2 ** -----------------------------------------------------------------------------
4 ** Perle Specialix driver for Linux
5 ** Ported from existing RIO Driver for SCO sources.
7 * (C) 1990 - 2000 Specialix International Ltd., Byfleet, Surrey, UK.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 ** Module : rioparam.c
25 ** Last Modified : 11/6/98 10:33:45
26 ** Retrieved : 11/6/98 10:33:50
28 ** ident @(#)rioparam.c 1.3
30 ** -----------------------------------------------------------------------------
34 static char *_rioparam_c_sccs_
= "@(#)rioparam.c 1.3";
37 #include <linux/module.h>
38 #include <linux/slab.h>
39 #include <linux/errno.h>
40 #include <linux/tty.h>
42 #include <asm/system.h>
43 #include <asm/string.h>
44 #include <asm/uaccess.h>
46 #include <linux/termios.h>
47 #include <linux/serial.h>
49 #include <linux/generic_serial.h>
52 #include "linux_compat.h"
53 #include "rio_linux.h"
83 ** The Scam, based on email from jeremyr@bugs.specialix.co.uk....
85 ** To send a command on a particular port, you put a packet with the
86 ** command bit set onto the port. The command bit is in the len field,
87 ** and gets ORed in with the actual byte count.
89 ** When you send a packet with the command bit set the first
90 ** data byte (data[0]) is interpreted as the command to execute.
91 ** It also governs what data structure overlay should accompany the packet.
92 ** Commands are defined in cirrus/cirrus.h
94 ** If you want the command to pre-emt data already on the queue for the
95 ** port, set the pre-emptive bit in conjunction with the command bit.
96 ** It is not defined what will happen if you set the preemptive bit
97 ** on a packet that is NOT a command.
99 ** Pre-emptive commands should be queued at the head of the queue using
100 ** add_start(), whereas normal commands and data are enqueued using
103 ** Most commands do not use the remaining bytes in the data array. The
104 ** exceptions are OPEN MOPEN and CONFIG. (NB. As with the SI CONFIG and
105 ** OPEN are currently analogous). With these three commands the following
106 ** 11 data bytes are all used to pass config information such as baud rate etc.
107 ** The fields are also defined in cirrus.h. Some contain straightforward
108 ** information such as the transmit XON character. Two contain the transmit and
109 ** receive baud rates respectively. For most baud rates there is a direct
110 ** mapping between the rates defined in <sys/termio.h> and the byte in the
111 ** packet. There are additional (non UNIX-standard) rates defined in
112 ** /u/dos/rio/cirrus/h/brates.h.
114 ** The rest of the data fields contain approximations to the Cirrus registers
115 ** that are used to program number of bits etc. Each registers bit fields is
116 ** defined in cirrus.h.
118 ** NB. Only use those bits that are defined as being driver specific
119 ** or common to the RTA and the driver.
121 ** All commands going from RTA->Host will be dealt with by the Host code - you
122 ** will never see them. As with the SI there will be three fields to look out
123 ** for in each phb (not yet defined - needs defining a.s.a.p).
125 ** modem_status - current state of handshake pins.
127 ** port_status - current port status - equivalent to hi_stat for SI, indicates
128 ** if port is IDLE_OPEN, IDLE_CLOSED etc.
130 ** break_status - bit X set if break has been received.
137 ** RIOParam is used to open or configure a port. You pass it a PortP,
138 ** which will have a tty struct attached to it. You also pass a command,
139 ** either OPEN or CONFIG. The port's setup is taken from the t_ fields
140 ** of the tty struct inside the PortP, and the port is either opened
141 ** or re-configured. You must also tell RIOParam if the device is a modem
142 ** device or not (i.e. top bit of minor number set or clear - take special
143 ** care when deciding on this!).
144 ** RIOParam neither flushes nor waits for drain, and is NOT preemptive.
146 ** RIOParam assumes it will be called at splrio(), and also assumes
147 ** that CookMode is set correctly in the port structure.
150 ** tty lock must NOT have been previously acquired.
152 int RIOParam(struct Port
*PortP
, int cmd
, int Modem
, int SleepFlag
)
154 struct tty_struct
*TtyP
;
156 struct phb_param __iomem
*phb_param_ptr
;
157 struct PKT __iomem
*PacketP
;
159 u8 Cor1
= 0, Cor2
= 0, Cor4
= 0, Cor5
= 0;
160 u8 TxXon
= 0, TxXoff
= 0, RxXon
= 0, RxXoff
= 0;
161 u8 LNext
= 0, TxBaud
= 0, RxBaud
= 0;
167 TtyP
= PortP
->gs
.tty
;
169 rio_dprintk(RIO_DEBUG_PARAM
, "RIOParam: Port:%d cmd:%d Modem:%d SleepFlag:%d Mapped: %d, tty=%p\n", PortP
->PortNum
, cmd
, Modem
, SleepFlag
, PortP
->Mapped
, TtyP
);
172 rio_dprintk(RIO_DEBUG_PARAM
, "Can't call rioparam with null tty.\n");
178 rio_spin_lock_irqsave(&PortP
->portSem
, flags
);
180 if (cmd
== RIOC_OPEN
) {
182 ** If the port is set to store or lock the parameters, and it is
183 ** paramed with OPEN, we want to restore the saved port termio, but
184 ** only if StoredTermio has been saved, i.e. NOT 1st open after reboot.
191 while (!(res
= can_add_transmit(&PacketP
, PortP
)) || (PortP
->InUse
!= NOT_INUSE
)) {
192 if (retries
-- <= 0) {
195 if (PortP
->InUse
!= NOT_INUSE
) {
196 rio_dprintk(RIO_DEBUG_PARAM
, "Port IN_USE for pre-emptive command\n");
200 rio_dprintk(RIO_DEBUG_PARAM
, "Port has no space on transmit queue\n");
203 if (SleepFlag
!= OK_TO_SLEEP
) {
204 rio_spin_unlock_irqrestore(&PortP
->portSem
, flags
);
210 rio_dprintk(RIO_DEBUG_PARAM
, "wait for can_add_transmit\n");
211 rio_spin_unlock_irqrestore(&PortP
->portSem
, flags
);
212 retval
= RIODelay(PortP
, HUNDRED_MS
);
213 rio_spin_lock_irqsave(&PortP
->portSem
, flags
);
214 if (retval
== RIO_FAIL
) {
215 rio_dprintk(RIO_DEBUG_PARAM
, "wait for can_add_transmit broken by signal\n");
216 rio_spin_unlock_irqrestore(&PortP
->portSem
, flags
);
220 if (PortP
->State
& RIO_DELETED
) {
221 rio_spin_unlock_irqrestore(&PortP
->portSem
, flags
);
228 rio_spin_unlock_irqrestore(&PortP
->portSem
, flags
);
234 rio_dprintk(RIO_DEBUG_PARAM
, "can_add_transmit() returns %x\n", res
);
235 rio_dprintk(RIO_DEBUG_PARAM
, "Packet is %p\n", PacketP
);
237 phb_param_ptr
= (struct phb_param __iomem
*) PacketP
->data
;
240 switch (TtyP
->termios
->c_cflag
& CSIZE
) {
243 rio_dprintk(RIO_DEBUG_PARAM
, "5 bit data\n");
244 Cor1
|= RIOC_COR1_5BITS
;
249 rio_dprintk(RIO_DEBUG_PARAM
, "6 bit data\n");
250 Cor1
|= RIOC_COR1_6BITS
;
255 rio_dprintk(RIO_DEBUG_PARAM
, "7 bit data\n");
256 Cor1
|= RIOC_COR1_7BITS
;
261 rio_dprintk(RIO_DEBUG_PARAM
, "8 bit data\n");
262 Cor1
|= RIOC_COR1_8BITS
;
267 if (TtyP
->termios
->c_cflag
& CSTOPB
) {
268 rio_dprintk(RIO_DEBUG_PARAM
, "2 stop bits\n");
269 Cor1
|= RIOC_COR1_2STOP
;
271 rio_dprintk(RIO_DEBUG_PARAM
, "1 stop bit\n");
272 Cor1
|= RIOC_COR1_1STOP
;
275 if (TtyP
->termios
->c_cflag
& PARENB
) {
276 rio_dprintk(RIO_DEBUG_PARAM
, "Enable parity\n");
277 Cor1
|= RIOC_COR1_NORMAL
;
279 rio_dprintk(RIO_DEBUG_PARAM
, "Disable parity\n");
280 Cor1
|= RIOC_COR1_NOP
;
282 if (TtyP
->termios
->c_cflag
& PARODD
) {
283 rio_dprintk(RIO_DEBUG_PARAM
, "Odd parity\n");
284 Cor1
|= RIOC_COR1_ODD
;
286 rio_dprintk(RIO_DEBUG_PARAM
, "Even parity\n");
287 Cor1
|= RIOC_COR1_EVEN
;
293 if (TtyP
->termios
->c_iflag
& IXON
) {
294 rio_dprintk(RIO_DEBUG_PARAM
, "Enable start/stop output control\n");
295 Cor2
|= RIOC_COR2_IXON
;
297 if (PortP
->Config
& RIO_IXON
) {
298 rio_dprintk(RIO_DEBUG_PARAM
, "Force enable start/stop output control\n");
299 Cor2
|= RIOC_COR2_IXON
;
301 rio_dprintk(RIO_DEBUG_PARAM
, "IXON has been disabled.\n");
304 if (TtyP
->termios
->c_iflag
& IXANY
) {
305 if (PortP
->Config
& RIO_IXANY
) {
306 rio_dprintk(RIO_DEBUG_PARAM
, "Enable any key to restart output\n");
307 Cor2
|= RIOC_COR2_IXANY
;
309 rio_dprintk(RIO_DEBUG_PARAM
, "IXANY has been disabled due to sanity reasons.\n");
312 if (TtyP
->termios
->c_iflag
& IXOFF
) {
313 rio_dprintk(RIO_DEBUG_PARAM
, "Enable start/stop input control 2\n");
314 Cor2
|= RIOC_COR2_IXOFF
;
317 if (TtyP
->termios
->c_cflag
& HUPCL
) {
318 rio_dprintk(RIO_DEBUG_PARAM
, "Hangup on last close\n");
319 Cor2
|= RIOC_COR2_HUPCL
;
322 if (C_CRTSCTS(TtyP
)) {
323 rio_dprintk(RIO_DEBUG_PARAM
, "Rx hardware flow control enabled\n");
324 Cor2
|= RIOC_COR2_CTSFLOW
;
325 Cor2
|= RIOC_COR2_RTSFLOW
;
327 rio_dprintk(RIO_DEBUG_PARAM
, "Rx hardware flow control disabled\n");
328 Cor2
&= ~RIOC_COR2_CTSFLOW
;
329 Cor2
&= ~RIOC_COR2_RTSFLOW
;
333 if (TtyP
->termios
->c_cflag
& CLOCAL
) {
334 rio_dprintk(RIO_DEBUG_PARAM
, "Local line\n");
336 rio_dprintk(RIO_DEBUG_PARAM
, "Possible Modem line\n");
340 ** COR 4 (there is no COR 3)
342 if (TtyP
->termios
->c_iflag
& IGNBRK
) {
343 rio_dprintk(RIO_DEBUG_PARAM
, "Ignore break condition\n");
344 Cor4
|= RIOC_COR4_IGNBRK
;
346 if (!(TtyP
->termios
->c_iflag
& BRKINT
)) {
347 rio_dprintk(RIO_DEBUG_PARAM
, "Break generates NULL condition\n");
348 Cor4
|= RIOC_COR4_NBRKINT
;
350 rio_dprintk(RIO_DEBUG_PARAM
, "Interrupt on break condition\n");
353 if (TtyP
->termios
->c_iflag
& INLCR
) {
354 rio_dprintk(RIO_DEBUG_PARAM
, "Map newline to carriage return on input\n");
355 Cor4
|= RIOC_COR4_INLCR
;
358 if (TtyP
->termios
->c_iflag
& IGNCR
) {
359 rio_dprintk(RIO_DEBUG_PARAM
, "Ignore carriage return on input\n");
360 Cor4
|= RIOC_COR4_IGNCR
;
363 if (TtyP
->termios
->c_iflag
& ICRNL
) {
364 rio_dprintk(RIO_DEBUG_PARAM
, "Map carriage return to newline on input\n");
365 Cor4
|= RIOC_COR4_ICRNL
;
367 if (TtyP
->termios
->c_iflag
& IGNPAR
) {
368 rio_dprintk(RIO_DEBUG_PARAM
, "Ignore characters with parity errors\n");
369 Cor4
|= RIOC_COR4_IGNPAR
;
371 if (TtyP
->termios
->c_iflag
& PARMRK
) {
372 rio_dprintk(RIO_DEBUG_PARAM
, "Mark parity errors\n");
373 Cor4
|= RIOC_COR4_PARMRK
;
377 ** Set the RAISEMOD flag to ensure that the modem lines are raised
378 ** on reception of a config packet.
379 ** The download code handles the zero baud condition.
381 Cor4
|= RIOC_COR4_RAISEMOD
;
387 Cor5
= RIOC_COR5_CMOE
;
390 ** Set to monitor tbusy/tstop (or not).
393 if (PortP
->MonitorTstate
)
394 Cor5
|= RIOC_COR5_TSTATE_ON
;
396 Cor5
|= RIOC_COR5_TSTATE_OFF
;
399 ** Could set LNE here if you wanted LNext processing. SVR4 will use it.
401 if (TtyP
->termios
->c_iflag
& ISTRIP
) {
402 rio_dprintk(RIO_DEBUG_PARAM
, "Strip input characters\n");
403 if (!(PortP
->State
& RIO_TRIAD_MODE
)) {
404 Cor5
|= RIOC_COR5_ISTRIP
;
408 if (TtyP
->termios
->c_oflag
& ONLCR
) {
409 rio_dprintk(RIO_DEBUG_PARAM
, "Map newline to carriage-return, newline on output\n");
410 if (PortP
->CookMode
== COOK_MEDIUM
)
411 Cor5
|= RIOC_COR5_ONLCR
;
413 if (TtyP
->termios
->c_oflag
& OCRNL
) {
414 rio_dprintk(RIO_DEBUG_PARAM
, "Map carriage return to newline on output\n");
415 if (PortP
->CookMode
== COOK_MEDIUM
)
416 Cor5
|= RIOC_COR5_OCRNL
;
418 if ((TtyP
->termios
->c_oflag
& TABDLY
) == TAB3
) {
419 rio_dprintk(RIO_DEBUG_PARAM
, "Tab delay 3 set\n");
420 if (PortP
->CookMode
== COOK_MEDIUM
)
421 Cor5
|= RIOC_COR5_TAB3
;
425 ** Flow control bytes.
427 TxXon
= TtyP
->termios
->c_cc
[VSTART
];
428 TxXoff
= TtyP
->termios
->c_cc
[VSTOP
];
429 RxXon
= TtyP
->termios
->c_cc
[VSTART
];
430 RxXoff
= TtyP
->termios
->c_cc
[VSTOP
];
439 rio_dprintk(RIO_DEBUG_PARAM
, "Mapping of rx/tx baud %x (%x)\n", TtyP
->termios
->c_cflag
, CBAUD
);
441 switch (TtyP
->termios
->c_cflag
& CBAUD
) {
442 #define e(b) case B ## b : RxBaud = TxBaud = RIO_B ## b ;break
459 e(115200); /* e(230400);e(460800); e(921600); */
462 rio_dprintk(RIO_DEBUG_PARAM
, "tx baud 0x%x, rx baud 0x%x\n", TxBaud
, RxBaud
);
468 if (TtyP
->termios
->c_cflag
& CREAD
)
469 rio_dprintk(RIO_DEBUG_PARAM
, "Enable receiver\n");
471 if (TtyP
->termios
->c_cflag
& RCV1EN
)
472 rio_dprintk(RIO_DEBUG_PARAM
, "RCV1EN (?)\n");
475 if (TtyP
->termios
->c_cflag
& XMT1EN
)
476 rio_dprintk(RIO_DEBUG_PARAM
, "XMT1EN (?)\n");
478 if (TtyP
->termios
->c_lflag
& ISIG
)
479 rio_dprintk(RIO_DEBUG_PARAM
, "Input character signal generating enabled\n");
480 if (TtyP
->termios
->c_lflag
& ICANON
)
481 rio_dprintk(RIO_DEBUG_PARAM
, "Canonical input: erase and kill enabled\n");
482 if (TtyP
->termios
->c_lflag
& XCASE
)
483 rio_dprintk(RIO_DEBUG_PARAM
, "Canonical upper/lower presentation\n");
484 if (TtyP
->termios
->c_lflag
& ECHO
)
485 rio_dprintk(RIO_DEBUG_PARAM
, "Enable input echo\n");
486 if (TtyP
->termios
->c_lflag
& ECHOE
)
487 rio_dprintk(RIO_DEBUG_PARAM
, "Enable echo erase\n");
488 if (TtyP
->termios
->c_lflag
& ECHOK
)
489 rio_dprintk(RIO_DEBUG_PARAM
, "Enable echo kill\n");
490 if (TtyP
->termios
->c_lflag
& ECHONL
)
491 rio_dprintk(RIO_DEBUG_PARAM
, "Enable echo newline\n");
492 if (TtyP
->termios
->c_lflag
& NOFLSH
)
493 rio_dprintk(RIO_DEBUG_PARAM
, "Disable flush after interrupt or quit\n");
495 if (TtyP
->termios
->c_lflag
& TOSTOP
)
496 rio_dprintk(RIO_DEBUG_PARAM
, "Send SIGTTOU for background output\n");
499 if (TtyP
->termios
->c_lflag
& XCLUDE
)
500 rio_dprintk(RIO_DEBUG_PARAM
, "Exclusive use of this line\n");
502 if (TtyP
->termios
->c_iflag
& IUCLC
)
503 rio_dprintk(RIO_DEBUG_PARAM
, "Map uppercase to lowercase on input\n");
504 if (TtyP
->termios
->c_oflag
& OPOST
)
505 rio_dprintk(RIO_DEBUG_PARAM
, "Enable output post-processing\n");
506 if (TtyP
->termios
->c_oflag
& OLCUC
)
507 rio_dprintk(RIO_DEBUG_PARAM
, "Map lowercase to uppercase on output\n");
508 if (TtyP
->termios
->c_oflag
& ONOCR
)
509 rio_dprintk(RIO_DEBUG_PARAM
, "No carriage return output at column 0\n");
510 if (TtyP
->termios
->c_oflag
& ONLRET
)
511 rio_dprintk(RIO_DEBUG_PARAM
, "Newline performs carriage return function\n");
512 if (TtyP
->termios
->c_oflag
& OFILL
)
513 rio_dprintk(RIO_DEBUG_PARAM
, "Use fill characters for delay\n");
514 if (TtyP
->termios
->c_oflag
& OFDEL
)
515 rio_dprintk(RIO_DEBUG_PARAM
, "Fill character is DEL\n");
516 if (TtyP
->termios
->c_oflag
& NLDLY
)
517 rio_dprintk(RIO_DEBUG_PARAM
, "Newline delay set\n");
518 if (TtyP
->termios
->c_oflag
& CRDLY
)
519 rio_dprintk(RIO_DEBUG_PARAM
, "Carriage return delay set\n");
520 if (TtyP
->termios
->c_oflag
& TABDLY
)
521 rio_dprintk(RIO_DEBUG_PARAM
, "Tab delay set\n");
523 ** These things are kind of useful in a later life!
525 PortP
->Cor2Copy
= Cor2
;
527 if (PortP
->State
& RIO_DELETED
) {
528 rio_spin_unlock_irqrestore(&PortP
->portSem
, flags
);
535 ** Actually write the info into the packet to be sent
537 writeb(cmd
, &phb_param_ptr
->Cmd
);
538 writeb(Cor1
, &phb_param_ptr
->Cor1
);
539 writeb(Cor2
, &phb_param_ptr
->Cor2
);
540 writeb(Cor4
, &phb_param_ptr
->Cor4
);
541 writeb(Cor5
, &phb_param_ptr
->Cor5
);
542 writeb(TxXon
, &phb_param_ptr
->TxXon
);
543 writeb(RxXon
, &phb_param_ptr
->RxXon
);
544 writeb(TxXoff
, &phb_param_ptr
->TxXoff
);
545 writeb(RxXoff
, &phb_param_ptr
->RxXoff
);
546 writeb(LNext
, &phb_param_ptr
->LNext
);
547 writeb(TxBaud
, &phb_param_ptr
->TxBaud
);
548 writeb(RxBaud
, &phb_param_ptr
->RxBaud
);
551 ** Set the length/command field
553 writeb(12 | PKT_CMD_BIT
, &PacketP
->len
);
556 ** The packet is formed - now, whack it off
557 ** to its final destination:
561 ** Count characters transmitted for port statistics reporting
563 if (PortP
->statsGather
)
564 PortP
->txchars
+= 12;
566 rio_spin_unlock_irqrestore(&PortP
->portSem
, flags
);
568 rio_dprintk(RIO_DEBUG_PARAM
, "add_transmit returned.\n");
579 ** We can add another packet to a transmit queue if the packet pointer pointed
580 ** to by the TxAdd pointer has PKT_IN_USE clear in its address.
582 int can_add_transmit(struct PKT __iomem
**PktP
, struct Port
*PortP
)
584 struct PKT __iomem
*tp
;
586 *PktP
= tp
= (struct PKT __iomem
*) RIO_PTR(PortP
->Caddr
, readw(PortP
->TxAdd
));
588 return !((unsigned long) tp
& PKT_IN_USE
);
592 ** To add a packet to the queue, you set the PKT_IN_USE bit in the address,
593 ** and then move the TxAdd pointer along one position to point to the next
594 ** packet pointer. You must wrap the pointer from the end back to the start.
596 void add_transmit(struct Port
*PortP
)
598 if (readw(PortP
->TxAdd
) & PKT_IN_USE
) {
599 rio_dprintk(RIO_DEBUG_PARAM
, "add_transmit: Packet has been stolen!");
601 writew(readw(PortP
->TxAdd
) | PKT_IN_USE
, PortP
->TxAdd
);
602 PortP
->TxAdd
= (PortP
->TxAdd
== PortP
->TxEnd
) ? PortP
->TxStart
: PortP
->TxAdd
+ 1;
603 writew(RIO_OFF(PortP
->Caddr
, PortP
->TxAdd
), &PortP
->PhbP
->tx_add
);
606 /****************************************
607 * Put a packet onto the end of the
609 ****************************************/
610 void put_free_end(struct Host
*HostP
, struct PKT __iomem
*PktP
)
612 struct rio_free_list __iomem
*tmp_pointer
;
613 unsigned short old_end
, new_end
;
616 rio_spin_lock_irqsave(&HostP
->HostLock
, flags
);
618 /*************************************************
619 * Put a packet back onto the back of the free list
621 ************************************************/
623 rio_dprintk(RIO_DEBUG_PFE
, "put_free_end(PktP=%p)\n", PktP
);
625 if ((old_end
= readw(&HostP
->ParmMapP
->free_list_end
)) != TPNULL
) {
626 new_end
= RIO_OFF(HostP
->Caddr
, PktP
);
627 tmp_pointer
= (struct rio_free_list __iomem
*) RIO_PTR(HostP
->Caddr
, old_end
);
628 writew(new_end
, &tmp_pointer
->next
);
629 writew(old_end
, &((struct rio_free_list __iomem
*) PktP
)->prev
);
630 writew(TPNULL
, &((struct rio_free_list __iomem
*) PktP
)->next
);
631 writew(new_end
, &HostP
->ParmMapP
->free_list_end
);
632 } else { /* First packet on the free list this should never happen! */
633 rio_dprintk(RIO_DEBUG_PFE
, "put_free_end(): This should never happen\n");
634 writew(RIO_OFF(HostP
->Caddr
, PktP
), &HostP
->ParmMapP
->free_list_end
);
635 tmp_pointer
= (struct rio_free_list __iomem
*) PktP
;
636 writew(TPNULL
, &tmp_pointer
->prev
);
637 writew(TPNULL
, &tmp_pointer
->next
);
639 rio_dprintk(RIO_DEBUG_CMD
, "Before unlock: %p\n", &HostP
->HostLock
);
640 rio_spin_unlock_irqrestore(&HostP
->HostLock
, flags
);
644 ** can_remove_receive(PktP,P) returns non-zero if PKT_IN_USE is set
645 ** for the next packet on the queue. It will also set PktP to point to the
646 ** relevant packet, [having cleared the PKT_IN_USE bit]. If PKT_IN_USE is clear,
647 ** then can_remove_receive() returns 0.
649 int can_remove_receive(struct PKT __iomem
**PktP
, struct Port
*PortP
)
651 if (readw(PortP
->RxRemove
) & PKT_IN_USE
) {
652 *PktP
= (struct PKT __iomem
*) RIO_PTR(PortP
->Caddr
, readw(PortP
->RxRemove
) & ~PKT_IN_USE
);
659 ** To remove a packet from the receive queue you clear its PKT_IN_USE bit,
660 ** and then bump the pointers. Once the pointers get to the end, they must
661 ** be wrapped back to the start.
663 void remove_receive(struct Port
*PortP
)
665 writew(readw(PortP
->RxRemove
) & ~PKT_IN_USE
, PortP
->RxRemove
);
666 PortP
->RxRemove
= (PortP
->RxRemove
== PortP
->RxEnd
) ? PortP
->RxStart
: PortP
->RxRemove
+ 1;
667 writew(RIO_OFF(PortP
->Caddr
, PortP
->RxRemove
), &PortP
->PhbP
->rx_remove
);