[linux-block.git] / drivers / usb / core / of.c

// SPDX-License-Identifier: GPL-2.0
/*
 * of.c		The helpers for hcd device tree support
 *
 * Copyright (C) 2016 Freescale Semiconductor, Inc.
 *	Author: Peter Chen <peter.chen@freescale.com>
 * Copyright (C) 2017 Johan Hovold <johan@kernel.org>
 */

#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/usb/of.h>

/**
 * usb_of_get_device_node() - get a USB device node
 * @hub: hub to which device is connected
 * @port1: one-based index of port
 *
 * Look up the node of a USB device given its parent hub device and one-based
 * port number.
 *
 * Return: A pointer to the node with incremented refcount if found, or
 * %NULL otherwise.
 */
struct device_node *usb_of_get_device_node(struct usb_device *hub, int port1)
{
	struct device_node *node;
	u32 reg;

	for_each_child_of_node(hub->dev.of_node, node) {
		if (of_property_read_u32(node, "reg", &reg))
			continue;

		if (reg == port1)
			return node;
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_device_node);

/**
 * usb_of_has_combined_node() - determine whether a device has a combined node
 * @udev: USB device
 *
 * Determine whether a USB device has a so called combined node which is
 * shared with its sole interface. This is the case if and only if the device
 * has a node and its decriptors report the following:
 *
 *	1) bDeviceClass is 0 or 9, and
 *	2) bNumConfigurations is 1, and
 *	3) bNumInterfaces is 1.
 *
 * Return: True iff the device has a device node and its descriptors match the
 * criteria for a combined node.
 */
bool usb_of_has_combined_node(struct usb_device *udev)
{
	struct usb_device_descriptor *ddesc = &udev->descriptor;
	struct usb_config_descriptor *cdesc;

	if (!udev->dev.of_node)
		return false;

	switch (ddesc->bDeviceClass) {
	case USB_CLASS_PER_INTERFACE:
	case USB_CLASS_HUB:
		if (ddesc->bNumConfigurations == 1) {
			cdesc = &udev->config->desc;
			if (cdesc->bNumInterfaces == 1)
				return true;
		}
	}

	return false;
}
EXPORT_SYMBOL_GPL(usb_of_has_combined_node);

/**
 * usb_of_get_interface_node() - get a USB interface node
 * @udev: USB device of interface
 * @config: configuration value
 * @ifnum: interface number
 *
 * Look up the node of a USB interface given its USB device, configuration
 * value and interface number.
 *
 * Return: A pointer to the node with incremented refcount if found, or
 * %NULL otherwise.
 */
struct device_node *
usb_of_get_interface_node(struct usb_device *udev, u8 config, u8 ifnum)
{
	struct device_node *node;
	u32 reg[2];

	for_each_child_of_node(udev->dev.of_node, node) {
		if (of_property_read_u32_array(node, "reg", reg, 2))
			continue;

		if (reg[0] == ifnum && reg[1] == config)
			return node;
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_interface_node);
Commit	Line	Data
5fd54ace	1	// SPDX-License-Identifier: GPL-2.0
69bec725 PC	2	/*
	3	* of.c The helpers for hcd device tree support
	4	*
	5	* Copyright (C) 2016 Freescale Semiconductor, Inc.
1a7e3948 JH	6	* Author: Peter Chen <peter.chen@freescale.com>
1a7e3948 JH	7	* Copyright (C) 2017 Johan Hovold <johan@kernel.org>
69bec725 PC	8	*/
	9
	10	#include <linux/of.h>
5095cb89	11	#include <linux/of_platform.h>
0573f2c5	12	#include <linux/usb/of.h>
69bec725 PC	13
69bec725 PC	14	/**
7739376e JH	15	* usb_of_get_device_node() - get a USB device node
	16	* @hub: hub to which device is connected
	17	* @port1: one-based index of port
69bec725	18	*
7739376e JH	19	* Look up the node of a USB device given its parent hub device and one-based
7739376e JH	20	* port number.
69bec725	21	*
60a93cff JH	22	* Return: A pointer to the node with incremented refcount if found, or
60a93cff JH	23	* %NULL otherwise.
69bec725	24	*/
7739376e	25	struct device_node usb_of_get_device_node(struct usb_device hub, int port1)
69bec725 PC	26	{
69bec725 PC	27	struct device_node *node;
7739376e	28	u32 reg;
69bec725	29
7739376e JH	30	for_each_child_of_node(hub->dev.of_node, node) {
	31	if (of_property_read_u32(node, "reg", &reg))
	32	continue;
	33
	34	if (reg == port1)
	35	return node;
69bec725 PC	36	}
	37
	38	return NULL;
	39	}
7739376e	40	EXPORT_SYMBOL_GPL(usb_of_get_device_node);
69bec725	41
1a7e3948 JH	42	/**
	43	* usb_of_has_combined_node() - determine whether a device has a combined node
	44	* @udev: USB device
	45	*
	46	* Determine whether a USB device has a so called combined node which is
	47	* shared with its sole interface. This is the case if and only if the device
	48	* has a node and its decriptors report the following:
	49	*
	50	* 1) bDeviceClass is 0 or 9, and
	51	* 2) bNumConfigurations is 1, and
	52	* 3) bNumInterfaces is 1.
	53	*
	54	* Return: True iff the device has a device node and its descriptors match the
	55	* criteria for a combined node.
	56	*/
	57	bool usb_of_has_combined_node(struct usb_device *udev)
	58	{
	59	struct usb_device_descriptor *ddesc = &udev->descriptor;
	60	struct usb_config_descriptor *cdesc;
	61
	62	if (!udev->dev.of_node)
	63	return false;
	64
	65	switch (ddesc->bDeviceClass) {
	66	case USB_CLASS_PER_INTERFACE:
	67	case USB_CLASS_HUB:
	68	if (ddesc->bNumConfigurations == 1) {
	69	cdesc = &udev->config->desc;
	70	if (cdesc->bNumInterfaces == 1)
	71	return true;
	72	}
	73	}
	74
	75	return false;
	76	}
	77	EXPORT_SYMBOL_GPL(usb_of_has_combined_node);
	78
	79	/**
	80	* usb_of_get_interface_node() - get a USB interface node
	81	* @udev: USB device of interface
	82	* @config: configuration value
	83	* @ifnum: interface number
	84	*
	85	* Look up the node of a USB interface given its USB device, configuration
	86	* value and interface number.
	87	*
	88	* Return: A pointer to the node with incremented refcount if found, or
	89	* %NULL otherwise.
	90	*/
	91	struct device_node *
	92	usb_of_get_interface_node(struct usb_device *udev, u8 config, u8 ifnum)
	93	{
	94	struct device_node *node;
	95	u32 reg[2];
	96
	97	for_each_child_of_node(udev->dev.of_node, node) {
	98	if (of_property_read_u32_array(node, "reg", reg, 2))
	99	continue;
	100
	101	if (reg[0] == ifnum && reg[1] == config)
	102	return node;
	103	}
	104
	105	return NULL;
106	}
107	EXPORT_SYMBOL_GPL(usb_of_get_interface_node);