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>
28 #ifdef CONFIG_MAGIC_SYSRQ
29 #include <linux/sysrq.h>
33 #include <linux/serial_core.h>
37 #define MUX_OFFSET 0x800
38 #define MUX_LINE_OFFSET 0x80
40 #define MUX_FIFO_SIZE 255
41 #define MUX_MIN_FREE_SIZE 32
43 #define MUX_FIFO_DRAIN_DELAY 1
44 #define MUX_POLL_DELAY (30 * HZ / 1000)
46 #define IO_COMMAND_REG_OFFSET 0x30
47 #define IO_STATUS_REG_OFFSET 0x34
48 #define IO_DATA_REG_OFFSET 0x3c
49 #define IO_DCOUNT_REG_OFFSET 0x40
50 #define IO_UCOUNT_REG_OFFSET 0x44
51 #define IO_FIFOS_REG_OFFSET 0x48
53 #define MUX_EOFIFO(status) ((status & 0xF000) == 0xF000)
54 #define MUX_STATUS(status) ((status & 0xF000) == 0x8000)
55 #define MUX_BREAK(status) ((status & 0xF000) == 0x2000)
58 static struct uart_port mux_ports
[MUX_NR
];
59 static struct timer_list mux_timer
;
61 #define UART_PUT_CHAR(p, c) __raw_writel((c), (unsigned long)(p)->membase + IO_DATA_REG_OFFSET)
62 #define UART_GET_FIFO_CNT(p) __raw_readl((unsigned long)(p)->membase + IO_DCOUNT_REG_OFFSET)
65 * mux_tx_empty - Check if the transmitter fifo is empty.
66 * @port: Ptr to the uart_port.
68 * This function test if the transmitter fifo for the port
69 * described by 'port' is empty. If it is empty, this function
70 * should return TIOCSER_TEMT, otherwise return 0.
72 static unsigned int mux_tx_empty(struct uart_port
*port
)
74 unsigned int cnt
= __raw_readl((unsigned long)port
->membase
75 + IO_DCOUNT_REG_OFFSET
);
77 return cnt
? 0 : TIOCSER_TEMT
;
81 * mux_set_mctrl - Set the current state of the modem control inputs.
82 * @ports: Ptr to the uart_port.
83 * @mctrl: Modem control bits.
85 * The Serial MUX does not support CTS, DCD or DSR so this function
88 static void mux_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
93 * mux_get_mctrl - Returns the current state of modem control inputs.
94 * @port: Ptr to the uart_port.
96 * The Serial MUX does not support CTS, DCD or DSR so these lines are
97 * treated as permanently active.
99 static unsigned int mux_get_mctrl(struct uart_port
*port
)
101 return TIOCM_CAR
| TIOCM_DSR
| TIOCM_CTS
;
105 * mux_stop_tx - Stop transmitting characters.
106 * @port: Ptr to the uart_port.
107 * @tty_stop: tty layer issue this command?
109 * The Serial MUX does not support this function.
111 static void mux_stop_tx(struct uart_port
*port
, unsigned int tty_stop
)
116 * mux_start_tx - Start transmitting characters.
117 * @port: Ptr to the uart_port.
118 * @tty_start: tty layer issue this command?
120 * The Serial Mux does not support this function.
122 static void mux_start_tx(struct uart_port
*port
, unsigned int tty_start
)
127 * mux_stop_rx - Stop receiving characters.
128 * @port: Ptr to the uart_port.
130 * The Serial Mux does not support this function.
132 static void mux_stop_rx(struct uart_port
*port
)
137 * mux_enable_ms - Enable modum status interrupts.
138 * @port: Ptr to the uart_port.
140 * The Serial Mux does not support this function.
142 static void mux_enable_ms(struct uart_port
*port
)
147 * mux_break_ctl - Control the transmitssion of a break signal.
148 * @port: Ptr to the uart_port.
149 * @break_state: Raise/Lower the break signal.
151 * The Serial Mux does not support this function.
153 static void mux_break_ctl(struct uart_port
*port
, int break_state
)
158 * mux_write - Write chars to the mux fifo.
159 * @port: Ptr to the uart_port.
161 * This function writes all the data from the uart buffer to
164 static void mux_write(struct uart_port
*port
)
167 struct circ_buf
*xmit
= &port
->info
->xmit
;
170 UART_PUT_CHAR(port
, port
->x_char
);
176 if(uart_circ_empty(xmit
) || uart_tx_stopped(port
)) {
177 mux_stop_tx(port
, 0);
181 count
= (port
->fifosize
>> 1) - UART_GET_FIFO_CNT(port
);
183 UART_PUT_CHAR(port
, xmit
->buf
[xmit
->tail
]);
184 xmit
->tail
= (xmit
->tail
+ 1) & (UART_XMIT_SIZE
- 1);
186 if(uart_circ_empty(xmit
))
189 } while(--count
> 0);
191 if(uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
192 uart_write_wakeup(port
);
194 if (uart_circ_empty(xmit
))
195 mux_stop_tx(port
, 0);
199 * mux_read - Read chars from the mux fifo.
200 * @port: Ptr to the uart_port.
202 * This reads all available data from the mux's fifo and pushes
203 * the data to the tty layer.
205 static void mux_read(struct uart_port
*port
)
208 __u32 start_count
= port
->icount
.rx
;
209 struct tty_struct
*tty
= port
->info
->tty
;
212 data
= __raw_readl((unsigned long)port
->membase
213 + IO_DATA_REG_OFFSET
);
215 if (MUX_STATUS(data
))
218 if (MUX_EOFIFO(data
))
221 if (tty
->flip
.count
>= TTY_FLIPBUF_SIZE
)
224 *tty
->flip
.char_buf_ptr
= data
& 0xffu
;
225 *tty
->flip
.flag_buf_ptr
= TTY_NORMAL
;
228 if (MUX_BREAK(data
)) {
230 if(uart_handle_break(port
))
234 if (uart_handle_sysrq_char(port
, data
& 0xffu
, NULL
))
237 tty
->flip
.flag_buf_ptr
++;
238 tty
->flip
.char_buf_ptr
++;
242 if (start_count
!= port
->icount
.rx
) {
243 tty_flip_buffer_push(tty
);
248 * mux_startup - Initialize the port.
249 * @port: Ptr to the uart_port.
251 * Grab any resources needed for this port and start the
254 static int mux_startup(struct uart_port
*port
)
256 mod_timer(&mux_timer
, jiffies
+ MUX_POLL_DELAY
);
261 * mux_shutdown - Disable the port.
262 * @port: Ptr to the uart_port.
264 * Release any resources needed for the port.
266 static void mux_shutdown(struct uart_port
*port
)
271 * mux_set_termios - Chane port parameters.
272 * @port: Ptr to the uart_port.
273 * @termios: new termios settings.
274 * @old: old termios settings.
276 * The Serial Mux does not support this function.
279 mux_set_termios(struct uart_port
*port
, struct termios
*termios
,
285 * mux_type - Describe the port.
286 * @port: Ptr to the uart_port.
288 * Return a pointer to a string constant describing the
291 static const char *mux_type(struct uart_port
*port
)
297 * release_port - Release memory and IO regions.
298 * @port: Ptr to the uart_port.
300 * Release any memory and IO region resources currently in use by
303 static void mux_release_port(struct uart_port
*port
)
308 * mux_request_port - Request memory and IO regions.
309 * @port: Ptr to the uart_port.
311 * Request any memory and IO region resources required by the port.
312 * If any fail, no resources should be registered when this function
313 * returns, and it should return -EBUSY on failure.
315 static int mux_request_port(struct uart_port
*port
)
321 * mux_config_port - Perform port autoconfiguration.
322 * @port: Ptr to the uart_port.
323 * @type: Bitmask of required configurations.
325 * Perform any autoconfiguration steps for the port. This functino is
326 * called if the UPF_BOOT_AUTOCONF flag is specified for the port.
327 * [Note: This is required for now because of a bug in the Serial core.
328 * rmk has already submitted a patch to linus, should be available for
331 static void mux_config_port(struct uart_port
*port
, int type
)
333 port
->type
= PORT_MUX
;
337 * mux_verify_port - Verify the port information.
338 * @port: Ptr to the uart_port.
339 * @ser: Ptr to the serial information.
341 * Verify the new serial port information contained within serinfo is
342 * suitable for this port type.
344 static int mux_verify_port(struct uart_port
*port
, struct serial_struct
*ser
)
346 if(port
->membase
== NULL
)
353 * mux_drv_poll - Mux poll function.
354 * @unused: Unused variable
356 * This function periodically polls the Serial MUX to check for new data.
358 static void mux_poll(unsigned long unused
)
360 struct uart_port
*port
= &mux_ports
[0];
364 mod_timer(&mux_timer
, jiffies
+ MUX_POLL_DELAY
);
368 #ifdef CONFIG_SERIAL_MUX_CONSOLE
369 static struct console mux_console
= {
371 .flags
= CON_PRINTBUFFER
,
374 #define MUX_CONSOLE &mux_console
376 #define MUX_CONSOLE NULL
379 static struct uart_ops mux_pops
= {
380 .tx_empty
= mux_tx_empty
,
381 .set_mctrl
= mux_set_mctrl
,
382 .get_mctrl
= mux_get_mctrl
,
383 .stop_tx
= mux_stop_tx
,
384 .start_tx
= mux_start_tx
,
385 .stop_rx
= mux_stop_rx
,
386 .enable_ms
= mux_enable_ms
,
387 .break_ctl
= mux_break_ctl
,
388 .startup
= mux_startup
,
389 .shutdown
= mux_shutdown
,
390 .set_termios
= mux_set_termios
,
392 .release_port
= mux_release_port
,
393 .request_port
= mux_request_port
,
394 .config_port
= mux_config_port
,
395 .verify_port
= mux_verify_port
,
398 static struct uart_driver mux_reg
= {
399 .owner
= THIS_MODULE
,
400 .driver_name
= "ttyB",
401 #ifdef CONFIG_DEVFS_FS
402 .dev_name
= "ttyB%d",
404 .dev_name
= "ttyB%d",
413 * mux_probe - Determine if the Serial Mux should claim this device.
414 * @dev: The parisc device.
416 * Deterimine if the Serial Mux should claim this chip (return 0)
419 static int __init
mux_probe(struct parisc_device
*dev
)
422 struct uart_port
*port
= &mux_ports
[0];
424 init_timer(&mux_timer
);
425 mux_timer
.function
= mux_poll
;
427 printk(KERN_INFO
"Serial mux driver Revision: 0.1\n");
429 ret
= uart_register_driver(&mux_reg
);
433 for (i
= 0; i
< MUX_NR
; i
++) {
434 port
= &mux_ports
[i
];
437 port
->mapbase
= dev
->hpa
+ MUX_OFFSET
+ (i
* MUX_LINE_OFFSET
);
438 port
->membase
= ioremap(port
->mapbase
, MUX_LINE_OFFSET
);
439 port
->iotype
= SERIAL_IO_MEM
;
440 port
->type
= PORT_MUX
;
441 port
->irq
= SERIAL_IRQ_NONE
;
443 port
->fifosize
= MUX_FIFO_SIZE
;
444 port
->ops
= &mux_pops
;
445 port
->flags
= UPF_BOOT_AUTOCONF
;
448 uart_add_one_port(&mux_reg
, port
);
454 static struct parisc_device_id mux_tbl
[] = {
455 { HPHW_A_DIRECT
, HVERSION_REV_ANY_ID
, HVERSION_ANY_ID
, 0x0000D },
459 MODULE_DEVICE_TABLE(parisc
, mux_tbl
);
461 static struct parisc_driver mux_driver
= {
462 .name
= "Serial MUX driver",
468 * mux_init - Serial MUX initalization procedure.
470 * Register the Serial MUX driver.
472 static int __init
mux_init(void)
474 return register_parisc_driver(&mux_driver
);
478 * mux_exit - Serial MUX cleanup procedure.
480 * Unregister the Serial MUX driver from the tty layer.
482 static void __exit
mux_exit(void)
486 for (i
= 0; i
< MUX_NR
; i
++) {
487 uart_remove_one_port(&mux_reg
, &mux_ports
[i
]);
490 uart_unregister_driver(&mux_reg
);
493 module_init(mux_init
);
494 module_exit(mux_exit
);
496 MODULE_AUTHOR("Ryan Bradetich");
497 MODULE_DESCRIPTION("Serial MUX driver");
498 MODULE_LICENSE("GPL");