cfq-iosched: limit coop preemption
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / serial / imx.c
blob18130f11238e6025b16682c9a00cca218727e370
1 /*
2 * linux/drivers/serial/imx.c
4 * Driver for Motorola IMX serial ports
6 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
8 * Author: Sascha Hauer <sascha@saschahauer.de>
9 * Copyright (C) 2004 Pengutronix
11 * Copyright (C) 2009 emlix GmbH
12 * Author: Fabian Godehardt (added IrDA support for iMX)
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 * [29-Mar-2005] Mike Lee
29 * Added hardware handshake
32 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
33 #define SUPPORT_SYSRQ
34 #endif
36 #include <linux/module.h>
37 #include <linux/ioport.h>
38 #include <linux/init.h>
39 #include <linux/console.h>
40 #include <linux/sysrq.h>
41 #include <linux/platform_device.h>
42 #include <linux/tty.h>
43 #include <linux/tty_flip.h>
44 #include <linux/serial_core.h>
45 #include <linux/serial.h>
46 #include <linux/clk.h>
47 #include <linux/delay.h>
48 #include <linux/rational.h>
50 #include <asm/io.h>
51 #include <asm/irq.h>
52 #include <mach/hardware.h>
53 #include <mach/imx-uart.h>
55 /* Register definitions */
56 #define URXD0 0x0 /* Receiver Register */
57 #define URTX0 0x40 /* Transmitter Register */
58 #define UCR1 0x80 /* Control Register 1 */
59 #define UCR2 0x84 /* Control Register 2 */
60 #define UCR3 0x88 /* Control Register 3 */
61 #define UCR4 0x8c /* Control Register 4 */
62 #define UFCR 0x90 /* FIFO Control Register */
63 #define USR1 0x94 /* Status Register 1 */
64 #define USR2 0x98 /* Status Register 2 */
65 #define UESC 0x9c /* Escape Character Register */
66 #define UTIM 0xa0 /* Escape Timer Register */
67 #define UBIR 0xa4 /* BRM Incremental Register */
68 #define UBMR 0xa8 /* BRM Modulator Register */
69 #define UBRC 0xac /* Baud Rate Count Register */
70 #define MX2_ONEMS 0xb0 /* One Millisecond register */
71 #define UTS (cpu_is_mx1() ? 0xd0 : 0xb4) /* UART Test Register */
73 /* UART Control Register Bit Fields.*/
74 #define URXD_CHARRDY (1<<15)
75 #define URXD_ERR (1<<14)
76 #define URXD_OVRRUN (1<<13)
77 #define URXD_FRMERR (1<<12)
78 #define URXD_BRK (1<<11)
79 #define URXD_PRERR (1<<10)
80 #define UCR1_ADEN (1<<15) /* Auto dectect interrupt */
81 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
82 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
83 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
84 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
85 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
86 #define UCR1_IREN (1<<7) /* Infrared interface enable */
87 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
88 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
89 #define UCR1_SNDBRK (1<<4) /* Send break */
90 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
91 #define MX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, mx1 only */
92 #define UCR1_DOZE (1<<1) /* Doze */
93 #define UCR1_UARTEN (1<<0) /* UART enabled */
94 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
95 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
96 #define UCR2_CTSC (1<<13) /* CTS pin control */
97 #define UCR2_CTS (1<<12) /* Clear to send */
98 #define UCR2_ESCEN (1<<11) /* Escape enable */
99 #define UCR2_PREN (1<<8) /* Parity enable */
100 #define UCR2_PROE (1<<7) /* Parity odd/even */
101 #define UCR2_STPB (1<<6) /* Stop */
102 #define UCR2_WS (1<<5) /* Word size */
103 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
104 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
105 #define UCR2_RXEN (1<<1) /* Receiver enabled */
106 #define UCR2_SRST (1<<0) /* SW reset */
107 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
108 #define UCR3_PARERREN (1<<12) /* Parity enable */
109 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
110 #define UCR3_DSR (1<<10) /* Data set ready */
111 #define UCR3_DCD (1<<9) /* Data carrier detect */
112 #define UCR3_RI (1<<8) /* Ring indicator */
113 #define UCR3_TIMEOUTEN (1<<7) /* Timeout interrupt enable */
114 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
115 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
116 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
117 #define MX1_UCR3_REF25 (1<<3) /* Ref freq 25 MHz, only on mx1 */
118 #define MX1_UCR3_REF30 (1<<2) /* Ref Freq 30 MHz, only on mx1 */
119 #define MX2_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select, on mx2/mx3 */
120 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
121 #define UCR3_BPEN (1<<0) /* Preset registers enable */
122 #define UCR4_CTSTL_32 (32<<10) /* CTS trigger level (32 chars) */
123 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
124 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
125 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
126 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
127 #define UCR4_IRSC (1<<5) /* IR special case */
128 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
129 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
130 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
131 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
132 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
133 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
134 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
135 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
136 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
137 #define USR1_RTSS (1<<14) /* RTS pin status */
138 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
139 #define USR1_RTSD (1<<12) /* RTS delta */
140 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
141 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
142 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
143 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
144 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
145 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
146 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
147 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
148 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
149 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
150 #define USR2_IDLE (1<<12) /* Idle condition */
151 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
152 #define USR2_WAKE (1<<7) /* Wake */
153 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
154 #define USR2_TXDC (1<<3) /* Transmitter complete */
155 #define USR2_BRCD (1<<2) /* Break condition */
156 #define USR2_ORE (1<<1) /* Overrun error */
157 #define USR2_RDR (1<<0) /* Recv data ready */
158 #define UTS_FRCPERR (1<<13) /* Force parity error */
159 #define UTS_LOOP (1<<12) /* Loop tx and rx */
160 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
161 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
162 #define UTS_TXFULL (1<<4) /* TxFIFO full */
163 #define UTS_RXFULL (1<<3) /* RxFIFO full */
164 #define UTS_SOFTRST (1<<0) /* Software reset */
166 /* We've been assigned a range on the "Low-density serial ports" major */
167 #define SERIAL_IMX_MAJOR 207
168 #define MINOR_START 16
169 #define DEV_NAME "ttymxc"
170 #define MAX_INTERNAL_IRQ MXC_INTERNAL_IRQS
173 * This determines how often we check the modem status signals
174 * for any change. They generally aren't connected to an IRQ
175 * so we have to poll them. We also check immediately before
176 * filling the TX fifo incase CTS has been dropped.
178 #define MCTRL_TIMEOUT (250*HZ/1000)
180 #define DRIVER_NAME "IMX-uart"
182 #define UART_NR 8
184 struct imx_port {
185 struct uart_port port;
186 struct timer_list timer;
187 unsigned int old_status;
188 int txirq,rxirq,rtsirq;
189 unsigned int have_rtscts:1;
190 unsigned int use_irda:1;
191 unsigned int irda_inv_rx:1;
192 unsigned int irda_inv_tx:1;
193 unsigned short trcv_delay; /* transceiver delay */
194 struct clk *clk;
197 #ifdef CONFIG_IRDA
198 #define USE_IRDA(sport) ((sport)->use_irda)
199 #else
200 #define USE_IRDA(sport) (0)
201 #endif
204 * Handle any change of modem status signal since we were last called.
206 static void imx_mctrl_check(struct imx_port *sport)
208 unsigned int status, changed;
210 status = sport->port.ops->get_mctrl(&sport->port);
211 changed = status ^ sport->old_status;
213 if (changed == 0)
214 return;
216 sport->old_status = status;
218 if (changed & TIOCM_RI)
219 sport->port.icount.rng++;
220 if (changed & TIOCM_DSR)
221 sport->port.icount.dsr++;
222 if (changed & TIOCM_CAR)
223 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
224 if (changed & TIOCM_CTS)
225 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
227 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
231 * This is our per-port timeout handler, for checking the
232 * modem status signals.
234 static void imx_timeout(unsigned long data)
236 struct imx_port *sport = (struct imx_port *)data;
237 unsigned long flags;
239 if (sport->port.state) {
240 spin_lock_irqsave(&sport->port.lock, flags);
241 imx_mctrl_check(sport);
242 spin_unlock_irqrestore(&sport->port.lock, flags);
244 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
249 * interrupts disabled on entry
251 static void imx_stop_tx(struct uart_port *port)
253 struct imx_port *sport = (struct imx_port *)port;
254 unsigned long temp;
256 if (USE_IRDA(sport)) {
257 /* half duplex - wait for end of transmission */
258 int n = 256;
259 while ((--n > 0) &&
260 !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
261 udelay(5);
262 barrier();
265 * irda transceiver - wait a bit more to avoid
266 * cutoff, hardware dependent
268 udelay(sport->trcv_delay);
271 * half duplex - reactivate receive mode,
272 * flush receive pipe echo crap
274 if (readl(sport->port.membase + USR2) & USR2_TXDC) {
275 temp = readl(sport->port.membase + UCR1);
276 temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
277 writel(temp, sport->port.membase + UCR1);
279 temp = readl(sport->port.membase + UCR4);
280 temp &= ~(UCR4_TCEN);
281 writel(temp, sport->port.membase + UCR4);
283 while (readl(sport->port.membase + URXD0) &
284 URXD_CHARRDY)
285 barrier();
287 temp = readl(sport->port.membase + UCR1);
288 temp |= UCR1_RRDYEN;
289 writel(temp, sport->port.membase + UCR1);
291 temp = readl(sport->port.membase + UCR4);
292 temp |= UCR4_DREN;
293 writel(temp, sport->port.membase + UCR4);
295 return;
298 temp = readl(sport->port.membase + UCR1);
299 writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
303 * interrupts disabled on entry
305 static void imx_stop_rx(struct uart_port *port)
307 struct imx_port *sport = (struct imx_port *)port;
308 unsigned long temp;
310 temp = readl(sport->port.membase + UCR2);
311 writel(temp &~ UCR2_RXEN, sport->port.membase + UCR2);
315 * Set the modem control timer to fire immediately.
317 static void imx_enable_ms(struct uart_port *port)
319 struct imx_port *sport = (struct imx_port *)port;
321 mod_timer(&sport->timer, jiffies);
324 static inline void imx_transmit_buffer(struct imx_port *sport)
326 struct circ_buf *xmit = &sport->port.state->xmit;
328 while (!(readl(sport->port.membase + UTS) & UTS_TXFULL)) {
329 /* send xmit->buf[xmit->tail]
330 * out the port here */
331 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
332 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
333 sport->port.icount.tx++;
334 if (uart_circ_empty(xmit))
335 break;
338 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
339 uart_write_wakeup(&sport->port);
341 if (uart_circ_empty(xmit))
342 imx_stop_tx(&sport->port);
346 * interrupts disabled on entry
348 static void imx_start_tx(struct uart_port *port)
350 struct imx_port *sport = (struct imx_port *)port;
351 unsigned long temp;
353 if (USE_IRDA(sport)) {
354 /* half duplex in IrDA mode; have to disable receive mode */
355 temp = readl(sport->port.membase + UCR4);
356 temp &= ~(UCR4_DREN);
357 writel(temp, sport->port.membase + UCR4);
359 temp = readl(sport->port.membase + UCR1);
360 temp &= ~(UCR1_RRDYEN);
361 writel(temp, sport->port.membase + UCR1);
364 temp = readl(sport->port.membase + UCR1);
365 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
367 if (USE_IRDA(sport)) {
368 temp = readl(sport->port.membase + UCR1);
369 temp |= UCR1_TRDYEN;
370 writel(temp, sport->port.membase + UCR1);
372 temp = readl(sport->port.membase + UCR4);
373 temp |= UCR4_TCEN;
374 writel(temp, sport->port.membase + UCR4);
377 if (readl(sport->port.membase + UTS) & UTS_TXEMPTY)
378 imx_transmit_buffer(sport);
381 static irqreturn_t imx_rtsint(int irq, void *dev_id)
383 struct imx_port *sport = dev_id;
384 unsigned int val = readl(sport->port.membase + USR1) & USR1_RTSS;
385 unsigned long flags;
387 spin_lock_irqsave(&sport->port.lock, flags);
389 writel(USR1_RTSD, sport->port.membase + USR1);
390 uart_handle_cts_change(&sport->port, !!val);
391 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
393 spin_unlock_irqrestore(&sport->port.lock, flags);
394 return IRQ_HANDLED;
397 static irqreturn_t imx_txint(int irq, void *dev_id)
399 struct imx_port *sport = dev_id;
400 struct circ_buf *xmit = &sport->port.state->xmit;
401 unsigned long flags;
403 spin_lock_irqsave(&sport->port.lock,flags);
404 if (sport->port.x_char)
406 /* Send next char */
407 writel(sport->port.x_char, sport->port.membase + URTX0);
408 goto out;
411 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
412 imx_stop_tx(&sport->port);
413 goto out;
416 imx_transmit_buffer(sport);
418 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
419 uart_write_wakeup(&sport->port);
421 out:
422 spin_unlock_irqrestore(&sport->port.lock,flags);
423 return IRQ_HANDLED;
426 static irqreturn_t imx_rxint(int irq, void *dev_id)
428 struct imx_port *sport = dev_id;
429 unsigned int rx,flg,ignored = 0;
430 struct tty_struct *tty = sport->port.state->port.tty;
431 unsigned long flags, temp;
433 spin_lock_irqsave(&sport->port.lock,flags);
435 while (readl(sport->port.membase + USR2) & USR2_RDR) {
436 flg = TTY_NORMAL;
437 sport->port.icount.rx++;
439 rx = readl(sport->port.membase + URXD0);
441 temp = readl(sport->port.membase + USR2);
442 if (temp & USR2_BRCD) {
443 writel(temp | USR2_BRCD, sport->port.membase + USR2);
444 if (uart_handle_break(&sport->port))
445 continue;
448 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
449 continue;
451 if (rx & (URXD_PRERR | URXD_OVRRUN | URXD_FRMERR) ) {
452 if (rx & URXD_PRERR)
453 sport->port.icount.parity++;
454 else if (rx & URXD_FRMERR)
455 sport->port.icount.frame++;
456 if (rx & URXD_OVRRUN)
457 sport->port.icount.overrun++;
459 if (rx & sport->port.ignore_status_mask) {
460 if (++ignored > 100)
461 goto out;
462 continue;
465 rx &= sport->port.read_status_mask;
467 if (rx & URXD_PRERR)
468 flg = TTY_PARITY;
469 else if (rx & URXD_FRMERR)
470 flg = TTY_FRAME;
471 if (rx & URXD_OVRRUN)
472 flg = TTY_OVERRUN;
474 #ifdef SUPPORT_SYSRQ
475 sport->port.sysrq = 0;
476 #endif
479 tty_insert_flip_char(tty, rx, flg);
482 out:
483 spin_unlock_irqrestore(&sport->port.lock,flags);
484 tty_flip_buffer_push(tty);
485 return IRQ_HANDLED;
488 static irqreturn_t imx_int(int irq, void *dev_id)
490 struct imx_port *sport = dev_id;
491 unsigned int sts;
493 sts = readl(sport->port.membase + USR1);
495 if (sts & USR1_RRDY)
496 imx_rxint(irq, dev_id);
498 if (sts & USR1_TRDY &&
499 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
500 imx_txint(irq, dev_id);
502 if (sts & USR1_RTSD)
503 imx_rtsint(irq, dev_id);
505 return IRQ_HANDLED;
509 * Return TIOCSER_TEMT when transmitter is not busy.
511 static unsigned int imx_tx_empty(struct uart_port *port)
513 struct imx_port *sport = (struct imx_port *)port;
515 return (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
519 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
521 static unsigned int imx_get_mctrl(struct uart_port *port)
523 struct imx_port *sport = (struct imx_port *)port;
524 unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
526 if (readl(sport->port.membase + USR1) & USR1_RTSS)
527 tmp |= TIOCM_CTS;
529 if (readl(sport->port.membase + UCR2) & UCR2_CTS)
530 tmp |= TIOCM_RTS;
532 return tmp;
535 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
537 struct imx_port *sport = (struct imx_port *)port;
538 unsigned long temp;
540 temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
542 if (mctrl & TIOCM_RTS)
543 temp |= UCR2_CTS;
545 writel(temp, sport->port.membase + UCR2);
549 * Interrupts always disabled.
551 static void imx_break_ctl(struct uart_port *port, int break_state)
553 struct imx_port *sport = (struct imx_port *)port;
554 unsigned long flags, temp;
556 spin_lock_irqsave(&sport->port.lock, flags);
558 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
560 if ( break_state != 0 )
561 temp |= UCR1_SNDBRK;
563 writel(temp, sport->port.membase + UCR1);
565 spin_unlock_irqrestore(&sport->port.lock, flags);
568 #define TXTL 2 /* reset default */
569 #define RXTL 1 /* reset default */
571 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
573 unsigned int val;
574 unsigned int ufcr_rfdiv;
576 /* set receiver / transmitter trigger level.
577 * RFDIV is set such way to satisfy requested uartclk value
579 val = TXTL << 10 | RXTL;
580 ufcr_rfdiv = (clk_get_rate(sport->clk) + sport->port.uartclk / 2)
581 / sport->port.uartclk;
583 if(!ufcr_rfdiv)
584 ufcr_rfdiv = 1;
586 val |= UFCR_RFDIV_REG(ufcr_rfdiv);
588 writel(val, sport->port.membase + UFCR);
590 return 0;
593 static int imx_startup(struct uart_port *port)
595 struct imx_port *sport = (struct imx_port *)port;
596 int retval;
597 unsigned long flags, temp;
599 imx_setup_ufcr(sport, 0);
601 /* disable the DREN bit (Data Ready interrupt enable) before
602 * requesting IRQs
604 temp = readl(sport->port.membase + UCR4);
606 if (USE_IRDA(sport))
607 temp |= UCR4_IRSC;
609 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
611 if (USE_IRDA(sport)) {
612 /* reset fifo's and state machines */
613 int i = 100;
614 temp = readl(sport->port.membase + UCR2);
615 temp &= ~UCR2_SRST;
616 writel(temp, sport->port.membase + UCR2);
617 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
618 (--i > 0)) {
619 udelay(1);
624 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
625 * chips only have one interrupt.
627 if (sport->txirq > 0) {
628 retval = request_irq(sport->rxirq, imx_rxint, 0,
629 DRIVER_NAME, sport);
630 if (retval)
631 goto error_out1;
633 retval = request_irq(sport->txirq, imx_txint, 0,
634 DRIVER_NAME, sport);
635 if (retval)
636 goto error_out2;
638 /* do not use RTS IRQ on IrDA */
639 if (!USE_IRDA(sport)) {
640 retval = request_irq(sport->rtsirq, imx_rtsint,
641 (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 :
642 IRQF_TRIGGER_FALLING |
643 IRQF_TRIGGER_RISING,
644 DRIVER_NAME, sport);
645 if (retval)
646 goto error_out3;
648 } else {
649 retval = request_irq(sport->port.irq, imx_int, 0,
650 DRIVER_NAME, sport);
651 if (retval) {
652 free_irq(sport->port.irq, sport);
653 goto error_out1;
658 * Finally, clear and enable interrupts
660 writel(USR1_RTSD, sport->port.membase + USR1);
662 temp = readl(sport->port.membase + UCR1);
663 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
665 if (USE_IRDA(sport)) {
666 temp |= UCR1_IREN;
667 temp &= ~(UCR1_RTSDEN);
670 writel(temp, sport->port.membase + UCR1);
672 temp = readl(sport->port.membase + UCR2);
673 temp |= (UCR2_RXEN | UCR2_TXEN);
674 writel(temp, sport->port.membase + UCR2);
676 if (USE_IRDA(sport)) {
677 /* clear RX-FIFO */
678 int i = 64;
679 while ((--i > 0) &&
680 (readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
681 barrier();
685 if (!cpu_is_mx1()) {
686 temp = readl(sport->port.membase + UCR3);
687 temp |= MX2_UCR3_RXDMUXSEL;
688 writel(temp, sport->port.membase + UCR3);
691 if (USE_IRDA(sport)) {
692 temp = readl(sport->port.membase + UCR4);
693 if (sport->irda_inv_rx)
694 temp |= UCR4_INVR;
695 else
696 temp &= ~(UCR4_INVR);
697 writel(temp | UCR4_DREN, sport->port.membase + UCR4);
699 temp = readl(sport->port.membase + UCR3);
700 if (sport->irda_inv_tx)
701 temp |= UCR3_INVT;
702 else
703 temp &= ~(UCR3_INVT);
704 writel(temp, sport->port.membase + UCR3);
708 * Enable modem status interrupts
710 spin_lock_irqsave(&sport->port.lock,flags);
711 imx_enable_ms(&sport->port);
712 spin_unlock_irqrestore(&sport->port.lock,flags);
714 if (USE_IRDA(sport)) {
715 struct imxuart_platform_data *pdata;
716 pdata = sport->port.dev->platform_data;
717 sport->irda_inv_rx = pdata->irda_inv_rx;
718 sport->irda_inv_tx = pdata->irda_inv_tx;
719 sport->trcv_delay = pdata->transceiver_delay;
720 if (pdata->irda_enable)
721 pdata->irda_enable(1);
724 return 0;
726 error_out3:
727 if (sport->txirq)
728 free_irq(sport->txirq, sport);
729 error_out2:
730 if (sport->rxirq)
731 free_irq(sport->rxirq, sport);
732 error_out1:
733 return retval;
736 static void imx_shutdown(struct uart_port *port)
738 struct imx_port *sport = (struct imx_port *)port;
739 unsigned long temp;
741 temp = readl(sport->port.membase + UCR2);
742 temp &= ~(UCR2_TXEN);
743 writel(temp, sport->port.membase + UCR2);
745 if (USE_IRDA(sport)) {
746 struct imxuart_platform_data *pdata;
747 pdata = sport->port.dev->platform_data;
748 if (pdata->irda_enable)
749 pdata->irda_enable(0);
753 * Stop our timer.
755 del_timer_sync(&sport->timer);
758 * Free the interrupts
760 if (sport->txirq > 0) {
761 if (!USE_IRDA(sport))
762 free_irq(sport->rtsirq, sport);
763 free_irq(sport->txirq, sport);
764 free_irq(sport->rxirq, sport);
765 } else
766 free_irq(sport->port.irq, sport);
769 * Disable all interrupts, port and break condition.
772 temp = readl(sport->port.membase + UCR1);
773 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
774 if (USE_IRDA(sport))
775 temp &= ~(UCR1_IREN);
777 writel(temp, sport->port.membase + UCR1);
780 static void
781 imx_set_termios(struct uart_port *port, struct ktermios *termios,
782 struct ktermios *old)
784 struct imx_port *sport = (struct imx_port *)port;
785 unsigned long flags;
786 unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
787 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
788 unsigned int div, ufcr;
789 unsigned long num, denom;
790 uint64_t tdiv64;
793 * If we don't support modem control lines, don't allow
794 * these to be set.
796 if (0) {
797 termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
798 termios->c_cflag |= CLOCAL;
802 * We only support CS7 and CS8.
804 while ((termios->c_cflag & CSIZE) != CS7 &&
805 (termios->c_cflag & CSIZE) != CS8) {
806 termios->c_cflag &= ~CSIZE;
807 termios->c_cflag |= old_csize;
808 old_csize = CS8;
811 if ((termios->c_cflag & CSIZE) == CS8)
812 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
813 else
814 ucr2 = UCR2_SRST | UCR2_IRTS;
816 if (termios->c_cflag & CRTSCTS) {
817 if( sport->have_rtscts ) {
818 ucr2 &= ~UCR2_IRTS;
819 ucr2 |= UCR2_CTSC;
820 } else {
821 termios->c_cflag &= ~CRTSCTS;
825 if (termios->c_cflag & CSTOPB)
826 ucr2 |= UCR2_STPB;
827 if (termios->c_cflag & PARENB) {
828 ucr2 |= UCR2_PREN;
829 if (termios->c_cflag & PARODD)
830 ucr2 |= UCR2_PROE;
834 * Ask the core to calculate the divisor for us.
836 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
837 quot = uart_get_divisor(port, baud);
839 spin_lock_irqsave(&sport->port.lock, flags);
841 sport->port.read_status_mask = 0;
842 if (termios->c_iflag & INPCK)
843 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
844 if (termios->c_iflag & (BRKINT | PARMRK))
845 sport->port.read_status_mask |= URXD_BRK;
848 * Characters to ignore
850 sport->port.ignore_status_mask = 0;
851 if (termios->c_iflag & IGNPAR)
852 sport->port.ignore_status_mask |= URXD_PRERR;
853 if (termios->c_iflag & IGNBRK) {
854 sport->port.ignore_status_mask |= URXD_BRK;
856 * If we're ignoring parity and break indicators,
857 * ignore overruns too (for real raw support).
859 if (termios->c_iflag & IGNPAR)
860 sport->port.ignore_status_mask |= URXD_OVRRUN;
863 del_timer_sync(&sport->timer);
866 * Update the per-port timeout.
868 uart_update_timeout(port, termios->c_cflag, baud);
871 * disable interrupts and drain transmitter
873 old_ucr1 = readl(sport->port.membase + UCR1);
874 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
875 sport->port.membase + UCR1);
877 while ( !(readl(sport->port.membase + USR2) & USR2_TXDC))
878 barrier();
880 /* then, disable everything */
881 old_txrxen = readl(sport->port.membase + UCR2);
882 writel(old_txrxen & ~( UCR2_TXEN | UCR2_RXEN),
883 sport->port.membase + UCR2);
884 old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
886 if (USE_IRDA(sport)) {
888 * use maximum available submodule frequency to
889 * avoid missing short pulses due to low sampling rate
891 div = 1;
892 } else {
893 div = sport->port.uartclk / (baud * 16);
894 if (div > 7)
895 div = 7;
896 if (!div)
897 div = 1;
900 rational_best_approximation(16 * div * baud, sport->port.uartclk,
901 1 << 16, 1 << 16, &num, &denom);
903 if (port->state && port->state->port.tty) {
904 tdiv64 = sport->port.uartclk;
905 tdiv64 *= num;
906 do_div(tdiv64, denom * 16 * div);
907 tty_encode_baud_rate(sport->port.state->port.tty,
908 (speed_t)tdiv64, (speed_t)tdiv64);
911 num -= 1;
912 denom -= 1;
914 ufcr = readl(sport->port.membase + UFCR);
915 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
916 writel(ufcr, sport->port.membase + UFCR);
918 writel(num, sport->port.membase + UBIR);
919 writel(denom, sport->port.membase + UBMR);
921 if (!cpu_is_mx1())
922 writel(sport->port.uartclk / div / 1000,
923 sport->port.membase + MX2_ONEMS);
925 writel(old_ucr1, sport->port.membase + UCR1);
927 /* set the parity, stop bits and data size */
928 writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
930 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
931 imx_enable_ms(&sport->port);
933 spin_unlock_irqrestore(&sport->port.lock, flags);
936 static const char *imx_type(struct uart_port *port)
938 struct imx_port *sport = (struct imx_port *)port;
940 return sport->port.type == PORT_IMX ? "IMX" : NULL;
944 * Release the memory region(s) being used by 'port'.
946 static void imx_release_port(struct uart_port *port)
948 struct platform_device *pdev = to_platform_device(port->dev);
949 struct resource *mmres;
951 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
952 release_mem_region(mmres->start, mmres->end - mmres->start + 1);
956 * Request the memory region(s) being used by 'port'.
958 static int imx_request_port(struct uart_port *port)
960 struct platform_device *pdev = to_platform_device(port->dev);
961 struct resource *mmres;
962 void *ret;
964 mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
965 if (!mmres)
966 return -ENODEV;
968 ret = request_mem_region(mmres->start, mmres->end - mmres->start + 1,
969 "imx-uart");
971 return ret ? 0 : -EBUSY;
975 * Configure/autoconfigure the port.
977 static void imx_config_port(struct uart_port *port, int flags)
979 struct imx_port *sport = (struct imx_port *)port;
981 if (flags & UART_CONFIG_TYPE &&
982 imx_request_port(&sport->port) == 0)
983 sport->port.type = PORT_IMX;
987 * Verify the new serial_struct (for TIOCSSERIAL).
988 * The only change we allow are to the flags and type, and
989 * even then only between PORT_IMX and PORT_UNKNOWN
991 static int
992 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
994 struct imx_port *sport = (struct imx_port *)port;
995 int ret = 0;
997 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
998 ret = -EINVAL;
999 if (sport->port.irq != ser->irq)
1000 ret = -EINVAL;
1001 if (ser->io_type != UPIO_MEM)
1002 ret = -EINVAL;
1003 if (sport->port.uartclk / 16 != ser->baud_base)
1004 ret = -EINVAL;
1005 if ((void *)sport->port.mapbase != ser->iomem_base)
1006 ret = -EINVAL;
1007 if (sport->port.iobase != ser->port)
1008 ret = -EINVAL;
1009 if (ser->hub6 != 0)
1010 ret = -EINVAL;
1011 return ret;
1014 static struct uart_ops imx_pops = {
1015 .tx_empty = imx_tx_empty,
1016 .set_mctrl = imx_set_mctrl,
1017 .get_mctrl = imx_get_mctrl,
1018 .stop_tx = imx_stop_tx,
1019 .start_tx = imx_start_tx,
1020 .stop_rx = imx_stop_rx,
1021 .enable_ms = imx_enable_ms,
1022 .break_ctl = imx_break_ctl,
1023 .startup = imx_startup,
1024 .shutdown = imx_shutdown,
1025 .set_termios = imx_set_termios,
1026 .type = imx_type,
1027 .release_port = imx_release_port,
1028 .request_port = imx_request_port,
1029 .config_port = imx_config_port,
1030 .verify_port = imx_verify_port,
1033 static struct imx_port *imx_ports[UART_NR];
1035 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1036 static void imx_console_putchar(struct uart_port *port, int ch)
1038 struct imx_port *sport = (struct imx_port *)port;
1040 while (readl(sport->port.membase + UTS) & UTS_TXFULL)
1041 barrier();
1043 writel(ch, sport->port.membase + URTX0);
1047 * Interrupts are disabled on entering
1049 static void
1050 imx_console_write(struct console *co, const char *s, unsigned int count)
1052 struct imx_port *sport = imx_ports[co->index];
1053 unsigned int old_ucr1, old_ucr2, ucr1;
1056 * First, save UCR1/2 and then disable interrupts
1058 ucr1 = old_ucr1 = readl(sport->port.membase + UCR1);
1059 old_ucr2 = readl(sport->port.membase + UCR2);
1061 if (cpu_is_mx1())
1062 ucr1 |= MX1_UCR1_UARTCLKEN;
1063 ucr1 |= UCR1_UARTEN;
1064 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1066 writel(ucr1, sport->port.membase + UCR1);
1068 writel(old_ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1070 uart_console_write(&sport->port, s, count, imx_console_putchar);
1073 * Finally, wait for transmitter to become empty
1074 * and restore UCR1/2
1076 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1078 writel(old_ucr1, sport->port.membase + UCR1);
1079 writel(old_ucr2, sport->port.membase + UCR2);
1083 * If the port was already initialised (eg, by a boot loader),
1084 * try to determine the current setup.
1086 static void __init
1087 imx_console_get_options(struct imx_port *sport, int *baud,
1088 int *parity, int *bits)
1091 if ( readl(sport->port.membase + UCR1) | UCR1_UARTEN ) {
1092 /* ok, the port was enabled */
1093 unsigned int ucr2, ubir,ubmr, uartclk;
1094 unsigned int baud_raw;
1095 unsigned int ucfr_rfdiv;
1097 ucr2 = readl(sport->port.membase + UCR2);
1099 *parity = 'n';
1100 if (ucr2 & UCR2_PREN) {
1101 if (ucr2 & UCR2_PROE)
1102 *parity = 'o';
1103 else
1104 *parity = 'e';
1107 if (ucr2 & UCR2_WS)
1108 *bits = 8;
1109 else
1110 *bits = 7;
1112 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1113 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1115 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1116 if (ucfr_rfdiv == 6)
1117 ucfr_rfdiv = 7;
1118 else
1119 ucfr_rfdiv = 6 - ucfr_rfdiv;
1121 uartclk = clk_get_rate(sport->clk);
1122 uartclk /= ucfr_rfdiv;
1124 { /*
1125 * The next code provides exact computation of
1126 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1127 * without need of float support or long long division,
1128 * which would be required to prevent 32bit arithmetic overflow
1130 unsigned int mul = ubir + 1;
1131 unsigned int div = 16 * (ubmr + 1);
1132 unsigned int rem = uartclk % div;
1134 baud_raw = (uartclk / div) * mul;
1135 baud_raw += (rem * mul + div / 2) / div;
1136 *baud = (baud_raw + 50) / 100 * 100;
1139 if(*baud != baud_raw)
1140 printk(KERN_INFO "Serial: Console IMX rounded baud rate from %d to %d\n",
1141 baud_raw, *baud);
1145 static int __init
1146 imx_console_setup(struct console *co, char *options)
1148 struct imx_port *sport;
1149 int baud = 9600;
1150 int bits = 8;
1151 int parity = 'n';
1152 int flow = 'n';
1155 * Check whether an invalid uart number has been specified, and
1156 * if so, search for the first available port that does have
1157 * console support.
1159 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1160 co->index = 0;
1161 sport = imx_ports[co->index];
1162 if(sport == NULL)
1163 return -ENODEV;
1165 if (options)
1166 uart_parse_options(options, &baud, &parity, &bits, &flow);
1167 else
1168 imx_console_get_options(sport, &baud, &parity, &bits);
1170 imx_setup_ufcr(sport, 0);
1172 return uart_set_options(&sport->port, co, baud, parity, bits, flow);
1175 static struct uart_driver imx_reg;
1176 static struct console imx_console = {
1177 .name = DEV_NAME,
1178 .write = imx_console_write,
1179 .device = uart_console_device,
1180 .setup = imx_console_setup,
1181 .flags = CON_PRINTBUFFER,
1182 .index = -1,
1183 .data = &imx_reg,
1186 #define IMX_CONSOLE &imx_console
1187 #else
1188 #define IMX_CONSOLE NULL
1189 #endif
1191 static struct uart_driver imx_reg = {
1192 .owner = THIS_MODULE,
1193 .driver_name = DRIVER_NAME,
1194 .dev_name = DEV_NAME,
1195 .major = SERIAL_IMX_MAJOR,
1196 .minor = MINOR_START,
1197 .nr = ARRAY_SIZE(imx_ports),
1198 .cons = IMX_CONSOLE,
1201 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1203 struct imx_port *sport = platform_get_drvdata(dev);
1205 if (sport)
1206 uart_suspend_port(&imx_reg, &sport->port);
1208 return 0;
1211 static int serial_imx_resume(struct platform_device *dev)
1213 struct imx_port *sport = platform_get_drvdata(dev);
1215 if (sport)
1216 uart_resume_port(&imx_reg, &sport->port);
1218 return 0;
1221 static int serial_imx_probe(struct platform_device *pdev)
1223 struct imx_port *sport;
1224 struct imxuart_platform_data *pdata;
1225 void __iomem *base;
1226 int ret = 0;
1227 struct resource *res;
1229 sport = kzalloc(sizeof(*sport), GFP_KERNEL);
1230 if (!sport)
1231 return -ENOMEM;
1233 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1234 if (!res) {
1235 ret = -ENODEV;
1236 goto free;
1239 base = ioremap(res->start, PAGE_SIZE);
1240 if (!base) {
1241 ret = -ENOMEM;
1242 goto free;
1245 sport->port.dev = &pdev->dev;
1246 sport->port.mapbase = res->start;
1247 sport->port.membase = base;
1248 sport->port.type = PORT_IMX,
1249 sport->port.iotype = UPIO_MEM;
1250 sport->port.irq = platform_get_irq(pdev, 0);
1251 sport->rxirq = platform_get_irq(pdev, 0);
1252 sport->txirq = platform_get_irq(pdev, 1);
1253 sport->rtsirq = platform_get_irq(pdev, 2);
1254 sport->port.fifosize = 32;
1255 sport->port.ops = &imx_pops;
1256 sport->port.flags = UPF_BOOT_AUTOCONF;
1257 sport->port.line = pdev->id;
1258 init_timer(&sport->timer);
1259 sport->timer.function = imx_timeout;
1260 sport->timer.data = (unsigned long)sport;
1262 sport->clk = clk_get(&pdev->dev, "uart");
1263 if (IS_ERR(sport->clk)) {
1264 ret = PTR_ERR(sport->clk);
1265 goto unmap;
1267 clk_enable(sport->clk);
1269 sport->port.uartclk = clk_get_rate(sport->clk);
1271 imx_ports[pdev->id] = sport;
1273 pdata = pdev->dev.platform_data;
1274 if (pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
1275 sport->have_rtscts = 1;
1277 #ifdef CONFIG_IRDA
1278 if (pdata && (pdata->flags & IMXUART_IRDA))
1279 sport->use_irda = 1;
1280 #endif
1282 if (pdata->init) {
1283 ret = pdata->init(pdev);
1284 if (ret)
1285 goto clkput;
1288 ret = uart_add_one_port(&imx_reg, &sport->port);
1289 if (ret)
1290 goto deinit;
1291 platform_set_drvdata(pdev, &sport->port);
1293 return 0;
1294 deinit:
1295 if (pdata->exit)
1296 pdata->exit(pdev);
1297 clkput:
1298 clk_put(sport->clk);
1299 clk_disable(sport->clk);
1300 unmap:
1301 iounmap(sport->port.membase);
1302 free:
1303 kfree(sport);
1305 return ret;
1308 static int serial_imx_remove(struct platform_device *pdev)
1310 struct imxuart_platform_data *pdata;
1311 struct imx_port *sport = platform_get_drvdata(pdev);
1313 pdata = pdev->dev.platform_data;
1315 platform_set_drvdata(pdev, NULL);
1317 if (sport) {
1318 uart_remove_one_port(&imx_reg, &sport->port);
1319 clk_put(sport->clk);
1322 clk_disable(sport->clk);
1324 if (pdata->exit)
1325 pdata->exit(pdev);
1327 iounmap(sport->port.membase);
1328 kfree(sport);
1330 return 0;
1333 static struct platform_driver serial_imx_driver = {
1334 .probe = serial_imx_probe,
1335 .remove = serial_imx_remove,
1337 .suspend = serial_imx_suspend,
1338 .resume = serial_imx_resume,
1339 .driver = {
1340 .name = "imx-uart",
1341 .owner = THIS_MODULE,
1345 static int __init imx_serial_init(void)
1347 int ret;
1349 printk(KERN_INFO "Serial: IMX driver\n");
1351 ret = uart_register_driver(&imx_reg);
1352 if (ret)
1353 return ret;
1355 ret = platform_driver_register(&serial_imx_driver);
1356 if (ret != 0)
1357 uart_unregister_driver(&imx_reg);
1359 return 0;
1362 static void __exit imx_serial_exit(void)
1364 platform_driver_unregister(&serial_imx_driver);
1365 uart_unregister_driver(&imx_reg);
1368 module_init(imx_serial_init);
1369 module_exit(imx_serial_exit);
1371 MODULE_AUTHOR("Sascha Hauer");
1372 MODULE_DESCRIPTION("IMX generic serial port driver");
1373 MODULE_LICENSE("GPL");
1374 MODULE_ALIAS("platform:imx-uart");