mirror of
https://github.com/riscv-software-src/opensbi.git
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4998a712b2
Initial commit of the xlnx-uartlite device and FDT support. This was tested by running OpenSBI on a modified QEMU virt machine using the xlnx-uartlite for serial. Signed-off-by: Alistair Francis <alistair.francis@wdc.com> Reviewed-by: Xiang W <wxjstz@126.com> Reviewed-by: Anup Patel <anup@brainfault.org>
68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
/*
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2022 Western Digital Corporation or its affiliates.
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*
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* Authors:
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* Alistair Francis <alistair.francis@wdc.com>
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*/
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#include <sbi/riscv_io.h>
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#include <sbi/sbi_console.h>
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#include <sbi_utils/serial/xlnx_uartlite.h>
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/* clang-format off */
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#define UART_RX_OFFSET 0x00
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#define UART_TX_OFFSET 0x04
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#define UART_STATUS_OFFSET 0x08
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# define UART_STATUS_RXVALID 0x01
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# define UART_STATUS_RXFULL 0x02
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# define UART_STATUS_TXEMPTY 0x04
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# define UART_STATUS_TXFULL 0x08
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# define UART_STATUS_IE 0x10
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# define UART_STATUS_OVERRUN 0x20
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# define UART_STATUS_FRAME 0x40
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# define UART_STATUS_PARITY 0x80
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#define UART_CTRL_OFFSET 0x0C
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# define UART_CTRL_RST_TX 0x01
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# define UART_CTRL_RST_RX 0x02
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# define UART_CTRL_IE 0x10
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/* clang-format on */
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static volatile char *xlnx_uartlite_base;
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static void xlnx_uartlite_putc(char ch)
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{
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while((readb(xlnx_uartlite_base + UART_STATUS_OFFSET) & UART_STATUS_TXFULL))
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;
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writeb(ch, xlnx_uartlite_base + UART_TX_OFFSET);
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}
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static int xlnx_uartlite_getc(void)
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{
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u16 status = readb(xlnx_uartlite_base + UART_STATUS_OFFSET);
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if (status & UART_STATUS_RXVALID)
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return readb(xlnx_uartlite_base + UART_RX_OFFSET);
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return -1;
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}
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static struct sbi_console_device xlnx_uartlite_console = {
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.name = "xlnx-uartlite",
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.console_putc = xlnx_uartlite_putc,
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.console_getc = xlnx_uartlite_getc
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};
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int xlnx_uartlite_init(unsigned long base)
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{
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xlnx_uartlite_base = (volatile char *)base;
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sbi_console_set_device(&xlnx_uartlite_console);
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return 0;
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}
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