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/***********************************************************************
*
* (C) Copyright 2004
* DENX Software Engineering
* Wolfgang Denk, wd@denx.de
* All rights reserved.
*
* Simple 16550A serial driver
*
* Originally from linux source (drivers/char/ps2ser.c)
*
* Used by the PS/2 multiplexer driver (ps2mult.c)
*
***********************************************************************/
#include <common.h>
#ifdef CONFIG_PS2SERIAL
#include <asm/io.h>
#include <asm/atomic.h>
#include <ps2mult.h>
/* #define DEBUG */
#define PS2SER_BAUD 57600
static int ps2ser_getc_hw(void);
static void ps2ser_interrupt(void *dev_id);
extern struct serial_state rs_table[]; /* in serial.c */
static struct serial_state *state;
static u_char ps2buf[PS2BUF_SIZE];
static atomic_t ps2buf_cnt;
static int ps2buf_in_idx;
static int ps2buf_out_idx;
static inline unsigned int ps2ser_in(int offset)
{
return readb((unsigned long) state->iomem_base + offset);
}
static inline void ps2ser_out(int offset, int value)
{
writeb(value, (unsigned long) state->iomem_base + offset);
}
int ps2ser_init(void)
{
int quot;
unsigned cval;
state = rs_table + CONFIG_PS2SERIAL;
quot = state->baud_base / PS2SER_BAUD;
cval = 0x3; /* 8N1 - 8 data bits, no parity bits, 1 stop bit */
/* Set speed, enable interrupts, enable FIFO
*/
ps2ser_out(UART_LCR, cval | UART_LCR_DLAB);
ps2ser_out(UART_DLL, quot & 0xff);
ps2ser_out(UART_DLM, quot >> 8);
ps2ser_out(UART_LCR, cval);
ps2ser_out(UART_IER, UART_IER_RDI);
ps2ser_out(UART_MCR, UART_MCR_OUT2 | UART_MCR_DTR | UART_MCR_RTS);
ps2ser_out(UART_FCR,
UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
/* If we read 0xff from the LSR, there is no UART here
*/
if (ps2ser_in(UART_LSR) == 0xff) {
printf ("ps2ser.c: no UART found\n");
return -1;
}
irq_install_handler(state->irq, ps2ser_interrupt, NULL);
return 0;
}
void ps2ser_putc(int chr)
{
#ifdef DEBUG
printf(">>>> 0x%02x\n", chr);
#endif
while (!(ps2ser_in(UART_LSR) & UART_LSR_THRE));
ps2ser_out(UART_TX, chr);
}
static int ps2ser_getc_hw(void)
{
int res = -1;
if (ps2ser_in(UART_LSR) & UART_LSR_DR) {
res = (ps2ser_in(UART_RX));
}
return res;
}
int ps2ser_getc(void)
{
volatile int chr;
int flags;
#ifdef DEBUG
printf("<< ");
#endif
flags = disable_interrupts();
do {
if (atomic_read(&ps2buf_cnt) != 0) {
chr = ps2buf[ps2buf_out_idx++];
ps2buf_out_idx &= (PS2BUF_SIZE - 1);
atomic_dec(&ps2buf_cnt);
} else {
chr = ps2ser_getc_hw();
}
}
while (chr < 0);
if (flags) enable_interrupts();
#ifdef DEBUG
printf("0x%02x\n", chr);
#endif
return chr;
}
int ps2ser_check(void)
{
int flags;
flags = disable_interrupts();
ps2ser_interrupt(NULL);
if (flags) enable_interrupts();
return atomic_read(&ps2buf_cnt);
}
static void ps2ser_interrupt(void *dev_id)
{
int chr;
int iir;
do {
chr = ps2ser_getc_hw();
iir = ps2ser_in(UART_IIR);
if (chr < 0) continue;
if (atomic_read(&ps2buf_cnt) < PS2BUF_SIZE) {
ps2buf[ps2buf_in_idx++] = chr;
ps2buf_in_idx &= (PS2BUF_SIZE - 1);
atomic_inc(&ps2buf_cnt);
} else {
printf ("ps2ser.c: buffer overflow\n");
}
} while (iir & UART_IIR_RDI);
if (atomic_read(&ps2buf_cnt)) {
ps2mult_callback(atomic_read(&ps2buf_cnt));
}
}
#endif /* CONFIG_PS2SERIAL */
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