3 ** serial driver for the Mux console found in some PA-RISC servers.
5 ** (c) Copyright 2002 Ryan Bradetich
6 ** (c) Copyright 2002 Hewlett-Packard Company
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.
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.
19 #include <linux/module.h>
20 #include <linux/tty.h>
21 #include <linux/ioport.h>
22 #include <linux/init.h>
23 #include <linux/serial.h>
24 #include <linux/console.h>
25 #include <linux/slab.h>
26 #include <linux/delay.h> /* for udelay */
27 #include <linux/device.h>
30 #include <asm/parisc-device.h>
32 #ifdef CONFIG_MAGIC_SYSRQ
33 #include <linux/sysrq.h>
37 #include <linux/serial_core.h>
39 #define MUX_OFFSET 0x800
40 #define MUX_LINE_OFFSET 0x80
42 #define MUX_FIFO_SIZE 255
43 #define MUX_POLL_DELAY (30 * HZ / 1000)
45 #define IO_DATA_REG_OFFSET 0x3c
46 #define IO_DCOUNT_REG_OFFSET 0x40
48 #define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
49 #define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
50 #define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
53 static unsigned int port_cnt __read_mostly;
55 struct uart_port port;
58 static struct mux_port mux_ports[MUX_NR];
60 static struct uart_driver mux_driver = {
62 .driver_name = "ttyB",
71 struct parisc_device *dev;
72 struct mux_card *next;
75 static struct mux_card *mux_card_head;
76 static struct timer_list mux_timer;
78 #define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET)
79 #define UART_GET_FIFO_CNT(p) __raw_readl((p)->membase + IO_DCOUNT_REG_OFFSET)
80 #define GET_MUX_PORTS(iodc_data) ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8
83 * mux_tx_empty - Check if the transmitter fifo is empty.
84 * @port: Ptr to the uart_port.
86 * This function test if the transmitter fifo for the port
87 * described by 'port' is empty. If it is empty, this function
88 * should return TIOCSER_TEMT, otherwise return 0.
90 static unsigned int mux_tx_empty(struct uart_port *port)
92 return UART_GET_FIFO_CNT(port) ? 0 : TIOCSER_TEMT;
96 * mux_set_mctrl - Set the current state of the modem control inputs.
97 * @ports: Ptr to the uart_port.
98 * @mctrl: Modem control bits.
100 * The Serial MUX does not support CTS, DCD or DSR so this function
103 static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl)
108 * mux_get_mctrl - Returns the current state of modem control inputs.
109 * @port: Ptr to the uart_port.
111 * The Serial MUX does not support CTS, DCD or DSR so these lines are
112 * treated as permanently active.
114 static unsigned int mux_get_mctrl(struct uart_port *port)
116 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
120 * mux_stop_tx - Stop transmitting characters.
121 * @port: Ptr to the uart_port.
123 * The Serial MUX does not support this function.
125 static void mux_stop_tx(struct uart_port *port)
130 * mux_start_tx - Start transmitting characters.
131 * @port: Ptr to the uart_port.
133 * The Serial Mux does not support this function.
135 static void mux_start_tx(struct uart_port *port)
140 * mux_stop_rx - Stop receiving characters.
141 * @port: Ptr to the uart_port.
143 * The Serial Mux does not support this function.
145 static void mux_stop_rx(struct uart_port *port)
150 * mux_enable_ms - Enable modum status interrupts.
151 * @port: Ptr to the uart_port.
153 * The Serial Mux does not support this function.
155 static void mux_enable_ms(struct uart_port *port)
160 * mux_break_ctl - Control the transmitssion of a break signal.
161 * @port: Ptr to the uart_port.
162 * @break_state: Raise/Lower the break signal.
164 * The Serial Mux does not support this function.
166 static void mux_break_ctl(struct uart_port *port, int break_state)
171 * mux_write - Write chars to the mux fifo.
172 * @port: Ptr to the uart_port.
174 * This function writes all the data from the uart buffer to
177 static void mux_write(struct uart_port *port)
180 struct circ_buf *xmit = &port->info->xmit;
183 UART_PUT_CHAR(port, port->x_char);
189 if(uart_circ_empty(xmit) || uart_tx_stopped(port)) {
194 count = (port->fifosize) - UART_GET_FIFO_CNT(port);
196 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
197 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
199 if(uart_circ_empty(xmit))
202 } while(--count > 0);
204 while(UART_GET_FIFO_CNT(port))
207 if(uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
208 uart_write_wakeup(port);
210 if (uart_circ_empty(xmit))
215 * mux_read - Read chars from the mux fifo.
216 * @port: Ptr to the uart_port.
218 * This reads all available data from the mux's fifo and pushes
219 * the data to the tty layer.
221 static void mux_read(struct uart_port *port)
224 struct tty_struct *tty = port->info->tty;
225 __u32 start_count = port->icount.rx;
228 data = __raw_readl(port->membase + IO_DATA_REG_OFFSET);
230 if (MUX_STATUS(data))
233 if (MUX_EOFIFO(data))
238 if (MUX_BREAK(data)) {
240 if(uart_handle_break(port))
244 if (uart_handle_sysrq_char(port, data & 0xffu))
247 tty_insert_flip_char(tty, data & 0xFF, TTY_NORMAL);
250 if (start_count != port->icount.rx) {
251 tty_flip_buffer_push(tty);
256 * mux_startup - Initialize the port.
257 * @port: Ptr to the uart_port.
259 * Grab any resources needed for this port and start the
262 static int mux_startup(struct uart_port *port)
264 mux_ports[port->line].enabled = 1;
269 * mux_shutdown - Disable the port.
270 * @port: Ptr to the uart_port.
272 * Release any resources needed for the port.
274 static void mux_shutdown(struct uart_port *port)
276 mux_ports[port->line].enabled = 0;
280 * mux_set_termios - Chane port parameters.
281 * @port: Ptr to the uart_port.
282 * @termios: new termios settings.
283 * @old: old termios settings.
285 * The Serial Mux does not support this function.
288 mux_set_termios(struct uart_port *port, struct termios *termios,
294 * mux_type - Describe the port.
295 * @port: Ptr to the uart_port.
297 * Return a pointer to a string constant describing the
300 static const char *mux_type(struct uart_port *port)
306 * mux_release_port - Release memory and IO regions.
307 * @port: Ptr to the uart_port.
309 * Release any memory and IO region resources currently in use by
312 static void mux_release_port(struct uart_port *port)
317 * mux_request_port - Request memory and IO regions.
318 * @port: Ptr to the uart_port.
320 * Request any memory and IO region resources required by the port.
321 * If any fail, no resources should be registered when this function
322 * returns, and it should return -EBUSY on failure.
324 static int mux_request_port(struct uart_port *port)
330 * mux_config_port - Perform port autoconfiguration.
331 * @port: Ptr to the uart_port.
332 * @type: Bitmask of required configurations.
334 * Perform any autoconfiguration steps for the port. This function is
335 * called if the UPF_BOOT_AUTOCONF flag is specified for the port.
336 * [Note: This is required for now because of a bug in the Serial core.
337 * rmk has already submitted a patch to linus, should be available for
340 static void mux_config_port(struct uart_port *port, int type)
342 port->type = PORT_MUX;
346 * mux_verify_port - Verify the port information.
347 * @port: Ptr to the uart_port.
348 * @ser: Ptr to the serial information.
350 * Verify the new serial port information contained within serinfo is
351 * suitable for this port type.
353 static int mux_verify_port(struct uart_port *port, struct serial_struct *ser)
355 if(port->membase == NULL)
362 * mux_drv_poll - Mux poll function.
363 * @unused: Unused variable
365 * This function periodically polls the Serial MUX to check for new data.
367 static void mux_poll(unsigned long unused)
371 for(i = 0; i < port_cnt; ++i) {
372 if(!mux_ports[i].enabled)
375 mux_read(&mux_ports[i].port);
376 mux_write(&mux_ports[i].port);
379 mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
383 #ifdef CONFIG_SERIAL_MUX_CONSOLE
384 static void mux_console_write(struct console *co, const char *s, unsigned count)
386 /* Wait until the FIFO drains. */
387 while(UART_GET_FIFO_CNT(&mux_ports[0].port))
392 UART_PUT_CHAR(&mux_ports[0].port, '\r');
394 UART_PUT_CHAR(&mux_ports[0].port, *s++);
399 static int mux_console_setup(struct console *co, char *options)
404 struct tty_driver *mux_console_device(struct console *co, int *index)
407 return mux_driver.tty_driver;
410 static struct console mux_console = {
412 .write = mux_console_write,
413 .device = mux_console_device,
414 .setup = mux_console_setup,
415 .flags = CON_ENABLED | CON_PRINTBUFFER,
419 #define MUX_CONSOLE &mux_console
421 #define MUX_CONSOLE NULL
424 static struct uart_ops mux_pops = {
425 .tx_empty = mux_tx_empty,
426 .set_mctrl = mux_set_mctrl,
427 .get_mctrl = mux_get_mctrl,
428 .stop_tx = mux_stop_tx,
429 .start_tx = mux_start_tx,
430 .stop_rx = mux_stop_rx,
431 .enable_ms = mux_enable_ms,
432 .break_ctl = mux_break_ctl,
433 .startup = mux_startup,
434 .shutdown = mux_shutdown,
435 .set_termios = mux_set_termios,
437 .release_port = mux_release_port,
438 .request_port = mux_request_port,
439 .config_port = mux_config_port,
440 .verify_port = mux_verify_port,
444 * get_new_mux_card - Allocate and return a new mux card.
446 * This function is used to allocate and return a new mux card.
448 static struct mux_card * __init get_new_mux_card(void)
450 struct mux_card *card = mux_card_head;
453 mux_card_head = kzalloc(sizeof(struct mux_card), GFP_KERNEL);
455 printk(KERN_ERR "MUX: Unable to allocate memory.\n");
458 return mux_card_head;
465 card->next = kzalloc(sizeof(struct mux_card), GFP_KERNEL);
467 printk(KERN_ERR "MUX: Unable to allocate memory.\n");
475 * mux_probe - Determine if the Serial Mux should claim this device.
476 * @dev: The parisc device.
478 * Deterimine if the Serial Mux should claim this chip (return 0)
481 static int __init mux_probe(struct parisc_device *dev)
483 int i, status, ports;
485 unsigned long bytecnt;
486 struct uart_port *port;
487 struct mux_card *card;
489 status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32);
490 if(status != PDC_OK) {
491 printk(KERN_ERR "Serial mux: Unable to read IODC.\n");
495 ports = GET_MUX_PORTS(iodc_data);
496 printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.4\n", ports);
498 card = get_new_mux_card();
503 card->port_count = ports;
504 request_mem_region(card->dev->hpa.start + MUX_OFFSET,
505 card->port_count * MUX_LINE_OFFSET, "Mux");
508 mux_driver.cons = MUX_CONSOLE;
510 status = uart_register_driver(&mux_driver);
512 printk(KERN_ERR "Serial mux: Unable to register driver.\n");
516 init_timer(&mux_timer);
517 mux_timer.function = mux_poll;
520 for(i = 0; i < ports; ++i, ++port_cnt) {
521 port = &mux_ports[port_cnt].port;
523 port->mapbase = dev->hpa.start + MUX_OFFSET +
524 (i * MUX_LINE_OFFSET);
525 port->membase = ioremap_nocache(port->mapbase, MUX_LINE_OFFSET);
526 port->iotype = UPIO_MEM;
527 port->type = PORT_MUX;
530 port->fifosize = MUX_FIFO_SIZE;
531 port->ops = &mux_pops;
532 port->flags = UPF_BOOT_AUTOCONF;
533 port->line = port_cnt;
535 /* The port->timeout needs to match what is present in
536 * uart_wait_until_sent in serial_core.c. Otherwise
537 * the time spent in msleep_interruptable will be very
538 * long, causing the appearance of a console hang.
540 port->timeout = HZ / 50;
541 spin_lock_init(&port->lock);
542 status = uart_add_one_port(&mux_driver, port);
546 #ifdef CONFIG_SERIAL_MUX_CONSOLE
547 register_console(&mux_console);
549 mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
554 static struct parisc_device_id mux_tbl[] = {
555 { HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D },
559 MODULE_DEVICE_TABLE(parisc, mux_tbl);
561 static struct parisc_driver serial_mux_driver = {
562 .name = "serial_mux",
568 * mux_init - Serial MUX initalization procedure.
570 * Register the Serial MUX driver.
572 static int __init mux_init(void)
574 return register_parisc_driver(&serial_mux_driver);
578 * mux_exit - Serial MUX cleanup procedure.
580 * Unregister the Serial MUX driver from the tty layer.
582 static void __exit mux_exit(void)
585 struct mux_card *next;
586 struct mux_card *card = mux_card_head;
588 for (i = 0; i < port_cnt; i++) {
589 uart_remove_one_port(&mux_driver, &mux_ports[i].port);
590 if (mux_ports[i].port.membase)
591 iounmap(mux_ports[i].port.membase);
594 while(card != NULL) {
595 release_mem_region(card->dev->hpa.start + MUX_OFFSET,
596 card->port_count * MUX_LINE_OFFSET);
603 uart_unregister_driver(&mux_driver);
606 module_init(mux_init);
607 module_exit(mux_exit);
609 MODULE_AUTHOR("Ryan Bradetich");
610 MODULE_DESCRIPTION("Serial MUX driver");
611 MODULE_LICENSE("GPL");
612 MODULE_ALIAS_CHARDEV_MAJOR(MUX_MAJOR);