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;
228 wait_queue_head_t dma_wait;
231 struct imx_port_ucrs {
238 #define USE_IRDA(sport) ((sport)->use_irda)
240 #define USE_IRDA(sport) (0)
243 static struct imx_uart_data imx_uart_devdata[] = {
246 .devtype = IMX1_UART,
249 .uts_reg = IMX21_UTS,
250 .devtype = IMX21_UART,
253 .uts_reg = IMX21_UTS,
254 .devtype = IMX6Q_UART,
258 static struct platform_device_id imx_uart_devtype[] = {
261 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
263 .name = "imx21-uart",
264 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
266 .name = "imx6q-uart",
267 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
272 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
274 static struct of_device_id imx_uart_dt_ids[] = {
275 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
276 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
277 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
280 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
282 static inline unsigned uts_reg(struct imx_port *sport)
284 return sport->devdata->uts_reg;
287 static inline int is_imx1_uart(struct imx_port *sport)
289 return sport->devdata->devtype == IMX1_UART;
292 static inline int is_imx21_uart(struct imx_port *sport)
294 return sport->devdata->devtype == IMX21_UART;
297 static inline int is_imx6q_uart(struct imx_port *sport)
299 return sport->devdata->devtype == IMX6Q_UART;
302 * Save and restore functions for UCR1, UCR2 and UCR3 registers
304 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
305 static void imx_port_ucrs_save(struct uart_port *port,
306 struct imx_port_ucrs *ucr)
308 /* save control registers */
309 ucr->ucr1 = readl(port->membase + UCR1);
310 ucr->ucr2 = readl(port->membase + UCR2);
311 ucr->ucr3 = readl(port->membase + UCR3);
314 static void imx_port_ucrs_restore(struct uart_port *port,
315 struct imx_port_ucrs *ucr)
317 /* restore control registers */
318 writel(ucr->ucr1, port->membase + UCR1);
319 writel(ucr->ucr2, port->membase + UCR2);
320 writel(ucr->ucr3, port->membase + UCR3);
325 * Handle any change of modem status signal since we were last called.
327 static void imx_mctrl_check(struct imx_port *sport)
329 unsigned int status, changed;
331 status = sport->port.ops->get_mctrl(&sport->port);
332 changed = status ^ sport->old_status;
337 sport->old_status = status;
339 if (changed & TIOCM_RI)
340 sport->port.icount.rng++;
341 if (changed & TIOCM_DSR)
342 sport->port.icount.dsr++;
343 if (changed & TIOCM_CAR)
344 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
345 if (changed & TIOCM_CTS)
346 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
348 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
352 * This is our per-port timeout handler, for checking the
353 * modem status signals.
355 static void imx_timeout(unsigned long data)
357 struct imx_port *sport = (struct imx_port *)data;
360 if (sport->port.state) {
361 spin_lock_irqsave(&sport->port.lock, flags);
362 imx_mctrl_check(sport);
363 spin_unlock_irqrestore(&sport->port.lock, flags);
365 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
370 * interrupts disabled on entry
372 static void imx_stop_tx(struct uart_port *port)
374 struct imx_port *sport = (struct imx_port *)port;
377 if (USE_IRDA(sport)) {
378 /* half duplex - wait for end of transmission */
381 !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
386 * irda transceiver - wait a bit more to avoid
387 * cutoff, hardware dependent
389 udelay(sport->trcv_delay);
392 * half duplex - reactivate receive mode,
393 * flush receive pipe echo crap
395 if (readl(sport->port.membase + USR2) & USR2_TXDC) {
396 temp = readl(sport->port.membase + UCR1);
397 temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
398 writel(temp, sport->port.membase + UCR1);
400 temp = readl(sport->port.membase + UCR4);
401 temp &= ~(UCR4_TCEN);
402 writel(temp, sport->port.membase + UCR4);
404 while (readl(sport->port.membase + URXD0) &
408 temp = readl(sport->port.membase + UCR1);
410 writel(temp, sport->port.membase + UCR1);
412 temp = readl(sport->port.membase + UCR4);
414 writel(temp, sport->port.membase + UCR4);
420 * We are maybe in the SMP context, so if the DMA TX thread is running
421 * on other cpu, we have to wait for it to finish.
423 if (sport->dma_is_enabled && sport->dma_is_txing)
426 temp = readl(sport->port.membase + UCR1);
427 writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
431 * interrupts disabled on entry
433 static void imx_stop_rx(struct uart_port *port)
435 struct imx_port *sport = (struct imx_port *)port;
439 * We are maybe in the SMP context, so if the DMA TX thread is running
440 * on other cpu, we have to wait for it to finish.
442 if (sport->dma_is_enabled && sport->dma_is_rxing)
445 temp = readl(sport->port.membase + UCR2);
446 writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
448 /* disable the `Receiver Ready Interrrupt` */
449 temp = readl(sport->port.membase + UCR1);
450 writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
454 * Set the modem control timer to fire immediately.
456 static void imx_enable_ms(struct uart_port *port)
458 struct imx_port *sport = (struct imx_port *)port;
460 mod_timer(&sport->timer, jiffies);
463 static inline void imx_transmit_buffer(struct imx_port *sport)
465 struct circ_buf *xmit = &sport->port.state->xmit;
467 while (!uart_circ_empty(xmit) &&
468 !(readl(sport->port.membase + uts_reg(sport))
470 /* send xmit->buf[xmit->tail]
471 * out the port here */
472 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
473 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
474 sport->port.icount.tx++;
477 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
478 uart_write_wakeup(&sport->port);
480 if (uart_circ_empty(xmit))
481 imx_stop_tx(&sport->port);
484 static void dma_tx_callback(void *data)
486 struct imx_port *sport = data;
487 struct scatterlist *sgl = &sport->tx_sgl[0];
488 struct circ_buf *xmit = &sport->port.state->xmit;
491 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
493 sport->dma_is_txing = 0;
495 /* update the stat */
496 spin_lock_irqsave(&sport->port.lock, flags);
497 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
498 sport->port.icount.tx += sport->tx_bytes;
499 spin_unlock_irqrestore(&sport->port.lock, flags);
501 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
503 uart_write_wakeup(&sport->port);
505 if (waitqueue_active(&sport->dma_wait)) {
506 wake_up(&sport->dma_wait);
507 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
512 static void imx_dma_tx(struct imx_port *sport)
514 struct circ_buf *xmit = &sport->port.state->xmit;
515 struct scatterlist *sgl = sport->tx_sgl;
516 struct dma_async_tx_descriptor *desc;
517 struct dma_chan *chan = sport->dma_chan_tx;
518 struct device *dev = sport->port.dev;
519 enum dma_status status;
522 status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
523 if (DMA_IN_PROGRESS == status)
526 sport->tx_bytes = uart_circ_chars_pending(xmit);
528 if (xmit->tail > xmit->head && xmit->head > 0) {
529 sport->dma_tx_nents = 2;
530 sg_init_table(sgl, 2);
531 sg_set_buf(sgl, xmit->buf + xmit->tail,
532 UART_XMIT_SIZE - xmit->tail);
533 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
535 sport->dma_tx_nents = 1;
536 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
539 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
541 dev_err(dev, "DMA mapping error for TX.\n");
544 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
545 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
547 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
550 desc->callback = dma_tx_callback;
551 desc->callback_param = sport;
553 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
554 uart_circ_chars_pending(xmit));
556 sport->dma_is_txing = 1;
557 dmaengine_submit(desc);
558 dma_async_issue_pending(chan);
563 * interrupts disabled on entry
565 static void imx_start_tx(struct uart_port *port)
567 struct imx_port *sport = (struct imx_port *)port;
570 if (USE_IRDA(sport)) {
571 /* half duplex in IrDA mode; have to disable receive mode */
572 temp = readl(sport->port.membase + UCR4);
573 temp &= ~(UCR4_DREN);
574 writel(temp, sport->port.membase + UCR4);
576 temp = readl(sport->port.membase + UCR1);
577 temp &= ~(UCR1_RRDYEN);
578 writel(temp, sport->port.membase + UCR1);
580 /* Clear any pending ORE flag before enabling interrupt */
581 temp = readl(sport->port.membase + USR2);
582 writel(temp | USR2_ORE, sport->port.membase + USR2);
584 temp = readl(sport->port.membase + UCR4);
586 writel(temp, sport->port.membase + UCR4);
588 if (!sport->dma_is_enabled) {
589 temp = readl(sport->port.membase + UCR1);
590 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
593 if (USE_IRDA(sport)) {
594 temp = readl(sport->port.membase + UCR1);
596 writel(temp, sport->port.membase + UCR1);
598 temp = readl(sport->port.membase + UCR4);
600 writel(temp, sport->port.membase + UCR4);
603 if (sport->dma_is_enabled) {
608 if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
609 imx_transmit_buffer(sport);
612 static irqreturn_t imx_rtsint(int irq, void *dev_id)
614 struct imx_port *sport = dev_id;
618 spin_lock_irqsave(&sport->port.lock, flags);
620 writel(USR1_RTSD, sport->port.membase + USR1);
621 val = readl(sport->port.membase + USR1) & USR1_RTSS;
622 uart_handle_cts_change(&sport->port, !!val);
623 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
625 spin_unlock_irqrestore(&sport->port.lock, flags);
629 static irqreturn_t imx_txint(int irq, void *dev_id)
631 struct imx_port *sport = dev_id;
632 struct circ_buf *xmit = &sport->port.state->xmit;
635 spin_lock_irqsave(&sport->port.lock, flags);
636 if (sport->port.x_char) {
638 writel(sport->port.x_char, sport->port.membase + URTX0);
642 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
643 imx_stop_tx(&sport->port);
647 imx_transmit_buffer(sport);
649 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
650 uart_write_wakeup(&sport->port);
653 spin_unlock_irqrestore(&sport->port.lock, flags);
657 static irqreturn_t imx_rxint(int irq, void *dev_id)
659 struct imx_port *sport = dev_id;
660 unsigned int rx, flg, ignored = 0;
661 struct tty_port *port = &sport->port.state->port;
662 unsigned long flags, temp;
664 spin_lock_irqsave(&sport->port.lock, flags);
666 while (readl(sport->port.membase + USR2) & USR2_RDR) {
668 sport->port.icount.rx++;
670 rx = readl(sport->port.membase + URXD0);
672 temp = readl(sport->port.membase + USR2);
673 if (temp & USR2_BRCD) {
674 writel(USR2_BRCD, sport->port.membase + USR2);
675 if (uart_handle_break(&sport->port))
679 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
682 if (unlikely(rx & URXD_ERR)) {
684 sport->port.icount.brk++;
685 else if (rx & URXD_PRERR)
686 sport->port.icount.parity++;
687 else if (rx & URXD_FRMERR)
688 sport->port.icount.frame++;
689 if (rx & URXD_OVRRUN)
690 sport->port.icount.overrun++;
692 if (rx & sport->port.ignore_status_mask) {
698 rx &= sport->port.read_status_mask;
702 else if (rx & URXD_PRERR)
704 else if (rx & URXD_FRMERR)
706 if (rx & URXD_OVRRUN)
710 sport->port.sysrq = 0;
714 tty_insert_flip_char(port, rx, flg);
718 spin_unlock_irqrestore(&sport->port.lock, flags);
719 tty_flip_buffer_push(port);
723 static int start_rx_dma(struct imx_port *sport);
725 * If the RXFIFO is filled with some data, and then we
726 * arise a DMA operation to receive them.
728 static void imx_dma_rxint(struct imx_port *sport)
732 temp = readl(sport->port.membase + USR2);
733 if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
734 sport->dma_is_rxing = 1;
736 /* disable the `Recerver Ready Interrrupt` */
737 temp = readl(sport->port.membase + UCR1);
738 temp &= ~(UCR1_RRDYEN);
739 writel(temp, sport->port.membase + UCR1);
741 /* tell the DMA to receive the data. */
746 static irqreturn_t imx_int(int irq, void *dev_id)
748 struct imx_port *sport = dev_id;
752 sts = readl(sport->port.membase + USR1);
754 if (sts & USR1_RRDY) {
755 if (sport->dma_is_enabled)
756 imx_dma_rxint(sport);
758 imx_rxint(irq, dev_id);
761 if (sts & USR1_TRDY &&
762 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
763 imx_txint(irq, dev_id);
766 imx_rtsint(irq, dev_id);
768 if (sts & USR1_AWAKE)
769 writel(USR1_AWAKE, sport->port.membase + USR1);
771 sts2 = readl(sport->port.membase + USR2);
772 if (sts2 & USR2_ORE) {
773 dev_err(sport->port.dev, "Rx FIFO overrun\n");
774 sport->port.icount.overrun++;
775 writel(sts2 | USR2_ORE, sport->port.membase + USR2);
782 * Return TIOCSER_TEMT when transmitter is not busy.
784 static unsigned int imx_tx_empty(struct uart_port *port)
786 struct imx_port *sport = (struct imx_port *)port;
789 ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
791 /* If the TX DMA is working, return 0. */
792 if (sport->dma_is_enabled && sport->dma_is_txing)
799 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
801 static unsigned int imx_get_mctrl(struct uart_port *port)
803 struct imx_port *sport = (struct imx_port *)port;
804 unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
806 if (readl(sport->port.membase + USR1) & USR1_RTSS)
809 if (readl(sport->port.membase + UCR2) & UCR2_CTS)
812 if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
818 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
820 struct imx_port *sport = (struct imx_port *)port;
823 temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
825 if (mctrl & TIOCM_RTS)
826 if (!sport->dma_is_enabled)
829 writel(temp, sport->port.membase + UCR2);
831 temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
832 if (mctrl & TIOCM_LOOP)
834 writel(temp, sport->port.membase + uts_reg(sport));
838 * Interrupts always disabled.
840 static void imx_break_ctl(struct uart_port *port, int break_state)
842 struct imx_port *sport = (struct imx_port *)port;
843 unsigned long flags, temp;
845 spin_lock_irqsave(&sport->port.lock, flags);
847 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
849 if (break_state != 0)
852 writel(temp, sport->port.membase + UCR1);
854 spin_unlock_irqrestore(&sport->port.lock, flags);
857 #define TXTL 2 /* reset default */
858 #define RXTL 1 /* reset default */
860 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
864 /* set receiver / transmitter trigger level */
865 val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
866 val |= TXTL << UFCR_TXTL_SHF | RXTL;
867 writel(val, sport->port.membase + UFCR);
871 #define RX_BUF_SIZE (PAGE_SIZE)
872 static void imx_rx_dma_done(struct imx_port *sport)
876 /* Enable this interrupt when the RXFIFO is empty. */
877 temp = readl(sport->port.membase + UCR1);
879 writel(temp, sport->port.membase + UCR1);
881 sport->dma_is_rxing = 0;
883 /* Is the shutdown waiting for us? */
884 if (waitqueue_active(&sport->dma_wait))
885 wake_up(&sport->dma_wait);
889 * There are three kinds of RX DMA interrupts(such as in the MX6Q):
890 * [1] the RX DMA buffer is full.
891 * [2] the Aging timer expires(wait for 8 bytes long)
892 * [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
894 * The [2] is trigger when a character was been sitting in the FIFO
895 * meanwhile [3] can wait for 32 bytes long when the RX line is
896 * on IDLE state and RxFIFO is empty.
898 static void dma_rx_callback(void *data)
900 struct imx_port *sport = data;
901 struct dma_chan *chan = sport->dma_chan_rx;
902 struct scatterlist *sgl = &sport->rx_sgl;
903 struct tty_port *port = &sport->port.state->port;
904 struct dma_tx_state state;
905 enum dma_status status;
909 dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
911 status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
912 count = RX_BUF_SIZE - state.residue;
913 dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
916 tty_insert_flip_string(port, sport->rx_buf, count);
917 tty_flip_buffer_push(port);
921 imx_rx_dma_done(sport);
924 static int start_rx_dma(struct imx_port *sport)
926 struct scatterlist *sgl = &sport->rx_sgl;
927 struct dma_chan *chan = sport->dma_chan_rx;
928 struct device *dev = sport->port.dev;
929 struct dma_async_tx_descriptor *desc;
932 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
933 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
935 dev_err(dev, "DMA mapping error for RX.\n");
938 desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
941 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
944 desc->callback = dma_rx_callback;
945 desc->callback_param = sport;
947 dev_dbg(dev, "RX: prepare for the DMA.\n");
948 dmaengine_submit(desc);
949 dma_async_issue_pending(chan);
953 static void imx_uart_dma_exit(struct imx_port *sport)
955 if (sport->dma_chan_rx) {
956 dma_release_channel(sport->dma_chan_rx);
957 sport->dma_chan_rx = NULL;
959 kfree(sport->rx_buf);
960 sport->rx_buf = NULL;
963 if (sport->dma_chan_tx) {
964 dma_release_channel(sport->dma_chan_tx);
965 sport->dma_chan_tx = NULL;
968 sport->dma_is_inited = 0;
971 static int imx_uart_dma_init(struct imx_port *sport)
973 struct dma_slave_config slave_config = {};
974 struct device *dev = sport->port.dev;
977 /* Prepare for RX : */
978 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
979 if (!sport->dma_chan_rx) {
980 dev_dbg(dev, "cannot get the DMA channel.\n");
985 slave_config.direction = DMA_DEV_TO_MEM;
986 slave_config.src_addr = sport->port.mapbase + URXD0;
987 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
988 slave_config.src_maxburst = RXTL;
989 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
991 dev_err(dev, "error in RX dma configuration.\n");
995 sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
996 if (!sport->rx_buf) {
997 dev_err(dev, "cannot alloc DMA buffer.\n");
1002 /* Prepare for TX : */
1003 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1004 if (!sport->dma_chan_tx) {
1005 dev_err(dev, "cannot get the TX DMA channel!\n");
1010 slave_config.direction = DMA_MEM_TO_DEV;
1011 slave_config.dst_addr = sport->port.mapbase + URTX0;
1012 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1013 slave_config.dst_maxburst = TXTL;
1014 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1016 dev_err(dev, "error in TX dma configuration.");
1020 sport->dma_is_inited = 1;
1024 imx_uart_dma_exit(sport);
1028 static void imx_enable_dma(struct imx_port *sport)
1032 init_waitqueue_head(&sport->dma_wait);
1035 temp = readl(sport->port.membase + UCR1);
1036 temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1037 /* wait for 32 idle frames for IDDMA interrupt */
1039 writel(temp, sport->port.membase + UCR1);
1042 temp = readl(sport->port.membase + UCR4);
1043 temp |= UCR4_IDDMAEN;
1044 writel(temp, sport->port.membase + UCR4);
1046 sport->dma_is_enabled = 1;
1049 static void imx_disable_dma(struct imx_port *sport)
1054 temp = readl(sport->port.membase + UCR1);
1055 temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1056 writel(temp, sport->port.membase + UCR1);
1059 temp = readl(sport->port.membase + UCR2);
1060 temp &= ~(UCR2_CTSC | UCR2_CTS);
1061 writel(temp, sport->port.membase + UCR2);
1064 temp = readl(sport->port.membase + UCR4);
1065 temp &= ~UCR4_IDDMAEN;
1066 writel(temp, sport->port.membase + UCR4);
1068 sport->dma_is_enabled = 0;
1071 /* half the RX buffer size */
1074 static int imx_startup(struct uart_port *port)
1076 struct imx_port *sport = (struct imx_port *)port;
1078 unsigned long flags, temp;
1080 retval = clk_prepare_enable(sport->clk_per);
1083 retval = clk_prepare_enable(sport->clk_ipg);
1085 clk_disable_unprepare(sport->clk_per);
1089 imx_setup_ufcr(sport, 0);
1091 /* disable the DREN bit (Data Ready interrupt enable) before
1094 temp = readl(sport->port.membase + UCR4);
1096 if (USE_IRDA(sport))
1099 /* set the trigger level for CTS */
1100 temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1101 temp |= CTSTL << UCR4_CTSTL_SHF;
1103 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1105 /* Reset fifo's and state machines */
1108 temp = readl(sport->port.membase + UCR2);
1110 writel(temp, sport->port.membase + UCR2);
1112 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1116 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1117 * chips only have one interrupt.
1119 if (sport->txirq > 0) {
1120 retval = request_irq(sport->rxirq, imx_rxint, 0,
1121 dev_name(port->dev), sport);
1125 retval = request_irq(sport->txirq, imx_txint, 0,
1126 dev_name(port->dev), sport);
1130 /* do not use RTS IRQ on IrDA */
1131 if (!USE_IRDA(sport)) {
1132 retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1133 dev_name(port->dev), sport);
1138 retval = request_irq(sport->port.irq, imx_int, 0,
1139 dev_name(port->dev), sport);
1141 free_irq(sport->port.irq, sport);
1146 spin_lock_irqsave(&sport->port.lock, flags);
1148 * Finally, clear and enable interrupts
1150 writel(USR1_RTSD, sport->port.membase + USR1);
1152 temp = readl(sport->port.membase + UCR1);
1153 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1155 if (USE_IRDA(sport)) {
1157 temp &= ~(UCR1_RTSDEN);
1160 writel(temp, sport->port.membase + UCR1);
1162 temp = readl(sport->port.membase + UCR2);
1163 temp |= (UCR2_RXEN | UCR2_TXEN);
1164 if (!sport->have_rtscts)
1166 writel(temp, sport->port.membase + UCR2);
1168 if (!is_imx1_uart(sport)) {
1169 temp = readl(sport->port.membase + UCR3);
1170 temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
1171 writel(temp, sport->port.membase + UCR3);
1174 if (USE_IRDA(sport)) {
1175 temp = readl(sport->port.membase + UCR4);
1176 if (sport->irda_inv_rx)
1179 temp &= ~(UCR4_INVR);
1180 writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1182 temp = readl(sport->port.membase + UCR3);
1183 if (sport->irda_inv_tx)
1186 temp &= ~(UCR3_INVT);
1187 writel(temp, sport->port.membase + UCR3);
1191 * Enable modem status interrupts
1193 imx_enable_ms(&sport->port);
1194 spin_unlock_irqrestore(&sport->port.lock, flags);
1196 if (USE_IRDA(sport)) {
1197 struct imxuart_platform_data *pdata;
1198 pdata = dev_get_platdata(sport->port.dev);
1199 sport->irda_inv_rx = pdata->irda_inv_rx;
1200 sport->irda_inv_tx = pdata->irda_inv_tx;
1201 sport->trcv_delay = pdata->transceiver_delay;
1202 if (pdata->irda_enable)
1203 pdata->irda_enable(1);
1210 free_irq(sport->txirq, sport);
1213 free_irq(sport->rxirq, sport);
1218 static void imx_shutdown(struct uart_port *port)
1220 struct imx_port *sport = (struct imx_port *)port;
1222 unsigned long flags;
1224 if (sport->dma_is_enabled) {
1225 /* We have to wait for the DMA to finish. */
1226 wait_event(sport->dma_wait,
1227 !sport->dma_is_rxing && !sport->dma_is_txing);
1229 imx_disable_dma(sport);
1230 imx_uart_dma_exit(sport);
1233 spin_lock_irqsave(&sport->port.lock, flags);
1234 temp = readl(sport->port.membase + UCR2);
1235 temp &= ~(UCR2_TXEN);
1236 writel(temp, sport->port.membase + UCR2);
1237 spin_unlock_irqrestore(&sport->port.lock, flags);
1239 if (USE_IRDA(sport)) {
1240 struct imxuart_platform_data *pdata;
1241 pdata = dev_get_platdata(sport->port.dev);
1242 if (pdata->irda_enable)
1243 pdata->irda_enable(0);
1249 del_timer_sync(&sport->timer);
1252 * Free the interrupts
1254 if (sport->txirq > 0) {
1255 if (!USE_IRDA(sport))
1256 free_irq(sport->rtsirq, sport);
1257 free_irq(sport->txirq, sport);
1258 free_irq(sport->rxirq, sport);
1260 free_irq(sport->port.irq, sport);
1263 * Disable all interrupts, port and break condition.
1266 spin_lock_irqsave(&sport->port.lock, flags);
1267 temp = readl(sport->port.membase + UCR1);
1268 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1269 if (USE_IRDA(sport))
1270 temp &= ~(UCR1_IREN);
1272 writel(temp, sport->port.membase + UCR1);
1273 spin_unlock_irqrestore(&sport->port.lock, flags);
1275 clk_disable_unprepare(sport->clk_per);
1276 clk_disable_unprepare(sport->clk_ipg);
1279 static void imx_flush_buffer(struct uart_port *port)
1281 struct imx_port *sport = (struct imx_port *)port;
1283 if (sport->dma_is_enabled) {
1284 sport->tx_bytes = 0;
1285 dmaengine_terminate_all(sport->dma_chan_tx);
1290 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1291 struct ktermios *old)
1293 struct imx_port *sport = (struct imx_port *)port;
1294 unsigned long flags;
1295 unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1296 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1297 unsigned int div, ufcr;
1298 unsigned long num, denom;
1302 * If we don't support modem control lines, don't allow
1306 termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1307 termios->c_cflag |= CLOCAL;
1311 * We only support CS7 and CS8.
1313 while ((termios->c_cflag & CSIZE) != CS7 &&
1314 (termios->c_cflag & CSIZE) != CS8) {
1315 termios->c_cflag &= ~CSIZE;
1316 termios->c_cflag |= old_csize;
1320 if ((termios->c_cflag & CSIZE) == CS8)
1321 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1323 ucr2 = UCR2_SRST | UCR2_IRTS;
1325 if (termios->c_cflag & CRTSCTS) {
1326 if (sport->have_rtscts) {
1330 /* Can we enable the DMA support? */
1331 if (is_imx6q_uart(sport) && !uart_console(port)
1332 && !sport->dma_is_inited)
1333 imx_uart_dma_init(sport);
1335 termios->c_cflag &= ~CRTSCTS;
1339 if (termios->c_cflag & CSTOPB)
1341 if (termios->c_cflag & PARENB) {
1343 if (termios->c_cflag & PARODD)
1347 del_timer_sync(&sport->timer);
1350 * Ask the core to calculate the divisor for us.
1352 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1353 quot = uart_get_divisor(port, baud);
1355 spin_lock_irqsave(&sport->port.lock, flags);
1357 sport->port.read_status_mask = 0;
1358 if (termios->c_iflag & INPCK)
1359 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1360 if (termios->c_iflag & (BRKINT | PARMRK))
1361 sport->port.read_status_mask |= URXD_BRK;
1364 * Characters to ignore
1366 sport->port.ignore_status_mask = 0;
1367 if (termios->c_iflag & IGNPAR)
1368 sport->port.ignore_status_mask |= URXD_PRERR;
1369 if (termios->c_iflag & IGNBRK) {
1370 sport->port.ignore_status_mask |= URXD_BRK;
1372 * If we're ignoring parity and break indicators,
1373 * ignore overruns too (for real raw support).
1375 if (termios->c_iflag & IGNPAR)
1376 sport->port.ignore_status_mask |= URXD_OVRRUN;
1380 * Update the per-port timeout.
1382 uart_update_timeout(port, termios->c_cflag, baud);
1385 * disable interrupts and drain transmitter
1387 old_ucr1 = readl(sport->port.membase + UCR1);
1388 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1389 sport->port.membase + UCR1);
1391 while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1394 /* then, disable everything */
1395 old_txrxen = readl(sport->port.membase + UCR2);
1396 writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1397 sport->port.membase + UCR2);
1398 old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1400 if (USE_IRDA(sport)) {
1402 * use maximum available submodule frequency to
1403 * avoid missing short pulses due to low sampling rate
1407 /* custom-baudrate handling */
1408 div = sport->port.uartclk / (baud * 16);
1409 if (baud == 38400 && quot != div)
1410 baud = sport->port.uartclk / (quot * 16);
1412 div = sport->port.uartclk / (baud * 16);
1419 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1420 1 << 16, 1 << 16, &num, &denom);
1422 tdiv64 = sport->port.uartclk;
1424 do_div(tdiv64, denom * 16 * div);
1425 tty_termios_encode_baud_rate(termios,
1426 (speed_t)tdiv64, (speed_t)tdiv64);
1431 ufcr = readl(sport->port.membase + UFCR);
1432 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1433 if (sport->dte_mode)
1434 ufcr |= UFCR_DCEDTE;
1435 writel(ufcr, sport->port.membase + UFCR);
1437 writel(num, sport->port.membase + UBIR);
1438 writel(denom, sport->port.membase + UBMR);
1440 if (!is_imx1_uart(sport))
1441 writel(sport->port.uartclk / div / 1000,
1442 sport->port.membase + IMX21_ONEMS);
1444 writel(old_ucr1, sport->port.membase + UCR1);
1446 /* set the parity, stop bits and data size */
1447 writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1449 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1450 imx_enable_ms(&sport->port);
1452 if (sport->dma_is_inited && !sport->dma_is_enabled)
1453 imx_enable_dma(sport);
1454 spin_unlock_irqrestore(&sport->port.lock, flags);
1457 static const char *imx_type(struct uart_port *port)
1459 struct imx_port *sport = (struct imx_port *)port;
1461 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1465 * Configure/autoconfigure the port.
1467 static void imx_config_port(struct uart_port *port, int flags)
1469 struct imx_port *sport = (struct imx_port *)port;
1471 if (flags & UART_CONFIG_TYPE)
1472 sport->port.type = PORT_IMX;
1476 * Verify the new serial_struct (for TIOCSSERIAL).
1477 * The only change we allow are to the flags and type, and
1478 * even then only between PORT_IMX and PORT_UNKNOWN
1481 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1483 struct imx_port *sport = (struct imx_port *)port;
1486 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1488 if (sport->port.irq != ser->irq)
1490 if (ser->io_type != UPIO_MEM)
1492 if (sport->port.uartclk / 16 != ser->baud_base)
1494 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1496 if (sport->port.iobase != ser->port)
1503 #if defined(CONFIG_CONSOLE_POLL)
1504 static int imx_poll_get_char(struct uart_port *port)
1506 struct imx_port_ucrs old_ucr;
1507 unsigned int status;
1510 /* save control registers */
1511 imx_port_ucrs_save(port, &old_ucr);
1513 /* disable interrupts */
1514 writel(UCR1_UARTEN, port->membase + UCR1);
1515 writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1516 port->membase + UCR2);
1517 writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1518 port->membase + UCR3);
1522 status = readl(port->membase + USR2);
1523 } while (~status & USR2_RDR);
1526 c = readl(port->membase + URXD0);
1528 /* restore control registers */
1529 imx_port_ucrs_restore(port, &old_ucr);
1534 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1536 struct imx_port_ucrs old_ucr;
1537 unsigned int status;
1539 /* save control registers */
1540 imx_port_ucrs_save(port, &old_ucr);
1542 /* disable interrupts */
1543 writel(UCR1_UARTEN, port->membase + UCR1);
1544 writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1545 port->membase + UCR2);
1546 writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1547 port->membase + UCR3);
1551 status = readl(port->membase + USR1);
1552 } while (~status & USR1_TRDY);
1555 writel(c, port->membase + URTX0);
1559 status = readl(port->membase + USR2);
1560 } while (~status & USR2_TXDC);
1562 /* restore control registers */
1563 imx_port_ucrs_restore(port, &old_ucr);
1567 static struct uart_ops imx_pops = {
1568 .tx_empty = imx_tx_empty,
1569 .set_mctrl = imx_set_mctrl,
1570 .get_mctrl = imx_get_mctrl,
1571 .stop_tx = imx_stop_tx,
1572 .start_tx = imx_start_tx,
1573 .stop_rx = imx_stop_rx,
1574 .enable_ms = imx_enable_ms,
1575 .break_ctl = imx_break_ctl,
1576 .startup = imx_startup,
1577 .shutdown = imx_shutdown,
1578 .flush_buffer = imx_flush_buffer,
1579 .set_termios = imx_set_termios,
1581 .config_port = imx_config_port,
1582 .verify_port = imx_verify_port,
1583 #if defined(CONFIG_CONSOLE_POLL)
1584 .poll_get_char = imx_poll_get_char,
1585 .poll_put_char = imx_poll_put_char,
1589 static struct imx_port *imx_ports[UART_NR];
1591 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1592 static void imx_console_putchar(struct uart_port *port, int ch)
1594 struct imx_port *sport = (struct imx_port *)port;
1596 while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1599 writel(ch, sport->port.membase + URTX0);
1603 * Interrupts are disabled on entering
1606 imx_console_write(struct console *co, const char *s, unsigned int count)
1608 struct imx_port *sport = imx_ports[co->index];
1609 struct imx_port_ucrs old_ucr;
1611 unsigned long flags = 0;
1615 retval = clk_enable(sport->clk_per);
1618 retval = clk_enable(sport->clk_ipg);
1620 clk_disable(sport->clk_per);
1624 if (sport->port.sysrq)
1626 else if (oops_in_progress)
1627 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1629 spin_lock_irqsave(&sport->port.lock, flags);
1632 * First, save UCR1/2/3 and then disable interrupts
1634 imx_port_ucrs_save(&sport->port, &old_ucr);
1635 ucr1 = old_ucr.ucr1;
1637 if (is_imx1_uart(sport))
1638 ucr1 |= IMX1_UCR1_UARTCLKEN;
1639 ucr1 |= UCR1_UARTEN;
1640 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1642 writel(ucr1, sport->port.membase + UCR1);
1644 writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1646 uart_console_write(&sport->port, s, count, imx_console_putchar);
1649 * Finally, wait for transmitter to become empty
1650 * and restore UCR1/2/3
1652 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1654 imx_port_ucrs_restore(&sport->port, &old_ucr);
1657 spin_unlock_irqrestore(&sport->port.lock, flags);
1659 clk_disable(sport->clk_ipg);
1660 clk_disable(sport->clk_per);
1664 * If the port was already initialised (eg, by a boot loader),
1665 * try to determine the current setup.
1668 imx_console_get_options(struct imx_port *sport, int *baud,
1669 int *parity, int *bits)
1672 if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1673 /* ok, the port was enabled */
1674 unsigned int ucr2, ubir, ubmr, uartclk;
1675 unsigned int baud_raw;
1676 unsigned int ucfr_rfdiv;
1678 ucr2 = readl(sport->port.membase + UCR2);
1681 if (ucr2 & UCR2_PREN) {
1682 if (ucr2 & UCR2_PROE)
1693 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1694 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1696 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1697 if (ucfr_rfdiv == 6)
1700 ucfr_rfdiv = 6 - ucfr_rfdiv;
1702 uartclk = clk_get_rate(sport->clk_per);
1703 uartclk /= ucfr_rfdiv;
1706 * The next code provides exact computation of
1707 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1708 * without need of float support or long long division,
1709 * which would be required to prevent 32bit arithmetic overflow
1711 unsigned int mul = ubir + 1;
1712 unsigned int div = 16 * (ubmr + 1);
1713 unsigned int rem = uartclk % div;
1715 baud_raw = (uartclk / div) * mul;
1716 baud_raw += (rem * mul + div / 2) / div;
1717 *baud = (baud_raw + 50) / 100 * 100;
1720 if (*baud != baud_raw)
1721 pr_info("Console IMX rounded baud rate from %d to %d\n",
1727 imx_console_setup(struct console *co, char *options)
1729 struct imx_port *sport;
1737 * Check whether an invalid uart number has been specified, and
1738 * if so, search for the first available port that does have
1741 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1743 sport = imx_ports[co->index];
1747 /* For setting the registers, we only need to enable the ipg clock. */
1748 retval = clk_prepare_enable(sport->clk_ipg);
1753 uart_parse_options(options, &baud, &parity, &bits, &flow);
1755 imx_console_get_options(sport, &baud, &parity, &bits);
1757 imx_setup_ufcr(sport, 0);
1759 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1761 clk_disable(sport->clk_ipg);
1763 clk_unprepare(sport->clk_ipg);
1767 retval = clk_prepare(sport->clk_per);
1769 clk_disable_unprepare(sport->clk_ipg);
1775 static struct uart_driver imx_reg;
1776 static struct console imx_console = {
1778 .write = imx_console_write,
1779 .device = uart_console_device,
1780 .setup = imx_console_setup,
1781 .flags = CON_PRINTBUFFER,
1786 #define IMX_CONSOLE &imx_console
1788 #define IMX_CONSOLE NULL
1791 static struct uart_driver imx_reg = {
1792 .owner = THIS_MODULE,
1793 .driver_name = DRIVER_NAME,
1794 .dev_name = DEV_NAME,
1795 .major = SERIAL_IMX_MAJOR,
1796 .minor = MINOR_START,
1797 .nr = ARRAY_SIZE(imx_ports),
1798 .cons = IMX_CONSOLE,
1801 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1803 struct imx_port *sport = platform_get_drvdata(dev);
1806 /* enable wakeup from i.MX UART */
1807 val = readl(sport->port.membase + UCR3);
1809 writel(val, sport->port.membase + UCR3);
1811 uart_suspend_port(&imx_reg, &sport->port);
1816 static int serial_imx_resume(struct platform_device *dev)
1818 struct imx_port *sport = platform_get_drvdata(dev);
1821 /* disable wakeup from i.MX UART */
1822 val = readl(sport->port.membase + UCR3);
1823 val &= ~UCR3_AWAKEN;
1824 writel(val, sport->port.membase + UCR3);
1826 uart_resume_port(&imx_reg, &sport->port);
1833 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1834 * could successfully get all information from dt or a negative errno.
1836 static int serial_imx_probe_dt(struct imx_port *sport,
1837 struct platform_device *pdev)
1839 struct device_node *np = pdev->dev.of_node;
1840 const struct of_device_id *of_id =
1841 of_match_device(imx_uart_dt_ids, &pdev->dev);
1845 /* no device tree device */
1848 ret = of_alias_get_id(np, "serial");
1850 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1853 sport->port.line = ret;
1855 if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1856 sport->have_rtscts = 1;
1858 if (of_get_property(np, "fsl,irda-mode", NULL))
1859 sport->use_irda = 1;
1861 if (of_get_property(np, "fsl,dte-mode", NULL))
1862 sport->dte_mode = 1;
1864 sport->devdata = of_id->data;
1869 static inline int serial_imx_probe_dt(struct imx_port *sport,
1870 struct platform_device *pdev)
1876 static void serial_imx_probe_pdata(struct imx_port *sport,
1877 struct platform_device *pdev)
1879 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1881 sport->port.line = pdev->id;
1882 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
1887 if (pdata->flags & IMXUART_HAVE_RTSCTS)
1888 sport->have_rtscts = 1;
1890 if (pdata->flags & IMXUART_IRDA)
1891 sport->use_irda = 1;
1894 static int serial_imx_probe(struct platform_device *pdev)
1896 struct imx_port *sport;
1899 struct resource *res;
1901 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1905 ret = serial_imx_probe_dt(sport, pdev);
1907 serial_imx_probe_pdata(sport, pdev);
1911 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1912 base = devm_ioremap_resource(&pdev->dev, res);
1914 return PTR_ERR(base);
1916 sport->port.dev = &pdev->dev;
1917 sport->port.mapbase = res->start;
1918 sport->port.membase = base;
1919 sport->port.type = PORT_IMX,
1920 sport->port.iotype = UPIO_MEM;
1921 sport->port.irq = platform_get_irq(pdev, 0);
1922 sport->rxirq = platform_get_irq(pdev, 0);
1923 sport->txirq = platform_get_irq(pdev, 1);
1924 sport->rtsirq = platform_get_irq(pdev, 2);
1925 sport->port.fifosize = 32;
1926 sport->port.ops = &imx_pops;
1927 sport->port.flags = UPF_BOOT_AUTOCONF;
1928 init_timer(&sport->timer);
1929 sport->timer.function = imx_timeout;
1930 sport->timer.data = (unsigned long)sport;
1932 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1933 if (IS_ERR(sport->clk_ipg)) {
1934 ret = PTR_ERR(sport->clk_ipg);
1935 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1939 sport->clk_per = devm_clk_get(&pdev->dev, "per");
1940 if (IS_ERR(sport->clk_per)) {
1941 ret = PTR_ERR(sport->clk_per);
1942 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1946 sport->port.uartclk = clk_get_rate(sport->clk_per);
1948 imx_ports[sport->port.line] = sport;
1950 platform_set_drvdata(pdev, sport);
1952 return uart_add_one_port(&imx_reg, &sport->port);
1955 static int serial_imx_remove(struct platform_device *pdev)
1957 struct imx_port *sport = platform_get_drvdata(pdev);
1959 return uart_remove_one_port(&imx_reg, &sport->port);
1962 static struct platform_driver serial_imx_driver = {
1963 .probe = serial_imx_probe,
1964 .remove = serial_imx_remove,
1966 .suspend = serial_imx_suspend,
1967 .resume = serial_imx_resume,
1968 .id_table = imx_uart_devtype,
1971 .owner = THIS_MODULE,
1972 .of_match_table = imx_uart_dt_ids,
1976 static int __init imx_serial_init(void)
1980 pr_info("Serial: IMX driver\n");
1982 ret = uart_register_driver(&imx_reg);
1986 ret = platform_driver_register(&serial_imx_driver);
1988 uart_unregister_driver(&imx_reg);
1993 static void __exit imx_serial_exit(void)
1995 platform_driver_unregister(&serial_imx_driver);
1996 uart_unregister_driver(&imx_reg);
1999 module_init(imx_serial_init);
2000 module_exit(imx_serial_exit);
2002 MODULE_AUTHOR("Sascha Hauer");
2003 MODULE_DESCRIPTION("IMX generic serial port driver");
2004 MODULE_LICENSE("GPL");
2005 MODULE_ALIAS("platform:imx-uart");