diff options
Diffstat (limited to 'drivers/ps2ser.c')
-rw-r--r-- | drivers/ps2ser.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/ps2ser.c b/drivers/ps2ser.c new file mode 100644 index 0000000..71658d7 --- /dev/null +++ b/drivers/ps2ser.c @@ -0,0 +1,166 @@ +/*********************************************************************** + * + * (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 = rs_table + CONFIG_PS2SERIAL; + +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 = state->baud_base / PS2SER_BAUD; + unsigned 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 */ |