u-boot/arch/mips/cpu/mips32/incaip/asc_serial.c

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/*
* (INCA) ASC UART support
*/
#include <config.h>
#include <common.h>
#include <asm/inca-ip.h>
#include "asc_serial.h"
#define SET_BIT(reg, mask) reg |= (mask)
#define CLEAR_BIT(reg, mask) reg &= (~mask)
#define CLEAR_BITS(reg, mask) CLEAR_BIT(reg, mask)
#define SET_BITS(reg, mask) SET_BIT(reg, mask)
#define SET_BITFIELD(reg, mask, off, val) {reg &= (~mask); reg |= (val << off);}
extern uint incaip_get_fpiclk(void);
static int serial_setopt (void);
/* pointer to ASC register base address */
static volatile incaAsc_t *pAsc = (incaAsc_t *)INCA_IP_ASC;
/******************************************************************************
*
* serial_init - initialize a INCAASC channel
*
* This routine initializes the number of data bits, parity
* and set the selected baud rate. Interrupts are disabled.
* Set the modem control signals if the option is selected.
*
* RETURNS: N/A
*/
int serial_init (void)
{
/* we have to set PMU.EN13 bit to enable an ASC device*/
INCAASC_PMU_ENABLE(13);
/* and we have to set CLC register*/
CLEAR_BIT(pAsc->asc_clc, ASCCLC_DISS);
SET_BITFIELD(pAsc->asc_clc, ASCCLC_RMCMASK, ASCCLC_RMCOFFSET, 0x0001);
/* initialy we are in async mode */
pAsc->asc_con = ASCCON_M_8ASYNC;
/* select input port */
pAsc->asc_pisel = (CONSOLE_TTY & 0x1);
/* TXFIFO's filling level */
SET_BITFIELD(pAsc->asc_txfcon, ASCTXFCON_TXFITLMASK,
ASCTXFCON_TXFITLOFF, INCAASC_TXFIFO_FL);
/* enable TXFIFO */
SET_BIT(pAsc->asc_txfcon, ASCTXFCON_TXFEN);
/* RXFIFO's filling level */
SET_BITFIELD(pAsc->asc_txfcon, ASCRXFCON_RXFITLMASK,
ASCRXFCON_RXFITLOFF, INCAASC_RXFIFO_FL);
/* enable RXFIFO */
SET_BIT(pAsc->asc_rxfcon, ASCRXFCON_RXFEN);
/* enable error signals */
SET_BIT(pAsc->asc_con, ASCCON_FEN);
SET_BIT(pAsc->asc_con, ASCCON_OEN);
/* acknowledge ASC interrupts */
ASC_INTERRUPTS_CLEAR(INCAASC_IRQ_LINE_ALL);
/* disable ASC interrupts */
ASC_INTERRUPTS_DISABLE(INCAASC_IRQ_LINE_ALL);
/* set FIFOs into the transparent mode */
SET_BIT(pAsc->asc_txfcon, ASCTXFCON_TXTMEN);
SET_BIT(pAsc->asc_rxfcon, ASCRXFCON_RXTMEN);
/* set baud rate */
serial_setbrg();
/* set the options */
serial_setopt();
return 0;
}
void serial_setbrg (void)
{
ulong uiReloadValue, fdv;
ulong f_ASC;
f_ASC = incaip_get_fpiclk();
#ifndef INCAASC_USE_FDV
fdv = 2;
uiReloadValue = (f_ASC / (fdv * 16 * CONFIG_BAUDRATE)) - 1;
#else
fdv = INCAASC_FDV_HIGH_BAUDRATE;
uiReloadValue = (f_ASC / (8192 * CONFIG_BAUDRATE / fdv)) - 1;
#endif /* INCAASC_USE_FDV */
if ( (uiReloadValue < 0) || (uiReloadValue > 8191) )
{
#ifndef INCAASC_USE_FDV
fdv = 3;
uiReloadValue = (f_ASC / (fdv * 16 * CONFIG_BAUDRATE)) - 1;
#else
fdv = INCAASC_FDV_LOW_BAUDRATE;
uiReloadValue = (f_ASC / (8192 * CONFIG_BAUDRATE / fdv)) - 1;
#endif /* INCAASC_USE_FDV */
if ( (uiReloadValue < 0) || (uiReloadValue > 8191) )
{
return; /* can't impossibly generate that baud rate */
}
}
/* Disable Baud Rate Generator; BG should only be written when R=0 */
CLEAR_BIT(pAsc->asc_con, ASCCON_R);
#ifndef INCAASC_USE_FDV
/*
* Disable Fractional Divider (FDE)
* Divide clock by reload-value + constant (BRS)
*/
/* FDE = 0 */
CLEAR_BIT(pAsc->asc_con, ASCCON_FDE);
if ( fdv == 2 )
CLEAR_BIT(pAsc->asc_con, ASCCON_BRS); /* BRS = 0 */
else
SET_BIT(pAsc->asc_con, ASCCON_BRS); /* BRS = 1 */
#else /* INCAASC_USE_FDV */
/* Enable Fractional Divider */
SET_BIT(pAsc->asc_con, ASCCON_FDE); /* FDE = 1 */
/* Set fractional divider value */
pAsc->asc_fdv = fdv & ASCFDV_VALUE_MASK;
#endif /* INCAASC_USE_FDV */
/* Set reload value in BG */
pAsc->asc_bg = uiReloadValue;
/* Enable Baud Rate Generator */
SET_BIT(pAsc->asc_con, ASCCON_R); /* R = 1 */
}
/*******************************************************************************
*
* serial_setopt - set the serial options
*
* Set the channel operating mode to that specified. Following options
* are supported: CREAD, CSIZE, PARENB, and PARODD.
*
* Note, this routine disables the transmitter. The calling routine
* may have to re-enable it.
*
* RETURNS:
* Returns 0 to indicate success, otherwise -1 is returned
*/
static int serial_setopt (void)
{
ulong con;
switch ( ASC_OPTIONS & ASCOPT_CSIZE )
{
/* 7-bit-data */
case ASCOPT_CS7:
con = ASCCON_M_7ASYNCPAR; /* 7-bit-data and parity bit */
break;
/* 8-bit-data */
case ASCOPT_CS8:
if ( ASC_OPTIONS & ASCOPT_PARENB )
con = ASCCON_M_8ASYNCPAR; /* 8-bit-data and parity bit */
else
con = ASCCON_M_8ASYNC; /* 8-bit-data no parity */
break;
/*
* only 7 and 8-bit frames are supported
* if we don't use IOCTL extensions
*/
default:
return -1;
}
if ( ASC_OPTIONS & ASCOPT_STOPB )
SET_BIT(con, ASCCON_STP); /* 2 stop bits */
else
CLEAR_BIT(con, ASCCON_STP); /* 1 stop bit */
if ( ASC_OPTIONS & ASCOPT_PARENB )
SET_BIT(con, ASCCON_PEN); /* enable parity checking */
else
CLEAR_BIT(con, ASCCON_PEN); /* disable parity checking */
if ( ASC_OPTIONS & ASCOPT_PARODD )
SET_BIT(con, ASCCON_ODD); /* odd parity */
else
CLEAR_BIT(con, ASCCON_ODD); /* even parity */
if ( ASC_OPTIONS & ASCOPT_CREAD )
SET_BIT(pAsc->asc_whbcon, ASCWHBCON_SETREN); /* Receiver enable */
pAsc->asc_con |= con;
return 0;
}
void serial_putc (const char c)
{
uint txFl = 0;
if (c == '\n') serial_putc ('\r');
/* check do we have a free space in the TX FIFO */
/* get current filling level */
do
{
txFl = ( pAsc->asc_fstat & ASCFSTAT_TXFFLMASK ) >> ASCFSTAT_TXFFLOFF;
}
while ( txFl == INCAASC_TXFIFO_FULL );
pAsc->asc_tbuf = c; /* write char to Transmit Buffer Register */
/* check for errors */
if ( pAsc->asc_con & ASCCON_OE )
{
SET_BIT(pAsc->asc_whbcon, ASCWHBCON_CLROE);
return;
}
}
void serial_puts (const char *s)
{
while (*s)
{
serial_putc (*s++);
}
}
int serial_getc (void)
{
ulong symbol_mask;
char c;
while (!serial_tstc());
symbol_mask =
((ASC_OPTIONS & ASCOPT_CSIZE) == ASCOPT_CS7) ? (0x7f) : (0xff);
c = (char)(pAsc->asc_rbuf & symbol_mask);
return c;
}
int serial_tstc (void)
{
int res = 1;
if ( (pAsc->asc_fstat & ASCFSTAT_RXFFLMASK) == 0 )
{
res = 0;
}
else if ( pAsc->asc_con & ASCCON_FE )
{
SET_BIT(pAsc->asc_whbcon, ASCWHBCON_CLRFE);
res = 0;
}
else if ( pAsc->asc_con & ASCCON_PE )
{
SET_BIT(pAsc->asc_whbcon, ASCWHBCON_CLRPE);
res = 0;
}
else if ( pAsc->asc_con & ASCCON_OE )
{
SET_BIT(pAsc->asc_whbcon, ASCWHBCON_CLROE);
res = 0;
}
return res;
}