[PATCH] lib: utils: Add Xilinx uartlite implementation

[Xiang W]

在 2021-03-30二的 10:59 +0800，Guokai Chen写道：
> Uartlite is a device commonly used on Xilinx platforms. We add
> OpenSBI support for uartlite so that OpenSBI boots on SoCs that
> utilize uartlite for output.
> 
> Signed-off-by: Guokai Chen <chenguokai17 at mails.ucas.ac.cn>
> ---
>  include/sbi_utils/serial/xilinx-uart.h | 20 ++++++++++++
>  lib/utils/serial/fdt_serial.c          |  2 ++
>  lib/utils/serial/fdt_serial_xilinx.c   | 36 ++++++++++++++++++++++
>  lib/utils/serial/objects.mk            |  2 ++
>  lib/utils/serial/xilinx-uart.c         | 42
> ++++++++++++++++++++++++++
>  5 files changed, 102 insertions(+)
>  create mode 100644 include/sbi_utils/serial/xilinx-uart.h
>  create mode 100644 lib/utils/serial/fdt_serial_xilinx.c
>  create mode 100644 lib/utils/serial/xilinx-uart.c
> 
> diff --git a/include/sbi_utils/serial/xilinx-uart.h
> b/include/sbi_utils/serial/xilinx-uart.h
> new file mode 100644
> index 0000000..e3d667e
> --- /dev/null
> +++ b/include/sbi_utils/serial/xilinx-uart.h
> @@ -0,0 +1,20 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 Guokai Chen <chenguokai17 at mails.ucas.ac.cn>
> + *
> + * This code is based on include/sbi_utils/serial/shakti-uart.h
> + */
> +
> +#ifndef __SERIAL_XILINX_UART_H__
> +#define __SERIAL_XILINX_UART_H__
> +
> +#include <sbi/sbi_types.h>
> +
> +void xilinx_uart_putc(char ch);
> +
> +int xilinx_uart_getc(void);
> +
> +int xilinx_uart_init(unsigned long base, u32 in_freq, u32 baudrate);
> +
> +#endif
> diff --git a/lib/utils/serial/fdt_serial.c
> b/lib/utils/serial/fdt_serial.c
> index b9ce67e..8671ee3 100644
> --- a/lib/utils/serial/fdt_serial.c
> +++ b/lib/utils/serial/fdt_serial.c
> @@ -16,12 +16,14 @@ extern struct fdt_serial fdt_serial_uart8250;
>  extern struct fdt_serial fdt_serial_sifive;
>  extern struct fdt_serial fdt_serial_htif;
>  extern struct fdt_serial fdt_serial_shakti;
> +extern struct fdt_serial fdt_serial_xilinx;
>  
>  static struct fdt_serial *serial_drivers[] = {
>  	&fdt_serial_uart8250,
>  	&fdt_serial_sifive,
>  	&fdt_serial_htif,
>  	&fdt_serial_shakti,
> +	&fdt_serial_xilinx,
>  };
>  
>  static void dummy_putc(char ch)
> diff --git a/lib/utils/serial/fdt_serial_xilinx.c
> b/lib/utils/serial/fdt_serial_xilinx.c
> new file mode 100644
> index 0000000..8b52a7d
> --- /dev/null
> +++ b/lib/utils/serial/fdt_serial_xilinx.c
> @@ -0,0 +1,36 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 Guokai Chen <chenguokai17 at mails.ucas.ac.cn>
> + * 
> + * This code is based on lib/utils/serial/fdt_serial_shakti.c
> + */
> +
> +#include <sbi_utils/fdt/fdt_helper.h>
> +#include <sbi_utils/serial/fdt_serial.h>
> +#include <sbi_utils/serial/xilinx-uart.h>
> +
> +static int serial_xilinx_init(void *fdt, int nodeoff,
> +				const struct fdt_match *match)
> +{
> +		
> +	int rc;
> +	struct platform_uart_data uart;
> +	// no need to reinvent a wheel
> +	rc = fdt_parse_shakti_uart_node(fdt, nodeoff, &uart);
> +	if (rc)
> +		return rc;
> +	return xilinx_uart_init(uart.addr, uart.freq, uart.baud);
> +}
> +
> +static const struct fdt_match serial_xilinx_match[] = {
> +	{ .compatible = "xilinx,uartlite" },
> +	{ },
> +};
> +
> +struct fdt_serial fdt_serial_xilinx = {
> +	.match_table = serial_xilinx_match,
> +	.init = serial_xilinx_init,
> +	.getc = xilinx_uart_getc,
> +	.putc = xilinx_uart_putc
> +};
> diff --git a/lib/utils/serial/objects.mk
> b/lib/utils/serial/objects.mk
> index c0746f0..6089944 100644
> --- a/lib/utils/serial/objects.mk
> +++ b/lib/utils/serial/objects.mk
> @@ -10,8 +10,10 @@
>  libsbiutils-objs-y += serial/fdt_serial.o
>  libsbiutils-objs-y += serial/fdt_serial_htif.o
>  libsbiutils-objs-y += serial/fdt_serial_shakti.o
> +libsbiutils-objs-y += serial/fdt_serial_xilinx.o
>  libsbiutils-objs-y += serial/fdt_serial_sifive.o
>  libsbiutils-objs-y += serial/fdt_serial_uart8250.o
>  libsbiutils-objs-y += serial/shakti-uart.o
> +libsbiutils-objs-y += serial/xilinx-uart.o
>  libsbiutils-objs-y += serial/sifive-uart.o
>  libsbiutils-objs-y += serial/uart8250.o
> diff --git a/lib/utils/serial/xilinx-uart.c
> b/lib/utils/serial/xilinx-uart.c
> new file mode 100644
> index 0000000..ea32d47
> --- /dev/null
> +++ b/lib/utils/serial/xilinx-uart.c
> @@ -0,0 +1,42 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 Guokai Chen <chenguokai17 at mails.ucas.ac.cn>
> + *
> + * This code is based on lib/utils/serial/xilinx-uart.c
> + */
> +
> +#include <sbi/riscv_io.h>
> +#include <sbi/sbi_console.h>
> +#include <sbi_utils/serial/xilinx-uart.h>
> +
> +#define REG_TX		0x04
> +#define REG_RX		0x00
> +#define REG_STATUS	0x08
> +#define REG_CONTROL	0x0C
> +
> +#define UART_TX_FULL    (1<<0x3)
> +#define UART_RX_VALID   (1<<0x0)
> +
> +static volatile void *uart_base;
> +
> +void xilinx_uart_putc(char ch)
> +{
> +	while((readb(uart_base + REG_STATUS) & UART_TX_FULL))
> +		;
> +	writeb(ch, uart_base + REG_TX);
> +}
> +
> +int xilinx_uart_getc(void)
> +{
> +	u16 status = readb(uart_base + REG_STATUS);
> +	if (status & UART_RX_VALID)
> +		return readb(uart_base + REG_RX);
> +	return -1;
> +}
> +
> +int xilinx_uart_init(unsigned long base, u32 in_freq, u32 baudrate)
> +{
> +	uart_base = (volatile void *)base;
> +	return 0;
> +}
> -- 
> 2.31.1
> 
> 
Looks good to me.

Reviewed-by: Xiang W <wxjstz at 126.com>