2 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 as published
6 * by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 * Copyright (C) 2004 Infineon IFAP DC COM CPE
18 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
19 * Copyright (C) 2007 John Crispin <blogic@openwrt.org>
20 * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/sysrq.h>
29 #include <linux/device.h>
30 #include <linux/tty.h>
31 #include <linux/tty_flip.h>
32 #include <linux/serial_core.h>
33 #include <linux/serial.h>
34 #include <linux/platform_device.h>
36 #include <linux/clk.h>
38 #include <lantiq_soc.h>
40 #define PORT_LTQ_ASC 111
42 #define UART_DUMMY_UER_RX 1
43 #define DRVNAME "ltq_asc"
45 #define LTQ_ASC_TBUF (0x0020 + 3)
46 #define LTQ_ASC_RBUF (0x0024 + 3)
48 #define LTQ_ASC_TBUF 0x0020
49 #define LTQ_ASC_RBUF 0x0024
51 #define LTQ_ASC_FSTAT 0x0048
52 #define LTQ_ASC_WHBSTATE 0x0018
53 #define LTQ_ASC_STATE 0x0014
54 #define LTQ_ASC_IRNCR 0x00F8
55 #define LTQ_ASC_CLC 0x0000
56 #define LTQ_ASC_ID 0x0008
57 #define LTQ_ASC_PISEL 0x0004
58 #define LTQ_ASC_TXFCON 0x0044
59 #define LTQ_ASC_RXFCON 0x0040
60 #define LTQ_ASC_CON 0x0010
61 #define LTQ_ASC_BG 0x0050
62 #define LTQ_ASC_IRNREN 0x00F4
64 #define ASC_IRNREN_TX 0x1
65 #define ASC_IRNREN_RX 0x2
66 #define ASC_IRNREN_ERR 0x4
67 #define ASC_IRNREN_TX_BUF 0x8
68 #define ASC_IRNCR_TIR 0x1
69 #define ASC_IRNCR_RIR 0x2
70 #define ASC_IRNCR_EIR 0x4
72 #define ASCOPT_CSIZE 0x3
75 #define ASCCLC_DISS 0x2
76 #define ASCCLC_RMCMASK 0x0000FF00
77 #define ASCCLC_RMCOFFSET 8
78 #define ASCCON_M_8ASYNC 0x0
79 #define ASCCON_M_7ASYNC 0x2
80 #define ASCCON_ODD 0x00000020
81 #define ASCCON_STP 0x00000080
82 #define ASCCON_BRS 0x00000100
83 #define ASCCON_FDE 0x00000200
84 #define ASCCON_R 0x00008000
85 #define ASCCON_FEN 0x00020000
86 #define ASCCON_ROEN 0x00080000
87 #define ASCCON_TOEN 0x00100000
88 #define ASCSTATE_PE 0x00010000
89 #define ASCSTATE_FE 0x00020000
90 #define ASCSTATE_ROE 0x00080000
91 #define ASCSTATE_ANY (ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
92 #define ASCWHBSTATE_CLRREN 0x00000001
93 #define ASCWHBSTATE_SETREN 0x00000002
94 #define ASCWHBSTATE_CLRPE 0x00000004
95 #define ASCWHBSTATE_CLRFE 0x00000008
96 #define ASCWHBSTATE_CLRROE 0x00000020
97 #define ASCTXFCON_TXFEN 0x0001
98 #define ASCTXFCON_TXFFLU 0x0002
99 #define ASCTXFCON_TXFITLMASK 0x3F00
100 #define ASCTXFCON_TXFITLOFF 8
101 #define ASCRXFCON_RXFEN 0x0001
102 #define ASCRXFCON_RXFFLU 0x0002
103 #define ASCRXFCON_RXFITLMASK 0x3F00
104 #define ASCRXFCON_RXFITLOFF 8
105 #define ASCFSTAT_RXFFLMASK 0x003F
106 #define ASCFSTAT_TXFFLMASK 0x3F00
107 #define ASCFSTAT_TXFREEMASK 0x3F000000
108 #define ASCFSTAT_TXFREEOFF 24
110 static void lqasc_tx_chars(struct uart_port
*port
);
111 static struct ltq_uart_port
*lqasc_port
[MAXPORTS
];
112 static struct uart_driver lqasc_reg
;
113 static DEFINE_SPINLOCK(ltq_asc_lock
);
115 struct ltq_uart_port
{
116 struct uart_port port
;
120 unsigned int err_irq
;
124 ltq_uart_port
*to_ltq_uart_port(struct uart_port
*port
)
126 return container_of(port
, struct ltq_uart_port
, port
);
130 lqasc_stop_tx(struct uart_port
*port
)
136 lqasc_start_tx(struct uart_port
*port
)
139 spin_lock_irqsave(<q_asc_lock
, flags
);
140 lqasc_tx_chars(port
);
141 spin_unlock_irqrestore(<q_asc_lock
, flags
);
146 lqasc_stop_rx(struct uart_port
*port
)
148 ltq_w32(ASCWHBSTATE_CLRREN
, port
->membase
+ LTQ_ASC_WHBSTATE
);
152 lqasc_enable_ms(struct uart_port
*port
)
157 lqasc_rx_chars(struct uart_port
*port
)
159 struct tty_struct
*tty
= tty_port_tty_get(&port
->state
->port
);
160 unsigned int ch
= 0, rsr
= 0, fifocnt
;
163 dev_dbg(port
->dev
, "%s:tty is busy now", __func__
);
167 ltq_r32(port
->membase
+ LTQ_ASC_FSTAT
) & ASCFSTAT_RXFFLMASK
;
169 u8 flag
= TTY_NORMAL
;
170 ch
= ltq_r8(port
->membase
+ LTQ_ASC_RBUF
);
171 rsr
= (ltq_r32(port
->membase
+ LTQ_ASC_STATE
)
172 & ASCSTATE_ANY
) | UART_DUMMY_UER_RX
;
173 tty_flip_buffer_push(tty
);
177 * Note that the error handling code is
178 * out of the main execution path
180 if (rsr
& ASCSTATE_ANY
) {
181 if (rsr
& ASCSTATE_PE
) {
182 port
->icount
.parity
++;
183 ltq_w32_mask(0, ASCWHBSTATE_CLRPE
,
184 port
->membase
+ LTQ_ASC_WHBSTATE
);
185 } else if (rsr
& ASCSTATE_FE
) {
186 port
->icount
.frame
++;
187 ltq_w32_mask(0, ASCWHBSTATE_CLRFE
,
188 port
->membase
+ LTQ_ASC_WHBSTATE
);
190 if (rsr
& ASCSTATE_ROE
) {
191 port
->icount
.overrun
++;
192 ltq_w32_mask(0, ASCWHBSTATE_CLRROE
,
193 port
->membase
+ LTQ_ASC_WHBSTATE
);
196 rsr
&= port
->read_status_mask
;
198 if (rsr
& ASCSTATE_PE
)
200 else if (rsr
& ASCSTATE_FE
)
204 if ((rsr
& port
->ignore_status_mask
) == 0)
205 tty_insert_flip_char(tty
, ch
, flag
);
207 if (rsr
& ASCSTATE_ROE
)
209 * Overrun is special, since it's reported
210 * immediately, and doesn't affect the current
213 tty_insert_flip_char(tty
, 0, TTY_OVERRUN
);
216 tty_flip_buffer_push(tty
);
222 lqasc_tx_chars(struct uart_port
*port
)
224 struct circ_buf
*xmit
= &port
->state
->xmit
;
225 if (uart_tx_stopped(port
)) {
230 while (((ltq_r32(port
->membase
+ LTQ_ASC_FSTAT
) &
231 ASCFSTAT_TXFREEMASK
) >> ASCFSTAT_TXFREEOFF
) != 0) {
233 ltq_w8(port
->x_char
, port
->membase
+ LTQ_ASC_TBUF
);
239 if (uart_circ_empty(xmit
))
242 ltq_w8(port
->state
->xmit
.buf
[port
->state
->xmit
.tail
],
243 port
->membase
+ LTQ_ASC_TBUF
);
244 xmit
->tail
= (xmit
->tail
+ 1) & (UART_XMIT_SIZE
- 1);
248 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
249 uart_write_wakeup(port
);
253 lqasc_tx_int(int irq
, void *_port
)
256 struct uart_port
*port
= (struct uart_port
*)_port
;
257 spin_lock_irqsave(<q_asc_lock
, flags
);
258 ltq_w32(ASC_IRNCR_TIR
, port
->membase
+ LTQ_ASC_IRNCR
);
259 spin_unlock_irqrestore(<q_asc_lock
, flags
);
260 lqasc_start_tx(port
);
265 lqasc_err_int(int irq
, void *_port
)
268 struct uart_port
*port
= (struct uart_port
*)_port
;
269 spin_lock_irqsave(<q_asc_lock
, flags
);
270 /* clear any pending interrupts */
271 ltq_w32_mask(0, ASCWHBSTATE_CLRPE
| ASCWHBSTATE_CLRFE
|
272 ASCWHBSTATE_CLRROE
, port
->membase
+ LTQ_ASC_WHBSTATE
);
273 spin_unlock_irqrestore(<q_asc_lock
, flags
);
278 lqasc_rx_int(int irq
, void *_port
)
281 struct uart_port
*port
= (struct uart_port
*)_port
;
282 spin_lock_irqsave(<q_asc_lock
, flags
);
283 ltq_w32(ASC_IRNCR_RIR
, port
->membase
+ LTQ_ASC_IRNCR
);
284 lqasc_rx_chars(port
);
285 spin_unlock_irqrestore(<q_asc_lock
, flags
);
290 lqasc_tx_empty(struct uart_port
*port
)
293 status
= ltq_r32(port
->membase
+ LTQ_ASC_FSTAT
) & ASCFSTAT_TXFFLMASK
;
294 return status
? 0 : TIOCSER_TEMT
;
298 lqasc_get_mctrl(struct uart_port
*port
)
300 return TIOCM_CTS
| TIOCM_CAR
| TIOCM_DSR
;
304 lqasc_set_mctrl(struct uart_port
*port
, u_int mctrl
)
309 lqasc_break_ctl(struct uart_port
*port
, int break_state
)
314 lqasc_startup(struct uart_port
*port
)
316 struct ltq_uart_port
*ltq_port
= to_ltq_uart_port(port
);
319 port
->uartclk
= clk_get_rate(ltq_port
->clk
);
321 ltq_w32_mask(ASCCLC_DISS
| ASCCLC_RMCMASK
, (1 << ASCCLC_RMCOFFSET
),
322 port
->membase
+ LTQ_ASC_CLC
);
324 ltq_w32(0, port
->membase
+ LTQ_ASC_PISEL
);
326 ((TXFIFO_FL
<< ASCTXFCON_TXFITLOFF
) & ASCTXFCON_TXFITLMASK
) |
327 ASCTXFCON_TXFEN
| ASCTXFCON_TXFFLU
,
328 port
->membase
+ LTQ_ASC_TXFCON
);
330 ((RXFIFO_FL
<< ASCRXFCON_RXFITLOFF
) & ASCRXFCON_RXFITLMASK
)
331 | ASCRXFCON_RXFEN
| ASCRXFCON_RXFFLU
,
332 port
->membase
+ LTQ_ASC_RXFCON
);
333 /* make sure other settings are written to hardware before
334 * setting enable bits
337 ltq_w32_mask(0, ASCCON_M_8ASYNC
| ASCCON_FEN
| ASCCON_TOEN
|
338 ASCCON_ROEN
, port
->membase
+ LTQ_ASC_CON
);
340 retval
= request_irq(ltq_port
->tx_irq
, lqasc_tx_int
,
341 IRQF_DISABLED
, "asc_tx", port
);
343 pr_err("failed to request lqasc_tx_int\n");
347 retval
= request_irq(ltq_port
->rx_irq
, lqasc_rx_int
,
348 IRQF_DISABLED
, "asc_rx", port
);
350 pr_err("failed to request lqasc_rx_int\n");
354 retval
= request_irq(ltq_port
->err_irq
, lqasc_err_int
,
355 IRQF_DISABLED
, "asc_err", port
);
357 pr_err("failed to request lqasc_err_int\n");
361 ltq_w32(ASC_IRNREN_RX
| ASC_IRNREN_ERR
| ASC_IRNREN_TX
,
362 port
->membase
+ LTQ_ASC_IRNREN
);
366 free_irq(ltq_port
->rx_irq
, port
);
368 free_irq(ltq_port
->tx_irq
, port
);
373 lqasc_shutdown(struct uart_port
*port
)
375 struct ltq_uart_port
*ltq_port
= to_ltq_uart_port(port
);
376 free_irq(ltq_port
->tx_irq
, port
);
377 free_irq(ltq_port
->rx_irq
, port
);
378 free_irq(ltq_port
->err_irq
, port
);
380 ltq_w32(0, port
->membase
+ LTQ_ASC_CON
);
381 ltq_w32_mask(ASCRXFCON_RXFEN
, ASCRXFCON_RXFFLU
,
382 port
->membase
+ LTQ_ASC_RXFCON
);
383 ltq_w32_mask(ASCTXFCON_TXFEN
, ASCTXFCON_TXFFLU
,
384 port
->membase
+ LTQ_ASC_TXFCON
);
388 lqasc_set_termios(struct uart_port
*port
,
389 struct ktermios
*new, struct ktermios
*old
)
393 unsigned int divisor
;
395 unsigned int con
= 0;
398 cflag
= new->c_cflag
;
399 iflag
= new->c_iflag
;
401 switch (cflag
& CSIZE
) {
403 con
= ASCCON_M_7ASYNC
;
409 new->c_cflag
&= ~ CSIZE
;
411 con
= ASCCON_M_8ASYNC
;
415 cflag
&= ~CMSPAR
; /* Mark/Space parity is not supported */
420 if (cflag
& PARENB
) {
421 if (!(cflag
& PARODD
))
427 port
->read_status_mask
= ASCSTATE_ROE
;
429 port
->read_status_mask
|= ASCSTATE_FE
| ASCSTATE_PE
;
431 port
->ignore_status_mask
= 0;
433 port
->ignore_status_mask
|= ASCSTATE_FE
| ASCSTATE_PE
;
435 if (iflag
& IGNBRK
) {
437 * If we're ignoring parity and break indicators,
438 * ignore overruns too (for real raw support).
441 port
->ignore_status_mask
|= ASCSTATE_ROE
;
444 if ((cflag
& CREAD
) == 0)
445 port
->ignore_status_mask
|= UART_DUMMY_UER_RX
;
447 /* set error signals - framing, parity and overrun, enable receiver */
448 con
|= ASCCON_FEN
| ASCCON_TOEN
| ASCCON_ROEN
;
450 spin_lock_irqsave(<q_asc_lock
, flags
);
453 ltq_w32_mask(0, con
, port
->membase
+ LTQ_ASC_CON
);
455 /* Set baud rate - take a divider of 2 into account */
456 baud
= uart_get_baud_rate(port
, new, old
, 0, port
->uartclk
/ 16);
457 divisor
= uart_get_divisor(port
, baud
);
458 divisor
= divisor
/ 2 - 1;
460 /* disable the baudrate generator */
461 ltq_w32_mask(ASCCON_R
, 0, port
->membase
+ LTQ_ASC_CON
);
463 /* make sure the fractional divider is off */
464 ltq_w32_mask(ASCCON_FDE
, 0, port
->membase
+ LTQ_ASC_CON
);
466 /* set up to use divisor of 2 */
467 ltq_w32_mask(ASCCON_BRS
, 0, port
->membase
+ LTQ_ASC_CON
);
469 /* now we can write the new baudrate into the register */
470 ltq_w32(divisor
, port
->membase
+ LTQ_ASC_BG
);
472 /* turn the baudrate generator back on */
473 ltq_w32_mask(0, ASCCON_R
, port
->membase
+ LTQ_ASC_CON
);
476 ltq_w32(ASCWHBSTATE_SETREN
, port
->membase
+ LTQ_ASC_WHBSTATE
);
478 spin_unlock_irqrestore(<q_asc_lock
, flags
);
480 /* Don't rewrite B0 */
481 if (tty_termios_baud_rate(new))
482 tty_termios_encode_baud_rate(new, baud
, baud
);
486 lqasc_type(struct uart_port
*port
)
488 if (port
->type
== PORT_LTQ_ASC
)
495 lqasc_release_port(struct uart_port
*port
)
497 if (port
->flags
& UPF_IOREMAP
) {
498 iounmap(port
->membase
);
499 port
->membase
= NULL
;
504 lqasc_request_port(struct uart_port
*port
)
506 struct platform_device
*pdev
= to_platform_device(port
->dev
);
507 struct resource
*res
;
510 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
512 dev_err(&pdev
->dev
, "cannot obtain I/O memory region");
515 size
= resource_size(res
);
517 res
= devm_request_mem_region(&pdev
->dev
, res
->start
,
518 size
, dev_name(&pdev
->dev
));
520 dev_err(&pdev
->dev
, "cannot request I/O memory region");
524 if (port
->flags
& UPF_IOREMAP
) {
525 port
->membase
= devm_ioremap_nocache(&pdev
->dev
,
526 port
->mapbase
, size
);
527 if (port
->membase
== NULL
)
534 lqasc_config_port(struct uart_port
*port
, int flags
)
536 if (flags
& UART_CONFIG_TYPE
) {
537 port
->type
= PORT_LTQ_ASC
;
538 lqasc_request_port(port
);
543 lqasc_verify_port(struct uart_port
*port
,
544 struct serial_struct
*ser
)
547 if (ser
->type
!= PORT_UNKNOWN
&& ser
->type
!= PORT_LTQ_ASC
)
549 if (ser
->irq
< 0 || ser
->irq
>= NR_IRQS
)
551 if (ser
->baud_base
< 9600)
556 static struct uart_ops lqasc_pops
= {
557 .tx_empty
= lqasc_tx_empty
,
558 .set_mctrl
= lqasc_set_mctrl
,
559 .get_mctrl
= lqasc_get_mctrl
,
560 .stop_tx
= lqasc_stop_tx
,
561 .start_tx
= lqasc_start_tx
,
562 .stop_rx
= lqasc_stop_rx
,
563 .enable_ms
= lqasc_enable_ms
,
564 .break_ctl
= lqasc_break_ctl
,
565 .startup
= lqasc_startup
,
566 .shutdown
= lqasc_shutdown
,
567 .set_termios
= lqasc_set_termios
,
569 .release_port
= lqasc_release_port
,
570 .request_port
= lqasc_request_port
,
571 .config_port
= lqasc_config_port
,
572 .verify_port
= lqasc_verify_port
,
576 lqasc_console_putchar(struct uart_port
*port
, int ch
)
584 fifofree
= (ltq_r32(port
->membase
+ LTQ_ASC_FSTAT
)
585 & ASCFSTAT_TXFREEMASK
) >> ASCFSTAT_TXFREEOFF
;
586 } while (fifofree
== 0);
587 ltq_w8(ch
, port
->membase
+ LTQ_ASC_TBUF
);
592 lqasc_console_write(struct console
*co
, const char *s
, u_int count
)
594 struct ltq_uart_port
*ltq_port
;
595 struct uart_port
*port
;
598 if (co
->index
>= MAXPORTS
)
601 ltq_port
= lqasc_port
[co
->index
];
605 port
= <q_port
->port
;
607 spin_lock_irqsave(<q_asc_lock
, flags
);
608 uart_console_write(port
, s
, count
, lqasc_console_putchar
);
609 spin_unlock_irqrestore(<q_asc_lock
, flags
);
613 lqasc_console_setup(struct console
*co
, char *options
)
615 struct ltq_uart_port
*ltq_port
;
616 struct uart_port
*port
;
622 if (co
->index
>= MAXPORTS
)
625 ltq_port
= lqasc_port
[co
->index
];
629 port
= <q_port
->port
;
631 port
->uartclk
= clk_get_rate(ltq_port
->clk
);
634 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
635 return uart_set_options(port
, co
, baud
, parity
, bits
, flow
);
638 static struct console lqasc_console
= {
640 .write
= lqasc_console_write
,
641 .device
= uart_console_device
,
642 .setup
= lqasc_console_setup
,
643 .flags
= CON_PRINTBUFFER
,
649 lqasc_console_init(void)
651 register_console(&lqasc_console
);
654 console_initcall(lqasc_console_init
);
656 static struct uart_driver lqasc_reg
= {
657 .owner
= THIS_MODULE
,
658 .driver_name
= DRVNAME
,
659 .dev_name
= "ttyLTQ",
663 .cons
= &lqasc_console
,
667 lqasc_probe(struct platform_device
*pdev
)
669 struct ltq_uart_port
*ltq_port
;
670 struct uart_port
*port
;
671 struct resource
*mmres
, *irqres
;
672 int tx_irq
, rx_irq
, err_irq
;
676 mmres
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
677 irqres
= platform_get_resource(pdev
, IORESOURCE_IRQ
, 0);
678 if (!mmres
|| !irqres
)
681 if (pdev
->id
>= MAXPORTS
)
684 if (lqasc_port
[pdev
->id
] != NULL
)
687 clk
= clk_get(&pdev
->dev
, "fpi");
689 pr_err("failed to get fpi clk\n");
693 tx_irq
= platform_get_irq_byname(pdev
, "tx");
694 rx_irq
= platform_get_irq_byname(pdev
, "rx");
695 err_irq
= platform_get_irq_byname(pdev
, "err");
696 if ((tx_irq
< 0) | (rx_irq
< 0) | (err_irq
< 0))
699 ltq_port
= kzalloc(sizeof(struct ltq_uart_port
), GFP_KERNEL
);
703 port
= <q_port
->port
;
705 port
->iotype
= SERIAL_IO_MEM
;
706 port
->flags
= ASYNC_BOOT_AUTOCONF
| UPF_IOREMAP
;
707 port
->ops
= &lqasc_pops
;
709 port
->type
= PORT_LTQ_ASC
,
710 port
->line
= pdev
->id
;
711 port
->dev
= &pdev
->dev
;
713 port
->irq
= tx_irq
; /* unused, just to be backward-compatibe */
714 port
->mapbase
= mmres
->start
;
718 ltq_port
->tx_irq
= tx_irq
;
719 ltq_port
->rx_irq
= rx_irq
;
720 ltq_port
->err_irq
= err_irq
;
722 lqasc_port
[pdev
->id
] = ltq_port
;
723 platform_set_drvdata(pdev
, ltq_port
);
725 ret
= uart_add_one_port(&lqasc_reg
, port
);
730 static struct platform_driver lqasc_driver
= {
733 .owner
= THIS_MODULE
,
742 ret
= uart_register_driver(&lqasc_reg
);
746 ret
= platform_driver_probe(&lqasc_driver
, lqasc_probe
);
748 uart_unregister_driver(&lqasc_reg
);
753 module_init(init_lqasc
);
755 MODULE_DESCRIPTION("Lantiq serial port driver");
756 MODULE_LICENSE("GPL");