1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Driver for Motorola/Freescale IMX serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Author: Sascha Hauer <sascha@saschahauer.de>
8 * Copyright (C) 2004 Pengutronix
9 */
10
11 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
12 #define SUPPORT_SYSRQ
13 #endif
14
15 #include <linux/module.h>
16 #include <linux/ioport.h>
17 #include <linux/init.h>
18 #include <linux/console.h>
19 #include <linux/sysrq.h>
20 #include <linux/platform_device.h>
21 #include <linux/tty.h>
22 #include <linux/tty_flip.h>
23 #include <linux/serial_core.h>
24 #include <linux/serial.h>
25 #include <linux/clk.h>
26 #include <linux/delay.h>
27 #include <linux/pinctrl/consumer.h>
28 #include <linux/rational.h>
29 #include <linux/slab.h>
30 #include <linux/of.h>
31 #include <linux/of_device.h>
32 #include <linux/io.h>
33 #include <linux/dma-mapping.h>
34
35 #include <asm/irq.h>
36 #include <linux/platform_data/serial-imx.h>
37 #include <linux/platform_data/dma-imx.h>
38
39 #include "serial_mctrl_gpio.h"
40
41 /* Register definitions */
42 #define URXD0 0x0 /* Receiver Register */
43 #define URTX0 0x40 /* Transmitter Register */
44 #define UCR1 0x80 /* Control Register 1 */
45 #define UCR2 0x84 /* Control Register 2 */
46 #define UCR3 0x88 /* Control Register 3 */
47 #define UCR4 0x8c /* Control Register 4 */
48 #define UFCR 0x90 /* FIFO Control Register */
49 #define USR1 0x94 /* Status Register 1 */
50 #define USR2 0x98 /* Status Register 2 */
51 #define UESC 0x9c /* Escape Character Register */
52 #define UTIM 0xa0 /* Escape Timer Register */
53 #define UBIR 0xa4 /* BRM Incremental Register */
54 #define UBMR 0xa8 /* BRM Modulator Register */
55 #define UBRC 0xac /* Baud Rate Count Register */
56 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
57 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
58 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
59
60 /* UART Control Register Bit Fields.*/
61 #define URXD_DUMMY_READ (1<<16)
62 #define URXD_CHARRDY (1<<15)
63 #define URXD_ERR (1<<14)
64 #define URXD_OVRRUN (1<<13)
65 #define URXD_FRMERR (1<<12)
66 #define URXD_BRK (1<<11)
67 #define URXD_PRERR (1<<10)
68 #define URXD_RX_DATA (0xFF<<0)
69 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
70 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
71 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
72 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
73 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
74 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
75 #define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
76 #define UCR1_IREN (1<<7) /* Infrared interface enable */
77 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
78 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
79 #define UCR1_SNDBRK (1<<4) /* Send break */
80 #define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
81 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
82 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
83 #define UCR1_DOZE (1<<1) /* Doze */
84 #define UCR1_UARTEN (1<<0) /* UART enabled */
85 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
86 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
87 #define UCR2_CTSC (1<<13) /* CTS pin control */
88 #define UCR2_CTS (1<<12) /* Clear to send */
89 #define UCR2_ESCEN (1<<11) /* Escape enable */
90 #define UCR2_PREN (1<<8) /* Parity enable */
91 #define UCR2_PROE (1<<7) /* Parity odd/even */
92 #define UCR2_STPB (1<<6) /* Stop */
93 #define UCR2_WS (1<<5) /* Word size */
94 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
95 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
96 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
97 #define UCR2_RXEN (1<<1) /* Receiver enabled */
98 #define UCR2_SRST (1<<0) /* SW reset */
99 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
100 #define UCR3_PARERREN (1<<12) /* Parity enable */
101 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
102 #define UCR3_DSR (1<<10) /* Data set ready */
103 #define UCR3_DCD (1<<9) /* Data carrier detect */
104 #define UCR3_RI (1<<8) /* Ring indicator */
105 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
106 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
107 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
108 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
109 #define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
110 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
111 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
112 #define UCR3_BPEN (1<<0) /* Preset registers enable */
113 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
114 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
115 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
116 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
117 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
118 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
119 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
120 #define UCR4_IRSC (1<<5) /* IR special case */
121 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
122 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
123 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
124 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
125 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
126 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
127 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
128 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
129 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
130 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
131 #define USR1_RTSS (1<<14) /* RTS pin status */
132 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
133 #define USR1_RTSD (1<<12) /* RTS delta */
134 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
135 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
136 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
137 #define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
138 #define USR1_DTRD (1<<7) /* DTR Delta */
139 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
140 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
141 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
142 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
143 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
144 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
145 #define USR2_IDLE (1<<12) /* Idle condition */
146 #define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
147 #define USR2_RIIN (1<<9) /* Ring Indicator Input */
148 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
149 #define USR2_WAKE (1<<7) /* Wake */
150 #define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
151 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
152 #define USR2_TXDC (1<<3) /* Transmitter complete */
153 #define USR2_BRCD (1<<2) /* Break condition */
154 #define USR2_ORE (1<<1) /* Overrun error */
155 #define USR2_RDR (1<<0) /* Recv data ready */
156 #define UTS_FRCPERR (1<<13) /* Force parity error */
157 #define UTS_LOOP (1<<12) /* Loop tx and rx */
158 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
159 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
160 #define UTS_TXFULL (1<<4) /* TxFIFO full */
161 #define UTS_RXFULL (1<<3) /* RxFIFO full */
162 #define UTS_SOFTRST (1<<0) /* Software reset */
163
164 /* We've been assigned a range on the "Low-density serial ports" major */
165 #define SERIAL_IMX_MAJOR 207
166 #define MINOR_START 16
167 #define DEV_NAME "ttymxc"
168
169 /*
170 * This determines how often we check the modem status signals
171 * for any change. They generally aren't connected to an IRQ
172 * so we have to poll them. We also check immediately before
173 * filling the TX fifo incase CTS has been dropped.
174 */
175 #define MCTRL_TIMEOUT (250*HZ/1000)
176
177 #define DRIVER_NAME "IMX-uart"
178
179 #define UART_NR 8
180
181 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
182 enum imx_uart_type {
183 IMX1_UART,
184 IMX21_UART,
185 IMX53_UART,
186 IMX6Q_UART,
187 };
188
189 /* device type dependent stuff */
190 struct imx_uart_data {
191 unsigned uts_reg;
192 enum imx_uart_type devtype;
193 };
194
195 struct imx_port {
196 struct uart_port port;
197 struct timer_list timer;
198 unsigned int old_status;
199 unsigned int have_rtscts:1;
200 unsigned int have_rtsgpio:1;
201 unsigned int dte_mode:1;
202 struct clk *clk_ipg;
203 struct clk *clk_per;
204 const struct imx_uart_data *devdata;
205
206 struct mctrl_gpios *gpios;
207
208 /* shadow registers */
209 unsigned int ucr1;
210 unsigned int ucr2;
211 unsigned int ucr3;
212 unsigned int ucr4;
213 unsigned int ufcr;
214
215 /* DMA fields */
216 unsigned int dma_is_enabled:1;
217 unsigned int dma_is_rxing:1;
218 unsigned int dma_is_txing:1;
219 struct dma_chan *dma_chan_rx, *dma_chan_tx;
220 struct scatterlist rx_sgl, tx_sgl[2];
221 void *rx_buf;
222 struct circ_buf rx_ring;
223 unsigned int rx_periods;
224 dma_cookie_t rx_cookie;
225 unsigned int tx_bytes;
226 unsigned int dma_tx_nents;
227 unsigned int saved_reg[10];
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 [IMX53_UART] = {
247 .uts_reg = IMX21_UTS,
248 .devtype = IMX53_UART,
249 },
250 [IMX6Q_UART] = {
251 .uts_reg = IMX21_UTS,
252 .devtype = IMX6Q_UART,
253 },
254 };
255
256 static const struct platform_device_id imx_uart_devtype[] = {
257 {
258 .name = "imx1-uart",
259 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
260 }, {
261 .name = "imx21-uart",
262 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
263 }, {
264 .name = "imx53-uart",
265 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
266 }, {
267 .name = "imx6q-uart",
268 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
269 }, {
270 /* sentinel */
271 }
272 };
273 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
274
275 static const struct of_device_id imx_uart_dt_ids[] = {
276 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
277 { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
278 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
279 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
280 { /* sentinel */ }
281 };
282 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
283
imx_uart_writel(struct imx_port * sport,u32 val,u32 offset)284 static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
285 {
286 switch (offset) {
287 case UCR1:
288 sport->ucr1 = val;
289 break;
290 case UCR2:
291 sport->ucr2 = val;
292 break;
293 case UCR3:
294 sport->ucr3 = val;
295 break;
296 case UCR4:
297 sport->ucr4 = val;
298 break;
299 case UFCR:
300 sport->ufcr = val;
301 break;
302 default:
303 break;
304 }
305 writel(val, sport->port.membase + offset);
306 }
307
imx_uart_readl(struct imx_port * sport,u32 offset)308 static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
309 {
310 switch (offset) {
311 case UCR1:
312 return sport->ucr1;
313 break;
314 case UCR2:
315 /*
316 * UCR2_SRST is the only bit in the cached registers that might
317 * differ from the value that was last written. As it only
318 * automatically becomes one after being cleared, reread
319 * conditionally.
320 */
321 if (!(sport->ucr2 & UCR2_SRST))
322 sport->ucr2 = readl(sport->port.membase + offset);
323 return sport->ucr2;
324 break;
325 case UCR3:
326 return sport->ucr3;
327 break;
328 case UCR4:
329 return sport->ucr4;
330 break;
331 case UFCR:
332 return sport->ufcr;
333 break;
334 default:
335 return readl(sport->port.membase + offset);
336 }
337 }
338
imx_uart_uts_reg(struct imx_port * sport)339 static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
340 {
341 return sport->devdata->uts_reg;
342 }
343
imx_uart_is_imx1(struct imx_port * sport)344 static inline int imx_uart_is_imx1(struct imx_port *sport)
345 {
346 return sport->devdata->devtype == IMX1_UART;
347 }
348
imx_uart_is_imx21(struct imx_port * sport)349 static inline int imx_uart_is_imx21(struct imx_port *sport)
350 {
351 return sport->devdata->devtype == IMX21_UART;
352 }
353
imx_uart_is_imx53(struct imx_port * sport)354 static inline int imx_uart_is_imx53(struct imx_port *sport)
355 {
356 return sport->devdata->devtype == IMX53_UART;
357 }
358
imx_uart_is_imx6q(struct imx_port * sport)359 static inline int imx_uart_is_imx6q(struct imx_port *sport)
360 {
361 return sport->devdata->devtype == IMX6Q_UART;
362 }
363 /*
364 * Save and restore functions for UCR1, UCR2 and UCR3 registers
365 */
366 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
imx_uart_ucrs_save(struct imx_port * sport,struct imx_port_ucrs * ucr)367 static void imx_uart_ucrs_save(struct imx_port *sport,
368 struct imx_port_ucrs *ucr)
369 {
370 /* save control registers */
371 ucr->ucr1 = imx_uart_readl(sport, UCR1);
372 ucr->ucr2 = imx_uart_readl(sport, UCR2);
373 ucr->ucr3 = imx_uart_readl(sport, UCR3);
374 }
375
imx_uart_ucrs_restore(struct imx_port * sport,struct imx_port_ucrs * ucr)376 static void imx_uart_ucrs_restore(struct imx_port *sport,
377 struct imx_port_ucrs *ucr)
378 {
379 /* restore control registers */
380 imx_uart_writel(sport, ucr->ucr1, UCR1);
381 imx_uart_writel(sport, ucr->ucr2, UCR2);
382 imx_uart_writel(sport, ucr->ucr3, UCR3);
383 }
384 #endif
385
386 /* called with port.lock taken and irqs caller dependent */
imx_uart_rts_active(struct imx_port * sport,u32 * ucr2)387 static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
388 {
389 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
390
391 sport->port.mctrl |= TIOCM_RTS;
392 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
393 }
394
395 /* called with port.lock taken and irqs caller dependent */
imx_uart_rts_inactive(struct imx_port * sport,u32 * ucr2)396 static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
397 {
398 *ucr2 &= ~UCR2_CTSC;
399 *ucr2 |= UCR2_CTS;
400
401 sport->port.mctrl &= ~TIOCM_RTS;
402 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
403 }
404
405 /* called with port.lock taken and irqs off */
imx_uart_start_rx(struct uart_port * port)406 static void imx_uart_start_rx(struct uart_port *port)
407 {
408 struct imx_port *sport = (struct imx_port *)port;
409 unsigned int ucr1, ucr2;
410
411 ucr1 = imx_uart_readl(sport, UCR1);
412 ucr2 = imx_uart_readl(sport, UCR2);
413
414 ucr2 |= UCR2_RXEN;
415
416 if (sport->dma_is_enabled) {
417 ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
418 } else {
419 ucr1 |= UCR1_RRDYEN;
420 ucr2 |= UCR2_ATEN;
421 }
422
423 /* Write UCR2 first as it includes RXEN */
424 imx_uart_writel(sport, ucr2, UCR2);
425 imx_uart_writel(sport, ucr1, UCR1);
426 }
427
428 /* called with port.lock taken and irqs off */
imx_uart_stop_tx(struct uart_port * port)429 static void imx_uart_stop_tx(struct uart_port *port)
430 {
431 struct imx_port *sport = (struct imx_port *)port;
432 u32 ucr1;
433
434 /*
435 * We are maybe in the SMP context, so if the DMA TX thread is running
436 * on other cpu, we have to wait for it to finish.
437 */
438 if (sport->dma_is_txing)
439 return;
440
441 ucr1 = imx_uart_readl(sport, UCR1);
442 imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
443
444 /* in rs485 mode disable transmitter if shifter is empty */
445 if (port->rs485.flags & SER_RS485_ENABLED &&
446 imx_uart_readl(sport, USR2) & USR2_TXDC) {
447 u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
448 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
449 imx_uart_rts_active(sport, &ucr2);
450 else
451 imx_uart_rts_inactive(sport, &ucr2);
452 imx_uart_writel(sport, ucr2, UCR2);
453
454 imx_uart_start_rx(port);
455
456 ucr4 = imx_uart_readl(sport, UCR4);
457 ucr4 &= ~UCR4_TCEN;
458 imx_uart_writel(sport, ucr4, UCR4);
459 }
460 }
461
462 /* called with port.lock taken and irqs off */
imx_uart_stop_rx(struct uart_port * port)463 static void imx_uart_stop_rx(struct uart_port *port)
464 {
465 struct imx_port *sport = (struct imx_port *)port;
466 u32 ucr1, ucr2;
467
468 ucr1 = imx_uart_readl(sport, UCR1);
469 ucr2 = imx_uart_readl(sport, UCR2);
470
471 if (sport->dma_is_enabled) {
472 ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
473 } else {
474 ucr1 &= ~UCR1_RRDYEN;
475 ucr2 &= ~UCR2_ATEN;
476 }
477 imx_uart_writel(sport, ucr1, UCR1);
478
479 ucr2 &= ~UCR2_RXEN;
480 imx_uart_writel(sport, ucr2, UCR2);
481 }
482
483 /* called with port.lock taken and irqs off */
imx_uart_enable_ms(struct uart_port * port)484 static void imx_uart_enable_ms(struct uart_port *port)
485 {
486 struct imx_port *sport = (struct imx_port *)port;
487
488 mod_timer(&sport->timer, jiffies);
489
490 mctrl_gpio_enable_ms(sport->gpios);
491 }
492
493 static void imx_uart_dma_tx(struct imx_port *sport);
494
495 /* called with port.lock taken and irqs off */
imx_uart_transmit_buffer(struct imx_port * sport)496 static inline void imx_uart_transmit_buffer(struct imx_port *sport)
497 {
498 struct circ_buf *xmit = &sport->port.state->xmit;
499
500 if (sport->port.x_char) {
501 /* Send next char */
502 imx_uart_writel(sport, sport->port.x_char, URTX0);
503 sport->port.icount.tx++;
504 sport->port.x_char = 0;
505 return;
506 }
507
508 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
509 imx_uart_stop_tx(&sport->port);
510 return;
511 }
512
513 if (sport->dma_is_enabled) {
514 u32 ucr1;
515 /*
516 * We've just sent a X-char Ensure the TX DMA is enabled
517 * and the TX IRQ is disabled.
518 **/
519 ucr1 = imx_uart_readl(sport, UCR1);
520 ucr1 &= ~UCR1_TRDYEN;
521 if (sport->dma_is_txing) {
522 ucr1 |= UCR1_TXDMAEN;
523 imx_uart_writel(sport, ucr1, UCR1);
524 } else {
525 imx_uart_writel(sport, ucr1, UCR1);
526 imx_uart_dma_tx(sport);
527 }
528
529 return;
530 }
531
532 while (!uart_circ_empty(xmit) &&
533 !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
534 /* send xmit->buf[xmit->tail]
535 * out the port here */
536 imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
537 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
538 sport->port.icount.tx++;
539 }
540
541 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
542 uart_write_wakeup(&sport->port);
543
544 if (uart_circ_empty(xmit))
545 imx_uart_stop_tx(&sport->port);
546 }
547
imx_uart_dma_tx_callback(void * data)548 static void imx_uart_dma_tx_callback(void *data)
549 {
550 struct imx_port *sport = data;
551 struct scatterlist *sgl = &sport->tx_sgl[0];
552 struct circ_buf *xmit = &sport->port.state->xmit;
553 unsigned long flags;
554 u32 ucr1;
555
556 spin_lock_irqsave(&sport->port.lock, flags);
557
558 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
559
560 ucr1 = imx_uart_readl(sport, UCR1);
561 ucr1 &= ~UCR1_TXDMAEN;
562 imx_uart_writel(sport, ucr1, UCR1);
563
564 /* update the stat */
565 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
566 sport->port.icount.tx += sport->tx_bytes;
567
568 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
569
570 sport->dma_is_txing = 0;
571
572 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
573 uart_write_wakeup(&sport->port);
574
575 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
576 imx_uart_dma_tx(sport);
577 else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
578 u32 ucr4 = imx_uart_readl(sport, UCR4);
579 ucr4 |= UCR4_TCEN;
580 imx_uart_writel(sport, ucr4, UCR4);
581 }
582
583 spin_unlock_irqrestore(&sport->port.lock, flags);
584 }
585
586 /* called with port.lock taken and irqs off */
imx_uart_dma_tx(struct imx_port * sport)587 static void imx_uart_dma_tx(struct imx_port *sport)
588 {
589 struct circ_buf *xmit = &sport->port.state->xmit;
590 struct scatterlist *sgl = sport->tx_sgl;
591 struct dma_async_tx_descriptor *desc;
592 struct dma_chan *chan = sport->dma_chan_tx;
593 struct device *dev = sport->port.dev;
594 u32 ucr1, ucr4;
595 int ret;
596
597 if (sport->dma_is_txing)
598 return;
599
600 ucr4 = imx_uart_readl(sport, UCR4);
601 ucr4 &= ~UCR4_TCEN;
602 imx_uart_writel(sport, ucr4, UCR4);
603
604 sport->tx_bytes = uart_circ_chars_pending(xmit);
605
606 if (xmit->tail < xmit->head) {
607 sport->dma_tx_nents = 1;
608 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
609 } else {
610 sport->dma_tx_nents = 2;
611 sg_init_table(sgl, 2);
612 sg_set_buf(sgl, xmit->buf + xmit->tail,
613 UART_XMIT_SIZE - xmit->tail);
614 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
615 }
616
617 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
618 if (ret == 0) {
619 dev_err(dev, "DMA mapping error for TX.\n");
620 return;
621 }
622 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
623 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
624 if (!desc) {
625 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
626 DMA_TO_DEVICE);
627 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
628 return;
629 }
630 desc->callback = imx_uart_dma_tx_callback;
631 desc->callback_param = sport;
632
633 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
634 uart_circ_chars_pending(xmit));
635
636 ucr1 = imx_uart_readl(sport, UCR1);
637 ucr1 |= UCR1_TXDMAEN;
638 imx_uart_writel(sport, ucr1, UCR1);
639
640 /* fire it */
641 sport->dma_is_txing = 1;
642 dmaengine_submit(desc);
643 dma_async_issue_pending(chan);
644 return;
645 }
646
647 /* called with port.lock taken and irqs off */
imx_uart_start_tx(struct uart_port * port)648 static void imx_uart_start_tx(struct uart_port *port)
649 {
650 struct imx_port *sport = (struct imx_port *)port;
651 u32 ucr1;
652
653 if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
654 return;
655
656 if (port->rs485.flags & SER_RS485_ENABLED) {
657 u32 ucr2;
658
659 ucr2 = imx_uart_readl(sport, UCR2);
660 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
661 imx_uart_rts_active(sport, &ucr2);
662 else
663 imx_uart_rts_inactive(sport, &ucr2);
664 imx_uart_writel(sport, ucr2, UCR2);
665
666 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
667 imx_uart_stop_rx(port);
668
669 /*
670 * Enable transmitter and shifter empty irq only if DMA is off.
671 * In the DMA case this is done in the tx-callback.
672 */
673 if (!sport->dma_is_enabled) {
674 u32 ucr4 = imx_uart_readl(sport, UCR4);
675 ucr4 |= UCR4_TCEN;
676 imx_uart_writel(sport, ucr4, UCR4);
677 }
678 }
679
680 if (!sport->dma_is_enabled) {
681 ucr1 = imx_uart_readl(sport, UCR1);
682 imx_uart_writel(sport, ucr1 | UCR1_TRDYEN, UCR1);
683 }
684
685 if (sport->dma_is_enabled) {
686 if (sport->port.x_char) {
687 /* We have X-char to send, so enable TX IRQ and
688 * disable TX DMA to let TX interrupt to send X-char */
689 ucr1 = imx_uart_readl(sport, UCR1);
690 ucr1 &= ~UCR1_TXDMAEN;
691 ucr1 |= UCR1_TRDYEN;
692 imx_uart_writel(sport, ucr1, UCR1);
693 return;
694 }
695
696 if (!uart_circ_empty(&port->state->xmit) &&
697 !uart_tx_stopped(port))
698 imx_uart_dma_tx(sport);
699 return;
700 }
701 }
702
imx_uart_rtsint(int irq,void * dev_id)703 static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
704 {
705 struct imx_port *sport = dev_id;
706 u32 usr1;
707
708 spin_lock(&sport->port.lock);
709
710 imx_uart_writel(sport, USR1_RTSD, USR1);
711 usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
712 uart_handle_cts_change(&sport->port, !!usr1);
713 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
714
715 spin_unlock(&sport->port.lock);
716 return IRQ_HANDLED;
717 }
718
imx_uart_txint(int irq,void * dev_id)719 static irqreturn_t imx_uart_txint(int irq, void *dev_id)
720 {
721 struct imx_port *sport = dev_id;
722
723 spin_lock(&sport->port.lock);
724 imx_uart_transmit_buffer(sport);
725 spin_unlock(&sport->port.lock);
726 return IRQ_HANDLED;
727 }
728
imx_uart_rxint(int irq,void * dev_id)729 static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
730 {
731 struct imx_port *sport = dev_id;
732 unsigned int rx, flg, ignored = 0;
733 struct tty_port *port = &sport->port.state->port;
734
735 spin_lock(&sport->port.lock);
736
737 while (imx_uart_readl(sport, USR2) & USR2_RDR) {
738 u32 usr2;
739
740 flg = TTY_NORMAL;
741 sport->port.icount.rx++;
742
743 rx = imx_uart_readl(sport, URXD0);
744
745 usr2 = imx_uart_readl(sport, USR2);
746 if (usr2 & USR2_BRCD) {
747 imx_uart_writel(sport, USR2_BRCD, USR2);
748 if (uart_handle_break(&sport->port))
749 continue;
750 }
751
752 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
753 continue;
754
755 if (unlikely(rx & URXD_ERR)) {
756 if (rx & URXD_BRK)
757 sport->port.icount.brk++;
758 else if (rx & URXD_PRERR)
759 sport->port.icount.parity++;
760 else if (rx & URXD_FRMERR)
761 sport->port.icount.frame++;
762 if (rx & URXD_OVRRUN)
763 sport->port.icount.overrun++;
764
765 if (rx & sport->port.ignore_status_mask) {
766 if (++ignored > 100)
767 goto out;
768 continue;
769 }
770
771 rx &= (sport->port.read_status_mask | 0xFF);
772
773 if (rx & URXD_BRK)
774 flg = TTY_BREAK;
775 else if (rx & URXD_PRERR)
776 flg = TTY_PARITY;
777 else if (rx & URXD_FRMERR)
778 flg = TTY_FRAME;
779 if (rx & URXD_OVRRUN)
780 flg = TTY_OVERRUN;
781
782 #ifdef SUPPORT_SYSRQ
783 sport->port.sysrq = 0;
784 #endif
785 }
786
787 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
788 goto out;
789
790 if (tty_insert_flip_char(port, rx, flg) == 0)
791 sport->port.icount.buf_overrun++;
792 }
793
794 out:
795 spin_unlock(&sport->port.lock);
796 tty_flip_buffer_push(port);
797 return IRQ_HANDLED;
798 }
799
800 static void imx_uart_clear_rx_errors(struct imx_port *sport);
801
802 /*
803 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
804 */
imx_uart_get_hwmctrl(struct imx_port * sport)805 static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
806 {
807 unsigned int tmp = TIOCM_DSR;
808 unsigned usr1 = imx_uart_readl(sport, USR1);
809 unsigned usr2 = imx_uart_readl(sport, USR2);
810
811 if (usr1 & USR1_RTSS)
812 tmp |= TIOCM_CTS;
813
814 /* in DCE mode DCDIN is always 0 */
815 if (!(usr2 & USR2_DCDIN))
816 tmp |= TIOCM_CAR;
817
818 if (sport->dte_mode)
819 if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
820 tmp |= TIOCM_RI;
821
822 return tmp;
823 }
824
825 /*
826 * Handle any change of modem status signal since we were last called.
827 */
imx_uart_mctrl_check(struct imx_port * sport)828 static void imx_uart_mctrl_check(struct imx_port *sport)
829 {
830 unsigned int status, changed;
831
832 status = imx_uart_get_hwmctrl(sport);
833 changed = status ^ sport->old_status;
834
835 if (changed == 0)
836 return;
837
838 sport->old_status = status;
839
840 if (changed & TIOCM_RI && status & TIOCM_RI)
841 sport->port.icount.rng++;
842 if (changed & TIOCM_DSR)
843 sport->port.icount.dsr++;
844 if (changed & TIOCM_CAR)
845 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
846 if (changed & TIOCM_CTS)
847 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
848
849 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
850 }
851
imx_uart_int(int irq,void * dev_id)852 static irqreturn_t imx_uart_int(int irq, void *dev_id)
853 {
854 struct imx_port *sport = dev_id;
855 unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
856 irqreturn_t ret = IRQ_NONE;
857
858 usr1 = imx_uart_readl(sport, USR1);
859 usr2 = imx_uart_readl(sport, USR2);
860 ucr1 = imx_uart_readl(sport, UCR1);
861 ucr2 = imx_uart_readl(sport, UCR2);
862 ucr3 = imx_uart_readl(sport, UCR3);
863 ucr4 = imx_uart_readl(sport, UCR4);
864
865 /*
866 * Even if a condition is true that can trigger an irq only handle it if
867 * the respective irq source is enabled. This prevents some undesired
868 * actions, for example if a character that sits in the RX FIFO and that
869 * should be fetched via DMA is tried to be fetched using PIO. Or the
870 * receiver is currently off and so reading from URXD0 results in an
871 * exception. So just mask the (raw) status bits for disabled irqs.
872 */
873 if ((ucr1 & UCR1_RRDYEN) == 0)
874 usr1 &= ~USR1_RRDY;
875 if ((ucr2 & UCR2_ATEN) == 0)
876 usr1 &= ~USR1_AGTIM;
877 if ((ucr1 & UCR1_TRDYEN) == 0)
878 usr1 &= ~USR1_TRDY;
879 if ((ucr4 & UCR4_TCEN) == 0)
880 usr2 &= ~USR2_TXDC;
881 if ((ucr3 & UCR3_DTRDEN) == 0)
882 usr1 &= ~USR1_DTRD;
883 if ((ucr1 & UCR1_RTSDEN) == 0)
884 usr1 &= ~USR1_RTSD;
885 if ((ucr3 & UCR3_AWAKEN) == 0)
886 usr1 &= ~USR1_AWAKE;
887 if ((ucr4 & UCR4_OREN) == 0)
888 usr2 &= ~USR2_ORE;
889
890 if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
891 imx_uart_rxint(irq, dev_id);
892 ret = IRQ_HANDLED;
893 }
894
895 if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
896 imx_uart_txint(irq, dev_id);
897 ret = IRQ_HANDLED;
898 }
899
900 if (usr1 & USR1_DTRD) {
901 imx_uart_writel(sport, USR1_DTRD, USR1);
902
903 spin_lock(&sport->port.lock);
904 imx_uart_mctrl_check(sport);
905 spin_unlock(&sport->port.lock);
906
907 ret = IRQ_HANDLED;
908 }
909
910 if (usr1 & USR1_RTSD) {
911 imx_uart_rtsint(irq, dev_id);
912 ret = IRQ_HANDLED;
913 }
914
915 if (usr1 & USR1_AWAKE) {
916 imx_uart_writel(sport, USR1_AWAKE, USR1);
917 ret = IRQ_HANDLED;
918 }
919
920 if (usr2 & USR2_ORE) {
921 sport->port.icount.overrun++;
922 imx_uart_writel(sport, USR2_ORE, USR2);
923 ret = IRQ_HANDLED;
924 }
925
926 return ret;
927 }
928
929 /*
930 * Return TIOCSER_TEMT when transmitter is not busy.
931 */
imx_uart_tx_empty(struct uart_port * port)932 static unsigned int imx_uart_tx_empty(struct uart_port *port)
933 {
934 struct imx_port *sport = (struct imx_port *)port;
935 unsigned int ret;
936
937 ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
938
939 /* If the TX DMA is working, return 0. */
940 if (sport->dma_is_txing)
941 ret = 0;
942
943 return ret;
944 }
945
946 /* called with port.lock taken and irqs off */
imx_uart_get_mctrl(struct uart_port * port)947 static unsigned int imx_uart_get_mctrl(struct uart_port *port)
948 {
949 struct imx_port *sport = (struct imx_port *)port;
950 unsigned int ret = imx_uart_get_hwmctrl(sport);
951
952 mctrl_gpio_get(sport->gpios, &ret);
953
954 return ret;
955 }
956
957 /* called with port.lock taken and irqs off */
imx_uart_set_mctrl(struct uart_port * port,unsigned int mctrl)958 static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
959 {
960 struct imx_port *sport = (struct imx_port *)port;
961 u32 ucr3, uts;
962
963 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
964 u32 ucr2;
965
966 /*
967 * Turn off autoRTS if RTS is lowered and restore autoRTS
968 * setting if RTS is raised.
969 */
970 ucr2 = imx_uart_readl(sport, UCR2);
971 ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
972 if (mctrl & TIOCM_RTS) {
973 ucr2 |= UCR2_CTS;
974 /*
975 * UCR2_IRTS is unset if and only if the port is
976 * configured for CRTSCTS, so we use inverted UCR2_IRTS
977 * to get the state to restore to.
978 */
979 if (!(ucr2 & UCR2_IRTS))
980 ucr2 |= UCR2_CTSC;
981 }
982 imx_uart_writel(sport, ucr2, UCR2);
983 }
984
985 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
986 if (!(mctrl & TIOCM_DTR))
987 ucr3 |= UCR3_DSR;
988 imx_uart_writel(sport, ucr3, UCR3);
989
990 uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
991 if (mctrl & TIOCM_LOOP)
992 uts |= UTS_LOOP;
993 imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
994
995 mctrl_gpio_set(sport->gpios, mctrl);
996 }
997
998 /*
999 * Interrupts always disabled.
1000 */
imx_uart_break_ctl(struct uart_port * port,int break_state)1001 static void imx_uart_break_ctl(struct uart_port *port, int break_state)
1002 {
1003 struct imx_port *sport = (struct imx_port *)port;
1004 unsigned long flags;
1005 u32 ucr1;
1006
1007 spin_lock_irqsave(&sport->port.lock, flags);
1008
1009 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
1010
1011 if (break_state != 0)
1012 ucr1 |= UCR1_SNDBRK;
1013
1014 imx_uart_writel(sport, ucr1, UCR1);
1015
1016 spin_unlock_irqrestore(&sport->port.lock, flags);
1017 }
1018
1019 /*
1020 * This is our per-port timeout handler, for checking the
1021 * modem status signals.
1022 */
imx_uart_timeout(struct timer_list * t)1023 static void imx_uart_timeout(struct timer_list *t)
1024 {
1025 struct imx_port *sport = from_timer(sport, t, timer);
1026 unsigned long flags;
1027
1028 if (sport->port.state) {
1029 spin_lock_irqsave(&sport->port.lock, flags);
1030 imx_uart_mctrl_check(sport);
1031 spin_unlock_irqrestore(&sport->port.lock, flags);
1032
1033 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
1034 }
1035 }
1036
1037 #define RX_BUF_SIZE (PAGE_SIZE)
1038
1039 /*
1040 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
1041 * [1] the RX DMA buffer is full.
1042 * [2] the aging timer expires
1043 *
1044 * Condition [2] is triggered when a character has been sitting in the FIFO
1045 * for at least 8 byte durations.
1046 */
imx_uart_dma_rx_callback(void * data)1047 static void imx_uart_dma_rx_callback(void *data)
1048 {
1049 struct imx_port *sport = data;
1050 struct dma_chan *chan = sport->dma_chan_rx;
1051 struct scatterlist *sgl = &sport->rx_sgl;
1052 struct tty_port *port = &sport->port.state->port;
1053 struct dma_tx_state state;
1054 struct circ_buf *rx_ring = &sport->rx_ring;
1055 enum dma_status status;
1056 unsigned int w_bytes = 0;
1057 unsigned int r_bytes;
1058 unsigned int bd_size;
1059
1060 status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
1061
1062 if (status == DMA_ERROR) {
1063 imx_uart_clear_rx_errors(sport);
1064 return;
1065 }
1066
1067 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
1068
1069 /*
1070 * The state-residue variable represents the empty space
1071 * relative to the entire buffer. Taking this in consideration
1072 * the head is always calculated base on the buffer total
1073 * length - DMA transaction residue. The UART script from the
1074 * SDMA firmware will jump to the next buffer descriptor,
1075 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1076 * Taking this in consideration the tail is always at the
1077 * beginning of the buffer descriptor that contains the head.
1078 */
1079
1080 /* Calculate the head */
1081 rx_ring->head = sg_dma_len(sgl) - state.residue;
1082
1083 /* Calculate the tail. */
1084 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1085 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1086
1087 if (rx_ring->head <= sg_dma_len(sgl) &&
1088 rx_ring->head > rx_ring->tail) {
1089
1090 /* Move data from tail to head */
1091 r_bytes = rx_ring->head - rx_ring->tail;
1092
1093 /* CPU claims ownership of RX DMA buffer */
1094 dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1095 DMA_FROM_DEVICE);
1096
1097 w_bytes = tty_insert_flip_string(port,
1098 sport->rx_buf + rx_ring->tail, r_bytes);
1099
1100 /* UART retrieves ownership of RX DMA buffer */
1101 dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1102 DMA_FROM_DEVICE);
1103
1104 if (w_bytes != r_bytes)
1105 sport->port.icount.buf_overrun++;
1106
1107 sport->port.icount.rx += w_bytes;
1108 } else {
1109 WARN_ON(rx_ring->head > sg_dma_len(sgl));
1110 WARN_ON(rx_ring->head <= rx_ring->tail);
1111 }
1112 }
1113
1114 if (w_bytes) {
1115 tty_flip_buffer_push(port);
1116 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1117 }
1118 }
1119
1120 /* RX DMA buffer periods */
1121 #define RX_DMA_PERIODS 4
1122
imx_uart_start_rx_dma(struct imx_port * sport)1123 static int imx_uart_start_rx_dma(struct imx_port *sport)
1124 {
1125 struct scatterlist *sgl = &sport->rx_sgl;
1126 struct dma_chan *chan = sport->dma_chan_rx;
1127 struct device *dev = sport->port.dev;
1128 struct dma_async_tx_descriptor *desc;
1129 int ret;
1130
1131 sport->rx_ring.head = 0;
1132 sport->rx_ring.tail = 0;
1133 sport->rx_periods = RX_DMA_PERIODS;
1134
1135 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1136 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1137 if (ret == 0) {
1138 dev_err(dev, "DMA mapping error for RX.\n");
1139 return -EINVAL;
1140 }
1141
1142 desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1143 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1144 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1145
1146 if (!desc) {
1147 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1148 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1149 return -EINVAL;
1150 }
1151 desc->callback = imx_uart_dma_rx_callback;
1152 desc->callback_param = sport;
1153
1154 dev_dbg(dev, "RX: prepare for the DMA.\n");
1155 sport->dma_is_rxing = 1;
1156 sport->rx_cookie = dmaengine_submit(desc);
1157 dma_async_issue_pending(chan);
1158 return 0;
1159 }
1160
imx_uart_clear_rx_errors(struct imx_port * sport)1161 static void imx_uart_clear_rx_errors(struct imx_port *sport)
1162 {
1163 struct tty_port *port = &sport->port.state->port;
1164 u32 usr1, usr2;
1165
1166 usr1 = imx_uart_readl(sport, USR1);
1167 usr2 = imx_uart_readl(sport, USR2);
1168
1169 if (usr2 & USR2_BRCD) {
1170 sport->port.icount.brk++;
1171 imx_uart_writel(sport, USR2_BRCD, USR2);
1172 uart_handle_break(&sport->port);
1173 if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
1174 sport->port.icount.buf_overrun++;
1175 tty_flip_buffer_push(port);
1176 } else {
1177 if (usr1 & USR1_FRAMERR) {
1178 sport->port.icount.frame++;
1179 imx_uart_writel(sport, USR1_FRAMERR, USR1);
1180 } else if (usr1 & USR1_PARITYERR) {
1181 sport->port.icount.parity++;
1182 imx_uart_writel(sport, USR1_PARITYERR, USR1);
1183 }
1184 }
1185
1186 if (usr2 & USR2_ORE) {
1187 sport->port.icount.overrun++;
1188 imx_uart_writel(sport, USR2_ORE, USR2);
1189 }
1190
1191 }
1192
1193 #define TXTL_DEFAULT 2 /* reset default */
1194 #define RXTL_DEFAULT 1 /* reset default */
1195 #define TXTL_DMA 8 /* DMA burst setting */
1196 #define RXTL_DMA 9 /* DMA burst setting */
1197
imx_uart_setup_ufcr(struct imx_port * sport,unsigned char txwl,unsigned char rxwl)1198 static void imx_uart_setup_ufcr(struct imx_port *sport,
1199 unsigned char txwl, unsigned char rxwl)
1200 {
1201 unsigned int val;
1202
1203 /* set receiver / transmitter trigger level */
1204 val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1205 val |= txwl << UFCR_TXTL_SHF | rxwl;
1206 imx_uart_writel(sport, val, UFCR);
1207 }
1208
imx_uart_dma_exit(struct imx_port * sport)1209 static void imx_uart_dma_exit(struct imx_port *sport)
1210 {
1211 if (sport->dma_chan_rx) {
1212 dmaengine_terminate_sync(sport->dma_chan_rx);
1213 dma_release_channel(sport->dma_chan_rx);
1214 sport->dma_chan_rx = NULL;
1215 sport->rx_cookie = -EINVAL;
1216 kfree(sport->rx_buf);
1217 sport->rx_buf = NULL;
1218 }
1219
1220 if (sport->dma_chan_tx) {
1221 dmaengine_terminate_sync(sport->dma_chan_tx);
1222 dma_release_channel(sport->dma_chan_tx);
1223 sport->dma_chan_tx = NULL;
1224 }
1225 }
1226
imx_uart_dma_init(struct imx_port * sport)1227 static int imx_uart_dma_init(struct imx_port *sport)
1228 {
1229 struct dma_slave_config slave_config = {};
1230 struct device *dev = sport->port.dev;
1231 int ret;
1232
1233 /* Prepare for RX : */
1234 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1235 if (!sport->dma_chan_rx) {
1236 dev_dbg(dev, "cannot get the DMA channel.\n");
1237 ret = -EINVAL;
1238 goto err;
1239 }
1240
1241 slave_config.direction = DMA_DEV_TO_MEM;
1242 slave_config.src_addr = sport->port.mapbase + URXD0;
1243 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1244 /* one byte less than the watermark level to enable the aging timer */
1245 slave_config.src_maxburst = RXTL_DMA - 1;
1246 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1247 if (ret) {
1248 dev_err(dev, "error in RX dma configuration.\n");
1249 goto err;
1250 }
1251
1252 sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
1253 if (!sport->rx_buf) {
1254 ret = -ENOMEM;
1255 goto err;
1256 }
1257 sport->rx_ring.buf = sport->rx_buf;
1258
1259 /* Prepare for TX : */
1260 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1261 if (!sport->dma_chan_tx) {
1262 dev_err(dev, "cannot get the TX DMA channel!\n");
1263 ret = -EINVAL;
1264 goto err;
1265 }
1266
1267 slave_config.direction = DMA_MEM_TO_DEV;
1268 slave_config.dst_addr = sport->port.mapbase + URTX0;
1269 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1270 slave_config.dst_maxburst = TXTL_DMA;
1271 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1272 if (ret) {
1273 dev_err(dev, "error in TX dma configuration.");
1274 goto err;
1275 }
1276
1277 return 0;
1278 err:
1279 imx_uart_dma_exit(sport);
1280 return ret;
1281 }
1282
imx_uart_enable_dma(struct imx_port * sport)1283 static void imx_uart_enable_dma(struct imx_port *sport)
1284 {
1285 u32 ucr1;
1286
1287 imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1288
1289 /* set UCR1 */
1290 ucr1 = imx_uart_readl(sport, UCR1);
1291 ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1292 imx_uart_writel(sport, ucr1, UCR1);
1293
1294 sport->dma_is_enabled = 1;
1295 }
1296
imx_uart_disable_dma(struct imx_port * sport)1297 static void imx_uart_disable_dma(struct imx_port *sport)
1298 {
1299 u32 ucr1;
1300
1301 /* clear UCR1 */
1302 ucr1 = imx_uart_readl(sport, UCR1);
1303 ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1304 imx_uart_writel(sport, ucr1, UCR1);
1305
1306 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1307
1308 sport->dma_is_enabled = 0;
1309 }
1310
1311 /* half the RX buffer size */
1312 #define CTSTL 16
1313
imx_uart_startup(struct uart_port * port)1314 static int imx_uart_startup(struct uart_port *port)
1315 {
1316 struct imx_port *sport = (struct imx_port *)port;
1317 int retval, i;
1318 unsigned long flags;
1319 int dma_is_inited = 0;
1320 u32 ucr1, ucr2, ucr4;
1321
1322 retval = clk_prepare_enable(sport->clk_per);
1323 if (retval)
1324 return retval;
1325 retval = clk_prepare_enable(sport->clk_ipg);
1326 if (retval) {
1327 clk_disable_unprepare(sport->clk_per);
1328 return retval;
1329 }
1330
1331 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1332
1333 /* disable the DREN bit (Data Ready interrupt enable) before
1334 * requesting IRQs
1335 */
1336 ucr4 = imx_uart_readl(sport, UCR4);
1337
1338 /* set the trigger level for CTS */
1339 ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1340 ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1341
1342 imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
1343
1344 /* Can we enable the DMA support? */
1345 if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1346 dma_is_inited = 1;
1347
1348 spin_lock_irqsave(&sport->port.lock, flags);
1349 /* Reset fifo's and state machines */
1350 i = 100;
1351
1352 ucr2 = imx_uart_readl(sport, UCR2);
1353 ucr2 &= ~UCR2_SRST;
1354 imx_uart_writel(sport, ucr2, UCR2);
1355
1356 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1357 udelay(1);
1358
1359 /*
1360 * Finally, clear and enable interrupts
1361 */
1362 imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1363 imx_uart_writel(sport, USR2_ORE, USR2);
1364
1365 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1366 ucr1 |= UCR1_UARTEN;
1367 if (sport->have_rtscts)
1368 ucr1 |= UCR1_RTSDEN;
1369
1370 imx_uart_writel(sport, ucr1, UCR1);
1371
1372 ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
1373 if (!sport->dma_is_enabled)
1374 ucr4 |= UCR4_OREN;
1375 imx_uart_writel(sport, ucr4, UCR4);
1376
1377 ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1378 ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1379 if (!sport->have_rtscts)
1380 ucr2 |= UCR2_IRTS;
1381 /*
1382 * make sure the edge sensitive RTS-irq is disabled,
1383 * we're using RTSD instead.
1384 */
1385 if (!imx_uart_is_imx1(sport))
1386 ucr2 &= ~UCR2_RTSEN;
1387 imx_uart_writel(sport, ucr2, UCR2);
1388
1389 if (!imx_uart_is_imx1(sport)) {
1390 u32 ucr3;
1391
1392 ucr3 = imx_uart_readl(sport, UCR3);
1393
1394 ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1395
1396 if (sport->dte_mode)
1397 /* disable broken interrupts */
1398 ucr3 &= ~(UCR3_RI | UCR3_DCD);
1399
1400 imx_uart_writel(sport, ucr3, UCR3);
1401 }
1402
1403 /*
1404 * Enable modem status interrupts
1405 */
1406 imx_uart_enable_ms(&sport->port);
1407
1408 if (dma_is_inited) {
1409 imx_uart_enable_dma(sport);
1410 imx_uart_start_rx_dma(sport);
1411 } else {
1412 ucr1 = imx_uart_readl(sport, UCR1);
1413 ucr1 |= UCR1_RRDYEN;
1414 imx_uart_writel(sport, ucr1, UCR1);
1415
1416 ucr2 = imx_uart_readl(sport, UCR2);
1417 ucr2 |= UCR2_ATEN;
1418 imx_uart_writel(sport, ucr2, UCR2);
1419 }
1420
1421 spin_unlock_irqrestore(&sport->port.lock, flags);
1422
1423 return 0;
1424 }
1425
imx_uart_shutdown(struct uart_port * port)1426 static void imx_uart_shutdown(struct uart_port *port)
1427 {
1428 struct imx_port *sport = (struct imx_port *)port;
1429 unsigned long flags;
1430 u32 ucr1, ucr2, ucr4;
1431
1432 if (sport->dma_is_enabled) {
1433 dmaengine_terminate_sync(sport->dma_chan_tx);
1434 if (sport->dma_is_txing) {
1435 dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
1436 sport->dma_tx_nents, DMA_TO_DEVICE);
1437 sport->dma_is_txing = 0;
1438 }
1439 dmaengine_terminate_sync(sport->dma_chan_rx);
1440 if (sport->dma_is_rxing) {
1441 dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
1442 1, DMA_FROM_DEVICE);
1443 sport->dma_is_rxing = 0;
1444 }
1445
1446 spin_lock_irqsave(&sport->port.lock, flags);
1447 imx_uart_stop_tx(port);
1448 imx_uart_stop_rx(port);
1449 imx_uart_disable_dma(sport);
1450 spin_unlock_irqrestore(&sport->port.lock, flags);
1451 imx_uart_dma_exit(sport);
1452 }
1453
1454 mctrl_gpio_disable_ms(sport->gpios);
1455
1456 spin_lock_irqsave(&sport->port.lock, flags);
1457 ucr2 = imx_uart_readl(sport, UCR2);
1458 ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1459 imx_uart_writel(sport, ucr2, UCR2);
1460
1461 ucr4 = imx_uart_readl(sport, UCR4);
1462 ucr4 &= ~UCR4_OREN;
1463 imx_uart_writel(sport, ucr4, UCR4);
1464 spin_unlock_irqrestore(&sport->port.lock, flags);
1465
1466 /*
1467 * Stop our timer.
1468 */
1469 del_timer_sync(&sport->timer);
1470
1471 /*
1472 * Disable all interrupts, port and break condition.
1473 */
1474
1475 spin_lock_irqsave(&sport->port.lock, flags);
1476 ucr1 = imx_uart_readl(sport, UCR1);
1477 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
1478
1479 imx_uart_writel(sport, ucr1, UCR1);
1480 spin_unlock_irqrestore(&sport->port.lock, flags);
1481
1482 clk_disable_unprepare(sport->clk_per);
1483 clk_disable_unprepare(sport->clk_ipg);
1484 }
1485
1486 /* called with port.lock taken and irqs off */
imx_uart_flush_buffer(struct uart_port * port)1487 static void imx_uart_flush_buffer(struct uart_port *port)
1488 {
1489 struct imx_port *sport = (struct imx_port *)port;
1490 struct scatterlist *sgl = &sport->tx_sgl[0];
1491 u32 ucr2;
1492 int i = 100, ubir, ubmr, uts;
1493
1494 if (!sport->dma_chan_tx)
1495 return;
1496
1497 sport->tx_bytes = 0;
1498 dmaengine_terminate_all(sport->dma_chan_tx);
1499 if (sport->dma_is_txing) {
1500 u32 ucr1;
1501
1502 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1503 DMA_TO_DEVICE);
1504 ucr1 = imx_uart_readl(sport, UCR1);
1505 ucr1 &= ~UCR1_TXDMAEN;
1506 imx_uart_writel(sport, ucr1, UCR1);
1507 sport->dma_is_txing = 0;
1508 }
1509
1510 /*
1511 * According to the Reference Manual description of the UART SRST bit:
1512 *
1513 * "Reset the transmit and receive state machines,
1514 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1515 * and UTS[6-3]".
1516 *
1517 * We don't need to restore the old values from USR1, USR2, URXD and
1518 * UTXD. UBRC is read only, so only save/restore the other three
1519 * registers.
1520 */
1521 ubir = imx_uart_readl(sport, UBIR);
1522 ubmr = imx_uart_readl(sport, UBMR);
1523 uts = imx_uart_readl(sport, IMX21_UTS);
1524
1525 ucr2 = imx_uart_readl(sport, UCR2);
1526 ucr2 &= ~UCR2_SRST;
1527 imx_uart_writel(sport, ucr2, UCR2);
1528
1529 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1530 udelay(1);
1531
1532 /* Restore the registers */
1533 imx_uart_writel(sport, ubir, UBIR);
1534 imx_uart_writel(sport, ubmr, UBMR);
1535 imx_uart_writel(sport, uts, IMX21_UTS);
1536 }
1537
1538 static void
imx_uart_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)1539 imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1540 struct ktermios *old)
1541 {
1542 struct imx_port *sport = (struct imx_port *)port;
1543 unsigned long flags;
1544 u32 ucr2, old_ucr2, ufcr;
1545 unsigned int baud, quot;
1546 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1547 unsigned long div;
1548 unsigned long num, denom, old_ubir, old_ubmr;
1549 uint64_t tdiv64;
1550
1551 /*
1552 * We only support CS7 and CS8.
1553 */
1554 while ((termios->c_cflag & CSIZE) != CS7 &&
1555 (termios->c_cflag & CSIZE) != CS8) {
1556 termios->c_cflag &= ~CSIZE;
1557 termios->c_cflag |= old_csize;
1558 old_csize = CS8;
1559 }
1560
1561 del_timer_sync(&sport->timer);
1562
1563 /*
1564 * Ask the core to calculate the divisor for us.
1565 */
1566 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1567 quot = uart_get_divisor(port, baud);
1568
1569 spin_lock_irqsave(&sport->port.lock, flags);
1570
1571 /*
1572 * Read current UCR2 and save it for future use, then clear all the bits
1573 * except those we will or may need to preserve.
1574 */
1575 old_ucr2 = imx_uart_readl(sport, UCR2);
1576 ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
1577
1578 ucr2 |= UCR2_SRST | UCR2_IRTS;
1579 if ((termios->c_cflag & CSIZE) == CS8)
1580 ucr2 |= UCR2_WS;
1581
1582 if (!sport->have_rtscts)
1583 termios->c_cflag &= ~CRTSCTS;
1584
1585 if (port->rs485.flags & SER_RS485_ENABLED) {
1586 /*
1587 * RTS is mandatory for rs485 operation, so keep
1588 * it under manual control and keep transmitter
1589 * disabled.
1590 */
1591 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1592 imx_uart_rts_active(sport, &ucr2);
1593 else
1594 imx_uart_rts_inactive(sport, &ucr2);
1595
1596 } else if (termios->c_cflag & CRTSCTS) {
1597 /*
1598 * Only let receiver control RTS output if we were not requested
1599 * to have RTS inactive (which then should take precedence).
1600 */
1601 if (ucr2 & UCR2_CTS)
1602 ucr2 |= UCR2_CTSC;
1603 }
1604
1605 if (termios->c_cflag & CRTSCTS)
1606 ucr2 &= ~UCR2_IRTS;
1607
1608 if (termios->c_cflag & CSTOPB)
1609 ucr2 |= UCR2_STPB;
1610 if (termios->c_cflag & PARENB) {
1611 ucr2 |= UCR2_PREN;
1612 if (termios->c_cflag & PARODD)
1613 ucr2 |= UCR2_PROE;
1614 }
1615
1616 sport->port.read_status_mask = 0;
1617 if (termios->c_iflag & INPCK)
1618 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1619 if (termios->c_iflag & (BRKINT | PARMRK))
1620 sport->port.read_status_mask |= URXD_BRK;
1621
1622 /*
1623 * Characters to ignore
1624 */
1625 sport->port.ignore_status_mask = 0;
1626 if (termios->c_iflag & IGNPAR)
1627 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1628 if (termios->c_iflag & IGNBRK) {
1629 sport->port.ignore_status_mask |= URXD_BRK;
1630 /*
1631 * If we're ignoring parity and break indicators,
1632 * ignore overruns too (for real raw support).
1633 */
1634 if (termios->c_iflag & IGNPAR)
1635 sport->port.ignore_status_mask |= URXD_OVRRUN;
1636 }
1637
1638 if ((termios->c_cflag & CREAD) == 0)
1639 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1640
1641 /*
1642 * Update the per-port timeout.
1643 */
1644 uart_update_timeout(port, termios->c_cflag, baud);
1645
1646 /* custom-baudrate handling */
1647 div = sport->port.uartclk / (baud * 16);
1648 if (baud == 38400 && quot != div)
1649 baud = sport->port.uartclk / (quot * 16);
1650
1651 div = sport->port.uartclk / (baud * 16);
1652 if (div > 7)
1653 div = 7;
1654 if (!div)
1655 div = 1;
1656
1657 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1658 1 << 16, 1 << 16, &num, &denom);
1659
1660 tdiv64 = sport->port.uartclk;
1661 tdiv64 *= num;
1662 do_div(tdiv64, denom * 16 * div);
1663 tty_termios_encode_baud_rate(termios,
1664 (speed_t)tdiv64, (speed_t)tdiv64);
1665
1666 num -= 1;
1667 denom -= 1;
1668
1669 ufcr = imx_uart_readl(sport, UFCR);
1670 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1671 imx_uart_writel(sport, ufcr, UFCR);
1672
1673 /*
1674 * Two registers below should always be written both and in this
1675 * particular order. One consequence is that we need to check if any of
1676 * them changes and then update both. We do need the check for change
1677 * as even writing the same values seem to "restart"
1678 * transmission/receiving logic in the hardware, that leads to data
1679 * breakage even when rate doesn't in fact change. E.g., user switches
1680 * RTS/CTS handshake and suddenly gets broken bytes.
1681 */
1682 old_ubir = imx_uart_readl(sport, UBIR);
1683 old_ubmr = imx_uart_readl(sport, UBMR);
1684 if (old_ubir != num || old_ubmr != denom) {
1685 imx_uart_writel(sport, num, UBIR);
1686 imx_uart_writel(sport, denom, UBMR);
1687 }
1688
1689 if (!imx_uart_is_imx1(sport))
1690 imx_uart_writel(sport, sport->port.uartclk / div / 1000,
1691 IMX21_ONEMS);
1692
1693 imx_uart_writel(sport, ucr2, UCR2);
1694
1695 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1696 imx_uart_enable_ms(&sport->port);
1697
1698 spin_unlock_irqrestore(&sport->port.lock, flags);
1699 }
1700
imx_uart_type(struct uart_port * port)1701 static const char *imx_uart_type(struct uart_port *port)
1702 {
1703 struct imx_port *sport = (struct imx_port *)port;
1704
1705 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1706 }
1707
1708 /*
1709 * Configure/autoconfigure the port.
1710 */
imx_uart_config_port(struct uart_port * port,int flags)1711 static void imx_uart_config_port(struct uart_port *port, int flags)
1712 {
1713 struct imx_port *sport = (struct imx_port *)port;
1714
1715 if (flags & UART_CONFIG_TYPE)
1716 sport->port.type = PORT_IMX;
1717 }
1718
1719 /*
1720 * Verify the new serial_struct (for TIOCSSERIAL).
1721 * The only change we allow are to the flags and type, and
1722 * even then only between PORT_IMX and PORT_UNKNOWN
1723 */
1724 static int
imx_uart_verify_port(struct uart_port * port,struct serial_struct * ser)1725 imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1726 {
1727 struct imx_port *sport = (struct imx_port *)port;
1728 int ret = 0;
1729
1730 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1731 ret = -EINVAL;
1732 if (sport->port.irq != ser->irq)
1733 ret = -EINVAL;
1734 if (ser->io_type != UPIO_MEM)
1735 ret = -EINVAL;
1736 if (sport->port.uartclk / 16 != ser->baud_base)
1737 ret = -EINVAL;
1738 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1739 ret = -EINVAL;
1740 if (sport->port.iobase != ser->port)
1741 ret = -EINVAL;
1742 if (ser->hub6 != 0)
1743 ret = -EINVAL;
1744 return ret;
1745 }
1746
1747 #if defined(CONFIG_CONSOLE_POLL)
1748
imx_uart_poll_init(struct uart_port * port)1749 static int imx_uart_poll_init(struct uart_port *port)
1750 {
1751 struct imx_port *sport = (struct imx_port *)port;
1752 unsigned long flags;
1753 u32 ucr1, ucr2;
1754 int retval;
1755
1756 retval = clk_prepare_enable(sport->clk_ipg);
1757 if (retval)
1758 return retval;
1759 retval = clk_prepare_enable(sport->clk_per);
1760 if (retval)
1761 clk_disable_unprepare(sport->clk_ipg);
1762
1763 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1764
1765 spin_lock_irqsave(&sport->port.lock, flags);
1766
1767 /*
1768 * Be careful about the order of enabling bits here. First enable the
1769 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1770 * This prevents that a character that already sits in the RX fifo is
1771 * triggering an irq but the try to fetch it from there results in an
1772 * exception because UARTEN or RXEN is still off.
1773 */
1774 ucr1 = imx_uart_readl(sport, UCR1);
1775 ucr2 = imx_uart_readl(sport, UCR2);
1776
1777 if (imx_uart_is_imx1(sport))
1778 ucr1 |= IMX1_UCR1_UARTCLKEN;
1779
1780 ucr1 |= UCR1_UARTEN;
1781 ucr1 &= ~(UCR1_TRDYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1782
1783 ucr2 |= UCR2_RXEN;
1784 ucr2 &= ~UCR2_ATEN;
1785
1786 imx_uart_writel(sport, ucr1, UCR1);
1787 imx_uart_writel(sport, ucr2, UCR2);
1788
1789 /* now enable irqs */
1790 imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1791 imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1792
1793 spin_unlock_irqrestore(&sport->port.lock, flags);
1794
1795 return 0;
1796 }
1797
imx_uart_poll_get_char(struct uart_port * port)1798 static int imx_uart_poll_get_char(struct uart_port *port)
1799 {
1800 struct imx_port *sport = (struct imx_port *)port;
1801 if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1802 return NO_POLL_CHAR;
1803
1804 return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1805 }
1806
imx_uart_poll_put_char(struct uart_port * port,unsigned char c)1807 static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1808 {
1809 struct imx_port *sport = (struct imx_port *)port;
1810 unsigned int status;
1811
1812 /* drain */
1813 do {
1814 status = imx_uart_readl(sport, USR1);
1815 } while (~status & USR1_TRDY);
1816
1817 /* write */
1818 imx_uart_writel(sport, c, URTX0);
1819
1820 /* flush */
1821 do {
1822 status = imx_uart_readl(sport, USR2);
1823 } while (~status & USR2_TXDC);
1824 }
1825 #endif
1826
1827 /* called with port.lock taken and irqs off or from .probe without locking */
imx_uart_rs485_config(struct uart_port * port,struct serial_rs485 * rs485conf)1828 static int imx_uart_rs485_config(struct uart_port *port,
1829 struct serial_rs485 *rs485conf)
1830 {
1831 struct imx_port *sport = (struct imx_port *)port;
1832 u32 ucr2;
1833
1834 /* unimplemented */
1835 rs485conf->delay_rts_before_send = 0;
1836 rs485conf->delay_rts_after_send = 0;
1837
1838 /* RTS is required to control the transmitter */
1839 if (!sport->have_rtscts && !sport->have_rtsgpio)
1840 rs485conf->flags &= ~SER_RS485_ENABLED;
1841
1842 if (rs485conf->flags & SER_RS485_ENABLED) {
1843 /* Enable receiver if low-active RTS signal is requested */
1844 if (sport->have_rtscts && !sport->have_rtsgpio &&
1845 !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1846 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1847
1848 /* disable transmitter */
1849 ucr2 = imx_uart_readl(sport, UCR2);
1850 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1851 imx_uart_rts_active(sport, &ucr2);
1852 else
1853 imx_uart_rts_inactive(sport, &ucr2);
1854 imx_uart_writel(sport, ucr2, UCR2);
1855 }
1856
1857 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1858 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1859 rs485conf->flags & SER_RS485_RX_DURING_TX)
1860 imx_uart_start_rx(port);
1861
1862 port->rs485 = *rs485conf;
1863
1864 return 0;
1865 }
1866
1867 static const struct uart_ops imx_uart_pops = {
1868 .tx_empty = imx_uart_tx_empty,
1869 .set_mctrl = imx_uart_set_mctrl,
1870 .get_mctrl = imx_uart_get_mctrl,
1871 .stop_tx = imx_uart_stop_tx,
1872 .start_tx = imx_uart_start_tx,
1873 .stop_rx = imx_uart_stop_rx,
1874 .enable_ms = imx_uart_enable_ms,
1875 .break_ctl = imx_uart_break_ctl,
1876 .startup = imx_uart_startup,
1877 .shutdown = imx_uart_shutdown,
1878 .flush_buffer = imx_uart_flush_buffer,
1879 .set_termios = imx_uart_set_termios,
1880 .type = imx_uart_type,
1881 .config_port = imx_uart_config_port,
1882 .verify_port = imx_uart_verify_port,
1883 #if defined(CONFIG_CONSOLE_POLL)
1884 .poll_init = imx_uart_poll_init,
1885 .poll_get_char = imx_uart_poll_get_char,
1886 .poll_put_char = imx_uart_poll_put_char,
1887 #endif
1888 };
1889
1890 static struct imx_port *imx_uart_ports[UART_NR];
1891
1892 #ifdef CONFIG_SERIAL_IMX_CONSOLE
imx_uart_console_putchar(struct uart_port * port,int ch)1893 static void imx_uart_console_putchar(struct uart_port *port, int ch)
1894 {
1895 struct imx_port *sport = (struct imx_port *)port;
1896
1897 while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1898 barrier();
1899
1900 imx_uart_writel(sport, ch, URTX0);
1901 }
1902
1903 /*
1904 * Interrupts are disabled on entering
1905 */
1906 static void
imx_uart_console_write(struct console * co,const char * s,unsigned int count)1907 imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1908 {
1909 struct imx_port *sport = imx_uart_ports[co->index];
1910 struct imx_port_ucrs old_ucr;
1911 unsigned int ucr1;
1912 unsigned long flags = 0;
1913 int locked = 1;
1914 int retval;
1915
1916 retval = clk_enable(sport->clk_per);
1917 if (retval)
1918 return;
1919 retval = clk_enable(sport->clk_ipg);
1920 if (retval) {
1921 clk_disable(sport->clk_per);
1922 return;
1923 }
1924
1925 if (sport->port.sysrq)
1926 locked = 0;
1927 else if (oops_in_progress)
1928 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1929 else
1930 spin_lock_irqsave(&sport->port.lock, flags);
1931
1932 /*
1933 * First, save UCR1/2/3 and then disable interrupts
1934 */
1935 imx_uart_ucrs_save(sport, &old_ucr);
1936 ucr1 = old_ucr.ucr1;
1937
1938 if (imx_uart_is_imx1(sport))
1939 ucr1 |= IMX1_UCR1_UARTCLKEN;
1940 ucr1 |= UCR1_UARTEN;
1941 ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1942
1943 imx_uart_writel(sport, ucr1, UCR1);
1944
1945 imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
1946
1947 uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
1948
1949 /*
1950 * Finally, wait for transmitter to become empty
1951 * and restore UCR1/2/3
1952 */
1953 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
1954
1955 imx_uart_ucrs_restore(sport, &old_ucr);
1956
1957 if (locked)
1958 spin_unlock_irqrestore(&sport->port.lock, flags);
1959
1960 clk_disable(sport->clk_ipg);
1961 clk_disable(sport->clk_per);
1962 }
1963
1964 /*
1965 * If the port was already initialised (eg, by a boot loader),
1966 * try to determine the current setup.
1967 */
1968 static void __init
imx_uart_console_get_options(struct imx_port * sport,int * baud,int * parity,int * bits)1969 imx_uart_console_get_options(struct imx_port *sport, int *baud,
1970 int *parity, int *bits)
1971 {
1972
1973 if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
1974 /* ok, the port was enabled */
1975 unsigned int ucr2, ubir, ubmr, uartclk;
1976 unsigned int baud_raw;
1977 unsigned int ucfr_rfdiv;
1978
1979 ucr2 = imx_uart_readl(sport, UCR2);
1980
1981 *parity = 'n';
1982 if (ucr2 & UCR2_PREN) {
1983 if (ucr2 & UCR2_PROE)
1984 *parity = 'o';
1985 else
1986 *parity = 'e';
1987 }
1988
1989 if (ucr2 & UCR2_WS)
1990 *bits = 8;
1991 else
1992 *bits = 7;
1993
1994 ubir = imx_uart_readl(sport, UBIR) & 0xffff;
1995 ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
1996
1997 ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
1998 if (ucfr_rfdiv == 6)
1999 ucfr_rfdiv = 7;
2000 else
2001 ucfr_rfdiv = 6 - ucfr_rfdiv;
2002
2003 uartclk = clk_get_rate(sport->clk_per);
2004 uartclk /= ucfr_rfdiv;
2005
2006 { /*
2007 * The next code provides exact computation of
2008 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2009 * without need of float support or long long division,
2010 * which would be required to prevent 32bit arithmetic overflow
2011 */
2012 unsigned int mul = ubir + 1;
2013 unsigned int div = 16 * (ubmr + 1);
2014 unsigned int rem = uartclk % div;
2015
2016 baud_raw = (uartclk / div) * mul;
2017 baud_raw += (rem * mul + div / 2) / div;
2018 *baud = (baud_raw + 50) / 100 * 100;
2019 }
2020
2021 if (*baud != baud_raw)
2022 dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
2023 baud_raw, *baud);
2024 }
2025 }
2026
2027 static int __init
imx_uart_console_setup(struct console * co,char * options)2028 imx_uart_console_setup(struct console *co, char *options)
2029 {
2030 struct imx_port *sport;
2031 int baud = 9600;
2032 int bits = 8;
2033 int parity = 'n';
2034 int flow = 'n';
2035 int retval;
2036
2037 /*
2038 * Check whether an invalid uart number has been specified, and
2039 * if so, search for the first available port that does have
2040 * console support.
2041 */
2042 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2043 co->index = 0;
2044 sport = imx_uart_ports[co->index];
2045 if (sport == NULL)
2046 return -ENODEV;
2047
2048 /* For setting the registers, we only need to enable the ipg clock. */
2049 retval = clk_prepare_enable(sport->clk_ipg);
2050 if (retval)
2051 goto error_console;
2052
2053 if (options)
2054 uart_parse_options(options, &baud, &parity, &bits, &flow);
2055 else
2056 imx_uart_console_get_options(sport, &baud, &parity, &bits);
2057
2058 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2059
2060 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2061
2062 clk_disable(sport->clk_ipg);
2063 if (retval) {
2064 clk_unprepare(sport->clk_ipg);
2065 goto error_console;
2066 }
2067
2068 retval = clk_prepare(sport->clk_per);
2069 if (retval)
2070 clk_unprepare(sport->clk_ipg);
2071
2072 error_console:
2073 return retval;
2074 }
2075
2076 static struct uart_driver imx_uart_uart_driver;
2077 static struct console imx_uart_console = {
2078 .name = DEV_NAME,
2079 .write = imx_uart_console_write,
2080 .device = uart_console_device,
2081 .setup = imx_uart_console_setup,
2082 .flags = CON_PRINTBUFFER,
2083 .index = -1,
2084 .data = &imx_uart_uart_driver,
2085 };
2086
2087 #define IMX_CONSOLE &imx_uart_console
2088
2089 #ifdef CONFIG_OF
imx_uart_console_early_putchar(struct uart_port * port,int ch)2090 static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
2091 {
2092 struct imx_port *sport = (struct imx_port *)port;
2093
2094 while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
2095 cpu_relax();
2096
2097 imx_uart_writel(sport, ch, URTX0);
2098 }
2099
imx_uart_console_early_write(struct console * con,const char * s,unsigned count)2100 static void imx_uart_console_early_write(struct console *con, const char *s,
2101 unsigned count)
2102 {
2103 struct earlycon_device *dev = con->data;
2104
2105 uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
2106 }
2107
2108 static int __init
imx_console_early_setup(struct earlycon_device * dev,const char * opt)2109 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
2110 {
2111 if (!dev->port.membase)
2112 return -ENODEV;
2113
2114 dev->con->write = imx_uart_console_early_write;
2115
2116 return 0;
2117 }
2118 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2119 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2120 #endif
2121
2122 #else
2123 #define IMX_CONSOLE NULL
2124 #endif
2125
2126 static struct uart_driver imx_uart_uart_driver = {
2127 .owner = THIS_MODULE,
2128 .driver_name = DRIVER_NAME,
2129 .dev_name = DEV_NAME,
2130 .major = SERIAL_IMX_MAJOR,
2131 .minor = MINOR_START,
2132 .nr = ARRAY_SIZE(imx_uart_ports),
2133 .cons = IMX_CONSOLE,
2134 };
2135
2136 #ifdef CONFIG_OF
2137 /*
2138 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2139 * could successfully get all information from dt or a negative errno.
2140 */
imx_uart_probe_dt(struct imx_port * sport,struct platform_device * pdev)2141 static int imx_uart_probe_dt(struct imx_port *sport,
2142 struct platform_device *pdev)
2143 {
2144 struct device_node *np = pdev->dev.of_node;
2145 int ret;
2146
2147 sport->devdata = of_device_get_match_data(&pdev->dev);
2148 if (!sport->devdata)
2149 /* no device tree device */
2150 return 1;
2151
2152 ret = of_alias_get_id(np, "serial");
2153 if (ret < 0) {
2154 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2155 return ret;
2156 }
2157 sport->port.line = ret;
2158
2159 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2160 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2161 sport->have_rtscts = 1;
2162
2163 if (of_get_property(np, "fsl,dte-mode", NULL))
2164 sport->dte_mode = 1;
2165
2166 if (of_get_property(np, "rts-gpios", NULL))
2167 sport->have_rtsgpio = 1;
2168
2169 return 0;
2170 }
2171 #else
imx_uart_probe_dt(struct imx_port * sport,struct platform_device * pdev)2172 static inline int imx_uart_probe_dt(struct imx_port *sport,
2173 struct platform_device *pdev)
2174 {
2175 return 1;
2176 }
2177 #endif
2178
imx_uart_probe_pdata(struct imx_port * sport,struct platform_device * pdev)2179 static void imx_uart_probe_pdata(struct imx_port *sport,
2180 struct platform_device *pdev)
2181 {
2182 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2183
2184 sport->port.line = pdev->id;
2185 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
2186
2187 if (!pdata)
2188 return;
2189
2190 if (pdata->flags & IMXUART_HAVE_RTSCTS)
2191 sport->have_rtscts = 1;
2192 }
2193
imx_uart_probe(struct platform_device * pdev)2194 static int imx_uart_probe(struct platform_device *pdev)
2195 {
2196 struct imx_port *sport;
2197 void __iomem *base;
2198 int ret = 0;
2199 u32 ucr1;
2200 struct resource *res;
2201 int txirq, rxirq, rtsirq;
2202
2203 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2204 if (!sport)
2205 return -ENOMEM;
2206
2207 ret = imx_uart_probe_dt(sport, pdev);
2208 if (ret > 0)
2209 imx_uart_probe_pdata(sport, pdev);
2210 else if (ret < 0)
2211 return ret;
2212
2213 if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2214 dev_err(&pdev->dev, "serial%d out of range\n",
2215 sport->port.line);
2216 return -EINVAL;
2217 }
2218
2219 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2220 base = devm_ioremap_resource(&pdev->dev, res);
2221 if (IS_ERR(base))
2222 return PTR_ERR(base);
2223
2224 rxirq = platform_get_irq(pdev, 0);
2225 txirq = platform_get_irq_optional(pdev, 1);
2226 rtsirq = platform_get_irq_optional(pdev, 2);
2227
2228 sport->port.dev = &pdev->dev;
2229 sport->port.mapbase = res->start;
2230 sport->port.membase = base;
2231 sport->port.type = PORT_IMX,
2232 sport->port.iotype = UPIO_MEM;
2233 sport->port.irq = rxirq;
2234 sport->port.fifosize = 32;
2235 sport->port.ops = &imx_uart_pops;
2236 sport->port.rs485_config = imx_uart_rs485_config;
2237 sport->port.flags = UPF_BOOT_AUTOCONF;
2238 timer_setup(&sport->timer, imx_uart_timeout, 0);
2239
2240 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2241 if (IS_ERR(sport->gpios))
2242 return PTR_ERR(sport->gpios);
2243
2244 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2245 if (IS_ERR(sport->clk_ipg)) {
2246 ret = PTR_ERR(sport->clk_ipg);
2247 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2248 return ret;
2249 }
2250
2251 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2252 if (IS_ERR(sport->clk_per)) {
2253 ret = PTR_ERR(sport->clk_per);
2254 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2255 return ret;
2256 }
2257
2258 sport->port.uartclk = clk_get_rate(sport->clk_per);
2259
2260 /* For register access, we only need to enable the ipg clock. */
2261 ret = clk_prepare_enable(sport->clk_ipg);
2262 if (ret) {
2263 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2264 return ret;
2265 }
2266
2267 /* initialize shadow register values */
2268 sport->ucr1 = readl(sport->port.membase + UCR1);
2269 sport->ucr2 = readl(sport->port.membase + UCR2);
2270 sport->ucr3 = readl(sport->port.membase + UCR3);
2271 sport->ucr4 = readl(sport->port.membase + UCR4);
2272 sport->ufcr = readl(sport->port.membase + UFCR);
2273
2274 uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2275
2276 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2277 (!sport->have_rtscts && !sport->have_rtsgpio))
2278 dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2279
2280 /*
2281 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2282 * signal cannot be set low during transmission in case the
2283 * receiver is off (limitation of the i.MX UART IP).
2284 */
2285 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2286 sport->have_rtscts && !sport->have_rtsgpio &&
2287 (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2288 !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2289 dev_err(&pdev->dev,
2290 "low-active RTS not possible when receiver is off, enabling receiver\n");
2291
2292 imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2293
2294 /* Disable interrupts before requesting them */
2295 ucr1 = imx_uart_readl(sport, UCR1);
2296 ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2297 UCR1_TRDYEN | UCR1_RTSDEN);
2298 imx_uart_writel(sport, ucr1, UCR1);
2299
2300 if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2301 /*
2302 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2303 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2304 * and DCD (when they are outputs) or enables the respective
2305 * irqs. So set this bit early, i.e. before requesting irqs.
2306 */
2307 u32 ufcr = imx_uart_readl(sport, UFCR);
2308 if (!(ufcr & UFCR_DCEDTE))
2309 imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2310
2311 /*
2312 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2313 * enabled later because they cannot be cleared
2314 * (confirmed on i.MX25) which makes them unusable.
2315 */
2316 imx_uart_writel(sport,
2317 IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2318 UCR3);
2319
2320 } else {
2321 u32 ucr3 = UCR3_DSR;
2322 u32 ufcr = imx_uart_readl(sport, UFCR);
2323 if (ufcr & UFCR_DCEDTE)
2324 imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2325
2326 if (!imx_uart_is_imx1(sport))
2327 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2328 imx_uart_writel(sport, ucr3, UCR3);
2329 }
2330
2331 clk_disable_unprepare(sport->clk_ipg);
2332
2333 /*
2334 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2335 * chips only have one interrupt.
2336 */
2337 if (txirq > 0) {
2338 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2339 dev_name(&pdev->dev), sport);
2340 if (ret) {
2341 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2342 ret);
2343 return ret;
2344 }
2345
2346 ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2347 dev_name(&pdev->dev), sport);
2348 if (ret) {
2349 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2350 ret);
2351 return ret;
2352 }
2353
2354 ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
2355 dev_name(&pdev->dev), sport);
2356 if (ret) {
2357 dev_err(&pdev->dev, "failed to request rts irq: %d\n",
2358 ret);
2359 return ret;
2360 }
2361 } else {
2362 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2363 dev_name(&pdev->dev), sport);
2364 if (ret) {
2365 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2366 return ret;
2367 }
2368 }
2369
2370 imx_uart_ports[sport->port.line] = sport;
2371
2372 platform_set_drvdata(pdev, sport);
2373
2374 return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2375 }
2376
imx_uart_remove(struct platform_device * pdev)2377 static int imx_uart_remove(struct platform_device *pdev)
2378 {
2379 struct imx_port *sport = platform_get_drvdata(pdev);
2380
2381 return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2382 }
2383
imx_uart_restore_context(struct imx_port * sport)2384 static void imx_uart_restore_context(struct imx_port *sport)
2385 {
2386 unsigned long flags;
2387
2388 spin_lock_irqsave(&sport->port.lock, flags);
2389 if (!sport->context_saved) {
2390 spin_unlock_irqrestore(&sport->port.lock, flags);
2391 return;
2392 }
2393
2394 imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2395 imx_uart_writel(sport, sport->saved_reg[5], UESC);
2396 imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2397 imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2398 imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2399 imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2400 imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2401 imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2402 imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2403 imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2404 sport->context_saved = false;
2405 spin_unlock_irqrestore(&sport->port.lock, flags);
2406 }
2407
imx_uart_save_context(struct imx_port * sport)2408 static void imx_uart_save_context(struct imx_port *sport)
2409 {
2410 unsigned long flags;
2411
2412 /* Save necessary regs */
2413 spin_lock_irqsave(&sport->port.lock, flags);
2414 sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2415 sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2416 sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2417 sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2418 sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2419 sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2420 sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2421 sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2422 sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2423 sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2424 sport->context_saved = true;
2425 spin_unlock_irqrestore(&sport->port.lock, flags);
2426 }
2427
imx_uart_enable_wakeup(struct imx_port * sport,bool on)2428 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2429 {
2430 u32 ucr3;
2431
2432 ucr3 = imx_uart_readl(sport, UCR3);
2433 if (on) {
2434 imx_uart_writel(sport, USR1_AWAKE, USR1);
2435 ucr3 |= UCR3_AWAKEN;
2436 } else {
2437 ucr3 &= ~UCR3_AWAKEN;
2438 }
2439 imx_uart_writel(sport, ucr3, UCR3);
2440
2441 if (sport->have_rtscts) {
2442 u32 ucr1 = imx_uart_readl(sport, UCR1);
2443 if (on)
2444 ucr1 |= UCR1_RTSDEN;
2445 else
2446 ucr1 &= ~UCR1_RTSDEN;
2447 imx_uart_writel(sport, ucr1, UCR1);
2448 }
2449 }
2450
imx_uart_suspend_noirq(struct device * dev)2451 static int imx_uart_suspend_noirq(struct device *dev)
2452 {
2453 struct imx_port *sport = dev_get_drvdata(dev);
2454
2455 imx_uart_save_context(sport);
2456
2457 clk_disable(sport->clk_ipg);
2458
2459 pinctrl_pm_select_sleep_state(dev);
2460
2461 return 0;
2462 }
2463
imx_uart_resume_noirq(struct device * dev)2464 static int imx_uart_resume_noirq(struct device *dev)
2465 {
2466 struct imx_port *sport = dev_get_drvdata(dev);
2467 int ret;
2468
2469 pinctrl_pm_select_default_state(dev);
2470
2471 ret = clk_enable(sport->clk_ipg);
2472 if (ret)
2473 return ret;
2474
2475 imx_uart_restore_context(sport);
2476
2477 return 0;
2478 }
2479
imx_uart_suspend(struct device * dev)2480 static int imx_uart_suspend(struct device *dev)
2481 {
2482 struct imx_port *sport = dev_get_drvdata(dev);
2483 int ret;
2484
2485 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2486 disable_irq(sport->port.irq);
2487
2488 ret = clk_prepare_enable(sport->clk_ipg);
2489 if (ret)
2490 return ret;
2491
2492 /* enable wakeup from i.MX UART */
2493 imx_uart_enable_wakeup(sport, true);
2494
2495 return 0;
2496 }
2497
imx_uart_resume(struct device * dev)2498 static int imx_uart_resume(struct device *dev)
2499 {
2500 struct imx_port *sport = dev_get_drvdata(dev);
2501
2502 /* disable wakeup from i.MX UART */
2503 imx_uart_enable_wakeup(sport, false);
2504
2505 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2506 enable_irq(sport->port.irq);
2507
2508 clk_disable_unprepare(sport->clk_ipg);
2509
2510 return 0;
2511 }
2512
imx_uart_freeze(struct device * dev)2513 static int imx_uart_freeze(struct device *dev)
2514 {
2515 struct imx_port *sport = dev_get_drvdata(dev);
2516
2517 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2518
2519 return clk_prepare_enable(sport->clk_ipg);
2520 }
2521
imx_uart_thaw(struct device * dev)2522 static int imx_uart_thaw(struct device *dev)
2523 {
2524 struct imx_port *sport = dev_get_drvdata(dev);
2525
2526 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2527
2528 clk_disable_unprepare(sport->clk_ipg);
2529
2530 return 0;
2531 }
2532
2533 static const struct dev_pm_ops imx_uart_pm_ops = {
2534 .suspend_noirq = imx_uart_suspend_noirq,
2535 .resume_noirq = imx_uart_resume_noirq,
2536 .freeze_noirq = imx_uart_suspend_noirq,
2537 .restore_noirq = imx_uart_resume_noirq,
2538 .suspend = imx_uart_suspend,
2539 .resume = imx_uart_resume,
2540 .freeze = imx_uart_freeze,
2541 .thaw = imx_uart_thaw,
2542 .restore = imx_uart_thaw,
2543 };
2544
2545 static struct platform_driver imx_uart_platform_driver = {
2546 .probe = imx_uart_probe,
2547 .remove = imx_uart_remove,
2548
2549 .id_table = imx_uart_devtype,
2550 .driver = {
2551 .name = "imx-uart",
2552 .of_match_table = imx_uart_dt_ids,
2553 .pm = &imx_uart_pm_ops,
2554 },
2555 };
2556
imx_uart_init(void)2557 static int __init imx_uart_init(void)
2558 {
2559 int ret = uart_register_driver(&imx_uart_uart_driver);
2560
2561 if (ret)
2562 return ret;
2563
2564 ret = platform_driver_register(&imx_uart_platform_driver);
2565 if (ret != 0)
2566 uart_unregister_driver(&imx_uart_uart_driver);
2567
2568 return ret;
2569 }
2570
imx_uart_exit(void)2571 static void __exit imx_uart_exit(void)
2572 {
2573 platform_driver_unregister(&imx_uart_platform_driver);
2574 uart_unregister_driver(&imx_uart_uart_driver);
2575 }
2576
2577 module_init(imx_uart_init);
2578 module_exit(imx_uart_exit);
2579
2580 MODULE_AUTHOR("Sascha Hauer");
2581 MODULE_DESCRIPTION("IMX generic serial port driver");
2582 MODULE_LICENSE("GPL");
2583 MODULE_ALIAS("platform:imx-uart");
2584
