2 * Driver for Motorola IMX serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Author: Sascha Hauer <sascha@saschahauer.de>
7 * Copyright (C) 2004 Pengutronix
9 * Copyright (C) 2009 emlix GmbH
10 * Author: Fabian Godehardt (added IrDA support for iMX)
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 * [29-Mar-2005] Mike Lee
27 * Added hardware handshake
30 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
34 #include <linux/module.h>
35 #include <linux/ioport.h>
36 #include <linux/init.h>
37 #include <linux/console.h>
38 #include <linux/sysrq.h>
39 #include <linux/platform_device.h>
40 #include <linux/tty.h>
41 #include <linux/tty_flip.h>
42 #include <linux/serial_core.h>
43 #include <linux/serial.h>
44 #include <linux/clk.h>
45 #include <linux/delay.h>
46 #include <linux/rational.h>
47 #include <linux/slab.h>
49 #include <linux/of_device.h>
51 #include <linux/dma-mapping.h>
54 #include <linux/platform_data/serial-imx.h>
55 #include <linux/platform_data/dma-imx.h>
57 /* Register definitions */
58 #define URXD0 0x0 /* Receiver Register */
59 #define URTX0 0x40 /* Transmitter Register */
60 #define UCR1 0x80 /* Control Register 1 */
61 #define UCR2 0x84 /* Control Register 2 */
62 #define UCR3 0x88 /* Control Register 3 */
63 #define UCR4 0x8c /* Control Register 4 */
64 #define UFCR 0x90 /* FIFO Control Register */
65 #define USR1 0x94 /* Status Register 1 */
66 #define USR2 0x98 /* Status Register 2 */
67 #define UESC 0x9c /* Escape Character Register */
68 #define UTIM 0xa0 /* Escape Timer Register */
69 #define UBIR 0xa4 /* BRM Incremental Register */
70 #define UBMR 0xa8 /* BRM Modulator Register */
71 #define UBRC 0xac /* Baud Rate Count Register */
72 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
73 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
74 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
76 /* UART Control Register Bit Fields.*/
77 #define URXD_CHARRDY (1<<15)
78 #define URXD_ERR (1<<14)
79 #define URXD_OVRRUN (1<<13)
80 #define URXD_FRMERR (1<<12)
81 #define URXD_BRK (1<<11)
82 #define URXD_PRERR (1<<10)
83 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
84 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
85 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
86 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
87 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
88 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
89 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
90 #define UCR1_IREN (1<<7) /* Infrared interface enable */
91 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
92 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
93 #define UCR1_SNDBRK (1<<4) /* Send break */
94 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
95 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
96 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
97 #define UCR1_DOZE (1<<1) /* Doze */
98 #define UCR1_UARTEN (1<<0) /* UART enabled */
99 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
100 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
101 #define UCR2_CTSC (1<<13) /* CTS pin control */
102 #define UCR2_CTS (1<<12) /* Clear to send */
103 #define UCR2_ESCEN (1<<11) /* Escape enable */
104 #define UCR2_PREN (1<<8) /* Parity enable */
105 #define UCR2_PROE (1<<7) /* Parity odd/even */
106 #define UCR2_STPB (1<<6) /* Stop */
107 #define UCR2_WS (1<<5) /* Word size */
108 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
109 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
110 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
111 #define UCR2_RXEN (1<<1) /* Receiver enabled */
112 #define UCR2_SRST (1<<0) /* SW reset */
113 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
114 #define UCR3_PARERREN (1<<12) /* Parity enable */
115 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
116 #define UCR3_DSR (1<<10) /* Data set ready */
117 #define UCR3_DCD (1<<9) /* Data carrier detect */
118 #define UCR3_RI (1<<8) /* Ring indicator */
119 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
120 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
121 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
122 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
123 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
124 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
125 #define UCR3_BPEN (1<<0) /* Preset registers enable */
126 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
127 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
128 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
129 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
130 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
131 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
132 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
133 #define UCR4_IRSC (1<<5) /* IR special case */
134 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
135 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
136 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
137 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
138 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
139 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
140 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
141 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
142 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
143 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
144 #define USR1_RTSS (1<<14) /* RTS pin status */
145 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
146 #define USR1_RTSD (1<<12) /* RTS delta */
147 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
148 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
149 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
150 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
151 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
152 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
153 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
154 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
155 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
156 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
157 #define USR2_IDLE (1<<12) /* Idle condition */
158 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
159 #define USR2_WAKE (1<<7) /* Wake */
160 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
161 #define USR2_TXDC (1<<3) /* Transmitter complete */
162 #define USR2_BRCD (1<<2) /* Break condition */
163 #define USR2_ORE (1<<1) /* Overrun error */
164 #define USR2_RDR (1<<0) /* Recv data ready */
165 #define UTS_FRCPERR (1<<13) /* Force parity error */
166 #define UTS_LOOP (1<<12) /* Loop tx and rx */
167 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
168 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
169 #define UTS_TXFULL (1<<4) /* TxFIFO full */
170 #define UTS_RXFULL (1<<3) /* RxFIFO full */
171 #define UTS_SOFTRST (1<<0) /* Software reset */
173 /* We've been assigned a range on the "Low-density serial ports" major */
174 #define SERIAL_IMX_MAJOR 207
175 #define MINOR_START 16
176 #define DEV_NAME "ttymxc"
179 * This determines how often we check the modem status signals
180 * for any change. They generally aren't connected to an IRQ
181 * so we have to poll them. We also check immediately before
182 * filling the TX fifo incase CTS has been dropped.
184 #define MCTRL_TIMEOUT (250*HZ/1000)
186 #define DRIVER_NAME "IMX-uart"
190 /* i.mx21 type uart runs on all i.mx except i.mx1 */
197 /* device type dependent stuff */
198 struct imx_uart_data {
200 enum imx_uart_type devtype;
204 struct uart_port port;
205 struct timer_list timer;
206 unsigned int old_status;
207 int txirq, rxirq, rtsirq;
208 unsigned int have_rtscts:1;
209 unsigned int dte_mode:1;
210 unsigned int use_irda:1;
211 unsigned int irda_inv_rx:1;
212 unsigned int irda_inv_tx:1;
213 unsigned short trcv_delay; /* transceiver delay */
216 const struct imx_uart_data *devdata;
219 unsigned int dma_is_inited:1;
220 unsigned int dma_is_enabled:1;
221 unsigned int dma_is_rxing:1;
222 unsigned int dma_is_txing:1;
223 struct dma_chan *dma_chan_rx, *dma_chan_tx;
224 struct scatterlist rx_sgl, tx_sgl[2];
226 unsigned int tx_bytes;
227 unsigned int dma_tx_nents;
230 struct imx_port_ucrs {
237 #define USE_IRDA(sport) ((sport)->use_irda)
239 #define USE_IRDA(sport) (0)
242 static struct imx_uart_data imx_uart_devdata[] = {
245 .devtype = IMX1_UART,
248 .uts_reg = IMX21_UTS,
249 .devtype = IMX21_UART,
252 .uts_reg = IMX21_UTS,
253 .devtype = IMX6Q_UART,
257 static struct platform_device_id imx_uart_devtype[] = {
260 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
262 .name = "imx21-uart",
263 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
265 .name = "imx6q-uart",
266 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
271 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
273 static struct of_device_id imx_uart_dt_ids[] = {
274 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
275 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
276 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
279 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
281 static inline unsigned uts_reg(struct imx_port *sport)
283 return sport->devdata->uts_reg;
286 static inline int is_imx1_uart(struct imx_port *sport)
288 return sport->devdata->devtype == IMX1_UART;
291 static inline int is_imx21_uart(struct imx_port *sport)
293 return sport->devdata->devtype == IMX21_UART;
296 static inline int is_imx6q_uart(struct imx_port *sport)
298 return sport->devdata->devtype == IMX6Q_UART;
301 * Save and restore functions for UCR1, UCR2 and UCR3 registers
303 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
304 static void imx_port_ucrs_save(struct uart_port *port,
305 struct imx_port_ucrs *ucr)
307 /* save control registers */
308 ucr->ucr1 = readl(port->membase + UCR1);
309 ucr->ucr2 = readl(port->membase + UCR2);
310 ucr->ucr3 = readl(port->membase + UCR3);
313 static void imx_port_ucrs_restore(struct uart_port *port,
314 struct imx_port_ucrs *ucr)
316 /* restore control registers */
317 writel(ucr->ucr1, port->membase + UCR1);
318 writel(ucr->ucr2, port->membase + UCR2);
319 writel(ucr->ucr3, port->membase + UCR3);
324 * Handle any change of modem status signal since we were last called.
326 static void imx_mctrl_check(struct imx_port *sport)
328 unsigned int status, changed;
330 status = sport->port.ops->get_mctrl(&sport->port);
331 changed = status ^ sport->old_status;
336 sport->old_status = status;
338 if (changed & TIOCM_RI)
339 sport->port.icount.rng++;
340 if (changed & TIOCM_DSR)
341 sport->port.icount.dsr++;
342 if (changed & TIOCM_CAR)
343 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
344 if (changed & TIOCM_CTS)
345 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
347 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
351 * This is our per-port timeout handler, for checking the
352 * modem status signals.
354 static void imx_timeout(unsigned long data)
356 struct imx_port *sport = (struct imx_port *)data;
359 if (sport->port.state) {
360 spin_lock_irqsave(&sport->port.lock, flags);
361 imx_mctrl_check(sport);
362 spin_unlock_irqrestore(&sport->port.lock, flags);
364 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
369 * interrupts disabled on entry
371 static void imx_stop_tx(struct uart_port *port)
373 struct imx_port *sport = (struct imx_port *)port;
376 if (USE_IRDA(sport)) {
377 /* half duplex - wait for end of transmission */
380 !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
385 * irda transceiver - wait a bit more to avoid
386 * cutoff, hardware dependent
388 udelay(sport->trcv_delay);
391 * half duplex - reactivate receive mode,
392 * flush receive pipe echo crap
394 if (readl(sport->port.membase + USR2) & USR2_TXDC) {
395 temp = readl(sport->port.membase + UCR1);
396 temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
397 writel(temp, sport->port.membase + UCR1);
399 temp = readl(sport->port.membase + UCR4);
400 temp &= ~(UCR4_TCEN);
401 writel(temp, sport->port.membase + UCR4);
403 while (readl(sport->port.membase + URXD0) &
407 temp = readl(sport->port.membase + UCR1);
409 writel(temp, sport->port.membase + UCR1);
411 temp = readl(sport->port.membase + UCR4);
413 writel(temp, sport->port.membase + UCR4);
418 if (sport->dma_is_enabled && sport->dma_is_txing) {
419 dmaengine_terminate_all(sport->dma_chan_tx);
420 sport->dma_is_txing = 0;
423 temp = readl(sport->port.membase + UCR1);
424 writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
428 * interrupts disabled on entry
430 static void imx_stop_rx(struct uart_port *port)
432 struct imx_port *sport = (struct imx_port *)port;
435 if (sport->dma_is_enabled && sport->dma_is_rxing) {
436 dmaengine_terminate_all(sport->dma_chan_rx);
437 sport->dma_is_rxing = 0;
440 temp = readl(sport->port.membase + UCR2);
441 writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
443 /* disable the `Receiver Ready Interrrupt` */
444 temp = readl(sport->port.membase + UCR1);
445 writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
449 * Set the modem control timer to fire immediately.
451 static void imx_enable_ms(struct uart_port *port)
453 struct imx_port *sport = (struct imx_port *)port;
455 mod_timer(&sport->timer, jiffies);
458 static inline void imx_transmit_buffer(struct imx_port *sport)
460 struct circ_buf *xmit = &sport->port.state->xmit;
462 while (!uart_circ_empty(xmit) &&
463 !(readl(sport->port.membase + uts_reg(sport))
465 /* send xmit->buf[xmit->tail]
466 * out the port here */
467 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
468 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
469 sport->port.icount.tx++;
472 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
473 uart_write_wakeup(&sport->port);
475 if (uart_circ_empty(xmit))
476 imx_stop_tx(&sport->port);
479 static void dma_tx_callback(void *data)
481 struct imx_port *sport = data;
482 struct scatterlist *sgl = &sport->tx_sgl[0];
483 struct circ_buf *xmit = &sport->port.state->xmit;
486 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
488 sport->dma_is_txing = 0;
490 /* update the stat */
491 spin_lock_irqsave(&sport->port.lock, flags);
492 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
493 sport->port.icount.tx += sport->tx_bytes;
494 spin_unlock_irqrestore(&sport->port.lock, flags);
496 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
498 uart_write_wakeup(&sport->port);
501 static void imx_dma_tx(struct imx_port *sport)
503 struct circ_buf *xmit = &sport->port.state->xmit;
504 struct scatterlist *sgl = sport->tx_sgl;
505 struct dma_async_tx_descriptor *desc;
506 struct dma_chan *chan = sport->dma_chan_tx;
507 struct device *dev = sport->port.dev;
508 enum dma_status status;
511 status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
512 if (DMA_IN_PROGRESS == status)
515 sport->tx_bytes = uart_circ_chars_pending(xmit);
517 if (xmit->tail > xmit->head && xmit->head > 0) {
518 sport->dma_tx_nents = 2;
519 sg_init_table(sgl, 2);
520 sg_set_buf(sgl, xmit->buf + xmit->tail,
521 UART_XMIT_SIZE - xmit->tail);
522 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
524 sport->dma_tx_nents = 1;
525 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
528 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
530 dev_err(dev, "DMA mapping error for TX.\n");
533 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
534 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
536 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
539 desc->callback = dma_tx_callback;
540 desc->callback_param = sport;
542 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
543 uart_circ_chars_pending(xmit));
545 sport->dma_is_txing = 1;
546 dmaengine_submit(desc);
547 dma_async_issue_pending(chan);
552 * interrupts disabled on entry
554 static void imx_start_tx(struct uart_port *port)
556 struct imx_port *sport = (struct imx_port *)port;
559 if (USE_IRDA(sport)) {
560 /* half duplex in IrDA mode; have to disable receive mode */
561 temp = readl(sport->port.membase + UCR4);
562 temp &= ~(UCR4_DREN);
563 writel(temp, sport->port.membase + UCR4);
565 temp = readl(sport->port.membase + UCR1);
566 temp &= ~(UCR1_RRDYEN);
567 writel(temp, sport->port.membase + UCR1);
569 /* Clear any pending ORE flag before enabling interrupt */
570 temp = readl(sport->port.membase + USR2);
571 writel(temp | USR2_ORE, sport->port.membase + USR2);
573 temp = readl(sport->port.membase + UCR4);
575 writel(temp, sport->port.membase + UCR4);
577 if (!sport->dma_is_enabled) {
578 temp = readl(sport->port.membase + UCR1);
579 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
582 if (USE_IRDA(sport)) {
583 temp = readl(sport->port.membase + UCR1);
585 writel(temp, sport->port.membase + UCR1);
587 temp = readl(sport->port.membase + UCR4);
589 writel(temp, sport->port.membase + UCR4);
592 if (sport->dma_is_enabled) {
597 if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
598 imx_transmit_buffer(sport);
601 static irqreturn_t imx_rtsint(int irq, void *dev_id)
603 struct imx_port *sport = dev_id;
607 spin_lock_irqsave(&sport->port.lock, flags);
609 writel(USR1_RTSD, sport->port.membase + USR1);
610 val = readl(sport->port.membase + USR1) & USR1_RTSS;
611 uart_handle_cts_change(&sport->port, !!val);
612 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
614 spin_unlock_irqrestore(&sport->port.lock, flags);
618 static irqreturn_t imx_txint(int irq, void *dev_id)
620 struct imx_port *sport = dev_id;
621 struct circ_buf *xmit = &sport->port.state->xmit;
624 spin_lock_irqsave(&sport->port.lock, flags);
625 if (sport->port.x_char) {
627 writel(sport->port.x_char, sport->port.membase + URTX0);
631 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
632 imx_stop_tx(&sport->port);
636 imx_transmit_buffer(sport);
638 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
639 uart_write_wakeup(&sport->port);
642 spin_unlock_irqrestore(&sport->port.lock, flags);
646 static irqreturn_t imx_rxint(int irq, void *dev_id)
648 struct imx_port *sport = dev_id;
649 unsigned int rx, flg, ignored = 0;
650 struct tty_port *port = &sport->port.state->port;
651 unsigned long flags, temp;
653 spin_lock_irqsave(&sport->port.lock, flags);
655 while (readl(sport->port.membase + USR2) & USR2_RDR) {
657 sport->port.icount.rx++;
659 rx = readl(sport->port.membase + URXD0);
661 temp = readl(sport->port.membase + USR2);
662 if (temp & USR2_BRCD) {
663 writel(USR2_BRCD, sport->port.membase + USR2);
664 if (uart_handle_break(&sport->port))
668 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
671 if (unlikely(rx & URXD_ERR)) {
673 sport->port.icount.brk++;
674 else if (rx & URXD_PRERR)
675 sport->port.icount.parity++;
676 else if (rx & URXD_FRMERR)
677 sport->port.icount.frame++;
678 if (rx & URXD_OVRRUN)
679 sport->port.icount.overrun++;
681 if (rx & sport->port.ignore_status_mask) {
687 rx &= sport->port.read_status_mask;
691 else if (rx & URXD_PRERR)
693 else if (rx & URXD_FRMERR)
695 if (rx & URXD_OVRRUN)
699 sport->port.sysrq = 0;
703 tty_insert_flip_char(port, rx, flg);
707 spin_unlock_irqrestore(&sport->port.lock, flags);
708 tty_flip_buffer_push(port);
712 static int start_rx_dma(struct imx_port *sport);
714 * If the RXFIFO is filled with some data, and then we
715 * arise a DMA operation to receive them.
717 static void imx_dma_rxint(struct imx_port *sport)
721 temp = readl(sport->port.membase + USR2);
722 if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
723 sport->dma_is_rxing = 1;
725 /* disable the `Recerver Ready Interrrupt` */
726 temp = readl(sport->port.membase + UCR1);
727 temp &= ~(UCR1_RRDYEN);
728 writel(temp, sport->port.membase + UCR1);
730 /* tell the DMA to receive the data. */
735 static irqreturn_t imx_int(int irq, void *dev_id)
737 struct imx_port *sport = dev_id;
741 sts = readl(sport->port.membase + USR1);
743 if (sts & USR1_RRDY) {
744 if (sport->dma_is_enabled)
745 imx_dma_rxint(sport);
747 imx_rxint(irq, dev_id);
750 if (sts & USR1_TRDY &&
751 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
752 imx_txint(irq, dev_id);
755 imx_rtsint(irq, dev_id);
757 if (sts & USR1_AWAKE)
758 writel(USR1_AWAKE, sport->port.membase + USR1);
760 sts2 = readl(sport->port.membase + USR2);
761 if (sts2 & USR2_ORE) {
762 dev_err(sport->port.dev, "Rx FIFO overrun\n");
763 sport->port.icount.overrun++;
764 writel(sts2 | USR2_ORE, sport->port.membase + USR2);
771 * Return TIOCSER_TEMT when transmitter is not busy.
773 static unsigned int imx_tx_empty(struct uart_port *port)
775 struct imx_port *sport = (struct imx_port *)port;
778 ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
780 /* If the TX DMA is working, return 0. */
781 if (sport->dma_is_enabled && sport->dma_is_txing)
788 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
790 static unsigned int imx_get_mctrl(struct uart_port *port)
792 struct imx_port *sport = (struct imx_port *)port;
793 unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
795 if (readl(sport->port.membase + USR1) & USR1_RTSS)
798 if (readl(sport->port.membase + UCR2) & UCR2_CTS)
801 if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
807 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
809 struct imx_port *sport = (struct imx_port *)port;
812 temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
814 if (mctrl & TIOCM_RTS)
815 if (!sport->dma_is_enabled)
818 writel(temp, sport->port.membase + UCR2);
820 temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
821 if (mctrl & TIOCM_LOOP)
823 writel(temp, sport->port.membase + uts_reg(sport));
827 * Interrupts always disabled.
829 static void imx_break_ctl(struct uart_port *port, int break_state)
831 struct imx_port *sport = (struct imx_port *)port;
832 unsigned long flags, temp;
834 spin_lock_irqsave(&sport->port.lock, flags);
836 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
838 if (break_state != 0)
841 writel(temp, sport->port.membase + UCR1);
843 spin_unlock_irqrestore(&sport->port.lock, flags);
846 #define TXTL 2 /* reset default */
847 #define RXTL 1 /* reset default */
849 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
853 /* set receiver / transmitter trigger level */
854 val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
855 val |= TXTL << UFCR_TXTL_SHF | RXTL;
856 writel(val, sport->port.membase + UFCR);
860 #define RX_BUF_SIZE (PAGE_SIZE)
861 static void imx_rx_dma_done(struct imx_port *sport)
865 /* Enable this interrupt when the RXFIFO is empty. */
866 temp = readl(sport->port.membase + UCR1);
868 writel(temp, sport->port.membase + UCR1);
870 sport->dma_is_rxing = 0;
874 * There are three kinds of RX DMA interrupts(such as in the MX6Q):
875 * [1] the RX DMA buffer is full.
876 * [2] the Aging timer expires(wait for 8 bytes long)
877 * [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
879 * The [2] is trigger when a character was been sitting in the FIFO
880 * meanwhile [3] can wait for 32 bytes long when the RX line is
881 * on IDLE state and RxFIFO is empty.
883 static void dma_rx_callback(void *data)
885 struct imx_port *sport = data;
886 struct dma_chan *chan = sport->dma_chan_rx;
887 struct scatterlist *sgl = &sport->rx_sgl;
888 struct tty_port *port = &sport->port.state->port;
889 struct dma_tx_state state;
890 enum dma_status status;
894 dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
896 status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
897 count = RX_BUF_SIZE - state.residue;
898 dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
901 tty_insert_flip_string(port, sport->rx_buf, count);
902 tty_flip_buffer_push(port);
906 imx_rx_dma_done(sport);
909 static int start_rx_dma(struct imx_port *sport)
911 struct scatterlist *sgl = &sport->rx_sgl;
912 struct dma_chan *chan = sport->dma_chan_rx;
913 struct device *dev = sport->port.dev;
914 struct dma_async_tx_descriptor *desc;
917 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
918 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
920 dev_err(dev, "DMA mapping error for RX.\n");
923 desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
926 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
929 desc->callback = dma_rx_callback;
930 desc->callback_param = sport;
932 dev_dbg(dev, "RX: prepare for the DMA.\n");
933 dmaengine_submit(desc);
934 dma_async_issue_pending(chan);
938 static void imx_uart_dma_exit(struct imx_port *sport)
940 if (sport->dma_chan_rx) {
941 dma_release_channel(sport->dma_chan_rx);
942 sport->dma_chan_rx = NULL;
944 kfree(sport->rx_buf);
945 sport->rx_buf = NULL;
948 if (sport->dma_chan_tx) {
949 dma_release_channel(sport->dma_chan_tx);
950 sport->dma_chan_tx = NULL;
953 sport->dma_is_inited = 0;
956 static int imx_uart_dma_init(struct imx_port *sport)
958 struct dma_slave_config slave_config = {};
959 struct device *dev = sport->port.dev;
962 /* Prepare for RX : */
963 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
964 if (!sport->dma_chan_rx) {
965 dev_dbg(dev, "cannot get the DMA channel.\n");
970 slave_config.direction = DMA_DEV_TO_MEM;
971 slave_config.src_addr = sport->port.mapbase + URXD0;
972 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
973 slave_config.src_maxburst = RXTL;
974 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
976 dev_err(dev, "error in RX dma configuration.\n");
980 sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
981 if (!sport->rx_buf) {
982 dev_err(dev, "cannot alloc DMA buffer.\n");
987 /* Prepare for TX : */
988 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
989 if (!sport->dma_chan_tx) {
990 dev_err(dev, "cannot get the TX DMA channel!\n");
995 slave_config.direction = DMA_MEM_TO_DEV;
996 slave_config.dst_addr = sport->port.mapbase + URTX0;
997 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
998 slave_config.dst_maxburst = TXTL;
999 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1001 dev_err(dev, "error in TX dma configuration.");
1005 sport->dma_is_inited = 1;
1009 imx_uart_dma_exit(sport);
1013 static void imx_enable_dma(struct imx_port *sport)
1018 temp = readl(sport->port.membase + UCR1);
1019 temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1020 /* wait for 32 idle frames for IDDMA interrupt */
1022 writel(temp, sport->port.membase + UCR1);
1025 temp = readl(sport->port.membase + UCR4);
1026 temp |= UCR4_IDDMAEN;
1027 writel(temp, sport->port.membase + UCR4);
1029 sport->dma_is_enabled = 1;
1032 static void imx_disable_dma(struct imx_port *sport)
1037 temp = readl(sport->port.membase + UCR1);
1038 temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1039 writel(temp, sport->port.membase + UCR1);
1042 temp = readl(sport->port.membase + UCR2);
1043 temp &= ~(UCR2_CTSC | UCR2_CTS);
1044 writel(temp, sport->port.membase + UCR2);
1047 temp = readl(sport->port.membase + UCR4);
1048 temp &= ~UCR4_IDDMAEN;
1049 writel(temp, sport->port.membase + UCR4);
1051 sport->dma_is_enabled = 0;
1054 /* half the RX buffer size */
1057 static int imx_startup(struct uart_port *port)
1059 struct imx_port *sport = (struct imx_port *)port;
1061 unsigned long flags, temp;
1063 retval = clk_prepare_enable(sport->clk_per);
1066 retval = clk_prepare_enable(sport->clk_ipg);
1068 clk_disable_unprepare(sport->clk_per);
1072 imx_setup_ufcr(sport, 0);
1074 /* disable the DREN bit (Data Ready interrupt enable) before
1077 temp = readl(sport->port.membase + UCR4);
1079 if (USE_IRDA(sport))
1082 /* set the trigger level for CTS */
1083 temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1084 temp |= CTSTL << UCR4_CTSTL_SHF;
1086 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1088 /* Reset fifo's and state machines */
1091 temp = readl(sport->port.membase + UCR2);
1093 writel(temp, sport->port.membase + UCR2);
1095 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1099 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1100 * chips only have one interrupt.
1102 if (sport->txirq > 0) {
1103 retval = request_irq(sport->rxirq, imx_rxint, 0,
1104 dev_name(port->dev), sport);
1108 retval = request_irq(sport->txirq, imx_txint, 0,
1109 dev_name(port->dev), sport);
1113 /* do not use RTS IRQ on IrDA */
1114 if (!USE_IRDA(sport)) {
1115 retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1116 dev_name(port->dev), sport);
1121 retval = request_irq(sport->port.irq, imx_int, 0,
1122 dev_name(port->dev), sport);
1124 free_irq(sport->port.irq, sport);
1129 spin_lock_irqsave(&sport->port.lock, flags);
1131 * Finally, clear and enable interrupts
1133 writel(USR1_RTSD, sport->port.membase + USR1);
1135 temp = readl(sport->port.membase + UCR1);
1136 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1138 if (USE_IRDA(sport)) {
1140 temp &= ~(UCR1_RTSDEN);
1143 writel(temp, sport->port.membase + UCR1);
1145 temp = readl(sport->port.membase + UCR2);
1146 temp |= (UCR2_RXEN | UCR2_TXEN);
1147 if (!sport->have_rtscts)
1149 writel(temp, sport->port.membase + UCR2);
1151 if (!is_imx1_uart(sport)) {
1152 temp = readl(sport->port.membase + UCR3);
1153 temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
1154 writel(temp, sport->port.membase + UCR3);
1157 if (USE_IRDA(sport)) {
1158 temp = readl(sport->port.membase + UCR4);
1159 if (sport->irda_inv_rx)
1162 temp &= ~(UCR4_INVR);
1163 writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1165 temp = readl(sport->port.membase + UCR3);
1166 if (sport->irda_inv_tx)
1169 temp &= ~(UCR3_INVT);
1170 writel(temp, sport->port.membase + UCR3);
1174 * Enable modem status interrupts
1176 imx_enable_ms(&sport->port);
1177 spin_unlock_irqrestore(&sport->port.lock, flags);
1179 if (USE_IRDA(sport)) {
1180 struct imxuart_platform_data *pdata;
1181 pdata = dev_get_platdata(sport->port.dev);
1182 sport->irda_inv_rx = pdata->irda_inv_rx;
1183 sport->irda_inv_tx = pdata->irda_inv_tx;
1184 sport->trcv_delay = pdata->transceiver_delay;
1185 if (pdata->irda_enable)
1186 pdata->irda_enable(1);
1193 free_irq(sport->txirq, sport);
1196 free_irq(sport->rxirq, sport);
1201 static void imx_shutdown(struct uart_port *port)
1203 struct imx_port *sport = (struct imx_port *)port;
1205 unsigned long flags;
1207 if (sport->dma_is_enabled) {
1209 * The upper layer may does not call the @->stop_tx and
1210 * @->stop_rx, so we call them ourselves.
1215 imx_disable_dma(sport);
1216 imx_uart_dma_exit(sport);
1219 spin_lock_irqsave(&sport->port.lock, flags);
1220 temp = readl(sport->port.membase + UCR2);
1221 temp &= ~(UCR2_TXEN);
1222 writel(temp, sport->port.membase + UCR2);
1223 spin_unlock_irqrestore(&sport->port.lock, flags);
1225 if (USE_IRDA(sport)) {
1226 struct imxuart_platform_data *pdata;
1227 pdata = dev_get_platdata(sport->port.dev);
1228 if (pdata->irda_enable)
1229 pdata->irda_enable(0);
1235 del_timer_sync(&sport->timer);
1238 * Free the interrupts
1240 if (sport->txirq > 0) {
1241 if (!USE_IRDA(sport))
1242 free_irq(sport->rtsirq, sport);
1243 free_irq(sport->txirq, sport);
1244 free_irq(sport->rxirq, sport);
1246 free_irq(sport->port.irq, sport);
1249 * Disable all interrupts, port and break condition.
1252 spin_lock_irqsave(&sport->port.lock, flags);
1253 temp = readl(sport->port.membase + UCR1);
1254 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1255 if (USE_IRDA(sport))
1256 temp &= ~(UCR1_IREN);
1258 writel(temp, sport->port.membase + UCR1);
1259 spin_unlock_irqrestore(&sport->port.lock, flags);
1261 clk_disable_unprepare(sport->clk_per);
1262 clk_disable_unprepare(sport->clk_ipg);
1265 static void imx_flush_buffer(struct uart_port *port)
1267 struct imx_port *sport = (struct imx_port *)port;
1269 if (sport->dma_is_enabled) {
1270 sport->tx_bytes = 0;
1271 dmaengine_terminate_all(sport->dma_chan_tx);
1276 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1277 struct ktermios *old)
1279 struct imx_port *sport = (struct imx_port *)port;
1280 unsigned long flags;
1281 unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1282 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1283 unsigned int div, ufcr;
1284 unsigned long num, denom;
1288 * If we don't support modem control lines, don't allow
1292 termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1293 termios->c_cflag |= CLOCAL;
1297 * We only support CS7 and CS8.
1299 while ((termios->c_cflag & CSIZE) != CS7 &&
1300 (termios->c_cflag & CSIZE) != CS8) {
1301 termios->c_cflag &= ~CSIZE;
1302 termios->c_cflag |= old_csize;
1306 if ((termios->c_cflag & CSIZE) == CS8)
1307 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1309 ucr2 = UCR2_SRST | UCR2_IRTS;
1311 if (termios->c_cflag & CRTSCTS) {
1312 if (sport->have_rtscts) {
1316 /* Can we enable the DMA support? */
1317 if (is_imx6q_uart(sport) && !uart_console(port)
1318 && !sport->dma_is_inited)
1319 imx_uart_dma_init(sport);
1321 termios->c_cflag &= ~CRTSCTS;
1325 if (termios->c_cflag & CSTOPB)
1327 if (termios->c_cflag & PARENB) {
1329 if (termios->c_cflag & PARODD)
1333 del_timer_sync(&sport->timer);
1336 * Ask the core to calculate the divisor for us.
1338 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1339 quot = uart_get_divisor(port, baud);
1341 spin_lock_irqsave(&sport->port.lock, flags);
1343 sport->port.read_status_mask = 0;
1344 if (termios->c_iflag & INPCK)
1345 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1346 if (termios->c_iflag & (BRKINT | PARMRK))
1347 sport->port.read_status_mask |= URXD_BRK;
1350 * Characters to ignore
1352 sport->port.ignore_status_mask = 0;
1353 if (termios->c_iflag & IGNPAR)
1354 sport->port.ignore_status_mask |= URXD_PRERR;
1355 if (termios->c_iflag & IGNBRK) {
1356 sport->port.ignore_status_mask |= URXD_BRK;
1358 * If we're ignoring parity and break indicators,
1359 * ignore overruns too (for real raw support).
1361 if (termios->c_iflag & IGNPAR)
1362 sport->port.ignore_status_mask |= URXD_OVRRUN;
1366 * Update the per-port timeout.
1368 uart_update_timeout(port, termios->c_cflag, baud);
1371 * disable interrupts and drain transmitter
1373 old_ucr1 = readl(sport->port.membase + UCR1);
1374 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1375 sport->port.membase + UCR1);
1377 while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1380 /* then, disable everything */
1381 old_txrxen = readl(sport->port.membase + UCR2);
1382 writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1383 sport->port.membase + UCR2);
1384 old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1386 if (USE_IRDA(sport)) {
1388 * use maximum available submodule frequency to
1389 * avoid missing short pulses due to low sampling rate
1393 /* custom-baudrate handling */
1394 div = sport->port.uartclk / (baud * 16);
1395 if (baud == 38400 && quot != div)
1396 baud = sport->port.uartclk / (quot * 16);
1398 div = sport->port.uartclk / (baud * 16);
1405 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1406 1 << 16, 1 << 16, &num, &denom);
1408 tdiv64 = sport->port.uartclk;
1410 do_div(tdiv64, denom * 16 * div);
1411 tty_termios_encode_baud_rate(termios,
1412 (speed_t)tdiv64, (speed_t)tdiv64);
1417 ufcr = readl(sport->port.membase + UFCR);
1418 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1419 if (sport->dte_mode)
1420 ufcr |= UFCR_DCEDTE;
1421 writel(ufcr, sport->port.membase + UFCR);
1423 writel(num, sport->port.membase + UBIR);
1424 writel(denom, sport->port.membase + UBMR);
1426 if (!is_imx1_uart(sport))
1427 writel(sport->port.uartclk / div / 1000,
1428 sport->port.membase + IMX21_ONEMS);
1430 writel(old_ucr1, sport->port.membase + UCR1);
1432 /* set the parity, stop bits and data size */
1433 writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1435 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1436 imx_enable_ms(&sport->port);
1438 if (sport->dma_is_inited && !sport->dma_is_enabled)
1439 imx_enable_dma(sport);
1440 spin_unlock_irqrestore(&sport->port.lock, flags);
1443 static const char *imx_type(struct uart_port *port)
1445 struct imx_port *sport = (struct imx_port *)port;
1447 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1451 * Configure/autoconfigure the port.
1453 static void imx_config_port(struct uart_port *port, int flags)
1455 struct imx_port *sport = (struct imx_port *)port;
1457 if (flags & UART_CONFIG_TYPE)
1458 sport->port.type = PORT_IMX;
1462 * Verify the new serial_struct (for TIOCSSERIAL).
1463 * The only change we allow are to the flags and type, and
1464 * even then only between PORT_IMX and PORT_UNKNOWN
1467 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1469 struct imx_port *sport = (struct imx_port *)port;
1472 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1474 if (sport->port.irq != ser->irq)
1476 if (ser->io_type != UPIO_MEM)
1478 if (sport->port.uartclk / 16 != ser->baud_base)
1480 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1482 if (sport->port.iobase != ser->port)
1489 #if defined(CONFIG_CONSOLE_POLL)
1490 static int imx_poll_get_char(struct uart_port *port)
1492 struct imx_port_ucrs old_ucr;
1493 unsigned int status;
1496 /* save control registers */
1497 imx_port_ucrs_save(port, &old_ucr);
1499 /* disable interrupts */
1500 writel(UCR1_UARTEN, port->membase + UCR1);
1501 writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1502 port->membase + UCR2);
1503 writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1504 port->membase + UCR3);
1508 status = readl(port->membase + USR2);
1509 } while (~status & USR2_RDR);
1512 c = readl(port->membase + URXD0);
1514 /* restore control registers */
1515 imx_port_ucrs_restore(port, &old_ucr);
1520 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1522 struct imx_port_ucrs old_ucr;
1523 unsigned int status;
1525 /* save control registers */
1526 imx_port_ucrs_save(port, &old_ucr);
1528 /* disable interrupts */
1529 writel(UCR1_UARTEN, port->membase + UCR1);
1530 writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1531 port->membase + UCR2);
1532 writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1533 port->membase + UCR3);
1537 status = readl(port->membase + USR1);
1538 } while (~status & USR1_TRDY);
1541 writel(c, port->membase + URTX0);
1545 status = readl(port->membase + USR2);
1546 } while (~status & USR2_TXDC);
1548 /* restore control registers */
1549 imx_port_ucrs_restore(port, &old_ucr);
1553 static struct uart_ops imx_pops = {
1554 .tx_empty = imx_tx_empty,
1555 .set_mctrl = imx_set_mctrl,
1556 .get_mctrl = imx_get_mctrl,
1557 .stop_tx = imx_stop_tx,
1558 .start_tx = imx_start_tx,
1559 .stop_rx = imx_stop_rx,
1560 .enable_ms = imx_enable_ms,
1561 .break_ctl = imx_break_ctl,
1562 .startup = imx_startup,
1563 .shutdown = imx_shutdown,
1564 .flush_buffer = imx_flush_buffer,
1565 .set_termios = imx_set_termios,
1567 .config_port = imx_config_port,
1568 .verify_port = imx_verify_port,
1569 #if defined(CONFIG_CONSOLE_POLL)
1570 .poll_get_char = imx_poll_get_char,
1571 .poll_put_char = imx_poll_put_char,
1575 static struct imx_port *imx_ports[UART_NR];
1577 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1578 static void imx_console_putchar(struct uart_port *port, int ch)
1580 struct imx_port *sport = (struct imx_port *)port;
1582 while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1585 writel(ch, sport->port.membase + URTX0);
1589 * Interrupts are disabled on entering
1592 imx_console_write(struct console *co, const char *s, unsigned int count)
1594 struct imx_port *sport = imx_ports[co->index];
1595 struct imx_port_ucrs old_ucr;
1597 unsigned long flags = 0;
1601 retval = clk_enable(sport->clk_per);
1604 retval = clk_enable(sport->clk_ipg);
1606 clk_disable(sport->clk_per);
1610 if (sport->port.sysrq)
1612 else if (oops_in_progress)
1613 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1615 spin_lock_irqsave(&sport->port.lock, flags);
1618 * First, save UCR1/2/3 and then disable interrupts
1620 imx_port_ucrs_save(&sport->port, &old_ucr);
1621 ucr1 = old_ucr.ucr1;
1623 if (is_imx1_uart(sport))
1624 ucr1 |= IMX1_UCR1_UARTCLKEN;
1625 ucr1 |= UCR1_UARTEN;
1626 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1628 writel(ucr1, sport->port.membase + UCR1);
1630 writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1632 uart_console_write(&sport->port, s, count, imx_console_putchar);
1635 * Finally, wait for transmitter to become empty
1636 * and restore UCR1/2/3
1638 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1640 imx_port_ucrs_restore(&sport->port, &old_ucr);
1643 spin_unlock_irqrestore(&sport->port.lock, flags);
1645 clk_disable(sport->clk_ipg);
1646 clk_disable(sport->clk_per);
1650 * If the port was already initialised (eg, by a boot loader),
1651 * try to determine the current setup.
1654 imx_console_get_options(struct imx_port *sport, int *baud,
1655 int *parity, int *bits)
1658 if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1659 /* ok, the port was enabled */
1660 unsigned int ucr2, ubir, ubmr, uartclk;
1661 unsigned int baud_raw;
1662 unsigned int ucfr_rfdiv;
1664 ucr2 = readl(sport->port.membase + UCR2);
1667 if (ucr2 & UCR2_PREN) {
1668 if (ucr2 & UCR2_PROE)
1679 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1680 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1682 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1683 if (ucfr_rfdiv == 6)
1686 ucfr_rfdiv = 6 - ucfr_rfdiv;
1688 uartclk = clk_get_rate(sport->clk_per);
1689 uartclk /= ucfr_rfdiv;
1692 * The next code provides exact computation of
1693 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1694 * without need of float support or long long division,
1695 * which would be required to prevent 32bit arithmetic overflow
1697 unsigned int mul = ubir + 1;
1698 unsigned int div = 16 * (ubmr + 1);
1699 unsigned int rem = uartclk % div;
1701 baud_raw = (uartclk / div) * mul;
1702 baud_raw += (rem * mul + div / 2) / div;
1703 *baud = (baud_raw + 50) / 100 * 100;
1706 if (*baud != baud_raw)
1707 pr_info("Console IMX rounded baud rate from %d to %d\n",
1713 imx_console_setup(struct console *co, char *options)
1715 struct imx_port *sport;
1723 * Check whether an invalid uart number has been specified, and
1724 * if so, search for the first available port that does have
1727 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1729 sport = imx_ports[co->index];
1733 /* For setting the registers, we only need to enable the ipg clock. */
1734 retval = clk_prepare_enable(sport->clk_ipg);
1739 uart_parse_options(options, &baud, &parity, &bits, &flow);
1741 imx_console_get_options(sport, &baud, &parity, &bits);
1743 imx_setup_ufcr(sport, 0);
1745 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1747 clk_disable(sport->clk_ipg);
1749 clk_unprepare(sport->clk_ipg);
1753 retval = clk_prepare(sport->clk_per);
1755 clk_disable_unprepare(sport->clk_ipg);
1761 static struct uart_driver imx_reg;
1762 static struct console imx_console = {
1764 .write = imx_console_write,
1765 .device = uart_console_device,
1766 .setup = imx_console_setup,
1767 .flags = CON_PRINTBUFFER,
1772 #define IMX_CONSOLE &imx_console
1774 #define IMX_CONSOLE NULL
1777 static struct uart_driver imx_reg = {
1778 .owner = THIS_MODULE,
1779 .driver_name = DRIVER_NAME,
1780 .dev_name = DEV_NAME,
1781 .major = SERIAL_IMX_MAJOR,
1782 .minor = MINOR_START,
1783 .nr = ARRAY_SIZE(imx_ports),
1784 .cons = IMX_CONSOLE,
1787 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1789 struct imx_port *sport = platform_get_drvdata(dev);
1792 /* enable wakeup from i.MX UART */
1793 val = readl(sport->port.membase + UCR3);
1795 writel(val, sport->port.membase + UCR3);
1797 uart_suspend_port(&imx_reg, &sport->port);
1802 static int serial_imx_resume(struct platform_device *dev)
1804 struct imx_port *sport = platform_get_drvdata(dev);
1807 /* disable wakeup from i.MX UART */
1808 val = readl(sport->port.membase + UCR3);
1809 val &= ~UCR3_AWAKEN;
1810 writel(val, sport->port.membase + UCR3);
1812 uart_resume_port(&imx_reg, &sport->port);
1819 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1820 * could successfully get all information from dt or a negative errno.
1822 static int serial_imx_probe_dt(struct imx_port *sport,
1823 struct platform_device *pdev)
1825 struct device_node *np = pdev->dev.of_node;
1826 const struct of_device_id *of_id =
1827 of_match_device(imx_uart_dt_ids, &pdev->dev);
1831 /* no device tree device */
1834 ret = of_alias_get_id(np, "serial");
1836 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1839 sport->port.line = ret;
1841 if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1842 sport->have_rtscts = 1;
1844 if (of_get_property(np, "fsl,irda-mode", NULL))
1845 sport->use_irda = 1;
1847 if (of_get_property(np, "fsl,dte-mode", NULL))
1848 sport->dte_mode = 1;
1850 sport->devdata = of_id->data;
1855 static inline int serial_imx_probe_dt(struct imx_port *sport,
1856 struct platform_device *pdev)
1862 static void serial_imx_probe_pdata(struct imx_port *sport,
1863 struct platform_device *pdev)
1865 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1867 sport->port.line = pdev->id;
1868 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
1873 if (pdata->flags & IMXUART_HAVE_RTSCTS)
1874 sport->have_rtscts = 1;
1876 if (pdata->flags & IMXUART_IRDA)
1877 sport->use_irda = 1;
1880 static int serial_imx_probe(struct platform_device *pdev)
1882 struct imx_port *sport;
1885 struct resource *res;
1887 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1891 ret = serial_imx_probe_dt(sport, pdev);
1893 serial_imx_probe_pdata(sport, pdev);
1897 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1898 base = devm_ioremap_resource(&pdev->dev, res);
1900 return PTR_ERR(base);
1902 sport->port.dev = &pdev->dev;
1903 sport->port.mapbase = res->start;
1904 sport->port.membase = base;
1905 sport->port.type = PORT_IMX,
1906 sport->port.iotype = UPIO_MEM;
1907 sport->port.irq = platform_get_irq(pdev, 0);
1908 sport->rxirq = platform_get_irq(pdev, 0);
1909 sport->txirq = platform_get_irq(pdev, 1);
1910 sport->rtsirq = platform_get_irq(pdev, 2);
1911 sport->port.fifosize = 32;
1912 sport->port.ops = &imx_pops;
1913 sport->port.flags = UPF_BOOT_AUTOCONF;
1914 init_timer(&sport->timer);
1915 sport->timer.function = imx_timeout;
1916 sport->timer.data = (unsigned long)sport;
1918 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1919 if (IS_ERR(sport->clk_ipg)) {
1920 ret = PTR_ERR(sport->clk_ipg);
1921 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1925 sport->clk_per = devm_clk_get(&pdev->dev, "per");
1926 if (IS_ERR(sport->clk_per)) {
1927 ret = PTR_ERR(sport->clk_per);
1928 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1932 sport->port.uartclk = clk_get_rate(sport->clk_per);
1934 imx_ports[sport->port.line] = sport;
1936 platform_set_drvdata(pdev, sport);
1938 return uart_add_one_port(&imx_reg, &sport->port);
1941 static int serial_imx_remove(struct platform_device *pdev)
1943 struct imx_port *sport = platform_get_drvdata(pdev);
1945 return uart_remove_one_port(&imx_reg, &sport->port);
1948 static struct platform_driver serial_imx_driver = {
1949 .probe = serial_imx_probe,
1950 .remove = serial_imx_remove,
1952 .suspend = serial_imx_suspend,
1953 .resume = serial_imx_resume,
1954 .id_table = imx_uart_devtype,
1957 .owner = THIS_MODULE,
1958 .of_match_table = imx_uart_dt_ids,
1962 static int __init imx_serial_init(void)
1966 pr_info("Serial: IMX driver\n");
1968 ret = uart_register_driver(&imx_reg);
1972 ret = platform_driver_register(&serial_imx_driver);
1974 uart_unregister_driver(&imx_reg);
1979 static void __exit imx_serial_exit(void)
1981 platform_driver_unregister(&serial_imx_driver);
1982 uart_unregister_driver(&imx_reg);
1985 module_init(imx_serial_init);
1986 module_exit(imx_serial_exit);
1988 MODULE_AUTHOR("Sascha Hauer");
1989 MODULE_DESCRIPTION("IMX generic serial port driver");
1990 MODULE_LICENSE("GPL");
1991 MODULE_ALIAS("platform:imx-uart");