cb51426c6a
Change-Id: Ie1d2a7f460132aa59791cd7d16c9068b79675f1b
807 lines
25 KiB
C
807 lines
25 KiB
C
#include <minix/config.h>
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/*---------------------------------------------------------------------------*
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* rs232.c - serial driver for 8250 and 16450 UARTs *
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* Added support for Atari ST M68901 and YM-2149 --kub *
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*---------------------------------------------------------------------------*/
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#include <minix/drivers.h>
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#include <termios.h>
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#include <signal.h>
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#include "tty.h"
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#if NR_RS_LINES > 0
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/* 8250 constants. */
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#define UART_FREQ 115200L /* timer frequency */
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/* Interrupt enable bits. */
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#define IE_RECEIVER_READY 1
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#define IE_TRANSMITTER_READY 2
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#define IE_LINE_STATUS_CHANGE 4
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#define IE_MODEM_STATUS_CHANGE 8
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/* Interrupt status bits. */
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#define IS_MODEM_STATUS_CHANGE 0
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#define IS_TRANSMITTER_READY 2
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#define IS_RECEIVER_READY 4
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#define IS_LINE_STATUS_CHANGE 6
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/* Line control bits. */
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#define LC_2STOP_BITS 0x04
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#define LC_PARITY 0x08
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#define LC_PAREVEN 0x10
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#define LC_BREAK 0x40
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#define LC_ADDRESS_DIVISOR 0x80
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/* Line status bits. */
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#define LS_OVERRUN_ERR 2
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#define LS_PARITY_ERR 4
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#define LS_FRAMING_ERR 8
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#define LS_BREAK_INTERRUPT 0x10
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#define LS_TRANSMITTER_READY 0x20
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/* Modem control bits. */
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#define MC_DTR 1
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#define MC_RTS 2
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#define MC_OUT2 8 /* required for PC & AT interrupts */
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/* Modem status bits. */
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#define MS_CTS 0x10
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#define MS_RLSD 0x80 /* Received Line Signal Detect */
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#define MS_DRLSD 0x08 /* RLSD Delta */
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#define DATA_BITS_SHIFT 8 /* amount data bits shifted in mode */
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#define DEF_BAUD 1200 /* default baud rate */
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#define RS_IBUFSIZE 1024 /* RS232 input buffer size */
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#define RS_OBUFSIZE 1024 /* RS232 output buffer size */
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/* Input buffer watermarks.
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* The external device is asked to stop sending when the buffer
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* exactly reaches high water, or when TTY requests it. Sending restarts
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* when the input buffer empties below the low watermark.
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*/
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#define RS_ILOWWATER (1 * RS_IBUFSIZE / 4)
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#define RS_IHIGHWATER (3 * RS_IBUFSIZE / 4)
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/* Output buffer low watermark.
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* TTY is notified when the output buffer empties below the low watermark, so
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* it may continue filling the buffer if doing a large write.
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*/
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#define RS_OLOWWATER (1 * RS_OBUFSIZE / 4)
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/* Macros to handle flow control.
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* Interrupts must be off when they are used.
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* Time is critical - already the function call for outb() is annoying.
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* If outb() can be done in-line, tests to avoid it can be dropped.
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* istart() tells external device we are ready by raising RTS.
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* istop() tells external device we are not ready by dropping RTS.
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* DTR is kept high all the time (it probably should be raised by open and
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* dropped by close of the device).
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* OUT2 is also kept high all the time.
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*/
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#define istart(rs) \
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(sys_outb((rs)->modem_ctl_port, MC_OUT2 | MC_RTS | MC_DTR), \
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(rs)->idevready = TRUE)
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#define istop(rs) \
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(sys_outb((rs)->modem_ctl_port, MC_OUT2 | MC_DTR), \
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(rs)->idevready = FALSE)
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/* Macro to tell if device is ready. The rs->cts field is set to MS_CTS if
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* CLOCAL is in effect for a line without a CTS wire.
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*/
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#define devready(rs) ((my_inb(rs->modem_status_port) | rs->cts) & MS_CTS)
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/* Macro to tell if transmitter is ready. */
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#define txready(rs) (my_inb(rs->line_status_port) & LS_TRANSMITTER_READY)
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/* Macro to tell if carrier has dropped.
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* The RS232 Carrier Detect (CD) line is usually connected to the 8250
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* Received Line Signal Detect pin, reflected by bit MS_RLSD in the Modem
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* Status Register. The MS_DRLSD bit tells if MS_RLSD has just changed state.
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* So if MS_DRLSD is set and MS_RLSD cleared, we know that carrier has just
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* dropped.
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*/
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#define devhup(rs) \
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((my_inb(rs->modem_status_port) & (MS_RLSD|MS_DRLSD)) == MS_DRLSD)
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/* Types. */
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typedef unsigned char bool_t; /* boolean */
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/* RS232 device structure, one per device. */
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typedef struct rs232 {
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tty_t *tty; /* associated TTY structure */
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int icount; /* number of bytes in the input buffer */
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char *ihead; /* next free spot in input buffer */
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char *itail; /* first byte to give to TTY */
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bool_t idevready; /* nonzero if we are ready to receive (RTS) */
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char cts; /* normally 0, but MS_CTS if CLOCAL is set */
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unsigned char ostate; /* combination of flags: */
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#define ODONE 1 /* output completed (< output enable bits) */
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#define ORAW 2 /* raw mode for xoff disable (< enab. bits) */
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#define OWAKEUP 4 /* tty_wakeup() pending (asm code only) */
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#define ODEVREADY MS_CTS /* external device hardware ready (CTS) */
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#define OQUEUED 0x20 /* output buffer not empty */
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#define OSWREADY 0x40 /* external device software ready (no xoff) */
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#define ODEVHUP MS_RLSD /* external device has dropped carrier */
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#define OSOFTBITS (ODONE | ORAW | OWAKEUP | OQUEUED | OSWREADY)
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/* user-defined bits */
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#if (OSOFTBITS | ODEVREADY | ODEVHUP) == OSOFTBITS
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/* a weak sanity check */
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#error /* bits are not unique */
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#endif
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unsigned char oxoff; /* char to stop output */
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bool_t inhibited; /* output inhibited? (follows tty_inhibited) */
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bool_t drain; /* if set drain output and reconfigure line */
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int ocount; /* number of bytes in the output buffer */
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char *ohead; /* next free spot in output buffer */
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char *otail; /* next char to output */
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#if defined(__i386__)
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port_t xmit_port; /* i/o ports */
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port_t recv_port;
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port_t div_low_port;
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port_t div_hi_port;
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port_t int_enab_port;
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port_t int_id_port;
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port_t line_ctl_port;
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port_t modem_ctl_port;
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port_t line_status_port;
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port_t modem_status_port;
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#endif
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unsigned char lstatus; /* last line status */
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unsigned char pad; /* ensure alignment for 16-bit ints */
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unsigned framing_errors; /* error counts (no reporting yet) */
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unsigned overrun_errors;
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unsigned parity_errors;
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unsigned break_interrupts;
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int irq; /* irq for this line */
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int irq_hook_id; /* interrupt hook */
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char ibuf[RS_IBUFSIZE]; /* input buffer */
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char obuf[RS_OBUFSIZE]; /* output buffer */
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} rs232_t;
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static rs232_t rs_lines[NR_RS_LINES];
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#if defined(__i386__)
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/* 8250 base addresses. */
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static port_t addr_8250[] = {
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0x3F8, /* COM1 */
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0x2F8, /* COM2 */
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0x3E8, /* COM3 */
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0x2E8, /* COM4 */
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};
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#endif
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static void in_int(rs232_t *rs);
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static void line_int(rs232_t *rs);
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static void modem_int(rs232_t *rs);
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static int rs_write(tty_t *tp, int try);
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static void rs_echo(tty_t *tp, int c);
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static int rs_ioctl(tty_t *tp, int try);
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static void rs_config(rs232_t *rs);
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static int rs_read(tty_t *tp, int try);
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static int rs_icancel(tty_t *tp, int try);
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static int rs_ocancel(tty_t *tp, int try);
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static void rs_ostart(rs232_t *rs);
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static int rs_break(tty_t *tp, int try);
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static int rs_close(tty_t *tp, int try);
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static void out_int(rs232_t *rs);
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static void rs232_handler(rs232_t *rs);
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static int my_inb(port_t port)
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{
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int r;
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u32_t v = 0;
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r = sys_inb(port, &v);
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if (r != OK)
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printf("RS232 warning: failed inb 0x%x\n", port);
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return (int) v;
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}
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/*===========================================================================*
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* rs_write *
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*===========================================================================*/
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static int rs_write(register tty_t *tp, int try)
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{
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/* (*devwrite)() routine for RS232. */
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rs232_t *rs = tp->tty_priv;
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int r, count, ocount;
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if (rs->inhibited != tp->tty_inhibited) {
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/* Inhibition state has changed. */
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rs->ostate |= OSWREADY;
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if (tp->tty_inhibited) rs->ostate &= ~OSWREADY;
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rs->inhibited = tp->tty_inhibited;
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}
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if (rs->drain) {
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/* Wait for the line to drain then reconfigure and continue output. */
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if (rs->ocount > 0) return 0;
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rs->drain = FALSE;
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rs_config(rs);
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}
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/* While there is something to do. */
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for (;;) {
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ocount = buflen(rs->obuf) - rs->ocount;
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count = bufend(rs->obuf) - rs->ohead;
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if (count > ocount) count = ocount;
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if (count > tp->tty_outleft) count = tp->tty_outleft;
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if (count == 0 || tp->tty_inhibited) {
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if (try) return 0;
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break;
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}
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if (try) return 1;
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/* Copy from user space to the RS232 output buffer. */
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if (tp->tty_outcaller == KERNEL) {
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/* We're trying to print on kernel's behalf */
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memcpy(rs->ohead, (void *) tp->tty_outgrant + tp->tty_outoffset, count);
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} else {
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if ((r = sys_safecopyfrom(tp->tty_outcaller, tp->tty_outgrant,
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tp->tty_outoffset, (vir_bytes) rs->ohead, count)) != OK)
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printf("TTY: sys_safecopyfrom() failed: %d", r);
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}
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/* Perform output processing on the output buffer. */
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out_process(tp, rs->obuf, rs->ohead, bufend(rs->obuf), &count, &ocount);
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if (count == 0) break;
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/* Assume echoing messed up by output. */
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tp->tty_reprint = TRUE;
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/* Bookkeeping. */
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rs->ocount += ocount;
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rs_ostart(rs);
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if ((rs->ohead += ocount) >= bufend(rs->obuf))
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rs->ohead -= buflen(rs->obuf);
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tp->tty_outoffset += count;
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tp->tty_outcum += count;
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if ((tp->tty_outleft -= count) == 0) {
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/* Output is finished, reply to the writer. */
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if(tp->tty_outrepcode == TTY_REVIVE) {
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notify(tp->tty_outcaller);
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tp->tty_outrevived = 1;
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} else {
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tty_reply(tp->tty_outrepcode, tp->tty_outcaller,
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tp->tty_outproc, tp->tty_outcum);
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tp->tty_outcum = 0;
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}
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}
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}
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if (tp->tty_outleft > 0 && tp->tty_termios.c_ospeed == B0) {
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/* Oops, the line has hung up. */
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if(tp->tty_outrepcode == TTY_REVIVE) {
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notify(tp->tty_outcaller);
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tp->tty_outrevived = 1;
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} else {
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tty_reply(tp->tty_outrepcode, tp->tty_outcaller,
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tp->tty_outproc, EIO);
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tp->tty_outleft = tp->tty_outcum = 0;
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}
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}
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return 1;
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}
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/*===========================================================================*
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* rs_echo *
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*===========================================================================*/
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static void rs_echo(tp, c)
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tty_t *tp; /* which TTY */
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int c; /* character to echo */
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{
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/* Echo one character. (Like rs_write, but only one character, optionally.) */
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rs232_t *rs = tp->tty_priv;
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int count, ocount;
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ocount = buflen(rs->obuf) - rs->ocount;
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if (ocount == 0) return; /* output buffer full */
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count = 1;
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*rs->ohead = c; /* add one character */
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out_process(tp, rs->obuf, rs->ohead, bufend(rs->obuf), &count, &ocount);
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if (count == 0) return;
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rs->ocount += ocount;
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rs_ostart(rs);
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if ((rs->ohead += ocount) >= bufend(rs->obuf)) rs->ohead -= buflen(rs->obuf);
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}
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/*===========================================================================*
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* rs_ioctl *
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*===========================================================================*/
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static int rs_ioctl(tty_t *tp, int UNUSED(dummy))
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/* tp; which TTY */
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{
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/* Reconfigure the line as soon as the output has drained. */
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rs232_t *rs = tp->tty_priv;
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rs->drain = TRUE;
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return 0; /* dummy */
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}
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/*===========================================================================*
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* rs_config *
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*===========================================================================*/
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static void rs_config(rs232_t *rs)
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/* rs which line */
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{
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/* Set various line control parameters for RS232 I/O.
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* If DataBits == 5 and StopBits == 2, 8250 will generate 1.5 stop bits.
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* The 8250 can't handle split speed, so we use the input speed.
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*/
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tty_t *tp = rs->tty;
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int divisor;
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int line_controls;
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static struct speed2divisor {
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speed_t speed;
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int divisor;
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} s2d[] = {
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#if defined(__i386__)
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{ B50, UART_FREQ / 50 },
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#endif
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{ B75, UART_FREQ / 75 },
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{ B110, UART_FREQ / 110 },
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{ B134, UART_FREQ * 10 / 1345 },
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{ B150, UART_FREQ / 150 },
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{ B200, UART_FREQ / 200 },
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{ B300, UART_FREQ / 300 },
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{ B600, UART_FREQ / 600 },
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{ B1200, UART_FREQ / 1200 },
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#if defined(__i386__)
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{ B1800, UART_FREQ / 1800 },
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#endif
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{ B2400, UART_FREQ / 2400 },
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{ B4800, UART_FREQ / 4800 },
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{ B9600, UART_FREQ / 9600 },
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{ B19200, UART_FREQ / 19200 },
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#if defined(__i386__)
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{ B38400, UART_FREQ / 38400 },
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{ B57600, UART_FREQ / 57600 },
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{ B115200, UART_FREQ / 115200L },
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#endif
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};
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struct speed2divisor *s2dp;
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/* RS232 needs to know the xoff character, and if CTS works. */
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rs->oxoff = tp->tty_termios.c_cc[VSTOP];
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rs->cts = (tp->tty_termios.c_cflag & CLOCAL) ? MS_CTS : 0;
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/* Look up the 8250 rate divisor from the output speed. */
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divisor = 0;
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for (s2dp = s2d; s2dp < s2d + sizeof(s2d)/sizeof(s2d[0]); s2dp++) {
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if (s2dp->speed == tp->tty_termios.c_ospeed) divisor = s2dp->divisor;
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}
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if (divisor == 0) return; /* B0? */
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/* Compute line control flag bits. */
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line_controls = 0;
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if (tp->tty_termios.c_cflag & PARENB) {
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line_controls |= LC_PARITY;
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if (!(tp->tty_termios.c_cflag & PARODD)) line_controls |= LC_PAREVEN;
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}
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if (divisor >= (UART_FREQ / 110)) line_controls |= LC_2STOP_BITS;
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line_controls |= (tp->tty_termios.c_cflag & CSIZE) >> 2;
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/* Select the baud rate divisor registers and change the rate. */
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sys_outb(rs->line_ctl_port, LC_ADDRESS_DIVISOR);
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sys_outb(rs->div_low_port, divisor);
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sys_outb(rs->div_hi_port, divisor >> 8);
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/* Change the line controls and reselect the usual registers. */
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sys_outb(rs->line_ctl_port, line_controls);
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rs->ostate = devready(rs) | ORAW | OSWREADY; /* reads modem_ctl_port */
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if ((tp->tty_termios.c_lflag & IXON) && rs->oxoff != _POSIX_VDISABLE)
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rs->ostate &= ~ORAW;
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}
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/*===========================================================================*
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* rs_init *
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*===========================================================================*/
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void rs_init(tty_t *tp)
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/* tp which TTY */
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{
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u32_t dummy;
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/* Initialize RS232 for one line. */
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register rs232_t *rs;
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int line;
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port_t this_8250;
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int s, irq;
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char l[10];
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/* Associate RS232 and TTY structures. */
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line = tp - &tty_table[NR_CONS];
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/* See if kernel debugging is enabled; if so, don't initialize this
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* serial line, making tty not look at the irq and returning ENXIO
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* for all requests on it from userland. (The kernel will use it.)
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*/
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if(env_get_param(SERVARNAME, l, sizeof(l)-1) == OK && atoi(l) == line) {
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printf("TTY: not initializing rs232 line %d (in use by kernel)\n",
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line);
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return;
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}
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rs = tp->tty_priv = &rs_lines[line];
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rs->tty = tp;
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/* Set up input queue. */
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rs->ihead = rs->itail = rs->ibuf;
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/* Precalculate port numbers for speed. Magic numbers in the code (once). */
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this_8250 = addr_8250[line];
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rs->xmit_port = this_8250 + 0;
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rs->recv_port = this_8250 + 0;
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rs->div_low_port = this_8250 + 0;
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rs->div_hi_port = this_8250 + 1;
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rs->int_enab_port = this_8250 + 1;
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rs->int_id_port = this_8250 + 2;
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rs->line_ctl_port = this_8250 + 3;
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rs->modem_ctl_port = this_8250 + 4;
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rs->line_status_port = this_8250 + 5;
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rs->modem_status_port = this_8250 + 6;
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/* Set up the hardware to a base state, in particular
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* o turn off DTR (MC_DTR) to try to stop the external device.
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* o be careful about the divisor latch. Some BIOS's leave it enabled
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* here and that caused trouble (no interrupts) in version 1.5 by
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* hiding the interrupt enable port in the next step, and worse trouble
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|
* (continual interrupts) in an old version by hiding the receiver
|
|
* port in the first interrupt. Call rs_ioctl() early to avoid this.
|
|
* o disable interrupts at the chip level, to force an edge transition
|
|
* on the 8259 line when interrupts are next enabled and active.
|
|
* RS232 interrupts are guaranteed to be disabled now by the 8259
|
|
* mask, but there used to be trouble if the mask was set without
|
|
* handling a previous interrupt.
|
|
*/
|
|
istop(rs); /* sets modem_ctl_port */
|
|
rs_config(rs);
|
|
sys_outb(rs->int_enab_port, 0);
|
|
|
|
/* Clear any harmful leftover interrupts. An output interrupt is harmless
|
|
* and will occur when interrupts are enabled anyway. Set up the output
|
|
* queue using the status from clearing the modem status interrupt.
|
|
*/
|
|
if ((s = sys_inb(rs->line_status_port, &dummy)) != OK)
|
|
printf("TTY: sys_inb() failed: %d", s);
|
|
if ((s = sys_inb(rs->recv_port, &dummy)) != OK)
|
|
printf("TTY: sys_inb() failed: %d", s);
|
|
rs->ostate = devready(rs) | ORAW | OSWREADY; /* reads modem_ctl_port */
|
|
rs->ohead = rs->otail = rs->obuf;
|
|
|
|
/* Enable interrupts for both interrupt controller and device. */
|
|
irq = (line & 1) == 0 ? RS232_IRQ : SECONDARY_IRQ;
|
|
|
|
rs->irq = irq;
|
|
rs->irq_hook_id = rs->irq; /* call back with irq line number */
|
|
if (sys_irqsetpolicy(irq, IRQ_REENABLE, &rs->irq_hook_id) != OK) {
|
|
printf("RS232: Couldn't obtain hook for irq %d\n", irq);
|
|
} else {
|
|
if (sys_irqenable(&rs->irq_hook_id) != OK) {
|
|
printf("RS232: Couldn't enable irq %d (hooked)\n", irq);
|
|
}
|
|
}
|
|
|
|
rs_irq_set |= (1 << irq);
|
|
|
|
sys_outb(rs->int_enab_port, IE_LINE_STATUS_CHANGE | IE_MODEM_STATUS_CHANGE
|
|
| IE_RECEIVER_READY | IE_TRANSMITTER_READY);
|
|
|
|
/* Fill in TTY function hooks. */
|
|
tp->tty_devread = rs_read;
|
|
tp->tty_devwrite = rs_write;
|
|
tp->tty_echo = rs_echo;
|
|
tp->tty_icancel = rs_icancel;
|
|
tp->tty_ocancel = rs_ocancel;
|
|
tp->tty_ioctl = rs_ioctl;
|
|
tp->tty_break = rs_break;
|
|
tp->tty_close = rs_close;
|
|
|
|
/* Tell external device we are ready. */
|
|
istart(rs);
|
|
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rs_interrupt *
|
|
*===========================================================================*/
|
|
void rs_interrupt(message *m)
|
|
{
|
|
unsigned long irq_set;
|
|
int i;
|
|
rs232_t *rs;
|
|
|
|
irq_set= m->NOTIFY_ARG;
|
|
for (i= 0, rs = rs_lines; i<NR_RS_LINES; i++, rs++)
|
|
{
|
|
if (irq_set & (1 << rs->irq))
|
|
rs232_handler(rs);
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rs_icancel *
|
|
*===========================================================================*/
|
|
static int rs_icancel(tty_t *tp, int UNUSED(dummy))
|
|
{
|
|
/* Cancel waiting input. */
|
|
rs232_t *rs = tp->tty_priv;
|
|
|
|
rs->icount = 0;
|
|
rs->itail = rs->ihead;
|
|
istart(rs);
|
|
|
|
return 0; /* dummy */
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rs_ocancel *
|
|
*===========================================================================*/
|
|
static int rs_ocancel(tty_t *tp, int UNUSED(dummy))
|
|
{
|
|
/* Cancel pending output. */
|
|
rs232_t *rs = tp->tty_priv;
|
|
|
|
rs->ostate &= ~(ODONE | OQUEUED);
|
|
rs->ocount = 0;
|
|
rs->otail = rs->ohead;
|
|
|
|
return 0; /* dummy */
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rs_read *
|
|
*===========================================================================*/
|
|
static int rs_read(tty_t *tp, int try)
|
|
{
|
|
/* Process characters from the circular input buffer. */
|
|
|
|
rs232_t *rs = tp->tty_priv;
|
|
int icount, count, ostate;
|
|
|
|
if (!(tp->tty_termios.c_cflag & CLOCAL)) {
|
|
if (try) return 1;
|
|
/* Send a SIGHUP if hangup detected. */
|
|
ostate = rs->ostate;
|
|
rs->ostate &= ~ODEVHUP; /* save ostate, clear DEVHUP */
|
|
if (ostate & ODEVHUP) {
|
|
sigchar(tp, SIGHUP, 1);
|
|
tp->tty_termios.c_ospeed = B0; /* Disable further I/O. */
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (try) {
|
|
if (rs->icount > 0)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
while ((count = rs->icount) > 0) {
|
|
icount = bufend(rs->ibuf) - rs->itail;
|
|
if (count > icount) count = icount;
|
|
|
|
/* Perform input processing on (part of) the input buffer. */
|
|
if ((count = in_process(tp, rs->itail, count, -1)) == 0) break;
|
|
|
|
rs->icount -= count;
|
|
if (!rs->idevready && rs->icount < RS_ILOWWATER) istart(rs);
|
|
if ((rs->itail += count) == bufend(rs->ibuf)) rs->itail = rs->ibuf;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rs_ostart *
|
|
*===========================================================================*/
|
|
static void rs_ostart(rs232_t *rs)
|
|
{
|
|
/* Tell RS232 there is something waiting in the output buffer. */
|
|
|
|
rs->ostate |= OQUEUED;
|
|
if (txready(rs)) out_int(rs);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rs_break *
|
|
*===========================================================================*/
|
|
static int rs_break(tty_t *tp, int UNUSED(dummy))
|
|
{
|
|
/* Generate a break condition by setting the BREAK bit for 0.4 sec. */
|
|
rs232_t *rs = tp->tty_priv;
|
|
u32_t line_controls;
|
|
int s;
|
|
|
|
if ((s = sys_inb(rs->line_ctl_port, &line_controls)) != OK)
|
|
printf("TTY: sys_inb() failed: %d", s);
|
|
sys_outb(rs->line_ctl_port, line_controls | LC_BREAK);
|
|
/* XXX */
|
|
/* milli_delay(400); */ /* ouch */
|
|
printf("RS232 break\n");
|
|
sys_outb(rs->line_ctl_port, line_controls);
|
|
return 0; /* dummy */
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* rs_close *
|
|
*===========================================================================*/
|
|
static int rs_close(tty_t *tp, int UNUSED(dummy))
|
|
{
|
|
/* The line is closed; optionally hang up. */
|
|
rs232_t *rs = tp->tty_priv;
|
|
|
|
if (tp->tty_termios.c_cflag & HUPCL) {
|
|
sys_outb(rs->modem_ctl_port, MC_OUT2 | MC_RTS);
|
|
}
|
|
return 0; /* dummy */
|
|
}
|
|
|
|
/* Low level (interrupt) routines. */
|
|
|
|
/*===========================================================================*
|
|
* rs232_handler *
|
|
*===========================================================================*/
|
|
static void rs232_handler(struct rs232 *rs)
|
|
{
|
|
/* Interrupt hander for RS232. */
|
|
int s;
|
|
|
|
while (TRUE) {
|
|
u32_t v;
|
|
/* Loop to pick up ALL pending interrupts for device.
|
|
* This usually just wastes time unless the hardware has a buffer
|
|
* (and then we have to worry about being stuck in the loop too long).
|
|
* Unfortunately, some serial cards lock up without this.
|
|
*/
|
|
if ((s = sys_inb(rs->int_id_port, &v)) != OK)
|
|
printf("TTY: sys_inb() failed: %d", s);
|
|
switch (v) {
|
|
case IS_RECEIVER_READY:
|
|
in_int(rs);
|
|
continue;
|
|
case IS_TRANSMITTER_READY:
|
|
out_int(rs);
|
|
continue;
|
|
case IS_MODEM_STATUS_CHANGE:
|
|
modem_int(rs);
|
|
continue;
|
|
case IS_LINE_STATUS_CHANGE:
|
|
line_int(rs);
|
|
continue;
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* in_int *
|
|
*===========================================================================*/
|
|
static void in_int(register rs232_t *rs)
|
|
/* rs line with input interrupt */
|
|
{
|
|
/* Read the data which just arrived.
|
|
* If it is the oxoff char, clear OSWREADY, else if OSWREADY was clear, set
|
|
* it and restart output (any char does this, not just xon).
|
|
* Put data in the buffer if room, otherwise discard it.
|
|
* Set a flag for the clock interrupt handler to eventually notify TTY.
|
|
*/
|
|
int s;
|
|
u32_t c;
|
|
|
|
#if 0 /* Enable this if you want serial input in the kernel */
|
|
return;
|
|
#endif
|
|
|
|
if ((s = sys_inb(rs->recv_port, &c)) != OK)
|
|
printf("TTY: sys_inb() failed: %d", s);
|
|
|
|
if (!(rs->ostate & ORAW)) {
|
|
if (c == rs->oxoff) {
|
|
rs->ostate &= ~OSWREADY;
|
|
} else
|
|
if (!(rs->ostate & OSWREADY)) {
|
|
rs->ostate |= OSWREADY;
|
|
if (txready(rs)) out_int(rs);
|
|
}
|
|
}
|
|
|
|
if (rs->icount == buflen(rs->ibuf))
|
|
{
|
|
printf("in_int: discarding byte\n");
|
|
return; /* input buffer full, discard */
|
|
}
|
|
|
|
if (++rs->icount == RS_IHIGHWATER && rs->idevready) istop(rs);
|
|
*rs->ihead = c;
|
|
if (++rs->ihead == bufend(rs->ibuf)) rs->ihead = rs->ibuf;
|
|
if (rs->icount == 1) {
|
|
rs->tty->tty_events = 1;
|
|
force_timeout();
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* line_int *
|
|
*===========================================================================*/
|
|
static void line_int(register rs232_t *rs)
|
|
/* rs line with line status interrupt */
|
|
{
|
|
/* Check for and record errors. */
|
|
int r;
|
|
u32_t s;
|
|
|
|
if ((r = sys_inb(rs->line_status_port, &s)) != OK)
|
|
printf("TTY: sys_inb() failed: %d", r);
|
|
rs->lstatus = s;
|
|
if (rs->lstatus & LS_FRAMING_ERR) ++rs->framing_errors;
|
|
if (rs->lstatus & LS_OVERRUN_ERR) ++rs->overrun_errors;
|
|
if (rs->lstatus & LS_PARITY_ERR) ++rs->parity_errors;
|
|
if (rs->lstatus & LS_BREAK_INTERRUPT) ++rs->break_interrupts;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* modem_int *
|
|
*===========================================================================*/
|
|
static void modem_int(register rs232_t *rs)
|
|
/* rs line with modem interrupt */
|
|
{
|
|
/* Get possibly new device-ready status, and clear ODEVREADY if necessary.
|
|
* If the device just became ready, restart output.
|
|
*/
|
|
|
|
if (devhup(rs)) {
|
|
rs->ostate |= ODEVHUP;
|
|
rs->tty->tty_events = 1;
|
|
force_timeout();
|
|
}
|
|
|
|
if (!devready(rs))
|
|
rs->ostate &= ~ODEVREADY;
|
|
else if (!(rs->ostate & ODEVREADY)) {
|
|
rs->ostate |= ODEVREADY;
|
|
if (txready(rs)) out_int(rs);
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* out_int *
|
|
*===========================================================================*/
|
|
static void out_int(register rs232_t *rs)
|
|
/* rs; line with output interrupt */
|
|
{
|
|
/* If there is output to do and everything is ready, do it (local device is
|
|
* known ready).
|
|
* Notify TTY when the buffer goes empty.
|
|
*/
|
|
|
|
if (rs->ostate >= (ODEVREADY | OQUEUED | OSWREADY)) {
|
|
/* Bit test allows ORAW and requires the others. */
|
|
sys_outb(rs->xmit_port, *rs->otail);
|
|
if (++rs->otail == bufend(rs->obuf)) rs->otail = rs->obuf;
|
|
if (--rs->ocount == 0) {
|
|
rs->ostate ^= (ODONE | OQUEUED); /* ODONE on, OQUEUED off */
|
|
rs->tty->tty_events = 1;
|
|
force_timeout();
|
|
} else
|
|
if (rs->ocount == RS_OLOWWATER) { /* running low? */
|
|
rs->tty->tty_events = 1;
|
|
force_timeout();
|
|
}
|
|
}
|
|
}
|
|
#endif /* NR_RS_LINES > 0 */
|
|
|