xref: /openbmc/linux/drivers/tty/serial/fsl_lpuart.c (revision 3213486f)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  Freescale lpuart serial port driver
4  *
5  *  Copyright 2012-2014 Freescale Semiconductor, Inc.
6  */
7 
8 #if defined(CONFIG_SERIAL_FSL_LPUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
9 #define SUPPORT_SYSRQ
10 #endif
11 
12 #include <linux/clk.h>
13 #include <linux/console.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/dmaengine.h>
16 #include <linux/dmapool.h>
17 #include <linux/io.h>
18 #include <linux/irq.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/of_dma.h>
23 #include <linux/serial_core.h>
24 #include <linux/slab.h>
25 #include <linux/tty_flip.h>
26 
27 /* All registers are 8-bit width */
28 #define UARTBDH			0x00
29 #define UARTBDL			0x01
30 #define UARTCR1			0x02
31 #define UARTCR2			0x03
32 #define UARTSR1			0x04
33 #define UARTCR3			0x06
34 #define UARTDR			0x07
35 #define UARTCR4			0x0a
36 #define UARTCR5			0x0b
37 #define UARTMODEM		0x0d
38 #define UARTPFIFO		0x10
39 #define UARTCFIFO		0x11
40 #define UARTSFIFO		0x12
41 #define UARTTWFIFO		0x13
42 #define UARTTCFIFO		0x14
43 #define UARTRWFIFO		0x15
44 
45 #define UARTBDH_LBKDIE		0x80
46 #define UARTBDH_RXEDGIE		0x40
47 #define UARTBDH_SBR_MASK	0x1f
48 
49 #define UARTCR1_LOOPS		0x80
50 #define UARTCR1_RSRC		0x20
51 #define UARTCR1_M		0x10
52 #define UARTCR1_WAKE		0x08
53 #define UARTCR1_ILT		0x04
54 #define UARTCR1_PE		0x02
55 #define UARTCR1_PT		0x01
56 
57 #define UARTCR2_TIE		0x80
58 #define UARTCR2_TCIE		0x40
59 #define UARTCR2_RIE		0x20
60 #define UARTCR2_ILIE		0x10
61 #define UARTCR2_TE		0x08
62 #define UARTCR2_RE		0x04
63 #define UARTCR2_RWU		0x02
64 #define UARTCR2_SBK		0x01
65 
66 #define UARTSR1_TDRE		0x80
67 #define UARTSR1_TC		0x40
68 #define UARTSR1_RDRF		0x20
69 #define UARTSR1_IDLE		0x10
70 #define UARTSR1_OR		0x08
71 #define UARTSR1_NF		0x04
72 #define UARTSR1_FE		0x02
73 #define UARTSR1_PE		0x01
74 
75 #define UARTCR3_R8		0x80
76 #define UARTCR3_T8		0x40
77 #define UARTCR3_TXDIR		0x20
78 #define UARTCR3_TXINV		0x10
79 #define UARTCR3_ORIE		0x08
80 #define UARTCR3_NEIE		0x04
81 #define UARTCR3_FEIE		0x02
82 #define UARTCR3_PEIE		0x01
83 
84 #define UARTCR4_MAEN1		0x80
85 #define UARTCR4_MAEN2		0x40
86 #define UARTCR4_M10		0x20
87 #define UARTCR4_BRFA_MASK	0x1f
88 #define UARTCR4_BRFA_OFF	0
89 
90 #define UARTCR5_TDMAS		0x80
91 #define UARTCR5_RDMAS		0x20
92 
93 #define UARTMODEM_RXRTSE	0x08
94 #define UARTMODEM_TXRTSPOL	0x04
95 #define UARTMODEM_TXRTSE	0x02
96 #define UARTMODEM_TXCTSE	0x01
97 
98 #define UARTPFIFO_TXFE		0x80
99 #define UARTPFIFO_FIFOSIZE_MASK	0x7
100 #define UARTPFIFO_TXSIZE_OFF	4
101 #define UARTPFIFO_RXFE		0x08
102 #define UARTPFIFO_RXSIZE_OFF	0
103 
104 #define UARTCFIFO_TXFLUSH	0x80
105 #define UARTCFIFO_RXFLUSH	0x40
106 #define UARTCFIFO_RXOFE		0x04
107 #define UARTCFIFO_TXOFE		0x02
108 #define UARTCFIFO_RXUFE		0x01
109 
110 #define UARTSFIFO_TXEMPT	0x80
111 #define UARTSFIFO_RXEMPT	0x40
112 #define UARTSFIFO_RXOF		0x04
113 #define UARTSFIFO_TXOF		0x02
114 #define UARTSFIFO_RXUF		0x01
115 
116 /* 32-bit register definition */
117 #define UARTBAUD		0x00
118 #define UARTSTAT		0x04
119 #define UARTCTRL		0x08
120 #define UARTDATA		0x0C
121 #define UARTMATCH		0x10
122 #define UARTMODIR		0x14
123 #define UARTFIFO		0x18
124 #define UARTWATER		0x1c
125 
126 #define UARTBAUD_MAEN1		0x80000000
127 #define UARTBAUD_MAEN2		0x40000000
128 #define UARTBAUD_M10		0x20000000
129 #define UARTBAUD_TDMAE		0x00800000
130 #define UARTBAUD_RDMAE		0x00200000
131 #define UARTBAUD_MATCFG		0x00400000
132 #define UARTBAUD_BOTHEDGE	0x00020000
133 #define UARTBAUD_RESYNCDIS	0x00010000
134 #define UARTBAUD_LBKDIE		0x00008000
135 #define UARTBAUD_RXEDGIE	0x00004000
136 #define UARTBAUD_SBNS		0x00002000
137 #define UARTBAUD_SBR		0x00000000
138 #define UARTBAUD_SBR_MASK	0x1fff
139 #define UARTBAUD_OSR_MASK       0x1f
140 #define UARTBAUD_OSR_SHIFT      24
141 
142 #define UARTSTAT_LBKDIF		0x80000000
143 #define UARTSTAT_RXEDGIF	0x40000000
144 #define UARTSTAT_MSBF		0x20000000
145 #define UARTSTAT_RXINV		0x10000000
146 #define UARTSTAT_RWUID		0x08000000
147 #define UARTSTAT_BRK13		0x04000000
148 #define UARTSTAT_LBKDE		0x02000000
149 #define UARTSTAT_RAF		0x01000000
150 #define UARTSTAT_TDRE		0x00800000
151 #define UARTSTAT_TC		0x00400000
152 #define UARTSTAT_RDRF		0x00200000
153 #define UARTSTAT_IDLE		0x00100000
154 #define UARTSTAT_OR		0x00080000
155 #define UARTSTAT_NF		0x00040000
156 #define UARTSTAT_FE		0x00020000
157 #define UARTSTAT_PE		0x00010000
158 #define UARTSTAT_MA1F		0x00008000
159 #define UARTSTAT_M21F		0x00004000
160 
161 #define UARTCTRL_R8T9		0x80000000
162 #define UARTCTRL_R9T8		0x40000000
163 #define UARTCTRL_TXDIR		0x20000000
164 #define UARTCTRL_TXINV		0x10000000
165 #define UARTCTRL_ORIE		0x08000000
166 #define UARTCTRL_NEIE		0x04000000
167 #define UARTCTRL_FEIE		0x02000000
168 #define UARTCTRL_PEIE		0x01000000
169 #define UARTCTRL_TIE		0x00800000
170 #define UARTCTRL_TCIE		0x00400000
171 #define UARTCTRL_RIE		0x00200000
172 #define UARTCTRL_ILIE		0x00100000
173 #define UARTCTRL_TE		0x00080000
174 #define UARTCTRL_RE		0x00040000
175 #define UARTCTRL_RWU		0x00020000
176 #define UARTCTRL_SBK		0x00010000
177 #define UARTCTRL_MA1IE		0x00008000
178 #define UARTCTRL_MA2IE		0x00004000
179 #define UARTCTRL_IDLECFG	0x00000100
180 #define UARTCTRL_LOOPS		0x00000080
181 #define UARTCTRL_DOZEEN		0x00000040
182 #define UARTCTRL_RSRC		0x00000020
183 #define UARTCTRL_M		0x00000010
184 #define UARTCTRL_WAKE		0x00000008
185 #define UARTCTRL_ILT		0x00000004
186 #define UARTCTRL_PE		0x00000002
187 #define UARTCTRL_PT		0x00000001
188 
189 #define UARTDATA_NOISY		0x00008000
190 #define UARTDATA_PARITYE	0x00004000
191 #define UARTDATA_FRETSC		0x00002000
192 #define UARTDATA_RXEMPT		0x00001000
193 #define UARTDATA_IDLINE		0x00000800
194 #define UARTDATA_MASK		0x3ff
195 
196 #define UARTMODIR_IREN		0x00020000
197 #define UARTMODIR_TXCTSSRC	0x00000020
198 #define UARTMODIR_TXCTSC	0x00000010
199 #define UARTMODIR_RXRTSE	0x00000008
200 #define UARTMODIR_TXRTSPOL	0x00000004
201 #define UARTMODIR_TXRTSE	0x00000002
202 #define UARTMODIR_TXCTSE	0x00000001
203 
204 #define UARTFIFO_TXEMPT		0x00800000
205 #define UARTFIFO_RXEMPT		0x00400000
206 #define UARTFIFO_TXOF		0x00020000
207 #define UARTFIFO_RXUF		0x00010000
208 #define UARTFIFO_TXFLUSH	0x00008000
209 #define UARTFIFO_RXFLUSH	0x00004000
210 #define UARTFIFO_TXOFE		0x00000200
211 #define UARTFIFO_RXUFE		0x00000100
212 #define UARTFIFO_TXFE		0x00000080
213 #define UARTFIFO_FIFOSIZE_MASK	0x7
214 #define UARTFIFO_TXSIZE_OFF	4
215 #define UARTFIFO_RXFE		0x00000008
216 #define UARTFIFO_RXSIZE_OFF	0
217 
218 #define UARTWATER_COUNT_MASK	0xff
219 #define UARTWATER_TXCNT_OFF	8
220 #define UARTWATER_RXCNT_OFF	24
221 #define UARTWATER_WATER_MASK	0xff
222 #define UARTWATER_TXWATER_OFF	0
223 #define UARTWATER_RXWATER_OFF	16
224 
225 /* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
226 #define DMA_RX_TIMEOUT		(10)
227 
228 #define DRIVER_NAME	"fsl-lpuart"
229 #define DEV_NAME	"ttyLP"
230 #define UART_NR		6
231 
232 /* IMX lpuart has four extra unused regs located at the beginning */
233 #define IMX_REG_OFF	0x10
234 
235 static DEFINE_IDA(fsl_lpuart_ida);
236 
237 struct lpuart_port {
238 	struct uart_port	port;
239 	struct clk		*clk;
240 	unsigned int		txfifo_size;
241 	unsigned int		rxfifo_size;
242 
243 	bool			lpuart_dma_tx_use;
244 	bool			lpuart_dma_rx_use;
245 	struct dma_chan		*dma_tx_chan;
246 	struct dma_chan		*dma_rx_chan;
247 	struct dma_async_tx_descriptor  *dma_tx_desc;
248 	struct dma_async_tx_descriptor  *dma_rx_desc;
249 	dma_cookie_t		dma_tx_cookie;
250 	dma_cookie_t		dma_rx_cookie;
251 	unsigned int		dma_tx_bytes;
252 	unsigned int		dma_rx_bytes;
253 	bool			dma_tx_in_progress;
254 	unsigned int		dma_rx_timeout;
255 	struct timer_list	lpuart_timer;
256 	struct scatterlist	rx_sgl, tx_sgl[2];
257 	struct circ_buf		rx_ring;
258 	int			rx_dma_rng_buf_len;
259 	unsigned int		dma_tx_nents;
260 	wait_queue_head_t	dma_wait;
261 };
262 
263 struct lpuart_soc_data {
264 	char	iotype;
265 	u8	reg_off;
266 };
267 
268 static const struct lpuart_soc_data vf_data = {
269 	.iotype = UPIO_MEM,
270 };
271 
272 static const struct lpuart_soc_data ls_data = {
273 	.iotype = UPIO_MEM32BE,
274 };
275 
276 static struct lpuart_soc_data imx_data = {
277 	.iotype = UPIO_MEM32,
278 	.reg_off = IMX_REG_OFF,
279 };
280 
281 static const struct of_device_id lpuart_dt_ids[] = {
282 	{ .compatible = "fsl,vf610-lpuart",	.data = &vf_data, },
283 	{ .compatible = "fsl,ls1021a-lpuart",	.data = &ls_data, },
284 	{ .compatible = "fsl,imx7ulp-lpuart",	.data = &imx_data, },
285 	{ /* sentinel */ }
286 };
287 MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
288 
289 /* Forward declare this for the dma callbacks*/
290 static void lpuart_dma_tx_complete(void *arg);
291 
292 static inline u32 lpuart32_read(struct uart_port *port, u32 off)
293 {
294 	switch (port->iotype) {
295 	case UPIO_MEM32:
296 		return readl(port->membase + off);
297 	case UPIO_MEM32BE:
298 		return ioread32be(port->membase + off);
299 	default:
300 		return 0;
301 	}
302 }
303 
304 static inline void lpuart32_write(struct uart_port *port, u32 val,
305 				  u32 off)
306 {
307 	switch (port->iotype) {
308 	case UPIO_MEM32:
309 		writel(val, port->membase + off);
310 		break;
311 	case UPIO_MEM32BE:
312 		iowrite32be(val, port->membase + off);
313 		break;
314 	}
315 }
316 
317 static void lpuart_stop_tx(struct uart_port *port)
318 {
319 	unsigned char temp;
320 
321 	temp = readb(port->membase + UARTCR2);
322 	temp &= ~(UARTCR2_TIE | UARTCR2_TCIE);
323 	writeb(temp, port->membase + UARTCR2);
324 }
325 
326 static void lpuart32_stop_tx(struct uart_port *port)
327 {
328 	unsigned long temp;
329 
330 	temp = lpuart32_read(port, UARTCTRL);
331 	temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE);
332 	lpuart32_write(port, temp, UARTCTRL);
333 }
334 
335 static void lpuart_stop_rx(struct uart_port *port)
336 {
337 	unsigned char temp;
338 
339 	temp = readb(port->membase + UARTCR2);
340 	writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2);
341 }
342 
343 static void lpuart32_stop_rx(struct uart_port *port)
344 {
345 	unsigned long temp;
346 
347 	temp = lpuart32_read(port, UARTCTRL);
348 	lpuart32_write(port, temp & ~UARTCTRL_RE, UARTCTRL);
349 }
350 
351 static void lpuart_dma_tx(struct lpuart_port *sport)
352 {
353 	struct circ_buf *xmit = &sport->port.state->xmit;
354 	struct scatterlist *sgl = sport->tx_sgl;
355 	struct device *dev = sport->port.dev;
356 	int ret;
357 
358 	if (sport->dma_tx_in_progress)
359 		return;
360 
361 	sport->dma_tx_bytes = uart_circ_chars_pending(xmit);
362 
363 	if (xmit->tail < xmit->head || xmit->head == 0) {
364 		sport->dma_tx_nents = 1;
365 		sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes);
366 	} else {
367 		sport->dma_tx_nents = 2;
368 		sg_init_table(sgl, 2);
369 		sg_set_buf(sgl, xmit->buf + xmit->tail,
370 				UART_XMIT_SIZE - xmit->tail);
371 		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
372 	}
373 
374 	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
375 	if (!ret) {
376 		dev_err(dev, "DMA mapping error for TX.\n");
377 		return;
378 	}
379 
380 	sport->dma_tx_desc = dmaengine_prep_slave_sg(sport->dma_tx_chan, sgl,
381 					sport->dma_tx_nents,
382 					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
383 	if (!sport->dma_tx_desc) {
384 		dma_unmap_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
385 		dev_err(dev, "Cannot prepare TX slave DMA!\n");
386 		return;
387 	}
388 
389 	sport->dma_tx_desc->callback = lpuart_dma_tx_complete;
390 	sport->dma_tx_desc->callback_param = sport;
391 	sport->dma_tx_in_progress = true;
392 	sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc);
393 	dma_async_issue_pending(sport->dma_tx_chan);
394 }
395 
396 static void lpuart_dma_tx_complete(void *arg)
397 {
398 	struct lpuart_port *sport = arg;
399 	struct scatterlist *sgl = &sport->tx_sgl[0];
400 	struct circ_buf *xmit = &sport->port.state->xmit;
401 	unsigned long flags;
402 
403 	spin_lock_irqsave(&sport->port.lock, flags);
404 
405 	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
406 
407 	xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1);
408 
409 	sport->port.icount.tx += sport->dma_tx_bytes;
410 	sport->dma_tx_in_progress = false;
411 	spin_unlock_irqrestore(&sport->port.lock, flags);
412 
413 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
414 		uart_write_wakeup(&sport->port);
415 
416 	if (waitqueue_active(&sport->dma_wait)) {
417 		wake_up(&sport->dma_wait);
418 		return;
419 	}
420 
421 	spin_lock_irqsave(&sport->port.lock, flags);
422 
423 	if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
424 		lpuart_dma_tx(sport);
425 
426 	spin_unlock_irqrestore(&sport->port.lock, flags);
427 }
428 
429 static dma_addr_t lpuart_dma_datareg_addr(struct lpuart_port *sport)
430 {
431 	switch (sport->port.iotype) {
432 	case UPIO_MEM32:
433 		return sport->port.mapbase + UARTDATA;
434 	case UPIO_MEM32BE:
435 		return sport->port.mapbase + UARTDATA + sizeof(u32) - 1;
436 	}
437 	return sport->port.mapbase + UARTDR;
438 }
439 
440 static int lpuart_dma_tx_request(struct uart_port *port)
441 {
442 	struct lpuart_port *sport = container_of(port,
443 					struct lpuart_port, port);
444 	struct dma_slave_config dma_tx_sconfig = {};
445 	int ret;
446 
447 	dma_tx_sconfig.dst_addr = lpuart_dma_datareg_addr(sport);
448 	dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
449 	dma_tx_sconfig.dst_maxburst = 1;
450 	dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
451 	ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig);
452 
453 	if (ret) {
454 		dev_err(sport->port.dev,
455 				"DMA slave config failed, err = %d\n", ret);
456 		return ret;
457 	}
458 
459 	return 0;
460 }
461 
462 static void lpuart_flush_buffer(struct uart_port *port)
463 {
464 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
465 
466 	if (sport->lpuart_dma_tx_use) {
467 		if (sport->dma_tx_in_progress) {
468 			dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
469 				sport->dma_tx_nents, DMA_TO_DEVICE);
470 			sport->dma_tx_in_progress = false;
471 		}
472 		dmaengine_terminate_all(sport->dma_tx_chan);
473 	}
474 }
475 
476 #if defined(CONFIG_CONSOLE_POLL)
477 
478 static int lpuart_poll_init(struct uart_port *port)
479 {
480 	struct lpuart_port *sport = container_of(port,
481 					struct lpuart_port, port);
482 	unsigned long flags;
483 	unsigned char temp;
484 
485 	sport->port.fifosize = 0;
486 
487 	spin_lock_irqsave(&sport->port.lock, flags);
488 	/* Disable Rx & Tx */
489 	writeb(0, sport->port.membase + UARTCR2);
490 
491 	temp = readb(sport->port.membase + UARTPFIFO);
492 	/* Enable Rx and Tx FIFO */
493 	writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE,
494 			sport->port.membase + UARTPFIFO);
495 
496 	/* flush Tx and Rx FIFO */
497 	writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
498 			sport->port.membase + UARTCFIFO);
499 
500 	/* explicitly clear RDRF */
501 	if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
502 		readb(sport->port.membase + UARTDR);
503 		writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
504 	}
505 
506 	writeb(0, sport->port.membase + UARTTWFIFO);
507 	writeb(1, sport->port.membase + UARTRWFIFO);
508 
509 	/* Enable Rx and Tx */
510 	writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2);
511 	spin_unlock_irqrestore(&sport->port.lock, flags);
512 
513 	return 0;
514 }
515 
516 static void lpuart_poll_put_char(struct uart_port *port, unsigned char c)
517 {
518 	/* drain */
519 	while (!(readb(port->membase + UARTSR1) & UARTSR1_TDRE))
520 		barrier();
521 
522 	writeb(c, port->membase + UARTDR);
523 }
524 
525 static int lpuart_poll_get_char(struct uart_port *port)
526 {
527 	if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF))
528 		return NO_POLL_CHAR;
529 
530 	return readb(port->membase + UARTDR);
531 }
532 
533 static int lpuart32_poll_init(struct uart_port *port)
534 {
535 	unsigned long flags;
536 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
537 	u32 temp;
538 
539 	sport->port.fifosize = 0;
540 
541 	spin_lock_irqsave(&sport->port.lock, flags);
542 
543 	/* Disable Rx & Tx */
544 	writel(0, sport->port.membase + UARTCTRL);
545 
546 	temp = readl(sport->port.membase + UARTFIFO);
547 
548 	/* Enable Rx and Tx FIFO */
549 	writel(temp | UARTFIFO_RXFE | UARTFIFO_TXFE,
550 		   sport->port.membase + UARTFIFO);
551 
552 	/* flush Tx and Rx FIFO */
553 	writel(UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH,
554 			sport->port.membase + UARTFIFO);
555 
556 	/* explicitly clear RDRF */
557 	if (readl(sport->port.membase + UARTSTAT) & UARTSTAT_RDRF) {
558 		readl(sport->port.membase + UARTDATA);
559 		writel(UARTFIFO_RXUF, sport->port.membase + UARTFIFO);
560 	}
561 
562 	/* Enable Rx and Tx */
563 	writel(UARTCTRL_RE | UARTCTRL_TE, sport->port.membase + UARTCTRL);
564 	spin_unlock_irqrestore(&sport->port.lock, flags);
565 
566 	return 0;
567 }
568 
569 static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c)
570 {
571 	while (!(readl(port->membase + UARTSTAT) & UARTSTAT_TDRE))
572 		barrier();
573 
574 	writel(c, port->membase + UARTDATA);
575 }
576 
577 static int lpuart32_poll_get_char(struct uart_port *port)
578 {
579 	if (!(readl(port->membase + UARTSTAT) & UARTSTAT_RDRF))
580 		return NO_POLL_CHAR;
581 
582 	return readl(port->membase + UARTDATA);
583 }
584 #endif
585 
586 static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
587 {
588 	struct circ_buf *xmit = &sport->port.state->xmit;
589 
590 	while (!uart_circ_empty(xmit) &&
591 		(readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) {
592 		writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
593 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
594 		sport->port.icount.tx++;
595 	}
596 
597 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
598 		uart_write_wakeup(&sport->port);
599 
600 	if (uart_circ_empty(xmit))
601 		lpuart_stop_tx(&sport->port);
602 }
603 
604 static inline void lpuart32_transmit_buffer(struct lpuart_port *sport)
605 {
606 	struct circ_buf *xmit = &sport->port.state->xmit;
607 	unsigned long txcnt;
608 
609 	txcnt = lpuart32_read(&sport->port, UARTWATER);
610 	txcnt = txcnt >> UARTWATER_TXCNT_OFF;
611 	txcnt &= UARTWATER_COUNT_MASK;
612 	while (!uart_circ_empty(xmit) && (txcnt < sport->txfifo_size)) {
613 		lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA);
614 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
615 		sport->port.icount.tx++;
616 		txcnt = lpuart32_read(&sport->port, UARTWATER);
617 		txcnt = txcnt >> UARTWATER_TXCNT_OFF;
618 		txcnt &= UARTWATER_COUNT_MASK;
619 	}
620 
621 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
622 		uart_write_wakeup(&sport->port);
623 
624 	if (uart_circ_empty(xmit))
625 		lpuart32_stop_tx(&sport->port);
626 }
627 
628 static void lpuart_start_tx(struct uart_port *port)
629 {
630 	struct lpuart_port *sport = container_of(port,
631 			struct lpuart_port, port);
632 	struct circ_buf *xmit = &sport->port.state->xmit;
633 	unsigned char temp;
634 
635 	temp = readb(port->membase + UARTCR2);
636 	writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
637 
638 	if (sport->lpuart_dma_tx_use) {
639 		if (!uart_circ_empty(xmit) && !uart_tx_stopped(port))
640 			lpuart_dma_tx(sport);
641 	} else {
642 		if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
643 			lpuart_transmit_buffer(sport);
644 	}
645 }
646 
647 static void lpuart32_start_tx(struct uart_port *port)
648 {
649 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
650 	struct circ_buf *xmit = &sport->port.state->xmit;
651 	unsigned long temp;
652 
653 	if (sport->lpuart_dma_tx_use) {
654 		if (!uart_circ_empty(xmit) && !uart_tx_stopped(port))
655 			lpuart_dma_tx(sport);
656 	} else {
657 		temp = lpuart32_read(port, UARTCTRL);
658 		lpuart32_write(port, temp | UARTCTRL_TIE, UARTCTRL);
659 
660 		if (lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE)
661 			lpuart32_transmit_buffer(sport);
662 	}
663 }
664 
665 /* return TIOCSER_TEMT when transmitter is not busy */
666 static unsigned int lpuart_tx_empty(struct uart_port *port)
667 {
668 	struct lpuart_port *sport = container_of(port,
669 			struct lpuart_port, port);
670 	unsigned char sr1 = readb(port->membase + UARTSR1);
671 	unsigned char sfifo = readb(port->membase + UARTSFIFO);
672 
673 	if (sport->dma_tx_in_progress)
674 		return 0;
675 
676 	if (sr1 & UARTSR1_TC && sfifo & UARTSFIFO_TXEMPT)
677 		return TIOCSER_TEMT;
678 
679 	return 0;
680 }
681 
682 static unsigned int lpuart32_tx_empty(struct uart_port *port)
683 {
684 	struct lpuart_port *sport = container_of(port,
685 			struct lpuart_port, port);
686 	unsigned long stat = lpuart32_read(port, UARTSTAT);
687 	unsigned long sfifo = lpuart32_read(port, UARTFIFO);
688 
689 	if (sport->dma_tx_in_progress)
690 		return 0;
691 
692 	if (stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT)
693 		return TIOCSER_TEMT;
694 
695 	return 0;
696 }
697 
698 static bool lpuart_is_32(struct lpuart_port *sport)
699 {
700 	return sport->port.iotype == UPIO_MEM32 ||
701 	       sport->port.iotype ==  UPIO_MEM32BE;
702 }
703 
704 static irqreturn_t lpuart_txint(int irq, void *dev_id)
705 {
706 	struct lpuart_port *sport = dev_id;
707 	struct circ_buf *xmit = &sport->port.state->xmit;
708 	unsigned long flags;
709 
710 	spin_lock_irqsave(&sport->port.lock, flags);
711 	if (sport->port.x_char) {
712 		if (lpuart_is_32(sport))
713 			lpuart32_write(&sport->port, sport->port.x_char, UARTDATA);
714 		else
715 			writeb(sport->port.x_char, sport->port.membase + UARTDR);
716 		goto out;
717 	}
718 
719 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
720 		if (lpuart_is_32(sport))
721 			lpuart32_stop_tx(&sport->port);
722 		else
723 			lpuart_stop_tx(&sport->port);
724 		goto out;
725 	}
726 
727 	if (lpuart_is_32(sport))
728 		lpuart32_transmit_buffer(sport);
729 	else
730 		lpuart_transmit_buffer(sport);
731 
732 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
733 		uart_write_wakeup(&sport->port);
734 
735 out:
736 	spin_unlock_irqrestore(&sport->port.lock, flags);
737 	return IRQ_HANDLED;
738 }
739 
740 static irqreturn_t lpuart_rxint(int irq, void *dev_id)
741 {
742 	struct lpuart_port *sport = dev_id;
743 	unsigned int flg, ignored = 0;
744 	struct tty_port *port = &sport->port.state->port;
745 	unsigned long flags;
746 	unsigned char rx, sr;
747 
748 	spin_lock_irqsave(&sport->port.lock, flags);
749 
750 	while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) {
751 		flg = TTY_NORMAL;
752 		sport->port.icount.rx++;
753 		/*
754 		 * to clear the FE, OR, NF, FE, PE flags,
755 		 * read SR1 then read DR
756 		 */
757 		sr = readb(sport->port.membase + UARTSR1);
758 		rx = readb(sport->port.membase + UARTDR);
759 
760 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
761 			continue;
762 
763 		if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) {
764 			if (sr & UARTSR1_PE)
765 				sport->port.icount.parity++;
766 			else if (sr & UARTSR1_FE)
767 				sport->port.icount.frame++;
768 
769 			if (sr & UARTSR1_OR)
770 				sport->port.icount.overrun++;
771 
772 			if (sr & sport->port.ignore_status_mask) {
773 				if (++ignored > 100)
774 					goto out;
775 				continue;
776 			}
777 
778 			sr &= sport->port.read_status_mask;
779 
780 			if (sr & UARTSR1_PE)
781 				flg = TTY_PARITY;
782 			else if (sr & UARTSR1_FE)
783 				flg = TTY_FRAME;
784 
785 			if (sr & UARTSR1_OR)
786 				flg = TTY_OVERRUN;
787 
788 #ifdef SUPPORT_SYSRQ
789 			sport->port.sysrq = 0;
790 #endif
791 		}
792 
793 		tty_insert_flip_char(port, rx, flg);
794 	}
795 
796 out:
797 	spin_unlock_irqrestore(&sport->port.lock, flags);
798 
799 	tty_flip_buffer_push(port);
800 	return IRQ_HANDLED;
801 }
802 
803 static irqreturn_t lpuart32_rxint(int irq, void *dev_id)
804 {
805 	struct lpuart_port *sport = dev_id;
806 	unsigned int flg, ignored = 0;
807 	struct tty_port *port = &sport->port.state->port;
808 	unsigned long flags;
809 	unsigned long rx, sr;
810 
811 	spin_lock_irqsave(&sport->port.lock, flags);
812 
813 	while (!(lpuart32_read(&sport->port, UARTFIFO) & UARTFIFO_RXEMPT)) {
814 		flg = TTY_NORMAL;
815 		sport->port.icount.rx++;
816 		/*
817 		 * to clear the FE, OR, NF, FE, PE flags,
818 		 * read STAT then read DATA reg
819 		 */
820 		sr = lpuart32_read(&sport->port, UARTSTAT);
821 		rx = lpuart32_read(&sport->port, UARTDATA);
822 		rx &= 0x3ff;
823 
824 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
825 			continue;
826 
827 		if (sr & (UARTSTAT_PE | UARTSTAT_OR | UARTSTAT_FE)) {
828 			if (sr & UARTSTAT_PE)
829 				sport->port.icount.parity++;
830 			else if (sr & UARTSTAT_FE)
831 				sport->port.icount.frame++;
832 
833 			if (sr & UARTSTAT_OR)
834 				sport->port.icount.overrun++;
835 
836 			if (sr & sport->port.ignore_status_mask) {
837 				if (++ignored > 100)
838 					goto out;
839 				continue;
840 			}
841 
842 			sr &= sport->port.read_status_mask;
843 
844 			if (sr & UARTSTAT_PE)
845 				flg = TTY_PARITY;
846 			else if (sr & UARTSTAT_FE)
847 				flg = TTY_FRAME;
848 
849 			if (sr & UARTSTAT_OR)
850 				flg = TTY_OVERRUN;
851 
852 #ifdef SUPPORT_SYSRQ
853 			sport->port.sysrq = 0;
854 #endif
855 		}
856 
857 		tty_insert_flip_char(port, rx, flg);
858 	}
859 
860 out:
861 	spin_unlock_irqrestore(&sport->port.lock, flags);
862 
863 	tty_flip_buffer_push(port);
864 	return IRQ_HANDLED;
865 }
866 
867 static irqreturn_t lpuart_int(int irq, void *dev_id)
868 {
869 	struct lpuart_port *sport = dev_id;
870 	unsigned char sts;
871 
872 	sts = readb(sport->port.membase + UARTSR1);
873 
874 	if (sts & UARTSR1_RDRF)
875 		lpuart_rxint(irq, dev_id);
876 
877 	if (sts & UARTSR1_TDRE)
878 		lpuart_txint(irq, dev_id);
879 
880 	return IRQ_HANDLED;
881 }
882 
883 static irqreturn_t lpuart32_int(int irq, void *dev_id)
884 {
885 	struct lpuart_port *sport = dev_id;
886 	unsigned long sts, rxcount;
887 
888 	sts = lpuart32_read(&sport->port, UARTSTAT);
889 	rxcount = lpuart32_read(&sport->port, UARTWATER);
890 	rxcount = rxcount >> UARTWATER_RXCNT_OFF;
891 
892 	if ((sts & UARTSTAT_RDRF || rxcount > 0) && !sport->lpuart_dma_rx_use)
893 		lpuart32_rxint(irq, dev_id);
894 
895 	if ((sts & UARTSTAT_TDRE) && !sport->lpuart_dma_tx_use)
896 		lpuart_txint(irq, dev_id);
897 
898 	lpuart32_write(&sport->port, sts, UARTSTAT);
899 	return IRQ_HANDLED;
900 }
901 
902 static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
903 {
904 	struct tty_port *port = &sport->port.state->port;
905 	struct dma_tx_state state;
906 	enum dma_status dmastat;
907 	struct circ_buf *ring = &sport->rx_ring;
908 	unsigned long flags;
909 	int count = 0;
910 
911 	if (lpuart_is_32(sport)) {
912 		unsigned long sr = lpuart32_read(&sport->port, UARTSTAT);
913 
914 		if (sr & (UARTSTAT_PE | UARTSTAT_FE)) {
915 			/* Read DR to clear the error flags */
916 			lpuart32_read(&sport->port, UARTDATA);
917 
918 			if (sr & UARTSTAT_PE)
919 				sport->port.icount.parity++;
920 			else if (sr & UARTSTAT_FE)
921 				sport->port.icount.frame++;
922 		}
923 	} else {
924 		unsigned char sr = readb(sport->port.membase + UARTSR1);
925 
926 		if (sr & (UARTSR1_PE | UARTSR1_FE)) {
927 			/* Read DR to clear the error flags */
928 			readb(sport->port.membase + UARTDR);
929 
930 			if (sr & UARTSR1_PE)
931 				sport->port.icount.parity++;
932 			else if (sr & UARTSR1_FE)
933 				sport->port.icount.frame++;
934 		}
935 	}
936 
937 	async_tx_ack(sport->dma_rx_desc);
938 
939 	spin_lock_irqsave(&sport->port.lock, flags);
940 
941 	dmastat = dmaengine_tx_status(sport->dma_rx_chan,
942 				sport->dma_rx_cookie,
943 				&state);
944 
945 	if (dmastat == DMA_ERROR) {
946 		dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
947 		spin_unlock_irqrestore(&sport->port.lock, flags);
948 		return;
949 	}
950 
951 	/* CPU claims ownership of RX DMA buffer */
952 	dma_sync_sg_for_cpu(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
953 
954 	/*
955 	 * ring->head points to the end of data already written by the DMA.
956 	 * ring->tail points to the beginning of data to be read by the
957 	 * framework.
958 	 * The current transfer size should not be larger than the dma buffer
959 	 * length.
960 	 */
961 	ring->head = sport->rx_sgl.length - state.residue;
962 	BUG_ON(ring->head > sport->rx_sgl.length);
963 	/*
964 	 * At this point ring->head may point to the first byte right after the
965 	 * last byte of the dma buffer:
966 	 * 0 <= ring->head <= sport->rx_sgl.length
967 	 *
968 	 * However ring->tail must always points inside the dma buffer:
969 	 * 0 <= ring->tail <= sport->rx_sgl.length - 1
970 	 *
971 	 * Since we use a ring buffer, we have to handle the case
972 	 * where head is lower than tail. In such a case, we first read from
973 	 * tail to the end of the buffer then reset tail.
974 	 */
975 	if (ring->head < ring->tail) {
976 		count = sport->rx_sgl.length - ring->tail;
977 
978 		tty_insert_flip_string(port, ring->buf + ring->tail, count);
979 		ring->tail = 0;
980 		sport->port.icount.rx += count;
981 	}
982 
983 	/* Finally we read data from tail to head */
984 	if (ring->tail < ring->head) {
985 		count = ring->head - ring->tail;
986 		tty_insert_flip_string(port, ring->buf + ring->tail, count);
987 		/* Wrap ring->head if needed */
988 		if (ring->head >= sport->rx_sgl.length)
989 			ring->head = 0;
990 		ring->tail = ring->head;
991 		sport->port.icount.rx += count;
992 	}
993 
994 	dma_sync_sg_for_device(sport->port.dev, &sport->rx_sgl, 1,
995 			       DMA_FROM_DEVICE);
996 
997 	spin_unlock_irqrestore(&sport->port.lock, flags);
998 
999 	tty_flip_buffer_push(port);
1000 	mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout);
1001 }
1002 
1003 static void lpuart_dma_rx_complete(void *arg)
1004 {
1005 	struct lpuart_port *sport = arg;
1006 
1007 	lpuart_copy_rx_to_tty(sport);
1008 }
1009 
1010 static void lpuart_timer_func(struct timer_list *t)
1011 {
1012 	struct lpuart_port *sport = from_timer(sport, t, lpuart_timer);
1013 
1014 	lpuart_copy_rx_to_tty(sport);
1015 }
1016 
1017 static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
1018 {
1019 	struct dma_slave_config dma_rx_sconfig = {};
1020 	struct circ_buf *ring = &sport->rx_ring;
1021 	int ret, nent;
1022 	int bits, baud;
1023 	struct tty_port *port = &sport->port.state->port;
1024 	struct tty_struct *tty = port->tty;
1025 	struct ktermios *termios = &tty->termios;
1026 
1027 	baud = tty_get_baud_rate(tty);
1028 
1029 	bits = (termios->c_cflag & CSIZE) == CS7 ? 9 : 10;
1030 	if (termios->c_cflag & PARENB)
1031 		bits++;
1032 
1033 	/*
1034 	 * Calculate length of one DMA buffer size to keep latency below
1035 	 * 10ms at any baud rate.
1036 	 */
1037 	sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud /  bits / 1000) * 2;
1038 	sport->rx_dma_rng_buf_len = (1 << (fls(sport->rx_dma_rng_buf_len) - 1));
1039 	if (sport->rx_dma_rng_buf_len < 16)
1040 		sport->rx_dma_rng_buf_len = 16;
1041 
1042 	ring->buf = kmalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC);
1043 	if (!ring->buf) {
1044 		dev_err(sport->port.dev, "Ring buf alloc failed\n");
1045 		return -ENOMEM;
1046 	}
1047 
1048 	sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
1049 	sg_set_buf(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
1050 	nent = dma_map_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
1051 
1052 	if (!nent) {
1053 		dev_err(sport->port.dev, "DMA Rx mapping error\n");
1054 		return -EINVAL;
1055 	}
1056 
1057 	dma_rx_sconfig.src_addr = lpuart_dma_datareg_addr(sport);
1058 	dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1059 	dma_rx_sconfig.src_maxburst = 1;
1060 	dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
1061 	ret = dmaengine_slave_config(sport->dma_rx_chan, &dma_rx_sconfig);
1062 
1063 	if (ret < 0) {
1064 		dev_err(sport->port.dev,
1065 				"DMA Rx slave config failed, err = %d\n", ret);
1066 		return ret;
1067 	}
1068 
1069 	sport->dma_rx_desc = dmaengine_prep_dma_cyclic(sport->dma_rx_chan,
1070 				 sg_dma_address(&sport->rx_sgl),
1071 				 sport->rx_sgl.length,
1072 				 sport->rx_sgl.length / 2,
1073 				 DMA_DEV_TO_MEM,
1074 				 DMA_PREP_INTERRUPT);
1075 	if (!sport->dma_rx_desc) {
1076 		dev_err(sport->port.dev, "Cannot prepare cyclic DMA\n");
1077 		return -EFAULT;
1078 	}
1079 
1080 	sport->dma_rx_desc->callback = lpuart_dma_rx_complete;
1081 	sport->dma_rx_desc->callback_param = sport;
1082 	sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc);
1083 	dma_async_issue_pending(sport->dma_rx_chan);
1084 
1085 	if (lpuart_is_32(sport)) {
1086 		unsigned long temp = lpuart32_read(&sport->port, UARTBAUD);
1087 
1088 		lpuart32_write(&sport->port, temp | UARTBAUD_RDMAE, UARTBAUD);
1089 	} else {
1090 		writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_RDMAS,
1091 		       sport->port.membase + UARTCR5);
1092 	}
1093 
1094 	return 0;
1095 }
1096 
1097 static void lpuart_dma_rx_free(struct uart_port *port)
1098 {
1099 	struct lpuart_port *sport = container_of(port,
1100 					struct lpuart_port, port);
1101 
1102 	if (sport->dma_rx_chan)
1103 		dmaengine_terminate_all(sport->dma_rx_chan);
1104 
1105 	dma_unmap_sg(sport->port.dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
1106 	kfree(sport->rx_ring.buf);
1107 	sport->rx_ring.tail = 0;
1108 	sport->rx_ring.head = 0;
1109 	sport->dma_rx_desc = NULL;
1110 	sport->dma_rx_cookie = -EINVAL;
1111 }
1112 
1113 static int lpuart_config_rs485(struct uart_port *port,
1114 			struct serial_rs485 *rs485)
1115 {
1116 	struct lpuart_port *sport = container_of(port,
1117 			struct lpuart_port, port);
1118 
1119 	u8 modem = readb(sport->port.membase + UARTMODEM) &
1120 		~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE);
1121 	writeb(modem, sport->port.membase + UARTMODEM);
1122 
1123 	/* clear unsupported configurations */
1124 	rs485->delay_rts_before_send = 0;
1125 	rs485->delay_rts_after_send = 0;
1126 	rs485->flags &= ~SER_RS485_RX_DURING_TX;
1127 
1128 	if (rs485->flags & SER_RS485_ENABLED) {
1129 		/* Enable auto RS-485 RTS mode */
1130 		modem |= UARTMODEM_TXRTSE;
1131 
1132 		/*
1133 		 * RTS needs to be logic HIGH either during transer _or_ after
1134 		 * transfer, other variants are not supported by the hardware.
1135 		 */
1136 
1137 		if (!(rs485->flags & (SER_RS485_RTS_ON_SEND |
1138 				SER_RS485_RTS_AFTER_SEND)))
1139 			rs485->flags |= SER_RS485_RTS_ON_SEND;
1140 
1141 		if (rs485->flags & SER_RS485_RTS_ON_SEND &&
1142 				rs485->flags & SER_RS485_RTS_AFTER_SEND)
1143 			rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
1144 
1145 		/*
1146 		 * The hardware defaults to RTS logic HIGH while transfer.
1147 		 * Switch polarity in case RTS shall be logic HIGH
1148 		 * after transfer.
1149 		 * Note: UART is assumed to be active high.
1150 		 */
1151 		if (rs485->flags & SER_RS485_RTS_ON_SEND)
1152 			modem &= ~UARTMODEM_TXRTSPOL;
1153 		else if (rs485->flags & SER_RS485_RTS_AFTER_SEND)
1154 			modem |= UARTMODEM_TXRTSPOL;
1155 	}
1156 
1157 	/* Store the new configuration */
1158 	sport->port.rs485 = *rs485;
1159 
1160 	writeb(modem, sport->port.membase + UARTMODEM);
1161 	return 0;
1162 }
1163 
1164 static unsigned int lpuart_get_mctrl(struct uart_port *port)
1165 {
1166 	unsigned int temp = 0;
1167 	unsigned char reg;
1168 
1169 	reg = readb(port->membase + UARTMODEM);
1170 	if (reg & UARTMODEM_TXCTSE)
1171 		temp |= TIOCM_CTS;
1172 
1173 	if (reg & UARTMODEM_RXRTSE)
1174 		temp |= TIOCM_RTS;
1175 
1176 	return temp;
1177 }
1178 
1179 static unsigned int lpuart32_get_mctrl(struct uart_port *port)
1180 {
1181 	unsigned int temp = 0;
1182 	unsigned long reg;
1183 
1184 	reg = lpuart32_read(port, UARTMODIR);
1185 	if (reg & UARTMODIR_TXCTSE)
1186 		temp |= TIOCM_CTS;
1187 
1188 	if (reg & UARTMODIR_RXRTSE)
1189 		temp |= TIOCM_RTS;
1190 
1191 	return temp;
1192 }
1193 
1194 static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
1195 {
1196 	unsigned char temp;
1197 	struct lpuart_port *sport = container_of(port,
1198 				struct lpuart_port, port);
1199 
1200 	/* Make sure RXRTSE bit is not set when RS485 is enabled */
1201 	if (!(sport->port.rs485.flags & SER_RS485_ENABLED)) {
1202 		temp = readb(sport->port.membase + UARTMODEM) &
1203 			~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1204 
1205 		if (mctrl & TIOCM_RTS)
1206 			temp |= UARTMODEM_RXRTSE;
1207 
1208 		if (mctrl & TIOCM_CTS)
1209 			temp |= UARTMODEM_TXCTSE;
1210 
1211 		writeb(temp, port->membase + UARTMODEM);
1212 	}
1213 }
1214 
1215 static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl)
1216 {
1217 	unsigned long temp;
1218 
1219 	temp = lpuart32_read(port, UARTMODIR) &
1220 			~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE);
1221 
1222 	if (mctrl & TIOCM_RTS)
1223 		temp |= UARTMODIR_RXRTSE;
1224 
1225 	if (mctrl & TIOCM_CTS)
1226 		temp |= UARTMODIR_TXCTSE;
1227 
1228 	lpuart32_write(port, temp, UARTMODIR);
1229 }
1230 
1231 static void lpuart_break_ctl(struct uart_port *port, int break_state)
1232 {
1233 	unsigned char temp;
1234 
1235 	temp = readb(port->membase + UARTCR2) & ~UARTCR2_SBK;
1236 
1237 	if (break_state != 0)
1238 		temp |= UARTCR2_SBK;
1239 
1240 	writeb(temp, port->membase + UARTCR2);
1241 }
1242 
1243 static void lpuart32_break_ctl(struct uart_port *port, int break_state)
1244 {
1245 	unsigned long temp;
1246 
1247 	temp = lpuart32_read(port, UARTCTRL) & ~UARTCTRL_SBK;
1248 
1249 	if (break_state != 0)
1250 		temp |= UARTCTRL_SBK;
1251 
1252 	lpuart32_write(port, temp, UARTCTRL);
1253 }
1254 
1255 static void lpuart_setup_watermark(struct lpuart_port *sport)
1256 {
1257 	unsigned char val, cr2;
1258 	unsigned char cr2_saved;
1259 
1260 	cr2 = readb(sport->port.membase + UARTCR2);
1261 	cr2_saved = cr2;
1262 	cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_TE |
1263 			UARTCR2_RIE | UARTCR2_RE);
1264 	writeb(cr2, sport->port.membase + UARTCR2);
1265 
1266 	val = readb(sport->port.membase + UARTPFIFO);
1267 	writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE,
1268 			sport->port.membase + UARTPFIFO);
1269 
1270 	/* flush Tx and Rx FIFO */
1271 	writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
1272 			sport->port.membase + UARTCFIFO);
1273 
1274 	/* explicitly clear RDRF */
1275 	if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) {
1276 		readb(sport->port.membase + UARTDR);
1277 		writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO);
1278 	}
1279 
1280 	writeb(0, sport->port.membase + UARTTWFIFO);
1281 	writeb(1, sport->port.membase + UARTRWFIFO);
1282 
1283 	/* Restore cr2 */
1284 	writeb(cr2_saved, sport->port.membase + UARTCR2);
1285 }
1286 
1287 static void lpuart32_setup_watermark(struct lpuart_port *sport)
1288 {
1289 	unsigned long val, ctrl;
1290 	unsigned long ctrl_saved;
1291 
1292 	ctrl = lpuart32_read(&sport->port, UARTCTRL);
1293 	ctrl_saved = ctrl;
1294 	ctrl &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_TE |
1295 			UARTCTRL_RIE | UARTCTRL_RE);
1296 	lpuart32_write(&sport->port, ctrl, UARTCTRL);
1297 
1298 	/* enable FIFO mode */
1299 	val = lpuart32_read(&sport->port, UARTFIFO);
1300 	val |= UARTFIFO_TXFE | UARTFIFO_RXFE;
1301 	val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
1302 	lpuart32_write(&sport->port, val, UARTFIFO);
1303 
1304 	/* set the watermark */
1305 	val = (0x1 << UARTWATER_RXWATER_OFF) | (0x0 << UARTWATER_TXWATER_OFF);
1306 	lpuart32_write(&sport->port, val, UARTWATER);
1307 
1308 	/* Restore cr2 */
1309 	lpuart32_write(&sport->port, ctrl_saved, UARTCTRL);
1310 }
1311 
1312 static void rx_dma_timer_init(struct lpuart_port *sport)
1313 {
1314 		timer_setup(&sport->lpuart_timer, lpuart_timer_func, 0);
1315 		sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout;
1316 		add_timer(&sport->lpuart_timer);
1317 }
1318 
1319 static int lpuart_startup(struct uart_port *port)
1320 {
1321 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1322 	unsigned long flags;
1323 	unsigned char temp;
1324 
1325 	/* determine FIFO size and enable FIFO mode */
1326 	temp = readb(sport->port.membase + UARTPFIFO);
1327 
1328 	sport->txfifo_size = 0x1 << (((temp >> UARTPFIFO_TXSIZE_OFF) &
1329 		UARTPFIFO_FIFOSIZE_MASK) + 1);
1330 
1331 	sport->port.fifosize = sport->txfifo_size;
1332 
1333 	sport->rxfifo_size = 0x1 << (((temp >> UARTPFIFO_RXSIZE_OFF) &
1334 		UARTPFIFO_FIFOSIZE_MASK) + 1);
1335 
1336 	spin_lock_irqsave(&sport->port.lock, flags);
1337 
1338 	lpuart_setup_watermark(sport);
1339 
1340 	temp = readb(sport->port.membase + UARTCR2);
1341 	temp |= (UARTCR2_RIE | UARTCR2_TIE | UARTCR2_RE | UARTCR2_TE);
1342 	writeb(temp, sport->port.membase + UARTCR2);
1343 
1344 	if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
1345 		/* set Rx DMA timeout */
1346 		sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
1347 		if (!sport->dma_rx_timeout)
1348 		     sport->dma_rx_timeout = 1;
1349 
1350 		sport->lpuart_dma_rx_use = true;
1351 		rx_dma_timer_init(sport);
1352 	} else {
1353 		sport->lpuart_dma_rx_use = false;
1354 	}
1355 
1356 	if (sport->dma_tx_chan && !lpuart_dma_tx_request(port)) {
1357 		init_waitqueue_head(&sport->dma_wait);
1358 		sport->lpuart_dma_tx_use = true;
1359 		temp = readb(port->membase + UARTCR5);
1360 		writeb(temp | UARTCR5_TDMAS, port->membase + UARTCR5);
1361 	} else {
1362 		sport->lpuart_dma_tx_use = false;
1363 	}
1364 
1365 	spin_unlock_irqrestore(&sport->port.lock, flags);
1366 
1367 	return 0;
1368 }
1369 
1370 static int lpuart32_startup(struct uart_port *port)
1371 {
1372 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1373 	unsigned long flags;
1374 	unsigned long temp;
1375 
1376 	/* determine FIFO size */
1377 	temp = lpuart32_read(&sport->port, UARTFIFO);
1378 
1379 	sport->txfifo_size = 0x1 << (((temp >> UARTFIFO_TXSIZE_OFF) &
1380 		UARTFIFO_FIFOSIZE_MASK) - 1);
1381 
1382 	sport->port.fifosize = sport->txfifo_size;
1383 
1384 	sport->rxfifo_size = 0x1 << (((temp >> UARTFIFO_RXSIZE_OFF) &
1385 		UARTFIFO_FIFOSIZE_MASK) - 1);
1386 
1387 	spin_lock_irqsave(&sport->port.lock, flags);
1388 
1389 	lpuart32_setup_watermark(sport);
1390 
1391 	temp = lpuart32_read(&sport->port, UARTCTRL);
1392 	temp |= UARTCTRL_RE | UARTCTRL_TE | UARTCTRL_ILIE;
1393 	lpuart32_write(&sport->port, temp, UARTCTRL);
1394 
1395 	if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) {
1396 		/* set Rx DMA timeout */
1397 		sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
1398 		if (!sport->dma_rx_timeout)
1399 			sport->dma_rx_timeout = 1;
1400 
1401 		sport->lpuart_dma_rx_use = true;
1402 		rx_dma_timer_init(sport);
1403 	} else {
1404 		sport->lpuart_dma_rx_use = false;
1405 	}
1406 
1407 	if (sport->dma_tx_chan && !lpuart_dma_tx_request(port)) {
1408 		init_waitqueue_head(&sport->dma_wait);
1409 		sport->lpuart_dma_tx_use = true;
1410 		temp = lpuart32_read(&sport->port, UARTBAUD);
1411 		lpuart32_write(&sport->port, temp | UARTBAUD_TDMAE, UARTBAUD);
1412 	} else {
1413 		sport->lpuart_dma_tx_use = false;
1414 	}
1415 
1416 	if (sport->lpuart_dma_rx_use) {
1417 		/* RXWATER must be 0 */
1418 		temp = lpuart32_read(&sport->port, UARTWATER);
1419 		temp &= ~(UARTWATER_WATER_MASK << UARTWATER_RXWATER_OFF);
1420 		lpuart32_write(&sport->port, temp, UARTWATER);
1421 	}
1422 	temp = lpuart32_read(&sport->port, UARTCTRL);
1423 	if (!sport->lpuart_dma_rx_use)
1424 		temp |= UARTCTRL_RIE;
1425 	if (!sport->lpuart_dma_tx_use)
1426 		temp |= UARTCTRL_TIE;
1427 	lpuart32_write(&sport->port, temp, UARTCTRL);
1428 
1429 	spin_unlock_irqrestore(&sport->port.lock, flags);
1430 	return 0;
1431 }
1432 
1433 static void lpuart_shutdown(struct uart_port *port)
1434 {
1435 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1436 	unsigned char temp;
1437 	unsigned long flags;
1438 
1439 	spin_lock_irqsave(&port->lock, flags);
1440 
1441 	/* disable Rx/Tx and interrupts */
1442 	temp = readb(port->membase + UARTCR2);
1443 	temp &= ~(UARTCR2_TE | UARTCR2_RE |
1444 			UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
1445 	writeb(temp, port->membase + UARTCR2);
1446 
1447 	spin_unlock_irqrestore(&port->lock, flags);
1448 
1449 	if (sport->lpuart_dma_rx_use) {
1450 		del_timer_sync(&sport->lpuart_timer);
1451 		lpuart_dma_rx_free(&sport->port);
1452 	}
1453 
1454 	if (sport->lpuart_dma_tx_use) {
1455 		if (wait_event_interruptible(sport->dma_wait,
1456 			!sport->dma_tx_in_progress) != false) {
1457 			sport->dma_tx_in_progress = false;
1458 			dmaengine_terminate_all(sport->dma_tx_chan);
1459 		}
1460 
1461 		lpuart_stop_tx(port);
1462 	}
1463 }
1464 
1465 static void lpuart32_shutdown(struct uart_port *port)
1466 {
1467 	struct lpuart_port *sport =
1468 		container_of(port, struct lpuart_port, port);
1469 	unsigned long temp;
1470 	unsigned long flags;
1471 
1472 	spin_lock_irqsave(&port->lock, flags);
1473 
1474 	/* disable Rx/Tx and interrupts */
1475 	temp = lpuart32_read(port, UARTCTRL);
1476 	temp &= ~(UARTCTRL_TE | UARTCTRL_RE |
1477 			UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
1478 	lpuart32_write(port, temp, UARTCTRL);
1479 
1480 	spin_unlock_irqrestore(&port->lock, flags);
1481 
1482 	if (sport->lpuart_dma_rx_use) {
1483 		del_timer_sync(&sport->lpuart_timer);
1484 		lpuart_dma_rx_free(&sport->port);
1485 	}
1486 
1487 	if (sport->lpuart_dma_tx_use) {
1488 		if (wait_event_interruptible(sport->dma_wait,
1489 					     !sport->dma_tx_in_progress)) {
1490 			sport->dma_tx_in_progress = false;
1491 			dmaengine_terminate_all(sport->dma_tx_chan);
1492 		}
1493 
1494 		lpuart32_stop_tx(port);
1495 	}
1496 }
1497 
1498 static void
1499 lpuart_set_termios(struct uart_port *port, struct ktermios *termios,
1500 		   struct ktermios *old)
1501 {
1502 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1503 	unsigned long flags;
1504 	unsigned char cr1, old_cr1, old_cr2, cr3, cr4, bdh, modem;
1505 	unsigned int  baud;
1506 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1507 	unsigned int sbr, brfa;
1508 
1509 	cr1 = old_cr1 = readb(sport->port.membase + UARTCR1);
1510 	old_cr2 = readb(sport->port.membase + UARTCR2);
1511 	cr3 = readb(sport->port.membase + UARTCR3);
1512 	cr4 = readb(sport->port.membase + UARTCR4);
1513 	bdh = readb(sport->port.membase + UARTBDH);
1514 	modem = readb(sport->port.membase + UARTMODEM);
1515 	/*
1516 	 * only support CS8 and CS7, and for CS7 must enable PE.
1517 	 * supported mode:
1518 	 *  - (7,e/o,1)
1519 	 *  - (8,n,1)
1520 	 *  - (8,m/s,1)
1521 	 *  - (8,e/o,1)
1522 	 */
1523 	while ((termios->c_cflag & CSIZE) != CS8 &&
1524 		(termios->c_cflag & CSIZE) != CS7) {
1525 		termios->c_cflag &= ~CSIZE;
1526 		termios->c_cflag |= old_csize;
1527 		old_csize = CS8;
1528 	}
1529 
1530 	if ((termios->c_cflag & CSIZE) == CS8 ||
1531 		(termios->c_cflag & CSIZE) == CS7)
1532 		cr1 = old_cr1 & ~UARTCR1_M;
1533 
1534 	if (termios->c_cflag & CMSPAR) {
1535 		if ((termios->c_cflag & CSIZE) != CS8) {
1536 			termios->c_cflag &= ~CSIZE;
1537 			termios->c_cflag |= CS8;
1538 		}
1539 		cr1 |= UARTCR1_M;
1540 	}
1541 
1542 	/*
1543 	 * When auto RS-485 RTS mode is enabled,
1544 	 * hardware flow control need to be disabled.
1545 	 */
1546 	if (sport->port.rs485.flags & SER_RS485_ENABLED)
1547 		termios->c_cflag &= ~CRTSCTS;
1548 
1549 	if (termios->c_cflag & CRTSCTS) {
1550 		modem |= (UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1551 	} else {
1552 		termios->c_cflag &= ~CRTSCTS;
1553 		modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1554 	}
1555 
1556 	if (termios->c_cflag & CSTOPB)
1557 		termios->c_cflag &= ~CSTOPB;
1558 
1559 	/* parity must be enabled when CS7 to match 8-bits format */
1560 	if ((termios->c_cflag & CSIZE) == CS7)
1561 		termios->c_cflag |= PARENB;
1562 
1563 	if ((termios->c_cflag & PARENB)) {
1564 		if (termios->c_cflag & CMSPAR) {
1565 			cr1 &= ~UARTCR1_PE;
1566 			if (termios->c_cflag & PARODD)
1567 				cr3 |= UARTCR3_T8;
1568 			else
1569 				cr3 &= ~UARTCR3_T8;
1570 		} else {
1571 			cr1 |= UARTCR1_PE;
1572 			if ((termios->c_cflag & CSIZE) == CS8)
1573 				cr1 |= UARTCR1_M;
1574 			if (termios->c_cflag & PARODD)
1575 				cr1 |= UARTCR1_PT;
1576 			else
1577 				cr1 &= ~UARTCR1_PT;
1578 		}
1579 	} else {
1580 		cr1 &= ~UARTCR1_PE;
1581 	}
1582 
1583 	/* ask the core to calculate the divisor */
1584 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1585 
1586 	/*
1587 	 * Need to update the Ring buffer length according to the selected
1588 	 * baud rate and restart Rx DMA path.
1589 	 *
1590 	 * Since timer function acqures sport->port.lock, need to stop before
1591 	 * acquring same lock because otherwise del_timer_sync() can deadlock.
1592 	 */
1593 	if (old && sport->lpuart_dma_rx_use) {
1594 		del_timer_sync(&sport->lpuart_timer);
1595 		lpuart_dma_rx_free(&sport->port);
1596 	}
1597 
1598 	spin_lock_irqsave(&sport->port.lock, flags);
1599 
1600 	sport->port.read_status_mask = 0;
1601 	if (termios->c_iflag & INPCK)
1602 		sport->port.read_status_mask |=	(UARTSR1_FE | UARTSR1_PE);
1603 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1604 		sport->port.read_status_mask |= UARTSR1_FE;
1605 
1606 	/* characters to ignore */
1607 	sport->port.ignore_status_mask = 0;
1608 	if (termios->c_iflag & IGNPAR)
1609 		sport->port.ignore_status_mask |= UARTSR1_PE;
1610 	if (termios->c_iflag & IGNBRK) {
1611 		sport->port.ignore_status_mask |= UARTSR1_FE;
1612 		/*
1613 		 * if we're ignoring parity and break indicators,
1614 		 * ignore overruns too (for real raw support).
1615 		 */
1616 		if (termios->c_iflag & IGNPAR)
1617 			sport->port.ignore_status_mask |= UARTSR1_OR;
1618 	}
1619 
1620 	/* update the per-port timeout */
1621 	uart_update_timeout(port, termios->c_cflag, baud);
1622 
1623 	/* wait transmit engin complete */
1624 	while (!(readb(sport->port.membase + UARTSR1) & UARTSR1_TC))
1625 		barrier();
1626 
1627 	/* disable transmit and receive */
1628 	writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE),
1629 			sport->port.membase + UARTCR2);
1630 
1631 	sbr = sport->port.uartclk / (16 * baud);
1632 	brfa = ((sport->port.uartclk - (16 * sbr * baud)) * 2) / baud;
1633 	bdh &= ~UARTBDH_SBR_MASK;
1634 	bdh |= (sbr >> 8) & 0x1F;
1635 	cr4 &= ~UARTCR4_BRFA_MASK;
1636 	brfa &= UARTCR4_BRFA_MASK;
1637 	writeb(cr4 | brfa, sport->port.membase + UARTCR4);
1638 	writeb(bdh, sport->port.membase + UARTBDH);
1639 	writeb(sbr & 0xFF, sport->port.membase + UARTBDL);
1640 	writeb(cr3, sport->port.membase + UARTCR3);
1641 	writeb(cr1, sport->port.membase + UARTCR1);
1642 	writeb(modem, sport->port.membase + UARTMODEM);
1643 
1644 	/* restore control register */
1645 	writeb(old_cr2, sport->port.membase + UARTCR2);
1646 
1647 	if (old && sport->lpuart_dma_rx_use) {
1648 		if (!lpuart_start_rx_dma(sport))
1649 			rx_dma_timer_init(sport);
1650 		else
1651 			sport->lpuart_dma_rx_use = false;
1652 	}
1653 
1654 	spin_unlock_irqrestore(&sport->port.lock, flags);
1655 }
1656 
1657 static void
1658 lpuart32_serial_setbrg(struct lpuart_port *sport, unsigned int baudrate)
1659 {
1660 	u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
1661 	u32 clk = sport->port.uartclk;
1662 
1663 	/*
1664 	 * The idea is to use the best OSR (over-sampling rate) possible.
1665 	 * Note, OSR is typically hard-set to 16 in other LPUART instantiations.
1666 	 * Loop to find the best OSR value possible, one that generates minimum
1667 	 * baud_diff iterate through the rest of the supported values of OSR.
1668 	 *
1669 	 * Calculation Formula:
1670 	 *  Baud Rate = baud clock / ((OSR+1) × SBR)
1671 	 */
1672 	baud_diff = baudrate;
1673 	osr = 0;
1674 	sbr = 0;
1675 
1676 	for (tmp_osr = 4; tmp_osr <= 32; tmp_osr++) {
1677 		/* calculate the temporary sbr value  */
1678 		tmp_sbr = (clk / (baudrate * tmp_osr));
1679 		if (tmp_sbr == 0)
1680 			tmp_sbr = 1;
1681 
1682 		/*
1683 		 * calculate the baud rate difference based on the temporary
1684 		 * osr and sbr values
1685 		 */
1686 		tmp_diff = clk / (tmp_osr * tmp_sbr) - baudrate;
1687 
1688 		/* select best values between sbr and sbr+1 */
1689 		tmp = clk / (tmp_osr * (tmp_sbr + 1));
1690 		if (tmp_diff > (baudrate - tmp)) {
1691 			tmp_diff = baudrate - tmp;
1692 			tmp_sbr++;
1693 		}
1694 
1695 		if (tmp_diff <= baud_diff) {
1696 			baud_diff = tmp_diff;
1697 			osr = tmp_osr;
1698 			sbr = tmp_sbr;
1699 
1700 			if (!baud_diff)
1701 				break;
1702 		}
1703 	}
1704 
1705 	/* handle buadrate outside acceptable rate */
1706 	if (baud_diff > ((baudrate / 100) * 3))
1707 		dev_warn(sport->port.dev,
1708 			 "unacceptable baud rate difference of more than 3%%\n");
1709 
1710 	tmp = lpuart32_read(&sport->port, UARTBAUD);
1711 
1712 	if ((osr > 3) && (osr < 8))
1713 		tmp |= UARTBAUD_BOTHEDGE;
1714 
1715 	tmp &= ~(UARTBAUD_OSR_MASK << UARTBAUD_OSR_SHIFT);
1716 	tmp |= (((osr-1) & UARTBAUD_OSR_MASK) << UARTBAUD_OSR_SHIFT);
1717 
1718 	tmp &= ~UARTBAUD_SBR_MASK;
1719 	tmp |= sbr & UARTBAUD_SBR_MASK;
1720 
1721 	if (!sport->lpuart_dma_rx_use)
1722 		tmp &= ~UARTBAUD_RDMAE;
1723 	if (!sport->lpuart_dma_tx_use)
1724 		tmp &= ~UARTBAUD_TDMAE;
1725 
1726 	lpuart32_write(&sport->port, tmp, UARTBAUD);
1727 }
1728 
1729 static void
1730 lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
1731 		   struct ktermios *old)
1732 {
1733 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
1734 	unsigned long flags;
1735 	unsigned long ctrl, old_ctrl, modem;
1736 	unsigned int  baud;
1737 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1738 
1739 	ctrl = old_ctrl = lpuart32_read(&sport->port, UARTCTRL);
1740 	modem = lpuart32_read(&sport->port, UARTMODIR);
1741 	/*
1742 	 * only support CS8 and CS7, and for CS7 must enable PE.
1743 	 * supported mode:
1744 	 *  - (7,e/o,1)
1745 	 *  - (8,n,1)
1746 	 *  - (8,m/s,1)
1747 	 *  - (8,e/o,1)
1748 	 */
1749 	while ((termios->c_cflag & CSIZE) != CS8 &&
1750 		(termios->c_cflag & CSIZE) != CS7) {
1751 		termios->c_cflag &= ~CSIZE;
1752 		termios->c_cflag |= old_csize;
1753 		old_csize = CS8;
1754 	}
1755 
1756 	if ((termios->c_cflag & CSIZE) == CS8 ||
1757 		(termios->c_cflag & CSIZE) == CS7)
1758 		ctrl = old_ctrl & ~UARTCTRL_M;
1759 
1760 	if (termios->c_cflag & CMSPAR) {
1761 		if ((termios->c_cflag & CSIZE) != CS8) {
1762 			termios->c_cflag &= ~CSIZE;
1763 			termios->c_cflag |= CS8;
1764 		}
1765 		ctrl |= UARTCTRL_M;
1766 	}
1767 
1768 	if (termios->c_cflag & CRTSCTS) {
1769 		modem |= (UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1770 	} else {
1771 		termios->c_cflag &= ~CRTSCTS;
1772 		modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE);
1773 	}
1774 
1775 	if (termios->c_cflag & CSTOPB)
1776 		termios->c_cflag &= ~CSTOPB;
1777 
1778 	/* parity must be enabled when CS7 to match 8-bits format */
1779 	if ((termios->c_cflag & CSIZE) == CS7)
1780 		termios->c_cflag |= PARENB;
1781 
1782 	if ((termios->c_cflag & PARENB)) {
1783 		if (termios->c_cflag & CMSPAR) {
1784 			ctrl &= ~UARTCTRL_PE;
1785 			ctrl |= UARTCTRL_M;
1786 		} else {
1787 			ctrl |= UARTCTRL_PE;
1788 			if ((termios->c_cflag & CSIZE) == CS8)
1789 				ctrl |= UARTCTRL_M;
1790 			if (termios->c_cflag & PARODD)
1791 				ctrl |= UARTCTRL_PT;
1792 			else
1793 				ctrl &= ~UARTCTRL_PT;
1794 		}
1795 	} else {
1796 		ctrl &= ~UARTCTRL_PE;
1797 	}
1798 
1799 	/* ask the core to calculate the divisor */
1800 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 4);
1801 
1802 	/*
1803 	 * Need to update the Ring buffer length according to the selected
1804 	 * baud rate and restart Rx DMA path.
1805 	 *
1806 	 * Since timer function acqures sport->port.lock, need to stop before
1807 	 * acquring same lock because otherwise del_timer_sync() can deadlock.
1808 	 */
1809 	if (old && sport->lpuart_dma_rx_use) {
1810 		del_timer_sync(&sport->lpuart_timer);
1811 		lpuart_dma_rx_free(&sport->port);
1812 	}
1813 
1814 	spin_lock_irqsave(&sport->port.lock, flags);
1815 
1816 	sport->port.read_status_mask = 0;
1817 	if (termios->c_iflag & INPCK)
1818 		sport->port.read_status_mask |=	(UARTSTAT_FE | UARTSTAT_PE);
1819 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
1820 		sport->port.read_status_mask |= UARTSTAT_FE;
1821 
1822 	/* characters to ignore */
1823 	sport->port.ignore_status_mask = 0;
1824 	if (termios->c_iflag & IGNPAR)
1825 		sport->port.ignore_status_mask |= UARTSTAT_PE;
1826 	if (termios->c_iflag & IGNBRK) {
1827 		sport->port.ignore_status_mask |= UARTSTAT_FE;
1828 		/*
1829 		 * if we're ignoring parity and break indicators,
1830 		 * ignore overruns too (for real raw support).
1831 		 */
1832 		if (termios->c_iflag & IGNPAR)
1833 			sport->port.ignore_status_mask |= UARTSTAT_OR;
1834 	}
1835 
1836 	/* update the per-port timeout */
1837 	uart_update_timeout(port, termios->c_cflag, baud);
1838 
1839 	/* wait transmit engin complete */
1840 	while (!(lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_TC))
1841 		barrier();
1842 
1843 	/* disable transmit and receive */
1844 	lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE),
1845 		       UARTCTRL);
1846 
1847 	lpuart32_serial_setbrg(sport, baud);
1848 	lpuart32_write(&sport->port, modem, UARTMODIR);
1849 	lpuart32_write(&sport->port, ctrl, UARTCTRL);
1850 	/* restore control register */
1851 
1852 	if (old && sport->lpuart_dma_rx_use) {
1853 		if (!lpuart_start_rx_dma(sport))
1854 			rx_dma_timer_init(sport);
1855 		else
1856 			sport->lpuart_dma_rx_use = false;
1857 	}
1858 
1859 	spin_unlock_irqrestore(&sport->port.lock, flags);
1860 }
1861 
1862 static const char *lpuart_type(struct uart_port *port)
1863 {
1864 	return "FSL_LPUART";
1865 }
1866 
1867 static void lpuart_release_port(struct uart_port *port)
1868 {
1869 	/* nothing to do */
1870 }
1871 
1872 static int lpuart_request_port(struct uart_port *port)
1873 {
1874 	return  0;
1875 }
1876 
1877 /* configure/autoconfigure the port */
1878 static void lpuart_config_port(struct uart_port *port, int flags)
1879 {
1880 	if (flags & UART_CONFIG_TYPE)
1881 		port->type = PORT_LPUART;
1882 }
1883 
1884 static int lpuart_verify_port(struct uart_port *port, struct serial_struct *ser)
1885 {
1886 	int ret = 0;
1887 
1888 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LPUART)
1889 		ret = -EINVAL;
1890 	if (port->irq != ser->irq)
1891 		ret = -EINVAL;
1892 	if (ser->io_type != UPIO_MEM)
1893 		ret = -EINVAL;
1894 	if (port->uartclk / 16 != ser->baud_base)
1895 		ret = -EINVAL;
1896 	if (port->iobase != ser->port)
1897 		ret = -EINVAL;
1898 	if (ser->hub6 != 0)
1899 		ret = -EINVAL;
1900 	return ret;
1901 }
1902 
1903 static const struct uart_ops lpuart_pops = {
1904 	.tx_empty	= lpuart_tx_empty,
1905 	.set_mctrl	= lpuart_set_mctrl,
1906 	.get_mctrl	= lpuart_get_mctrl,
1907 	.stop_tx	= lpuart_stop_tx,
1908 	.start_tx	= lpuart_start_tx,
1909 	.stop_rx	= lpuart_stop_rx,
1910 	.break_ctl	= lpuart_break_ctl,
1911 	.startup	= lpuart_startup,
1912 	.shutdown	= lpuart_shutdown,
1913 	.set_termios	= lpuart_set_termios,
1914 	.type		= lpuart_type,
1915 	.request_port	= lpuart_request_port,
1916 	.release_port	= lpuart_release_port,
1917 	.config_port	= lpuart_config_port,
1918 	.verify_port	= lpuart_verify_port,
1919 	.flush_buffer	= lpuart_flush_buffer,
1920 #if defined(CONFIG_CONSOLE_POLL)
1921 	.poll_init	= lpuart_poll_init,
1922 	.poll_get_char	= lpuart_poll_get_char,
1923 	.poll_put_char	= lpuart_poll_put_char,
1924 #endif
1925 };
1926 
1927 static const struct uart_ops lpuart32_pops = {
1928 	.tx_empty	= lpuart32_tx_empty,
1929 	.set_mctrl	= lpuart32_set_mctrl,
1930 	.get_mctrl	= lpuart32_get_mctrl,
1931 	.stop_tx	= lpuart32_stop_tx,
1932 	.start_tx	= lpuart32_start_tx,
1933 	.stop_rx	= lpuart32_stop_rx,
1934 	.break_ctl	= lpuart32_break_ctl,
1935 	.startup	= lpuart32_startup,
1936 	.shutdown	= lpuart32_shutdown,
1937 	.set_termios	= lpuart32_set_termios,
1938 	.type		= lpuart_type,
1939 	.request_port	= lpuart_request_port,
1940 	.release_port	= lpuart_release_port,
1941 	.config_port	= lpuart_config_port,
1942 	.verify_port	= lpuart_verify_port,
1943 	.flush_buffer	= lpuart_flush_buffer,
1944 #if defined(CONFIG_CONSOLE_POLL)
1945 	.poll_init	= lpuart32_poll_init,
1946 	.poll_get_char	= lpuart32_poll_get_char,
1947 	.poll_put_char	= lpuart32_poll_put_char,
1948 #endif
1949 };
1950 
1951 static struct lpuart_port *lpuart_ports[UART_NR];
1952 
1953 #ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE
1954 static void lpuart_console_putchar(struct uart_port *port, int ch)
1955 {
1956 	while (!(readb(port->membase + UARTSR1) & UARTSR1_TDRE))
1957 		barrier();
1958 
1959 	writeb(ch, port->membase + UARTDR);
1960 }
1961 
1962 static void lpuart32_console_putchar(struct uart_port *port, int ch)
1963 {
1964 	while (!(lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE))
1965 		barrier();
1966 
1967 	lpuart32_write(port, ch, UARTDATA);
1968 }
1969 
1970 static void
1971 lpuart_console_write(struct console *co, const char *s, unsigned int count)
1972 {
1973 	struct lpuart_port *sport = lpuart_ports[co->index];
1974 	unsigned char  old_cr2, cr2;
1975 	unsigned long flags;
1976 	int locked = 1;
1977 
1978 	if (sport->port.sysrq || oops_in_progress)
1979 		locked = spin_trylock_irqsave(&sport->port.lock, flags);
1980 	else
1981 		spin_lock_irqsave(&sport->port.lock, flags);
1982 
1983 	/* first save CR2 and then disable interrupts */
1984 	cr2 = old_cr2 = readb(sport->port.membase + UARTCR2);
1985 	cr2 |= (UARTCR2_TE |  UARTCR2_RE);
1986 	cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE);
1987 	writeb(cr2, sport->port.membase + UARTCR2);
1988 
1989 	uart_console_write(&sport->port, s, count, lpuart_console_putchar);
1990 
1991 	/* wait for transmitter finish complete and restore CR2 */
1992 	while (!(readb(sport->port.membase + UARTSR1) & UARTSR1_TC))
1993 		barrier();
1994 
1995 	writeb(old_cr2, sport->port.membase + UARTCR2);
1996 
1997 	if (locked)
1998 		spin_unlock_irqrestore(&sport->port.lock, flags);
1999 }
2000 
2001 static void
2002 lpuart32_console_write(struct console *co, const char *s, unsigned int count)
2003 {
2004 	struct lpuart_port *sport = lpuart_ports[co->index];
2005 	unsigned long  old_cr, cr;
2006 	unsigned long flags;
2007 	int locked = 1;
2008 
2009 	if (sport->port.sysrq || oops_in_progress)
2010 		locked = spin_trylock_irqsave(&sport->port.lock, flags);
2011 	else
2012 		spin_lock_irqsave(&sport->port.lock, flags);
2013 
2014 	/* first save CR2 and then disable interrupts */
2015 	cr = old_cr = lpuart32_read(&sport->port, UARTCTRL);
2016 	cr |= (UARTCTRL_TE |  UARTCTRL_RE);
2017 	cr &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE);
2018 	lpuart32_write(&sport->port, cr, UARTCTRL);
2019 
2020 	uart_console_write(&sport->port, s, count, lpuart32_console_putchar);
2021 
2022 	/* wait for transmitter finish complete and restore CR2 */
2023 	while (!(lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_TC))
2024 		barrier();
2025 
2026 	lpuart32_write(&sport->port, old_cr, UARTCTRL);
2027 
2028 	if (locked)
2029 		spin_unlock_irqrestore(&sport->port.lock, flags);
2030 }
2031 
2032 /*
2033  * if the port was already initialised (eg, by a boot loader),
2034  * try to determine the current setup.
2035  */
2036 static void __init
2037 lpuart_console_get_options(struct lpuart_port *sport, int *baud,
2038 			   int *parity, int *bits)
2039 {
2040 	unsigned char cr, bdh, bdl, brfa;
2041 	unsigned int sbr, uartclk, baud_raw;
2042 
2043 	cr = readb(sport->port.membase + UARTCR2);
2044 	cr &= UARTCR2_TE | UARTCR2_RE;
2045 	if (!cr)
2046 		return;
2047 
2048 	/* ok, the port was enabled */
2049 
2050 	cr = readb(sport->port.membase + UARTCR1);
2051 
2052 	*parity = 'n';
2053 	if (cr & UARTCR1_PE) {
2054 		if (cr & UARTCR1_PT)
2055 			*parity = 'o';
2056 		else
2057 			*parity = 'e';
2058 	}
2059 
2060 	if (cr & UARTCR1_M)
2061 		*bits = 9;
2062 	else
2063 		*bits = 8;
2064 
2065 	bdh = readb(sport->port.membase + UARTBDH);
2066 	bdh &= UARTBDH_SBR_MASK;
2067 	bdl = readb(sport->port.membase + UARTBDL);
2068 	sbr = bdh;
2069 	sbr <<= 8;
2070 	sbr |= bdl;
2071 	brfa = readb(sport->port.membase + UARTCR4);
2072 	brfa &= UARTCR4_BRFA_MASK;
2073 
2074 	uartclk = clk_get_rate(sport->clk);
2075 	/*
2076 	 * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
2077 	 */
2078 	baud_raw = uartclk / (16 * (sbr + brfa / 32));
2079 
2080 	if (*baud != baud_raw)
2081 		printk(KERN_INFO "Serial: Console lpuart rounded baud rate"
2082 				"from %d to %d\n", baud_raw, *baud);
2083 }
2084 
2085 static void __init
2086 lpuart32_console_get_options(struct lpuart_port *sport, int *baud,
2087 			   int *parity, int *bits)
2088 {
2089 	unsigned long cr, bd;
2090 	unsigned int sbr, uartclk, baud_raw;
2091 
2092 	cr = lpuart32_read(&sport->port, UARTCTRL);
2093 	cr &= UARTCTRL_TE | UARTCTRL_RE;
2094 	if (!cr)
2095 		return;
2096 
2097 	/* ok, the port was enabled */
2098 
2099 	cr = lpuart32_read(&sport->port, UARTCTRL);
2100 
2101 	*parity = 'n';
2102 	if (cr & UARTCTRL_PE) {
2103 		if (cr & UARTCTRL_PT)
2104 			*parity = 'o';
2105 		else
2106 			*parity = 'e';
2107 	}
2108 
2109 	if (cr & UARTCTRL_M)
2110 		*bits = 9;
2111 	else
2112 		*bits = 8;
2113 
2114 	bd = lpuart32_read(&sport->port, UARTBAUD);
2115 	bd &= UARTBAUD_SBR_MASK;
2116 	sbr = bd;
2117 	uartclk = clk_get_rate(sport->clk);
2118 	/*
2119 	 * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
2120 	 */
2121 	baud_raw = uartclk / (16 * sbr);
2122 
2123 	if (*baud != baud_raw)
2124 		printk(KERN_INFO "Serial: Console lpuart rounded baud rate"
2125 				"from %d to %d\n", baud_raw, *baud);
2126 }
2127 
2128 static int __init lpuart_console_setup(struct console *co, char *options)
2129 {
2130 	struct lpuart_port *sport;
2131 	int baud = 115200;
2132 	int bits = 8;
2133 	int parity = 'n';
2134 	int flow = 'n';
2135 
2136 	/*
2137 	 * check whether an invalid uart number has been specified, and
2138 	 * if so, search for the first available port that does have
2139 	 * console support.
2140 	 */
2141 	if (co->index == -1 || co->index >= ARRAY_SIZE(lpuart_ports))
2142 		co->index = 0;
2143 
2144 	sport = lpuart_ports[co->index];
2145 	if (sport == NULL)
2146 		return -ENODEV;
2147 
2148 	if (options)
2149 		uart_parse_options(options, &baud, &parity, &bits, &flow);
2150 	else
2151 		if (lpuart_is_32(sport))
2152 			lpuart32_console_get_options(sport, &baud, &parity, &bits);
2153 		else
2154 			lpuart_console_get_options(sport, &baud, &parity, &bits);
2155 
2156 	if (lpuart_is_32(sport))
2157 		lpuart32_setup_watermark(sport);
2158 	else
2159 		lpuart_setup_watermark(sport);
2160 
2161 	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
2162 }
2163 
2164 static struct uart_driver lpuart_reg;
2165 static struct console lpuart_console = {
2166 	.name		= DEV_NAME,
2167 	.write		= lpuart_console_write,
2168 	.device		= uart_console_device,
2169 	.setup		= lpuart_console_setup,
2170 	.flags		= CON_PRINTBUFFER,
2171 	.index		= -1,
2172 	.data		= &lpuart_reg,
2173 };
2174 
2175 static struct console lpuart32_console = {
2176 	.name		= DEV_NAME,
2177 	.write		= lpuart32_console_write,
2178 	.device		= uart_console_device,
2179 	.setup		= lpuart_console_setup,
2180 	.flags		= CON_PRINTBUFFER,
2181 	.index		= -1,
2182 	.data		= &lpuart_reg,
2183 };
2184 
2185 static void lpuart_early_write(struct console *con, const char *s, unsigned n)
2186 {
2187 	struct earlycon_device *dev = con->data;
2188 
2189 	uart_console_write(&dev->port, s, n, lpuart_console_putchar);
2190 }
2191 
2192 static void lpuart32_early_write(struct console *con, const char *s, unsigned n)
2193 {
2194 	struct earlycon_device *dev = con->data;
2195 
2196 	uart_console_write(&dev->port, s, n, lpuart32_console_putchar);
2197 }
2198 
2199 static int __init lpuart_early_console_setup(struct earlycon_device *device,
2200 					  const char *opt)
2201 {
2202 	if (!device->port.membase)
2203 		return -ENODEV;
2204 
2205 	device->con->write = lpuart_early_write;
2206 	return 0;
2207 }
2208 
2209 static int __init lpuart32_early_console_setup(struct earlycon_device *device,
2210 					  const char *opt)
2211 {
2212 	if (!device->port.membase)
2213 		return -ENODEV;
2214 
2215 	device->port.iotype = UPIO_MEM32BE;
2216 	device->con->write = lpuart32_early_write;
2217 	return 0;
2218 }
2219 
2220 static int __init lpuart32_imx_early_console_setup(struct earlycon_device *device,
2221 						   const char *opt)
2222 {
2223 	if (!device->port.membase)
2224 		return -ENODEV;
2225 
2226 	device->port.iotype = UPIO_MEM32;
2227 	device->port.membase += IMX_REG_OFF;
2228 	device->con->write = lpuart32_early_write;
2229 
2230 	return 0;
2231 }
2232 OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
2233 OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
2234 OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
2235 EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
2236 EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup);
2237 
2238 #define LPUART_CONSOLE	(&lpuart_console)
2239 #define LPUART32_CONSOLE	(&lpuart32_console)
2240 #else
2241 #define LPUART_CONSOLE	NULL
2242 #define LPUART32_CONSOLE	NULL
2243 #endif
2244 
2245 static struct uart_driver lpuart_reg = {
2246 	.owner		= THIS_MODULE,
2247 	.driver_name	= DRIVER_NAME,
2248 	.dev_name	= DEV_NAME,
2249 	.nr		= ARRAY_SIZE(lpuart_ports),
2250 	.cons		= LPUART_CONSOLE,
2251 };
2252 
2253 static int lpuart_probe(struct platform_device *pdev)
2254 {
2255 	const struct of_device_id *of_id = of_match_device(lpuart_dt_ids,
2256 							   &pdev->dev);
2257 	const struct lpuart_soc_data *sdata = of_id->data;
2258 	struct device_node *np = pdev->dev.of_node;
2259 	struct lpuart_port *sport;
2260 	struct resource *res;
2261 	int ret;
2262 
2263 	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
2264 	if (!sport)
2265 		return -ENOMEM;
2266 
2267 	pdev->dev.coherent_dma_mask = 0;
2268 
2269 	ret = of_alias_get_id(np, "serial");
2270 	if (ret < 0) {
2271 		ret = ida_simple_get(&fsl_lpuart_ida, 0, UART_NR, GFP_KERNEL);
2272 		if (ret < 0) {
2273 			dev_err(&pdev->dev, "port line is full, add device failed\n");
2274 			return ret;
2275 		}
2276 	}
2277 	if (ret >= ARRAY_SIZE(lpuart_ports)) {
2278 		dev_err(&pdev->dev, "serial%d out of range\n", ret);
2279 		return -EINVAL;
2280 	}
2281 	sport->port.line = ret;
2282 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
2283 	sport->port.membase = devm_ioremap_resource(&pdev->dev, res);
2284 	if (IS_ERR(sport->port.membase))
2285 		return PTR_ERR(sport->port.membase);
2286 
2287 	sport->port.membase += sdata->reg_off;
2288 	sport->port.mapbase = res->start;
2289 	sport->port.dev = &pdev->dev;
2290 	sport->port.type = PORT_LPUART;
2291 	ret = platform_get_irq(pdev, 0);
2292 	if (ret < 0) {
2293 		dev_err(&pdev->dev, "cannot obtain irq\n");
2294 		return ret;
2295 	}
2296 	sport->port.irq = ret;
2297 	sport->port.iotype = sdata->iotype;
2298 	if (lpuart_is_32(sport))
2299 		sport->port.ops = &lpuart32_pops;
2300 	else
2301 		sport->port.ops = &lpuart_pops;
2302 	sport->port.flags = UPF_BOOT_AUTOCONF;
2303 
2304 	sport->port.rs485_config = lpuart_config_rs485;
2305 
2306 	sport->clk = devm_clk_get(&pdev->dev, "ipg");
2307 	if (IS_ERR(sport->clk)) {
2308 		ret = PTR_ERR(sport->clk);
2309 		dev_err(&pdev->dev, "failed to get uart clk: %d\n", ret);
2310 		return ret;
2311 	}
2312 
2313 	ret = clk_prepare_enable(sport->clk);
2314 	if (ret) {
2315 		dev_err(&pdev->dev, "failed to enable uart clk: %d\n", ret);
2316 		return ret;
2317 	}
2318 
2319 	sport->port.uartclk = clk_get_rate(sport->clk);
2320 
2321 	lpuart_ports[sport->port.line] = sport;
2322 
2323 	platform_set_drvdata(pdev, &sport->port);
2324 
2325 	if (lpuart_is_32(sport)) {
2326 		lpuart_reg.cons = LPUART32_CONSOLE;
2327 		ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart32_int, 0,
2328 					DRIVER_NAME, sport);
2329 	} else {
2330 		lpuart_reg.cons = LPUART_CONSOLE;
2331 		ret = devm_request_irq(&pdev->dev, sport->port.irq, lpuart_int, 0,
2332 					DRIVER_NAME, sport);
2333 	}
2334 
2335 	if (ret)
2336 		goto failed_irq_request;
2337 
2338 	ret = uart_add_one_port(&lpuart_reg, &sport->port);
2339 	if (ret)
2340 		goto failed_attach_port;
2341 
2342 	uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
2343 
2344 	if (sport->port.rs485.flags & SER_RS485_RX_DURING_TX)
2345 		dev_err(&pdev->dev, "driver doesn't support RX during TX\n");
2346 
2347 	if (sport->port.rs485.delay_rts_before_send ||
2348 	    sport->port.rs485.delay_rts_after_send)
2349 		dev_err(&pdev->dev, "driver doesn't support RTS delays\n");
2350 
2351 	lpuart_config_rs485(&sport->port, &sport->port.rs485);
2352 
2353 	sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
2354 	if (!sport->dma_tx_chan)
2355 		dev_info(sport->port.dev, "DMA tx channel request failed, "
2356 				"operating without tx DMA\n");
2357 
2358 	sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx");
2359 	if (!sport->dma_rx_chan)
2360 		dev_info(sport->port.dev, "DMA rx channel request failed, "
2361 				"operating without rx DMA\n");
2362 
2363 	return 0;
2364 
2365 failed_attach_port:
2366 failed_irq_request:
2367 	clk_disable_unprepare(sport->clk);
2368 	return ret;
2369 }
2370 
2371 static int lpuart_remove(struct platform_device *pdev)
2372 {
2373 	struct lpuart_port *sport = platform_get_drvdata(pdev);
2374 
2375 	uart_remove_one_port(&lpuart_reg, &sport->port);
2376 
2377 	ida_simple_remove(&fsl_lpuart_ida, sport->port.line);
2378 
2379 	clk_disable_unprepare(sport->clk);
2380 
2381 	if (sport->dma_tx_chan)
2382 		dma_release_channel(sport->dma_tx_chan);
2383 
2384 	if (sport->dma_rx_chan)
2385 		dma_release_channel(sport->dma_rx_chan);
2386 
2387 	return 0;
2388 }
2389 
2390 #ifdef CONFIG_PM_SLEEP
2391 static int lpuart_suspend(struct device *dev)
2392 {
2393 	struct lpuart_port *sport = dev_get_drvdata(dev);
2394 	unsigned long temp;
2395 	bool irq_wake;
2396 
2397 	if (lpuart_is_32(sport)) {
2398 		/* disable Rx/Tx and interrupts */
2399 		temp = lpuart32_read(&sport->port, UARTCTRL);
2400 		temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE);
2401 		lpuart32_write(&sport->port, temp, UARTCTRL);
2402 	} else {
2403 		/* disable Rx/Tx and interrupts */
2404 		temp = readb(sport->port.membase + UARTCR2);
2405 		temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE);
2406 		writeb(temp, sport->port.membase + UARTCR2);
2407 	}
2408 
2409 	uart_suspend_port(&lpuart_reg, &sport->port);
2410 
2411 	/* uart_suspend_port() might set wakeup flag */
2412 	irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
2413 
2414 	if (sport->lpuart_dma_rx_use) {
2415 		/*
2416 		 * EDMA driver during suspend will forcefully release any
2417 		 * non-idle DMA channels. If port wakeup is enabled or if port
2418 		 * is console port or 'no_console_suspend' is set the Rx DMA
2419 		 * cannot resume as as expected, hence gracefully release the
2420 		 * Rx DMA path before suspend and start Rx DMA path on resume.
2421 		 */
2422 		if (irq_wake) {
2423 			del_timer_sync(&sport->lpuart_timer);
2424 			lpuart_dma_rx_free(&sport->port);
2425 		}
2426 
2427 		/* Disable Rx DMA to use UART port as wakeup source */
2428 		if (lpuart_is_32(sport)) {
2429 			temp = lpuart32_read(&sport->port, UARTBAUD);
2430 			lpuart32_write(&sport->port, temp & ~UARTBAUD_RDMAE,
2431 				       UARTBAUD);
2432 		} else {
2433 			writeb(readb(sport->port.membase + UARTCR5) &
2434 			       ~UARTCR5_RDMAS, sport->port.membase + UARTCR5);
2435 		}
2436 	}
2437 
2438 	if (sport->lpuart_dma_tx_use) {
2439 		sport->dma_tx_in_progress = false;
2440 		dmaengine_terminate_all(sport->dma_tx_chan);
2441 	}
2442 
2443 	if (sport->port.suspended && !irq_wake)
2444 		clk_disable_unprepare(sport->clk);
2445 
2446 	return 0;
2447 }
2448 
2449 static int lpuart_resume(struct device *dev)
2450 {
2451 	struct lpuart_port *sport = dev_get_drvdata(dev);
2452 	bool irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq));
2453 	unsigned long temp;
2454 
2455 	if (sport->port.suspended && !irq_wake)
2456 		clk_prepare_enable(sport->clk);
2457 
2458 	if (lpuart_is_32(sport)) {
2459 		lpuart32_setup_watermark(sport);
2460 		temp = lpuart32_read(&sport->port, UARTCTRL);
2461 		temp |= UARTCTRL_RE | UARTCTRL_TE | UARTCTRL_ILIE;
2462 		lpuart32_write(&sport->port, temp, UARTCTRL);
2463 	} else {
2464 		lpuart_setup_watermark(sport);
2465 		temp = readb(sport->port.membase + UARTCR2);
2466 		temp |= (UARTCR2_RIE | UARTCR2_TIE | UARTCR2_RE | UARTCR2_TE);
2467 		writeb(temp, sport->port.membase + UARTCR2);
2468 	}
2469 
2470 	if (sport->lpuart_dma_rx_use) {
2471 		if (irq_wake) {
2472 			if (!lpuart_start_rx_dma(sport))
2473 				rx_dma_timer_init(sport);
2474 			else
2475 				sport->lpuart_dma_rx_use = false;
2476 		}
2477 	}
2478 
2479 	if (sport->dma_tx_chan && !lpuart_dma_tx_request(&sport->port)) {
2480 		init_waitqueue_head(&sport->dma_wait);
2481 		sport->lpuart_dma_tx_use = true;
2482 		if (lpuart_is_32(sport)) {
2483 			temp = lpuart32_read(&sport->port, UARTBAUD);
2484 			lpuart32_write(&sport->port,
2485 				       temp | UARTBAUD_TDMAE, UARTBAUD);
2486 		} else {
2487 			writeb(readb(sport->port.membase + UARTCR5) |
2488 				UARTCR5_TDMAS, sport->port.membase + UARTCR5);
2489 		}
2490 	} else {
2491 		sport->lpuart_dma_tx_use = false;
2492 	}
2493 
2494 	if (lpuart_is_32(sport)) {
2495 		if (sport->lpuart_dma_rx_use) {
2496 			/* RXWATER must be 0 */
2497 			temp = lpuart32_read(&sport->port, UARTWATER);
2498 			temp &= ~(UARTWATER_WATER_MASK <<
2499 				  UARTWATER_RXWATER_OFF);
2500 			lpuart32_write(&sport->port, temp, UARTWATER);
2501 		}
2502 		temp = lpuart32_read(&sport->port, UARTCTRL);
2503 		if (!sport->lpuart_dma_rx_use)
2504 			temp |= UARTCTRL_RIE;
2505 		if (!sport->lpuart_dma_tx_use)
2506 			temp |= UARTCTRL_TIE;
2507 		lpuart32_write(&sport->port, temp, UARTCTRL);
2508 	}
2509 
2510 	uart_resume_port(&lpuart_reg, &sport->port);
2511 
2512 	return 0;
2513 }
2514 #endif
2515 
2516 static SIMPLE_DEV_PM_OPS(lpuart_pm_ops, lpuart_suspend, lpuart_resume);
2517 
2518 static struct platform_driver lpuart_driver = {
2519 	.probe		= lpuart_probe,
2520 	.remove		= lpuart_remove,
2521 	.driver		= {
2522 		.name	= "fsl-lpuart",
2523 		.of_match_table = lpuart_dt_ids,
2524 		.pm	= &lpuart_pm_ops,
2525 	},
2526 };
2527 
2528 static int __init lpuart_serial_init(void)
2529 {
2530 	int ret = uart_register_driver(&lpuart_reg);
2531 
2532 	if (ret)
2533 		return ret;
2534 
2535 	ret = platform_driver_register(&lpuart_driver);
2536 	if (ret)
2537 		uart_unregister_driver(&lpuart_reg);
2538 
2539 	return ret;
2540 }
2541 
2542 static void __exit lpuart_serial_exit(void)
2543 {
2544 	ida_destroy(&fsl_lpuart_ida);
2545 	platform_driver_unregister(&lpuart_driver);
2546 	uart_unregister_driver(&lpuart_reg);
2547 }
2548 
2549 module_init(lpuart_serial_init);
2550 module_exit(lpuart_serial_exit);
2551 
2552 MODULE_DESCRIPTION("Freescale lpuart serial port driver");
2553 MODULE_LICENSE("GPL v2");
2554