lib: utils/serial: Add support for Gaisler APBUART

This patch adds support for the UART used by the NOEL-V processor.

Cobham Gaisler's NOEL-V RISC-V processor IP is available under GPL
and commercial license and is described in more detail at
https://www.gaisler.com/noelv.

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Daniel Cederman 2021-04-30 08:35:56 +02:00 committed by Anup Patel
parent 632e27bb91
commit 117fb6dcb1
7 changed files with 185 additions and 0 deletions

View file

@ -39,6 +39,9 @@ int fdt_parse_hart_id(void *fdt, int cpu_offset, u32 *hartid);
int fdt_parse_max_hart_id(void *fdt, u32 *max_hartid);
int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
struct platform_uart_data *uart);
int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset,
struct platform_uart_data *uart);

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@ -0,0 +1,17 @@
/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021 Cobham Gaisler AB.
*
* Authors:
* Daniel Cederman <cederman@gaisler.com>
*/
#ifndef __SERIAL_GAISLER_APBUART_H__
#define __SERIAL_GAISLER_APBUART_H__
#include <sbi/sbi_types.h>
int gaisler_uart_init(unsigned long base, u32 in_freq, u32 baudrate);
#endif

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@ -26,6 +26,8 @@
#define DEFAULT_SIFIVE_UART_REG_SHIFT 0
#define DEFAULT_SIFIVE_UART_REG_IO_WIDTH 4
#define DEFAULT_GAISLER_UART_REG_IO_WIDTH 4
#define DEFAULT_SHAKTI_UART_FREQ 50000000
#define DEFAULT_SHAKTI_UART_BAUD 115200
@ -213,6 +215,44 @@ int fdt_parse_max_hart_id(void *fdt, u32 *max_hartid)
return 0;
}
int fdt_parse_gaisler_uart_node(void *fdt, int nodeoffset,
struct platform_uart_data *uart)
{
int len, rc;
const fdt32_t *val;
unsigned long reg_addr, reg_size;
if (nodeoffset < 0 || !uart || !fdt)
return SBI_ENODEV;
rc = fdt_get_node_addr_size(fdt, nodeoffset, &reg_addr, &reg_size);
if (rc < 0 || !reg_addr || !reg_size)
return SBI_ENODEV;
uart->addr = reg_addr;
/**
* UART address is mandatory. clock-frequency and current-speed
* may not be present. Don't return error.
*/
val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "clock-frequency", &len);
if (len > 0 && val)
uart->freq = fdt32_to_cpu(*val);
else
uart->freq = DEFAULT_UART_FREQ;
val = (fdt32_t *)fdt_getprop(fdt, nodeoffset, "current-speed", &len);
if (len > 0 && val)
uart->baud = fdt32_to_cpu(*val);
else
uart->baud = DEFAULT_UART_BAUD;
/* For Gaisler APBUART, the reg-shift and reg-io-width are fixed .*/
uart->reg_shift = DEFAULT_UART_REG_SHIFT;
uart->reg_io_width = DEFAULT_GAISLER_UART_REG_IO_WIDTH;
return 0;
}
int fdt_parse_shakti_uart_node(void *fdt, int nodeoffset,
struct platform_uart_data *uart)
{

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@ -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_gaisler;
static struct fdt_serial *serial_drivers[] = {
&fdt_serial_uart8250,
&fdt_serial_sifive,
&fdt_serial_htif,
&fdt_serial_shakti,
&fdt_serial_gaisler
};
static struct fdt_serial dummy = {

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@ -0,0 +1,35 @@
/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021 Cobham Gaisler AB.
*
* Authors:
* Daniel Cederman <cederman@gaisler.com>
*/
#include <sbi_utils/fdt/fdt_helper.h>
#include <sbi_utils/serial/fdt_serial.h>
#include <sbi_utils/serial/gaisler-uart.h>
static int serial_gaisler_init(void *fdt, int nodeoff,
const struct fdt_match *match)
{
int rc;
struct platform_uart_data uart;
rc = fdt_parse_gaisler_uart_node(fdt, nodeoff, &uart);
if (rc)
return rc;
return gaisler_uart_init(uart.addr, uart.freq, uart.baud);
}
static const struct fdt_match serial_gaisler_match[] = {
{ .compatible = "gaisler,apbuart" },
{},
};
struct fdt_serial fdt_serial_gaisler = {
.match_table = serial_gaisler_match,
.init = serial_gaisler_init
};

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@ -0,0 +1,86 @@
/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021 Cobham Gaisler AB.
*
* Authors:
* Daniel Cederman <cederman@gaisler.com>
*/
#include <sbi/riscv_io.h>
#include <sbi/sbi_console.h>
#include <sbi_utils/serial/gaisler-uart.h>
/* clang-format off */
#define UART_REG_DATA 0
#define UART_REG_STATUS 1
#define UART_REG_CTRL 2
#define UART_REG_SCALER 3
#define UART_DATA_DATA 0x000000ff
#define UART_STATUS_FIFOFULL 0x00000200
#define UART_STATUS_DATAREADY 0x00000001
#define UART_CTRL_DB (1<<11)
#define UART_CTRL_FL (1<<6)
#define UART_CTRL_TE (1<<1)
#define UART_CTRL_RE (1<<0)
/* clang-format on */
static volatile void *uart_base;
static u32 get_reg(u32 num)
{
return readl(uart_base + (num * 0x4));
}
static void set_reg(u32 num, u32 val)
{
writel(val, uart_base + (num * 0x4));
}
static void gaisler_uart_putc(char ch)
{
while (get_reg(UART_REG_STATUS) & UART_STATUS_FIFOFULL)
;
set_reg(UART_REG_DATA, ch);
}
static int gaisler_uart_getc(void)
{
u32 ret = get_reg(UART_REG_STATUS);
if (!(ret & UART_STATUS_DATAREADY))
return -1;
return get_reg(UART_REG_DATA) & UART_DATA_DATA;
}
static struct sbi_console_device gaisler_console = {
.name = "gaisler_uart",
.console_putc = gaisler_uart_putc,
.console_getc = gaisler_uart_getc
};
int gaisler_uart_init(unsigned long base, u32 in_freq, u32 baudrate)
{
u32 ctrl;
uart_base = (volatile void *)base;
/* Configure baudrate */
if (in_freq)
set_reg(UART_REG_SCALER, in_freq / (baudrate * 8 + 7));
ctrl = get_reg(UART_REG_CTRL);
/* Preserve debug mode and flow control */
ctrl &= (UART_CTRL_DB | UART_CTRL_FL);
/* Enable TX and RX */
ctrl |= UART_CTRL_TE | UART_CTRL_RE;
set_reg(UART_REG_CTRL, ctrl);
sbi_console_set_device(&gaisler_console);
return 0;
}

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@ -8,10 +8,12 @@
#
libsbiutils-objs-y += serial/fdt_serial.o
libsbiutils-objs-y += serial/fdt_serial_gaisler.o
libsbiutils-objs-y += serial/fdt_serial_htif.o
libsbiutils-objs-y += serial/fdt_serial_shakti.o
libsbiutils-objs-y += serial/fdt_serial_sifive.o
libsbiutils-objs-y += serial/fdt_serial_uart8250.o
libsbiutils-objs-y += serial/gaisler-uart.o
libsbiutils-objs-y += serial/shakti-uart.o
libsbiutils-objs-y += serial/sifive-uart.o
libsbiutils-objs-y += serial/uart8250.o