1 /************************************************************************
2 * Copyright 2003 Digi International (www.digi.com)
4 * Copyright (C) 2004 IBM Corporation. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2, or (at your option)
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
13 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
14 * PURPOSE. See the GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 * Temple Place - Suite 330, Boston,
21 * Contact Information:
22 * Scott H Kilau <Scott_Kilau@digi.com>
23 * Ananda Venkatarman <mansarov@us.ibm.com>
25 * 01/19/06: changed jsm_input routine to use the dynamically allocated
26 * tty_buffer changes. Contributors: Scott Kilau and Ananda V.
27 ***********************************************************************/
28 #include <linux/tty.h>
29 #include <linux/tty_flip.h>
30 #include <linux/serial_reg.h>
31 #include <linux/delay.h> /* For udelay */
32 #include <linux/pci.h>
36 static void jsm_carrier(struct jsm_channel
*ch
);
38 static inline int jsm_get_mstat(struct jsm_channel
*ch
)
43 jsm_printk(IOCTL
, INFO
, &ch
->ch_bd
->pci_dev
, "start\n");
45 mstat
= (ch
->ch_mostat
| ch
->ch_mistat
);
49 if (mstat
& UART_MCR_DTR
)
51 if (mstat
& UART_MCR_RTS
)
53 if (mstat
& UART_MSR_CTS
)
55 if (mstat
& UART_MSR_DSR
)
57 if (mstat
& UART_MSR_RI
)
59 if (mstat
& UART_MSR_DCD
)
62 jsm_printk(IOCTL
, INFO
, &ch
->ch_bd
->pci_dev
, "finish\n");
66 static unsigned int jsm_tty_tx_empty(struct uart_port
*port
)
72 * Return modem signals to ld.
74 static unsigned int jsm_tty_get_mctrl(struct uart_port
*port
)
77 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
79 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "start\n");
81 result
= jsm_get_mstat(channel
);
86 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "finish\n");
92 * jsm_set_modem_info()
94 * Set modem signals, called by ld.
96 static void jsm_tty_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
98 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
100 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "start\n");
102 if (mctrl
& TIOCM_RTS
)
103 channel
->ch_mostat
|= UART_MCR_RTS
;
105 channel
->ch_mostat
&= ~UART_MCR_RTS
;
107 if (mctrl
& TIOCM_DTR
)
108 channel
->ch_mostat
|= UART_MCR_DTR
;
110 channel
->ch_mostat
&= ~UART_MCR_DTR
;
112 channel
->ch_bd
->bd_ops
->assert_modem_signals(channel
);
114 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "finish\n");
118 static void jsm_tty_start_tx(struct uart_port
*port
)
120 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
122 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "start\n");
124 channel
->ch_flags
&= ~(CH_STOP
);
127 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "finish\n");
130 static void jsm_tty_stop_tx(struct uart_port
*port
)
132 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
134 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "start\n");
136 channel
->ch_flags
|= (CH_STOP
);
138 jsm_printk(IOCTL
, INFO
, &channel
->ch_bd
->pci_dev
, "finish\n");
141 static void jsm_tty_send_xchar(struct uart_port
*port
, char ch
)
143 unsigned long lock_flags
;
144 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
145 struct termios
*termios
;
147 spin_lock_irqsave(&port
->lock
, lock_flags
);
148 termios
= port
->info
->tty
->termios
;
149 if (ch
== termios
->c_cc
[VSTART
])
150 channel
->ch_bd
->bd_ops
->send_start_character(channel
);
152 if (ch
== termios
->c_cc
[VSTOP
])
153 channel
->ch_bd
->bd_ops
->send_stop_character(channel
);
154 spin_unlock_irqrestore(&port
->lock
, lock_flags
);
157 static void jsm_tty_stop_rx(struct uart_port
*port
)
159 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
161 channel
->ch_bd
->bd_ops
->disable_receiver(channel
);
164 static void jsm_tty_break(struct uart_port
*port
, int break_state
)
166 unsigned long lock_flags
;
167 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
169 spin_lock_irqsave(&port
->lock
, lock_flags
);
170 if (break_state
== -1)
171 channel
->ch_bd
->bd_ops
->send_break(channel
);
173 channel
->ch_bd
->bd_ops
->clear_break(channel
, 0);
175 spin_unlock_irqrestore(&port
->lock
, lock_flags
);
178 static int jsm_tty_open(struct uart_port
*port
)
180 struct jsm_board
*brd
;
182 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
183 struct termios
*termios
;
185 /* Get board pointer from our array of majors we have allocated */
186 brd
= channel
->ch_bd
;
189 * Allocate channel buffers for read/write/error.
190 * Set flag, so we don't get trounced on.
192 channel
->ch_flags
|= (CH_OPENING
);
194 /* Drop locks, as malloc with GFP_KERNEL can sleep */
196 if (!channel
->ch_rqueue
) {
197 channel
->ch_rqueue
= (u8
*) kmalloc(RQUEUESIZE
, GFP_KERNEL
);
198 if (!channel
->ch_rqueue
) {
199 jsm_printk(INIT
, ERR
, &channel
->ch_bd
->pci_dev
,
200 "unable to allocate read queue buf");
203 memset(channel
->ch_rqueue
, 0, RQUEUESIZE
);
205 if (!channel
->ch_equeue
) {
206 channel
->ch_equeue
= (u8
*) kmalloc(EQUEUESIZE
, GFP_KERNEL
);
207 if (!channel
->ch_equeue
) {
208 jsm_printk(INIT
, ERR
, &channel
->ch_bd
->pci_dev
,
209 "unable to allocate error queue buf");
212 memset(channel
->ch_equeue
, 0, EQUEUESIZE
);
214 if (!channel
->ch_wqueue
) {
215 channel
->ch_wqueue
= (u8
*) kmalloc(WQUEUESIZE
, GFP_KERNEL
);
216 if (!channel
->ch_wqueue
) {
217 jsm_printk(INIT
, ERR
, &channel
->ch_bd
->pci_dev
,
218 "unable to allocate write queue buf");
221 memset(channel
->ch_wqueue
, 0, WQUEUESIZE
);
224 channel
->ch_flags
&= ~(CH_OPENING
);
226 * Initialize if neither terminal is open.
228 jsm_printk(OPEN
, INFO
, &channel
->ch_bd
->pci_dev
,
229 "jsm_open: initializing channel in open...\n");
232 * Flush input queues.
234 channel
->ch_r_head
= channel
->ch_r_tail
= 0;
235 channel
->ch_e_head
= channel
->ch_e_tail
= 0;
236 channel
->ch_w_head
= channel
->ch_w_tail
= 0;
238 brd
->bd_ops
->flush_uart_write(channel
);
239 brd
->bd_ops
->flush_uart_read(channel
);
241 channel
->ch_flags
= 0;
242 channel
->ch_cached_lsr
= 0;
243 channel
->ch_stops_sent
= 0;
245 termios
= port
->info
->tty
->termios
;
246 channel
->ch_c_cflag
= termios
->c_cflag
;
247 channel
->ch_c_iflag
= termios
->c_iflag
;
248 channel
->ch_c_oflag
= termios
->c_oflag
;
249 channel
->ch_c_lflag
= termios
->c_lflag
;
250 channel
->ch_startc
= termios
->c_cc
[VSTART
];
251 channel
->ch_stopc
= termios
->c_cc
[VSTOP
];
253 /* Tell UART to init itself */
254 brd
->bd_ops
->uart_init(channel
);
257 * Run param in case we changed anything
259 brd
->bd_ops
->param(channel
);
261 jsm_carrier(channel
);
263 channel
->ch_open_count
++;
265 jsm_printk(OPEN
, INFO
, &channel
->ch_bd
->pci_dev
, "finish\n");
269 static void jsm_tty_close(struct uart_port
*port
)
271 struct jsm_board
*bd
;
273 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
275 jsm_printk(CLOSE
, INFO
, &channel
->ch_bd
->pci_dev
, "start\n");
278 ts
= channel
->uart_port
.info
->tty
->termios
;
280 channel
->ch_flags
&= ~(CH_STOPI
);
282 channel
->ch_open_count
--;
285 * If we have HUPCL set, lower DTR and RTS
287 if (channel
->ch_c_cflag
& HUPCL
) {
288 jsm_printk(CLOSE
, INFO
, &channel
->ch_bd
->pci_dev
,
289 "Close. HUPCL set, dropping DTR/RTS\n");
292 channel
->ch_mostat
&= ~(UART_MCR_DTR
| UART_MCR_RTS
);
293 bd
->bd_ops
->assert_modem_signals(channel
);
296 channel
->ch_old_baud
= 0;
298 /* Turn off UART interrupts for this port */
299 channel
->ch_bd
->bd_ops
->uart_off(channel
);
301 jsm_printk(CLOSE
, INFO
, &channel
->ch_bd
->pci_dev
, "finish\n");
304 static void jsm_tty_set_termios(struct uart_port
*port
,
305 struct termios
*termios
,
306 struct termios
*old_termios
)
308 unsigned long lock_flags
;
309 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
311 spin_lock_irqsave(&port
->lock
, lock_flags
);
312 channel
->ch_c_cflag
= termios
->c_cflag
;
313 channel
->ch_c_iflag
= termios
->c_iflag
;
314 channel
->ch_c_oflag
= termios
->c_oflag
;
315 channel
->ch_c_lflag
= termios
->c_lflag
;
316 channel
->ch_startc
= termios
->c_cc
[VSTART
];
317 channel
->ch_stopc
= termios
->c_cc
[VSTOP
];
319 channel
->ch_bd
->bd_ops
->param(channel
);
320 jsm_carrier(channel
);
321 spin_unlock_irqrestore(&port
->lock
, lock_flags
);
324 static const char *jsm_tty_type(struct uart_port
*port
)
329 static void jsm_tty_release_port(struct uart_port
*port
)
333 static int jsm_tty_request_port(struct uart_port
*port
)
338 static void jsm_config_port(struct uart_port
*port
, int flags
)
340 port
->type
= PORT_JSM
;
343 static struct uart_ops jsm_ops
= {
344 .tx_empty
= jsm_tty_tx_empty
,
345 .set_mctrl
= jsm_tty_set_mctrl
,
346 .get_mctrl
= jsm_tty_get_mctrl
,
347 .stop_tx
= jsm_tty_stop_tx
,
348 .start_tx
= jsm_tty_start_tx
,
349 .send_xchar
= jsm_tty_send_xchar
,
350 .stop_rx
= jsm_tty_stop_rx
,
351 .break_ctl
= jsm_tty_break
,
352 .startup
= jsm_tty_open
,
353 .shutdown
= jsm_tty_close
,
354 .set_termios
= jsm_tty_set_termios
,
355 .type
= jsm_tty_type
,
356 .release_port
= jsm_tty_release_port
,
357 .request_port
= jsm_tty_request_port
,
358 .config_port
= jsm_config_port
,
364 * Init the tty subsystem. Called once per board after board has been
365 * downloaded and init'ed.
367 int jsm_tty_init(struct jsm_board
*brd
)
371 struct jsm_channel
*ch
;
376 jsm_printk(INIT
, INFO
, &brd
->pci_dev
, "start\n");
379 * Initialize board structure elements.
382 brd
->nasync
= brd
->maxports
;
385 * Allocate channel memory that might not have been allocated
386 * when the driver was first loaded.
388 for (i
= 0; i
< brd
->nasync
; i
++) {
389 if (!brd
->channels
[i
]) {
392 * Okay to malloc with GFP_KERNEL, we are not at
393 * interrupt context, and there are no locks held.
395 brd
->channels
[i
] = kmalloc(sizeof(struct jsm_channel
), GFP_KERNEL
);
396 if (!brd
->channels
[i
]) {
397 jsm_printk(CORE
, ERR
, &brd
->pci_dev
,
398 "%s:%d Unable to allocate memory for channel struct\n",
401 memset(brd
->channels
[i
], 0, sizeof(struct jsm_channel
));
405 ch
= brd
->channels
[0];
406 vaddr
= brd
->re_map_membase
;
408 /* Set up channel variables */
409 for (i
= 0; i
< brd
->nasync
; i
++, ch
= brd
->channels
[i
]) {
411 if (!brd
->channels
[i
])
414 spin_lock_init(&ch
->ch_lock
);
416 if (brd
->bd_uart_offset
== 0x200)
417 ch
->ch_neo_uart
= vaddr
+ (brd
->bd_uart_offset
* i
);
422 /* .25 second delay */
423 ch
->ch_close_delay
= 250;
425 init_waitqueue_head(&ch
->ch_flags_wait
);
428 jsm_printk(INIT
, INFO
, &brd
->pci_dev
, "finish\n");
432 int jsm_uart_port_init(struct jsm_board
*brd
)
435 struct jsm_channel
*ch
;
440 jsm_printk(INIT
, INFO
, &brd
->pci_dev
, "start\n");
443 * Initialize board structure elements.
446 brd
->nasync
= brd
->maxports
;
448 /* Set up channel variables */
449 for (i
= 0; i
< brd
->nasync
; i
++, ch
= brd
->channels
[i
]) {
451 if (!brd
->channels
[i
])
454 brd
->channels
[i
]->uart_port
.irq
= brd
->irq
;
455 brd
->channels
[i
]->uart_port
.type
= PORT_JSM
;
456 brd
->channels
[i
]->uart_port
.iotype
= UPIO_MEM
;
457 brd
->channels
[i
]->uart_port
.membase
= brd
->re_map_membase
;
458 brd
->channels
[i
]->uart_port
.fifosize
= 16;
459 brd
->channels
[i
]->uart_port
.ops
= &jsm_ops
;
460 brd
->channels
[i
]->uart_port
.line
= brd
->channels
[i
]->ch_portnum
+ brd
->boardnum
* 2;
461 if (uart_add_one_port (&jsm_uart_driver
, &brd
->channels
[i
]->uart_port
))
462 printk(KERN_INFO
"Added device failed\n");
464 printk(KERN_INFO
"Added device \n");
467 jsm_printk(INIT
, INFO
, &brd
->pci_dev
, "finish\n");
471 int jsm_remove_uart_port(struct jsm_board
*brd
)
474 struct jsm_channel
*ch
;
479 jsm_printk(INIT
, INFO
, &brd
->pci_dev
, "start\n");
482 * Initialize board structure elements.
485 brd
->nasync
= brd
->maxports
;
487 /* Set up channel variables */
488 for (i
= 0; i
< brd
->nasync
; i
++) {
490 if (!brd
->channels
[i
])
493 ch
= brd
->channels
[i
];
495 uart_remove_one_port(&jsm_uart_driver
, &brd
->channels
[i
]->uart_port
);
498 jsm_printk(INIT
, INFO
, &brd
->pci_dev
, "finish\n");
502 void jsm_input(struct jsm_channel
*ch
)
504 struct jsm_board
*bd
;
505 struct tty_struct
*tp
;
506 struct tty_ldisc
*ld
;
511 unsigned long lock_flags
;
518 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
, "start\n");
523 tp
= ch
->uart_port
.info
->tty
;
529 spin_lock_irqsave(&ch
->ch_lock
, lock_flags
);
532 *Figure the number of characters in the buffer.
533 *Exit immediately if none.
538 head
= ch
->ch_r_head
& rmask
;
539 tail
= ch
->ch_r_tail
& rmask
;
541 data_len
= (head
- tail
) & rmask
;
543 spin_unlock_irqrestore(&ch
->ch_lock
, lock_flags
);
547 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
, "start\n");
550 *If the device is not open, or CREAD is off, flush
551 *input data and return immediately.
554 !(tp
->termios
->c_cflag
& CREAD
) ) {
556 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
,
557 "input. dropping %d bytes on port %d...\n", data_len
, ch
->ch_portnum
);
558 ch
->ch_r_head
= tail
;
560 /* Force queue flow control to be released, if needed */
561 jsm_check_queue_flow_control(ch
);
563 spin_unlock_irqrestore(&ch
->ch_lock
, lock_flags
);
568 * If we are throttled, simply don't read any data.
570 if (ch
->ch_flags
& CH_STOPI
) {
571 spin_unlock_irqrestore(&ch
->ch_lock
, lock_flags
);
572 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
,
573 "Port %d throttled, not reading any data. head: %x tail: %x\n",
574 ch
->ch_portnum
, head
, tail
);
578 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
, "start 2\n");
581 * If the rxbuf is empty and we are not throttled, put as much
582 * as we can directly into the linux TTY buffer.
585 flip_len
= TTY_FLIPBUF_SIZE
;
587 len
= min(data_len
, flip_len
);
588 len
= min(len
, (N_TTY_BUF_SIZE
- 1) - tp
->read_cnt
);
589 ld
= tty_ldisc_ref(tp
);
592 * If the DONT_FLIP flag is on, don't flush our buffer, and act
593 * like the ld doesn't have any space to put the data right now.
595 if (test_bit(TTY_DONT_FLIP
, &tp
->flags
))
599 * If we were unable to get a reference to the ld,
600 * don't flush our buffer, and act like the ld doesn't
601 * have any space to put the data right now.
607 * If ld doesn't have a pointer to a receive_buf function,
608 * flush the data, then act like the ld doesn't have any
609 * space to put the data right now.
611 if (!ld
->receive_buf
) {
612 ch
->ch_r_head
= ch
->ch_r_tail
;
618 spin_unlock_irqrestore(&ch
->ch_lock
, lock_flags
);
619 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
, "jsm_input 1\n");
625 len
= tty_buffer_request_room(tp
, len
);
629 * n now contains the most amount of data we can copy,
630 * bounded either by the flip buffer size or the amount
631 * of data the card actually has pending...
634 s
= ((head
>= tail
) ? head
: RQUEUESIZE
) - tail
;
641 * If conditions are such that ld needs to see all
642 * UART errors, we will have to walk each character
643 * and error byte and send them to the buffer one at
647 if (I_PARMRK(tp
) || I_BRKINT(tp
) || I_INPCK(tp
)) {
648 for (i
= 0; i
< s
; i
++) {
650 * Give the Linux ld the flags in the
653 if (*(ch
->ch_equeue
+tail
+i
) & UART_LSR_BI
)
654 tty_insert_flip_char(tp
, *(ch
->ch_rqueue
+tail
+i
), TTY_BREAK
);
655 else if (*(ch
->ch_equeue
+tail
+i
) & UART_LSR_PE
)
656 tty_insert_flip_char(tp
, *(ch
->ch_rqueue
+tail
+i
), TTY_PARITY
);
657 else if (*(ch
->ch_equeue
+tail
+i
) & UART_LSR_FE
)
658 tty_insert_flip_char(tp
, *(ch
->ch_rqueue
+tail
+i
), TTY_FRAME
);
660 tty_insert_flip_char(tp
, *(ch
->ch_rqueue
+tail
+i
), TTY_NORMAL
);
663 tty_insert_flip_string(tp
, ch
->ch_rqueue
+ tail
, s
) ;
667 /* Flip queue if needed */
671 ch
->ch_r_tail
= tail
& rmask
;
672 ch
->ch_e_tail
= tail
& rmask
;
673 jsm_check_queue_flow_control(ch
);
674 spin_unlock_irqrestore(&ch
->ch_lock
, lock_flags
);
676 /* Tell the tty layer its okay to "eat" the data now */
677 tty_flip_buffer_push(tp
);
682 jsm_printk(IOCTL
, INFO
, &ch
->ch_bd
->pci_dev
, "finish\n");
685 static void jsm_carrier(struct jsm_channel
*ch
)
687 struct jsm_board
*bd
;
689 int virt_carrier
= 0;
690 int phys_carrier
= 0;
692 jsm_printk(CARR
, INFO
, &ch
->ch_bd
->pci_dev
, "start\n");
701 if (ch
->ch_mistat
& UART_MSR_DCD
) {
702 jsm_printk(CARR
, INFO
, &ch
->ch_bd
->pci_dev
,
703 "mistat: %x D_CD: %x\n", ch
->ch_mistat
, ch
->ch_mistat
& UART_MSR_DCD
);
707 if (ch
->ch_c_cflag
& CLOCAL
)
710 jsm_printk(CARR
, INFO
, &ch
->ch_bd
->pci_dev
,
711 "DCD: physical: %d virt: %d\n", phys_carrier
, virt_carrier
);
714 * Test for a VIRTUAL carrier transition to HIGH.
716 if (((ch
->ch_flags
& CH_FCAR
) == 0) && (virt_carrier
== 1)) {
719 * When carrier rises, wake any threads waiting
720 * for carrier in the open routine.
723 jsm_printk(CARR
, INFO
, &ch
->ch_bd
->pci_dev
,
724 "carrier: virt DCD rose\n");
726 if (waitqueue_active(&(ch
->ch_flags_wait
)))
727 wake_up_interruptible(&ch
->ch_flags_wait
);
731 * Test for a PHYSICAL carrier transition to HIGH.
733 if (((ch
->ch_flags
& CH_CD
) == 0) && (phys_carrier
== 1)) {
736 * When carrier rises, wake any threads waiting
737 * for carrier in the open routine.
740 jsm_printk(CARR
, INFO
, &ch
->ch_bd
->pci_dev
,
741 "carrier: physical DCD rose\n");
743 if (waitqueue_active(&(ch
->ch_flags_wait
)))
744 wake_up_interruptible(&ch
->ch_flags_wait
);
748 * Test for a PHYSICAL transition to low, so long as we aren't
749 * currently ignoring physical transitions (which is what "virtual
750 * carrier" indicates).
752 * The transition of the virtual carrier to low really doesn't
753 * matter... it really only means "ignore carrier state", not
754 * "make pretend that carrier is there".
756 if ((virt_carrier
== 0) && ((ch
->ch_flags
& CH_CD
) != 0)
757 && (phys_carrier
== 0)) {
759 * When carrier drops:
761 * Drop carrier on all open units.
763 * Flush queues, waking up any task waiting in the
766 * Send a hangup to the control terminal.
768 * Enable all select calls.
770 if (waitqueue_active(&(ch
->ch_flags_wait
)))
771 wake_up_interruptible(&ch
->ch_flags_wait
);
775 * Make sure that our cached values reflect the current reality.
777 if (virt_carrier
== 1)
778 ch
->ch_flags
|= CH_FCAR
;
780 ch
->ch_flags
&= ~CH_FCAR
;
782 if (phys_carrier
== 1)
783 ch
->ch_flags
|= CH_CD
;
785 ch
->ch_flags
&= ~CH_CD
;
789 void jsm_check_queue_flow_control(struct jsm_channel
*ch
)
791 struct board_ops
*bd_ops
= ch
->ch_bd
->bd_ops
;
794 /* Store how much space we have left in the queue */
795 if ((qleft
= ch
->ch_r_tail
- ch
->ch_r_head
- 1) < 0)
796 qleft
+= RQUEUEMASK
+ 1;
799 * Check to see if we should enforce flow control on our queue because
800 * the ld (or user) isn't reading data out of our queue fast enuf.
802 * NOTE: This is done based on what the current flow control of the
805 * 1) HWFLOW (RTS) - Turn off the UART's Receive interrupt.
806 * This will cause the UART's FIFO to back up, and force
807 * the RTS signal to be dropped.
808 * 2) SWFLOW (IXOFF) - Keep trying to send a stop character to
809 * the other side, in hopes it will stop sending data to us.
810 * 3) NONE - Nothing we can do. We will simply drop any extra data
811 * that gets sent into us when the queue fills up.
815 if (ch
->ch_c_cflag
& CRTSCTS
) {
816 if(!(ch
->ch_flags
& CH_RECEIVER_OFF
)) {
817 bd_ops
->disable_receiver(ch
);
818 ch
->ch_flags
|= (CH_RECEIVER_OFF
);
819 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
,
820 "Internal queue hit hilevel mark (%d)! Turning off interrupts.\n",
825 else if (ch
->ch_c_iflag
& IXOFF
) {
826 if (ch
->ch_stops_sent
<= MAX_STOPS_SENT
) {
827 bd_ops
->send_stop_character(ch
);
829 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
,
830 "Sending stop char! Times sent: %x\n", ch
->ch_stops_sent
);
836 * Check to see if we should unenforce flow control because
837 * ld (or user) finally read enuf data out of our queue.
839 * NOTE: This is done based on what the current flow control of the
842 * 1) HWFLOW (RTS) - Turn back on the UART's Receive interrupt.
843 * This will cause the UART's FIFO to raise RTS back up,
844 * which will allow the other side to start sending data again.
845 * 2) SWFLOW (IXOFF) - Send a start character to
846 * the other side, so it will start sending data to us again.
847 * 3) NONE - Do nothing. Since we didn't do anything to turn off the
848 * other side, we don't need to do anything now.
850 if (qleft
> (RQUEUESIZE
/ 2)) {
852 if (ch
->ch_c_cflag
& CRTSCTS
) {
853 if (ch
->ch_flags
& CH_RECEIVER_OFF
) {
854 bd_ops
->enable_receiver(ch
);
855 ch
->ch_flags
&= ~(CH_RECEIVER_OFF
);
856 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
,
857 "Internal queue hit lowlevel mark (%d)! Turning on interrupts.\n",
862 else if (ch
->ch_c_iflag
& IXOFF
&& ch
->ch_stops_sent
) {
863 ch
->ch_stops_sent
= 0;
864 bd_ops
->send_start_character(ch
);
865 jsm_printk(READ
, INFO
, &ch
->ch_bd
->pci_dev
, "Sending start char!\n");
873 * Take data from the user or kernel and send it out to the FEP.
874 * In here exists all the Transparent Print magic as well.
876 int jsm_tty_write(struct uart_port
*port
)
878 int bufcount
= 0, n
= 0;
879 int data_count
= 0,data_count1
=0;
884 int temp_tail
= port
->info
->xmit
.tail
;
885 struct jsm_channel
*channel
= (struct jsm_channel
*)port
;
888 head
= (channel
->ch_w_head
) & tmask
;
889 tail
= (channel
->ch_w_tail
) & tmask
;
891 if ((bufcount
= tail
- head
- 1) < 0)
892 bufcount
+= WQUEUESIZE
;
897 remain
= WQUEUESIZE
- head
;
902 while ((port
->info
->xmit
.head
!= temp_tail
) &&
903 (data_count
< remain
)) {
904 channel
->ch_wqueue
[head
++] =
905 port
->info
->xmit
.buf
[temp_tail
];
908 temp_tail
&= (UART_XMIT_SIZE
- 1);
911 if (data_count
== remain
) head
= 0;
917 while ((port
->info
->xmit
.head
!= temp_tail
) &&
918 (data_count1
< remain
)) {
919 channel
->ch_wqueue
[head
++] =
920 port
->info
->xmit
.buf
[temp_tail
];
923 temp_tail
&= (UART_XMIT_SIZE
- 1);
929 port
->info
->xmit
.tail
= temp_tail
;
931 data_count
+= data_count1
;
934 channel
->ch_w_head
= head
;
938 channel
->ch_bd
->bd_ops
->copy_data_from_queue_to_uart(channel
);