68 lines
1.4 KiB
C
68 lines
1.4 KiB
C
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/*
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2020 Florent Kermarrec <florent@enjoy-digital.fr>
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* Copyright (c) 2020 Dolu1990 <charles.papon.90@gmail.com>
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*
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*/
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#include <stdint.h>
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#define UART_EV_TX 0x1
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#define UART_EV_RX 0x2
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#define MMPTR(a) (*((volatile uint32_t *)(a)))
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static inline void csr_write_simple(unsigned long v, unsigned long a)
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{
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MMPTR(a) = v;
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}
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static inline unsigned long csr_read_simple(unsigned long a)
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{
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return MMPTR(a);
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}
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#define CSR_BASE 0xf0000000L
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static inline uint8_t uart_rxtx_read(void) {
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return csr_read_simple(CSR_BASE + 0x1000L);
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}
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static inline void uart_rxtx_write(uint8_t v) {
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csr_write_simple(v, CSR_BASE + 0x1000L);
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}
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static inline uint8_t uart_txfull_read(void) {
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return csr_read_simple(CSR_BASE + 0x1004L);
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}
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static inline uint8_t uart_rxempty_read(void) {
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return csr_read_simple(CSR_BASE + 0x1008L);
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}
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static inline void uart_ev_pending_write(uint8_t v) {
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csr_write_simple(v, CSR_BASE + 0x1010L);
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}
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static inline uint8_t uart_txempty_read(void) {
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return csr_read_simple(CSR_BASE + 0x1018L);
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}
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static inline uint8_t uart_rxfull_read(void) {
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return csr_read_simple(CSR_BASE + 0x101cL);
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}
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void vex_putc(char c){
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while (uart_txfull_read());
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uart_rxtx_write(c);
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uart_ev_pending_write(UART_EV_TX);
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}
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int vex_getc(void){
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char c;
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if (uart_rxempty_read()) return -1;
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c = uart_rxtx_read();
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uart_ev_pending_write(UART_EV_RX);
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return c;
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}
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