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// SPDX-License-Identifier: BSD-2-Clause
/*
* Copyright (c) 2015, Linaro Limited
*/
#include <compiler.h>
#include <console.h>
#include <drivers/serial8250_uart.h>
#include <io.h>
#include <keep.h>
#include <util.h>
#include <kernel/dt.h>
/* uart register defines */
#define UART_RHR 0x0
#define UART_THR 0x0
#define UART_IER 0x4
#define UART_ISR 0x8
#define UART_FCR 0x8
#define UART_LCR 0xc
#define UART_MCR 0x10
#define UART_LSR 0x14
#define UART_MSR 0x18
#define UART_SPR 0x1c
/* uart status register bits */
#define LSR_TEMT 0x40 /* Transmitter empty */
#define LSR_THRE 0x20 /* Transmit-hold-register empty */
#define LSR_EMPTY (LSR_TEMT | LSR_THRE)
#define LSR_DR 0x01 /* DATA Ready */
static vaddr_t chip_to_base(struct serial_chip *chip)
{
struct serial8250_uart_data *pd =
container_of(chip, struct serial8250_uart_data, chip);
return io_pa_or_va(&pd->base);
}
static void serial8250_uart_flush(struct serial_chip *chip)
{
vaddr_t base = chip_to_base(chip);
while (1) {
uint32_t state = io_read32(base + UART_LSR);
/* Wait until transmit FIFO is empty */
if ((state & LSR_EMPTY) == LSR_EMPTY)
break;
}
}
static bool serial8250_uart_have_rx_data(struct serial_chip *chip)
{
vaddr_t base = chip_to_base(chip);
return (io_read32(base + UART_LSR) & LSR_DR);
}
static int serial8250_uart_getchar(struct serial_chip *chip)
{
vaddr_t base = chip_to_base(chip);
while (!serial8250_uart_have_rx_data(chip)) {
/* Transmit FIFO is empty, waiting again */
;
}
return io_read32(base + UART_RHR) & 0xff;
}
static void serial8250_uart_putc(struct serial_chip *chip, int ch)
{
vaddr_t base = chip_to_base(chip);
serial8250_uart_flush(chip);
/* Write out character to transmit FIFO */
io_write32(base + UART_THR, ch);
}
static const struct serial_ops serial8250_uart_ops = {
.flush = serial8250_uart_flush,
.getchar = serial8250_uart_getchar,
.have_rx_data = serial8250_uart_have_rx_data,
.putc = serial8250_uart_putc,
};
KEEP_PAGER(serial8250_uart_ops);
void serial8250_uart_init(struct serial8250_uart_data *pd, paddr_t base,
uint32_t __unused uart_clk,
uint32_t __unused baud_rate)
{
pd->base.pa = base;
pd->chip.ops = &serial8250_uart_ops;
/*
* do nothing, debug uart(uart0) share with normal world,
* everything for uart0 is ready now.
*/
}
#ifdef CFG_DT
static struct serial_chip *serial8250_uart_dev_alloc(void)
{
struct serial8250_uart_data *pd = calloc(1, sizeof(*pd));
if (!pd)
return NULL;
return &pd->chip;
}
static int serial8250_uart_dev_init(struct serial_chip *chip,
const void *fdt,
int offs,
const char *parms)
{
struct serial8250_uart_data *pd =
container_of(chip, struct serial8250_uart_data, chip);
vaddr_t vbase;
paddr_t pbase;
size_t size;
if (parms && parms[0])
IMSG("serial8250_uart: device parameters ignored (%s)", parms);
if (dt_map_dev(fdt, offs, &vbase, &size) < 0)
return -1;
if (size < SERIAL8250_UART_REG_SIZE) {
EMSG("serial8250_uart: register size too small: %zx", size);
return -1;
}
pbase = virt_to_phys((void *)vbase);
serial8250_uart_init(pd, pbase, 0, 0);
return 0;
}
static void serial8250_uart_dev_free(struct serial_chip *chip)
{
struct serial8250_uart_data *pd =
container_of(chip, struct serial8250_uart_data, chip);
free(pd);
}
static const struct serial_driver serial8250_driver = {
.dev_alloc = serial8250_uart_dev_alloc,
.dev_init = serial8250_uart_dev_init,
.dev_free = serial8250_uart_dev_free,
};
static const struct dt_device_match serial8250_match_table[] = {
{ .compatible = "snps,dw-apb-uart" },
{ 0 }
};
const struct dt_driver serial8250_dt_driver __dt_driver = {
.name = "serial8250_uart",
.match_table = serial8250_match_table,
.driver = &serial8250_driver,
};
#endif /* CFG_DT */
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