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Diffstat (limited to 'sys-utils/lp.h')
| -rw-r--r-- | sys-utils/lp.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/sys-utils/lp.h b/sys-utils/lp.h new file mode 100644 index 000000000..7fa83dde2 --- /dev/null +++ b/sys-utils/lp.h @@ -0,0 +1,83 @@ +/* Line printer stuff mostly follows the original Centronics printers. See + IEEE Std.1284-1994 Standard Signaling Method for a Bi-directional Parallel + Peripheral Interface for Personal Computers for 5 modes of data transfer. */ + +/* Parallel port registers: data (0x3bc, 0x378, 0x278), status=data+1, control=data+2 */ + +/* Parallel port status register (read only): +bit 7: NBSY (1: ready, 0: busy or error or off-line) +bit 6: NACK (if NBSY=1, then 1; if NBSY=0 then 1: sending data, 0: ready with data) +bit 5: PAP (1: out-of-paper) +bit 4: OFON (1: on-line) +bit 3: NFEH (1: OK, 0: printer error) +bits 2-0: 07 + +On out-of-paper: PAP=1, OFON=0, NFEH=1. + +"When reading the busy status, read twice in a row and use the value +obtained from the second read. This improves the reliability on some +parallel ports when the busy line may not be connected and is floating." +"On some Okidata printers when the busy signal switches from high to low, +the printer sends a 50 ns glitch on the paper out signal line. Before +declaring a paper out condition, check the status again." +(The Undocumented PC, F. van Gilluwe, p. 711) +*/ + +/* Parallel port control register (read/write): +bit 4: IRQ (1: we want an interrupt when NACK goes from 1 to 0) +bit 3: DSL (1: activate printer) +bit 2: NINI (0: initialise printer) +bit 1: ALF (1: printer performs automatic linefeed after each line) +bit 0: STR (0->1: generate a Strobe pulse: transport data to printer) +*/ + +/* Parallel port timing: + 1. wait for NBSY=1 + 2. outb(data byte, data port) + 3. wait for at least 0.5us + 4. read control port, OR with STR=0x1, output to control port - purpose: + generate strobe pulse; this will make the busy line go high + 5. wait for at least 0.5us + 6. read control port, AND with !STR, output to control port + 7. wait for at least 0.5us + 8. in a loop: read status register until NACK bit is 0 or NBSY=1 + (the printer will keep NACK=0 for at least 0.5us, then NACK=NBSY=1). +*/ + + +/* lp ioctls */ +#define LPCHAR 0x0601 /* specify the number of times we ask for the status + (waiting for ready) before giving up with a timeout + The duration may mainly depend on the timing of an inb. */ +#define LPTIME 0x0602 /* time to sleep after each timeout (in units of 0.01 sec) */ +#define LPABORT 0x0604 /* call with TRUE arg to abort on error, + FALSE to retry. Default is retry. */ +#define LPSETIRQ 0x0605 /* call with new IRQ number, + or 0 for polling (no IRQ) */ +#define LPGETIRQ 0x0606 /* get the current IRQ number */ +#define LPWAIT 0x0608 /* #of loops to wait before taking strobe high */ +#define LPCAREFUL 0x0609 /* call with TRUE arg to require out-of-paper, off- + line, and error indicators good on all writes, + FALSE to ignore them. Default is ignore. */ +#define LPABORTOPEN 0x060a /* call with TRUE arg to abort open() on error, + FALSE to ignore error. Default is ignore. */ +#define LPGETSTATUS 0x060b /* return LP_S(minor) */ +#define LPRESET 0x060c /* reset printer */ +#define LPGETFLAGS 0x060e /* get status flags */ + +#define LPSTRICT 0x060f /* enable/disable strict compliance (2.0.36) */ + /* Strict: wait until !READY before taking strobe low; + this may be bad for the Epson Stylus 800. + Not strict: wait a constant time as given by LPWAIT */ +#define LPTRUSTIRQ 0x060f /* set/unset the LP_TRUST_IRQ flag (2.1.131) */ + +/* + * bit defines for 8255 status port + * base + 1 + * accessed with LP_S(minor), which gets the byte... + */ +#define LP_PBUSY 0x80 /* inverted input, active high */ +#define LP_PACK 0x40 /* unchanged input, active low */ +#define LP_POUTPA 0x20 /* unchanged input, active high */ +#define LP_PSELECD 0x10 /* unchanged input, active high */ +#define LP_PERRORP 0x08 /* unchanged input, active low */ |