2 * Driver for GRLIB serial ports (APBUART)
4 * Based on linux/drivers/serial/amba.c
6 * Copyright (C) 2000 Deep Blue Solutions Ltd.
7 * Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
8 * Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
9 * Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
10 * Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
13 #if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
17 #include <linux/module.h>
18 #include <linux/tty.h>
19 #include <linux/ioport.h>
20 #include <linux/init.h>
21 #include <linux/serial.h>
22 #include <linux/console.h>
23 #include <linux/sysrq.h>
24 #include <linux/kthread.h>
25 #include <linux/device.h>
27 #include <linux/of_device.h>
28 #include <linux/of_platform.h>
29 #include <linux/platform_device.h>
31 #include <linux/serial_core.h>
36 #define SERIAL_APBUART_MAJOR TTY_MAJOR
37 #define SERIAL_APBUART_MINOR 64
38 #define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
40 static void apbuart_tx_chars(struct uart_port
*port
);
42 static void apbuart_stop_tx(struct uart_port
*port
)
46 cr
= UART_GET_CTRL(port
);
48 UART_PUT_CTRL(port
, cr
);
51 static void apbuart_start_tx(struct uart_port
*port
)
55 cr
= UART_GET_CTRL(port
);
57 UART_PUT_CTRL(port
, cr
);
59 if (UART_GET_STATUS(port
) & UART_STATUS_THE
)
60 apbuart_tx_chars(port
);
63 static void apbuart_stop_rx(struct uart_port
*port
)
67 cr
= UART_GET_CTRL(port
);
68 cr
&= ~(UART_CTRL_RI
);
69 UART_PUT_CTRL(port
, cr
);
72 static void apbuart_enable_ms(struct uart_port
*port
)
74 /* No modem status change interrupts for APBUART */
77 static void apbuart_rx_chars(struct uart_port
*port
)
79 struct tty_struct
*tty
= port
->state
->port
.tty
;
80 unsigned int status
, ch
, rsr
, flag
;
81 unsigned int max_chars
= port
->fifosize
;
83 status
= UART_GET_STATUS(port
);
85 while (UART_RX_DATA(status
) && (max_chars
--)) {
87 ch
= UART_GET_CHAR(port
);
92 rsr
= UART_GET_STATUS(port
) | UART_DUMMY_RSR_RX
;
93 UART_PUT_STATUS(port
, 0);
94 if (rsr
& UART_STATUS_ERR
) {
96 if (rsr
& UART_STATUS_BR
) {
97 rsr
&= ~(UART_STATUS_FE
| UART_STATUS_PE
);
99 if (uart_handle_break(port
))
101 } else if (rsr
& UART_STATUS_PE
) {
102 port
->icount
.parity
++;
103 } else if (rsr
& UART_STATUS_FE
) {
104 port
->icount
.frame
++;
106 if (rsr
& UART_STATUS_OE
)
107 port
->icount
.overrun
++;
109 rsr
&= port
->read_status_mask
;
111 if (rsr
& UART_STATUS_PE
)
113 else if (rsr
& UART_STATUS_FE
)
117 if (uart_handle_sysrq_char(port
, ch
))
120 uart_insert_char(port
, rsr
, UART_STATUS_OE
, ch
, flag
);
124 status
= UART_GET_STATUS(port
);
127 tty_flip_buffer_push(tty
);
130 static void apbuart_tx_chars(struct uart_port
*port
)
132 struct circ_buf
*xmit
= &port
->state
->xmit
;
136 UART_PUT_CHAR(port
, port
->x_char
);
142 if (uart_circ_empty(xmit
) || uart_tx_stopped(port
)) {
143 apbuart_stop_tx(port
);
147 /* amba: fill FIFO */
148 count
= port
->fifosize
>> 1;
150 UART_PUT_CHAR(port
, xmit
->buf
[xmit
->tail
]);
151 xmit
->tail
= (xmit
->tail
+ 1) & (UART_XMIT_SIZE
- 1);
153 if (uart_circ_empty(xmit
))
155 } while (--count
> 0);
157 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
158 uart_write_wakeup(port
);
160 if (uart_circ_empty(xmit
))
161 apbuart_stop_tx(port
);
164 static irqreturn_t
apbuart_int(int irq
, void *dev_id
)
166 struct uart_port
*port
= dev_id
;
169 spin_lock(&port
->lock
);
171 status
= UART_GET_STATUS(port
);
172 if (status
& UART_STATUS_DR
)
173 apbuart_rx_chars(port
);
174 if (status
& UART_STATUS_THE
)
175 apbuart_tx_chars(port
);
177 spin_unlock(&port
->lock
);
182 static unsigned int apbuart_tx_empty(struct uart_port
*port
)
184 unsigned int status
= UART_GET_STATUS(port
);
185 return status
& UART_STATUS_THE
? TIOCSER_TEMT
: 0;
188 static unsigned int apbuart_get_mctrl(struct uart_port
*port
)
190 /* The GRLIB APBUART handles flow control in hardware */
191 return TIOCM_CAR
| TIOCM_DSR
| TIOCM_CTS
;
194 static void apbuart_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
196 /* The GRLIB APBUART handles flow control in hardware */
199 static void apbuart_break_ctl(struct uart_port
*port
, int break_state
)
201 /* We don't support sending break */
204 static int apbuart_startup(struct uart_port
*port
)
209 /* Allocate the IRQ */
210 retval
= request_irq(port
->irq
, apbuart_int
, 0, "apbuart", port
);
214 /* Finally, enable interrupts */
215 cr
= UART_GET_CTRL(port
);
217 cr
| UART_CTRL_RE
| UART_CTRL_TE
|
218 UART_CTRL_RI
| UART_CTRL_TI
);
223 static void apbuart_shutdown(struct uart_port
*port
)
227 /* disable all interrupts, disable the port */
228 cr
= UART_GET_CTRL(port
);
230 cr
& ~(UART_CTRL_RE
| UART_CTRL_TE
|
231 UART_CTRL_RI
| UART_CTRL_TI
));
233 /* Free the interrupt */
234 free_irq(port
->irq
, port
);
237 static void apbuart_set_termios(struct uart_port
*port
,
238 struct ktermios
*termios
, struct ktermios
*old
)
242 unsigned int baud
, quot
;
244 /* Ask the core to calculate the divisor for us. */
245 baud
= uart_get_baud_rate(port
, termios
, old
, 0, port
->uartclk
/ 16);
247 panic("invalid baudrate %i\n", port
->uartclk
/ 16);
249 /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
250 quot
= (uart_get_divisor(port
, baud
)) * 2;
251 cr
= UART_GET_CTRL(port
);
252 cr
&= ~(UART_CTRL_PE
| UART_CTRL_PS
);
254 if (termios
->c_cflag
& PARENB
) {
256 if ((termios
->c_cflag
& PARODD
))
260 /* Enable flow control. */
261 if (termios
->c_cflag
& CRTSCTS
)
264 spin_lock_irqsave(&port
->lock
, flags
);
266 /* Update the per-port timeout. */
267 uart_update_timeout(port
, termios
->c_cflag
, baud
);
269 port
->read_status_mask
= UART_STATUS_OE
;
270 if (termios
->c_iflag
& INPCK
)
271 port
->read_status_mask
|= UART_STATUS_FE
| UART_STATUS_PE
;
273 /* Characters to ignore */
274 port
->ignore_status_mask
= 0;
275 if (termios
->c_iflag
& IGNPAR
)
276 port
->ignore_status_mask
|= UART_STATUS_FE
| UART_STATUS_PE
;
278 /* Ignore all characters if CREAD is not set. */
279 if ((termios
->c_cflag
& CREAD
) == 0)
280 port
->ignore_status_mask
|= UART_DUMMY_RSR_RX
;
284 UART_PUT_SCAL(port
, quot
);
285 UART_PUT_CTRL(port
, cr
);
287 spin_unlock_irqrestore(&port
->lock
, flags
);
290 static const char *apbuart_type(struct uart_port
*port
)
292 return port
->type
== PORT_APBUART
? "GRLIB/APBUART" : NULL
;
295 static void apbuart_release_port(struct uart_port
*port
)
297 release_mem_region(port
->mapbase
, 0x100);
300 static int apbuart_request_port(struct uart_port
*port
)
302 return request_mem_region(port
->mapbase
, 0x100, "grlib-apbuart")
303 != NULL
? 0 : -EBUSY
;
307 /* Configure/autoconfigure the port */
308 static void apbuart_config_port(struct uart_port
*port
, int flags
)
310 if (flags
& UART_CONFIG_TYPE
) {
311 port
->type
= PORT_APBUART
;
312 apbuart_request_port(port
);
316 /* Verify the new serial_struct (for TIOCSSERIAL) */
317 static int apbuart_verify_port(struct uart_port
*port
,
318 struct serial_struct
*ser
)
321 if (ser
->type
!= PORT_UNKNOWN
&& ser
->type
!= PORT_APBUART
)
323 if (ser
->irq
< 0 || ser
->irq
>= NR_IRQS
)
325 if (ser
->baud_base
< 9600)
330 static struct uart_ops grlib_apbuart_ops
= {
331 .tx_empty
= apbuart_tx_empty
,
332 .set_mctrl
= apbuart_set_mctrl
,
333 .get_mctrl
= apbuart_get_mctrl
,
334 .stop_tx
= apbuart_stop_tx
,
335 .start_tx
= apbuart_start_tx
,
336 .stop_rx
= apbuart_stop_rx
,
337 .enable_ms
= apbuart_enable_ms
,
338 .break_ctl
= apbuart_break_ctl
,
339 .startup
= apbuart_startup
,
340 .shutdown
= apbuart_shutdown
,
341 .set_termios
= apbuart_set_termios
,
342 .type
= apbuart_type
,
343 .release_port
= apbuart_release_port
,
344 .request_port
= apbuart_request_port
,
345 .config_port
= apbuart_config_port
,
346 .verify_port
= apbuart_verify_port
,
349 static struct uart_port grlib_apbuart_ports
[UART_NR
];
350 static struct device_node
*grlib_apbuart_nodes
[UART_NR
];
352 static int apbuart_scan_fifo_size(struct uart_port
*port
, int portnumber
)
359 ctrl
= UART_GET_CTRL(port
);
362 * Enable the transceiver and wait for it to be ready to send data.
363 * Clear interrupts so that this process will not be externally
364 * interrupted in the middle (which can cause the transceiver to
365 * drain prematurely).
368 local_irq_save(flags
);
370 UART_PUT_CTRL(port
, ctrl
| UART_CTRL_TE
);
372 while (!UART_TX_READY(UART_GET_STATUS(port
)))
376 * Disable the transceiver so data isn't actually sent during the
380 UART_PUT_CTRL(port
, ctrl
& ~(UART_CTRL_TE
));
383 UART_PUT_CHAR(port
, 0);
386 * So long as transmitting a character increments the tranceivier FIFO
387 * length the FIFO must be at least that big. These bytes will
388 * automatically drain off of the FIFO.
391 status
= UART_GET_STATUS(port
);
392 while (((status
>> 20) & 0x3F) == fifosize
) {
394 UART_PUT_CHAR(port
, 0);
395 status
= UART_GET_STATUS(port
);
400 UART_PUT_CTRL(port
, ctrl
);
401 local_irq_restore(flags
);
409 static void apbuart_flush_fifo(struct uart_port
*port
)
413 for (i
= 0; i
< port
->fifosize
; i
++)
418 /* ======================================================================== */
419 /* Console driver, if enabled */
420 /* ======================================================================== */
422 #ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
424 static void apbuart_console_putchar(struct uart_port
*port
, int ch
)
428 status
= UART_GET_STATUS(port
);
429 } while (!UART_TX_READY(status
));
430 UART_PUT_CHAR(port
, ch
);
434 apbuart_console_write(struct console
*co
, const char *s
, unsigned int count
)
436 struct uart_port
*port
= &grlib_apbuart_ports
[co
->index
];
437 unsigned int status
, old_cr
, new_cr
;
439 /* First save the CR then disable the interrupts */
440 old_cr
= UART_GET_CTRL(port
);
441 new_cr
= old_cr
& ~(UART_CTRL_RI
| UART_CTRL_TI
);
442 UART_PUT_CTRL(port
, new_cr
);
444 uart_console_write(port
, s
, count
, apbuart_console_putchar
);
447 * Finally, wait for transmitter to become empty
448 * and restore the TCR
451 status
= UART_GET_STATUS(port
);
452 } while (!UART_TX_READY(status
));
453 UART_PUT_CTRL(port
, old_cr
);
457 apbuart_console_get_options(struct uart_port
*port
, int *baud
,
458 int *parity
, int *bits
)
460 if (UART_GET_CTRL(port
) & (UART_CTRL_RE
| UART_CTRL_TE
)) {
462 unsigned int quot
, status
;
463 status
= UART_GET_STATUS(port
);
466 if (status
& UART_CTRL_PE
) {
467 if ((status
& UART_CTRL_PS
) == 0)
474 quot
= UART_GET_SCAL(port
) / 8;
475 *baud
= port
->uartclk
/ (16 * (quot
+ 1));
479 static int __init
apbuart_console_setup(struct console
*co
, char *options
)
481 struct uart_port
*port
;
487 pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
488 co
, co
->index
, options
);
491 * Check whether an invalid uart number has been specified, and
492 * if so, search for the first available port that does have
495 if (co
->index
>= grlib_apbuart_port_nr
)
498 port
= &grlib_apbuart_ports
[co
->index
];
500 spin_lock_init(&port
->lock
);
503 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
505 apbuart_console_get_options(port
, &baud
, &parity
, &bits
);
507 return uart_set_options(port
, co
, baud
, parity
, bits
, flow
);
510 static struct uart_driver grlib_apbuart_driver
;
512 static struct console grlib_apbuart_console
= {
514 .write
= apbuart_console_write
,
515 .device
= uart_console_device
,
516 .setup
= apbuart_console_setup
,
517 .flags
= CON_PRINTBUFFER
,
519 .data
= &grlib_apbuart_driver
,
523 static void grlib_apbuart_configure(void);
525 static int __init
apbuart_console_init(void)
527 grlib_apbuart_configure();
528 register_console(&grlib_apbuart_console
);
532 console_initcall(apbuart_console_init
);
534 #define APBUART_CONSOLE (&grlib_apbuart_console)
536 #define APBUART_CONSOLE NULL
539 static struct uart_driver grlib_apbuart_driver
= {
540 .owner
= THIS_MODULE
,
541 .driver_name
= "serial",
543 .major
= SERIAL_APBUART_MAJOR
,
544 .minor
= SERIAL_APBUART_MINOR
,
546 .cons
= APBUART_CONSOLE
,
550 /* ======================================================================== */
551 /* OF Platform Driver */
552 /* ======================================================================== */
554 static int __devinit
apbuart_probe(struct of_device
*op
,
555 const struct of_device_id
*match
)
558 struct uart_port
*port
= NULL
;
561 for (i
= 0; i
< grlib_apbuart_port_nr
; i
++) {
562 if (op
->node
== grlib_apbuart_nodes
[i
])
566 port
= &grlib_apbuart_ports
[i
];
567 port
->dev
= &op
->dev
;
569 uart_add_one_port(&grlib_apbuart_driver
, (struct uart_port
*) port
);
571 apbuart_flush_fifo((struct uart_port
*) port
);
573 printk(KERN_INFO
"grlib-apbuart at 0x%llx, irq %d\n",
574 (unsigned long long) port
->mapbase
, port
->irq
);
579 static struct of_device_id __initdata apbuart_match
[] = {
581 .name
= "GAISLER_APBUART",
586 static struct of_platform_driver grlib_apbuart_of_driver
= {
587 .match_table
= apbuart_match
,
588 .probe
= apbuart_probe
,
590 .owner
= THIS_MODULE
,
591 .name
= "grlib-apbuart",
596 static void grlib_apbuart_configure(void)
598 static int enum_done
;
599 struct device_node
*np
, *rp
;
600 struct uart_port
*port
= NULL
;
606 struct amba_prom_registers
*regs
;
611 /* Get bus frequency */
612 rp
= of_find_node_by_path("/");
613 rp
= of_get_next_child(rp
, NULL
);
614 prop
= of_get_property(rp
, "clock-frequency", NULL
);
618 for_each_matching_node(np
, apbuart_match
) {
620 int *vendor
= (int *) of_get_property(np
, "vendor", NULL
);
621 int *device
= (int *) of_get_property(np
, "device", NULL
);
622 int *irqs
= (int *) of_get_property(np
, "interrupts", NULL
);
623 regs
= (struct amba_prom_registers
*)
624 of_get_property(np
, "reg", NULL
);
634 grlib_apbuart_nodes
[line
] = np
;
636 addr
= regs
->phys_addr
;
639 port
= &grlib_apbuart_ports
[line
];
641 port
->mapbase
= addr
;
642 port
->membase
= ioremap(addr
, sizeof(struct grlib_apbuart_regs_map
));
644 port
->iotype
= UPIO_MEM
;
645 port
->ops
= &grlib_apbuart_ops
;
646 port
->flags
= UPF_BOOT_AUTOCONF
;
648 port
->uartclk
= freq_khz
* 1000;
649 port
->fifosize
= apbuart_scan_fifo_size((struct uart_port
*) port
, line
);
652 /* We support maximum UART_NR uarts ... */
660 grlib_apbuart_driver
.nr
= grlib_apbuart_port_nr
= line
;
663 static int __init
grlib_apbuart_init(void)
667 /* Find all APBUARTS in device the tree and initialize their ports */
668 grlib_apbuart_configure();
670 printk(KERN_INFO
"Serial: GRLIB APBUART driver\n");
672 ret
= uart_register_driver(&grlib_apbuart_driver
);
675 printk(KERN_ERR
"%s: uart_register_driver failed (%i)\n",
680 ret
= of_register_platform_driver(&grlib_apbuart_of_driver
);
683 "%s: of_register_platform_driver failed (%i)\n",
685 uart_unregister_driver(&grlib_apbuart_driver
);
692 static void __exit
grlib_apbuart_exit(void)
696 for (i
= 0; i
< grlib_apbuart_port_nr
; i
++)
697 uart_remove_one_port(&grlib_apbuart_driver
,
698 &grlib_apbuart_ports
[i
]);
700 uart_unregister_driver(&grlib_apbuart_driver
);
701 of_unregister_platform_driver(&grlib_apbuart_of_driver
);
704 module_init(grlib_apbuart_init
);
705 module_exit(grlib_apbuart_exit
);
707 MODULE_AUTHOR("Aeroflex Gaisler AB");
708 MODULE_DESCRIPTION("GRLIB APBUART serial driver");
709 MODULE_VERSION("2.1");
710 MODULE_LICENSE("GPL");