lm4f: Add USB to serial (CDCACM) example
Implements a USB-to-serial adapter, compliant to the CDCACM subclass. UART1 is used for the TX/RX lines. Although UART1 also has lines for flow control, they are not used. Instead, the control lines are implemented in software via GPIOA. Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
This commit is contained in:
Alexandru Gagniuc
committed by
Piotr Esden-Tempski
Piotr Esden-Tempski
parent
f5b0aa5638
commit
28f92cce2b
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/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2010 Gareth McMullin <gareth@blacksphere.co.nz>
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* Copyright (C) 2013 Alexandru Gagniuc <mr.nuke.me@gmail.com>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "usb_to_serial_cdcacm.h"
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#include <stdlib.h>
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#include <libopencm3/usb/usbd.h>
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#include <libopencm3/usb/cdc.h>
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#include <libopencm3/lm4f/rcc.h>
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#include <libopencm3/cm3/scb.h>
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#include <libopencm3/lm4f/nvic.h>
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#include <libopencm3/lm4f/usb.h>
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static const struct usb_device_descriptor dev = {
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.bLength = USB_DT_DEVICE_SIZE,
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.bDescriptorType = USB_DT_DEVICE,
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.bcdUSB = 0x2000,
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.bDeviceClass = USB_CLASS_CDC,
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.bDeviceSubClass = 0,
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.bDeviceProtocol = 0,
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.bMaxPacketSize0 = 64,
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.idVendor = 0xc03e,
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.idProduct = 0xb007,
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.bcdDevice = 0x2000,
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.iManufacturer = 1,
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.iProduct = 2,
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.iSerialNumber = 3,
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.bNumConfigurations = 1,
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};
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/*
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* This notification endpoint isn't implemented. According to CDC spec it's
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* optional, but its absence causes a NULL pointer dereference in the
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* Linux cdc_acm driver.
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*/
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static const struct usb_endpoint_descriptor comm_endp[] = {{
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = 0x83,
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.bmAttributes = USB_ENDPOINT_ATTR_INTERRUPT,
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.wMaxPacketSize = 16,
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.bInterval = 1,
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}};
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static const struct usb_endpoint_descriptor data_endp[] = {{
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = 0x01,
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.bmAttributes = USB_ENDPOINT_ATTR_BULK,
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.wMaxPacketSize = 64,
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.bInterval = 1,
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}, {
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.bLength = USB_DT_ENDPOINT_SIZE,
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.bDescriptorType = USB_DT_ENDPOINT,
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.bEndpointAddress = 0x82,
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.bmAttributes = USB_ENDPOINT_ATTR_BULK,
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.wMaxPacketSize = 64,
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.bInterval = 1,
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}};
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static const struct {
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struct usb_cdc_header_descriptor header;
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struct usb_cdc_call_management_descriptor call_mgmt;
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struct usb_cdc_acm_descriptor acm;
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struct usb_cdc_union_descriptor cdc_union;
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} __attribute__ ((packed)) cdcacm_functional_descriptors = {
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.header = {
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.bFunctionLength = sizeof(struct usb_cdc_header_descriptor),
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.bDescriptorType = CS_INTERFACE,
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.bDescriptorSubtype = USB_CDC_TYPE_HEADER,
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.bcdCDC = 0x0110,
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},
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.call_mgmt = {
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.bFunctionLength =
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sizeof(struct usb_cdc_call_management_descriptor),
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.bDescriptorType = CS_INTERFACE,
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.bDescriptorSubtype = USB_CDC_TYPE_CALL_MANAGEMENT,
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.bmCapabilities = 0,
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.bDataInterface = 1,
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},
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.acm = {
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.bFunctionLength = sizeof(struct usb_cdc_acm_descriptor),
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.bDescriptorType = CS_INTERFACE,
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.bDescriptorSubtype = USB_CDC_TYPE_ACM,
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.bmCapabilities = (1 << 1),
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},
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.cdc_union = {
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.bFunctionLength = sizeof(struct usb_cdc_union_descriptor),
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.bDescriptorType = CS_INTERFACE,
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.bDescriptorSubtype = USB_CDC_TYPE_UNION,
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.bControlInterface = 0,
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.bSubordinateInterface0 = 1,
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}
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};
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static const struct usb_interface_descriptor comm_iface[] = {{
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.bLength = USB_DT_INTERFACE_SIZE,
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.bDescriptorType = USB_DT_INTERFACE,
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.bInterfaceNumber = 0,
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.bAlternateSetting = 0,
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.bNumEndpoints = 1,
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.bInterfaceClass = USB_CLASS_CDC,
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.bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
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.bInterfaceProtocol = USB_CDC_PROTOCOL_AT,
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.iInterface = 0,
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.endpoint = comm_endp,
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.extra = &cdcacm_functional_descriptors,
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.extralen = sizeof(cdcacm_functional_descriptors)
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}};
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static const struct usb_interface_descriptor data_iface[] = {{
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.bLength = USB_DT_INTERFACE_SIZE,
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.bDescriptorType = USB_DT_INTERFACE,
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.bInterfaceNumber = 1,
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.bAlternateSetting = 0,
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.bNumEndpoints = 2,
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.bInterfaceClass = USB_CLASS_DATA,
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.bInterfaceSubClass = 0,
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.bInterfaceProtocol = 0,
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.iInterface = 0,
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.endpoint = data_endp,
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}};
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static const struct usb_interface ifaces[] = {{
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.num_altsetting = 1,
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.altsetting = comm_iface,
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}, {
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.num_altsetting = 1,
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.altsetting = data_iface,
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}};
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static const struct usb_config_descriptor config = {
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.bLength = USB_DT_CONFIGURATION_SIZE,
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.bDescriptorType = USB_DT_CONFIGURATION,
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.wTotalLength = 0,
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.bNumInterfaces = 2,
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.bConfigurationValue = 1,
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.iConfiguration = 0,
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.bmAttributes = 0x80,
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.bMaxPower = 0x32,
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.interface = ifaces,
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};
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static const char *usb_strings[] = {
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"libopencm3",
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"usb_to_serial_cdcacm",
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"none",
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"DEMO",
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};
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usbd_device *acm_dev;
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u8 usbd_control_buffer[128];
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extern usbd_driver lm4f_usb_driver;
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static int cdcacm_control_request(usbd_device * usbd_dev,
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struct usb_setup_data *req, u8 ** buf,
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u16 * len,
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void (**complete) (usbd_device * usbd_dev,
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struct usb_setup_data *
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req))
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{
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u8 dtr, rts;
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(void)complete;
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(void)buf;
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(void)usbd_dev;
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switch (req->bRequest) {
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case USB_CDC_REQ_SET_CONTROL_LINE_STATE:{
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/*
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* This Linux cdc_acm driver requires this to be implemented
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* even though it's optional in the CDC spec, and we don't
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* advertise it in the ACM functional descriptor.
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*/
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dtr = (req->wValue & (1 << 0)) ? 1 : 0;
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rts = (req->wValue & (1 << 1)) ? 1 : 0;
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glue_set_line_state_cb(dtr, rts);
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return 1;
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}
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case USB_CDC_REQ_SET_LINE_CODING:{
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struct usb_cdc_line_coding *coding;
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if (*len < sizeof(struct usb_cdc_line_coding))
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return 0;
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coding = (struct usb_cdc_line_coding *)*buf;
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return glue_set_line_coding_cb(coding->dwDTERate,
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coding->bDataBits,
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coding->bParityType,
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coding->bCharFormat);
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}
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}
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return 0;
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}
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static void cdcacm_data_rx_cb(usbd_device * usbd_dev, u8 ep)
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{
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u8 buf[64];
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(void)ep;
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int len = usbd_ep_read_packet(usbd_dev, 0x01, buf, 64);
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glue_send_data_cb(buf, len);
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}
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void cdcacm_send_data(u8 * buf, u16 len)
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{
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usbd_ep_write_packet(acm_dev, 0x82, buf, len);
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}
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static void cdcacm_set_config(usbd_device * usbd_dev, u16 wValue)
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{
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(void)wValue;
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usbd_ep_setup(usbd_dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64,
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cdcacm_data_rx_cb);
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usbd_ep_setup(usbd_dev, 0x82, USB_ENDPOINT_ATTR_BULK, 64, NULL);
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usbd_ep_setup(usbd_dev, 0x83, USB_ENDPOINT_ATTR_INTERRUPT, 16, NULL);
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usbd_register_control_callback(usbd_dev,
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USB_REQ_TYPE_CLASS |
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USB_REQ_TYPE_INTERFACE,
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USB_REQ_TYPE_TYPE |
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USB_REQ_TYPE_RECIPIENT,
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cdcacm_control_request);
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}
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void cdcacm_line_state_changed_cb(u8 linemask)
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{
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const int size = sizeof(struct usb_cdc_notification) + 2;
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u8 buf[size];
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struct usb_cdc_notification *notify = (void *)buf;
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notify->bmRequestType = 0xa1;
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notify->bNotification = USB_CDC_NOTIFY_SERIAL_STATE;
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notify->wValue = 0;
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notify->wIndex = 1;
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notify->wLength = 2;
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u16 *data = (void *)&buf[sizeof(struct usb_cdc_notification)];
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*data = linemask;
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while (usbd_ep_write_packet(acm_dev, 0x83, buf, size) == size) ;
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}
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static void usb_pins_setup(void)
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{
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/* USB pins are connected to port D */
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periph_clock_enable(RCC_GPIOD);
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/* Mux USB pins to their analog function */
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gpio_mode_setup(GPIOD, GPIO_MODE_ANALOG, GPIO_PUPD_NONE, GPIO4 | GPIO5);
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}
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static void usb_ints_setup(void)
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{
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u8 usbints;
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/* Gimme some interrupts */
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usbints = USB_INT_RESET | USB_INT_DISCON | USB_INT_RESUME | USB_INT_SUSPEND; //| USB_IM_SOF;
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usb_enable_interrupts(usbints, 0xff, 0xff);
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nvic_enable_irq(NVIC_USB0_IRQ);
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}
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void cdcacm_init(void)
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{
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usbd_device *usbd_dev;
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usb_pins_setup();
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usbd_dev = usbd_init(&lm4f_usb_driver, &dev, &config, usb_strings, 4,
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usbd_control_buffer, sizeof(usbd_control_buffer));
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acm_dev = usbd_dev;
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usbd_register_set_config_callback(usbd_dev, cdcacm_set_config);
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usb_ints_setup();
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}
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void usb0_isr(void)
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{
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usbd_poll(acm_dev);
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}
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