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Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[deliverable/linux.git] / drivers / tty / serial / imx.c
1 /*
2 * Driver for Motorola/Freescale IMX serial ports
3 *
4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5 *
6 * Author: Sascha Hauer <sascha@saschahauer.de>
7 * Copyright (C) 2004 Pengutronix
8 *
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.
13 *
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.
18 */
19
20 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
21 #define SUPPORT_SYSRQ
22 #endif
23
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>
42
43 #include <asm/irq.h>
44 #include <linux/platform_data/serial-imx.h>
45 #include <linux/platform_data/dma-imx.h>
46
47 #include "serial_mctrl_gpio.h"
48
49 /* Register definitions */
50 #define URXD0 0x0 /* Receiver Register */
51 #define URTX0 0x40 /* Transmitter Register */
52 #define UCR1 0x80 /* Control Register 1 */
53 #define UCR2 0x84 /* Control Register 2 */
54 #define UCR3 0x88 /* Control Register 3 */
55 #define UCR4 0x8c /* Control Register 4 */
56 #define UFCR 0x90 /* FIFO Control Register */
57 #define USR1 0x94 /* Status Register 1 */
58 #define USR2 0x98 /* Status Register 2 */
59 #define UESC 0x9c /* Escape Character Register */
60 #define UTIM 0xa0 /* Escape Timer Register */
61 #define UBIR 0xa4 /* BRM Incremental Register */
62 #define UBMR 0xa8 /* BRM Modulator Register */
63 #define UBRC 0xac /* Baud Rate Count Register */
64 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
65 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
66 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
67
68 /* UART Control Register Bit Fields.*/
69 #define URXD_DUMMY_READ (1<<16)
70 #define URXD_CHARRDY (1<<15)
71 #define URXD_ERR (1<<14)
72 #define URXD_OVRRUN (1<<13)
73 #define URXD_FRMERR (1<<12)
74 #define URXD_BRK (1<<11)
75 #define URXD_PRERR (1<<10)
76 #define URXD_RX_DATA (0xFF<<0)
77 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
78 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
79 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
80 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
81 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
82 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
83 #define UCR1_RDMAEN (1<<8) /* Recv ready DMA enable */
84 #define UCR1_IREN (1<<7) /* Infrared interface enable */
85 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
86 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
87 #define UCR1_SNDBRK (1<<4) /* Send break */
88 #define UCR1_TDMAEN (1<<3) /* Transmitter ready DMA enable */
89 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
90 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
91 #define UCR1_DOZE (1<<1) /* Doze */
92 #define UCR1_UARTEN (1<<0) /* UART enabled */
93 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
94 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
95 #define UCR2_CTSC (1<<13) /* CTS pin control */
96 #define UCR2_CTS (1<<12) /* Clear to send */
97 #define UCR2_ESCEN (1<<11) /* Escape enable */
98 #define UCR2_PREN (1<<8) /* Parity enable */
99 #define UCR2_PROE (1<<7) /* Parity odd/even */
100 #define UCR2_STPB (1<<6) /* Stop */
101 #define UCR2_WS (1<<5) /* Word size */
102 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
103 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
104 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
105 #define UCR2_RXEN (1<<1) /* Receiver enabled */
106 #define UCR2_SRST (1<<0) /* SW reset */
107 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
108 #define UCR3_PARERREN (1<<12) /* Parity enable */
109 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
110 #define UCR3_DSR (1<<10) /* Data set ready */
111 #define UCR3_DCD (1<<9) /* Data carrier detect */
112 #define UCR3_RI (1<<8) /* Ring indicator */
113 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
114 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
115 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
116 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
117 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
118 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
119 #define UCR3_BPEN (1<<0) /* Preset registers enable */
120 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
121 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
122 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
123 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
124 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
125 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
126 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
127 #define UCR4_IRSC (1<<5) /* IR special case */
128 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
129 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
130 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
131 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
132 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
133 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
134 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
135 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
136 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
137 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
138 #define USR1_RTSS (1<<14) /* RTS pin status */
139 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
140 #define USR1_RTSD (1<<12) /* RTS delta */
141 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
142 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
143 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
144 #define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
145 #define USR1_TIMEOUT (1<<7) /* Receive timeout interrupt status */
146 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
147 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
148 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
149 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
150 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
151 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
152 #define USR2_IDLE (1<<12) /* Idle condition */
153 #define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
154 #define USR2_RIIN (1<<9) /* Ring Indicator Input */
155 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
156 #define USR2_WAKE (1<<7) /* Wake */
157 #define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
158 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
159 #define USR2_TXDC (1<<3) /* Transmitter complete */
160 #define USR2_BRCD (1<<2) /* Break condition */
161 #define USR2_ORE (1<<1) /* Overrun error */
162 #define USR2_RDR (1<<0) /* Recv data ready */
163 #define UTS_FRCPERR (1<<13) /* Force parity error */
164 #define UTS_LOOP (1<<12) /* Loop tx and rx */
165 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
166 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
167 #define UTS_TXFULL (1<<4) /* TxFIFO full */
168 #define UTS_RXFULL (1<<3) /* RxFIFO full */
169 #define UTS_SOFTRST (1<<0) /* Software reset */
170
171 /* We've been assigned a range on the "Low-density serial ports" major */
172 #define SERIAL_IMX_MAJOR 207
173 #define MINOR_START 16
174 #define DEV_NAME "ttymxc"
175
176 /*
177 * This determines how often we check the modem status signals
178 * for any change. They generally aren't connected to an IRQ
179 * so we have to poll them. We also check immediately before
180 * filling the TX fifo incase CTS has been dropped.
181 */
182 #define MCTRL_TIMEOUT (250*HZ/1000)
183
184 #define DRIVER_NAME "IMX-uart"
185
186 #define UART_NR 8
187
188 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
189 enum imx_uart_type {
190 IMX1_UART,
191 IMX21_UART,
192 IMX6Q_UART,
193 };
194
195 /* device type dependent stuff */
196 struct imx_uart_data {
197 unsigned uts_reg;
198 enum imx_uart_type devtype;
199 };
200
201 struct imx_port {
202 struct uart_port port;
203 struct timer_list timer;
204 unsigned int old_status;
205 unsigned int have_rtscts:1;
206 unsigned int dte_mode:1;
207 unsigned int irda_inv_rx:1;
208 unsigned int irda_inv_tx:1;
209 unsigned short trcv_delay; /* transceiver delay */
210 struct clk *clk_ipg;
211 struct clk *clk_per;
212 const struct imx_uart_data *devdata;
213
214 struct mctrl_gpios *gpios;
215
216 /* DMA fields */
217 unsigned int dma_is_inited:1;
218 unsigned int dma_is_enabled:1;
219 unsigned int dma_is_rxing:1;
220 unsigned int dma_is_txing:1;
221 struct dma_chan *dma_chan_rx, *dma_chan_tx;
222 struct scatterlist rx_sgl, tx_sgl[2];
223 void *rx_buf;
224 unsigned int tx_bytes;
225 unsigned int dma_tx_nents;
226 wait_queue_head_t dma_wait;
227 unsigned int saved_reg[10];
228 bool context_saved;
229 };
230
231 struct imx_port_ucrs {
232 unsigned int ucr1;
233 unsigned int ucr2;
234 unsigned int ucr3;
235 };
236
237 static struct imx_uart_data imx_uart_devdata[] = {
238 [IMX1_UART] = {
239 .uts_reg = IMX1_UTS,
240 .devtype = IMX1_UART,
241 },
242 [IMX21_UART] = {
243 .uts_reg = IMX21_UTS,
244 .devtype = IMX21_UART,
245 },
246 [IMX6Q_UART] = {
247 .uts_reg = IMX21_UTS,
248 .devtype = IMX6Q_UART,
249 },
250 };
251
252 static const struct platform_device_id imx_uart_devtype[] = {
253 {
254 .name = "imx1-uart",
255 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
256 }, {
257 .name = "imx21-uart",
258 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
259 }, {
260 .name = "imx6q-uart",
261 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
262 }, {
263 /* sentinel */
264 }
265 };
266 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
267
268 static const struct of_device_id imx_uart_dt_ids[] = {
269 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
270 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
271 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
272 { /* sentinel */ }
273 };
274 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
275
276 static inline unsigned uts_reg(struct imx_port *sport)
277 {
278 return sport->devdata->uts_reg;
279 }
280
281 static inline int is_imx1_uart(struct imx_port *sport)
282 {
283 return sport->devdata->devtype == IMX1_UART;
284 }
285
286 static inline int is_imx21_uart(struct imx_port *sport)
287 {
288 return sport->devdata->devtype == IMX21_UART;
289 }
290
291 static inline int is_imx6q_uart(struct imx_port *sport)
292 {
293 return sport->devdata->devtype == IMX6Q_UART;
294 }
295 /*
296 * Save and restore functions for UCR1, UCR2 and UCR3 registers
297 */
298 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
299 static void imx_port_ucrs_save(struct uart_port *port,
300 struct imx_port_ucrs *ucr)
301 {
302 /* save control registers */
303 ucr->ucr1 = readl(port->membase + UCR1);
304 ucr->ucr2 = readl(port->membase + UCR2);
305 ucr->ucr3 = readl(port->membase + UCR3);
306 }
307
308 static void imx_port_ucrs_restore(struct uart_port *port,
309 struct imx_port_ucrs *ucr)
310 {
311 /* restore control registers */
312 writel(ucr->ucr1, port->membase + UCR1);
313 writel(ucr->ucr2, port->membase + UCR2);
314 writel(ucr->ucr3, port->membase + UCR3);
315 }
316 #endif
317
318 static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2)
319 {
320 *ucr2 &= ~UCR2_CTSC;
321 *ucr2 |= UCR2_CTS;
322
323 mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
324 }
325
326 static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
327 {
328 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
329
330 mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
331 }
332
333 static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
334 {
335 *ucr2 |= UCR2_CTSC;
336 }
337
338 /*
339 * interrupts disabled on entry
340 */
341 static void imx_stop_tx(struct uart_port *port)
342 {
343 struct imx_port *sport = (struct imx_port *)port;
344 unsigned long temp;
345
346 /*
347 * We are maybe in the SMP context, so if the DMA TX thread is running
348 * on other cpu, we have to wait for it to finish.
349 */
350 if (sport->dma_is_enabled && sport->dma_is_txing)
351 return;
352
353 temp = readl(port->membase + UCR1);
354 writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
355
356 /* in rs485 mode disable transmitter if shifter is empty */
357 if (port->rs485.flags & SER_RS485_ENABLED &&
358 readl(port->membase + USR2) & USR2_TXDC) {
359 temp = readl(port->membase + UCR2);
360 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
361 imx_port_rts_inactive(sport, &temp);
362 else
363 imx_port_rts_active(sport, &temp);
364 writel(temp, port->membase + UCR2);
365
366 temp = readl(port->membase + UCR4);
367 temp &= ~UCR4_TCEN;
368 writel(temp, port->membase + UCR4);
369 }
370 }
371
372 /*
373 * interrupts disabled on entry
374 */
375 static void imx_stop_rx(struct uart_port *port)
376 {
377 struct imx_port *sport = (struct imx_port *)port;
378 unsigned long temp;
379
380 if (sport->dma_is_enabled && sport->dma_is_rxing) {
381 if (sport->port.suspended) {
382 dmaengine_terminate_all(sport->dma_chan_rx);
383 sport->dma_is_rxing = 0;
384 } else {
385 return;
386 }
387 }
388
389 temp = readl(sport->port.membase + UCR2);
390 writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
391
392 /* disable the `Receiver Ready Interrrupt` */
393 temp = readl(sport->port.membase + UCR1);
394 writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
395 }
396
397 /*
398 * Set the modem control timer to fire immediately.
399 */
400 static void imx_enable_ms(struct uart_port *port)
401 {
402 struct imx_port *sport = (struct imx_port *)port;
403
404 mod_timer(&sport->timer, jiffies);
405
406 mctrl_gpio_enable_ms(sport->gpios);
407 }
408
409 static void imx_dma_tx(struct imx_port *sport);
410 static inline void imx_transmit_buffer(struct imx_port *sport)
411 {
412 struct circ_buf *xmit = &sport->port.state->xmit;
413 unsigned long temp;
414
415 if (sport->port.x_char) {
416 /* Send next char */
417 writel(sport->port.x_char, sport->port.membase + URTX0);
418 sport->port.icount.tx++;
419 sport->port.x_char = 0;
420 return;
421 }
422
423 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
424 imx_stop_tx(&sport->port);
425 return;
426 }
427
428 if (sport->dma_is_enabled) {
429 /*
430 * We've just sent a X-char Ensure the TX DMA is enabled
431 * and the TX IRQ is disabled.
432 **/
433 temp = readl(sport->port.membase + UCR1);
434 temp &= ~UCR1_TXMPTYEN;
435 if (sport->dma_is_txing) {
436 temp |= UCR1_TDMAEN;
437 writel(temp, sport->port.membase + UCR1);
438 } else {
439 writel(temp, sport->port.membase + UCR1);
440 imx_dma_tx(sport);
441 }
442 }
443
444 while (!uart_circ_empty(xmit) &&
445 !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
446 /* send xmit->buf[xmit->tail]
447 * out the port here */
448 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
449 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
450 sport->port.icount.tx++;
451 }
452
453 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
454 uart_write_wakeup(&sport->port);
455
456 if (uart_circ_empty(xmit))
457 imx_stop_tx(&sport->port);
458 }
459
460 static void dma_tx_callback(void *data)
461 {
462 struct imx_port *sport = data;
463 struct scatterlist *sgl = &sport->tx_sgl[0];
464 struct circ_buf *xmit = &sport->port.state->xmit;
465 unsigned long flags;
466 unsigned long temp;
467
468 spin_lock_irqsave(&sport->port.lock, flags);
469
470 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
471
472 temp = readl(sport->port.membase + UCR1);
473 temp &= ~UCR1_TDMAEN;
474 writel(temp, sport->port.membase + UCR1);
475
476 /* update the stat */
477 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
478 sport->port.icount.tx += sport->tx_bytes;
479
480 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
481
482 sport->dma_is_txing = 0;
483
484 spin_unlock_irqrestore(&sport->port.lock, flags);
485
486 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
487 uart_write_wakeup(&sport->port);
488
489 if (waitqueue_active(&sport->dma_wait)) {
490 wake_up(&sport->dma_wait);
491 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
492 return;
493 }
494
495 spin_lock_irqsave(&sport->port.lock, flags);
496 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
497 imx_dma_tx(sport);
498 spin_unlock_irqrestore(&sport->port.lock, flags);
499 }
500
501 static void imx_dma_tx(struct imx_port *sport)
502 {
503 struct circ_buf *xmit = &sport->port.state->xmit;
504 struct scatterlist *sgl = sport->tx_sgl;
505 struct dma_async_tx_descriptor *desc;
506 struct dma_chan *chan = sport->dma_chan_tx;
507 struct device *dev = sport->port.dev;
508 unsigned long temp;
509 int ret;
510
511 if (sport->dma_is_txing)
512 return;
513
514 sport->tx_bytes = uart_circ_chars_pending(xmit);
515
516 if (xmit->tail < xmit->head) {
517 sport->dma_tx_nents = 1;
518 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
519 } else {
520 sport->dma_tx_nents = 2;
521 sg_init_table(sgl, 2);
522 sg_set_buf(sgl, xmit->buf + xmit->tail,
523 UART_XMIT_SIZE - xmit->tail);
524 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
525 }
526
527 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
528 if (ret == 0) {
529 dev_err(dev, "DMA mapping error for TX.\n");
530 return;
531 }
532 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
533 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
534 if (!desc) {
535 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
536 DMA_TO_DEVICE);
537 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
538 return;
539 }
540 desc->callback = dma_tx_callback;
541 desc->callback_param = sport;
542
543 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
544 uart_circ_chars_pending(xmit));
545
546 temp = readl(sport->port.membase + UCR1);
547 temp |= UCR1_TDMAEN;
548 writel(temp, sport->port.membase + UCR1);
549
550 /* fire it */
551 sport->dma_is_txing = 1;
552 dmaengine_submit(desc);
553 dma_async_issue_pending(chan);
554 return;
555 }
556
557 /*
558 * interrupts disabled on entry
559 */
560 static void imx_start_tx(struct uart_port *port)
561 {
562 struct imx_port *sport = (struct imx_port *)port;
563 unsigned long temp;
564
565 if (port->rs485.flags & SER_RS485_ENABLED) {
566 temp = readl(port->membase + UCR2);
567 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
568 imx_port_rts_inactive(sport, &temp);
569 else
570 imx_port_rts_active(sport, &temp);
571 writel(temp, port->membase + UCR2);
572
573 /* enable transmitter and shifter empty irq */
574 temp = readl(port->membase + UCR4);
575 temp |= UCR4_TCEN;
576 writel(temp, port->membase + UCR4);
577 }
578
579 if (!sport->dma_is_enabled) {
580 temp = readl(sport->port.membase + UCR1);
581 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
582 }
583
584 if (sport->dma_is_enabled) {
585 if (sport->port.x_char) {
586 /* We have X-char to send, so enable TX IRQ and
587 * disable TX DMA to let TX interrupt to send X-char */
588 temp = readl(sport->port.membase + UCR1);
589 temp &= ~UCR1_TDMAEN;
590 temp |= UCR1_TXMPTYEN;
591 writel(temp, sport->port.membase + UCR1);
592 return;
593 }
594
595 if (!uart_circ_empty(&port->state->xmit) &&
596 !uart_tx_stopped(port))
597 imx_dma_tx(sport);
598 return;
599 }
600 }
601
602 static irqreturn_t imx_rtsint(int irq, void *dev_id)
603 {
604 struct imx_port *sport = dev_id;
605 unsigned int val;
606 unsigned long flags;
607
608 spin_lock_irqsave(&sport->port.lock, flags);
609
610 writel(USR1_RTSD, sport->port.membase + USR1);
611 val = readl(sport->port.membase + USR1) & USR1_RTSS;
612 uart_handle_cts_change(&sport->port, !!val);
613 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
614
615 spin_unlock_irqrestore(&sport->port.lock, flags);
616 return IRQ_HANDLED;
617 }
618
619 static irqreturn_t imx_txint(int irq, void *dev_id)
620 {
621 struct imx_port *sport = dev_id;
622 unsigned long flags;
623
624 spin_lock_irqsave(&sport->port.lock, flags);
625 imx_transmit_buffer(sport);
626 spin_unlock_irqrestore(&sport->port.lock, flags);
627 return IRQ_HANDLED;
628 }
629
630 static irqreturn_t imx_rxint(int irq, void *dev_id)
631 {
632 struct imx_port *sport = dev_id;
633 unsigned int rx, flg, ignored = 0;
634 struct tty_port *port = &sport->port.state->port;
635 unsigned long flags, temp;
636
637 spin_lock_irqsave(&sport->port.lock, flags);
638
639 while (readl(sport->port.membase + USR2) & USR2_RDR) {
640 flg = TTY_NORMAL;
641 sport->port.icount.rx++;
642
643 rx = readl(sport->port.membase + URXD0);
644
645 temp = readl(sport->port.membase + USR2);
646 if (temp & USR2_BRCD) {
647 writel(USR2_BRCD, sport->port.membase + USR2);
648 if (uart_handle_break(&sport->port))
649 continue;
650 }
651
652 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
653 continue;
654
655 if (unlikely(rx & URXD_ERR)) {
656 if (rx & URXD_BRK)
657 sport->port.icount.brk++;
658 else if (rx & URXD_PRERR)
659 sport->port.icount.parity++;
660 else if (rx & URXD_FRMERR)
661 sport->port.icount.frame++;
662 if (rx & URXD_OVRRUN)
663 sport->port.icount.overrun++;
664
665 if (rx & sport->port.ignore_status_mask) {
666 if (++ignored > 100)
667 goto out;
668 continue;
669 }
670
671 rx &= (sport->port.read_status_mask | 0xFF);
672
673 if (rx & URXD_BRK)
674 flg = TTY_BREAK;
675 else if (rx & URXD_PRERR)
676 flg = TTY_PARITY;
677 else if (rx & URXD_FRMERR)
678 flg = TTY_FRAME;
679 if (rx & URXD_OVRRUN)
680 flg = TTY_OVERRUN;
681
682 #ifdef SUPPORT_SYSRQ
683 sport->port.sysrq = 0;
684 #endif
685 }
686
687 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
688 goto out;
689
690 if (tty_insert_flip_char(port, rx, flg) == 0)
691 sport->port.icount.buf_overrun++;
692 }
693
694 out:
695 spin_unlock_irqrestore(&sport->port.lock, flags);
696 tty_flip_buffer_push(port);
697 return IRQ_HANDLED;
698 }
699
700 static int start_rx_dma(struct imx_port *sport);
701 /*
702 * If the RXFIFO is filled with some data, and then we
703 * arise a DMA operation to receive them.
704 */
705 static void imx_dma_rxint(struct imx_port *sport)
706 {
707 unsigned long temp;
708 unsigned long flags;
709
710 spin_lock_irqsave(&sport->port.lock, flags);
711
712 temp = readl(sport->port.membase + USR2);
713 if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
714 sport->dma_is_rxing = 1;
715
716 /* disable the receiver ready and aging timer interrupts */
717 temp = readl(sport->port.membase + UCR1);
718 temp &= ~(UCR1_RRDYEN);
719 writel(temp, sport->port.membase + UCR1);
720
721 temp = readl(sport->port.membase + UCR2);
722 temp &= ~(UCR2_ATEN);
723 writel(temp, sport->port.membase + UCR2);
724
725 /* tell the DMA to receive the data. */
726 start_rx_dma(sport);
727 }
728
729 spin_unlock_irqrestore(&sport->port.lock, flags);
730 }
731
732 static irqreturn_t imx_int(int irq, void *dev_id)
733 {
734 struct imx_port *sport = dev_id;
735 unsigned int sts;
736 unsigned int sts2;
737
738 sts = readl(sport->port.membase + USR1);
739 sts2 = readl(sport->port.membase + USR2);
740
741 if (sts & (USR1_RRDY | USR1_AGTIM)) {
742 if (sport->dma_is_enabled)
743 imx_dma_rxint(sport);
744 else
745 imx_rxint(irq, dev_id);
746 }
747
748 if ((sts & USR1_TRDY &&
749 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) ||
750 (sts2 & USR2_TXDC &&
751 readl(sport->port.membase + UCR4) & UCR4_TCEN))
752 imx_txint(irq, dev_id);
753
754 if (sts & USR1_RTSD)
755 imx_rtsint(irq, dev_id);
756
757 if (sts & USR1_AWAKE)
758 writel(USR1_AWAKE, sport->port.membase + USR1);
759
760 if (sts2 & USR2_ORE) {
761 sport->port.icount.overrun++;
762 writel(USR2_ORE, sport->port.membase + USR2);
763 }
764
765 return IRQ_HANDLED;
766 }
767
768 /*
769 * Return TIOCSER_TEMT when transmitter is not busy.
770 */
771 static unsigned int imx_tx_empty(struct uart_port *port)
772 {
773 struct imx_port *sport = (struct imx_port *)port;
774 unsigned int ret;
775
776 ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
777
778 /* If the TX DMA is working, return 0. */
779 if (sport->dma_is_enabled && sport->dma_is_txing)
780 ret = 0;
781
782 return ret;
783 }
784
785 /*
786 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
787 */
788 static unsigned int imx_get_hwmctrl(struct imx_port *sport)
789 {
790 unsigned int tmp = TIOCM_DSR;
791 unsigned usr1 = readl(sport->port.membase + USR1);
792
793 if (usr1 & USR1_RTSS)
794 tmp |= TIOCM_CTS;
795
796 /* in DCE mode DCDIN is always 0 */
797 if (!(usr1 & USR2_DCDIN))
798 tmp |= TIOCM_CAR;
799
800 /* in DCE mode RIIN is always 0 */
801 if (readl(sport->port.membase + USR2) & USR2_RIIN)
802 tmp |= TIOCM_RI;
803
804 return tmp;
805 }
806
807 static unsigned int imx_get_mctrl(struct uart_port *port)
808 {
809 struct imx_port *sport = (struct imx_port *)port;
810 unsigned int ret = imx_get_hwmctrl(sport);
811
812 mctrl_gpio_get(sport->gpios, &ret);
813
814 return ret;
815 }
816
817 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
818 {
819 struct imx_port *sport = (struct imx_port *)port;
820 unsigned long temp;
821
822 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
823 temp = readl(sport->port.membase + UCR2);
824 temp &= ~(UCR2_CTS | UCR2_CTSC);
825 if (mctrl & TIOCM_RTS)
826 temp |= UCR2_CTS | UCR2_CTSC;
827 writel(temp, sport->port.membase + UCR2);
828 }
829
830 temp = readl(sport->port.membase + UCR3) & ~UCR3_DSR;
831 if (!(mctrl & TIOCM_DTR))
832 temp |= UCR3_DSR;
833 writel(temp, sport->port.membase + UCR3);
834
835 temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
836 if (mctrl & TIOCM_LOOP)
837 temp |= UTS_LOOP;
838 writel(temp, sport->port.membase + uts_reg(sport));
839
840 mctrl_gpio_set(sport->gpios, mctrl);
841 }
842
843 /*
844 * Interrupts always disabled.
845 */
846 static void imx_break_ctl(struct uart_port *port, int break_state)
847 {
848 struct imx_port *sport = (struct imx_port *)port;
849 unsigned long flags, temp;
850
851 spin_lock_irqsave(&sport->port.lock, flags);
852
853 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
854
855 if (break_state != 0)
856 temp |= UCR1_SNDBRK;
857
858 writel(temp, sport->port.membase + UCR1);
859
860 spin_unlock_irqrestore(&sport->port.lock, flags);
861 }
862
863 /*
864 * Handle any change of modem status signal since we were last called.
865 */
866 static void imx_mctrl_check(struct imx_port *sport)
867 {
868 unsigned int status, changed;
869
870 status = imx_get_hwmctrl(sport);
871 changed = status ^ sport->old_status;
872
873 if (changed == 0)
874 return;
875
876 sport->old_status = status;
877
878 if (changed & TIOCM_RI)
879 sport->port.icount.rng++;
880 if (changed & TIOCM_DSR)
881 sport->port.icount.dsr++;
882 if (changed & TIOCM_CAR)
883 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
884 if (changed & TIOCM_CTS)
885 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
886
887 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
888 }
889
890 /*
891 * This is our per-port timeout handler, for checking the
892 * modem status signals.
893 */
894 static void imx_timeout(unsigned long data)
895 {
896 struct imx_port *sport = (struct imx_port *)data;
897 unsigned long flags;
898
899 if (sport->port.state) {
900 spin_lock_irqsave(&sport->port.lock, flags);
901 imx_mctrl_check(sport);
902 spin_unlock_irqrestore(&sport->port.lock, flags);
903
904 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
905 }
906 }
907
908 #define RX_BUF_SIZE (PAGE_SIZE)
909 static void imx_rx_dma_done(struct imx_port *sport)
910 {
911 unsigned long temp;
912 unsigned long flags;
913
914 spin_lock_irqsave(&sport->port.lock, flags);
915
916 /* re-enable interrupts to get notified when new symbols are incoming */
917 temp = readl(sport->port.membase + UCR1);
918 temp |= UCR1_RRDYEN;
919 writel(temp, sport->port.membase + UCR1);
920
921 temp = readl(sport->port.membase + UCR2);
922 temp |= UCR2_ATEN;
923 writel(temp, sport->port.membase + UCR2);
924
925 sport->dma_is_rxing = 0;
926
927 /* Is the shutdown waiting for us? */
928 if (waitqueue_active(&sport->dma_wait))
929 wake_up(&sport->dma_wait);
930
931 spin_unlock_irqrestore(&sport->port.lock, flags);
932 }
933
934 /*
935 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
936 * [1] the RX DMA buffer is full.
937 * [2] the aging timer expires
938 *
939 * Condition [2] is triggered when a character has been sitting in the FIFO
940 * for at least 8 byte durations.
941 */
942 static void dma_rx_callback(void *data)
943 {
944 struct imx_port *sport = data;
945 struct dma_chan *chan = sport->dma_chan_rx;
946 struct scatterlist *sgl = &sport->rx_sgl;
947 struct tty_port *port = &sport->port.state->port;
948 struct dma_tx_state state;
949 enum dma_status status;
950 unsigned int count;
951
952 /* unmap it first */
953 dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
954
955 status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
956 count = RX_BUF_SIZE - state.residue;
957
958 dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
959
960 if (count) {
961 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
962 int bytes = tty_insert_flip_string(port, sport->rx_buf,
963 count);
964
965 if (bytes != count)
966 sport->port.icount.buf_overrun++;
967 }
968 tty_flip_buffer_push(port);
969 sport->port.icount.rx += count;
970 }
971
972 /*
973 * Restart RX DMA directly if more data is available in order to skip
974 * the roundtrip through the IRQ handler. If there is some data already
975 * in the FIFO, DMA needs to be restarted soon anyways.
976 *
977 * Otherwise stop the DMA and reactivate FIFO IRQs to restart DMA once
978 * data starts to arrive again.
979 */
980 if (readl(sport->port.membase + USR2) & USR2_RDR)
981 start_rx_dma(sport);
982 else
983 imx_rx_dma_done(sport);
984 }
985
986 static int start_rx_dma(struct imx_port *sport)
987 {
988 struct scatterlist *sgl = &sport->rx_sgl;
989 struct dma_chan *chan = sport->dma_chan_rx;
990 struct device *dev = sport->port.dev;
991 struct dma_async_tx_descriptor *desc;
992 int ret;
993
994 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
995 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
996 if (ret == 0) {
997 dev_err(dev, "DMA mapping error for RX.\n");
998 return -EINVAL;
999 }
1000 desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
1001 DMA_PREP_INTERRUPT);
1002 if (!desc) {
1003 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1004 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1005 return -EINVAL;
1006 }
1007 desc->callback = dma_rx_callback;
1008 desc->callback_param = sport;
1009
1010 dev_dbg(dev, "RX: prepare for the DMA.\n");
1011 dmaengine_submit(desc);
1012 dma_async_issue_pending(chan);
1013 return 0;
1014 }
1015
1016 #define TXTL_DEFAULT 2 /* reset default */
1017 #define RXTL_DEFAULT 1 /* reset default */
1018 #define TXTL_DMA 8 /* DMA burst setting */
1019 #define RXTL_DMA 9 /* DMA burst setting */
1020
1021 static void imx_setup_ufcr(struct imx_port *sport,
1022 unsigned char txwl, unsigned char rxwl)
1023 {
1024 unsigned int val;
1025
1026 /* set receiver / transmitter trigger level */
1027 val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1028 val |= txwl << UFCR_TXTL_SHF | rxwl;
1029 writel(val, sport->port.membase + UFCR);
1030 }
1031
1032 static void imx_uart_dma_exit(struct imx_port *sport)
1033 {
1034 if (sport->dma_chan_rx) {
1035 dma_release_channel(sport->dma_chan_rx);
1036 sport->dma_chan_rx = NULL;
1037
1038 kfree(sport->rx_buf);
1039 sport->rx_buf = NULL;
1040 }
1041
1042 if (sport->dma_chan_tx) {
1043 dma_release_channel(sport->dma_chan_tx);
1044 sport->dma_chan_tx = NULL;
1045 }
1046
1047 sport->dma_is_inited = 0;
1048 }
1049
1050 static int imx_uart_dma_init(struct imx_port *sport)
1051 {
1052 struct dma_slave_config slave_config = {};
1053 struct device *dev = sport->port.dev;
1054 int ret;
1055
1056 /* Prepare for RX : */
1057 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1058 if (!sport->dma_chan_rx) {
1059 dev_dbg(dev, "cannot get the DMA channel.\n");
1060 ret = -EINVAL;
1061 goto err;
1062 }
1063
1064 slave_config.direction = DMA_DEV_TO_MEM;
1065 slave_config.src_addr = sport->port.mapbase + URXD0;
1066 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1067 /* one byte less than the watermark level to enable the aging timer */
1068 slave_config.src_maxburst = RXTL_DMA - 1;
1069 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1070 if (ret) {
1071 dev_err(dev, "error in RX dma configuration.\n");
1072 goto err;
1073 }
1074
1075 sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1076 if (!sport->rx_buf) {
1077 ret = -ENOMEM;
1078 goto err;
1079 }
1080
1081 /* Prepare for TX : */
1082 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1083 if (!sport->dma_chan_tx) {
1084 dev_err(dev, "cannot get the TX DMA channel!\n");
1085 ret = -EINVAL;
1086 goto err;
1087 }
1088
1089 slave_config.direction = DMA_MEM_TO_DEV;
1090 slave_config.dst_addr = sport->port.mapbase + URTX0;
1091 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1092 slave_config.dst_maxburst = TXTL_DMA;
1093 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1094 if (ret) {
1095 dev_err(dev, "error in TX dma configuration.");
1096 goto err;
1097 }
1098
1099 sport->dma_is_inited = 1;
1100
1101 return 0;
1102 err:
1103 imx_uart_dma_exit(sport);
1104 return ret;
1105 }
1106
1107 static void imx_enable_dma(struct imx_port *sport)
1108 {
1109 unsigned long temp;
1110
1111 init_waitqueue_head(&sport->dma_wait);
1112
1113 /* set UCR1 */
1114 temp = readl(sport->port.membase + UCR1);
1115 temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN;
1116 writel(temp, sport->port.membase + UCR1);
1117
1118 temp = readl(sport->port.membase + UCR2);
1119 temp |= UCR2_ATEN;
1120 writel(temp, sport->port.membase + UCR2);
1121
1122 imx_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1123
1124 sport->dma_is_enabled = 1;
1125 }
1126
1127 static void imx_disable_dma(struct imx_port *sport)
1128 {
1129 unsigned long temp;
1130
1131 /* clear UCR1 */
1132 temp = readl(sport->port.membase + UCR1);
1133 temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1134 writel(temp, sport->port.membase + UCR1);
1135
1136 /* clear UCR2 */
1137 temp = readl(sport->port.membase + UCR2);
1138 temp &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
1139 writel(temp, sport->port.membase + UCR2);
1140
1141 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1142
1143 sport->dma_is_enabled = 0;
1144 }
1145
1146 /* half the RX buffer size */
1147 #define CTSTL 16
1148
1149 static int imx_startup(struct uart_port *port)
1150 {
1151 struct imx_port *sport = (struct imx_port *)port;
1152 int retval, i;
1153 unsigned long flags, temp;
1154
1155 retval = clk_prepare_enable(sport->clk_per);
1156 if (retval)
1157 return retval;
1158 retval = clk_prepare_enable(sport->clk_ipg);
1159 if (retval) {
1160 clk_disable_unprepare(sport->clk_per);
1161 return retval;
1162 }
1163
1164 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1165
1166 /* disable the DREN bit (Data Ready interrupt enable) before
1167 * requesting IRQs
1168 */
1169 temp = readl(sport->port.membase + UCR4);
1170
1171 /* set the trigger level for CTS */
1172 temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1173 temp |= CTSTL << UCR4_CTSTL_SHF;
1174
1175 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1176
1177 /* Can we enable the DMA support? */
1178 if (is_imx6q_uart(sport) && !uart_console(port) &&
1179 !sport->dma_is_inited)
1180 imx_uart_dma_init(sport);
1181
1182 spin_lock_irqsave(&sport->port.lock, flags);
1183 /* Reset fifo's and state machines */
1184 i = 100;
1185
1186 temp = readl(sport->port.membase + UCR2);
1187 temp &= ~UCR2_SRST;
1188 writel(temp, sport->port.membase + UCR2);
1189
1190 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1191 udelay(1);
1192
1193 /*
1194 * Finally, clear and enable interrupts
1195 */
1196 writel(USR1_RTSD, sport->port.membase + USR1);
1197 writel(USR2_ORE, sport->port.membase + USR2);
1198
1199 if (sport->dma_is_inited && !sport->dma_is_enabled)
1200 imx_enable_dma(sport);
1201
1202 temp = readl(sport->port.membase + UCR1);
1203 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1204
1205 writel(temp, sport->port.membase + UCR1);
1206
1207 temp = readl(sport->port.membase + UCR4);
1208 temp |= UCR4_OREN;
1209 writel(temp, sport->port.membase + UCR4);
1210
1211 temp = readl(sport->port.membase + UCR2);
1212 temp |= (UCR2_RXEN | UCR2_TXEN);
1213 if (!sport->have_rtscts)
1214 temp |= UCR2_IRTS;
1215 writel(temp, sport->port.membase + UCR2);
1216
1217 if (!is_imx1_uart(sport)) {
1218 temp = readl(sport->port.membase + UCR3);
1219 temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
1220 writel(temp, sport->port.membase + UCR3);
1221 }
1222
1223 /*
1224 * Enable modem status interrupts
1225 */
1226 imx_enable_ms(&sport->port);
1227 spin_unlock_irqrestore(&sport->port.lock, flags);
1228
1229 return 0;
1230 }
1231
1232 static void imx_shutdown(struct uart_port *port)
1233 {
1234 struct imx_port *sport = (struct imx_port *)port;
1235 unsigned long temp;
1236 unsigned long flags;
1237
1238 if (sport->dma_is_enabled) {
1239 int ret;
1240
1241 /* We have to wait for the DMA to finish. */
1242 ret = wait_event_interruptible(sport->dma_wait,
1243 !sport->dma_is_rxing && !sport->dma_is_txing);
1244 if (ret != 0) {
1245 sport->dma_is_rxing = 0;
1246 sport->dma_is_txing = 0;
1247 dmaengine_terminate_all(sport->dma_chan_tx);
1248 dmaengine_terminate_all(sport->dma_chan_rx);
1249 }
1250 spin_lock_irqsave(&sport->port.lock, flags);
1251 imx_stop_tx(port);
1252 imx_stop_rx(port);
1253 imx_disable_dma(sport);
1254 spin_unlock_irqrestore(&sport->port.lock, flags);
1255 imx_uart_dma_exit(sport);
1256 }
1257
1258 mctrl_gpio_disable_ms(sport->gpios);
1259
1260 spin_lock_irqsave(&sport->port.lock, flags);
1261 temp = readl(sport->port.membase + UCR2);
1262 temp &= ~(UCR2_TXEN);
1263 writel(temp, sport->port.membase + UCR2);
1264 spin_unlock_irqrestore(&sport->port.lock, flags);
1265
1266 /*
1267 * Stop our timer.
1268 */
1269 del_timer_sync(&sport->timer);
1270
1271 /*
1272 * Disable all interrupts, port and break condition.
1273 */
1274
1275 spin_lock_irqsave(&sport->port.lock, flags);
1276 temp = readl(sport->port.membase + UCR1);
1277 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1278
1279 writel(temp, sport->port.membase + UCR1);
1280 spin_unlock_irqrestore(&sport->port.lock, flags);
1281
1282 clk_disable_unprepare(sport->clk_per);
1283 clk_disable_unprepare(sport->clk_ipg);
1284 }
1285
1286 static void imx_flush_buffer(struct uart_port *port)
1287 {
1288 struct imx_port *sport = (struct imx_port *)port;
1289 struct scatterlist *sgl = &sport->tx_sgl[0];
1290 unsigned long temp;
1291 int i = 100, ubir, ubmr, uts;
1292
1293 if (!sport->dma_chan_tx)
1294 return;
1295
1296 sport->tx_bytes = 0;
1297 dmaengine_terminate_all(sport->dma_chan_tx);
1298 if (sport->dma_is_txing) {
1299 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1300 DMA_TO_DEVICE);
1301 temp = readl(sport->port.membase + UCR1);
1302 temp &= ~UCR1_TDMAEN;
1303 writel(temp, sport->port.membase + UCR1);
1304 sport->dma_is_txing = false;
1305 }
1306
1307 /*
1308 * According to the Reference Manual description of the UART SRST bit:
1309 * "Reset the transmit and receive state machines,
1310 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1311 * and UTS[6-3]". As we don't need to restore the old values from
1312 * USR1, USR2, URXD, UTXD, only save/restore the other four registers
1313 */
1314 ubir = readl(sport->port.membase + UBIR);
1315 ubmr = readl(sport->port.membase + UBMR);
1316 uts = readl(sport->port.membase + IMX21_UTS);
1317
1318 temp = readl(sport->port.membase + UCR2);
1319 temp &= ~UCR2_SRST;
1320 writel(temp, sport->port.membase + UCR2);
1321
1322 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1323 udelay(1);
1324
1325 /* Restore the registers */
1326 writel(ubir, sport->port.membase + UBIR);
1327 writel(ubmr, sport->port.membase + UBMR);
1328 writel(uts, sport->port.membase + IMX21_UTS);
1329 }
1330
1331 static void
1332 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1333 struct ktermios *old)
1334 {
1335 struct imx_port *sport = (struct imx_port *)port;
1336 unsigned long flags;
1337 unsigned long ucr2, old_ucr1, old_ucr2;
1338 unsigned int baud, quot;
1339 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1340 unsigned long div, ufcr;
1341 unsigned long num, denom;
1342 uint64_t tdiv64;
1343
1344 /*
1345 * We only support CS7 and CS8.
1346 */
1347 while ((termios->c_cflag & CSIZE) != CS7 &&
1348 (termios->c_cflag & CSIZE) != CS8) {
1349 termios->c_cflag &= ~CSIZE;
1350 termios->c_cflag |= old_csize;
1351 old_csize = CS8;
1352 }
1353
1354 if ((termios->c_cflag & CSIZE) == CS8)
1355 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1356 else
1357 ucr2 = UCR2_SRST | UCR2_IRTS;
1358
1359 if (termios->c_cflag & CRTSCTS) {
1360 if (sport->have_rtscts) {
1361 ucr2 &= ~UCR2_IRTS;
1362
1363 if (port->rs485.flags & SER_RS485_ENABLED) {
1364 /*
1365 * RTS is mandatory for rs485 operation, so keep
1366 * it under manual control and keep transmitter
1367 * disabled.
1368 */
1369 if (port->rs485.flags &
1370 SER_RS485_RTS_AFTER_SEND)
1371 imx_port_rts_inactive(sport, &ucr2);
1372 else
1373 imx_port_rts_active(sport, &ucr2);
1374 } else {
1375 imx_port_rts_auto(sport, &ucr2);
1376 }
1377 } else {
1378 termios->c_cflag &= ~CRTSCTS;
1379 }
1380 } else if (port->rs485.flags & SER_RS485_ENABLED) {
1381 /* disable transmitter */
1382 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1383 imx_port_rts_inactive(sport, &ucr2);
1384 else
1385 imx_port_rts_active(sport, &ucr2);
1386 }
1387
1388
1389 if (termios->c_cflag & CSTOPB)
1390 ucr2 |= UCR2_STPB;
1391 if (termios->c_cflag & PARENB) {
1392 ucr2 |= UCR2_PREN;
1393 if (termios->c_cflag & PARODD)
1394 ucr2 |= UCR2_PROE;
1395 }
1396
1397 del_timer_sync(&sport->timer);
1398
1399 /*
1400 * Ask the core to calculate the divisor for us.
1401 */
1402 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1403 quot = uart_get_divisor(port, baud);
1404
1405 spin_lock_irqsave(&sport->port.lock, flags);
1406
1407 sport->port.read_status_mask = 0;
1408 if (termios->c_iflag & INPCK)
1409 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1410 if (termios->c_iflag & (BRKINT | PARMRK))
1411 sport->port.read_status_mask |= URXD_BRK;
1412
1413 /*
1414 * Characters to ignore
1415 */
1416 sport->port.ignore_status_mask = 0;
1417 if (termios->c_iflag & IGNPAR)
1418 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1419 if (termios->c_iflag & IGNBRK) {
1420 sport->port.ignore_status_mask |= URXD_BRK;
1421 /*
1422 * If we're ignoring parity and break indicators,
1423 * ignore overruns too (for real raw support).
1424 */
1425 if (termios->c_iflag & IGNPAR)
1426 sport->port.ignore_status_mask |= URXD_OVRRUN;
1427 }
1428
1429 if ((termios->c_cflag & CREAD) == 0)
1430 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1431
1432 /*
1433 * Update the per-port timeout.
1434 */
1435 uart_update_timeout(port, termios->c_cflag, baud);
1436
1437 /*
1438 * disable interrupts and drain transmitter
1439 */
1440 old_ucr1 = readl(sport->port.membase + UCR1);
1441 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1442 sport->port.membase + UCR1);
1443
1444 while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1445 barrier();
1446
1447 /* then, disable everything */
1448 old_ucr2 = readl(sport->port.membase + UCR2);
1449 writel(old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN),
1450 sport->port.membase + UCR2);
1451 old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
1452
1453 /* custom-baudrate handling */
1454 div = sport->port.uartclk / (baud * 16);
1455 if (baud == 38400 && quot != div)
1456 baud = sport->port.uartclk / (quot * 16);
1457
1458 div = sport->port.uartclk / (baud * 16);
1459 if (div > 7)
1460 div = 7;
1461 if (!div)
1462 div = 1;
1463
1464 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1465 1 << 16, 1 << 16, &num, &denom);
1466
1467 tdiv64 = sport->port.uartclk;
1468 tdiv64 *= num;
1469 do_div(tdiv64, denom * 16 * div);
1470 tty_termios_encode_baud_rate(termios,
1471 (speed_t)tdiv64, (speed_t)tdiv64);
1472
1473 num -= 1;
1474 denom -= 1;
1475
1476 ufcr = readl(sport->port.membase + UFCR);
1477 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1478 if (sport->dte_mode)
1479 ufcr |= UFCR_DCEDTE;
1480 writel(ufcr, sport->port.membase + UFCR);
1481
1482 writel(num, sport->port.membase + UBIR);
1483 writel(denom, sport->port.membase + UBMR);
1484
1485 if (!is_imx1_uart(sport))
1486 writel(sport->port.uartclk / div / 1000,
1487 sport->port.membase + IMX21_ONEMS);
1488
1489 writel(old_ucr1, sport->port.membase + UCR1);
1490
1491 /* set the parity, stop bits and data size */
1492 writel(ucr2 | old_ucr2, sport->port.membase + UCR2);
1493
1494 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1495 imx_enable_ms(&sport->port);
1496
1497 spin_unlock_irqrestore(&sport->port.lock, flags);
1498 }
1499
1500 static const char *imx_type(struct uart_port *port)
1501 {
1502 struct imx_port *sport = (struct imx_port *)port;
1503
1504 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1505 }
1506
1507 /*
1508 * Configure/autoconfigure the port.
1509 */
1510 static void imx_config_port(struct uart_port *port, int flags)
1511 {
1512 struct imx_port *sport = (struct imx_port *)port;
1513
1514 if (flags & UART_CONFIG_TYPE)
1515 sport->port.type = PORT_IMX;
1516 }
1517
1518 /*
1519 * Verify the new serial_struct (for TIOCSSERIAL).
1520 * The only change we allow are to the flags and type, and
1521 * even then only between PORT_IMX and PORT_UNKNOWN
1522 */
1523 static int
1524 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1525 {
1526 struct imx_port *sport = (struct imx_port *)port;
1527 int ret = 0;
1528
1529 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1530 ret = -EINVAL;
1531 if (sport->port.irq != ser->irq)
1532 ret = -EINVAL;
1533 if (ser->io_type != UPIO_MEM)
1534 ret = -EINVAL;
1535 if (sport->port.uartclk / 16 != ser->baud_base)
1536 ret = -EINVAL;
1537 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1538 ret = -EINVAL;
1539 if (sport->port.iobase != ser->port)
1540 ret = -EINVAL;
1541 if (ser->hub6 != 0)
1542 ret = -EINVAL;
1543 return ret;
1544 }
1545
1546 #if defined(CONFIG_CONSOLE_POLL)
1547
1548 static int imx_poll_init(struct uart_port *port)
1549 {
1550 struct imx_port *sport = (struct imx_port *)port;
1551 unsigned long flags;
1552 unsigned long temp;
1553 int retval;
1554
1555 retval = clk_prepare_enable(sport->clk_ipg);
1556 if (retval)
1557 return retval;
1558 retval = clk_prepare_enable(sport->clk_per);
1559 if (retval)
1560 clk_disable_unprepare(sport->clk_ipg);
1561
1562 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1563
1564 spin_lock_irqsave(&sport->port.lock, flags);
1565
1566 temp = readl(sport->port.membase + UCR1);
1567 if (is_imx1_uart(sport))
1568 temp |= IMX1_UCR1_UARTCLKEN;
1569 temp |= UCR1_UARTEN | UCR1_RRDYEN;
1570 temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN);
1571 writel(temp, sport->port.membase + UCR1);
1572
1573 temp = readl(sport->port.membase + UCR2);
1574 temp |= UCR2_RXEN;
1575 writel(temp, sport->port.membase + UCR2);
1576
1577 spin_unlock_irqrestore(&sport->port.lock, flags);
1578
1579 return 0;
1580 }
1581
1582 static int imx_poll_get_char(struct uart_port *port)
1583 {
1584 if (!(readl_relaxed(port->membase + USR2) & USR2_RDR))
1585 return NO_POLL_CHAR;
1586
1587 return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA;
1588 }
1589
1590 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1591 {
1592 unsigned int status;
1593
1594 /* drain */
1595 do {
1596 status = readl_relaxed(port->membase + USR1);
1597 } while (~status & USR1_TRDY);
1598
1599 /* write */
1600 writel_relaxed(c, port->membase + URTX0);
1601
1602 /* flush */
1603 do {
1604 status = readl_relaxed(port->membase + USR2);
1605 } while (~status & USR2_TXDC);
1606 }
1607 #endif
1608
1609 static int imx_rs485_config(struct uart_port *port,
1610 struct serial_rs485 *rs485conf)
1611 {
1612 struct imx_port *sport = (struct imx_port *)port;
1613
1614 /* unimplemented */
1615 rs485conf->delay_rts_before_send = 0;
1616 rs485conf->delay_rts_after_send = 0;
1617 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1618
1619 /* RTS is required to control the transmitter */
1620 if (!sport->have_rtscts)
1621 rs485conf->flags &= ~SER_RS485_ENABLED;
1622
1623 if (rs485conf->flags & SER_RS485_ENABLED) {
1624 unsigned long temp;
1625
1626 /* disable transmitter */
1627 temp = readl(sport->port.membase + UCR2);
1628 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1629 imx_port_rts_inactive(sport, &temp);
1630 else
1631 imx_port_rts_active(sport, &temp);
1632 writel(temp, sport->port.membase + UCR2);
1633 }
1634
1635 port->rs485 = *rs485conf;
1636
1637 return 0;
1638 }
1639
1640 static struct uart_ops imx_pops = {
1641 .tx_empty = imx_tx_empty,
1642 .set_mctrl = imx_set_mctrl,
1643 .get_mctrl = imx_get_mctrl,
1644 .stop_tx = imx_stop_tx,
1645 .start_tx = imx_start_tx,
1646 .stop_rx = imx_stop_rx,
1647 .enable_ms = imx_enable_ms,
1648 .break_ctl = imx_break_ctl,
1649 .startup = imx_startup,
1650 .shutdown = imx_shutdown,
1651 .flush_buffer = imx_flush_buffer,
1652 .set_termios = imx_set_termios,
1653 .type = imx_type,
1654 .config_port = imx_config_port,
1655 .verify_port = imx_verify_port,
1656 #if defined(CONFIG_CONSOLE_POLL)
1657 .poll_init = imx_poll_init,
1658 .poll_get_char = imx_poll_get_char,
1659 .poll_put_char = imx_poll_put_char,
1660 #endif
1661 };
1662
1663 static struct imx_port *imx_ports[UART_NR];
1664
1665 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1666 static void imx_console_putchar(struct uart_port *port, int ch)
1667 {
1668 struct imx_port *sport = (struct imx_port *)port;
1669
1670 while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1671 barrier();
1672
1673 writel(ch, sport->port.membase + URTX0);
1674 }
1675
1676 /*
1677 * Interrupts are disabled on entering
1678 */
1679 static void
1680 imx_console_write(struct console *co, const char *s, unsigned int count)
1681 {
1682 struct imx_port *sport = imx_ports[co->index];
1683 struct imx_port_ucrs old_ucr;
1684 unsigned int ucr1;
1685 unsigned long flags = 0;
1686 int locked = 1;
1687 int retval;
1688
1689 retval = clk_enable(sport->clk_per);
1690 if (retval)
1691 return;
1692 retval = clk_enable(sport->clk_ipg);
1693 if (retval) {
1694 clk_disable(sport->clk_per);
1695 return;
1696 }
1697
1698 if (sport->port.sysrq)
1699 locked = 0;
1700 else if (oops_in_progress)
1701 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1702 else
1703 spin_lock_irqsave(&sport->port.lock, flags);
1704
1705 /*
1706 * First, save UCR1/2/3 and then disable interrupts
1707 */
1708 imx_port_ucrs_save(&sport->port, &old_ucr);
1709 ucr1 = old_ucr.ucr1;
1710
1711 if (is_imx1_uart(sport))
1712 ucr1 |= IMX1_UCR1_UARTCLKEN;
1713 ucr1 |= UCR1_UARTEN;
1714 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1715
1716 writel(ucr1, sport->port.membase + UCR1);
1717
1718 writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1719
1720 uart_console_write(&sport->port, s, count, imx_console_putchar);
1721
1722 /*
1723 * Finally, wait for transmitter to become empty
1724 * and restore UCR1/2/3
1725 */
1726 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1727
1728 imx_port_ucrs_restore(&sport->port, &old_ucr);
1729
1730 if (locked)
1731 spin_unlock_irqrestore(&sport->port.lock, flags);
1732
1733 clk_disable(sport->clk_ipg);
1734 clk_disable(sport->clk_per);
1735 }
1736
1737 /*
1738 * If the port was already initialised (eg, by a boot loader),
1739 * try to determine the current setup.
1740 */
1741 static void __init
1742 imx_console_get_options(struct imx_port *sport, int *baud,
1743 int *parity, int *bits)
1744 {
1745
1746 if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1747 /* ok, the port was enabled */
1748 unsigned int ucr2, ubir, ubmr, uartclk;
1749 unsigned int baud_raw;
1750 unsigned int ucfr_rfdiv;
1751
1752 ucr2 = readl(sport->port.membase + UCR2);
1753
1754 *parity = 'n';
1755 if (ucr2 & UCR2_PREN) {
1756 if (ucr2 & UCR2_PROE)
1757 *parity = 'o';
1758 else
1759 *parity = 'e';
1760 }
1761
1762 if (ucr2 & UCR2_WS)
1763 *bits = 8;
1764 else
1765 *bits = 7;
1766
1767 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1768 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1769
1770 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1771 if (ucfr_rfdiv == 6)
1772 ucfr_rfdiv = 7;
1773 else
1774 ucfr_rfdiv = 6 - ucfr_rfdiv;
1775
1776 uartclk = clk_get_rate(sport->clk_per);
1777 uartclk /= ucfr_rfdiv;
1778
1779 { /*
1780 * The next code provides exact computation of
1781 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1782 * without need of float support or long long division,
1783 * which would be required to prevent 32bit arithmetic overflow
1784 */
1785 unsigned int mul = ubir + 1;
1786 unsigned int div = 16 * (ubmr + 1);
1787 unsigned int rem = uartclk % div;
1788
1789 baud_raw = (uartclk / div) * mul;
1790 baud_raw += (rem * mul + div / 2) / div;
1791 *baud = (baud_raw + 50) / 100 * 100;
1792 }
1793
1794 if (*baud != baud_raw)
1795 pr_info("Console IMX rounded baud rate from %d to %d\n",
1796 baud_raw, *baud);
1797 }
1798 }
1799
1800 static int __init
1801 imx_console_setup(struct console *co, char *options)
1802 {
1803 struct imx_port *sport;
1804 int baud = 9600;
1805 int bits = 8;
1806 int parity = 'n';
1807 int flow = 'n';
1808 int retval;
1809
1810 /*
1811 * Check whether an invalid uart number has been specified, and
1812 * if so, search for the first available port that does have
1813 * console support.
1814 */
1815 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1816 co->index = 0;
1817 sport = imx_ports[co->index];
1818 if (sport == NULL)
1819 return -ENODEV;
1820
1821 /* For setting the registers, we only need to enable the ipg clock. */
1822 retval = clk_prepare_enable(sport->clk_ipg);
1823 if (retval)
1824 goto error_console;
1825
1826 if (options)
1827 uart_parse_options(options, &baud, &parity, &bits, &flow);
1828 else
1829 imx_console_get_options(sport, &baud, &parity, &bits);
1830
1831 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1832
1833 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1834
1835 clk_disable(sport->clk_ipg);
1836 if (retval) {
1837 clk_unprepare(sport->clk_ipg);
1838 goto error_console;
1839 }
1840
1841 retval = clk_prepare(sport->clk_per);
1842 if (retval)
1843 clk_disable_unprepare(sport->clk_ipg);
1844
1845 error_console:
1846 return retval;
1847 }
1848
1849 static struct uart_driver imx_reg;
1850 static struct console imx_console = {
1851 .name = DEV_NAME,
1852 .write = imx_console_write,
1853 .device = uart_console_device,
1854 .setup = imx_console_setup,
1855 .flags = CON_PRINTBUFFER,
1856 .index = -1,
1857 .data = &imx_reg,
1858 };
1859
1860 #define IMX_CONSOLE &imx_console
1861
1862 #ifdef CONFIG_OF
1863 static void imx_console_early_putchar(struct uart_port *port, int ch)
1864 {
1865 while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
1866 cpu_relax();
1867
1868 writel_relaxed(ch, port->membase + URTX0);
1869 }
1870
1871 static void imx_console_early_write(struct console *con, const char *s,
1872 unsigned count)
1873 {
1874 struct earlycon_device *dev = con->data;
1875
1876 uart_console_write(&dev->port, s, count, imx_console_early_putchar);
1877 }
1878
1879 static int __init
1880 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
1881 {
1882 if (!dev->port.membase)
1883 return -ENODEV;
1884
1885 dev->con->write = imx_console_early_write;
1886
1887 return 0;
1888 }
1889 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
1890 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
1891 #endif
1892
1893 #else
1894 #define IMX_CONSOLE NULL
1895 #endif
1896
1897 static struct uart_driver imx_reg = {
1898 .owner = THIS_MODULE,
1899 .driver_name = DRIVER_NAME,
1900 .dev_name = DEV_NAME,
1901 .major = SERIAL_IMX_MAJOR,
1902 .minor = MINOR_START,
1903 .nr = ARRAY_SIZE(imx_ports),
1904 .cons = IMX_CONSOLE,
1905 };
1906
1907 #ifdef CONFIG_OF
1908 /*
1909 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1910 * could successfully get all information from dt or a negative errno.
1911 */
1912 static int serial_imx_probe_dt(struct imx_port *sport,
1913 struct platform_device *pdev)
1914 {
1915 struct device_node *np = pdev->dev.of_node;
1916 int ret;
1917
1918 sport->devdata = of_device_get_match_data(&pdev->dev);
1919 if (!sport->devdata)
1920 /* no device tree device */
1921 return 1;
1922
1923 ret = of_alias_get_id(np, "serial");
1924 if (ret < 0) {
1925 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1926 return ret;
1927 }
1928 sport->port.line = ret;
1929
1930 if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1931 sport->have_rtscts = 1;
1932
1933 if (of_get_property(np, "fsl,dte-mode", NULL))
1934 sport->dte_mode = 1;
1935
1936 return 0;
1937 }
1938 #else
1939 static inline int serial_imx_probe_dt(struct imx_port *sport,
1940 struct platform_device *pdev)
1941 {
1942 return 1;
1943 }
1944 #endif
1945
1946 static void serial_imx_probe_pdata(struct imx_port *sport,
1947 struct platform_device *pdev)
1948 {
1949 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1950
1951 sport->port.line = pdev->id;
1952 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
1953
1954 if (!pdata)
1955 return;
1956
1957 if (pdata->flags & IMXUART_HAVE_RTSCTS)
1958 sport->have_rtscts = 1;
1959 }
1960
1961 static int serial_imx_probe(struct platform_device *pdev)
1962 {
1963 struct imx_port *sport;
1964 void __iomem *base;
1965 int ret = 0, reg;
1966 struct resource *res;
1967 int txirq, rxirq, rtsirq;
1968
1969 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1970 if (!sport)
1971 return -ENOMEM;
1972
1973 ret = serial_imx_probe_dt(sport, pdev);
1974 if (ret > 0)
1975 serial_imx_probe_pdata(sport, pdev);
1976 else if (ret < 0)
1977 return ret;
1978
1979 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1980 base = devm_ioremap_resource(&pdev->dev, res);
1981 if (IS_ERR(base))
1982 return PTR_ERR(base);
1983
1984 rxirq = platform_get_irq(pdev, 0);
1985 txirq = platform_get_irq(pdev, 1);
1986 rtsirq = platform_get_irq(pdev, 2);
1987
1988 sport->port.dev = &pdev->dev;
1989 sport->port.mapbase = res->start;
1990 sport->port.membase = base;
1991 sport->port.type = PORT_IMX,
1992 sport->port.iotype = UPIO_MEM;
1993 sport->port.irq = rxirq;
1994 sport->port.fifosize = 32;
1995 sport->port.ops = &imx_pops;
1996 sport->port.rs485_config = imx_rs485_config;
1997 sport->port.rs485.flags =
1998 SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX;
1999 sport->port.flags = UPF_BOOT_AUTOCONF;
2000 init_timer(&sport->timer);
2001 sport->timer.function = imx_timeout;
2002 sport->timer.data = (unsigned long)sport;
2003
2004 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2005 if (IS_ERR(sport->gpios))
2006 return PTR_ERR(sport->gpios);
2007
2008 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2009 if (IS_ERR(sport->clk_ipg)) {
2010 ret = PTR_ERR(sport->clk_ipg);
2011 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2012 return ret;
2013 }
2014
2015 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2016 if (IS_ERR(sport->clk_per)) {
2017 ret = PTR_ERR(sport->clk_per);
2018 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2019 return ret;
2020 }
2021
2022 sport->port.uartclk = clk_get_rate(sport->clk_per);
2023
2024 /* For register access, we only need to enable the ipg clock. */
2025 ret = clk_prepare_enable(sport->clk_ipg);
2026 if (ret)
2027 return ret;
2028
2029 /* Disable interrupts before requesting them */
2030 reg = readl_relaxed(sport->port.membase + UCR1);
2031 reg &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2032 UCR1_TXMPTYEN | UCR1_RTSDEN);
2033 writel_relaxed(reg, sport->port.membase + UCR1);
2034
2035 clk_disable_unprepare(sport->clk_ipg);
2036
2037 /*
2038 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2039 * chips only have one interrupt.
2040 */
2041 if (txirq > 0) {
2042 ret = devm_request_irq(&pdev->dev, rxirq, imx_rxint, 0,
2043 dev_name(&pdev->dev), sport);
2044 if (ret)
2045 return ret;
2046
2047 ret = devm_request_irq(&pdev->dev, txirq, imx_txint, 0,
2048 dev_name(&pdev->dev), sport);
2049 if (ret)
2050 return ret;
2051 } else {
2052 ret = devm_request_irq(&pdev->dev, rxirq, imx_int, 0,
2053 dev_name(&pdev->dev), sport);
2054 if (ret)
2055 return ret;
2056 }
2057
2058 imx_ports[sport->port.line] = sport;
2059
2060 platform_set_drvdata(pdev, sport);
2061
2062 return uart_add_one_port(&imx_reg, &sport->port);
2063 }
2064
2065 static int serial_imx_remove(struct platform_device *pdev)
2066 {
2067 struct imx_port *sport = platform_get_drvdata(pdev);
2068
2069 return uart_remove_one_port(&imx_reg, &sport->port);
2070 }
2071
2072 static void serial_imx_restore_context(struct imx_port *sport)
2073 {
2074 if (!sport->context_saved)
2075 return;
2076
2077 writel(sport->saved_reg[4], sport->port.membase + UFCR);
2078 writel(sport->saved_reg[5], sport->port.membase + UESC);
2079 writel(sport->saved_reg[6], sport->port.membase + UTIM);
2080 writel(sport->saved_reg[7], sport->port.membase + UBIR);
2081 writel(sport->saved_reg[8], sport->port.membase + UBMR);
2082 writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS);
2083 writel(sport->saved_reg[0], sport->port.membase + UCR1);
2084 writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2);
2085 writel(sport->saved_reg[2], sport->port.membase + UCR3);
2086 writel(sport->saved_reg[3], sport->port.membase + UCR4);
2087 sport->context_saved = false;
2088 }
2089
2090 static void serial_imx_save_context(struct imx_port *sport)
2091 {
2092 /* Save necessary regs */
2093 sport->saved_reg[0] = readl(sport->port.membase + UCR1);
2094 sport->saved_reg[1] = readl(sport->port.membase + UCR2);
2095 sport->saved_reg[2] = readl(sport->port.membase + UCR3);
2096 sport->saved_reg[3] = readl(sport->port.membase + UCR4);
2097 sport->saved_reg[4] = readl(sport->port.membase + UFCR);
2098 sport->saved_reg[5] = readl(sport->port.membase + UESC);
2099 sport->saved_reg[6] = readl(sport->port.membase + UTIM);
2100 sport->saved_reg[7] = readl(sport->port.membase + UBIR);
2101 sport->saved_reg[8] = readl(sport->port.membase + UBMR);
2102 sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS);
2103 sport->context_saved = true;
2104 }
2105
2106 static void serial_imx_enable_wakeup(struct imx_port *sport, bool on)
2107 {
2108 unsigned int val;
2109
2110 val = readl(sport->port.membase + UCR3);
2111 if (on)
2112 val |= UCR3_AWAKEN;
2113 else
2114 val &= ~UCR3_AWAKEN;
2115 writel(val, sport->port.membase + UCR3);
2116
2117 val = readl(sport->port.membase + UCR1);
2118 if (on)
2119 val |= UCR1_RTSDEN;
2120 else
2121 val &= ~UCR1_RTSDEN;
2122 writel(val, sport->port.membase + UCR1);
2123 }
2124
2125 static int imx_serial_port_suspend_noirq(struct device *dev)
2126 {
2127 struct platform_device *pdev = to_platform_device(dev);
2128 struct imx_port *sport = platform_get_drvdata(pdev);
2129 int ret;
2130
2131 ret = clk_enable(sport->clk_ipg);
2132 if (ret)
2133 return ret;
2134
2135 serial_imx_save_context(sport);
2136
2137 clk_disable(sport->clk_ipg);
2138
2139 return 0;
2140 }
2141
2142 static int imx_serial_port_resume_noirq(struct device *dev)
2143 {
2144 struct platform_device *pdev = to_platform_device(dev);
2145 struct imx_port *sport = platform_get_drvdata(pdev);
2146 int ret;
2147
2148 ret = clk_enable(sport->clk_ipg);
2149 if (ret)
2150 return ret;
2151
2152 serial_imx_restore_context(sport);
2153
2154 clk_disable(sport->clk_ipg);
2155
2156 return 0;
2157 }
2158
2159 static int imx_serial_port_suspend(struct device *dev)
2160 {
2161 struct platform_device *pdev = to_platform_device(dev);
2162 struct imx_port *sport = platform_get_drvdata(pdev);
2163
2164 /* enable wakeup from i.MX UART */
2165 serial_imx_enable_wakeup(sport, true);
2166
2167 uart_suspend_port(&imx_reg, &sport->port);
2168
2169 return 0;
2170 }
2171
2172 static int imx_serial_port_resume(struct device *dev)
2173 {
2174 struct platform_device *pdev = to_platform_device(dev);
2175 struct imx_port *sport = platform_get_drvdata(pdev);
2176
2177 /* disable wakeup from i.MX UART */
2178 serial_imx_enable_wakeup(sport, false);
2179
2180 uart_resume_port(&imx_reg, &sport->port);
2181
2182 return 0;
2183 }
2184
2185 static const struct dev_pm_ops imx_serial_port_pm_ops = {
2186 .suspend_noirq = imx_serial_port_suspend_noirq,
2187 .resume_noirq = imx_serial_port_resume_noirq,
2188 .suspend = imx_serial_port_suspend,
2189 .resume = imx_serial_port_resume,
2190 };
2191
2192 static struct platform_driver serial_imx_driver = {
2193 .probe = serial_imx_probe,
2194 .remove = serial_imx_remove,
2195
2196 .id_table = imx_uart_devtype,
2197 .driver = {
2198 .name = "imx-uart",
2199 .of_match_table = imx_uart_dt_ids,
2200 .pm = &imx_serial_port_pm_ops,
2201 },
2202 };
2203
2204 static int __init imx_serial_init(void)
2205 {
2206 int ret = uart_register_driver(&imx_reg);
2207
2208 if (ret)
2209 return ret;
2210
2211 ret = platform_driver_register(&serial_imx_driver);
2212 if (ret != 0)
2213 uart_unregister_driver(&imx_reg);
2214
2215 return ret;
2216 }
2217
2218 static void __exit imx_serial_exit(void)
2219 {
2220 platform_driver_unregister(&serial_imx_driver);
2221 uart_unregister_driver(&imx_reg);
2222 }
2223
2224 module_init(imx_serial_init);
2225 module_exit(imx_serial_exit);
2226
2227 MODULE_AUTHOR("Sascha Hauer");
2228 MODULE_DESCRIPTION("IMX generic serial port driver");
2229 MODULE_LICENSE("GPL");
2230 MODULE_ALIAS("platform:imx-uart");
Linux kernel - Deliverables
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