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- /*
- * SPDX-License-Identifier: BSD-2-Clause
- *
- * Copyright (c) 2020 Vijai Kumar K <vijai@behindbytes.com>
- */
- #include <sbi/riscv_io.h>
- #include <sbi/sbi_console.h>
- #include <sbi_utils/serial/shakti-uart.h>
- #define REG_BAUD 0x00
- #define REG_TX 0x04
- #define REG_RX 0x08
- #define REG_STATUS 0x0C
- #define REG_DELAY 0x10
- #define REG_CONTROL 0x14
- #define REG_INT_EN 0x18
- #define REG_IQ_CYCLES 0x1C
- #define REG_RX_THRES 0x20
- #define UART_TX_FULL 0x2
- #define UART_RX_NOT_EMPTY 0x4
- #define UART_RX_FULL 0x8
- static volatile char *uart_base;
- static void shakti_uart_putc(char ch)
- {
- while ((readb(uart_base + REG_STATUS) & UART_TX_FULL))
- ;
- writeb(ch, uart_base + REG_TX);
- }
- static int shakti_uart_getc(void)
- {
- if (readb(uart_base + REG_STATUS) & UART_RX_NOT_EMPTY)
- return readb(uart_base + REG_RX);
- return -1;
- }
- static struct sbi_console_device shakti_console = {
- .name = "shakti_uart",
- .console_putc = shakti_uart_putc,
- .console_getc = shakti_uart_getc
- };
- int shakti_uart_init(unsigned long base, u32 in_freq, u32 baudrate)
- {
- uart_base = (volatile char *)base;
- u16 baud;
- if (baudrate) {
- baud = (u16)(in_freq / (16 * baudrate));
- writew(baud, uart_base + REG_BAUD);
- }
- sbi_console_set_device(&shakti_console);
- return 0;
- }
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