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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/serial/mux.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/serial/mux.c')
-rw-r--r--drivers/serial/mux.c539
1 files changed, 539 insertions, 0 deletions
diff --git a/drivers/serial/mux.c b/drivers/serial/mux.c
new file mode 100644
index 00000000000..dadd7e19714
--- /dev/null
+++ b/drivers/serial/mux.c
@@ -0,0 +1,539 @@
1/*
2** mux.c:
3** serial driver for the Mux console found in some PA-RISC servers.
4**
5** (c) Copyright 2002 Ryan Bradetich
6** (c) Copyright 2002 Hewlett-Packard Company
7**
8** This program is free software; you can redistribute it and/or modify
9** it under the terms of the GNU General Public License as published by
10** the Free Software Foundation; either version 2 of the License, or
11** (at your option) any later version.
12**
13** This Driver currently only supports the console (port 0) on the MUX.
14** Additional work will be needed on this driver to enable the full
15** functionality of the MUX.
16**
17*/
18
19#include <linux/config.h>
20#include <linux/module.h>
21#include <linux/tty.h>
22#include <linux/ioport.h>
23#include <linux/init.h>
24#include <linux/serial.h>
25#include <linux/console.h>
26#include <linux/slab.h>
27#include <linux/delay.h> /* for udelay */
28#include <linux/device.h>
29#include <asm/io.h>
30#include <asm/parisc-device.h>
31
32#ifdef CONFIG_MAGIC_SYSRQ
33#include <linux/sysrq.h>
34#define SUPPORT_SYSRQ
35#endif
36
37#include <linux/serial_core.h>
38
39#define MUX_OFFSET 0x800
40#define MUX_LINE_OFFSET 0x80
41
42#define MUX_FIFO_SIZE 255
43#define MUX_POLL_DELAY (30 * HZ / 1000)
44
45#define IO_DATA_REG_OFFSET 0x3c
46#define IO_DCOUNT_REG_OFFSET 0x40
47
48#define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
49#define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
50#define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
51
52#define MUX_NR 256
53static unsigned int port_cnt = 0;
54static struct uart_port mux_ports[MUX_NR];
55
56static struct uart_driver mux_driver = {
57 .owner = THIS_MODULE,
58 .driver_name = "ttyB",
59 .dev_name = "ttyB",
60 .major = MUX_MAJOR,
61 .minor = 0,
62 .nr = MUX_NR,
63};
64
65static struct timer_list mux_timer;
66
67#define UART_PUT_CHAR(p, c) __raw_writel((c), (unsigned long)(p)->membase + IO_DATA_REG_OFFSET)
68#define UART_GET_FIFO_CNT(p) __raw_readl((unsigned long)(p)->membase + IO_DCOUNT_REG_OFFSET)
69#define GET_MUX_PORTS(iodc_data) ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8
70
71/**
72 * mux_tx_empty - Check if the transmitter fifo is empty.
73 * @port: Ptr to the uart_port.
74 *
75 * This function test if the transmitter fifo for the port
76 * described by 'port' is empty. If it is empty, this function
77 * should return TIOCSER_TEMT, otherwise return 0.
78 */
79static unsigned int mux_tx_empty(struct uart_port *port)
80{
81 unsigned int cnt = __raw_readl((unsigned long)port->membase
82 + IO_DCOUNT_REG_OFFSET);
83
84 return cnt ? 0 : TIOCSER_TEMT;
85}
86
87/**
88 * mux_set_mctrl - Set the current state of the modem control inputs.
89 * @ports: Ptr to the uart_port.
90 * @mctrl: Modem control bits.
91 *
92 * The Serial MUX does not support CTS, DCD or DSR so this function
93 * is ignored.
94 */
95static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl)
96{
97}
98
99/**
100 * mux_get_mctrl - Returns the current state of modem control inputs.
101 * @port: Ptr to the uart_port.
102 *
103 * The Serial MUX does not support CTS, DCD or DSR so these lines are
104 * treated as permanently active.
105 */
106static unsigned int mux_get_mctrl(struct uart_port *port)
107{
108 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
109}
110
111/**
112 * mux_stop_tx - Stop transmitting characters.
113 * @port: Ptr to the uart_port.
114 * @tty_stop: tty layer issue this command?
115 *
116 * The Serial MUX does not support this function.
117 */
118static void mux_stop_tx(struct uart_port *port, unsigned int tty_stop)
119{
120}
121
122/**
123 * mux_start_tx - Start transmitting characters.
124 * @port: Ptr to the uart_port.
125 * @tty_start: tty layer issue this command?
126 *
127 * The Serial Mux does not support this function.
128 */
129static void mux_start_tx(struct uart_port *port, unsigned int tty_start)
130{
131}
132
133/**
134 * mux_stop_rx - Stop receiving characters.
135 * @port: Ptr to the uart_port.
136 *
137 * The Serial Mux does not support this function.
138 */
139static void mux_stop_rx(struct uart_port *port)
140{
141}
142
143/**
144 * mux_enable_ms - Enable modum status interrupts.
145 * @port: Ptr to the uart_port.
146 *
147 * The Serial Mux does not support this function.
148 */
149static void mux_enable_ms(struct uart_port *port)
150{
151}
152
153/**
154 * mux_break_ctl - Control the transmitssion of a break signal.
155 * @port: Ptr to the uart_port.
156 * @break_state: Raise/Lower the break signal.
157 *
158 * The Serial Mux does not support this function.
159 */
160static void mux_break_ctl(struct uart_port *port, int break_state)
161{
162}
163
164/**
165 * mux_write - Write chars to the mux fifo.
166 * @port: Ptr to the uart_port.
167 *
168 * This function writes all the data from the uart buffer to
169 * the mux fifo.
170 */
171static void mux_write(struct uart_port *port)
172{
173 int count;
174 struct circ_buf *xmit = &port->info->xmit;
175
176 if(port->x_char) {
177 UART_PUT_CHAR(port, port->x_char);
178 port->icount.tx++;
179 port->x_char = 0;
180 return;
181 }
182
183 if(uart_circ_empty(xmit) || uart_tx_stopped(port)) {
184 mux_stop_tx(port, 0);
185 return;
186 }
187
188 count = (port->fifosize) - UART_GET_FIFO_CNT(port);
189 do {
190 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
191 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
192 port->icount.tx++;
193 if(uart_circ_empty(xmit))
194 break;
195
196 } while(--count > 0);
197
198 while(UART_GET_FIFO_CNT(port))
199 udelay(1);
200
201 if(uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
202 uart_write_wakeup(port);
203
204 if (uart_circ_empty(xmit))
205 mux_stop_tx(port, 0);
206}
207
208/**
209 * mux_read - Read chars from the mux fifo.
210 * @port: Ptr to the uart_port.
211 *
212 * This reads all available data from the mux's fifo and pushes
213 * the data to the tty layer.
214 */
215static void mux_read(struct uart_port *port)
216{
217 int data;
218 struct tty_struct *tty = port->info->tty;
219 __u32 start_count = port->icount.rx;
220
221 while(1) {
222 data = __raw_readl((unsigned long)port->membase
223 + IO_DATA_REG_OFFSET);
224
225 if (MUX_STATUS(data))
226 continue;
227
228 if (MUX_EOFIFO(data))
229 break;
230
231 if (tty->flip.count >= TTY_FLIPBUF_SIZE)
232 continue;
233
234 *tty->flip.char_buf_ptr = data & 0xffu;
235 *tty->flip.flag_buf_ptr = TTY_NORMAL;
236 port->icount.rx++;
237
238 if (MUX_BREAK(data)) {
239 port->icount.brk++;
240 if(uart_handle_break(port))
241 continue;
242 }
243
244 if (uart_handle_sysrq_char(port, data & 0xffu, NULL))
245 continue;
246
247 tty->flip.flag_buf_ptr++;
248 tty->flip.char_buf_ptr++;
249 tty->flip.count++;
250 }
251
252 if (start_count != port->icount.rx) {
253 tty_flip_buffer_push(tty);
254 }
255}
256
257/**
258 * mux_startup - Initialize the port.
259 * @port: Ptr to the uart_port.
260 *
261 * Grab any resources needed for this port and start the
262 * mux timer.
263 */
264static int mux_startup(struct uart_port *port)
265{
266 mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
267 return 0;
268}
269
270/**
271 * mux_shutdown - Disable the port.
272 * @port: Ptr to the uart_port.
273 *
274 * Release any resources needed for the port.
275 */
276static void mux_shutdown(struct uart_port *port)
277{
278}
279
280/**
281 * mux_set_termios - Chane port parameters.
282 * @port: Ptr to the uart_port.
283 * @termios: new termios settings.
284 * @old: old termios settings.
285 *
286 * The Serial Mux does not support this function.
287 */
288static void
289mux_set_termios(struct uart_port *port, struct termios *termios,
290 struct termios *old)
291{
292}
293
294/**
295 * mux_type - Describe the port.
296 * @port: Ptr to the uart_port.
297 *
298 * Return a pointer to a string constant describing the
299 * specified port.
300 */
301static const char *mux_type(struct uart_port *port)
302{
303 return "Mux";
304}
305
306/**
307 * mux_release_port - Release memory and IO regions.
308 * @port: Ptr to the uart_port.
309 *
310 * Release any memory and IO region resources currently in use by
311 * the port.
312 */
313static void mux_release_port(struct uart_port *port)
314{
315}
316
317/**
318 * mux_request_port - Request memory and IO regions.
319 * @port: Ptr to the uart_port.
320 *
321 * Request any memory and IO region resources required by the port.
322 * If any fail, no resources should be registered when this function
323 * returns, and it should return -EBUSY on failure.
324 */
325static int mux_request_port(struct uart_port *port)
326{
327 return 0;
328}
329
330/**
331 * mux_config_port - Perform port autoconfiguration.
332 * @port: Ptr to the uart_port.
333 * @type: Bitmask of required configurations.
334 *
335 * Perform any autoconfiguration steps for the port. This functino is
336 * called if the UPF_BOOT_AUTOCONF flag is specified for the port.
337 * [Note: This is required for now because of a bug in the Serial core.
338 * rmk has already submitted a patch to linus, should be available for
339 * 2.5.47.]
340 */
341static void mux_config_port(struct uart_port *port, int type)
342{
343 port->type = PORT_MUX;
344}
345
346/**
347 * mux_verify_port - Verify the port information.
348 * @port: Ptr to the uart_port.
349 * @ser: Ptr to the serial information.
350 *
351 * Verify the new serial port information contained within serinfo is
352 * suitable for this port type.
353 */
354static int mux_verify_port(struct uart_port *port, struct serial_struct *ser)
355{
356 if(port->membase == NULL)
357 return -EINVAL;
358
359 return 0;
360}
361
362/**
363 * mux_drv_poll - Mux poll function.
364 * @unused: Unused variable
365 *
366 * This function periodically polls the Serial MUX to check for new data.
367 */
368static void mux_poll(unsigned long unused)
369{
370 int i;
371
372 for(i = 0; i < port_cnt; ++i) {
373 if(!mux_ports[i].info)
374 continue;
375
376 mux_read(&mux_ports[i]);
377 mux_write(&mux_ports[i]);
378 }
379
380 mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
381}
382
383
384#ifdef CONFIG_SERIAL_MUX_CONSOLE
385static void mux_console_write(struct console *co, const char *s, unsigned count)
386{
387 while(count--)
388 pdc_iodc_putc(*s++);
389}
390
391static int mux_console_setup(struct console *co, char *options)
392{
393 return 0;
394}
395
396struct tty_driver *mux_console_device(struct console *co, int *index)
397{
398 *index = co->index;
399 return mux_driver.tty_driver;
400}
401
402static struct console mux_console = {
403 .name = "ttyB",
404 .write = mux_console_write,
405 .device = mux_console_device,
406 .setup = mux_console_setup,
407 .flags = CON_ENABLED | CON_PRINTBUFFER,
408 .index = 0,
409};
410
411#define MUX_CONSOLE &mux_console
412#else
413#define MUX_CONSOLE NULL
414#endif
415
416static struct uart_ops mux_pops = {
417 .tx_empty = mux_tx_empty,
418 .set_mctrl = mux_set_mctrl,
419 .get_mctrl = mux_get_mctrl,
420 .stop_tx = mux_stop_tx,
421 .start_tx = mux_start_tx,
422 .stop_rx = mux_stop_rx,
423 .enable_ms = mux_enable_ms,
424 .break_ctl = mux_break_ctl,
425 .startup = mux_startup,
426 .shutdown = mux_shutdown,
427 .set_termios = mux_set_termios,
428 .type = mux_type,
429 .release_port = mux_release_port,
430 .request_port = mux_request_port,
431 .config_port = mux_config_port,
432 .verify_port = mux_verify_port,
433};
434
435/**
436 * mux_probe - Determine if the Serial Mux should claim this device.
437 * @dev: The parisc device.
438 *
439 * Deterimine if the Serial Mux should claim this chip (return 0)
440 * or not (return 1).
441 */
442static int __init mux_probe(struct parisc_device *dev)
443{
444 int i, status, ports;
445 u8 iodc_data[32];
446 unsigned long bytecnt;
447 struct uart_port *port;
448
449 status = pdc_iodc_read(&bytecnt, dev->hpa, 0, iodc_data, 32);
450 if(status != PDC_OK) {
451 printk(KERN_ERR "Serial mux: Unable to read IODC.\n");
452 return 1;
453 }
454
455 ports = GET_MUX_PORTS(iodc_data);
456 printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.3\n", ports);
457
458 if(!port_cnt) {
459 mux_driver.cons = MUX_CONSOLE;
460
461 status = uart_register_driver(&mux_driver);
462 if(status) {
463 printk(KERN_ERR "Serial mux: Unable to register driver.\n");
464 return 1;
465 }
466
467 init_timer(&mux_timer);
468 mux_timer.function = mux_poll;
469 }
470
471 for(i = 0; i < ports; ++i, ++port_cnt) {
472 port = &mux_ports[port_cnt];
473 port->iobase = 0;
474 port->mapbase = dev->hpa + MUX_OFFSET + (i * MUX_LINE_OFFSET);
475 port->membase = ioremap(port->mapbase, MUX_LINE_OFFSET);
476 port->iotype = SERIAL_IO_MEM;
477 port->type = PORT_MUX;
478 port->irq = SERIAL_IRQ_NONE;
479 port->uartclk = 0;
480 port->fifosize = MUX_FIFO_SIZE;
481 port->ops = &mux_pops;
482 port->flags = UPF_BOOT_AUTOCONF;
483 port->line = port_cnt;
484 status = uart_add_one_port(&mux_driver, port);
485 BUG_ON(status);
486 }
487
488#ifdef CONFIG_SERIAL_MUX_CONSOLE
489 register_console(&mux_console);
490#endif
491 return 0;
492}
493
494static struct parisc_device_id mux_tbl[] = {
495 { HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D },
496 { 0, }
497};
498
499MODULE_DEVICE_TABLE(parisc, mux_tbl);
500
501static struct parisc_driver serial_mux_driver = {
502 .name = "Serial MUX",
503 .id_table = mux_tbl,
504 .probe = mux_probe,
505};
506
507/**
508 * mux_init - Serial MUX initalization procedure.
509 *
510 * Register the Serial MUX driver.
511 */
512static int __init mux_init(void)
513{
514 return register_parisc_driver(&serial_mux_driver);
515}
516
517/**
518 * mux_exit - Serial MUX cleanup procedure.
519 *
520 * Unregister the Serial MUX driver from the tty layer.
521 */
522static void __exit mux_exit(void)
523{
524 int i;
525
526 for (i = 0; i < port_cnt; i++) {
527 uart_remove_one_port(&mux_driver, &mux_ports[i]);
528 }
529
530 uart_unregister_driver(&mux_driver);
531}
532
533module_init(mux_init);
534module_exit(mux_exit);
535
536MODULE_AUTHOR("Ryan Bradetich");
537MODULE_DESCRIPTION("Serial MUX driver");
538MODULE_LICENSE("GPL");
539MODULE_ALIAS_CHARDEV_MAJOR(MUX_MAJOR);