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/*
* (C) Copyright 2003
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
* (C) Copyright 2009
* Infineon Technologies AG, http://www.infineon.com
*
* 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 <config.h>
#include <common.h>
#include <asm/io.h>
#include <asm/addrspace.h>
#include "ifx_asc.h"
#define SET_BIT(reg, mask) asc_writel(reg, asc_readl(reg) | (mask))
#define CLEAR_BIT(reg, mask) asc_writel(reg, asc_readl(reg) & (~mask))
#define SET_BITFIELD(reg, mask, off, val) asc_writel(reg, (asc_readl(reg) & (~mask)) | (val << off) )
#undef DEBUG_ASC_RAW
#ifdef DEBUG_ASC_RAW
#define DEBUG_ASC_RAW_RX_BUF 0xA0800000
#define DEBUG_ASC_RAW_TX_BUF 0xA0900000
#endif
DECLARE_GLOBAL_DATA_PTR;
static IfxAsc_t *pAsc = (IfxAsc_t *)CKSEG1ADDR(CONFIG_SYS_IFX_ASC_BASE);
/*
* FDV fASC
* BaudRate = ----- * --------------------
* 512 16 * (ReloadValue+1)
*/
/*
* FDV fASC
* ReloadValue = ( ----- * --------------- ) - 1
* 512 16 * BaudRate
*/
static void serial_divs(u32 baudrate, u32 fasc, u32 *pfdv, u32 *preload)
{
u32 clock = fasc / 16;
u32 fdv; /* best fdv */
u32 reload = 0; /* best reload */
u32 diff; /* smallest diff */
u32 idiff; /* current diff */
u32 ireload; /* current reload */
u32 i; /* current fdv */
u32 result; /* current resulting baudrate */
if (clock > 0x7FFFFF)
clock /= 512;
else
baudrate *= 512;
fdv = 512; /* start with 1:1 fraction */
diff = baudrate; /* highest possible */
/* i is the test fdv value -- start with the largest possible */
for (i = 512; i > 0; i--)
{
ireload = (clock * i) / baudrate;
if (ireload < 1)
break; /* already invalid */
result = (clock * i) / ireload;
idiff = (result > baudrate) ? (result - baudrate) : (baudrate - result);
if (idiff == 0)
{
fdv = i;
reload = ireload;
break; /* can't do better */
}
else if (idiff < diff)
{
fdv = i; /* best so far */
reload = ireload;
diff = idiff; /* update lowest diff*/
}
}
*pfdv = (fdv == 512) ? 0 : fdv;
*preload = reload - 1;
}
void serial_setbrg (void)
{
u32 ReloadValue, fdv;
serial_divs(gd->baudrate, get_bus_freq(0), &fdv, &ReloadValue);
/* Disable Baud Rate Generator; BG should only be written when R=0 */
CLEAR_BIT(asc_con, ASCCON_R);
/* Enable Fractional Divider */
SET_BIT(asc_con, ASCCON_FDE); /* FDE = 1 */
/* Set fractional divider value */
asc_writel(asc_fdv, fdv & ASCFDV_VALUE_MASK);
/* Set reload value in BG */
asc_writel(asc_bg, ReloadValue);
/* Enable Baud Rate Generator */
SET_BIT(asc_con, ASCCON_R); /* R = 1 */
}
int serial_init (void)
{
/* and we have to set CLC register*/
CLEAR_BIT(asc_clc, ASCCLC_DISS);
SET_BITFIELD(asc_clc, ASCCLC_RMCMASK, ASCCLC_RMCOFFSET, 0x0001);
/* initialy we are in async mode */
asc_writel(asc_con, ASCCON_M_8ASYNC);
/* select input port */
asc_writel(asc_pisel, CONSOLE_TTY & 0x1);
/* TXFIFO's filling level */
SET_BITFIELD(asc_txfcon, ASCTXFCON_TXFITLMASK,
ASCTXFCON_TXFITLOFF, ASC_TXFIFO_FL);
/* enable TXFIFO */
SET_BIT(asc_txfcon, ASCTXFCON_TXFEN);
/* RXFIFO's filling level */
SET_BITFIELD(asc_txfcon, ASCRXFCON_RXFITLMASK,
ASCRXFCON_RXFITLOFF, ASC_RXFIFO_FL);
/* enable RXFIFO */
SET_BIT(asc_rxfcon, ASCRXFCON_RXFEN);
/* set baud rate */
serial_setbrg();
/* enable error signals & Receiver enable */
SET_BIT(asc_whbstate, ASCWHBSTATE_SETREN|ASCCON_FEN|ASCCON_TOEN|ASCCON_ROEN);
return 0;
}
void serial_putc (const char c)
{
u32 txFl = 0;
#ifdef DEBUG_ASC_RAW
static u8 * debug = (u8 *) DEBUG_ASC_RAW_TX_BUF;
*debug++=c;
#endif
if (c == '\n')
serial_putc ('\r');
/* check do we have a free space in the TX FIFO */
/* get current filling level */
do {
txFl = ( asc_readl(asc_fstat) & ASCFSTAT_TXFFLMASK ) >> ASCFSTAT_TXFFLOFF;
}
while ( txFl == ASC_TXFIFO_FULL );
asc_writel(asc_tbuf, c); /* write char to Transmit Buffer Register */
/* check for errors */
if ( asc_readl(asc_state) & ASCSTATE_TOE ) {
SET_BIT(asc_whbstate, ASCWHBSTATE_CLRTOE);
return;
}
}
void serial_puts (const char *s)
{
while (*s) {
serial_putc (*s++);
}
}
int serial_getc (void)
{
char c;
while ((asc_readl(asc_fstat) & ASCFSTAT_RXFFLMASK) == 0 );
c = (char)(asc_readl(asc_rbuf) & 0xff);
#ifdef DEBUG_ASC_RAW
static u8* debug=(u8*)(DEBUG_ASC_RAW_RX_BUF);
*debug++=c;
#endif
return c;
}
int serial_tstc (void)
{
int res = 1;
if ( (asc_readl(asc_fstat) & ASCFSTAT_RXFFLMASK) == 0 ) {
res = 0;
}
return res;
}
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