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/rational.h>
28 #include <linux/slab.h>
30 #include <linux/of_device.h>
32 #include <linux/dma-mapping.h>
35 #include <linux/platform_data/serial-imx.h>
36 #include <linux/platform_data/dma-imx.h>
38 #include "serial_mctrl_gpio.h"
40 /* Register definitions */
41 #define URXD0 0x0 /* Receiver Register */
42 #define URTX0 0x40 /* Transmitter Register */
43 #define UCR1 0x80 /* Control Register 1 */
44 #define UCR2 0x84 /* Control Register 2 */
45 #define UCR3 0x88 /* Control Register 3 */
46 #define UCR4 0x8c /* Control Register 4 */
47 #define UFCR 0x90 /* FIFO Control Register */
48 #define USR1 0x94 /* Status Register 1 */
49 #define USR2 0x98 /* Status Register 2 */
50 #define UESC 0x9c /* Escape Character Register */
51 #define UTIM 0xa0 /* Escape Timer Register */
52 #define UBIR 0xa4 /* BRM Incremental Register */
53 #define UBMR 0xa8 /* BRM Modulator Register */
54 #define UBRC 0xac /* Baud Rate Count Register */
55 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
56 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
57 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
59 /* UART Control Register Bit Fields.*/
60 #define URXD_DUMMY_READ (1<<16)
61 #define URXD_CHARRDY (1<<15)
62 #define URXD_ERR (1<<14)
63 #define URXD_OVRRUN (1<<13)
64 #define URXD_FRMERR (1<<12)
65 #define URXD_BRK (1<<11)
66 #define URXD_PRERR (1<<10)
67 #define URXD_RX_DATA (0xFF<<0)
68 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
69 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
70 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
71 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
72 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
73 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
74 #define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
75 #define UCR1_IREN (1<<7) /* Infrared interface enable */
76 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
77 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
78 #define UCR1_SNDBRK (1<<4) /* Send break */
79 #define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
80 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
81 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
82 #define UCR1_DOZE (1<<1) /* Doze */
83 #define UCR1_UARTEN (1<<0) /* UART enabled */
84 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
85 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
86 #define UCR2_CTSC (1<<13) /* CTS pin control */
87 #define UCR2_CTS (1<<12) /* Clear to send */
88 #define UCR2_ESCEN (1<<11) /* Escape enable */
89 #define UCR2_PREN (1<<8) /* Parity enable */
90 #define UCR2_PROE (1<<7) /* Parity odd/even */
91 #define UCR2_STPB (1<<6) /* Stop */
92 #define UCR2_WS (1<<5) /* Word size */
93 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
94 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
95 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
96 #define UCR2_RXEN (1<<1) /* Receiver enabled */
97 #define UCR2_SRST (1<<0) /* SW reset */
98 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
99 #define UCR3_PARERREN (1<<12) /* Parity enable */
100 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
101 #define UCR3_DSR (1<<10) /* Data set ready */
102 #define UCR3_DCD (1<<9) /* Data carrier detect */
103 #define UCR3_RI (1<<8) /* Ring indicator */
104 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
105 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
106 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
107 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
108 #define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
109 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
110 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
111 #define UCR3_BPEN (1<<0) /* Preset registers enable */
112 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
113 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
114 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
115 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
116 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
117 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
118 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
119 #define UCR4_IRSC (1<<5) /* IR special case */
120 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
121 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
122 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
123 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
124 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
125 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
126 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
127 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
128 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
129 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
130 #define USR1_RTSS (1<<14) /* RTS pin status */
131 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
132 #define USR1_RTSD (1<<12) /* RTS delta */
133 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
134 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
135 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
136 #define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
137 #define USR1_DTRD (1<<7) /* DTR Delta */
138 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
139 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
140 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
141 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
142 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
143 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
144 #define USR2_IDLE (1<<12) /* Idle condition */
145 #define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
146 #define USR2_RIIN (1<<9) /* Ring Indicator Input */
147 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
148 #define USR2_WAKE (1<<7) /* Wake */
149 #define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
150 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
151 #define USR2_TXDC (1<<3) /* Transmitter complete */
152 #define USR2_BRCD (1<<2) /* Break condition */
153 #define USR2_ORE (1<<1) /* Overrun error */
154 #define USR2_RDR (1<<0) /* Recv data ready */
155 #define UTS_FRCPERR (1<<13) /* Force parity error */
156 #define UTS_LOOP (1<<12) /* Loop tx and rx */
157 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
158 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
159 #define UTS_TXFULL (1<<4) /* TxFIFO full */
160 #define UTS_RXFULL (1<<3) /* RxFIFO full */
161 #define UTS_SOFTRST (1<<0) /* Software reset */
163 /* We've been assigned a range on the "Low-density serial ports" major */
164 #define SERIAL_IMX_MAJOR 207
165 #define MINOR_START 16
166 #define DEV_NAME "ttymxc"
169 * This determines how often we check the modem status signals
170 * for any change. They generally aren't connected to an IRQ
171 * so we have to poll them. We also check immediately before
172 * filling the TX fifo incase CTS has been dropped.
174 #define MCTRL_TIMEOUT (250*HZ/1000)
176 #define DRIVER_NAME "IMX-uart"
180 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
188 /* device type dependent stuff */
189 struct imx_uart_data {
191 enum imx_uart_type devtype;
195 struct uart_port port;
196 struct timer_list timer;
197 unsigned int old_status;
198 unsigned int have_rtscts:1;
199 unsigned int have_rtsgpio:1;
200 unsigned int dte_mode:1;
203 const struct imx_uart_data *devdata;
205 struct mctrl_gpios *gpios;
207 /* shadow registers */
215 unsigned int dma_is_enabled:1;
216 unsigned int dma_is_rxing:1;
217 unsigned int dma_is_txing:1;
218 struct dma_chan *dma_chan_rx, *dma_chan_tx;
219 struct scatterlist rx_sgl, tx_sgl[2];
221 struct circ_buf rx_ring;
222 unsigned int rx_periods;
223 dma_cookie_t rx_cookie;
224 unsigned int tx_bytes;
225 unsigned int dma_tx_nents;
226 unsigned int saved_reg[10];
230 struct imx_port_ucrs {
236 static struct imx_uart_data imx_uart_devdata[] = {
239 .devtype = IMX1_UART,
242 .uts_reg = IMX21_UTS,
243 .devtype = IMX21_UART,
246 .uts_reg = IMX21_UTS,
247 .devtype = IMX53_UART,
250 .uts_reg = IMX21_UTS,
251 .devtype = IMX6Q_UART,
255 static const struct platform_device_id imx_uart_devtype[] = {
258 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
260 .name = "imx21-uart",
261 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
263 .name = "imx53-uart",
264 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
266 .name = "imx6q-uart",
267 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
272 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
274 static const struct of_device_id imx_uart_dt_ids[] = {
275 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
276 { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
277 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
278 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
281 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
283 static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
304 writel(val, sport->port.membase + offset);
307 static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
315 * UCR2_SRST is the only bit in the cached registers that might
316 * differ from the value that was last written. As it only
317 * clears after being set, reread conditionally.
319 if (!(sport->ucr2 & UCR2_SRST))
320 sport->ucr2 = readl(sport->port.membase + offset);
333 return readl(sport->port.membase + offset);
337 static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
339 return sport->devdata->uts_reg;
342 static inline int imx_uart_is_imx1(struct imx_port *sport)
344 return sport->devdata->devtype == IMX1_UART;
347 static inline int imx_uart_is_imx21(struct imx_port *sport)
349 return sport->devdata->devtype == IMX21_UART;
352 static inline int imx_uart_is_imx53(struct imx_port *sport)
354 return sport->devdata->devtype == IMX53_UART;
357 static inline int imx_uart_is_imx6q(struct imx_port *sport)
359 return sport->devdata->devtype == IMX6Q_UART;
362 * Save and restore functions for UCR1, UCR2 and UCR3 registers
364 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
365 static void imx_uart_ucrs_save(struct imx_port *sport,
366 struct imx_port_ucrs *ucr)
368 /* save control registers */
369 ucr->ucr1 = imx_uart_readl(sport, UCR1);
370 ucr->ucr2 = imx_uart_readl(sport, UCR2);
371 ucr->ucr3 = imx_uart_readl(sport, UCR3);
374 static void imx_uart_ucrs_restore(struct imx_port *sport,
375 struct imx_port_ucrs *ucr)
377 /* restore control registers */
378 imx_uart_writel(sport, ucr->ucr1, UCR1);
379 imx_uart_writel(sport, ucr->ucr2, UCR2);
380 imx_uart_writel(sport, ucr->ucr3, UCR3);
384 static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
386 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
388 sport->port.mctrl |= TIOCM_RTS;
389 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
392 static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
397 sport->port.mctrl &= ~TIOCM_RTS;
398 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
401 static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
406 /* called with port.lock taken and irqs off */
407 static void imx_uart_start_rx(struct uart_port *port)
409 struct imx_port *sport = (struct imx_port *)port;
410 unsigned int ucr1, ucr2;
412 ucr1 = imx_uart_readl(sport, UCR1);
413 ucr2 = imx_uart_readl(sport, UCR2);
417 if (sport->dma_is_enabled) {
418 ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
424 /* Write UCR2 first as it includes RXEN */
425 imx_uart_writel(sport, ucr2, UCR2);
426 imx_uart_writel(sport, ucr1, UCR1);
429 /* called with port.lock taken and irqs off */
430 static void imx_uart_stop_tx(struct uart_port *port)
432 struct imx_port *sport = (struct imx_port *)port;
436 * We are maybe in the SMP context, so if the DMA TX thread is running
437 * on other cpu, we have to wait for it to finish.
439 if (sport->dma_is_txing)
442 ucr1 = imx_uart_readl(sport, UCR1);
443 imx_uart_writel(sport, ucr1 & ~UCR1_TXMPTYEN, UCR1);
445 /* in rs485 mode disable transmitter if shifter is empty */
446 if (port->rs485.flags & SER_RS485_ENABLED &&
447 imx_uart_readl(sport, USR2) & USR2_TXDC) {
448 u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
449 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
450 imx_uart_rts_active(sport, &ucr2);
452 imx_uart_rts_inactive(sport, &ucr2);
453 imx_uart_writel(sport, ucr2, UCR2);
455 imx_uart_start_rx(port);
457 ucr4 = imx_uart_readl(sport, UCR4);
459 imx_uart_writel(sport, ucr4, UCR4);
463 /* called with port.lock taken and irqs off */
464 static void imx_uart_stop_rx(struct uart_port *port)
466 struct imx_port *sport = (struct imx_port *)port;
469 ucr1 = imx_uart_readl(sport, UCR1);
470 ucr2 = imx_uart_readl(sport, UCR2);
472 if (sport->dma_is_enabled) {
473 ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
475 ucr1 &= ~UCR1_RRDYEN;
478 imx_uart_writel(sport, ucr1, UCR1);
481 imx_uart_writel(sport, ucr2, UCR2);
484 /* called with port.lock taken and irqs off */
485 static void imx_uart_enable_ms(struct uart_port *port)
487 struct imx_port *sport = (struct imx_port *)port;
489 mod_timer(&sport->timer, jiffies);
491 mctrl_gpio_enable_ms(sport->gpios);
494 static void imx_uart_dma_tx(struct imx_port *sport);
496 /* called with port.lock taken and irqs off */
497 static inline void imx_uart_transmit_buffer(struct imx_port *sport)
499 struct circ_buf *xmit = &sport->port.state->xmit;
501 if (sport->port.x_char) {
503 imx_uart_writel(sport, sport->port.x_char, URTX0);
504 sport->port.icount.tx++;
505 sport->port.x_char = 0;
509 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
510 imx_uart_stop_tx(&sport->port);
514 if (sport->dma_is_enabled) {
517 * We've just sent a X-char Ensure the TX DMA is enabled
518 * and the TX IRQ is disabled.
520 ucr1 = imx_uart_readl(sport, UCR1);
521 ucr1 &= ~UCR1_TXMPTYEN;
522 if (sport->dma_is_txing) {
523 ucr1 |= UCR1_TXDMAEN;
524 imx_uart_writel(sport, ucr1, UCR1);
526 imx_uart_writel(sport, ucr1, UCR1);
527 imx_uart_dma_tx(sport);
533 while (!uart_circ_empty(xmit) &&
534 !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
535 /* send xmit->buf[xmit->tail]
536 * out the port here */
537 imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
538 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
539 sport->port.icount.tx++;
542 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
543 uart_write_wakeup(&sport->port);
545 if (uart_circ_empty(xmit))
546 imx_uart_stop_tx(&sport->port);
549 static void imx_uart_dma_tx_callback(void *data)
551 struct imx_port *sport = data;
552 struct scatterlist *sgl = &sport->tx_sgl[0];
553 struct circ_buf *xmit = &sport->port.state->xmit;
557 spin_lock_irqsave(&sport->port.lock, flags);
559 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
561 ucr1 = imx_uart_readl(sport, UCR1);
562 ucr1 &= ~UCR1_TXDMAEN;
563 imx_uart_writel(sport, ucr1, UCR1);
565 /* update the stat */
566 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
567 sport->port.icount.tx += sport->tx_bytes;
569 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
571 sport->dma_is_txing = 0;
573 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
574 uart_write_wakeup(&sport->port);
576 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
577 imx_uart_dma_tx(sport);
578 else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
579 u32 ucr4 = imx_uart_readl(sport, UCR4);
581 imx_uart_writel(sport, ucr4, UCR4);
584 spin_unlock_irqrestore(&sport->port.lock, flags);
587 /* called with port.lock taken and irqs off */
588 static void imx_uart_dma_tx(struct imx_port *sport)
590 struct circ_buf *xmit = &sport->port.state->xmit;
591 struct scatterlist *sgl = sport->tx_sgl;
592 struct dma_async_tx_descriptor *desc;
593 struct dma_chan *chan = sport->dma_chan_tx;
594 struct device *dev = sport->port.dev;
598 if (sport->dma_is_txing)
601 ucr4 = imx_uart_readl(sport, UCR4);
603 imx_uart_writel(sport, ucr4, UCR4);
605 sport->tx_bytes = uart_circ_chars_pending(xmit);
607 if (xmit->tail < xmit->head) {
608 sport->dma_tx_nents = 1;
609 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
611 sport->dma_tx_nents = 2;
612 sg_init_table(sgl, 2);
613 sg_set_buf(sgl, xmit->buf + xmit->tail,
614 UART_XMIT_SIZE - xmit->tail);
615 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
618 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
620 dev_err(dev, "DMA mapping error for TX.\n");
623 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
624 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
626 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
628 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
631 desc->callback = imx_uart_dma_tx_callback;
632 desc->callback_param = sport;
634 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
635 uart_circ_chars_pending(xmit));
637 ucr1 = imx_uart_readl(sport, UCR1);
638 ucr1 |= UCR1_TXDMAEN;
639 imx_uart_writel(sport, ucr1, UCR1);
642 sport->dma_is_txing = 1;
643 dmaengine_submit(desc);
644 dma_async_issue_pending(chan);
648 /* called with port.lock taken and irqs off */
649 static void imx_uart_start_tx(struct uart_port *port)
651 struct imx_port *sport = (struct imx_port *)port;
654 if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
657 if (port->rs485.flags & SER_RS485_ENABLED) {
660 ucr2 = imx_uart_readl(sport, UCR2);
661 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
662 imx_uart_rts_active(sport, &ucr2);
664 imx_uart_rts_inactive(sport, &ucr2);
665 imx_uart_writel(sport, ucr2, UCR2);
667 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
668 imx_uart_stop_rx(port);
671 * Enable transmitter and shifter empty irq only if DMA is off.
672 * In the DMA case this is done in the tx-callback.
674 if (!sport->dma_is_enabled) {
675 u32 ucr4 = imx_uart_readl(sport, UCR4);
677 imx_uart_writel(sport, ucr4, UCR4);
681 if (!sport->dma_is_enabled) {
682 ucr1 = imx_uart_readl(sport, UCR1);
683 imx_uart_writel(sport, ucr1 | UCR1_TXMPTYEN, UCR1);
686 if (sport->dma_is_enabled) {
687 if (sport->port.x_char) {
688 /* We have X-char to send, so enable TX IRQ and
689 * disable TX DMA to let TX interrupt to send X-char */
690 ucr1 = imx_uart_readl(sport, UCR1);
691 ucr1 &= ~UCR1_TXDMAEN;
692 ucr1 |= UCR1_TXMPTYEN;
693 imx_uart_writel(sport, ucr1, UCR1);
697 if (!uart_circ_empty(&port->state->xmit) &&
698 !uart_tx_stopped(port))
699 imx_uart_dma_tx(sport);
704 static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
706 struct imx_port *sport = dev_id;
710 spin_lock_irqsave(&sport->port.lock, flags);
712 imx_uart_writel(sport, USR1_RTSD, USR1);
713 usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
714 uart_handle_cts_change(&sport->port, !!usr1);
715 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
717 spin_unlock_irqrestore(&sport->port.lock, flags);
721 static irqreturn_t imx_uart_txint(int irq, void *dev_id)
723 struct imx_port *sport = dev_id;
726 spin_lock_irqsave(&sport->port.lock, flags);
727 imx_uart_transmit_buffer(sport);
728 spin_unlock_irqrestore(&sport->port.lock, flags);
732 static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
734 struct imx_port *sport = dev_id;
735 unsigned int rx, flg, ignored = 0;
736 struct tty_port *port = &sport->port.state->port;
739 spin_lock_irqsave(&sport->port.lock, flags);
741 while (imx_uart_readl(sport, USR2) & USR2_RDR) {
745 sport->port.icount.rx++;
747 rx = imx_uart_readl(sport, URXD0);
749 usr2 = imx_uart_readl(sport, USR2);
750 if (usr2 & USR2_BRCD) {
751 imx_uart_writel(sport, USR2_BRCD, USR2);
752 if (uart_handle_break(&sport->port))
756 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
759 if (unlikely(rx & URXD_ERR)) {
761 sport->port.icount.brk++;
762 else if (rx & URXD_PRERR)
763 sport->port.icount.parity++;
764 else if (rx & URXD_FRMERR)
765 sport->port.icount.frame++;
766 if (rx & URXD_OVRRUN)
767 sport->port.icount.overrun++;
769 if (rx & sport->port.ignore_status_mask) {
775 rx &= (sport->port.read_status_mask | 0xFF);
779 else if (rx & URXD_PRERR)
781 else if (rx & URXD_FRMERR)
783 if (rx & URXD_OVRRUN)
787 sport->port.sysrq = 0;
791 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
794 if (tty_insert_flip_char(port, rx, flg) == 0)
795 sport->port.icount.buf_overrun++;
799 spin_unlock_irqrestore(&sport->port.lock, flags);
800 tty_flip_buffer_push(port);
804 static void imx_uart_clear_rx_errors(struct imx_port *sport);
807 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
809 static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
811 unsigned int tmp = TIOCM_DSR;
812 unsigned usr1 = imx_uart_readl(sport, USR1);
813 unsigned usr2 = imx_uart_readl(sport, USR2);
815 if (usr1 & USR1_RTSS)
818 /* in DCE mode DCDIN is always 0 */
819 if (!(usr2 & USR2_DCDIN))
823 if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
830 * Handle any change of modem status signal since we were last called.
832 static void imx_uart_mctrl_check(struct imx_port *sport)
834 unsigned int status, changed;
836 status = imx_uart_get_hwmctrl(sport);
837 changed = status ^ sport->old_status;
842 sport->old_status = status;
844 if (changed & TIOCM_RI && status & TIOCM_RI)
845 sport->port.icount.rng++;
846 if (changed & TIOCM_DSR)
847 sport->port.icount.dsr++;
848 if (changed & TIOCM_CAR)
849 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
850 if (changed & TIOCM_CTS)
851 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
853 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
856 static irqreturn_t imx_uart_int(int irq, void *dev_id)
858 struct imx_port *sport = dev_id;
859 unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
860 irqreturn_t ret = IRQ_NONE;
862 usr1 = imx_uart_readl(sport, USR1);
863 usr2 = imx_uart_readl(sport, USR2);
864 ucr1 = imx_uart_readl(sport, UCR1);
865 ucr2 = imx_uart_readl(sport, UCR2);
866 ucr3 = imx_uart_readl(sport, UCR3);
867 ucr4 = imx_uart_readl(sport, UCR4);
870 * Even if a condition is true that can trigger an irq only handle it if
871 * the respective irq source is enabled. This prevents some undesired
872 * actions, for example if a character that sits in the RX FIFO and that
873 * should be fetched via DMA is tried to be fetched using PIO. Or the
874 * receiver is currently off and so reading from URXD0 results in an
875 * exception. So just mask the (raw) status bits for disabled irqs.
877 if ((ucr1 & UCR1_RRDYEN) == 0)
879 if ((ucr2 & UCR2_ATEN) == 0)
881 if ((ucr1 & UCR1_TXMPTYEN) == 0)
883 if ((ucr4 & UCR4_TCEN) == 0)
885 if ((ucr3 & UCR3_DTRDEN) == 0)
887 if ((ucr1 & UCR1_RTSDEN) == 0)
889 if ((ucr3 & UCR3_AWAKEN) == 0)
891 if ((ucr4 & UCR4_OREN) == 0)
894 if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
895 imx_uart_rxint(irq, dev_id);
899 if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
900 imx_uart_txint(irq, dev_id);
904 if (usr1 & USR1_DTRD) {
907 imx_uart_writel(sport, USR1_DTRD, USR1);
909 spin_lock_irqsave(&sport->port.lock, flags);
910 imx_uart_mctrl_check(sport);
911 spin_unlock_irqrestore(&sport->port.lock, flags);
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, (dma_cookie_t)0, &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 dev_err(sport->port.dev, "DMA transaction error.\n");
1172 if (usr1 & USR1_FRAMERR) {
1173 sport->port.icount.frame++;
1174 imx_uart_writel(sport, USR1_FRAMERR, USR1);
1175 } else if (usr1 & USR1_PARITYERR) {
1176 sport->port.icount.parity++;
1177 imx_uart_writel(sport, USR1_PARITYERR, USR1);
1181 if (usr2 & USR2_ORE) {
1182 sport->port.icount.overrun++;
1183 imx_uart_writel(sport, USR2_ORE, USR2);
1188 #define TXTL_DEFAULT 2 /* reset default */
1189 #define RXTL_DEFAULT 1 /* reset default */
1190 #define TXTL_DMA 8 /* DMA burst setting */
1191 #define RXTL_DMA 9 /* DMA burst setting */
1193 static void imx_uart_setup_ufcr(struct imx_port *sport,
1194 unsigned char txwl, unsigned char rxwl)
1198 /* set receiver / transmitter trigger level */
1199 val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1200 val |= txwl << UFCR_TXTL_SHF | rxwl;
1201 imx_uart_writel(sport, val, UFCR);
1204 static void imx_uart_dma_exit(struct imx_port *sport)
1206 if (sport->dma_chan_rx) {
1207 dmaengine_terminate_sync(sport->dma_chan_rx);
1208 dma_release_channel(sport->dma_chan_rx);
1209 sport->dma_chan_rx = NULL;
1210 sport->rx_cookie = -EINVAL;
1211 kfree(sport->rx_buf);
1212 sport->rx_buf = NULL;
1215 if (sport->dma_chan_tx) {
1216 dmaengine_terminate_sync(sport->dma_chan_tx);
1217 dma_release_channel(sport->dma_chan_tx);
1218 sport->dma_chan_tx = NULL;
1222 static int imx_uart_dma_init(struct imx_port *sport)
1224 struct dma_slave_config slave_config = {};
1225 struct device *dev = sport->port.dev;
1228 /* Prepare for RX : */
1229 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1230 if (!sport->dma_chan_rx) {
1231 dev_dbg(dev, "cannot get the DMA channel.\n");
1236 slave_config.direction = DMA_DEV_TO_MEM;
1237 slave_config.src_addr = sport->port.mapbase + URXD0;
1238 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1239 /* one byte less than the watermark level to enable the aging timer */
1240 slave_config.src_maxburst = RXTL_DMA - 1;
1241 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1243 dev_err(dev, "error in RX dma configuration.\n");
1247 sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
1248 if (!sport->rx_buf) {
1252 sport->rx_ring.buf = sport->rx_buf;
1254 /* Prepare for TX : */
1255 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1256 if (!sport->dma_chan_tx) {
1257 dev_err(dev, "cannot get the TX DMA channel!\n");
1262 slave_config.direction = DMA_MEM_TO_DEV;
1263 slave_config.dst_addr = sport->port.mapbase + URTX0;
1264 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1265 slave_config.dst_maxburst = TXTL_DMA;
1266 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1268 dev_err(dev, "error in TX dma configuration.");
1274 imx_uart_dma_exit(sport);
1278 static void imx_uart_enable_dma(struct imx_port *sport)
1282 imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1285 ucr1 = imx_uart_readl(sport, UCR1);
1286 ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1287 imx_uart_writel(sport, ucr1, UCR1);
1289 sport->dma_is_enabled = 1;
1292 static void imx_uart_disable_dma(struct imx_port *sport)
1297 ucr1 = imx_uart_readl(sport, UCR1);
1298 ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1299 imx_uart_writel(sport, ucr1, UCR1);
1302 ucr2 = imx_uart_readl(sport, UCR2);
1303 ucr2 &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
1304 imx_uart_writel(sport, ucr2, UCR2);
1306 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1308 sport->dma_is_enabled = 0;
1311 /* half the RX buffer size */
1314 static int imx_uart_startup(struct uart_port *port)
1316 struct imx_port *sport = (struct imx_port *)port;
1318 unsigned long flags;
1319 int dma_is_inited = 0;
1320 u32 ucr1, ucr2, ucr4;
1322 retval = clk_prepare_enable(sport->clk_per);
1325 retval = clk_prepare_enable(sport->clk_ipg);
1327 clk_disable_unprepare(sport->clk_per);
1331 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1333 /* disable the DREN bit (Data Ready interrupt enable) before
1336 ucr4 = imx_uart_readl(sport, UCR4);
1338 /* set the trigger level for CTS */
1339 ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1340 ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1342 imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
1344 /* Can we enable the DMA support? */
1345 if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1348 spin_lock_irqsave(&sport->port.lock, flags);
1349 /* Reset fifo's and state machines */
1352 ucr2 = imx_uart_readl(sport, UCR2);
1354 imx_uart_writel(sport, ucr2, UCR2);
1356 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1360 * Finally, clear and enable interrupts
1362 imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1363 imx_uart_writel(sport, USR2_ORE, USR2);
1365 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1366 ucr1 |= UCR1_UARTEN;
1367 if (sport->have_rtscts)
1368 ucr1 |= UCR1_RTSDEN;
1370 imx_uart_writel(sport, ucr1, UCR1);
1372 ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
1373 if (!sport->dma_is_enabled)
1375 imx_uart_writel(sport, ucr4, UCR4);
1377 ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1378 ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1379 if (!sport->have_rtscts)
1382 * make sure the edge sensitive RTS-irq is disabled,
1383 * we're using RTSD instead.
1385 if (!imx_uart_is_imx1(sport))
1386 ucr2 &= ~UCR2_RTSEN;
1387 imx_uart_writel(sport, ucr2, UCR2);
1389 if (!imx_uart_is_imx1(sport)) {
1392 ucr3 = imx_uart_readl(sport, UCR3);
1394 ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1396 if (sport->dte_mode)
1397 /* disable broken interrupts */
1398 ucr3 &= ~(UCR3_RI | UCR3_DCD);
1400 imx_uart_writel(sport, ucr3, UCR3);
1404 * Enable modem status interrupts
1406 imx_uart_enable_ms(&sport->port);
1408 if (dma_is_inited) {
1409 imx_uart_enable_dma(sport);
1410 imx_uart_start_rx_dma(sport);
1412 ucr1 = imx_uart_readl(sport, UCR1);
1413 ucr1 |= UCR1_RRDYEN;
1414 imx_uart_writel(sport, ucr1, UCR1);
1416 ucr2 = imx_uart_readl(sport, UCR2);
1418 imx_uart_writel(sport, ucr2, UCR2);
1421 spin_unlock_irqrestore(&sport->port.lock, flags);
1426 static void imx_uart_shutdown(struct uart_port *port)
1428 struct imx_port *sport = (struct imx_port *)port;
1429 unsigned long flags;
1432 if (sport->dma_is_enabled) {
1433 sport->dma_is_rxing = 0;
1434 sport->dma_is_txing = 0;
1435 dmaengine_terminate_sync(sport->dma_chan_tx);
1436 dmaengine_terminate_sync(sport->dma_chan_rx);
1438 spin_lock_irqsave(&sport->port.lock, flags);
1439 imx_uart_stop_tx(port);
1440 imx_uart_stop_rx(port);
1441 imx_uart_disable_dma(sport);
1442 spin_unlock_irqrestore(&sport->port.lock, flags);
1443 imx_uart_dma_exit(sport);
1446 mctrl_gpio_disable_ms(sport->gpios);
1448 spin_lock_irqsave(&sport->port.lock, flags);
1449 ucr2 = imx_uart_readl(sport, UCR2);
1450 ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1451 imx_uart_writel(sport, ucr2, UCR2);
1452 spin_unlock_irqrestore(&sport->port.lock, flags);
1457 del_timer_sync(&sport->timer);
1460 * Disable all interrupts, port and break condition.
1463 spin_lock_irqsave(&sport->port.lock, flags);
1464 ucr1 = imx_uart_readl(sport, UCR1);
1465 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
1467 imx_uart_writel(sport, ucr1, UCR1);
1468 spin_unlock_irqrestore(&sport->port.lock, flags);
1470 clk_disable_unprepare(sport->clk_per);
1471 clk_disable_unprepare(sport->clk_ipg);
1474 /* called with port.lock taken and irqs off */
1475 static void imx_uart_flush_buffer(struct uart_port *port)
1477 struct imx_port *sport = (struct imx_port *)port;
1478 struct scatterlist *sgl = &sport->tx_sgl[0];
1480 int i = 100, ubir, ubmr, uts;
1482 if (!sport->dma_chan_tx)
1485 sport->tx_bytes = 0;
1486 dmaengine_terminate_all(sport->dma_chan_tx);
1487 if (sport->dma_is_txing) {
1490 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1492 ucr1 = imx_uart_readl(sport, UCR1);
1493 ucr1 &= ~UCR1_TXDMAEN;
1494 imx_uart_writel(sport, ucr1, UCR1);
1495 sport->dma_is_txing = 0;
1499 * According to the Reference Manual description of the UART SRST bit:
1501 * "Reset the transmit and receive state machines,
1502 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1505 * We don't need to restore the old values from USR1, USR2, URXD and
1506 * UTXD. UBRC is read only, so only save/restore the other three
1509 ubir = imx_uart_readl(sport, UBIR);
1510 ubmr = imx_uart_readl(sport, UBMR);
1511 uts = imx_uart_readl(sport, IMX21_UTS);
1513 ucr2 = imx_uart_readl(sport, UCR2);
1515 imx_uart_writel(sport, ucr2, UCR2);
1517 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1520 /* Restore the registers */
1521 imx_uart_writel(sport, ubir, UBIR);
1522 imx_uart_writel(sport, ubmr, UBMR);
1523 imx_uart_writel(sport, uts, IMX21_UTS);
1527 imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1528 struct ktermios *old)
1530 struct imx_port *sport = (struct imx_port *)port;
1531 unsigned long flags;
1532 u32 ucr2, old_ucr1, old_ucr2, ufcr;
1533 unsigned int baud, quot;
1534 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1536 unsigned long num, denom;
1540 * We only support CS7 and CS8.
1542 while ((termios->c_cflag & CSIZE) != CS7 &&
1543 (termios->c_cflag & CSIZE) != CS8) {
1544 termios->c_cflag &= ~CSIZE;
1545 termios->c_cflag |= old_csize;
1549 if ((termios->c_cflag & CSIZE) == CS8)
1550 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1552 ucr2 = UCR2_SRST | UCR2_IRTS;
1554 if (termios->c_cflag & CRTSCTS) {
1555 if (sport->have_rtscts) {
1558 if (port->rs485.flags & SER_RS485_ENABLED) {
1560 * RTS is mandatory for rs485 operation, so keep
1561 * it under manual control and keep transmitter
1564 if (port->rs485.flags &
1565 SER_RS485_RTS_AFTER_SEND)
1566 imx_uart_rts_active(sport, &ucr2);
1568 imx_uart_rts_inactive(sport, &ucr2);
1570 imx_uart_rts_auto(sport, &ucr2);
1573 termios->c_cflag &= ~CRTSCTS;
1575 } else if (port->rs485.flags & SER_RS485_ENABLED) {
1576 /* disable transmitter */
1577 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1578 imx_uart_rts_active(sport, &ucr2);
1580 imx_uart_rts_inactive(sport, &ucr2);
1584 if (termios->c_cflag & CSTOPB)
1586 if (termios->c_cflag & PARENB) {
1588 if (termios->c_cflag & PARODD)
1592 del_timer_sync(&sport->timer);
1595 * Ask the core to calculate the divisor for us.
1597 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1598 quot = uart_get_divisor(port, baud);
1600 spin_lock_irqsave(&sport->port.lock, flags);
1602 sport->port.read_status_mask = 0;
1603 if (termios->c_iflag & INPCK)
1604 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1605 if (termios->c_iflag & (BRKINT | PARMRK))
1606 sport->port.read_status_mask |= URXD_BRK;
1609 * Characters to ignore
1611 sport->port.ignore_status_mask = 0;
1612 if (termios->c_iflag & IGNPAR)
1613 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1614 if (termios->c_iflag & IGNBRK) {
1615 sport->port.ignore_status_mask |= URXD_BRK;
1617 * If we're ignoring parity and break indicators,
1618 * ignore overruns too (for real raw support).
1620 if (termios->c_iflag & IGNPAR)
1621 sport->port.ignore_status_mask |= URXD_OVRRUN;
1624 if ((termios->c_cflag & CREAD) == 0)
1625 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1628 * Update the per-port timeout.
1630 uart_update_timeout(port, termios->c_cflag, baud);
1633 * disable interrupts and drain transmitter
1635 old_ucr1 = imx_uart_readl(sport, UCR1);
1636 imx_uart_writel(sport,
1637 old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1639 old_ucr2 = imx_uart_readl(sport, UCR2);
1640 imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
1642 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
1645 /* then, disable everything */
1646 imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
1647 old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
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 /* set the parity, stop bits and data size */
1686 imx_uart_writel(sport, ucr2 | old_ucr2, UCR2);
1688 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1689 imx_uart_enable_ms(&sport->port);
1691 spin_unlock_irqrestore(&sport->port.lock, flags);
1694 static const char *imx_uart_type(struct uart_port *port)
1696 struct imx_port *sport = (struct imx_port *)port;
1698 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1702 * Configure/autoconfigure the port.
1704 static void imx_uart_config_port(struct uart_port *port, int flags)
1706 struct imx_port *sport = (struct imx_port *)port;
1708 if (flags & UART_CONFIG_TYPE)
1709 sport->port.type = PORT_IMX;
1713 * Verify the new serial_struct (for TIOCSSERIAL).
1714 * The only change we allow are to the flags and type, and
1715 * even then only between PORT_IMX and PORT_UNKNOWN
1718 imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1720 struct imx_port *sport = (struct imx_port *)port;
1723 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1725 if (sport->port.irq != ser->irq)
1727 if (ser->io_type != UPIO_MEM)
1729 if (sport->port.uartclk / 16 != ser->baud_base)
1731 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1733 if (sport->port.iobase != ser->port)
1740 #if defined(CONFIG_CONSOLE_POLL)
1742 static int imx_uart_poll_init(struct uart_port *port)
1744 struct imx_port *sport = (struct imx_port *)port;
1745 unsigned long flags;
1749 retval = clk_prepare_enable(sport->clk_ipg);
1752 retval = clk_prepare_enable(sport->clk_per);
1754 clk_disable_unprepare(sport->clk_ipg);
1756 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1758 spin_lock_irqsave(&sport->port.lock, flags);
1761 * Be careful about the order of enabling bits here. First enable the
1762 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1763 * This prevents that a character that already sits in the RX fifo is
1764 * triggering an irq but the try to fetch it from there results in an
1765 * exception because UARTEN or RXEN is still off.
1767 ucr1 = imx_uart_readl(sport, UCR1);
1768 ucr2 = imx_uart_readl(sport, UCR2);
1770 if (imx_uart_is_imx1(sport))
1771 ucr1 |= IMX1_UCR1_UARTCLKEN;
1773 ucr1 |= UCR1_UARTEN;
1774 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1779 imx_uart_writel(sport, ucr1, UCR1);
1780 imx_uart_writel(sport, ucr2, UCR2);
1782 /* now enable irqs */
1783 imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1784 imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1786 spin_unlock_irqrestore(&sport->port.lock, flags);
1791 static int imx_uart_poll_get_char(struct uart_port *port)
1793 struct imx_port *sport = (struct imx_port *)port;
1794 if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1795 return NO_POLL_CHAR;
1797 return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1800 static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1802 struct imx_port *sport = (struct imx_port *)port;
1803 unsigned int status;
1807 status = imx_uart_readl(sport, USR1);
1808 } while (~status & USR1_TRDY);
1811 imx_uart_writel(sport, c, URTX0);
1815 status = imx_uart_readl(sport, USR2);
1816 } while (~status & USR2_TXDC);
1820 /* called with port.lock taken and irqs off or from .probe without locking */
1821 static int imx_uart_rs485_config(struct uart_port *port,
1822 struct serial_rs485 *rs485conf)
1824 struct imx_port *sport = (struct imx_port *)port;
1828 rs485conf->delay_rts_before_send = 0;
1829 rs485conf->delay_rts_after_send = 0;
1831 /* RTS is required to control the transmitter */
1832 if (!sport->have_rtscts && !sport->have_rtsgpio)
1833 rs485conf->flags &= ~SER_RS485_ENABLED;
1835 if (rs485conf->flags & SER_RS485_ENABLED) {
1836 /* Enable receiver if low-active RTS signal is requested */
1837 if (sport->have_rtscts && !sport->have_rtsgpio &&
1838 !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1839 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1841 /* disable transmitter */
1842 ucr2 = imx_uart_readl(sport, UCR2);
1843 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1844 imx_uart_rts_active(sport, &ucr2);
1846 imx_uart_rts_inactive(sport, &ucr2);
1847 imx_uart_writel(sport, ucr2, UCR2);
1850 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1851 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1852 rs485conf->flags & SER_RS485_RX_DURING_TX)
1853 imx_uart_start_rx(port);
1855 port->rs485 = *rs485conf;
1860 static const struct uart_ops imx_uart_pops = {
1861 .tx_empty = imx_uart_tx_empty,
1862 .set_mctrl = imx_uart_set_mctrl,
1863 .get_mctrl = imx_uart_get_mctrl,
1864 .stop_tx = imx_uart_stop_tx,
1865 .start_tx = imx_uart_start_tx,
1866 .stop_rx = imx_uart_stop_rx,
1867 .enable_ms = imx_uart_enable_ms,
1868 .break_ctl = imx_uart_break_ctl,
1869 .startup = imx_uart_startup,
1870 .shutdown = imx_uart_shutdown,
1871 .flush_buffer = imx_uart_flush_buffer,
1872 .set_termios = imx_uart_set_termios,
1873 .type = imx_uart_type,
1874 .config_port = imx_uart_config_port,
1875 .verify_port = imx_uart_verify_port,
1876 #if defined(CONFIG_CONSOLE_POLL)
1877 .poll_init = imx_uart_poll_init,
1878 .poll_get_char = imx_uart_poll_get_char,
1879 .poll_put_char = imx_uart_poll_put_char,
1883 static struct imx_port *imx_uart_ports[UART_NR];
1885 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1886 static void imx_uart_console_putchar(struct uart_port *port, int ch)
1888 struct imx_port *sport = (struct imx_port *)port;
1890 while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1893 imx_uart_writel(sport, ch, URTX0);
1897 * Interrupts are disabled on entering
1900 imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1902 struct imx_port *sport = imx_uart_ports[co->index];
1903 struct imx_port_ucrs old_ucr;
1905 unsigned long flags = 0;
1909 retval = clk_enable(sport->clk_per);
1912 retval = clk_enable(sport->clk_ipg);
1914 clk_disable(sport->clk_per);
1918 if (sport->port.sysrq)
1920 else if (oops_in_progress)
1921 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1923 spin_lock_irqsave(&sport->port.lock, flags);
1926 * First, save UCR1/2/3 and then disable interrupts
1928 imx_uart_ucrs_save(sport, &old_ucr);
1929 ucr1 = old_ucr.ucr1;
1931 if (imx_uart_is_imx1(sport))
1932 ucr1 |= IMX1_UCR1_UARTCLKEN;
1933 ucr1 |= UCR1_UARTEN;
1934 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1936 imx_uart_writel(sport, ucr1, UCR1);
1938 imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
1940 uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
1943 * Finally, wait for transmitter to become empty
1944 * and restore UCR1/2/3
1946 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
1948 imx_uart_ucrs_restore(sport, &old_ucr);
1951 spin_unlock_irqrestore(&sport->port.lock, flags);
1953 clk_disable(sport->clk_ipg);
1954 clk_disable(sport->clk_per);
1958 * If the port was already initialised (eg, by a boot loader),
1959 * try to determine the current setup.
1962 imx_uart_console_get_options(struct imx_port *sport, int *baud,
1963 int *parity, int *bits)
1966 if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
1967 /* ok, the port was enabled */
1968 unsigned int ucr2, ubir, ubmr, uartclk;
1969 unsigned int baud_raw;
1970 unsigned int ucfr_rfdiv;
1972 ucr2 = imx_uart_readl(sport, UCR2);
1975 if (ucr2 & UCR2_PREN) {
1976 if (ucr2 & UCR2_PROE)
1987 ubir = imx_uart_readl(sport, UBIR) & 0xffff;
1988 ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
1990 ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
1991 if (ucfr_rfdiv == 6)
1994 ucfr_rfdiv = 6 - ucfr_rfdiv;
1996 uartclk = clk_get_rate(sport->clk_per);
1997 uartclk /= ucfr_rfdiv;
2000 * The next code provides exact computation of
2001 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2002 * without need of float support or long long division,
2003 * which would be required to prevent 32bit arithmetic overflow
2005 unsigned int mul = ubir + 1;
2006 unsigned int div = 16 * (ubmr + 1);
2007 unsigned int rem = uartclk % div;
2009 baud_raw = (uartclk / div) * mul;
2010 baud_raw += (rem * mul + div / 2) / div;
2011 *baud = (baud_raw + 50) / 100 * 100;
2014 if (*baud != baud_raw)
2015 pr_info("Console IMX rounded baud rate from %d to %d\n",
2021 imx_uart_console_setup(struct console *co, char *options)
2023 struct imx_port *sport;
2031 * Check whether an invalid uart number has been specified, and
2032 * if so, search for the first available port that does have
2035 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2037 sport = imx_uart_ports[co->index];
2041 /* For setting the registers, we only need to enable the ipg clock. */
2042 retval = clk_prepare_enable(sport->clk_ipg);
2047 uart_parse_options(options, &baud, &parity, &bits, &flow);
2049 imx_uart_console_get_options(sport, &baud, &parity, &bits);
2051 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2053 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2055 clk_disable(sport->clk_ipg);
2057 clk_unprepare(sport->clk_ipg);
2061 retval = clk_prepare(sport->clk_per);
2063 clk_disable_unprepare(sport->clk_ipg);
2069 static struct uart_driver imx_uart_uart_driver;
2070 static struct console imx_uart_console = {
2072 .write = imx_uart_console_write,
2073 .device = uart_console_device,
2074 .setup = imx_uart_console_setup,
2075 .flags = CON_PRINTBUFFER,
2077 .data = &imx_uart_uart_driver,
2080 #define IMX_CONSOLE &imx_uart_console
2083 static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
2085 struct imx_port *sport = (struct imx_port *)port;
2087 while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
2090 imx_uart_writel(sport, ch, URTX0);
2093 static void imx_uart_console_early_write(struct console *con, const char *s,
2096 struct earlycon_device *dev = con->data;
2098 uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
2102 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
2104 if (!dev->port.membase)
2107 dev->con->write = imx_uart_console_early_write;
2111 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2112 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2116 #define IMX_CONSOLE NULL
2119 static struct uart_driver imx_uart_uart_driver = {
2120 .owner = THIS_MODULE,
2121 .driver_name = DRIVER_NAME,
2122 .dev_name = DEV_NAME,
2123 .major = SERIAL_IMX_MAJOR,
2124 .minor = MINOR_START,
2125 .nr = ARRAY_SIZE(imx_uart_ports),
2126 .cons = IMX_CONSOLE,
2131 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2132 * could successfully get all information from dt or a negative errno.
2134 static int imx_uart_probe_dt(struct imx_port *sport,
2135 struct platform_device *pdev)
2137 struct device_node *np = pdev->dev.of_node;
2140 sport->devdata = of_device_get_match_data(&pdev->dev);
2141 if (!sport->devdata)
2142 /* no device tree device */
2145 ret = of_alias_get_id(np, "serial");
2147 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2150 sport->port.line = ret;
2152 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2153 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2154 sport->have_rtscts = 1;
2156 if (of_get_property(np, "fsl,dte-mode", NULL))
2157 sport->dte_mode = 1;
2159 if (of_get_property(np, "rts-gpios", NULL))
2160 sport->have_rtsgpio = 1;
2165 static inline int imx_uart_probe_dt(struct imx_port *sport,
2166 struct platform_device *pdev)
2172 static void imx_uart_probe_pdata(struct imx_port *sport,
2173 struct platform_device *pdev)
2175 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2177 sport->port.line = pdev->id;
2178 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
2183 if (pdata->flags & IMXUART_HAVE_RTSCTS)
2184 sport->have_rtscts = 1;
2187 static int imx_uart_probe(struct platform_device *pdev)
2189 struct imx_port *sport;
2193 struct resource *res;
2194 int txirq, rxirq, rtsirq;
2196 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2200 ret = imx_uart_probe_dt(sport, pdev);
2202 imx_uart_probe_pdata(sport, pdev);
2206 if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2207 dev_err(&pdev->dev, "serial%d out of range\n",
2212 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2213 base = devm_ioremap_resource(&pdev->dev, res);
2215 return PTR_ERR(base);
2217 rxirq = platform_get_irq(pdev, 0);
2218 txirq = platform_get_irq(pdev, 1);
2219 rtsirq = platform_get_irq(pdev, 2);
2221 sport->port.dev = &pdev->dev;
2222 sport->port.mapbase = res->start;
2223 sport->port.membase = base;
2224 sport->port.type = PORT_IMX,
2225 sport->port.iotype = UPIO_MEM;
2226 sport->port.irq = rxirq;
2227 sport->port.fifosize = 32;
2228 sport->port.ops = &imx_uart_pops;
2229 sport->port.rs485_config = imx_uart_rs485_config;
2230 sport->port.flags = UPF_BOOT_AUTOCONF;
2231 timer_setup(&sport->timer, imx_uart_timeout, 0);
2233 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2234 if (IS_ERR(sport->gpios))
2235 return PTR_ERR(sport->gpios);
2237 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2238 if (IS_ERR(sport->clk_ipg)) {
2239 ret = PTR_ERR(sport->clk_ipg);
2240 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2244 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2245 if (IS_ERR(sport->clk_per)) {
2246 ret = PTR_ERR(sport->clk_per);
2247 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2251 sport->port.uartclk = clk_get_rate(sport->clk_per);
2253 /* For register access, we only need to enable the ipg clock. */
2254 ret = clk_prepare_enable(sport->clk_ipg);
2256 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2260 /* initialize shadow register values */
2261 sport->ucr1 = readl(sport->port.membase + UCR1);
2262 sport->ucr2 = readl(sport->port.membase + UCR2);
2263 sport->ucr3 = readl(sport->port.membase + UCR3);
2264 sport->ucr4 = readl(sport->port.membase + UCR4);
2265 sport->ufcr = readl(sport->port.membase + UFCR);
2267 uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2269 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2270 (!sport->have_rtscts && !sport->have_rtsgpio))
2271 dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2274 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2275 * signal cannot be set low during transmission in case the
2276 * receiver is off (limitation of the i.MX UART IP).
2278 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2279 sport->have_rtscts && !sport->have_rtsgpio &&
2280 (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2281 !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2283 "low-active RTS not possible when receiver is off, enabling receiver\n");
2285 imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2287 /* Disable interrupts before requesting them */
2288 ucr1 = imx_uart_readl(sport, UCR1);
2289 ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2290 UCR1_TXMPTYEN | UCR1_RTSDEN);
2291 imx_uart_writel(sport, ucr1, UCR1);
2293 if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2295 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2296 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2297 * and DCD (when they are outputs) or enables the respective
2298 * irqs. So set this bit early, i.e. before requesting irqs.
2300 u32 ufcr = imx_uart_readl(sport, UFCR);
2301 if (!(ufcr & UFCR_DCEDTE))
2302 imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2305 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2306 * enabled later because they cannot be cleared
2307 * (confirmed on i.MX25) which makes them unusable.
2309 imx_uart_writel(sport,
2310 IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2314 u32 ucr3 = UCR3_DSR;
2315 u32 ufcr = imx_uart_readl(sport, UFCR);
2316 if (ufcr & UFCR_DCEDTE)
2317 imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2319 if (!imx_uart_is_imx1(sport))
2320 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2321 imx_uart_writel(sport, ucr3, UCR3);
2324 clk_disable_unprepare(sport->clk_ipg);
2327 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2328 * chips only have one interrupt.
2331 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2332 dev_name(&pdev->dev), sport);
2334 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2339 ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2340 dev_name(&pdev->dev), sport);
2342 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2347 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2348 dev_name(&pdev->dev), sport);
2350 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2355 imx_uart_ports[sport->port.line] = sport;
2357 platform_set_drvdata(pdev, sport);
2359 return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2362 static int imx_uart_remove(struct platform_device *pdev)
2364 struct imx_port *sport = platform_get_drvdata(pdev);
2366 return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2369 static void imx_uart_restore_context(struct imx_port *sport)
2371 if (!sport->context_saved)
2374 imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2375 imx_uart_writel(sport, sport->saved_reg[5], UESC);
2376 imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2377 imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2378 imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2379 imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2380 imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2381 imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2382 imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2383 imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2384 sport->context_saved = false;
2387 static void imx_uart_save_context(struct imx_port *sport)
2389 /* Save necessary regs */
2390 sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2391 sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2392 sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2393 sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2394 sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2395 sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2396 sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2397 sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2398 sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2399 sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2400 sport->context_saved = true;
2403 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2407 ucr3 = imx_uart_readl(sport, UCR3);
2409 imx_uart_writel(sport, USR1_AWAKE, USR1);
2410 ucr3 |= UCR3_AWAKEN;
2412 ucr3 &= ~UCR3_AWAKEN;
2414 imx_uart_writel(sport, ucr3, UCR3);
2416 if (sport->have_rtscts) {
2417 u32 ucr1 = imx_uart_readl(sport, UCR1);
2419 ucr1 |= UCR1_RTSDEN;
2421 ucr1 &= ~UCR1_RTSDEN;
2422 imx_uart_writel(sport, ucr1, UCR1);
2426 static int imx_uart_suspend_noirq(struct device *dev)
2428 struct platform_device *pdev = to_platform_device(dev);
2429 struct imx_port *sport = platform_get_drvdata(pdev);
2431 imx_uart_save_context(sport);
2433 clk_disable(sport->clk_ipg);
2438 static int imx_uart_resume_noirq(struct device *dev)
2440 struct platform_device *pdev = to_platform_device(dev);
2441 struct imx_port *sport = platform_get_drvdata(pdev);
2444 ret = clk_enable(sport->clk_ipg);
2448 imx_uart_restore_context(sport);
2453 static int imx_uart_suspend(struct device *dev)
2455 struct platform_device *pdev = to_platform_device(dev);
2456 struct imx_port *sport = platform_get_drvdata(pdev);
2459 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2460 disable_irq(sport->port.irq);
2462 ret = clk_prepare_enable(sport->clk_ipg);
2466 /* enable wakeup from i.MX UART */
2467 imx_uart_enable_wakeup(sport, true);
2472 static int imx_uart_resume(struct device *dev)
2474 struct platform_device *pdev = to_platform_device(dev);
2475 struct imx_port *sport = platform_get_drvdata(pdev);
2477 /* disable wakeup from i.MX UART */
2478 imx_uart_enable_wakeup(sport, false);
2480 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2481 enable_irq(sport->port.irq);
2483 clk_disable_unprepare(sport->clk_ipg);
2488 static int imx_uart_freeze(struct device *dev)
2490 struct platform_device *pdev = to_platform_device(dev);
2491 struct imx_port *sport = platform_get_drvdata(pdev);
2493 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2495 return clk_prepare_enable(sport->clk_ipg);
2498 static int imx_uart_thaw(struct device *dev)
2500 struct platform_device *pdev = to_platform_device(dev);
2501 struct imx_port *sport = platform_get_drvdata(pdev);
2503 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2505 clk_disable_unprepare(sport->clk_ipg);
2510 static const struct dev_pm_ops imx_uart_pm_ops = {
2511 .suspend_noirq = imx_uart_suspend_noirq,
2512 .resume_noirq = imx_uart_resume_noirq,
2513 .freeze_noirq = imx_uart_suspend_noirq,
2514 .restore_noirq = imx_uart_resume_noirq,
2515 .suspend = imx_uart_suspend,
2516 .resume = imx_uart_resume,
2517 .freeze = imx_uart_freeze,
2518 .thaw = imx_uart_thaw,
2519 .restore = imx_uart_thaw,
2522 static struct platform_driver imx_uart_platform_driver = {
2523 .probe = imx_uart_probe,
2524 .remove = imx_uart_remove,
2526 .id_table = imx_uart_devtype,
2529 .of_match_table = imx_uart_dt_ids,
2530 .pm = &imx_uart_pm_ops,
2534 static int __init imx_uart_init(void)
2536 int ret = uart_register_driver(&imx_uart_uart_driver);
2541 ret = platform_driver_register(&imx_uart_platform_driver);
2543 uart_unregister_driver(&imx_uart_uart_driver);
2548 static void __exit imx_uart_exit(void)
2550 platform_driver_unregister(&imx_uart_platform_driver);
2551 uart_unregister_driver(&imx_uart_uart_driver);
2554 module_init(imx_uart_init);
2555 module_exit(imx_uart_exit);
2557 MODULE_AUTHOR("Sascha Hauer");
2558 MODULE_DESCRIPTION("IMX generic serial port driver");
2559 MODULE_LICENSE("GPL");
2560 MODULE_ALIAS("platform:imx-uart");