p4-clockmod: Replace cpu_sibling_mask() with topology_sibling_cpumask()
[linux/fpc-iii.git] / drivers / tty / serial / imx.c
blobc8cfa06371280af6abfd63bd379ee5c121523ad7
1 /*
2 * Driver for Motorola/Freescale IMX serial ports
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 * Author: Sascha Hauer <sascha@saschahauer.de>
7 * Copyright (C) 2004 Pengutronix
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
20 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
21 #define SUPPORT_SYSRQ
22 #endif
24 #include <linux/module.h>
25 #include <linux/ioport.h>
26 #include <linux/init.h>
27 #include <linux/console.h>
28 #include <linux/sysrq.h>
29 #include <linux/platform_device.h>
30 #include <linux/tty.h>
31 #include <linux/tty_flip.h>
32 #include <linux/serial_core.h>
33 #include <linux/serial.h>
34 #include <linux/clk.h>
35 #include <linux/delay.h>
36 #include <linux/rational.h>
37 #include <linux/slab.h>
38 #include <linux/of.h>
39 #include <linux/of_device.h>
40 #include <linux/io.h>
41 #include <linux/dma-mapping.h>
43 #include <asm/irq.h>
44 #include <linux/platform_data/serial-imx.h>
45 #include <linux/platform_data/dma-imx.h>
47 /* Register definitions */
48 #define URXD0 0x0 /* Receiver Register */
49 #define URTX0 0x40 /* Transmitter Register */
50 #define UCR1 0x80 /* Control Register 1 */
51 #define UCR2 0x84 /* Control Register 2 */
52 #define UCR3 0x88 /* Control Register 3 */
53 #define UCR4 0x8c /* Control Register 4 */
54 #define UFCR 0x90 /* FIFO Control Register */
55 #define USR1 0x94 /* Status Register 1 */
56 #define USR2 0x98 /* Status Register 2 */
57 #define UESC 0x9c /* Escape Character Register */
58 #define UTIM 0xa0 /* Escape Timer Register */
59 #define UBIR 0xa4 /* BRM Incremental Register */
60 #define UBMR 0xa8 /* BRM Modulator Register */
61 #define UBRC 0xac /* Baud Rate Count Register */
62 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
63 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
64 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
66 /* UART Control Register Bit Fields.*/
67 #define URXD_DUMMY_READ (1<<16)
68 #define URXD_CHARRDY (1<<15)
69 #define URXD_ERR (1<<14)
70 #define URXD_OVRRUN (1<<13)
71 #define URXD_FRMERR (1<<12)
72 #define URXD_BRK (1<<11)
73 #define URXD_PRERR (1<<10)
74 #define URXD_RX_DATA (0xFF<<0)
75 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
76 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
77 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
78 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
79 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
80 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
81 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
82 #define UCR1_IREN (1<<7) /* Infrared interface enable */
83 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
84 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
85 #define UCR1_SNDBRK (1<<4) /* Send break */
86 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
87 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
88 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
89 #define UCR1_DOZE (1<<1) /* Doze */
90 #define UCR1_UARTEN (1<<0) /* UART enabled */
91 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
92 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
93 #define UCR2_CTSC (1<<13) /* CTS pin control */
94 #define UCR2_CTS (1<<12) /* Clear to send */
95 #define UCR2_ESCEN (1<<11) /* Escape enable */
96 #define UCR2_PREN (1<<8) /* Parity enable */
97 #define UCR2_PROE (1<<7) /* Parity odd/even */
98 #define UCR2_STPB (1<<6) /* Stop */
99 #define UCR2_WS (1<<5) /* Word size */
100 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
101 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
102 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
103 #define UCR2_RXEN (1<<1) /* Receiver enabled */
104 #define UCR2_SRST (1<<0) /* SW reset */
105 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
106 #define UCR3_PARERREN (1<<12) /* Parity enable */
107 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
108 #define UCR3_DSR (1<<10) /* Data set ready */
109 #define UCR3_DCD (1<<9) /* Data carrier detect */
110 #define UCR3_RI (1<<8) /* Ring indicator */
111 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
112 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
113 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
114 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
115 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
116 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
117 #define UCR3_BPEN (1<<0) /* Preset registers enable */
118 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
119 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
120 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
121 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
122 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
123 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
124 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
125 #define UCR4_IRSC (1<<5) /* IR special case */
126 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
127 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
128 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
129 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
130 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
131 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
132 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
133 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
134 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
135 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
136 #define USR1_RTSS (1<<14) /* RTS pin status */
137 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
138 #define USR1_RTSD (1<<12) /* RTS delta */
139 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
140 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
141 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
142 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
143 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
144 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
145 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
146 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
147 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
148 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
149 #define USR2_IDLE (1<<12) /* Idle condition */
150 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
151 #define USR2_WAKE (1<<7) /* Wake */
152 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
153 #define USR2_TXDC (1<<3) /* Transmitter complete */
154 #define USR2_BRCD (1<<2) /* Break condition */
155 #define USR2_ORE (1<<1) /* Overrun error */
156 #define USR2_RDR (1<<0) /* Recv data ready */
157 #define UTS_FRCPERR (1<<13) /* Force parity error */
158 #define UTS_LOOP (1<<12) /* Loop tx and rx */
159 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
160 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
161 #define UTS_TXFULL (1<<4) /* TxFIFO full */
162 #define UTS_RXFULL (1<<3) /* RxFIFO full */
163 #define UTS_SOFTRST (1<<0) /* Software reset */
165 /* We've been assigned a range on the "Low-density serial ports" major */
166 #define SERIAL_IMX_MAJOR 207
167 #define MINOR_START 16
168 #define DEV_NAME "ttymxc"
171 * This determines how often we check the modem status signals
172 * for any change. They generally aren't connected to an IRQ
173 * so we have to poll them. We also check immediately before
174 * filling the TX fifo incase CTS has been dropped.
176 #define MCTRL_TIMEOUT (250*HZ/1000)
178 #define DRIVER_NAME "IMX-uart"
180 #define UART_NR 8
182 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
183 enum imx_uart_type {
184 IMX1_UART,
185 IMX21_UART,
186 IMX6Q_UART,
189 /* device type dependent stuff */
190 struct imx_uart_data {
191 unsigned uts_reg;
192 enum imx_uart_type devtype;
195 struct imx_port {
196 struct uart_port port;
197 struct timer_list timer;
198 unsigned int old_status;
199 unsigned int have_rtscts:1;
200 unsigned int dte_mode:1;
201 unsigned int irda_inv_rx:1;
202 unsigned int irda_inv_tx:1;
203 unsigned short trcv_delay; /* transceiver delay */
204 struct clk *clk_ipg;
205 struct clk *clk_per;
206 const struct imx_uart_data *devdata;
208 /* DMA fields */
209 unsigned int dma_is_inited:1;
210 unsigned int dma_is_enabled:1;
211 unsigned int dma_is_rxing:1;
212 unsigned int dma_is_txing:1;
213 struct dma_chan *dma_chan_rx, *dma_chan_tx;
214 struct scatterlist rx_sgl, tx_sgl[2];
215 void *rx_buf;
216 unsigned int tx_bytes;
217 unsigned int dma_tx_nents;
218 wait_queue_head_t dma_wait;
221 struct imx_port_ucrs {
222 unsigned int ucr1;
223 unsigned int ucr2;
224 unsigned int ucr3;
227 static struct imx_uart_data imx_uart_devdata[] = {
228 [IMX1_UART] = {
229 .uts_reg = IMX1_UTS,
230 .devtype = IMX1_UART,
232 [IMX21_UART] = {
233 .uts_reg = IMX21_UTS,
234 .devtype = IMX21_UART,
236 [IMX6Q_UART] = {
237 .uts_reg = IMX21_UTS,
238 .devtype = IMX6Q_UART,
242 static struct platform_device_id imx_uart_devtype[] = {
244 .name = "imx1-uart",
245 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
246 }, {
247 .name = "imx21-uart",
248 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
249 }, {
250 .name = "imx6q-uart",
251 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
252 }, {
253 /* sentinel */
256 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
258 static const struct of_device_id imx_uart_dt_ids[] = {
259 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
260 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
261 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
262 { /* sentinel */ }
264 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
266 static inline unsigned uts_reg(struct imx_port *sport)
268 return sport->devdata->uts_reg;
271 static inline int is_imx1_uart(struct imx_port *sport)
273 return sport->devdata->devtype == IMX1_UART;
276 static inline int is_imx21_uart(struct imx_port *sport)
278 return sport->devdata->devtype == IMX21_UART;
281 static inline int is_imx6q_uart(struct imx_port *sport)
283 return sport->devdata->devtype == IMX6Q_UART;
286 * Save and restore functions for UCR1, UCR2 and UCR3 registers
288 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
289 static void imx_port_ucrs_save(struct uart_port *port,
290 struct imx_port_ucrs *ucr)
292 /* save control registers */
293 ucr->ucr1 = readl(port->membase + UCR1);
294 ucr->ucr2 = readl(port->membase + UCR2);
295 ucr->ucr3 = readl(port->membase + UCR3);
298 static void imx_port_ucrs_restore(struct uart_port *port,
299 struct imx_port_ucrs *ucr)
301 /* restore control registers */
302 writel(ucr->ucr1, port->membase + UCR1);
303 writel(ucr->ucr2, port->membase + UCR2);
304 writel(ucr->ucr3, port->membase + UCR3);
306 #endif
309 * Handle any change of modem status signal since we were last called.
311 static void imx_mctrl_check(struct imx_port *sport)
313 unsigned int status, changed;
315 status = sport->port.ops->get_mctrl(&sport->port);
316 changed = status ^ sport->old_status;
318 if (changed == 0)
319 return;
321 sport->old_status = status;
323 if (changed & TIOCM_RI)
324 sport->port.icount.rng++;
325 if (changed & TIOCM_DSR)
326 sport->port.icount.dsr++;
327 if (changed & TIOCM_CAR)
328 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
329 if (changed & TIOCM_CTS)
330 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
332 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
336 * This is our per-port timeout handler, for checking the
337 * modem status signals.
339 static void imx_timeout(unsigned long data)
341 struct imx_port *sport = (struct imx_port *)data;
342 unsigned long flags;
344 if (sport->port.state) {
345 spin_lock_irqsave(&sport->port.lock, flags);
346 imx_mctrl_check(sport);
347 spin_unlock_irqrestore(&sport->port.lock, flags);
349 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
354 * interrupts disabled on entry
356 static void imx_stop_tx(struct uart_port *port)
358 struct imx_port *sport = (struct imx_port *)port;
359 unsigned long temp;
362 * We are maybe in the SMP context, so if the DMA TX thread is running
363 * on other cpu, we have to wait for it to finish.
365 if (sport->dma_is_enabled && sport->dma_is_txing)
366 return;
368 temp = readl(port->membase + UCR1);
369 writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
371 /* in rs485 mode disable transmitter if shifter is empty */
372 if (port->rs485.flags & SER_RS485_ENABLED &&
373 readl(port->membase + USR2) & USR2_TXDC) {
374 temp = readl(port->membase + UCR2);
375 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
376 temp &= ~UCR2_CTS;
377 else
378 temp |= UCR2_CTS;
379 writel(temp, port->membase + UCR2);
381 temp = readl(port->membase + UCR4);
382 temp &= ~UCR4_TCEN;
383 writel(temp, port->membase + UCR4);
388 * interrupts disabled on entry
390 static void imx_stop_rx(struct uart_port *port)
392 struct imx_port *sport = (struct imx_port *)port;
393 unsigned long temp;
395 if (sport->dma_is_enabled && sport->dma_is_rxing) {
396 if (sport->port.suspended) {
397 dmaengine_terminate_all(sport->dma_chan_rx);
398 sport->dma_is_rxing = 0;
399 } else {
400 return;
404 temp = readl(sport->port.membase + UCR2);
405 writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
407 /* disable the `Receiver Ready Interrrupt` */
408 temp = readl(sport->port.membase + UCR1);
409 writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
413 * Set the modem control timer to fire immediately.
415 static void imx_enable_ms(struct uart_port *port)
417 struct imx_port *sport = (struct imx_port *)port;
419 mod_timer(&sport->timer, jiffies);
422 static void imx_dma_tx(struct imx_port *sport);
423 static inline void imx_transmit_buffer(struct imx_port *sport)
425 struct circ_buf *xmit = &sport->port.state->xmit;
426 unsigned long temp;
428 if (sport->port.x_char) {
429 /* Send next char */
430 writel(sport->port.x_char, sport->port.membase + URTX0);
431 sport->port.icount.tx++;
432 sport->port.x_char = 0;
433 return;
436 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
437 imx_stop_tx(&sport->port);
438 return;
441 if (sport->dma_is_enabled) {
443 * We've just sent a X-char Ensure the TX DMA is enabled
444 * and the TX IRQ is disabled.
446 temp = readl(sport->port.membase + UCR1);
447 temp &= ~UCR1_TXMPTYEN;
448 if (sport->dma_is_txing) {
449 temp |= UCR1_TDMAEN;
450 writel(temp, sport->port.membase + UCR1);
451 } else {
452 writel(temp, sport->port.membase + UCR1);
453 imx_dma_tx(sport);
457 while (!uart_circ_empty(xmit) &&
458 !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
459 /* send xmit->buf[xmit->tail]
460 * out the port here */
461 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
462 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
463 sport->port.icount.tx++;
466 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
467 uart_write_wakeup(&sport->port);
469 if (uart_circ_empty(xmit))
470 imx_stop_tx(&sport->port);
473 static void dma_tx_callback(void *data)
475 struct imx_port *sport = data;
476 struct scatterlist *sgl = &sport->tx_sgl[0];
477 struct circ_buf *xmit = &sport->port.state->xmit;
478 unsigned long flags;
479 unsigned long temp;
481 spin_lock_irqsave(&sport->port.lock, flags);
483 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
485 temp = readl(sport->port.membase + UCR1);
486 temp &= ~UCR1_TDMAEN;
487 writel(temp, sport->port.membase + UCR1);
489 /* update the stat */
490 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
491 sport->port.icount.tx += sport->tx_bytes;
493 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
495 sport->dma_is_txing = 0;
497 spin_unlock_irqrestore(&sport->port.lock, flags);
499 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
500 uart_write_wakeup(&sport->port);
502 if (waitqueue_active(&sport->dma_wait)) {
503 wake_up(&sport->dma_wait);
504 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
505 return;
508 spin_lock_irqsave(&sport->port.lock, flags);
509 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
510 imx_dma_tx(sport);
511 spin_unlock_irqrestore(&sport->port.lock, flags);
514 static void imx_dma_tx(struct imx_port *sport)
516 struct circ_buf *xmit = &sport->port.state->xmit;
517 struct scatterlist *sgl = sport->tx_sgl;
518 struct dma_async_tx_descriptor *desc;
519 struct dma_chan *chan = sport->dma_chan_tx;
520 struct device *dev = sport->port.dev;
521 unsigned long temp;
522 int ret;
524 if (sport->dma_is_txing)
525 return;
527 sport->tx_bytes = uart_circ_chars_pending(xmit);
529 if (xmit->tail < xmit->head) {
530 sport->dma_tx_nents = 1;
531 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
532 } else {
533 sport->dma_tx_nents = 2;
534 sg_init_table(sgl, 2);
535 sg_set_buf(sgl, xmit->buf + xmit->tail,
536 UART_XMIT_SIZE - xmit->tail);
537 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
540 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
541 if (ret == 0) {
542 dev_err(dev, "DMA mapping error for TX.\n");
543 return;
545 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
546 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
547 if (!desc) {
548 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
549 DMA_TO_DEVICE);
550 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
551 return;
553 desc->callback = dma_tx_callback;
554 desc->callback_param = sport;
556 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
557 uart_circ_chars_pending(xmit));
559 temp = readl(sport->port.membase + UCR1);
560 temp |= UCR1_TDMAEN;
561 writel(temp, sport->port.membase + UCR1);
563 /* fire it */
564 sport->dma_is_txing = 1;
565 dmaengine_submit(desc);
566 dma_async_issue_pending(chan);
567 return;
571 * interrupts disabled on entry
573 static void imx_start_tx(struct uart_port *port)
575 struct imx_port *sport = (struct imx_port *)port;
576 unsigned long temp;
578 if (port->rs485.flags & SER_RS485_ENABLED) {
579 /* enable transmitter and shifter empty irq */
580 temp = readl(port->membase + UCR2);
581 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
582 temp &= ~UCR2_CTS;
583 else
584 temp |= UCR2_CTS;
585 writel(temp, port->membase + UCR2);
587 temp = readl(port->membase + UCR4);
588 temp |= UCR4_TCEN;
589 writel(temp, port->membase + UCR4);
592 if (!sport->dma_is_enabled) {
593 temp = readl(sport->port.membase + UCR1);
594 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
597 if (sport->dma_is_enabled) {
598 if (sport->port.x_char) {
599 /* We have X-char to send, so enable TX IRQ and
600 * disable TX DMA to let TX interrupt to send X-char */
601 temp = readl(sport->port.membase + UCR1);
602 temp &= ~UCR1_TDMAEN;
603 temp |= UCR1_TXMPTYEN;
604 writel(temp, sport->port.membase + UCR1);
605 return;
608 if (!uart_circ_empty(&port->state->xmit) &&
609 !uart_tx_stopped(port))
610 imx_dma_tx(sport);
611 return;
615 static irqreturn_t imx_rtsint(int irq, void *dev_id)
617 struct imx_port *sport = dev_id;
618 unsigned int val;
619 unsigned long flags;
621 spin_lock_irqsave(&sport->port.lock, flags);
623 writel(USR1_RTSD, sport->port.membase + USR1);
624 val = readl(sport->port.membase + USR1) & USR1_RTSS;
625 uart_handle_cts_change(&sport->port, !!val);
626 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
628 spin_unlock_irqrestore(&sport->port.lock, flags);
629 return IRQ_HANDLED;
632 static irqreturn_t imx_txint(int irq, void *dev_id)
634 struct imx_port *sport = dev_id;
635 unsigned long flags;
637 spin_lock_irqsave(&sport->port.lock, flags);
638 imx_transmit_buffer(sport);
639 spin_unlock_irqrestore(&sport->port.lock, flags);
640 return IRQ_HANDLED;
643 static irqreturn_t imx_rxint(int irq, void *dev_id)
645 struct imx_port *sport = dev_id;
646 unsigned int rx, flg, ignored = 0;
647 struct tty_port *port = &sport->port.state->port;
648 unsigned long flags, temp;
650 spin_lock_irqsave(&sport->port.lock, flags);
652 while (readl(sport->port.membase + USR2) & USR2_RDR) {
653 flg = TTY_NORMAL;
654 sport->port.icount.rx++;
656 rx = readl(sport->port.membase + URXD0);
658 temp = readl(sport->port.membase + USR2);
659 if (temp & USR2_BRCD) {
660 writel(USR2_BRCD, sport->port.membase + USR2);
661 if (uart_handle_break(&sport->port))
662 continue;
665 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
666 continue;
668 if (unlikely(rx & URXD_ERR)) {
669 if (rx & URXD_BRK)
670 sport->port.icount.brk++;
671 else if (rx & URXD_PRERR)
672 sport->port.icount.parity++;
673 else if (rx & URXD_FRMERR)
674 sport->port.icount.frame++;
675 if (rx & URXD_OVRRUN)
676 sport->port.icount.overrun++;
678 if (rx & sport->port.ignore_status_mask) {
679 if (++ignored > 100)
680 goto out;
681 continue;
684 rx &= (sport->port.read_status_mask | 0xFF);
686 if (rx & URXD_BRK)
687 flg = TTY_BREAK;
688 else if (rx & URXD_PRERR)
689 flg = TTY_PARITY;
690 else if (rx & URXD_FRMERR)
691 flg = TTY_FRAME;
692 if (rx & URXD_OVRRUN)
693 flg = TTY_OVERRUN;
695 #ifdef SUPPORT_SYSRQ
696 sport->port.sysrq = 0;
697 #endif
700 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
701 goto out;
703 tty_insert_flip_char(port, rx, flg);
706 out:
707 spin_unlock_irqrestore(&sport->port.lock, flags);
708 tty_flip_buffer_push(port);
709 return IRQ_HANDLED;
712 static int start_rx_dma(struct imx_port *sport);
714 * If the RXFIFO is filled with some data, and then we
715 * arise a DMA operation to receive them.
717 static void imx_dma_rxint(struct imx_port *sport)
719 unsigned long temp;
720 unsigned long flags;
722 spin_lock_irqsave(&sport->port.lock, flags);
724 temp = readl(sport->port.membase + USR2);
725 if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
726 sport->dma_is_rxing = 1;
728 /* disable the `Recerver Ready Interrrupt` */
729 temp = readl(sport->port.membase + UCR1);
730 temp &= ~(UCR1_RRDYEN);
731 writel(temp, sport->port.membase + UCR1);
733 /* tell the DMA to receive the data. */
734 start_rx_dma(sport);
737 spin_unlock_irqrestore(&sport->port.lock, flags);
740 static irqreturn_t imx_int(int irq, void *dev_id)
742 struct imx_port *sport = dev_id;
743 unsigned int sts;
744 unsigned int sts2;
746 sts = readl(sport->port.membase + USR1);
747 sts2 = readl(sport->port.membase + USR2);
749 if (sts & USR1_RRDY) {
750 if (sport->dma_is_enabled)
751 imx_dma_rxint(sport);
752 else
753 imx_rxint(irq, dev_id);
756 if ((sts & USR1_TRDY &&
757 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) ||
758 (sts2 & USR2_TXDC &&
759 readl(sport->port.membase + UCR4) & UCR4_TCEN))
760 imx_txint(irq, dev_id);
762 if (sts & USR1_RTSD)
763 imx_rtsint(irq, dev_id);
765 if (sts & USR1_AWAKE)
766 writel(USR1_AWAKE, sport->port.membase + USR1);
768 if (sts2 & USR2_ORE) {
769 dev_err(sport->port.dev, "Rx FIFO overrun\n");
770 sport->port.icount.overrun++;
771 writel(USR2_ORE, sport->port.membase + USR2);
774 return IRQ_HANDLED;
778 * Return TIOCSER_TEMT when transmitter is not busy.
780 static unsigned int imx_tx_empty(struct uart_port *port)
782 struct imx_port *sport = (struct imx_port *)port;
783 unsigned int ret;
785 ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
787 /* If the TX DMA is working, return 0. */
788 if (sport->dma_is_enabled && sport->dma_is_txing)
789 ret = 0;
791 return ret;
795 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
797 static unsigned int imx_get_mctrl(struct uart_port *port)
799 struct imx_port *sport = (struct imx_port *)port;
800 unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
802 if (readl(sport->port.membase + USR1) & USR1_RTSS)
803 tmp |= TIOCM_CTS;
805 if (readl(sport->port.membase + UCR2) & UCR2_CTS)
806 tmp |= TIOCM_RTS;
808 if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
809 tmp |= TIOCM_LOOP;
811 return tmp;
814 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
816 struct imx_port *sport = (struct imx_port *)port;
817 unsigned long temp;
819 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
820 temp = readl(sport->port.membase + UCR2);
821 temp &= ~(UCR2_CTS | UCR2_CTSC);
822 if (mctrl & TIOCM_RTS)
823 temp |= UCR2_CTS | UCR2_CTSC;
824 writel(temp, sport->port.membase + UCR2);
827 temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
828 if (mctrl & TIOCM_LOOP)
829 temp |= UTS_LOOP;
830 writel(temp, sport->port.membase + uts_reg(sport));
834 * Interrupts always disabled.
836 static void imx_break_ctl(struct uart_port *port, int break_state)
838 struct imx_port *sport = (struct imx_port *)port;
839 unsigned long flags, temp;
841 spin_lock_irqsave(&sport->port.lock, flags);
843 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
845 if (break_state != 0)
846 temp |= UCR1_SNDBRK;
848 writel(temp, sport->port.membase + UCR1);
850 spin_unlock_irqrestore(&sport->port.lock, flags);
853 #define TXTL 2 /* reset default */
854 #define RXTL 1 /* reset default */
856 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
858 unsigned int val;
860 /* set receiver / transmitter trigger level */
861 val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
862 val |= TXTL << UFCR_TXTL_SHF | RXTL;
863 writel(val, sport->port.membase + UFCR);
864 return 0;
867 #define RX_BUF_SIZE (PAGE_SIZE)
868 static void imx_rx_dma_done(struct imx_port *sport)
870 unsigned long temp;
871 unsigned long flags;
873 spin_lock_irqsave(&sport->port.lock, flags);
875 /* Enable this interrupt when the RXFIFO is empty. */
876 temp = readl(sport->port.membase + UCR1);
877 temp |= UCR1_RRDYEN;
878 writel(temp, sport->port.membase + UCR1);
880 sport->dma_is_rxing = 0;
882 /* Is the shutdown waiting for us? */
883 if (waitqueue_active(&sport->dma_wait))
884 wake_up(&sport->dma_wait);
886 spin_unlock_irqrestore(&sport->port.lock, flags);
890 * There are three kinds of RX DMA interrupts(such as in the MX6Q):
891 * [1] the RX DMA buffer is full.
892 * [2] the Aging timer expires(wait for 8 bytes long)
893 * [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
895 * The [2] is trigger when a character was been sitting in the FIFO
896 * meanwhile [3] can wait for 32 bytes long when the RX line is
897 * on IDLE state and RxFIFO is empty.
899 static void dma_rx_callback(void *data)
901 struct imx_port *sport = data;
902 struct dma_chan *chan = sport->dma_chan_rx;
903 struct scatterlist *sgl = &sport->rx_sgl;
904 struct tty_port *port = &sport->port.state->port;
905 struct dma_tx_state state;
906 enum dma_status status;
907 unsigned int count;
909 /* unmap it first */
910 dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
912 status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
913 count = RX_BUF_SIZE - state.residue;
914 dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
916 if (count) {
917 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ))
918 tty_insert_flip_string(port, sport->rx_buf, count);
919 tty_flip_buffer_push(port);
921 start_rx_dma(sport);
922 } else if (readl(sport->port.membase + USR2) & USR2_RDR) {
924 * start rx_dma directly once data in RXFIFO, more efficient
925 * than before:
926 * 1. call imx_rx_dma_done to stop dma if no data received
927 * 2. wait next RDR interrupt to start dma transfer.
929 start_rx_dma(sport);
930 } else {
932 * stop dma to prevent too many IDLE event trigged if no data
933 * in RXFIFO
935 imx_rx_dma_done(sport);
939 static int start_rx_dma(struct imx_port *sport)
941 struct scatterlist *sgl = &sport->rx_sgl;
942 struct dma_chan *chan = sport->dma_chan_rx;
943 struct device *dev = sport->port.dev;
944 struct dma_async_tx_descriptor *desc;
945 int ret;
947 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
948 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
949 if (ret == 0) {
950 dev_err(dev, "DMA mapping error for RX.\n");
951 return -EINVAL;
953 desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
954 DMA_PREP_INTERRUPT);
955 if (!desc) {
956 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
957 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
958 return -EINVAL;
960 desc->callback = dma_rx_callback;
961 desc->callback_param = sport;
963 dev_dbg(dev, "RX: prepare for the DMA.\n");
964 dmaengine_submit(desc);
965 dma_async_issue_pending(chan);
966 return 0;
969 static void imx_uart_dma_exit(struct imx_port *sport)
971 if (sport->dma_chan_rx) {
972 dma_release_channel(sport->dma_chan_rx);
973 sport->dma_chan_rx = NULL;
975 kfree(sport->rx_buf);
976 sport->rx_buf = NULL;
979 if (sport->dma_chan_tx) {
980 dma_release_channel(sport->dma_chan_tx);
981 sport->dma_chan_tx = NULL;
984 sport->dma_is_inited = 0;
987 static int imx_uart_dma_init(struct imx_port *sport)
989 struct dma_slave_config slave_config = {};
990 struct device *dev = sport->port.dev;
991 int ret;
993 /* Prepare for RX : */
994 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
995 if (!sport->dma_chan_rx) {
996 dev_dbg(dev, "cannot get the DMA channel.\n");
997 ret = -EINVAL;
998 goto err;
1001 slave_config.direction = DMA_DEV_TO_MEM;
1002 slave_config.src_addr = sport->port.mapbase + URXD0;
1003 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1004 slave_config.src_maxburst = RXTL;
1005 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1006 if (ret) {
1007 dev_err(dev, "error in RX dma configuration.\n");
1008 goto err;
1011 sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1012 if (!sport->rx_buf) {
1013 ret = -ENOMEM;
1014 goto err;
1017 /* Prepare for TX : */
1018 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1019 if (!sport->dma_chan_tx) {
1020 dev_err(dev, "cannot get the TX DMA channel!\n");
1021 ret = -EINVAL;
1022 goto err;
1025 slave_config.direction = DMA_MEM_TO_DEV;
1026 slave_config.dst_addr = sport->port.mapbase + URTX0;
1027 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1028 slave_config.dst_maxburst = TXTL;
1029 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1030 if (ret) {
1031 dev_err(dev, "error in TX dma configuration.");
1032 goto err;
1035 sport->dma_is_inited = 1;
1037 return 0;
1038 err:
1039 imx_uart_dma_exit(sport);
1040 return ret;
1043 static void imx_enable_dma(struct imx_port *sport)
1045 unsigned long temp;
1047 init_waitqueue_head(&sport->dma_wait);
1049 /* set UCR1 */
1050 temp = readl(sport->port.membase + UCR1);
1051 temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1052 /* wait for 32 idle frames for IDDMA interrupt */
1053 UCR1_ICD_REG(3);
1054 writel(temp, sport->port.membase + UCR1);
1056 /* set UCR4 */
1057 temp = readl(sport->port.membase + UCR4);
1058 temp |= UCR4_IDDMAEN;
1059 writel(temp, sport->port.membase + UCR4);
1061 sport->dma_is_enabled = 1;
1064 static void imx_disable_dma(struct imx_port *sport)
1066 unsigned long temp;
1068 /* clear UCR1 */
1069 temp = readl(sport->port.membase + UCR1);
1070 temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1071 writel(temp, sport->port.membase + UCR1);
1073 /* clear UCR2 */
1074 temp = readl(sport->port.membase + UCR2);
1075 temp &= ~(UCR2_CTSC | UCR2_CTS);
1076 writel(temp, sport->port.membase + UCR2);
1078 /* clear UCR4 */
1079 temp = readl(sport->port.membase + UCR4);
1080 temp &= ~UCR4_IDDMAEN;
1081 writel(temp, sport->port.membase + UCR4);
1083 sport->dma_is_enabled = 0;
1086 /* half the RX buffer size */
1087 #define CTSTL 16
1089 static int imx_startup(struct uart_port *port)
1091 struct imx_port *sport = (struct imx_port *)port;
1092 int retval, i;
1093 unsigned long flags, temp;
1095 retval = clk_prepare_enable(sport->clk_per);
1096 if (retval)
1097 return retval;
1098 retval = clk_prepare_enable(sport->clk_ipg);
1099 if (retval) {
1100 clk_disable_unprepare(sport->clk_per);
1101 return retval;
1104 imx_setup_ufcr(sport, 0);
1106 /* disable the DREN bit (Data Ready interrupt enable) before
1107 * requesting IRQs
1109 temp = readl(sport->port.membase + UCR4);
1111 /* set the trigger level for CTS */
1112 temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1113 temp |= CTSTL << UCR4_CTSTL_SHF;
1115 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1117 /* Reset fifo's and state machines */
1118 i = 100;
1120 temp = readl(sport->port.membase + UCR2);
1121 temp &= ~UCR2_SRST;
1122 writel(temp, sport->port.membase + UCR2);
1124 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1125 udelay(1);
1127 /* Can we enable the DMA support? */
1128 if (is_imx6q_uart(sport) && !uart_console(port) &&
1129 !sport->dma_is_inited)
1130 imx_uart_dma_init(sport);
1132 spin_lock_irqsave(&sport->port.lock, flags);
1135 * Finally, clear and enable interrupts
1137 writel(USR1_RTSD, sport->port.membase + USR1);
1138 writel(USR2_ORE, sport->port.membase + USR2);
1140 if (sport->dma_is_inited && !sport->dma_is_enabled)
1141 imx_enable_dma(sport);
1143 temp = readl(sport->port.membase + UCR1);
1144 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1146 writel(temp, sport->port.membase + UCR1);
1148 temp = readl(sport->port.membase + UCR4);
1149 temp |= UCR4_OREN;
1150 writel(temp, sport->port.membase + UCR4);
1152 temp = readl(sport->port.membase + UCR2);
1153 temp |= (UCR2_RXEN | UCR2_TXEN);
1154 if (!sport->have_rtscts)
1155 temp |= UCR2_IRTS;
1156 writel(temp, sport->port.membase + UCR2);
1158 if (!is_imx1_uart(sport)) {
1159 temp = readl(sport->port.membase + UCR3);
1160 temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
1161 writel(temp, sport->port.membase + UCR3);
1165 * Enable modem status interrupts
1167 imx_enable_ms(&sport->port);
1168 spin_unlock_irqrestore(&sport->port.lock, flags);
1170 return 0;
1173 static void imx_shutdown(struct uart_port *port)
1175 struct imx_port *sport = (struct imx_port *)port;
1176 unsigned long temp;
1177 unsigned long flags;
1179 if (sport->dma_is_enabled) {
1180 int ret;
1182 /* We have to wait for the DMA to finish. */
1183 ret = wait_event_interruptible(sport->dma_wait,
1184 !sport->dma_is_rxing && !sport->dma_is_txing);
1185 if (ret != 0) {
1186 sport->dma_is_rxing = 0;
1187 sport->dma_is_txing = 0;
1188 dmaengine_terminate_all(sport->dma_chan_tx);
1189 dmaengine_terminate_all(sport->dma_chan_rx);
1191 spin_lock_irqsave(&sport->port.lock, flags);
1192 imx_stop_tx(port);
1193 imx_stop_rx(port);
1194 imx_disable_dma(sport);
1195 spin_unlock_irqrestore(&sport->port.lock, flags);
1196 imx_uart_dma_exit(sport);
1199 spin_lock_irqsave(&sport->port.lock, flags);
1200 temp = readl(sport->port.membase + UCR2);
1201 temp &= ~(UCR2_TXEN);
1202 writel(temp, sport->port.membase + UCR2);
1203 spin_unlock_irqrestore(&sport->port.lock, flags);
1206 * Stop our timer.
1208 del_timer_sync(&sport->timer);
1211 * Disable all interrupts, port and break condition.
1214 spin_lock_irqsave(&sport->port.lock, flags);
1215 temp = readl(sport->port.membase + UCR1);
1216 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1218 writel(temp, sport->port.membase + UCR1);
1219 spin_unlock_irqrestore(&sport->port.lock, flags);
1221 clk_disable_unprepare(sport->clk_per);
1222 clk_disable_unprepare(sport->clk_ipg);
1225 static void imx_flush_buffer(struct uart_port *port)
1227 struct imx_port *sport = (struct imx_port *)port;
1228 struct scatterlist *sgl = &sport->tx_sgl[0];
1229 unsigned long temp;
1230 int i = 100, ubir, ubmr, uts;
1232 if (!sport->dma_chan_tx)
1233 return;
1235 sport->tx_bytes = 0;
1236 dmaengine_terminate_all(sport->dma_chan_tx);
1237 if (sport->dma_is_txing) {
1238 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1239 DMA_TO_DEVICE);
1240 temp = readl(sport->port.membase + UCR1);
1241 temp &= ~UCR1_TDMAEN;
1242 writel(temp, sport->port.membase + UCR1);
1243 sport->dma_is_txing = false;
1247 * According to the Reference Manual description of the UART SRST bit:
1248 * "Reset the transmit and receive state machines,
1249 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1250 * and UTS[6-3]". As we don't need to restore the old values from
1251 * USR1, USR2, URXD, UTXD, only save/restore the other four registers
1253 ubir = readl(sport->port.membase + UBIR);
1254 ubmr = readl(sport->port.membase + UBMR);
1255 uts = readl(sport->port.membase + IMX21_UTS);
1257 temp = readl(sport->port.membase + UCR2);
1258 temp &= ~UCR2_SRST;
1259 writel(temp, sport->port.membase + UCR2);
1261 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1262 udelay(1);
1264 /* Restore the registers */
1265 writel(ubir, sport->port.membase + UBIR);
1266 writel(ubmr, sport->port.membase + UBMR);
1267 writel(uts, sport->port.membase + IMX21_UTS);
1270 static void
1271 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1272 struct ktermios *old)
1274 struct imx_port *sport = (struct imx_port *)port;
1275 unsigned long flags;
1276 unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1277 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1278 unsigned int div, ufcr;
1279 unsigned long num, denom;
1280 uint64_t tdiv64;
1283 * We only support CS7 and CS8.
1285 while ((termios->c_cflag & CSIZE) != CS7 &&
1286 (termios->c_cflag & CSIZE) != CS8) {
1287 termios->c_cflag &= ~CSIZE;
1288 termios->c_cflag |= old_csize;
1289 old_csize = CS8;
1292 if ((termios->c_cflag & CSIZE) == CS8)
1293 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1294 else
1295 ucr2 = UCR2_SRST | UCR2_IRTS;
1297 if (termios->c_cflag & CRTSCTS) {
1298 if (sport->have_rtscts) {
1299 ucr2 &= ~UCR2_IRTS;
1301 if (port->rs485.flags & SER_RS485_ENABLED) {
1303 * RTS is mandatory for rs485 operation, so keep
1304 * it under manual control and keep transmitter
1305 * disabled.
1307 if (!(port->rs485.flags &
1308 SER_RS485_RTS_AFTER_SEND))
1309 ucr2 |= UCR2_CTS;
1310 } else {
1311 ucr2 |= UCR2_CTSC;
1313 } else {
1314 termios->c_cflag &= ~CRTSCTS;
1316 } else if (port->rs485.flags & SER_RS485_ENABLED)
1317 /* disable transmitter */
1318 if (!(port->rs485.flags & SER_RS485_RTS_AFTER_SEND))
1319 ucr2 |= UCR2_CTS;
1321 if (termios->c_cflag & CSTOPB)
1322 ucr2 |= UCR2_STPB;
1323 if (termios->c_cflag & PARENB) {
1324 ucr2 |= UCR2_PREN;
1325 if (termios->c_cflag & PARODD)
1326 ucr2 |= UCR2_PROE;
1329 del_timer_sync(&sport->timer);
1332 * Ask the core to calculate the divisor for us.
1334 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1335 quot = uart_get_divisor(port, baud);
1337 spin_lock_irqsave(&sport->port.lock, flags);
1339 sport->port.read_status_mask = 0;
1340 if (termios->c_iflag & INPCK)
1341 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1342 if (termios->c_iflag & (BRKINT | PARMRK))
1343 sport->port.read_status_mask |= URXD_BRK;
1346 * Characters to ignore
1348 sport->port.ignore_status_mask = 0;
1349 if (termios->c_iflag & IGNPAR)
1350 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1351 if (termios->c_iflag & IGNBRK) {
1352 sport->port.ignore_status_mask |= URXD_BRK;
1354 * If we're ignoring parity and break indicators,
1355 * ignore overruns too (for real raw support).
1357 if (termios->c_iflag & IGNPAR)
1358 sport->port.ignore_status_mask |= URXD_OVRRUN;
1361 if ((termios->c_cflag & CREAD) == 0)
1362 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1365 * Update the per-port timeout.
1367 uart_update_timeout(port, termios->c_cflag, baud);
1370 * disable interrupts and drain transmitter
1372 old_ucr1 = readl(sport->port.membase + UCR1);
1373 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1374 sport->port.membase + UCR1);
1376 while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1377 barrier();
1379 /* then, disable everything */
1380 old_txrxen = readl(sport->port.membase + UCR2);
1381 writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1382 sport->port.membase + UCR2);
1383 old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1385 /* custom-baudrate handling */
1386 div = sport->port.uartclk / (baud * 16);
1387 if (baud == 38400 && quot != div)
1388 baud = sport->port.uartclk / (quot * 16);
1390 div = sport->port.uartclk / (baud * 16);
1391 if (div > 7)
1392 div = 7;
1393 if (!div)
1394 div = 1;
1396 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1397 1 << 16, 1 << 16, &num, &denom);
1399 tdiv64 = sport->port.uartclk;
1400 tdiv64 *= num;
1401 do_div(tdiv64, denom * 16 * div);
1402 tty_termios_encode_baud_rate(termios,
1403 (speed_t)tdiv64, (speed_t)tdiv64);
1405 num -= 1;
1406 denom -= 1;
1408 ufcr = readl(sport->port.membase + UFCR);
1409 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1410 if (sport->dte_mode)
1411 ufcr |= UFCR_DCEDTE;
1412 writel(ufcr, sport->port.membase + UFCR);
1414 writel(num, sport->port.membase + UBIR);
1415 writel(denom, sport->port.membase + UBMR);
1417 if (!is_imx1_uart(sport))
1418 writel(sport->port.uartclk / div / 1000,
1419 sport->port.membase + IMX21_ONEMS);
1421 writel(old_ucr1, sport->port.membase + UCR1);
1423 /* set the parity, stop bits and data size */
1424 writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1426 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1427 imx_enable_ms(&sport->port);
1429 spin_unlock_irqrestore(&sport->port.lock, flags);
1432 static const char *imx_type(struct uart_port *port)
1434 struct imx_port *sport = (struct imx_port *)port;
1436 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1440 * Configure/autoconfigure the port.
1442 static void imx_config_port(struct uart_port *port, int flags)
1444 struct imx_port *sport = (struct imx_port *)port;
1446 if (flags & UART_CONFIG_TYPE)
1447 sport->port.type = PORT_IMX;
1451 * Verify the new serial_struct (for TIOCSSERIAL).
1452 * The only change we allow are to the flags and type, and
1453 * even then only between PORT_IMX and PORT_UNKNOWN
1455 static int
1456 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1458 struct imx_port *sport = (struct imx_port *)port;
1459 int ret = 0;
1461 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1462 ret = -EINVAL;
1463 if (sport->port.irq != ser->irq)
1464 ret = -EINVAL;
1465 if (ser->io_type != UPIO_MEM)
1466 ret = -EINVAL;
1467 if (sport->port.uartclk / 16 != ser->baud_base)
1468 ret = -EINVAL;
1469 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1470 ret = -EINVAL;
1471 if (sport->port.iobase != ser->port)
1472 ret = -EINVAL;
1473 if (ser->hub6 != 0)
1474 ret = -EINVAL;
1475 return ret;
1478 #if defined(CONFIG_CONSOLE_POLL)
1480 static int imx_poll_init(struct uart_port *port)
1482 struct imx_port *sport = (struct imx_port *)port;
1483 unsigned long flags;
1484 unsigned long temp;
1485 int retval;
1487 retval = clk_prepare_enable(sport->clk_ipg);
1488 if (retval)
1489 return retval;
1490 retval = clk_prepare_enable(sport->clk_per);
1491 if (retval)
1492 clk_disable_unprepare(sport->clk_ipg);
1494 imx_setup_ufcr(sport, 0);
1496 spin_lock_irqsave(&sport->port.lock, flags);
1498 temp = readl(sport->port.membase + UCR1);
1499 if (is_imx1_uart(sport))
1500 temp |= IMX1_UCR1_UARTCLKEN;
1501 temp |= UCR1_UARTEN | UCR1_RRDYEN;
1502 temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN);
1503 writel(temp, sport->port.membase + UCR1);
1505 temp = readl(sport->port.membase + UCR2);
1506 temp |= UCR2_RXEN;
1507 writel(temp, sport->port.membase + UCR2);
1509 spin_unlock_irqrestore(&sport->port.lock, flags);
1511 return 0;
1514 static int imx_poll_get_char(struct uart_port *port)
1516 if (!(readl_relaxed(port->membase + USR2) & USR2_RDR))
1517 return NO_POLL_CHAR;
1519 return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA;
1522 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1524 unsigned int status;
1526 /* drain */
1527 do {
1528 status = readl_relaxed(port->membase + USR1);
1529 } while (~status & USR1_TRDY);
1531 /* write */
1532 writel_relaxed(c, port->membase + URTX0);
1534 /* flush */
1535 do {
1536 status = readl_relaxed(port->membase + USR2);
1537 } while (~status & USR2_TXDC);
1539 #endif
1541 static int imx_rs485_config(struct uart_port *port,
1542 struct serial_rs485 *rs485conf)
1544 struct imx_port *sport = (struct imx_port *)port;
1546 /* unimplemented */
1547 rs485conf->delay_rts_before_send = 0;
1548 rs485conf->delay_rts_after_send = 0;
1549 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1551 /* RTS is required to control the transmitter */
1552 if (!sport->have_rtscts)
1553 rs485conf->flags &= ~SER_RS485_ENABLED;
1555 if (rs485conf->flags & SER_RS485_ENABLED) {
1556 unsigned long temp;
1558 /* disable transmitter */
1559 temp = readl(sport->port.membase + UCR2);
1560 temp &= ~UCR2_CTSC;
1561 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1562 temp &= ~UCR2_CTS;
1563 else
1564 temp |= UCR2_CTS;
1565 writel(temp, sport->port.membase + UCR2);
1568 port->rs485 = *rs485conf;
1570 return 0;
1573 static struct uart_ops imx_pops = {
1574 .tx_empty = imx_tx_empty,
1575 .set_mctrl = imx_set_mctrl,
1576 .get_mctrl = imx_get_mctrl,
1577 .stop_tx = imx_stop_tx,
1578 .start_tx = imx_start_tx,
1579 .stop_rx = imx_stop_rx,
1580 .enable_ms = imx_enable_ms,
1581 .break_ctl = imx_break_ctl,
1582 .startup = imx_startup,
1583 .shutdown = imx_shutdown,
1584 .flush_buffer = imx_flush_buffer,
1585 .set_termios = imx_set_termios,
1586 .type = imx_type,
1587 .config_port = imx_config_port,
1588 .verify_port = imx_verify_port,
1589 #if defined(CONFIG_CONSOLE_POLL)
1590 .poll_init = imx_poll_init,
1591 .poll_get_char = imx_poll_get_char,
1592 .poll_put_char = imx_poll_put_char,
1593 #endif
1596 static struct imx_port *imx_ports[UART_NR];
1598 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1599 static void imx_console_putchar(struct uart_port *port, int ch)
1601 struct imx_port *sport = (struct imx_port *)port;
1603 while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1604 barrier();
1606 writel(ch, sport->port.membase + URTX0);
1610 * Interrupts are disabled on entering
1612 static void
1613 imx_console_write(struct console *co, const char *s, unsigned int count)
1615 struct imx_port *sport = imx_ports[co->index];
1616 struct imx_port_ucrs old_ucr;
1617 unsigned int ucr1;
1618 unsigned long flags = 0;
1619 int locked = 1;
1620 int retval;
1622 retval = clk_enable(sport->clk_per);
1623 if (retval)
1624 return;
1625 retval = clk_enable(sport->clk_ipg);
1626 if (retval) {
1627 clk_disable(sport->clk_per);
1628 return;
1631 if (sport->port.sysrq)
1632 locked = 0;
1633 else if (oops_in_progress)
1634 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1635 else
1636 spin_lock_irqsave(&sport->port.lock, flags);
1639 * First, save UCR1/2/3 and then disable interrupts
1641 imx_port_ucrs_save(&sport->port, &old_ucr);
1642 ucr1 = old_ucr.ucr1;
1644 if (is_imx1_uart(sport))
1645 ucr1 |= IMX1_UCR1_UARTCLKEN;
1646 ucr1 |= UCR1_UARTEN;
1647 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1649 writel(ucr1, sport->port.membase + UCR1);
1651 writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1653 uart_console_write(&sport->port, s, count, imx_console_putchar);
1656 * Finally, wait for transmitter to become empty
1657 * and restore UCR1/2/3
1659 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1661 imx_port_ucrs_restore(&sport->port, &old_ucr);
1663 if (locked)
1664 spin_unlock_irqrestore(&sport->port.lock, flags);
1666 clk_disable(sport->clk_ipg);
1667 clk_disable(sport->clk_per);
1671 * If the port was already initialised (eg, by a boot loader),
1672 * try to determine the current setup.
1674 static void __init
1675 imx_console_get_options(struct imx_port *sport, int *baud,
1676 int *parity, int *bits)
1679 if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1680 /* ok, the port was enabled */
1681 unsigned int ucr2, ubir, ubmr, uartclk;
1682 unsigned int baud_raw;
1683 unsigned int ucfr_rfdiv;
1685 ucr2 = readl(sport->port.membase + UCR2);
1687 *parity = 'n';
1688 if (ucr2 & UCR2_PREN) {
1689 if (ucr2 & UCR2_PROE)
1690 *parity = 'o';
1691 else
1692 *parity = 'e';
1695 if (ucr2 & UCR2_WS)
1696 *bits = 8;
1697 else
1698 *bits = 7;
1700 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1701 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1703 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1704 if (ucfr_rfdiv == 6)
1705 ucfr_rfdiv = 7;
1706 else
1707 ucfr_rfdiv = 6 - ucfr_rfdiv;
1709 uartclk = clk_get_rate(sport->clk_per);
1710 uartclk /= ucfr_rfdiv;
1712 { /*
1713 * The next code provides exact computation of
1714 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1715 * without need of float support or long long division,
1716 * which would be required to prevent 32bit arithmetic overflow
1718 unsigned int mul = ubir + 1;
1719 unsigned int div = 16 * (ubmr + 1);
1720 unsigned int rem = uartclk % div;
1722 baud_raw = (uartclk / div) * mul;
1723 baud_raw += (rem * mul + div / 2) / div;
1724 *baud = (baud_raw + 50) / 100 * 100;
1727 if (*baud != baud_raw)
1728 pr_info("Console IMX rounded baud rate from %d to %d\n",
1729 baud_raw, *baud);
1733 static int __init
1734 imx_console_setup(struct console *co, char *options)
1736 struct imx_port *sport;
1737 int baud = 9600;
1738 int bits = 8;
1739 int parity = 'n';
1740 int flow = 'n';
1741 int retval;
1744 * Check whether an invalid uart number has been specified, and
1745 * if so, search for the first available port that does have
1746 * console support.
1748 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1749 co->index = 0;
1750 sport = imx_ports[co->index];
1751 if (sport == NULL)
1752 return -ENODEV;
1754 /* For setting the registers, we only need to enable the ipg clock. */
1755 retval = clk_prepare_enable(sport->clk_ipg);
1756 if (retval)
1757 goto error_console;
1759 if (options)
1760 uart_parse_options(options, &baud, &parity, &bits, &flow);
1761 else
1762 imx_console_get_options(sport, &baud, &parity, &bits);
1764 imx_setup_ufcr(sport, 0);
1766 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1768 clk_disable(sport->clk_ipg);
1769 if (retval) {
1770 clk_unprepare(sport->clk_ipg);
1771 goto error_console;
1774 retval = clk_prepare(sport->clk_per);
1775 if (retval)
1776 clk_disable_unprepare(sport->clk_ipg);
1778 error_console:
1779 return retval;
1782 static struct uart_driver imx_reg;
1783 static struct console imx_console = {
1784 .name = DEV_NAME,
1785 .write = imx_console_write,
1786 .device = uart_console_device,
1787 .setup = imx_console_setup,
1788 .flags = CON_PRINTBUFFER,
1789 .index = -1,
1790 .data = &imx_reg,
1793 #define IMX_CONSOLE &imx_console
1794 #else
1795 #define IMX_CONSOLE NULL
1796 #endif
1798 static struct uart_driver imx_reg = {
1799 .owner = THIS_MODULE,
1800 .driver_name = DRIVER_NAME,
1801 .dev_name = DEV_NAME,
1802 .major = SERIAL_IMX_MAJOR,
1803 .minor = MINOR_START,
1804 .nr = ARRAY_SIZE(imx_ports),
1805 .cons = IMX_CONSOLE,
1808 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1810 struct imx_port *sport = platform_get_drvdata(dev);
1811 unsigned int val;
1813 /* enable wakeup from i.MX UART */
1814 val = readl(sport->port.membase + UCR3);
1815 val |= UCR3_AWAKEN;
1816 writel(val, sport->port.membase + UCR3);
1818 uart_suspend_port(&imx_reg, &sport->port);
1820 return 0;
1823 static int serial_imx_resume(struct platform_device *dev)
1825 struct imx_port *sport = platform_get_drvdata(dev);
1826 unsigned int val;
1828 /* disable wakeup from i.MX UART */
1829 val = readl(sport->port.membase + UCR3);
1830 val &= ~UCR3_AWAKEN;
1831 writel(val, sport->port.membase + UCR3);
1833 uart_resume_port(&imx_reg, &sport->port);
1835 return 0;
1838 #ifdef CONFIG_OF
1840 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1841 * could successfully get all information from dt or a negative errno.
1843 static int serial_imx_probe_dt(struct imx_port *sport,
1844 struct platform_device *pdev)
1846 struct device_node *np = pdev->dev.of_node;
1847 const struct of_device_id *of_id =
1848 of_match_device(imx_uart_dt_ids, &pdev->dev);
1849 int ret;
1851 if (!np)
1852 /* no device tree device */
1853 return 1;
1855 ret = of_alias_get_id(np, "serial");
1856 if (ret < 0) {
1857 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1858 return ret;
1860 sport->port.line = ret;
1862 if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1863 sport->have_rtscts = 1;
1865 if (of_get_property(np, "fsl,dte-mode", NULL))
1866 sport->dte_mode = 1;
1868 sport->devdata = of_id->data;
1870 return 0;
1872 #else
1873 static inline int serial_imx_probe_dt(struct imx_port *sport,
1874 struct platform_device *pdev)
1876 return 1;
1878 #endif
1880 static void serial_imx_probe_pdata(struct imx_port *sport,
1881 struct platform_device *pdev)
1883 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1885 sport->port.line = pdev->id;
1886 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
1888 if (!pdata)
1889 return;
1891 if (pdata->flags & IMXUART_HAVE_RTSCTS)
1892 sport->have_rtscts = 1;
1895 static int serial_imx_probe(struct platform_device *pdev)
1897 struct imx_port *sport;
1898 void __iomem *base;
1899 int ret = 0;
1900 struct resource *res;
1901 int txirq, rxirq, rtsirq;
1903 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1904 if (!sport)
1905 return -ENOMEM;
1907 ret = serial_imx_probe_dt(sport, pdev);
1908 if (ret > 0)
1909 serial_imx_probe_pdata(sport, pdev);
1910 else if (ret < 0)
1911 return ret;
1913 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1914 base = devm_ioremap_resource(&pdev->dev, res);
1915 if (IS_ERR(base))
1916 return PTR_ERR(base);
1918 rxirq = platform_get_irq(pdev, 0);
1919 txirq = platform_get_irq(pdev, 1);
1920 rtsirq = platform_get_irq(pdev, 2);
1922 sport->port.dev = &pdev->dev;
1923 sport->port.mapbase = res->start;
1924 sport->port.membase = base;
1925 sport->port.type = PORT_IMX,
1926 sport->port.iotype = UPIO_MEM;
1927 sport->port.irq = rxirq;
1928 sport->port.fifosize = 32;
1929 sport->port.ops = &imx_pops;
1930 sport->port.rs485_config = imx_rs485_config;
1931 sport->port.rs485.flags =
1932 SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX;
1933 sport->port.flags = UPF_BOOT_AUTOCONF;
1934 init_timer(&sport->timer);
1935 sport->timer.function = imx_timeout;
1936 sport->timer.data = (unsigned long)sport;
1938 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1939 if (IS_ERR(sport->clk_ipg)) {
1940 ret = PTR_ERR(sport->clk_ipg);
1941 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1942 return ret;
1945 sport->clk_per = devm_clk_get(&pdev->dev, "per");
1946 if (IS_ERR(sport->clk_per)) {
1947 ret = PTR_ERR(sport->clk_per);
1948 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1949 return ret;
1952 sport->port.uartclk = clk_get_rate(sport->clk_per);
1955 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1956 * chips only have one interrupt.
1958 if (txirq > 0) {
1959 ret = devm_request_irq(&pdev->dev, rxirq, imx_rxint, 0,
1960 dev_name(&pdev->dev), sport);
1961 if (ret)
1962 return ret;
1964 ret = devm_request_irq(&pdev->dev, txirq, imx_txint, 0,
1965 dev_name(&pdev->dev), sport);
1966 if (ret)
1967 return ret;
1968 } else {
1969 ret = devm_request_irq(&pdev->dev, rxirq, imx_int, 0,
1970 dev_name(&pdev->dev), sport);
1971 if (ret)
1972 return ret;
1975 imx_ports[sport->port.line] = sport;
1977 platform_set_drvdata(pdev, sport);
1979 return uart_add_one_port(&imx_reg, &sport->port);
1982 static int serial_imx_remove(struct platform_device *pdev)
1984 struct imx_port *sport = platform_get_drvdata(pdev);
1986 return uart_remove_one_port(&imx_reg, &sport->port);
1989 static struct platform_driver serial_imx_driver = {
1990 .probe = serial_imx_probe,
1991 .remove = serial_imx_remove,
1993 .suspend = serial_imx_suspend,
1994 .resume = serial_imx_resume,
1995 .id_table = imx_uart_devtype,
1996 .driver = {
1997 .name = "imx-uart",
1998 .of_match_table = imx_uart_dt_ids,
2002 static int __init imx_serial_init(void)
2004 int ret = uart_register_driver(&imx_reg);
2006 if (ret)
2007 return ret;
2009 ret = platform_driver_register(&serial_imx_driver);
2010 if (ret != 0)
2011 uart_unregister_driver(&imx_reg);
2013 return ret;
2016 static void __exit imx_serial_exit(void)
2018 platform_driver_unregister(&serial_imx_driver);
2019 uart_unregister_driver(&imx_reg);
2022 module_init(imx_serial_init);
2023 module_exit(imx_serial_exit);
2025 MODULE_AUTHOR("Sascha Hauer");
2026 MODULE_DESCRIPTION("IMX generic serial port driver");
2027 MODULE_LICENSE("GPL");
2028 MODULE_ALIAS("platform:imx-uart");