tiva(stellaris)/lpc: Use directory structure as stm32

EDIT: Whitespace changes to the files stripped out.

examples/tiva/lm4f/stellaris-ek-lm4f120xl/usb_to_serial_cdcacm/Makefile

@@ -0,0 +1,27 @@
+##
+## This file is part of the libopencm3 project.
+##
+## Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+##
+## 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/>.
+##
+
+BINARY = usb_to_serial_cdcacm
+
+LDSCRIPT = ../ek-lm4f120xl.ld
+
+
+OBJS += uart.o usb_cdcacm.o
+
+include ../../Makefile.include

examples/tiva/lm4f/stellaris-ek-lm4f120xl/usb_to_serial_cdcacm/README

@@ -0,0 +1,68 @@
+------------------------------------------------------------------------------
+README
+------------------------------------------------------------------------------
+
+This example demonstrates the following:
+ * Using the USB controller
+ * Setting up a simple usb to serial converter (CDCACM)
+
+File list:
+ * usb_cdcacm.c - implementation of the CDCACM subclass
+ * uart.c - implementation of UART peripheral
+ * usb_to_serial_cdcacm.c - glue logic between UART and CDCACM device
+ * usb_to_serial_cdcacm.h - common definitions
+
+
+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.
+
+The following pinout is used:
+	Tx  <-  PB1
+	Rx   -> PB0
+	DCD  -> PA2
+	DSR  -> PA3
+	RI   -> PA4
+	CTS  -> PA5 (UNUSED)
+	DTR <-  PA6
+	RTS <-  PA7
+
+Note that the CTS pin is unused. The CDCACM specification does not define a way
+to control this pin, nor does it define a way to switch between flow control
+mechanisms.
+
+The glue logic in usb_to_serial_cdcacm.c receives requests from both the UART
+and CDCACM interface, and forward them to their destination, while also
+controlling the LEDs
+
+The green LED is lit as long as either DTR or RTS are high.
+The red LED is lit while the UART is sending data.
+The blue LED is lit while data is read from the UART.
+The red and blue LEDs will only be lit for very short periods of time, thus they
+may be difficult to notice.
+
+------------------------------------------------------------------------------
+Windows Quirks
+------------------------------------------------------------------------------
+On openening the CDCACM port Windows send a SET_LINE_CODING request with the
+desired baud rate but without valid databits. To run this example CDDACM device
+under Windows you have to return always 1 when a SET_LINE_CODING request is
+received. The following code should work:
+
+File: usb_cdcacm.c
+Function: cdcacm_control_request()
+
+	case USB_CDC_REQ_SET_LINE_CODING:{
+			struct usb_cdc_line_coding *coding;
+
+			if (*len < sizeof(struct usb_cdc_line_coding))
+			{
+				return 0;
+			}
+
+			coding = (struct usb_cdc_line_coding *)*buf;
+			glue_set_line_coding_cb(coding->dwDTERate,
+						coding->bDataBits,
+						coding->bParityType,
+						coding->bCharFormat);
+			return 1;

examples/tiva/lm4f/stellaris-ek-lm4f120xl/usb_to_serial_cdcacm/uart.c

@@ -0,0 +1,99 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012-2013 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ *
+ * 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/>.
+ */
+
+/**
+ * \addtogroup Examples
+ *
+ */
+/*
+ * Pins handled by hw peripheral:
+ * Tx  <-> PB1
+ * Rx  <-> PB0
+ * Input pins handled manually via interrupts:
+ * DCD <-> PA2
+ * DSR <-> PA3
+ * RI  <-> PA4
+ * CTS <-> PA5 (UNUSED)
+ * Output pins handled via commands from the host:
+ * DTR <-> PA6
+ * RTS <-> PA7
+ */
+
+#include "usb_to_serial_cdcacm.h"
+
+#include <libopencm3/lm4f/rcc.h>
+#include <libopencm3/lm4f/uart.h>
+#include <libopencm3/lm4f/nvic.h>
+
+static void uart_ctl_line_setup(void)
+{
+	uint32_t inpins, outpins;
+
+	inpins = PIN_DCD | PIN_DSR | PIN_RI | PIN_CTS;
+	outpins = PIN_DTR | PIN_RTS;
+
+	gpio_mode_setup(GPIOA, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, outpins);
+	gpio_mode_setup(GPIOA, GPIO_MODE_INPUT, GPIO_PUPD_PULLUP, inpins);
+}
+
+void uart_init(void)
+{
+	/* Enable GPIOA and GPIOB in run mode. */
+	periph_clock_enable(RCC_GPIOB);
+	periph_clock_enable(RCC_GPIOA);
+	uart_ctl_line_setup();
+	/* Mux PB0 and PB1 to AF1 (UART1 in this case) */
+	gpio_set_af(GPIOB, 1, GPIO0 | GPIO1);
+
+	/* Enable the UART clock */
+	periph_clock_enable(RCC_UART1);
+	/* Disable the UART while we mess with its setings */
+	uart_disable(UART1);
+	/* Configure the UART clock source */
+	uart_clock_from_piosc(UART1);
+	/* We don't make any other settings here. */
+	uart_enable(UART1);
+
+	/* Ping us when something comes in */
+	uart_enable_rx_interrupt(UART1);
+	nvic_enable_irq(NVIC_UART1_IRQ);
+}
+
+uint8_t uart_get_ctl_line_state(void)
+{
+	return gpio_read(GPIOA, PIN_RI | PIN_DSR | PIN_DCD);
+}
+
+void uart_set_ctl_line_state(uint8_t dtr, uint8_t rts)
+{
+	uint8_t val = 0;
+
+	val |= dtr ? PIN_DTR : 0;
+	val |= rts ? PIN_RTS : 0;
+
+	gpio_write(GPIOA, PIN_DTR | PIN_RTS, val);
+}
+
+void uart1_isr(void)
+{
+	uint8_t rx;
+	rx = uart_recv(UART1);
+	glue_data_received_cb(&rx, 1);
+	uart_clear_interrupt_flag(UART1, UART_INT_RX);
+}

examples/tiva/lm4f/stellaris-ek-lm4f120xl/usb_to_serial_cdcacm/usb_cdcacm.c

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+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2010 Gareth McMullin <gareth@blacksphere.co.nz>
+ * Copyright (C) 2013 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ *
+ * 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 "usb_to_serial_cdcacm.h"
+
+#include <stdlib.h>
+#include <libopencm3/usb/usbd.h>
+#include <libopencm3/usb/cdc.h>
+#include <libopencm3/lm4f/rcc.h>
+#include <libopencm3/cm3/scb.h>
+#include <libopencm3/lm4f/nvic.h>
+#include <libopencm3/lm4f/usb.h>
+
+static const struct usb_device_descriptor dev = {
+	.bLength = USB_DT_DEVICE_SIZE,
+	.bDescriptorType = USB_DT_DEVICE,
+	.bcdUSB = 0x2000,
+	.bDeviceClass = USB_CLASS_CDC,
+	.bDeviceSubClass = 0,
+	.bDeviceProtocol = 0,
+	.bMaxPacketSize0 = 64,
+	.idVendor = 0xc03e,
+	.idProduct = 0xb007,
+	.bcdDevice = 0x2000,
+	.iManufacturer = 1,
+	.iProduct = 2,
+	.iSerialNumber = 3,
+	.bNumConfigurations = 1,
+};
+
+/*
+ * This notification endpoint isn't implemented. According to CDC spec it's
+ * optional, but its absence causes a NULL pointer dereference in the
+ * Linux cdc_acm driver.
+ */
+static const struct usb_endpoint_descriptor comm_endp[] = {{
+	.bLength = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+	.bEndpointAddress = 0x83,
+	.bmAttributes = USB_ENDPOINT_ATTR_INTERRUPT,
+	.wMaxPacketSize = 16,
+	.bInterval = 1,
+}};
+
+static const struct usb_endpoint_descriptor data_endp[] = {{
+	.bLength = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+	.bEndpointAddress = 0x01,
+	.bmAttributes = USB_ENDPOINT_ATTR_BULK,
+	.wMaxPacketSize = 64,
+	.bInterval = 1,
+}, {
+	.bLength = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+	.bEndpointAddress = 0x82,
+	.bmAttributes = USB_ENDPOINT_ATTR_BULK,
+	.wMaxPacketSize = 64,
+	.bInterval = 1,
+}};
+
+static const struct {
+	struct usb_cdc_header_descriptor header;
+	struct usb_cdc_call_management_descriptor call_mgmt;
+	struct usb_cdc_acm_descriptor acm;
+	struct usb_cdc_union_descriptor cdc_union;
+} __attribute__ ((packed)) cdcacm_functional_descriptors = {
+	.header = {
+		.bFunctionLength = sizeof(struct usb_cdc_header_descriptor),
+		.bDescriptorType = CS_INTERFACE,
+		.bDescriptorSubtype = USB_CDC_TYPE_HEADER,
+		.bcdCDC = 0x0110,
+	},
+	.call_mgmt = {
+		.bFunctionLength =
+			sizeof(struct usb_cdc_call_management_descriptor),
+		.bDescriptorType = CS_INTERFACE,
+		.bDescriptorSubtype = USB_CDC_TYPE_CALL_MANAGEMENT,
+		.bmCapabilities = 0,
+		.bDataInterface = 1,
+	},
+	.acm = {
+		.bFunctionLength = sizeof(struct usb_cdc_acm_descriptor),
+		.bDescriptorType = CS_INTERFACE,
+		.bDescriptorSubtype = USB_CDC_TYPE_ACM,
+		.bmCapabilities = (1 << 1),
+	},
+	.cdc_union = {
+		.bFunctionLength = sizeof(struct usb_cdc_union_descriptor),
+		.bDescriptorType = CS_INTERFACE,
+		.bDescriptorSubtype = USB_CDC_TYPE_UNION,
+		.bControlInterface = 0,
+		.bSubordinateInterface0 = 1,
+	}
+};
+
+static const struct usb_interface_descriptor comm_iface[] = {{
+	.bLength = USB_DT_INTERFACE_SIZE,
+	.bDescriptorType = USB_DT_INTERFACE,
+	.bInterfaceNumber = 0,
+	.bAlternateSetting = 0,
+	.bNumEndpoints = 1,
+	.bInterfaceClass = USB_CLASS_CDC,
+	.bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
+	.bInterfaceProtocol = USB_CDC_PROTOCOL_AT,
+	.iInterface = 0,
+
+	.endpoint = comm_endp,
+
+	.extra = &cdcacm_functional_descriptors,
+	.extralen = sizeof(cdcacm_functional_descriptors)
+}};
+
+static const struct usb_interface_descriptor data_iface[] = {{
+	.bLength = USB_DT_INTERFACE_SIZE,
+	.bDescriptorType = USB_DT_INTERFACE,
+	.bInterfaceNumber = 1,
+	.bAlternateSetting = 0,
+	.bNumEndpoints = 2,
+	.bInterfaceClass = USB_CLASS_DATA,
+	.bInterfaceSubClass = 0,
+	.bInterfaceProtocol = 0,
+	.iInterface = 0,
+
+	.endpoint = data_endp,
+}};
+
+static const struct usb_interface ifaces[] = {{
+	.num_altsetting = 1,
+	.altsetting = comm_iface,
+}, {
+	.num_altsetting = 1,
+	.altsetting = data_iface,
+}};
+
+static const struct usb_config_descriptor config = {
+	.bLength = USB_DT_CONFIGURATION_SIZE,
+	.bDescriptorType = USB_DT_CONFIGURATION,
+	.wTotalLength = 0,
+	.bNumInterfaces = 2,
+	.bConfigurationValue = 1,
+	.iConfiguration = 0,
+	.bmAttributes = 0x80,
+	.bMaxPower = 0x32,
+
+	.interface = ifaces,
+};
+
+static const char *usb_strings[] = {
+	"libopencm3",
+	"usb_to_serial_cdcacm",
+	"none",
+	"DEMO",
+};
+
+usbd_device *acm_dev;
+uint8_t usbd_control_buffer[128];
+extern usbd_driver lm4f_usb_driver;
+
+static int cdcacm_control_request(usbd_device * usbd_dev,
+				  struct usb_setup_data *req, uint8_t ** buf,
+				  uint16_t * len,
+				  void (**complete) (usbd_device * usbd_dev,
+						     struct usb_setup_data *
+						     req))
+{
+	uint8_t dtr, rts;
+
+	(void)complete;
+	(void)buf;
+	(void)usbd_dev;
+
+	switch (req->bRequest) {
+	case USB_CDC_REQ_SET_CONTROL_LINE_STATE:{
+			/*
+			 * This Linux cdc_acm driver requires this to be implemented
+			 * even though it's optional in the CDC spec, and we don't
+			 * advertise it in the ACM functional descriptor.
+			 */
+
+			dtr = (req->wValue & (1 << 0)) ? 1 : 0;
+			rts = (req->wValue & (1 << 1)) ? 1 : 0;
+
+			glue_set_line_state_cb(dtr, rts);
+
+			return 1;
+		}
+	case USB_CDC_REQ_SET_LINE_CODING:{
+			struct usb_cdc_line_coding *coding;
+
+			if (*len < sizeof(struct usb_cdc_line_coding))
+				return 0;
+
+			coding = (struct usb_cdc_line_coding *)*buf;
+			return glue_set_line_coding_cb(coding->dwDTERate,
+						       coding->bDataBits,
+						       coding->bParityType,
+						       coding->bCharFormat);
+		}
+	}
+	return 0;
+}
+
+static void cdcacm_data_rx_cb(usbd_device * usbd_dev, uint8_t ep)
+{
+	uint8_t buf[64];
+
+	(void)ep;
+
+	int len = usbd_ep_read_packet(usbd_dev, 0x01, buf, 64);
+	glue_send_data_cb(buf, len);
+}
+
+void cdcacm_send_data(uint8_t * buf, uint16_t len)
+{
+	usbd_ep_write_packet(acm_dev, 0x82, buf, len);
+}
+
+static void cdcacm_set_config(usbd_device * usbd_dev, uint16_t wValue)
+{
+	(void)wValue;
+
+	usbd_ep_setup(usbd_dev, 0x01, USB_ENDPOINT_ATTR_BULK, 64,
+		      cdcacm_data_rx_cb);
+	usbd_ep_setup(usbd_dev, 0x82, USB_ENDPOINT_ATTR_BULK, 64, NULL);
+	usbd_ep_setup(usbd_dev, 0x83, USB_ENDPOINT_ATTR_INTERRUPT, 16, NULL);
+
+	usbd_register_control_callback(usbd_dev,
+				       USB_REQ_TYPE_CLASS |
+				       USB_REQ_TYPE_INTERFACE,
+				       USB_REQ_TYPE_TYPE |
+				       USB_REQ_TYPE_RECIPIENT,
+				       cdcacm_control_request);
+}
+
+void cdcacm_line_state_changed_cb(uint8_t linemask)
+{
+	const int size = sizeof(struct usb_cdc_notification) + 2;
+	uint8_t buf[size];
+
+	struct usb_cdc_notification *notify = (void *)buf;
+	notify->bmRequestType = 0xa1;
+	notify->bNotification = USB_CDC_NOTIFY_SERIAL_STATE;
+	notify->wValue = 0;
+	notify->wIndex = 1;
+	notify->wLength = 2;
+	uint16_t *data = (void *)&buf[sizeof(struct usb_cdc_notification)];
+	*data = linemask;
+
+	while (usbd_ep_write_packet(acm_dev, 0x83, buf, size) == size) ;
+}
+
+static void usb_pins_setup(void)
+{
+	/* USB pins are connected to port D */
+	periph_clock_enable(RCC_GPIOD);
+	/* Mux USB pins to their analog function */
+	gpio_mode_setup(GPIOD, GPIO_MODE_ANALOG, GPIO_PUPD_NONE, GPIO4 | GPIO5);
+}
+
+static void usb_ints_setup(void)
+{
+	uint8_t usbints;
+	/* Gimme some interrupts */
+	usbints = USB_INT_RESET | USB_INT_DISCON | USB_INT_RESUME | USB_INT_SUSPEND;	//| USB_IM_SOF;
+	usb_enable_interrupts(usbints, 0xff, 0xff);
+	nvic_enable_irq(NVIC_USB0_IRQ);
+}
+
+void cdcacm_init(void)
+{
+	usbd_device *usbd_dev;
+
+	usb_pins_setup();
+
+	usbd_dev = usbd_init(&lm4f_usb_driver, &dev, &config, usb_strings, 4,
+			     usbd_control_buffer, sizeof(usbd_control_buffer));
+	acm_dev = usbd_dev;
+	usbd_register_set_config_callback(usbd_dev, cdcacm_set_config);
+
+	usb_ints_setup();
+}
+
+void usb0_isr(void)
+{
+	usbd_poll(acm_dev);
+}

examples/tiva/lm4f/stellaris-ek-lm4f120xl/usb_to_serial_cdcacm/usb_to_serial_cdcacm.c

@@ -0,0 +1,206 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2011 Gareth McMullin <gareth@blacksphere.co.nz>
+ * Copyright (C) 2012-2013 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ *
+ * 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/>.
+ */
+
+/**
+ * \addtogroup Examples
+ *
+ * Flashes the Red, Green and Blue diodes on the board, in order.
+ *
+ * RED controlled by PF1
+ * Green controlled by PF3
+ * Blue controlled by PF2
+ */
+
+#include "usb_to_serial_cdcacm.h"
+
+#include <libopencm3/lm4f/systemcontrol.h>
+#include <libopencm3/lm4f/rcc.h>
+#include <libopencm3/lm4f/gpio.h>
+#include <libopencm3/lm4f/uart.h>
+#include <libopencm3/lm4f/nvic.h>
+#include <libopencm3/cm3/scb.h>
+
+#define PLL_DIV_80MHZ		5
+/* This is how the RGB LED is connected on the stellaris launchpad */
+#define RGB_PORT	GPIOF
+enum {
+	LED_R	= GPIO1,
+	LED_G	= GPIO3,
+	LED_B	= GPIO2,
+};
+
+/*
+ * Clock setup:
+ * Take the main crystal oscillator at 16MHz, run it through the PLL, and divide
+ * the 400MHz PLL clock to get a system clock of 80MHz.
+ */
+static void clock_setup(void)
+{
+	rcc_sysclk_config(OSCSRC_MOSC, XTAL_16M, PLL_DIV_80MHZ);
+}
+
+/*
+ * GPIO setup:
+ * Enable the pins driving the RGB LED as outputs.
+ */
+static void gpio_setup(void)
+{
+	/*
+	 * Configure GPIOF
+	 * This port is used to control the RGB LED
+	 */
+	periph_clock_enable(RCC_GPIOF);
+	const uint32_t opins = (LED_R | LED_G | LED_B);
+
+	gpio_mode_setup(RGB_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, opins);
+	gpio_set_output_config(RGB_PORT, GPIO_OTYPE_PP, GPIO_DRIVE_2MA, opins);
+
+}
+
+static void cm4f_enable_fpu(void)
+{
+	/* Enable FPU */
+	SCB_CPACR |= SCB_CPACR_FULL * (SCB_CPACR_CP10 | SCB_CPACR_CP11);
+	/* Wait for store to complete */
+	__asm__("DSB");
+	/* Reset pipeline. Now the FPU is enabled */
+	__asm__("ISB");
+
+}
+
+void glue_data_received_cb(uint8_t * buf, uint16_t len)
+{
+	/* Blue LED indicates data coming in */
+	gpio_set(RGB_PORT, LED_B);
+	cdcacm_send_data(buf, len);
+	gpio_clear(RGB_PORT, LED_B);
+}
+
+void glue_set_line_state_cb(uint8_t dtr, uint8_t rts)
+{
+	/* Green LED indicated one of the control lines are active */
+	if (dtr || rts)
+		gpio_set(RGB_PORT, LED_G);
+	else
+		gpio_clear(RGB_PORT, LED_G);
+
+	uart_set_ctl_line_state(dtr, rts);
+}
+
+int glue_set_line_coding_cb(uint32_t baud, uint8_t databits,
+			    enum usb_cdc_line_coding_bParityType cdc_parity,
+			    enum usb_cdc_line_coding_bCharFormat cdc_stopbits)
+{
+	enum uart_parity parity;
+	uint8_t uart_stopbits;
+
+	if (databits < 5 || databits > 8)
+		return 0;
+
+	switch (cdc_parity) {
+	case USB_CDC_NO_PARITY:
+		parity = UART_PARITY_NONE;
+		break;
+	case USB_CDC_ODD_PARITY:
+		parity = UART_PARITY_ODD;
+		break;
+	case USB_CDC_EVEN_PARITY:
+		parity = UART_PARITY_EVEN;
+		break;
+	default:
+		return 0;
+	}
+
+	switch (cdc_stopbits) {
+	case USB_CDC_1_STOP_BITS:
+		uart_stopbits = 1;
+		break;
+	case USB_CDC_2_STOP_BITS:
+		uart_stopbits = 2;
+		break;
+	default:
+		return 0;
+	}
+
+	/* Disable the UART while we mess with its settings */
+	uart_disable(UART1);
+	/* Set communication parameters */
+	uart_set_baudrate(UART1, baud);
+	uart_set_databits(UART1, databits);
+	uart_set_parity(UART1, parity);
+	uart_set_stopbits(UART1, uart_stopbits);
+	/* Back to work. */
+	uart_enable(UART1);
+
+	return 1;
+}
+
+void glue_send_data_cb(uint8_t * buf, uint16_t len)
+{
+	int i;
+
+	/* Red LED indicates data going out */
+	gpio_set(RGB_PORT, LED_R);
+
+	for (i = 0; i < len; i++) {
+		uart_send_blocking(UART1, buf[i]);
+	}
+
+	gpio_clear(RGB_PORT, LED_R);
+}
+
+static void mainloop(void)
+{
+	uint8_t linestate, cdcacmstate;
+	static uint8_t oldlinestate = 0;
+
+	/* See if the state of control lines has changed */
+	linestate = uart_get_ctl_line_state();
+	if (oldlinestate != linestate) {
+		/* Inform host of state change */
+		cdcacmstate = 0;
+		if (linestate & PIN_RI)
+			cdcacmstate |= CDCACM_RI;
+		if (linestate & PIN_DSR)
+			cdcacmstate |= CDCACM_DSR;
+		if (linestate & PIN_DCD)
+			cdcacmstate |= CDCACM_DCD;
+
+		cdcacm_line_state_changed_cb(cdcacmstate);
+	}
+	oldlinestate = linestate;
+}
+
+int main(void)
+{
+	gpio_enable_ahb_aperture();
+	clock_setup();
+	gpio_setup();
+
+	cdcacm_init();
+	uart_init();
+
+	cm4f_enable_fpu();
+
+	while (1)
+		mainloop();
+
+	return 0;
+}

examples/tiva/lm4f/stellaris-ek-lm4f120xl/usb_to_serial_cdcacm/usb_to_serial_cdcacm.h

@@ -0,0 +1,69 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ *
+ * 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/>.
+ */
+
+/**@{*/
+
+#ifndef __STELLARIS_EK_LM4F120XL_USB_TO_SERIAL_CDCACM_H
+#define __STELLARIS_EK_LM4F120XL_USB_TO_SERIAL_CDCACM_H
+
+#include <libopencm3/cm3/common.h>
+#include <libopencm3/lm4f/gpio.h>
+#include <libopencm3/usb/cdc.h>
+
+/* =============================================================================
+ * UART control
+ * ---------------------------------------------------------------------------*/
+enum rs232pin {
+	PIN_DCD					= GPIO2,
+	PIN_DSR					= GPIO3,
+	PIN_RI					= GPIO4,
+	PIN_CTS					= GPIO5,
+	PIN_DTR					= GPIO6,
+	PIN_RTS					= GPIO7,
+};
+
+void uart_init(void);
+uint8_t uart_get_ctl_line_state(void);
+void uart_set_ctl_line_state(uint8_t dtr, uint8_t rts);
+/* =============================================================================
+ * CDCACM control
+ * ---------------------------------------------------------------------------*/
+enum cdc_serial_state_line {
+	CDCACM_DCD				= (1 << 0),
+	CDCACM_DSR				= (1 << 1),
+	CDCACM_RI				= (1 << 3),
+};
+
+void cdcacm_init(void);
+void cdcacm_line_state_changed_cb(uint8_t linemask);
+void cdcacm_send_data(uint8_t *buf, uint16_t len);
+/* =============================================================================
+ * CDCACM <-> UART glue
+ * ---------------------------------------------------------------------------*/
+void glue_data_received_cb(uint8_t *buf, uint16_t len);
+void glue_set_line_state_cb(uint8_t dtr, uint8_t rts);
+int glue_set_line_coding_cb(uint32_t baud, uint8_t databits,
+			    enum usb_cdc_line_coding_bParityType cdc_parity,
+			    enum usb_cdc_line_coding_bCharFormat cdc_stopbits);
+void glue_send_data_cb(uint8_t *buf, uint16_t len);
+
+#endif /* __STELLARIS_EK_LM4F120XL_USB_TO_SERIAL_CDCACM_H */
+
+/**@}*/
+