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1 /*
2  *  Driver for Motorola IMX serial ports
3  *
4  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
5  *
6  *  Author: Sascha Hauer <sascha@saschahauer.de>
7  *  Copyright (C) 2004 Pengutronix
8  *
9  *  Copyright (C) 2009 emlix GmbH
10  *  Author: Fabian Godehardt (added IrDA support for iMX)
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  *
26  * [29-Mar-2005] Mike Lee
27  * Added hardware handshake
28  */
29 
30 #if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
31 #define SUPPORT_SYSRQ
32 #endif
33 
34 #include <linux/module.h>
35 #include <linux/ioport.h>
36 #include <linux/init.h>
37 #include <linux/console.h>
38 #include <linux/sysrq.h>
39 #include <linux/platform_device.h>
40 #include <linux/tty.h>
41 #include <linux/tty_flip.h>
42 #include <linux/serial_core.h>
43 #include <linux/serial.h>
44 #include <linux/clk.h>
45 #include <linux/delay.h>
46 #include <linux/rational.h>
47 #include <linux/slab.h>
48 #include <linux/of.h>
49 #include <linux/of_device.h>
50 #include <linux/io.h>
51 #include <linux/dma-mapping.h>
52 
53 #include <asm/irq.h>
54 #include <linux/platform_data/serial-imx.h>
55 #include <linux/platform_data/dma-imx.h>
56 
57 /* Register definitions */
58 #define URXD0 0x0  /* Receiver Register */
59 #define URTX0 0x40 /* Transmitter Register */
60 #define UCR1  0x80 /* Control Register 1 */
61 #define UCR2  0x84 /* Control Register 2 */
62 #define UCR3  0x88 /* Control Register 3 */
63 #define UCR4  0x8c /* Control Register 4 */
64 #define UFCR  0x90 /* FIFO Control Register */
65 #define USR1  0x94 /* Status Register 1 */
66 #define USR2  0x98 /* Status Register 2 */
67 #define UESC  0x9c /* Escape Character Register */
68 #define UTIM  0xa0 /* Escape Timer Register */
69 #define UBIR  0xa4 /* BRM Incremental Register */
70 #define UBMR  0xa8 /* BRM Modulator Register */
71 #define UBRC  0xac /* Baud Rate Count Register */
72 #define IMX21_ONEMS 0xb0 /* One Millisecond register */
73 #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
74 #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
75 
76 /* UART Control Register Bit Fields.*/
77 #define URXD_CHARRDY	(1<<15)
78 #define URXD_ERR	(1<<14)
79 #define URXD_OVRRUN	(1<<13)
80 #define URXD_FRMERR	(1<<12)
81 #define URXD_BRK	(1<<11)
82 #define URXD_PRERR	(1<<10)
83 #define URXD_RX_DATA	(0xFF<<0)
84 #define UCR1_ADEN	(1<<15) /* Auto detect interrupt */
85 #define UCR1_ADBR	(1<<14) /* Auto detect baud rate */
86 #define UCR1_TRDYEN	(1<<13) /* Transmitter ready interrupt enable */
87 #define UCR1_IDEN	(1<<12) /* Idle condition interrupt */
88 #define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
89 #define UCR1_RRDYEN	(1<<9)	/* Recv ready interrupt enable */
90 #define UCR1_RDMAEN	(1<<8)	/* Recv ready DMA enable */
91 #define UCR1_IREN	(1<<7)	/* Infrared interface enable */
92 #define UCR1_TXMPTYEN	(1<<6)	/* Transimitter empty interrupt enable */
93 #define UCR1_RTSDEN	(1<<5)	/* RTS delta interrupt enable */
94 #define UCR1_SNDBRK	(1<<4)	/* Send break */
95 #define UCR1_TDMAEN	(1<<3)	/* Transmitter ready DMA enable */
96 #define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
97 #define UCR1_ATDMAEN    (1<<2)  /* Aging DMA Timer Enable */
98 #define UCR1_DOZE	(1<<1)	/* Doze */
99 #define UCR1_UARTEN	(1<<0)	/* UART enabled */
100 #define UCR2_ESCI	(1<<15)	/* Escape seq interrupt enable */
101 #define UCR2_IRTS	(1<<14)	/* Ignore RTS pin */
102 #define UCR2_CTSC	(1<<13)	/* CTS pin control */
103 #define UCR2_CTS	(1<<12)	/* Clear to send */
104 #define UCR2_ESCEN	(1<<11)	/* Escape enable */
105 #define UCR2_PREN	(1<<8)	/* Parity enable */
106 #define UCR2_PROE	(1<<7)	/* Parity odd/even */
107 #define UCR2_STPB	(1<<6)	/* Stop */
108 #define UCR2_WS		(1<<5)	/* Word size */
109 #define UCR2_RTSEN	(1<<4)	/* Request to send interrupt enable */
110 #define UCR2_ATEN	(1<<3)	/* Aging Timer Enable */
111 #define UCR2_TXEN	(1<<2)	/* Transmitter enabled */
112 #define UCR2_RXEN	(1<<1)	/* Receiver enabled */
113 #define UCR2_SRST	(1<<0)	/* SW reset */
114 #define UCR3_DTREN	(1<<13) /* DTR interrupt enable */
115 #define UCR3_PARERREN	(1<<12) /* Parity enable */
116 #define UCR3_FRAERREN	(1<<11) /* Frame error interrupt enable */
117 #define UCR3_DSR	(1<<10) /* Data set ready */
118 #define UCR3_DCD	(1<<9)	/* Data carrier detect */
119 #define UCR3_RI		(1<<8)	/* Ring indicator */
120 #define UCR3_ADNIMP	(1<<7)	/* Autobaud Detection Not Improved */
121 #define UCR3_RXDSEN	(1<<6)	/* Receive status interrupt enable */
122 #define UCR3_AIRINTEN	(1<<5)	/* Async IR wake interrupt enable */
123 #define UCR3_AWAKEN	(1<<4)	/* Async wake interrupt enable */
124 #define IMX21_UCR3_RXDMUXSEL	(1<<2)	/* RXD Muxed Input Select */
125 #define UCR3_INVT	(1<<1)	/* Inverted Infrared transmission */
126 #define UCR3_BPEN	(1<<0)	/* Preset registers enable */
127 #define UCR4_CTSTL_SHF	10	/* CTS trigger level shift */
128 #define UCR4_CTSTL_MASK	0x3F	/* CTS trigger is 6 bits wide */
129 #define UCR4_INVR	(1<<9)	/* Inverted infrared reception */
130 #define UCR4_ENIRI	(1<<8)	/* Serial infrared interrupt enable */
131 #define UCR4_WKEN	(1<<7)	/* Wake interrupt enable */
132 #define UCR4_REF16	(1<<6)	/* Ref freq 16 MHz */
133 #define UCR4_IDDMAEN    (1<<6)  /* DMA IDLE Condition Detected */
134 #define UCR4_IRSC	(1<<5)	/* IR special case */
135 #define UCR4_TCEN	(1<<3)	/* Transmit complete interrupt enable */
136 #define UCR4_BKEN	(1<<2)	/* Break condition interrupt enable */
137 #define UCR4_OREN	(1<<1)	/* Receiver overrun interrupt enable */
138 #define UCR4_DREN	(1<<0)	/* Recv data ready interrupt enable */
139 #define UFCR_RXTL_SHF	0	/* Receiver trigger level shift */
140 #define UFCR_DCEDTE	(1<<6)	/* DCE/DTE mode select */
141 #define UFCR_RFDIV	(7<<7)	/* Reference freq divider mask */
142 #define UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
143 #define UFCR_TXTL_SHF	10	/* Transmitter trigger level shift */
144 #define USR1_PARITYERR	(1<<15) /* Parity error interrupt flag */
145 #define USR1_RTSS	(1<<14) /* RTS pin status */
146 #define USR1_TRDY	(1<<13) /* Transmitter ready interrupt/dma flag */
147 #define USR1_RTSD	(1<<12) /* RTS delta */
148 #define USR1_ESCF	(1<<11) /* Escape seq interrupt flag */
149 #define USR1_FRAMERR	(1<<10) /* Frame error interrupt flag */
150 #define USR1_RRDY	(1<<9)	 /* Receiver ready interrupt/dma flag */
151 #define USR1_TIMEOUT	(1<<7)	 /* Receive timeout interrupt status */
152 #define USR1_RXDS	 (1<<6)	 /* Receiver idle interrupt flag */
153 #define USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
154 #define USR1_AWAKE	 (1<<4)	 /* Aysnc wake interrupt flag */
155 #define USR2_ADET	 (1<<15) /* Auto baud rate detect complete */
156 #define USR2_TXFE	 (1<<14) /* Transmit buffer FIFO empty */
157 #define USR2_DTRF	 (1<<13) /* DTR edge interrupt flag */
158 #define USR2_IDLE	 (1<<12) /* Idle condition */
159 #define USR2_IRINT	 (1<<8)	 /* Serial infrared interrupt flag */
160 #define USR2_WAKE	 (1<<7)	 /* Wake */
161 #define USR2_RTSF	 (1<<4)	 /* RTS edge interrupt flag */
162 #define USR2_TXDC	 (1<<3)	 /* Transmitter complete */
163 #define USR2_BRCD	 (1<<2)	 /* Break condition */
164 #define USR2_ORE	(1<<1)	 /* Overrun error */
165 #define USR2_RDR	(1<<0)	 /* Recv data ready */
166 #define UTS_FRCPERR	(1<<13) /* Force parity error */
167 #define UTS_LOOP	(1<<12)	 /* Loop tx and rx */
168 #define UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
169 #define UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
170 #define UTS_TXFULL	 (1<<4)	 /* TxFIFO full */
171 #define UTS_RXFULL	 (1<<3)	 /* RxFIFO full */
172 #define UTS_SOFTRST	 (1<<0)	 /* Software reset */
173 
174 /* We've been assigned a range on the "Low-density serial ports" major */
175 #define SERIAL_IMX_MAJOR	207
176 #define MINOR_START		16
177 #define DEV_NAME		"ttymxc"
178 
179 /*
180  * This determines how often we check the modem status signals
181  * for any change.  They generally aren't connected to an IRQ
182  * so we have to poll them.  We also check immediately before
183  * filling the TX fifo incase CTS has been dropped.
184  */
185 #define MCTRL_TIMEOUT	(250*HZ/1000)
186 
187 #define DRIVER_NAME "IMX-uart"
188 
189 #define UART_NR 8
190 
191 /* i.mx21 type uart runs on all i.mx except i.mx1 */
192 enum imx_uart_type {
193 	IMX1_UART,
194 	IMX21_UART,
195 	IMX6Q_UART,
196 };
197 
198 /* device type dependent stuff */
199 struct imx_uart_data {
200 	unsigned uts_reg;
201 	enum imx_uart_type devtype;
202 };
203 
204 struct imx_port {
205 	struct uart_port	port;
206 	struct timer_list	timer;
207 	unsigned int		old_status;
208 	int			txirq, rxirq, rtsirq;
209 	unsigned int		have_rtscts:1;
210 	unsigned int		dte_mode:1;
211 	unsigned int		use_irda:1;
212 	unsigned int		irda_inv_rx:1;
213 	unsigned int		irda_inv_tx:1;
214 	unsigned short		trcv_delay; /* transceiver delay */
215 	struct clk		*clk_ipg;
216 	struct clk		*clk_per;
217 	const struct imx_uart_data *devdata;
218 
219 	/* DMA fields */
220 	unsigned int		dma_is_inited:1;
221 	unsigned int		dma_is_enabled:1;
222 	unsigned int		dma_is_rxing:1;
223 	unsigned int		dma_is_txing:1;
224 	struct dma_chan		*dma_chan_rx, *dma_chan_tx;
225 	struct scatterlist	rx_sgl, tx_sgl[2];
226 	void			*rx_buf;
227 	unsigned int		tx_bytes;
228 	unsigned int		dma_tx_nents;
229 	wait_queue_head_t	dma_wait;
230 };
231 
232 struct imx_port_ucrs {
233 	unsigned int	ucr1;
234 	unsigned int	ucr2;
235 	unsigned int	ucr3;
236 };
237 
238 #ifdef CONFIG_IRDA
239 #define USE_IRDA(sport)	((sport)->use_irda)
240 #else
241 #define USE_IRDA(sport)	(0)
242 #endif
243 
244 static struct imx_uart_data imx_uart_devdata[] = {
245 	[IMX1_UART] = {
246 		.uts_reg = IMX1_UTS,
247 		.devtype = IMX1_UART,
248 	},
249 	[IMX21_UART] = {
250 		.uts_reg = IMX21_UTS,
251 		.devtype = IMX21_UART,
252 	},
253 	[IMX6Q_UART] = {
254 		.uts_reg = IMX21_UTS,
255 		.devtype = IMX6Q_UART,
256 	},
257 };
258 
259 static struct platform_device_id imx_uart_devtype[] = {
260 	{
261 		.name = "imx1-uart",
262 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
263 	}, {
264 		.name = "imx21-uart",
265 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
266 	}, {
267 		.name = "imx6q-uart",
268 		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
269 	}, {
270 		/* sentinel */
271 	}
272 };
273 MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
274 
275 static struct of_device_id imx_uart_dt_ids[] = {
276 	{ .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_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 
uts_reg(struct imx_port * sport)283 static inline unsigned uts_reg(struct imx_port *sport)
284 {
285 	return sport->devdata->uts_reg;
286 }
287 
is_imx1_uart(struct imx_port * sport)288 static inline int is_imx1_uart(struct imx_port *sport)
289 {
290 	return sport->devdata->devtype == IMX1_UART;
291 }
292 
is_imx21_uart(struct imx_port * sport)293 static inline int is_imx21_uart(struct imx_port *sport)
294 {
295 	return sport->devdata->devtype == IMX21_UART;
296 }
297 
is_imx6q_uart(struct imx_port * sport)298 static inline int is_imx6q_uart(struct imx_port *sport)
299 {
300 	return sport->devdata->devtype == IMX6Q_UART;
301 }
302 /*
303  * Save and restore functions for UCR1, UCR2 and UCR3 registers
304  */
305 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_IMX_CONSOLE)
imx_port_ucrs_save(struct uart_port * port,struct imx_port_ucrs * ucr)306 static void imx_port_ucrs_save(struct uart_port *port,
307 			       struct imx_port_ucrs *ucr)
308 {
309 	/* save control registers */
310 	ucr->ucr1 = readl(port->membase + UCR1);
311 	ucr->ucr2 = readl(port->membase + UCR2);
312 	ucr->ucr3 = readl(port->membase + UCR3);
313 }
314 
imx_port_ucrs_restore(struct uart_port * port,struct imx_port_ucrs * ucr)315 static void imx_port_ucrs_restore(struct uart_port *port,
316 				  struct imx_port_ucrs *ucr)
317 {
318 	/* restore control registers */
319 	writel(ucr->ucr1, port->membase + UCR1);
320 	writel(ucr->ucr2, port->membase + UCR2);
321 	writel(ucr->ucr3, port->membase + UCR3);
322 }
323 #endif
324 
325 /*
326  * Handle any change of modem status signal since we were last called.
327  */
imx_mctrl_check(struct imx_port * sport)328 static void imx_mctrl_check(struct imx_port *sport)
329 {
330 	unsigned int status, changed;
331 
332 	status = sport->port.ops->get_mctrl(&sport->port);
333 	changed = status ^ sport->old_status;
334 
335 	if (changed == 0)
336 		return;
337 
338 	sport->old_status = status;
339 
340 	if (changed & TIOCM_RI)
341 		sport->port.icount.rng++;
342 	if (changed & TIOCM_DSR)
343 		sport->port.icount.dsr++;
344 	if (changed & TIOCM_CAR)
345 		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
346 	if (changed & TIOCM_CTS)
347 		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
348 
349 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
350 }
351 
352 /*
353  * This is our per-port timeout handler, for checking the
354  * modem status signals.
355  */
imx_timeout(unsigned long data)356 static void imx_timeout(unsigned long data)
357 {
358 	struct imx_port *sport = (struct imx_port *)data;
359 	unsigned long flags;
360 
361 	if (sport->port.state) {
362 		spin_lock_irqsave(&sport->port.lock, flags);
363 		imx_mctrl_check(sport);
364 		spin_unlock_irqrestore(&sport->port.lock, flags);
365 
366 		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
367 	}
368 }
369 
370 /*
371  * interrupts disabled on entry
372  */
imx_stop_tx(struct uart_port * port)373 static void imx_stop_tx(struct uart_port *port)
374 {
375 	struct imx_port *sport = (struct imx_port *)port;
376 	unsigned long temp;
377 
378 	if (USE_IRDA(sport)) {
379 		/* half duplex - wait for end of transmission */
380 		int n = 256;
381 		while ((--n > 0) &&
382 		      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
383 			udelay(5);
384 			barrier();
385 		}
386 		/*
387 		 * irda transceiver - wait a bit more to avoid
388 		 * cutoff, hardware dependent
389 		 */
390 		udelay(sport->trcv_delay);
391 
392 		/*
393 		 * half duplex - reactivate receive mode,
394 		 * flush receive pipe echo crap
395 		 */
396 		if (readl(sport->port.membase + USR2) & USR2_TXDC) {
397 			temp = readl(sport->port.membase + UCR1);
398 			temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
399 			writel(temp, sport->port.membase + UCR1);
400 
401 			temp = readl(sport->port.membase + UCR4);
402 			temp &= ~(UCR4_TCEN);
403 			writel(temp, sport->port.membase + UCR4);
404 
405 			while (readl(sport->port.membase + URXD0) &
406 			       URXD_CHARRDY)
407 				barrier();
408 
409 			temp = readl(sport->port.membase + UCR1);
410 			temp |= UCR1_RRDYEN;
411 			writel(temp, sport->port.membase + UCR1);
412 
413 			temp = readl(sport->port.membase + UCR4);
414 			temp |= UCR4_DREN;
415 			writel(temp, sport->port.membase + UCR4);
416 		}
417 		return;
418 	}
419 
420 	/*
421 	 * We are maybe in the SMP context, so if the DMA TX thread is running
422 	 * on other cpu, we have to wait for it to finish.
423 	 */
424 	if (sport->dma_is_enabled && sport->dma_is_txing)
425 		return;
426 
427 	temp = readl(sport->port.membase + UCR1);
428 	writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
429 }
430 
431 /*
432  * interrupts disabled on entry
433  */
imx_stop_rx(struct uart_port * port)434 static void imx_stop_rx(struct uart_port *port)
435 {
436 	struct imx_port *sport = (struct imx_port *)port;
437 	unsigned long temp;
438 
439 	if (sport->dma_is_enabled && sport->dma_is_rxing) {
440 		if (sport->port.suspended) {
441 			dmaengine_terminate_all(sport->dma_chan_rx);
442 			sport->dma_is_rxing = 0;
443 		} else {
444 			return;
445 		}
446 	}
447 
448 	temp = readl(sport->port.membase + UCR2);
449 	writel(temp & ~UCR2_RXEN, sport->port.membase + UCR2);
450 
451 	/* disable the `Receiver Ready Interrrupt` */
452 	temp = readl(sport->port.membase + UCR1);
453 	writel(temp & ~UCR1_RRDYEN, sport->port.membase + UCR1);
454 }
455 
456 /*
457  * Set the modem control timer to fire immediately.
458  */
imx_enable_ms(struct uart_port * port)459 static void imx_enable_ms(struct uart_port *port)
460 {
461 	struct imx_port *sport = (struct imx_port *)port;
462 
463 	mod_timer(&sport->timer, jiffies);
464 }
465 
imx_transmit_buffer(struct imx_port * sport)466 static inline void imx_transmit_buffer(struct imx_port *sport)
467 {
468 	struct circ_buf *xmit = &sport->port.state->xmit;
469 
470 	if (sport->port.x_char) {
471 		/* Send next char */
472 		writel(sport->port.x_char, sport->port.membase + URTX0);
473 		return;
474 	}
475 
476 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
477 		imx_stop_tx(&sport->port);
478 		return;
479 	}
480 
481 	while (!uart_circ_empty(xmit) &&
482 	       !(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
483 		/* send xmit->buf[xmit->tail]
484 		 * out the port here */
485 		writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
486 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
487 		sport->port.icount.tx++;
488 	}
489 
490 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
491 		uart_write_wakeup(&sport->port);
492 
493 	if (uart_circ_empty(xmit))
494 		imx_stop_tx(&sport->port);
495 }
496 
dma_tx_callback(void * data)497 static void dma_tx_callback(void *data)
498 {
499 	struct imx_port *sport = data;
500 	struct scatterlist *sgl = &sport->tx_sgl[0];
501 	struct circ_buf *xmit = &sport->port.state->xmit;
502 	unsigned long flags;
503 
504 	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
505 
506 	sport->dma_is_txing = 0;
507 
508 	/* update the stat */
509 	spin_lock_irqsave(&sport->port.lock, flags);
510 	xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
511 	sport->port.icount.tx += sport->tx_bytes;
512 	spin_unlock_irqrestore(&sport->port.lock, flags);
513 
514 	dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
515 
516 	uart_write_wakeup(&sport->port);
517 
518 	if (waitqueue_active(&sport->dma_wait)) {
519 		wake_up(&sport->dma_wait);
520 		dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
521 		return;
522 	}
523 }
524 
imx_dma_tx(struct imx_port * sport)525 static void imx_dma_tx(struct imx_port *sport)
526 {
527 	struct circ_buf *xmit = &sport->port.state->xmit;
528 	struct scatterlist *sgl = sport->tx_sgl;
529 	struct dma_async_tx_descriptor *desc;
530 	struct dma_chan	*chan = sport->dma_chan_tx;
531 	struct device *dev = sport->port.dev;
532 	enum dma_status status;
533 	int ret;
534 
535 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
536 	if (DMA_IN_PROGRESS == status)
537 		return;
538 
539 	sport->tx_bytes = uart_circ_chars_pending(xmit);
540 
541 	if (xmit->tail > xmit->head && xmit->head > 0) {
542 		sport->dma_tx_nents = 2;
543 		sg_init_table(sgl, 2);
544 		sg_set_buf(sgl, xmit->buf + xmit->tail,
545 				UART_XMIT_SIZE - xmit->tail);
546 		sg_set_buf(sgl + 1, xmit->buf, xmit->head);
547 	} else {
548 		sport->dma_tx_nents = 1;
549 		sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
550 	}
551 
552 	ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
553 	if (ret == 0) {
554 		dev_err(dev, "DMA mapping error for TX.\n");
555 		return;
556 	}
557 	desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
558 					DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
559 	if (!desc) {
560 		dev_err(dev, "We cannot prepare for the TX slave dma!\n");
561 		return;
562 	}
563 	desc->callback = dma_tx_callback;
564 	desc->callback_param = sport;
565 
566 	dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
567 			uart_circ_chars_pending(xmit));
568 	/* fire it */
569 	sport->dma_is_txing = 1;
570 	dmaengine_submit(desc);
571 	dma_async_issue_pending(chan);
572 	return;
573 }
574 
575 /*
576  * interrupts disabled on entry
577  */
imx_start_tx(struct uart_port * port)578 static void imx_start_tx(struct uart_port *port)
579 {
580 	struct imx_port *sport = (struct imx_port *)port;
581 	unsigned long temp;
582 
583 	if (USE_IRDA(sport)) {
584 		/* half duplex in IrDA mode; have to disable receive mode */
585 		temp = readl(sport->port.membase + UCR4);
586 		temp &= ~(UCR4_DREN);
587 		writel(temp, sport->port.membase + UCR4);
588 
589 		temp = readl(sport->port.membase + UCR1);
590 		temp &= ~(UCR1_RRDYEN);
591 		writel(temp, sport->port.membase + UCR1);
592 	}
593 
594 	if (!sport->dma_is_enabled) {
595 		temp = readl(sport->port.membase + UCR1);
596 		writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
597 	}
598 
599 	if (USE_IRDA(sport)) {
600 		temp = readl(sport->port.membase + UCR1);
601 		temp |= UCR1_TRDYEN;
602 		writel(temp, sport->port.membase + UCR1);
603 
604 		temp = readl(sport->port.membase + UCR4);
605 		temp |= UCR4_TCEN;
606 		writel(temp, sport->port.membase + UCR4);
607 	}
608 
609 	if (sport->dma_is_enabled) {
610 		/* FIXME: port->x_char must be transmitted if != 0 */
611 		if (!uart_circ_empty(&port->state->xmit) &&
612 		    !uart_tx_stopped(port))
613 			imx_dma_tx(sport);
614 		return;
615 	}
616 
617 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
618 		imx_transmit_buffer(sport);
619 }
620 
imx_rtsint(int irq,void * dev_id)621 static irqreturn_t imx_rtsint(int irq, void *dev_id)
622 {
623 	struct imx_port *sport = dev_id;
624 	unsigned int val;
625 	unsigned long flags;
626 
627 	spin_lock_irqsave(&sport->port.lock, flags);
628 
629 	writel(USR1_RTSD, sport->port.membase + USR1);
630 	val = readl(sport->port.membase + USR1) & USR1_RTSS;
631 	uart_handle_cts_change(&sport->port, !!val);
632 	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
633 
634 	spin_unlock_irqrestore(&sport->port.lock, flags);
635 	return IRQ_HANDLED;
636 }
637 
imx_txint(int irq,void * dev_id)638 static irqreturn_t imx_txint(int irq, void *dev_id)
639 {
640 	struct imx_port *sport = dev_id;
641 	unsigned long flags;
642 
643 	spin_lock_irqsave(&sport->port.lock, flags);
644 	imx_transmit_buffer(sport);
645 	spin_unlock_irqrestore(&sport->port.lock, flags);
646 	return IRQ_HANDLED;
647 }
648 
imx_rxint(int irq,void * dev_id)649 static irqreturn_t imx_rxint(int irq, void *dev_id)
650 {
651 	struct imx_port *sport = dev_id;
652 	unsigned int rx, flg, ignored = 0;
653 	struct tty_port *port = &sport->port.state->port;
654 	unsigned long flags, temp;
655 
656 	spin_lock_irqsave(&sport->port.lock, flags);
657 
658 	while (readl(sport->port.membase + USR2) & USR2_RDR) {
659 		flg = TTY_NORMAL;
660 		sport->port.icount.rx++;
661 
662 		rx = readl(sport->port.membase + URXD0);
663 
664 		temp = readl(sport->port.membase + USR2);
665 		if (temp & USR2_BRCD) {
666 			writel(USR2_BRCD, sport->port.membase + USR2);
667 			if (uart_handle_break(&sport->port))
668 				continue;
669 		}
670 
671 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
672 			continue;
673 
674 		if (unlikely(rx & URXD_ERR)) {
675 			if (rx & URXD_BRK)
676 				sport->port.icount.brk++;
677 			else if (rx & URXD_PRERR)
678 				sport->port.icount.parity++;
679 			else if (rx & URXD_FRMERR)
680 				sport->port.icount.frame++;
681 			if (rx & URXD_OVRRUN)
682 				sport->port.icount.overrun++;
683 
684 			if (rx & sport->port.ignore_status_mask) {
685 				if (++ignored > 100)
686 					goto out;
687 				continue;
688 			}
689 
690 			rx &= sport->port.read_status_mask;
691 
692 			if (rx & URXD_BRK)
693 				flg = TTY_BREAK;
694 			else if (rx & URXD_PRERR)
695 				flg = TTY_PARITY;
696 			else if (rx & URXD_FRMERR)
697 				flg = TTY_FRAME;
698 			if (rx & URXD_OVRRUN)
699 				flg = TTY_OVERRUN;
700 
701 #ifdef SUPPORT_SYSRQ
702 			sport->port.sysrq = 0;
703 #endif
704 		}
705 
706 		tty_insert_flip_char(port, rx, flg);
707 	}
708 
709 out:
710 	spin_unlock_irqrestore(&sport->port.lock, flags);
711 	tty_flip_buffer_push(port);
712 	return IRQ_HANDLED;
713 }
714 
715 static int start_rx_dma(struct imx_port *sport);
716 /*
717  * If the RXFIFO is filled with some data, and then we
718  * arise a DMA operation to receive them.
719  */
imx_dma_rxint(struct imx_port * sport)720 static void imx_dma_rxint(struct imx_port *sport)
721 {
722 	unsigned long temp;
723 
724 	temp = readl(sport->port.membase + USR2);
725 	if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
726 		sport->dma_is_rxing = 1;
727 
728 		/* disable the `Recerver Ready Interrrupt` */
729 		temp = readl(sport->port.membase + UCR1);
730 		temp &= ~(UCR1_RRDYEN);
731 		writel(temp, sport->port.membase + UCR1);
732 
733 		/* tell the DMA to receive the data. */
734 		start_rx_dma(sport);
735 	}
736 }
737 
imx_int(int irq,void * dev_id)738 static irqreturn_t imx_int(int irq, void *dev_id)
739 {
740 	struct imx_port *sport = dev_id;
741 	unsigned int sts;
742 	unsigned int sts2;
743 
744 	sts = readl(sport->port.membase + USR1);
745 
746 	if (sts & USR1_RRDY) {
747 		if (sport->dma_is_enabled)
748 			imx_dma_rxint(sport);
749 		else
750 			imx_rxint(irq, dev_id);
751 	}
752 
753 	if (sts & USR1_TRDY &&
754 			readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
755 		imx_txint(irq, dev_id);
756 
757 	if (sts & USR1_RTSD)
758 		imx_rtsint(irq, dev_id);
759 
760 	if (sts & USR1_AWAKE)
761 		writel(USR1_AWAKE, sport->port.membase + USR1);
762 
763 	sts2 = readl(sport->port.membase + USR2);
764 	if (sts2 & USR2_ORE) {
765 		dev_err(sport->port.dev, "Rx FIFO overrun\n");
766 		sport->port.icount.overrun++;
767 		writel(USR2_ORE, sport->port.membase + USR2);
768 	}
769 
770 	return IRQ_HANDLED;
771 }
772 
773 /*
774  * Return TIOCSER_TEMT when transmitter is not busy.
775  */
imx_tx_empty(struct uart_port * port)776 static unsigned int imx_tx_empty(struct uart_port *port)
777 {
778 	struct imx_port *sport = (struct imx_port *)port;
779 	unsigned int ret;
780 
781 	ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
782 
783 	/* If the TX DMA is working, return 0. */
784 	if (sport->dma_is_enabled && sport->dma_is_txing)
785 		ret = 0;
786 
787 	return ret;
788 }
789 
790 /*
791  * We have a modem side uart, so the meanings of RTS and CTS are inverted.
792  */
imx_get_mctrl(struct uart_port * port)793 static unsigned int imx_get_mctrl(struct uart_port *port)
794 {
795 	struct imx_port *sport = (struct imx_port *)port;
796 	unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
797 
798 	if (readl(sport->port.membase + USR1) & USR1_RTSS)
799 		tmp |= TIOCM_CTS;
800 
801 	if (readl(sport->port.membase + UCR2) & UCR2_CTS)
802 		tmp |= TIOCM_RTS;
803 
804 	if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
805 		tmp |= TIOCM_LOOP;
806 
807 	return tmp;
808 }
809 
imx_set_mctrl(struct uart_port * port,unsigned int mctrl)810 static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
811 {
812 	struct imx_port *sport = (struct imx_port *)port;
813 	unsigned long temp;
814 
815 	temp = readl(sport->port.membase + UCR2) & ~(UCR2_CTS | UCR2_CTSC);
816 	if (mctrl & TIOCM_RTS)
817 		temp |= UCR2_CTS | UCR2_CTSC;
818 
819 	writel(temp, sport->port.membase + UCR2);
820 
821 	temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
822 	if (mctrl & TIOCM_LOOP)
823 		temp |= UTS_LOOP;
824 	writel(temp, sport->port.membase + uts_reg(sport));
825 }
826 
827 /*
828  * Interrupts always disabled.
829  */
imx_break_ctl(struct uart_port * port,int break_state)830 static void imx_break_ctl(struct uart_port *port, int break_state)
831 {
832 	struct imx_port *sport = (struct imx_port *)port;
833 	unsigned long flags, temp;
834 
835 	spin_lock_irqsave(&sport->port.lock, flags);
836 
837 	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
838 
839 	if (break_state != 0)
840 		temp |= UCR1_SNDBRK;
841 
842 	writel(temp, sport->port.membase + UCR1);
843 
844 	spin_unlock_irqrestore(&sport->port.lock, flags);
845 }
846 
847 #define TXTL 2 /* reset default */
848 #define RXTL 1 /* reset default */
849 
imx_setup_ufcr(struct imx_port * sport,unsigned int mode)850 static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
851 {
852 	unsigned int val;
853 
854 	/* set receiver / transmitter trigger level */
855 	val = readl(sport->port.membase + UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
856 	val |= TXTL << UFCR_TXTL_SHF | RXTL;
857 	writel(val, sport->port.membase + UFCR);
858 	return 0;
859 }
860 
861 #define RX_BUF_SIZE	(PAGE_SIZE)
imx_rx_dma_done(struct imx_port * sport)862 static void imx_rx_dma_done(struct imx_port *sport)
863 {
864 	unsigned long temp;
865 
866 	/* Enable this interrupt when the RXFIFO is empty. */
867 	temp = readl(sport->port.membase + UCR1);
868 	temp |= UCR1_RRDYEN;
869 	writel(temp, sport->port.membase + UCR1);
870 
871 	sport->dma_is_rxing = 0;
872 
873 	/* Is the shutdown waiting for us? */
874 	if (waitqueue_active(&sport->dma_wait))
875 		wake_up(&sport->dma_wait);
876 }
877 
878 /*
879  * There are three kinds of RX DMA interrupts(such as in the MX6Q):
880  *   [1] the RX DMA buffer is full.
881  *   [2] the Aging timer expires(wait for 8 bytes long)
882  *   [3] the Idle Condition Detect(enabled the UCR4_IDDMAEN).
883  *
884  * The [2] is trigger when a character was been sitting in the FIFO
885  * meanwhile [3] can wait for 32 bytes long when the RX line is
886  * on IDLE state and RxFIFO is empty.
887  */
dma_rx_callback(void * data)888 static void dma_rx_callback(void *data)
889 {
890 	struct imx_port *sport = data;
891 	struct dma_chan	*chan = sport->dma_chan_rx;
892 	struct scatterlist *sgl = &sport->rx_sgl;
893 	struct tty_port *port = &sport->port.state->port;
894 	struct dma_tx_state state;
895 	enum dma_status status;
896 	unsigned int count;
897 
898 	/* unmap it first */
899 	dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
900 
901 	status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
902 	count = RX_BUF_SIZE - state.residue;
903 
904 	if (readl(sport->port.membase + USR2) & USR2_IDLE) {
905 		/* In condition [3] the SDMA counted up too early */
906 		count--;
907 
908 		writel(USR2_IDLE, sport->port.membase + USR2);
909 	}
910 
911 	dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
912 
913 	if (count) {
914 		tty_insert_flip_string(port, sport->rx_buf, count);
915 		tty_flip_buffer_push(port);
916 
917 		start_rx_dma(sport);
918 	} else
919 		imx_rx_dma_done(sport);
920 }
921 
start_rx_dma(struct imx_port * sport)922 static int start_rx_dma(struct imx_port *sport)
923 {
924 	struct scatterlist *sgl = &sport->rx_sgl;
925 	struct dma_chan	*chan = sport->dma_chan_rx;
926 	struct device *dev = sport->port.dev;
927 	struct dma_async_tx_descriptor *desc;
928 	int ret;
929 
930 	sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
931 	ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
932 	if (ret == 0) {
933 		dev_err(dev, "DMA mapping error for RX.\n");
934 		return -EINVAL;
935 	}
936 	desc = dmaengine_prep_slave_sg(chan, sgl, 1, DMA_DEV_TO_MEM,
937 					DMA_PREP_INTERRUPT);
938 	if (!desc) {
939 		dev_err(dev, "We cannot prepare for the RX slave dma!\n");
940 		return -EINVAL;
941 	}
942 	desc->callback = dma_rx_callback;
943 	desc->callback_param = sport;
944 
945 	dev_dbg(dev, "RX: prepare for the DMA.\n");
946 	dmaengine_submit(desc);
947 	dma_async_issue_pending(chan);
948 	return 0;
949 }
950 
imx_uart_dma_exit(struct imx_port * sport)951 static void imx_uart_dma_exit(struct imx_port *sport)
952 {
953 	if (sport->dma_chan_rx) {
954 		dma_release_channel(sport->dma_chan_rx);
955 		sport->dma_chan_rx = NULL;
956 
957 		kfree(sport->rx_buf);
958 		sport->rx_buf = NULL;
959 	}
960 
961 	if (sport->dma_chan_tx) {
962 		dma_release_channel(sport->dma_chan_tx);
963 		sport->dma_chan_tx = NULL;
964 	}
965 
966 	sport->dma_is_inited = 0;
967 }
968 
imx_uart_dma_init(struct imx_port * sport)969 static int imx_uart_dma_init(struct imx_port *sport)
970 {
971 	struct dma_slave_config slave_config = {};
972 	struct device *dev = sport->port.dev;
973 	int ret;
974 
975 	/* Prepare for RX : */
976 	sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
977 	if (!sport->dma_chan_rx) {
978 		dev_dbg(dev, "cannot get the DMA channel.\n");
979 		ret = -EINVAL;
980 		goto err;
981 	}
982 
983 	slave_config.direction = DMA_DEV_TO_MEM;
984 	slave_config.src_addr = sport->port.mapbase + URXD0;
985 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
986 	slave_config.src_maxburst = RXTL;
987 	ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
988 	if (ret) {
989 		dev_err(dev, "error in RX dma configuration.\n");
990 		goto err;
991 	}
992 
993 	sport->rx_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
994 	if (!sport->rx_buf) {
995 		dev_err(dev, "cannot alloc DMA buffer.\n");
996 		ret = -ENOMEM;
997 		goto err;
998 	}
999 
1000 	/* Prepare for TX : */
1001 	sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
1002 	if (!sport->dma_chan_tx) {
1003 		dev_err(dev, "cannot get the TX DMA channel!\n");
1004 		ret = -EINVAL;
1005 		goto err;
1006 	}
1007 
1008 	slave_config.direction = DMA_MEM_TO_DEV;
1009 	slave_config.dst_addr = sport->port.mapbase + URTX0;
1010 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1011 	slave_config.dst_maxburst = TXTL;
1012 	ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
1013 	if (ret) {
1014 		dev_err(dev, "error in TX dma configuration.");
1015 		goto err;
1016 	}
1017 
1018 	sport->dma_is_inited = 1;
1019 
1020 	return 0;
1021 err:
1022 	imx_uart_dma_exit(sport);
1023 	return ret;
1024 }
1025 
imx_enable_dma(struct imx_port * sport)1026 static void imx_enable_dma(struct imx_port *sport)
1027 {
1028 	unsigned long temp;
1029 
1030 	init_waitqueue_head(&sport->dma_wait);
1031 
1032 	/* set UCR1 */
1033 	temp = readl(sport->port.membase + UCR1);
1034 	temp |= UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN |
1035 		/* wait for 32 idle frames for IDDMA interrupt */
1036 		UCR1_ICD_REG(3);
1037 	writel(temp, sport->port.membase + UCR1);
1038 
1039 	/* set UCR4 */
1040 	temp = readl(sport->port.membase + UCR4);
1041 	temp |= UCR4_IDDMAEN;
1042 	writel(temp, sport->port.membase + UCR4);
1043 
1044 	sport->dma_is_enabled = 1;
1045 }
1046 
imx_disable_dma(struct imx_port * sport)1047 static void imx_disable_dma(struct imx_port *sport)
1048 {
1049 	unsigned long temp;
1050 
1051 	/* clear UCR1 */
1052 	temp = readl(sport->port.membase + UCR1);
1053 	temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
1054 	writel(temp, sport->port.membase + UCR1);
1055 
1056 	/* clear UCR2 */
1057 	temp = readl(sport->port.membase + UCR2);
1058 	temp &= ~(UCR2_CTSC | UCR2_CTS);
1059 	writel(temp, sport->port.membase + UCR2);
1060 
1061 	/* clear UCR4 */
1062 	temp = readl(sport->port.membase + UCR4);
1063 	temp &= ~UCR4_IDDMAEN;
1064 	writel(temp, sport->port.membase + UCR4);
1065 
1066 	sport->dma_is_enabled = 0;
1067 }
1068 
1069 /* half the RX buffer size */
1070 #define CTSTL 16
1071 
imx_startup(struct uart_port * port)1072 static int imx_startup(struct uart_port *port)
1073 {
1074 	struct imx_port *sport = (struct imx_port *)port;
1075 	int retval, i;
1076 	unsigned long flags, temp;
1077 
1078 	retval = clk_prepare_enable(sport->clk_per);
1079 	if (retval)
1080 		goto error_out1;
1081 	retval = clk_prepare_enable(sport->clk_ipg);
1082 	if (retval) {
1083 		clk_disable_unprepare(sport->clk_per);
1084 		goto error_out1;
1085 	}
1086 
1087 	imx_setup_ufcr(sport, 0);
1088 
1089 	/* disable the DREN bit (Data Ready interrupt enable) before
1090 	 * requesting IRQs
1091 	 */
1092 	temp = readl(sport->port.membase + UCR4);
1093 
1094 	if (USE_IRDA(sport))
1095 		temp |= UCR4_IRSC;
1096 
1097 	/* set the trigger level for CTS */
1098 	temp &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
1099 	temp |= CTSTL << UCR4_CTSTL_SHF;
1100 
1101 	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
1102 
1103 	/* Reset fifo's and state machines */
1104 	i = 100;
1105 
1106 	temp = readl(sport->port.membase + UCR2);
1107 	temp &= ~UCR2_SRST;
1108 	writel(temp, sport->port.membase + UCR2);
1109 
1110 	while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && (--i > 0))
1111 		udelay(1);
1112 
1113 	/*
1114 	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
1115 	 * chips only have one interrupt.
1116 	 */
1117 	if (sport->txirq > 0) {
1118 		retval = request_irq(sport->rxirq, imx_rxint, 0,
1119 				     dev_name(port->dev), sport);
1120 		if (retval)
1121 			goto error_out1;
1122 
1123 		retval = request_irq(sport->txirq, imx_txint, 0,
1124 				     dev_name(port->dev), sport);
1125 		if (retval)
1126 			goto error_out2;
1127 
1128 		/* do not use RTS IRQ on IrDA */
1129 		if (!USE_IRDA(sport)) {
1130 			retval = request_irq(sport->rtsirq, imx_rtsint, 0,
1131 					     dev_name(port->dev), sport);
1132 			if (retval)
1133 				goto error_out3;
1134 		}
1135 	} else {
1136 		retval = request_irq(sport->port.irq, imx_int, 0,
1137 				     dev_name(port->dev), sport);
1138 		if (retval) {
1139 			free_irq(sport->port.irq, sport);
1140 			goto error_out1;
1141 		}
1142 	}
1143 
1144 	spin_lock_irqsave(&sport->port.lock, flags);
1145 
1146 	/*
1147 	 * Finally, clear and enable interrupts
1148 	 */
1149 	writel(USR1_RTSD, sport->port.membase + USR1);
1150 	writel(USR2_ORE, sport->port.membase + USR2);
1151 
1152 	temp = readl(sport->port.membase + UCR1);
1153 	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
1154 
1155 	if (USE_IRDA(sport)) {
1156 		temp |= UCR1_IREN;
1157 		temp &= ~(UCR1_RTSDEN);
1158 	}
1159 
1160 	writel(temp, sport->port.membase + UCR1);
1161 
1162 	temp = readl(sport->port.membase + UCR4);
1163 	temp |= UCR4_OREN;
1164 	writel(temp, sport->port.membase + UCR4);
1165 
1166 	temp = readl(sport->port.membase + UCR2);
1167 	temp |= (UCR2_RXEN | UCR2_TXEN);
1168 	if (!sport->have_rtscts)
1169 		temp |= UCR2_IRTS;
1170 	writel(temp, sport->port.membase + UCR2);
1171 
1172 	if (!is_imx1_uart(sport)) {
1173 		temp = readl(sport->port.membase + UCR3);
1174 		temp |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
1175 		writel(temp, sport->port.membase + UCR3);
1176 	}
1177 
1178 	if (USE_IRDA(sport)) {
1179 		temp = readl(sport->port.membase + UCR4);
1180 		if (sport->irda_inv_rx)
1181 			temp |= UCR4_INVR;
1182 		else
1183 			temp &= ~(UCR4_INVR);
1184 		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
1185 
1186 		temp = readl(sport->port.membase + UCR3);
1187 		if (sport->irda_inv_tx)
1188 			temp |= UCR3_INVT;
1189 		else
1190 			temp &= ~(UCR3_INVT);
1191 		writel(temp, sport->port.membase + UCR3);
1192 	}
1193 
1194 	/*
1195 	 * Enable modem status interrupts
1196 	 */
1197 	imx_enable_ms(&sport->port);
1198 	spin_unlock_irqrestore(&sport->port.lock, flags);
1199 
1200 	if (USE_IRDA(sport)) {
1201 		struct imxuart_platform_data *pdata;
1202 		pdata = dev_get_platdata(sport->port.dev);
1203 		sport->irda_inv_rx = pdata->irda_inv_rx;
1204 		sport->irda_inv_tx = pdata->irda_inv_tx;
1205 		sport->trcv_delay = pdata->transceiver_delay;
1206 		if (pdata->irda_enable)
1207 			pdata->irda_enable(1);
1208 	}
1209 
1210 	return 0;
1211 
1212 error_out3:
1213 	if (sport->txirq)
1214 		free_irq(sport->txirq, sport);
1215 error_out2:
1216 	if (sport->rxirq)
1217 		free_irq(sport->rxirq, sport);
1218 error_out1:
1219 	return retval;
1220 }
1221 
imx_shutdown(struct uart_port * port)1222 static void imx_shutdown(struct uart_port *port)
1223 {
1224 	struct imx_port *sport = (struct imx_port *)port;
1225 	unsigned long temp;
1226 	unsigned long flags;
1227 
1228 	if (sport->dma_is_enabled) {
1229 		int ret;
1230 
1231 		/* We have to wait for the DMA to finish. */
1232 		ret = wait_event_interruptible(sport->dma_wait,
1233 			!sport->dma_is_rxing && !sport->dma_is_txing);
1234 		if (ret != 0) {
1235 			sport->dma_is_rxing = 0;
1236 			sport->dma_is_txing = 0;
1237 			dmaengine_terminate_all(sport->dma_chan_tx);
1238 			dmaengine_terminate_all(sport->dma_chan_rx);
1239 		}
1240 		imx_stop_tx(port);
1241 		imx_stop_rx(port);
1242 		imx_disable_dma(sport);
1243 		imx_uart_dma_exit(sport);
1244 	}
1245 
1246 	spin_lock_irqsave(&sport->port.lock, flags);
1247 	temp = readl(sport->port.membase + UCR2);
1248 	temp &= ~(UCR2_TXEN);
1249 	writel(temp, sport->port.membase + UCR2);
1250 	spin_unlock_irqrestore(&sport->port.lock, flags);
1251 
1252 	if (USE_IRDA(sport)) {
1253 		struct imxuart_platform_data *pdata;
1254 		pdata = dev_get_platdata(sport->port.dev);
1255 		if (pdata->irda_enable)
1256 			pdata->irda_enable(0);
1257 	}
1258 
1259 	/*
1260 	 * Stop our timer.
1261 	 */
1262 	del_timer_sync(&sport->timer);
1263 
1264 	/*
1265 	 * Free the interrupts
1266 	 */
1267 	if (sport->txirq > 0) {
1268 		if (!USE_IRDA(sport))
1269 			free_irq(sport->rtsirq, sport);
1270 		free_irq(sport->txirq, sport);
1271 		free_irq(sport->rxirq, sport);
1272 	} else
1273 		free_irq(sport->port.irq, sport);
1274 
1275 	/*
1276 	 * Disable all interrupts, port and break condition.
1277 	 */
1278 
1279 	spin_lock_irqsave(&sport->port.lock, flags);
1280 	temp = readl(sport->port.membase + UCR1);
1281 	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
1282 	if (USE_IRDA(sport))
1283 		temp &= ~(UCR1_IREN);
1284 
1285 	writel(temp, sport->port.membase + UCR1);
1286 	spin_unlock_irqrestore(&sport->port.lock, flags);
1287 
1288 	clk_disable_unprepare(sport->clk_per);
1289 	clk_disable_unprepare(sport->clk_ipg);
1290 }
1291 
imx_flush_buffer(struct uart_port * port)1292 static void imx_flush_buffer(struct uart_port *port)
1293 {
1294 	struct imx_port *sport = (struct imx_port *)port;
1295 
1296 	if (sport->dma_is_enabled) {
1297 		sport->tx_bytes = 0;
1298 		dmaengine_terminate_all(sport->dma_chan_tx);
1299 	}
1300 }
1301 
1302 static void
imx_set_termios(struct uart_port * port,struct ktermios * termios,struct ktermios * old)1303 imx_set_termios(struct uart_port *port, struct ktermios *termios,
1304 		   struct ktermios *old)
1305 {
1306 	struct imx_port *sport = (struct imx_port *)port;
1307 	unsigned long flags;
1308 	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
1309 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
1310 	unsigned int div, ufcr;
1311 	unsigned long num, denom;
1312 	uint64_t tdiv64;
1313 
1314 	/*
1315 	 * If we don't support modem control lines, don't allow
1316 	 * these to be set.
1317 	 */
1318 	if (0) {
1319 		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
1320 		termios->c_cflag |= CLOCAL;
1321 	}
1322 
1323 	/*
1324 	 * We only support CS7 and CS8.
1325 	 */
1326 	while ((termios->c_cflag & CSIZE) != CS7 &&
1327 	       (termios->c_cflag & CSIZE) != CS8) {
1328 		termios->c_cflag &= ~CSIZE;
1329 		termios->c_cflag |= old_csize;
1330 		old_csize = CS8;
1331 	}
1332 
1333 	if ((termios->c_cflag & CSIZE) == CS8)
1334 		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
1335 	else
1336 		ucr2 = UCR2_SRST | UCR2_IRTS;
1337 
1338 	if (termios->c_cflag & CRTSCTS) {
1339 		if (sport->have_rtscts) {
1340 			ucr2 &= ~UCR2_IRTS;
1341 			ucr2 |= UCR2_CTSC;
1342 
1343 			/* Can we enable the DMA support? */
1344 			if (is_imx6q_uart(sport) && !uart_console(port)
1345 				&& !sport->dma_is_inited)
1346 				imx_uart_dma_init(sport);
1347 		} else {
1348 			termios->c_cflag &= ~CRTSCTS;
1349 		}
1350 	}
1351 
1352 	if (termios->c_cflag & CSTOPB)
1353 		ucr2 |= UCR2_STPB;
1354 	if (termios->c_cflag & PARENB) {
1355 		ucr2 |= UCR2_PREN;
1356 		if (termios->c_cflag & PARODD)
1357 			ucr2 |= UCR2_PROE;
1358 	}
1359 
1360 	del_timer_sync(&sport->timer);
1361 
1362 	/*
1363 	 * Ask the core to calculate the divisor for us.
1364 	 */
1365 	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
1366 	quot = uart_get_divisor(port, baud);
1367 
1368 	spin_lock_irqsave(&sport->port.lock, flags);
1369 
1370 	sport->port.read_status_mask = 0;
1371 	if (termios->c_iflag & INPCK)
1372 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
1373 	if (termios->c_iflag & (BRKINT | PARMRK))
1374 		sport->port.read_status_mask |= URXD_BRK;
1375 
1376 	/*
1377 	 * Characters to ignore
1378 	 */
1379 	sport->port.ignore_status_mask = 0;
1380 	if (termios->c_iflag & IGNPAR)
1381 		sport->port.ignore_status_mask |= URXD_PRERR;
1382 	if (termios->c_iflag & IGNBRK) {
1383 		sport->port.ignore_status_mask |= URXD_BRK;
1384 		/*
1385 		 * If we're ignoring parity and break indicators,
1386 		 * ignore overruns too (for real raw support).
1387 		 */
1388 		if (termios->c_iflag & IGNPAR)
1389 			sport->port.ignore_status_mask |= URXD_OVRRUN;
1390 	}
1391 
1392 	/*
1393 	 * Update the per-port timeout.
1394 	 */
1395 	uart_update_timeout(port, termios->c_cflag, baud);
1396 
1397 	/*
1398 	 * disable interrupts and drain transmitter
1399 	 */
1400 	old_ucr1 = readl(sport->port.membase + UCR1);
1401 	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
1402 			sport->port.membase + UCR1);
1403 
1404 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC))
1405 		barrier();
1406 
1407 	/* then, disable everything */
1408 	old_txrxen = readl(sport->port.membase + UCR2);
1409 	writel(old_txrxen & ~(UCR2_TXEN | UCR2_RXEN),
1410 			sport->port.membase + UCR2);
1411 	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
1412 
1413 	if (USE_IRDA(sport)) {
1414 		/*
1415 		 * use maximum available submodule frequency to
1416 		 * avoid missing short pulses due to low sampling rate
1417 		 */
1418 		div = 1;
1419 	} else {
1420 		/* custom-baudrate handling */
1421 		div = sport->port.uartclk / (baud * 16);
1422 		if (baud == 38400 && quot != div)
1423 			baud = sport->port.uartclk / (quot * 16);
1424 
1425 		div = sport->port.uartclk / (baud * 16);
1426 		if (div > 7)
1427 			div = 7;
1428 		if (!div)
1429 			div = 1;
1430 	}
1431 
1432 	rational_best_approximation(16 * div * baud, sport->port.uartclk,
1433 		1 << 16, 1 << 16, &num, &denom);
1434 
1435 	tdiv64 = sport->port.uartclk;
1436 	tdiv64 *= num;
1437 	do_div(tdiv64, denom * 16 * div);
1438 	tty_termios_encode_baud_rate(termios,
1439 				(speed_t)tdiv64, (speed_t)tdiv64);
1440 
1441 	num -= 1;
1442 	denom -= 1;
1443 
1444 	ufcr = readl(sport->port.membase + UFCR);
1445 	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
1446 	if (sport->dte_mode)
1447 		ufcr |= UFCR_DCEDTE;
1448 	writel(ufcr, sport->port.membase + UFCR);
1449 
1450 	writel(num, sport->port.membase + UBIR);
1451 	writel(denom, sport->port.membase + UBMR);
1452 
1453 	if (!is_imx1_uart(sport))
1454 		writel(sport->port.uartclk / div / 1000,
1455 				sport->port.membase + IMX21_ONEMS);
1456 
1457 	writel(old_ucr1, sport->port.membase + UCR1);
1458 
1459 	/* set the parity, stop bits and data size */
1460 	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
1461 
1462 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
1463 		imx_enable_ms(&sport->port);
1464 
1465 	if (sport->dma_is_inited && !sport->dma_is_enabled)
1466 		imx_enable_dma(sport);
1467 	spin_unlock_irqrestore(&sport->port.lock, flags);
1468 }
1469 
imx_type(struct uart_port * port)1470 static const char *imx_type(struct uart_port *port)
1471 {
1472 	struct imx_port *sport = (struct imx_port *)port;
1473 
1474 	return sport->port.type == PORT_IMX ? "IMX" : NULL;
1475 }
1476 
1477 /*
1478  * Configure/autoconfigure the port.
1479  */
imx_config_port(struct uart_port * port,int flags)1480 static void imx_config_port(struct uart_port *port, int flags)
1481 {
1482 	struct imx_port *sport = (struct imx_port *)port;
1483 
1484 	if (flags & UART_CONFIG_TYPE)
1485 		sport->port.type = PORT_IMX;
1486 }
1487 
1488 /*
1489  * Verify the new serial_struct (for TIOCSSERIAL).
1490  * The only change we allow are to the flags and type, and
1491  * even then only between PORT_IMX and PORT_UNKNOWN
1492  */
1493 static int
imx_verify_port(struct uart_port * port,struct serial_struct * ser)1494 imx_verify_port(struct uart_port *port, struct serial_struct *ser)
1495 {
1496 	struct imx_port *sport = (struct imx_port *)port;
1497 	int ret = 0;
1498 
1499 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
1500 		ret = -EINVAL;
1501 	if (sport->port.irq != ser->irq)
1502 		ret = -EINVAL;
1503 	if (ser->io_type != UPIO_MEM)
1504 		ret = -EINVAL;
1505 	if (sport->port.uartclk / 16 != ser->baud_base)
1506 		ret = -EINVAL;
1507 	if (sport->port.mapbase != (unsigned long)ser->iomem_base)
1508 		ret = -EINVAL;
1509 	if (sport->port.iobase != ser->port)
1510 		ret = -EINVAL;
1511 	if (ser->hub6 != 0)
1512 		ret = -EINVAL;
1513 	return ret;
1514 }
1515 
1516 #if defined(CONFIG_CONSOLE_POLL)
imx_poll_get_char(struct uart_port * port)1517 static int imx_poll_get_char(struct uart_port *port)
1518 {
1519 	if (!(readl(port->membase + USR2) & USR2_RDR))
1520 		return NO_POLL_CHAR;
1521 
1522 	return readl(port->membase + URXD0) & URXD_RX_DATA;
1523 }
1524 
imx_poll_put_char(struct uart_port * port,unsigned char c)1525 static void imx_poll_put_char(struct uart_port *port, unsigned char c)
1526 {
1527 	struct imx_port_ucrs old_ucr;
1528 	unsigned int status;
1529 
1530 	/* save control registers */
1531 	imx_port_ucrs_save(port, &old_ucr);
1532 
1533 	/* disable interrupts */
1534 	writel(UCR1_UARTEN, port->membase + UCR1);
1535 	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
1536 	       port->membase + UCR2);
1537 	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
1538 	       port->membase + UCR3);
1539 
1540 	/* drain */
1541 	do {
1542 		status = readl(port->membase + USR1);
1543 	} while (~status & USR1_TRDY);
1544 
1545 	/* write */
1546 	writel(c, port->membase + URTX0);
1547 
1548 	/* flush */
1549 	do {
1550 		status = readl(port->membase + USR2);
1551 	} while (~status & USR2_TXDC);
1552 
1553 	/* restore control registers */
1554 	imx_port_ucrs_restore(port, &old_ucr);
1555 }
1556 #endif
1557 
1558 static struct uart_ops imx_pops = {
1559 	.tx_empty	= imx_tx_empty,
1560 	.set_mctrl	= imx_set_mctrl,
1561 	.get_mctrl	= imx_get_mctrl,
1562 	.stop_tx	= imx_stop_tx,
1563 	.start_tx	= imx_start_tx,
1564 	.stop_rx	= imx_stop_rx,
1565 	.enable_ms	= imx_enable_ms,
1566 	.break_ctl	= imx_break_ctl,
1567 	.startup	= imx_startup,
1568 	.shutdown	= imx_shutdown,
1569 	.flush_buffer	= imx_flush_buffer,
1570 	.set_termios	= imx_set_termios,
1571 	.type		= imx_type,
1572 	.config_port	= imx_config_port,
1573 	.verify_port	= imx_verify_port,
1574 #if defined(CONFIG_CONSOLE_POLL)
1575 	.poll_get_char  = imx_poll_get_char,
1576 	.poll_put_char  = imx_poll_put_char,
1577 #endif
1578 };
1579 
1580 static struct imx_port *imx_ports[UART_NR];
1581 
1582 #ifdef CONFIG_SERIAL_IMX_CONSOLE
imx_console_putchar(struct uart_port * port,int ch)1583 static void imx_console_putchar(struct uart_port *port, int ch)
1584 {
1585 	struct imx_port *sport = (struct imx_port *)port;
1586 
1587 	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
1588 		barrier();
1589 
1590 	writel(ch, sport->port.membase + URTX0);
1591 }
1592 
1593 /*
1594  * Interrupts are disabled on entering
1595  */
1596 static void
imx_console_write(struct console * co,const char * s,unsigned int count)1597 imx_console_write(struct console *co, const char *s, unsigned int count)
1598 {
1599 	struct imx_port *sport = imx_ports[co->index];
1600 	struct imx_port_ucrs old_ucr;
1601 	unsigned int ucr1;
1602 	unsigned long flags = 0;
1603 	int locked = 1;
1604 	int retval;
1605 
1606 	retval = clk_enable(sport->clk_per);
1607 	if (retval)
1608 		return;
1609 	retval = clk_enable(sport->clk_ipg);
1610 	if (retval) {
1611 		clk_disable(sport->clk_per);
1612 		return;
1613 	}
1614 
1615 	if (sport->port.sysrq)
1616 		locked = 0;
1617 	else if (oops_in_progress)
1618 		locked = spin_trylock_irqsave(&sport->port.lock, flags);
1619 	else
1620 		spin_lock_irqsave(&sport->port.lock, flags);
1621 
1622 	/*
1623 	 *	First, save UCR1/2/3 and then disable interrupts
1624 	 */
1625 	imx_port_ucrs_save(&sport->port, &old_ucr);
1626 	ucr1 = old_ucr.ucr1;
1627 
1628 	if (is_imx1_uart(sport))
1629 		ucr1 |= IMX1_UCR1_UARTCLKEN;
1630 	ucr1 |= UCR1_UARTEN;
1631 	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
1632 
1633 	writel(ucr1, sport->port.membase + UCR1);
1634 
1635 	writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
1636 
1637 	uart_console_write(&sport->port, s, count, imx_console_putchar);
1638 
1639 	/*
1640 	 *	Finally, wait for transmitter to become empty
1641 	 *	and restore UCR1/2/3
1642 	 */
1643 	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
1644 
1645 	imx_port_ucrs_restore(&sport->port, &old_ucr);
1646 
1647 	if (locked)
1648 		spin_unlock_irqrestore(&sport->port.lock, flags);
1649 
1650 	clk_disable(sport->clk_ipg);
1651 	clk_disable(sport->clk_per);
1652 }
1653 
1654 /*
1655  * If the port was already initialised (eg, by a boot loader),
1656  * try to determine the current setup.
1657  */
1658 static void __init
imx_console_get_options(struct imx_port * sport,int * baud,int * parity,int * bits)1659 imx_console_get_options(struct imx_port *sport, int *baud,
1660 			   int *parity, int *bits)
1661 {
1662 
1663 	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
1664 		/* ok, the port was enabled */
1665 		unsigned int ucr2, ubir, ubmr, uartclk;
1666 		unsigned int baud_raw;
1667 		unsigned int ucfr_rfdiv;
1668 
1669 		ucr2 = readl(sport->port.membase + UCR2);
1670 
1671 		*parity = 'n';
1672 		if (ucr2 & UCR2_PREN) {
1673 			if (ucr2 & UCR2_PROE)
1674 				*parity = 'o';
1675 			else
1676 				*parity = 'e';
1677 		}
1678 
1679 		if (ucr2 & UCR2_WS)
1680 			*bits = 8;
1681 		else
1682 			*bits = 7;
1683 
1684 		ubir = readl(sport->port.membase + UBIR) & 0xffff;
1685 		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
1686 
1687 		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
1688 		if (ucfr_rfdiv == 6)
1689 			ucfr_rfdiv = 7;
1690 		else
1691 			ucfr_rfdiv = 6 - ucfr_rfdiv;
1692 
1693 		uartclk = clk_get_rate(sport->clk_per);
1694 		uartclk /= ucfr_rfdiv;
1695 
1696 		{	/*
1697 			 * The next code provides exact computation of
1698 			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
1699 			 * without need of float support or long long division,
1700 			 * which would be required to prevent 32bit arithmetic overflow
1701 			 */
1702 			unsigned int mul = ubir + 1;
1703 			unsigned int div = 16 * (ubmr + 1);
1704 			unsigned int rem = uartclk % div;
1705 
1706 			baud_raw = (uartclk / div) * mul;
1707 			baud_raw += (rem * mul + div / 2) / div;
1708 			*baud = (baud_raw + 50) / 100 * 100;
1709 		}
1710 
1711 		if (*baud != baud_raw)
1712 			pr_info("Console IMX rounded baud rate from %d to %d\n",
1713 				baud_raw, *baud);
1714 	}
1715 }
1716 
1717 static int __init
imx_console_setup(struct console * co,char * options)1718 imx_console_setup(struct console *co, char *options)
1719 {
1720 	struct imx_port *sport;
1721 	int baud = 9600;
1722 	int bits = 8;
1723 	int parity = 'n';
1724 	int flow = 'n';
1725 	int retval;
1726 
1727 	/*
1728 	 * Check whether an invalid uart number has been specified, and
1729 	 * if so, search for the first available port that does have
1730 	 * console support.
1731 	 */
1732 	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
1733 		co->index = 0;
1734 	sport = imx_ports[co->index];
1735 	if (sport == NULL)
1736 		return -ENODEV;
1737 
1738 	/* For setting the registers, we only need to enable the ipg clock. */
1739 	retval = clk_prepare_enable(sport->clk_ipg);
1740 	if (retval)
1741 		goto error_console;
1742 
1743 	if (options)
1744 		uart_parse_options(options, &baud, &parity, &bits, &flow);
1745 	else
1746 		imx_console_get_options(sport, &baud, &parity, &bits);
1747 
1748 	imx_setup_ufcr(sport, 0);
1749 
1750 	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
1751 
1752 	clk_disable(sport->clk_ipg);
1753 	if (retval) {
1754 		clk_unprepare(sport->clk_ipg);
1755 		goto error_console;
1756 	}
1757 
1758 	retval = clk_prepare(sport->clk_per);
1759 	if (retval)
1760 		clk_disable_unprepare(sport->clk_ipg);
1761 
1762 error_console:
1763 	return retval;
1764 }
1765 
1766 static struct uart_driver imx_reg;
1767 static struct console imx_console = {
1768 	.name		= DEV_NAME,
1769 	.write		= imx_console_write,
1770 	.device		= uart_console_device,
1771 	.setup		= imx_console_setup,
1772 	.flags		= CON_PRINTBUFFER,
1773 	.index		= -1,
1774 	.data		= &imx_reg,
1775 };
1776 
1777 #define IMX_CONSOLE	&imx_console
1778 #else
1779 #define IMX_CONSOLE	NULL
1780 #endif
1781 
1782 static struct uart_driver imx_reg = {
1783 	.owner          = THIS_MODULE,
1784 	.driver_name    = DRIVER_NAME,
1785 	.dev_name       = DEV_NAME,
1786 	.major          = SERIAL_IMX_MAJOR,
1787 	.minor          = MINOR_START,
1788 	.nr             = ARRAY_SIZE(imx_ports),
1789 	.cons           = IMX_CONSOLE,
1790 };
1791 
serial_imx_suspend(struct platform_device * dev,pm_message_t state)1792 static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
1793 {
1794 	struct imx_port *sport = platform_get_drvdata(dev);
1795 	unsigned int val;
1796 
1797 	/* enable wakeup from i.MX UART */
1798 	val = readl(sport->port.membase + UCR3);
1799 	val |= UCR3_AWAKEN;
1800 	writel(val, sport->port.membase + UCR3);
1801 
1802 	uart_suspend_port(&imx_reg, &sport->port);
1803 
1804 	return 0;
1805 }
1806 
serial_imx_resume(struct platform_device * dev)1807 static int serial_imx_resume(struct platform_device *dev)
1808 {
1809 	struct imx_port *sport = platform_get_drvdata(dev);
1810 	unsigned int val;
1811 
1812 	/* disable wakeup from i.MX UART */
1813 	val = readl(sport->port.membase + UCR3);
1814 	val &= ~UCR3_AWAKEN;
1815 	writel(val, sport->port.membase + UCR3);
1816 
1817 	uart_resume_port(&imx_reg, &sport->port);
1818 
1819 	return 0;
1820 }
1821 
1822 #ifdef CONFIG_OF
1823 /*
1824  * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
1825  * could successfully get all information from dt or a negative errno.
1826  */
serial_imx_probe_dt(struct imx_port * sport,struct platform_device * pdev)1827 static int serial_imx_probe_dt(struct imx_port *sport,
1828 		struct platform_device *pdev)
1829 {
1830 	struct device_node *np = pdev->dev.of_node;
1831 	const struct of_device_id *of_id =
1832 			of_match_device(imx_uart_dt_ids, &pdev->dev);
1833 	int ret;
1834 
1835 	if (!np)
1836 		/* no device tree device */
1837 		return 1;
1838 
1839 	ret = of_alias_get_id(np, "serial");
1840 	if (ret < 0) {
1841 		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
1842 		return ret;
1843 	}
1844 	sport->port.line = ret;
1845 
1846 	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
1847 		sport->have_rtscts = 1;
1848 
1849 	if (of_get_property(np, "fsl,irda-mode", NULL))
1850 		sport->use_irda = 1;
1851 
1852 	if (of_get_property(np, "fsl,dte-mode", NULL))
1853 		sport->dte_mode = 1;
1854 
1855 	sport->devdata = of_id->data;
1856 
1857 	return 0;
1858 }
1859 #else
serial_imx_probe_dt(struct imx_port * sport,struct platform_device * pdev)1860 static inline int serial_imx_probe_dt(struct imx_port *sport,
1861 		struct platform_device *pdev)
1862 {
1863 	return 1;
1864 }
1865 #endif
1866 
serial_imx_probe_pdata(struct imx_port * sport,struct platform_device * pdev)1867 static void serial_imx_probe_pdata(struct imx_port *sport,
1868 		struct platform_device *pdev)
1869 {
1870 	struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
1871 
1872 	sport->port.line = pdev->id;
1873 	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
1874 
1875 	if (!pdata)
1876 		return;
1877 
1878 	if (pdata->flags & IMXUART_HAVE_RTSCTS)
1879 		sport->have_rtscts = 1;
1880 
1881 	if (pdata->flags & IMXUART_IRDA)
1882 		sport->use_irda = 1;
1883 }
1884 
serial_imx_probe(struct platform_device * pdev)1885 static int serial_imx_probe(struct platform_device *pdev)
1886 {
1887 	struct imx_port *sport;
1888 	void __iomem *base;
1889 	int ret = 0;
1890 	struct resource *res;
1891 
1892 	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
1893 	if (!sport)
1894 		return -ENOMEM;
1895 
1896 	ret = serial_imx_probe_dt(sport, pdev);
1897 	if (ret > 0)
1898 		serial_imx_probe_pdata(sport, pdev);
1899 	else if (ret < 0)
1900 		return ret;
1901 
1902 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1903 	base = devm_ioremap_resource(&pdev->dev, res);
1904 	if (IS_ERR(base))
1905 		return PTR_ERR(base);
1906 
1907 	sport->port.dev = &pdev->dev;
1908 	sport->port.mapbase = res->start;
1909 	sport->port.membase = base;
1910 	sport->port.type = PORT_IMX,
1911 	sport->port.iotype = UPIO_MEM;
1912 	sport->port.irq = platform_get_irq(pdev, 0);
1913 	sport->rxirq = platform_get_irq(pdev, 0);
1914 	sport->txirq = platform_get_irq(pdev, 1);
1915 	sport->rtsirq = platform_get_irq(pdev, 2);
1916 	sport->port.fifosize = 32;
1917 	sport->port.ops = &imx_pops;
1918 	sport->port.flags = UPF_BOOT_AUTOCONF;
1919 	init_timer(&sport->timer);
1920 	sport->timer.function = imx_timeout;
1921 	sport->timer.data     = (unsigned long)sport;
1922 
1923 	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1924 	if (IS_ERR(sport->clk_ipg)) {
1925 		ret = PTR_ERR(sport->clk_ipg);
1926 		dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
1927 		return ret;
1928 	}
1929 
1930 	sport->clk_per = devm_clk_get(&pdev->dev, "per");
1931 	if (IS_ERR(sport->clk_per)) {
1932 		ret = PTR_ERR(sport->clk_per);
1933 		dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
1934 		return ret;
1935 	}
1936 
1937 	sport->port.uartclk = clk_get_rate(sport->clk_per);
1938 
1939 	imx_ports[sport->port.line] = sport;
1940 
1941 	platform_set_drvdata(pdev, sport);
1942 
1943 	return uart_add_one_port(&imx_reg, &sport->port);
1944 }
1945 
serial_imx_remove(struct platform_device * pdev)1946 static int serial_imx_remove(struct platform_device *pdev)
1947 {
1948 	struct imx_port *sport = platform_get_drvdata(pdev);
1949 
1950 	return uart_remove_one_port(&imx_reg, &sport->port);
1951 }
1952 
1953 static struct platform_driver serial_imx_driver = {
1954 	.probe		= serial_imx_probe,
1955 	.remove		= serial_imx_remove,
1956 
1957 	.suspend	= serial_imx_suspend,
1958 	.resume		= serial_imx_resume,
1959 	.id_table	= imx_uart_devtype,
1960 	.driver		= {
1961 		.name	= "imx-uart",
1962 		.owner	= THIS_MODULE,
1963 		.of_match_table = imx_uart_dt_ids,
1964 	},
1965 };
1966 
imx_serial_init(void)1967 static int __init imx_serial_init(void)
1968 {
1969 	int ret;
1970 
1971 	pr_info("Serial: IMX driver\n");
1972 
1973 	ret = uart_register_driver(&imx_reg);
1974 	if (ret)
1975 		return ret;
1976 
1977 	ret = platform_driver_register(&serial_imx_driver);
1978 	if (ret != 0)
1979 		uart_unregister_driver(&imx_reg);
1980 
1981 	return ret;
1982 }
1983 
imx_serial_exit(void)1984 static void __exit imx_serial_exit(void)
1985 {
1986 	platform_driver_unregister(&serial_imx_driver);
1987 	uart_unregister_driver(&imx_reg);
1988 }
1989 
1990 module_init(imx_serial_init);
1991 module_exit(imx_serial_exit);
1992 
1993 MODULE_AUTHOR("Sascha Hauer");
1994 MODULE_DESCRIPTION("IMX generic serial port driver");
1995 MODULE_LICENSE("GPL");
1996 MODULE_ALIAS("platform:imx-uart");
1997