1 /* MN10300 On-chip serial port UART driver
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12 static const char serial_name[] = "MN10300 Serial driver";
13 static const char serial_version[] = "mn10300_serial-1.0";
14 static const char serial_revdate[] = "2007-11-06";
15
16 #if defined(CONFIG_MN10300_TTYSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
17 #define SUPPORT_SYSRQ
18 #endif
19
20 #include <linux/module.h>
21 #include <linux/serial.h>
22 #include <linux/circ_buf.h>
23 #include <linux/errno.h>
24 #include <linux/signal.h>
25 #include <linux/sched.h>
26 #include <linux/timer.h>
27 #include <linux/interrupt.h>
28 #include <linux/tty.h>
29 #include <linux/tty_flip.h>
30 #include <linux/major.h>
31 #include <linux/string.h>
32 #include <linux/ioport.h>
33 #include <linux/mm.h>
34 #include <linux/slab.h>
35 #include <linux/init.h>
36 #include <linux/console.h>
37 #include <linux/sysrq.h>
38
39 #include <asm/io.h>
40 #include <asm/irq.h>
41 #include <asm/bitops.h>
42 #include <asm/serial-regs.h>
43 #include <unit/timex.h>
44 #include "mn10300-serial.h"
45
46 #ifdef CONFIG_SMP
47 #undef GxICR
48 #define GxICR(X) CROSS_GxICR(X, 0)
49 #endif /* CONFIG_SMP */
50
51 #define kenter(FMT, ...) \
52 printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
53 #define _enter(FMT, ...) \
54 no_printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
55 #define kdebug(FMT, ...) \
56 printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
57 #define _debug(FMT, ...) \
58 no_printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
59 #define kproto(FMT, ...) \
60 printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
61 #define _proto(FMT, ...) \
62 no_printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
63
64 #ifndef CODMSB
65 /* c_cflag bit meaning */
66 #define CODMSB 004000000000 /* change Transfer bit-order */
67 #endif
68
69 #define NR_UARTS 3
70
71 #ifdef CONFIG_MN10300_TTYSM_CONSOLE
72 static void mn10300_serial_console_write(struct console *co,
73 const char *s, unsigned count);
74 static int __init mn10300_serial_console_setup(struct console *co,
75 char *options);
76
77 static struct uart_driver mn10300_serial_driver;
78 static struct console mn10300_serial_console = {
79 .name = "ttySM",
80 .write = mn10300_serial_console_write,
81 .device = uart_console_device,
82 .setup = mn10300_serial_console_setup,
83 .flags = CON_PRINTBUFFER,
84 .index = -1,
85 .data = &mn10300_serial_driver,
86 };
87 #endif
88
89 static struct uart_driver mn10300_serial_driver = {
90 .owner = NULL,
91 .driver_name = "mn10300-serial",
92 .dev_name = "ttySM",
93 .major = TTY_MAJOR,
94 .minor = 128,
95 .nr = NR_UARTS,
96 #ifdef CONFIG_MN10300_TTYSM_CONSOLE
97 .cons = &mn10300_serial_console,
98 #endif
99 };
100
101 static unsigned int mn10300_serial_tx_empty(struct uart_port *);
102 static void mn10300_serial_set_mctrl(struct uart_port *, unsigned int mctrl);
103 static unsigned int mn10300_serial_get_mctrl(struct uart_port *);
104 static void mn10300_serial_stop_tx(struct uart_port *);
105 static void mn10300_serial_start_tx(struct uart_port *);
106 static void mn10300_serial_send_xchar(struct uart_port *, char ch);
107 static void mn10300_serial_stop_rx(struct uart_port *);
108 static void mn10300_serial_enable_ms(struct uart_port *);
109 static void mn10300_serial_break_ctl(struct uart_port *, int ctl);
110 static int mn10300_serial_startup(struct uart_port *);
111 static void mn10300_serial_shutdown(struct uart_port *);
112 static void mn10300_serial_set_termios(struct uart_port *,
113 struct ktermios *new,
114 struct ktermios *old);
115 static const char *mn10300_serial_type(struct uart_port *);
116 static void mn10300_serial_release_port(struct uart_port *);
117 static int mn10300_serial_request_port(struct uart_port *);
118 static void mn10300_serial_config_port(struct uart_port *, int);
119 static int mn10300_serial_verify_port(struct uart_port *,
120 struct serial_struct *);
121 #ifdef CONFIG_CONSOLE_POLL
122 static void mn10300_serial_poll_put_char(struct uart_port *, unsigned char);
123 static int mn10300_serial_poll_get_char(struct uart_port *);
124 #endif
125
126 static const struct uart_ops mn10300_serial_ops = {
127 .tx_empty = mn10300_serial_tx_empty,
128 .set_mctrl = mn10300_serial_set_mctrl,
129 .get_mctrl = mn10300_serial_get_mctrl,
130 .stop_tx = mn10300_serial_stop_tx,
131 .start_tx = mn10300_serial_start_tx,
132 .send_xchar = mn10300_serial_send_xchar,
133 .stop_rx = mn10300_serial_stop_rx,
134 .enable_ms = mn10300_serial_enable_ms,
135 .break_ctl = mn10300_serial_break_ctl,
136 .startup = mn10300_serial_startup,
137 .shutdown = mn10300_serial_shutdown,
138 .set_termios = mn10300_serial_set_termios,
139 .type = mn10300_serial_type,
140 .release_port = mn10300_serial_release_port,
141 .request_port = mn10300_serial_request_port,
142 .config_port = mn10300_serial_config_port,
143 .verify_port = mn10300_serial_verify_port,
144 #ifdef CONFIG_CONSOLE_POLL
145 .poll_put_char = mn10300_serial_poll_put_char,
146 .poll_get_char = mn10300_serial_poll_get_char,
147 #endif
148 };
149
150 static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id);
151
152 /*
153 * the first on-chip serial port: ttySM0 (aka SIF0)
154 */
155 #ifdef CONFIG_MN10300_TTYSM0
156 struct mn10300_serial_port mn10300_serial_port_sif0 = {
157 .uart.ops = &mn10300_serial_ops,
158 .uart.membase = (void __iomem *) &SC0CTR,
159 .uart.mapbase = (unsigned long) &SC0CTR,
160 .uart.iotype = UPIO_MEM,
161 .uart.irq = 0,
162 .uart.uartclk = 0, /* MN10300_IOCLK, */
163 .uart.fifosize = 1,
164 .uart.flags = UPF_BOOT_AUTOCONF,
165 .uart.line = 0,
166 .uart.type = PORT_MN10300,
167 .uart.lock =
168 __SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif0.uart.lock),
169 .name = "ttySM0",
170 ._iobase = &SC0CTR,
171 ._control = &SC0CTR,
172 ._status = (volatile u8 *)&SC0STR,
173 ._intr = &SC0ICR,
174 ._rxb = &SC0RXB,
175 ._txb = &SC0TXB,
176 .rx_name = "ttySM0:Rx",
177 .tx_name = "ttySM0:Tx",
178 #if defined(CONFIG_MN10300_TTYSM0_TIMER8)
179 .tm_name = "ttySM0:Timer8",
180 ._tmxmd = &TM8MD,
181 ._tmxbr = &TM8BR,
182 ._tmicr = &TM8ICR,
183 .tm_irq = TM8IRQ,
184 .div_timer = MNSCx_DIV_TIMER_16BIT,
185 #elif defined(CONFIG_MN10300_TTYSM0_TIMER0)
186 .tm_name = "ttySM0:Timer0",
187 ._tmxmd = &TM0MD,
188 ._tmxbr = (volatile u16 *)&TM0BR,
189 ._tmicr = &TM0ICR,
190 .tm_irq = TM0IRQ,
191 .div_timer = MNSCx_DIV_TIMER_8BIT,
192 #elif defined(CONFIG_MN10300_TTYSM0_TIMER2)
193 .tm_name = "ttySM0:Timer2",
194 ._tmxmd = &TM2MD,
195 ._tmxbr = (volatile u16 *)&TM2BR,
196 ._tmicr = &TM2ICR,
197 .tm_irq = TM2IRQ,
198 .div_timer = MNSCx_DIV_TIMER_8BIT,
199 #else
200 #error "Unknown config for ttySM0"
201 #endif
202 .rx_irq = SC0RXIRQ,
203 .tx_irq = SC0TXIRQ,
204 .rx_icr = &GxICR(SC0RXIRQ),
205 .tx_icr = &GxICR(SC0TXIRQ),
206 .clock_src = MNSCx_CLOCK_SRC_IOCLK,
207 .options = 0,
208 #ifdef CONFIG_GDBSTUB_ON_TTYSM0
209 .gdbstub = 1,
210 #endif
211 };
212 #endif /* CONFIG_MN10300_TTYSM0 */
213
214 /*
215 * the second on-chip serial port: ttySM1 (aka SIF1)
216 */
217 #ifdef CONFIG_MN10300_TTYSM1
218 struct mn10300_serial_port mn10300_serial_port_sif1 = {
219 .uart.ops = &mn10300_serial_ops,
220 .uart.membase = (void __iomem *) &SC1CTR,
221 .uart.mapbase = (unsigned long) &SC1CTR,
222 .uart.iotype = UPIO_MEM,
223 .uart.irq = 0,
224 .uart.uartclk = 0, /* MN10300_IOCLK, */
225 .uart.fifosize = 1,
226 .uart.flags = UPF_BOOT_AUTOCONF,
227 .uart.line = 1,
228 .uart.type = PORT_MN10300,
229 .uart.lock =
230 __SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif1.uart.lock),
231 .name = "ttySM1",
232 ._iobase = &SC1CTR,
233 ._control = &SC1CTR,
234 ._status = (volatile u8 *)&SC1STR,
235 ._intr = &SC1ICR,
236 ._rxb = &SC1RXB,
237 ._txb = &SC1TXB,
238 .rx_name = "ttySM1:Rx",
239 .tx_name = "ttySM1:Tx",
240 #if defined(CONFIG_MN10300_TTYSM1_TIMER9)
241 .tm_name = "ttySM1:Timer9",
242 ._tmxmd = &TM9MD,
243 ._tmxbr = &TM9BR,
244 ._tmicr = &TM9ICR,
245 .tm_irq = TM9IRQ,
246 .div_timer = MNSCx_DIV_TIMER_16BIT,
247 #elif defined(CONFIG_MN10300_TTYSM1_TIMER3)
248 .tm_name = "ttySM1:Timer3",
249 ._tmxmd = &TM3MD,
250 ._tmxbr = (volatile u16 *)&TM3BR,
251 ._tmicr = &TM3ICR,
252 .tm_irq = TM3IRQ,
253 .div_timer = MNSCx_DIV_TIMER_8BIT,
254 #elif defined(CONFIG_MN10300_TTYSM1_TIMER12)
255 .tm_name = "ttySM1/Timer12",
256 ._tmxmd = &TM12MD,
257 ._tmxbr = &TM12BR,
258 ._tmicr = &TM12ICR,
259 .tm_irq = TM12IRQ,
260 .div_timer = MNSCx_DIV_TIMER_16BIT,
261 #else
262 #error "Unknown config for ttySM1"
263 #endif
264 .rx_irq = SC1RXIRQ,
265 .tx_irq = SC1TXIRQ,
266 .rx_icr = &GxICR(SC1RXIRQ),
267 .tx_icr = &GxICR(SC1TXIRQ),
268 .clock_src = MNSCx_CLOCK_SRC_IOCLK,
269 .options = 0,
270 #ifdef CONFIG_GDBSTUB_ON_TTYSM1
271 .gdbstub = 1,
272 #endif
273 };
274 #endif /* CONFIG_MN10300_TTYSM1 */
275
276 /*
277 * the third on-chip serial port: ttySM2 (aka SIF2)
278 */
279 #ifdef CONFIG_MN10300_TTYSM2
280 struct mn10300_serial_port mn10300_serial_port_sif2 = {
281 .uart.ops = &mn10300_serial_ops,
282 .uart.membase = (void __iomem *) &SC2CTR,
283 .uart.mapbase = (unsigned long) &SC2CTR,
284 .uart.iotype = UPIO_MEM,
285 .uart.irq = 0,
286 .uart.uartclk = 0, /* MN10300_IOCLK, */
287 .uart.fifosize = 1,
288 .uart.flags = UPF_BOOT_AUTOCONF,
289 .uart.line = 2,
290 #ifdef CONFIG_MN10300_TTYSM2_CTS
291 .uart.type = PORT_MN10300_CTS,
292 #else
293 .uart.type = PORT_MN10300,
294 #endif
295 .uart.lock =
296 __SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif2.uart.lock),
297 .name = "ttySM2",
298 ._iobase = &SC2CTR,
299 ._control = &SC2CTR,
300 ._status = (volatile u8 *)&SC2STR,
301 ._intr = &SC2ICR,
302 ._rxb = &SC2RXB,
303 ._txb = &SC2TXB,
304 .rx_name = "ttySM2:Rx",
305 .tx_name = "ttySM2:Tx",
306 #if defined(CONFIG_MN10300_TTYSM2_TIMER10)
307 .tm_name = "ttySM2/Timer10",
308 ._tmxmd = &TM10MD,
309 ._tmxbr = &TM10BR,
310 ._tmicr = &TM10ICR,
311 .tm_irq = TM10IRQ,
312 .div_timer = MNSCx_DIV_TIMER_16BIT,
313 #elif defined(CONFIG_MN10300_TTYSM2_TIMER9)
314 .tm_name = "ttySM2/Timer9",
315 ._tmxmd = &TM9MD,
316 ._tmxbr = &TM9BR,
317 ._tmicr = &TM9ICR,
318 .tm_irq = TM9IRQ,
319 .div_timer = MNSCx_DIV_TIMER_16BIT,
320 #elif defined(CONFIG_MN10300_TTYSM2_TIMER1)
321 .tm_name = "ttySM2/Timer1",
322 ._tmxmd = &TM1MD,
323 ._tmxbr = (volatile u16 *)&TM1BR,
324 ._tmicr = &TM1ICR,
325 .tm_irq = TM1IRQ,
326 .div_timer = MNSCx_DIV_TIMER_8BIT,
327 #elif defined(CONFIG_MN10300_TTYSM2_TIMER3)
328 .tm_name = "ttySM2/Timer3",
329 ._tmxmd = &TM3MD,
330 ._tmxbr = (volatile u16 *)&TM3BR,
331 ._tmicr = &TM3ICR,
332 .tm_irq = TM3IRQ,
333 .div_timer = MNSCx_DIV_TIMER_8BIT,
334 #else
335 #error "Unknown config for ttySM2"
336 #endif
337 .rx_irq = SC2RXIRQ,
338 .tx_irq = SC2TXIRQ,
339 .rx_icr = &GxICR(SC2RXIRQ),
340 .tx_icr = &GxICR(SC2TXIRQ),
341 .clock_src = MNSCx_CLOCK_SRC_IOCLK,
342 #ifdef CONFIG_MN10300_TTYSM2_CTS
343 .options = MNSCx_OPT_CTS,
344 #else
345 .options = 0,
346 #endif
347 #ifdef CONFIG_GDBSTUB_ON_TTYSM2
348 .gdbstub = 1,
349 #endif
350 };
351 #endif /* CONFIG_MN10300_TTYSM2 */
352
353
354 /*
355 * list of available serial ports
356 */
357 struct mn10300_serial_port *mn10300_serial_ports[NR_UARTS + 1] = {
358 #ifdef CONFIG_MN10300_TTYSM0
359 [0] = &mn10300_serial_port_sif0,
360 #endif
361 #ifdef CONFIG_MN10300_TTYSM1
362 [1] = &mn10300_serial_port_sif1,
363 #endif
364 #ifdef CONFIG_MN10300_TTYSM2
365 [2] = &mn10300_serial_port_sif2,
366 #endif
367 [NR_UARTS] = NULL,
368 };
369
370
371 /*
372 * we abuse the serial ports' baud timers' interrupt lines to get the ability
373 * to deliver interrupts to userspace as we use the ports' interrupt lines to
374 * do virtual DMA on account of the ports having no hardware FIFOs
375 *
376 * we can generate an interrupt manually in the assembly stubs by writing to
377 * the enable and detect bits in the interrupt control register, so all we need
378 * to do here is disable the interrupt line
379 *
380 * note that we can't just leave the line enabled as the baud rate timer *also*
381 * generates interrupts
382 */
mn10300_serial_mask_ack(unsigned int irq)383 static void mn10300_serial_mask_ack(unsigned int irq)
384 {
385 unsigned long flags;
386 u16 tmp;
387
388 flags = arch_local_cli_save();
389 GxICR(irq) = GxICR_LEVEL_6;
390 tmp = GxICR(irq); /* flush write buffer */
391 arch_local_irq_restore(flags);
392 }
393
mn10300_serial_chip_mask_ack(struct irq_data * d)394 static void mn10300_serial_chip_mask_ack(struct irq_data *d)
395 {
396 mn10300_serial_mask_ack(d->irq);
397 }
398
mn10300_serial_nop(struct irq_data * d)399 static void mn10300_serial_nop(struct irq_data *d)
400 {
401 }
402
403 static struct irq_chip mn10300_serial_pic = {
404 .name = "mnserial",
405 .irq_ack = mn10300_serial_chip_mask_ack,
406 .irq_mask = mn10300_serial_chip_mask_ack,
407 .irq_mask_ack = mn10300_serial_chip_mask_ack,
408 .irq_unmask = mn10300_serial_nop,
409 };
410
mn10300_serial_low_mask(struct irq_data * d)411 static void mn10300_serial_low_mask(struct irq_data *d)
412 {
413 unsigned long flags;
414 u16 tmp;
415
416 flags = arch_local_cli_save();
417 GxICR(d->irq) = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
418 tmp = GxICR(d->irq); /* flush write buffer */
419 arch_local_irq_restore(flags);
420 }
421
mn10300_serial_low_unmask(struct irq_data * d)422 static void mn10300_serial_low_unmask(struct irq_data *d)
423 {
424 unsigned long flags;
425 u16 tmp;
426
427 flags = arch_local_cli_save();
428 GxICR(d->irq) =
429 NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL) | GxICR_ENABLE;
430 tmp = GxICR(d->irq); /* flush write buffer */
431 arch_local_irq_restore(flags);
432 }
433
434 static struct irq_chip mn10300_serial_low_pic = {
435 .name = "mnserial-low",
436 .irq_mask = mn10300_serial_low_mask,
437 .irq_unmask = mn10300_serial_low_unmask,
438 };
439
440 /*
441 * serial virtual DMA interrupt jump table
442 */
443 struct mn10300_serial_int mn10300_serial_int_tbl[NR_IRQS];
444
mn10300_serial_dis_tx_intr(struct mn10300_serial_port * port)445 static void mn10300_serial_dis_tx_intr(struct mn10300_serial_port *port)
446 {
447 int retries = 100;
448 u16 x;
449
450 /* nothing to do if irq isn't set up */
451 if (!mn10300_serial_int_tbl[port->tx_irq].port)
452 return;
453
454 port->tx_flags |= MNSCx_TX_STOP;
455 mb();
456
457 /*
458 * Here we wait for the irq to be disabled. Either it already is
459 * disabled or we wait some number of retries for the VDMA handler
460 * to disable it. The retries give the VDMA handler enough time to
461 * run to completion if it was already in progress. If the VDMA IRQ
462 * is enabled but the handler is not yet running when arrive here,
463 * the STOP flag will prevent the handler from conflicting with the
464 * driver code following this loop.
465 */
466 while ((*port->tx_icr & GxICR_ENABLE) && retries-- > 0)
467 ;
468 if (retries <= 0) {
469 *port->tx_icr =
470 NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
471 x = *port->tx_icr;
472 }
473 }
474
mn10300_serial_en_tx_intr(struct mn10300_serial_port * port)475 static void mn10300_serial_en_tx_intr(struct mn10300_serial_port *port)
476 {
477 u16 x;
478
479 /* nothing to do if irq isn't set up */
480 if (!mn10300_serial_int_tbl[port->tx_irq].port)
481 return;
482
483 /* stop vdma irq if not already stopped */
484 if (!(port->tx_flags & MNSCx_TX_STOP))
485 mn10300_serial_dis_tx_intr(port);
486
487 port->tx_flags &= ~MNSCx_TX_STOP;
488 mb();
489
490 *port->tx_icr =
491 NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL) |
492 GxICR_ENABLE | GxICR_REQUEST | GxICR_DETECT;
493 x = *port->tx_icr;
494 }
495
mn10300_serial_dis_rx_intr(struct mn10300_serial_port * port)496 static void mn10300_serial_dis_rx_intr(struct mn10300_serial_port *port)
497 {
498 unsigned long flags;
499 u16 x;
500
501 flags = arch_local_cli_save();
502 *port->rx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
503 x = *port->rx_icr;
504 arch_local_irq_restore(flags);
505 }
506
507 /*
508 * multi-bit equivalent of test_and_clear_bit()
509 */
mask_test_and_clear(volatile u8 * ptr,u8 mask)510 static int mask_test_and_clear(volatile u8 *ptr, u8 mask)
511 {
512 u32 epsw;
513 asm volatile(" bclr %1,(%2) \n"
514 " mov epsw,%0 \n"
515 : "=d"(epsw) : "d"(mask), "a"(ptr)
516 : "cc", "memory");
517 return !(epsw & EPSW_FLAG_Z);
518 }
519
520 /*
521 * receive chars from the ring buffer for this serial port
522 * - must do break detection here (not done in the UART)
523 */
mn10300_serial_receive_interrupt(struct mn10300_serial_port * port)524 static void mn10300_serial_receive_interrupt(struct mn10300_serial_port *port)
525 {
526 struct uart_icount *icount = &port->uart.icount;
527 struct tty_port *tport = &port->uart.state->port;
528 unsigned ix;
529 int count;
530 u8 st, ch, push, status, overrun;
531
532 _enter("%s", port->name);
533
534 push = 0;
535
536 count = CIRC_CNT(port->rx_inp, port->rx_outp, MNSC_BUFFER_SIZE);
537 count = tty_buffer_request_room(tport, count);
538 if (count == 0) {
539 if (!tport->low_latency)
540 tty_flip_buffer_push(tport);
541 return;
542 }
543
544 try_again:
545 /* pull chars out of the hat */
546 ix = ACCESS_ONCE(port->rx_outp);
547 if (CIRC_CNT(port->rx_inp, ix, MNSC_BUFFER_SIZE) == 0) {
548 if (push && !tport->low_latency)
549 tty_flip_buffer_push(tport);
550 return;
551 }
552
553 smp_read_barrier_depends();
554 ch = port->rx_buffer[ix++];
555 st = port->rx_buffer[ix++];
556 smp_mb();
557 port->rx_outp = ix & (MNSC_BUFFER_SIZE - 1);
558 port->uart.icount.rx++;
559
560 st &= SC01STR_FEF | SC01STR_PEF | SC01STR_OEF;
561 status = 0;
562 overrun = 0;
563
564 /* the UART doesn't detect BREAK, so we have to do that ourselves
565 * - it starts as a framing error on a NUL character
566 * - then we count another two NUL characters before issuing TTY_BREAK
567 * - then we end on a normal char or one that has all the bottom bits
568 * zero and the top bits set
569 */
570 switch (port->rx_brk) {
571 case 0:
572 /* not breaking at the moment */
573 break;
574
575 case 1:
576 if (st & SC01STR_FEF && ch == 0) {
577 port->rx_brk = 2;
578 goto try_again;
579 }
580 goto not_break;
581
582 case 2:
583 if (st & SC01STR_FEF && ch == 0) {
584 port->rx_brk = 3;
585 _proto("Rx Break Detected");
586 icount->brk++;
587 if (uart_handle_break(&port->uart))
588 goto ignore_char;
589 status |= 1 << TTY_BREAK;
590 goto insert;
591 }
592 goto not_break;
593
594 default:
595 if (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF))
596 goto try_again; /* still breaking */
597
598 port->rx_brk = 0; /* end of the break */
599
600 switch (ch) {
601 case 0xFF:
602 case 0xFE:
603 case 0xFC:
604 case 0xF8:
605 case 0xF0:
606 case 0xE0:
607 case 0xC0:
608 case 0x80:
609 case 0x00:
610 /* discard char at probable break end */
611 goto try_again;
612 }
613 break;
614 }
615
616 process_errors:
617 /* handle framing error */
618 if (st & SC01STR_FEF) {
619 if (ch == 0) {
620 /* framing error with NUL char is probably a BREAK */
621 port->rx_brk = 1;
622 goto try_again;
623 }
624
625 _proto("Rx Framing Error");
626 icount->frame++;
627 status |= 1 << TTY_FRAME;
628 }
629
630 /* handle parity error */
631 if (st & SC01STR_PEF) {
632 _proto("Rx Parity Error");
633 icount->parity++;
634 status = TTY_PARITY;
635 }
636
637 /* handle normal char */
638 if (status == 0) {
639 if (uart_handle_sysrq_char(&port->uart, ch))
640 goto ignore_char;
641 status = (1 << TTY_NORMAL);
642 }
643
644 /* handle overrun error */
645 if (st & SC01STR_OEF) {
646 if (port->rx_brk)
647 goto try_again;
648
649 _proto("Rx Overrun Error");
650 icount->overrun++;
651 overrun = 1;
652 }
653
654 insert:
655 status &= port->uart.read_status_mask;
656
657 if (!overrun && !(status & port->uart.ignore_status_mask)) {
658 int flag;
659
660 if (status & (1 << TTY_BREAK))
661 flag = TTY_BREAK;
662 else if (status & (1 << TTY_PARITY))
663 flag = TTY_PARITY;
664 else if (status & (1 << TTY_FRAME))
665 flag = TTY_FRAME;
666 else
667 flag = TTY_NORMAL;
668
669 tty_insert_flip_char(tport, ch, flag);
670 }
671
672 /* overrun is special, since it's reported immediately, and doesn't
673 * affect the current character
674 */
675 if (overrun)
676 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
677
678 count--;
679 if (count <= 0) {
680 if (!tport->low_latency)
681 tty_flip_buffer_push(tport);
682 return;
683 }
684
685 ignore_char:
686 push = 1;
687 goto try_again;
688
689 not_break:
690 port->rx_brk = 0;
691 goto process_errors;
692 }
693
694 /*
695 * handle an interrupt from the serial transmission "virtual DMA" driver
696 * - note: the interrupt routine will disable its own interrupts when the Tx
697 * buffer is empty
698 */
mn10300_serial_transmit_interrupt(struct mn10300_serial_port * port)699 static void mn10300_serial_transmit_interrupt(struct mn10300_serial_port *port)
700 {
701 _enter("%s", port->name);
702
703 if (!port->uart.state || !port->uart.state->port.tty) {
704 mn10300_serial_dis_tx_intr(port);
705 return;
706 }
707
708 if (uart_tx_stopped(&port->uart) ||
709 uart_circ_empty(&port->uart.state->xmit))
710 mn10300_serial_dis_tx_intr(port);
711
712 if (uart_circ_chars_pending(&port->uart.state->xmit) < WAKEUP_CHARS)
713 uart_write_wakeup(&port->uart);
714 }
715
716 /*
717 * deal with a change in the status of the CTS line
718 */
mn10300_serial_cts_changed(struct mn10300_serial_port * port,u8 st)719 static void mn10300_serial_cts_changed(struct mn10300_serial_port *port, u8 st)
720 {
721 u16 ctr;
722
723 port->tx_cts = st;
724 port->uart.icount.cts++;
725
726 /* flip the CTS state selector flag to interrupt when it changes
727 * back */
728 ctr = *port->_control;
729 ctr ^= SC2CTR_TWS;
730 *port->_control = ctr;
731
732 uart_handle_cts_change(&port->uart, st & SC2STR_CTS);
733 wake_up_interruptible(&port->uart.state->port.delta_msr_wait);
734 }
735
736 /*
737 * handle a virtual interrupt generated by the lower level "virtual DMA"
738 * routines (irq is the baud timer interrupt)
739 */
mn10300_serial_interrupt(int irq,void * dev_id)740 static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id)
741 {
742 struct mn10300_serial_port *port = dev_id;
743 u8 st;
744
745 spin_lock(&port->uart.lock);
746
747 if (port->intr_flags) {
748 _debug("INT %s: %x", port->name, port->intr_flags);
749
750 if (mask_test_and_clear(&port->intr_flags, MNSCx_RX_AVAIL))
751 mn10300_serial_receive_interrupt(port);
752
753 if (mask_test_and_clear(&port->intr_flags,
754 MNSCx_TX_SPACE | MNSCx_TX_EMPTY))
755 mn10300_serial_transmit_interrupt(port);
756 }
757
758 /* the only modem control line amongst the whole lot is CTS on
759 * serial port 2 */
760 if (port->type == PORT_MN10300_CTS) {
761 st = *port->_status;
762 if ((port->tx_cts ^ st) & SC2STR_CTS)
763 mn10300_serial_cts_changed(port, st);
764 }
765
766 spin_unlock(&port->uart.lock);
767
768 return IRQ_HANDLED;
769 }
770
771 /*
772 * return indication of whether the hardware transmit buffer is empty
773 */
mn10300_serial_tx_empty(struct uart_port * _port)774 static unsigned int mn10300_serial_tx_empty(struct uart_port *_port)
775 {
776 struct mn10300_serial_port *port =
777 container_of(_port, struct mn10300_serial_port, uart);
778
779 _enter("%s", port->name);
780
781 return (*port->_status & (SC01STR_TXF | SC01STR_TBF)) ?
782 0 : TIOCSER_TEMT;
783 }
784
785 /*
786 * set the modem control lines (we don't have any)
787 */
mn10300_serial_set_mctrl(struct uart_port * _port,unsigned int mctrl)788 static void mn10300_serial_set_mctrl(struct uart_port *_port,
789 unsigned int mctrl)
790 {
791 struct mn10300_serial_port *port __attribute__ ((unused)) =
792 container_of(_port, struct mn10300_serial_port, uart);
793
794 _enter("%s,%x", port->name, mctrl);
795 }
796
797 /*
798 * get the modem control line statuses
799 */
mn10300_serial_get_mctrl(struct uart_port * _port)800 static unsigned int mn10300_serial_get_mctrl(struct uart_port *_port)
801 {
802 struct mn10300_serial_port *port =
803 container_of(_port, struct mn10300_serial_port, uart);
804
805 _enter("%s", port->name);
806
807 if (port->type == PORT_MN10300_CTS && !(*port->_status & SC2STR_CTS))
808 return TIOCM_CAR | TIOCM_DSR;
809
810 return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
811 }
812
813 /*
814 * stop transmitting characters
815 */
mn10300_serial_stop_tx(struct uart_port * _port)816 static void mn10300_serial_stop_tx(struct uart_port *_port)
817 {
818 struct mn10300_serial_port *port =
819 container_of(_port, struct mn10300_serial_port, uart);
820
821 _enter("%s", port->name);
822
823 /* disable the virtual DMA */
824 mn10300_serial_dis_tx_intr(port);
825 }
826
827 /*
828 * start transmitting characters
829 * - jump-start transmission if it has stalled
830 * - enable the serial Tx interrupt (used by the virtual DMA controller)
831 * - force an interrupt to happen if necessary
832 */
mn10300_serial_start_tx(struct uart_port * _port)833 static void mn10300_serial_start_tx(struct uart_port *_port)
834 {
835 struct mn10300_serial_port *port =
836 container_of(_port, struct mn10300_serial_port, uart);
837
838 _enter("%s{%lu}",
839 port->name,
840 CIRC_CNT(&port->uart.state->xmit.head,
841 &port->uart.state->xmit.tail,
842 UART_XMIT_SIZE));
843
844 /* kick the virtual DMA controller */
845 mn10300_serial_en_tx_intr(port);
846
847 _debug("CTR=%04hx ICR=%02hx STR=%04x TMD=%02hx TBR=%04hx ICR=%04hx",
848 *port->_control, *port->_intr, *port->_status,
849 *port->_tmxmd,
850 (port->div_timer == MNSCx_DIV_TIMER_8BIT) ?
851 *(volatile u8 *)port->_tmxbr : *port->_tmxbr,
852 *port->tx_icr);
853 }
854
855 /*
856 * transmit a high-priority XON/XOFF character
857 */
mn10300_serial_send_xchar(struct uart_port * _port,char ch)858 static void mn10300_serial_send_xchar(struct uart_port *_port, char ch)
859 {
860 struct mn10300_serial_port *port =
861 container_of(_port, struct mn10300_serial_port, uart);
862 unsigned long flags;
863
864 _enter("%s,%02x", port->name, ch);
865
866 if (likely(port->gdbstub)) {
867 port->tx_xchar = ch;
868 if (ch) {
869 spin_lock_irqsave(&port->uart.lock, flags);
870 mn10300_serial_en_tx_intr(port);
871 spin_unlock_irqrestore(&port->uart.lock, flags);
872 }
873 }
874 }
875
876 /*
877 * stop receiving characters
878 * - called whilst the port is being closed
879 */
mn10300_serial_stop_rx(struct uart_port * _port)880 static void mn10300_serial_stop_rx(struct uart_port *_port)
881 {
882 struct mn10300_serial_port *port =
883 container_of(_port, struct mn10300_serial_port, uart);
884
885 u16 ctr;
886
887 _enter("%s", port->name);
888
889 ctr = *port->_control;
890 ctr &= ~SC01CTR_RXE;
891 *port->_control = ctr;
892
893 mn10300_serial_dis_rx_intr(port);
894 }
895
896 /*
897 * enable modem status interrupts
898 */
mn10300_serial_enable_ms(struct uart_port * _port)899 static void mn10300_serial_enable_ms(struct uart_port *_port)
900 {
901 struct mn10300_serial_port *port =
902 container_of(_port, struct mn10300_serial_port, uart);
903
904 u16 ctr, cts;
905
906 _enter("%s", port->name);
907
908 if (port->type == PORT_MN10300_CTS) {
909 /* want to interrupt when CTS goes low if CTS is now high and
910 * vice versa
911 */
912 port->tx_cts = *port->_status;
913
914 cts = (port->tx_cts & SC2STR_CTS) ?
915 SC2CTR_TWE : SC2CTR_TWE | SC2CTR_TWS;
916
917 ctr = *port->_control;
918 ctr &= ~SC2CTR_TWS;
919 ctr |= cts;
920 *port->_control = ctr;
921
922 mn10300_serial_en_tx_intr(port);
923 }
924 }
925
926 /*
927 * transmit or cease transmitting a break signal
928 */
mn10300_serial_break_ctl(struct uart_port * _port,int ctl)929 static void mn10300_serial_break_ctl(struct uart_port *_port, int ctl)
930 {
931 struct mn10300_serial_port *port =
932 container_of(_port, struct mn10300_serial_port, uart);
933 unsigned long flags;
934
935 _enter("%s,%d", port->name, ctl);
936
937 spin_lock_irqsave(&port->uart.lock, flags);
938 if (ctl) {
939 /* tell the virtual DMA handler to assert BREAK */
940 port->tx_flags |= MNSCx_TX_BREAK;
941 mn10300_serial_en_tx_intr(port);
942 } else {
943 port->tx_flags &= ~MNSCx_TX_BREAK;
944 *port->_control &= ~SC01CTR_BKE;
945 mn10300_serial_en_tx_intr(port);
946 }
947 spin_unlock_irqrestore(&port->uart.lock, flags);
948 }
949
950 /*
951 * grab the interrupts and enable the port for reception
952 */
mn10300_serial_startup(struct uart_port * _port)953 static int mn10300_serial_startup(struct uart_port *_port)
954 {
955 struct mn10300_serial_port *port =
956 container_of(_port, struct mn10300_serial_port, uart);
957 struct mn10300_serial_int *pint;
958
959 _enter("%s{%d}", port->name, port->gdbstub);
960
961 if (unlikely(port->gdbstub))
962 return -EBUSY;
963
964 /* allocate an Rx buffer for the virtual DMA handler */
965 port->rx_buffer = kmalloc(MNSC_BUFFER_SIZE, GFP_KERNEL);
966 if (!port->rx_buffer)
967 return -ENOMEM;
968
969 port->rx_inp = port->rx_outp = 0;
970 port->tx_flags = 0;
971
972 /* finally, enable the device */
973 *port->_intr = SC01ICR_TI;
974 *port->_control |= SC01CTR_TXE | SC01CTR_RXE;
975
976 pint = &mn10300_serial_int_tbl[port->rx_irq];
977 pint->port = port;
978 pint->vdma = mn10300_serial_vdma_rx_handler;
979 pint = &mn10300_serial_int_tbl[port->tx_irq];
980 pint->port = port;
981 pint->vdma = mn10300_serial_vdma_tx_handler;
982
983 irq_set_chip(port->rx_irq, &mn10300_serial_low_pic);
984 irq_set_chip(port->tx_irq, &mn10300_serial_low_pic);
985 irq_set_chip(port->tm_irq, &mn10300_serial_pic);
986
987 if (request_irq(port->rx_irq, mn10300_serial_interrupt,
988 IRQF_DISABLED | IRQF_NOBALANCING,
989 port->rx_name, port) < 0)
990 goto error;
991
992 if (request_irq(port->tx_irq, mn10300_serial_interrupt,
993 IRQF_DISABLED | IRQF_NOBALANCING,
994 port->tx_name, port) < 0)
995 goto error2;
996
997 if (request_irq(port->tm_irq, mn10300_serial_interrupt,
998 IRQF_DISABLED | IRQF_NOBALANCING,
999 port->tm_name, port) < 0)
1000 goto error3;
1001 mn10300_serial_mask_ack(port->tm_irq);
1002
1003 return 0;
1004
1005 error3:
1006 free_irq(port->tx_irq, port);
1007 error2:
1008 free_irq(port->rx_irq, port);
1009 error:
1010 kfree(port->rx_buffer);
1011 port->rx_buffer = NULL;
1012 return -EBUSY;
1013 }
1014
1015 /*
1016 * shutdown the port and release interrupts
1017 */
mn10300_serial_shutdown(struct uart_port * _port)1018 static void mn10300_serial_shutdown(struct uart_port *_port)
1019 {
1020 unsigned long flags;
1021 u16 x;
1022 struct mn10300_serial_port *port =
1023 container_of(_port, struct mn10300_serial_port, uart);
1024
1025 _enter("%s", port->name);
1026
1027 spin_lock_irqsave(&_port->lock, flags);
1028 mn10300_serial_dis_tx_intr(port);
1029
1030 *port->rx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
1031 x = *port->rx_icr;
1032 port->tx_flags = 0;
1033 spin_unlock_irqrestore(&_port->lock, flags);
1034
1035 /* disable the serial port and its baud rate timer */
1036 *port->_control &= ~(SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
1037 *port->_tmxmd = 0;
1038
1039 if (port->rx_buffer) {
1040 void *buf = port->rx_buffer;
1041 port->rx_buffer = NULL;
1042 kfree(buf);
1043 }
1044
1045 /* disable all intrs */
1046 free_irq(port->tm_irq, port);
1047 free_irq(port->rx_irq, port);
1048 free_irq(port->tx_irq, port);
1049
1050 mn10300_serial_int_tbl[port->tx_irq].port = NULL;
1051 mn10300_serial_int_tbl[port->rx_irq].port = NULL;
1052 }
1053
1054 /*
1055 * this routine is called to set the UART divisor registers to match the
1056 * specified baud rate for a serial port.
1057 */
mn10300_serial_change_speed(struct mn10300_serial_port * port,struct ktermios * new,struct ktermios * old)1058 static void mn10300_serial_change_speed(struct mn10300_serial_port *port,
1059 struct ktermios *new,
1060 struct ktermios *old)
1061 {
1062 unsigned long flags;
1063 unsigned long ioclk = port->ioclk;
1064 unsigned cflag;
1065 int baud, bits, xdiv, tmp;
1066 u16 tmxbr, scxctr;
1067 u8 tmxmd, battempt;
1068 u8 div_timer = port->div_timer;
1069
1070 _enter("%s{%lu}", port->name, ioclk);
1071
1072 /* byte size and parity */
1073 cflag = new->c_cflag;
1074 switch (cflag & CSIZE) {
1075 case CS7: scxctr = SC01CTR_CLN_7BIT; bits = 9; break;
1076 case CS8: scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
1077 default: scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
1078 }
1079
1080 if (cflag & CSTOPB) {
1081 scxctr |= SC01CTR_STB_2BIT;
1082 bits++;
1083 }
1084
1085 if (cflag & PARENB) {
1086 bits++;
1087 if (cflag & PARODD)
1088 scxctr |= SC01CTR_PB_ODD;
1089 #ifdef CMSPAR
1090 else if (cflag & CMSPAR)
1091 scxctr |= SC01CTR_PB_FIXED0;
1092 #endif
1093 else
1094 scxctr |= SC01CTR_PB_EVEN;
1095 }
1096
1097 /* Determine divisor based on baud rate */
1098 battempt = 0;
1099
1100 switch (port->uart.line) {
1101 #ifdef CONFIG_MN10300_TTYSM0
1102 case 0: /* ttySM0 */
1103 #if defined(CONFIG_MN10300_TTYSM0_TIMER8)
1104 scxctr |= SC0CTR_CK_TM8UFLOW_8;
1105 #elif defined(CONFIG_MN10300_TTYSM0_TIMER0)
1106 scxctr |= SC0CTR_CK_TM0UFLOW_8;
1107 #elif defined(CONFIG_MN10300_TTYSM0_TIMER2)
1108 scxctr |= SC0CTR_CK_TM2UFLOW_8;
1109 #else
1110 #error "Unknown config for ttySM0"
1111 #endif
1112 break;
1113 #endif /* CONFIG_MN10300_TTYSM0 */
1114
1115 #ifdef CONFIG_MN10300_TTYSM1
1116 case 1: /* ttySM1 */
1117 #if defined(CONFIG_AM33_2) || defined(CONFIG_AM33_3)
1118 #if defined(CONFIG_MN10300_TTYSM1_TIMER9)
1119 scxctr |= SC1CTR_CK_TM9UFLOW_8;
1120 #elif defined(CONFIG_MN10300_TTYSM1_TIMER3)
1121 scxctr |= SC1CTR_CK_TM3UFLOW_8;
1122 #else
1123 #error "Unknown config for ttySM1"
1124 #endif
1125 #else /* CONFIG_AM33_2 || CONFIG_AM33_3 */
1126 #if defined(CONFIG_MN10300_TTYSM1_TIMER12)
1127 scxctr |= SC1CTR_CK_TM12UFLOW_8;
1128 #else
1129 #error "Unknown config for ttySM1"
1130 #endif
1131 #endif /* CONFIG_AM33_2 || CONFIG_AM33_3 */
1132 break;
1133 #endif /* CONFIG_MN10300_TTYSM1 */
1134
1135 #ifdef CONFIG_MN10300_TTYSM2
1136 case 2: /* ttySM2 */
1137 #if defined(CONFIG_AM33_2)
1138 #if defined(CONFIG_MN10300_TTYSM2_TIMER10)
1139 scxctr |= SC2CTR_CK_TM10UFLOW;
1140 #else
1141 #error "Unknown config for ttySM2"
1142 #endif
1143 #else /* CONFIG_AM33_2 */
1144 #if defined(CONFIG_MN10300_TTYSM2_TIMER9)
1145 scxctr |= SC2CTR_CK_TM9UFLOW_8;
1146 #elif defined(CONFIG_MN10300_TTYSM2_TIMER1)
1147 scxctr |= SC2CTR_CK_TM1UFLOW_8;
1148 #elif defined(CONFIG_MN10300_TTYSM2_TIMER3)
1149 scxctr |= SC2CTR_CK_TM3UFLOW_8;
1150 #else
1151 #error "Unknown config for ttySM2"
1152 #endif
1153 #endif /* CONFIG_AM33_2 */
1154 break;
1155 #endif /* CONFIG_MN10300_TTYSM2 */
1156
1157 default:
1158 break;
1159 }
1160
1161 try_alternative:
1162 baud = uart_get_baud_rate(&port->uart, new, old, 0,
1163 port->ioclk / 8);
1164
1165 _debug("ALT %d [baud %d]", battempt, baud);
1166
1167 if (!baud)
1168 baud = 9600; /* B0 transition handled in rs_set_termios */
1169 xdiv = 1;
1170 if (baud == 134) {
1171 baud = 269; /* 134 is really 134.5 */
1172 xdiv = 2;
1173 }
1174
1175 if (baud == 38400 &&
1176 (port->uart.flags & UPF_SPD_MASK) == UPF_SPD_CUST
1177 ) {
1178 _debug("CUSTOM %u", port->uart.custom_divisor);
1179
1180 if (div_timer == MNSCx_DIV_TIMER_16BIT) {
1181 if (port->uart.custom_divisor <= 65535) {
1182 tmxmd = TM8MD_SRC_IOCLK;
1183 tmxbr = port->uart.custom_divisor;
1184 port->uart.uartclk = ioclk;
1185 goto timer_okay;
1186 }
1187 if (port->uart.custom_divisor / 8 <= 65535) {
1188 tmxmd = TM8MD_SRC_IOCLK_8;
1189 tmxbr = port->uart.custom_divisor / 8;
1190 port->uart.custom_divisor = tmxbr * 8;
1191 port->uart.uartclk = ioclk / 8;
1192 goto timer_okay;
1193 }
1194 if (port->uart.custom_divisor / 32 <= 65535) {
1195 tmxmd = TM8MD_SRC_IOCLK_32;
1196 tmxbr = port->uart.custom_divisor / 32;
1197 port->uart.custom_divisor = tmxbr * 32;
1198 port->uart.uartclk = ioclk / 32;
1199 goto timer_okay;
1200 }
1201
1202 } else if (div_timer == MNSCx_DIV_TIMER_8BIT) {
1203 if (port->uart.custom_divisor <= 255) {
1204 tmxmd = TM2MD_SRC_IOCLK;
1205 tmxbr = port->uart.custom_divisor;
1206 port->uart.uartclk = ioclk;
1207 goto timer_okay;
1208 }
1209 if (port->uart.custom_divisor / 8 <= 255) {
1210 tmxmd = TM2MD_SRC_IOCLK_8;
1211 tmxbr = port->uart.custom_divisor / 8;
1212 port->uart.custom_divisor = tmxbr * 8;
1213 port->uart.uartclk = ioclk / 8;
1214 goto timer_okay;
1215 }
1216 if (port->uart.custom_divisor / 32 <= 255) {
1217 tmxmd = TM2MD_SRC_IOCLK_32;
1218 tmxbr = port->uart.custom_divisor / 32;
1219 port->uart.custom_divisor = tmxbr * 32;
1220 port->uart.uartclk = ioclk / 32;
1221 goto timer_okay;
1222 }
1223 }
1224 }
1225
1226 switch (div_timer) {
1227 case MNSCx_DIV_TIMER_16BIT:
1228 port->uart.uartclk = ioclk;
1229 tmxmd = TM8MD_SRC_IOCLK;
1230 tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
1231 if (tmp > 0 && tmp <= 65535)
1232 goto timer_okay;
1233
1234 port->uart.uartclk = ioclk / 8;
1235 tmxmd = TM8MD_SRC_IOCLK_8;
1236 tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
1237 if (tmp > 0 && tmp <= 65535)
1238 goto timer_okay;
1239
1240 port->uart.uartclk = ioclk / 32;
1241 tmxmd = TM8MD_SRC_IOCLK_32;
1242 tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
1243 if (tmp > 0 && tmp <= 65535)
1244 goto timer_okay;
1245 break;
1246
1247 case MNSCx_DIV_TIMER_8BIT:
1248 port->uart.uartclk = ioclk;
1249 tmxmd = TM2MD_SRC_IOCLK;
1250 tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
1251 if (tmp > 0 && tmp <= 255)
1252 goto timer_okay;
1253
1254 port->uart.uartclk = ioclk / 8;
1255 tmxmd = TM2MD_SRC_IOCLK_8;
1256 tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
1257 if (tmp > 0 && tmp <= 255)
1258 goto timer_okay;
1259
1260 port->uart.uartclk = ioclk / 32;
1261 tmxmd = TM2MD_SRC_IOCLK_32;
1262 tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
1263 if (tmp > 0 && tmp <= 255)
1264 goto timer_okay;
1265 break;
1266
1267 default:
1268 BUG();
1269 return;
1270 }
1271
1272 /* refuse to change to a baud rate we can't support */
1273 _debug("CAN'T SUPPORT");
1274
1275 switch (battempt) {
1276 case 0:
1277 if (old) {
1278 new->c_cflag &= ~CBAUD;
1279 new->c_cflag |= (old->c_cflag & CBAUD);
1280 battempt = 1;
1281 goto try_alternative;
1282 }
1283
1284 case 1:
1285 /* as a last resort, if the quotient is zero, default to 9600
1286 * bps */
1287 new->c_cflag &= ~CBAUD;
1288 new->c_cflag |= B9600;
1289 battempt = 2;
1290 goto try_alternative;
1291
1292 default:
1293 /* hmmm... can't seem to support 9600 either
1294 * - we could try iterating through the speeds we know about to
1295 * find the lowest
1296 */
1297 new->c_cflag &= ~CBAUD;
1298 new->c_cflag |= B0;
1299
1300 if (div_timer == MNSCx_DIV_TIMER_16BIT)
1301 tmxmd = TM8MD_SRC_IOCLK_32;
1302 else if (div_timer == MNSCx_DIV_TIMER_8BIT)
1303 tmxmd = TM2MD_SRC_IOCLK_32;
1304 tmxbr = 1;
1305
1306 port->uart.uartclk = ioclk / 32;
1307 break;
1308 }
1309 timer_okay:
1310
1311 _debug("UARTCLK: %u / %hu", port->uart.uartclk, tmxbr);
1312
1313 /* make the changes */
1314 spin_lock_irqsave(&port->uart.lock, flags);
1315
1316 uart_update_timeout(&port->uart, new->c_cflag, baud);
1317
1318 /* set the timer to produce the required baud rate */
1319 switch (div_timer) {
1320 case MNSCx_DIV_TIMER_16BIT:
1321 *port->_tmxmd = 0;
1322 *port->_tmxbr = tmxbr;
1323 *port->_tmxmd = TM8MD_INIT_COUNTER;
1324 *port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
1325 break;
1326
1327 case MNSCx_DIV_TIMER_8BIT:
1328 *port->_tmxmd = 0;
1329 *(volatile u8 *) port->_tmxbr = (u8) tmxbr;
1330 *port->_tmxmd = TM2MD_INIT_COUNTER;
1331 *port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
1332 break;
1333 }
1334
1335 /* CTS flow control flag and modem status interrupts */
1336 scxctr &= ~(SC2CTR_TWE | SC2CTR_TWS);
1337
1338 if (port->type == PORT_MN10300_CTS && cflag & CRTSCTS) {
1339 /* want to interrupt when CTS goes low if CTS is now
1340 * high and vice versa
1341 */
1342 port->tx_cts = *port->_status;
1343
1344 if (port->tx_cts & SC2STR_CTS)
1345 scxctr |= SC2CTR_TWE;
1346 else
1347 scxctr |= SC2CTR_TWE | SC2CTR_TWS;
1348 }
1349
1350 /* set up parity check flag */
1351 port->uart.read_status_mask = (1 << TTY_NORMAL) | (1 << TTY_OVERRUN);
1352 if (new->c_iflag & INPCK)
1353 port->uart.read_status_mask |=
1354 (1 << TTY_PARITY) | (1 << TTY_FRAME);
1355 if (new->c_iflag & (BRKINT | PARMRK))
1356 port->uart.read_status_mask |= (1 << TTY_BREAK);
1357
1358 /* characters to ignore */
1359 port->uart.ignore_status_mask = 0;
1360 if (new->c_iflag & IGNPAR)
1361 port->uart.ignore_status_mask |=
1362 (1 << TTY_PARITY) | (1 << TTY_FRAME);
1363 if (new->c_iflag & IGNBRK) {
1364 port->uart.ignore_status_mask |= (1 << TTY_BREAK);
1365 /*
1366 * If we're ignoring parity and break indicators,
1367 * ignore overruns to (for real raw support).
1368 */
1369 if (new->c_iflag & IGNPAR)
1370 port->uart.ignore_status_mask |= (1 << TTY_OVERRUN);
1371 }
1372
1373 /* Ignore all characters if CREAD is not set */
1374 if ((new->c_cflag & CREAD) == 0)
1375 port->uart.ignore_status_mask |= (1 << TTY_NORMAL);
1376
1377 scxctr |= SC01CTR_TXE | SC01CTR_RXE;
1378 scxctr |= *port->_control & SC01CTR_BKE;
1379 *port->_control = scxctr;
1380
1381 spin_unlock_irqrestore(&port->uart.lock, flags);
1382 }
1383
1384 /*
1385 * set the terminal I/O parameters
1386 */
mn10300_serial_set_termios(struct uart_port * _port,struct ktermios * new,struct ktermios * old)1387 static void mn10300_serial_set_termios(struct uart_port *_port,
1388 struct ktermios *new,
1389 struct ktermios *old)
1390 {
1391 struct mn10300_serial_port *port =
1392 container_of(_port, struct mn10300_serial_port, uart);
1393
1394 _enter("%s,%p,%p", port->name, new, old);
1395
1396 mn10300_serial_change_speed(port, new, old);
1397
1398 /* handle turning off CRTSCTS */
1399 if (!(new->c_cflag & CRTSCTS)) {
1400 u16 ctr = *port->_control;
1401 ctr &= ~SC2CTR_TWE;
1402 *port->_control = ctr;
1403 }
1404
1405 /* change Transfer bit-order (LSB/MSB) */
1406 if (new->c_cflag & CODMSB)
1407 *port->_control |= SC01CTR_OD_MSBFIRST; /* MSB MODE */
1408 else
1409 *port->_control &= ~SC01CTR_OD_MSBFIRST; /* LSB MODE */
1410 }
1411
1412 /*
1413 * return description of port type
1414 */
mn10300_serial_type(struct uart_port * _port)1415 static const char *mn10300_serial_type(struct uart_port *_port)
1416 {
1417 struct mn10300_serial_port *port =
1418 container_of(_port, struct mn10300_serial_port, uart);
1419
1420 if (port->uart.type == PORT_MN10300_CTS)
1421 return "MN10300 SIF_CTS";
1422
1423 return "MN10300 SIF";
1424 }
1425
1426 /*
1427 * release I/O and memory regions in use by port
1428 */
mn10300_serial_release_port(struct uart_port * _port)1429 static void mn10300_serial_release_port(struct uart_port *_port)
1430 {
1431 struct mn10300_serial_port *port =
1432 container_of(_port, struct mn10300_serial_port, uart);
1433
1434 _enter("%s", port->name);
1435
1436 release_mem_region((unsigned long) port->_iobase, 16);
1437 }
1438
1439 /*
1440 * request I/O and memory regions for port
1441 */
mn10300_serial_request_port(struct uart_port * _port)1442 static int mn10300_serial_request_port(struct uart_port *_port)
1443 {
1444 struct mn10300_serial_port *port =
1445 container_of(_port, struct mn10300_serial_port, uart);
1446
1447 _enter("%s", port->name);
1448
1449 request_mem_region((unsigned long) port->_iobase, 16, port->name);
1450 return 0;
1451 }
1452
1453 /*
1454 * configure the type and reserve the ports
1455 */
mn10300_serial_config_port(struct uart_port * _port,int type)1456 static void mn10300_serial_config_port(struct uart_port *_port, int type)
1457 {
1458 struct mn10300_serial_port *port =
1459 container_of(_port, struct mn10300_serial_port, uart);
1460
1461 _enter("%s", port->name);
1462
1463 port->uart.type = PORT_MN10300;
1464
1465 if (port->options & MNSCx_OPT_CTS)
1466 port->uart.type = PORT_MN10300_CTS;
1467
1468 mn10300_serial_request_port(_port);
1469 }
1470
1471 /*
1472 * verify serial parameters are suitable for this port type
1473 */
mn10300_serial_verify_port(struct uart_port * _port,struct serial_struct * ss)1474 static int mn10300_serial_verify_port(struct uart_port *_port,
1475 struct serial_struct *ss)
1476 {
1477 struct mn10300_serial_port *port =
1478 container_of(_port, struct mn10300_serial_port, uart);
1479 void *mapbase = (void *) (unsigned long) port->uart.mapbase;
1480
1481 _enter("%s", port->name);
1482
1483 /* these things may not be changed */
1484 if (ss->irq != port->uart.irq ||
1485 ss->port != port->uart.iobase ||
1486 ss->io_type != port->uart.iotype ||
1487 ss->iomem_base != mapbase ||
1488 ss->iomem_reg_shift != port->uart.regshift ||
1489 ss->hub6 != port->uart.hub6 ||
1490 ss->xmit_fifo_size != port->uart.fifosize)
1491 return -EINVAL;
1492
1493 /* type may be changed on a port that supports CTS */
1494 if (ss->type != port->uart.type) {
1495 if (!(port->options & MNSCx_OPT_CTS))
1496 return -EINVAL;
1497
1498 if (ss->type != PORT_MN10300 &&
1499 ss->type != PORT_MN10300_CTS)
1500 return -EINVAL;
1501 }
1502
1503 return 0;
1504 }
1505
1506 /*
1507 * initialise the MN10300 on-chip UARTs
1508 */
mn10300_serial_init(void)1509 static int __init mn10300_serial_init(void)
1510 {
1511 struct mn10300_serial_port *port;
1512 int ret, i;
1513
1514 printk(KERN_INFO "%s version %s (%s)\n",
1515 serial_name, serial_version, serial_revdate);
1516
1517 #if defined(CONFIG_MN10300_TTYSM2) && defined(CONFIG_AM33_2)
1518 {
1519 int tmp;
1520 SC2TIM = 8; /* make the baud base of timer 2 IOCLK/8 */
1521 tmp = SC2TIM;
1522 }
1523 #endif
1524
1525 set_intr_stub(NUM2EXCEP_IRQ_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL),
1526 mn10300_serial_vdma_interrupt);
1527
1528 ret = uart_register_driver(&mn10300_serial_driver);
1529 if (!ret) {
1530 for (i = 0 ; i < NR_PORTS ; i++) {
1531 port = mn10300_serial_ports[i];
1532 if (!port || port->gdbstub)
1533 continue;
1534
1535 switch (port->clock_src) {
1536 case MNSCx_CLOCK_SRC_IOCLK:
1537 port->ioclk = MN10300_IOCLK;
1538 break;
1539
1540 #ifdef MN10300_IOBCLK
1541 case MNSCx_CLOCK_SRC_IOBCLK:
1542 port->ioclk = MN10300_IOBCLK;
1543 break;
1544 #endif
1545 default:
1546 BUG();
1547 }
1548
1549 ret = uart_add_one_port(&mn10300_serial_driver,
1550 &port->uart);
1551
1552 if (ret < 0) {
1553 _debug("ERROR %d", -ret);
1554 break;
1555 }
1556 }
1557
1558 if (ret)
1559 uart_unregister_driver(&mn10300_serial_driver);
1560 }
1561
1562 return ret;
1563 }
1564
1565 __initcall(mn10300_serial_init);
1566
1567
1568 #ifdef CONFIG_MN10300_TTYSM_CONSOLE
1569
1570 /*
1571 * print a string to the serial port without disturbing the real user of the
1572 * port too much
1573 * - the console must be locked by the caller
1574 */
mn10300_serial_console_write(struct console * co,const char * s,unsigned count)1575 static void mn10300_serial_console_write(struct console *co,
1576 const char *s, unsigned count)
1577 {
1578 struct mn10300_serial_port *port;
1579 unsigned i;
1580 u16 scxctr;
1581 u8 tmxmd;
1582 unsigned long flags;
1583 int locked = 1;
1584
1585 port = mn10300_serial_ports[co->index];
1586
1587 local_irq_save(flags);
1588 if (port->uart.sysrq) {
1589 /* mn10300_serial_interrupt() already took the lock */
1590 locked = 0;
1591 } else if (oops_in_progress) {
1592 locked = spin_trylock(&port->uart.lock);
1593 } else
1594 spin_lock(&port->uart.lock);
1595
1596 /* firstly hijack the serial port from the "virtual DMA" controller */
1597 mn10300_serial_dis_tx_intr(port);
1598
1599 /* the transmitter may be disabled */
1600 scxctr = *port->_control;
1601 if (!(scxctr & SC01CTR_TXE)) {
1602 /* restart the UART clock */
1603 tmxmd = *port->_tmxmd;
1604
1605 switch (port->div_timer) {
1606 case MNSCx_DIV_TIMER_16BIT:
1607 *port->_tmxmd = 0;
1608 *port->_tmxmd = TM8MD_INIT_COUNTER;
1609 *port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
1610 break;
1611
1612 case MNSCx_DIV_TIMER_8BIT:
1613 *port->_tmxmd = 0;
1614 *port->_tmxmd = TM2MD_INIT_COUNTER;
1615 *port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
1616 break;
1617 }
1618
1619 /* enable the transmitter */
1620 *port->_control = (scxctr & ~SC01CTR_BKE) | SC01CTR_TXE;
1621
1622 } else if (scxctr & SC01CTR_BKE) {
1623 /* stop transmitting BREAK */
1624 *port->_control = (scxctr & ~SC01CTR_BKE);
1625 }
1626
1627 /* send the chars into the serial port (with LF -> LFCR conversion) */
1628 for (i = 0; i < count; i++) {
1629 char ch = *s++;
1630
1631 while (*port->_status & SC01STR_TBF)
1632 continue;
1633 *port->_txb = ch;
1634
1635 if (ch == 0x0a) {
1636 while (*port->_status & SC01STR_TBF)
1637 continue;
1638 *port->_txb = 0xd;
1639 }
1640 }
1641
1642 /* can't let the transmitter be turned off if it's actually
1643 * transmitting */
1644 while (*port->_status & (SC01STR_TXF | SC01STR_TBF))
1645 continue;
1646
1647 /* disable the transmitter if we re-enabled it */
1648 if (!(scxctr & SC01CTR_TXE))
1649 *port->_control = scxctr;
1650
1651 mn10300_serial_en_tx_intr(port);
1652
1653 if (locked)
1654 spin_unlock(&port->uart.lock);
1655 local_irq_restore(flags);
1656 }
1657
1658 /*
1659 * set up a serial port as a console
1660 * - construct a cflag setting for the first rs_open()
1661 * - initialize the serial port
1662 * - return non-zero if we didn't find a serial port.
1663 */
mn10300_serial_console_setup(struct console * co,char * options)1664 static int __init mn10300_serial_console_setup(struct console *co,
1665 char *options)
1666 {
1667 struct mn10300_serial_port *port;
1668 int i, parity = 'n', baud = 9600, bits = 8, flow = 0;
1669
1670 for (i = 0 ; i < NR_PORTS ; i++) {
1671 port = mn10300_serial_ports[i];
1672 if (port && !port->gdbstub && port->uart.line == co->index)
1673 goto found_device;
1674 }
1675
1676 return -ENODEV;
1677
1678 found_device:
1679 switch (port->clock_src) {
1680 case MNSCx_CLOCK_SRC_IOCLK:
1681 port->ioclk = MN10300_IOCLK;
1682 break;
1683
1684 #ifdef MN10300_IOBCLK
1685 case MNSCx_CLOCK_SRC_IOBCLK:
1686 port->ioclk = MN10300_IOBCLK;
1687 break;
1688 #endif
1689 default:
1690 BUG();
1691 }
1692
1693 if (options)
1694 uart_parse_options(options, &baud, &parity, &bits, &flow);
1695
1696 return uart_set_options(&port->uart, co, baud, parity, bits, flow);
1697 }
1698
1699 /*
1700 * register console
1701 */
mn10300_serial_console_init(void)1702 static int __init mn10300_serial_console_init(void)
1703 {
1704 register_console(&mn10300_serial_console);
1705 return 0;
1706 }
1707
1708 console_initcall(mn10300_serial_console_init);
1709 #endif
1710
1711 #ifdef CONFIG_CONSOLE_POLL
1712 /*
1713 * Polled character reception for the kernel debugger
1714 */
mn10300_serial_poll_get_char(struct uart_port * _port)1715 static int mn10300_serial_poll_get_char(struct uart_port *_port)
1716 {
1717 struct mn10300_serial_port *port =
1718 container_of(_port, struct mn10300_serial_port, uart);
1719 unsigned ix;
1720 u8 st, ch;
1721
1722 _enter("%s", port->name);
1723
1724 if (mn10300_serial_int_tbl[port->rx_irq].port != NULL) {
1725 do {
1726 /* pull chars out of the hat */
1727 ix = ACCESS_ONCE(port->rx_outp);
1728 if (CIRC_CNT(port->rx_inp, ix, MNSC_BUFFER_SIZE) == 0)
1729 return NO_POLL_CHAR;
1730
1731 smp_read_barrier_depends();
1732 ch = port->rx_buffer[ix++];
1733 st = port->rx_buffer[ix++];
1734 smp_mb();
1735 port->rx_outp = ix & (MNSC_BUFFER_SIZE - 1);
1736
1737 } while (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF));
1738 } else {
1739 do {
1740 st = *port->_status;
1741 if (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF))
1742 continue;
1743 } while (!(st & SC01STR_RBF));
1744
1745 ch = *port->_rxb;
1746 }
1747
1748 return ch;
1749 }
1750
1751
1752 /*
1753 * Polled character transmission for the kernel debugger
1754 */
mn10300_serial_poll_put_char(struct uart_port * _port,unsigned char ch)1755 static void mn10300_serial_poll_put_char(struct uart_port *_port,
1756 unsigned char ch)
1757 {
1758 struct mn10300_serial_port *port =
1759 container_of(_port, struct mn10300_serial_port, uart);
1760 u8 intr, tmp;
1761
1762 /* wait for the transmitter to finish anything it might be doing (and
1763 * this includes the virtual DMA handler, so it might take a while) */
1764 while (*port->_status & (SC01STR_TBF | SC01STR_TXF))
1765 continue;
1766
1767 /* disable the Tx ready interrupt */
1768 intr = *port->_intr;
1769 *port->_intr = intr & ~SC01ICR_TI;
1770 tmp = *port->_intr;
1771
1772 if (ch == 0x0a) {
1773 *port->_txb = 0x0d;
1774 while (*port->_status & SC01STR_TBF)
1775 continue;
1776 }
1777
1778 *port->_txb = ch;
1779 while (*port->_status & SC01STR_TBF)
1780 continue;
1781
1782 /* restore the Tx interrupt flag */
1783 *port->_intr = intr;
1784 tmp = *port->_intr;
1785 }
1786
1787 #endif /* CONFIG_CONSOLE_POLL */
1788