uboot-vybrid_public/arch/powerpc/cpu/ppc4xx/iop480_uart.c

/*
 * (C) Copyright 2000-2006
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * 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 <commproc.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <watchdog.h>
#include <serial.h>
#include <linux/compiler.h>

DECLARE_GLOBAL_DATA_PTR;

#ifdef CONFIG_IOP480

#define SPU_BASE         0x40000000

#define spu_LineStat_rc  0x00	/* Line Status Register (Read/Clear) */
#define spu_LineStat_w   0x04	/* Line Status Register (Set) */
#define spu_Handshk_rc   0x08	/* Handshake Status Register (Read/Clear) */
#define spu_Handshk_w    0x0c	/* Handshake Status Register (Set) */
#define spu_BRateDivh    0x10	/* Baud rate divisor high */
#define spu_BRateDivl    0x14	/* Baud rate divisor low */
#define spu_CtlReg       0x18	/* Control Register */
#define spu_RxCmd        0x1c	/* Rx Command Register */
#define spu_TxCmd        0x20	/* Tx Command Register */
#define spu_RxBuff       0x24	/* Rx data buffer */
#define spu_TxBuff       0x24	/* Tx data buffer */

/*-----------------------------------------------------------------------------+
  | Line Status Register.
  +-----------------------------------------------------------------------------*/
#define asyncLSRport1           0x40000000
#define asyncLSRport1set        0x40000004
#define asyncLSRDataReady             0x80
#define asyncLSRFramingError          0x40
#define asyncLSROverrunError          0x20
#define asyncLSRParityError           0x10
#define asyncLSRBreakInterrupt        0x08
#define asyncLSRTxHoldEmpty           0x04
#define asyncLSRTxShiftEmpty          0x02

/*-----------------------------------------------------------------------------+
  | Handshake Status Register.
  +-----------------------------------------------------------------------------*/
#define asyncHSRport1           0x40000008
#define asyncHSRport1set        0x4000000c
#define asyncHSRDsr                   0x80
#define asyncLSRCts                   0x40

/*-----------------------------------------------------------------------------+
  | Control Register.
  +-----------------------------------------------------------------------------*/
#define asyncCRport1            0x40000018
#define asyncCRNormal                 0x00
#define asyncCRLoopback               0x40
#define asyncCRAutoEcho               0x80
#define asyncCRDtr                    0x20
#define asyncCRRts                    0x10
#define asyncCRWordLength7            0x00
#define asyncCRWordLength8            0x08
#define asyncCRParityDisable          0x00
#define asyncCRParityEnable           0x04
#define asyncCREvenParity             0x00
#define asyncCROddParity              0x02
#define asyncCRStopBitsOne            0x00
#define asyncCRStopBitsTwo            0x01
#define asyncCRDisableDtrRts          0x00

/*-----------------------------------------------------------------------------+
  | Receiver Command Register.
  +-----------------------------------------------------------------------------*/
#define asyncRCRport1           0x4000001c
#define asyncRCRDisable               0x00
#define asyncRCREnable                0x80
#define asyncRCRIntDisable            0x00
#define asyncRCRIntEnabled            0x20
#define asyncRCRDMACh2                0x40
#define asyncRCRDMACh3                0x60
#define asyncRCRErrorInt              0x10
#define asyncRCRPauseEnable           0x08

/*-----------------------------------------------------------------------------+
  | Transmitter Command Register.
  +-----------------------------------------------------------------------------*/
#define asyncTCRport1           0x40000020
#define asyncTCRDisable               0x00
#define asyncTCREnable                0x80
#define asyncTCRIntDisable            0x00
#define asyncTCRIntEnabled            0x20
#define asyncTCRDMACh2                0x40
#define asyncTCRDMACh3                0x60
#define asyncTCRTxEmpty               0x10
#define asyncTCRErrorInt              0x08
#define asyncTCRStopPause             0x04
#define asyncTCRBreakGen              0x02

/*-----------------------------------------------------------------------------+
  | Miscellanies defines.
  +-----------------------------------------------------------------------------*/
#define asyncTxBufferport1      0x40000024
#define asyncRxBufferport1      0x40000024
#define asyncDLABLsbport1       0x40000014
#define asyncDLABMsbport1       0x40000010
#define asyncXOFFchar                 0x13
#define asyncXONchar                  0x11

/*
 * Minimal serial functions needed to use one of the SMC ports
 * as serial console interface.
 */

static int iop480_serial_init(void)
{
	unsigned short br_reg;

	br_reg = ((((CONFIG_CPUCLOCK * 1000000) / 16) / gd->baudrate) - 1);

	/*
	 * Init onboard UART
	 */
	out_8((u8 *)SPU_BASE + spu_LineStat_rc, 0x78); /* Clear all bits in Line Status Reg */
	out_8((u8 *)SPU_BASE + spu_BRateDivl, (br_reg & 0x00ff)); /* Set baud rate divisor... */
	out_8((u8 *)SPU_BASE + spu_BRateDivh, ((br_reg & 0xff00) >> 8)); /* ... */
	out_8((u8 *)SPU_BASE + spu_CtlReg, 0x08);	/* Set 8 bits, no parity and 1 stop bit */
	out_8((u8 *)SPU_BASE + spu_RxCmd, 0xb0);	/* Enable Rx */
	out_8((u8 *)SPU_BASE + spu_TxCmd, 0x9c);	/* Enable Tx */
	out_8((u8 *)SPU_BASE + spu_Handshk_rc, 0xff);	/* Clear Handshake */
	in_8((u8 *)SPU_BASE + spu_RxBuff);	/* Dummy read, to clear receiver */

	return (0);
}

static void iop480_serial_setbrg(void)
{
	unsigned short br_reg;

	br_reg = ((((CONFIG_CPUCLOCK * 1000000) / 16) / gd->baudrate) - 1);

	out_8((u8 *)SPU_BASE + spu_BRateDivl,
	      (br_reg & 0x00ff)); /* Set baud rate divisor... */
	out_8((u8 *)SPU_BASE + spu_BRateDivh,
	      ((br_reg & 0xff00) >> 8)); /* ... */
}

static void iop480_serial_putc(const char c)
{
	if (c == '\n')
		serial_putc ('\r');

	/* load status from handshake register */
	if (in_8((u8 *)SPU_BASE + spu_Handshk_rc) != 00)
		out_8((u8 *)SPU_BASE + spu_Handshk_rc, 0xff);	/* Clear Handshake */

	out_8((u8 *)SPU_BASE + spu_TxBuff, c);	/* Put char */

	while ((in_8((u8 *)SPU_BASE + spu_LineStat_rc) & 04) != 04) {
		if (in_8((u8 *)SPU_BASE + spu_Handshk_rc) != 00)
			out_8((u8 *)SPU_BASE + spu_Handshk_rc, 0xff);	/* Clear Handshake */
	}
}

static void iop480_serial_puts(const char *s)
{
	while (*s) {
		serial_putc (*s++);
	}
}

static int iop480_serial_getc(void)
{
	unsigned char status = 0;

	while (1) {
		status = in_8((u8 *)asyncLSRport1);
		if ((status & asyncLSRDataReady) != 0x0) {
			break;
		}
		if ((status & ( asyncLSRFramingError |
				asyncLSROverrunError |
				asyncLSRParityError  |
				asyncLSRBreakInterrupt )) != 0) {
			(void) out_8((u8 *)asyncLSRport1,
				     asyncLSRFramingError |
				     asyncLSROverrunError |
				     asyncLSRParityError  |
				     asyncLSRBreakInterrupt );
		}
	}
	return (0x000000ff & (int) in_8((u8 *)asyncRxBufferport1));
}

static int iop480_serial_tstc(void)
{
	unsigned char status;

	status = in_8((u8 *)asyncLSRport1);
	if ((status & asyncLSRDataReady) != 0x0) {
		return (1);
	}
	if ((status & ( asyncLSRFramingError |
			asyncLSROverrunError |
			asyncLSRParityError  |
			asyncLSRBreakInterrupt )) != 0) {
		(void) out_8((u8 *)asyncLSRport1,
			     asyncLSRFramingError |
			     asyncLSROverrunError |
			     asyncLSRParityError  |
			     asyncLSRBreakInterrupt);
	}
	return 0;
}

static struct serial_device iop480_serial_drv = {
	.name	= "iop480_serial",
	.start	= iop480_serial_init,
	.stop	= NULL,
	.setbrg	= iop480_serial_setbrg,
	.putc	= iop480_serial_putc,
	.puts	= iop480_serial_puts,
	.getc	= iop480_serial_getc,
	.tstc	= iop480_serial_tstc,
};

void iop480_serial_initialize(void)
{
	serial_register(&iop480_serial_drv);
}

__weak struct serial_device *default_serial_console(void)
{
	return &iop480_serial_drv;
}
#endif	/* CONFIG_IOP480 */