drivers/usb/gadget/ep0.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2003
 * Gerry Hamel, geh@ti.com, Texas Instruments
 *
 * (C) Copyright 2006
 * Bryan O'Donoghue, deckard@CodeHermit.ie
 *
 * Based on
 * linux/drivers/usbd/ep0.c
 *
 * Copyright (c) 2000, 2001, 2002 Lineo
 * Copyright (c) 2001 Hewlett Packard
 *
 * By:
 *	Stuart Lynne <sl@lineo.com>,
 *	Tom Rushworth <tbr@lineo.com>,
 *	Bruce Balden <balden@lineo.com>
 */

/*
 * This is the builtin ep0 control function. It implements all required functionality
 * for responding to control requests (SETUP packets).
 *
 * XXX
 *
 * Currently we do not pass any SETUP packets (or other) to the configured
 * function driver. This may need to change.
 *
 * XXX
 *
 * As alluded to above, a simple callback cdc_recv_setup has been implemented
 * in the usb_device data structure to facilicate passing
 * Common Device Class packets to a function driver.
 *
 * XXX
 */

#include <serial.h>
#include <usbdevice.h>

#if 0
#define dbg_ep0(lvl,fmt,args...) serial_printf("[%s] %s:%d: "fmt"\n",__FILE__,__FUNCTION__,__LINE__,##args)
#else
#define dbg_ep0(lvl,fmt,args...)
#endif

__maybe_unused static char *usbd_device_descriptors[] = {
	"UNKNOWN",		/* 0 */
	"DEVICE",		/* 1 */
	"CONFIG",		/* 2 */
	"STRING",		/* 3 */
	"INTERFACE",		/* 4 */
	"ENDPOINT",		/* 5 */
	"DEVICE QUALIFIER",	/* 6 */
	"OTHER SPEED",		/* 7 */
	"INTERFACE POWER",	/* 8 */
};

#define USBD_DEVICE_DESCRIPTORS(x) (((unsigned int)x <= USB_DESCRIPTOR_TYPE_INTERFACE_POWER) ? \
		usbd_device_descriptors[x] : "UNKNOWN")

__maybe_unused static char *usbd_device_states[] = {
	"STATE_INIT",
	"STATE_CREATED",
	"STATE_ATTACHED",
	"STATE_POWERED",
	"STATE_DEFAULT",
	"STATE_ADDRESSED",
	"STATE_CONFIGURED",
	"STATE_UNKNOWN",
};

#define USBD_DEVICE_STATE(x) (((unsigned int)x <= STATE_UNKNOWN) ? usbd_device_states[x] : "UNKNOWN")

__maybe_unused static char *usbd_device_requests[] = {
	"GET STATUS",		/* 0 */
	"CLEAR FEATURE",	/* 1 */
	"RESERVED",		/* 2 */
	"SET FEATURE",		/* 3 */
	"RESERVED",		/* 4 */
	"SET ADDRESS",		/* 5 */
	"GET DESCRIPTOR",	/* 6 */
	"SET DESCRIPTOR",	/* 7 */
	"GET CONFIGURATION",	/* 8 */
	"SET CONFIGURATION",	/* 9 */
	"GET INTERFACE",	/* 10 */
	"SET INTERFACE",	/* 11 */
	"SYNC FRAME",		/* 12 */
};

#define USBD_DEVICE_REQUESTS(x) (((unsigned int)x <= USB_REQ_SYNCH_FRAME) ? usbd_device_requests[x] : "UNKNOWN")

/* EP0 Configuration Set ********************************************************************* */

/**
 * ep0_get_status - fill in URB data with appropriate status
 * @device:
 * @urb:
 * @index:
 * @requesttype:
 *
 */
static int ep0_get_status (struct usb_device_instance *device,
			   struct urb *urb, int index, int requesttype)
{
	char *cp;

	urb->actual_length = 2;
	cp = (char*)urb->buffer;
	cp[0] = cp[1] = 0;

	switch (requesttype) {
	case USB_REQ_RECIPIENT_DEVICE:
		cp[0] = USB_STATUS_SELFPOWERED;
		break;
	case USB_REQ_RECIPIENT_INTERFACE:
		break;
	case USB_REQ_RECIPIENT_ENDPOINT:
		cp[0] = usbd_endpoint_halted (device, index);
		break;
	case USB_REQ_RECIPIENT_OTHER:
		urb->actual_length = 0;
	default:
		break;
	}
	dbg_ep0 (2, "%02x %02x", cp[0], cp[1]);
	return 0;
}

/**
 * ep0_get_one
 * @device:
 * @urb:
 * @result:
 *
 * Set a single byte value in the urb send buffer. Return non-zero to signal
 * a request error.
 */
static int ep0_get_one (struct usb_device_instance *device, struct urb *urb,
			__u8 result)
{
	urb->actual_length = 1;	/* XXX 2? */
	((char *) urb->buffer)[0] = result;
	return 0;
}

/**
 * copy_config
 * @urb: pointer to urb
 * @data: pointer to configuration data
 * @length: length of data
 *
 * Copy configuration data to urb transfer buffer if there is room for it.
 */
void copy_config (struct urb *urb, void *data, int max_length,
			 int max_buf)
{
	int available;
	int length;

	/*dbg_ep0(3, "-> actual: %d buf: %d max_buf: %d max_length: %d data: %p", */
	/*        urb->actual_length, urb->buffer_length, max_buf, max_length, data); */

	if (!data) {
		dbg_ep0 (1, "data is NULL");
		return;
	}
	length = max_length;

	if (length > max_length) {
		dbg_ep0 (1, "length: %d >= max_length: %d", length,
			 max_length);
		return;
	}
	/*dbg_ep0(1, "   actual: %d buf: %d max_buf: %d max_length: %d length: %d", */
	/*        urb->actual_length, urb->buffer_length, max_buf, max_length, length); */

	if ((available =
	     /*urb->buffer_length */ max_buf - urb->actual_length) <= 0) {
		return;
	}
	/*dbg_ep0(1, "actual: %d buf: %d max_buf: %d length: %d available: %d", */
	/*        urb->actual_length, urb->buffer_length, max_buf, length, available); */

	if (length > available) {
		length = available;
	}
	/*dbg_ep0(1, "actual: %d buf: %d max_buf: %d length: %d available: %d", */
	/*        urb->actual_length, urb->buffer_length, max_buf, length, available); */

	memcpy (urb->buffer + urb->actual_length, data, length);
	urb->actual_length += length;

	dbg_ep0 (3,
		 "copy_config: <- actual: %d buf: %d max_buf: %d max_length: %d available: %d",
		 urb->actual_length, urb->buffer_length, max_buf, max_length,
		 available);
}

/**
 * ep0_get_descriptor
 * @device:
 * @urb:
 * @max:
 * @descriptor_type:
 * @index:
 *
 * Called by ep0_rx_process for a get descriptor device command. Determine what
 * descriptor is being requested, copy to send buffer. Return zero if ok to send,
 * return non-zero to signal a request error.
 */
static int ep0_get_descriptor (struct usb_device_instance *device,
			       struct urb *urb, int max, int descriptor_type,
			       int index)
{
	int port = 0;		/* XXX compound device */

	/*dbg_ep0(3, "max: %x type: %x index: %x", max, descriptor_type, index); */

	if (!urb || !urb->buffer || !urb->buffer_length
	    || (urb->buffer_length < 255)) {
		dbg_ep0 (2, "invalid urb %p", urb);
		return -1L;
	}

	/* setup tx urb */
	urb->actual_length = 0;

	dbg_ep0 (2, "%s", USBD_DEVICE_DESCRIPTORS (descriptor_type));

	switch (descriptor_type) {
	case USB_DESCRIPTOR_TYPE_DEVICE:
		{
			struct usb_device_descriptor *device_descriptor;
			if (!
			    (device_descriptor =
			     usbd_device_device_descriptor (device, port))) {
				return -1;
			}
			/* copy descriptor for this device */
			copy_config (urb, device_descriptor,
				     sizeof (struct usb_device_descriptor),
				     max);

			/* correct the correct control endpoint 0 max packet size into the descriptor */
			device_descriptor =
				(struct usb_device_descriptor *) urb->buffer;

		}
		dbg_ep0(3, "copied device configuration, actual_length: 0x%x", urb->actual_length);
		break;

	case USB_DESCRIPTOR_TYPE_CONFIGURATION:
		{
			struct usb_configuration_descriptor
				*configuration_descriptor;
			struct usb_device_descriptor *device_descriptor;
			if (!
			    (device_descriptor =
			     usbd_device_device_descriptor (device, port))) {
				return -1;
			}
			/*dbg_ep0(2, "%d %d", index, device_descriptor->bNumConfigurations); */
			if (index >= device_descriptor->bNumConfigurations) {
				dbg_ep0 (0, "index too large: %d >= %d", index,
					 device_descriptor->
					 bNumConfigurations);
				return -1;
			}

			if (!
			    (configuration_descriptor =
			     usbd_device_configuration_descriptor (device,
								   port,
								   index))) {
				dbg_ep0 (0,
					 "usbd_device_configuration_descriptor failed: %d",
					 index);
				return -1;
			}
			dbg_ep0(0, "attempt to copy %d bytes to urb\n",cpu_to_le16(configuration_descriptor->wTotalLength));
			copy_config (urb, configuration_descriptor,

					cpu_to_le16(configuration_descriptor->wTotalLength),
				     max);
		}

		break;

	case USB_DESCRIPTOR_TYPE_STRING:
		{
			struct usb_string_descriptor *string_descriptor;
			if (!(string_descriptor = usbd_get_string (index))) {
				dbg_ep0(0, "Invalid string index %d\n", index);
				return -1;
			}
			dbg_ep0(3, "string_descriptor: %p length %d", string_descriptor, string_descriptor->bLength);
			copy_config (urb, string_descriptor, string_descriptor->bLength, max);
		}
		break;
	case USB_DESCRIPTOR_TYPE_INTERFACE:
		dbg_ep0(2, "USB_DESCRIPTOR_TYPE_INTERFACE - error not implemented\n");
		return -1;
	case USB_DESCRIPTOR_TYPE_ENDPOINT:
		dbg_ep0(2, "USB_DESCRIPTOR_TYPE_ENDPOINT - error not implemented\n");
		return -1;
	case USB_DESCRIPTOR_TYPE_HID:
		{
			dbg_ep0(2, "USB_DESCRIPTOR_TYPE_HID - error not implemented\n");
			return -1;	/* unsupported at this time */
#if 0
			int bNumInterface =
				le16_to_cpu (urb->device_request.wIndex);
			int bAlternateSetting = 0;
			int class = 0;
			struct usb_class_descriptor *class_descriptor;

			if (!(class_descriptor =
			      usbd_device_class_descriptor_index (device,
								  port, 0,
								  bNumInterface,
								  bAlternateSetting,
								  class))
			    || class_descriptor->descriptor.hid.bDescriptorType != USB_DT_HID) {
				dbg_ep0 (3, "[%d] interface is not HID",
					 bNumInterface);
				return -1;
			}
			/* copy descriptor for this class */
			copy_config (urb, class_descriptor,
				     class_descriptor->descriptor.hid.bLength,
				     max);
#endif
		}
		break;
	case USB_DESCRIPTOR_TYPE_REPORT:
		{
			dbg_ep0(2, "USB_DESCRIPTOR_TYPE_REPORT - error not implemented\n");
			return -1;	/* unsupported at this time */
#if 0
			int bNumInterface =
				le16_to_cpu (urb->device_request.wIndex);
			int bAlternateSetting = 0;
			int class = 0;
			struct usb_class_report_descriptor *report_descriptor;

			if (!(report_descriptor =
			      usbd_device_class_report_descriptor_index
			      (device, port, 0, bNumInterface,
			       bAlternateSetting, class))
			    || report_descriptor->bDescriptorType !=
			    USB_DT_REPORT) {
				dbg_ep0 (3, "[%d] descriptor is not REPORT",
					 bNumInterface);
				return -1;
			}
			/* copy report descriptor for this class */
			/*copy_config(urb, &report_descriptor->bData[0], report_descriptor->wLength, max); */
			if (max - urb->actual_length > 0) {
				int length =
					min(report_descriptor->wLength,
					     max - urb->actual_length);
				memcpy (urb->buffer + urb->actual_length,
					&report_descriptor->bData[0], length);
				urb->actual_length += length;
			}
#endif
		}
		break;
	case USB_DESCRIPTOR_TYPE_DEVICE_QUALIFIER:
		return -1;

	default:
		return -1;
	}

	dbg_ep0 (1, "urb: buffer: %p buffer_length: %2d actual_length: %2d tx_packetSize: %2d",
		 urb->buffer, urb->buffer_length, urb->actual_length,
		 device->bus->endpoint_array[0].tx_packetSize);
/*
    if ((urb->actual_length < max) && !(urb->actual_length % device->bus->endpoint_array[0].tx_packetSize)) {
	dbg_ep0(0, "adding null byte");
	urb->buffer[urb->actual_length++] = 0;
	dbg_ep0(0, "urb: buffer_length: %2d actual_length: %2d packet size: %2d",
		urb->buffer_length, urb->actual_length device->bus->endpoint_array[0].tx_packetSize);
    }
*/
	return 0;

}

/**
 * ep0_recv_setup - called to indicate URB has been received
 * @urb: pointer to struct urb
 *
 * Check if this is a setup packet, process the device request, put results
 * back into the urb and return zero or non-zero to indicate success (DATA)
 * or failure (STALL).
 *
 */
int ep0_recv_setup (struct urb *urb)
{
	/*struct usb_device_request *request = urb->buffer; */
	/*struct usb_device_instance *device = urb->device; */

	struct usb_device_request *request;
	struct usb_device_instance *device;
	int address;

	dbg_ep0 (0, "entering ep0_recv_setup()");
	if (!urb || !urb->device) {
		dbg_ep0 (3, "invalid URB %p", urb);
		return -1;
	}

	request = &urb->device_request;
	device = urb->device;

	dbg_ep0 (3, "urb: %p device: %p", urb, urb->device);

	/*dbg_ep0(2, "-       -       -       -       -       -       -       -       -       -"); */

	dbg_ep0 (2,
		 "bmRequestType:%02x bRequest:%02x wValue:%04x wIndex:%04x wLength:%04x %s",
		 request->bmRequestType, request->bRequest,
		 le16_to_cpu (request->wValue), le16_to_cpu (request->wIndex),
		 le16_to_cpu (request->wLength),
		 USBD_DEVICE_REQUESTS (request->bRequest));

	/* handle USB Standard Request (c.f. USB Spec table 9-2) */
	if ((request->bmRequestType & USB_REQ_TYPE_MASK) != 0) {
		if(device->device_state <= STATE_CONFIGURED){
			/*	Attempt to handle a CDC specific request if we are
			 *	in the configured state.
			 */
			return device->cdc_recv_setup(request,urb);
		}
		dbg_ep0 (1, "non standard request: %x",
			 request->bmRequestType & USB_REQ_TYPE_MASK);
		return -1;	/* Stall here */
	}

	switch (device->device_state) {
	case STATE_CREATED:
	case STATE_ATTACHED:
	case STATE_POWERED:
		/* It actually is important to allow requests in these states,
		 * Windows will request descriptors before assigning an
		 * address to the client.
		 */

		/*dbg_ep0 (1, "request %s not allowed in this state: %s", */
		/*                USBD_DEVICE_REQUESTS(request->bRequest), */
		/*                usbd_device_states[device->device_state]); */
		/*return -1; */
		break;

	case STATE_INIT:
	case STATE_DEFAULT:
		switch (request->bRequest) {
		case USB_REQ_GET_STATUS:
		case USB_REQ_GET_INTERFACE:
		case USB_REQ_SYNCH_FRAME:	/* XXX should never see this (?) */
		case USB_REQ_CLEAR_FEATURE:
		case USB_REQ_SET_FEATURE:
		case USB_REQ_SET_DESCRIPTOR:
			/* case USB_REQ_SET_CONFIGURATION: */
		case USB_REQ_SET_INTERFACE:
			dbg_ep0 (1,
				 "request %s not allowed in DEFAULT state: %s",
				 USBD_DEVICE_REQUESTS (request->bRequest),
				 usbd_device_states[device->device_state]);
			return -1;

		case USB_REQ_SET_CONFIGURATION:
		case USB_REQ_SET_ADDRESS:
		case USB_REQ_GET_DESCRIPTOR:
		case USB_REQ_GET_CONFIGURATION:
			break;
		}
	case STATE_ADDRESSED:
	case STATE_CONFIGURED:
		break;
	case STATE_UNKNOWN:
		dbg_ep0 (1, "request %s not allowed in UNKNOWN state: %s",
			 USBD_DEVICE_REQUESTS (request->bRequest),
			 usbd_device_states[device->device_state]);
		return -1;
	}

	/* handle all requests that return data (direction bit set on bm RequestType) */
	if ((request->bmRequestType & USB_REQ_DIRECTION_MASK)) {

		dbg_ep0 (3, "Device-to-Host");

		switch (request->bRequest) {

		case USB_REQ_GET_STATUS:
			return ep0_get_status (device, urb, request->wIndex,
					       request->bmRequestType &
					       USB_REQ_RECIPIENT_MASK);

		case USB_REQ_GET_DESCRIPTOR:
			return ep0_get_descriptor (device, urb,
						   le16_to_cpu (request->wLength),
						   le16_to_cpu (request->wValue) >> 8,
						   le16_to_cpu (request->wValue) & 0xff);

		case USB_REQ_GET_CONFIGURATION:
			dbg_ep0(2, "get config %d\n", device->configuration);
			return ep0_get_one (device, urb,
					    device->configuration);

		case USB_REQ_GET_INTERFACE:
			return ep0_get_one (device, urb, device->alternate);

		case USB_REQ_SYNCH_FRAME:	/* XXX should never see this (?) */
			return -1;

		case USB_REQ_CLEAR_FEATURE:
		case USB_REQ_SET_FEATURE:
		case USB_REQ_SET_ADDRESS:
		case USB_REQ_SET_DESCRIPTOR:
		case USB_REQ_SET_CONFIGURATION:
		case USB_REQ_SET_INTERFACE:
			return -1;
		}
	}
	/* handle the requests that do not return data */
	else {

		/*dbg_ep0(3, "Host-to-Device"); */
		switch (request->bRequest) {

		case USB_REQ_CLEAR_FEATURE:
		case USB_REQ_SET_FEATURE:
			dbg_ep0 (0, "Host-to-Device");
			switch (request->
				bmRequestType & USB_REQ_RECIPIENT_MASK) {
			case USB_REQ_RECIPIENT_DEVICE:
				/* XXX DEVICE_REMOTE_WAKEUP or TEST_MODE would be added here */
				/* XXX fall through for now as we do not support either */
			case USB_REQ_RECIPIENT_INTERFACE:
			case USB_REQ_RECIPIENT_OTHER:
				dbg_ep0 (0, "request %s not",
					 USBD_DEVICE_REQUESTS (request->bRequest));
			default:
				return -1;

			case USB_REQ_RECIPIENT_ENDPOINT:
				dbg_ep0 (0, "ENDPOINT: %x", le16_to_cpu (request->wValue));
				if (le16_to_cpu (request->wValue) == USB_ENDPOINT_HALT) {
					/*return usbd_device_feature (device, le16_to_cpu (request->wIndex), */
					/*                    request->bRequest == USB_REQ_SET_FEATURE); */
					/* NEED TO IMPLEMENT THIS!!! */
					return -1;
				} else {
					dbg_ep0 (1, "request %s bad wValue: %04x",
						 USBD_DEVICE_REQUESTS
						 (request->bRequest),
						 le16_to_cpu (request->wValue));
					return -1;
				}
			}

		case USB_REQ_SET_ADDRESS:
			/* check if this is a re-address, reset first if it is (this shouldn't be possible) */
			if (device->device_state != STATE_DEFAULT) {
				dbg_ep0 (1, "set_address: %02x state: %s",
					 le16_to_cpu (request->wValue),
					 usbd_device_states[device->device_state]);
				return -1;
			}
			address = le16_to_cpu (request->wValue);
			if ((address & 0x7f) != address) {
				dbg_ep0 (1, "invalid address %04x %04x",
					 address, address & 0x7f);
				return -1;
			}
			device->address = address;

			/*dbg_ep0(2, "address: %d %d %d", */
			/*        request->wValue, le16_to_cpu(request->wValue), device->address); */

			return 0;

		case USB_REQ_SET_DESCRIPTOR:	/* XXX should we support this? */
			dbg_ep0 (0, "set descriptor: NOT SUPPORTED");
			return -1;

		case USB_REQ_SET_CONFIGURATION:
			/* c.f. 9.4.7 - the top half of wValue is reserved */
			device->configuration = le16_to_cpu(request->wValue) & 0xff;

			/* reset interface and alternate settings */
			device->interface = device->alternate = 0;

			/*dbg_ep0(2, "set configuration: %d", device->configuration); */
			/*dbg_ep0(2, "DEVICE_CONFIGURED.. event?\n"); */
			return 0;

		case USB_REQ_SET_INTERFACE:
			device->interface = le16_to_cpu (request->wIndex);
			device->alternate = le16_to_cpu (request->wValue);
			/*dbg_ep0(2, "set interface: %d alternate: %d", device->interface, device->alternate); */
			dbg_ep0(2, "DEVICE_SET_INTERFACE.. event?\n");
			return 0;

		case USB_REQ_GET_STATUS:
		case USB_REQ_GET_DESCRIPTOR:
		case USB_REQ_GET_CONFIGURATION:
		case USB_REQ_GET_INTERFACE:
		case USB_REQ_SYNCH_FRAME:	/* XXX should never see this (?) */
			return -1;
		}
	}
	return -1;
}