2 * Driver for Motorola/Freescale 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 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
20 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
24 #include <linux/module.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/sysrq.h>
29 #include <linux/platform_device.h>
30 #include <linux/tty.h>
31 #include <linux/tty_flip.h>
32 #include <linux/serial_core.h>
33 #include <linux/serial.h>
34 #include <linux/clk.h>
35 #include <linux/delay.h>
36 #include <linux/rational.h>
37 #include <linux/slab.h>
39 #include <linux/of_device.h>
41 #include <linux/dma-mapping.h>
44 #include <linux/platform_data/serial-imx.h>
45 #include <linux/platform_data/dma-imx.h>
47 /* Register definitions */
48 #define URXD0 0x0 /* Receiver Register */
49 #define URTX0 0x40 /* Transmitter Register */
50 #define UCR1 0x80 /* Control Register 1 */
51 #define UCR2 0x84 /* Control Register 2 */
52 #define UCR3 0x88 /* Control Register 3 */
53 #define UCR4 0x8c /* Control Register 4 */
54 #define UFCR 0x90 /* FIFO Control Register */
55 #define USR1 0x94 /* Status Register 1 */
56 #define USR2 0x98 /* Status Register 2 */
57 #define UESC 0x9c /* Escape Character Register */
58 #define UTIM 0xa0 /* Escape Timer Register */
59 #define UBIR 0xa4 /* BRM Incremental Register */
60 #define UBMR 0xa8 /* BRM Modulator Register */
61 #define UBRC 0xac /* Baud Rate Count Register */
62 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
63 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
64 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
66 /* UART Control Register Bit Fields.*/
67 #define URXD_DUMMY_READ (1<<16)
68 #define URXD_CHARRDY (1<<15)
69 #define URXD_ERR (1<<14)
70 #define URXD_OVRRUN (1<<13)
71 #define URXD_FRMERR (1<<12)
72 #define URXD_BRK (1<<11)
73 #define URXD_PRERR (1<<10)
74 #define URXD_RX_DATA (0xFF<<0)
75 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
76 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
77 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
78 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
79 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
80 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
81 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
82 #define UCR1_IREN (1<<7) /* Infrared interface enable */
83 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
84 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
85 #define UCR1_SNDBRK (1<<4) /* Send break */
86 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
87 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
88 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
89 #define UCR1_DOZE (1<<1) /* Doze */
90 #define UCR1_UARTEN (1<<0) /* UART enabled */
91 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
92 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
93 #define UCR2_CTSC (1<<13) /* CTS pin control */
94 #define UCR2_CTS (1<<12) /* Clear to send */
95 #define UCR2_ESCEN (1<<11) /* Escape enable */
96 #define UCR2_PREN (1<<8) /* Parity enable */
97 #define UCR2_PROE (1<<7) /* Parity odd/even */
98 #define UCR2_STPB (1<<6) /* Stop */
99 #define UCR2_WS (1<<5) /* Word size */
100 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
101 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
102 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
103 #define UCR2_RXEN (1<<1) /* Receiver enabled */
104 #define UCR2_SRST (1<<0) /* SW reset */
105 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
106 #define UCR3_PARERREN (1<<12) /* Parity enable */
107 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
108 #define UCR3_DSR (1<<10) /* Data set ready */
109 #define UCR3_DCD (1<<9) /* Data carrier detect */
110 #define UCR3_RI (1<<8) /* Ring indicator */
111 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
112 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
113 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
114 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
115 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
116 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
117 #define UCR3_BPEN (1<<0) /* Preset registers enable */
118 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
119 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
120 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
121 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
122 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
123 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
124 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
125 #define UCR4_IRSC (1<<5) /* IR special case */
126 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
127 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
128 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
129 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
130 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
131 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
132 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
133 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
134 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
135 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
136 #define USR1_RTSS (1<<14) /* RTS pin status */
137 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
138 #define USR1_RTSD (1<<12) /* RTS delta */
139 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
140 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
141 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
142 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
143 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
144 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
145 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
146 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
147 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
148 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
149 #define USR2_IDLE (1<<12) /* Idle condition */
150 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
151 #define USR2_WAKE (1<<7) /* Wake */
152 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
153 #define USR2_TXDC (1<<3) /* Transmitter complete */
154 #define USR2_BRCD (1<<2) /* Break condition */
155 #define USR2_ORE (1<<1) /* Overrun error */
156 #define USR2_RDR (1<<0) /* Recv data ready */
157 #define UTS_FRCPERR (1<<13) /* Force parity error */
158 #define UTS_LOOP (1<<12) /* Loop tx and rx */
159 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
160 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
161 #define UTS_TXFULL (1<<4) /* TxFIFO full */
162 #define UTS_RXFULL (1<<3) /* RxFIFO full */
163 #define UTS_SOFTRST (1<<0) /* Software reset */
165 /* We've been assigned a range on the "Low-density serial ports" major */
166 #define SERIAL_IMX_MAJOR 207
167 #define MINOR_START 16
168 #define DEV_NAME "ttymxc"
171 * This determines how often we check the modem status signals
172 * for any change. They generally aren't connected to an IRQ
173 * so we have to poll them. We also check immediately before
174 * filling the TX fifo incase CTS has been dropped.
176 #define MCTRL_TIMEOUT (250*HZ/1000)
178 #define DRIVER_NAME "IMX-uart"
182 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
189 /* device type dependent stuff */
190 struct imx_uart_data
{
192 enum imx_uart_type devtype
;
196 struct uart_port port
;
197 struct timer_list timer
;
198 unsigned int old_status
;
199 unsigned int have_rtscts
:1;
200 unsigned int dte_mode
:1;
201 unsigned int irda_inv_rx
:1;
202 unsigned int irda_inv_tx
:1;
203 unsigned short trcv_delay
; /* transceiver delay */
206 const struct imx_uart_data
*devdata
;
209 unsigned int dma_is_inited
:1;
210 unsigned int dma_is_enabled
:1;
211 unsigned int dma_is_rxing
:1;
212 unsigned int dma_is_txing
:1;
213 struct dma_chan
*dma_chan_rx
, *dma_chan_tx
;
214 struct scatterlist rx_sgl
, tx_sgl
[2];
216 unsigned int tx_bytes
;
217 unsigned int dma_tx_nents
;
218 wait_queue_head_t dma_wait
;
221 struct imx_port_ucrs
{
227 static struct imx_uart_data imx_uart_devdata
[] = {
230 .devtype
= IMX1_UART
,
233 .uts_reg
= IMX21_UTS
,
234 .devtype
= IMX21_UART
,
237 .uts_reg
= IMX21_UTS
,
238 .devtype
= IMX6Q_UART
,
242 static const struct platform_device_id imx_uart_devtype
[] = {
245 .driver_data
= (kernel_ulong_t
) &imx_uart_devdata
[IMX1_UART
],
247 .name
= "imx21-uart",
248 .driver_data
= (kernel_ulong_t
) &imx_uart_devdata
[IMX21_UART
],
250 .name
= "imx6q-uart",
251 .driver_data
= (kernel_ulong_t
) &imx_uart_devdata
[IMX6Q_UART
],
256 MODULE_DEVICE_TABLE(platform
, imx_uart_devtype
);
258 static const struct of_device_id imx_uart_dt_ids
[] = {
259 { .compatible
= "fsl,imx6q-uart", .data
= &imx_uart_devdata
[IMX6Q_UART
], },
260 { .compatible
= "fsl,imx1-uart", .data
= &imx_uart_devdata
[IMX1_UART
], },
261 { .compatible
= "fsl,imx21-uart", .data
= &imx_uart_devdata
[IMX21_UART
], },
264 MODULE_DEVICE_TABLE(of
, imx_uart_dt_ids
);
266 static inline unsigned uts_reg(struct imx_port
*sport
)
268 return sport
->devdata
->uts_reg
;
271 static inline int is_imx1_uart(struct imx_port
*sport
)
273 return sport
->devdata
->devtype
== IMX1_UART
;
276 static inline int is_imx21_uart(struct imx_port
*sport
)
278 return sport
->devdata
->devtype
== IMX21_UART
;
281 static inline int is_imx6q_uart(struct imx_port
*sport
)
283 return sport
->devdata
->devtype
== IMX6Q_UART
;
286 * Save and restore functions for UCR1, UCR2 and UCR3 registers
288 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
289 static void imx_port_ucrs_save(struct uart_port
*port
,
290 struct imx_port_ucrs
*ucr
)
292 /* save control registers */
293 ucr
->ucr1
= readl(port
->membase
+ UCR1
);
294 ucr
->ucr2
= readl(port
->membase
+ UCR2
);
295 ucr
->ucr3
= readl(port
->membase
+ UCR3
);
298 static void imx_port_ucrs_restore(struct uart_port
*port
,
299 struct imx_port_ucrs
*ucr
)
301 /* restore control registers */
302 writel(ucr
->ucr1
, port
->membase
+ UCR1
);
303 writel(ucr
->ucr2
, port
->membase
+ UCR2
);
304 writel(ucr
->ucr3
, port
->membase
+ UCR3
);
309 * Handle any change of modem status signal since we were last called.
311 static void imx_mctrl_check(struct imx_port
*sport
)
313 unsigned int status
, changed
;
315 status
= sport
->port
.ops
->get_mctrl(&sport
->port
);
316 changed
= status
^ sport
->old_status
;
321 sport
->old_status
= status
;
323 if (changed
& TIOCM_RI
)
324 sport
->port
.icount
.rng
++;
325 if (changed
& TIOCM_DSR
)
326 sport
->port
.icount
.dsr
++;
327 if (changed
& TIOCM_CAR
)
328 uart_handle_dcd_change(&sport
->port
, status
& TIOCM_CAR
);
329 if (changed
& TIOCM_CTS
)
330 uart_handle_cts_change(&sport
->port
, status
& TIOCM_CTS
);
332 wake_up_interruptible(&sport
->port
.state
->port
.delta_msr_wait
);
336 * This is our per-port timeout handler, for checking the
337 * modem status signals.
339 static void imx_timeout(unsigned long data
)
341 struct imx_port
*sport
= (struct imx_port
*)data
;
344 if (sport
->port
.state
) {
345 spin_lock_irqsave(&sport
->port
.lock
, flags
);
346 imx_mctrl_check(sport
);
347 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
349 mod_timer(&sport
->timer
, jiffies
+ MCTRL_TIMEOUT
);
354 * interrupts disabled on entry
356 static void imx_stop_tx(struct uart_port
*port
)
358 struct imx_port
*sport
= (struct imx_port
*)port
;
362 * We are maybe in the SMP context, so if the DMA TX thread is running
363 * on other cpu, we have to wait for it to finish.
365 if (sport
->dma_is_enabled
&& sport
->dma_is_txing
)
368 temp
= readl(port
->membase
+ UCR1
);
369 writel(temp
& ~UCR1_TXMPTYEN
, port
->membase
+ UCR1
);
371 /* in rs485 mode disable transmitter if shifter is empty */
372 if (port
->rs485
.flags
& SER_RS485_ENABLED
&&
373 readl(port
->membase
+ USR2
) & USR2_TXDC
) {
374 temp
= readl(port
->membase
+ UCR2
);
375 if (port
->rs485
.flags
& SER_RS485_RTS_AFTER_SEND
)
379 writel(temp
, port
->membase
+ UCR2
);
381 temp
= readl(port
->membase
+ UCR4
);
383 writel(temp
, port
->membase
+ UCR4
);
388 * interrupts disabled on entry
390 static void imx_stop_rx(struct uart_port
*port
)
392 struct imx_port
*sport
= (struct imx_port
*)port
;
395 if (sport
->dma_is_enabled
&& sport
->dma_is_rxing
) {
396 if (sport
->port
.suspended
) {
397 dmaengine_terminate_all(sport
->dma_chan_rx
);
398 sport
->dma_is_rxing
= 0;
404 temp
= readl(sport
->port
.membase
+ UCR2
);
405 writel(temp
& ~UCR2_RXEN
, sport
->port
.membase
+ UCR2
);
407 /* disable the `Receiver Ready Interrrupt` */
408 temp
= readl(sport
->port
.membase
+ UCR1
);
409 writel(temp
& ~UCR1_RRDYEN
, sport
->port
.membase
+ UCR1
);
413 * Set the modem control timer to fire immediately.
415 static void imx_enable_ms(struct uart_port
*port
)
417 struct imx_port
*sport
= (struct imx_port
*)port
;
419 mod_timer(&sport
->timer
, jiffies
);
422 static void imx_dma_tx(struct imx_port
*sport
);
423 static inline void imx_transmit_buffer(struct imx_port
*sport
)
425 struct circ_buf
*xmit
= &sport
->port
.state
->xmit
;
428 if (sport
->port
.x_char
) {
430 writel(sport
->port
.x_char
, sport
->port
.membase
+ URTX0
);
431 sport
->port
.icount
.tx
++;
432 sport
->port
.x_char
= 0;
436 if (uart_circ_empty(xmit
) || uart_tx_stopped(&sport
->port
)) {
437 imx_stop_tx(&sport
->port
);
441 if (sport
->dma_is_enabled
) {
443 * We've just sent a X-char Ensure the TX DMA is enabled
444 * and the TX IRQ is disabled.
446 temp
= readl(sport
->port
.membase
+ UCR1
);
447 temp
&= ~UCR1_TXMPTYEN
;
448 if (sport
->dma_is_txing
) {
450 writel(temp
, sport
->port
.membase
+ UCR1
);
452 writel(temp
, sport
->port
.membase
+ UCR1
);
457 while (!uart_circ_empty(xmit
) &&
458 !(readl(sport
->port
.membase
+ uts_reg(sport
)) & UTS_TXFULL
)) {
459 /* send xmit->buf[xmit->tail]
460 * out the port here */
461 writel(xmit
->buf
[xmit
->tail
], sport
->port
.membase
+ URTX0
);
462 xmit
->tail
= (xmit
->tail
+ 1) & (UART_XMIT_SIZE
- 1);
463 sport
->port
.icount
.tx
++;
466 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
467 uart_write_wakeup(&sport
->port
);
469 if (uart_circ_empty(xmit
))
470 imx_stop_tx(&sport
->port
);
473 static void dma_tx_callback(void *data
)
475 struct imx_port
*sport
= data
;
476 struct scatterlist
*sgl
= &sport
->tx_sgl
[0];
477 struct circ_buf
*xmit
= &sport
->port
.state
->xmit
;
481 spin_lock_irqsave(&sport
->port
.lock
, flags
);
483 dma_unmap_sg(sport
->port
.dev
, sgl
, sport
->dma_tx_nents
, DMA_TO_DEVICE
);
485 temp
= readl(sport
->port
.membase
+ UCR1
);
486 temp
&= ~UCR1_TDMAEN
;
487 writel(temp
, sport
->port
.membase
+ UCR1
);
489 /* update the stat */
490 xmit
->tail
= (xmit
->tail
+ sport
->tx_bytes
) & (UART_XMIT_SIZE
- 1);
491 sport
->port
.icount
.tx
+= sport
->tx_bytes
;
493 dev_dbg(sport
->port
.dev
, "we finish the TX DMA.\n");
495 sport
->dma_is_txing
= 0;
497 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
499 if (uart_circ_chars_pending(xmit
) < WAKEUP_CHARS
)
500 uart_write_wakeup(&sport
->port
);
502 if (waitqueue_active(&sport
->dma_wait
)) {
503 wake_up(&sport
->dma_wait
);
504 dev_dbg(sport
->port
.dev
, "exit in %s.\n", __func__
);
508 spin_lock_irqsave(&sport
->port
.lock
, flags
);
509 if (!uart_circ_empty(xmit
) && !uart_tx_stopped(&sport
->port
))
511 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
514 static void imx_dma_tx(struct imx_port
*sport
)
516 struct circ_buf
*xmit
= &sport
->port
.state
->xmit
;
517 struct scatterlist
*sgl
= sport
->tx_sgl
;
518 struct dma_async_tx_descriptor
*desc
;
519 struct dma_chan
*chan
= sport
->dma_chan_tx
;
520 struct device
*dev
= sport
->port
.dev
;
524 if (sport
->dma_is_txing
)
527 sport
->tx_bytes
= uart_circ_chars_pending(xmit
);
529 if (xmit
->tail
< xmit
->head
) {
530 sport
->dma_tx_nents
= 1;
531 sg_init_one(sgl
, xmit
->buf
+ xmit
->tail
, sport
->tx_bytes
);
533 sport
->dma_tx_nents
= 2;
534 sg_init_table(sgl
, 2);
535 sg_set_buf(sgl
, xmit
->buf
+ xmit
->tail
,
536 UART_XMIT_SIZE
- xmit
->tail
);
537 sg_set_buf(sgl
+ 1, xmit
->buf
, xmit
->head
);
540 ret
= dma_map_sg(dev
, sgl
, sport
->dma_tx_nents
, DMA_TO_DEVICE
);
542 dev_err(dev
, "DMA mapping error for TX.\n");
545 desc
= dmaengine_prep_slave_sg(chan
, sgl
, sport
->dma_tx_nents
,
546 DMA_MEM_TO_DEV
, DMA_PREP_INTERRUPT
);
548 dma_unmap_sg(dev
, sgl
, sport
->dma_tx_nents
,
550 dev_err(dev
, "We cannot prepare for the TX slave dma!\n");
553 desc
->callback
= dma_tx_callback
;
554 desc
->callback_param
= sport
;
556 dev_dbg(dev
, "TX: prepare to send %lu bytes by DMA.\n",
557 uart_circ_chars_pending(xmit
));
559 temp
= readl(sport
->port
.membase
+ UCR1
);
561 writel(temp
, sport
->port
.membase
+ UCR1
);
564 sport
->dma_is_txing
= 1;
565 dmaengine_submit(desc
);
566 dma_async_issue_pending(chan
);
571 * interrupts disabled on entry
573 static void imx_start_tx(struct uart_port
*port
)
575 struct imx_port
*sport
= (struct imx_port
*)port
;
578 if (port
->rs485
.flags
& SER_RS485_ENABLED
) {
579 /* enable transmitter and shifter empty irq */
580 temp
= readl(port
->membase
+ UCR2
);
581 if (port
->rs485
.flags
& SER_RS485_RTS_ON_SEND
)
585 writel(temp
, port
->membase
+ UCR2
);
587 temp
= readl(port
->membase
+ UCR4
);
589 writel(temp
, port
->membase
+ UCR4
);
592 if (!sport
->dma_is_enabled
) {
593 temp
= readl(sport
->port
.membase
+ UCR1
);
594 writel(temp
| UCR1_TXMPTYEN
, sport
->port
.membase
+ UCR1
);
597 if (sport
->dma_is_enabled
) {
598 if (sport
->port
.x_char
) {
599 /* We have X-char to send, so enable TX IRQ and
600 * disable TX DMA to let TX interrupt to send X-char */
601 temp
= readl(sport
->port
.membase
+ UCR1
);
602 temp
&= ~UCR1_TDMAEN
;
603 temp
|= UCR1_TXMPTYEN
;
604 writel(temp
, sport
->port
.membase
+ UCR1
);
608 if (!uart_circ_empty(&port
->state
->xmit
) &&
609 !uart_tx_stopped(port
))
615 static irqreturn_t
imx_rtsint(int irq
, void *dev_id
)
617 struct imx_port
*sport
= dev_id
;
621 spin_lock_irqsave(&sport
->port
.lock
, flags
);
623 writel(USR1_RTSD
, sport
->port
.membase
+ USR1
);
624 val
= readl(sport
->port
.membase
+ USR1
) & USR1_RTSS
;
625 uart_handle_cts_change(&sport
->port
, !!val
);
626 wake_up_interruptible(&sport
->port
.state
->port
.delta_msr_wait
);
628 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
632 static irqreturn_t
imx_txint(int irq
, void *dev_id
)
634 struct imx_port
*sport
= dev_id
;
637 spin_lock_irqsave(&sport
->port
.lock
, flags
);
638 imx_transmit_buffer(sport
);
639 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
643 static irqreturn_t
imx_rxint(int irq
, void *dev_id
)
645 struct imx_port
*sport
= dev_id
;
646 unsigned int rx
, flg
, ignored
= 0;
647 struct tty_port
*port
= &sport
->port
.state
->port
;
648 unsigned long flags
, temp
;
650 spin_lock_irqsave(&sport
->port
.lock
, flags
);
652 while (readl(sport
->port
.membase
+ USR2
) & USR2_RDR
) {
654 sport
->port
.icount
.rx
++;
656 rx
= readl(sport
->port
.membase
+ URXD0
);
658 temp
= readl(sport
->port
.membase
+ USR2
);
659 if (temp
& USR2_BRCD
) {
660 writel(USR2_BRCD
, sport
->port
.membase
+ USR2
);
661 if (uart_handle_break(&sport
->port
))
665 if (uart_handle_sysrq_char(&sport
->port
, (unsigned char)rx
))
668 if (unlikely(rx
& URXD_ERR
)) {
670 sport
->port
.icount
.brk
++;
671 else if (rx
& URXD_PRERR
)
672 sport
->port
.icount
.parity
++;
673 else if (rx
& URXD_FRMERR
)
674 sport
->port
.icount
.frame
++;
675 if (rx
& URXD_OVRRUN
)
676 sport
->port
.icount
.overrun
++;
678 if (rx
& sport
->port
.ignore_status_mask
) {
684 rx
&= (sport
->port
.read_status_mask
| 0xFF);
688 else if (rx
& URXD_PRERR
)
690 else if (rx
& URXD_FRMERR
)
692 if (rx
& URXD_OVRRUN
)
696 sport
->port
.sysrq
= 0;
700 if (sport
->port
.ignore_status_mask
& URXD_DUMMY_READ
)
703 tty_insert_flip_char(port
, rx
, flg
);
707 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
708 tty_flip_buffer_push(port
);
712 static int start_rx_dma(struct imx_port
*sport
);
714 * If the RXFIFO is filled with some data, and then we
715 * arise a DMA operation to receive them.
717 static void imx_dma_rxint(struct imx_port
*sport
)
722 spin_lock_irqsave(&sport
->port
.lock
, flags
);
724 temp
= readl(sport
->port
.membase
+ USR2
);
725 if ((temp
& USR2_RDR
) && !sport
->dma_is_rxing
) {
726 sport
->dma_is_rxing
= 1;
728 /* disable the `Recerver Ready Interrrupt` */
729 temp
= readl(sport
->port
.membase
+ UCR1
);
730 temp
&= ~(UCR1_RRDYEN
);
731 writel(temp
, sport
->port
.membase
+ UCR1
);
733 /* tell the DMA to receive the data. */
737 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
740 static irqreturn_t
imx_int(int irq
, void *dev_id
)
742 struct imx_port
*sport
= dev_id
;
746 sts
= readl(sport
->port
.membase
+ USR1
);
747 sts2
= readl(sport
->port
.membase
+ USR2
);
749 if (sts
& USR1_RRDY
) {
750 if (sport
->dma_is_enabled
)
751 imx_dma_rxint(sport
);
753 imx_rxint(irq
, dev_id
);
756 if ((sts
& USR1_TRDY
&&
757 readl(sport
->port
.membase
+ UCR1
) & UCR1_TXMPTYEN
) ||
759 readl(sport
->port
.membase
+ UCR4
) & UCR4_TCEN
))
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 if (sts2
& USR2_ORE
) {
769 dev_err(sport
->port
.dev
, "Rx FIFO overrun\n");
770 sport
->port
.icount
.overrun
++;
771 writel(USR2_ORE
, sport
->port
.membase
+ USR2
);
778 * Return TIOCSER_TEMT when transmitter is not busy.
780 static unsigned int imx_tx_empty(struct uart_port
*port
)
782 struct imx_port
*sport
= (struct imx_port
*)port
;
785 ret
= (readl(sport
->port
.membase
+ USR2
) & USR2_TXDC
) ? TIOCSER_TEMT
: 0;
787 /* If the TX DMA is working, return 0. */
788 if (sport
->dma_is_enabled
&& sport
->dma_is_txing
)
795 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
797 static unsigned int imx_get_mctrl(struct uart_port
*port
)
799 struct imx_port
*sport
= (struct imx_port
*)port
;
800 unsigned int tmp
= TIOCM_DSR
| TIOCM_CAR
;
802 if (readl(sport
->port
.membase
+ USR1
) & USR1_RTSS
)
805 if (readl(sport
->port
.membase
+ UCR2
) & UCR2_CTS
)
808 if (readl(sport
->port
.membase
+ uts_reg(sport
)) & UTS_LOOP
)
814 static void imx_set_mctrl(struct uart_port
*port
, unsigned int mctrl
)
816 struct imx_port
*sport
= (struct imx_port
*)port
;
819 if (!(port
->rs485
.flags
& SER_RS485_ENABLED
)) {
820 temp
= readl(sport
->port
.membase
+ UCR2
);
821 temp
&= ~(UCR2_CTS
| UCR2_CTSC
);
822 if (mctrl
& TIOCM_RTS
)
823 temp
|= UCR2_CTS
| UCR2_CTSC
;
824 writel(temp
, sport
->port
.membase
+ UCR2
);
827 temp
= readl(sport
->port
.membase
+ uts_reg(sport
)) & ~UTS_LOOP
;
828 if (mctrl
& TIOCM_LOOP
)
830 writel(temp
, sport
->port
.membase
+ uts_reg(sport
));
834 * Interrupts always disabled.
836 static void imx_break_ctl(struct uart_port
*port
, int break_state
)
838 struct imx_port
*sport
= (struct imx_port
*)port
;
839 unsigned long flags
, temp
;
841 spin_lock_irqsave(&sport
->port
.lock
, flags
);
843 temp
= readl(sport
->port
.membase
+ UCR1
) & ~UCR1_SNDBRK
;
845 if (break_state
!= 0)
848 writel(temp
, sport
->port
.membase
+ UCR1
);
850 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
853 #define TXTL 2 /* reset default */
854 #define RXTL 1 /* reset default */
856 static void imx_setup_ufcr(struct imx_port
*sport
, unsigned int mode
)
860 /* set receiver / transmitter trigger level */
861 val
= readl(sport
->port
.membase
+ UFCR
) & (UFCR_RFDIV
| UFCR_DCEDTE
);
862 val
|= TXTL
<< UFCR_TXTL_SHF
| RXTL
;
863 writel(val
, sport
->port
.membase
+ UFCR
);
866 #define RX_BUF_SIZE (PAGE_SIZE)
867 static void imx_rx_dma_done(struct imx_port
*sport
)
872 spin_lock_irqsave(&sport
->port
.lock
, flags
);
874 /* Enable this interrupt when the RXFIFO is empty. */
875 temp
= readl(sport
->port
.membase
+ UCR1
);
877 writel(temp
, sport
->port
.membase
+ UCR1
);
879 sport
->dma_is_rxing
= 0;
881 /* Is the shutdown waiting for us? */
882 if (waitqueue_active(&sport
->dma_wait
))
883 wake_up(&sport
->dma_wait
);
885 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
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 if (!(sport
->port
.ignore_status_mask
& URXD_DUMMY_READ
))
917 tty_insert_flip_string(port
, sport
->rx_buf
, count
);
918 tty_flip_buffer_push(port
);
921 } else if (readl(sport
->port
.membase
+ USR2
) & USR2_RDR
) {
923 * start rx_dma directly once data in RXFIFO, more efficient
925 * 1. call imx_rx_dma_done to stop dma if no data received
926 * 2. wait next RDR interrupt to start dma transfer.
931 * stop dma to prevent too many IDLE event trigged if no data
934 imx_rx_dma_done(sport
);
938 static int start_rx_dma(struct imx_port
*sport
)
940 struct scatterlist
*sgl
= &sport
->rx_sgl
;
941 struct dma_chan
*chan
= sport
->dma_chan_rx
;
942 struct device
*dev
= sport
->port
.dev
;
943 struct dma_async_tx_descriptor
*desc
;
946 sg_init_one(sgl
, sport
->rx_buf
, RX_BUF_SIZE
);
947 ret
= dma_map_sg(dev
, sgl
, 1, DMA_FROM_DEVICE
);
949 dev_err(dev
, "DMA mapping error for RX.\n");
952 desc
= dmaengine_prep_slave_sg(chan
, sgl
, 1, DMA_DEV_TO_MEM
,
955 dma_unmap_sg(dev
, sgl
, 1, DMA_FROM_DEVICE
);
956 dev_err(dev
, "We cannot prepare for the RX slave dma!\n");
959 desc
->callback
= dma_rx_callback
;
960 desc
->callback_param
= sport
;
962 dev_dbg(dev
, "RX: prepare for the DMA.\n");
963 dmaengine_submit(desc
);
964 dma_async_issue_pending(chan
);
968 static void imx_uart_dma_exit(struct imx_port
*sport
)
970 if (sport
->dma_chan_rx
) {
971 dma_release_channel(sport
->dma_chan_rx
);
972 sport
->dma_chan_rx
= NULL
;
974 kfree(sport
->rx_buf
);
975 sport
->rx_buf
= NULL
;
978 if (sport
->dma_chan_tx
) {
979 dma_release_channel(sport
->dma_chan_tx
);
980 sport
->dma_chan_tx
= NULL
;
983 sport
->dma_is_inited
= 0;
986 static int imx_uart_dma_init(struct imx_port
*sport
)
988 struct dma_slave_config slave_config
= {};
989 struct device
*dev
= sport
->port
.dev
;
992 /* Prepare for RX : */
993 sport
->dma_chan_rx
= dma_request_slave_channel(dev
, "rx");
994 if (!sport
->dma_chan_rx
) {
995 dev_dbg(dev
, "cannot get the DMA channel.\n");
1000 slave_config
.direction
= DMA_DEV_TO_MEM
;
1001 slave_config
.src_addr
= sport
->port
.mapbase
+ URXD0
;
1002 slave_config
.src_addr_width
= DMA_SLAVE_BUSWIDTH_1_BYTE
;
1003 slave_config
.src_maxburst
= RXTL
;
1004 ret
= dmaengine_slave_config(sport
->dma_chan_rx
, &slave_config
);
1006 dev_err(dev
, "error in RX dma configuration.\n");
1010 sport
->rx_buf
= kzalloc(PAGE_SIZE
, GFP_KERNEL
);
1011 if (!sport
->rx_buf
) {
1016 /* Prepare for TX : */
1017 sport
->dma_chan_tx
= dma_request_slave_channel(dev
, "tx");
1018 if (!sport
->dma_chan_tx
) {
1019 dev_err(dev
, "cannot get the TX DMA channel!\n");
1024 slave_config
.direction
= DMA_MEM_TO_DEV
;
1025 slave_config
.dst_addr
= sport
->port
.mapbase
+ URTX0
;
1026 slave_config
.dst_addr_width
= DMA_SLAVE_BUSWIDTH_1_BYTE
;
1027 slave_config
.dst_maxburst
= TXTL
;
1028 ret
= dmaengine_slave_config(sport
->dma_chan_tx
, &slave_config
);
1030 dev_err(dev
, "error in TX dma configuration.");
1034 sport
->dma_is_inited
= 1;
1038 imx_uart_dma_exit(sport
);
1042 static void imx_enable_dma(struct imx_port
*sport
)
1046 init_waitqueue_head(&sport
->dma_wait
);
1049 temp
= readl(sport
->port
.membase
+ UCR1
);
1050 temp
|= UCR1_RDMAEN
| UCR1_TDMAEN
| UCR1_ATDMAEN
|
1051 /* wait for 32 idle frames for IDDMA interrupt */
1053 writel(temp
, sport
->port
.membase
+ UCR1
);
1056 temp
= readl(sport
->port
.membase
+ UCR4
);
1057 temp
|= UCR4_IDDMAEN
;
1058 writel(temp
, sport
->port
.membase
+ UCR4
);
1060 sport
->dma_is_enabled
= 1;
1063 static void imx_disable_dma(struct imx_port
*sport
)
1068 temp
= readl(sport
->port
.membase
+ UCR1
);
1069 temp
&= ~(UCR1_RDMAEN
| UCR1_TDMAEN
| UCR1_ATDMAEN
);
1070 writel(temp
, sport
->port
.membase
+ UCR1
);
1073 temp
= readl(sport
->port
.membase
+ UCR2
);
1074 temp
&= ~(UCR2_CTSC
| UCR2_CTS
);
1075 writel(temp
, sport
->port
.membase
+ UCR2
);
1078 temp
= readl(sport
->port
.membase
+ UCR4
);
1079 temp
&= ~UCR4_IDDMAEN
;
1080 writel(temp
, sport
->port
.membase
+ UCR4
);
1082 sport
->dma_is_enabled
= 0;
1085 /* half the RX buffer size */
1088 static int imx_startup(struct uart_port
*port
)
1090 struct imx_port
*sport
= (struct imx_port
*)port
;
1092 unsigned long flags
, temp
;
1094 retval
= clk_prepare_enable(sport
->clk_per
);
1097 retval
= clk_prepare_enable(sport
->clk_ipg
);
1099 clk_disable_unprepare(sport
->clk_per
);
1103 imx_setup_ufcr(sport
, 0);
1105 /* disable the DREN bit (Data Ready interrupt enable) before
1108 temp
= readl(sport
->port
.membase
+ UCR4
);
1110 /* set the trigger level for CTS */
1111 temp
&= ~(UCR4_CTSTL_MASK
<< UCR4_CTSTL_SHF
);
1112 temp
|= CTSTL
<< UCR4_CTSTL_SHF
;
1114 writel(temp
& ~UCR4_DREN
, sport
->port
.membase
+ UCR4
);
1116 /* Can we enable the DMA support? */
1117 if (is_imx6q_uart(sport
) && !uart_console(port
) &&
1118 !sport
->dma_is_inited
)
1119 imx_uart_dma_init(sport
);
1121 spin_lock_irqsave(&sport
->port
.lock
, flags
);
1122 /* Reset fifo's and state machines */
1125 temp
= readl(sport
->port
.membase
+ UCR2
);
1127 writel(temp
, sport
->port
.membase
+ UCR2
);
1129 while (!(readl(sport
->port
.membase
+ UCR2
) & UCR2_SRST
) && (--i
> 0))
1133 * Finally, clear and enable interrupts
1135 writel(USR1_RTSD
, sport
->port
.membase
+ USR1
);
1136 writel(USR2_ORE
, sport
->port
.membase
+ USR2
);
1138 if (sport
->dma_is_inited
&& !sport
->dma_is_enabled
)
1139 imx_enable_dma(sport
);
1141 temp
= readl(sport
->port
.membase
+ UCR1
);
1142 temp
|= UCR1_RRDYEN
| UCR1_RTSDEN
| UCR1_UARTEN
;
1144 writel(temp
, sport
->port
.membase
+ UCR1
);
1146 temp
= readl(sport
->port
.membase
+ UCR4
);
1148 writel(temp
, sport
->port
.membase
+ UCR4
);
1150 temp
= readl(sport
->port
.membase
+ UCR2
);
1151 temp
|= (UCR2_RXEN
| UCR2_TXEN
);
1152 if (!sport
->have_rtscts
)
1154 writel(temp
, sport
->port
.membase
+ UCR2
);
1156 if (!is_imx1_uart(sport
)) {
1157 temp
= readl(sport
->port
.membase
+ UCR3
);
1158 temp
|= IMX21_UCR3_RXDMUXSEL
| UCR3_ADNIMP
;
1159 writel(temp
, sport
->port
.membase
+ UCR3
);
1163 * Enable modem status interrupts
1165 imx_enable_ms(&sport
->port
);
1166 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
1171 static void imx_shutdown(struct uart_port
*port
)
1173 struct imx_port
*sport
= (struct imx_port
*)port
;
1175 unsigned long flags
;
1177 if (sport
->dma_is_enabled
) {
1180 /* We have to wait for the DMA to finish. */
1181 ret
= wait_event_interruptible(sport
->dma_wait
,
1182 !sport
->dma_is_rxing
&& !sport
->dma_is_txing
);
1184 sport
->dma_is_rxing
= 0;
1185 sport
->dma_is_txing
= 0;
1186 dmaengine_terminate_all(sport
->dma_chan_tx
);
1187 dmaengine_terminate_all(sport
->dma_chan_rx
);
1189 spin_lock_irqsave(&sport
->port
.lock
, flags
);
1192 imx_disable_dma(sport
);
1193 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
1194 imx_uart_dma_exit(sport
);
1197 spin_lock_irqsave(&sport
->port
.lock
, flags
);
1198 temp
= readl(sport
->port
.membase
+ UCR2
);
1199 temp
&= ~(UCR2_TXEN
);
1200 writel(temp
, sport
->port
.membase
+ UCR2
);
1201 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
1206 del_timer_sync(&sport
->timer
);
1209 * Disable all interrupts, port and break condition.
1212 spin_lock_irqsave(&sport
->port
.lock
, flags
);
1213 temp
= readl(sport
->port
.membase
+ UCR1
);
1214 temp
&= ~(UCR1_TXMPTYEN
| UCR1_RRDYEN
| UCR1_RTSDEN
| UCR1_UARTEN
);
1216 writel(temp
, sport
->port
.membase
+ UCR1
);
1217 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
1219 clk_disable_unprepare(sport
->clk_per
);
1220 clk_disable_unprepare(sport
->clk_ipg
);
1223 static void imx_flush_buffer(struct uart_port
*port
)
1225 struct imx_port
*sport
= (struct imx_port
*)port
;
1226 struct scatterlist
*sgl
= &sport
->tx_sgl
[0];
1228 int i
= 100, ubir
, ubmr
, uts
;
1230 if (!sport
->dma_chan_tx
)
1233 sport
->tx_bytes
= 0;
1234 dmaengine_terminate_all(sport
->dma_chan_tx
);
1235 if (sport
->dma_is_txing
) {
1236 dma_unmap_sg(sport
->port
.dev
, sgl
, sport
->dma_tx_nents
,
1238 temp
= readl(sport
->port
.membase
+ UCR1
);
1239 temp
&= ~UCR1_TDMAEN
;
1240 writel(temp
, sport
->port
.membase
+ UCR1
);
1241 sport
->dma_is_txing
= false;
1245 * According to the Reference Manual description of the UART SRST bit:
1246 * "Reset the transmit and receive state machines,
1247 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1248 * and UTS[6-3]". As we don't need to restore the old values from
1249 * USR1, USR2, URXD, UTXD, only save/restore the other four registers
1251 ubir
= readl(sport
->port
.membase
+ UBIR
);
1252 ubmr
= readl(sport
->port
.membase
+ UBMR
);
1253 uts
= readl(sport
->port
.membase
+ IMX21_UTS
);
1255 temp
= readl(sport
->port
.membase
+ UCR2
);
1257 writel(temp
, sport
->port
.membase
+ UCR2
);
1259 while (!(readl(sport
->port
.membase
+ UCR2
) & UCR2_SRST
) && (--i
> 0))
1262 /* Restore the registers */
1263 writel(ubir
, sport
->port
.membase
+ UBIR
);
1264 writel(ubmr
, sport
->port
.membase
+ UBMR
);
1265 writel(uts
, sport
->port
.membase
+ IMX21_UTS
);
1269 imx_set_termios(struct uart_port
*port
, struct ktermios
*termios
,
1270 struct ktermios
*old
)
1272 struct imx_port
*sport
= (struct imx_port
*)port
;
1273 unsigned long flags
;
1274 unsigned int ucr2
, old_ucr1
, old_txrxen
, baud
, quot
;
1275 unsigned int old_csize
= old
? old
->c_cflag
& CSIZE
: CS8
;
1276 unsigned int div
, ufcr
;
1277 unsigned long num
, denom
;
1281 * We only support CS7 and CS8.
1283 while ((termios
->c_cflag
& CSIZE
) != CS7
&&
1284 (termios
->c_cflag
& CSIZE
) != CS8
) {
1285 termios
->c_cflag
&= ~CSIZE
;
1286 termios
->c_cflag
|= old_csize
;
1290 if ((termios
->c_cflag
& CSIZE
) == CS8
)
1291 ucr2
= UCR2_WS
| UCR2_SRST
| UCR2_IRTS
;
1293 ucr2
= UCR2_SRST
| UCR2_IRTS
;
1295 if (termios
->c_cflag
& CRTSCTS
) {
1296 if (sport
->have_rtscts
) {
1299 if (port
->rs485
.flags
& SER_RS485_ENABLED
) {
1301 * RTS is mandatory for rs485 operation, so keep
1302 * it under manual control and keep transmitter
1305 if (!(port
->rs485
.flags
&
1306 SER_RS485_RTS_AFTER_SEND
))
1312 termios
->c_cflag
&= ~CRTSCTS
;
1314 } else if (port
->rs485
.flags
& SER_RS485_ENABLED
)
1315 /* disable transmitter */
1316 if (!(port
->rs485
.flags
& SER_RS485_RTS_AFTER_SEND
))
1319 if (termios
->c_cflag
& CSTOPB
)
1321 if (termios
->c_cflag
& PARENB
) {
1323 if (termios
->c_cflag
& PARODD
)
1327 del_timer_sync(&sport
->timer
);
1330 * Ask the core to calculate the divisor for us.
1332 baud
= uart_get_baud_rate(port
, termios
, old
, 50, port
->uartclk
/ 16);
1333 quot
= uart_get_divisor(port
, baud
);
1335 spin_lock_irqsave(&sport
->port
.lock
, flags
);
1337 sport
->port
.read_status_mask
= 0;
1338 if (termios
->c_iflag
& INPCK
)
1339 sport
->port
.read_status_mask
|= (URXD_FRMERR
| URXD_PRERR
);
1340 if (termios
->c_iflag
& (BRKINT
| PARMRK
))
1341 sport
->port
.read_status_mask
|= URXD_BRK
;
1344 * Characters to ignore
1346 sport
->port
.ignore_status_mask
= 0;
1347 if (termios
->c_iflag
& IGNPAR
)
1348 sport
->port
.ignore_status_mask
|= URXD_PRERR
| URXD_FRMERR
;
1349 if (termios
->c_iflag
& IGNBRK
) {
1350 sport
->port
.ignore_status_mask
|= URXD_BRK
;
1352 * If we're ignoring parity and break indicators,
1353 * ignore overruns too (for real raw support).
1355 if (termios
->c_iflag
& IGNPAR
)
1356 sport
->port
.ignore_status_mask
|= URXD_OVRRUN
;
1359 if ((termios
->c_cflag
& CREAD
) == 0)
1360 sport
->port
.ignore_status_mask
|= URXD_DUMMY_READ
;
1363 * Update the per-port timeout.
1365 uart_update_timeout(port
, termios
->c_cflag
, baud
);
1368 * disable interrupts and drain transmitter
1370 old_ucr1
= readl(sport
->port
.membase
+ UCR1
);
1371 writel(old_ucr1
& ~(UCR1_TXMPTYEN
| UCR1_RRDYEN
| UCR1_RTSDEN
),
1372 sport
->port
.membase
+ UCR1
);
1374 while (!(readl(sport
->port
.membase
+ USR2
) & USR2_TXDC
))
1377 /* then, disable everything */
1378 old_txrxen
= readl(sport
->port
.membase
+ UCR2
);
1379 writel(old_txrxen
& ~(UCR2_TXEN
| UCR2_RXEN
),
1380 sport
->port
.membase
+ UCR2
);
1381 old_txrxen
&= (UCR2_TXEN
| UCR2_RXEN
);
1383 /* custom-baudrate handling */
1384 div
= sport
->port
.uartclk
/ (baud
* 16);
1385 if (baud
== 38400 && quot
!= div
)
1386 baud
= sport
->port
.uartclk
/ (quot
* 16);
1388 div
= sport
->port
.uartclk
/ (baud
* 16);
1394 rational_best_approximation(16 * div
* baud
, sport
->port
.uartclk
,
1395 1 << 16, 1 << 16, &num
, &denom
);
1397 tdiv64
= sport
->port
.uartclk
;
1399 do_div(tdiv64
, denom
* 16 * div
);
1400 tty_termios_encode_baud_rate(termios
,
1401 (speed_t
)tdiv64
, (speed_t
)tdiv64
);
1406 ufcr
= readl(sport
->port
.membase
+ UFCR
);
1407 ufcr
= (ufcr
& (~UFCR_RFDIV
)) | UFCR_RFDIV_REG(div
);
1408 if (sport
->dte_mode
)
1409 ufcr
|= UFCR_DCEDTE
;
1410 writel(ufcr
, sport
->port
.membase
+ UFCR
);
1412 writel(num
, sport
->port
.membase
+ UBIR
);
1413 writel(denom
, sport
->port
.membase
+ UBMR
);
1415 if (!is_imx1_uart(sport
))
1416 writel(sport
->port
.uartclk
/ div
/ 1000,
1417 sport
->port
.membase
+ IMX21_ONEMS
);
1419 writel(old_ucr1
, sport
->port
.membase
+ UCR1
);
1421 /* set the parity, stop bits and data size */
1422 writel(ucr2
| old_txrxen
, sport
->port
.membase
+ UCR2
);
1424 if (UART_ENABLE_MS(&sport
->port
, termios
->c_cflag
))
1425 imx_enable_ms(&sport
->port
);
1427 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
1430 static const char *imx_type(struct uart_port
*port
)
1432 struct imx_port
*sport
= (struct imx_port
*)port
;
1434 return sport
->port
.type
== PORT_IMX
? "IMX" : NULL
;
1438 * Configure/autoconfigure the port.
1440 static void imx_config_port(struct uart_port
*port
, int flags
)
1442 struct imx_port
*sport
= (struct imx_port
*)port
;
1444 if (flags
& UART_CONFIG_TYPE
)
1445 sport
->port
.type
= PORT_IMX
;
1449 * Verify the new serial_struct (for TIOCSSERIAL).
1450 * The only change we allow are to the flags and type, and
1451 * even then only between PORT_IMX and PORT_UNKNOWN
1454 imx_verify_port(struct uart_port
*port
, struct serial_struct
*ser
)
1456 struct imx_port
*sport
= (struct imx_port
*)port
;
1459 if (ser
->type
!= PORT_UNKNOWN
&& ser
->type
!= PORT_IMX
)
1461 if (sport
->port
.irq
!= ser
->irq
)
1463 if (ser
->io_type
!= UPIO_MEM
)
1465 if (sport
->port
.uartclk
/ 16 != ser
->baud_base
)
1467 if (sport
->port
.mapbase
!= (unsigned long)ser
->iomem_base
)
1469 if (sport
->port
.iobase
!= ser
->port
)
1476 #if defined(CONFIG_CONSOLE_POLL)
1478 static int imx_poll_init(struct uart_port
*port
)
1480 struct imx_port
*sport
= (struct imx_port
*)port
;
1481 unsigned long flags
;
1485 retval
= clk_prepare_enable(sport
->clk_ipg
);
1488 retval
= clk_prepare_enable(sport
->clk_per
);
1490 clk_disable_unprepare(sport
->clk_ipg
);
1492 imx_setup_ufcr(sport
, 0);
1494 spin_lock_irqsave(&sport
->port
.lock
, flags
);
1496 temp
= readl(sport
->port
.membase
+ UCR1
);
1497 if (is_imx1_uart(sport
))
1498 temp
|= IMX1_UCR1_UARTCLKEN
;
1499 temp
|= UCR1_UARTEN
| UCR1_RRDYEN
;
1500 temp
&= ~(UCR1_TXMPTYEN
| UCR1_RTSDEN
);
1501 writel(temp
, sport
->port
.membase
+ UCR1
);
1503 temp
= readl(sport
->port
.membase
+ UCR2
);
1505 writel(temp
, sport
->port
.membase
+ UCR2
);
1507 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
1512 static int imx_poll_get_char(struct uart_port
*port
)
1514 if (!(readl_relaxed(port
->membase
+ USR2
) & USR2_RDR
))
1515 return NO_POLL_CHAR
;
1517 return readl_relaxed(port
->membase
+ URXD0
) & URXD_RX_DATA
;
1520 static void imx_poll_put_char(struct uart_port
*port
, unsigned char c
)
1522 unsigned int status
;
1526 status
= readl_relaxed(port
->membase
+ USR1
);
1527 } while (~status
& USR1_TRDY
);
1530 writel_relaxed(c
, port
->membase
+ URTX0
);
1534 status
= readl_relaxed(port
->membase
+ USR2
);
1535 } while (~status
& USR2_TXDC
);
1539 static int imx_rs485_config(struct uart_port
*port
,
1540 struct serial_rs485
*rs485conf
)
1542 struct imx_port
*sport
= (struct imx_port
*)port
;
1545 rs485conf
->delay_rts_before_send
= 0;
1546 rs485conf
->delay_rts_after_send
= 0;
1547 rs485conf
->flags
|= SER_RS485_RX_DURING_TX
;
1549 /* RTS is required to control the transmitter */
1550 if (!sport
->have_rtscts
)
1551 rs485conf
->flags
&= ~SER_RS485_ENABLED
;
1553 if (rs485conf
->flags
& SER_RS485_ENABLED
) {
1556 /* disable transmitter */
1557 temp
= readl(sport
->port
.membase
+ UCR2
);
1559 if (rs485conf
->flags
& SER_RS485_RTS_AFTER_SEND
)
1563 writel(temp
, sport
->port
.membase
+ UCR2
);
1566 port
->rs485
= *rs485conf
;
1571 static struct uart_ops imx_pops
= {
1572 .tx_empty
= imx_tx_empty
,
1573 .set_mctrl
= imx_set_mctrl
,
1574 .get_mctrl
= imx_get_mctrl
,
1575 .stop_tx
= imx_stop_tx
,
1576 .start_tx
= imx_start_tx
,
1577 .stop_rx
= imx_stop_rx
,
1578 .enable_ms
= imx_enable_ms
,
1579 .break_ctl
= imx_break_ctl
,
1580 .startup
= imx_startup
,
1581 .shutdown
= imx_shutdown
,
1582 .flush_buffer
= imx_flush_buffer
,
1583 .set_termios
= imx_set_termios
,
1585 .config_port
= imx_config_port
,
1586 .verify_port
= imx_verify_port
,
1587 #if defined(CONFIG_CONSOLE_POLL)
1588 .poll_init
= imx_poll_init
,
1589 .poll_get_char
= imx_poll_get_char
,
1590 .poll_put_char
= imx_poll_put_char
,
1594 static struct imx_port
*imx_ports
[UART_NR
];
1596 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1597 static void imx_console_putchar(struct uart_port
*port
, int ch
)
1599 struct imx_port
*sport
= (struct imx_port
*)port
;
1601 while (readl(sport
->port
.membase
+ uts_reg(sport
)) & UTS_TXFULL
)
1604 writel(ch
, sport
->port
.membase
+ URTX0
);
1608 * Interrupts are disabled on entering
1611 imx_console_write(struct console
*co
, const char *s
, unsigned int count
)
1613 struct imx_port
*sport
= imx_ports
[co
->index
];
1614 struct imx_port_ucrs old_ucr
;
1616 unsigned long flags
= 0;
1620 retval
= clk_enable(sport
->clk_per
);
1623 retval
= clk_enable(sport
->clk_ipg
);
1625 clk_disable(sport
->clk_per
);
1629 if (sport
->port
.sysrq
)
1631 else if (oops_in_progress
)
1632 locked
= spin_trylock_irqsave(&sport
->port
.lock
, flags
);
1634 spin_lock_irqsave(&sport
->port
.lock
, flags
);
1637 * First, save UCR1/2/3 and then disable interrupts
1639 imx_port_ucrs_save(&sport
->port
, &old_ucr
);
1640 ucr1
= old_ucr
.ucr1
;
1642 if (is_imx1_uart(sport
))
1643 ucr1
|= IMX1_UCR1_UARTCLKEN
;
1644 ucr1
|= UCR1_UARTEN
;
1645 ucr1
&= ~(UCR1_TXMPTYEN
| UCR1_RRDYEN
| UCR1_RTSDEN
);
1647 writel(ucr1
, sport
->port
.membase
+ UCR1
);
1649 writel(old_ucr
.ucr2
| UCR2_TXEN
, sport
->port
.membase
+ UCR2
);
1651 uart_console_write(&sport
->port
, s
, count
, imx_console_putchar
);
1654 * Finally, wait for transmitter to become empty
1655 * and restore UCR1/2/3
1657 while (!(readl(sport
->port
.membase
+ USR2
) & USR2_TXDC
));
1659 imx_port_ucrs_restore(&sport
->port
, &old_ucr
);
1662 spin_unlock_irqrestore(&sport
->port
.lock
, flags
);
1664 clk_disable(sport
->clk_ipg
);
1665 clk_disable(sport
->clk_per
);
1669 * If the port was already initialised (eg, by a boot loader),
1670 * try to determine the current setup.
1673 imx_console_get_options(struct imx_port
*sport
, int *baud
,
1674 int *parity
, int *bits
)
1677 if (readl(sport
->port
.membase
+ UCR1
) & UCR1_UARTEN
) {
1678 /* ok, the port was enabled */
1679 unsigned int ucr2
, ubir
, ubmr
, uartclk
;
1680 unsigned int baud_raw
;
1681 unsigned int ucfr_rfdiv
;
1683 ucr2
= readl(sport
->port
.membase
+ UCR2
);
1686 if (ucr2
& UCR2_PREN
) {
1687 if (ucr2
& UCR2_PROE
)
1698 ubir
= readl(sport
->port
.membase
+ UBIR
) & 0xffff;
1699 ubmr
= readl(sport
->port
.membase
+ UBMR
) & 0xffff;
1701 ucfr_rfdiv
= (readl(sport
->port
.membase
+ UFCR
) & UFCR_RFDIV
) >> 7;
1702 if (ucfr_rfdiv
== 6)
1705 ucfr_rfdiv
= 6 - ucfr_rfdiv
;
1707 uartclk
= clk_get_rate(sport
->clk_per
);
1708 uartclk
/= ucfr_rfdiv
;
1711 * The next code provides exact computation of
1712 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1713 * without need of float support or long long division,
1714 * which would be required to prevent 32bit arithmetic overflow
1716 unsigned int mul
= ubir
+ 1;
1717 unsigned int div
= 16 * (ubmr
+ 1);
1718 unsigned int rem
= uartclk
% div
;
1720 baud_raw
= (uartclk
/ div
) * mul
;
1721 baud_raw
+= (rem
* mul
+ div
/ 2) / div
;
1722 *baud
= (baud_raw
+ 50) / 100 * 100;
1725 if (*baud
!= baud_raw
)
1726 pr_info("Console IMX rounded baud rate from %d to %d\n",
1732 imx_console_setup(struct console
*co
, char *options
)
1734 struct imx_port
*sport
;
1742 * Check whether an invalid uart number has been specified, and
1743 * if so, search for the first available port that does have
1746 if (co
->index
== -1 || co
->index
>= ARRAY_SIZE(imx_ports
))
1748 sport
= imx_ports
[co
->index
];
1752 /* For setting the registers, we only need to enable the ipg clock. */
1753 retval
= clk_prepare_enable(sport
->clk_ipg
);
1758 uart_parse_options(options
, &baud
, &parity
, &bits
, &flow
);
1760 imx_console_get_options(sport
, &baud
, &parity
, &bits
);
1762 imx_setup_ufcr(sport
, 0);
1764 retval
= uart_set_options(&sport
->port
, co
, baud
, parity
, bits
, flow
);
1766 clk_disable(sport
->clk_ipg
);
1768 clk_unprepare(sport
->clk_ipg
);
1772 retval
= clk_prepare(sport
->clk_per
);
1774 clk_disable_unprepare(sport
->clk_ipg
);
1780 static struct uart_driver imx_reg
;
1781 static struct console imx_console
= {
1783 .write
= imx_console_write
,
1784 .device
= uart_console_device
,
1785 .setup
= imx_console_setup
,
1786 .flags
= CON_PRINTBUFFER
,
1791 #define IMX_CONSOLE &imx_console
1793 #define IMX_CONSOLE NULL
1796 static struct uart_driver imx_reg
= {
1797 .owner
= THIS_MODULE
,
1798 .driver_name
= DRIVER_NAME
,
1799 .dev_name
= DEV_NAME
,
1800 .major
= SERIAL_IMX_MAJOR
,
1801 .minor
= MINOR_START
,
1802 .nr
= ARRAY_SIZE(imx_ports
),
1803 .cons
= IMX_CONSOLE
,
1806 static int serial_imx_suspend(struct platform_device
*dev
, pm_message_t state
)
1808 struct imx_port
*sport
= platform_get_drvdata(dev
);
1811 /* enable wakeup from i.MX UART */
1812 val
= readl(sport
->port
.membase
+ UCR3
);
1814 writel(val
, sport
->port
.membase
+ UCR3
);
1816 uart_suspend_port(&imx_reg
, &sport
->port
);
1821 static int serial_imx_resume(struct platform_device
*dev
)
1823 struct imx_port
*sport
= platform_get_drvdata(dev
);
1826 /* disable wakeup from i.MX UART */
1827 val
= readl(sport
->port
.membase
+ UCR3
);
1828 val
&= ~UCR3_AWAKEN
;
1829 writel(val
, sport
->port
.membase
+ UCR3
);
1831 uart_resume_port(&imx_reg
, &sport
->port
);
1838 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1839 * could successfully get all information from dt or a negative errno.
1841 static int serial_imx_probe_dt(struct imx_port
*sport
,
1842 struct platform_device
*pdev
)
1844 struct device_node
*np
= pdev
->dev
.of_node
;
1845 const struct of_device_id
*of_id
=
1846 of_match_device(imx_uart_dt_ids
, &pdev
->dev
);
1850 /* no device tree device */
1853 ret
= of_alias_get_id(np
, "serial");
1855 dev_err(&pdev
->dev
, "failed to get alias id, errno %d\n", ret
);
1858 sport
->port
.line
= ret
;
1860 if (of_get_property(np
, "fsl,uart-has-rtscts", NULL
))
1861 sport
->have_rtscts
= 1;
1863 if (of_get_property(np
, "fsl,dte-mode", NULL
))
1864 sport
->dte_mode
= 1;
1866 sport
->devdata
= of_id
->data
;
1871 static inline int serial_imx_probe_dt(struct imx_port
*sport
,
1872 struct platform_device
*pdev
)
1878 static void serial_imx_probe_pdata(struct imx_port
*sport
,
1879 struct platform_device
*pdev
)
1881 struct imxuart_platform_data
*pdata
= dev_get_platdata(&pdev
->dev
);
1883 sport
->port
.line
= pdev
->id
;
1884 sport
->devdata
= (struct imx_uart_data
*) pdev
->id_entry
->driver_data
;
1889 if (pdata
->flags
& IMXUART_HAVE_RTSCTS
)
1890 sport
->have_rtscts
= 1;
1893 static int serial_imx_probe(struct platform_device
*pdev
)
1895 struct imx_port
*sport
;
1898 struct resource
*res
;
1899 int txirq
, rxirq
, rtsirq
;
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 rxirq
= platform_get_irq(pdev
, 0);
1917 txirq
= platform_get_irq(pdev
, 1);
1918 rtsirq
= platform_get_irq(pdev
, 2);
1920 sport
->port
.dev
= &pdev
->dev
;
1921 sport
->port
.mapbase
= res
->start
;
1922 sport
->port
.membase
= base
;
1923 sport
->port
.type
= PORT_IMX
,
1924 sport
->port
.iotype
= UPIO_MEM
;
1925 sport
->port
.irq
= rxirq
;
1926 sport
->port
.fifosize
= 32;
1927 sport
->port
.ops
= &imx_pops
;
1928 sport
->port
.rs485_config
= imx_rs485_config
;
1929 sport
->port
.rs485
.flags
=
1930 SER_RS485_RTS_ON_SEND
| SER_RS485_RX_DURING_TX
;
1931 sport
->port
.flags
= UPF_BOOT_AUTOCONF
;
1932 init_timer(&sport
->timer
);
1933 sport
->timer
.function
= imx_timeout
;
1934 sport
->timer
.data
= (unsigned long)sport
;
1936 sport
->clk_ipg
= devm_clk_get(&pdev
->dev
, "ipg");
1937 if (IS_ERR(sport
->clk_ipg
)) {
1938 ret
= PTR_ERR(sport
->clk_ipg
);
1939 dev_err(&pdev
->dev
, "failed to get ipg clk: %d\n", ret
);
1943 sport
->clk_per
= devm_clk_get(&pdev
->dev
, "per");
1944 if (IS_ERR(sport
->clk_per
)) {
1945 ret
= PTR_ERR(sport
->clk_per
);
1946 dev_err(&pdev
->dev
, "failed to get per clk: %d\n", ret
);
1950 sport
->port
.uartclk
= clk_get_rate(sport
->clk_per
);
1953 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1954 * chips only have one interrupt.
1957 ret
= devm_request_irq(&pdev
->dev
, rxirq
, imx_rxint
, 0,
1958 dev_name(&pdev
->dev
), sport
);
1962 ret
= devm_request_irq(&pdev
->dev
, txirq
, imx_txint
, 0,
1963 dev_name(&pdev
->dev
), sport
);
1967 ret
= devm_request_irq(&pdev
->dev
, rxirq
, imx_int
, 0,
1968 dev_name(&pdev
->dev
), sport
);
1973 imx_ports
[sport
->port
.line
] = sport
;
1975 platform_set_drvdata(pdev
, sport
);
1977 return uart_add_one_port(&imx_reg
, &sport
->port
);
1980 static int serial_imx_remove(struct platform_device
*pdev
)
1982 struct imx_port
*sport
= platform_get_drvdata(pdev
);
1984 return uart_remove_one_port(&imx_reg
, &sport
->port
);
1987 static struct platform_driver serial_imx_driver
= {
1988 .probe
= serial_imx_probe
,
1989 .remove
= serial_imx_remove
,
1991 .suspend
= serial_imx_suspend
,
1992 .resume
= serial_imx_resume
,
1993 .id_table
= imx_uart_devtype
,
1996 .of_match_table
= imx_uart_dt_ids
,
2000 static int __init
imx_serial_init(void)
2002 int ret
= uart_register_driver(&imx_reg
);
2007 ret
= platform_driver_register(&serial_imx_driver
);
2009 uart_unregister_driver(&imx_reg
);
2014 static void __exit
imx_serial_exit(void)
2016 platform_driver_unregister(&serial_imx_driver
);
2017 uart_unregister_driver(&imx_reg
);
2020 module_init(imx_serial_init
);
2021 module_exit(imx_serial_exit
);
2023 MODULE_AUTHOR("Sascha Hauer");
2024 MODULE_DESCRIPTION("IMX generic serial port driver");
2025 MODULE_LICENSE("GPL");
2026 MODULE_ALIAS("platform:imx-uart");