drivers/serial/serial_netarm.c

/*
 * Serial Port stuff - taken from Linux
 *
 * (C) Copyright 2002
 * MAZeT GmbH <www.mazet.de>
 * Stephan Linz <linz@mazet.de>, <linz@li-pro.net>
 *
 * (c) 2004
 * IMMS gGmbH <www.imms.de>
 * Thomas Elste <info@elste.org>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <common.h>
#include <asm/hardware.h>

DECLARE_GLOBAL_DATA_PTR;

#define PORTA	(*(volatile unsigned int *)(NETARM_GEN_MODULE_BASE + NETARM_GEN_PORTA))
#if !defined(CONFIG_NETARM_NS7520)
#define PORTB	(*(volatile unsigned int *)(NETARM_GEN_MODULE_BASE + NETARM_GEN_PORTB))
#else
#define PORTC	(*(volatile unsigned int *)(NETARM_GEN_MODULE_BASE + NETARM_GEN_PORTC))
#endif

/* wait until transmitter is ready for another character */
#define TXWAITRDY(registers)							\
{										\
	ulong tmo = get_timer(0) + 1 * CONFIG_SYS_HZ;					\
	while (((registers)->status_a & NETARM_SER_STATA_TX_RDY) == 0 )	{	\
		if (get_timer(0) > tmo)						\
			break;							\
	}									\
}


volatile netarm_serial_channel_t *serial_reg_ch1 = get_serial_channel(0);
volatile netarm_serial_channel_t *serial_reg_ch2 = get_serial_channel(1);

extern void _netarm_led_FAIL1(void);

/*
 * Setup both serial i/f with given baudrate
 */
static void netarm_serial_setbrg(void)
{
	/* set 0 ... make sure pins are configured for serial */
#if !defined(CONFIG_NETARM_NS7520)
	PORTA = PORTB =
		NETARM_GEN_PORT_MODE (0xef) | NETARM_GEN_PORT_DIR (0xe0);
#else
	PORTA = NETARM_GEN_PORT_MODE (0xef) | NETARM_GEN_PORT_DIR (0xe0);
	PORTC = NETARM_GEN_PORT_CSF (0xef) | NETARM_GEN_PORT_MODE (0xef) | NETARM_GEN_PORT_DIR (0xe0);
#endif

	/* first turn em off */
	serial_reg_ch1->ctrl_a = serial_reg_ch2->ctrl_a = 0;

	/* clear match register, we don't need it */
	serial_reg_ch1->rx_match = serial_reg_ch2->rx_match = 0;

	/* setup bit rate generator and rx buffer gap timer (1 byte only) */
	if ((gd->baudrate >= MIN_BAUD_RATE)
	    && (gd->baudrate <= MAX_BAUD_RATE)) {
		serial_reg_ch1->bitrate = serial_reg_ch2->bitrate =
			NETARM_SER_BR_X16 (gd->baudrate);
		serial_reg_ch1->rx_buf_timer = serial_reg_ch2->rx_buf_timer =
			0;
		serial_reg_ch1->rx_char_timer = serial_reg_ch2->rx_char_timer =
			NETARM_SER_RXGAP (gd->baudrate);
	} else {
		hang ();
	}

	/* setup port mode */
	serial_reg_ch1->ctrl_b = serial_reg_ch2->ctrl_b =
		( NETARM_SER_CTLB_RCGT_EN |
		  NETARM_SER_CTLB_UART_MODE);
	serial_reg_ch1->ctrl_a = serial_reg_ch2->ctrl_a =
		( NETARM_SER_CTLA_ENABLE |
		  NETARM_SER_CTLA_P_NONE |
		  /* see errata */
		  NETARM_SER_CTLA_2STOP |
		  NETARM_SER_CTLA_8BITS |
		  NETARM_SER_CTLA_DTR_EN |
		  NETARM_SER_CTLA_RTS_EN);
}


/*
 * Initialise the serial port with the given baudrate. The settings
 * are always 8 data bits, no parity, 1 stop bit, no start bits.
 */
static int netarm_serial_init(void)
{
	serial_setbrg ();
	return 0;
}


/*
 * Output a single byte to the serial port.
 */
static void netarm_serial_putc(const char c)
{
	volatile unsigned char *fifo;

	/* If \n, also do \r */
	if (c == '\n')
		serial_putc ('\r');

	fifo = (volatile unsigned char *) &(serial_reg_ch1->fifo);
	TXWAITRDY (serial_reg_ch1);
	*fifo = c;
}

/*
 * Test of a single byte from the serial port. Returns 1 on success, 0
 * otherwise.
 */
static int netarm_serial_tstc(void)
{
	return serial_reg_ch1->status_a & NETARM_SER_STATA_RX_RDY;
}

/*
 * Read a single byte from the serial port. Returns 1 on success, 0
 * otherwise.
 */
static int netarm_serial_getc(void)
{
	unsigned int ch_uint;
	volatile unsigned int *fifo;
	volatile unsigned char *fifo_char = NULL;
	int buf_count = 0;

	while (!(serial_reg_ch1->status_a & NETARM_SER_STATA_RX_RDY))
		/* NOP */ ;

	fifo = (volatile unsigned int *) &(serial_reg_ch1->fifo);
	fifo_char = (unsigned char *) &ch_uint;
	ch_uint = *fifo;

	buf_count = NETARM_SER_STATA_RXFDB (serial_reg_ch1->status_a);
	switch (buf_count) {
	case NETARM_SER_STATA_RXFDB_4BYTES:
		buf_count = 4;
		break;
	case NETARM_SER_STATA_RXFDB_3BYTES:
		buf_count = 3;
		break;
	case NETARM_SER_STATA_RXFDB_2BYTES:
		buf_count = 2;
		break;
	case NETARM_SER_STATA_RXFDB_1BYTES:
		buf_count = 1;
		break;
	default:
		/* panic, be never here */
		break;
	}

	serial_reg_ch1->status_a |= NETARM_SER_STATA_RX_CLOSED;

	return ch_uint & 0xff;
}

static struct serial_device netarm_serial_drv = {
	.name	= "netarm_serial",
	.start	= netarm_serial_init,
	.stop	= NULL,
	.setbrg	= netarm_serial_setbrg,
	.putc	= netarm_serial_putc,
	.puts	= default_serial_puts,
	.getc	= netarm_serial_getc,
	.tstc	= netarm_serial_tstc,
};

void netarm_serial_initialize(void)
{
	serial_register(&netarm_serial_drv);
}

__weak struct serial_device *default_serial_console(void)
{
	return &netarm_serial_drv;
}