77ffa0d3ad
The register indexes and bitfield masks were guarded by the UART8250 config options, but it might be (is) necessary to use them in a driver that is UART8250 like without actually using the 8250 driver itself. To avoid any name collision with other drivers, also change the constant prefix from UART_ to UART8250_. Change-Id: Ie606d9e0329132961c3004688176204a829569dc Signed-off-by: Gabe Black <gabeblack@google.com> Reviewed-on: https://chromium-review.googlesource.com/171336 Reviewed-by: Ronald Minnich <rminnich@chromium.org> Commit-Queue: Gabe Black <gabeblack@chromium.org> Tested-by: Gabe Black <gabeblack@chromium.org> (cherry picked from commit a93900be8d8a8260db49e30737608f9161fbf249) Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com> Reviewed-on: http://review.coreboot.org/6715 Tested-by: build bot (Jenkins) Reviewed-by: David Hendricks <dhendrix@chromium.org>
126 lines
3.3 KiB
C
126 lines
3.3 KiB
C
/*
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* This file is part of the coreboot project.
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*
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* Copyright (C) 2003 Eric Biederman
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* Copyright (C) 2006-2010 coresystems GmbH
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <arch/io.h>
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#include <console/uart.h>
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#include <device/device.h>
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#include <delay.h>
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#include "uart8250reg.h"
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/* Should support 8250, 16450, 16550, 16550A type UARTs */
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/* Expected character delay at 1200bps is 9ms for a working UART
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* and no flow-control. Assume UART as stuck if shift register
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* or FIFO takes more than 50ms per character to appear empty.
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*/
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#define SINGLE_CHAR_TIMEOUT (50 * 1000)
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#define FIFO_TIMEOUT (16 * SINGLE_CHAR_TIMEOUT)
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static int uart8250_mem_can_tx_byte(unsigned base_port)
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{
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return read8(base_port + UART8250_LSR) & UART8250_LSR_THRE;
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}
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static void uart8250_mem_tx_byte(unsigned base_port, unsigned char data)
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{
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unsigned long int i = SINGLE_CHAR_TIMEOUT;
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while(i-- && !uart8250_mem_can_tx_byte(base_port))
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udelay(1);
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write8(base_port + UART8250_TBR, data);
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}
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static void uart8250_mem_tx_flush(unsigned base_port)
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{
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unsigned long int i = FIFO_TIMEOUT;
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while(i-- && !(read8(base_port + UART8250_LSR) & UART8250_LSR_TEMT))
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udelay(1);
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}
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static int uart8250_mem_can_rx_byte(unsigned base_port)
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{
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return read8(base_port + UART8250_LSR) & UART8250_LSR_DR;
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}
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static unsigned char uart8250_mem_rx_byte(unsigned base_port)
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{
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unsigned long int i = SINGLE_CHAR_TIMEOUT;
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while(i-- && !uart8250_mem_can_rx_byte(base_port))
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udelay(1);
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if (i)
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return read8(base_port + UART8250_RBR);
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else
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return 0x0;
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}
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static void uart8250_mem_init(unsigned base_port, unsigned divisor)
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{
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/* Disable interrupts */
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write8(base_port + UART8250_IER, 0x0);
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/* Enable FIFOs */
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write8(base_port + UART8250_FCR, UART8250_FCR_FIFO_EN);
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/* Assert DTR and RTS so the other end is happy */
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write8(base_port + UART8250_MCR, UART8250_MCR_DTR | UART8250_MCR_RTS);
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/* DLAB on */
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write8(base_port + UART8250_LCR, UART8250_LCR_DLAB | CONFIG_TTYS0_LCS);
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write8(base_port + UART8250_DLL, divisor & 0xFF);
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write8(base_port + UART8250_DLM, (divisor >> 8) & 0xFF);
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/* Set to 3 for 8N1 */
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write8(base_port + UART8250_LCR, CONFIG_TTYS0_LCS);
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}
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void uart_init(int idx)
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{
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u32 base = uart_platform_base(idx);
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if (!base)
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return;
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unsigned int div;
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div = uart_baudrate_divisor(default_baudrate(), uart_platform_refclk(), 16);
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uart8250_mem_init(base, div);
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}
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void uart_tx_byte(int idx, unsigned char data)
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{
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u32 base = uart_platform_base(idx);
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if (!base)
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return;
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uart8250_mem_tx_byte(base, data);
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}
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unsigned char uart_rx_byte(int idx)
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{
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u32 base = uart_platform_base(idx);
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if (!base)
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return 0xff;
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return uart8250_mem_rx_byte(base);
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}
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void uart_tx_flush(int idx)
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{
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u32 base = uart_platform_base(idx);
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if (!base)
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return;
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uart8250_mem_tx_flush(base);
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}
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