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 caller dependent */
406 static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
411 /* called with port.lock taken and irqs off */
412 static void imx_uart_start_rx(struct uart_port *port)
414 struct imx_port *sport = (struct imx_port *)port;
415 unsigned int ucr1, ucr2;
417 ucr1 = imx_uart_readl(sport, UCR1);
418 ucr2 = imx_uart_readl(sport, UCR2);
422 if (sport->dma_is_enabled) {
423 ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
429 /* Write UCR2 first as it includes RXEN */
430 imx_uart_writel(sport, ucr2, UCR2);
431 imx_uart_writel(sport, ucr1, UCR1);
434 /* called with port.lock taken and irqs off */
435 static void imx_uart_stop_tx(struct uart_port *port)
437 struct imx_port *sport = (struct imx_port *)port;
441 * We are maybe in the SMP context, so if the DMA TX thread is running
442 * on other cpu, we have to wait for it to finish.
444 if (sport->dma_is_txing)
447 ucr1 = imx_uart_readl(sport, UCR1);
448 imx_uart_writel(sport, ucr1 & ~UCR1_TXMPTYEN, UCR1);
450 /* in rs485 mode disable transmitter if shifter is empty */
451 if (port->rs485.flags & SER_RS485_ENABLED &&
452 imx_uart_readl(sport, USR2) & USR2_TXDC) {
453 u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
454 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
455 imx_uart_rts_active(sport, &ucr2);
457 imx_uart_rts_inactive(sport, &ucr2);
458 imx_uart_writel(sport, ucr2, UCR2);
460 imx_uart_start_rx(port);
462 ucr4 = imx_uart_readl(sport, UCR4);
464 imx_uart_writel(sport, ucr4, UCR4);
468 /* called with port.lock taken and irqs off */
469 static void imx_uart_stop_rx(struct uart_port *port)
471 struct imx_port *sport = (struct imx_port *)port;
474 ucr1 = imx_uart_readl(sport, UCR1);
475 ucr2 = imx_uart_readl(sport, UCR2);
477 if (sport->dma_is_enabled) {
478 ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
480 ucr1 &= ~UCR1_RRDYEN;
483 imx_uart_writel(sport, ucr1, UCR1);
486 imx_uart_writel(sport, ucr2, UCR2);
489 /* called with port.lock taken and irqs off */
490 static void imx_uart_enable_ms(struct uart_port *port)
492 struct imx_port *sport = (struct imx_port *)port;
494 mod_timer(&sport->timer, jiffies);
496 mctrl_gpio_enable_ms(sport->gpios);
499 static void imx_uart_dma_tx(struct imx_port *sport);
501 /* called with port.lock taken and irqs off */
502 static inline void imx_uart_transmit_buffer(struct imx_port *sport)
504 struct circ_buf *xmit = &sport->port.state->xmit;
506 if (sport->port.x_char) {
508 imx_uart_writel(sport, sport->port.x_char, URTX0);
509 sport->port.icount.tx++;
510 sport->port.x_char = 0;
514 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
515 imx_uart_stop_tx(&sport->port);
519 if (sport->dma_is_enabled) {
522 * We've just sent a X-char Ensure the TX DMA is enabled
523 * and the TX IRQ is disabled.
525 ucr1 = imx_uart_readl(sport, UCR1);
526 ucr1 &= ~UCR1_TXMPTYEN;
527 if (sport->dma_is_txing) {
528 ucr1 |= UCR1_TXDMAEN;
529 imx_uart_writel(sport, ucr1, UCR1);
531 imx_uart_writel(sport, ucr1, UCR1);
532 imx_uart_dma_tx(sport);
538 while (!uart_circ_empty(xmit) &&
539 !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
540 /* send xmit->buf[xmit->tail]
541 * out the port here */
542 imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
543 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
544 sport->port.icount.tx++;
547 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
548 uart_write_wakeup(&sport->port);
550 if (uart_circ_empty(xmit))
551 imx_uart_stop_tx(&sport->port);
554 static void imx_uart_dma_tx_callback(void *data)
556 struct imx_port *sport = data;
557 struct scatterlist *sgl = &sport->tx_sgl[0];
558 struct circ_buf *xmit = &sport->port.state->xmit;
562 spin_lock_irqsave(&sport->port.lock, flags);
564 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
566 ucr1 = imx_uart_readl(sport, UCR1);
567 ucr1 &= ~UCR1_TXDMAEN;
568 imx_uart_writel(sport, ucr1, UCR1);
570 /* update the stat */
571 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
572 sport->port.icount.tx += sport->tx_bytes;
574 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
576 sport->dma_is_txing = 0;
578 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
579 uart_write_wakeup(&sport->port);
581 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
582 imx_uart_dma_tx(sport);
583 else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
584 u32 ucr4 = imx_uart_readl(sport, UCR4);
586 imx_uart_writel(sport, ucr4, UCR4);
589 spin_unlock_irqrestore(&sport->port.lock, flags);
592 /* called with port.lock taken and irqs off */
593 static void imx_uart_dma_tx(struct imx_port *sport)
595 struct circ_buf *xmit = &sport->port.state->xmit;
596 struct scatterlist *sgl = sport->tx_sgl;
597 struct dma_async_tx_descriptor *desc;
598 struct dma_chan *chan = sport->dma_chan_tx;
599 struct device *dev = sport->port.dev;
603 if (sport->dma_is_txing)
606 ucr4 = imx_uart_readl(sport, UCR4);
608 imx_uart_writel(sport, ucr4, UCR4);
610 sport->tx_bytes = uart_circ_chars_pending(xmit);
612 if (xmit->tail < xmit->head) {
613 sport->dma_tx_nents = 1;
614 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
616 sport->dma_tx_nents = 2;
617 sg_init_table(sgl, 2);
618 sg_set_buf(sgl, xmit->buf + xmit->tail,
619 UART_XMIT_SIZE - xmit->tail);
620 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
623 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
625 dev_err(dev, "DMA mapping error for TX.\n");
628 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
629 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
631 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
633 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
636 desc->callback = imx_uart_dma_tx_callback;
637 desc->callback_param = sport;
639 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
640 uart_circ_chars_pending(xmit));
642 ucr1 = imx_uart_readl(sport, UCR1);
643 ucr1 |= UCR1_TXDMAEN;
644 imx_uart_writel(sport, ucr1, UCR1);
647 sport->dma_is_txing = 1;
648 dmaengine_submit(desc);
649 dma_async_issue_pending(chan);
653 /* called with port.lock taken and irqs off */
654 static void imx_uart_start_tx(struct uart_port *port)
656 struct imx_port *sport = (struct imx_port *)port;
659 if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
662 if (port->rs485.flags & SER_RS485_ENABLED) {
665 ucr2 = imx_uart_readl(sport, UCR2);
666 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
667 imx_uart_rts_active(sport, &ucr2);
669 imx_uart_rts_inactive(sport, &ucr2);
670 imx_uart_writel(sport, ucr2, UCR2);
672 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
673 imx_uart_stop_rx(port);
676 * Enable transmitter and shifter empty irq only if DMA is off.
677 * In the DMA case this is done in the tx-callback.
679 if (!sport->dma_is_enabled) {
680 u32 ucr4 = imx_uart_readl(sport, UCR4);
682 imx_uart_writel(sport, ucr4, UCR4);
686 if (!sport->dma_is_enabled) {
687 ucr1 = imx_uart_readl(sport, UCR1);
688 imx_uart_writel(sport, ucr1 | UCR1_TXMPTYEN, UCR1);
691 if (sport->dma_is_enabled) {
692 if (sport->port.x_char) {
693 /* We have X-char to send, so enable TX IRQ and
694 * disable TX DMA to let TX interrupt to send X-char */
695 ucr1 = imx_uart_readl(sport, UCR1);
696 ucr1 &= ~UCR1_TXDMAEN;
697 ucr1 |= UCR1_TXMPTYEN;
698 imx_uart_writel(sport, ucr1, UCR1);
702 if (!uart_circ_empty(&port->state->xmit) &&
703 !uart_tx_stopped(port))
704 imx_uart_dma_tx(sport);
709 static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
711 struct imx_port *sport = dev_id;
714 spin_lock(&sport->port.lock);
716 imx_uart_writel(sport, USR1_RTSD, USR1);
717 usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
718 uart_handle_cts_change(&sport->port, !!usr1);
719 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
721 spin_unlock(&sport->port.lock);
725 static irqreturn_t imx_uart_txint(int irq, void *dev_id)
727 struct imx_port *sport = dev_id;
729 spin_lock(&sport->port.lock);
730 imx_uart_transmit_buffer(sport);
731 spin_unlock(&sport->port.lock);
735 static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
737 struct imx_port *sport = dev_id;
738 unsigned int rx, flg, ignored = 0;
739 struct tty_port *port = &sport->port.state->port;
741 spin_lock(&sport->port.lock);
743 while (imx_uart_readl(sport, USR2) & USR2_RDR) {
747 sport->port.icount.rx++;
749 rx = imx_uart_readl(sport, URXD0);
751 usr2 = imx_uart_readl(sport, USR2);
752 if (usr2 & USR2_BRCD) {
753 imx_uart_writel(sport, USR2_BRCD, USR2);
754 if (uart_handle_break(&sport->port))
758 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
761 if (unlikely(rx & URXD_ERR)) {
763 sport->port.icount.brk++;
764 else if (rx & URXD_PRERR)
765 sport->port.icount.parity++;
766 else if (rx & URXD_FRMERR)
767 sport->port.icount.frame++;
768 if (rx & URXD_OVRRUN)
769 sport->port.icount.overrun++;
771 if (rx & sport->port.ignore_status_mask) {
777 rx &= (sport->port.read_status_mask | 0xFF);
781 else if (rx & URXD_PRERR)
783 else if (rx & URXD_FRMERR)
785 if (rx & URXD_OVRRUN)
789 sport->port.sysrq = 0;
793 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
796 if (tty_insert_flip_char(port, rx, flg) == 0)
797 sport->port.icount.buf_overrun++;
801 spin_unlock(&sport->port.lock);
802 tty_flip_buffer_push(port);
806 static void imx_uart_clear_rx_errors(struct imx_port *sport);
809 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
811 static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
813 unsigned int tmp = TIOCM_DSR;
814 unsigned usr1 = imx_uart_readl(sport, USR1);
815 unsigned usr2 = imx_uart_readl(sport, USR2);
817 if (usr1 & USR1_RTSS)
820 /* in DCE mode DCDIN is always 0 */
821 if (!(usr2 & USR2_DCDIN))
825 if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
832 * Handle any change of modem status signal since we were last called.
834 static void imx_uart_mctrl_check(struct imx_port *sport)
836 unsigned int status, changed;
838 status = imx_uart_get_hwmctrl(sport);
839 changed = status ^ sport->old_status;
844 sport->old_status = status;
846 if (changed & TIOCM_RI && status & TIOCM_RI)
847 sport->port.icount.rng++;
848 if (changed & TIOCM_DSR)
849 sport->port.icount.dsr++;
850 if (changed & TIOCM_CAR)
851 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
852 if (changed & TIOCM_CTS)
853 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
855 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
858 static irqreturn_t imx_uart_int(int irq, void *dev_id)
860 struct imx_port *sport = dev_id;
861 unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
862 irqreturn_t ret = IRQ_NONE;
864 usr1 = imx_uart_readl(sport, USR1);
865 usr2 = imx_uart_readl(sport, USR2);
866 ucr1 = imx_uart_readl(sport, UCR1);
867 ucr2 = imx_uart_readl(sport, UCR2);
868 ucr3 = imx_uart_readl(sport, UCR3);
869 ucr4 = imx_uart_readl(sport, UCR4);
872 * Even if a condition is true that can trigger an irq only handle it if
873 * the respective irq source is enabled. This prevents some undesired
874 * actions, for example if a character that sits in the RX FIFO and that
875 * should be fetched via DMA is tried to be fetched using PIO. Or the
876 * receiver is currently off and so reading from URXD0 results in an
877 * exception. So just mask the (raw) status bits for disabled irqs.
879 if ((ucr1 & UCR1_RRDYEN) == 0)
881 if ((ucr2 & UCR2_ATEN) == 0)
883 if ((ucr1 & UCR1_TXMPTYEN) == 0)
885 if ((ucr4 & UCR4_TCEN) == 0)
887 if ((ucr3 & UCR3_DTRDEN) == 0)
889 if ((ucr1 & UCR1_RTSDEN) == 0)
891 if ((ucr3 & UCR3_AWAKEN) == 0)
893 if ((ucr4 & UCR4_OREN) == 0)
896 if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
897 imx_uart_rxint(irq, dev_id);
901 if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
902 imx_uart_txint(irq, dev_id);
906 if (usr1 & USR1_DTRD) {
907 imx_uart_writel(sport, USR1_DTRD, USR1);
909 spin_lock(&sport->port.lock);
910 imx_uart_mctrl_check(sport);
911 spin_unlock(&sport->port.lock);
916 if (usr1 & USR1_RTSD) {
917 imx_uart_rtsint(irq, dev_id);
921 if (usr1 & USR1_AWAKE) {
922 imx_uart_writel(sport, USR1_AWAKE, USR1);
926 if (usr2 & USR2_ORE) {
927 sport->port.icount.overrun++;
928 imx_uart_writel(sport, USR2_ORE, USR2);
936 * Return TIOCSER_TEMT when transmitter is not busy.
938 static unsigned int imx_uart_tx_empty(struct uart_port *port)
940 struct imx_port *sport = (struct imx_port *)port;
943 ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
945 /* If the TX DMA is working, return 0. */
946 if (sport->dma_is_txing)
952 /* called with port.lock taken and irqs off */
953 static unsigned int imx_uart_get_mctrl(struct uart_port *port)
955 struct imx_port *sport = (struct imx_port *)port;
956 unsigned int ret = imx_uart_get_hwmctrl(sport);
958 mctrl_gpio_get(sport->gpios, &ret);
963 /* called with port.lock taken and irqs off */
964 static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
966 struct imx_port *sport = (struct imx_port *)port;
969 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
972 ucr2 = imx_uart_readl(sport, UCR2);
973 ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
974 if (mctrl & TIOCM_RTS)
975 ucr2 |= UCR2_CTS | UCR2_CTSC;
976 imx_uart_writel(sport, ucr2, UCR2);
979 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
980 if (!(mctrl & TIOCM_DTR))
982 imx_uart_writel(sport, ucr3, UCR3);
984 uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
985 if (mctrl & TIOCM_LOOP)
987 imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
989 mctrl_gpio_set(sport->gpios, mctrl);
993 * Interrupts always disabled.
995 static void imx_uart_break_ctl(struct uart_port *port, int break_state)
997 struct imx_port *sport = (struct imx_port *)port;
1001 spin_lock_irqsave(&sport->port.lock, flags);
1003 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
1005 if (break_state != 0)
1006 ucr1 |= UCR1_SNDBRK;
1008 imx_uart_writel(sport, ucr1, UCR1);
1010 spin_unlock_irqrestore(&sport->port.lock, flags);
1014 * This is our per-port timeout handler, for checking the
1015 * modem status signals.
1017 static void imx_uart_timeout(struct timer_list *t)
1019 struct imx_port *sport = from_timer(sport, t, timer);
1020 unsigned long flags;
1022 if (sport->port.state) {
1023 spin_lock_irqsave(&sport->port.lock, flags);
1024 imx_uart_mctrl_check(sport);
1025 spin_unlock_irqrestore(&sport->port.lock, flags);
1027 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
1031 #define RX_BUF_SIZE (PAGE_SIZE)
1034 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
1035 * [1] the RX DMA buffer is full.
1036 * [2] the aging timer expires
1038 * Condition [2] is triggered when a character has been sitting in the FIFO
1039 * for at least 8 byte durations.
1041 static void imx_uart_dma_rx_callback(void *data)
1043 struct imx_port *sport = data;
1044 struct dma_chan *chan = sport->dma_chan_rx;
1045 struct scatterlist *sgl = &sport->rx_sgl;
1046 struct tty_port *port = &sport->port.state->port;
1047 struct dma_tx_state state;
1048 struct circ_buf *rx_ring = &sport->rx_ring;
1049 enum dma_status status;
1050 unsigned int w_bytes = 0;
1051 unsigned int r_bytes;
1052 unsigned int bd_size;
1054 status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
1056 if (status == DMA_ERROR) {
1057 imx_uart_clear_rx_errors(sport);
1061 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
1064 * The state-residue variable represents the empty space
1065 * relative to the entire buffer. Taking this in consideration
1066 * the head is always calculated base on the buffer total
1067 * length - DMA transaction residue. The UART script from the
1068 * SDMA firmware will jump to the next buffer descriptor,
1069 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1070 * Taking this in consideration the tail is always at the
1071 * beginning of the buffer descriptor that contains the head.
1074 /* Calculate the head */
1075 rx_ring->head = sg_dma_len(sgl) - state.residue;
1077 /* Calculate the tail. */
1078 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1079 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1081 if (rx_ring->head <= sg_dma_len(sgl) &&
1082 rx_ring->head > rx_ring->tail) {
1084 /* Move data from tail to head */
1085 r_bytes = rx_ring->head - rx_ring->tail;
1087 /* CPU claims ownership of RX DMA buffer */
1088 dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1091 w_bytes = tty_insert_flip_string(port,
1092 sport->rx_buf + rx_ring->tail, r_bytes);
1094 /* UART retrieves ownership of RX DMA buffer */
1095 dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1098 if (w_bytes != r_bytes)
1099 sport->port.icount.buf_overrun++;
1101 sport->port.icount.rx += w_bytes;
1103 WARN_ON(rx_ring->head > sg_dma_len(sgl));
1104 WARN_ON(rx_ring->head <= rx_ring->tail);
1109 tty_flip_buffer_push(port);
1110 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1114 /* RX DMA buffer periods */
1115 #define RX_DMA_PERIODS 4
1117 static int imx_uart_start_rx_dma(struct imx_port *sport)
1119 struct scatterlist *sgl = &sport->rx_sgl;
1120 struct dma_chan *chan = sport->dma_chan_rx;
1121 struct device *dev = sport->port.dev;
1122 struct dma_async_tx_descriptor *desc;
1125 sport->rx_ring.head = 0;
1126 sport->rx_ring.tail = 0;
1127 sport->rx_periods = RX_DMA_PERIODS;
1129 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1130 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1132 dev_err(dev, "DMA mapping error for RX.\n");
1136 desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1137 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1138 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1141 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1142 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1145 desc->callback = imx_uart_dma_rx_callback;
1146 desc->callback_param = sport;
1148 dev_dbg(dev, "RX: prepare for the DMA.\n");
1149 sport->dma_is_rxing = 1;
1150 sport->rx_cookie = dmaengine_submit(desc);
1151 dma_async_issue_pending(chan);
1155 static void imx_uart_clear_rx_errors(struct imx_port *sport)
1157 struct tty_port *port = &sport->port.state->port;
1160 usr1 = imx_uart_readl(sport, USR1);
1161 usr2 = imx_uart_readl(sport, USR2);
1163 if (usr2 & USR2_BRCD) {
1164 sport->port.icount.brk++;
1165 imx_uart_writel(sport, USR2_BRCD, USR2);
1166 uart_handle_break(&sport->port);
1167 if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
1168 sport->port.icount.buf_overrun++;
1169 tty_flip_buffer_push(port);
1171 if (usr1 & USR1_FRAMERR) {
1172 sport->port.icount.frame++;
1173 imx_uart_writel(sport, USR1_FRAMERR, USR1);
1174 } else if (usr1 & USR1_PARITYERR) {
1175 sport->port.icount.parity++;
1176 imx_uart_writel(sport, USR1_PARITYERR, USR1);
1180 if (usr2 & USR2_ORE) {
1181 sport->port.icount.overrun++;
1182 imx_uart_writel(sport, USR2_ORE, USR2);
1187 #define TXTL_DEFAULT 2 /* reset default */
1188 #define RXTL_DEFAULT 1 /* reset default */
1189 #define TXTL_DMA 8 /* DMA burst setting */
1190 #define RXTL_DMA 9 /* DMA burst setting */
1192 static void imx_uart_setup_ufcr(struct imx_port *sport,
1193 unsigned char txwl, unsigned char rxwl)
1197 /* set receiver / transmitter trigger level */
1198 val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1199 val |= txwl << UFCR_TXTL_SHF | rxwl;
1200 imx_uart_writel(sport, val, UFCR);
1203 static void imx_uart_dma_exit(struct imx_port *sport)
1205 if (sport->dma_chan_rx) {
1206 dmaengine_terminate_sync(sport->dma_chan_rx);
1207 dma_release_channel(sport->dma_chan_rx);
1208 sport->dma_chan_rx = NULL;
1209 sport->rx_cookie = -EINVAL;
1210 kfree(sport->rx_buf);
1211 sport->rx_buf = NULL;
1214 if (sport->dma_chan_tx) {
1215 dmaengine_terminate_sync(sport->dma_chan_tx);
1216 dma_release_channel(sport->dma_chan_tx);
1217 sport->dma_chan_tx = NULL;
1221 static int imx_uart_dma_init(struct imx_port *sport)
1223 struct dma_slave_config slave_config = {};
1224 struct device *dev = sport->port.dev;
1227 /* Prepare for RX : */
1228 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1229 if (!sport->dma_chan_rx) {
1230 dev_dbg(dev, "cannot get the DMA channel.\n");
1235 slave_config.direction = DMA_DEV_TO_MEM;
1236 slave_config.src_addr = sport->port.mapbase + URXD0;
1237 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1238 /* one byte less than the watermark level to enable the aging timer */
1239 slave_config.src_maxburst = RXTL_DMA - 1;
1240 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1242 dev_err(dev, "error in RX dma configuration.\n");
1246 sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
1247 if (!sport->rx_buf) {
1251 sport->rx_ring.buf = sport->rx_buf;
1253 /* Prepare for TX : */
1254 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1255 if (!sport->dma_chan_tx) {
1256 dev_err(dev, "cannot get the TX DMA channel!\n");
1261 slave_config.direction = DMA_MEM_TO_DEV;
1262 slave_config.dst_addr = sport->port.mapbase + URTX0;
1263 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1264 slave_config.dst_maxburst = TXTL_DMA;
1265 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1267 dev_err(dev, "error in TX dma configuration.");
1273 imx_uart_dma_exit(sport);
1277 static void imx_uart_enable_dma(struct imx_port *sport)
1281 imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1284 ucr1 = imx_uart_readl(sport, UCR1);
1285 ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1286 imx_uart_writel(sport, ucr1, UCR1);
1288 sport->dma_is_enabled = 1;
1291 static void imx_uart_disable_dma(struct imx_port *sport)
1296 ucr1 = imx_uart_readl(sport, UCR1);
1297 ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1298 imx_uart_writel(sport, ucr1, UCR1);
1300 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1302 sport->dma_is_enabled = 0;
1305 /* half the RX buffer size */
1308 static int imx_uart_startup(struct uart_port *port)
1310 struct imx_port *sport = (struct imx_port *)port;
1312 unsigned long flags;
1313 int dma_is_inited = 0;
1314 u32 ucr1, ucr2, ucr4;
1316 retval = clk_prepare_enable(sport->clk_per);
1319 retval = clk_prepare_enable(sport->clk_ipg);
1321 clk_disable_unprepare(sport->clk_per);
1325 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1327 /* disable the DREN bit (Data Ready interrupt enable) before
1330 ucr4 = imx_uart_readl(sport, UCR4);
1332 /* set the trigger level for CTS */
1333 ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1334 ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1336 imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
1338 /* Can we enable the DMA support? */
1339 if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1342 spin_lock_irqsave(&sport->port.lock, flags);
1343 /* Reset fifo's and state machines */
1346 ucr2 = imx_uart_readl(sport, UCR2);
1348 imx_uart_writel(sport, ucr2, UCR2);
1350 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1354 * Finally, clear and enable interrupts
1356 imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1357 imx_uart_writel(sport, USR2_ORE, USR2);
1359 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1360 ucr1 |= UCR1_UARTEN;
1361 if (sport->have_rtscts)
1362 ucr1 |= UCR1_RTSDEN;
1364 imx_uart_writel(sport, ucr1, UCR1);
1366 ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
1367 if (!sport->dma_is_enabled)
1369 imx_uart_writel(sport, ucr4, UCR4);
1371 ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1372 ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1373 if (!sport->have_rtscts)
1376 * make sure the edge sensitive RTS-irq is disabled,
1377 * we're using RTSD instead.
1379 if (!imx_uart_is_imx1(sport))
1380 ucr2 &= ~UCR2_RTSEN;
1381 imx_uart_writel(sport, ucr2, UCR2);
1383 if (!imx_uart_is_imx1(sport)) {
1386 ucr3 = imx_uart_readl(sport, UCR3);
1388 ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1390 if (sport->dte_mode)
1391 /* disable broken interrupts */
1392 ucr3 &= ~(UCR3_RI | UCR3_DCD);
1394 imx_uart_writel(sport, ucr3, UCR3);
1398 * Enable modem status interrupts
1400 imx_uart_enable_ms(&sport->port);
1402 if (dma_is_inited) {
1403 imx_uart_enable_dma(sport);
1404 imx_uart_start_rx_dma(sport);
1406 ucr1 = imx_uart_readl(sport, UCR1);
1407 ucr1 |= UCR1_RRDYEN;
1408 imx_uart_writel(sport, ucr1, UCR1);
1410 ucr2 = imx_uart_readl(sport, UCR2);
1412 imx_uart_writel(sport, ucr2, UCR2);
1415 spin_unlock_irqrestore(&sport->port.lock, flags);
1420 static void imx_uart_shutdown(struct uart_port *port)
1422 struct imx_port *sport = (struct imx_port *)port;
1423 unsigned long flags;
1424 u32 ucr1, ucr2, ucr4;
1426 if (sport->dma_is_enabled) {
1427 dmaengine_terminate_sync(sport->dma_chan_tx);
1428 if (sport->dma_is_txing) {
1429 dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
1430 sport->dma_tx_nents, DMA_TO_DEVICE);
1431 sport->dma_is_txing = 0;
1433 dmaengine_terminate_sync(sport->dma_chan_rx);
1434 if (sport->dma_is_rxing) {
1435 dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
1436 1, DMA_FROM_DEVICE);
1437 sport->dma_is_rxing = 0;
1440 spin_lock_irqsave(&sport->port.lock, flags);
1441 imx_uart_stop_tx(port);
1442 imx_uart_stop_rx(port);
1443 imx_uart_disable_dma(sport);
1444 spin_unlock_irqrestore(&sport->port.lock, flags);
1445 imx_uart_dma_exit(sport);
1448 mctrl_gpio_disable_ms(sport->gpios);
1450 spin_lock_irqsave(&sport->port.lock, flags);
1451 ucr2 = imx_uart_readl(sport, UCR2);
1452 ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1453 imx_uart_writel(sport, ucr2, UCR2);
1455 ucr4 = imx_uart_readl(sport, UCR4);
1457 imx_uart_writel(sport, ucr4, UCR4);
1458 spin_unlock_irqrestore(&sport->port.lock, flags);
1463 del_timer_sync(&sport->timer);
1466 * Disable all interrupts, port and break condition.
1469 spin_lock_irqsave(&sport->port.lock, flags);
1470 ucr1 = imx_uart_readl(sport, UCR1);
1471 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
1473 imx_uart_writel(sport, ucr1, UCR1);
1474 spin_unlock_irqrestore(&sport->port.lock, flags);
1476 clk_disable_unprepare(sport->clk_per);
1477 clk_disable_unprepare(sport->clk_ipg);
1480 /* called with port.lock taken and irqs off */
1481 static void imx_uart_flush_buffer(struct uart_port *port)
1483 struct imx_port *sport = (struct imx_port *)port;
1484 struct scatterlist *sgl = &sport->tx_sgl[0];
1486 int i = 100, ubir, ubmr, uts;
1488 if (!sport->dma_chan_tx)
1491 sport->tx_bytes = 0;
1492 dmaengine_terminate_all(sport->dma_chan_tx);
1493 if (sport->dma_is_txing) {
1496 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1498 ucr1 = imx_uart_readl(sport, UCR1);
1499 ucr1 &= ~UCR1_TXDMAEN;
1500 imx_uart_writel(sport, ucr1, UCR1);
1501 sport->dma_is_txing = 0;
1505 * According to the Reference Manual description of the UART SRST bit:
1507 * "Reset the transmit and receive state machines,
1508 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1511 * We don't need to restore the old values from USR1, USR2, URXD and
1512 * UTXD. UBRC is read only, so only save/restore the other three
1515 ubir = imx_uart_readl(sport, UBIR);
1516 ubmr = imx_uart_readl(sport, UBMR);
1517 uts = imx_uart_readl(sport, IMX21_UTS);
1519 ucr2 = imx_uart_readl(sport, UCR2);
1521 imx_uart_writel(sport, ucr2, UCR2);
1523 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1526 /* Restore the registers */
1527 imx_uart_writel(sport, ubir, UBIR);
1528 imx_uart_writel(sport, ubmr, UBMR);
1529 imx_uart_writel(sport, uts, IMX21_UTS);
1533 imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1534 struct ktermios *old)
1536 struct imx_port *sport = (struct imx_port *)port;
1537 unsigned long flags;
1538 u32 ucr2, old_ucr1, old_ucr2, ufcr;
1539 unsigned int baud, quot;
1540 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1542 unsigned long num, denom;
1546 * We only support CS7 and CS8.
1548 while ((termios->c_cflag & CSIZE) != CS7 &&
1549 (termios->c_cflag & CSIZE) != CS8) {
1550 termios->c_cflag &= ~CSIZE;
1551 termios->c_cflag |= old_csize;
1555 del_timer_sync(&sport->timer);
1558 * Ask the core to calculate the divisor for us.
1560 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1561 quot = uart_get_divisor(port, baud);
1563 spin_lock_irqsave(&sport->port.lock, flags);
1566 * Read current UCR2 and save it for future use, then clear all the bits
1567 * except those we will or may need to preserve.
1569 old_ucr2 = imx_uart_readl(sport, UCR2);
1570 ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
1572 ucr2 |= UCR2_SRST | UCR2_IRTS;
1573 if ((termios->c_cflag & CSIZE) == CS8)
1576 if (!sport->have_rtscts)
1577 termios->c_cflag &= ~CRTSCTS;
1579 if (port->rs485.flags & SER_RS485_ENABLED) {
1581 * RTS is mandatory for rs485 operation, so keep
1582 * it under manual control and keep transmitter
1585 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1586 imx_uart_rts_active(sport, &ucr2);
1588 imx_uart_rts_inactive(sport, &ucr2);
1590 } else if (termios->c_cflag & CRTSCTS)
1591 imx_uart_rts_auto(sport, &ucr2);
1593 if (termios->c_cflag & CRTSCTS)
1596 if (termios->c_cflag & CSTOPB)
1598 if (termios->c_cflag & PARENB) {
1600 if (termios->c_cflag & PARODD)
1604 sport->port.read_status_mask = 0;
1605 if (termios->c_iflag & INPCK)
1606 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1607 if (termios->c_iflag & (BRKINT | PARMRK))
1608 sport->port.read_status_mask |= URXD_BRK;
1611 * Characters to ignore
1613 sport->port.ignore_status_mask = 0;
1614 if (termios->c_iflag & IGNPAR)
1615 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1616 if (termios->c_iflag & IGNBRK) {
1617 sport->port.ignore_status_mask |= URXD_BRK;
1619 * If we're ignoring parity and break indicators,
1620 * ignore overruns too (for real raw support).
1622 if (termios->c_iflag & IGNPAR)
1623 sport->port.ignore_status_mask |= URXD_OVRRUN;
1626 if ((termios->c_cflag & CREAD) == 0)
1627 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1630 * Update the per-port timeout.
1632 uart_update_timeout(port, termios->c_cflag, baud);
1635 * disable interrupts and drain transmitter
1637 old_ucr1 = imx_uart_readl(sport, UCR1);
1638 imx_uart_writel(sport,
1639 old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1641 imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
1643 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
1646 /* then, disable everything */
1647 imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
1649 /* custom-baudrate handling */
1650 div = sport->port.uartclk / (baud * 16);
1651 if (baud == 38400 && quot != div)
1652 baud = sport->port.uartclk / (quot * 16);
1654 div = sport->port.uartclk / (baud * 16);
1660 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1661 1 << 16, 1 << 16, &num, &denom);
1663 tdiv64 = sport->port.uartclk;
1665 do_div(tdiv64, denom * 16 * div);
1666 tty_termios_encode_baud_rate(termios,
1667 (speed_t)tdiv64, (speed_t)tdiv64);
1672 ufcr = imx_uart_readl(sport, UFCR);
1673 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1674 imx_uart_writel(sport, ufcr, UFCR);
1676 imx_uart_writel(sport, num, UBIR);
1677 imx_uart_writel(sport, denom, UBMR);
1679 if (!imx_uart_is_imx1(sport))
1680 imx_uart_writel(sport, sport->port.uartclk / div / 1000,
1683 imx_uart_writel(sport, old_ucr1, UCR1);
1685 imx_uart_writel(sport, ucr2, UCR2);
1687 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1688 imx_uart_enable_ms(&sport->port);
1690 spin_unlock_irqrestore(&sport->port.lock, flags);
1693 static const char *imx_uart_type(struct uart_port *port)
1695 struct imx_port *sport = (struct imx_port *)port;
1697 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1701 * Configure/autoconfigure the port.
1703 static void imx_uart_config_port(struct uart_port *port, int flags)
1705 struct imx_port *sport = (struct imx_port *)port;
1707 if (flags & UART_CONFIG_TYPE)
1708 sport->port.type = PORT_IMX;
1712 * Verify the new serial_struct (for TIOCSSERIAL).
1713 * The only change we allow are to the flags and type, and
1714 * even then only between PORT_IMX and PORT_UNKNOWN
1717 imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1719 struct imx_port *sport = (struct imx_port *)port;
1722 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1724 if (sport->port.irq != ser->irq)
1726 if (ser->io_type != UPIO_MEM)
1728 if (sport->port.uartclk / 16 != ser->baud_base)
1730 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1732 if (sport->port.iobase != ser->port)
1739 #if defined(CONFIG_CONSOLE_POLL)
1741 static int imx_uart_poll_init(struct uart_port *port)
1743 struct imx_port *sport = (struct imx_port *)port;
1744 unsigned long flags;
1748 retval = clk_prepare_enable(sport->clk_ipg);
1751 retval = clk_prepare_enable(sport->clk_per);
1753 clk_disable_unprepare(sport->clk_ipg);
1755 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1757 spin_lock_irqsave(&sport->port.lock, flags);
1760 * Be careful about the order of enabling bits here. First enable the
1761 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1762 * This prevents that a character that already sits in the RX fifo is
1763 * triggering an irq but the try to fetch it from there results in an
1764 * exception because UARTEN or RXEN is still off.
1766 ucr1 = imx_uart_readl(sport, UCR1);
1767 ucr2 = imx_uart_readl(sport, UCR2);
1769 if (imx_uart_is_imx1(sport))
1770 ucr1 |= IMX1_UCR1_UARTCLKEN;
1772 ucr1 |= UCR1_UARTEN;
1773 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1778 imx_uart_writel(sport, ucr1, UCR1);
1779 imx_uart_writel(sport, ucr2, UCR2);
1781 /* now enable irqs */
1782 imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1783 imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1785 spin_unlock_irqrestore(&sport->port.lock, flags);
1790 static int imx_uart_poll_get_char(struct uart_port *port)
1792 struct imx_port *sport = (struct imx_port *)port;
1793 if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1794 return NO_POLL_CHAR;
1796 return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1799 static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1801 struct imx_port *sport = (struct imx_port *)port;
1802 unsigned int status;
1806 status = imx_uart_readl(sport, USR1);
1807 } while (~status & USR1_TRDY);
1810 imx_uart_writel(sport, c, URTX0);
1814 status = imx_uart_readl(sport, USR2);
1815 } while (~status & USR2_TXDC);
1819 /* called with port.lock taken and irqs off or from .probe without locking */
1820 static int imx_uart_rs485_config(struct uart_port *port,
1821 struct serial_rs485 *rs485conf)
1823 struct imx_port *sport = (struct imx_port *)port;
1827 rs485conf->delay_rts_before_send = 0;
1828 rs485conf->delay_rts_after_send = 0;
1830 /* RTS is required to control the transmitter */
1831 if (!sport->have_rtscts && !sport->have_rtsgpio)
1832 rs485conf->flags &= ~SER_RS485_ENABLED;
1834 if (rs485conf->flags & SER_RS485_ENABLED) {
1835 /* Enable receiver if low-active RTS signal is requested */
1836 if (sport->have_rtscts && !sport->have_rtsgpio &&
1837 !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1838 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1840 /* disable transmitter */
1841 ucr2 = imx_uart_readl(sport, UCR2);
1842 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1843 imx_uart_rts_active(sport, &ucr2);
1845 imx_uart_rts_inactive(sport, &ucr2);
1846 imx_uart_writel(sport, ucr2, UCR2);
1849 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1850 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1851 rs485conf->flags & SER_RS485_RX_DURING_TX)
1852 imx_uart_start_rx(port);
1854 port->rs485 = *rs485conf;
1859 static const struct uart_ops imx_uart_pops = {
1860 .tx_empty = imx_uart_tx_empty,
1861 .set_mctrl = imx_uart_set_mctrl,
1862 .get_mctrl = imx_uart_get_mctrl,
1863 .stop_tx = imx_uart_stop_tx,
1864 .start_tx = imx_uart_start_tx,
1865 .stop_rx = imx_uart_stop_rx,
1866 .enable_ms = imx_uart_enable_ms,
1867 .break_ctl = imx_uart_break_ctl,
1868 .startup = imx_uart_startup,
1869 .shutdown = imx_uart_shutdown,
1870 .flush_buffer = imx_uart_flush_buffer,
1871 .set_termios = imx_uart_set_termios,
1872 .type = imx_uart_type,
1873 .config_port = imx_uart_config_port,
1874 .verify_port = imx_uart_verify_port,
1875 #if defined(CONFIG_CONSOLE_POLL)
1876 .poll_init = imx_uart_poll_init,
1877 .poll_get_char = imx_uart_poll_get_char,
1878 .poll_put_char = imx_uart_poll_put_char,
1882 static struct imx_port *imx_uart_ports[UART_NR];
1884 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1885 static void imx_uart_console_putchar(struct uart_port *port, int ch)
1887 struct imx_port *sport = (struct imx_port *)port;
1889 while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1892 imx_uart_writel(sport, ch, URTX0);
1896 * Interrupts are disabled on entering
1899 imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1901 struct imx_port *sport = imx_uart_ports[co->index];
1902 struct imx_port_ucrs old_ucr;
1904 unsigned long flags = 0;
1908 retval = clk_enable(sport->clk_per);
1911 retval = clk_enable(sport->clk_ipg);
1913 clk_disable(sport->clk_per);
1917 if (sport->port.sysrq)
1919 else if (oops_in_progress)
1920 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1922 spin_lock_irqsave(&sport->port.lock, flags);
1925 * First, save UCR1/2/3 and then disable interrupts
1927 imx_uart_ucrs_save(sport, &old_ucr);
1928 ucr1 = old_ucr.ucr1;
1930 if (imx_uart_is_imx1(sport))
1931 ucr1 |= IMX1_UCR1_UARTCLKEN;
1932 ucr1 |= UCR1_UARTEN;
1933 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1935 imx_uart_writel(sport, ucr1, UCR1);
1937 imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
1939 uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
1942 * Finally, wait for transmitter to become empty
1943 * and restore UCR1/2/3
1945 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
1947 imx_uart_ucrs_restore(sport, &old_ucr);
1950 spin_unlock_irqrestore(&sport->port.lock, flags);
1952 clk_disable(sport->clk_ipg);
1953 clk_disable(sport->clk_per);
1957 * If the port was already initialised (eg, by a boot loader),
1958 * try to determine the current setup.
1961 imx_uart_console_get_options(struct imx_port *sport, int *baud,
1962 int *parity, int *bits)
1965 if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
1966 /* ok, the port was enabled */
1967 unsigned int ucr2, ubir, ubmr, uartclk;
1968 unsigned int baud_raw;
1969 unsigned int ucfr_rfdiv;
1971 ucr2 = imx_uart_readl(sport, UCR2);
1974 if (ucr2 & UCR2_PREN) {
1975 if (ucr2 & UCR2_PROE)
1986 ubir = imx_uart_readl(sport, UBIR) & 0xffff;
1987 ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
1989 ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
1990 if (ucfr_rfdiv == 6)
1993 ucfr_rfdiv = 6 - ucfr_rfdiv;
1995 uartclk = clk_get_rate(sport->clk_per);
1996 uartclk /= ucfr_rfdiv;
1999 * The next code provides exact computation of
2000 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2001 * without need of float support or long long division,
2002 * which would be required to prevent 32bit arithmetic overflow
2004 unsigned int mul = ubir + 1;
2005 unsigned int div = 16 * (ubmr + 1);
2006 unsigned int rem = uartclk % div;
2008 baud_raw = (uartclk / div) * mul;
2009 baud_raw += (rem * mul + div / 2) / div;
2010 *baud = (baud_raw + 50) / 100 * 100;
2013 if (*baud != baud_raw)
2014 dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
2020 imx_uart_console_setup(struct console *co, char *options)
2022 struct imx_port *sport;
2030 * Check whether an invalid uart number has been specified, and
2031 * if so, search for the first available port that does have
2034 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2036 sport = imx_uart_ports[co->index];
2040 /* For setting the registers, we only need to enable the ipg clock. */
2041 retval = clk_prepare_enable(sport->clk_ipg);
2046 uart_parse_options(options, &baud, &parity, &bits, &flow);
2048 imx_uart_console_get_options(sport, &baud, &parity, &bits);
2050 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2052 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2054 clk_disable(sport->clk_ipg);
2056 clk_unprepare(sport->clk_ipg);
2060 retval = clk_prepare(sport->clk_per);
2062 clk_unprepare(sport->clk_ipg);
2068 static struct uart_driver imx_uart_uart_driver;
2069 static struct console imx_uart_console = {
2071 .write = imx_uart_console_write,
2072 .device = uart_console_device,
2073 .setup = imx_uart_console_setup,
2074 .flags = CON_PRINTBUFFER,
2076 .data = &imx_uart_uart_driver,
2079 #define IMX_CONSOLE &imx_uart_console
2082 static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
2084 struct imx_port *sport = (struct imx_port *)port;
2086 while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
2089 imx_uart_writel(sport, ch, URTX0);
2092 static void imx_uart_console_early_write(struct console *con, const char *s,
2095 struct earlycon_device *dev = con->data;
2097 uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
2101 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
2103 if (!dev->port.membase)
2106 dev->con->write = imx_uart_console_early_write;
2110 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2111 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2115 #define IMX_CONSOLE NULL
2118 static struct uart_driver imx_uart_uart_driver = {
2119 .owner = THIS_MODULE,
2120 .driver_name = DRIVER_NAME,
2121 .dev_name = DEV_NAME,
2122 .major = SERIAL_IMX_MAJOR,
2123 .minor = MINOR_START,
2124 .nr = ARRAY_SIZE(imx_uart_ports),
2125 .cons = IMX_CONSOLE,
2130 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2131 * could successfully get all information from dt or a negative errno.
2133 static int imx_uart_probe_dt(struct imx_port *sport,
2134 struct platform_device *pdev)
2136 struct device_node *np = pdev->dev.of_node;
2139 sport->devdata = of_device_get_match_data(&pdev->dev);
2140 if (!sport->devdata)
2141 /* no device tree device */
2144 ret = of_alias_get_id(np, "serial");
2146 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2149 sport->port.line = ret;
2151 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2152 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2153 sport->have_rtscts = 1;
2155 if (of_get_property(np, "fsl,dte-mode", NULL))
2156 sport->dte_mode = 1;
2158 if (of_get_property(np, "rts-gpios", NULL))
2159 sport->have_rtsgpio = 1;
2164 static inline int imx_uart_probe_dt(struct imx_port *sport,
2165 struct platform_device *pdev)
2171 static void imx_uart_probe_pdata(struct imx_port *sport,
2172 struct platform_device *pdev)
2174 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2176 sport->port.line = pdev->id;
2177 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
2182 if (pdata->flags & IMXUART_HAVE_RTSCTS)
2183 sport->have_rtscts = 1;
2186 static int imx_uart_probe(struct platform_device *pdev)
2188 struct imx_port *sport;
2192 struct resource *res;
2193 int txirq, rxirq, rtsirq;
2195 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2199 ret = imx_uart_probe_dt(sport, pdev);
2201 imx_uart_probe_pdata(sport, pdev);
2205 if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2206 dev_err(&pdev->dev, "serial%d out of range\n",
2211 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2212 base = devm_ioremap_resource(&pdev->dev, res);
2214 return PTR_ERR(base);
2216 rxirq = platform_get_irq(pdev, 0);
2217 txirq = platform_get_irq(pdev, 1);
2218 rtsirq = platform_get_irq(pdev, 2);
2220 sport->port.dev = &pdev->dev;
2221 sport->port.mapbase = res->start;
2222 sport->port.membase = base;
2223 sport->port.type = PORT_IMX,
2224 sport->port.iotype = UPIO_MEM;
2225 sport->port.irq = rxirq;
2226 sport->port.fifosize = 32;
2227 sport->port.ops = &imx_uart_pops;
2228 sport->port.rs485_config = imx_uart_rs485_config;
2229 sport->port.flags = UPF_BOOT_AUTOCONF;
2230 timer_setup(&sport->timer, imx_uart_timeout, 0);
2232 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2233 if (IS_ERR(sport->gpios))
2234 return PTR_ERR(sport->gpios);
2236 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2237 if (IS_ERR(sport->clk_ipg)) {
2238 ret = PTR_ERR(sport->clk_ipg);
2239 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2243 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2244 if (IS_ERR(sport->clk_per)) {
2245 ret = PTR_ERR(sport->clk_per);
2246 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2250 sport->port.uartclk = clk_get_rate(sport->clk_per);
2252 /* For register access, we only need to enable the ipg clock. */
2253 ret = clk_prepare_enable(sport->clk_ipg);
2255 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2259 /* initialize shadow register values */
2260 sport->ucr1 = readl(sport->port.membase + UCR1);
2261 sport->ucr2 = readl(sport->port.membase + UCR2);
2262 sport->ucr3 = readl(sport->port.membase + UCR3);
2263 sport->ucr4 = readl(sport->port.membase + UCR4);
2264 sport->ufcr = readl(sport->port.membase + UFCR);
2266 uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2268 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2269 (!sport->have_rtscts && !sport->have_rtsgpio))
2270 dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2273 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2274 * signal cannot be set low during transmission in case the
2275 * receiver is off (limitation of the i.MX UART IP).
2277 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2278 sport->have_rtscts && !sport->have_rtsgpio &&
2279 (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2280 !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2282 "low-active RTS not possible when receiver is off, enabling receiver\n");
2284 imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2286 /* Disable interrupts before requesting them */
2287 ucr1 = imx_uart_readl(sport, UCR1);
2288 ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2289 UCR1_TXMPTYEN | UCR1_RTSDEN);
2290 imx_uart_writel(sport, ucr1, UCR1);
2292 if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2294 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2295 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2296 * and DCD (when they are outputs) or enables the respective
2297 * irqs. So set this bit early, i.e. before requesting irqs.
2299 u32 ufcr = imx_uart_readl(sport, UFCR);
2300 if (!(ufcr & UFCR_DCEDTE))
2301 imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2304 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2305 * enabled later because they cannot be cleared
2306 * (confirmed on i.MX25) which makes them unusable.
2308 imx_uart_writel(sport,
2309 IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2313 u32 ucr3 = UCR3_DSR;
2314 u32 ufcr = imx_uart_readl(sport, UFCR);
2315 if (ufcr & UFCR_DCEDTE)
2316 imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2318 if (!imx_uart_is_imx1(sport))
2319 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2320 imx_uart_writel(sport, ucr3, UCR3);
2323 clk_disable_unprepare(sport->clk_ipg);
2326 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2327 * chips only have one interrupt.
2330 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2331 dev_name(&pdev->dev), sport);
2333 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2338 ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2339 dev_name(&pdev->dev), sport);
2341 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2346 ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
2347 dev_name(&pdev->dev), sport);
2349 dev_err(&pdev->dev, "failed to request rts irq: %d\n",
2354 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2355 dev_name(&pdev->dev), sport);
2357 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2362 imx_uart_ports[sport->port.line] = sport;
2364 platform_set_drvdata(pdev, sport);
2366 return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2369 static int imx_uart_remove(struct platform_device *pdev)
2371 struct imx_port *sport = platform_get_drvdata(pdev);
2373 return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2376 static void imx_uart_restore_context(struct imx_port *sport)
2378 unsigned long flags;
2380 spin_lock_irqsave(&sport->port.lock, flags);
2381 if (!sport->context_saved) {
2382 spin_unlock_irqrestore(&sport->port.lock, flags);
2386 imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2387 imx_uart_writel(sport, sport->saved_reg[5], UESC);
2388 imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2389 imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2390 imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2391 imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2392 imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2393 imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2394 imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2395 imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2396 sport->context_saved = false;
2397 spin_unlock_irqrestore(&sport->port.lock, flags);
2400 static void imx_uart_save_context(struct imx_port *sport)
2402 unsigned long flags;
2404 /* Save necessary regs */
2405 spin_lock_irqsave(&sport->port.lock, flags);
2406 sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2407 sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2408 sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2409 sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2410 sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2411 sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2412 sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2413 sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2414 sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2415 sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2416 sport->context_saved = true;
2417 spin_unlock_irqrestore(&sport->port.lock, flags);
2420 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2424 ucr3 = imx_uart_readl(sport, UCR3);
2426 imx_uart_writel(sport, USR1_AWAKE, USR1);
2427 ucr3 |= UCR3_AWAKEN;
2429 ucr3 &= ~UCR3_AWAKEN;
2431 imx_uart_writel(sport, ucr3, UCR3);
2433 if (sport->have_rtscts) {
2434 u32 ucr1 = imx_uart_readl(sport, UCR1);
2436 ucr1 |= UCR1_RTSDEN;
2438 ucr1 &= ~UCR1_RTSDEN;
2439 imx_uart_writel(sport, ucr1, UCR1);
2443 static int imx_uart_suspend_noirq(struct device *dev)
2445 struct imx_port *sport = dev_get_drvdata(dev);
2447 imx_uart_save_context(sport);
2449 clk_disable(sport->clk_ipg);
2451 pinctrl_pm_select_sleep_state(dev);
2456 static int imx_uart_resume_noirq(struct device *dev)
2458 struct imx_port *sport = dev_get_drvdata(dev);
2461 pinctrl_pm_select_default_state(dev);
2463 ret = clk_enable(sport->clk_ipg);
2467 imx_uart_restore_context(sport);
2472 static int imx_uart_suspend(struct device *dev)
2474 struct imx_port *sport = dev_get_drvdata(dev);
2477 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2478 disable_irq(sport->port.irq);
2480 ret = clk_prepare_enable(sport->clk_ipg);
2484 /* enable wakeup from i.MX UART */
2485 imx_uart_enable_wakeup(sport, true);
2490 static int imx_uart_resume(struct device *dev)
2492 struct imx_port *sport = dev_get_drvdata(dev);
2494 /* disable wakeup from i.MX UART */
2495 imx_uart_enable_wakeup(sport, false);
2497 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2498 enable_irq(sport->port.irq);
2500 clk_disable_unprepare(sport->clk_ipg);
2505 static int imx_uart_freeze(struct device *dev)
2507 struct imx_port *sport = dev_get_drvdata(dev);
2509 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2511 return clk_prepare_enable(sport->clk_ipg);
2514 static int imx_uart_thaw(struct device *dev)
2516 struct imx_port *sport = dev_get_drvdata(dev);
2518 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2520 clk_disable_unprepare(sport->clk_ipg);
2525 static const struct dev_pm_ops imx_uart_pm_ops = {
2526 .suspend_noirq = imx_uart_suspend_noirq,
2527 .resume_noirq = imx_uart_resume_noirq,
2528 .freeze_noirq = imx_uart_suspend_noirq,
2529 .restore_noirq = imx_uart_resume_noirq,
2530 .suspend = imx_uart_suspend,
2531 .resume = imx_uart_resume,
2532 .freeze = imx_uart_freeze,
2533 .thaw = imx_uart_thaw,
2534 .restore = imx_uart_thaw,
2537 static struct platform_driver imx_uart_platform_driver = {
2538 .probe = imx_uart_probe,
2539 .remove = imx_uart_remove,
2541 .id_table = imx_uart_devtype,
2544 .of_match_table = imx_uart_dt_ids,
2545 .pm = &imx_uart_pm_ops,
2549 static int __init imx_uart_init(void)
2551 int ret = uart_register_driver(&imx_uart_uart_driver);
2556 ret = platform_driver_register(&imx_uart_platform_driver);
2558 uart_unregister_driver(&imx_uart_uart_driver);
2563 static void __exit imx_uart_exit(void)
2565 platform_driver_unregister(&imx_uart_platform_driver);
2566 uart_unregister_driver(&imx_uart_uart_driver);
2569 module_init(imx_uart_init);
2570 module_exit(imx_uart_exit);
2572 MODULE_AUTHOR("Sascha Hauer");
2573 MODULE_DESCRIPTION("IMX generic serial port driver");
2574 MODULE_LICENSE("GPL");
2575 MODULE_ALIAS("platform:imx-uart");