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r8152: fix tx packets accounting
[linux/fpc-iii.git] / drivers / tty / serial / imx.c
blobb24edf6349855fdaa40c7489a08fb3c88348ef43
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 UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
118 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
119 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
120 #define UCR3_BPEN (1<<0) /* Preset registers enable */
121 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
122 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
123 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
124 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
125 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
126 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
127 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
128 #define UCR4_IRSC (1<<5) /* IR special case */
129 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
130 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
131 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
132 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
133 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
134 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
135 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
136 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
137 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
138 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
139 #define USR1_RTSS (1<<14) /* RTS pin status */
140 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
141 #define USR1_RTSD (1<<12) /* RTS delta */
142 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
143 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
144 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
145 #define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
146 #define USR1_DTRD (1<<7) /* DTR Delta */
147 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
148 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
149 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
150 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
151 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
152 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
153 #define USR2_IDLE (1<<12) /* Idle condition */
154 #define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
155 #define USR2_RIIN (1<<9) /* Ring Indicator Input */
156 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
157 #define USR2_WAKE (1<<7) /* Wake */
158 #define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
159 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
160 #define USR2_TXDC (1<<3) /* Transmitter complete */
161 #define USR2_BRCD (1<<2) /* Break condition */
162 #define USR2_ORE (1<<1) /* Overrun error */
163 #define USR2_RDR (1<<0) /* Recv data ready */
164 #define UTS_FRCPERR (1<<13) /* Force parity error */
165 #define UTS_LOOP (1<<12) /* Loop tx and rx */
166 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
167 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
168 #define UTS_TXFULL (1<<4) /* TxFIFO full */
169 #define UTS_RXFULL (1<<3) /* RxFIFO full */
170 #define UTS_SOFTRST (1<<0) /* Software reset */
171
172 /* We've been assigned a range on the "Low-density serial ports" major */
173 #define SERIAL_IMX_MAJOR 207
174 #define MINOR_START 16
175 #define DEV_NAME "ttymxc"
176
177 /*
178 * This determines how often we check the modem status signals
179 * for any change. They generally aren't connected to an IRQ
180 * so we have to poll them. We also check immediately before
181 * filling the TX fifo incase CTS has been dropped.
182 */
183 #define MCTRL_TIMEOUT (250*HZ/1000)
184
185 #define DRIVER_NAME "IMX-uart"
186
187 #define UART_NR 8
188
189 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
190 enum imx_uart_type {
191 IMX1_UART,
192 IMX21_UART,
193 IMX53_UART,
194 IMX6Q_UART,
195 };
196
197 /* device type dependent stuff */
198 struct imx_uart_data {
199 unsigned uts_reg;
200 enum imx_uart_type devtype;
201 };
202
203 struct imx_port {
204 struct uart_port port;
205 struct timer_list timer;
206 unsigned int old_status;
207 unsigned int have_rtscts:1;
208 unsigned int dte_mode:1;
209 unsigned int irda_inv_rx:1;
210 unsigned int irda_inv_tx:1;
211 unsigned short trcv_delay; /* transceiver delay */
212 struct clk *clk_ipg;
213 struct clk *clk_per;
214 const struct imx_uart_data *devdata;
215
216 struct mctrl_gpios *gpios;
217
218 /* DMA fields */
219 unsigned int dma_is_inited:1;
220 unsigned int dma_is_enabled:1;
221 unsigned int dma_is_rxing:1;
222 unsigned int dma_is_txing:1;
223 struct dma_chan *dma_chan_rx, *dma_chan_tx;
224 struct scatterlist rx_sgl, tx_sgl[2];
225 void *rx_buf;
226 struct circ_buf rx_ring;
227 unsigned int rx_periods;
228 dma_cookie_t rx_cookie;
229 unsigned int tx_bytes;
230 unsigned int dma_tx_nents;
231 wait_queue_head_t dma_wait;
232 unsigned int saved_reg[10];
233 bool context_saved;
234 };
235
236 struct imx_port_ucrs {
237 unsigned int ucr1;
238 unsigned int ucr2;
239 unsigned int ucr3;
240 };
241
242 static struct imx_uart_data imx_uart_devdata[] = {
243 [IMX1_UART] = {
244 .uts_reg = IMX1_UTS,
245 .devtype = IMX1_UART,
246 },
247 [IMX21_UART] = {
248 .uts_reg = IMX21_UTS,
249 .devtype = IMX21_UART,
250 },
251 [IMX53_UART] = {
252 .uts_reg = IMX21_UTS,
253 .devtype = IMX53_UART,
254 },
255 [IMX6Q_UART] = {
256 .uts_reg = IMX21_UTS,
257 .devtype = IMX6Q_UART,
258 },
259 };
260
261 static const struct platform_device_id imx_uart_devtype[] = {
262 {
263 .name = "imx1-uart",
264 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
265 }, {
266 .name = "imx21-uart",
267 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
268 }, {
269 .name = "imx53-uart",
270 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
271 }, {
272 .name = "imx6q-uart",
273 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
274 }, {
275 /* sentinel */
276 }
277 };
278 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
279
280 static const struct of_device_id imx_uart_dt_ids[] = {
281 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
282 { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
283 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
284 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
285 { /* sentinel */ }
286 };
287 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
288
289 static inline unsigned uts_reg(struct imx_port *sport)
290 {
291 return sport->devdata->uts_reg;
292 }
293
294 static inline int is_imx1_uart(struct imx_port *sport)
295 {
296 return sport->devdata->devtype == IMX1_UART;
297 }
298
299 static inline int is_imx21_uart(struct imx_port *sport)
300 {
301 return sport->devdata->devtype == IMX21_UART;
302 }
303
304 static inline int is_imx53_uart(struct imx_port *sport)
305 {
306 return sport->devdata->devtype == IMX53_UART;
307 }
308
309 static inline int is_imx6q_uart(struct imx_port *sport)
310 {
311 return sport->devdata->devtype == IMX6Q_UART;
312 }
313 /*
314 * Save and restore functions for UCR1, UCR2 and UCR3 registers
315 */
316 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
317 static void imx_port_ucrs_save(struct uart_port *port,
318 struct imx_port_ucrs *ucr)
319 {
320 /* save control registers */
321 ucr->ucr1 = readl(port->membase + UCR1);
322 ucr->ucr2 = readl(port->membase + UCR2);
323 ucr->ucr3 = readl(port->membase + UCR3);
324 }
325
326 static void imx_port_ucrs_restore(struct uart_port *port,
327 struct imx_port_ucrs *ucr)
328 {
329 /* restore control registers */
330 writel(ucr->ucr1, port->membase + UCR1);
331 writel(ucr->ucr2, port->membase + UCR2);
332 writel(ucr->ucr3, port->membase + UCR3);
333 }
334 #endif
335
336 static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2)
337 {
338 *ucr2 &= ~UCR2_CTSC;
339 *ucr2 |= UCR2_CTS;
340
341 mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
342 }
343
344 static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
345 {
346 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
347
348 mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
349 }
350
351 static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
352 {
353 *ucr2 |= UCR2_CTSC;
354 }
355
356 /*
357 * interrupts disabled on entry
358 */
359 static void imx_stop_tx(struct uart_port *port)
360 {
361 struct imx_port *sport = (struct imx_port *)port;
362 unsigned long temp;
363
364 /*
365 * We are maybe in the SMP context, so if the DMA TX thread is running
366 * on other cpu, we have to wait for it to finish.
367 */
368 if (sport->dma_is_enabled && sport->dma_is_txing)
369 return;
370
371 temp = readl(port->membase + UCR1);
372 writel(temp & ~UCR1_TXMPTYEN, port->membase + UCR1);
373
374 /* in rs485 mode disable transmitter if shifter is empty */
375 if (port->rs485.flags & SER_RS485_ENABLED &&
376 readl(port->membase + USR2) & USR2_TXDC) {
377 temp = readl(port->membase + UCR2);
378 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
379 imx_port_rts_inactive(sport, &temp);
380 else
381 imx_port_rts_active(sport, &temp);
382 temp |= UCR2_RXEN;
383 writel(temp, port->membase + UCR2);
384
385 temp = readl(port->membase + UCR4);
386 temp &= ~UCR4_TCEN;
387 writel(temp, port->membase + UCR4);
388 }
389 }
390
391 /*
392 * interrupts disabled on entry
393 */
394 static void imx_stop_rx(struct uart_port *port)
395 {
396 struct imx_port *sport = (struct imx_port *)port;
397 unsigned long temp;
398
399 if (sport->dma_is_enabled && sport->dma_is_rxing) {
400 if (sport->port.suspended) {
401 dmaengine_terminate_all(sport->dma_chan_rx);
402 sport->dma_is_rxing = 0;
403 } else {
404 return;
405 }
406 }
407
408 temp = readl(sport->port.membase + UCR2);
409 writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
410
411 /* disable the `Receiver Ready Interrrupt` */
412 temp = readl(sport->port.membase + UCR1);
413 writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
414 }
415
416 /*
417 * Set the modem control timer to fire immediately.
418 */
419 static void imx_enable_ms(struct uart_port *port)
420 {
421 struct imx_port *sport = (struct imx_port *)port;
422
423 mod_timer(&sport->timer, jiffies);
424
425 mctrl_gpio_enable_ms(sport->gpios);
426 }
427
428 static void imx_dma_tx(struct imx_port *sport);
429 static inline void imx_transmit_buffer(struct imx_port *sport)
430 {
431 struct circ_buf *xmit = &sport->port.state->xmit;
432 unsigned long temp;
433
434 if (sport->port.x_char) {
435 /* Send next char */
436 writel(sport->port.x_char, sport->port.membase + URTX0);
437 sport->port.icount.tx++;
438 sport->port.x_char = 0;
439 return;
440 }
441
442 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
443 imx_stop_tx(&sport->port);
444 return;
445 }
446
447 if (sport->dma_is_enabled) {
448 /*
449 * We've just sent a X-char Ensure the TX DMA is enabled
450 * and the TX IRQ is disabled.
451 **/
452 temp = readl(sport->port.membase + UCR1);
453 temp &= ~UCR1_TXMPTYEN;
454 if (sport->dma_is_txing) {
455 temp |= UCR1_TDMAEN;
456 writel(temp, sport->port.membase + UCR1);
457 } else {
458 writel(temp, sport->port.membase + UCR1);
459 imx_dma_tx(sport);
460 }
461 }
462
463 while (!uart_circ_empty(xmit) &&
464 !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
465 /* send xmit->buf[xmit->tail]
466 * out the port here */
467 writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
468 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
469 sport->port.icount.tx++;
470 }
471
472 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
473 uart_write_wakeup(&sport->port);
474
475 if (uart_circ_empty(xmit))
476 imx_stop_tx(&sport->port);
477 }
478
479 static void dma_tx_callback(void *data)
480 {
481 struct imx_port *sport = data;
482 struct scatterlist *sgl = &sport->tx_sgl[0];
483 struct circ_buf *xmit = &sport->port.state->xmit;
484 unsigned long flags;
485 unsigned long temp;
486
487 spin_lock_irqsave(&sport->port.lock, flags);
488
489 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
490
491 temp = readl(sport->port.membase + UCR1);
492 temp &= ~UCR1_TDMAEN;
493 writel(temp, sport->port.membase + UCR1);
494
495 /* update the stat */
496 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
497 sport->port.icount.tx += sport->tx_bytes;
498
499 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
500
501 sport->dma_is_txing = 0;
502
503 spin_unlock_irqrestore(&sport->port.lock, flags);
504
505 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
506 uart_write_wakeup(&sport->port);
507
508 if (waitqueue_active(&sport->dma_wait)) {
509 wake_up(&sport->dma_wait);
510 dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
511 return;
512 }
513
514 spin_lock_irqsave(&sport->port.lock, flags);
515 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
516 imx_dma_tx(sport);
517 spin_unlock_irqrestore(&sport->port.lock, flags);
518 }
519
520 static void imx_dma_tx(struct imx_port *sport)
521 {
522 struct circ_buf *xmit = &sport->port.state->xmit;
523 struct scatterlist *sgl = sport->tx_sgl;
524 struct dma_async_tx_descriptor *desc;
525 struct dma_chan *chan = sport->dma_chan_tx;
526 struct device *dev = sport->port.dev;
527 unsigned long temp;
528 int ret;
529
530 if (sport->dma_is_txing)
531 return;
532
533 sport->tx_bytes = uart_circ_chars_pending(xmit);
534
535 if (xmit->tail < xmit->head) {
536 sport->dma_tx_nents = 1;
537 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
538 } else {
539 sport->dma_tx_nents = 2;
540 sg_init_table(sgl, 2);
541 sg_set_buf(sgl, xmit->buf + xmit->tail,
542 UART_XMIT_SIZE - xmit->tail);
543 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
544 }
545
546 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
547 if (ret == 0) {
548 dev_err(dev, "DMA mapping error for TX.\n");
549 return;
550 }
551 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
552 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
553 if (!desc) {
554 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
555 DMA_TO_DEVICE);
556 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
557 return;
558 }
559 desc->callback = dma_tx_callback;
560 desc->callback_param = sport;
561
562 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
563 uart_circ_chars_pending(xmit));
564
565 temp = readl(sport->port.membase + UCR1);
566 temp |= UCR1_TDMAEN;
567 writel(temp, sport->port.membase + UCR1);
568
569 /* fire it */
570 sport->dma_is_txing = 1;
571 dmaengine_submit(desc);
572 dma_async_issue_pending(chan);
573 return;
574 }
575
576 /*
577 * interrupts disabled on entry
578 */
579 static void imx_start_tx(struct uart_port *port)
580 {
581 struct imx_port *sport = (struct imx_port *)port;
582 unsigned long temp;
583
584 if (port->rs485.flags & SER_RS485_ENABLED) {
585 temp = readl(port->membase + UCR2);
586 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
587 imx_port_rts_inactive(sport, &temp);
588 else
589 imx_port_rts_active(sport, &temp);
590 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
591 temp &= ~UCR2_RXEN;
592 writel(temp, port->membase + UCR2);
593
594 /* enable transmitter and shifter empty irq */
595 temp = readl(port->membase + UCR4);
596 temp |= UCR4_TCEN;
597 writel(temp, port->membase + UCR4);
598 }
599
600 if (!sport->dma_is_enabled) {
601 temp = readl(sport->port.membase + UCR1);
602 writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
603 }
604
605 if (sport->dma_is_enabled) {
606 if (sport->port.x_char) {
607 /* We have X-char to send, so enable TX IRQ and
608 * disable TX DMA to let TX interrupt to send X-char */
609 temp = readl(sport->port.membase + UCR1);
610 temp &= ~UCR1_TDMAEN;
611 temp |= UCR1_TXMPTYEN;
612 writel(temp, sport->port.membase + UCR1);
613 return;
614 }
615
616 if (!uart_circ_empty(&port->state->xmit) &&
617 !uart_tx_stopped(port))
618 imx_dma_tx(sport);
619 return;
620 }
621 }
622
623 static irqreturn_t imx_rtsint(int irq, void *dev_id)
624 {
625 struct imx_port *sport = dev_id;
626 unsigned int val;
627 unsigned long flags;
628
629 spin_lock_irqsave(&sport->port.lock, flags);
630
631 writel(USR1_RTSD, sport->port.membase + USR1);
632 val = readl(sport->port.membase + USR1) & USR1_RTSS;
633 uart_handle_cts_change(&sport->port, !!val);
634 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
635
636 spin_unlock_irqrestore(&sport->port.lock, flags);
637 return IRQ_HANDLED;
638 }
639
640 static irqreturn_t imx_txint(int irq, void *dev_id)
641 {
642 struct imx_port *sport = dev_id;
643 unsigned long flags;
644
645 spin_lock_irqsave(&sport->port.lock, flags);
646 imx_transmit_buffer(sport);
647 spin_unlock_irqrestore(&sport->port.lock, flags);
648 return IRQ_HANDLED;
649 }
650
651 static irqreturn_t imx_rxint(int irq, void *dev_id)
652 {
653 struct imx_port *sport = dev_id;
654 unsigned int rx, flg, ignored = 0;
655 struct tty_port *port = &sport->port.state->port;
656 unsigned long flags, temp;
657
658 spin_lock_irqsave(&sport->port.lock, flags);
659
660 while (readl(sport->port.membase + USR2) & USR2_RDR) {
661 flg = TTY_NORMAL;
662 sport->port.icount.rx++;
663
664 rx = readl(sport->port.membase + URXD0);
665
666 temp = readl(sport->port.membase + USR2);
667 if (temp & USR2_BRCD) {
668 writel(USR2_BRCD, sport->port.membase + USR2);
669 if (uart_handle_break(&sport->port))
670 continue;
671 }
672
673 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
674 continue;
675
676 if (unlikely(rx & URXD_ERR)) {
677 if (rx & URXD_BRK)
678 sport->port.icount.brk++;
679 else if (rx & URXD_PRERR)
680 sport->port.icount.parity++;
681 else if (rx & URXD_FRMERR)
682 sport->port.icount.frame++;
683 if (rx & URXD_OVRRUN)
684 sport->port.icount.overrun++;
685
686 if (rx & sport->port.ignore_status_mask) {
687 if (++ignored > 100)
688 goto out;
689 continue;
690 }
691
692 rx &= (sport->port.read_status_mask | 0xFF);
693
694 if (rx & URXD_BRK)
695 flg = TTY_BREAK;
696 else if (rx & URXD_PRERR)
697 flg = TTY_PARITY;
698 else if (rx & URXD_FRMERR)
699 flg = TTY_FRAME;
700 if (rx & URXD_OVRRUN)
701 flg = TTY_OVERRUN;
702
703 #ifdef SUPPORT_SYSRQ
704 sport->port.sysrq = 0;
705 #endif
706 }
707
708 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
709 goto out;
710
711 if (tty_insert_flip_char(port, rx, flg) == 0)
712 sport->port.icount.buf_overrun++;
713 }
714
715 out:
716 spin_unlock_irqrestore(&sport->port.lock, flags);
717 tty_flip_buffer_push(port);
718 return IRQ_HANDLED;
719 }
720
721 static void clear_rx_errors(struct imx_port *sport);
722 static int start_rx_dma(struct imx_port *sport);
723 /*
724 * If the RXFIFO is filled with some data, and then we
725 * arise a DMA operation to receive them.
726 */
727 static void imx_dma_rxint(struct imx_port *sport)
728 {
729 unsigned long temp;
730 unsigned long flags;
731
732 spin_lock_irqsave(&sport->port.lock, flags);
733
734 temp = readl(sport->port.membase + USR2);
735 if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
736 sport->dma_is_rxing = 1;
737
738 /* disable the receiver ready and aging timer interrupts */
739 temp = readl(sport->port.membase + UCR1);
740 temp &= ~(UCR1_RRDYEN);
741 writel(temp, sport->port.membase + UCR1);
742
743 temp = readl(sport->port.membase + UCR2);
744 temp &= ~(UCR2_ATEN);
745 writel(temp, sport->port.membase + UCR2);
746
747 /* disable the rx errors interrupts */
748 temp = readl(sport->port.membase + UCR4);
749 temp &= ~UCR4_OREN;
750 writel(temp, sport->port.membase + UCR4);
751
752 /* tell the DMA to receive the data. */
753 start_rx_dma(sport);
754 }
755
756 spin_unlock_irqrestore(&sport->port.lock, flags);
757 }
758
759 /*
760 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
761 */
762 static unsigned int imx_get_hwmctrl(struct imx_port *sport)
763 {
764 unsigned int tmp = TIOCM_DSR;
765 unsigned usr1 = readl(sport->port.membase + USR1);
766 unsigned usr2 = readl(sport->port.membase + USR2);
767
768 if (usr1 & USR1_RTSS)
769 tmp |= TIOCM_CTS;
770
771 /* in DCE mode DCDIN is always 0 */
772 if (!(usr2 & USR2_DCDIN))
773 tmp |= TIOCM_CAR;
774
775 if (sport->dte_mode)
776 if (!(readl(sport->port.membase + USR2) & USR2_RIIN))
777 tmp |= TIOCM_RI;
778
779 return tmp;
780 }
781
782 /*
783 * Handle any change of modem status signal since we were last called.
784 */
785 static void imx_mctrl_check(struct imx_port *sport)
786 {
787 unsigned int status, changed;
788
789 status = imx_get_hwmctrl(sport);
790 changed = status ^ sport->old_status;
791
792 if (changed == 0)
793 return;
794
795 sport->old_status = status;
796
797 if (changed & TIOCM_RI && status & TIOCM_RI)
798 sport->port.icount.rng++;
799 if (changed & TIOCM_DSR)
800 sport->port.icount.dsr++;
801 if (changed & TIOCM_CAR)
802 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
803 if (changed & TIOCM_CTS)
804 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
805
806 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
807 }
808
809 static irqreturn_t imx_int(int irq, void *dev_id)
810 {
811 struct imx_port *sport = dev_id;
812 unsigned int sts;
813 unsigned int sts2;
814 irqreturn_t ret = IRQ_NONE;
815
816 sts = readl(sport->port.membase + USR1);
817 sts2 = readl(sport->port.membase + USR2);
818
819 if (sts & (USR1_RRDY | USR1_AGTIM)) {
820 if (sport->dma_is_enabled)
821 imx_dma_rxint(sport);
822 else
823 imx_rxint(irq, dev_id);
824 ret = IRQ_HANDLED;
825 }
826
827 if ((sts & USR1_TRDY &&
828 readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN) ||
829 (sts2 & USR2_TXDC &&
830 readl(sport->port.membase + UCR4) & UCR4_TCEN)) {
831 imx_txint(irq, dev_id);
832 ret = IRQ_HANDLED;
833 }
834
835 if (sts & USR1_DTRD) {
836 unsigned long flags;
837
838 if (sts & USR1_DTRD)
839 writel(USR1_DTRD, sport->port.membase + USR1);
840
841 spin_lock_irqsave(&sport->port.lock, flags);
842 imx_mctrl_check(sport);
843 spin_unlock_irqrestore(&sport->port.lock, flags);
844
845 ret = IRQ_HANDLED;
846 }
847
848 if (sts & USR1_RTSD) {
849 imx_rtsint(irq, dev_id);
850 ret = IRQ_HANDLED;
851 }
852
853 if (sts & USR1_AWAKE) {
854 writel(USR1_AWAKE, sport->port.membase + USR1);
855 ret = IRQ_HANDLED;
856 }
857
858 if (sts2 & USR2_ORE) {
859 sport->port.icount.overrun++;
860 writel(USR2_ORE, sport->port.membase + USR2);
861 ret = IRQ_HANDLED;
862 }
863
864 return ret;
865 }
866
867 /*
868 * Return TIOCSER_TEMT when transmitter is not busy.
869 */
870 static unsigned int imx_tx_empty(struct uart_port *port)
871 {
872 struct imx_port *sport = (struct imx_port *)port;
873 unsigned int ret;
874
875 ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
876
877 /* If the TX DMA is working, return 0. */
878 if (sport->dma_is_enabled && sport->dma_is_txing)
879 ret = 0;
880
881 return ret;
882 }
883
884 static unsigned int imx_get_mctrl(struct uart_port *port)
885 {
886 struct imx_port *sport = (struct imx_port *)port;
887 unsigned int ret = imx_get_hwmctrl(sport);
888
889 mctrl_gpio_get(sport->gpios, &ret);
890
891 return ret;
892 }
893
894 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
895 {
896 struct imx_port *sport = (struct imx_port *)port;
897 unsigned long temp;
898
899 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
900 temp = readl(sport->port.membase + UCR2);
901 temp &= ~(UCR2_CTS | UCR2_CTSC);
902 if (mctrl & TIOCM_RTS)
903 temp |= UCR2_CTS | UCR2_CTSC;
904 writel(temp, sport->port.membase + UCR2);
905 }
906
907 temp = readl(sport->port.membase + UCR3) & ~UCR3_DSR;
908 if (!(mctrl & TIOCM_DTR))
909 temp |= UCR3_DSR;
910 writel(temp, sport->port.membase + UCR3);
911
912 temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
913 if (mctrl & TIOCM_LOOP)
914 temp |= UTS_LOOP;
915 writel(temp, sport->port.membase + uts_reg(sport));
916
917 mctrl_gpio_set(sport->gpios, mctrl);
918 }
919
920 /*
921 * Interrupts always disabled.
922 */
923 static void imx_break_ctl(struct uart_port *port, int break_state)
924 {
925 struct imx_port *sport = (struct imx_port *)port;
926 unsigned long flags, temp;
927
928 spin_lock_irqsave(&sport->port.lock, flags);
929
930 temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
931
932 if (break_state != 0)
933 temp |= UCR1_SNDBRK;
934
935 writel(temp, sport->port.membase + UCR1);
936
937 spin_unlock_irqrestore(&sport->port.lock, flags);
938 }
939
940 /*
941 * This is our per-port timeout handler, for checking the
942 * modem status signals.
943 */
944 static void imx_timeout(unsigned long data)
945 {
946 struct imx_port *sport = (struct imx_port *)data;
947 unsigned long flags;
948
949 if (sport->port.state) {
950 spin_lock_irqsave(&sport->port.lock, flags);
951 imx_mctrl_check(sport);
952 spin_unlock_irqrestore(&sport->port.lock, flags);
953
954 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
955 }
956 }
957
958 #define RX_BUF_SIZE (PAGE_SIZE)
959
960 /*
961 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
962 * [1] the RX DMA buffer is full.
963 * [2] the aging timer expires
964 *
965 * Condition [2] is triggered when a character has been sitting in the FIFO
966 * for at least 8 byte durations.
967 */
968 static void dma_rx_callback(void *data)
969 {
970 struct imx_port *sport = data;
971 struct dma_chan *chan = sport->dma_chan_rx;
972 struct scatterlist *sgl = &sport->rx_sgl;
973 struct tty_port *port = &sport->port.state->port;
974 struct dma_tx_state state;
975 struct circ_buf *rx_ring = &sport->rx_ring;
976 enum dma_status status;
977 unsigned int w_bytes = 0;
978 unsigned int r_bytes;
979 unsigned int bd_size;
980
981 status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
982
983 if (status == DMA_ERROR) {
984 dev_err(sport->port.dev, "DMA transaction error.\n");
985 clear_rx_errors(sport);
986 return;
987 }
988
989 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
990
991 /*
992 * The state-residue variable represents the empty space
993 * relative to the entire buffer. Taking this in consideration
994 * the head is always calculated base on the buffer total
995 * length - DMA transaction residue. The UART script from the
996 * SDMA firmware will jump to the next buffer descriptor,
997 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
998 * Taking this in consideration the tail is always at the
999 * beginning of the buffer descriptor that contains the head.
1000 */
1001
1002 /* Calculate the head */
1003 rx_ring->head = sg_dma_len(sgl) - state.residue;
1004
1005 /* Calculate the tail. */
1006 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1007 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1008
1009 if (rx_ring->head <= sg_dma_len(sgl) &&
1010 rx_ring->head > rx_ring->tail) {
1011
1012 /* Move data from tail to head */
1013 r_bytes = rx_ring->head - rx_ring->tail;
1014
1015 /* CPU claims ownership of RX DMA buffer */
1016 dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1017 DMA_FROM_DEVICE);
1018
1019 w_bytes = tty_insert_flip_string(port,
1020 sport->rx_buf + rx_ring->tail, r_bytes);
1021
1022 /* UART retrieves ownership of RX DMA buffer */
1023 dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1024 DMA_FROM_DEVICE);
1025
1026 if (w_bytes != r_bytes)
1027 sport->port.icount.buf_overrun++;
1028
1029 sport->port.icount.rx += w_bytes;
1030 } else {
1031 WARN_ON(rx_ring->head > sg_dma_len(sgl));
1032 WARN_ON(rx_ring->head <= rx_ring->tail);
1033 }
1034 }
1035
1036 if (w_bytes) {
1037 tty_flip_buffer_push(port);
1038 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1039 }
1040 }
1041
1042 /* RX DMA buffer periods */
1043 #define RX_DMA_PERIODS 4
1044
1045 static int start_rx_dma(struct imx_port *sport)
1046 {
1047 struct scatterlist *sgl = &sport->rx_sgl;
1048 struct dma_chan *chan = sport->dma_chan_rx;
1049 struct device *dev = sport->port.dev;
1050 struct dma_async_tx_descriptor *desc;
1051 int ret;
1052
1053 sport->rx_ring.head = 0;
1054 sport->rx_ring.tail = 0;
1055 sport->rx_periods = RX_DMA_PERIODS;
1056
1057 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1058 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1059 if (ret == 0) {
1060 dev_err(dev, "DMA mapping error for RX.\n");
1061 return -EINVAL;
1062 }
1063
1064 desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1065 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1066 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1067
1068 if (!desc) {
1069 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1070 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1071 return -EINVAL;
1072 }
1073 desc->callback = dma_rx_callback;
1074 desc->callback_param = sport;
1075
1076 dev_dbg(dev, "RX: prepare for the DMA.\n");
1077 sport->rx_cookie = dmaengine_submit(desc);
1078 dma_async_issue_pending(chan);
1079 return 0;
1080 }
1081
1082 static void clear_rx_errors(struct imx_port *sport)
1083 {
1084 unsigned int status_usr1, status_usr2;
1085
1086 status_usr1 = readl(sport->port.membase + USR1);
1087 status_usr2 = readl(sport->port.membase + USR2);
1088
1089 if (status_usr2 & USR2_BRCD) {
1090 sport->port.icount.brk++;
1091 writel(USR2_BRCD, sport->port.membase + USR2);
1092 } else if (status_usr1 & USR1_FRAMERR) {
1093 sport->port.icount.frame++;
1094 writel(USR1_FRAMERR, sport->port.membase + USR1);
1095 } else if (status_usr1 & USR1_PARITYERR) {
1096 sport->port.icount.parity++;
1097 writel(USR1_PARITYERR, sport->port.membase + USR1);
1098 }
1099
1100 if (status_usr2 & USR2_ORE) {
1101 sport->port.icount.overrun++;
1102 writel(USR2_ORE, sport->port.membase + USR2);
1103 }
1104
1105 }
1106
1107 #define TXTL_DEFAULT 2 /* reset default */
1108 #define RXTL_DEFAULT 1 /* reset default */
1109 #define TXTL_DMA 8 /* DMA burst setting */
1110 #define RXTL_DMA 9 /* DMA burst setting */
1111
1112 static void imx_setup_ufcr(struct imx_port *sport,
1113 unsigned char txwl, unsigned char rxwl)
1114 {
1115 unsigned int val;
1116
1117 /* set receiver / transmitter trigger level */
1118 val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1119 val |= txwl << UFCR_TXTL_SHF | rxwl;
1120 writel(val, sport->port.membase + UFCR);
1121 }
1122
1123 static void imx_uart_dma_exit(struct imx_port *sport)
1124 {
1125 if (sport->dma_chan_rx) {
1126 dmaengine_terminate_sync(sport->dma_chan_rx);
1127 dma_release_channel(sport->dma_chan_rx);
1128 sport->dma_chan_rx = NULL;
1129 sport->rx_cookie = -EINVAL;
1130 kfree(sport->rx_buf);
1131 sport->rx_buf = NULL;
1132 }
1133
1134 if (sport->dma_chan_tx) {
1135 dmaengine_terminate_sync(sport->dma_chan_tx);
1136 dma_release_channel(sport->dma_chan_tx);
1137 sport->dma_chan_tx = NULL;
1138 }
1139
1140 sport->dma_is_inited = 0;
1141 }
1142
1143 static int imx_uart_dma_init(struct imx_port *sport)
1144 {
1145 struct dma_slave_config slave_config = {};
1146 struct device *dev = sport->port.dev;
1147 int ret;
1148
1149 /* Prepare for RX : */
1150 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1151 if (!sport->dma_chan_rx) {
1152 dev_dbg(dev, "cannot get the DMA channel.\n");
1153 ret = -EINVAL;
1154 goto err;
1155 }
1156
1157 slave_config.direction = DMA_DEV_TO_MEM;
1158 slave_config.src_addr = sport->port.mapbase + URXD0;
1159 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1160 /* one byte less than the watermark level to enable the aging timer */
1161 slave_config.src_maxburst = RXTL_DMA - 1;
1162 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1163 if (ret) {
1164 dev_err(dev, "error in RX dma configuration.\n");
1165 goto err;
1166 }
1167
1168 sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1169 if (!sport->rx_buf) {
1170 ret = -ENOMEM;
1171 goto err;
1172 }
1173 sport->rx_ring.buf = sport->rx_buf;
1174
1175 /* Prepare for TX : */
1176 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1177 if (!sport->dma_chan_tx) {
1178 dev_err(dev, "cannot get the TX DMA channel!\n");
1179 ret = -EINVAL;
1180 goto err;
1181 }
1182
1183 slave_config.direction = DMA_MEM_TO_DEV;
1184 slave_config.dst_addr = sport->port.mapbase + URTX0;
1185 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1186 slave_config.dst_maxburst = TXTL_DMA;
1187 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1188 if (ret) {
1189 dev_err(dev, "error in TX dma configuration.");
1190 goto err;
1191 }
1192
1193 sport->dma_is_inited = 1;
1194
1195 return 0;
1196 err:
1197 imx_uart_dma_exit(sport);
1198 return ret;
1199 }
1200
1201 static void imx_enable_dma(struct imx_port *sport)
1202 {
1203 unsigned long temp;
1204
1205 init_waitqueue_head(&sport->dma_wait);
1206
1207 /* set UCR1 */
1208 temp = readl(sport->port.membase + UCR1);
1209 temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN;
1210 writel(temp, sport->port.membase + UCR1);
1211
1212 temp = readl(sport->port.membase + UCR2);
1213 temp |= UCR2_ATEN;
1214 writel(temp, sport->port.membase + UCR2);
1215
1216 imx_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1217
1218 sport->dma_is_enabled = 1;
1219 }
1220
1221 static void imx_disable_dma(struct imx_port *sport)
1222 {
1223 unsigned long temp;
1224
1225 /* clear UCR1 */
1226 temp = readl(sport->port.membase + UCR1);
1227 temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1228 writel(temp, sport->port.membase + UCR1);
1229
1230 /* clear UCR2 */
1231 temp = readl(sport->port.membase + UCR2);
1232 temp &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
1233 writel(temp, sport->port.membase + UCR2);
1234
1235 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1236
1237 sport->dma_is_enabled = 0;
1238 }
1239
1240 /* half the RX buffer size */
1241 #define CTSTL 16
1242
1243 static int imx_startup(struct uart_port *port)
1244 {
1245 struct imx_port *sport = (struct imx_port *)port;
1246 int retval, i;
1247 unsigned long flags, temp;
1248
1249 retval = clk_prepare_enable(sport->clk_per);
1250 if (retval)
1251 return retval;
1252 retval = clk_prepare_enable(sport->clk_ipg);
1253 if (retval) {
1254 clk_disable_unprepare(sport->clk_per);
1255 return retval;
1256 }
1257
1258 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1259
1260 /* disable the DREN bit (Data Ready interrupt enable) before
1261 * requesting IRQs
1262 */
1263 temp = readl(sport->port.membase + UCR4);
1264
1265 /* set the trigger level for CTS */
1266 temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1267 temp |= CTSTL << UCR4_CTSTL_SHF;
1268
1269 writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1270
1271 /* Can we enable the DMA support? */
1272 if (!uart_console(port) && !sport->dma_is_inited)
1273 imx_uart_dma_init(sport);
1274
1275 spin_lock_irqsave(&sport->port.lock, flags);
1276 /* Reset fifo's and state machines */
1277 i = 100;
1278
1279 temp = readl(sport->port.membase + UCR2);
1280 temp &= ~UCR2_SRST;
1281 writel(temp, sport->port.membase + UCR2);
1282
1283 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1284 udelay(1);
1285
1286 /*
1287 * Finally, clear and enable interrupts
1288 */
1289 writel(USR1_RTSD | USR1_DTRD, sport->port.membase + USR1);
1290 writel(USR2_ORE, sport->port.membase + USR2);
1291
1292 if (sport->dma_is_inited && !sport->dma_is_enabled)
1293 imx_enable_dma(sport);
1294
1295 temp = readl(sport->port.membase + UCR1);
1296 temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1297
1298 writel(temp, sport->port.membase + UCR1);
1299
1300 temp = readl(sport->port.membase + UCR4);
1301 temp |= UCR4_OREN;
1302 writel(temp, sport->port.membase + UCR4);
1303
1304 temp = readl(sport->port.membase + UCR2);
1305 temp |= (UCR2_RXEN | UCR2_TXEN);
1306 if (!sport->have_rtscts)
1307 temp |= UCR2_IRTS;
1308 /*
1309 * make sure the edge sensitive RTS-irq is disabled,
1310 * we're using RTSD instead.
1311 */
1312 if (!is_imx1_uart(sport))
1313 temp &= ~UCR2_RTSEN;
1314 writel(temp, sport->port.membase + UCR2);
1315
1316 if (!is_imx1_uart(sport)) {
1317 temp = readl(sport->port.membase + UCR3);
1318
1319 temp |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1320
1321 if (sport->dte_mode)
1322 /* disable broken interrupts */
1323 temp &= ~(UCR3_RI | UCR3_DCD);
1324
1325 writel(temp, sport->port.membase + UCR3);
1326 }
1327
1328 /*
1329 * Enable modem status interrupts
1330 */
1331 imx_enable_ms(&sport->port);
1332 spin_unlock_irqrestore(&sport->port.lock, flags);
1333
1334 return 0;
1335 }
1336
1337 static void imx_shutdown(struct uart_port *port)
1338 {
1339 struct imx_port *sport = (struct imx_port *)port;
1340 unsigned long temp;
1341 unsigned long flags;
1342
1343 if (sport->dma_is_enabled) {
1344 sport->dma_is_rxing = 0;
1345 sport->dma_is_txing = 0;
1346 dmaengine_terminate_sync(sport->dma_chan_tx);
1347 dmaengine_terminate_sync(sport->dma_chan_rx);
1348
1349 spin_lock_irqsave(&sport->port.lock, flags);
1350 imx_stop_tx(port);
1351 imx_stop_rx(port);
1352 imx_disable_dma(sport);
1353 spin_unlock_irqrestore(&sport->port.lock, flags);
1354 imx_uart_dma_exit(sport);
1355 }
1356
1357 mctrl_gpio_disable_ms(sport->gpios);
1358
1359 spin_lock_irqsave(&sport->port.lock, flags);
1360 temp = readl(sport->port.membase + UCR2);
1361 temp &= ~(UCR2_TXEN);
1362 writel(temp, sport->port.membase + UCR2);
1363 spin_unlock_irqrestore(&sport->port.lock, flags);
1364
1365 /*
1366 * Stop our timer.
1367 */
1368 del_timer_sync(&sport->timer);
1369
1370 /*
1371 * Disable all interrupts, port and break condition.
1372 */
1373
1374 spin_lock_irqsave(&sport->port.lock, flags);
1375 temp = readl(sport->port.membase + UCR1);
1376 temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1377
1378 writel(temp, sport->port.membase + UCR1);
1379 spin_unlock_irqrestore(&sport->port.lock, flags);
1380
1381 clk_disable_unprepare(sport->clk_per);
1382 clk_disable_unprepare(sport->clk_ipg);
1383 }
1384
1385 static void imx_flush_buffer(struct uart_port *port)
1386 {
1387 struct imx_port *sport = (struct imx_port *)port;
1388 struct scatterlist *sgl = &sport->tx_sgl[0];
1389 unsigned long temp;
1390 int i = 100, ubir, ubmr, uts;
1391
1392 if (!sport->dma_chan_tx)
1393 return;
1394
1395 sport->tx_bytes = 0;
1396 dmaengine_terminate_all(sport->dma_chan_tx);
1397 if (sport->dma_is_txing) {
1398 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1399 DMA_TO_DEVICE);
1400 temp = readl(sport->port.membase + UCR1);
1401 temp &= ~UCR1_TDMAEN;
1402 writel(temp, sport->port.membase + UCR1);
1403 sport->dma_is_txing = false;
1404 }
1405
1406 /*
1407 * According to the Reference Manual description of the UART SRST bit:
1408 * "Reset the transmit and receive state machines,
1409 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1410 * and UTS[6-3]". As we don't need to restore the old values from
1411 * USR1, USR2, URXD, UTXD, only save/restore the other four registers
1412 */
1413 ubir = readl(sport->port.membase + UBIR);
1414 ubmr = readl(sport->port.membase + UBMR);
1415 uts = readl(sport->port.membase + IMX21_UTS);
1416
1417 temp = readl(sport->port.membase + UCR2);
1418 temp &= ~UCR2_SRST;
1419 writel(temp, sport->port.membase + UCR2);
1420
1421 while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1422 udelay(1);
1423
1424 /* Restore the registers */
1425 writel(ubir, sport->port.membase + UBIR);
1426 writel(ubmr, sport->port.membase + UBMR);
1427 writel(uts, sport->port.membase + IMX21_UTS);
1428 }
1429
1430 static void
1431 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1432 struct ktermios *old)
1433 {
1434 struct imx_port *sport = (struct imx_port *)port;
1435 unsigned long flags;
1436 unsigned long ucr2, old_ucr1, old_ucr2;
1437 unsigned int baud, quot;
1438 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1439 unsigned long div, ufcr;
1440 unsigned long num, denom;
1441 uint64_t tdiv64;
1442
1443 /*
1444 * We only support CS7 and CS8.
1445 */
1446 while ((termios->c_cflag & CSIZE) != CS7 &&
1447 (termios->c_cflag & CSIZE) != CS8) {
1448 termios->c_cflag &= ~CSIZE;
1449 termios->c_cflag |= old_csize;
1450 old_csize = CS8;
1451 }
1452
1453 if ((termios->c_cflag & CSIZE) == CS8)
1454 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1455 else
1456 ucr2 = UCR2_SRST | UCR2_IRTS;
1457
1458 if (termios->c_cflag & CRTSCTS) {
1459 if (sport->have_rtscts) {
1460 ucr2 &= ~UCR2_IRTS;
1461
1462 if (port->rs485.flags & SER_RS485_ENABLED) {
1463 /*
1464 * RTS is mandatory for rs485 operation, so keep
1465 * it under manual control and keep transmitter
1466 * disabled.
1467 */
1468 if (port->rs485.flags &
1469 SER_RS485_RTS_AFTER_SEND)
1470 imx_port_rts_inactive(sport, &ucr2);
1471 else
1472 imx_port_rts_active(sport, &ucr2);
1473 } else {
1474 imx_port_rts_auto(sport, &ucr2);
1475 }
1476 } else {
1477 termios->c_cflag &= ~CRTSCTS;
1478 }
1479 } else if (port->rs485.flags & SER_RS485_ENABLED) {
1480 /* disable transmitter */
1481 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1482 imx_port_rts_inactive(sport, &ucr2);
1483 else
1484 imx_port_rts_active(sport, &ucr2);
1485 }
1486
1487
1488 if (termios->c_cflag & CSTOPB)
1489 ucr2 |= UCR2_STPB;
1490 if (termios->c_cflag & PARENB) {
1491 ucr2 |= UCR2_PREN;
1492 if (termios->c_cflag & PARODD)
1493 ucr2 |= UCR2_PROE;
1494 }
1495
1496 del_timer_sync(&sport->timer);
1497
1498 /*
1499 * Ask the core to calculate the divisor for us.
1500 */
1501 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1502 quot = uart_get_divisor(port, baud);
1503
1504 spin_lock_irqsave(&sport->port.lock, flags);
1505
1506 sport->port.read_status_mask = 0;
1507 if (termios->c_iflag & INPCK)
1508 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1509 if (termios->c_iflag & (BRKINT | PARMRK))
1510 sport->port.read_status_mask |= URXD_BRK;
1511
1512 /*
1513 * Characters to ignore
1514 */
1515 sport->port.ignore_status_mask = 0;
1516 if (termios->c_iflag & IGNPAR)
1517 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1518 if (termios->c_iflag & IGNBRK) {
1519 sport->port.ignore_status_mask |= URXD_BRK;
1520 /*
1521 * If we're ignoring parity and break indicators,
1522 * ignore overruns too (for real raw support).
1523 */
1524 if (termios->c_iflag & IGNPAR)
1525 sport->port.ignore_status_mask |= URXD_OVRRUN;
1526 }
1527
1528 if ((termios->c_cflag & CREAD) == 0)
1529 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1530
1531 /*
1532 * Update the per-port timeout.
1533 */
1534 uart_update_timeout(port, termios->c_cflag, baud);
1535
1536 /*
1537 * disable interrupts and drain transmitter
1538 */
1539 old_ucr1 = readl(sport->port.membase + UCR1);
1540 writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1541 sport->port.membase + UCR1);
1542
1543 while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1544 barrier();
1545
1546 /* then, disable everything */
1547 old_ucr2 = readl(sport->port.membase + UCR2);
1548 writel(old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN),
1549 sport->port.membase + UCR2);
1550 old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
1551
1552 /* custom-baudrate handling */
1553 div = sport->port.uartclk / (baud * 16);
1554 if (baud == 38400 && quot != div)
1555 baud = sport->port.uartclk / (quot * 16);
1556
1557 div = sport->port.uartclk / (baud * 16);
1558 if (div > 7)
1559 div = 7;
1560 if (!div)
1561 div = 1;
1562
1563 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1564 1 << 16, 1 << 16, &num, &denom);
1565
1566 tdiv64 = sport->port.uartclk;
1567 tdiv64 *= num;
1568 do_div(tdiv64, denom * 16 * div);
1569 tty_termios_encode_baud_rate(termios,
1570 (speed_t)tdiv64, (speed_t)tdiv64);
1571
1572 num -= 1;
1573 denom -= 1;
1574
1575 ufcr = readl(sport->port.membase + UFCR);
1576 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1577 writel(ufcr, sport->port.membase + UFCR);
1578
1579 writel(num, sport->port.membase + UBIR);
1580 writel(denom, sport->port.membase + UBMR);
1581
1582 if (!is_imx1_uart(sport))
1583 writel(sport->port.uartclk / div / 1000,
1584 sport->port.membase + IMX21_ONEMS);
1585
1586 writel(old_ucr1, sport->port.membase + UCR1);
1587
1588 /* set the parity, stop bits and data size */
1589 writel(ucr2 | old_ucr2, sport->port.membase + UCR2);
1590
1591 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1592 imx_enable_ms(&sport->port);
1593
1594 spin_unlock_irqrestore(&sport->port.lock, flags);
1595 }
1596
1597 static const char *imx_type(struct uart_port *port)
1598 {
1599 struct imx_port *sport = (struct imx_port *)port;
1600
1601 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1602 }
1603
1604 /*
1605 * Configure/autoconfigure the port.
1606 */
1607 static void imx_config_port(struct uart_port *port, int flags)
1608 {
1609 struct imx_port *sport = (struct imx_port *)port;
1610
1611 if (flags & UART_CONFIG_TYPE)
1612 sport->port.type = PORT_IMX;
1613 }
1614
1615 /*
1616 * Verify the new serial_struct (for TIOCSSERIAL).
1617 * The only change we allow are to the flags and type, and
1618 * even then only between PORT_IMX and PORT_UNKNOWN
1619 */
1620 static int
1621 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1622 {
1623 struct imx_port *sport = (struct imx_port *)port;
1624 int ret = 0;
1625
1626 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1627 ret = -EINVAL;
1628 if (sport->port.irq != ser->irq)
1629 ret = -EINVAL;
1630 if (ser->io_type != UPIO_MEM)
1631 ret = -EINVAL;
1632 if (sport->port.uartclk / 16 != ser->baud_base)
1633 ret = -EINVAL;
1634 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1635 ret = -EINVAL;
1636 if (sport->port.iobase != ser->port)
1637 ret = -EINVAL;
1638 if (ser->hub6 != 0)
1639 ret = -EINVAL;
1640 return ret;
1641 }
1642
1643 #if defined(CONFIG_CONSOLE_POLL)
1644
1645 static int imx_poll_init(struct uart_port *port)
1646 {
1647 struct imx_port *sport = (struct imx_port *)port;
1648 unsigned long flags;
1649 unsigned long temp;
1650 int retval;
1651
1652 retval = clk_prepare_enable(sport->clk_ipg);
1653 if (retval)
1654 return retval;
1655 retval = clk_prepare_enable(sport->clk_per);
1656 if (retval)
1657 clk_disable_unprepare(sport->clk_ipg);
1658
1659 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1660
1661 spin_lock_irqsave(&sport->port.lock, flags);
1662
1663 temp = readl(sport->port.membase + UCR1);
1664 if (is_imx1_uart(sport))
1665 temp |= IMX1_UCR1_UARTCLKEN;
1666 temp |= UCR1_UARTEN | UCR1_RRDYEN;
1667 temp &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN);
1668 writel(temp, sport->port.membase + UCR1);
1669
1670 temp = readl(sport->port.membase + UCR2);
1671 temp |= UCR2_RXEN;
1672 writel(temp, sport->port.membase + UCR2);
1673
1674 spin_unlock_irqrestore(&sport->port.lock, flags);
1675
1676 return 0;
1677 }
1678
1679 static int imx_poll_get_char(struct uart_port *port)
1680 {
1681 if (!(readl_relaxed(port->membase + USR2) & USR2_RDR))
1682 return NO_POLL_CHAR;
1683
1684 return readl_relaxed(port->membase + URXD0) & URXD_RX_DATA;
1685 }
1686
1687 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1688 {
1689 unsigned int status;
1690
1691 /* drain */
1692 do {
1693 status = readl_relaxed(port->membase + USR1);
1694 } while (~status & USR1_TRDY);
1695
1696 /* write */
1697 writel_relaxed(c, port->membase + URTX0);
1698
1699 /* flush */
1700 do {
1701 status = readl_relaxed(port->membase + USR2);
1702 } while (~status & USR2_TXDC);
1703 }
1704 #endif
1705
1706 static int imx_rs485_config(struct uart_port *port,
1707 struct serial_rs485 *rs485conf)
1708 {
1709 struct imx_port *sport = (struct imx_port *)port;
1710 unsigned long temp;
1711
1712 /* unimplemented */
1713 rs485conf->delay_rts_before_send = 0;
1714 rs485conf->delay_rts_after_send = 0;
1715
1716 /* RTS is required to control the transmitter */
1717 if (!sport->have_rtscts)
1718 rs485conf->flags &= ~SER_RS485_ENABLED;
1719
1720 if (rs485conf->flags & SER_RS485_ENABLED) {
1721 /* disable transmitter */
1722 temp = readl(sport->port.membase + UCR2);
1723 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1724 imx_port_rts_inactive(sport, &temp);
1725 else
1726 imx_port_rts_active(sport, &temp);
1727 writel(temp, sport->port.membase + UCR2);
1728 }
1729
1730 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1731 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1732 rs485conf->flags & SER_RS485_RX_DURING_TX) {
1733 temp = readl(sport->port.membase + UCR2);
1734 temp |= UCR2_RXEN;
1735 writel(temp, sport->port.membase + UCR2);
1736 }
1737
1738 port->rs485 = *rs485conf;
1739
1740 return 0;
1741 }
1742
1743 static const struct uart_ops imx_pops = {
1744 .tx_empty = imx_tx_empty,
1745 .set_mctrl = imx_set_mctrl,
1746 .get_mctrl = imx_get_mctrl,
1747 .stop_tx = imx_stop_tx,
1748 .start_tx = imx_start_tx,
1749 .stop_rx = imx_stop_rx,
1750 .enable_ms = imx_enable_ms,
1751 .break_ctl = imx_break_ctl,
1752 .startup = imx_startup,
1753 .shutdown = imx_shutdown,
1754 .flush_buffer = imx_flush_buffer,
1755 .set_termios = imx_set_termios,
1756 .type = imx_type,
1757 .config_port = imx_config_port,
1758 .verify_port = imx_verify_port,
1759 #if defined(CONFIG_CONSOLE_POLL)
1760 .poll_init = imx_poll_init,
1761 .poll_get_char = imx_poll_get_char,
1762 .poll_put_char = imx_poll_put_char,
1763 #endif
1764 };
1765
1766 static struct imx_port *imx_ports[UART_NR];
1767
1768 #ifdef CONFIG_SERIAL_IMX_CONSOLE
1769 static void imx_console_putchar(struct uart_port *port, int ch)
1770 {
1771 struct imx_port *sport = (struct imx_port *)port;
1772
1773 while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1774 barrier();
1775
1776 writel(ch, sport->port.membase + URTX0);
1777 }
1778
1779 /*
1780 * Interrupts are disabled on entering
1781 */
1782 static void
1783 imx_console_write(struct console *co, const char *s, unsigned int count)
1784 {
1785 struct imx_port *sport = imx_ports[co->index];
1786 struct imx_port_ucrs old_ucr;
1787 unsigned int ucr1;
1788 unsigned long flags = 0;
1789 int locked = 1;
1790 int retval;
1791
1792 retval = clk_enable(sport->clk_per);
1793 if (retval)
1794 return;
1795 retval = clk_enable(sport->clk_ipg);
1796 if (retval) {
1797 clk_disable(sport->clk_per);
1798 return;
1799 }
1800
1801 if (sport->port.sysrq)
1802 locked = 0;
1803 else if (oops_in_progress)
1804 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1805 else
1806 spin_lock_irqsave(&sport->port.lock, flags);
1807
1808 /*
1809 * First, save UCR1/2/3 and then disable interrupts
1810 */
1811 imx_port_ucrs_save(&sport->port, &old_ucr);
1812 ucr1 = old_ucr.ucr1;
1813
1814 if (is_imx1_uart(sport))
1815 ucr1 |= IMX1_UCR1_UARTCLKEN;
1816 ucr1 |= UCR1_UARTEN;
1817 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1818
1819 writel(ucr1, sport->port.membase + UCR1);
1820
1821 writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1822
1823 uart_console_write(&sport->port, s, count, imx_console_putchar);
1824
1825 /*
1826 * Finally, wait for transmitter to become empty
1827 * and restore UCR1/2/3
1828 */
1829 while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1830
1831 imx_port_ucrs_restore(&sport->port, &old_ucr);
1832
1833 if (locked)
1834 spin_unlock_irqrestore(&sport->port.lock, flags);
1835
1836 clk_disable(sport->clk_ipg);
1837 clk_disable(sport->clk_per);
1838 }
1839
1840 /*
1841 * If the port was already initialised (eg, by a boot loader),
1842 * try to determine the current setup.
1843 */
1844 static void __init
1845 imx_console_get_options(struct imx_port *sport, int *baud,
1846 int *parity, int *bits)
1847 {
1848
1849 if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1850 /* ok, the port was enabled */
1851 unsigned int ucr2, ubir, ubmr, uartclk;
1852 unsigned int baud_raw;
1853 unsigned int ucfr_rfdiv;
1854
1855 ucr2 = readl(sport->port.membase + UCR2);
1856
1857 *parity = 'n';
1858 if (ucr2 & UCR2_PREN) {
1859 if (ucr2 & UCR2_PROE)
1860 *parity = 'o';
1861 else
1862 *parity = 'e';
1863 }
1864
1865 if (ucr2 & UCR2_WS)
1866 *bits = 8;
1867 else
1868 *bits = 7;
1869
1870 ubir = readl(sport->port.membase + UBIR) & 0xffff;
1871 ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1872
1873 ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1874 if (ucfr_rfdiv == 6)
1875 ucfr_rfdiv = 7;
1876 else
1877 ucfr_rfdiv = 6 - ucfr_rfdiv;
1878
1879 uartclk = clk_get_rate(sport->clk_per);
1880 uartclk /= ucfr_rfdiv;
1881
1882 { /*
1883 * The next code provides exact computation of
1884 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1885 * without need of float support or long long division,
1886 * which would be required to prevent 32bit arithmetic overflow
1887 */
1888 unsigned int mul = ubir + 1;
1889 unsigned int div = 16 * (ubmr + 1);
1890 unsigned int rem = uartclk % div;
1891
1892 baud_raw = (uartclk / div) * mul;
1893 baud_raw += (rem * mul + div / 2) / div;
1894 *baud = (baud_raw + 50) / 100 * 100;
1895 }
1896
1897 if (*baud != baud_raw)
1898 pr_info("Console IMX rounded baud rate from %d to %d\n",
1899 baud_raw, *baud);
1900 }
1901 }
1902
1903 static int __init
1904 imx_console_setup(struct console *co, char *options)
1905 {
1906 struct imx_port *sport;
1907 int baud = 9600;
1908 int bits = 8;
1909 int parity = 'n';
1910 int flow = 'n';
1911 int retval;
1912
1913 /*
1914 * Check whether an invalid uart number has been specified, and
1915 * if so, search for the first available port that does have
1916 * console support.
1917 */
1918 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1919 co->index = 0;
1920 sport = imx_ports[co->index];
1921 if (sport == NULL)
1922 return -ENODEV;
1923
1924 /* For setting the registers, we only need to enable the ipg clock. */
1925 retval = clk_prepare_enable(sport->clk_ipg);
1926 if (retval)
1927 goto error_console;
1928
1929 if (options)
1930 uart_parse_options(options, &baud, &parity, &bits, &flow);
1931 else
1932 imx_console_get_options(sport, &baud, &parity, &bits);
1933
1934 imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1935
1936 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1937
1938 clk_disable(sport->clk_ipg);
1939 if (retval) {
1940 clk_unprepare(sport->clk_ipg);
1941 goto error_console;
1942 }
1943
1944 retval = clk_prepare(sport->clk_per);
1945 if (retval)
1946 clk_disable_unprepare(sport->clk_ipg);
1947
1948 error_console:
1949 return retval;
1950 }
1951
1952 static struct uart_driver imx_reg;
1953 static struct console imx_console = {
1954 .name = DEV_NAME,
1955 .write = imx_console_write,
1956 .device = uart_console_device,
1957 .setup = imx_console_setup,
1958 .flags = CON_PRINTBUFFER,
1959 .index = -1,
1960 .data = &imx_reg,
1961 };
1962
1963 #define IMX_CONSOLE &imx_console
1964
1965 #ifdef CONFIG_OF
1966 static void imx_console_early_putchar(struct uart_port *port, int ch)
1967 {
1968 while (readl_relaxed(port->membase + IMX21_UTS) & UTS_TXFULL)
1969 cpu_relax();
1970
1971 writel_relaxed(ch, port->membase + URTX0);
1972 }
1973
1974 static void imx_console_early_write(struct console *con, const char *s,
1975 unsigned count)
1976 {
1977 struct earlycon_device *dev = con->data;
1978
1979 uart_console_write(&dev->port, s, count, imx_console_early_putchar);
1980 }
1981
1982 static int __init
1983 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
1984 {
1985 if (!dev->port.membase)
1986 return -ENODEV;
1987
1988 dev->con->write = imx_console_early_write;
1989
1990 return 0;
1991 }
1992 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
1993 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
1994 #endif
1995
1996 #else
1997 #define IMX_CONSOLE NULL
1998 #endif
1999
2000 static struct uart_driver imx_reg = {
2001 .owner = THIS_MODULE,
2002 .driver_name = DRIVER_NAME,
2003 .dev_name = DEV_NAME,
2004 .major = SERIAL_IMX_MAJOR,
2005 .minor = MINOR_START,
2006 .nr = ARRAY_SIZE(imx_ports),
2007 .cons = IMX_CONSOLE,
2008 };
2009
2010 #ifdef CONFIG_OF
2011 /*
2012 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2013 * could successfully get all information from dt or a negative errno.
2014 */
2015 static int serial_imx_probe_dt(struct imx_port *sport,
2016 struct platform_device *pdev)
2017 {
2018 struct device_node *np = pdev->dev.of_node;
2019 int ret;
2020
2021 sport->devdata = of_device_get_match_data(&pdev->dev);
2022 if (!sport->devdata)
2023 /* no device tree device */
2024 return 1;
2025
2026 ret = of_alias_get_id(np, "serial");
2027 if (ret < 0) {
2028 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2029 return ret;
2030 }
2031 sport->port.line = ret;
2032
2033 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2034 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2035 sport->have_rtscts = 1;
2036
2037 if (of_get_property(np, "fsl,dte-mode", NULL))
2038 sport->dte_mode = 1;
2039
2040 return 0;
2041 }
2042 #else
2043 static inline int serial_imx_probe_dt(struct imx_port *sport,
2044 struct platform_device *pdev)
2045 {
2046 return 1;
2047 }
2048 #endif
2049
2050 static void serial_imx_probe_pdata(struct imx_port *sport,
2051 struct platform_device *pdev)
2052 {
2053 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2054
2055 sport->port.line = pdev->id;
2056 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
2057
2058 if (!pdata)
2059 return;
2060
2061 if (pdata->flags & IMXUART_HAVE_RTSCTS)
2062 sport->have_rtscts = 1;
2063 }
2064
2065 static int serial_imx_probe(struct platform_device *pdev)
2066 {
2067 struct imx_port *sport;
2068 void __iomem *base;
2069 int ret = 0, reg;
2070 struct resource *res;
2071 int txirq, rxirq, rtsirq;
2072
2073 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2074 if (!sport)
2075 return -ENOMEM;
2076
2077 ret = serial_imx_probe_dt(sport, pdev);
2078 if (ret > 0)
2079 serial_imx_probe_pdata(sport, pdev);
2080 else if (ret < 0)
2081 return ret;
2082
2083 if (sport->port.line >= ARRAY_SIZE(imx_ports)) {
2084 dev_err(&pdev->dev, "serial%d out of range\n",
2085 sport->port.line);
2086 return -EINVAL;
2087 }
2088
2089 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2090 base = devm_ioremap_resource(&pdev->dev, res);
2091 if (IS_ERR(base))
2092 return PTR_ERR(base);
2093
2094 rxirq = platform_get_irq(pdev, 0);
2095 txirq = platform_get_irq(pdev, 1);
2096 rtsirq = platform_get_irq(pdev, 2);
2097
2098 sport->port.dev = &pdev->dev;
2099 sport->port.mapbase = res->start;
2100 sport->port.membase = base;
2101 sport->port.type = PORT_IMX,
2102 sport->port.iotype = UPIO_MEM;
2103 sport->port.irq = rxirq;
2104 sport->port.fifosize = 32;
2105 sport->port.ops = &imx_pops;
2106 sport->port.rs485_config = imx_rs485_config;
2107 sport->port.rs485.flags =
2108 SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX;
2109 sport->port.flags = UPF_BOOT_AUTOCONF;
2110 init_timer(&sport->timer);
2111 sport->timer.function = imx_timeout;
2112 sport->timer.data = (unsigned long)sport;
2113
2114 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2115 if (IS_ERR(sport->gpios))
2116 return PTR_ERR(sport->gpios);
2117
2118 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2119 if (IS_ERR(sport->clk_ipg)) {
2120 ret = PTR_ERR(sport->clk_ipg);
2121 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2122 return ret;
2123 }
2124
2125 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2126 if (IS_ERR(sport->clk_per)) {
2127 ret = PTR_ERR(sport->clk_per);
2128 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2129 return ret;
2130 }
2131
2132 sport->port.uartclk = clk_get_rate(sport->clk_per);
2133
2134 /* For register access, we only need to enable the ipg clock. */
2135 ret = clk_prepare_enable(sport->clk_ipg);
2136 if (ret) {
2137 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2138 return ret;
2139 }
2140
2141 /* Disable interrupts before requesting them */
2142 reg = readl_relaxed(sport->port.membase + UCR1);
2143 reg &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2144 UCR1_TXMPTYEN | UCR1_RTSDEN);
2145 writel_relaxed(reg, sport->port.membase + UCR1);
2146
2147 if (!is_imx1_uart(sport) && sport->dte_mode) {
2148 /*
2149 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2150 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2151 * and DCD (when they are outputs) or enables the respective
2152 * irqs. So set this bit early, i.e. before requesting irqs.
2153 */
2154 reg = readl(sport->port.membase + UFCR);
2155 if (!(reg & UFCR_DCEDTE))
2156 writel(reg | UFCR_DCEDTE, sport->port.membase + UFCR);
2157
2158 /*
2159 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2160 * enabled later because they cannot be cleared
2161 * (confirmed on i.MX25) which makes them unusable.
2162 */
2163 writel(IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2164 sport->port.membase + UCR3);
2165
2166 } else {
2167 unsigned long ucr3 = UCR3_DSR;
2168
2169 reg = readl(sport->port.membase + UFCR);
2170 if (reg & UFCR_DCEDTE)
2171 writel(reg & ~UFCR_DCEDTE, sport->port.membase + UFCR);
2172
2173 if (!is_imx1_uart(sport))
2174 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2175 writel(ucr3, sport->port.membase + UCR3);
2176 }
2177
2178 clk_disable_unprepare(sport->clk_ipg);
2179
2180 /*
2181 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2182 * chips only have one interrupt.
2183 */
2184 if (txirq > 0) {
2185 ret = devm_request_irq(&pdev->dev, rxirq, imx_rxint, 0,
2186 dev_name(&pdev->dev), sport);
2187 if (ret) {
2188 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2189 ret);
2190 return ret;
2191 }
2192
2193 ret = devm_request_irq(&pdev->dev, txirq, imx_txint, 0,
2194 dev_name(&pdev->dev), sport);
2195 if (ret) {
2196 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2197 ret);
2198 return ret;
2199 }
2200 } else {
2201 ret = devm_request_irq(&pdev->dev, rxirq, imx_int, 0,
2202 dev_name(&pdev->dev), sport);
2203 if (ret) {
2204 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2205 return ret;
2206 }
2207 }
2208
2209 imx_ports[sport->port.line] = sport;
2210
2211 platform_set_drvdata(pdev, sport);
2212
2213 return uart_add_one_port(&imx_reg, &sport->port);
2214 }
2215
2216 static int serial_imx_remove(struct platform_device *pdev)
2217 {
2218 struct imx_port *sport = platform_get_drvdata(pdev);
2219
2220 return uart_remove_one_port(&imx_reg, &sport->port);
2221 }
2222
2223 static void serial_imx_restore_context(struct imx_port *sport)
2224 {
2225 if (!sport->context_saved)
2226 return;
2227
2228 writel(sport->saved_reg[4], sport->port.membase + UFCR);
2229 writel(sport->saved_reg[5], sport->port.membase + UESC);
2230 writel(sport->saved_reg[6], sport->port.membase + UTIM);
2231 writel(sport->saved_reg[7], sport->port.membase + UBIR);
2232 writel(sport->saved_reg[8], sport->port.membase + UBMR);
2233 writel(sport->saved_reg[9], sport->port.membase + IMX21_UTS);
2234 writel(sport->saved_reg[0], sport->port.membase + UCR1);
2235 writel(sport->saved_reg[1] | UCR2_SRST, sport->port.membase + UCR2);
2236 writel(sport->saved_reg[2], sport->port.membase + UCR3);
2237 writel(sport->saved_reg[3], sport->port.membase + UCR4);
2238 sport->context_saved = false;
2239 }
2240
2241 static void serial_imx_save_context(struct imx_port *sport)
2242 {
2243 /* Save necessary regs */
2244 sport->saved_reg[0] = readl(sport->port.membase + UCR1);
2245 sport->saved_reg[1] = readl(sport->port.membase + UCR2);
2246 sport->saved_reg[2] = readl(sport->port.membase + UCR3);
2247 sport->saved_reg[3] = readl(sport->port.membase + UCR4);
2248 sport->saved_reg[4] = readl(sport->port.membase + UFCR);
2249 sport->saved_reg[5] = readl(sport->port.membase + UESC);
2250 sport->saved_reg[6] = readl(sport->port.membase + UTIM);
2251 sport->saved_reg[7] = readl(sport->port.membase + UBIR);
2252 sport->saved_reg[8] = readl(sport->port.membase + UBMR);
2253 sport->saved_reg[9] = readl(sport->port.membase + IMX21_UTS);
2254 sport->context_saved = true;
2255 }
2256
2257 static void serial_imx_enable_wakeup(struct imx_port *sport, bool on)
2258 {
2259 unsigned int val;
2260
2261 val = readl(sport->port.membase + UCR3);
2262 if (on)
2263 val |= UCR3_AWAKEN;
2264 else
2265 val &= ~UCR3_AWAKEN;
2266 writel(val, sport->port.membase + UCR3);
2267
2268 if (sport->have_rtscts) {
2269 val = readl(sport->port.membase + UCR1);
2270 if (on)
2271 val |= UCR1_RTSDEN;
2272 else
2273 val &= ~UCR1_RTSDEN;
2274 writel(val, sport->port.membase + UCR1);
2275 }
2276 }
2277
2278 static int imx_serial_port_suspend_noirq(struct device *dev)
2279 {
2280 struct platform_device *pdev = to_platform_device(dev);
2281 struct imx_port *sport = platform_get_drvdata(pdev);
2282 int ret;
2283
2284 ret = clk_enable(sport->clk_ipg);
2285 if (ret)
2286 return ret;
2287
2288 serial_imx_save_context(sport);
2289
2290 clk_disable(sport->clk_ipg);
2291
2292 return 0;
2293 }
2294
2295 static int imx_serial_port_resume_noirq(struct device *dev)
2296 {
2297 struct platform_device *pdev = to_platform_device(dev);
2298 struct imx_port *sport = platform_get_drvdata(pdev);
2299 int ret;
2300
2301 ret = clk_enable(sport->clk_ipg);
2302 if (ret)
2303 return ret;
2304
2305 serial_imx_restore_context(sport);
2306
2307 clk_disable(sport->clk_ipg);
2308
2309 return 0;
2310 }
2311
2312 static int imx_serial_port_suspend(struct device *dev)
2313 {
2314 struct platform_device *pdev = to_platform_device(dev);
2315 struct imx_port *sport = platform_get_drvdata(pdev);
2316
2317 /* enable wakeup from i.MX UART */
2318 serial_imx_enable_wakeup(sport, true);
2319
2320 uart_suspend_port(&imx_reg, &sport->port);
2321
2322 /* Needed to enable clock in suspend_noirq */
2323 return clk_prepare(sport->clk_ipg);
2324 }
2325
2326 static int imx_serial_port_resume(struct device *dev)
2327 {
2328 struct platform_device *pdev = to_platform_device(dev);
2329 struct imx_port *sport = platform_get_drvdata(pdev);
2330
2331 /* disable wakeup from i.MX UART */
2332 serial_imx_enable_wakeup(sport, false);
2333
2334 uart_resume_port(&imx_reg, &sport->port);
2335
2336 clk_unprepare(sport->clk_ipg);
2337
2338 return 0;
2339 }
2340
2341 static const struct dev_pm_ops imx_serial_port_pm_ops = {
2342 .suspend_noirq = imx_serial_port_suspend_noirq,
2343 .resume_noirq = imx_serial_port_resume_noirq,
2344 .suspend = imx_serial_port_suspend,
2345 .resume = imx_serial_port_resume,
2346 };
2347
2348 static struct platform_driver serial_imx_driver = {
2349 .probe = serial_imx_probe,
2350 .remove = serial_imx_remove,
2351
2352 .id_table = imx_uart_devtype,
2353 .driver = {
2354 .name = "imx-uart",
2355 .of_match_table = imx_uart_dt_ids,
2356 .pm = &imx_serial_port_pm_ops,
2357 },
2358 };
2359
2360 static int __init imx_serial_init(void)
2361 {
2362 int ret = uart_register_driver(&imx_reg);
2363
2364 if (ret)
2365 return ret;
2366
2367 ret = platform_driver_register(&serial_imx_driver);
2368 if (ret != 0)
2369 uart_unregister_driver(&imx_reg);
2370
2371 return ret;
2372 }
2373
2374 static void __exit imx_serial_exit(void)
2375 {
2376 platform_driver_unregister(&serial_imx_driver);
2377 uart_unregister_driver(&imx_reg);
2378 }
2379
2380 module_init(imx_serial_init);
2381 module_exit(imx_serial_exit);
2382
2383 MODULE_AUTHOR("Sascha Hauer");
2384 MODULE_DESCRIPTION("IMX generic serial port driver");
2385 MODULE_LICENSE("GPL");
2386 MODULE_ALIAS("platform:imx-uart");
Linux with added FPC-III support