usb_standard.c

Go to the documentation of this file.

/** @defgroup usb_standard_file Generic USB Standard Request Interface
 
@ingroup USB
 
@brief <b>Generic USB Standard Request Interface</b>
 
@version 1.0.0
 
@author @htmlonly &copy; @endhtmlonly 2010
Gareth McMullin <gareth@blacksphere.co.nz>
 
@date 10 March 2013
 
LGPL License Terms @ref lgpl_license
*/
 
/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2010 Gareth McMullin <gareth@blacksphere.co.nz>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
 
/**@{*/
 
#include <string.h>
#include <libopencm3/usb/usbd.h>
#include "usb_private.h"
 
int usbd_register_set_config_callback(usbd_device *usbd_dev,
                                       usbd_set_config_callback callback)
{
        int i;
 
        for (i = 0; i < MAX_USER_SET_CONFIG_CALLBACK; i++) {
                if (usbd_dev->user_callback_set_config[i]) {
                        if (usbd_dev->user_callback_set_config[i] == callback) {
                                return 0;
                        }
                        continue;
                }
 
                usbd_dev->user_callback_set_config[i] = callback;
                return 0;
        }
 
        return -1;
}
 
void usbd_register_set_altsetting_callback(usbd_device *usbd_dev,
                                        usbd_set_altsetting_callback callback)
{
        usbd_dev->user_callback_set_altsetting = callback;
}
 
static uint16_t build_config_descriptor(usbd_device *usbd_dev,
                                   uint8_t index, uint8_t *buf, uint16_t len)
{
        uint8_t *tmpbuf = buf;
        const struct usb_config_descriptor *cfg = &usbd_dev->config[index];
        uint16_t count, total = 0, totallen = 0;
        uint16_t i, j, k;
 
        memcpy(buf, cfg, count = MIN(len, cfg->bLength));
        buf += count;
        len -= count;
        total += count;
        totallen += cfg->bLength;
 
        /* For each interface... */
        for (i = 0; i < cfg->bNumInterfaces; i++) {
                /* Interface Association Descriptor, if any */
                if (cfg->interface[i].iface_assoc) {
                        const struct usb_iface_assoc_descriptor *assoc =
                                        cfg->interface[i].iface_assoc;
                        memcpy(buf, assoc, count = MIN(len, assoc->bLength));
                        buf += count;
                        len -= count;
                        total += count;
                        totallen += assoc->bLength;
                }
                /* For each alternate setting... */
                for (j = 0; j < cfg->interface[i].num_altsetting; j++) {
                        const struct usb_interface_descriptor *iface =
                                        &cfg->interface[i].altsetting[j];
                        /* Copy interface descriptor. */
                        memcpy(buf, iface, count = MIN(len, iface->bLength));
                        buf += count;
                        len -= count;
                        total += count;
                        totallen += iface->bLength;
                        /* Copy extra bytes (function descriptors). */
                        if (iface->extra) {
                                memcpy(buf, iface->extra,
                                       count = MIN(len, iface->extralen));
                                buf += count;
                                len -= count;
                                total += count;
                                totallen += iface->extralen;
                        }
                        /* For each endpoint... */
                        for (k = 0; k < iface->bNumEndpoints; k++) {
                                const struct usb_endpoint_descriptor *ep =
                                    &iface->endpoint[k];
                                memcpy(buf, ep, count = MIN(len, ep->bLength));
                                buf += count;
                                len -= count;
                                total += count;
                                totallen += ep->bLength;
                                /* Copy extra bytes (class specific). */
                                if (ep->extra) {
                                        memcpy(buf, ep->extra,
                                               count = MIN(len, ep->extralen));
                                        buf += count;
                                        len -= count;
                                        total += count;
                                        totallen += ep->extralen;
                                }
                        }
                }
        }
 
        /* Fill in wTotalLength.
         * Note that tmpbuf is sometimes not halfword-aligned */
        memcpy((tmpbuf + 2), &totallen, sizeof(uint16_t));
 
        return total;
}
 
static int usb_descriptor_type(uint16_t wValue)
{
        return wValue >> 8;
}
 
static int usb_descriptor_index(uint16_t wValue)
{
        return wValue & 0xFF;
}
 
static enum usbd_request_return_codes
usb_standard_get_descriptor(usbd_device *usbd_dev,
                            struct usb_setup_data *req,
                            uint8_t **buf, uint16_t *len)
{
        int i, array_idx, descr_idx;
        struct usb_string_descriptor *sd;
 
        descr_idx = usb_descriptor_index(req->wValue);
 
        switch (usb_descriptor_type(req->wValue)) {
        case USB_DT_DEVICE:
                *buf = (uint8_t *) usbd_dev->desc;
                *len = MIN(*len, usbd_dev->desc->bLength);
                return USBD_REQ_HANDLED;
        case USB_DT_CONFIGURATION:
                *buf = usbd_dev->ctrl_buf;
                *len = build_config_descriptor(usbd_dev, descr_idx, *buf, *len);
                return USBD_REQ_HANDLED;
        case USB_DT_STRING:
                sd = (struct usb_string_descriptor *)usbd_dev->ctrl_buf;
 
                if (descr_idx == 0) {
                        /* Send sane Language ID descriptor... */
                        sd->wData[0] = USB_LANGID_ENGLISH_US;
                        sd->bLength = sizeof(sd->bLength) +
                                      sizeof(sd->bDescriptorType) +
                                      sizeof(sd->wData[0]);
 
                        *len = MIN(*len, sd->bLength);
                } else if (descr_idx == usbd_dev->extra_string_idx) {
                        /* This string is returned as UTF16, hence the
                         * multiplication
                         */
                        sd->bLength = strlen(usbd_dev->extra_string) * 2 +
                                      sizeof(sd->bLength) +
                                      sizeof(sd->bDescriptorType);
 
                        *len = MIN(*len, sd->bLength);
 
                        for (i = 0; i < (*len / 2) - 1; i++) {
                                sd->wData[i] =
                                        usbd_dev->extra_string[i];
                        }
        } else {
                        array_idx = descr_idx - 1;
 
                        if (!usbd_dev->strings) {
                                /* Device doesn't support strings. */
                                return USBD_REQ_NOTSUPP;
                        }
 
                        /* Check that string index is in range. */
                        if (array_idx >= usbd_dev->num_strings) {
                                return USBD_REQ_NOTSUPP;
                        }
 
                        /* Strings with Language ID differnet from
                         * USB_LANGID_ENGLISH_US are not supported */
                        if (req->wIndex != USB_LANGID_ENGLISH_US) {
                                return USBD_REQ_NOTSUPP;
                        }
 
                        /* This string is returned as UTF16, hence the
                         * multiplication
                         */
                        sd->bLength = strlen(usbd_dev->strings[array_idx]) * 2 +
                                      sizeof(sd->bLength) +
                                      sizeof(sd->bDescriptorType);
 
                        *len = MIN(*len, sd->bLength);
 
                        for (i = 0; i < (*len / 2) - 1; i++) {
                                sd->wData[i] =
                                        usbd_dev->strings[array_idx][i];
                        }
                }
 
                sd->bDescriptorType = USB_DT_STRING;
                *buf = (uint8_t *)sd;
 
                return USBD_REQ_HANDLED;
        }
        return USBD_REQ_NOTSUPP;
}
 
static enum usbd_request_return_codes
usb_standard_set_address(usbd_device *usbd_dev,
                         struct usb_setup_data *req, uint8_t **buf,
                         uint16_t *len)
{
        (void)req;
        (void)buf;
        (void)len;
 
        /* The actual address is only latched at the STATUS IN stage. */
        if ((req->bmRequestType != 0) || (req->wValue >= 128)) {
                return USBD_REQ_NOTSUPP;
        }
 
        usbd_dev->current_address = req->wValue;
 
        /*
         * Special workaround for STM32F10[57] that require the address
         * to be set here. This is undocumented!
         */
        if (usbd_dev->driver->set_address_before_status) {
                usbd_dev->driver->set_address(usbd_dev, req->wValue);
        }
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_set_configuration(usbd_device *usbd_dev,
                               struct usb_setup_data *req,
                               uint8_t **buf, uint16_t *len)
{
        unsigned i;
        int found_index = -1;
        const struct usb_config_descriptor *cfg;
 
        (void)req;
        (void)buf;
        (void)len;
 
        if (req->wValue > 0) {
                for (i = 0; i < usbd_dev->desc->bNumConfigurations; i++) {
                        if (req->wValue
                            == usbd_dev->config[i].bConfigurationValue) {
                                found_index = i;
                                break;
                        }
                }
                if (found_index < 0) {
                        return USBD_REQ_NOTSUPP;
                }
        }
 
        usbd_dev->current_config = found_index + 1;
 
        if (usbd_dev->current_config > 0) {
                cfg = &usbd_dev->config[usbd_dev->current_config - 1];
 
                /* reset all alternate settings configuration */
                for (i = 0; i < cfg->bNumInterfaces; i++) {
                        if (cfg->interface[i].cur_altsetting) {
                                *cfg->interface[i].cur_altsetting = 0;
                        }
                }
        }
 
        /* Reset all endpoints. */
        usbd_dev->driver->ep_reset(usbd_dev);
 
        if (usbd_dev->user_callback_set_config[0]) {
                /*
                 * Flush control callbacks. These will be reregistered
                 * by the user handler.
                 */
                for (i = 0; i < MAX_USER_CONTROL_CALLBACK; i++) {
                        usbd_dev->user_control_callback[i].cb = NULL;
                }
 
                for (i = 0; i < MAX_USER_SET_CONFIG_CALLBACK; i++) {
                        if (usbd_dev->user_callback_set_config[i]) {
                                usbd_dev->user_callback_set_config[i](usbd_dev,
                                                                req->wValue);
                        }
                }
        }
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_get_configuration(usbd_device *usbd_dev,
                               struct usb_setup_data *req,
                               uint8_t **buf, uint16_t *len)
{
        (void)req;
 
        if (*len > 1) {
                *len = 1;
        }
        if (usbd_dev->current_config > 0) {
                const struct usb_config_descriptor *cfg =
                        &usbd_dev->config[usbd_dev->current_config - 1];
                (*buf)[0] = cfg->bConfigurationValue;
        } else {
                (*buf)[0] = 0;
        }
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_set_interface(usbd_device *usbd_dev,
                           struct usb_setup_data *req,
                           uint8_t **buf, uint16_t *len)
{
        const struct usb_config_descriptor *cfx =
                &usbd_dev->config[usbd_dev->current_config - 1];
        const struct usb_interface *iface;
 
        (void)buf;
 
        if (req->wIndex >= cfx->bNumInterfaces) {
                return USBD_REQ_NOTSUPP;
        }
 
        iface = &cfx->interface[req->wIndex];
 
        if (req->wValue >= iface->num_altsetting) {
                return USBD_REQ_NOTSUPP;
        }
 
        if (iface->cur_altsetting) {
                *iface->cur_altsetting = req->wValue;
        } else if (req->wValue > 0) {
                return USBD_REQ_NOTSUPP;
        }
 
        if (usbd_dev->user_callback_set_altsetting) {
                        usbd_dev->user_callback_set_altsetting(usbd_dev,
                                                               req->wIndex,
                                                               req->wValue);
        }
 
        *len = 0;
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_get_interface(usbd_device *usbd_dev,
                           struct usb_setup_data *req,
                           uint8_t **buf, uint16_t *len)
{
        uint8_t *cur_altsetting;
        const struct usb_config_descriptor *cfx =
                &usbd_dev->config[usbd_dev->current_config - 1];
 
        if (req->wIndex >= cfx->bNumInterfaces) {
                return USBD_REQ_NOTSUPP;
        }
 
        *len = 1;
        cur_altsetting = cfx->interface[req->wIndex].cur_altsetting;
        (*buf)[0] = (cur_altsetting) ? *cur_altsetting : 0;
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_device_get_status(usbd_device *usbd_dev,
                               struct usb_setup_data *req,
                               uint8_t **buf, uint16_t *len)
{
        (void)usbd_dev;
        (void)req;
 
        /* bit 0: self powered */
        /* bit 1: remote wakeup */
        if (*len > 2) {
                *len = 2;
        }
        (*buf)[0] = 0;
        (*buf)[1] = 0;
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_interface_get_status(usbd_device *usbd_dev,
                                  struct usb_setup_data *req,
                                  uint8_t **buf, uint16_t *len)
{
        (void)usbd_dev;
        (void)req;
        /* not defined */
 
        if (*len > 2) {
                *len = 2;
        }
        (*buf)[0] = 0;
        (*buf)[1] = 0;
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_endpoint_get_status(usbd_device *usbd_dev,
                                 struct usb_setup_data *req,
                                 uint8_t **buf, uint16_t *len)
{
        (void)req;
 
        if (*len > 2) {
                *len = 2;
        }
        (*buf)[0] = usbd_ep_stall_get(usbd_dev, req->wIndex) ? 1 : 0;
        (*buf)[1] = 0;
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_endpoint_stall(usbd_device *usbd_dev,
                            struct usb_setup_data *req,
                            uint8_t **buf, uint16_t *len)
{
        (void)buf;
        (void)len;
 
        usbd_ep_stall_set(usbd_dev, req->wIndex, 1);
 
        return USBD_REQ_HANDLED;
}
 
static enum usbd_request_return_codes
usb_standard_endpoint_unstall(usbd_device *usbd_dev,
                              struct usb_setup_data *req,
                              uint8_t **buf, uint16_t *len)
{
        (void)buf;
        (void)len;
 
        usbd_ep_stall_set(usbd_dev, req->wIndex, 0);
 
        return USBD_REQ_HANDLED;
}
 
/* Do not appear to belong to the API, so are omitted from docs */
/**@}*/
 
enum usbd_request_return_codes
_usbd_standard_request_device(usbd_device *usbd_dev,
                              struct usb_setup_data *req, uint8_t **buf,
                              uint16_t *len)
{
        enum usbd_request_return_codes (*command)(usbd_device *usbd_dev,
                struct usb_setup_data *req,
                uint8_t **buf, uint16_t *len) = NULL;
 
        switch (req->bRequest) {
        case USB_REQ_CLEAR_FEATURE:
        case USB_REQ_SET_FEATURE:
                if (req->wValue == USB_FEAT_DEVICE_REMOTE_WAKEUP) {
                        /* Device wakeup code goes here. */
                }
 
                if (req->wValue == USB_FEAT_TEST_MODE) {
                        /* Test mode code goes here. */
                }
 
                break;
        case USB_REQ_SET_ADDRESS:
                /*
                 * SET ADDRESS is an exception.
                 * It is only processed at STATUS stage.
                 */
                command = usb_standard_set_address;
                break;
        case USB_REQ_SET_CONFIGURATION:
                command = usb_standard_set_configuration;
                break;
        case USB_REQ_GET_CONFIGURATION:
                command = usb_standard_get_configuration;
                break;
        case USB_REQ_GET_DESCRIPTOR:
                command = usb_standard_get_descriptor;
                break;
        case USB_REQ_GET_STATUS:
                /*
                 * GET_STATUS always responds with zero reply.
                 * The application may override this behaviour.
                 */
                command = usb_standard_device_get_status;
                break;
        case USB_REQ_SET_DESCRIPTOR:
                /* SET_DESCRIPTOR is optional and not implemented. */
                break;
        }
 
        if (!command) {
                return USBD_REQ_NOTSUPP;
        }
 
        return command(usbd_dev, req, buf, len);
}
 
enum usbd_request_return_codes
_usbd_standard_request_interface(usbd_device *usbd_dev,
                                 struct usb_setup_data *req, uint8_t **buf,
                                 uint16_t *len)
{
        enum usbd_request_return_codes (*command)(usbd_device *usbd_dev,
                struct usb_setup_data *req,
                uint8_t **buf, uint16_t *len) = NULL;
 
        switch (req->bRequest) {
        case USB_REQ_CLEAR_FEATURE:
        case USB_REQ_SET_FEATURE:
                /* not defined */
                break;
        case USB_REQ_GET_INTERFACE:
                command = usb_standard_get_interface;
                break;
        case USB_REQ_SET_INTERFACE:
                command = usb_standard_set_interface;
                break;
        case USB_REQ_GET_STATUS:
                command = usb_standard_interface_get_status;
                break;
        }
 
        if (!command) {
                return USBD_REQ_NOTSUPP;
        }
 
        return command(usbd_dev, req, buf, len);
}
 
enum usbd_request_return_codes
_usbd_standard_request_endpoint(usbd_device *usbd_dev,
                                struct usb_setup_data *req, uint8_t **buf,
                                uint16_t *len)
{
        enum usbd_request_return_codes (*command) (usbd_device *usbd_dev,
                struct usb_setup_data *req,
                uint8_t **buf, uint16_t *len) = NULL;
 
        switch (req->bRequest) {
        case USB_REQ_CLEAR_FEATURE:
                if (req->wValue == USB_FEAT_ENDPOINT_HALT) {
                        command = usb_standard_endpoint_unstall;
                }
                break;
        case USB_REQ_SET_FEATURE:
                if (req->wValue == USB_FEAT_ENDPOINT_HALT) {
                        command = usb_standard_endpoint_stall;
                }
                break;
        case USB_REQ_GET_STATUS:
                command = usb_standard_endpoint_get_status;
                break;
        case USB_REQ_SET_SYNCH_FRAME:
                /* FIXME: SYNCH_FRAME is not implemented. */
                /*
                 * SYNCH_FRAME is used for synchronization of isochronous
                 * endpoints which are not yet implemented.
                 */
                break;
        }
 
        if (!command) {
                return USBD_REQ_NOTSUPP;
        }
 
        return command(usbd_dev, req, buf, len);
}
 
enum usbd_request_return_codes
_usbd_standard_request(usbd_device *usbd_dev, struct usb_setup_data *req,
                       uint8_t **buf, uint16_t *len)
{
        /* FIXME: Have class/vendor requests as well. */
        if ((req->bmRequestType & USB_REQ_TYPE_TYPE) != USB_REQ_TYPE_STANDARD) {
                return USBD_REQ_NOTSUPP;
        }
 
        switch (req->bmRequestType & USB_REQ_TYPE_RECIPIENT) {
        case USB_REQ_TYPE_DEVICE:
                return _usbd_standard_request_device(usbd_dev, req, buf, len);
        case USB_REQ_TYPE_INTERFACE:
                return _usbd_standard_request_interface(usbd_dev, req,
                                                        buf, len);
        case USB_REQ_TYPE_ENDPOINT:
                return _usbd_standard_request_endpoint(usbd_dev, req, buf, len);
        default:
                return USBD_REQ_NOTSUPP;
        }
}