28f92cce2b
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>
100 lines
2.5 KiB
C
100 lines
2.5 KiB
C
/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2012-2013 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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/**
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* \addtogroup Examples
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*
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*/
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/*
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* Pins handled by hw peripheral:
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* Tx <-> PB1
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* Rx <-> PB0
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* Input pins handled manually via interrupts:
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* DCD <-> PA2
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* DSR <-> PA3
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* RI <-> PA4
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* CTS <-> PA5 (UNUSED)
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* Output pins handled via commands from the host:
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* DTR <-> PA6
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* RTS <-> PA7
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*/
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#include "usb_to_serial_cdcacm.h"
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#include <libopencm3/lm4f/rcc.h>
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#include <libopencm3/lm4f/uart.h>
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#include <libopencm3/lm4f/nvic.h>
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static void uart_ctl_line_setup(void)
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{
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u32 inpins, outpins;
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inpins = PIN_DCD | PIN_DSR | PIN_RI | PIN_CTS;
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outpins = PIN_DTR | PIN_RTS;
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gpio_mode_setup(GPIOA, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, outpins);
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gpio_mode_setup(GPIOA, GPIO_MODE_INPUT, GPIO_PUPD_PULLUP, inpins);
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}
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void uart_init(void)
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{
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/* Enable GPIOA and GPIOB in run mode. */
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periph_clock_enable(RCC_GPIOB);
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periph_clock_enable(RCC_GPIOA);
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uart_ctl_line_setup();
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/* Mux PB0 and PB1 to AF1 (UART1 in this case) */
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gpio_set_af(GPIOB, 1, GPIO0 | GPIO1);
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/* Enable the UART clock */
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periph_clock_enable(RCC_UART1);
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/* Disable the UART while we mess with its setings */
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uart_disable(UART1);
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/* Configure the UART clock source */
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uart_clock_from_piosc(UART1);
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/* We don't make any other settings here. */
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uart_enable(UART1);
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/* Ping us when something comes in */
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uart_enable_rx_interrupt(UART1);
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nvic_enable_irq(NVIC_UART1_IRQ);
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}
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u8 uart_get_ctl_line_state(void)
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{
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return gpio_read(GPIOA, PIN_RI | PIN_DSR | PIN_DCD);
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}
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void uart_set_ctl_line_state(u8 dtr, u8 rts)
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{
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u8 val = 0;
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val |= dtr ? PIN_DTR : 0;
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val |= rts ? PIN_RTS : 0;
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gpio_write(GPIOA, PIN_DTR | PIN_RTS, val);
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}
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void uart1_isr(void)
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{
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u8 rx;
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rx = uart_recv(UART1);
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glue_data_recieved_cb(&rx, 1);
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uart_clear_interrupt_flag(UART1, UART_INT_RX);
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}
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