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/*
* Copyright (c) 2006-2022, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2022-11-16 GuEe-GUI first version
*/
#include "8250.h"
struct serial8250 early_serial8250 = { 0 };
static rt_uint32_t serial8250_early_in(struct serial8250 *serial, int offset)
{
return serial8250_in(serial, offset);
}
static void serial8250_early_out(struct serial8250 *serial, int offset, int value)
{
serial8250_out(serial, offset, value);
}
int serial8250_early_putc(struct rt_serial_device *raw_serial, char c)
{
if (raw_serial)
{
/* FIFO and shifting register empty */
const int uart_lsr_both_empty = (UART_LSR_TEMT | UART_LSR_THRE);
struct serial8250 *serial = rt_container_of(raw_serial, struct serial8250, parent);
serial8250_early_out(serial, UART_TX, c);
while ((serial8250_early_in(serial, UART_LSR) & uart_lsr_both_empty) != uart_lsr_both_empty)
{
rt_hw_cpu_relax();
}
}
return 1;
}
static void init_serial(struct serial8250 *serial)
{
unsigned char c;
rt_uint32_t ier, divisor;
serial8250_early_out(serial, UART_LCR, 0x3); /* 8n1 */
ier = serial8250_early_in(serial, UART_IER);
serial8250_early_out(serial, UART_IER, ier & UART_IER_UUE); /* No interrupt */
serial8250_early_out(serial, UART_FCR, 0); /* No fifo */
serial8250_early_out(serial, UART_MCR, 0x3); /* DTR + RTS */
if (serial->freq)
{
divisor = RT_DIV_ROUND_CLOSEST(serial->freq, 16 * serial->parent.config.baud_rate);
c = serial8250_early_in(serial, UART_LCR);
serial8250_early_out(serial, UART_LCR, c | UART_LCR_DLAB);
serial8250_early_out(serial, UART_DLL, divisor & 0xff);
serial8250_early_out(serial, UART_DLM, (divisor >> 8) & 0xff);
serial8250_early_out(serial, UART_LCR, c & ~UART_LCR_DLAB);
}
}
static void serial8250_early_kick(struct rt_fdt_earlycon *con, int why)
{
struct serial8250 *serial = raw_to_serial8250(con->data);
switch (why)
{
case FDT_EARLYCON_KICK_UPDATE:
serial->base = rt_ioremap((void *)con->mmio, con->size);
break;
case FDT_EARLYCON_KICK_COMPLETED:
rt_iounmap(serial->base);
break;
default:
break;
}
}
rt_err_t serial8250_early_fdt_setup(struct serial8250 *serial, struct rt_fdt_earlycon *con, const char *options)
{
rt_err_t ret = RT_EOK;
if (!serial->base && con)
{
serial8250_config(serial, options);
con->mmio = (rt_ubase_t)serial->base;
con->size = serial->size;
}
if (serial->base && con)
{
serial->base = rt_ioremap_early((void *)serial->base, serial->size);
}
if (serial->base && con)
{
con->console_putc = (typeof(con->console_putc))&serial8250_early_putc;
con->console_kick = serial8250_early_kick;
con->data = &serial->parent;
if (!serial->parent.config.baud_rate)
{
/* Assume the device was initialized, only mask interrupts */
rt_uint32_t ier = serial8250_early_in(serial, UART_IER);
serial8250_early_out(serial, UART_IER, ier & UART_IER_UUE);
}
else
{
init_serial(serial);
}
}
else
{
ret = -RT_ERROR;
}
return ret;
}
static void common_init(struct serial8250 *serial, struct rt_fdt_earlycon *con)
{
serial->base = (void *)con->mmio;
serial->size = con->size;
serial->iotype = PORT_MMIO32;
}
static rt_err_t common_early_setup(struct rt_fdt_earlycon *con, const char *options)
{
struct serial8250 *serial = &early_serial8250;
common_init(serial, con);
serial->regshift = 2;
fdt_getprop_u32(con->fdt, con->nodeoffset, "reg-shift", &serial->regshift, RT_NULL);
return serial8250_early_fdt_setup(serial, con, options);
}
RT_FDT_EARLYCON_EXPORT(bcm2835aux, "uart8250", "brcm,bcm2835-aux-uart", common_early_setup);
RT_FDT_EARLYCON_EXPORT(tegra20, "uart8250", "nvidia,tegra20-uart", common_early_setup);
RT_FDT_EARLYCON_EXPORT(dw8250, "uart8250", "snps,dw-apb-uart", common_early_setup);
RT_FDT_EARLYCON_EXPORT(ns16550a, "uart8250", "ns16550a", common_early_setup);
RT_FDT_EARLYCON_EXPORT(ns16550, "uart8250", "ns16550", common_early_setup);
#ifdef RT_USING_8250_OMAP
static rt_err_t omap8250_early_setup(struct rt_fdt_earlycon *con, const char *options)
{
struct serial8250 *serial = &early_serial8250;
common_init(serial, con);
serial->regshift = 2;
return serial8250_early_fdt_setup(serial, con, options);
}
RT_FDT_EARLYCON_EXPORT(omap8250, "uart8250", "ti,omap2-uart", omap8250_early_setup);
RT_FDT_EARLYCON_EXPORT(omap8250, "uart8250", "ti,omap3-uart", omap8250_early_setup);
RT_FDT_EARLYCON_EXPORT(omap8250, "uart8250", "ti,omap4-uart", omap8250_early_setup);
#endif /* RT_USING_8250_OMAP */
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