162 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			162 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * (C) Copyright 2000
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|  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
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|  *
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|  * (C) Copyright 2004
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|  * ARM Ltd.
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|  * Philippe Robin, <philippe.robin@arm.com>
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|  *
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|  * See file CREDITS for list of people who contributed to this
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|  * project.
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License as
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|  * published by the Free Software Foundation; either version 2 of
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|  * the License, or (at your option) any later version.
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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., 59 Temple Place, Suite 330, Boston,
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|  * MA 02111-1307 USA
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|  */
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| 
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| /* Simple U-Boot driver for the PrimeCell PL011 UARTs on the IntegratorCP */
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| /* Should be fairly simple to make it work with the PL010 as well */
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| 
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| #include <common.h>
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| 
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| #ifdef CFG_PL011_SERIAL
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| 
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| #include "serial_pl011.h"
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| 
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| #define IO_WRITE(addr, val) (*(volatile unsigned int *)(addr) = (val))
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| #define IO_READ(addr) (*(volatile unsigned int *)(addr))
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| 
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| /*
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|  * IntegratorCP has two UARTs, use the first one, at 38400-8-N-1
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|  * Versatile PB has four UARTs.
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|  */
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| 
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| #define CONSOLE_PORT CONFIG_CONS_INDEX
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| #define baudRate CONFIG_BAUDRATE
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| static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
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| #define NUM_PORTS (sizeof(port)/sizeof(port[0]))
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| 
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| static void pl011_putc (int portnum, char c);
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| static int pl011_getc (int portnum);
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| static int pl011_tstc (int portnum);
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| 
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| 
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| int serial_init (void)
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| {
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| 	unsigned int temp;
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| 	unsigned int divider;
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| 	unsigned int remainder;
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| 	unsigned int fraction;
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| 
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| 	/*
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| 	 ** First, disable everything.
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| 	 */
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| 	IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR, 0x0);
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| 
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| 	/*
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| 	 ** Set baud rate
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| 	 **
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| 	 ** IBRD = UART_CLK / (16 * BAUD_RATE)
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| 	 ** FBRD = ROUND((64 * MOD(UART_CLK,(16 * BAUD_RATE))) / (16 * BAUD_RATE))
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| 	 */
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| 	temp = 16 * baudRate;
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| 	divider = CONFIG_PL011_CLOCK / temp;
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| 	remainder = CONFIG_PL011_CLOCK % temp;
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| 	temp = (8 * remainder) / baudRate;
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| 	fraction = (temp >> 1) + (temp & 1);
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| 
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| 	IO_WRITE (port[CONSOLE_PORT] + UART_PL011_IBRD, divider);
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| 	IO_WRITE (port[CONSOLE_PORT] + UART_PL011_FBRD, fraction);
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| 
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| 	/*
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| 	 ** Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled.
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| 	 */
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| 	IO_WRITE (port[CONSOLE_PORT] + UART_PL011_LCRH,
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| 		  (UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN));
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| 
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| 	/*
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| 	 ** Finally, enable the UART
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| 	 */
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| 	IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR,
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| 		  (UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
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| 		   UART_PL011_CR_RXE));
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| 
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| 	return 0;
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| }
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| 
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| void serial_putc (const char c)
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| {
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| 	if (c == '\n')
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| 		pl011_putc (CONSOLE_PORT, '\r');
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| 
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| 	pl011_putc (CONSOLE_PORT, c);
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| }
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| 
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| void serial_puts (const char *s)
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| {
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| 	while (*s) {
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| 		serial_putc (*s++);
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| 	}
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| }
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| 
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| int serial_getc (void)
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| {
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| 	return pl011_getc (CONSOLE_PORT);
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| }
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| 
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| int serial_tstc (void)
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| {
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| 	return pl011_tstc (CONSOLE_PORT);
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| }
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| 
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| void serial_setbrg (void)
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| {
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| }
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| 
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| static void pl011_putc (int portnum, char c)
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| {
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| 	/* Wait until there is space in the FIFO */
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| 	while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_TXFF);
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| 
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| 	/* Send the character */
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| 	IO_WRITE (port[portnum] + UART_PL01x_DR, c);
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| }
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| 
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| static int pl011_getc (int portnum)
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| {
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| 	unsigned int data;
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| 
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| 	/* Wait until there is data in the FIFO */
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| 	while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_RXFE);
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| 
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| 	data = IO_READ (port[portnum] + UART_PL01x_DR);
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| 
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| 	/* Check for an error flag */
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| 	if (data & 0xFFFFFF00) {
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| 		/* Clear the error */
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| 		IO_WRITE (port[portnum] + UART_PL01x_ECR, 0xFFFFFFFF);
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| 		return -1;
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| 	}
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| 
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| 	return (int) data;
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| }
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| 
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| static int pl011_tstc (int portnum)
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| {
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| 	return !(IO_READ (port[portnum] + UART_PL01x_FR) &
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| 		 UART_PL01x_FR_RXFE);
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| }
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| 
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| #endif
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