1/*
  2 * USB-ACPI glue code
  3 *
  4 * Copyright 2012 Red Hat <mjg@redhat.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify it
  7 * under the terms of the GNU General Public License as published by the Free
  8 * Software Foundation, version 2.
  9 *
 10 */
 11#include <linux/module.h>
 12#include <linux/usb.h>
 13#include <linux/device.h>
 14#include <linux/errno.h>
 15#include <linux/kernel.h>
 16#include <linux/acpi.h>
 17#include <linux/pci.h>
 18#include <linux/usb/hcd.h>
 19
 20#include "usb.h"
 21
 22/**
 23 * usb_acpi_power_manageable - check whether usb port has
 24 * acpi power resource.
 25 * @hdev: USB device belonging to the usb hub
 26 * @index: port index based zero
 27 *
 28 * Return true if the port has acpi power resource and false if no.
 29 */
 30bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
 31{
 32	acpi_handle port_handle;
 33	int port1 = index + 1;
 34
 35	port_handle = usb_get_hub_port_acpi_handle(hdev,
 36		port1);
 37	if (port_handle)
 38		return acpi_bus_power_manageable(port_handle);
 39	else
 40		return false;
 41}
 42EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
 43
 44/**
 45 * usb_acpi_set_power_state - control usb port's power via acpi power
 46 * resource
 47 * @hdev: USB device belonging to the usb hub
 48 * @index: port index based zero
 49 * @enable: power state expected to be set
 50 *
 51 * Notice to use usb_acpi_power_manageable() to check whether the usb port
 52 * has acpi power resource before invoking this function.
 53 *
 54 * Returns 0 on success, else negative errno.
 55 */
 56int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
 57{
 58	acpi_handle port_handle;
 59	unsigned char state;
 60	int port1 = index + 1;
 61	int error = -EINVAL;
 62
 63	port_handle = (acpi_handle)usb_get_hub_port_acpi_handle(hdev,
 64		port1);
 65	if (!port_handle)
 66		return error;
 67
 68	if (enable)
 69		state = ACPI_STATE_D0;
 70	else
 71		state = ACPI_STATE_D3_COLD;
 72
 73	error = acpi_bus_set_power(port_handle, state);
 74	if (!error)
 75		dev_dbg(&hdev->dev, "The power of hub port %d was set to %d\n",
 76			port1, enable);
 77	else
 78		dev_dbg(&hdev->dev, "The power of hub port failed to be set\n");
 79
 80	return error;
 81}
 82EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
 83
 84static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
 85	acpi_handle handle, int port1)
 86{
 87	acpi_status status;
 88	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 89	union acpi_object *upc;
 90	struct acpi_pld_info *pld;
 91	int ret = 0;
 92
 93	/*
 94	 * According to ACPI Spec 9.13. PLD indicates whether usb port is
 95	 * user visible and _UPC indicates whether it is connectable. If
 96	 * the port was visible and connectable, it could be freely connected
 97	 * and disconnected with USB devices. If no visible and connectable,
 98	 * a usb device is directly hard-wired to the port. If no visible and
 99	 * no connectable, the port would be not used.
100	 */
101	status = acpi_get_physical_device_location(handle, &pld);
102	if (ACPI_FAILURE(status))
103		return -ENODEV;
104
105	status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
106	upc = buffer.pointer;
107	if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
108		|| upc->package.count != 4) {
109		ret = -EINVAL;
110		goto out;
111	}
112
113	if (upc->package.elements[0].integer.value)
114		if (pld->user_visible)
115			usb_set_hub_port_connect_type(hdev, port1,
116				USB_PORT_CONNECT_TYPE_HOT_PLUG);
117		else
118			usb_set_hub_port_connect_type(hdev, port1,
119				USB_PORT_CONNECT_TYPE_HARD_WIRED);
120	else if (!pld->user_visible)
121		usb_set_hub_port_connect_type(hdev, port1, USB_PORT_NOT_USED);
122
123out:
124	ACPI_FREE(pld);
125	kfree(upc);
126	return ret;
127}
128
129static struct acpi_device *usb_acpi_find_companion(struct device *dev)
130{
131	struct usb_device *udev;
132	acpi_handle *parent_handle;
133	int port_num;
134
135	/*
136	 * In the ACPI DSDT table, only usb root hub and usb ports are
137	 * acpi device nodes. The hierarchy like following.
138	 * Device (EHC1)
139	 *	Device (HUBN)
140	 *		Device (PR01)
141	 *			Device (PR11)
142	 *			Device (PR12)
143	 *			Device (PR13)
144	 *			...
145	 * So all binding process is divided into two parts. binding
146	 * root hub and usb ports.
147	 */
148	if (is_usb_device(dev)) {
149		udev = to_usb_device(dev);
150		if (udev->parent) {
151			enum usb_port_connect_type type;
152
153			/*
154			 * According usb port's connect type to set usb device's
155			 * removability.
156			 */
157			type = usb_get_hub_port_connect_type(udev->parent,
158				udev->portnum);
159			switch (type) {
160			case USB_PORT_CONNECT_TYPE_HOT_PLUG:
161				udev->removable = USB_DEVICE_REMOVABLE;
162				break;
163			case USB_PORT_CONNECT_TYPE_HARD_WIRED:
164				udev->removable = USB_DEVICE_FIXED;
165				break;
166			default:
167				udev->removable = USB_DEVICE_REMOVABLE_UNKNOWN;
168				break;
169			}
170
171			return NULL;
172		}
173
174		/* root hub's parent is the usb hcd. */
175		return acpi_find_child_device(ACPI_COMPANION(dev->parent),
176					      udev->portnum, false);
177	} else if (is_usb_port(dev)) {
178		struct acpi_device *adev = NULL;
179
180		sscanf(dev_name(dev), "port%d", &port_num);
181		/* Get the struct usb_device point of port's hub */
182		udev = to_usb_device(dev->parent->parent);
183
184		/*
185		 * The root hub ports' parent is the root hub. The non-root-hub
186		 * ports' parent is the parent hub port which the hub is
187		 * connected to.
188		 */
189		if (!udev->parent) {
190			struct usb_hcd *hcd = bus_to_hcd(udev->bus);
191			int raw_port_num;
192
193			raw_port_num = usb_hcd_find_raw_port_number(hcd,
194				port_num);
195			adev = acpi_find_child_device(ACPI_COMPANION(&udev->dev),
196						      raw_port_num, false);
197			if (!adev)
198				return NULL;
199		} else {
200			parent_handle =
201				usb_get_hub_port_acpi_handle(udev->parent,
202				udev->portnum);
203			if (!parent_handle)
204				return NULL;
205
206			acpi_bus_get_device(parent_handle, &adev);
207			adev = acpi_find_child_device(adev, port_num, false);
208			if (!adev)
209				return NULL;
210		}
211		usb_acpi_check_port_connect_type(udev, adev->handle, port_num);
212		return adev;
213	}
214
215	return NULL;
216}
217
218static bool usb_acpi_bus_match(struct device *dev)
219{
220	return is_usb_device(dev) || is_usb_port(dev);
221}
222
223static struct acpi_bus_type usb_acpi_bus = {
224	.name = "USB",
225	.match = usb_acpi_bus_match,
226	.find_companion = usb_acpi_find_companion,
227};
228
229int usb_acpi_register(void)
230{
231	return register_acpi_bus_type(&usb_acpi_bus);
232}
233
234void usb_acpi_unregister(void)
235{
236	unregister_acpi_bus_type(&usb_acpi_bus);
237}