1 // SPDX-License-Identifier: GPL-2.0+
3 * Driver for Motorola/Freescale IMX serial ports
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 * Author: Sascha Hauer <sascha@saschahauer.de>
8 * Copyright (C) 2004 Pengutronix
11 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
15 #include <linux/module.h>
16 #include <linux/ioport.h>
17 #include <linux/init.h>
18 #include <linux/console.h>
19 #include <linux/sysrq.h>
20 #include <linux/platform_device.h>
21 #include <linux/tty.h>
22 #include <linux/tty_flip.h>
23 #include <linux/serial_core.h>
24 #include <linux/serial.h>
25 #include <linux/clk.h>
26 #include <linux/delay.h>
27 #include <linux/pinctrl/consumer.h>
28 #include <linux/rational.h>
29 #include <linux/slab.h>
31 #include <linux/of_device.h>
33 #include <linux/dma-mapping.h>
36 #include <linux/platform_data/serial-imx.h>
37 #include <linux/platform_data/dma-imx.h>
39 #include "serial_mctrl_gpio.h"
41 /* Register definitions */
42 #define URXD0 0x0 /* Receiver Register */
43 #define URTX0 0x40 /* Transmitter Register */
44 #define UCR1 0x80 /* Control Register 1 */
45 #define UCR2 0x84 /* Control Register 2 */
46 #define UCR3 0x88 /* Control Register 3 */
47 #define UCR4 0x8c /* Control Register 4 */
48 #define UFCR 0x90 /* FIFO Control Register */
49 #define USR1 0x94 /* Status Register 1 */
50 #define USR2 0x98 /* Status Register 2 */
51 #define UESC 0x9c /* Escape Character Register */
52 #define UTIM 0xa0 /* Escape Timer Register */
53 #define UBIR 0xa4 /* BRM Incremental Register */
54 #define UBMR 0xa8 /* BRM Modulator Register */
55 #define UBRC 0xac /* Baud Rate Count Register */
56 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
57 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
58 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
60 /* UART Control Register Bit Fields.*/
61 #define URXD_DUMMY_READ (1<<16)
62 #define URXD_CHARRDY (1<<15)
63 #define URXD_ERR (1<<14)
64 #define URXD_OVRRUN (1<<13)
65 #define URXD_FRMERR (1<<12)
66 #define URXD_BRK (1<<11)
67 #define URXD_PRERR (1<<10)
68 #define URXD_RX_DATA (0xFF<<0)
69 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
70 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
71 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
72 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
73 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
74 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
75 #define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
76 #define UCR1_IREN (1<<7) /* Infrared interface enable */
77 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
78 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
79 #define UCR1_SNDBRK (1<<4) /* Send break */
80 #define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
81 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
82 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
83 #define UCR1_DOZE (1<<1) /* Doze */
84 #define UCR1_UARTEN (1<<0) /* UART enabled */
85 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
86 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
87 #define UCR2_CTSC (1<<13) /* CTS pin control */
88 #define UCR2_CTS (1<<12) /* Clear to send */
89 #define UCR2_ESCEN (1<<11) /* Escape enable */
90 #define UCR2_PREN (1<<8) /* Parity enable */
91 #define UCR2_PROE (1<<7) /* Parity odd/even */
92 #define UCR2_STPB (1<<6) /* Stop */
93 #define UCR2_WS (1<<5) /* Word size */
94 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
95 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
96 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
97 #define UCR2_RXEN (1<<1) /* Receiver enabled */
98 #define UCR2_SRST (1<<0) /* SW reset */
99 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
100 #define UCR3_PARERREN (1<<12) /* Parity enable */
101 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
102 #define UCR3_DSR (1<<10) /* Data set ready */
103 #define UCR3_DCD (1<<9) /* Data carrier detect */
104 #define UCR3_RI (1<<8) /* Ring indicator */
105 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
106 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
107 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
108 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
109 #define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
110 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
111 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
112 #define UCR3_BPEN (1<<0) /* Preset registers enable */
113 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
114 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
115 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
116 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
117 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
118 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
119 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
120 #define UCR4_IRSC (1<<5) /* IR special case */
121 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
122 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
123 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
124 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
125 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
126 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
127 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
128 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
129 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
130 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
131 #define USR1_RTSS (1<<14) /* RTS pin status */
132 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
133 #define USR1_RTSD (1<<12) /* RTS delta */
134 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
135 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
136 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
137 #define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
138 #define USR1_DTRD (1<<7) /* DTR Delta */
139 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
140 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
141 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
142 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
143 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
144 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
145 #define USR2_IDLE (1<<12) /* Idle condition */
146 #define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
147 #define USR2_RIIN (1<<9) /* Ring Indicator Input */
148 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
149 #define USR2_WAKE (1<<7) /* Wake */
150 #define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
151 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
152 #define USR2_TXDC (1<<3) /* Transmitter complete */
153 #define USR2_BRCD (1<<2) /* Break condition */
154 #define USR2_ORE (1<<1) /* Overrun error */
155 #define USR2_RDR (1<<0) /* Recv data ready */
156 #define UTS_FRCPERR (1<<13) /* Force parity error */
157 #define UTS_LOOP (1<<12) /* Loop tx and rx */
158 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
159 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
160 #define UTS_TXFULL (1<<4) /* TxFIFO full */
161 #define UTS_RXFULL (1<<3) /* RxFIFO full */
162 #define UTS_SOFTRST (1<<0) /* Software reset */
164 /* We've been assigned a range on the "Low-density serial ports" major */
165 #define SERIAL_IMX_MAJOR 207
166 #define MINOR_START 16
167 #define DEV_NAME "ttymxc"
170 * This determines how often we check the modem status signals
171 * for any change. They generally aren't connected to an IRQ
172 * so we have to poll them. We also check immediately before
173 * filling the TX fifo incase CTS has been dropped.
175 #define MCTRL_TIMEOUT (250*HZ/1000)
177 #define DRIVER_NAME "IMX-uart"
181 /* 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 have_rtsgpio:1;
201 unsigned int dte_mode:1;
204 const struct imx_uart_data *devdata;
206 struct mctrl_gpios *gpios;
208 /* shadow registers */
216 unsigned int dma_is_enabled:1;
217 unsigned int dma_is_rxing:1;
218 unsigned int dma_is_txing:1;
219 struct dma_chan *dma_chan_rx, *dma_chan_tx;
220 struct scatterlist rx_sgl, tx_sgl[2];
222 struct circ_buf rx_ring;
223 unsigned int rx_periods;
224 dma_cookie_t rx_cookie;
225 unsigned int tx_bytes;
226 unsigned int dma_tx_nents;
227 unsigned int saved_reg[10];
231 struct imx_port_ucrs {
237 static struct imx_uart_data imx_uart_devdata[] = {
240 .devtype = IMX1_UART,
243 .uts_reg = IMX21_UTS,
244 .devtype = IMX21_UART,
247 .uts_reg = IMX21_UTS,
248 .devtype = IMX53_UART,
251 .uts_reg = IMX21_UTS,
252 .devtype = IMX6Q_UART,
256 static const struct platform_device_id imx_uart_devtype[] = {
259 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
261 .name = "imx21-uart",
262 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
264 .name = "imx53-uart",
265 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_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 const struct of_device_id imx_uart_dt_ids[] = {
276 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
277 { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
278 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
279 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
282 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
284 static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
305 writel(val, sport->port.membase + offset);
308 static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
316 * UCR2_SRST is the only bit in the cached registers that might
317 * differ from the value that was last written. As it only
318 * automatically becomes one after being cleared, reread
321 if (!(sport->ucr2 & UCR2_SRST))
322 sport->ucr2 = readl(sport->port.membase + offset);
335 return readl(sport->port.membase + offset);
339 static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
341 return sport->devdata->uts_reg;
344 static inline int imx_uart_is_imx1(struct imx_port *sport)
346 return sport->devdata->devtype == IMX1_UART;
349 static inline int imx_uart_is_imx21(struct imx_port *sport)
351 return sport->devdata->devtype == IMX21_UART;
354 static inline int imx_uart_is_imx53(struct imx_port *sport)
356 return sport->devdata->devtype == IMX53_UART;
359 static inline int imx_uart_is_imx6q(struct imx_port *sport)
361 return sport->devdata->devtype == IMX6Q_UART;
364 * Save and restore functions for UCR1, UCR2 and UCR3 registers
366 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
367 static void imx_uart_ucrs_save(struct imx_port *sport,
368 struct imx_port_ucrs *ucr)
370 /* save control registers */
371 ucr->ucr1 = imx_uart_readl(sport, UCR1);
372 ucr->ucr2 = imx_uart_readl(sport, UCR2);
373 ucr->ucr3 = imx_uart_readl(sport, UCR3);
376 static void imx_uart_ucrs_restore(struct imx_port *sport,
377 struct imx_port_ucrs *ucr)
379 /* restore control registers */
380 imx_uart_writel(sport, ucr->ucr1, UCR1);
381 imx_uart_writel(sport, ucr->ucr2, UCR2);
382 imx_uart_writel(sport, ucr->ucr3, UCR3);
386 /* called with port.lock taken and irqs caller dependent */
387 static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
389 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
391 sport->port.mctrl |= TIOCM_RTS;
392 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
395 /* called with port.lock taken and irqs caller dependent */
396 static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
401 sport->port.mctrl &= ~TIOCM_RTS;
402 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
405 /* called with port.lock taken and irqs off */
406 static void imx_uart_start_rx(struct uart_port *port)
408 struct imx_port *sport = (struct imx_port *)port;
409 unsigned int ucr1, ucr2;
411 ucr1 = imx_uart_readl(sport, UCR1);
412 ucr2 = imx_uart_readl(sport, UCR2);
416 if (sport->dma_is_enabled) {
417 ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
423 /* Write UCR2 first as it includes RXEN */
424 imx_uart_writel(sport, ucr2, UCR2);
425 imx_uart_writel(sport, ucr1, UCR1);
428 /* called with port.lock taken and irqs off */
429 static void imx_uart_stop_tx(struct uart_port *port)
431 struct imx_port *sport = (struct imx_port *)port;
435 * We are maybe in the SMP context, so if the DMA TX thread is running
436 * on other cpu, we have to wait for it to finish.
438 if (sport->dma_is_txing)
441 ucr1 = imx_uart_readl(sport, UCR1);
442 imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
444 /* in rs485 mode disable transmitter if shifter is empty */
445 if (port->rs485.flags & SER_RS485_ENABLED &&
446 imx_uart_readl(sport, USR2) & USR2_TXDC) {
447 u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
448 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
449 imx_uart_rts_active(sport, &ucr2);
451 imx_uart_rts_inactive(sport, &ucr2);
452 imx_uart_writel(sport, ucr2, UCR2);
454 imx_uart_start_rx(port);
456 ucr4 = imx_uart_readl(sport, UCR4);
458 imx_uart_writel(sport, ucr4, UCR4);
462 /* called with port.lock taken and irqs off */
463 static void imx_uart_stop_rx(struct uart_port *port)
465 struct imx_port *sport = (struct imx_port *)port;
468 ucr1 = imx_uart_readl(sport, UCR1);
469 ucr2 = imx_uart_readl(sport, UCR2);
471 if (sport->dma_is_enabled) {
472 ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
474 ucr1 &= ~UCR1_RRDYEN;
477 imx_uart_writel(sport, ucr1, UCR1);
480 imx_uart_writel(sport, ucr2, UCR2);
483 /* called with port.lock taken and irqs off */
484 static void imx_uart_enable_ms(struct uart_port *port)
486 struct imx_port *sport = (struct imx_port *)port;
488 mod_timer(&sport->timer, jiffies);
490 mctrl_gpio_enable_ms(sport->gpios);
493 static void imx_uart_dma_tx(struct imx_port *sport);
495 /* called with port.lock taken and irqs off */
496 static inline void imx_uart_transmit_buffer(struct imx_port *sport)
498 struct circ_buf *xmit = &sport->port.state->xmit;
500 if (sport->port.x_char) {
502 imx_uart_writel(sport, sport->port.x_char, URTX0);
503 sport->port.icount.tx++;
504 sport->port.x_char = 0;
508 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
509 imx_uart_stop_tx(&sport->port);
513 if (sport->dma_is_enabled) {
516 * We've just sent a X-char Ensure the TX DMA is enabled
517 * and the TX IRQ is disabled.
519 ucr1 = imx_uart_readl(sport, UCR1);
520 ucr1 &= ~UCR1_TRDYEN;
521 if (sport->dma_is_txing) {
522 ucr1 |= UCR1_TXDMAEN;
523 imx_uart_writel(sport, ucr1, UCR1);
525 imx_uart_writel(sport, ucr1, UCR1);
526 imx_uart_dma_tx(sport);
532 while (!uart_circ_empty(xmit) &&
533 !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
534 /* send xmit->buf[xmit->tail]
535 * out the port here */
536 imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
537 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
538 sport->port.icount.tx++;
541 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
542 uart_write_wakeup(&sport->port);
544 if (uart_circ_empty(xmit))
545 imx_uart_stop_tx(&sport->port);
548 static void imx_uart_dma_tx_callback(void *data)
550 struct imx_port *sport = data;
551 struct scatterlist *sgl = &sport->tx_sgl[0];
552 struct circ_buf *xmit = &sport->port.state->xmit;
556 spin_lock_irqsave(&sport->port.lock, flags);
558 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
560 ucr1 = imx_uart_readl(sport, UCR1);
561 ucr1 &= ~UCR1_TXDMAEN;
562 imx_uart_writel(sport, ucr1, UCR1);
564 /* update the stat */
565 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
566 sport->port.icount.tx += sport->tx_bytes;
568 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
570 sport->dma_is_txing = 0;
572 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
573 uart_write_wakeup(&sport->port);
575 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
576 imx_uart_dma_tx(sport);
577 else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
578 u32 ucr4 = imx_uart_readl(sport, UCR4);
580 imx_uart_writel(sport, ucr4, UCR4);
583 spin_unlock_irqrestore(&sport->port.lock, flags);
586 /* called with port.lock taken and irqs off */
587 static void imx_uart_dma_tx(struct imx_port *sport)
589 struct circ_buf *xmit = &sport->port.state->xmit;
590 struct scatterlist *sgl = sport->tx_sgl;
591 struct dma_async_tx_descriptor *desc;
592 struct dma_chan *chan = sport->dma_chan_tx;
593 struct device *dev = sport->port.dev;
597 if (sport->dma_is_txing)
600 ucr4 = imx_uart_readl(sport, UCR4);
602 imx_uart_writel(sport, ucr4, UCR4);
604 sport->tx_bytes = uart_circ_chars_pending(xmit);
606 if (xmit->tail < xmit->head) {
607 sport->dma_tx_nents = 1;
608 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
610 sport->dma_tx_nents = 2;
611 sg_init_table(sgl, 2);
612 sg_set_buf(sgl, xmit->buf + xmit->tail,
613 UART_XMIT_SIZE - xmit->tail);
614 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
617 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
619 dev_err(dev, "DMA mapping error for TX.\n");
622 desc = dmaengine_prep_slave_sg(chan, sgl, ret,
623 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
625 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
627 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
630 desc->callback = imx_uart_dma_tx_callback;
631 desc->callback_param = sport;
633 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
634 uart_circ_chars_pending(xmit));
636 ucr1 = imx_uart_readl(sport, UCR1);
637 ucr1 |= UCR1_TXDMAEN;
638 imx_uart_writel(sport, ucr1, UCR1);
641 sport->dma_is_txing = 1;
642 dmaengine_submit(desc);
643 dma_async_issue_pending(chan);
647 /* called with port.lock taken and irqs off */
648 static void imx_uart_start_tx(struct uart_port *port)
650 struct imx_port *sport = (struct imx_port *)port;
653 if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
656 if (port->rs485.flags & SER_RS485_ENABLED) {
659 ucr2 = imx_uart_readl(sport, UCR2);
660 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
661 imx_uart_rts_active(sport, &ucr2);
663 imx_uart_rts_inactive(sport, &ucr2);
664 imx_uart_writel(sport, ucr2, UCR2);
666 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
667 imx_uart_stop_rx(port);
670 * Enable transmitter and shifter empty irq only if DMA is off.
671 * In the DMA case this is done in the tx-callback.
673 if (!sport->dma_is_enabled) {
674 u32 ucr4 = imx_uart_readl(sport, UCR4);
676 imx_uart_writel(sport, ucr4, UCR4);
680 if (!sport->dma_is_enabled) {
681 ucr1 = imx_uart_readl(sport, UCR1);
682 imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
685 if (sport->dma_is_enabled) {
686 if (sport->port.x_char) {
687 /* We have X-char to send, so enable TX IRQ and
688 * disable TX DMA to let TX interrupt to send X-char */
689 ucr1 = imx_uart_readl(sport, UCR1);
690 ucr1 &= ~UCR1_TXDMAEN;
692 imx_uart_writel(sport, ucr1, UCR1);
696 if (!uart_circ_empty(&port->state->xmit) &&
697 !uart_tx_stopped(port))
698 imx_uart_dma_tx(sport);
703 static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
705 struct imx_port *sport = dev_id;
708 spin_lock(&sport->port.lock);
710 imx_uart_writel(sport, USR1_RTSD, USR1);
711 usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
712 uart_handle_cts_change(&sport->port, !!usr1);
713 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
715 spin_unlock(&sport->port.lock);
719 static irqreturn_t imx_uart_txint(int irq, void *dev_id)
721 struct imx_port *sport = dev_id;
723 spin_lock(&sport->port.lock);
724 imx_uart_transmit_buffer(sport);
725 spin_unlock(&sport->port.lock);
729 static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
731 struct imx_port *sport = dev_id;
732 unsigned int rx, flg, ignored = 0;
733 struct tty_port *port = &sport->port.state->port;
735 spin_lock(&sport->port.lock);
737 while (imx_uart_readl(sport, USR2) & USR2_RDR) {
741 sport->port.icount.rx++;
743 rx = imx_uart_readl(sport, URXD0);
745 usr2 = imx_uart_readl(sport, USR2);
746 if (usr2 & USR2_BRCD) {
747 imx_uart_writel(sport, USR2_BRCD, USR2);
748 if (uart_handle_break(&sport->port))
752 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
755 if (unlikely(rx & URXD_ERR)) {
757 sport->port.icount.brk++;
758 else if (rx & URXD_PRERR)
759 sport->port.icount.parity++;
760 else if (rx & URXD_FRMERR)
761 sport->port.icount.frame++;
762 if (rx & URXD_OVRRUN)
763 sport->port.icount.overrun++;
765 if (rx & sport->port.ignore_status_mask) {
771 rx &= (sport->port.read_status_mask | 0xFF);
775 else if (rx & URXD_PRERR)
777 else if (rx & URXD_FRMERR)
779 if (rx & URXD_OVRRUN)
783 sport->port.sysrq = 0;
787 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
790 if (tty_insert_flip_char(port, rx, flg) == 0)
791 sport->port.icount.buf_overrun++;
795 spin_unlock(&sport->port.lock);
796 tty_flip_buffer_push(port);
800 static void imx_uart_clear_rx_errors(struct imx_port *sport);
803 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
805 static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
807 unsigned int tmp = TIOCM_DSR;
808 unsigned usr1 = imx_uart_readl(sport, USR1);
809 unsigned usr2 = imx_uart_readl(sport, USR2);
811 if (usr1 & USR1_RTSS)
814 /* in DCE mode DCDIN is always 0 */
815 if (!(usr2 & USR2_DCDIN))
819 if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
826 * Handle any change of modem status signal since we were last called.
828 static void imx_uart_mctrl_check(struct imx_port *sport)
830 unsigned int status, changed;
832 status = imx_uart_get_hwmctrl(sport);
833 changed = status ^ sport->old_status;
838 sport->old_status = status;
840 if (changed & TIOCM_RI && status & TIOCM_RI)
841 sport->port.icount.rng++;
842 if (changed & TIOCM_DSR)
843 sport->port.icount.dsr++;
844 if (changed & TIOCM_CAR)
845 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
846 if (changed & TIOCM_CTS)
847 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
849 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
852 static irqreturn_t imx_uart_int(int irq, void *dev_id)
854 struct imx_port *sport = dev_id;
855 unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
856 irqreturn_t ret = IRQ_NONE;
858 usr1 = imx_uart_readl(sport, USR1);
859 usr2 = imx_uart_readl(sport, USR2);
860 ucr1 = imx_uart_readl(sport, UCR1);
861 ucr2 = imx_uart_readl(sport, UCR2);
862 ucr3 = imx_uart_readl(sport, UCR3);
863 ucr4 = imx_uart_readl(sport, UCR4);
866 * Even if a condition is true that can trigger an irq only handle it if
867 * the respective irq source is enabled. This prevents some undesired
868 * actions, for example if a character that sits in the RX FIFO and that
869 * should be fetched via DMA is tried to be fetched using PIO. Or the
870 * receiver is currently off and so reading from URXD0 results in an
871 * exception. So just mask the (raw) status bits for disabled irqs.
873 if ((ucr1 & UCR1_RRDYEN) == 0)
875 if ((ucr2 & UCR2_ATEN) == 0)
877 if ((ucr1 & UCR1_TRDYEN) == 0)
879 if ((ucr4 & UCR4_TCEN) == 0)
881 if ((ucr3 & UCR3_DTRDEN) == 0)
883 if ((ucr1 & UCR1_RTSDEN) == 0)
885 if ((ucr3 & UCR3_AWAKEN) == 0)
887 if ((ucr4 & UCR4_OREN) == 0)
890 if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
891 imx_uart_rxint(irq, dev_id);
895 if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
896 imx_uart_txint(irq, dev_id);
900 if (usr1 & USR1_DTRD) {
901 imx_uart_writel(sport, USR1_DTRD, USR1);
903 spin_lock(&sport->port.lock);
904 imx_uart_mctrl_check(sport);
905 spin_unlock(&sport->port.lock);
910 if (usr1 & USR1_RTSD) {
911 imx_uart_rtsint(irq, dev_id);
915 if (usr1 & USR1_AWAKE) {
916 imx_uart_writel(sport, USR1_AWAKE, USR1);
920 if (usr2 & USR2_ORE) {
921 sport->port.icount.overrun++;
922 imx_uart_writel(sport, USR2_ORE, USR2);
930 * Return TIOCSER_TEMT when transmitter is not busy.
932 static unsigned int imx_uart_tx_empty(struct uart_port *port)
934 struct imx_port *sport = (struct imx_port *)port;
937 ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
939 /* If the TX DMA is working, return 0. */
940 if (sport->dma_is_txing)
946 /* called with port.lock taken and irqs off */
947 static unsigned int imx_uart_get_mctrl(struct uart_port *port)
949 struct imx_port *sport = (struct imx_port *)port;
950 unsigned int ret = imx_uart_get_hwmctrl(sport);
952 mctrl_gpio_get(sport->gpios, &ret);
957 /* called with port.lock taken and irqs off */
958 static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
960 struct imx_port *sport = (struct imx_port *)port;
963 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
967 * Turn off autoRTS if RTS is lowered and restore autoRTS
968 * setting if RTS is raised.
970 ucr2 = imx_uart_readl(sport, UCR2);
971 ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
972 if (mctrl & TIOCM_RTS) {
975 * UCR2_IRTS is unset if and only if the port is
976 * configured for CRTSCTS, so we use inverted UCR2_IRTS
977 * to get the state to restore to.
979 if (!(ucr2 & UCR2_IRTS))
982 imx_uart_writel(sport, ucr2, UCR2);
985 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
986 if (!(mctrl & TIOCM_DTR))
988 imx_uart_writel(sport, ucr3, UCR3);
990 uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
991 if (mctrl & TIOCM_LOOP)
993 imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
995 mctrl_gpio_set(sport->gpios, mctrl);
999 * Interrupts always disabled.
1001 static void imx_uart_break_ctl(struct uart_port *port, int break_state)
1003 struct imx_port *sport = (struct imx_port *)port;
1004 unsigned long flags;
1007 spin_lock_irqsave(&sport->port.lock, flags);
1009 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
1011 if (break_state != 0)
1012 ucr1 |= UCR1_SNDBRK;
1014 imx_uart_writel(sport, ucr1, UCR1);
1016 spin_unlock_irqrestore(&sport->port.lock, flags);
1020 * This is our per-port timeout handler, for checking the
1021 * modem status signals.
1023 static void imx_uart_timeout(struct timer_list *t)
1025 struct imx_port *sport = from_timer(sport, t, timer);
1026 unsigned long flags;
1028 if (sport->port.state) {
1029 spin_lock_irqsave(&sport->port.lock, flags);
1030 imx_uart_mctrl_check(sport);
1031 spin_unlock_irqrestore(&sport->port.lock, flags);
1033 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
1038 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
1039 * [1] the RX DMA buffer is full.
1040 * [2] the aging timer expires
1042 * Condition [2] is triggered when a character has been sitting in the FIFO
1043 * for at least 8 byte durations.
1045 static void imx_uart_dma_rx_callback(void *data)
1047 struct imx_port *sport = data;
1048 struct dma_chan *chan = sport->dma_chan_rx;
1049 struct scatterlist *sgl = &sport->rx_sgl;
1050 struct tty_port *port = &sport->port.state->port;
1051 struct dma_tx_state state;
1052 struct circ_buf *rx_ring = &sport->rx_ring;
1053 enum dma_status status;
1054 unsigned int w_bytes = 0;
1055 unsigned int r_bytes;
1056 unsigned int bd_size;
1058 status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
1060 if (status == DMA_ERROR) {
1061 imx_uart_clear_rx_errors(sport);
1065 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
1068 * The state-residue variable represents the empty space
1069 * relative to the entire buffer. Taking this in consideration
1070 * the head is always calculated base on the buffer total
1071 * length - DMA transaction residue. The UART script from the
1072 * SDMA firmware will jump to the next buffer descriptor,
1073 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1074 * Taking this in consideration the tail is always at the
1075 * beginning of the buffer descriptor that contains the head.
1078 /* Calculate the head */
1079 rx_ring->head = sg_dma_len(sgl) - state.residue;
1081 /* Calculate the tail. */
1082 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1083 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1085 if (rx_ring->head <= sg_dma_len(sgl) &&
1086 rx_ring->head > rx_ring->tail) {
1088 /* Move data from tail to head */
1089 r_bytes = rx_ring->head - rx_ring->tail;
1091 /* CPU claims ownership of RX DMA buffer */
1092 dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1095 w_bytes = tty_insert_flip_string(port,
1096 sport->rx_buf + rx_ring->tail, r_bytes);
1098 /* UART retrieves ownership of RX DMA buffer */
1099 dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1102 if (w_bytes != r_bytes)
1103 sport->port.icount.buf_overrun++;
1105 sport->port.icount.rx += w_bytes;
1107 WARN_ON(rx_ring->head > sg_dma_len(sgl));
1108 WARN_ON(rx_ring->head <= rx_ring->tail);
1113 tty_flip_buffer_push(port);
1114 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1118 /* RX DMA buffer periods */
1119 #define RX_DMA_PERIODS 16
1120 #define RX_BUF_SIZE (RX_DMA_PERIODS * PAGE_SIZE / 4)
1122 static int imx_uart_start_rx_dma(struct imx_port *sport)
1124 struct scatterlist *sgl = &sport->rx_sgl;
1125 struct dma_chan *chan = sport->dma_chan_rx;
1126 struct device *dev = sport->port.dev;
1127 struct dma_async_tx_descriptor *desc;
1130 sport->rx_ring.head = 0;
1131 sport->rx_ring.tail = 0;
1132 sport->rx_periods = RX_DMA_PERIODS;
1134 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1135 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1137 dev_err(dev, "DMA mapping error for RX.\n");
1141 desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1142 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1143 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1146 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1147 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1150 desc->callback = imx_uart_dma_rx_callback;
1151 desc->callback_param = sport;
1153 dev_dbg(dev, "RX: prepare for the DMA.\n");
1154 sport->dma_is_rxing = 1;
1155 sport->rx_cookie = dmaengine_submit(desc);
1156 dma_async_issue_pending(chan);
1160 static void imx_uart_clear_rx_errors(struct imx_port *sport)
1162 struct tty_port *port = &sport->port.state->port;
1165 usr1 = imx_uart_readl(sport, USR1);
1166 usr2 = imx_uart_readl(sport, USR2);
1168 if (usr2 & USR2_BRCD) {
1169 sport->port.icount.brk++;
1170 imx_uart_writel(sport, USR2_BRCD, USR2);
1171 uart_handle_break(&sport->port);
1172 if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
1173 sport->port.icount.buf_overrun++;
1174 tty_flip_buffer_push(port);
1176 if (usr1 & USR1_FRAMERR) {
1177 sport->port.icount.frame++;
1178 imx_uart_writel(sport, USR1_FRAMERR, USR1);
1179 } else if (usr1 & USR1_PARITYERR) {
1180 sport->port.icount.parity++;
1181 imx_uart_writel(sport, USR1_PARITYERR, USR1);
1185 if (usr2 & USR2_ORE) {
1186 sport->port.icount.overrun++;
1187 imx_uart_writel(sport, USR2_ORE, USR2);
1192 #define TXTL_DEFAULT 2 /* reset default */
1193 #define RXTL_DEFAULT 1 /* reset default */
1194 #define TXTL_DMA 8 /* DMA burst setting */
1195 #define RXTL_DMA 9 /* DMA burst setting */
1197 static void imx_uart_setup_ufcr(struct imx_port *sport,
1198 unsigned char txwl, unsigned char rxwl)
1202 /* set receiver / transmitter trigger level */
1203 val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1204 val |= txwl << UFCR_TXTL_SHF | rxwl;
1205 imx_uart_writel(sport, val, UFCR);
1208 static void imx_uart_dma_exit(struct imx_port *sport)
1210 if (sport->dma_chan_rx) {
1211 dmaengine_terminate_sync(sport->dma_chan_rx);
1212 dma_release_channel(sport->dma_chan_rx);
1213 sport->dma_chan_rx = NULL;
1214 sport->rx_cookie = -EINVAL;
1215 kfree(sport->rx_buf);
1216 sport->rx_buf = NULL;
1219 if (sport->dma_chan_tx) {
1220 dmaengine_terminate_sync(sport->dma_chan_tx);
1221 dma_release_channel(sport->dma_chan_tx);
1222 sport->dma_chan_tx = NULL;
1226 static int imx_uart_dma_init(struct imx_port *sport)
1228 struct dma_slave_config slave_config = {};
1229 struct device *dev = sport->port.dev;
1232 /* Prepare for RX : */
1233 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1234 if (!sport->dma_chan_rx) {
1235 dev_dbg(dev, "cannot get the DMA channel.\n");
1240 slave_config.direction = DMA_DEV_TO_MEM;
1241 slave_config.src_addr = sport->port.mapbase + URXD0;
1242 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1243 /* one byte less than the watermark level to enable the aging timer */
1244 slave_config.src_maxburst = RXTL_DMA - 1;
1245 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1247 dev_err(dev, "error in RX dma configuration.\n");
1251 sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
1252 if (!sport->rx_buf) {
1256 sport->rx_ring.buf = sport->rx_buf;
1258 /* Prepare for TX : */
1259 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1260 if (!sport->dma_chan_tx) {
1261 dev_err(dev, "cannot get the TX DMA channel!\n");
1266 slave_config.direction = DMA_MEM_TO_DEV;
1267 slave_config.dst_addr = sport->port.mapbase + URTX0;
1268 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1269 slave_config.dst_maxburst = TXTL_DMA;
1270 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1272 dev_err(dev, "error in TX dma configuration.");
1278 imx_uart_dma_exit(sport);
1282 static void imx_uart_enable_dma(struct imx_port *sport)
1286 imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1289 ucr1 = imx_uart_readl(sport, UCR1);
1290 ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1291 imx_uart_writel(sport, ucr1, UCR1);
1293 sport->dma_is_enabled = 1;
1296 static void imx_uart_disable_dma(struct imx_port *sport)
1301 ucr1 = imx_uart_readl(sport, UCR1);
1302 ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1303 imx_uart_writel(sport, ucr1, UCR1);
1305 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1307 sport->dma_is_enabled = 0;
1310 /* half the RX buffer size */
1313 static int imx_uart_startup(struct uart_port *port)
1315 struct imx_port *sport = (struct imx_port *)port;
1317 unsigned long flags;
1318 int dma_is_inited = 0;
1319 u32 ucr1, ucr2, ucr4;
1321 retval = clk_prepare_enable(sport->clk_per);
1324 retval = clk_prepare_enable(sport->clk_ipg);
1326 clk_disable_unprepare(sport->clk_per);
1330 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1332 /* disable the DREN bit (Data Ready interrupt enable) before
1335 ucr4 = imx_uart_readl(sport, UCR4);
1337 /* set the trigger level for CTS */
1338 ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1339 ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1341 imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
1343 /* Can we enable the DMA support? */
1344 if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1347 spin_lock_irqsave(&sport->port.lock, flags);
1348 /* Reset fifo's and state machines */
1351 ucr2 = imx_uart_readl(sport, UCR2);
1353 imx_uart_writel(sport, ucr2, UCR2);
1355 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1359 * Finally, clear and enable interrupts
1361 imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1362 imx_uart_writel(sport, USR2_ORE, USR2);
1364 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1365 ucr1 |= UCR1_UARTEN;
1366 if (sport->have_rtscts)
1367 ucr1 |= UCR1_RTSDEN;
1369 imx_uart_writel(sport, ucr1, UCR1);
1371 ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
1372 if (!sport->dma_is_enabled)
1374 imx_uart_writel(sport, ucr4, UCR4);
1376 ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1377 ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1378 if (!sport->have_rtscts)
1381 * make sure the edge sensitive RTS-irq is disabled,
1382 * we're using RTSD instead.
1384 if (!imx_uart_is_imx1(sport))
1385 ucr2 &= ~UCR2_RTSEN;
1386 imx_uart_writel(sport, ucr2, UCR2);
1388 if (!imx_uart_is_imx1(sport)) {
1391 ucr3 = imx_uart_readl(sport, UCR3);
1393 ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1395 if (sport->dte_mode)
1396 /* disable broken interrupts */
1397 ucr3 &= ~(UCR3_RI | UCR3_DCD);
1399 imx_uart_writel(sport, ucr3, UCR3);
1403 * Enable modem status interrupts
1405 imx_uart_enable_ms(&sport->port);
1407 if (dma_is_inited) {
1408 imx_uart_enable_dma(sport);
1409 imx_uart_start_rx_dma(sport);
1411 ucr1 = imx_uart_readl(sport, UCR1);
1412 ucr1 |= UCR1_RRDYEN;
1413 imx_uart_writel(sport, ucr1, UCR1);
1415 ucr2 = imx_uart_readl(sport, UCR2);
1417 imx_uart_writel(sport, ucr2, UCR2);
1420 spin_unlock_irqrestore(&sport->port.lock, flags);
1425 static void imx_uart_shutdown(struct uart_port *port)
1427 struct imx_port *sport = (struct imx_port *)port;
1428 unsigned long flags;
1429 u32 ucr1, ucr2, ucr4;
1431 if (sport->dma_is_enabled) {
1432 dmaengine_terminate_sync(sport->dma_chan_tx);
1433 if (sport->dma_is_txing) {
1434 dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
1435 sport->dma_tx_nents, DMA_TO_DEVICE);
1436 sport->dma_is_txing = 0;
1438 dmaengine_terminate_sync(sport->dma_chan_rx);
1439 if (sport->dma_is_rxing) {
1440 dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
1441 1, DMA_FROM_DEVICE);
1442 sport->dma_is_rxing = 0;
1445 spin_lock_irqsave(&sport->port.lock, flags);
1446 imx_uart_stop_tx(port);
1447 imx_uart_stop_rx(port);
1448 imx_uart_disable_dma(sport);
1449 spin_unlock_irqrestore(&sport->port.lock, flags);
1450 imx_uart_dma_exit(sport);
1453 mctrl_gpio_disable_ms(sport->gpios);
1455 spin_lock_irqsave(&sport->port.lock, flags);
1456 ucr2 = imx_uart_readl(sport, UCR2);
1457 ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1458 imx_uart_writel(sport, ucr2, UCR2);
1460 ucr4 = imx_uart_readl(sport, UCR4);
1462 imx_uart_writel(sport, ucr4, UCR4);
1463 spin_unlock_irqrestore(&sport->port.lock, flags);
1468 del_timer_sync(&sport->timer);
1471 * Disable all interrupts, port and break condition.
1474 spin_lock_irqsave(&sport->port.lock, flags);
1475 ucr1 = imx_uart_readl(sport, UCR1);
1476 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
1478 imx_uart_writel(sport, ucr1, UCR1);
1479 spin_unlock_irqrestore(&sport->port.lock, flags);
1481 clk_disable_unprepare(sport->clk_per);
1482 clk_disable_unprepare(sport->clk_ipg);
1485 /* called with port.lock taken and irqs off */
1486 static void imx_uart_flush_buffer(struct uart_port *port)
1488 struct imx_port *sport = (struct imx_port *)port;
1489 struct scatterlist *sgl = &sport->tx_sgl[0];
1491 int i = 100, ubir, ubmr, uts;
1493 if (!sport->dma_chan_tx)
1496 sport->tx_bytes = 0;
1497 dmaengine_terminate_all(sport->dma_chan_tx);
1498 if (sport->dma_is_txing) {
1501 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1503 ucr1 = imx_uart_readl(sport, UCR1);
1504 ucr1 &= ~UCR1_TXDMAEN;
1505 imx_uart_writel(sport, ucr1, UCR1);
1506 sport->dma_is_txing = 0;
1510 * According to the Reference Manual description of the UART SRST bit:
1512 * "Reset the transmit and receive state machines,
1513 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1516 * We don't need to restore the old values from USR1, USR2, URXD and
1517 * UTXD. UBRC is read only, so only save/restore the other three
1520 ubir = imx_uart_readl(sport, UBIR);
1521 ubmr = imx_uart_readl(sport, UBMR);
1522 uts = imx_uart_readl(sport, IMX21_UTS);
1524 ucr2 = imx_uart_readl(sport, UCR2);
1526 imx_uart_writel(sport, ucr2, UCR2);
1528 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1531 /* Restore the registers */
1532 imx_uart_writel(sport, ubir, UBIR);
1533 imx_uart_writel(sport, ubmr, UBMR);
1534 imx_uart_writel(sport, uts, IMX21_UTS);
1538 imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1539 struct ktermios *old)
1541 struct imx_port *sport = (struct imx_port *)port;
1542 unsigned long flags;
1543 u32 ucr2, old_ucr2, ufcr;
1544 unsigned int baud, quot;
1545 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1547 unsigned long num, denom, old_ubir, old_ubmr;
1551 * We only support CS7 and CS8.
1553 while ((termios->c_cflag & CSIZE) != CS7 &&
1554 (termios->c_cflag & CSIZE) != CS8) {
1555 termios->c_cflag &= ~CSIZE;
1556 termios->c_cflag |= old_csize;
1560 del_timer_sync(&sport->timer);
1563 * Ask the core to calculate the divisor for us.
1565 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1566 quot = uart_get_divisor(port, baud);
1568 spin_lock_irqsave(&sport->port.lock, flags);
1571 * Read current UCR2 and save it for future use, then clear all the bits
1572 * except those we will or may need to preserve.
1574 old_ucr2 = imx_uart_readl(sport, UCR2);
1575 ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
1577 ucr2 |= UCR2_SRST | UCR2_IRTS;
1578 if ((termios->c_cflag & CSIZE) == CS8)
1581 if (!sport->have_rtscts)
1582 termios->c_cflag &= ~CRTSCTS;
1584 if (port->rs485.flags & SER_RS485_ENABLED) {
1586 * RTS is mandatory for rs485 operation, so keep
1587 * it under manual control and keep transmitter
1590 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1591 imx_uart_rts_active(sport, &ucr2);
1593 imx_uart_rts_inactive(sport, &ucr2);
1595 } else if (termios->c_cflag & CRTSCTS) {
1597 * Only let receiver control RTS output if we were not requested
1598 * to have RTS inactive (which then should take precedence).
1600 if (ucr2 & UCR2_CTS)
1604 if (termios->c_cflag & CRTSCTS)
1607 if (termios->c_cflag & CSTOPB)
1609 if (termios->c_cflag & PARENB) {
1611 if (termios->c_cflag & PARODD)
1615 sport->port.read_status_mask = 0;
1616 if (termios->c_iflag & INPCK)
1617 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1618 if (termios->c_iflag & (BRKINT | PARMRK))
1619 sport->port.read_status_mask |= URXD_BRK;
1622 * Characters to ignore
1624 sport->port.ignore_status_mask = 0;
1625 if (termios->c_iflag & IGNPAR)
1626 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1627 if (termios->c_iflag & IGNBRK) {
1628 sport->port.ignore_status_mask |= URXD_BRK;
1630 * If we're ignoring parity and break indicators,
1631 * ignore overruns too (for real raw support).
1633 if (termios->c_iflag & IGNPAR)
1634 sport->port.ignore_status_mask |= URXD_OVRRUN;
1637 if ((termios->c_cflag & CREAD) == 0)
1638 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1641 * Update the per-port timeout.
1643 uart_update_timeout(port, termios->c_cflag, baud);
1645 /* custom-baudrate handling */
1646 div = sport->port.uartclk / (baud * 16);
1647 if (baud == 38400 && quot != div)
1648 baud = sport->port.uartclk / (quot * 16);
1650 div = sport->port.uartclk / (baud * 16);
1656 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1657 1 << 16, 1 << 16, &num, &denom);
1659 tdiv64 = sport->port.uartclk;
1661 do_div(tdiv64, denom * 16 * div);
1662 tty_termios_encode_baud_rate(termios,
1663 (speed_t)tdiv64, (speed_t)tdiv64);
1668 ufcr = imx_uart_readl(sport, UFCR);
1669 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1670 imx_uart_writel(sport, ufcr, UFCR);
1673 * Two registers below should always be written both and in this
1674 * particular order. One consequence is that we need to check if any of
1675 * them changes and then update both. We do need the check for change
1676 * as even writing the same values seem to "restart"
1677 * transmission/receiving logic in the hardware, that leads to data
1678 * breakage even when rate doesn't in fact change. E.g., user switches
1679 * RTS/CTS handshake and suddenly gets broken bytes.
1681 old_ubir = imx_uart_readl(sport, UBIR);
1682 old_ubmr = imx_uart_readl(sport, UBMR);
1683 if (old_ubir != num || old_ubmr != denom) {
1684 imx_uart_writel(sport, num, UBIR);
1685 imx_uart_writel(sport, denom, UBMR);
1688 if (!imx_uart_is_imx1(sport))
1689 imx_uart_writel(sport, sport->port.uartclk / div / 1000,
1692 imx_uart_writel(sport, ucr2, UCR2);
1694 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1695 imx_uart_enable_ms(&sport->port);
1697 spin_unlock_irqrestore(&sport->port.lock, flags);
1700 static const char *imx_uart_type(struct uart_port *port)
1702 struct imx_port *sport = (struct imx_port *)port;
1704 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1708 * Configure/autoconfigure the port.
1710 static void imx_uart_config_port(struct uart_port *port, int flags)
1712 struct imx_port *sport = (struct imx_port *)port;
1714 if (flags & UART_CONFIG_TYPE)
1715 sport->port.type = PORT_IMX;
1719 * Verify the new serial_struct (for TIOCSSERIAL).
1720 * The only change we allow are to the flags and type, and
1721 * even then only between PORT_IMX and PORT_UNKNOWN
1724 imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1726 struct imx_port *sport = (struct imx_port *)port;
1729 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1731 if (sport->port.irq != ser->irq)
1733 if (ser->io_type != UPIO_MEM)
1735 if (sport->port.uartclk / 16 != ser->baud_base)
1737 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1739 if (sport->port.iobase != ser->port)
1746 #if defined(CONFIG_CONSOLE_POLL)
1748 static int imx_uart_poll_init(struct uart_port *port)
1750 struct imx_port *sport = (struct imx_port *)port;
1751 unsigned long flags;
1755 retval = clk_prepare_enable(sport->clk_ipg);
1758 retval = clk_prepare_enable(sport->clk_per);
1760 clk_disable_unprepare(sport->clk_ipg);
1762 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1764 spin_lock_irqsave(&sport->port.lock, flags);
1767 * Be careful about the order of enabling bits here. First enable the
1768 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1769 * This prevents that a character that already sits in the RX fifo is
1770 * triggering an irq but the try to fetch it from there results in an
1771 * exception because UARTEN or RXEN is still off.
1773 ucr1 = imx_uart_readl(sport, UCR1);
1774 ucr2 = imx_uart_readl(sport, UCR2);
1776 if (imx_uart_is_imx1(sport))
1777 ucr1 |= IMX1_UCR1_UARTCLKEN;
1779 ucr1 |= UCR1_UARTEN;
1780 ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1785 imx_uart_writel(sport, ucr1, UCR1);
1786 imx_uart_writel(sport, ucr2, UCR2);
1788 /* now enable irqs */
1789 imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1790 imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1792 spin_unlock_irqrestore(&sport->port.lock, flags);
1797 static int imx_uart_poll_get_char(struct uart_port *port)
1799 struct imx_port *sport = (struct imx_port *)port;
1800 if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1801 return NO_POLL_CHAR;
1803 return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1806 static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1808 struct imx_port *sport = (struct imx_port *)port;
1809 unsigned int status;
1813 status = imx_uart_readl(sport, USR1);
1814 } while (~status & USR1_TRDY);
1817 imx_uart_writel(sport, c, URTX0);
1821 status = imx_uart_readl(sport, USR2);
1822 } while (~status & USR2_TXDC);
1826 /* called with port.lock taken and irqs off or from .probe without locking */
1827 static int imx_uart_rs485_config(struct uart_port *port,
1828 struct serial_rs485 *rs485conf)
1830 struct imx_port *sport = (struct imx_port *)port;
1834 rs485conf->delay_rts_before_send = 0;
1835 rs485conf->delay_rts_after_send = 0;
1837 /* RTS is required to control the transmitter */
1838 if (!sport->have_rtscts && !sport->have_rtsgpio)
1839 rs485conf->flags &= ~SER_RS485_ENABLED;
1841 if (rs485conf->flags & SER_RS485_ENABLED) {
1842 /* Enable receiver if low-active RTS signal is requested */
1843 if (sport->have_rtscts && !sport->have_rtsgpio &&
1844 !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1845 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1847 /* disable transmitter */
1848 ucr2 = imx_uart_readl(sport, UCR2);
1849 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1850 imx_uart_rts_active(sport, &ucr2);
1852 imx_uart_rts_inactive(sport, &ucr2);
1853 imx_uart_writel(sport, ucr2, UCR2);
1856 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1857 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1858 rs485conf->flags & SER_RS485_RX_DURING_TX)
1859 imx_uart_start_rx(port);
1861 port->rs485 = *rs485conf;
1866 static const struct uart_ops imx_uart_pops = {
1867 .tx_empty = imx_uart_tx_empty,
1868 .set_mctrl = imx_uart_set_mctrl,
1869 .get_mctrl = imx_uart_get_mctrl,
1870 .stop_tx = imx_uart_stop_tx,
1871 .start_tx = imx_uart_start_tx,
1872 .stop_rx = imx_uart_stop_rx,
1873 .enable_ms = imx_uart_enable_ms,
1874 .break_ctl = imx_uart_break_ctl,
1875 .startup = imx_uart_startup,
1876 .shutdown = imx_uart_shutdown,
1877 .flush_buffer = imx_uart_flush_buffer,
1878 .set_termios = imx_uart_set_termios,
1879 .type = imx_uart_type,
1880 .config_port = imx_uart_config_port,
1881 .verify_port = imx_uart_verify_port,
1882 #if defined(CONFIG_CONSOLE_POLL)
1883 .poll_init = imx_uart_poll_init,
1884 .poll_get_char = imx_uart_poll_get_char,
1885 .poll_put_char = imx_uart_poll_put_char,
1889 static struct imx_port *imx_uart_ports[UART_NR];
1891 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1892 static void imx_uart_console_putchar(struct uart_port *port, int ch)
1894 struct imx_port *sport = (struct imx_port *)port;
1896 while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1899 imx_uart_writel(sport, ch, URTX0);
1903 * Interrupts are disabled on entering
1906 imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1908 struct imx_port *sport = imx_uart_ports[co->index];
1909 struct imx_port_ucrs old_ucr;
1911 unsigned long flags = 0;
1915 retval = clk_enable(sport->clk_per);
1918 retval = clk_enable(sport->clk_ipg);
1920 clk_disable(sport->clk_per);
1924 if (sport->port.sysrq)
1926 else if (oops_in_progress)
1927 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1929 spin_lock_irqsave(&sport->port.lock, flags);
1932 * First, save UCR1/2/3 and then disable interrupts
1934 imx_uart_ucrs_save(sport, &old_ucr);
1935 ucr1 = old_ucr.ucr1;
1937 if (imx_uart_is_imx1(sport))
1938 ucr1 |= IMX1_UCR1_UARTCLKEN;
1939 ucr1 |= UCR1_UARTEN;
1940 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1942 imx_uart_writel(sport, ucr1, UCR1);
1944 imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
1946 uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
1949 * Finally, wait for transmitter to become empty
1950 * and restore UCR1/2/3
1952 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
1954 imx_uart_ucrs_restore(sport, &old_ucr);
1957 spin_unlock_irqrestore(&sport->port.lock, flags);
1959 clk_disable(sport->clk_ipg);
1960 clk_disable(sport->clk_per);
1964 * If the port was already initialised (eg, by a boot loader),
1965 * try to determine the current setup.
1968 imx_uart_console_get_options(struct imx_port *sport, int *baud,
1969 int *parity, int *bits)
1972 if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
1973 /* ok, the port was enabled */
1974 unsigned int ucr2, ubir, ubmr, uartclk;
1975 unsigned int baud_raw;
1976 unsigned int ucfr_rfdiv;
1978 ucr2 = imx_uart_readl(sport, UCR2);
1981 if (ucr2 & UCR2_PREN) {
1982 if (ucr2 & UCR2_PROE)
1993 ubir = imx_uart_readl(sport, UBIR) & 0xffff;
1994 ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
1996 ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
1997 if (ucfr_rfdiv == 6)
2000 ucfr_rfdiv = 6 - ucfr_rfdiv;
2002 uartclk = clk_get_rate(sport->clk_per);
2003 uartclk /= ucfr_rfdiv;
2006 * The next code provides exact computation of
2007 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2008 * without need of float support or long long division,
2009 * which would be required to prevent 32bit arithmetic overflow
2011 unsigned int mul = ubir + 1;
2012 unsigned int div = 16 * (ubmr + 1);
2013 unsigned int rem = uartclk % div;
2015 baud_raw = (uartclk / div) * mul;
2016 baud_raw += (rem * mul + div / 2) / div;
2017 *baud = (baud_raw + 50) / 100 * 100;
2020 if (*baud != baud_raw)
2021 dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
2027 imx_uart_console_setup(struct console *co, char *options)
2029 struct imx_port *sport;
2037 * Check whether an invalid uart number has been specified, and
2038 * if so, search for the first available port that does have
2041 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2043 sport = imx_uart_ports[co->index];
2047 /* For setting the registers, we only need to enable the ipg clock. */
2048 retval = clk_prepare_enable(sport->clk_ipg);
2053 uart_parse_options(options, &baud, &parity, &bits, &flow);
2055 imx_uart_console_get_options(sport, &baud, &parity, &bits);
2057 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2059 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2061 clk_disable(sport->clk_ipg);
2063 clk_unprepare(sport->clk_ipg);
2067 retval = clk_prepare(sport->clk_per);
2069 clk_unprepare(sport->clk_ipg);
2075 static struct uart_driver imx_uart_uart_driver;
2076 static struct console imx_uart_console = {
2078 .write = imx_uart_console_write,
2079 .device = uart_console_device,
2080 .setup = imx_uart_console_setup,
2081 .flags = CON_PRINTBUFFER,
2083 .data = &imx_uart_uart_driver,
2086 #define IMX_CONSOLE &imx_uart_console
2089 static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
2091 struct imx_port *sport = (struct imx_port *)port;
2093 while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
2096 imx_uart_writel(sport, ch, URTX0);
2099 static void imx_uart_console_early_write(struct console *con, const char *s,
2102 struct earlycon_device *dev = con->data;
2104 uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
2108 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
2110 if (!dev->port.membase)
2113 dev->con->write = imx_uart_console_early_write;
2117 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2118 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2122 #define IMX_CONSOLE NULL
2125 static struct uart_driver imx_uart_uart_driver = {
2126 .owner = THIS_MODULE,
2127 .driver_name = DRIVER_NAME,
2128 .dev_name = DEV_NAME,
2129 .major = SERIAL_IMX_MAJOR,
2130 .minor = MINOR_START,
2131 .nr = ARRAY_SIZE(imx_uart_ports),
2132 .cons = IMX_CONSOLE,
2137 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2138 * could successfully get all information from dt or a negative errno.
2140 static int imx_uart_probe_dt(struct imx_port *sport,
2141 struct platform_device *pdev)
2143 struct device_node *np = pdev->dev.of_node;
2146 sport->devdata = of_device_get_match_data(&pdev->dev);
2147 if (!sport->devdata)
2148 /* no device tree device */
2151 ret = of_alias_get_id(np, "serial");
2153 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2156 sport->port.line = ret;
2158 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2159 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2160 sport->have_rtscts = 1;
2162 if (of_get_property(np, "fsl,dte-mode", NULL))
2163 sport->dte_mode = 1;
2165 if (of_get_property(np, "rts-gpios", NULL))
2166 sport->have_rtsgpio = 1;
2171 static inline int imx_uart_probe_dt(struct imx_port *sport,
2172 struct platform_device *pdev)
2178 static void imx_uart_probe_pdata(struct imx_port *sport,
2179 struct platform_device *pdev)
2181 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2183 sport->port.line = pdev->id;
2184 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
2189 if (pdata->flags & IMXUART_HAVE_RTSCTS)
2190 sport->have_rtscts = 1;
2193 static int imx_uart_probe(struct platform_device *pdev)
2195 struct imx_port *sport;
2199 struct resource *res;
2200 int txirq, rxirq, rtsirq;
2202 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2206 ret = imx_uart_probe_dt(sport, pdev);
2208 imx_uart_probe_pdata(sport, pdev);
2212 if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2213 dev_err(&pdev->dev, "serial%d out of range\n",
2218 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2219 base = devm_ioremap_resource(&pdev->dev, res);
2221 return PTR_ERR(base);
2223 rxirq = platform_get_irq(pdev, 0);
2224 txirq = platform_get_irq_optional(pdev, 1);
2225 rtsirq = platform_get_irq_optional(pdev, 2);
2227 sport->port.dev = &pdev->dev;
2228 sport->port.mapbase = res->start;
2229 sport->port.membase = base;
2230 sport->port.type = PORT_IMX,
2231 sport->port.iotype = UPIO_MEM;
2232 sport->port.irq = rxirq;
2233 sport->port.fifosize = 32;
2234 sport->port.ops = &imx_uart_pops;
2235 sport->port.rs485_config = imx_uart_rs485_config;
2236 sport->port.flags = UPF_BOOT_AUTOCONF;
2237 timer_setup(&sport->timer, imx_uart_timeout, 0);
2239 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2240 if (IS_ERR(sport->gpios))
2241 return PTR_ERR(sport->gpios);
2243 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2244 if (IS_ERR(sport->clk_ipg)) {
2245 ret = PTR_ERR(sport->clk_ipg);
2246 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2250 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2251 if (IS_ERR(sport->clk_per)) {
2252 ret = PTR_ERR(sport->clk_per);
2253 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2257 sport->port.uartclk = clk_get_rate(sport->clk_per);
2259 /* For register access, we only need to enable the ipg clock. */
2260 ret = clk_prepare_enable(sport->clk_ipg);
2262 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2266 /* initialize shadow register values */
2267 sport->ucr1 = readl(sport->port.membase + UCR1);
2268 sport->ucr2 = readl(sport->port.membase + UCR2);
2269 sport->ucr3 = readl(sport->port.membase + UCR3);
2270 sport->ucr4 = readl(sport->port.membase + UCR4);
2271 sport->ufcr = readl(sport->port.membase + UFCR);
2273 uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2275 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2276 (!sport->have_rtscts && !sport->have_rtsgpio))
2277 dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2280 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2281 * signal cannot be set low during transmission in case the
2282 * receiver is off (limitation of the i.MX UART IP).
2284 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2285 sport->have_rtscts && !sport->have_rtsgpio &&
2286 (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2287 !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2289 "low-active RTS not possible when receiver is off, enabling receiver\n");
2291 imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2293 /* Disable interrupts before requesting them */
2294 ucr1 = imx_uart_readl(sport, UCR1);
2295 ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2296 UCR1_TRDYEN | UCR1_RTSDEN);
2297 imx_uart_writel(sport, ucr1, UCR1);
2299 if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2301 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2302 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2303 * and DCD (when they are outputs) or enables the respective
2304 * irqs. So set this bit early, i.e. before requesting irqs.
2306 u32 ufcr = imx_uart_readl(sport, UFCR);
2307 if (!(ufcr & UFCR_DCEDTE))
2308 imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2311 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2312 * enabled later because they cannot be cleared
2313 * (confirmed on i.MX25) which makes them unusable.
2315 imx_uart_writel(sport,
2316 IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2320 u32 ucr3 = UCR3_DSR;
2321 u32 ufcr = imx_uart_readl(sport, UFCR);
2322 if (ufcr & UFCR_DCEDTE)
2323 imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2325 if (!imx_uart_is_imx1(sport))
2326 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2327 imx_uart_writel(sport, ucr3, UCR3);
2330 clk_disable_unprepare(sport->clk_ipg);
2333 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2334 * chips only have one interrupt.
2337 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2338 dev_name(&pdev->dev), sport);
2340 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2345 ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2346 dev_name(&pdev->dev), sport);
2348 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2353 ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
2354 dev_name(&pdev->dev), sport);
2356 dev_err(&pdev->dev, "failed to request rts irq: %d\n",
2361 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2362 dev_name(&pdev->dev), sport);
2364 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2369 imx_uart_ports[sport->port.line] = sport;
2371 platform_set_drvdata(pdev, sport);
2373 return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2376 static int imx_uart_remove(struct platform_device *pdev)
2378 struct imx_port *sport = platform_get_drvdata(pdev);
2380 return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2383 static void imx_uart_restore_context(struct imx_port *sport)
2385 unsigned long flags;
2387 spin_lock_irqsave(&sport->port.lock, flags);
2388 if (!sport->context_saved) {
2389 spin_unlock_irqrestore(&sport->port.lock, flags);
2393 imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2394 imx_uart_writel(sport, sport->saved_reg[5], UESC);
2395 imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2396 imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2397 imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2398 imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2399 imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2400 imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2401 imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2402 imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2403 sport->context_saved = false;
2404 spin_unlock_irqrestore(&sport->port.lock, flags);
2407 static void imx_uart_save_context(struct imx_port *sport)
2409 unsigned long flags;
2411 /* Save necessary regs */
2412 spin_lock_irqsave(&sport->port.lock, flags);
2413 sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2414 sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2415 sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2416 sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2417 sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2418 sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2419 sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2420 sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2421 sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2422 sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2423 sport->context_saved = true;
2424 spin_unlock_irqrestore(&sport->port.lock, flags);
2427 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2431 ucr3 = imx_uart_readl(sport, UCR3);
2433 imx_uart_writel(sport, USR1_AWAKE, USR1);
2434 ucr3 |= UCR3_AWAKEN;
2436 ucr3 &= ~UCR3_AWAKEN;
2438 imx_uart_writel(sport, ucr3, UCR3);
2440 if (sport->have_rtscts) {
2441 u32 ucr1 = imx_uart_readl(sport, UCR1);
2443 ucr1 |= UCR1_RTSDEN;
2445 ucr1 &= ~UCR1_RTSDEN;
2446 imx_uart_writel(sport, ucr1, UCR1);
2450 static int imx_uart_suspend_noirq(struct device *dev)
2452 struct imx_port *sport = dev_get_drvdata(dev);
2454 imx_uart_save_context(sport);
2456 clk_disable(sport->clk_ipg);
2458 pinctrl_pm_select_sleep_state(dev);
2463 static int imx_uart_resume_noirq(struct device *dev)
2465 struct imx_port *sport = dev_get_drvdata(dev);
2468 pinctrl_pm_select_default_state(dev);
2470 ret = clk_enable(sport->clk_ipg);
2474 imx_uart_restore_context(sport);
2479 static int imx_uart_suspend(struct device *dev)
2481 struct imx_port *sport = dev_get_drvdata(dev);
2484 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2485 disable_irq(sport->port.irq);
2487 ret = clk_prepare_enable(sport->clk_ipg);
2491 /* enable wakeup from i.MX UART */
2492 imx_uart_enable_wakeup(sport, true);
2497 static int imx_uart_resume(struct device *dev)
2499 struct imx_port *sport = dev_get_drvdata(dev);
2501 /* disable wakeup from i.MX UART */
2502 imx_uart_enable_wakeup(sport, false);
2504 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2505 enable_irq(sport->port.irq);
2507 clk_disable_unprepare(sport->clk_ipg);
2512 static int imx_uart_freeze(struct device *dev)
2514 struct imx_port *sport = dev_get_drvdata(dev);
2516 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2518 return clk_prepare_enable(sport->clk_ipg);
2521 static int imx_uart_thaw(struct device *dev)
2523 struct imx_port *sport = dev_get_drvdata(dev);
2525 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2527 clk_disable_unprepare(sport->clk_ipg);
2532 static const struct dev_pm_ops imx_uart_pm_ops = {
2533 .suspend_noirq = imx_uart_suspend_noirq,
2534 .resume_noirq = imx_uart_resume_noirq,
2535 .freeze_noirq = imx_uart_suspend_noirq,
2536 .restore_noirq = imx_uart_resume_noirq,
2537 .suspend = imx_uart_suspend,
2538 .resume = imx_uart_resume,
2539 .freeze = imx_uart_freeze,
2540 .thaw = imx_uart_thaw,
2541 .restore = imx_uart_thaw,
2544 static struct platform_driver imx_uart_platform_driver = {
2545 .probe = imx_uart_probe,
2546 .remove = imx_uart_remove,
2548 .id_table = imx_uart_devtype,
2551 .of_match_table = imx_uart_dt_ids,
2552 .pm = &imx_uart_pm_ops,
2556 static int __init imx_uart_init(void)
2558 int ret = uart_register_driver(&imx_uart_uart_driver);
2563 ret = platform_driver_register(&imx_uart_platform_driver);
2565 uart_unregister_driver(&imx_uart_uart_driver);
2570 static void __exit imx_uart_exit(void)
2572 platform_driver_unregister(&imx_uart_platform_driver);
2573 uart_unregister_driver(&imx_uart_uart_driver);
2576 module_init(imx_uart_init);
2577 module_exit(imx_uart_exit);
2579 MODULE_AUTHOR("Sascha Hauer");
2580 MODULE_DESCRIPTION("IMX generic serial port driver");
2581 MODULE_LICENSE("GPL");
2582 MODULE_ALIAS("platform:imx-uart");