uevent_modalias(struct acpi_device *adev,
241				  struct kobj_uevent_env *env)
242{
243	int len;
244
245	if (!adev)
246		return -ENODEV;
247
248	if (list_empty(&adev->pnp.ids))
249		return 0;
250
251	if (add_uevent_var(env, "MODALIAS="))
252		return -ENOMEM;
253
254	len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
255				  sizeof(env->buf) - env->buflen);
256	if (len < 0)
257		return len;
258
259	env->buflen += len;
260	if (!adev->data.of_compatible)
261		return 0;
262
263	if (len > 0 && add_uevent_var(env, "MODALIAS="))
264		return -ENOMEM;
265
266	len = create_of_modalias(adev, &env->buf[env->buflen - 1],
267				 sizeof(env->buf) - env->buflen);
268	if (len < 0)
269		return len;
270
271	env->buflen += len;
272
273	return 0;
274}
275
276/**
277 * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
278 *
279 * Create the uevent modalias field for ACPI-enumerated devices.
280 *
281 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
282 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
283 */
284int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
285{
286	return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
287}
288EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
289
290static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
291{
292	int len, count;
293
294	if (!adev)
295		return -ENODEV;
296
297	if (list_empty(&adev->pnp.ids))
298		return 0;
299
300	len = create_pnp_modalias(adev, buf, size - 1);
301	if (len < 0) {
302		return len;
303	} else if (len > 0) {
304		buf[len++] = '\n';
305		size -= len;
306	}
307	if (!adev->data.of_compatible)
308		return len;
309
310	count = create_of_modalias(adev, buf + len, size - 1);
311	if (count < 0) {
312		return count;
313	} else if (count > 0) {
314		len += count;
315		buf[len++] = '\n';
316	}
317
318	return len;
319}
320
321/**
322 * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
323 *
324 * Create the modalias sysfs attribute for ACPI-enumerated devices.
325 *
326 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
327 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
328 */
329int acpi_device_modalias(struct device *dev, char *buf, int size)
330{
331	return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
332}
333EXPORT_SYMBOL_GPL(acpi_device_modalias);
334
335static ssize_t
336acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
337	return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
338}
339static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
340
341static ssize_t real_power_state_show(struct device *dev,
342				     struct device_attribute *attr, char *buf)
343{
344	struct acpi_device *adev = to_acpi_device(dev);
345	int state;
346	int ret;
347
348	ret = acpi_device_get_power(adev, &state);
349	if (ret)
350		return ret;
351
352	return sprintf(buf, "%s\n", acpi_power_state_string(state));
353}
354
355static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
356
357static ssize_t power_state_show(struct device *dev,
358				struct device_attribute *attr, char *buf)
359{
360	struct acpi_device *adev = to_acpi_device(dev);
361
362	return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
363}
364
365static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
366
367static ssize_t
368acpi_eject_store(struct device *d, struct device_attribute *attr,
369		const char *buf, size_t count)
370{
371	struct acpi_device *acpi_device = to_acpi_device(d);
372	acpi_object_type not_used;
373	acpi_status status;
374
375	if (!count || buf[0] != '1')
376		return -EINVAL;
377
378	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
379	    && !acpi_device->driver)
380		return -ENODEV;
381
382	status = acpi_get_type(acpi_device->handle, &not_used);
383	if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
384		return -ENODEV;
385
386	get_device(&acpi_device->dev);
387	status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
388	if (ACPI_SUCCESS(status))
389		return count;
390
391	put_device(&acpi_device->dev);
392	acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
393			  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
394	return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
395}
396
397static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
398
399static ssize_t
400acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
401	struct acpi_device *acpi_dev = to_acpi_device(dev);
402
403	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
404}
405static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
406
407static ssize_t acpi_device_uid_show(struct device *dev,
408				    struct device_attribute *attr, char *buf)
409{
410	struct acpi_device *acpi_dev = to_acpi_device(dev);
411
412	return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
413}
414static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
415
416static ssize_t acpi_device_adr_show(struct device *dev,
417				    struct device_attribute *attr, char *buf)
418{
419	struct acpi_device *acpi_dev = to_acpi_device(dev);
420
421	return sprintf(buf, "0x%08x\n",
422		       (unsigned int)(acpi_dev->pnp.bus_address));
423}
424static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
425
426static ssize_t acpi_device_path_show(struct device *dev,
427				     struct device_attribute *attr, char *buf)
428{
429	struct acpi_device *acpi_dev = to_acpi_device(dev);
430
431	return acpi_object_path(acpi_dev->handle, buf);
432}
433static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
434
435/* sysfs file that shows description text from the ACPI _STR method */
436static ssize_t description_show(struct device *dev,
437				struct device_attribute *attr,
438				char *buf) {
439	struct acpi_device *acpi_dev = to_acpi_device(dev);
440	int result;
441
442	if (acpi_dev->pnp.str_obj == NULL)
443		return 0;
444
445	/*
446	 * The _STR object contains a Unicode identifier for a device.
447	 * We need to convert to utf-8 so it can be displayed.
448	 */
449	result = utf16s_to_utf8s(
450		(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
451		acpi_dev->pnp.str_obj->buffer.length,
452		UTF16_LITTLE_ENDIAN, buf,
453		PAGE_SIZE);
454
455	buf[result++] = '\n';
456
457	return result;
458}
459static DEVICE_ATTR(description, 0444, description_show, NULL);
460
461static ssize_t
462acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
463		     char *buf) {
464	struct acpi_device *acpi_dev = to_acpi_device(dev);
465	acpi_status status;
466	unsigned long long sun;
467
468	status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
469	if (ACPI_FAILURE(status))
470		return -ENODEV;
471
472	return sprintf(buf, "%llu\n", sun);
473}
474static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
475
476static ssize_t status_show(struct device *dev, struct device_attribute *attr,
477				char *buf) {
478	struct acpi_device *acpi_dev = to_acpi_device(dev);
479	acpi_status status;
480	unsigned long long sta;
481
482	status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
483	if (ACPI_FAILURE(status))
484		return -ENODEV;
485
486	return sprintf(buf, "%llu\n", sta);
487}
488static DEVICE_ATTR_RO(status);
489
490/**
491 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
492 * @dev: ACPI device object.
493 */
494int acpi_device_setup_files(struct acpi_device *dev)
495{
496	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
497	acpi_status status;
498	int result = 0;
499
500	/*
501	 * Devices gotten from FADT don't have a "path" attribute
502	 */
503	if (dev->handle) {
504		result = device_create_file(&dev->dev, &dev_attr_path);
505		if (result)
506			goto end;
507	}
508
509	if (!list_empty(&dev->pnp.ids)) {
510		result = device_create_file(&dev->dev, &dev_attr_hid);
511		if (result)
512			goto end;
513
514		result = device_create_file(&dev->dev, &dev_attr_modalias);
515		if (result)
516			goto end;
517	}
518
519	/*
520	 * If device has _STR, 'description' file is created
521	 */
522	if (acpi_has_method(dev->handle, "_STR")) {
523		status = acpi_evaluate_object(dev->handle, "_STR",
524					NULL, &buffer);
525		if (ACPI_FAILURE(status))
526			buffer.pointer = NULL;
527		dev->pnp.str_obj = buffer.pointer;
528		result = device_create_file(&dev->dev, &dev_attr_description);
529		if (result)
530			goto end;
531	}
532
533	if (dev->pnp.type.bus_address)
534		result = device_create_file(&dev->dev, &dev_attr_adr);
535	if (dev->pnp.unique_id)
536		result = device_create_file(&dev->dev, &dev_attr_uid);
537
538	if (acpi_has_method(dev->handle, "_SUN")) {
539		result = device_create_file(&dev->dev, &dev_attr_sun);
540		if (result)
541			goto end;
542	}
543
544	if (acpi_has_method(dev->handle, "_STA")) {
545		result = device_create_file(&dev->dev, &dev_attr_status);
546		if (result)
547			goto end;
548	}
549
550        /*
551         * If device has _EJ0, 'eject' file is created that is used to trigger
552         * hot-removal function from userland.
553         */
554	if (acpi_has_method(dev->handle, "_EJ0")) {
555		result = device_create_file(&dev->dev, &dev_attr_eject);
556		if (result)
557			return result;
558	}
559
560	if (dev->flags.power_manageable) {
561		result = device_create_file(&dev->dev, &dev_attr_power_state);
562		if (result)
563			return result;
564
565		if (dev->power.flags.power_resources)
566			result = device_create_file(&dev->dev,
567						    &dev_attr_real_power_state);
568	}
569
570	acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
571
572end:
573	return result;
574}
575
576/**
577 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
578 * @dev: ACPI device object.
579 */
580void acpi_device_remove_files(struct acpi_device *dev)
581{
582	acpi_hide_nondev_subnodes(&dev->data);
583
584	if (dev->flags.power_manageable) {
585		device_remove_file(&dev->dev, &dev_attr_power_state);
586		if (dev->power.flags.power_resources)
587			device_remove_file(&dev->dev,
588					   &dev_attr_real_power_state);
589	}
590
591	/*
592	 * If device has _STR, remove 'description' file
593	 */
594	if (acpi_has_method(dev->handle, "_STR")) {
595		kfree(dev->pnp.str_obj);
596		device_remove_file(&dev->dev, &dev_attr_description);
597	}
598	/*
599	 * If device has _EJ0, remove 'eject' file.
600	 */
601	if (acpi_has_method(dev->handle, "_EJ0"))
602		device_remove_file(&dev->dev, &dev_attr_eject);
603
604	if (acpi_has_method(dev->handle, "_SUN"))
605		device_remove_file(&dev->dev, &dev_attr_sun);
606
607	if (dev->pnp.unique_id)
608		device_remove_file(&dev->dev, &dev_attr_uid);
609	if (dev->pnp.type.bus_address)
610		device_remove_file(&dev->dev, &dev_attr_adr);
611	device_remove_file(&dev->dev, &dev_attr_modalias);
612	device_remove_file(&dev->dev, &dev_attr_hid);
613	if (acpi_has_method(dev->handle, "_STA"))
614		device_remove_file(&dev->dev, &dev_attr_status);
615	if (dev->handle)
616		device_remove_file(&dev->dev, &dev_attr_path);
617}