/*
* Change the port parameters
*/
static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
unsigned long flags;
unsigned int mode, imr, quot, baud, fidi;
if(AT91SAM9260_BASE_US3 != (port)->mapbase)
{
/* Get current mode register */
mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL
| ATMEL_US_NBSTOP | ATMEL_US_PAR
| ATMEL_US_USMODE);
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16); // figure out the baud that allowed
quot = uart_get_divisor(port, baud); // for BRGR(baud rate generator register)
if (quot > 65535) { /* BRGR is 16-bit, so switch to slower clock */
quot /= 8;
mode |= ATMEL_US_USCLKS_MCK_DIV8;
}
/* byte size */
switch (termios->c_cflag & CSIZE) {
case CS5:
mode |= ATMEL_US_CHRL_5;
break;
case CS6:
mode |= ATMEL_US_CHRL_6;
break;
case CS7:
mode |= ATMEL_US_CHRL_7;
break;
default:
mode |= ATMEL_US_CHRL_8;
break;
}
/* stop bits */
if (termios->c_cflag & CSTOPB)
mode |= ATMEL_US_NBSTOP_2;
/* parity */
if (termios->c_cflag & PARENB) {
/* Mark or Space parity */
if (termios->c_cflag & CMSPAR) {
if (termios->c_cflag & PARODD)
mode |= ATMEL_US_PAR_MARK;
else
mode |= ATMEL_US_PAR_SPACE;
} else if (termios->c_cflag & PARODD)
mode |= ATMEL_US_PAR_ODD;
else
mode |= ATMEL_US_PAR_EVEN;
} else
mode |= ATMEL_US_PAR_NONE;
/* hardware handshake (RTS/CTS) */
if (termios->c_cflag & CRTSCTS)
mode |= ATMEL_US_USMODE_HWHS;
else
mode |= ATMEL_US_USMODE_NORMAL;
}
else
{
/* Get current mode register */
printk("set_iso7816.\n");
mode = ATMEL_US_USMODE_ISO7816_T0 |
ATMEL_US_USCLKS_MCK |
ATMEL_US_CLKO |
//ATMEL_US_NBSTOP_2 |
ATMEL_US_FILTER |
ATMEL_US_INACK |
ATMEL_US_DSNACK;
//_DIV8;//ATMEL_US_USCLKS; | ATMEL_US_SYNC /* mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL ATMEL_US_USMODE_NORMAL | ATMEL_US_NBSTOP | ATMEL_US_PAR | ATMEL_US_USMODE);*/
printk("mode:%x.\n",mode);
printk("port->uartclk:%d.\n",port->uartclk);
quot = (port->uartclk) / 3570000; // for SCK
baud = 9600;
fidi = 0x174; // for etu
printk("fidi:%d;quot:%d.\n",fidi,quot);
if (quot > 65535)
{ /* BRGR is 16-bit, so switch to slower clock */
quot /= 8;
mode |= ATMEL_US_USCLKS_MCK_DIV8;
}
}
spin_lock_irqsave(&port->lock, flags);
port->read_status_mask = ATMEL_US_OVRE;
if (termios->c_iflag & INPCK)
port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= ATMEL_US_RXBRK;
if (atmel_use_dma_rx(port))
/* need to enable error interrupts */
UART_PUT_IER(port, port->read_status_mask);
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= ATMEL_US_RXBRK;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= ATMEL_US_OVRE;
}
/* TODO: Ignore all characters if CREAD is set.*/
/* update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
/*
* save/disable interrupts. The tty layer will ensure that the
* transmitter is empty if requested by the caller, so there's
* no need to wait for it here.
*/
imr = UART_GET_IMR(port);
UART_PUT_IDR(port, -1);
/* disable receiver and transmitter */
UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);
/* set the parity, stop bits and data size */
UART_PUT_MR(port, mode);
/* set the baud rate */
UART_PUT_BRGR(port, quot);
if(AT91SAM9260_BASE_US3 == (port)->mapbase)
{
UART_PUT_FIDI(port, fidi); // add
}
UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);
/* restore interrupts */
UART_PUT_IER(port, imr);
/* CTS flow-control and modem-status interrupts */
if (UART_ENABLE_MS(port, termios->c_cflag))
port->ops->enable_ms(port);
spin_unlock_irqrestore(&port->lock, flags);
}
以上是我对原有驱动做了修改的部分（只是将指定串口设置为iso7816模式），请各位高手帮助下
嵌入式系统