1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
  4 *
  5 * Copyright (C) 2015, Intel Corp.
  6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
  7 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  8 *
  9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 10 *
 11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 12 */
 13
 14#include <linux/acpi.h>
 15#include <linux/device.h>
 16#include <linux/export.h>
 17#include <linux/nls.h>
 18
 19#include "internal.h"
 20
 21static ssize_t acpi_object_path(acpi_handle handle, char *buf)
 22{
 23	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
 24	int result;
 25
 26	result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
 27	if (result)
 28		return result;
 29
 30	result = sprintf(buf, "%s\n", (char *)path.pointer);
 31	kfree(path.pointer);
 32	return result;
 33}
 34
 35struct acpi_data_node_attr {
 36	struct attribute attr;
 37	ssize_t (*show)(struct acpi_data_node *, char *);
 38	ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
 39};
 40
 41#define DATA_NODE_ATTR(_name)			\
 42	static struct acpi_data_node_attr data_node_##_name =	\
 43		__ATTR(_name, 0444, data_node_show_##_name, NULL)
 44
 45static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
 46{
 47	return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
 48}
 49
 50DATA_NODE_ATTR(path);
 51
 52static struct attribute *acpi_data_node_default_attrs[] = {
 53	&data_node_path.attr,
 54	NULL
 55};
 56ATTRIBUTE_GROUPS(acpi_data_node_default);
 57
 58#define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
 59#define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
 60
 61static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
 62					struct attribute *attr, char *buf)
 63{
 64	struct acpi_data_node *dn = to_data_node(kobj);
 65	struct acpi_data_node_attr *dn_attr = to_attr(attr);
 66
 67	return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
 68}
 69
 70static const struct sysfs_ops acpi_data_node_sysfs_ops = {
 71	.show	= acpi_data_node_attr_show,
 72};
 73
 74static void acpi_data_node_release(struct kobject *kobj)
 75{
 76	struct acpi_data_node *dn = to_data_node(kobj);
 77
 78	complete(&dn->kobj_done);
 79}
 80
 81static const struct kobj_type acpi_data_node_ktype = {
 82	.sysfs_ops = &acpi_data_node_sysfs_ops,
 83	.default_groups = acpi_data_node_default_groups,
 84	.release = acpi_data_node_release,
 85};
 86
 87static void acpi_expose_nondev_subnodes(struct kobject *kobj,
 88					struct acpi_device_data *data)
 89{
 90	struct list_head *list = &data->subnodes;
 91	struct acpi_data_node *dn;
 92
 93	if (list_empty(list))
 94		return;
 95
 96	list_for_each_entry(dn, list, sibling) {
 97		int ret;
 98
 99		init_completion(&dn->kobj_done);
100		ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
101					   kobj, "%s", dn->name);
102		if (!ret)
103			acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
104		else if (dn->handle)
105			acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
106	}
107}
108
109static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
110{
111	struct list_head *list = &data->subnodes;
112	struct acpi_data_node *dn;
113
114	if (list_empty(list))
115		return;
116
117	list_for_each_entry_reverse(dn, list, sibling) {
118		acpi_hide_nondev_subnodes(&dn->data);
119		kobject_put(&dn->kobj);
120	}
121}
122
123/**
124 * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
125 * @acpi_dev: ACPI device object.
126 * @modalias: Buffer to print into.
127 * @size: Size of the buffer.
128 *
129 * Creates hid/cid(s) string needed for modalias and uevent
130 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
131 * char *modalias: "acpi:IBM0001:ACPI0001"
132 * Return: 0: no _HID and no _CID
133 *         -EINVAL: output error
134 *         -ENOMEM: output is truncated
135 */
136static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalias,
137			       int size)
138{
139	int len;
140	int count;
141	struct acpi_hardware_id *id;
142
143	/* Avoid unnecessarily loading modules for non present devices. */
144	if (!acpi_device_is_present(acpi_dev))
145		return 0;
146
147	/*
148	 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
149	 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
150	 * device's list.
151	 */
152	count = 0;
153	list_for_each_entry(id, &acpi_dev->pnp.ids, list)
154		if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
155			count++;
156
157	if (!count)
158		return 0;
159
160	len = snprintf(modalias, size, "acpi:");
161	if (len >= size)
162		return -ENOMEM;
163
164	size -= len;
165
166	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
167		if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
168			continue;
169
170		count = snprintf(&modalias[len], size, "%s:", id->id);
171
172		if (count >= size)
173			return -ENOMEM;
174
175		len += count;
176		size -= count;
177	}
178
179	return len;
180}
181
182/**
183 * create_of_modalias - Creates DT compatible string for modalias and uevent
184 * @acpi_dev: ACPI device object.
185 * @modalias: Buffer to print into.
186 * @size: Size of the buffer.
187 *
188 * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
189 * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
190 * ACPI/PNP IDs.
191 */
192static int create_of_modalias(const struct acpi_device *acpi_dev, char *modalias,
193			      int size)
194{
195	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
196	const union acpi_object *of_compatible, *obj;
197	acpi_status status;
198	int len, count;
199	int i, nval;
200	char *c;
201
202	status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
203	if (ACPI_FAILURE(status))
204		return -ENODEV;
205
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 >= size)
214		return -ENOMEM;
215
216	size -= len;
217
218	of_compatible = acpi_dev->data.of_compatible;
219	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
220		nval = of_compatible->package.count;
221		obj = of_compatible->package.elements;
222	} else { /* Must be ACPI_TYPE_STRING. */
223		nval = 1;
224		obj = of_compatible;
225	}
226	for (i = 0; i < nval; i++, obj++) {
227		count = snprintf(&modalias[len], size, "C%s",
228				 obj->string.pointer);
229
230		if (count >= size)
231			return -ENOMEM;
232
233		len += count;
234		size -= count;
235	}
236
237	return len;
238}
239
240int __acpi_device_uevent_modalias(const 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	if (adev->data.of_compatible)
255		len = create_of_modalias(adev, &env->buf[env->buflen - 1],
256					 sizeof(env->buf) - env->buflen);
257	else
258		len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
259					  sizeof(env->buf) - env->buflen);
260	if (len < 0)
261		return len;
262
263	env->buflen += len;
264
265	return 0;
266}
267
268/**
269 * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
270 * @dev: Struct device to get ACPI device node.
271 * @env: Environment variables of the kobject uevent.
272 *
273 * Create the uevent modalias field for ACPI-enumerated devices.
274 *
275 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
276 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
277 */
278int acpi_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
279{
280	return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
281}
282EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
283
284static int __acpi_device_modalias(const struct acpi_device *adev, char *buf, int size)
285{
286	int len, count;
287
288	if (!adev)
289		return -ENODEV;
290
291	if (list_empty(&adev->pnp.ids))
292		return 0;
293
294	len = create_pnp_modalias(adev, buf, size - 1);
295	if (len < 0) {
296		return len;
297	} else if (len > 0) {
298		buf[len++] = '\n';
299		size -= len;
300	}
301	if (!adev->data.of_compatible)
302		return len;
303
304	count = create_of_modalias(adev, buf + len, size - 1);
305	if (count < 0) {
306		return count;
307	} else if (count > 0) {
308		len += count;
309		buf[len++] = '\n';
310	}
311
312	return len;
313}
314
315/**
316 * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
317 * @dev: Struct device to get ACPI device node.
318 * @buf: The buffer to save pnp_modalias and of_modalias.
319 * @size: Size of buffer.
320 *
321 * Create the modalias sysfs attribute for ACPI-enumerated devices.
322 *
323 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
324 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
325 */
326int acpi_device_modalias(struct device *dev, char *buf, int size)
327{
328	return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
329}
330EXPORT_SYMBOL_GPL(acpi_device_modalias);
331
332static ssize_t
333modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
334{
335	return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
336}
337static DEVICE_ATTR_RO(modalias);
338
339static ssize_t real_power_state_show(struct device *dev,
340				     struct device_attribute *attr, char *buf)
341{
342	struct acpi_device *adev = to_acpi_device(dev);
343	int state;
344	int ret;
345
346	ret = acpi_device_get_power(adev, &state);
347	if (ret)
348		return ret;
349
350	return sprintf(buf, "%s\n", acpi_power_state_string(state));
351}
352
353static DEVICE_ATTR_RO(real_power_state);
354
355static ssize_t power_state_show(struct device *dev,
356				struct device_attribute *attr, char *buf)
357{
358	struct acpi_device *adev = to_acpi_device(dev);
359
360	return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
361}
362
363static DEVICE_ATTR_RO(power_state);
364
365static ssize_t
366eject_store(struct device *d, struct device_attribute *attr,
367	    const char *buf, size_t count)
368{
369	struct acpi_device *acpi_device = to_acpi_device(d);
370	acpi_object_type not_used;
371	acpi_status status;
372
373	if (!count || buf[0] != '1')
374		return -EINVAL;
375
376	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
377	    && !d->driver)
378		return -ENODEV;
379
380	status = acpi_get_type(acpi_device->handle, &not_used);
381	if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
382		return -ENODEV;
383
384	acpi_dev_get(acpi_device);
385	status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
386	if (ACPI_SUCCESS(status))
387		return count;
388
389	acpi_dev_put(acpi_device);
390	acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
391			  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
392	return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
393}
394
395static DEVICE_ATTR_WO(eject);
396
397static ssize_t
398hid_show(struct device *dev, struct device_attribute *attr, char *buf)
399{
400	struct acpi_device *acpi_dev = to_acpi_device(dev);
401
402	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
403}
404static DEVICE_ATTR_RO(hid);
405
406static ssize_t uid_show(struct device *dev,
407			struct device_attribute *attr, char *buf)
408{
409	struct acpi_device *acpi_dev = to_acpi_device(dev);
410
411	return sprintf(buf, "%s\n", acpi_device_uid(acpi_dev));
412}
413static DEVICE_ATTR_RO(uid);
414
415static ssize_t adr_show(struct device *dev,
416			struct device_attribute *attr, char *buf)
417{
418	struct acpi_device *acpi_dev = to_acpi_device(dev);
419
420	if (acpi_dev->pnp.bus_address > U32_MAX)
421		return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
422	else
423		return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
424}
425static DEVICE_ATTR_RO(adr);
426
427static ssize_t path_show(struct device *dev,
428			 struct device_attribute *attr, char *buf)
429{
430	struct acpi_device *acpi_dev = to_acpi_device(dev);
431
432	return acpi_object_path(acpi_dev->handle, buf);
433}
434static DEVICE_ATTR_RO(path);
435
436/* sysfs file that shows description text from the ACPI _STR method */
437static ssize_t description_show(struct device *dev,
438				struct device_attribute *attr,
439				char *buf)
440{
441	struct acpi_device *acpi_dev = to_acpi_device(dev);
442	int result;
443
444	if (acpi_dev->pnp.str_obj == NULL)
445		return 0;
446
447	/*
448	 * The _STR object contains a Unicode identifier for a device.
449	 * We need to convert to utf-8 so it can be displayed.
450	 */
451	result = utf16s_to_utf8s(
452		(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
453		acpi_dev->pnp.str_obj->buffer.length,
454		UTF16_LITTLE_ENDIAN, buf,
455		PAGE_SIZE - 1);
456
457	buf[result++] = '\n';
458
459	return result;
460}
461static DEVICE_ATTR_RO(description);
462
463static ssize_t
464sun_show(struct device *dev, struct device_attribute *attr,
465	 char *buf)
466{
467	struct acpi_device *acpi_dev = to_acpi_device(dev);
468	acpi_status status;
469	unsigned long long sun;
470
471	status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
472	if (ACPI_FAILURE(status))
473		return -EIO;
474
475	return sprintf(buf, "%llu\n", sun);
476}
477static DEVICE_ATTR_RO(sun);
478
479static ssize_t
480hrv_show(struct device *dev, struct device_attribute *attr,
481	 char *buf)
482{
483	struct acpi_device *acpi_dev = to_acpi_device(dev);
484	acpi_status status;
485	unsigned long long hrv;
486
487	status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
488	if (ACPI_FAILURE(status))
489		return -EIO;
490
491	return sprintf(buf, "%llu\n", hrv);
492}
493static DEVICE_ATTR_RO(hrv);
494
495static ssize_t status_show(struct device *dev, struct device_attribute *attr,
496				char *buf)
497{
498	struct acpi_device *acpi_dev = to_acpi_device(dev);
499	acpi_status status;
500	unsigned long long sta;
501
502	status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
503	if (ACPI_FAILURE(status))
504		return -EIO;
505
506	return sprintf(buf, "%llu\n", sta);
507}
508static DEVICE_ATTR_RO(status);
509
510/**
511 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
512 * @dev: ACPI device object.
513 */
514int acpi_device_setup_files(struct acpi_device *dev)
515{
516	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
517	acpi_status status;
518	int result = 0;
519
520	/*
521	 * Devices gotten from FADT don't have a "path" attribute
522	 */
523	if (dev->handle) {
524		result = device_create_file(&dev->dev, &dev_attr_path);
525		if (result)
526			goto end;
527	}
528
529	if (!list_empty(&dev->pnp.ids)) {
530		result = device_create_file(&dev->dev, &dev_attr_hid);
531		if (result)
532			goto end;
533
534		result = device_create_file(&dev->dev, &dev_attr_modalias);
535		if (result)
536			goto end;
537	}
538
539	/*
540	 * If device has _STR, 'description' file is created
541	 */
542	if (acpi_has_method(dev->handle, "_STR")) {
543		status = acpi_evaluate_object(dev->handle, "_STR",
544					NULL, &buffer);
545		if (ACPI_FAILURE(status))
546			buffer.pointer = NULL;
547		dev->pnp.str_obj = buffer.pointer;
548		result = device_create_file(&dev->dev, &dev_attr_description);
549		if (result)
550			goto end;
551	}
552
553	if (dev->pnp.type.bus_address)
554		result = device_create_file(&dev->dev, &dev_attr_adr);
555	if (acpi_device_uid(dev))
556		result = device_create_file(&dev->dev, &dev_attr_uid);
557
558	if (acpi_has_method(dev->handle, "_SUN")) {
559		result = device_create_file(&dev->dev, &dev_attr_sun);
560		if (result)
561			goto end;
562	}
563
564	if (acpi_has_method(dev->handle, "_HRV")) {
565		result = device_create_file(&dev->dev, &dev_attr_hrv);
566		if (result)
567			goto end;
568	}
569
570	if (acpi_has_method(dev->handle, "_STA")) {
571		result = device_create_file(&dev->dev, &dev_attr_status);
572		if (result)
573			goto end;
574	}
575
576	/*
577	 * If device has _EJ0, 'eject' file is created that is used to trigger
578	 * hot-removal function from userland.
579	 */
580	if (acpi_has_method(dev->handle, "_EJ0")) {
581		result = device_create_file(&dev->dev, &dev_attr_eject);
582		if (result)
583			return result;
584	}
585
586	if (dev->flags.power_manageable) {
587		result = device_create_file(&dev->dev, &dev_attr_power_state);
588		if (result)
589			return result;
590
591		if (dev->power.flags.power_resources)
592			result = device_create_file(&dev->dev,
593						    &dev_attr_real_power_state);
594	}
595
596	acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
597
598end:
599	return result;
600}
601
602/**
603 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
604 * @dev: ACPI device object.
605 */
606void acpi_device_remove_files(struct acpi_device *dev)
607{
608	acpi_hide_nondev_subnodes(&dev->data);
609
610	if (dev->flags.power_manageable) {
611		device_remove_file(&dev->dev, &dev_attr_power_state);
612		if (dev->power.flags.power_resources)
613			device_remove_file(&dev->dev,
614					   &dev_attr_real_power_state);
615	}
616
617	/*
618	 * If device has _STR, remove 'description' file
619	 */
620	if (acpi_has_method(dev->handle, "_STR")) {
621		kfree(dev->pnp.str_obj);
622		device_remove_file(&dev->dev, &dev_attr_description);
623	}
624	/*
625	 * If device has _EJ0, remove 'eject' file.
626	 */
627	if (acpi_has_method(dev->handle, "_EJ0"))
628		device_remove_file(&dev->dev, &dev_attr_eject);
629
630	if (acpi_has_method(dev->handle, "_SUN"))
631		device_remove_file(&dev->dev, &dev_attr_sun);
632
633	if (acpi_has_method(dev->handle, "_HRV"))
634		device_remove_file(&dev->dev, &dev_attr_hrv);
635
636	if (acpi_device_uid(dev))
637		device_remove_file(&dev->dev, &dev_attr_uid);
638	if (dev->pnp.type.bus_address)
639		device_remove_file(&dev->dev, &dev_attr_adr);
640	device_remove_file(&dev->dev, &dev_attr_modalias);
641	device_remove_file(&dev->dev, &dev_attr_hid);
642	if (acpi_has_method(dev->handle, "_STA"))
643		device_remove_file(&dev->dev, &dev_attr_status);
644	if (dev->handle)
645		device_remove_file(&dev->dev, &dev_attr_path);
646}