blob: ef02241706ba92983ee49c67bb6b8ce03ef8696b [file] [log] [blame]
/*
* This file is part of the coreboot project.
*
* Copyright 2014 Rockchip Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <uart.h>
#include <arch/io.h>
#include <console/console.h> /* for __console definition */
#include <stdint.h>
#include <uart8250.h>
struct rk3288_uart {
union {
uint32_t thr; /* Transmit holding register. */
uint32_t rbr; /* Receive buffer register. */
uint32_t dll; /* Divisor latch lsb. */
};
union {
uint32_t ier; /* Interrupt enable register. */
uint32_t dlm; /* Divisor latch msb. */
};
union {
uint32_t iir; /* Interrupt identification register. */
uint32_t fcr; /* FIFO control register. */
};
uint32_t lcr; /* Line control register. */
uint32_t mcr; /* Modem control register. */
uint32_t lsr; /* Line status register. */
uint32_t msr; /* Modem status register. */
uint32_t scr;
uint32_t reserved1[(0x30 - 0x20) / 4];
uint32_t srbr[(0x70 - 0x30) / 4];
uint32_t far;
uint32_t tfr;
uint32_t rfw;
uint32_t usr;
uint32_t tfl;
uint32_t rfl;
uint32_t srr;
uint32_t srts;
uint32_t sbcr;
uint32_t sdmam;
uint32_t sfe;
uint32_t srt;
uint32_t stet;
uint32_t htx;
uint32_t dmasa;
uint32_t reserver2[(0xf4 - 0xac) / 4];
uint32_t cpr;
uint32_t ucv;
uint32_t ctr;
} __attribute__ ((packed));
static struct rk3288_uart * const uart_ptr =
(void *)CONFIG_CONSOLE_SERIAL_UART_ADDRESS;
static void rk3288_uart_tx_flush(void);
static int rk3288_uart_tst_byte(void);
static void rk3288_uart_init(void)
{
// Use a hardcoded divisor for now.
const unsigned divisor = 13;
const uint8_t line_config = UART8250_LCR_WLS_8; // 8n1
rk3288_uart_tx_flush();
// Disable interrupts.
writel(0, &uart_ptr->ier);
// Force DTR and RTS to high.
writel(UART8250_MCR_DTR | UART8250_MCR_RTS, &uart_ptr->mcr);
// Set line configuration, access divisor latches.
writel(UART8250_LCR_DLAB | line_config, &uart_ptr->lcr);
// Set the divisor.
writel(divisor & 0xff, &uart_ptr->dll);
writel((divisor >> 8) & 0xff, &uart_ptr->dlm);
// Hide the divisor latches.
writel(line_config, &uart_ptr->lcr);
// Enable FIFOs, and clear receive and transmit.
writel(UART8250_FCR_FIFO_EN |
UART8250_FCR_CLEAR_RCVR |
UART8250_FCR_CLEAR_XMIT, &uart_ptr->fcr);
}
static void rk3288_uart_tx_byte(unsigned char data)
{
while (!(readl(&uart_ptr->lsr) & UART8250_LSR_THRE));
writel(data, &uart_ptr->thr);
}
static void rk3288_uart_tx_flush(void)
{
while (!(readl(&uart_ptr->lsr) & UART8250_LSR_TEMT));
}
static unsigned char rk3288_uart_rx_byte(void)
{
if (!rk3288_uart_tst_byte())
return 0;
return readl(&uart_ptr->rbr);
}
static int rk3288_uart_tst_byte(void)
{
return (readl(&uart_ptr->lsr) & UART8250_LSR_DR) == UART8250_LSR_DR;
}
#if !defined(__PRE_RAM__)
static const struct console_driver rk3288_uart_console __console = {
.init = rk3288_uart_init,
.tx_byte = rk3288_uart_tx_byte,
.tx_flush = rk3288_uart_tx_flush,
.rx_byte = rk3288_uart_rx_byte,
.tst_byte = rk3288_uart_tst_byte,
};
uint32_t uartmem_getbaseaddr(void)
{
return (uintptr_t)uart_ptr;
}
#else
void uart_init(void)
{
rk3288_uart_init();
}
void uart_tx_byte(unsigned char data)
{
rk3288_uart_tx_byte(data);
}
void uart_tx_flush(void)
{
rk3288_uart_tx_flush();
}
unsigned char uart_rx_byte(void)
{
return rk3288_uart_rx_byte();
}
#endif