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/rational.h>
28 #include <linux/slab.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31 #include <linux/io.h>
32 #include <linux/dma-mapping.h>
33
34 #include <asm/irq.h>
35 #include <linux/platform_data/serial-imx.h>
36 #include <linux/platform_data/dma-imx.h>
37
38 #include "serial_mctrl_gpio.h"
39
40 /* Register definitions */
41 #define URXD0 0x0 /* Receiver Register */
42 #define URTX0 0x40 /* Transmitter Register */
43 #define UCR1 0x80 /* Control Register 1 */
44 #define UCR2 0x84 /* Control Register 2 */
45 #define UCR3 0x88 /* Control Register 3 */
46 #define UCR4 0x8c /* Control Register 4 */
47 #define UFCR 0x90 /* FIFO Control Register */
48 #define USR1 0x94 /* Status Register 1 */
49 #define USR2 0x98 /* Status Register 2 */
50 #define UESC 0x9c /* Escape Character Register */
51 #define UTIM 0xa0 /* Escape Timer Register */
52 #define UBIR 0xa4 /* BRM Incremental Register */
53 #define UBMR 0xa8 /* BRM Modulator Register */
54 #define UBRC 0xac /* Baud Rate Count Register */
55 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
56 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
57 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
58
59 /* UART Control Register Bit Fields.*/
60 #define URXD_DUMMY_READ (1<<16)
61 #define URXD_CHARRDY (1<<15)
62 #define URXD_ERR (1<<14)
63 #define URXD_OVRRUN (1<<13)
64 #define URXD_FRMERR (1<<12)
65 #define URXD_BRK (1<<11)
66 #define URXD_PRERR (1<<10)
67 #define URXD_RX_DATA (0xFF<<0)
68 #define UCR1_ADEN (1<<15) /* Auto detect interrupt */
69 #define UCR1_ADBR (1<<14) /* Auto detect baud rate */
70 #define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
71 #define UCR1_IDEN (1<<12) /* Idle condition interrupt */
72 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
73 #define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
74 #define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
75 #define UCR1_IREN (1<<7) /* Infrared interface enable */
76 #define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
77 #define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
78 #define UCR1_SNDBRK (1<<4) /* Send break */
79 #define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
80 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
81 #define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
82 #define UCR1_DOZE (1<<1) /* Doze */
83 #define UCR1_UARTEN (1<<0) /* UART enabled */
84 #define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
85 #define UCR2_IRTS (1<<14) /* Ignore RTS pin */
86 #define UCR2_CTSC (1<<13) /* CTS pin control */
87 #define UCR2_CTS (1<<12) /* Clear to send */
88 #define UCR2_ESCEN (1<<11) /* Escape enable */
89 #define UCR2_PREN (1<<8) /* Parity enable */
90 #define UCR2_PROE (1<<7) /* Parity odd/even */
91 #define UCR2_STPB (1<<6) /* Stop */
92 #define UCR2_WS (1<<5) /* Word size */
93 #define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
94 #define UCR2_ATEN (1<<3) /* Aging Timer Enable */
95 #define UCR2_TXEN (1<<2) /* Transmitter enabled */
96 #define UCR2_RXEN (1<<1) /* Receiver enabled */
97 #define UCR2_SRST (1<<0) /* SW reset */
98 #define UCR3_DTREN (1<<13) /* DTR interrupt enable */
99 #define UCR3_PARERREN (1<<12) /* Parity enable */
100 #define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
101 #define UCR3_DSR (1<<10) /* Data set ready */
102 #define UCR3_DCD (1<<9) /* Data carrier detect */
103 #define UCR3_RI (1<<8) /* Ring indicator */
104 #define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
105 #define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
106 #define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
107 #define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
108 #define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
109 #define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
110 #define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
111 #define UCR3_BPEN (1<<0) /* Preset registers enable */
112 #define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
113 #define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
114 #define UCR4_INVR (1<<9) /* Inverted infrared reception */
115 #define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
116 #define UCR4_WKEN (1<<7) /* Wake interrupt enable */
117 #define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
118 #define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
119 #define UCR4_IRSC (1<<5) /* IR special case */
120 #define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
121 #define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
122 #define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
123 #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
124 #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
125 #define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
126 #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
127 #define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
128 #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
129 #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
130 #define USR1_RTSS (1<<14) /* RTS pin status */
131 #define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
132 #define USR1_RTSD (1<<12) /* RTS delta */
133 #define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
134 #define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
135 #define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
136 #define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
137 #define USR1_DTRD (1<<7) /* DTR Delta */
138 #define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
139 #define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
140 #define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
141 #define USR2_ADET (1<<15) /* Auto baud rate detect complete */
142 #define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
143 #define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
144 #define USR2_IDLE (1<<12) /* Idle condition */
145 #define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
146 #define USR2_RIIN (1<<9) /* Ring Indicator Input */
147 #define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
148 #define USR2_WAKE (1<<7) /* Wake */
149 #define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
150 #define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
151 #define USR2_TXDC (1<<3) /* Transmitter complete */
152 #define USR2_BRCD (1<<2) /* Break condition */
153 #define USR2_ORE (1<<1) /* Overrun error */
154 #define USR2_RDR (1<<0) /* Recv data ready */
155 #define UTS_FRCPERR (1<<13) /* Force parity error */
156 #define UTS_LOOP (1<<12) /* Loop tx and rx */
157 #define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
158 #define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
159 #define UTS_TXFULL (1<<4) /* TxFIFO full */
160 #define UTS_RXFULL (1<<3) /* RxFIFO full */
161 #define UTS_SOFTRST (1<<0) /* Software reset */
162
163 /* We've been assigned a range on the "Low-density serial ports" major */
164 #define SERIAL_IMX_MAJOR 207
165 #define MINOR_START 16
166 #define DEV_NAME "ttymxc"
167
168 /*
169 * This determines how often we check the modem status signals
170 * for any change. They generally aren't connected to an IRQ
171 * so we have to poll them. We also check immediately before
172 * filling the TX fifo incase CTS has been dropped.
173 */
174 #define MCTRL_TIMEOUT (250*HZ/1000)
175
176 #define DRIVER_NAME "IMX-uart"
177
178 #define UART_NR 8
179
180 /* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
181 enum imx_uart_type {
182 IMX1_UART,
183 IMX21_UART,
184 IMX53_UART,
185 IMX6Q_UART,
186 };
187
188 /* device type dependent stuff */
189 struct imx_uart_data {
190 unsigned uts_reg;
191 enum imx_uart_type devtype;
192 };
193
194 struct imx_port {
195 struct uart_port port;
196 struct timer_list timer;
197 unsigned int old_status;
198 unsigned int have_rtscts:1;
199 unsigned int have_rtsgpio:1;
200 unsigned int dte_mode:1;
201 struct clk *clk_ipg;
202 struct clk *clk_per;
203 const struct imx_uart_data *devdata;
204
205 struct mctrl_gpios *gpios;
206
207 /* shadow registers */
208 unsigned int ucr1;
209 unsigned int ucr2;
210 unsigned int ucr3;
211 unsigned int ucr4;
212 unsigned int ufcr;
213
214 /* DMA fields */
215 unsigned int dma_is_enabled:1;
216 unsigned int dma_is_rxing:1;
217 unsigned int dma_is_txing:1;
218 struct dma_chan *dma_chan_rx, *dma_chan_tx;
219 struct scatterlist rx_sgl, tx_sgl[2];
220 void *rx_buf;
221 struct circ_buf rx_ring;
222 unsigned int rx_periods;
223 dma_cookie_t rx_cookie;
224 unsigned int tx_bytes;
225 unsigned int dma_tx_nents;
226 unsigned int saved_reg[10];
227 bool context_saved;
228 };
229
230 struct imx_port_ucrs {
231 unsigned int ucr1;
232 unsigned int ucr2;
233 unsigned int ucr3;
234 };
235
236 static struct imx_uart_data imx_uart_devdata[] = {
237 [IMX1_UART] = {
238 .uts_reg = IMX1_UTS,
239 .devtype = IMX1_UART,
240 },
241 [IMX21_UART] = {
242 .uts_reg = IMX21_UTS,
243 .devtype = IMX21_UART,
244 },
245 [IMX53_UART] = {
246 .uts_reg = IMX21_UTS,
247 .devtype = IMX53_UART,
248 },
249 [IMX6Q_UART] = {
250 .uts_reg = IMX21_UTS,
251 .devtype = IMX6Q_UART,
252 },
253 };
254
255 static const struct platform_device_id imx_uart_devtype[] = {
256 {
257 .name = "imx1-uart",
258 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
259 }, {
260 .name = "imx21-uart",
261 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
262 }, {
263 .name = "imx53-uart",
264 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
265 }, {
266 .name = "imx6q-uart",
267 .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
268 }, {
269 /* sentinel */
270 }
271 };
272 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
273
274 static const struct of_device_id imx_uart_dt_ids[] = {
275 { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
276 { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
277 { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
278 { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
279 { /* sentinel */ }
280 };
281 MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
282
imx_uart_writel(struct imx_port * sport,u32 val,u32 offset)283 static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
284 {
285 switch (offset) {
286 case UCR1:
287 sport->ucr1 = val;
288 break;
289 case UCR2:
290 sport->ucr2 = val;
291 break;
292 case UCR3:
293 sport->ucr3 = val;
294 break;
295 case UCR4:
296 sport->ucr4 = val;
297 break;
298 case UFCR:
299 sport->ufcr = val;
300 break;
301 default:
302 break;
303 }
304 writel(val, sport->port.membase + offset);
305 }
306
imx_uart_readl(struct imx_port * sport,u32 offset)307 static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
308 {
309 switch (offset) {
310 case UCR1:
311 return sport->ucr1;
312 break;
313 case UCR2:
314 /*
315 * UCR2_SRST is the only bit in the cached registers that might
316 * differ from the value that was last written. As it only
317 * automatically becomes one after being cleared, reread
318 * conditionally.
319 */
320 if (!(sport->ucr2 & UCR2_SRST))
321 sport->ucr2 = readl(sport->port.membase + offset);
322 return sport->ucr2;
323 break;
324 case UCR3:
325 return sport->ucr3;
326 break;
327 case UCR4:
328 return sport->ucr4;
329 break;
330 case UFCR:
331 return sport->ufcr;
332 break;
333 default:
334 return readl(sport->port.membase + offset);
335 }
336 }
337
imx_uart_uts_reg(struct imx_port * sport)338 static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
339 {
340 return sport->devdata->uts_reg;
341 }
342
imx_uart_is_imx1(struct imx_port * sport)343 static inline int imx_uart_is_imx1(struct imx_port *sport)
344 {
345 return sport->devdata->devtype == IMX1_UART;
346 }
347
imx_uart_is_imx21(struct imx_port * sport)348 static inline int imx_uart_is_imx21(struct imx_port *sport)
349 {
350 return sport->devdata->devtype == IMX21_UART;
351 }
352
imx_uart_is_imx53(struct imx_port * sport)353 static inline int imx_uart_is_imx53(struct imx_port *sport)
354 {
355 return sport->devdata->devtype == IMX53_UART;
356 }
357
imx_uart_is_imx6q(struct imx_port * sport)358 static inline int imx_uart_is_imx6q(struct imx_port *sport)
359 {
360 return sport->devdata->devtype == IMX6Q_UART;
361 }
362 /*
363 * Save and restore functions for UCR1, UCR2 and UCR3 registers
364 */
365 #if defined(CONFIG_SERIAL_IMX_CONSOLE)
imx_uart_ucrs_save(struct imx_port * sport,struct imx_port_ucrs * ucr)366 static void imx_uart_ucrs_save(struct imx_port *sport,
367 struct imx_port_ucrs *ucr)
368 {
369 /* save control registers */
370 ucr->ucr1 = imx_uart_readl(sport, UCR1);
371 ucr->ucr2 = imx_uart_readl(sport, UCR2);
372 ucr->ucr3 = imx_uart_readl(sport, UCR3);
373 }
374
imx_uart_ucrs_restore(struct imx_port * sport,struct imx_port_ucrs * ucr)375 static void imx_uart_ucrs_restore(struct imx_port *sport,
376 struct imx_port_ucrs *ucr)
377 {
378 /* restore control registers */
379 imx_uart_writel(sport, ucr->ucr1, UCR1);
380 imx_uart_writel(sport, ucr->ucr2, UCR2);
381 imx_uart_writel(sport, ucr->ucr3, UCR3);
382 }
383 #endif
384
imx_uart_rts_active(struct imx_port * sport,u32 * ucr2)385 static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
386 {
387 *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
388
389 sport->port.mctrl |= TIOCM_RTS;
390 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
391 }
392
imx_uart_rts_inactive(struct imx_port * sport,u32 * ucr2)393 static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
394 {
395 *ucr2 &= ~UCR2_CTSC;
396 *ucr2 |= UCR2_CTS;
397
398 sport->port.mctrl &= ~TIOCM_RTS;
399 mctrl_gpio_set(sport->gpios, sport->port.mctrl);
400 }
401
imx_uart_rts_auto(struct imx_port * sport,u32 * ucr2)402 static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
403 {
404 *ucr2 |= UCR2_CTSC;
405 }
406
407 /* called with port.lock taken and irqs off */
imx_uart_start_rx(struct uart_port * port)408 static void imx_uart_start_rx(struct uart_port *port)
409 {
410 struct imx_port *sport = (struct imx_port *)port;
411 unsigned int ucr1, ucr2;
412
413 ucr1 = imx_uart_readl(sport, UCR1);
414 ucr2 = imx_uart_readl(sport, UCR2);
415
416 ucr2 |= UCR2_RXEN;
417
418 if (sport->dma_is_enabled) {
419 ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
420 } else {
421 ucr1 |= UCR1_RRDYEN;
422 ucr2 |= UCR2_ATEN;
423 }
424
425 /* Write UCR2 first as it includes RXEN */
426 imx_uart_writel(sport, ucr2, UCR2);
427 imx_uart_writel(sport, ucr1, UCR1);
428 }
429
430 /* called with port.lock taken and irqs off */
imx_uart_stop_tx(struct uart_port * port)431 static void imx_uart_stop_tx(struct uart_port *port)
432 {
433 struct imx_port *sport = (struct imx_port *)port;
434 u32 ucr1;
435
436 /*
437 * We are maybe in the SMP context, so if the DMA TX thread is running
438 * on other cpu, we have to wait for it to finish.
439 */
440 if (sport->dma_is_txing)
441 return;
442
443 ucr1 = imx_uart_readl(sport, UCR1);
444 imx_uart_writel(sport, ucr1 & ~UCR1_TXMPTYEN, UCR1);
445
446 /* in rs485 mode disable transmitter if shifter is empty */
447 if (port->rs485.flags & SER_RS485_ENABLED &&
448 imx_uart_readl(sport, USR2) & USR2_TXDC) {
449 u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
450 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
451 imx_uart_rts_active(sport, &ucr2);
452 else
453 imx_uart_rts_inactive(sport, &ucr2);
454 imx_uart_writel(sport, ucr2, UCR2);
455
456 imx_uart_start_rx(port);
457
458 ucr4 = imx_uart_readl(sport, UCR4);
459 ucr4 &= ~UCR4_TCEN;
460 imx_uart_writel(sport, ucr4, UCR4);
461 }
462 }
463
464 /* called with port.lock taken and irqs off */
imx_uart_stop_rx(struct uart_port * port)465 static void imx_uart_stop_rx(struct uart_port *port)
466 {
467 struct imx_port *sport = (struct imx_port *)port;
468 u32 ucr1, ucr2;
469
470 ucr1 = imx_uart_readl(sport, UCR1);
471 ucr2 = imx_uart_readl(sport, UCR2);
472
473 if (sport->dma_is_enabled) {
474 ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
475 } else {
476 ucr1 &= ~UCR1_RRDYEN;
477 ucr2 &= ~UCR2_ATEN;
478 }
479 imx_uart_writel(sport, ucr1, UCR1);
480
481 ucr2 &= ~UCR2_RXEN;
482 imx_uart_writel(sport, ucr2, UCR2);
483 }
484
485 /* called with port.lock taken and irqs off */
imx_uart_enable_ms(struct uart_port * port)486 static void imx_uart_enable_ms(struct uart_port *port)
487 {
488 struct imx_port *sport = (struct imx_port *)port;
489
490 mod_timer(&sport->timer, jiffies);
491
492 mctrl_gpio_enable_ms(sport->gpios);
493 }
494
495 static void imx_uart_dma_tx(struct imx_port *sport);
496
497 /* called with port.lock taken and irqs off */
imx_uart_transmit_buffer(struct imx_port * sport)498 static inline void imx_uart_transmit_buffer(struct imx_port *sport)
499 {
500 struct circ_buf *xmit = &sport->port.state->xmit;
501
502 if (sport->port.x_char) {
503 /* Send next char */
504 imx_uart_writel(sport, sport->port.x_char, URTX0);
505 sport->port.icount.tx++;
506 sport->port.x_char = 0;
507 return;
508 }
509
510 if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
511 imx_uart_stop_tx(&sport->port);
512 return;
513 }
514
515 if (sport->dma_is_enabled) {
516 u32 ucr1;
517 /*
518 * We've just sent a X-char Ensure the TX DMA is enabled
519 * and the TX IRQ is disabled.
520 **/
521 ucr1 = imx_uart_readl(sport, UCR1);
522 ucr1 &= ~UCR1_TXMPTYEN;
523 if (sport->dma_is_txing) {
524 ucr1 |= UCR1_TXDMAEN;
525 imx_uart_writel(sport, ucr1, UCR1);
526 } else {
527 imx_uart_writel(sport, ucr1, UCR1);
528 imx_uart_dma_tx(sport);
529 }
530
531 return;
532 }
533
534 while (!uart_circ_empty(xmit) &&
535 !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
536 /* send xmit->buf[xmit->tail]
537 * out the port here */
538 imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
539 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
540 sport->port.icount.tx++;
541 }
542
543 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
544 uart_write_wakeup(&sport->port);
545
546 if (uart_circ_empty(xmit))
547 imx_uart_stop_tx(&sport->port);
548 }
549
imx_uart_dma_tx_callback(void * data)550 static void imx_uart_dma_tx_callback(void *data)
551 {
552 struct imx_port *sport = data;
553 struct scatterlist *sgl = &sport->tx_sgl[0];
554 struct circ_buf *xmit = &sport->port.state->xmit;
555 unsigned long flags;
556 u32 ucr1;
557
558 spin_lock_irqsave(&sport->port.lock, flags);
559
560 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
561
562 ucr1 = imx_uart_readl(sport, UCR1);
563 ucr1 &= ~UCR1_TXDMAEN;
564 imx_uart_writel(sport, ucr1, UCR1);
565
566 /* update the stat */
567 xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
568 sport->port.icount.tx += sport->tx_bytes;
569
570 dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
571
572 sport->dma_is_txing = 0;
573
574 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
575 uart_write_wakeup(&sport->port);
576
577 if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
578 imx_uart_dma_tx(sport);
579 else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
580 u32 ucr4 = imx_uart_readl(sport, UCR4);
581 ucr4 |= UCR4_TCEN;
582 imx_uart_writel(sport, ucr4, UCR4);
583 }
584
585 spin_unlock_irqrestore(&sport->port.lock, flags);
586 }
587
588 /* called with port.lock taken and irqs off */
imx_uart_dma_tx(struct imx_port * sport)589 static void imx_uart_dma_tx(struct imx_port *sport)
590 {
591 struct circ_buf *xmit = &sport->port.state->xmit;
592 struct scatterlist *sgl = sport->tx_sgl;
593 struct dma_async_tx_descriptor *desc;
594 struct dma_chan *chan = sport->dma_chan_tx;
595 struct device *dev = sport->port.dev;
596 u32 ucr1, ucr4;
597 int ret;
598
599 if (sport->dma_is_txing)
600 return;
601
602 ucr4 = imx_uart_readl(sport, UCR4);
603 ucr4 &= ~UCR4_TCEN;
604 imx_uart_writel(sport, ucr4, UCR4);
605
606 sport->tx_bytes = uart_circ_chars_pending(xmit);
607
608 if (xmit->tail < xmit->head) {
609 sport->dma_tx_nents = 1;
610 sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
611 } else {
612 sport->dma_tx_nents = 2;
613 sg_init_table(sgl, 2);
614 sg_set_buf(sgl, xmit->buf + xmit->tail,
615 UART_XMIT_SIZE - xmit->tail);
616 sg_set_buf(sgl + 1, xmit->buf, xmit->head);
617 }
618
619 ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
620 if (ret == 0) {
621 dev_err(dev, "DMA mapping error for TX.\n");
622 return;
623 }
624 desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
625 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
626 if (!desc) {
627 dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
628 DMA_TO_DEVICE);
629 dev_err(dev, "We cannot prepare for the TX slave dma!\n");
630 return;
631 }
632 desc->callback = imx_uart_dma_tx_callback;
633 desc->callback_param = sport;
634
635 dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
636 uart_circ_chars_pending(xmit));
637
638 ucr1 = imx_uart_readl(sport, UCR1);
639 ucr1 |= UCR1_TXDMAEN;
640 imx_uart_writel(sport, ucr1, UCR1);
641
642 /* fire it */
643 sport->dma_is_txing = 1;
644 dmaengine_submit(desc);
645 dma_async_issue_pending(chan);
646 return;
647 }
648
649 /* called with port.lock taken and irqs off */
imx_uart_start_tx(struct uart_port * port)650 static void imx_uart_start_tx(struct uart_port *port)
651 {
652 struct imx_port *sport = (struct imx_port *)port;
653 u32 ucr1;
654
655 if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
656 return;
657
658 if (port->rs485.flags & SER_RS485_ENABLED) {
659 u32 ucr2;
660
661 ucr2 = imx_uart_readl(sport, UCR2);
662 if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
663 imx_uart_rts_active(sport, &ucr2);
664 else
665 imx_uart_rts_inactive(sport, &ucr2);
666 imx_uart_writel(sport, ucr2, UCR2);
667
668 if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
669 imx_uart_stop_rx(port);
670
671 /*
672 * Enable transmitter and shifter empty irq only if DMA is off.
673 * In the DMA case this is done in the tx-callback.
674 */
675 if (!sport->dma_is_enabled) {
676 u32 ucr4 = imx_uart_readl(sport, UCR4);
677 ucr4 |= UCR4_TCEN;
678 imx_uart_writel(sport, ucr4, UCR4);
679 }
680 }
681
682 if (!sport->dma_is_enabled) {
683 ucr1 = imx_uart_readl(sport, UCR1);
684 imx_uart_writel(sport, ucr1 | UCR1_TXMPTYEN, UCR1);
685 }
686
687 if (sport->dma_is_enabled) {
688 if (sport->port.x_char) {
689 /* We have X-char to send, so enable TX IRQ and
690 * disable TX DMA to let TX interrupt to send X-char */
691 ucr1 = imx_uart_readl(sport, UCR1);
692 ucr1 &= ~UCR1_TXDMAEN;
693 ucr1 |= UCR1_TXMPTYEN;
694 imx_uart_writel(sport, ucr1, UCR1);
695 return;
696 }
697
698 if (!uart_circ_empty(&port->state->xmit) &&
699 !uart_tx_stopped(port))
700 imx_uart_dma_tx(sport);
701 return;
702 }
703 }
704
imx_uart_rtsint(int irq,void * dev_id)705 static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
706 {
707 struct imx_port *sport = dev_id;
708 u32 usr1;
709 unsigned long flags;
710
711 spin_lock_irqsave(&sport->port.lock, flags);
712
713 imx_uart_writel(sport, USR1_RTSD, USR1);
714 usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
715 uart_handle_cts_change(&sport->port, !!usr1);
716 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
717
718 spin_unlock_irqrestore(&sport->port.lock, flags);
719 return IRQ_HANDLED;
720 }
721
imx_uart_txint(int irq,void * dev_id)722 static irqreturn_t imx_uart_txint(int irq, void *dev_id)
723 {
724 struct imx_port *sport = dev_id;
725 unsigned long flags;
726
727 spin_lock_irqsave(&sport->port.lock, flags);
728 imx_uart_transmit_buffer(sport);
729 spin_unlock_irqrestore(&sport->port.lock, flags);
730 return IRQ_HANDLED;
731 }
732
imx_uart_rxint(int irq,void * dev_id)733 static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
734 {
735 struct imx_port *sport = dev_id;
736 unsigned int rx, flg, ignored = 0;
737 struct tty_port *port = &sport->port.state->port;
738 unsigned long flags;
739
740 spin_lock_irqsave(&sport->port.lock, flags);
741
742 while (imx_uart_readl(sport, USR2) & USR2_RDR) {
743 u32 usr2;
744
745 flg = TTY_NORMAL;
746 sport->port.icount.rx++;
747
748 rx = imx_uart_readl(sport, URXD0);
749
750 usr2 = imx_uart_readl(sport, USR2);
751 if (usr2 & USR2_BRCD) {
752 imx_uart_writel(sport, USR2_BRCD, USR2);
753 if (uart_handle_break(&sport->port))
754 continue;
755 }
756
757 if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
758 continue;
759
760 if (unlikely(rx & URXD_ERR)) {
761 if (rx & URXD_BRK)
762 sport->port.icount.brk++;
763 else if (rx & URXD_PRERR)
764 sport->port.icount.parity++;
765 else if (rx & URXD_FRMERR)
766 sport->port.icount.frame++;
767 if (rx & URXD_OVRRUN)
768 sport->port.icount.overrun++;
769
770 if (rx & sport->port.ignore_status_mask) {
771 if (++ignored > 100)
772 goto out;
773 continue;
774 }
775
776 rx &= (sport->port.read_status_mask | 0xFF);
777
778 if (rx & URXD_BRK)
779 flg = TTY_BREAK;
780 else if (rx & URXD_PRERR)
781 flg = TTY_PARITY;
782 else if (rx & URXD_FRMERR)
783 flg = TTY_FRAME;
784 if (rx & URXD_OVRRUN)
785 flg = TTY_OVERRUN;
786
787 #ifdef SUPPORT_SYSRQ
788 sport->port.sysrq = 0;
789 #endif
790 }
791
792 if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
793 goto out;
794
795 if (tty_insert_flip_char(port, rx, flg) == 0)
796 sport->port.icount.buf_overrun++;
797 }
798
799 out:
800 spin_unlock_irqrestore(&sport->port.lock, flags);
801 tty_flip_buffer_push(port);
802 return IRQ_HANDLED;
803 }
804
805 static void imx_uart_clear_rx_errors(struct imx_port *sport);
806
807 /*
808 * We have a modem side uart, so the meanings of RTS and CTS are inverted.
809 */
imx_uart_get_hwmctrl(struct imx_port * sport)810 static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
811 {
812 unsigned int tmp = TIOCM_DSR;
813 unsigned usr1 = imx_uart_readl(sport, USR1);
814 unsigned usr2 = imx_uart_readl(sport, USR2);
815
816 if (usr1 & USR1_RTSS)
817 tmp |= TIOCM_CTS;
818
819 /* in DCE mode DCDIN is always 0 */
820 if (!(usr2 & USR2_DCDIN))
821 tmp |= TIOCM_CAR;
822
823 if (sport->dte_mode)
824 if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
825 tmp |= TIOCM_RI;
826
827 return tmp;
828 }
829
830 /*
831 * Handle any change of modem status signal since we were last called.
832 */
imx_uart_mctrl_check(struct imx_port * sport)833 static void imx_uart_mctrl_check(struct imx_port *sport)
834 {
835 unsigned int status, changed;
836
837 status = imx_uart_get_hwmctrl(sport);
838 changed = status ^ sport->old_status;
839
840 if (changed == 0)
841 return;
842
843 sport->old_status = status;
844
845 if (changed & TIOCM_RI && status & TIOCM_RI)
846 sport->port.icount.rng++;
847 if (changed & TIOCM_DSR)
848 sport->port.icount.dsr++;
849 if (changed & TIOCM_CAR)
850 uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
851 if (changed & TIOCM_CTS)
852 uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
853
854 wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
855 }
856
imx_uart_int(int irq,void * dev_id)857 static irqreturn_t imx_uart_int(int irq, void *dev_id)
858 {
859 struct imx_port *sport = dev_id;
860 unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
861 irqreturn_t ret = IRQ_NONE;
862
863 usr1 = imx_uart_readl(sport, USR1);
864 usr2 = imx_uart_readl(sport, USR2);
865 ucr1 = imx_uart_readl(sport, UCR1);
866 ucr2 = imx_uart_readl(sport, UCR2);
867 ucr3 = imx_uart_readl(sport, UCR3);
868 ucr4 = imx_uart_readl(sport, UCR4);
869
870 /*
871 * Even if a condition is true that can trigger an irq only handle it if
872 * the respective irq source is enabled. This prevents some undesired
873 * actions, for example if a character that sits in the RX FIFO and that
874 * should be fetched via DMA is tried to be fetched using PIO. Or the
875 * receiver is currently off and so reading from URXD0 results in an
876 * exception. So just mask the (raw) status bits for disabled irqs.
877 */
878 if ((ucr1 & UCR1_RRDYEN) == 0)
879 usr1 &= ~USR1_RRDY;
880 if ((ucr2 & UCR2_ATEN) == 0)
881 usr1 &= ~USR1_AGTIM;
882 if ((ucr1 & UCR1_TXMPTYEN) == 0)
883 usr1 &= ~USR1_TRDY;
884 if ((ucr4 & UCR4_TCEN) == 0)
885 usr2 &= ~USR2_TXDC;
886 if ((ucr3 & UCR3_DTRDEN) == 0)
887 usr1 &= ~USR1_DTRD;
888 if ((ucr1 & UCR1_RTSDEN) == 0)
889 usr1 &= ~USR1_RTSD;
890 if ((ucr3 & UCR3_AWAKEN) == 0)
891 usr1 &= ~USR1_AWAKE;
892 if ((ucr4 & UCR4_OREN) == 0)
893 usr2 &= ~USR2_ORE;
894
895 if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
896 imx_uart_rxint(irq, dev_id);
897 ret = IRQ_HANDLED;
898 }
899
900 if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
901 imx_uart_txint(irq, dev_id);
902 ret = IRQ_HANDLED;
903 }
904
905 if (usr1 & USR1_DTRD) {
906 unsigned long flags;
907
908 imx_uart_writel(sport, USR1_DTRD, USR1);
909
910 spin_lock_irqsave(&sport->port.lock, flags);
911 imx_uart_mctrl_check(sport);
912 spin_unlock_irqrestore(&sport->port.lock, flags);
913
914 ret = IRQ_HANDLED;
915 }
916
917 if (usr1 & USR1_RTSD) {
918 imx_uart_rtsint(irq, dev_id);
919 ret = IRQ_HANDLED;
920 }
921
922 if (usr1 & USR1_AWAKE) {
923 imx_uart_writel(sport, USR1_AWAKE, USR1);
924 ret = IRQ_HANDLED;
925 }
926
927 if (usr2 & USR2_ORE) {
928 sport->port.icount.overrun++;
929 imx_uart_writel(sport, USR2_ORE, USR2);
930 ret = IRQ_HANDLED;
931 }
932
933 return ret;
934 }
935
936 /*
937 * Return TIOCSER_TEMT when transmitter is not busy.
938 */
imx_uart_tx_empty(struct uart_port * port)939 static unsigned int imx_uart_tx_empty(struct uart_port *port)
940 {
941 struct imx_port *sport = (struct imx_port *)port;
942 unsigned int ret;
943
944 ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
945
946 /* If the TX DMA is working, return 0. */
947 if (sport->dma_is_txing)
948 ret = 0;
949
950 return ret;
951 }
952
953 /* called with port.lock taken and irqs off */
imx_uart_get_mctrl(struct uart_port * port)954 static unsigned int imx_uart_get_mctrl(struct uart_port *port)
955 {
956 struct imx_port *sport = (struct imx_port *)port;
957 unsigned int ret = imx_uart_get_hwmctrl(sport);
958
959 mctrl_gpio_get(sport->gpios, &ret);
960
961 return ret;
962 }
963
964 /* called with port.lock taken and irqs off */
imx_uart_set_mctrl(struct uart_port * port,unsigned int mctrl)965 static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
966 {
967 struct imx_port *sport = (struct imx_port *)port;
968 u32 ucr3, uts;
969
970 if (!(port->rs485.flags & SER_RS485_ENABLED)) {
971 u32 ucr2;
972
973 ucr2 = imx_uart_readl(sport, UCR2);
974 ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
975 if (mctrl & TIOCM_RTS)
976 ucr2 |= UCR2_CTS | UCR2_CTSC;
977 imx_uart_writel(sport, ucr2, UCR2);
978 }
979
980 ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
981 if (!(mctrl & TIOCM_DTR))
982 ucr3 |= UCR3_DSR;
983 imx_uart_writel(sport, ucr3, UCR3);
984
985 uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
986 if (mctrl & TIOCM_LOOP)
987 uts |= UTS_LOOP;
988 imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
989
990 mctrl_gpio_set(sport->gpios, mctrl);
991 }
992
993 /*
994 * Interrupts always disabled.
995 */
imx_uart_break_ctl(struct uart_port * port,int break_state)996 static void imx_uart_break_ctl(struct uart_port *port, int break_state)
997 {
998 struct imx_port *sport = (struct imx_port *)port;
999 unsigned long flags;
1000 u32 ucr1;
1001
1002 spin_lock_irqsave(&sport->port.lock, flags);
1003
1004 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
1005
1006 if (break_state != 0)
1007 ucr1 |= UCR1_SNDBRK;
1008
1009 imx_uart_writel(sport, ucr1, UCR1);
1010
1011 spin_unlock_irqrestore(&sport->port.lock, flags);
1012 }
1013
1014 /*
1015 * This is our per-port timeout handler, for checking the
1016 * modem status signals.
1017 */
imx_uart_timeout(struct timer_list * t)1018 static void imx_uart_timeout(struct timer_list *t)
1019 {
1020 struct imx_port *sport = from_timer(sport, t, timer);
1021 unsigned long flags;
1022
1023 if (sport->port.state) {
1024 spin_lock_irqsave(&sport->port.lock, flags);
1025 imx_uart_mctrl_check(sport);
1026 spin_unlock_irqrestore(&sport->port.lock, flags);
1027
1028 mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
1029 }
1030 }
1031
1032 #define RX_BUF_SIZE (PAGE_SIZE)
1033
1034 /*
1035 * There are two kinds of RX DMA interrupts(such as in the MX6Q):
1036 * [1] the RX DMA buffer is full.
1037 * [2] the aging timer expires
1038 *
1039 * Condition [2] is triggered when a character has been sitting in the FIFO
1040 * for at least 8 byte durations.
1041 */
imx_uart_dma_rx_callback(void * data)1042 static void imx_uart_dma_rx_callback(void *data)
1043 {
1044 struct imx_port *sport = data;
1045 struct dma_chan *chan = sport->dma_chan_rx;
1046 struct scatterlist *sgl = &sport->rx_sgl;
1047 struct tty_port *port = &sport->port.state->port;
1048 struct dma_tx_state state;
1049 struct circ_buf *rx_ring = &sport->rx_ring;
1050 enum dma_status status;
1051 unsigned int w_bytes = 0;
1052 unsigned int r_bytes;
1053 unsigned int bd_size;
1054
1055 status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
1056
1057 if (status == DMA_ERROR) {
1058 imx_uart_clear_rx_errors(sport);
1059 return;
1060 }
1061
1062 if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
1063
1064 /*
1065 * The state-residue variable represents the empty space
1066 * relative to the entire buffer. Taking this in consideration
1067 * the head is always calculated base on the buffer total
1068 * length - DMA transaction residue. The UART script from the
1069 * SDMA firmware will jump to the next buffer descriptor,
1070 * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
1071 * Taking this in consideration the tail is always at the
1072 * beginning of the buffer descriptor that contains the head.
1073 */
1074
1075 /* Calculate the head */
1076 rx_ring->head = sg_dma_len(sgl) - state.residue;
1077
1078 /* Calculate the tail. */
1079 bd_size = sg_dma_len(sgl) / sport->rx_periods;
1080 rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
1081
1082 if (rx_ring->head <= sg_dma_len(sgl) &&
1083 rx_ring->head > rx_ring->tail) {
1084
1085 /* Move data from tail to head */
1086 r_bytes = rx_ring->head - rx_ring->tail;
1087
1088 /* CPU claims ownership of RX DMA buffer */
1089 dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
1090 DMA_FROM_DEVICE);
1091
1092 w_bytes = tty_insert_flip_string(port,
1093 sport->rx_buf + rx_ring->tail, r_bytes);
1094
1095 /* UART retrieves ownership of RX DMA buffer */
1096 dma_sync_sg_for_device(sport->port.dev, sgl, 1,
1097 DMA_FROM_DEVICE);
1098
1099 if (w_bytes != r_bytes)
1100 sport->port.icount.buf_overrun++;
1101
1102 sport->port.icount.rx += w_bytes;
1103 } else {
1104 WARN_ON(rx_ring->head > sg_dma_len(sgl));
1105 WARN_ON(rx_ring->head <= rx_ring->tail);
1106 }
1107 }
1108
1109 if (w_bytes) {
1110 tty_flip_buffer_push(port);
1111 dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
1112 }
1113 }
1114
1115 /* RX DMA buffer periods */
1116 #define RX_DMA_PERIODS 4
1117
imx_uart_start_rx_dma(struct imx_port * sport)1118 static int imx_uart_start_rx_dma(struct imx_port *sport)
1119 {
1120 struct scatterlist *sgl = &sport->rx_sgl;
1121 struct dma_chan *chan = sport->dma_chan_rx;
1122 struct device *dev = sport->port.dev;
1123 struct dma_async_tx_descriptor *desc;
1124 int ret;
1125
1126 sport->rx_ring.head = 0;
1127 sport->rx_ring.tail = 0;
1128 sport->rx_periods = RX_DMA_PERIODS;
1129
1130 sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
1131 ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1132 if (ret == 0) {
1133 dev_err(dev, "DMA mapping error for RX.\n");
1134 return -EINVAL;
1135 }
1136
1137 desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
1138 sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
1139 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1140
1141 if (!desc) {
1142 dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
1143 dev_err(dev, "We cannot prepare for the RX slave dma!\n");
1144 return -EINVAL;
1145 }
1146 desc->callback = imx_uart_dma_rx_callback;
1147 desc->callback_param = sport;
1148
1149 dev_dbg(dev, "RX: prepare for the DMA.\n");
1150 sport->dma_is_rxing = 1;
1151 sport->rx_cookie = dmaengine_submit(desc);
1152 dma_async_issue_pending(chan);
1153 return 0;
1154 }
1155
imx_uart_clear_rx_errors(struct imx_port * sport)1156 static void imx_uart_clear_rx_errors(struct imx_port *sport)
1157 {
1158 struct tty_port *port = &sport->port.state->port;
1159 u32 usr1, usr2;
1160
1161 usr1 = imx_uart_readl(sport, USR1);
1162 usr2 = imx_uart_readl(sport, USR2);
1163
1164 if (usr2 & USR2_BRCD) {
1165 sport->port.icount.brk++;
1166 imx_uart_writel(sport, USR2_BRCD, USR2);
1167 uart_handle_break(&sport->port);
1168 if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
1169 sport->port.icount.buf_overrun++;
1170 tty_flip_buffer_push(port);
1171 } else {
1172 dev_err(sport->port.dev, "DMA transaction error.\n");
1173 if (usr1 & USR1_FRAMERR) {
1174 sport->port.icount.frame++;
1175 imx_uart_writel(sport, USR1_FRAMERR, USR1);
1176 } else if (usr1 & USR1_PARITYERR) {
1177 sport->port.icount.parity++;
1178 imx_uart_writel(sport, USR1_PARITYERR, USR1);
1179 }
1180 }
1181
1182 if (usr2 & USR2_ORE) {
1183 sport->port.icount.overrun++;
1184 imx_uart_writel(sport, USR2_ORE, USR2);
1185 }
1186
1187 }
1188
1189 #define TXTL_DEFAULT 2 /* reset default */
1190 #define RXTL_DEFAULT 1 /* reset default */
1191 #define TXTL_DMA 8 /* DMA burst setting */
1192 #define RXTL_DMA 9 /* DMA burst setting */
1193
imx_uart_setup_ufcr(struct imx_port * sport,unsigned char txwl,unsigned char rxwl)1194 static void imx_uart_setup_ufcr(struct imx_port *sport,
1195 unsigned char txwl, unsigned char rxwl)
1196 {
1197 unsigned int val;
1198
1199 /* set receiver / transmitter trigger level */
1200 val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
1201 val |= txwl << UFCR_TXTL_SHF | rxwl;
1202 imx_uart_writel(sport, val, UFCR);
1203 }
1204
imx_uart_dma_exit(struct imx_port * sport)1205 static void imx_uart_dma_exit(struct imx_port *sport)
1206 {
1207 if (sport->dma_chan_rx) {
1208 dmaengine_terminate_sync(sport->dma_chan_rx);
1209 dma_release_channel(sport->dma_chan_rx);
1210 sport->dma_chan_rx = NULL;
1211 sport->rx_cookie = -EINVAL;
1212 kfree(sport->rx_buf);
1213 sport->rx_buf = NULL;
1214 }
1215
1216 if (sport->dma_chan_tx) {
1217 dmaengine_terminate_sync(sport->dma_chan_tx);
1218 dma_release_channel(sport->dma_chan_tx);
1219 sport->dma_chan_tx = NULL;
1220 }
1221 }
1222
imx_uart_dma_init(struct imx_port * sport)1223 static int imx_uart_dma_init(struct imx_port *sport)
1224 {
1225 struct dma_slave_config slave_config = {};
1226 struct device *dev = sport->port.dev;
1227 int ret;
1228
1229 /* Prepare for RX : */
1230 sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
1231 if (!sport->dma_chan_rx) {
1232 dev_dbg(dev, "cannot get the DMA channel.\n");
1233 ret = -EINVAL;
1234 goto err;
1235 }
1236
1237 slave_config.direction = DMA_DEV_TO_MEM;
1238 slave_config.src_addr = sport->port.mapbase + URXD0;
1239 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1240 /* one byte less than the watermark level to enable the aging timer */
1241 slave_config.src_maxburst = RXTL_DMA - 1;
1242 ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
1243 if (ret) {
1244 dev_err(dev, "error in RX dma configuration.\n");
1245 goto err;
1246 }
1247
1248 sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
1249 if (!sport->rx_buf) {
1250 ret = -ENOMEM;
1251 goto err;
1252 }
1253 sport->rx_ring.buf = sport->rx_buf;
1254
1255 /* Prepare for TX : */
1256 sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1257 if (!sport->dma_chan_tx) {
1258 dev_err(dev, "cannot get the TX DMA channel!\n");
1259 ret = -EINVAL;
1260 goto err;
1261 }
1262
1263 slave_config.direction = DMA_MEM_TO_DEV;
1264 slave_config.dst_addr = sport->port.mapbase + URTX0;
1265 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1266 slave_config.dst_maxburst = TXTL_DMA;
1267 ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1268 if (ret) {
1269 dev_err(dev, "error in TX dma configuration.");
1270 goto err;
1271 }
1272
1273 return 0;
1274 err:
1275 imx_uart_dma_exit(sport);
1276 return ret;
1277 }
1278
imx_uart_enable_dma(struct imx_port * sport)1279 static void imx_uart_enable_dma(struct imx_port *sport)
1280 {
1281 u32 ucr1;
1282
1283 imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
1284
1285 /* set UCR1 */
1286 ucr1 = imx_uart_readl(sport, UCR1);
1287 ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
1288 imx_uart_writel(sport, ucr1, UCR1);
1289
1290 sport->dma_is_enabled = 1;
1291 }
1292
imx_uart_disable_dma(struct imx_port * sport)1293 static void imx_uart_disable_dma(struct imx_port *sport)
1294 {
1295 u32 ucr1;
1296
1297 /* clear UCR1 */
1298 ucr1 = imx_uart_readl(sport, UCR1);
1299 ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
1300 imx_uart_writel(sport, ucr1, UCR1);
1301
1302 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1303
1304 sport->dma_is_enabled = 0;
1305 }
1306
1307 /* half the RX buffer size */
1308 #define CTSTL 16
1309
imx_uart_startup(struct uart_port * port)1310 static int imx_uart_startup(struct uart_port *port)
1311 {
1312 struct imx_port *sport = (struct imx_port *)port;
1313 int retval, i;
1314 unsigned long flags;
1315 int dma_is_inited = 0;
1316 u32 ucr1, ucr2, ucr4;
1317
1318 retval = clk_prepare_enable(sport->clk_per);
1319 if (retval)
1320 return retval;
1321 retval = clk_prepare_enable(sport->clk_ipg);
1322 if (retval) {
1323 clk_disable_unprepare(sport->clk_per);
1324 return retval;
1325 }
1326
1327 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1328
1329 /* disable the DREN bit (Data Ready interrupt enable) before
1330 * requesting IRQs
1331 */
1332 ucr4 = imx_uart_readl(sport, UCR4);
1333
1334 /* set the trigger level for CTS */
1335 ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1336 ucr4 |= CTSTL << UCR4_CTSTL_SHF;
1337
1338 imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
1339
1340 /* Can we enable the DMA support? */
1341 if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
1342 dma_is_inited = 1;
1343
1344 spin_lock_irqsave(&sport->port.lock, flags);
1345 /* Reset fifo's and state machines */
1346 i = 100;
1347
1348 ucr2 = imx_uart_readl(sport, UCR2);
1349 ucr2 &= ~UCR2_SRST;
1350 imx_uart_writel(sport, ucr2, UCR2);
1351
1352 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1353 udelay(1);
1354
1355 /*
1356 * Finally, clear and enable interrupts
1357 */
1358 imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
1359 imx_uart_writel(sport, USR2_ORE, USR2);
1360
1361 ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
1362 ucr1 |= UCR1_UARTEN;
1363 if (sport->have_rtscts)
1364 ucr1 |= UCR1_RTSDEN;
1365
1366 imx_uart_writel(sport, ucr1, UCR1);
1367
1368 ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
1369 if (!sport->dma_is_enabled)
1370 ucr4 |= UCR4_OREN;
1371 imx_uart_writel(sport, ucr4, UCR4);
1372
1373 ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
1374 ucr2 |= (UCR2_RXEN | UCR2_TXEN);
1375 if (!sport->have_rtscts)
1376 ucr2 |= UCR2_IRTS;
1377 /*
1378 * make sure the edge sensitive RTS-irq is disabled,
1379 * we're using RTSD instead.
1380 */
1381 if (!imx_uart_is_imx1(sport))
1382 ucr2 &= ~UCR2_RTSEN;
1383 imx_uart_writel(sport, ucr2, UCR2);
1384
1385 if (!imx_uart_is_imx1(sport)) {
1386 u32 ucr3;
1387
1388 ucr3 = imx_uart_readl(sport, UCR3);
1389
1390 ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
1391
1392 if (sport->dte_mode)
1393 /* disable broken interrupts */
1394 ucr3 &= ~(UCR3_RI | UCR3_DCD);
1395
1396 imx_uart_writel(sport, ucr3, UCR3);
1397 }
1398
1399 /*
1400 * Enable modem status interrupts
1401 */
1402 imx_uart_enable_ms(&sport->port);
1403
1404 if (dma_is_inited) {
1405 imx_uart_enable_dma(sport);
1406 imx_uart_start_rx_dma(sport);
1407 } else {
1408 ucr1 = imx_uart_readl(sport, UCR1);
1409 ucr1 |= UCR1_RRDYEN;
1410 imx_uart_writel(sport, ucr1, UCR1);
1411
1412 ucr2 = imx_uart_readl(sport, UCR2);
1413 ucr2 |= UCR2_ATEN;
1414 imx_uart_writel(sport, ucr2, UCR2);
1415 }
1416
1417 spin_unlock_irqrestore(&sport->port.lock, flags);
1418
1419 return 0;
1420 }
1421
imx_uart_shutdown(struct uart_port * port)1422 static void imx_uart_shutdown(struct uart_port *port)
1423 {
1424 struct imx_port *sport = (struct imx_port *)port;
1425 unsigned long flags;
1426 u32 ucr1, ucr2, ucr4;
1427
1428 if (sport->dma_is_enabled) {
1429 dmaengine_terminate_sync(sport->dma_chan_tx);
1430 if (sport->dma_is_txing) {
1431 dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
1432 sport->dma_tx_nents, DMA_TO_DEVICE);
1433 sport->dma_is_txing = 0;
1434 }
1435 dmaengine_terminate_sync(sport->dma_chan_rx);
1436 if (sport->dma_is_rxing) {
1437 dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
1438 1, DMA_FROM_DEVICE);
1439 sport->dma_is_rxing = 0;
1440 }
1441
1442 spin_lock_irqsave(&sport->port.lock, flags);
1443 imx_uart_stop_tx(port);
1444 imx_uart_stop_rx(port);
1445 imx_uart_disable_dma(sport);
1446 spin_unlock_irqrestore(&sport->port.lock, flags);
1447 imx_uart_dma_exit(sport);
1448 }
1449
1450 mctrl_gpio_disable_ms(sport->gpios);
1451
1452 spin_lock_irqsave(&sport->port.lock, flags);
1453 ucr2 = imx_uart_readl(sport, UCR2);
1454 ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
1455 imx_uart_writel(sport, ucr2, UCR2);
1456
1457 ucr4 = imx_uart_readl(sport, UCR4);
1458 ucr4 &= ~UCR4_OREN;
1459 imx_uart_writel(sport, ucr4, UCR4);
1460 spin_unlock_irqrestore(&sport->port.lock, flags);
1461
1462 /*
1463 * Stop our timer.
1464 */
1465 del_timer_sync(&sport->timer);
1466
1467 /*
1468 * Disable all interrupts, port and break condition.
1469 */
1470
1471 spin_lock_irqsave(&sport->port.lock, flags);
1472 ucr1 = imx_uart_readl(sport, UCR1);
1473 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
1474
1475 imx_uart_writel(sport, ucr1, UCR1);
1476 spin_unlock_irqrestore(&sport->port.lock, flags);
1477
1478 clk_disable_unprepare(sport->clk_per);
1479 clk_disable_unprepare(sport->clk_ipg);
1480 }
1481
1482 /* called with port.lock taken and irqs off */
imx_uart_flush_buffer(struct uart_port * port)1483 static void imx_uart_flush_buffer(struct uart_port *port)
1484 {
1485 struct imx_port *sport = (struct imx_port *)port;
1486 struct scatterlist *sgl = &sport->tx_sgl[0];
1487 u32 ucr2;
1488 int i = 100, ubir, ubmr, uts;
1489
1490 if (!sport->dma_chan_tx)
1491 return;
1492
1493 sport->tx_bytes = 0;
1494 dmaengine_terminate_all(sport->dma_chan_tx);
1495 if (sport->dma_is_txing) {
1496 u32 ucr1;
1497
1498 dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
1499 DMA_TO_DEVICE);
1500 ucr1 = imx_uart_readl(sport, UCR1);
1501 ucr1 &= ~UCR1_TXDMAEN;
1502 imx_uart_writel(sport, ucr1, UCR1);
1503 sport->dma_is_txing = 0;
1504 }
1505
1506 /*
1507 * According to the Reference Manual description of the UART SRST bit:
1508 *
1509 * "Reset the transmit and receive state machines,
1510 * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
1511 * and UTS[6-3]".
1512 *
1513 * We don't need to restore the old values from USR1, USR2, URXD and
1514 * UTXD. UBRC is read only, so only save/restore the other three
1515 * registers.
1516 */
1517 ubir = imx_uart_readl(sport, UBIR);
1518 ubmr = imx_uart_readl(sport, UBMR);
1519 uts = imx_uart_readl(sport, IMX21_UTS);
1520
1521 ucr2 = imx_uart_readl(sport, UCR2);
1522 ucr2 &= ~UCR2_SRST;
1523 imx_uart_writel(sport, ucr2, UCR2);
1524
1525 while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
1526 udelay(1);
1527
1528 /* Restore the registers */
1529 imx_uart_writel(sport, ubir, UBIR);
1530 imx_uart_writel(sport, ubmr, UBMR);
1531 imx_uart_writel(sport, uts, IMX21_UTS);
1532 }
1533
1534 static void
imx_uart_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)1535 imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
1536 struct ktermios *old)
1537 {
1538 struct imx_port *sport = (struct imx_port *)port;
1539 unsigned long flags;
1540 u32 ucr2, old_ucr1, old_ucr2, ufcr;
1541 unsigned int baud, quot;
1542 unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1543 unsigned long div;
1544 unsigned long num, denom;
1545 uint64_t tdiv64;
1546
1547 /*
1548 * We only support CS7 and CS8.
1549 */
1550 while ((termios->c_cflag & CSIZE) != CS7 &&
1551 (termios->c_cflag & CSIZE) != CS8) {
1552 termios->c_cflag &= ~CSIZE;
1553 termios->c_cflag |= old_csize;
1554 old_csize = CS8;
1555 }
1556
1557 if ((termios->c_cflag & CSIZE) == CS8)
1558 ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1559 else
1560 ucr2 = UCR2_SRST | UCR2_IRTS;
1561
1562 if (termios->c_cflag & CRTSCTS) {
1563 if (sport->have_rtscts) {
1564 ucr2 &= ~UCR2_IRTS;
1565
1566 if (port->rs485.flags & SER_RS485_ENABLED) {
1567 /*
1568 * RTS is mandatory for rs485 operation, so keep
1569 * it under manual control and keep transmitter
1570 * disabled.
1571 */
1572 if (port->rs485.flags &
1573 SER_RS485_RTS_AFTER_SEND)
1574 imx_uart_rts_active(sport, &ucr2);
1575 else
1576 imx_uart_rts_inactive(sport, &ucr2);
1577 } else {
1578 imx_uart_rts_auto(sport, &ucr2);
1579 }
1580 } else {
1581 termios->c_cflag &= ~CRTSCTS;
1582 }
1583 } else if (port->rs485.flags & SER_RS485_ENABLED) {
1584 /* disable transmitter */
1585 if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
1586 imx_uart_rts_active(sport, &ucr2);
1587 else
1588 imx_uart_rts_inactive(sport, &ucr2);
1589 }
1590
1591
1592 if (termios->c_cflag & CSTOPB)
1593 ucr2 |= UCR2_STPB;
1594 if (termios->c_cflag & PARENB) {
1595 ucr2 |= UCR2_PREN;
1596 if (termios->c_cflag & PARODD)
1597 ucr2 |= UCR2_PROE;
1598 }
1599
1600 del_timer_sync(&sport->timer);
1601
1602 /*
1603 * Ask the core to calculate the divisor for us.
1604 */
1605 baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1606 quot = uart_get_divisor(port, baud);
1607
1608 spin_lock_irqsave(&sport->port.lock, flags);
1609
1610 sport->port.read_status_mask = 0;
1611 if (termios->c_iflag & INPCK)
1612 sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1613 if (termios->c_iflag & (BRKINT | PARMRK))
1614 sport->port.read_status_mask |= URXD_BRK;
1615
1616 /*
1617 * Characters to ignore
1618 */
1619 sport->port.ignore_status_mask = 0;
1620 if (termios->c_iflag & IGNPAR)
1621 sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
1622 if (termios->c_iflag & IGNBRK) {
1623 sport->port.ignore_status_mask |= URXD_BRK;
1624 /*
1625 * If we're ignoring parity and break indicators,
1626 * ignore overruns too (for real raw support).
1627 */
1628 if (termios->c_iflag & IGNPAR)
1629 sport->port.ignore_status_mask |= URXD_OVRRUN;
1630 }
1631
1632 if ((termios->c_cflag & CREAD) == 0)
1633 sport->port.ignore_status_mask |= URXD_DUMMY_READ;
1634
1635 /*
1636 * Update the per-port timeout.
1637 */
1638 uart_update_timeout(port, termios->c_cflag, baud);
1639
1640 /*
1641 * disable interrupts and drain transmitter
1642 */
1643 old_ucr1 = imx_uart_readl(sport, UCR1);
1644 imx_uart_writel(sport,
1645 old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1646 UCR1);
1647 old_ucr2 = imx_uart_readl(sport, UCR2);
1648 imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
1649
1650 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
1651 barrier();
1652
1653 /* then, disable everything */
1654 imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
1655 old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
1656
1657 /* custom-baudrate handling */
1658 div = sport->port.uartclk / (baud * 16);
1659 if (baud == 38400 && quot != div)
1660 baud = sport->port.uartclk / (quot * 16);
1661
1662 div = sport->port.uartclk / (baud * 16);
1663 if (div > 7)
1664 div = 7;
1665 if (!div)
1666 div = 1;
1667
1668 rational_best_approximation(16 * div * baud, sport->port.uartclk,
1669 1 << 16, 1 << 16, &num, &denom);
1670
1671 tdiv64 = sport->port.uartclk;
1672 tdiv64 *= num;
1673 do_div(tdiv64, denom * 16 * div);
1674 tty_termios_encode_baud_rate(termios,
1675 (speed_t)tdiv64, (speed_t)tdiv64);
1676
1677 num -= 1;
1678 denom -= 1;
1679
1680 ufcr = imx_uart_readl(sport, UFCR);
1681 ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1682 imx_uart_writel(sport, ufcr, UFCR);
1683
1684 imx_uart_writel(sport, num, UBIR);
1685 imx_uart_writel(sport, denom, UBMR);
1686
1687 if (!imx_uart_is_imx1(sport))
1688 imx_uart_writel(sport, sport->port.uartclk / div / 1000,
1689 IMX21_ONEMS);
1690
1691 imx_uart_writel(sport, old_ucr1, UCR1);
1692
1693 /* set the parity, stop bits and data size */
1694 imx_uart_writel(sport, ucr2 | old_ucr2, UCR2);
1695
1696 if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1697 imx_uart_enable_ms(&sport->port);
1698
1699 spin_unlock_irqrestore(&sport->port.lock, flags);
1700 }
1701
imx_uart_type(struct uart_port * port)1702 static const char *imx_uart_type(struct uart_port *port)
1703 {
1704 struct imx_port *sport = (struct imx_port *)port;
1705
1706 return sport->port.type == PORT_IMX ? "IMX" : NULL;
1707 }
1708
1709 /*
1710 * Configure/autoconfigure the port.
1711 */
imx_uart_config_port(struct uart_port * port,int flags)1712 static void imx_uart_config_port(struct uart_port *port, int flags)
1713 {
1714 struct imx_port *sport = (struct imx_port *)port;
1715
1716 if (flags & UART_CONFIG_TYPE)
1717 sport->port.type = PORT_IMX;
1718 }
1719
1720 /*
1721 * Verify the new serial_struct (for TIOCSSERIAL).
1722 * The only change we allow are to the flags and type, and
1723 * even then only between PORT_IMX and PORT_UNKNOWN
1724 */
1725 static int
imx_uart_verify_port(struct uart_port * port,struct serial_struct * ser)1726 imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
1727 {
1728 struct imx_port *sport = (struct imx_port *)port;
1729 int ret = 0;
1730
1731 if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1732 ret = -EINVAL;
1733 if (sport->port.irq != ser->irq)
1734 ret = -EINVAL;
1735 if (ser->io_type != UPIO_MEM)
1736 ret = -EINVAL;
1737 if (sport->port.uartclk / 16 != ser->baud_base)
1738 ret = -EINVAL;
1739 if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1740 ret = -EINVAL;
1741 if (sport->port.iobase != ser->port)
1742 ret = -EINVAL;
1743 if (ser->hub6 != 0)
1744 ret = -EINVAL;
1745 return ret;
1746 }
1747
1748 #if defined(CONFIG_CONSOLE_POLL)
1749
imx_uart_poll_init(struct uart_port * port)1750 static int imx_uart_poll_init(struct uart_port *port)
1751 {
1752 struct imx_port *sport = (struct imx_port *)port;
1753 unsigned long flags;
1754 u32 ucr1, ucr2;
1755 int retval;
1756
1757 retval = clk_prepare_enable(sport->clk_ipg);
1758 if (retval)
1759 return retval;
1760 retval = clk_prepare_enable(sport->clk_per);
1761 if (retval)
1762 clk_disable_unprepare(sport->clk_ipg);
1763
1764 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
1765
1766 spin_lock_irqsave(&sport->port.lock, flags);
1767
1768 /*
1769 * Be careful about the order of enabling bits here. First enable the
1770 * receiver (UARTEN + RXEN) and only then the corresponding irqs.
1771 * This prevents that a character that already sits in the RX fifo is
1772 * triggering an irq but the try to fetch it from there results in an
1773 * exception because UARTEN or RXEN is still off.
1774 */
1775 ucr1 = imx_uart_readl(sport, UCR1);
1776 ucr2 = imx_uart_readl(sport, UCR2);
1777
1778 if (imx_uart_is_imx1(sport))
1779 ucr1 |= IMX1_UCR1_UARTCLKEN;
1780
1781 ucr1 |= UCR1_UARTEN;
1782 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN);
1783
1784 ucr2 |= UCR2_RXEN;
1785 ucr2 &= ~UCR2_ATEN;
1786
1787 imx_uart_writel(sport, ucr1, UCR1);
1788 imx_uart_writel(sport, ucr2, UCR2);
1789
1790 /* now enable irqs */
1791 imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
1792 imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
1793
1794 spin_unlock_irqrestore(&sport->port.lock, flags);
1795
1796 return 0;
1797 }
1798
imx_uart_poll_get_char(struct uart_port * port)1799 static int imx_uart_poll_get_char(struct uart_port *port)
1800 {
1801 struct imx_port *sport = (struct imx_port *)port;
1802 if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
1803 return NO_POLL_CHAR;
1804
1805 return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
1806 }
1807
imx_uart_poll_put_char(struct uart_port * port,unsigned char c)1808 static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
1809 {
1810 struct imx_port *sport = (struct imx_port *)port;
1811 unsigned int status;
1812
1813 /* drain */
1814 do {
1815 status = imx_uart_readl(sport, USR1);
1816 } while (~status & USR1_TRDY);
1817
1818 /* write */
1819 imx_uart_writel(sport, c, URTX0);
1820
1821 /* flush */
1822 do {
1823 status = imx_uart_readl(sport, USR2);
1824 } while (~status & USR2_TXDC);
1825 }
1826 #endif
1827
1828 /* 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)1829 static int imx_uart_rs485_config(struct uart_port *port,
1830 struct serial_rs485 *rs485conf)
1831 {
1832 struct imx_port *sport = (struct imx_port *)port;
1833 u32 ucr2;
1834
1835 /* unimplemented */
1836 rs485conf->delay_rts_before_send = 0;
1837 rs485conf->delay_rts_after_send = 0;
1838
1839 /* RTS is required to control the transmitter */
1840 if (!sport->have_rtscts && !sport->have_rtsgpio)
1841 rs485conf->flags &= ~SER_RS485_ENABLED;
1842
1843 if (rs485conf->flags & SER_RS485_ENABLED) {
1844 /* Enable receiver if low-active RTS signal is requested */
1845 if (sport->have_rtscts && !sport->have_rtsgpio &&
1846 !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
1847 rs485conf->flags |= SER_RS485_RX_DURING_TX;
1848
1849 /* disable transmitter */
1850 ucr2 = imx_uart_readl(sport, UCR2);
1851 if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
1852 imx_uart_rts_active(sport, &ucr2);
1853 else
1854 imx_uart_rts_inactive(sport, &ucr2);
1855 imx_uart_writel(sport, ucr2, UCR2);
1856 }
1857
1858 /* Make sure Rx is enabled in case Tx is active with Rx disabled */
1859 if (!(rs485conf->flags & SER_RS485_ENABLED) ||
1860 rs485conf->flags & SER_RS485_RX_DURING_TX)
1861 imx_uart_start_rx(port);
1862
1863 port->rs485 = *rs485conf;
1864
1865 return 0;
1866 }
1867
1868 static const struct uart_ops imx_uart_pops = {
1869 .tx_empty = imx_uart_tx_empty,
1870 .set_mctrl = imx_uart_set_mctrl,
1871 .get_mctrl = imx_uart_get_mctrl,
1872 .stop_tx = imx_uart_stop_tx,
1873 .start_tx = imx_uart_start_tx,
1874 .stop_rx = imx_uart_stop_rx,
1875 .enable_ms = imx_uart_enable_ms,
1876 .break_ctl = imx_uart_break_ctl,
1877 .startup = imx_uart_startup,
1878 .shutdown = imx_uart_shutdown,
1879 .flush_buffer = imx_uart_flush_buffer,
1880 .set_termios = imx_uart_set_termios,
1881 .type = imx_uart_type,
1882 .config_port = imx_uart_config_port,
1883 .verify_port = imx_uart_verify_port,
1884 #if defined(CONFIG_CONSOLE_POLL)
1885 .poll_init = imx_uart_poll_init,
1886 .poll_get_char = imx_uart_poll_get_char,
1887 .poll_put_char = imx_uart_poll_put_char,
1888 #endif
1889 };
1890
1891 static struct imx_port *imx_uart_ports[UART_NR];
1892
1893 #ifdef CONFIG_SERIAL_IMX_CONSOLE
imx_uart_console_putchar(struct uart_port * port,int ch)1894 static void imx_uart_console_putchar(struct uart_port *port, int ch)
1895 {
1896 struct imx_port *sport = (struct imx_port *)port;
1897
1898 while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
1899 barrier();
1900
1901 imx_uart_writel(sport, ch, URTX0);
1902 }
1903
1904 /*
1905 * Interrupts are disabled on entering
1906 */
1907 static void
imx_uart_console_write(struct console * co,const char * s,unsigned int count)1908 imx_uart_console_write(struct console *co, const char *s, unsigned int count)
1909 {
1910 struct imx_port *sport = imx_uart_ports[co->index];
1911 struct imx_port_ucrs old_ucr;
1912 unsigned int ucr1;
1913 unsigned long flags = 0;
1914 int locked = 1;
1915 int retval;
1916
1917 retval = clk_enable(sport->clk_per);
1918 if (retval)
1919 return;
1920 retval = clk_enable(sport->clk_ipg);
1921 if (retval) {
1922 clk_disable(sport->clk_per);
1923 return;
1924 }
1925
1926 if (sport->port.sysrq)
1927 locked = 0;
1928 else if (oops_in_progress)
1929 locked = spin_trylock_irqsave(&sport->port.lock, flags);
1930 else
1931 spin_lock_irqsave(&sport->port.lock, flags);
1932
1933 /*
1934 * First, save UCR1/2/3 and then disable interrupts
1935 */
1936 imx_uart_ucrs_save(sport, &old_ucr);
1937 ucr1 = old_ucr.ucr1;
1938
1939 if (imx_uart_is_imx1(sport))
1940 ucr1 |= IMX1_UCR1_UARTCLKEN;
1941 ucr1 |= UCR1_UARTEN;
1942 ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1943
1944 imx_uart_writel(sport, ucr1, UCR1);
1945
1946 imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
1947
1948 uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
1949
1950 /*
1951 * Finally, wait for transmitter to become empty
1952 * and restore UCR1/2/3
1953 */
1954 while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
1955
1956 imx_uart_ucrs_restore(sport, &old_ucr);
1957
1958 if (locked)
1959 spin_unlock_irqrestore(&sport->port.lock, flags);
1960
1961 clk_disable(sport->clk_ipg);
1962 clk_disable(sport->clk_per);
1963 }
1964
1965 /*
1966 * If the port was already initialised (eg, by a boot loader),
1967 * try to determine the current setup.
1968 */
1969 static void __init
imx_uart_console_get_options(struct imx_port * sport,int * baud,int * parity,int * bits)1970 imx_uart_console_get_options(struct imx_port *sport, int *baud,
1971 int *parity, int *bits)
1972 {
1973
1974 if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
1975 /* ok, the port was enabled */
1976 unsigned int ucr2, ubir, ubmr, uartclk;
1977 unsigned int baud_raw;
1978 unsigned int ucfr_rfdiv;
1979
1980 ucr2 = imx_uart_readl(sport, UCR2);
1981
1982 *parity = 'n';
1983 if (ucr2 & UCR2_PREN) {
1984 if (ucr2 & UCR2_PROE)
1985 *parity = 'o';
1986 else
1987 *parity = 'e';
1988 }
1989
1990 if (ucr2 & UCR2_WS)
1991 *bits = 8;
1992 else
1993 *bits = 7;
1994
1995 ubir = imx_uart_readl(sport, UBIR) & 0xffff;
1996 ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
1997
1998 ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
1999 if (ucfr_rfdiv == 6)
2000 ucfr_rfdiv = 7;
2001 else
2002 ucfr_rfdiv = 6 - ucfr_rfdiv;
2003
2004 uartclk = clk_get_rate(sport->clk_per);
2005 uartclk /= ucfr_rfdiv;
2006
2007 { /*
2008 * The next code provides exact computation of
2009 * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
2010 * without need of float support or long long division,
2011 * which would be required to prevent 32bit arithmetic overflow
2012 */
2013 unsigned int mul = ubir + 1;
2014 unsigned int div = 16 * (ubmr + 1);
2015 unsigned int rem = uartclk % div;
2016
2017 baud_raw = (uartclk / div) * mul;
2018 baud_raw += (rem * mul + div / 2) / div;
2019 *baud = (baud_raw + 50) / 100 * 100;
2020 }
2021
2022 if (*baud != baud_raw)
2023 pr_info("Console IMX rounded baud rate from %d to %d\n",
2024 baud_raw, *baud);
2025 }
2026 }
2027
2028 static int __init
imx_uart_console_setup(struct console * co,char * options)2029 imx_uart_console_setup(struct console *co, char *options)
2030 {
2031 struct imx_port *sport;
2032 int baud = 9600;
2033 int bits = 8;
2034 int parity = 'n';
2035 int flow = 'n';
2036 int retval;
2037
2038 /*
2039 * Check whether an invalid uart number has been specified, and
2040 * if so, search for the first available port that does have
2041 * console support.
2042 */
2043 if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
2044 co->index = 0;
2045 sport = imx_uart_ports[co->index];
2046 if (sport == NULL)
2047 return -ENODEV;
2048
2049 /* For setting the registers, we only need to enable the ipg clock. */
2050 retval = clk_prepare_enable(sport->clk_ipg);
2051 if (retval)
2052 goto error_console;
2053
2054 if (options)
2055 uart_parse_options(options, &baud, &parity, &bits, &flow);
2056 else
2057 imx_uart_console_get_options(sport, &baud, &parity, &bits);
2058
2059 imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
2060
2061 retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
2062
2063 clk_disable(sport->clk_ipg);
2064 if (retval) {
2065 clk_unprepare(sport->clk_ipg);
2066 goto error_console;
2067 }
2068
2069 retval = clk_prepare(sport->clk_per);
2070 if (retval)
2071 clk_disable_unprepare(sport->clk_ipg);
2072
2073 error_console:
2074 return retval;
2075 }
2076
2077 static struct uart_driver imx_uart_uart_driver;
2078 static struct console imx_uart_console = {
2079 .name = DEV_NAME,
2080 .write = imx_uart_console_write,
2081 .device = uart_console_device,
2082 .setup = imx_uart_console_setup,
2083 .flags = CON_PRINTBUFFER,
2084 .index = -1,
2085 .data = &imx_uart_uart_driver,
2086 };
2087
2088 #define IMX_CONSOLE &imx_uart_console
2089
2090 #ifdef CONFIG_OF
imx_uart_console_early_putchar(struct uart_port * port,int ch)2091 static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
2092 {
2093 struct imx_port *sport = (struct imx_port *)port;
2094
2095 while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
2096 cpu_relax();
2097
2098 imx_uart_writel(sport, ch, URTX0);
2099 }
2100
imx_uart_console_early_write(struct console * con,const char * s,unsigned count)2101 static void imx_uart_console_early_write(struct console *con, const char *s,
2102 unsigned count)
2103 {
2104 struct earlycon_device *dev = con->data;
2105
2106 uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
2107 }
2108
2109 static int __init
imx_console_early_setup(struct earlycon_device * dev,const char * opt)2110 imx_console_early_setup(struct earlycon_device *dev, const char *opt)
2111 {
2112 if (!dev->port.membase)
2113 return -ENODEV;
2114
2115 dev->con->write = imx_uart_console_early_write;
2116
2117 return 0;
2118 }
2119 OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
2120 OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
2121 #endif
2122
2123 #else
2124 #define IMX_CONSOLE NULL
2125 #endif
2126
2127 static struct uart_driver imx_uart_uart_driver = {
2128 .owner = THIS_MODULE,
2129 .driver_name = DRIVER_NAME,
2130 .dev_name = DEV_NAME,
2131 .major = SERIAL_IMX_MAJOR,
2132 .minor = MINOR_START,
2133 .nr = ARRAY_SIZE(imx_uart_ports),
2134 .cons = IMX_CONSOLE,
2135 };
2136
2137 #ifdef CONFIG_OF
2138 /*
2139 * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
2140 * could successfully get all information from dt or a negative errno.
2141 */
imx_uart_probe_dt(struct imx_port * sport,struct platform_device * pdev)2142 static int imx_uart_probe_dt(struct imx_port *sport,
2143 struct platform_device *pdev)
2144 {
2145 struct device_node *np = pdev->dev.of_node;
2146 int ret;
2147
2148 sport->devdata = of_device_get_match_data(&pdev->dev);
2149 if (!sport->devdata)
2150 /* no device tree device */
2151 return 1;
2152
2153 ret = of_alias_get_id(np, "serial");
2154 if (ret < 0) {
2155 dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
2156 return ret;
2157 }
2158 sport->port.line = ret;
2159
2160 if (of_get_property(np, "uart-has-rtscts", NULL) ||
2161 of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
2162 sport->have_rtscts = 1;
2163
2164 if (of_get_property(np, "fsl,dte-mode", NULL))
2165 sport->dte_mode = 1;
2166
2167 if (of_get_property(np, "rts-gpios", NULL))
2168 sport->have_rtsgpio = 1;
2169
2170 return 0;
2171 }
2172 #else
imx_uart_probe_dt(struct imx_port * sport,struct platform_device * pdev)2173 static inline int imx_uart_probe_dt(struct imx_port *sport,
2174 struct platform_device *pdev)
2175 {
2176 return 1;
2177 }
2178 #endif
2179
imx_uart_probe_pdata(struct imx_port * sport,struct platform_device * pdev)2180 static void imx_uart_probe_pdata(struct imx_port *sport,
2181 struct platform_device *pdev)
2182 {
2183 struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
2184
2185 sport->port.line = pdev->id;
2186 sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
2187
2188 if (!pdata)
2189 return;
2190
2191 if (pdata->flags & IMXUART_HAVE_RTSCTS)
2192 sport->have_rtscts = 1;
2193 }
2194
imx_uart_probe(struct platform_device * pdev)2195 static int imx_uart_probe(struct platform_device *pdev)
2196 {
2197 struct imx_port *sport;
2198 void __iomem *base;
2199 int ret = 0;
2200 u32 ucr1;
2201 struct resource *res;
2202 int txirq, rxirq, rtsirq;
2203
2204 sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2205 if (!sport)
2206 return -ENOMEM;
2207
2208 ret = imx_uart_probe_dt(sport, pdev);
2209 if (ret > 0)
2210 imx_uart_probe_pdata(sport, pdev);
2211 else if (ret < 0)
2212 return ret;
2213
2214 if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
2215 dev_err(&pdev->dev, "serial%d out of range\n",
2216 sport->port.line);
2217 return -EINVAL;
2218 }
2219
2220 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2221 base = devm_ioremap_resource(&pdev->dev, res);
2222 if (IS_ERR(base))
2223 return PTR_ERR(base);
2224
2225 rxirq = platform_get_irq(pdev, 0);
2226 txirq = platform_get_irq(pdev, 1);
2227 rtsirq = platform_get_irq(pdev, 2);
2228
2229 sport->port.dev = &pdev->dev;
2230 sport->port.mapbase = res->start;
2231 sport->port.membase = base;
2232 sport->port.type = PORT_IMX,
2233 sport->port.iotype = UPIO_MEM;
2234 sport->port.irq = rxirq;
2235 sport->port.fifosize = 32;
2236 sport->port.ops = &imx_uart_pops;
2237 sport->port.rs485_config = imx_uart_rs485_config;
2238 sport->port.flags = UPF_BOOT_AUTOCONF;
2239 timer_setup(&sport->timer, imx_uart_timeout, 0);
2240
2241 sport->gpios = mctrl_gpio_init(&sport->port, 0);
2242 if (IS_ERR(sport->gpios))
2243 return PTR_ERR(sport->gpios);
2244
2245 sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2246 if (IS_ERR(sport->clk_ipg)) {
2247 ret = PTR_ERR(sport->clk_ipg);
2248 dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
2249 return ret;
2250 }
2251
2252 sport->clk_per = devm_clk_get(&pdev->dev, "per");
2253 if (IS_ERR(sport->clk_per)) {
2254 ret = PTR_ERR(sport->clk_per);
2255 dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
2256 return ret;
2257 }
2258
2259 sport->port.uartclk = clk_get_rate(sport->clk_per);
2260
2261 /* For register access, we only need to enable the ipg clock. */
2262 ret = clk_prepare_enable(sport->clk_ipg);
2263 if (ret) {
2264 dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
2265 return ret;
2266 }
2267
2268 /* initialize shadow register values */
2269 sport->ucr1 = readl(sport->port.membase + UCR1);
2270 sport->ucr2 = readl(sport->port.membase + UCR2);
2271 sport->ucr3 = readl(sport->port.membase + UCR3);
2272 sport->ucr4 = readl(sport->port.membase + UCR4);
2273 sport->ufcr = readl(sport->port.membase + UFCR);
2274
2275 uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2276
2277 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2278 (!sport->have_rtscts && !sport->have_rtsgpio))
2279 dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
2280
2281 /*
2282 * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
2283 * signal cannot be set low during transmission in case the
2284 * receiver is off (limitation of the i.MX UART IP).
2285 */
2286 if (sport->port.rs485.flags & SER_RS485_ENABLED &&
2287 sport->have_rtscts && !sport->have_rtsgpio &&
2288 (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
2289 !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
2290 dev_err(&pdev->dev,
2291 "low-active RTS not possible when receiver is off, enabling receiver\n");
2292
2293 imx_uart_rs485_config(&sport->port, &sport->port.rs485);
2294
2295 /* Disable interrupts before requesting them */
2296 ucr1 = imx_uart_readl(sport, UCR1);
2297 ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
2298 UCR1_TXMPTYEN | UCR1_RTSDEN);
2299 imx_uart_writel(sport, ucr1, UCR1);
2300
2301 if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
2302 /*
2303 * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
2304 * and influences if UCR3_RI and UCR3_DCD changes the level of RI
2305 * and DCD (when they are outputs) or enables the respective
2306 * irqs. So set this bit early, i.e. before requesting irqs.
2307 */
2308 u32 ufcr = imx_uart_readl(sport, UFCR);
2309 if (!(ufcr & UFCR_DCEDTE))
2310 imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
2311
2312 /*
2313 * Disable UCR3_RI and UCR3_DCD irqs. They are also not
2314 * enabled later because they cannot be cleared
2315 * (confirmed on i.MX25) which makes them unusable.
2316 */
2317 imx_uart_writel(sport,
2318 IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
2319 UCR3);
2320
2321 } else {
2322 u32 ucr3 = UCR3_DSR;
2323 u32 ufcr = imx_uart_readl(sport, UFCR);
2324 if (ufcr & UFCR_DCEDTE)
2325 imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
2326
2327 if (!imx_uart_is_imx1(sport))
2328 ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
2329 imx_uart_writel(sport, ucr3, UCR3);
2330 }
2331
2332 clk_disable_unprepare(sport->clk_ipg);
2333
2334 /*
2335 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
2336 * chips only have one interrupt.
2337 */
2338 if (txirq > 0) {
2339 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
2340 dev_name(&pdev->dev), sport);
2341 if (ret) {
2342 dev_err(&pdev->dev, "failed to request rx irq: %d\n",
2343 ret);
2344 return ret;
2345 }
2346
2347 ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
2348 dev_name(&pdev->dev), sport);
2349 if (ret) {
2350 dev_err(&pdev->dev, "failed to request tx irq: %d\n",
2351 ret);
2352 return ret;
2353 }
2354
2355 ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
2356 dev_name(&pdev->dev), sport);
2357 if (ret) {
2358 dev_err(&pdev->dev, "failed to request rts irq: %d\n",
2359 ret);
2360 return ret;
2361 }
2362 } else {
2363 ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
2364 dev_name(&pdev->dev), sport);
2365 if (ret) {
2366 dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
2367 return ret;
2368 }
2369 }
2370
2371 imx_uart_ports[sport->port.line] = sport;
2372
2373 platform_set_drvdata(pdev, sport);
2374
2375 return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
2376 }
2377
imx_uart_remove(struct platform_device * pdev)2378 static int imx_uart_remove(struct platform_device *pdev)
2379 {
2380 struct imx_port *sport = platform_get_drvdata(pdev);
2381
2382 return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
2383 }
2384
imx_uart_restore_context(struct imx_port * sport)2385 static void imx_uart_restore_context(struct imx_port *sport)
2386 {
2387 if (!sport->context_saved)
2388 return;
2389
2390 imx_uart_writel(sport, sport->saved_reg[4], UFCR);
2391 imx_uart_writel(sport, sport->saved_reg[5], UESC);
2392 imx_uart_writel(sport, sport->saved_reg[6], UTIM);
2393 imx_uart_writel(sport, sport->saved_reg[7], UBIR);
2394 imx_uart_writel(sport, sport->saved_reg[8], UBMR);
2395 imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
2396 imx_uart_writel(sport, sport->saved_reg[0], UCR1);
2397 imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
2398 imx_uart_writel(sport, sport->saved_reg[2], UCR3);
2399 imx_uart_writel(sport, sport->saved_reg[3], UCR4);
2400 sport->context_saved = false;
2401 }
2402
imx_uart_save_context(struct imx_port * sport)2403 static void imx_uart_save_context(struct imx_port *sport)
2404 {
2405 /* Save necessary regs */
2406 sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
2407 sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
2408 sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
2409 sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
2410 sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
2411 sport->saved_reg[5] = imx_uart_readl(sport, UESC);
2412 sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
2413 sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
2414 sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
2415 sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
2416 sport->context_saved = true;
2417 }
2418
imx_uart_enable_wakeup(struct imx_port * sport,bool on)2419 static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
2420 {
2421 u32 ucr3;
2422
2423 ucr3 = imx_uart_readl(sport, UCR3);
2424 if (on) {
2425 imx_uart_writel(sport, USR1_AWAKE, USR1);
2426 ucr3 |= UCR3_AWAKEN;
2427 } else {
2428 ucr3 &= ~UCR3_AWAKEN;
2429 }
2430 imx_uart_writel(sport, ucr3, UCR3);
2431
2432 if (sport->have_rtscts) {
2433 u32 ucr1 = imx_uart_readl(sport, UCR1);
2434 if (on)
2435 ucr1 |= UCR1_RTSDEN;
2436 else
2437 ucr1 &= ~UCR1_RTSDEN;
2438 imx_uart_writel(sport, ucr1, UCR1);
2439 }
2440 }
2441
imx_uart_suspend_noirq(struct device * dev)2442 static int imx_uart_suspend_noirq(struct device *dev)
2443 {
2444 struct imx_port *sport = dev_get_drvdata(dev);
2445
2446 imx_uart_save_context(sport);
2447
2448 clk_disable(sport->clk_ipg);
2449
2450 return 0;
2451 }
2452
imx_uart_resume_noirq(struct device * dev)2453 static int imx_uart_resume_noirq(struct device *dev)
2454 {
2455 struct imx_port *sport = dev_get_drvdata(dev);
2456 int ret;
2457
2458 ret = clk_enable(sport->clk_ipg);
2459 if (ret)
2460 return ret;
2461
2462 imx_uart_restore_context(sport);
2463
2464 return 0;
2465 }
2466
imx_uart_suspend(struct device * dev)2467 static int imx_uart_suspend(struct device *dev)
2468 {
2469 struct imx_port *sport = dev_get_drvdata(dev);
2470 int ret;
2471
2472 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2473 disable_irq(sport->port.irq);
2474
2475 ret = clk_prepare_enable(sport->clk_ipg);
2476 if (ret)
2477 return ret;
2478
2479 /* enable wakeup from i.MX UART */
2480 imx_uart_enable_wakeup(sport, true);
2481
2482 return 0;
2483 }
2484
imx_uart_resume(struct device * dev)2485 static int imx_uart_resume(struct device *dev)
2486 {
2487 struct imx_port *sport = dev_get_drvdata(dev);
2488
2489 /* disable wakeup from i.MX UART */
2490 imx_uart_enable_wakeup(sport, false);
2491
2492 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2493 enable_irq(sport->port.irq);
2494
2495 clk_disable_unprepare(sport->clk_ipg);
2496
2497 return 0;
2498 }
2499
imx_uart_freeze(struct device * dev)2500 static int imx_uart_freeze(struct device *dev)
2501 {
2502 struct imx_port *sport = dev_get_drvdata(dev);
2503
2504 uart_suspend_port(&imx_uart_uart_driver, &sport->port);
2505
2506 return clk_prepare_enable(sport->clk_ipg);
2507 }
2508
imx_uart_thaw(struct device * dev)2509 static int imx_uart_thaw(struct device *dev)
2510 {
2511 struct imx_port *sport = dev_get_drvdata(dev);
2512
2513 uart_resume_port(&imx_uart_uart_driver, &sport->port);
2514
2515 clk_disable_unprepare(sport->clk_ipg);
2516
2517 return 0;
2518 }
2519
2520 static const struct dev_pm_ops imx_uart_pm_ops = {
2521 .suspend_noirq = imx_uart_suspend_noirq,
2522 .resume_noirq = imx_uart_resume_noirq,
2523 .freeze_noirq = imx_uart_suspend_noirq,
2524 .restore_noirq = imx_uart_resume_noirq,
2525 .suspend = imx_uart_suspend,
2526 .resume = imx_uart_resume,
2527 .freeze = imx_uart_freeze,
2528 .thaw = imx_uart_thaw,
2529 .restore = imx_uart_thaw,
2530 };
2531
2532 static struct platform_driver imx_uart_platform_driver = {
2533 .probe = imx_uart_probe,
2534 .remove = imx_uart_remove,
2535
2536 .id_table = imx_uart_devtype,
2537 .driver = {
2538 .name = "imx-uart",
2539 .of_match_table = imx_uart_dt_ids,
2540 .pm = &imx_uart_pm_ops,
2541 },
2542 };
2543
imx_uart_init(void)2544 static int __init imx_uart_init(void)
2545 {
2546 int ret = uart_register_driver(&imx_uart_uart_driver);
2547
2548 if (ret)
2549 return ret;
2550
2551 ret = platform_driver_register(&imx_uart_platform_driver);
2552 if (ret != 0)
2553 uart_unregister_driver(&imx_uart_uart_driver);
2554
2555 return ret;
2556 }
2557
imx_uart_exit(void)2558 static void __exit imx_uart_exit(void)
2559 {
2560 platform_driver_unregister(&imx_uart_platform_driver);
2561 uart_unregister_driver(&imx_uart_uart_driver);
2562 }
2563
2564 module_init(imx_uart_init);
2565 module_exit(imx_uart_exit);
2566
2567 MODULE_AUTHOR("Sascha Hauer");
2568 MODULE_DESCRIPTION("IMX generic serial port driver");
2569 MODULE_LICENSE("GPL");
2570 MODULE_ALIAS("platform:imx-uart");
2571
