ACPI / scan: Move sysfs-related device code to a separate file

To reduce the size of scan.c and improve the readability of it, move
all code related to device sysfs, modalias creation etc. to a new
file called device_sysfs.c.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 521 insertions, 0 deletions

diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
new file mode 100644
index 0000000000000..4ab4582e586b7
--- /dev/null
+++ b/drivers/acpi/device_sysfs.c
@@ -0,0 +1,521 @@
+/*
+ * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
+ *
+ * Copyright (C) 2015, Intel Corp.
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that 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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/nls.h>
+
+#include "internal.h"
+
+/**
+ * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
+ * @acpi_dev: ACPI device object.
+ * @modalias: Buffer to print into.
+ * @size: Size of the buffer.
+ *
+ * Creates hid/cid(s) string needed for modalias and uevent
+ * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
+ * char *modalias: "acpi:IBM0001:ACPI0001"
+ * Return: 0: no _HID and no _CID
+ *         -EINVAL: output error
+ *         -ENOMEM: output is truncated
+*/
+static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
+			       int size)
+{
+	int len;
+	int count;
+	struct acpi_hardware_id *id;
+
+	/*
+	 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
+	 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
+	 * device's list.
+	 */
+	count = 0;
+	list_for_each_entry(id, &acpi_dev->pnp.ids, list)
+		if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
+			count++;
+
+	if (!count)
+		return 0;
+
+	len = snprintf(modalias, size, "acpi:");
+	if (len <= 0)
+		return len;
+
+	size -= len;
+
+	list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
+		if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
+			continue;
+
+		count = snprintf(&modalias[len], size, "%s:", id->id);
+		if (count < 0)
+			return -EINVAL;
+
+		if (count >= size)
+			return -ENOMEM;
+
+		len += count;
+		size -= count;
+	}
+	modalias[len] = '\0';
+	return len;
+}
+
+/**
+ * create_of_modalias - Creates DT compatible string for modalias and uevent
+ * @acpi_dev: ACPI device object.
+ * @modalias: Buffer to print into.
+ * @size: Size of the buffer.
+ *
+ * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
+ * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
+ * ACPI/PNP IDs.
+ */
+static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
+			      int size)
+{
+	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
+	const union acpi_object *of_compatible, *obj;
+	int len, count;
+	int i, nval;
+	char *c;
+
+	acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
+	/* DT strings are all in lower case */
+	for (c = buf.pointer; *c != '\0'; c++)
+		*c = tolower(*c);
+
+	len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
+	ACPI_FREE(buf.pointer);
+
+	if (len <= 0)
+		return len;
+
+	of_compatible = acpi_dev->data.of_compatible;
+	if (of_compatible->type == ACPI_TYPE_PACKAGE) {
+		nval = of_compatible->package.count;
+		obj = of_compatible->package.elements;
+	} else { /* Must be ACPI_TYPE_STRING. */
+		nval = 1;
+		obj = of_compatible;
+	}
+	for (i = 0; i < nval; i++, obj++) {
+		count = snprintf(&modalias[len], size, "C%s",
+				 obj->string.pointer);
+		if (count < 0)
+			return -EINVAL;
+
+		if (count >= size)
+			return -ENOMEM;
+
+		len += count;
+		size -= count;
+	}
+	modalias[len] = '\0';
+	return len;
+}
+
+int __acpi_device_uevent_modalias(struct acpi_device *adev,
+				  struct kobj_uevent_env *env)
+{
+	int len;
+
+	if (!adev)
+		return -ENODEV;
+
+	if (list_empty(&adev->pnp.ids))
+		return 0;
+
+	if (add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+
+	len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
+				  sizeof(env->buf) - env->buflen);
+	if (len < 0)
+		return len;
+
+	env->buflen += len;
+	if (!adev->data.of_compatible)
+		return 0;
+
+	if (len > 0 && add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+
+	len = create_of_modalias(adev, &env->buf[env->buflen - 1],
+				 sizeof(env->buf) - env->buflen);
+	if (len < 0)
+		return len;
+
+	env->buflen += len;
+
+	return 0;
+}
+
+/**
+ * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
+ *
+ * Create the uevent modalias field for ACPI-enumerated devices.
+ *
+ * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
+ * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
+ */
+int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
+{
+	return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
+}
+EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
+
+static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
+{
+	int len, count;
+
+	if (!adev)
+		return -ENODEV;
+
+	if (list_empty(&adev->pnp.ids))
+		return 0;
+
+	len = create_pnp_modalias(adev, buf, size - 1);
+	if (len < 0) {
+		return len;
+	} else if (len > 0) {
+		buf[len++] = '\n';
+		size -= len;
+	}
+	if (!adev->data.of_compatible)
+		return len;
+
+	count = create_of_modalias(adev, buf + len, size - 1);
+	if (count < 0) {
+		return count;
+	} else if (count > 0) {
+		len += count;
+		buf[len++] = '\n';
+	}
+
+	return len;
+}
+
+/**
+ * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
+ *
+ * Create the modalias sysfs attribute for ACPI-enumerated devices.
+ *
+ * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
+ * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
+ */
+int acpi_device_modalias(struct device *dev, char *buf, int size)
+{
+	return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
+}
+EXPORT_SYMBOL_GPL(acpi_device_modalias);
+
+static ssize_t
+acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
+	return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
+}
+static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
+
+static ssize_t real_power_state_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *adev = to_acpi_device(dev);
+	int state;
+	int ret;
+
+	ret = acpi_device_get_power(adev, &state);
+	if (ret)
+		return ret;
+
+	return sprintf(buf, "%s\n", acpi_power_state_string(state));
+}
+
+static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
+
+static ssize_t power_state_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *adev = to_acpi_device(dev);
+
+	return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
+}
+
+static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
+
+static ssize_t
+acpi_eject_store(struct device *d, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct acpi_device *acpi_device = to_acpi_device(d);
+	acpi_object_type not_used;
+	acpi_status status;
+
+	if (!count || buf[0] != '1')
+		return -EINVAL;
+
+	if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
+	    && !acpi_device->driver)
+		return -ENODEV;
+
+	status = acpi_get_type(acpi_device->handle, &not_used);
+	if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
+		return -ENODEV;
+
+	get_device(&acpi_device->dev);
+	status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
+	if (ACPI_SUCCESS(status))
+		return count;
+
+	put_device(&acpi_device->dev);
+	acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
+			  ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
+	return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
+}
+
+static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
+
+static ssize_t
+acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+
+	return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
+}
+static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
+
+static ssize_t acpi_device_uid_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+
+	return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
+}
+static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
+
+static ssize_t acpi_device_adr_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+
+	return sprintf(buf, "0x%08x\n",
+		       (unsigned int)(acpi_dev->pnp.bus_address));
+}
+static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
+
+static ssize_t
+acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
+	int result;
+
+	result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path);
+	if (result)
+		goto end;
+
+	result = sprintf(buf, "%s\n", (char*)path.pointer);
+	kfree(path.pointer);
+end:
+	return result;
+}
+static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
+
+/* sysfs file that shows description text from the ACPI _STR method */
+static ssize_t description_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	int result;
+
+	if (acpi_dev->pnp.str_obj == NULL)
+		return 0;
+
+	/*
+	 * The _STR object contains a Unicode identifier for a device.
+	 * We need to convert to utf-8 so it can be displayed.
+	 */
+	result = utf16s_to_utf8s(
+		(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
+		acpi_dev->pnp.str_obj->buffer.length,
+		UTF16_LITTLE_ENDIAN, buf,
+		PAGE_SIZE);
+
+	buf[result++] = '\n';
+
+	return result;
+}
+static DEVICE_ATTR(description, 0444, description_show, NULL);
+
+static ssize_t
+acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
+		     char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	acpi_status status;
+	unsigned long long sun;
+
+	status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	return sprintf(buf, "%llu\n", sun);
+}
+static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
+
+static ssize_t status_show(struct device *dev, struct device_attribute *attr,
+				char *buf) {
+	struct acpi_device *acpi_dev = to_acpi_device(dev);
+	acpi_status status;
+	unsigned long long sta;
+
+	status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	return sprintf(buf, "%llu\n", sta);
+}
+static DEVICE_ATTR_RO(status);
+
+/**
+ * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
+ * @dev: ACPI device object.
+ */
+int acpi_device_setup_files(struct acpi_device *dev)
+{
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	acpi_status status;
+	int result = 0;
+
+	/*
+	 * Devices gotten from FADT don't have a "path" attribute
+	 */
+	if (dev->handle) {
+		result = device_create_file(&dev->dev, &dev_attr_path);
+		if (result)
+			goto end;
+	}
+
+	if (!list_empty(&dev->pnp.ids)) {
+		result = device_create_file(&dev->dev, &dev_attr_hid);
+		if (result)
+			goto end;
+
+		result = device_create_file(&dev->dev, &dev_attr_modalias);
+		if (result)
+			goto end;
+	}
+
+	/*
+	 * If device has _STR, 'description' file is created
+	 */
+	if (acpi_has_method(dev->handle, "_STR")) {
+		status = acpi_evaluate_object(dev->handle, "_STR",
+					NULL, &buffer);
+		if (ACPI_FAILURE(status))
+			buffer.pointer = NULL;
+		dev->pnp.str_obj = buffer.pointer;
+		result = device_create_file(&dev->dev, &dev_attr_description);
+		if (result)
+			goto end;
+	}
+
+	if (dev->pnp.type.bus_address)
+		result = device_create_file(&dev->dev, &dev_attr_adr);
+	if (dev->pnp.unique_id)
+		result = device_create_file(&dev->dev, &dev_attr_uid);
+
+	if (acpi_has_method(dev->handle, "_SUN")) {
+		result = device_create_file(&dev->dev, &dev_attr_sun);
+		if (result)
+			goto end;
+	}
+
+	if (acpi_has_method(dev->handle, "_STA")) {
+		result = device_create_file(&dev->dev, &dev_attr_status);
+		if (result)
+			goto end;
+	}
+
+        /*
+         * If device has _EJ0, 'eject' file is created that is used to trigger
+         * hot-removal function from userland.
+         */
+	if (acpi_has_method(dev->handle, "_EJ0")) {
+		result = device_create_file(&dev->dev, &dev_attr_eject);
+		if (result)
+			return result;
+	}
+
+	if (dev->flags.power_manageable) {
+		result = device_create_file(&dev->dev, &dev_attr_power_state);
+		if (result)
+			return result;
+
+		if (dev->power.flags.power_resources)
+			result = device_create_file(&dev->dev,
+						    &dev_attr_real_power_state);
+	}
+
+end:
+	return result;
+}
+
+/**
+ * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
+ * @dev: ACPI device object.
+ */
+void acpi_device_remove_files(struct acpi_device *dev)
+{
+	if (dev->flags.power_manageable) {
+		device_remove_file(&dev->dev, &dev_attr_power_state);
+		if (dev->power.flags.power_resources)
+			device_remove_file(&dev->dev,
+					   &dev_attr_real_power_state);
+	}
+
+	/*
+	 * If device has _STR, remove 'description' file
+	 */
+	if (acpi_has_method(dev->handle, "_STR")) {
+		kfree(dev->pnp.str_obj);
+		device_remove_file(&dev->dev, &dev_attr_description);
+	}
+	/*
+	 * If device has _EJ0, remove 'eject' file.
+	 */
+	if (acpi_has_method(dev->handle, "_EJ0"))
+		device_remove_file(&dev->dev, &dev_attr_eject);
+
+	if (acpi_has_method(dev->handle, "_SUN"))
+		device_remove_file(&dev->dev, &dev_attr_sun);
+
+	if (dev->pnp.unique_id)
+		device_remove_file(&dev->dev, &dev_attr_uid);
+	if (dev->pnp.type.bus_address)
+		device_remove_file(&dev->dev, &dev_attr_adr);
+	device_remove_file(&dev->dev, &dev_attr_modalias);
+	device_remove_file(&dev->dev, &dev_attr_hid);
+	if (acpi_has_method(dev->handle, "_STA"))
+		device_remove_file(&dev->dev, &dev_attr_status);
+	if (dev->handle)
+		device_remove_file(&dev->dev, &dev_attr_path);
+}