1 /*
2 * linux/drivers/serial/imx.c
3 *
4 * Driver for Motorola IMX serial ports
5 *
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 *
8 * Author: Sascha Hauer <sascha@saschahauer.de>
9 * Copyright (C) 2004 Pengutronix
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 *
25 * [29-Mar-2005] Mike Lee
26 * Added hardware handshake
27 */
28
29 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
30 #define SUPPORT_SYSRQ
31 #endif
32
33 #include <linux/module.h>
34 #include <linux/ioport.h>
35 #include <linux/init.h>
36 #include <linux/console.h>
37 #include <linux/sysrq.h>
38 #include <linux/platform_device.h>
39 #include <linux/tty.h>
40 #include <linux/tty_flip.h>
41 #include <linux/serial_core.h>
42 #include <linux/serial.h>
43 #include <linux/clk.h>
44
45 #include <asm/io.h>
46 #include <asm/irq.h>
47 #include <mach/hardware.h>
48 #include <mach/imx-uart.h>
49
50 /* Register definitions */
51 #define URXD0 0x0 /* Receiver Register */
52 #define URTX0 0x40 /* Transmitter Register */
53 #define UCR1 0x80 /* Control Register 1 */
54 #define UCR2 0x84 /* Control Register 2 */
55 #define UCR3 0x88 /* Control Register 3 */
56 #define UCR4 0x8c /* Control Register 4 */
57 #define UFCR 0x90 /* FIFO Control Register */
58 #define USR1 0x94 /* Status Register 1 */
59 #define USR2 0x98 /* Status Register 2 */
60 #define UESC 0x9c /* Escape Character Register */
61 #define UTIM 0xa0 /* Escape Timer Register */
62 #define UBIR 0xa4 /* BRM Incremental Register */
63 #define UBMR 0xa8 /* BRM Modulator Register */
64 #define UBRC 0xac /* Baud Rate Count Register */
65 #if defined CONFIG_ARCH_MX3 || defined CONFIG_ARCH_MX2
66 #define ONEMS 0xb0 /* One Millisecond register */
67 #define UTS 0xb4 /* UART Test Register */
68 #endif
69 #if defined(CONFIG_ARCH_IMX) || defined(CONFIG_ARCH_MX1)
70 #define BIPR1 0xb0 /* Incremental Preset Register 1 */
71 #define BIPR2 0xb4 /* Incremental Preset Register 2 */
72 #define BIPR3 0xb8 /* Incremental Preset Register 3 */
73 #define BIPR4 0xbc /* Incremental Preset Register 4 */
74 #define BMPR1 0xc0 /* BRM Modulator Register 1 */
75 #define BMPR2 0xc4 /* BRM Modulator Register 2 */
76 #define BMPR3 0xc8 /* BRM Modulator Register 3 */
77 #define BMPR4 0xcc /* BRM Modulator Register 4 */
78 #define UTS 0xd0 /* UART Test Register */
79 #endif
80
81 /* UART Control Register Bit Fields.*/
82 #define URXD_CHARRDY (1<<15)
83 #define URXD_ERR (1<<14)
84 #define URXD_OVRRUN (1<<13)
85 #define URXD_FRMERR (1<<12)
86 #define URXD_BRK (1<<11)
87 #define URXD_PRERR (1<<10)
88 #define UCR1_ADEN (1<<15) /* Auto dectect interrupt */
89 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
90 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
91 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
92 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
93 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
94 #define UCR1_IREN (1<<7) /* Infrared interface enable */
95 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
96 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
97 #define UCR1_SNDBRK (1<<4) /* Send break */
98 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
99 #if defined(CONFIG_ARCH_IMX) || defined(CONFIG_ARCH_MX1)
100 #define UCR1_UARTCLKEN (1<<2) /* UART clock enabled */
101 #endif
102 #if defined CONFIG_ARCH_MX3 || defined CONFIG_ARCH_MX2
103 #define UCR1_UARTCLKEN (0) /* not present on mx2/mx3 */
104 #endif
105 #define UCR1_DOZE (1<<1) /* Doze */
106 #define UCR1_UARTEN (1<<0) /* UART enabled */
107 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
108 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
109 #define UCR2_CTSC (1<<13) /* CTS pin control */
110 #define UCR2_CTS (1<<12) /* Clear to send */
111 #define UCR2_ESCEN (1<<11) /* Escape enable */
112 #define UCR2_PREN (1<<8) /* Parity enable */
113 #define UCR2_PROE (1<<7) /* Parity odd/even */
114 #define UCR2_STPB (1<<6) /* Stop */
115 #define UCR2_WS (1<<5) /* Word size */
116 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
117 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
118 #define UCR2_RXEN (1<<1) /* Receiver enabled */
119 #define UCR2_SRST (1<<0) /* SW reset */
120 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
121 #define UCR3_PARERREN (1<<12) /* Parity enable */
122 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
123 #define UCR3_DSR (1<<10) /* Data set ready */
124 #define UCR3_DCD (1<<9) /* Data carrier detect */
125 #define UCR3_RI (1<<8) /* Ring indicator */
126 #define UCR3_TIMEOUTEN (1<<7) /* Timeout interrupt enable */
127 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
128 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
129 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
130 #ifdef CONFIG_ARCH_IMX
131 #define UCR3_REF25 (1<<3) /* Ref freq 25 MHz, only on mx1 */
132 #define UCR3_REF30 (1<<2) /* Ref Freq 30 MHz, only on mx1 */
133 #endif
134 #if defined CONFIG_ARCH_MX2 || defined CONFIG_ARCH_MX3
135 #define UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select, on mx2/mx3 */
136 #endif
137 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
138 #define UCR3_BPEN (1<<0) /* Preset registers enable */
139 #define UCR4_CTSTL_32 (32<<10) /* CTS trigger level (32 chars) */
140 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
141 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
142 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
143 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
144 #define UCR4_IRSC (1<<5) /* IR special case */
145 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
146 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
147 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
148 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
149 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
150 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
151 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
152 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
153 #define USR1_RTSS (1<<14) /* RTS pin status */
154 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
155 #define USR1_RTSD (1<<12) /* RTS delta */
156 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
157 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
158 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
159 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
160 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
161 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
162 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
163 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
164 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
165 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
166 #define USR2_IDLE (1<<12) /* Idle condition */
167 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
168 #define USR2_WAKE (1<<7) /* Wake */
169 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
170 #define USR2_TXDC (1<<3) /* Transmitter complete */
171 #define USR2_BRCD (1<<2) /* Break condition */
172 #define USR2_ORE (1<<1) /* Overrun error */
173 #define USR2_RDR (1<<0) /* Recv data ready */
174 #define UTS_FRCPERR (1<<13) /* Force parity error */
175 #define UTS_LOOP (1<<12) /* Loop tx and rx */
176 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
177 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
178 #define UTS_TXFULL (1<<4) /* TxFIFO full */
179 #define UTS_RXFULL (1<<3) /* RxFIFO full */
180 #define UTS_SOFTRST (1<<0) /* Software reset */
181
182 /* We've been assigned a range on the "Low-density serial ports" major */
183 #ifdef CONFIG_ARCH_IMX
184 #define SERIAL_IMX_MAJOR 204
185 #define MINOR_START 41
186 #define DEV_NAME "ttySMX"
187 #define MAX_INTERNAL_IRQ IMX_IRQS
188 #endif
189
190 #ifdef CONFIG_ARCH_MXC
191 #define SERIAL_IMX_MAJOR 207
192 #define MINOR_START 16
193 #define DEV_NAME "ttymxc"
194 #define MAX_INTERNAL_IRQ MXC_INTERNAL_IRQS
195 #endif
196
197 /*
198 * This determines how often we check the modem status signals
199 * for any change. They generally aren't connected to an IRQ
200 * so we have to poll them. We also check immediately before
201 * filling the TX fifo incase CTS has been dropped.
202 */
203 #define MCTRL_TIMEOUT (250*HZ/1000)
204
205 #define DRIVER_NAME "IMX-uart"
206
207 #define UART_NR 8
208
209 struct imx_port {
210 struct uart_port port;
211 struct timer_list timer;
212 unsigned int old_status;
213 int txirq,rxirq,rtsirq;
214 int have_rtscts:1;
215 struct clk *clk;
216 };
217
218 /*
219 * Handle any change of modem status signal since we were last called.
220 */
imx_mctrl_check(struct imx_port * sport)221 static void imx_mctrl_check(struct imx_port *sport)
222 {
223 unsigned int status, changed;
224
225 status = sport->port.ops->get_mctrl(&sport->port);
226 changed = status ^ sport->old_status;
227
228 if (changed == 0)
229 return;
230
231 sport->old_status = status;
232
233 if (changed & TIOCM_RI)
234 sport->port.icount.rng++;
235 if (changed & TIOCM_DSR)
236 sport->port.icount.dsr++;
237 if (changed & TIOCM_CAR)
238 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
239 if (changed & TIOCM_CTS)
240 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
241
242 wake_up_interruptible(&sport->port.info->delta_msr_wait);
243 }
244
245 /*
246 * This is our per-port timeout handler, for checking the
247 * modem status signals.
248 */
imx_timeout(unsigned long data)249 static void imx_timeout(unsigned long data)
250 {
251 struct imx_port *sport = (struct imx_port *)data;
252 unsigned long flags;
253
254 if (sport->port.info) {
255 spin_lock_irqsave(&sport->port.lock, flags);
256 imx_mctrl_check(sport);
257 spin_unlock_irqrestore(&sport->port.lock, flags);
258
259 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
260 }
261 }
262
263 /*
264 * interrupts disabled on entry
265 */
imx_stop_tx(struct uart_port * port)266 static void imx_stop_tx(struct uart_port *port)
267 {
268 struct imx_port *sport = (struct imx_port *)port;
269 unsigned long temp;
270
271 temp = readl(sport->port.membase + UCR1);
272 writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
273 }
274
275 /*
276 * interrupts disabled on entry
277 */
imx_stop_rx(struct uart_port * port)278 static void imx_stop_rx(struct uart_port *port)
279 {
280 struct imx_port *sport = (struct imx_port *)port;
281 unsigned long temp;
282
283 temp = readl(sport->port.membase + UCR2);
284 writel(temp &~ UCR2_RXEN, sport->port.membase + UCR2);
285 }
286
287 /*
288 * Set the modem control timer to fire immediately.
289 */
imx_enable_ms(struct uart_port * port)290 static void imx_enable_ms(struct uart_port *port)
291 {
292 struct imx_port *sport = (struct imx_port *)port;
293
294 mod_timer(&sport->timer, jiffies);
295 }
296
imx_transmit_buffer(struct imx_port * sport)297 static inline void imx_transmit_buffer(struct imx_port *sport)
298 {
299 struct circ_buf *xmit = &sport->port.info->xmit;
300
301 while (!(readl(sport->port.membase + UTS) & UTS_TXFULL)) {
302 /* send xmit->buf[xmit->tail]
303 * out the port here */
304 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
305 xmit->tail = (xmit->tail + 1) &
306 (UART_XMIT_SIZE - 1);
307 sport->port.icount.tx++;
308 if (uart_circ_empty(xmit))
309 break;
310 }
311
312 if (uart_circ_empty(xmit))
313 imx_stop_tx(&sport->port);
314 }
315
316 /*
317 * interrupts disabled on entry
318 */
imx_start_tx(struct uart_port * port)319 static void imx_start_tx(struct uart_port *port)
320 {
321 struct imx_port *sport = (struct imx_port *)port;
322 unsigned long temp;
323
324 temp = readl(sport->port.membase + UCR1);
325 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
326
327 if (readl(sport->port.membase + UTS) & UTS_TXEMPTY)
328 imx_transmit_buffer(sport);
329 }
330
imx_rtsint(int irq,void * dev_id)331 static irqreturn_t imx_rtsint(int irq, void *dev_id)
332 {
333 struct imx_port *sport = dev_id;
334 unsigned int val = readl(sport->port.membase + USR1) & USR1_RTSS;
335 unsigned long flags;
336
337 spin_lock_irqsave(&sport->port.lock, flags);
338
339 writel(USR1_RTSD, sport->port.membase + USR1);
340 uart_handle_cts_change(&sport->port, !!val);
341 wake_up_interruptible(&sport->port.info->delta_msr_wait);
342
343 spin_unlock_irqrestore(&sport->port.lock, flags);
344 return IRQ_HANDLED;
345 }
346
imx_txint(int irq,void * dev_id)347 static irqreturn_t imx_txint(int irq, void *dev_id)
348 {
349 struct imx_port *sport = dev_id;
350 struct circ_buf *xmit = &sport->port.info->xmit;
351 unsigned long flags;
352
353 spin_lock_irqsave(&sport->port.lock,flags);
354 if (sport->port.x_char)
355 {
356 /* Send next char */
357 writel(sport->port.x_char, sport->port.membase + URTX0);
358 goto out;
359 }
360
361 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
362 imx_stop_tx(&sport->port);
363 goto out;
364 }
365
366 imx_transmit_buffer(sport);
367
368 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
369 uart_write_wakeup(&sport->port);
370
371 out:
372 spin_unlock_irqrestore(&sport->port.lock,flags);
373 return IRQ_HANDLED;
374 }
375
imx_rxint(int irq,void * dev_id)376 static irqreturn_t imx_rxint(int irq, void *dev_id)
377 {
378 struct imx_port *sport = dev_id;
379 unsigned int rx,flg,ignored = 0;
380 struct tty_struct *tty = sport->port.info->port.tty;
381 unsigned long flags, temp;
382
383 spin_lock_irqsave(&sport->port.lock,flags);
384
385 while (readl(sport->port.membase + USR2) & USR2_RDR) {
386 flg = TTY_NORMAL;
387 sport->port.icount.rx++;
388
389 rx = readl(sport->port.membase + URXD0);
390
391 temp = readl(sport->port.membase + USR2);
392 if (temp & USR2_BRCD) {
393 writel(temp | USR2_BRCD, sport->port.membase + USR2);
394 if (uart_handle_break(&sport->port))
395 continue;
396 }
397
398 if (uart_handle_sysrq_char
399 (&sport->port, (unsigned char)rx))
400 continue;
401
402 if (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) {
403 if (rx & URXD_PRERR)
404 sport->port.icount.parity++;
405 else if (rx & URXD_FRMERR)
406 sport->port.icount.frame++;
407 if (rx & URXD_OVRRUN)
408 sport->port.icount.overrun++;
409
410 if (rx & sport->port.ignore_status_mask) {
411 if (++ignored > 100)
412 goto out;
413 continue;
414 }
415
416 rx &= sport->port.read_status_mask;
417
418 if (rx & URXD_PRERR)
419 flg = TTY_PARITY;
420 else if (rx & URXD_FRMERR)
421 flg = TTY_FRAME;
422 if (rx & URXD_OVRRUN)
423 flg = TTY_OVERRUN;
424
425 #ifdef SUPPORT_SYSRQ
426 sport->port.sysrq = 0;
427 #endif
428 }
429
430 tty_insert_flip_char(tty, rx, flg);
431 }
432
433 out:
434 spin_unlock_irqrestore(&sport->port.lock,flags);
435 tty_flip_buffer_push(tty);
436 return IRQ_HANDLED;
437 }
438
imx_int(int irq,void * dev_id)439 static irqreturn_t imx_int(int irq, void *dev_id)
440 {
441 struct imx_port *sport = dev_id;
442 unsigned int sts;
443
444 sts = readl(sport->port.membase + USR1);
445
446 if (sts & USR1_RRDY)
447 imx_rxint(irq, dev_id);
448
449 if (sts & USR1_TRDY &&
450 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
451 imx_txint(irq, dev_id);
452
453 if (sts & USR1_RTSD)
454 imx_rtsint(irq, dev_id);
455
456 return IRQ_HANDLED;
457 }
458
459 /*
460 * Return TIOCSER_TEMT when transmitter is not busy.
461 */
imx_tx_empty(struct uart_port * port)462 static unsigned int imx_tx_empty(struct uart_port *port)
463 {
464 struct imx_port *sport = (struct imx_port *)port;
465
466 return (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
467 }
468
469 /*
470 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
471 */
imx_get_mctrl(struct uart_port * port)472 static unsigned int imx_get_mctrl(struct uart_port *port)
473 {
474 struct imx_port *sport = (struct imx_port *)port;
475 unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
476
477 if (readl(sport->port.membase + USR1) & USR1_RTSS)
478 tmp |= TIOCM_CTS;
479
480 if (readl(sport->port.membase + UCR2) & UCR2_CTS)
481 tmp |= TIOCM_RTS;
482
483 return tmp;
484 }
485
imx_set_mctrl(struct uart_port * port,unsigned int mctrl)486 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
487 {
488 struct imx_port *sport = (struct imx_port *)port;
489 unsigned long temp;
490
491 temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
492
493 if (mctrl & TIOCM_RTS)
494 temp |= UCR2_CTS;
495
496 writel(temp, sport->port.membase + UCR2);
497 }
498
499 /*
500 * Interrupts always disabled.
501 */
imx_break_ctl(struct uart_port * port,int break_state)502 static void imx_break_ctl(struct uart_port *port, int break_state)
503 {
504 struct imx_port *sport = (struct imx_port *)port;
505 unsigned long flags, temp;
506
507 spin_lock_irqsave(&sport->port.lock, flags);
508
509 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
510
511 if ( break_state != 0 )
512 temp |= UCR1_SNDBRK;
513
514 writel(temp, sport->port.membase + UCR1);
515
516 spin_unlock_irqrestore(&sport->port.lock, flags);
517 }
518
519 #define TXTL 2 /* reset default */
520 #define RXTL 1 /* reset default */
521
imx_setup_ufcr(struct imx_port * sport,unsigned int mode)522 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
523 {
524 unsigned int val;
525 unsigned int ufcr_rfdiv;
526
527 /* set receiver / transmitter trigger level.
528 * RFDIV is set such way to satisfy requested uartclk value
529 */
530 val = TXTL << 10 | RXTL;
531 ufcr_rfdiv = (clk_get_rate(sport->clk) + sport->port.uartclk / 2)
532 / sport->port.uartclk;
533
534 if(!ufcr_rfdiv)
535 ufcr_rfdiv = 1;
536
537 if(ufcr_rfdiv >= 7)
538 ufcr_rfdiv = 6;
539 else
540 ufcr_rfdiv = 6 - ufcr_rfdiv;
541
542 val |= UFCR_RFDIV & (ufcr_rfdiv << 7);
543
544 writel(val, sport->port.membase + UFCR);
545
546 return 0;
547 }
548
imx_startup(struct uart_port * port)549 static int imx_startup(struct uart_port *port)
550 {
551 struct imx_port *sport = (struct imx_port *)port;
552 int retval;
553 unsigned long flags, temp;
554
555 imx_setup_ufcr(sport, 0);
556
557 /* disable the DREN bit (Data Ready interrupt enable) before
558 * requesting IRQs
559 */
560 temp = readl(sport->port.membase + UCR4);
561 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
562
563 /*
564 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
565 * chips only have one interrupt.
566 */
567 if (sport->txirq > 0) {
568 retval = request_irq(sport->rxirq, imx_rxint, 0,
569 DRIVER_NAME, sport);
570 if (retval)
571 goto error_out1;
572
573 retval = request_irq(sport->txirq, imx_txint, 0,
574 DRIVER_NAME, sport);
575 if (retval)
576 goto error_out2;
577
578 retval = request_irq(sport->rtsirq, imx_rtsint,
579 (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 :
580 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
581 DRIVER_NAME, sport);
582 if (retval)
583 goto error_out3;
584 } else {
585 retval = request_irq(sport->port.irq, imx_int, 0,
586 DRIVER_NAME, sport);
587 if (retval) {
588 free_irq(sport->port.irq, sport);
589 goto error_out1;
590 }
591 }
592
593 /*
594 * Finally, clear and enable interrupts
595 */
596 writel(USR1_RTSD, sport->port.membase + USR1);
597
598 temp = readl(sport->port.membase + UCR1);
599 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
600 writel(temp, sport->port.membase + UCR1);
601
602 temp = readl(sport->port.membase + UCR2);
603 temp |= (UCR2_RXEN | UCR2_TXEN);
604 writel(temp, sport->port.membase + UCR2);
605
606 #if defined CONFIG_ARCH_MX2 || defined CONFIG_ARCH_MX3
607 temp = readl(sport->port.membase + UCR3);
608 temp |= UCR3_RXDMUXSEL;
609 writel(temp, sport->port.membase + UCR3);
610 #endif
611
612 /*
613 * Enable modem status interrupts
614 */
615 spin_lock_irqsave(&sport->port.lock,flags);
616 imx_enable_ms(&sport->port);
617 spin_unlock_irqrestore(&sport->port.lock,flags);
618
619 return 0;
620
621 error_out3:
622 if (sport->txirq)
623 free_irq(sport->txirq, sport);
624 error_out2:
625 if (sport->rxirq)
626 free_irq(sport->rxirq, sport);
627 error_out1:
628 return retval;
629 }
630
imx_shutdown(struct uart_port * port)631 static void imx_shutdown(struct uart_port *port)
632 {
633 struct imx_port *sport = (struct imx_port *)port;
634 unsigned long temp;
635
636 /*
637 * Stop our timer.
638 */
639 del_timer_sync(&sport->timer);
640
641 /*
642 * Free the interrupts
643 */
644 if (sport->txirq > 0) {
645 free_irq(sport->rtsirq, sport);
646 free_irq(sport->txirq, sport);
647 free_irq(sport->rxirq, sport);
648 } else
649 free_irq(sport->port.irq, sport);
650
651 /*
652 * Disable all interrupts, port and break condition.
653 */
654
655 temp = readl(sport->port.membase + UCR1);
656 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
657 writel(temp, sport->port.membase + UCR1);
658 }
659
660 static void
imx_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)661 imx_set_termios(struct uart_port *port, struct ktermios *termios,
662 struct ktermios *old)
663 {
664 struct imx_port *sport = (struct imx_port *)port;
665 unsigned long flags;
666 unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
667 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
668 unsigned int div, num, denom, ufcr;
669
670 /*
671 * If we don't support modem control lines, don't allow
672 * these to be set.
673 */
674 if (0) {
675 termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
676 termios->c_cflag |= CLOCAL;
677 }
678
679 /*
680 * We only support CS7 and CS8.
681 */
682 while ((termios->c_cflag & CSIZE) != CS7 &&
683 (termios->c_cflag & CSIZE) != CS8) {
684 termios->c_cflag &= ~CSIZE;
685 termios->c_cflag |= old_csize;
686 old_csize = CS8;
687 }
688
689 if ((termios->c_cflag & CSIZE) == CS8)
690 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
691 else
692 ucr2 = UCR2_SRST | UCR2_IRTS;
693
694 if (termios->c_cflag & CRTSCTS) {
695 if( sport->have_rtscts ) {
696 ucr2 &= ~UCR2_IRTS;
697 ucr2 |= UCR2_CTSC;
698 } else {
699 termios->c_cflag &= ~CRTSCTS;
700 }
701 }
702
703 if (termios->c_cflag & CSTOPB)
704 ucr2 |= UCR2_STPB;
705 if (termios->c_cflag & PARENB) {
706 ucr2 |= UCR2_PREN;
707 if (termios->c_cflag & PARODD)
708 ucr2 |= UCR2_PROE;
709 }
710
711 /*
712 * Ask the core to calculate the divisor for us.
713 */
714 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
715 quot = uart_get_divisor(port, baud);
716
717 spin_lock_irqsave(&sport->port.lock, flags);
718
719 sport->port.read_status_mask = 0;
720 if (termios->c_iflag & INPCK)
721 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
722 if (termios->c_iflag & (BRKINT | PARMRK))
723 sport->port.read_status_mask |= URXD_BRK;
724
725 /*
726 * Characters to ignore
727 */
728 sport->port.ignore_status_mask = 0;
729 if (termios->c_iflag & IGNPAR)
730 sport->port.ignore_status_mask |= URXD_PRERR;
731 if (termios->c_iflag & IGNBRK) {
732 sport->port.ignore_status_mask |= URXD_BRK;
733 /*
734 * If we're ignoring parity and break indicators,
735 * ignore overruns too (for real raw support).
736 */
737 if (termios->c_iflag & IGNPAR)
738 sport->port.ignore_status_mask |= URXD_OVRRUN;
739 }
740
741 del_timer_sync(&sport->timer);
742
743 /*
744 * Update the per-port timeout.
745 */
746 uart_update_timeout(port, termios->c_cflag, baud);
747
748 /*
749 * disable interrupts and drain transmitter
750 */
751 old_ucr1 = readl(sport->port.membase + UCR1);
752 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
753 sport->port.membase + UCR1);
754
755 while ( !(readl(sport->port.membase + USR2) & USR2_TXDC))
756 barrier();
757
758 /* then, disable everything */
759 old_txrxen = readl(sport->port.membase + UCR2);
760 writel(old_txrxen & ~( UCR2_TXEN | UCR2_RXEN),
761 sport->port.membase + UCR2);
762 old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
763
764 div = sport->port.uartclk / (baud * 16);
765 if (div > 7)
766 div = 7;
767 if (!div)
768 div = 1;
769
770 num = baud;
771 denom = port->uartclk / div / 16;
772
773 /* shift num and denom right until they fit into 16 bits */
774 while (num > 0x10000 || denom > 0x10000) {
775 num >>= 1;
776 denom >>= 1;
777 }
778 if (num > 0)
779 num -= 1;
780 if (denom > 0)
781 denom -= 1;
782
783 writel(num, sport->port.membase + UBIR);
784 writel(denom, sport->port.membase + UBMR);
785
786 if (div == 7)
787 div = 6; /* 6 in RFDIV means divide by 7 */
788 else
789 div = 6 - div;
790
791 ufcr = readl(sport->port.membase + UFCR);
792 ufcr = (ufcr & (~UFCR_RFDIV)) |
793 (div << 7);
794 writel(ufcr, sport->port.membase + UFCR);
795
796 #ifdef ONEMS
797 writel(sport->port.uartclk / div / 1000, sport->port.membase + ONEMS);
798 #endif
799
800 writel(old_ucr1, sport->port.membase + UCR1);
801
802 /* set the parity, stop bits and data size */
803 writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
804
805 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
806 imx_enable_ms(&sport->port);
807
808 spin_unlock_irqrestore(&sport->port.lock, flags);
809 }
810
imx_type(struct uart_port * port)811 static const char *imx_type(struct uart_port *port)
812 {
813 struct imx_port *sport = (struct imx_port *)port;
814
815 return sport->port.type == PORT_IMX ? "IMX" : NULL;
816 }
817
818 /*
819 * Release the memory region(s) being used by 'port'.
820 */
imx_release_port(struct uart_port * port)821 static void imx_release_port(struct uart_port *port)
822 {
823 struct platform_device *pdev = to_platform_device(port->dev);
824 struct resource *mmres;
825
826 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
827 release_mem_region(mmres->start, mmres->end - mmres->start + 1);
828 }
829
830 /*
831 * Request the memory region(s) being used by 'port'.
832 */
imx_request_port(struct uart_port * port)833 static int imx_request_port(struct uart_port *port)
834 {
835 struct platform_device *pdev = to_platform_device(port->dev);
836 struct resource *mmres;
837 void *ret;
838
839 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
840 if (!mmres)
841 return -ENODEV;
842
843 ret = request_mem_region(mmres->start, mmres->end - mmres->start + 1,
844 "imx-uart");
845
846 return ret ? 0 : -EBUSY;
847 }
848
849 /*
850 * Configure/autoconfigure the port.
851 */
imx_config_port(struct uart_port * port,int flags)852 static void imx_config_port(struct uart_port *port, int flags)
853 {
854 struct imx_port *sport = (struct imx_port *)port;
855
856 if (flags & UART_CONFIG_TYPE &&
857 imx_request_port(&sport->port) == 0)
858 sport->port.type = PORT_IMX;
859 }
860
861 /*
862 * Verify the new serial_struct (for TIOCSSERIAL).
863 * The only change we allow are to the flags and type, and
864 * even then only between PORT_IMX and PORT_UNKNOWN
865 */
866 static int
imx_verify_port(struct uart_port * port,struct serial_struct * ser)867 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
868 {
869 struct imx_port *sport = (struct imx_port *)port;
870 int ret = 0;
871
872 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
873 ret = -EINVAL;
874 if (sport->port.irq != ser->irq)
875 ret = -EINVAL;
876 if (ser->io_type != UPIO_MEM)
877 ret = -EINVAL;
878 if (sport->port.uartclk / 16 != ser->baud_base)
879 ret = -EINVAL;
880 if ((void *)sport->port.mapbase != ser->iomem_base)
881 ret = -EINVAL;
882 if (sport->port.iobase != ser->port)
883 ret = -EINVAL;
884 if (ser->hub6 != 0)
885 ret = -EINVAL;
886 return ret;
887 }
888
889 static struct uart_ops imx_pops = {
890 .tx_empty = imx_tx_empty,
891 .set_mctrl = imx_set_mctrl,
892 .get_mctrl = imx_get_mctrl,
893 .stop_tx = imx_stop_tx,
894 .start_tx = imx_start_tx,
895 .stop_rx = imx_stop_rx,
896 .enable_ms = imx_enable_ms,
897 .break_ctl = imx_break_ctl,
898 .startup = imx_startup,
899 .shutdown = imx_shutdown,
900 .set_termios = imx_set_termios,
901 .type = imx_type,
902 .release_port = imx_release_port,
903 .request_port = imx_request_port,
904 .config_port = imx_config_port,
905 .verify_port = imx_verify_port,
906 };
907
908 static struct imx_port *imx_ports[UART_NR];
909
910 #ifdef CONFIG_SERIAL_IMX_CONSOLE
imx_console_putchar(struct uart_port * port,int ch)911 static void imx_console_putchar(struct uart_port *port, int ch)
912 {
913 struct imx_port *sport = (struct imx_port *)port;
914
915 while (readl(sport->port.membase + UTS) & UTS_TXFULL)
916 barrier();
917
918 writel(ch, sport->port.membase + URTX0);
919 }
920
921 /*
922 * Interrupts are disabled on entering
923 */
924 static void
imx_console_write(struct console * co,const char * s,unsigned int count)925 imx_console_write(struct console *co, const char *s, unsigned int count)
926 {
927 struct imx_port *sport = imx_ports[co->index];
928 unsigned int old_ucr1, old_ucr2;
929
930 /*
931 * First, save UCR1/2 and then disable interrupts
932 */
933 old_ucr1 = readl(sport->port.membase + UCR1);
934 old_ucr2 = readl(sport->port.membase + UCR2);
935
936 writel((old_ucr1 | UCR1_UARTCLKEN | UCR1_UARTEN) &
937 ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
938 sport->port.membase + UCR1);
939
940 writel(old_ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
941
942 uart_console_write(&sport->port, s, count, imx_console_putchar);
943
944 /*
945 * Finally, wait for transmitter to become empty
946 * and restore UCR1/2
947 */
948 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
949
950 writel(old_ucr1, sport->port.membase + UCR1);
951 writel(old_ucr2, sport->port.membase + UCR2);
952 }
953
954 /*
955 * If the port was already initialised (eg, by a boot loader),
956 * try to determine the current setup.
957 */
958 static void __init
imx_console_get_options(struct imx_port * sport,int * baud,int * parity,int * bits)959 imx_console_get_options(struct imx_port *sport, int *baud,
960 int *parity, int *bits)
961 {
962
963 if ( readl(sport->port.membase + UCR1) | UCR1_UARTEN ) {
964 /* ok, the port was enabled */
965 unsigned int ucr2, ubir,ubmr, uartclk;
966 unsigned int baud_raw;
967 unsigned int ucfr_rfdiv;
968
969 ucr2 = readl(sport->port.membase + UCR2);
970
971 *parity = 'n';
972 if (ucr2 & UCR2_PREN) {
973 if (ucr2 & UCR2_PROE)
974 *parity = 'o';
975 else
976 *parity = 'e';
977 }
978
979 if (ucr2 & UCR2_WS)
980 *bits = 8;
981 else
982 *bits = 7;
983
984 ubir = readl(sport->port.membase + UBIR) & 0xffff;
985 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
986
987 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
988 if (ucfr_rfdiv == 6)
989 ucfr_rfdiv = 7;
990 else
991 ucfr_rfdiv = 6 - ucfr_rfdiv;
992
993 uartclk = clk_get_rate(sport->clk);
994 uartclk /= ucfr_rfdiv;
995
996 { /*
997 * The next code provides exact computation of
998 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
999 * without need of float support or long long division,
1000 * which would be required to prevent 32bit arithmetic overflow
1001 */
1002 unsigned int mul = ubir + 1;
1003 unsigned int div = 16 * (ubmr + 1);
1004 unsigned int rem = uartclk % div;
1005
1006 baud_raw = (uartclk / div) * mul;
1007 baud_raw += (rem * mul + div / 2) / div;
1008 *baud = (baud_raw + 50) / 100 * 100;
1009 }
1010
1011 if(*baud != baud_raw)
1012 printk(KERN_INFO "Serial: Console IMX rounded baud rate from %d to %d\n",
1013 baud_raw, *baud);
1014 }
1015 }
1016
1017 static int __init
imx_console_setup(struct console * co,char * options)1018 imx_console_setup(struct console *co, char *options)
1019 {
1020 struct imx_port *sport;
1021 int baud = 9600;
1022 int bits = 8;
1023 int parity = 'n';
1024 int flow = 'n';
1025
1026 /*
1027 * Check whether an invalid uart number has been specified, and
1028 * if so, search for the first available port that does have
1029 * console support.
1030 */
1031 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1032 co->index = 0;
1033 sport = imx_ports[co->index];
1034
1035 if (options)
1036 uart_parse_options(options, &baud, &parity, &bits, &flow);
1037 else
1038 imx_console_get_options(sport, &baud, &parity, &bits);
1039
1040 imx_setup_ufcr(sport, 0);
1041
1042 return uart_set_options(&sport->port, co, baud, parity, bits, flow);
1043 }
1044
1045 static struct uart_driver imx_reg;
1046 static struct console imx_console = {
1047 .name = DEV_NAME,
1048 .write = imx_console_write,
1049 .device = uart_console_device,
1050 .setup = imx_console_setup,
1051 .flags = CON_PRINTBUFFER,
1052 .index = -1,
1053 .data = &imx_reg,
1054 };
1055
1056 #define IMX_CONSOLE &imx_console
1057 #else
1058 #define IMX_CONSOLE NULL
1059 #endif
1060
1061 static struct uart_driver imx_reg = {
1062 .owner = THIS_MODULE,
1063 .driver_name = DRIVER_NAME,
1064 .dev_name = DEV_NAME,
1065 .major = SERIAL_IMX_MAJOR,
1066 .minor = MINOR_START,
1067 .nr = ARRAY_SIZE(imx_ports),
1068 .cons = IMX_CONSOLE,
1069 };
1070
serial_imx_suspend(struct platform_device * dev,pm_message_t state)1071 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1072 {
1073 struct imx_port *sport = platform_get_drvdata(dev);
1074
1075 if (sport)
1076 uart_suspend_port(&imx_reg, &sport->port);
1077
1078 return 0;
1079 }
1080
serial_imx_resume(struct platform_device * dev)1081 static int serial_imx_resume(struct platform_device *dev)
1082 {
1083 struct imx_port *sport = platform_get_drvdata(dev);
1084
1085 if (sport)
1086 uart_resume_port(&imx_reg, &sport->port);
1087
1088 return 0;
1089 }
1090
serial_imx_probe(struct platform_device * pdev)1091 static int serial_imx_probe(struct platform_device *pdev)
1092 {
1093 struct imx_port *sport;
1094 struct imxuart_platform_data *pdata;
1095 void __iomem *base;
1096 int ret = 0;
1097 struct resource *res;
1098
1099 sport = kzalloc(sizeof(*sport), GFP_KERNEL);
1100 if (!sport)
1101 return -ENOMEM;
1102
1103 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1104 if (!res) {
1105 ret = -ENODEV;
1106 goto free;
1107 }
1108
1109 base = ioremap(res->start, PAGE_SIZE);
1110 if (!base) {
1111 ret = -ENOMEM;
1112 goto free;
1113 }
1114
1115 sport->port.dev = &pdev->dev;
1116 sport->port.mapbase = res->start;
1117 sport->port.membase = base;
1118 sport->port.type = PORT_IMX,
1119 sport->port.iotype = UPIO_MEM;
1120 sport->port.irq = platform_get_irq(pdev, 0);
1121 sport->rxirq = platform_get_irq(pdev, 0);
1122 sport->txirq = platform_get_irq(pdev, 1);
1123 sport->rtsirq = platform_get_irq(pdev, 2);
1124 sport->port.fifosize = 32;
1125 sport->port.ops = &imx_pops;
1126 sport->port.flags = UPF_BOOT_AUTOCONF;
1127 sport->port.line = pdev->id;
1128 init_timer(&sport->timer);
1129 sport->timer.function = imx_timeout;
1130 sport->timer.data = (unsigned long)sport;
1131
1132 sport->clk = clk_get(&pdev->dev, "uart_clk");
1133 if (IS_ERR(sport->clk)) {
1134 ret = PTR_ERR(sport->clk);
1135 goto unmap;
1136 }
1137 clk_enable(sport->clk);
1138
1139 sport->port.uartclk = clk_get_rate(sport->clk);
1140
1141 imx_ports[pdev->id] = sport;
1142
1143 pdata = pdev->dev.platform_data;
1144 if(pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
1145 sport->have_rtscts = 1;
1146
1147 if (pdata->init) {
1148 ret = pdata->init(pdev);
1149 if (ret)
1150 goto clkput;
1151 }
1152
1153 uart_add_one_port(&imx_reg, &sport->port);
1154 platform_set_drvdata(pdev, &sport->port);
1155
1156 return 0;
1157 clkput:
1158 clk_put(sport->clk);
1159 clk_disable(sport->clk);
1160 unmap:
1161 iounmap(sport->port.membase);
1162 free:
1163 kfree(sport);
1164
1165 return ret;
1166 }
1167
serial_imx_remove(struct platform_device * pdev)1168 static int serial_imx_remove(struct platform_device *pdev)
1169 {
1170 struct imxuart_platform_data *pdata;
1171 struct imx_port *sport = platform_get_drvdata(pdev);
1172
1173 pdata = pdev->dev.platform_data;
1174
1175 platform_set_drvdata(pdev, NULL);
1176
1177 if (sport) {
1178 uart_remove_one_port(&imx_reg, &sport->port);
1179 clk_put(sport->clk);
1180 }
1181
1182 clk_disable(sport->clk);
1183
1184 if (pdata->exit)
1185 pdata->exit(pdev);
1186
1187 iounmap(sport->port.membase);
1188 kfree(sport);
1189
1190 return 0;
1191 }
1192
1193 static struct platform_driver serial_imx_driver = {
1194 .probe = serial_imx_probe,
1195 .remove = serial_imx_remove,
1196
1197 .suspend = serial_imx_suspend,
1198 .resume = serial_imx_resume,
1199 .driver = {
1200 .name = "imx-uart",
1201 .owner = THIS_MODULE,
1202 },
1203 };
1204
imx_serial_init(void)1205 static int __init imx_serial_init(void)
1206 {
1207 int ret;
1208
1209 printk(KERN_INFO "Serial: IMX driver\n");
1210
1211 ret = uart_register_driver(&imx_reg);
1212 if (ret)
1213 return ret;
1214
1215 ret = platform_driver_register(&serial_imx_driver);
1216 if (ret != 0)
1217 uart_unregister_driver(&imx_reg);
1218
1219 return 0;
1220 }
1221
imx_serial_exit(void)1222 static void __exit imx_serial_exit(void)
1223 {
1224 platform_driver_unregister(&serial_imx_driver);
1225 uart_unregister_driver(&imx_reg);
1226 }
1227
1228 module_init(imx_serial_init);
1229 module_exit(imx_serial_exit);
1230
1231 MODULE_AUTHOR("Sascha Hauer");
1232 MODULE_DESCRIPTION("IMX generic serial port driver");
1233 MODULE_LICENSE("GPL");
1234 MODULE_ALIAS("platform:imx-uart");
1235