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 URXD_RX_DATA (0xFF<<0)
84 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
85 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
86 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
87 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
88 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
89 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
90 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
91 #define UCR1_IREN (1<<7) /* Infrared interface enable */
92 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
93 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
94 #define UCR1_SNDBRK (1<<4) /* Send break */
95 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
96 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
97 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
98 #define UCR1_DOZE (1<<1) /* Doze */
99 #define UCR1_UARTEN (1<<0) /* UART enabled */
100 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
101 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
102 #define UCR2_CTSC (1<<13) /* CTS pin control */
103 #define UCR2_CTS (1<<12) /* Clear to send */
104 #define UCR2_ESCEN (1<<11) /* Escape enable */
105 #define UCR2_PREN (1<<8) /* Parity enable */
106 #define UCR2_PROE (1<<7) /* Parity odd/even */
107 #define UCR2_STPB (1<<6) /* Stop */
108 #define UCR2_WS (1<<5) /* Word size */
109 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
110 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
111 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
112 #define UCR2_RXEN (1<<1) /* Receiver enabled */
113 #define UCR2_SRST (1<<0) /* SW reset */
114 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
115 #define UCR3_PARERREN (1<<12) /* Parity enable */
116 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
117 #define UCR3_DSR (1<<10) /* Data set ready */
118 #define UCR3_DCD (1<<9) /* Data carrier detect */
119 #define UCR3_RI (1<<8) /* Ring indicator */
120 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
121 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
122 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
123 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
124 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
125 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
126 #define UCR3_BPEN (1<<0) /* Preset registers enable */
127 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
128 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
129 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
130 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
131 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
132 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
133 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
134 #define UCR4_IRSC (1<<5) /* IR special case */
135 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
136 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
137 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
138 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
139 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
140 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
141 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
142 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
143 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
144 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
145 #define USR1_RTSS (1<<14) /* RTS pin status */
146 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
147 #define USR1_RTSD (1<<12) /* RTS delta */
148 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
149 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
150 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
151 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
152 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
153 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
154 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
155 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
156 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
157 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
158 #define USR2_IDLE (1<<12) /* Idle condition */
159 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
160 #define USR2_WAKE (1<<7) /* Wake */
161 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
162 #define USR2_TXDC (1<<3) /* Transmitter complete */
163 #define USR2_BRCD (1<<2) /* Break condition */
164 #define USR2_ORE (1<<1) /* Overrun error */
165 #define USR2_RDR (1<<0) /* Recv data ready */
166 #define UTS_FRCPERR (1<<13) /* Force parity error */
167 #define UTS_LOOP (1<<12) /* Loop tx and rx */
168 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
169 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
170 #define UTS_TXFULL (1<<4) /* TxFIFO full */
171 #define UTS_RXFULL (1<<3) /* RxFIFO full */
172 #define UTS_SOFTRST (1<<0) /* Software reset */
174 /* We've been assigned a range on the "Low-density serial ports" major */
175 #define SERIAL_IMX_MAJOR 207
176 #define MINOR_START 16
177 #define DEV_NAME "ttymxc"
180 * This determines how often we check the modem status signals
181 * for any change. They generally aren't connected to an IRQ
182 * so we have to poll them. We also check immediately before
183 * filling the TX fifo incase CTS has been dropped.
185 #define MCTRL_TIMEOUT (250*HZ/1000)
187 #define DRIVER_NAME "IMX-uart"
191 /* i.mx21 type uart runs on all i.mx except i.mx1 */
198 /* device type dependent stuff */
199 struct imx_uart_data {
201 enum imx_uart_type devtype;
205 struct uart_port port;
206 struct timer_list timer;
207 unsigned int old_status;
208 int txirq, rxirq, rtsirq;
209 unsigned int have_rtscts:1;
210 unsigned int dte_mode:1;
211 unsigned int use_irda:1;
212 unsigned int irda_inv_rx:1;
213 unsigned int irda_inv_tx:1;
214 unsigned short trcv_delay; /* transceiver delay */
217 const struct imx_uart_data *devdata;
220 unsigned int dma_is_inited:1;
221 unsigned int dma_is_enabled:1;
222 unsigned int dma_is_rxing:1;
223 unsigned int dma_is_txing:1;
224 struct dma_chan *dma_chan_rx, *dma_chan_tx;
225 struct scatterlist rx_sgl, tx_sgl[2];
227 unsigned int tx_bytes;
228 unsigned int dma_tx_nents;
229 wait_queue_head_t dma_wait;
232 struct imx_port_ucrs {
239 #define USE_IRDA(sport) ((sport)->use_irda)
241 #define USE_IRDA(sport) (0)
244 static struct imx_uart_data imx_uart_devdata[] = {
247 .devtype = IMX1_UART,
250 .uts_reg = IMX21_UTS,
251 .devtype = IMX21_UART,
254 .uts_reg = IMX21_UTS,
255 .devtype = IMX6Q_UART,
259 static struct platform_device_id imx_uart_devtype[] = {
262 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
264 .name = "imx21-uart",
265 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
267 .name = "imx6q-uart",
268 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
273 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
275 static struct of_device_id imx_uart_dt_ids[] = {
276 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
277 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
278 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
281 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
283 static inline unsigned uts_reg(struct imx_port *sport)
285 return sport->devdata->uts_reg;
288 static inline int is_imx1_uart(struct imx_port *sport)
290 return sport->devdata->devtype == IMX1_UART;
293 static inline int is_imx21_uart(struct imx_port *sport)
295 return sport->devdata->devtype == IMX21_UART;
298 static inline int is_imx6q_uart(struct imx_port *sport)
300 return sport->devdata->devtype == IMX6Q_UART;
303 * Save and restore functions for UCR1, UCR2 and UCR3 registers
305 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
306 static void imx_port_ucrs_save(struct uart_port *port,
307 struct imx_port_ucrs *ucr)
309 /* save control registers */
310 ucr->ucr1 = readl(port->membase + UCR1);
311 ucr->ucr2 = readl(port->membase + UCR2);
312 ucr->ucr3 = readl(port->membase + UCR3);
315 static void imx_port_ucrs_restore(struct uart_port *port,
316 struct imx_port_ucrs *ucr)
318 /* restore control registers */
319 writel(ucr->ucr1, port->membase + UCR1);
320 writel(ucr->ucr2, port->membase + UCR2);
321 writel(ucr->ucr3, port->membase + UCR3);
326 * Handle any change of modem status signal since we were last called.
328 static void imx_mctrl_check(struct imx_port *sport)
330 unsigned int status, changed;
332 status = sport->port.ops->get_mctrl(&sport->port);
333 changed = status ^ sport->old_status;
338 sport->old_status = status;
340 if (changed & TIOCM_RI)
341 sport->port.icount.rng++;
342 if (changed & TIOCM_DSR)
343 sport->port.icount.dsr++;
344 if (changed & TIOCM_CAR)
345 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
346 if (changed & TIOCM_CTS)
347 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
349 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
353 * This is our per-port timeout handler, for checking the
354 * modem status signals.
356 static void imx_timeout(unsigned long data)
358 struct imx_port *sport = (struct imx_port *)data;
361 if (sport->port.state) {
362 spin_lock_irqsave(&sport->port.lock, flags);
363 imx_mctrl_check(sport);
364 spin_unlock_irqrestore(&sport->port.lock, flags);
366 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
371 * interrupts disabled on entry
373 static void imx_stop_tx(struct uart_port *port)
375 struct imx_port *sport = (struct imx_port *)port;
378 if (USE_IRDA(sport)) {
379 /* half duplex - wait for end of transmission */
382 !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
387 * irda transceiver - wait a bit more to avoid
388 * cutoff, hardware dependent
390 udelay(sport->trcv_delay);
393 * half duplex - reactivate receive mode,
394 * flush receive pipe echo crap
396 if (readl(sport->port.membase + USR2) & USR2_TXDC) {
397 temp = readl(sport->port.membase + UCR1);
398 temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
399 writel(temp, sport->port.membase + UCR1);
401 temp = readl(sport->port.membase + UCR4);
402 temp &= ~(UCR4_TCEN);
403 writel(temp, sport->port.membase + UCR4);
405 while (readl(sport->port.membase + URXD0) &
409 temp = readl(sport->port.membase + UCR1);
411 writel(temp, sport->port.membase + UCR1);
413 temp = readl(sport->port.membase + UCR4);
415 writel(temp, sport->port.membase + UCR4);
421 * We are maybe in the SMP context, so if the DMA TX thread is running
422 * on other cpu, we have to wait for it to finish.
424 if (sport->dma_is_enabled && sport->dma_is_txing)
427 temp = readl(sport->port.membase + UCR1);
428 writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
432 * interrupts disabled on entry
434 static void imx_stop_rx(struct uart_port *port)
436 struct imx_port *sport = (struct imx_port *)port;
440 * We are maybe in the SMP context, so if the DMA TX thread is running
441 * on other cpu, we have to wait for it to finish.
443 if (sport->dma_is_enabled && sport->dma_is_rxing)
446 temp = readl(sport->port.membase + UCR2);
447 writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
449 /* disable the `Receiver Ready Interrrupt` */
450 temp = readl(sport->port.membase + UCR1);
451 writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
455 * Set the modem control timer to fire immediately.
457 static void imx_enable_ms(struct uart_port *port)
459 struct imx_port *sport = (struct imx_port *)port;
461 mod_timer(&sport->timer, jiffies);
464 static inline void imx_transmit_buffer(struct imx_port *sport)
466 struct circ_buf *xmit = &sport->port.state->xmit;
468 if (sport->port.x_char) {
470 writel(sport->port.x_char, sport->port.membase + URTX0);
474 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
475 imx_stop_tx(&sport->port);
479 while (!uart_circ_empty(xmit) &&
480 !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
481 /* send xmit->buf[xmit->tail]
482 * out the port here */
483 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
484 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
485 sport->port.icount.tx++;
488 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
489 uart_write_wakeup(&sport->port);
491 if (uart_circ_empty(xmit))
492 imx_stop_tx(&sport->port);
495 static void dma_tx_callback(void *data)
497 struct imx_port *sport = data;
498 struct scatterlist *sgl = &sport->tx_sgl[0];
499 struct circ_buf *xmit = &sport->port.state->xmit;
502 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
504 sport->dma_is_txing = 0;
506 /* update the stat */
507 spin_lock_irqsave(&sport->port.lock, flags);
508 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
509 sport->port.icount.tx += sport->tx_bytes;
510 spin_unlock_irqrestore(&sport->port.lock, flags);
512 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
514 uart_write_wakeup(&sport->port);
516 if (waitqueue_active(&sport->dma_wait)) {
517 wake_up(&sport->dma_wait);
518 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
523 static void imx_dma_tx(struct imx_port *sport)
525 struct circ_buf *xmit = &sport->port.state->xmit;
526 struct scatterlist *sgl = sport->tx_sgl;
527 struct dma_async_tx_descriptor *desc;
528 struct dma_chan *chan = sport->dma_chan_tx;
529 struct device *dev = sport->port.dev;
530 enum dma_status status;
533 status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
534 if (DMA_IN_PROGRESS == status)
537 sport->tx_bytes = uart_circ_chars_pending(xmit);
539 if (xmit->tail > xmit->head && xmit->head > 0) {
540 sport->dma_tx_nents = 2;
541 sg_init_table(sgl, 2);
542 sg_set_buf(sgl, xmit->buf + xmit->tail,
543 UART_XMIT_SIZE - xmit->tail);
544 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
546 sport->dma_tx_nents = 1;
547 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
550 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
552 dev_err(dev, "DMA mapping error for TX.\n");
555 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
556 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
558 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
561 desc->callback = dma_tx_callback;
562 desc->callback_param = sport;
564 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
565 uart_circ_chars_pending(xmit));
567 sport->dma_is_txing = 1;
568 dmaengine_submit(desc);
569 dma_async_issue_pending(chan);
574 * interrupts disabled on entry
576 static void imx_start_tx(struct uart_port *port)
578 struct imx_port *sport = (struct imx_port *)port;
581 if (USE_IRDA(sport)) {
582 /* half duplex in IrDA mode; have to disable receive mode */
583 temp = readl(sport->port.membase + UCR4);
584 temp &= ~(UCR4_DREN);
585 writel(temp, sport->port.membase + UCR4);
587 temp = readl(sport->port.membase + UCR1);
588 temp &= ~(UCR1_RRDYEN);
589 writel(temp, sport->port.membase + UCR1);
591 /* Clear any pending ORE flag before enabling interrupt */
592 temp = readl(sport->port.membase + USR2);
593 writel(temp | USR2_ORE, sport->port.membase + USR2);
595 temp = readl(sport->port.membase + UCR4);
597 writel(temp, sport->port.membase + UCR4);
599 if (!sport->dma_is_enabled) {
600 temp = readl(sport->port.membase + UCR1);
601 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
604 if (USE_IRDA(sport)) {
605 temp = readl(sport->port.membase + UCR1);
607 writel(temp, sport->port.membase + UCR1);
609 temp = readl(sport->port.membase + UCR4);
611 writel(temp, sport->port.membase + UCR4);
614 if (sport->dma_is_enabled) {
615 /* FIXME: port->x_char must be transmitted if != 0 */
616 if (!uart_circ_empty(&port->state->xmit) &&
617 !uart_tx_stopped(port))
622 if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
623 imx_transmit_buffer(sport);
626 static irqreturn_t imx_rtsint(int irq, void *dev_id)
628 struct imx_port *sport = dev_id;
632 spin_lock_irqsave(&sport->port.lock, flags);
634 writel(USR1_RTSD, sport->port.membase + USR1);
635 val = readl(sport->port.membase + USR1) & USR1_RTSS;
636 uart_handle_cts_change(&sport->port, !!val);
637 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
639 spin_unlock_irqrestore(&sport->port.lock, flags);
643 static irqreturn_t imx_txint(int irq, void *dev_id)
645 struct imx_port *sport = dev_id;
648 spin_lock_irqsave(&sport->port.lock, flags);
649 imx_transmit_buffer(sport);
650 spin_unlock_irqrestore(&sport->port.lock, flags);
654 static irqreturn_t imx_rxint(int irq, void *dev_id)
656 struct imx_port *sport = dev_id;
657 unsigned int rx, flg, ignored = 0;
658 struct tty_port *port = &sport->port.state->port;
659 unsigned long flags, temp;
661 spin_lock_irqsave(&sport->port.lock, flags);
663 while (readl(sport->port.membase + USR2) & USR2_RDR) {
665 sport->port.icount.rx++;
667 rx = readl(sport->port.membase + URXD0);
669 temp = readl(sport->port.membase + USR2);
670 if (temp & USR2_BRCD) {
671 writel(USR2_BRCD, sport->port.membase + USR2);
672 if (uart_handle_break(&sport->port))
676 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
679 if (unlikely(rx & URXD_ERR)) {
681 sport->port.icount.brk++;
682 else if (rx & URXD_PRERR)
683 sport->port.icount.parity++;
684 else if (rx & URXD_FRMERR)
685 sport->port.icount.frame++;
686 if (rx & URXD_OVRRUN)
687 sport->port.icount.overrun++;
689 if (rx & sport->port.ignore_status_mask) {
695 rx &= sport->port.read_status_mask;
699 else if (rx & URXD_PRERR)
701 else if (rx & URXD_FRMERR)
703 if (rx & URXD_OVRRUN)
707 sport->port.sysrq = 0;
711 tty_insert_flip_char(port, rx, flg);
715 spin_unlock_irqrestore(&sport->port.lock, flags);
716 tty_flip_buffer_push(port);
720 static int start_rx_dma(struct imx_port *sport);
722 * If the RXFIFO is filled with some data, and then we
723 * arise a DMA operation to receive them.
725 static void imx_dma_rxint(struct imx_port *sport)
729 temp = readl(sport->port.membase + USR2);
730 if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
731 sport->dma_is_rxing = 1;
733 /* disable the `Recerver Ready Interrrupt` */
734 temp = readl(sport->port.membase + UCR1);
735 temp &= ~(UCR1_RRDYEN);
736 writel(temp, sport->port.membase + UCR1);
738 /* tell the DMA to receive the data. */
743 static irqreturn_t imx_int(int irq, void *dev_id)
745 struct imx_port *sport = dev_id;
749 sts = readl(sport->port.membase + USR1);
751 if (sts & USR1_RRDY) {
752 if (sport->dma_is_enabled)
753 imx_dma_rxint(sport);
755 imx_rxint(irq, dev_id);
758 if (sts & USR1_TRDY &&
759 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
760 imx_txint(irq, dev_id);
763 imx_rtsint(irq, dev_id);
765 if (sts & USR1_AWAKE)
766 writel(USR1_AWAKE, sport->port.membase + USR1);
768 sts2 = readl(sport->port.membase + USR2);
769 if (sts2 & USR2_ORE) {
770 dev_err(sport->port.dev, "Rx FIFO overrun\n");
771 sport->port.icount.overrun++;
772 writel(sts2 | USR2_ORE, sport->port.membase + USR2);
779 * Return TIOCSER_TEMT when transmitter is not busy.
781 static unsigned int imx_tx_empty(struct uart_port *port)
783 struct imx_port *sport = (struct imx_port *)port;
786 ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
788 /* If the TX DMA is working, return 0. */
789 if (sport->dma_is_enabled && sport->dma_is_txing)
796 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
798 static unsigned int imx_get_mctrl(struct uart_port *port)
800 struct imx_port *sport = (struct imx_port *)port;
801 unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
803 if (readl(sport->port.membase + USR1) & USR1_RTSS)
806 if (readl(sport->port.membase + UCR2) & UCR2_CTS)
809 if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
815 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
817 struct imx_port *sport = (struct imx_port *)port;
820 temp = readl(sport->port.membase + UCR2) & ~(UCR2_CTS | UCR2_CTSC);
821 if (mctrl & TIOCM_RTS)
822 temp |= UCR2_CTS | UCR2_CTSC;
824 writel(temp, sport->port.membase + UCR2);
826 temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
827 if (mctrl & TIOCM_LOOP)
829 writel(temp, sport->port.membase + uts_reg(sport));
833 * Interrupts always disabled.
835 static void imx_break_ctl(struct uart_port *port, int break_state)
837 struct imx_port *sport = (struct imx_port *)port;
838 unsigned long flags, temp;
840 spin_lock_irqsave(&sport->port.lock, flags);
842 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
844 if (break_state != 0)
847 writel(temp, sport->port.membase + UCR1);
849 spin_unlock_irqrestore(&sport->port.lock, flags);
852 #define TXTL 2 /* reset default */
853 #define RXTL 1 /* reset default */
855 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
859 /* set receiver / transmitter trigger level */
860 val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
861 val |= TXTL << UFCR_TXTL_SHF | RXTL;
862 writel(val, sport->port.membase + UFCR);
866 #define RX_BUF_SIZE (PAGE_SIZE)
867 static void imx_rx_dma_done(struct imx_port *sport)
871 /* Enable this interrupt when the RXFIFO is empty. */
872 temp = readl(sport->port.membase + UCR1);
874 writel(temp, sport->port.membase + UCR1);
876 sport->dma_is_rxing = 0;
878 /* Is the shutdown waiting for us? */
879 if (waitqueue_active(&sport->dma_wait))
880 wake_up(&sport->dma_wait);
884 * There are three kinds of RX DMA interrupts(such as in the MX6Q):
885 * [1] the RX DMA buffer is full.
886 * [2] the Aging timer expires(wait for 8 bytes long)
887 * [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
889 * The [2] is trigger when a character was been sitting in the FIFO
890 * meanwhile [3] can wait for 32 bytes long when the RX line is
891 * on IDLE state and RxFIFO is empty.
893 static void dma_rx_callback(void *data)
895 struct imx_port *sport = data;
896 struct dma_chan *chan = sport->dma_chan_rx;
897 struct scatterlist *sgl = &sport->rx_sgl;
898 struct tty_port *port = &sport->port.state->port;
899 struct dma_tx_state state;
900 enum dma_status status;
904 dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
906 status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
907 count = RX_BUF_SIZE - state.residue;
908 dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
911 tty_insert_flip_string(port, sport->rx_buf, count);
912 tty_flip_buffer_push(port);
916 imx_rx_dma_done(sport);
919 static int start_rx_dma(struct imx_port *sport)
921 struct scatterlist *sgl = &sport->rx_sgl;
922 struct dma_chan *chan = sport->dma_chan_rx;
923 struct device *dev = sport->port.dev;
924 struct dma_async_tx_descriptor *desc;
927 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
928 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
930 dev_err(dev, "DMA mapping error for RX.\n");
933 desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
936 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
939 desc->callback = dma_rx_callback;
940 desc->callback_param = sport;
942 dev_dbg(dev, "RX: prepare for the DMA.\n");
943 dmaengine_submit(desc);
944 dma_async_issue_pending(chan);
948 static void imx_uart_dma_exit(struct imx_port *sport)
950 if (sport->dma_chan_rx) {
951 dma_release_channel(sport->dma_chan_rx);
952 sport->dma_chan_rx = NULL;
954 kfree(sport->rx_buf);
955 sport->rx_buf = NULL;
958 if (sport->dma_chan_tx) {
959 dma_release_channel(sport->dma_chan_tx);
960 sport->dma_chan_tx = NULL;
963 sport->dma_is_inited = 0;
966 static int imx_uart_dma_init(struct imx_port *sport)
968 struct dma_slave_config slave_config = {};
969 struct device *dev = sport->port.dev;
972 /* Prepare for RX : */
973 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
974 if (!sport->dma_chan_rx) {
975 dev_dbg(dev, "cannot get the DMA channel.\n");
980 slave_config.direction = DMA_DEV_TO_MEM;
981 slave_config.src_addr = sport->port.mapbase + URXD0;
982 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
983 slave_config.src_maxburst = RXTL;
984 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
986 dev_err(dev, "error in RX dma configuration.\n");
990 sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
991 if (!sport->rx_buf) {
992 dev_err(dev, "cannot alloc DMA buffer.\n");
997 /* Prepare for TX : */
998 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
999 if (!sport->dma_chan_tx) {
1000 dev_err(dev, "cannot get the TX DMA channel!\n");
1005 slave_config.direction = DMA_MEM_TO_DEV;
1006 slave_config.dst_addr = sport->port.mapbase + URTX0;
1007 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1008 slave_config.dst_maxburst = TXTL;
1009 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1011 dev_err(dev, "error in TX dma configuration.");
1015 sport->dma_is_inited = 1;
1019 imx_uart_dma_exit(sport);
1023 static void imx_enable_dma(struct imx_port *sport)
1027 init_waitqueue_head(&sport->dma_wait);
1030 temp = readl(sport->port.membase + UCR1);
1031 temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1032 /* wait for 32 idle frames for IDDMA interrupt */
1034 writel(temp, sport->port.membase + UCR1);
1037 temp = readl(sport->port.membase + UCR4);
1038 temp |= UCR4_IDDMAEN;
1039 writel(temp, sport->port.membase + UCR4);
1041 sport->dma_is_enabled = 1;
1044 static void imx_disable_dma(struct imx_port *sport)
1049 temp = readl(sport->port.membase + UCR1);
1050 temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1051 writel(temp, sport->port.membase + UCR1);
1054 temp = readl(sport->port.membase + UCR2);
1055 temp &= ~(UCR2_CTSC | UCR2_CTS);
1056 writel(temp, sport->port.membase + UCR2);
1059 temp = readl(sport->port.membase + UCR4);
1060 temp &= ~UCR4_IDDMAEN;
1061 writel(temp, sport->port.membase + UCR4);
1063 sport->dma_is_enabled = 0;
1066 /* half the RX buffer size */
1069 static int imx_startup(struct uart_port *port)
1071 struct imx_port *sport = (struct imx_port *)port;
1073 unsigned long flags, temp;
1075 retval = clk_prepare_enable(sport->clk_per);
1078 retval = clk_prepare_enable(sport->clk_ipg);
1080 clk_disable_unprepare(sport->clk_per);
1084 imx_setup_ufcr(sport, 0);
1086 /* disable the DREN bit (Data Ready interrupt enable) before
1089 temp = readl(sport->port.membase + UCR4);
1091 if (USE_IRDA(sport))
1094 /* set the trigger level for CTS */
1095 temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1096 temp |= CTSTL << UCR4_CTSTL_SHF;
1098 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1100 /* Reset fifo's and state machines */
1103 temp = readl(sport->port.membase + UCR2);
1105 writel(temp, sport->port.membase + UCR2);
1107 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1111 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1112 * chips only have one interrupt.
1114 if (sport->txirq > 0) {
1115 retval = request_irq(sport->rxirq, imx_rxint, 0,
1116 dev_name(port->dev), sport);
1120 retval = request_irq(sport->txirq, imx_txint, 0,
1121 dev_name(port->dev), sport);
1125 /* do not use RTS IRQ on IrDA */
1126 if (!USE_IRDA(sport)) {
1127 retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1128 dev_name(port->dev), sport);
1133 retval = request_irq(sport->port.irq, imx_int, 0,
1134 dev_name(port->dev), sport);
1136 free_irq(sport->port.irq, sport);
1141 spin_lock_irqsave(&sport->port.lock, flags);
1143 * Finally, clear and enable interrupts
1145 writel(USR1_RTSD, sport->port.membase + USR1);
1147 temp = readl(sport->port.membase + UCR1);
1148 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1150 if (USE_IRDA(sport)) {
1152 temp &= ~(UCR1_RTSDEN);
1155 writel(temp, sport->port.membase + UCR1);
1157 temp = readl(sport->port.membase + UCR2);
1158 temp |= (UCR2_RXEN | UCR2_TXEN);
1159 if (!sport->have_rtscts)
1161 writel(temp, sport->port.membase + UCR2);
1163 if (!is_imx1_uart(sport)) {
1164 temp = readl(sport->port.membase + UCR3);
1165 temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
1166 writel(temp, sport->port.membase + UCR3);
1169 if (USE_IRDA(sport)) {
1170 temp = readl(sport->port.membase + UCR4);
1171 if (sport->irda_inv_rx)
1174 temp &= ~(UCR4_INVR);
1175 writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1177 temp = readl(sport->port.membase + UCR3);
1178 if (sport->irda_inv_tx)
1181 temp &= ~(UCR3_INVT);
1182 writel(temp, sport->port.membase + UCR3);
1186 * Enable modem status interrupts
1188 imx_enable_ms(&sport->port);
1189 spin_unlock_irqrestore(&sport->port.lock, flags);
1191 if (USE_IRDA(sport)) {
1192 struct imxuart_platform_data *pdata;
1193 pdata = dev_get_platdata(sport->port.dev);
1194 sport->irda_inv_rx = pdata->irda_inv_rx;
1195 sport->irda_inv_tx = pdata->irda_inv_tx;
1196 sport->trcv_delay = pdata->transceiver_delay;
1197 if (pdata->irda_enable)
1198 pdata->irda_enable(1);
1205 free_irq(sport->txirq, sport);
1208 free_irq(sport->rxirq, sport);
1213 static void imx_shutdown(struct uart_port *port)
1215 struct imx_port *sport = (struct imx_port *)port;
1217 unsigned long flags;
1219 if (sport->dma_is_enabled) {
1220 /* We have to wait for the DMA to finish. */
1221 wait_event(sport->dma_wait,
1222 !sport->dma_is_rxing && !sport->dma_is_txing);
1224 imx_disable_dma(sport);
1225 imx_uart_dma_exit(sport);
1228 spin_lock_irqsave(&sport->port.lock, flags);
1229 temp = readl(sport->port.membase + UCR2);
1230 temp &= ~(UCR2_TXEN);
1231 writel(temp, sport->port.membase + UCR2);
1232 spin_unlock_irqrestore(&sport->port.lock, flags);
1234 if (USE_IRDA(sport)) {
1235 struct imxuart_platform_data *pdata;
1236 pdata = dev_get_platdata(sport->port.dev);
1237 if (pdata->irda_enable)
1238 pdata->irda_enable(0);
1244 del_timer_sync(&sport->timer);
1247 * Free the interrupts
1249 if (sport->txirq > 0) {
1250 if (!USE_IRDA(sport))
1251 free_irq(sport->rtsirq, sport);
1252 free_irq(sport->txirq, sport);
1253 free_irq(sport->rxirq, sport);
1255 free_irq(sport->port.irq, sport);
1258 * Disable all interrupts, port and break condition.
1261 spin_lock_irqsave(&sport->port.lock, flags);
1262 temp = readl(sport->port.membase + UCR1);
1263 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1264 if (USE_IRDA(sport))
1265 temp &= ~(UCR1_IREN);
1267 writel(temp, sport->port.membase + UCR1);
1268 spin_unlock_irqrestore(&sport->port.lock, flags);
1270 clk_disable_unprepare(sport->clk_per);
1271 clk_disable_unprepare(sport->clk_ipg);
1274 static void imx_flush_buffer(struct uart_port *port)
1276 struct imx_port *sport = (struct imx_port *)port;
1278 if (sport->dma_is_enabled) {
1279 sport->tx_bytes = 0;
1280 dmaengine_terminate_all(sport->dma_chan_tx);
1285 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1286 struct ktermios *old)
1288 struct imx_port *sport = (struct imx_port *)port;
1289 unsigned long flags;
1290 unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1291 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1292 unsigned int div, ufcr;
1293 unsigned long num, denom;
1297 * If we don't support modem control lines, don't allow
1301 termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1302 termios->c_cflag |= CLOCAL;
1306 * We only support CS7 and CS8.
1308 while ((termios->c_cflag & CSIZE) != CS7 &&
1309 (termios->c_cflag & CSIZE) != CS8) {
1310 termios->c_cflag &= ~CSIZE;
1311 termios->c_cflag |= old_csize;
1315 if ((termios->c_cflag & CSIZE) == CS8)
1316 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1318 ucr2 = UCR2_SRST | UCR2_IRTS;
1320 if (termios->c_cflag & CRTSCTS) {
1321 if (sport->have_rtscts) {
1325 /* Can we enable the DMA support? */
1326 if (is_imx6q_uart(sport) && !uart_console(port)
1327 && !sport->dma_is_inited)
1328 imx_uart_dma_init(sport);
1330 termios->c_cflag &= ~CRTSCTS;
1334 if (termios->c_cflag & CSTOPB)
1336 if (termios->c_cflag & PARENB) {
1338 if (termios->c_cflag & PARODD)
1342 del_timer_sync(&sport->timer);
1345 * Ask the core to calculate the divisor for us.
1347 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1348 quot = uart_get_divisor(port, baud);
1350 spin_lock_irqsave(&sport->port.lock, flags);
1352 sport->port.read_status_mask = 0;
1353 if (termios->c_iflag & INPCK)
1354 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1355 if (termios->c_iflag & (BRKINT | PARMRK))
1356 sport->port.read_status_mask |= URXD_BRK;
1359 * Characters to ignore
1361 sport->port.ignore_status_mask = 0;
1362 if (termios->c_iflag & IGNPAR)
1363 sport->port.ignore_status_mask |= URXD_PRERR;
1364 if (termios->c_iflag & IGNBRK) {
1365 sport->port.ignore_status_mask |= URXD_BRK;
1367 * If we're ignoring parity and break indicators,
1368 * ignore overruns too (for real raw support).
1370 if (termios->c_iflag & IGNPAR)
1371 sport->port.ignore_status_mask |= URXD_OVRRUN;
1375 * Update the per-port timeout.
1377 uart_update_timeout(port, termios->c_cflag, baud);
1380 * disable interrupts and drain transmitter
1382 old_ucr1 = readl(sport->port.membase + UCR1);
1383 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1384 sport->port.membase + UCR1);
1386 while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1389 /* then, disable everything */
1390 old_txrxen = readl(sport->port.membase + UCR2);
1391 writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1392 sport->port.membase + UCR2);
1393 old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1395 if (USE_IRDA(sport)) {
1397 * use maximum available submodule frequency to
1398 * avoid missing short pulses due to low sampling rate
1402 /* custom-baudrate handling */
1403 div = sport->port.uartclk / (baud * 16);
1404 if (baud == 38400 && quot != div)
1405 baud = sport->port.uartclk / (quot * 16);
1407 div = sport->port.uartclk / (baud * 16);
1414 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1415 1 << 16, 1 << 16, &num, &denom);
1417 tdiv64 = sport->port.uartclk;
1419 do_div(tdiv64, denom * 16 * div);
1420 tty_termios_encode_baud_rate(termios,
1421 (speed_t)tdiv64, (speed_t)tdiv64);
1426 ufcr = readl(sport->port.membase + UFCR);
1427 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1428 if (sport->dte_mode)
1429 ufcr |= UFCR_DCEDTE;
1430 writel(ufcr, sport->port.membase + UFCR);
1432 writel(num, sport->port.membase + UBIR);
1433 writel(denom, sport->port.membase + UBMR);
1435 if (!is_imx1_uart(sport))
1436 writel(sport->port.uartclk / div / 1000,
1437 sport->port.membase + IMX21_ONEMS);
1439 writel(old_ucr1, sport->port.membase + UCR1);
1441 /* set the parity, stop bits and data size */
1442 writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1444 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1445 imx_enable_ms(&sport->port);
1447 if (sport->dma_is_inited && !sport->dma_is_enabled)
1448 imx_enable_dma(sport);
1449 spin_unlock_irqrestore(&sport->port.lock, flags);
1452 static const char *imx_type(struct uart_port *port)
1454 struct imx_port *sport = (struct imx_port *)port;
1456 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1460 * Configure/autoconfigure the port.
1462 static void imx_config_port(struct uart_port *port, int flags)
1464 struct imx_port *sport = (struct imx_port *)port;
1466 if (flags & UART_CONFIG_TYPE)
1467 sport->port.type = PORT_IMX;
1471 * Verify the new serial_struct (for TIOCSSERIAL).
1472 * The only change we allow are to the flags and type, and
1473 * even then only between PORT_IMX and PORT_UNKNOWN
1476 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1478 struct imx_port *sport = (struct imx_port *)port;
1481 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1483 if (sport->port.irq != ser->irq)
1485 if (ser->io_type != UPIO_MEM)
1487 if (sport->port.uartclk / 16 != ser->baud_base)
1489 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1491 if (sport->port.iobase != ser->port)
1498 #if defined(CONFIG_CONSOLE_POLL)
1499 static int imx_poll_get_char(struct uart_port *port)
1501 if (!(readl(port->membase + USR2) & USR2_RDR))
1502 return NO_POLL_CHAR;
1504 return readl(port->membase + URXD0) & URXD_RX_DATA;
1507 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1509 struct imx_port_ucrs old_ucr;
1510 unsigned int status;
1512 /* save control registers */
1513 imx_port_ucrs_save(port, &old_ucr);
1515 /* disable interrupts */
1516 writel(UCR1_UARTEN, port->membase + UCR1);
1517 writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1518 port->membase + UCR2);
1519 writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1520 port->membase + UCR3);
1524 status = readl(port->membase + USR1);
1525 } while (~status & USR1_TRDY);
1528 writel(c, port->membase + URTX0);
1532 status = readl(port->membase + USR2);
1533 } while (~status & USR2_TXDC);
1535 /* restore control registers */
1536 imx_port_ucrs_restore(port, &old_ucr);
1540 static struct uart_ops imx_pops = {
1541 .tx_empty = imx_tx_empty,
1542 .set_mctrl = imx_set_mctrl,
1543 .get_mctrl = imx_get_mctrl,
1544 .stop_tx = imx_stop_tx,
1545 .start_tx = imx_start_tx,
1546 .stop_rx = imx_stop_rx,
1547 .enable_ms = imx_enable_ms,
1548 .break_ctl = imx_break_ctl,
1549 .startup = imx_startup,
1550 .shutdown = imx_shutdown,
1551 .flush_buffer = imx_flush_buffer,
1552 .set_termios = imx_set_termios,
1554 .config_port = imx_config_port,
1555 .verify_port = imx_verify_port,
1556 #if defined(CONFIG_CONSOLE_POLL)
1557 .poll_get_char = imx_poll_get_char,
1558 .poll_put_char = imx_poll_put_char,
1562 static struct imx_port *imx_ports[UART_NR];
1564 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1565 static void imx_console_putchar(struct uart_port *port, int ch)
1567 struct imx_port *sport = (struct imx_port *)port;
1569 while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1572 writel(ch, sport->port.membase + URTX0);
1576 * Interrupts are disabled on entering
1579 imx_console_write(struct console *co, const char *s, unsigned int count)
1581 struct imx_port *sport = imx_ports[co->index];
1582 struct imx_port_ucrs old_ucr;
1584 unsigned long flags = 0;
1588 retval = clk_enable(sport->clk_per);
1591 retval = clk_enable(sport->clk_ipg);
1593 clk_disable(sport->clk_per);
1597 if (sport->port.sysrq)
1599 else if (oops_in_progress)
1600 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1602 spin_lock_irqsave(&sport->port.lock, flags);
1605 * First, save UCR1/2/3 and then disable interrupts
1607 imx_port_ucrs_save(&sport->port, &old_ucr);
1608 ucr1 = old_ucr.ucr1;
1610 if (is_imx1_uart(sport))
1611 ucr1 |= IMX1_UCR1_UARTCLKEN;
1612 ucr1 |= UCR1_UARTEN;
1613 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1615 writel(ucr1, sport->port.membase + UCR1);
1617 writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1619 uart_console_write(&sport->port, s, count, imx_console_putchar);
1622 * Finally, wait for transmitter to become empty
1623 * and restore UCR1/2/3
1625 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1627 imx_port_ucrs_restore(&sport->port, &old_ucr);
1630 spin_unlock_irqrestore(&sport->port.lock, flags);
1632 clk_disable(sport->clk_ipg);
1633 clk_disable(sport->clk_per);
1637 * If the port was already initialised (eg, by a boot loader),
1638 * try to determine the current setup.
1641 imx_console_get_options(struct imx_port *sport, int *baud,
1642 int *parity, int *bits)
1645 if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1646 /* ok, the port was enabled */
1647 unsigned int ucr2, ubir, ubmr, uartclk;
1648 unsigned int baud_raw;
1649 unsigned int ucfr_rfdiv;
1651 ucr2 = readl(sport->port.membase + UCR2);
1654 if (ucr2 & UCR2_PREN) {
1655 if (ucr2 & UCR2_PROE)
1666 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1667 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1669 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1670 if (ucfr_rfdiv == 6)
1673 ucfr_rfdiv = 6 - ucfr_rfdiv;
1675 uartclk = clk_get_rate(sport->clk_per);
1676 uartclk /= ucfr_rfdiv;
1679 * The next code provides exact computation of
1680 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1681 * without need of float support or long long division,
1682 * which would be required to prevent 32bit arithmetic overflow
1684 unsigned int mul = ubir + 1;
1685 unsigned int div = 16 * (ubmr + 1);
1686 unsigned int rem = uartclk % div;
1688 baud_raw = (uartclk / div) * mul;
1689 baud_raw += (rem * mul + div / 2) / div;
1690 *baud = (baud_raw + 50) / 100 * 100;
1693 if (*baud != baud_raw)
1694 pr_info("Console IMX rounded baud rate from %d to %d\n",
1700 imx_console_setup(struct console *co, char *options)
1702 struct imx_port *sport;
1710 * Check whether an invalid uart number has been specified, and
1711 * if so, search for the first available port that does have
1714 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1716 sport = imx_ports[co->index];
1720 /* For setting the registers, we only need to enable the ipg clock. */
1721 retval = clk_prepare_enable(sport->clk_ipg);
1726 uart_parse_options(options, &baud, &parity, &bits, &flow);
1728 imx_console_get_options(sport, &baud, &parity, &bits);
1730 imx_setup_ufcr(sport, 0);
1732 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1734 clk_disable(sport->clk_ipg);
1736 clk_unprepare(sport->clk_ipg);
1740 retval = clk_prepare(sport->clk_per);
1742 clk_disable_unprepare(sport->clk_ipg);
1748 static struct uart_driver imx_reg;
1749 static struct console imx_console = {
1751 .write = imx_console_write,
1752 .device = uart_console_device,
1753 .setup = imx_console_setup,
1754 .flags = CON_PRINTBUFFER,
1759 #define IMX_CONSOLE &imx_console
1761 #define IMX_CONSOLE NULL
1764 static struct uart_driver imx_reg = {
1765 .owner = THIS_MODULE,
1766 .driver_name = DRIVER_NAME,
1767 .dev_name = DEV_NAME,
1768 .major = SERIAL_IMX_MAJOR,
1769 .minor = MINOR_START,
1770 .nr = ARRAY_SIZE(imx_ports),
1771 .cons = IMX_CONSOLE,
1774 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1776 struct imx_port *sport = platform_get_drvdata(dev);
1779 /* enable wakeup from i.MX UART */
1780 val = readl(sport->port.membase + UCR3);
1782 writel(val, sport->port.membase + UCR3);
1784 uart_suspend_port(&imx_reg, &sport->port);
1789 static int serial_imx_resume(struct platform_device *dev)
1791 struct imx_port *sport = platform_get_drvdata(dev);
1794 /* disable wakeup from i.MX UART */
1795 val = readl(sport->port.membase + UCR3);
1796 val &= ~UCR3_AWAKEN;
1797 writel(val, sport->port.membase + UCR3);
1799 uart_resume_port(&imx_reg, &sport->port);
1806 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1807 * could successfully get all information from dt or a negative errno.
1809 static int serial_imx_probe_dt(struct imx_port *sport,
1810 struct platform_device *pdev)
1812 struct device_node *np = pdev->dev.of_node;
1813 const struct of_device_id *of_id =
1814 of_match_device(imx_uart_dt_ids, &pdev->dev);
1818 /* no device tree device */
1821 ret = of_alias_get_id(np, "serial");
1823 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1826 sport->port.line = ret;
1828 if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1829 sport->have_rtscts = 1;
1831 if (of_get_property(np, "fsl,irda-mode", NULL))
1832 sport->use_irda = 1;
1834 if (of_get_property(np, "fsl,dte-mode", NULL))
1835 sport->dte_mode = 1;
1837 sport->devdata = of_id->data;
1842 static inline int serial_imx_probe_dt(struct imx_port *sport,
1843 struct platform_device *pdev)
1849 static void serial_imx_probe_pdata(struct imx_port *sport,
1850 struct platform_device *pdev)
1852 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1854 sport->port.line = pdev->id;
1855 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
1860 if (pdata->flags & IMXUART_HAVE_RTSCTS)
1861 sport->have_rtscts = 1;
1863 if (pdata->flags & IMXUART_IRDA)
1864 sport->use_irda = 1;
1867 static int serial_imx_probe(struct platform_device *pdev)
1869 struct imx_port *sport;
1872 struct resource *res;
1874 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1878 ret = serial_imx_probe_dt(sport, pdev);
1880 serial_imx_probe_pdata(sport, pdev);
1884 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1885 base = devm_ioremap_resource(&pdev->dev, res);
1887 return PTR_ERR(base);
1889 sport->port.dev = &pdev->dev;
1890 sport->port.mapbase = res->start;
1891 sport->port.membase = base;
1892 sport->port.type = PORT_IMX,
1893 sport->port.iotype = UPIO_MEM;
1894 sport->port.irq = platform_get_irq(pdev, 0);
1895 sport->rxirq = platform_get_irq(pdev, 0);
1896 sport->txirq = platform_get_irq(pdev, 1);
1897 sport->rtsirq = platform_get_irq(pdev, 2);
1898 sport->port.fifosize = 32;
1899 sport->port.ops = &imx_pops;
1900 sport->port.flags = UPF_BOOT_AUTOCONF;
1901 init_timer(&sport->timer);
1902 sport->timer.function = imx_timeout;
1903 sport->timer.data = (unsigned long)sport;
1905 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1906 if (IS_ERR(sport->clk_ipg)) {
1907 ret = PTR_ERR(sport->clk_ipg);
1908 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1912 sport->clk_per = devm_clk_get(&pdev->dev, "per");
1913 if (IS_ERR(sport->clk_per)) {
1914 ret = PTR_ERR(sport->clk_per);
1915 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1919 sport->port.uartclk = clk_get_rate(sport->clk_per);
1921 imx_ports[sport->port.line] = sport;
1923 platform_set_drvdata(pdev, sport);
1925 return uart_add_one_port(&imx_reg, &sport->port);
1928 static int serial_imx_remove(struct platform_device *pdev)
1930 struct imx_port *sport = platform_get_drvdata(pdev);
1932 return uart_remove_one_port(&imx_reg, &sport->port);
1935 static struct platform_driver serial_imx_driver = {
1936 .probe = serial_imx_probe,
1937 .remove = serial_imx_remove,
1939 .suspend = serial_imx_suspend,
1940 .resume = serial_imx_resume,
1941 .id_table = imx_uart_devtype,
1944 .owner = THIS_MODULE,
1945 .of_match_table = imx_uart_dt_ids,
1949 static int __init imx_serial_init(void)
1953 pr_info("Serial: IMX driver\n");
1955 ret = uart_register_driver(&imx_reg);
1959 ret = platform_driver_register(&serial_imx_driver);
1961 uart_unregister_driver(&imx_reg);
1966 static void __exit imx_serial_exit(void)
1968 platform_driver_unregister(&serial_imx_driver);
1969 uart_unregister_driver(&imx_reg);
1972 module_init(imx_serial_init);
1973 module_exit(imx_serial_exit);
1975 MODULE_AUTHOR("Sascha Hauer");
1976 MODULE_DESCRIPTION("IMX generic serial port driver");
1977 MODULE_LICENSE("GPL");
1978 MODULE_ALIAS("platform:imx-uart");