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/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>
31 #include <asm/parisc-device.h>
33 #ifdef CONFIG_MAGIC_SYSRQ
34 #include <linux/sysrq.h>
38 #include <linux/serial_core.h>
40 #define MUX_OFFSET 0x800
41 #define MUX_LINE_OFFSET 0x80
43 #define MUX_FIFO_SIZE 255
44 #define MUX_POLL_DELAY (30 * HZ / 1000)
46 #define IO_DATA_REG_OFFSET 0x3c
47 #define IO_DCOUNT_REG_OFFSET 0x40
49 #define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
50 #define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
51 #define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
54 static unsigned int port_cnt = 0;
55 static struct uart_port mux_ports[MUX_NR];
57 static struct uart_driver mux_driver = {
59 .driver_name = "ttyB",
66 static struct timer_list mux_timer;
68 #define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + IO_DATA_REG_OFFSET)
69 #define UART_GET_FIFO_CNT(p) __raw_readl((p)->membase + IO_DCOUNT_REG_OFFSET)
70 #define GET_MUX_PORTS(iodc_data) ((((iodc_data)[4] & 0xf0) >> 4) * 8) + 8
73 * mux_tx_empty - Check if the transmitter fifo is empty.
74 * @port: Ptr to the uart_port.
76 * This function test if the transmitter fifo for the port
77 * described by 'port' is empty. If it is empty, this function
78 * should return TIOCSER_TEMT, otherwise return 0.
80 static unsigned int mux_tx_empty(struct uart_port *port)
82 return UART_GET_FIFO_CNT(port) ? 0 : TIOCSER_TEMT;
86 * mux_set_mctrl - Set the current state of the modem control inputs.
87 * @ports: Ptr to the uart_port.
88 * @mctrl: Modem control bits.
90 * The Serial MUX does not support CTS, DCD or DSR so this function
93 static void mux_set_mctrl(struct uart_port *port, unsigned int mctrl)
98 * mux_get_mctrl - Returns the current state of modem control inputs.
99 * @port: Ptr to the uart_port.
101 * The Serial MUX does not support CTS, DCD or DSR so these lines are
102 * treated as permanently active.
104 static unsigned int mux_get_mctrl(struct uart_port *port)
106 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
110 * mux_stop_tx - Stop transmitting characters.
111 * @port: Ptr to the uart_port.
113 * The Serial MUX does not support this function.
115 static void mux_stop_tx(struct uart_port *port)
120 * mux_start_tx - Start transmitting characters.
121 * @port: Ptr to the uart_port.
123 * The Serial Mux does not support this function.
125 static void mux_start_tx(struct uart_port *port)
130 * mux_stop_rx - Stop receiving characters.
131 * @port: Ptr to the uart_port.
133 * The Serial Mux does not support this function.
135 static void mux_stop_rx(struct uart_port *port)
140 * mux_enable_ms - Enable modum status interrupts.
141 * @port: Ptr to the uart_port.
143 * The Serial Mux does not support this function.
145 static void mux_enable_ms(struct uart_port *port)
150 * mux_break_ctl - Control the transmitssion of a break signal.
151 * @port: Ptr to the uart_port.
152 * @break_state: Raise/Lower the break signal.
154 * The Serial Mux does not support this function.
156 static void mux_break_ctl(struct uart_port *port, int break_state)
161 * mux_write - Write chars to the mux fifo.
162 * @port: Ptr to the uart_port.
164 * This function writes all the data from the uart buffer to
167 static void mux_write(struct uart_port *port)
170 struct circ_buf *xmit = &port->info->xmit;
173 UART_PUT_CHAR(port, port->x_char);
179 if(uart_circ_empty(xmit) || uart_tx_stopped(port)) {
184 count = (port->fifosize) - UART_GET_FIFO_CNT(port);
186 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
187 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
189 if(uart_circ_empty(xmit))
192 } while(--count > 0);
194 while(UART_GET_FIFO_CNT(port))
197 if(uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
198 uart_write_wakeup(port);
200 if (uart_circ_empty(xmit))
205 * mux_read - Read chars from the mux fifo.
206 * @port: Ptr to the uart_port.
208 * This reads all available data from the mux's fifo and pushes
209 * the data to the tty layer.
211 static void mux_read(struct uart_port *port)
214 struct tty_struct *tty = port->info->tty;
215 __u32 start_count = port->icount.rx;
218 data = __raw_readl(port->membase + IO_DATA_REG_OFFSET);
220 if (MUX_STATUS(data))
223 if (MUX_EOFIFO(data))
226 if (tty->flip.count >= TTY_FLIPBUF_SIZE)
229 *tty->flip.char_buf_ptr = data & 0xffu;
230 *tty->flip.flag_buf_ptr = TTY_NORMAL;
233 if (MUX_BREAK(data)) {
235 if(uart_handle_break(port))
239 if (uart_handle_sysrq_char(port, data & 0xffu, NULL))
242 tty->flip.flag_buf_ptr++;
243 tty->flip.char_buf_ptr++;
247 if (start_count != port->icount.rx) {
248 tty_flip_buffer_push(tty);
253 * mux_startup - Initialize the port.
254 * @port: Ptr to the uart_port.
256 * Grab any resources needed for this port and start the
259 static int mux_startup(struct uart_port *port)
261 mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
266 * mux_shutdown - Disable the port.
267 * @port: Ptr to the uart_port.
269 * Release any resources needed for the port.
271 static void mux_shutdown(struct uart_port *port)
276 * mux_set_termios - Chane port parameters.
277 * @port: Ptr to the uart_port.
278 * @termios: new termios settings.
279 * @old: old termios settings.
281 * The Serial Mux does not support this function.
284 mux_set_termios(struct uart_port *port, struct termios *termios,
290 * mux_type - Describe the port.
291 * @port: Ptr to the uart_port.
293 * Return a pointer to a string constant describing the
296 static const char *mux_type(struct uart_port *port)
302 * mux_release_port - Release memory and IO regions.
303 * @port: Ptr to the uart_port.
305 * Release any memory and IO region resources currently in use by
308 static void mux_release_port(struct uart_port *port)
313 * mux_request_port - Request memory and IO regions.
314 * @port: Ptr to the uart_port.
316 * Request any memory and IO region resources required by the port.
317 * If any fail, no resources should be registered when this function
318 * returns, and it should return -EBUSY on failure.
320 static int mux_request_port(struct uart_port *port)
326 * mux_config_port - Perform port autoconfiguration.
327 * @port: Ptr to the uart_port.
328 * @type: Bitmask of required configurations.
330 * Perform any autoconfiguration steps for the port. This functino is
331 * called if the UPF_BOOT_AUTOCONF flag is specified for the port.
332 * [Note: This is required for now because of a bug in the Serial core.
333 * rmk has already submitted a patch to linus, should be available for
336 static void mux_config_port(struct uart_port *port, int type)
338 port->type = PORT_MUX;
342 * mux_verify_port - Verify the port information.
343 * @port: Ptr to the uart_port.
344 * @ser: Ptr to the serial information.
346 * Verify the new serial port information contained within serinfo is
347 * suitable for this port type.
349 static int mux_verify_port(struct uart_port *port, struct serial_struct *ser)
351 if(port->membase == NULL)
358 * mux_drv_poll - Mux poll function.
359 * @unused: Unused variable
361 * This function periodically polls the Serial MUX to check for new data.
363 static void mux_poll(unsigned long unused)
367 for(i = 0; i < port_cnt; ++i) {
368 if(!mux_ports[i].info)
371 mux_read(&mux_ports[i]);
372 mux_write(&mux_ports[i]);
375 mod_timer(&mux_timer, jiffies + MUX_POLL_DELAY);
379 #ifdef CONFIG_SERIAL_MUX_CONSOLE
380 static void mux_console_write(struct console *co, const char *s, unsigned count)
386 static int mux_console_setup(struct console *co, char *options)
391 struct tty_driver *mux_console_device(struct console *co, int *index)
394 return mux_driver.tty_driver;
397 static struct console mux_console = {
399 .write = mux_console_write,
400 .device = mux_console_device,
401 .setup = mux_console_setup,
402 .flags = CON_ENABLED | CON_PRINTBUFFER,
406 #define MUX_CONSOLE &mux_console
408 #define MUX_CONSOLE NULL
411 static struct uart_ops mux_pops = {
412 .tx_empty = mux_tx_empty,
413 .set_mctrl = mux_set_mctrl,
414 .get_mctrl = mux_get_mctrl,
415 .stop_tx = mux_stop_tx,
416 .start_tx = mux_start_tx,
417 .stop_rx = mux_stop_rx,
418 .enable_ms = mux_enable_ms,
419 .break_ctl = mux_break_ctl,
420 .startup = mux_startup,
421 .shutdown = mux_shutdown,
422 .set_termios = mux_set_termios,
424 .release_port = mux_release_port,
425 .request_port = mux_request_port,
426 .config_port = mux_config_port,
427 .verify_port = mux_verify_port,
431 * mux_probe - Determine if the Serial Mux should claim this device.
432 * @dev: The parisc device.
434 * Deterimine if the Serial Mux should claim this chip (return 0)
437 static int __init mux_probe(struct parisc_device *dev)
439 int i, status, ports;
441 unsigned long bytecnt;
442 struct uart_port *port;
444 status = pdc_iodc_read(&bytecnt, dev->hpa.start, 0, iodc_data, 32);
445 if(status != PDC_OK) {
446 printk(KERN_ERR "Serial mux: Unable to read IODC.\n");
450 ports = GET_MUX_PORTS(iodc_data);
451 printk(KERN_INFO "Serial mux driver (%d ports) Revision: 0.3\n", ports);
454 mux_driver.cons = MUX_CONSOLE;
456 status = uart_register_driver(&mux_driver);
458 printk(KERN_ERR "Serial mux: Unable to register driver.\n");
462 init_timer(&mux_timer);
463 mux_timer.function = mux_poll;
466 for(i = 0; i < ports; ++i, ++port_cnt) {
467 port = &mux_ports[port_cnt];
469 port->mapbase = dev->hpa.start + MUX_OFFSET +
470 (i * MUX_LINE_OFFSET);
471 port->membase = ioremap(port->mapbase, MUX_LINE_OFFSET);
472 port->iotype = SERIAL_IO_MEM;
473 port->type = PORT_MUX;
476 port->fifosize = MUX_FIFO_SIZE;
477 port->ops = &mux_pops;
478 port->flags = UPF_BOOT_AUTOCONF;
479 port->line = port_cnt;
481 /* The port->timeout needs to match what is present in
482 * uart_wait_until_sent in serial_core.c. Otherwise
483 * the time spent in msleep_interruptable will be very
484 * long, causing the appearance of a console hang.
486 port->timeout = HZ / 50;
487 spin_lock_init(&port->lock);
488 status = uart_add_one_port(&mux_driver, port);
492 #ifdef CONFIG_SERIAL_MUX_CONSOLE
493 register_console(&mux_console);
498 static struct parisc_device_id mux_tbl[] = {
499 { HPHW_A_DIRECT, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0000D },
503 MODULE_DEVICE_TABLE(parisc, mux_tbl);
505 static struct parisc_driver serial_mux_driver = {
506 .name = "serial_mux",
512 * mux_init - Serial MUX initalization procedure.
514 * Register the Serial MUX driver.
516 static int __init mux_init(void)
518 return register_parisc_driver(&serial_mux_driver);
522 * mux_exit - Serial MUX cleanup procedure.
524 * Unregister the Serial MUX driver from the tty layer.
526 static void __exit mux_exit(void)
530 for (i = 0; i < port_cnt; i++) {
531 uart_remove_one_port(&mux_driver, &mux_ports[i]);
534 uart_unregister_driver(&mux_driver);
537 module_init(mux_init);
538 module_exit(mux_exit);
540 MODULE_AUTHOR("Ryan Bradetich");
541 MODULE_DESCRIPTION("Serial MUX driver");
542 MODULE_LICENSE("GPL");
543 MODULE_ALIAS_CHARDEV_MAJOR(MUX_MAJOR);