425 lines
15 KiB
C
425 lines
15 KiB
C
/* This file contains the printer driver. It is a fairly simple driver,
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* supporting only one printer. Characters that are written to the driver
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* are written to the printer without any changes at all.
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*
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* Changes:
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* May 07, 2004 fix: wait until printer is ready (Jorrit N. Herder)
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* May 06, 2004 printer driver moved to user-space (Jorrit N. Herder)
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*
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* The valid messages and their parameters are:
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*
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* DEV_OPEN: initializes the printer
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* DEV_CLOSE: does nothing
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* HARD_INT: interrupt handler has finished current chunk of output
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* DEV_WRITE: a process wants to write on a terminal
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* CANCEL: terminate a previous incomplete system call immediately
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*
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* m_type TTY_LINE PROC_NR COUNT ADDRESS
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* |-------------+---------+---------+---------+---------|
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* | DEV_OPEN | | | | |
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* |-------------+---------+---------+---------+---------|
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* | DEV_CLOSE | | proc nr | | |
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* -------------------------------------------------------
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* | HARD_INT | | | | |
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* |-------------+---------+---------+---------+---------|
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* | SYS_EVENT | | | | |
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* |-------------+---------+---------+---------+---------|
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* | DEV_WRITE |minor dev| proc nr | count | buf ptr |
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* |-------------+---------+---------+---------+---------|
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* | CANCEL |minor dev| proc nr | | |
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* -------------------------------------------------------
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*
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* Note: since only 1 printer is supported, minor dev is not used at present.
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*/
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#include "../drivers.h"
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/* Control bits (in port_base + 2). "+" means positive logic and "-" means
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* negative logic. Most of the signals are negative logic on the pins but
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* many are converted to positive logic in the ports. Some manuals are
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* misleading because they only document the pin logic.
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*
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* +0x01 Pin 1 -Strobe
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* +0x02 Pin 14 -Auto Feed
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* -0x04 Pin 16 -Initialize Printer
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* +0x08 Pin 17 -Select Printer
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* +0x10 IRQ7 Enable
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*
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* Auto Feed and Select Printer are always enabled. Strobe is enabled briefly
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* when characters are output. Initialize Printer is enabled briefly when
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* the task is started. IRQ7 is enabled when the first character is output
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* and left enabled until output is completed (or later after certain
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* abnormal completions).
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*/
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#define ASSERT_STROBE 0x1D /* strobe a character to the interface */
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#define NEGATE_STROBE 0x1C /* enable interrupt on interface */
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#define PR_SELECT 0x0C /* select printer bit */
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#define INIT_PRINTER 0x08 /* init printer bits */
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/* Status bits (in port_base + 2).
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*
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* -0x08 Pin 15 -Error
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* +0x10 Pin 13 +Select Status
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* +0x20 Pin 12 +Out of Paper
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* -0x40 Pin 10 -Acknowledge
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* -0x80 Pin 11 +Busy
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*/
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#define BUSY_STATUS 0x10 /* printer gives this status when busy */
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#define NO_PAPER 0x20 /* status bit saying that paper is out */
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#define NORMAL_STATUS 0x90 /* printer gives this status when idle */
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#define ON_LINE 0x10 /* status bit saying that printer is online */
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#define STATUS_MASK 0xB0 /* mask to filter out status bits */
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#define MAX_ONLINE_RETRIES 120 /* about 60s: waits 0.5s after each retry */
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/* Centronics interface timing that must be met by software (in microsec).
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*
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* Strobe length: 0.5u to 100u (not sure about the upper limit).
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* Data set up: 0.5u before strobe.
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* Data hold: 0.5u after strobe.
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* Init pulse length: over 200u (not sure).
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*
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* The strobe length is about 50u with the code here and function calls for
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* sys_outb() - not much to spare. The 0.5u minimums will not be violated
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* with the sys_outb() messages exchanged.
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*/
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PRIVATE int caller; /* process to tell when printing done (FS) */
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PRIVATE int revive_pending; /* set to true if revive is pending */
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PRIVATE int revive_status; /* revive status */
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PRIVATE int done_status; /* status of last output completion */
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PRIVATE int oleft; /* bytes of output left in obuf */
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PRIVATE char obuf[128]; /* output buffer */
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PRIVATE char *optr; /* ptr to next char in obuf to print */
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PRIVATE int orig_count; /* original byte count */
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PRIVATE int port_base; /* I/O port for printer */
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PRIVATE int proc_nr; /* user requesting the printing */
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PRIVATE int user_left; /* bytes of output left in user buf */
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PRIVATE vir_bytes user_vir; /* address of remainder of user buf */
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PRIVATE int writing; /* nonzero while write is in progress */
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PRIVATE int irq_hook_id; /* id of irq hook at kernel */
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extern int errno; /* error number */
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FORWARD _PROTOTYPE( void do_cancel, (message *m_ptr) );
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FORWARD _PROTOTYPE( void output_done, (void) );
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FORWARD _PROTOTYPE( void do_write, (message *m_ptr) );
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FORWARD _PROTOTYPE( void do_status, (message *m_ptr) );
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FORWARD _PROTOTYPE( void prepare_output, (void) );
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FORWARD _PROTOTYPE( void do_initialize, (void) );
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FORWARD _PROTOTYPE( void reply, (int code,int replyee,int proc,int status));
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FORWARD _PROTOTYPE( void do_printer_output, (void) );
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FORWARD _PROTOTYPE( void signal_handler, (int sig) );
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/*===========================================================================*
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* signal_handler *
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*===========================================================================*/
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PRIVATE void signal_handler(sig)
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int sig; /* signal number */
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{
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/* Expect a SIGTERM signal when this server must shutdown. */
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if (sig == SIGTERM) {
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printf("Shutting down PRINTER driver\n");
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exit(0);
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} else {
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printf("PRINTER got unknown signal\n");
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}
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}
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/*===========================================================================*
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* printer_task *
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*===========================================================================*/
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PUBLIC void main(void)
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{
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/* Main routine of the printer task. */
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message pr_mess; /* buffer for all incoming messages */
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while (TRUE) {
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receive(ANY, &pr_mess);
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switch(pr_mess.m_type) {
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case DEV_OPEN:
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do_initialize(); /* initialize */
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/* fall through */
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case DEV_CLOSE:
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reply(TASK_REPLY, pr_mess.m_source, pr_mess.PROC_NR, OK);
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break;
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case DEV_WRITE: do_write(&pr_mess); break;
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case DEV_STATUS: do_status(&pr_mess); break;
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case CANCEL: do_cancel(&pr_mess); break;
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case HARD_INT: do_printer_output(); break;
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case SYS_SIG: /* do nothing */ break;
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default:
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reply(TASK_REPLY, pr_mess.m_source, pr_mess.PROC_NR, EINVAL);
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}
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}
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}
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/*===========================================================================*
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* do_write *
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*===========================================================================*/
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PRIVATE void do_write(m_ptr)
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register message *m_ptr; /* pointer to the newly arrived message */
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{
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/* The printer is used by sending DEV_WRITE messages to it. Process one. */
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register int r = SUSPEND;
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int retries;
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int status;
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/* Reject command if last write is not yet finished, the count is not
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* positive, or the user address is bad.
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*/
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if (writing) r = EIO;
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else if (m_ptr->COUNT <= 0) r = EINVAL;
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/* Reply to FS, no matter what happened, possible SUSPEND caller. */
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reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, r);
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/* If no errors occurred, continue printing with SUSPENDED caller.
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* First wait until the printer is online to prevent stupid errors.
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*/
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if (SUSPEND == r) {
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caller = m_ptr->m_source;
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proc_nr = m_ptr->PROC_NR;
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user_left = m_ptr->COUNT;
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orig_count = m_ptr->COUNT;
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user_vir = (vir_bytes) m_ptr->ADDRESS;
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writing = TRUE;
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retries = MAX_ONLINE_RETRIES + 1;
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while (--retries > 0) {
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sys_inb(port_base + 1, &status);
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if ((status & ON_LINE)) { /* printer online! */
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prepare_output();
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do_printer_output();
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return;
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}
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tickdelay(30); /* wait before retry */
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}
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/* If we reach this point, the printer was not online in time. */
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done_status = status;
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output_done();
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}
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}
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/*===========================================================================*
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* output_done *
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*===========================================================================*/
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PRIVATE void output_done()
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{
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/* Previous chunk of printing is finished. Continue if OK and more.
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* Otherwise, reply to caller (FS).
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*/
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register int status;
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if (!writing) return; /* probably leftover interrupt */
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if (done_status != OK) { /* printer error occurred */
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status = EIO;
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if ((done_status & ON_LINE) == 0) {
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printf("Printer is not on line\n");
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} else if ((done_status & NO_PAPER)) {
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printf("Printer is out of paper\n");
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status = EAGAIN;
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} else {
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printf("Printer error, status is 0x%02X\n", done_status);
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}
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/* Some characters have been printed, tell how many. */
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if (status == EAGAIN && user_left < orig_count) {
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status = orig_count - user_left;
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}
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oleft = 0; /* cancel further output */
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}
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else if (user_left != 0) { /* not yet done, continue! */
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prepare_output();
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return;
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}
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else { /* done! report back to FS */
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status = orig_count;
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}
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#if DEAD_CODE
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reply(REVIVE, caller, proc_nr, status);
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writing = FALSE;
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#else
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revive_pending = TRUE;
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revive_status = status;
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notify(caller);
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#endif
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}
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/*===========================================================================*
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* do_status *
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*===========================================================================*/
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PRIVATE void do_status(m_ptr)
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register message *m_ptr; /* pointer to the newly arrived message */
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{
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if (revive_pending) {
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m_ptr->m_type = DEV_REVIVE; /* build message */
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m_ptr->REP_PROC_NR = proc_nr;
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m_ptr->REP_STATUS = revive_status;
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writing = FALSE; /* unmark event */
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revive_pending = FALSE; /* unmark event */
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} else {
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m_ptr->m_type = DEV_NO_STATUS;
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}
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send(m_ptr->m_source, m_ptr); /* send the message */
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}
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/*===========================================================================*
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* do_cancel *
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*===========================================================================*/
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PRIVATE void do_cancel(m_ptr)
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register message *m_ptr; /* pointer to the newly arrived message */
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{
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/* Cancel a print request that has already started. Usually this means that
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* the process doing the printing has been killed by a signal. It is not
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* clear if there are race conditions. Try not to cancel the wrong process,
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* but rely on FS to handle the EINTR reply and de-suspension properly.
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*/
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if (writing && m_ptr->PROC_NR == proc_nr) {
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oleft = 0; /* cancel output by interrupt handler */
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writing = FALSE;
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revive_pending = FALSE;
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}
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reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, EINTR);
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}
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/*===========================================================================*
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* reply *
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*===========================================================================*/
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PRIVATE void reply(code, replyee, process, status)
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int code; /* TASK_REPLY or REVIVE */
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int replyee; /* destination for message (normally FS) */
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int process; /* which user requested the printing */
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int status; /* number of chars printed or error code */
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{
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/* Send a reply telling FS that printing has started or stopped. */
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message pr_mess;
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pr_mess.m_type = code; /* TASK_REPLY or REVIVE */
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pr_mess.REP_STATUS = status; /* count or EIO */
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pr_mess.REP_PROC_NR = process; /* which user does this pertain to */
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send(replyee, &pr_mess); /* send the message */
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}
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/*===========================================================================*
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* do_initialize *
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*===========================================================================*/
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PRIVATE void do_initialize()
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{
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/* Set global variables and initialize the printer. */
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static int initialized = FALSE;
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if (initialized) return;
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initialized = TRUE;
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/* Get the base port for first printer. */
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sys_vircopy(SELF, BIOS_SEG, LPT1_IO_PORT_ADDR,
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SELF, D, (vir_bytes) &port_base, LPT1_IO_PORT_SIZE);
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sys_outb(port_base + 2, INIT_PRINTER);
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tickdelay(1); /* easily satisfies Centronics minimum */
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/* was 2 millisecs; now is ~17 millisecs */
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sys_outb(port_base + 2, PR_SELECT);
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irq_hook_id = 0;
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sys_irqsetpolicy(PRINTER_IRQ, 0, &irq_hook_id);
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sys_irqenable(&irq_hook_id);
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}
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/*==========================================================================*
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* prepare_output *
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*==========================================================================*/
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PRIVATE void prepare_output()
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{
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/* Start next chunk of printer output. Fetch the data from user space. */
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register int chunk;
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if ( (chunk = user_left) > sizeof obuf) chunk = sizeof obuf;
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if (OK!=sys_datacopy(proc_nr, user_vir, SELF, (vir_bytes) obuf, chunk)) {
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done_status = EFAULT;
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output_done();
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return;
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}
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optr = obuf;
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oleft = chunk;
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}
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/*===========================================================================*
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* do_printer_output *
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*===========================================================================*/
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PRIVATE void do_printer_output()
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{
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/* This function does the actual output to the printer. This is called on
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* a HARD_INT message sent from the generic interrupt handler that 'forwards'
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* interrupts to this driver. The generic handler did not reenable the
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* printer IRQ yet!
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*/
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int status;
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pvb_pair_t char_out[3];
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if (oleft == 0) {
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/* Nothing more to print. Turn off printer interrupts in case they
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* are level-sensitive as on the PS/2. This should be safe even
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* when the printer is busy with a previous character, because the
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* interrupt status does not affect the printer.
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*/
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sys_outb(port_base + 2, PR_SELECT);
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sys_irqenable(&irq_hook_id);
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return;
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}
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do {
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/* Loop to handle fast (buffered) printers. It is important that
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* processor interrupts are not disabled here, just printer interrupts.
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*/
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(void) sys_inb(port_base + 1, &status);
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if ((status & STATUS_MASK) == BUSY_STATUS) {
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/* Still busy with last output. This normally happens
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* immediately after doing output to an unbuffered or slow
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* printer. It may happen after a call from prepare_output or
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* pr_restart, since they are not synchronized with printer
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* interrupts. It may happen after a spurious interrupt.
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*/
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sys_irqenable(&irq_hook_id);
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return;
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}
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if ((status & STATUS_MASK) == NORMAL_STATUS) {
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/* Everything is all right. Output another character. */
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pv_set(char_out[0], port_base, *optr++);
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pv_set(char_out[1], port_base+2, ASSERT_STROBE);
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pv_set(char_out[2], port_base+2, NEGATE_STROBE);
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sys_voutb(char_out, 3); /* request series of port outb */
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user_vir++;
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user_left--;
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} else {
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/* Error. This would be better ignored (treat as busy). */
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done_status = status;
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output_done();
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sys_irqenable(&irq_hook_id);
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return;
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}
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}
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while (--oleft != 0);
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/* Finished printing chunk OK. */
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done_status = OK;
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output_done();
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sys_irqenable(&irq_hook_id);
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}
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