1 /****************************************************************************
2  *
3  * Driver for the IFX 6x60 spi modem.
4  *
5  * Copyright (C) 2008 Option International
6  * Copyright (C) 2008 Filip Aben <f.aben@option.com>
7  *		      Denis Joseph Barrow <d.barow@option.com>
8  *		      Jan Dumon <j.dumon@option.com>
9  *
10  * Copyright (C) 2009, 2010 Intel Corp
11  * Russ Gorby <russ.gorby@intel.com>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License version 2 as
15  * published by the Free Software Foundation.
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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
25  * USA
26  *
27  * Driver modified by Intel from Option gtm501l_spi.c
28  *
29  * Notes
30  * o	The driver currently assumes a single device only. If you need to
31  *	change this then look for saved_ifx_dev and add a device lookup
32  * o	The driver is intended to be big-endian safe but has never been
33  *	tested that way (no suitable hardware). There are a couple of FIXME
34  *	notes by areas that may need addressing
35  * o	Some of the GPIO naming/setup assumptions may need revisiting if
36  *	you need to use this driver for another platform.
37  *
38  *****************************************************************************/
39 #include <linux/dma-mapping.h>
40 #include <linux/module.h>
41 #include <linux/termios.h>
42 #include <linux/tty.h>
43 #include <linux/device.h>
44 #include <linux/spi/spi.h>
45 #include <linux/kfifo.h>
46 #include <linux/tty_flip.h>
47 #include <linux/timer.h>
48 #include <linux/serial.h>
49 #include <linux/interrupt.h>
50 #include <linux/irq.h>
51 #include <linux/rfkill.h>
52 #include <linux/fs.h>
53 #include <linux/ip.h>
54 #include <linux/dmapool.h>
55 #include <linux/gpio.h>
56 #include <linux/sched.h>
57 #include <linux/time.h>
58 #include <linux/wait.h>
59 #include <linux/pm.h>
60 #include <linux/pm_runtime.h>
61 #include <linux/spi/ifx_modem.h>
62 #include <linux/delay.h>
63 
64 #include "ifx6x60.h"
65 
66 #define IFX_SPI_MORE_MASK		0x10
67 #define IFX_SPI_MORE_BIT		12	/* bit position in u16 */
68 #define IFX_SPI_CTS_BIT			13	/* bit position in u16 */
69 #define IFX_SPI_MODE			SPI_MODE_1
70 #define IFX_SPI_TTY_ID			0
71 #define IFX_SPI_TIMEOUT_SEC		2
72 #define IFX_SPI_HEADER_0		(-1)
73 #define IFX_SPI_HEADER_F		(-2)
74 
75 /* forward reference */
76 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev);
77 
78 /* local variables */
79 static int spi_bpw = 16;		/* 8, 16 or 32 bit word length */
80 static struct tty_driver *tty_drv;
81 static struct ifx_spi_device *saved_ifx_dev;
82 static struct lock_class_key ifx_spi_key;
83 
84 /* GPIO/GPE settings */
85 
86 /**
87  *	mrdy_set_high		-	set MRDY GPIO
88  *	@ifx: device we are controlling
89  *
90  */
mrdy_set_high(struct ifx_spi_device * ifx)91 static inline void mrdy_set_high(struct ifx_spi_device *ifx)
92 {
93 	gpio_set_value(ifx->gpio.mrdy, 1);
94 }
95 
96 /**
97  *	mrdy_set_low		-	clear MRDY GPIO
98  *	@ifx: device we are controlling
99  *
100  */
mrdy_set_low(struct ifx_spi_device * ifx)101 static inline void mrdy_set_low(struct ifx_spi_device *ifx)
102 {
103 	gpio_set_value(ifx->gpio.mrdy, 0);
104 }
105 
106 /**
107  *	ifx_spi_power_state_set
108  *	@ifx_dev: our SPI device
109  *	@val: bits to set
110  *
111  *	Set bit in power status and signal power system if status becomes non-0
112  */
113 static void
ifx_spi_power_state_set(struct ifx_spi_device * ifx_dev,unsigned char val)114 ifx_spi_power_state_set(struct ifx_spi_device *ifx_dev, unsigned char val)
115 {
116 	unsigned long flags;
117 
118 	spin_lock_irqsave(&ifx_dev->power_lock, flags);
119 
120 	/*
121 	 * if power status is already non-0, just update, else
122 	 * tell power system
123 	 */
124 	if (!ifx_dev->power_status)
125 		pm_runtime_get(&ifx_dev->spi_dev->dev);
126 	ifx_dev->power_status |= val;
127 
128 	spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
129 }
130 
131 /**
132  *	ifx_spi_power_state_clear	-	clear power bit
133  *	@ifx_dev: our SPI device
134  *	@val: bits to clear
135  *
136  *	clear bit in power status and signal power system if status becomes 0
137  */
138 static void
ifx_spi_power_state_clear(struct ifx_spi_device * ifx_dev,unsigned char val)139 ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val)
140 {
141 	unsigned long flags;
142 
143 	spin_lock_irqsave(&ifx_dev->power_lock, flags);
144 
145 	if (ifx_dev->power_status) {
146 		ifx_dev->power_status &= ~val;
147 		if (!ifx_dev->power_status)
148 			pm_runtime_put(&ifx_dev->spi_dev->dev);
149 	}
150 
151 	spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
152 }
153 
154 /**
155  *	swap_buf
156  *	@buf: our buffer
157  *	@len : number of bytes (not words) in the buffer
158  *	@end: end of buffer
159  *
160  *	Swap the contents of a buffer into big endian format
161  */
swap_buf(u16 * buf,int len,void * end)162 static inline void swap_buf(u16 *buf, int len, void *end)
163 {
164 	int n;
165 
166 	len = ((len + 1) >> 1);
167 	if ((void *)&buf[len] > end) {
168 		pr_err("swap_buf: swap exceeds boundary (%p > %p)!",
169 		       &buf[len], end);
170 		return;
171 	}
172 	for (n = 0; n < len; n++) {
173 		*buf = cpu_to_be16(*buf);
174 		buf++;
175 	}
176 }
177 
178 /**
179  *	mrdy_assert		-	assert MRDY line
180  *	@ifx_dev: our SPI device
181  *
182  *	Assert mrdy and set timer to wait for SRDY interrupt, if SRDY is low
183  *	now.
184  *
185  *	FIXME: Can SRDY even go high as we are running this code ?
186  */
mrdy_assert(struct ifx_spi_device * ifx_dev)187 static void mrdy_assert(struct ifx_spi_device *ifx_dev)
188 {
189 	int val = gpio_get_value(ifx_dev->gpio.srdy);
190 	if (!val) {
191 		if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING,
192 				      &ifx_dev->flags)) {
193 			ifx_dev->spi_timer.expires =
194 				jiffies + IFX_SPI_TIMEOUT_SEC*HZ;
195 			add_timer(&ifx_dev->spi_timer);
196 
197 		}
198 	}
199 	ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_DATA_PENDING);
200 	mrdy_set_high(ifx_dev);
201 }
202 
203 /**
204  *	ifx_spi_hangup		-	hang up an IFX device
205  *	@ifx_dev: our SPI device
206  *
207  *	Hang up the tty attached to the IFX device if one is currently
208  *	open. If not take no action
209  */
ifx_spi_ttyhangup(struct ifx_spi_device * ifx_dev)210 static void ifx_spi_ttyhangup(struct ifx_spi_device *ifx_dev)
211 {
212 	struct tty_port *pport = &ifx_dev->tty_port;
213 	struct tty_struct *tty = tty_port_tty_get(pport);
214 	if (tty) {
215 		tty_hangup(tty);
216 		tty_kref_put(tty);
217 	}
218 }
219 
220 /**
221  *	ifx_spi_timeout		-	SPI timeout
222  *	@arg: our SPI device
223  *
224  *	The SPI has timed out: hang up the tty. Users will then see a hangup
225  *	and error events.
226  */
ifx_spi_timeout(unsigned long arg)227 static void ifx_spi_timeout(unsigned long arg)
228 {
229 	struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *)arg;
230 
231 	dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***");
232 	ifx_spi_ttyhangup(ifx_dev);
233 	mrdy_set_low(ifx_dev);
234 	clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
235 }
236 
237 /* char/tty operations */
238 
239 /**
240  *	ifx_spi_tiocmget	-	get modem lines
241  *	@tty: our tty device
242  *	@filp: file handle issuing the request
243  *
244  *	Map the signal state into Linux modem flags and report the value
245  *	in Linux terms
246  */
ifx_spi_tiocmget(struct tty_struct * tty)247 static int ifx_spi_tiocmget(struct tty_struct *tty)
248 {
249 	unsigned int value;
250 	struct ifx_spi_device *ifx_dev = tty->driver_data;
251 
252 	value =
253 	(test_bit(IFX_SPI_RTS, &ifx_dev->signal_state) ? TIOCM_RTS : 0) |
254 	(test_bit(IFX_SPI_DTR, &ifx_dev->signal_state) ? TIOCM_DTR : 0) |
255 	(test_bit(IFX_SPI_CTS, &ifx_dev->signal_state) ? TIOCM_CTS : 0) |
256 	(test_bit(IFX_SPI_DSR, &ifx_dev->signal_state) ? TIOCM_DSR : 0) |
257 	(test_bit(IFX_SPI_DCD, &ifx_dev->signal_state) ? TIOCM_CAR : 0) |
258 	(test_bit(IFX_SPI_RI, &ifx_dev->signal_state) ? TIOCM_RNG : 0);
259 	return value;
260 }
261 
262 /**
263  *	ifx_spi_tiocmset	-	set modem bits
264  *	@tty: the tty structure
265  *	@set: bits to set
266  *	@clear: bits to clear
267  *
268  *	The IFX6x60 only supports DTR and RTS. Set them accordingly
269  *	and flag that an update to the modem is needed.
270  *
271  *	FIXME: do we need to kick the tranfers when we do this ?
272  */
ifx_spi_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)273 static int ifx_spi_tiocmset(struct tty_struct *tty,
274 			    unsigned int set, unsigned int clear)
275 {
276 	struct ifx_spi_device *ifx_dev = tty->driver_data;
277 
278 	if (set & TIOCM_RTS)
279 		set_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
280 	if (set & TIOCM_DTR)
281 		set_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
282 	if (clear & TIOCM_RTS)
283 		clear_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
284 	if (clear & TIOCM_DTR)
285 		clear_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
286 
287 	set_bit(IFX_SPI_UPDATE, &ifx_dev->signal_state);
288 	return 0;
289 }
290 
291 /**
292  *	ifx_spi_open	-	called on tty open
293  *	@tty: our tty device
294  *	@filp: file handle being associated with the tty
295  *
296  *	Open the tty interface. We let the tty_port layer do all the work
297  *	for us.
298  *
299  *	FIXME: Remove single device assumption and saved_ifx_dev
300  */
ifx_spi_open(struct tty_struct * tty,struct file * filp)301 static int ifx_spi_open(struct tty_struct *tty, struct file *filp)
302 {
303 	return tty_port_open(&saved_ifx_dev->tty_port, tty, filp);
304 }
305 
306 /**
307  *	ifx_spi_close	-	called when our tty closes
308  *	@tty: the tty being closed
309  *	@filp: the file handle being closed
310  *
311  *	Perform the close of the tty. We use the tty_port layer to do all
312  *	our hard work.
313  */
ifx_spi_close(struct tty_struct * tty,struct file * filp)314 static void ifx_spi_close(struct tty_struct *tty, struct file *filp)
315 {
316 	struct ifx_spi_device *ifx_dev = tty->driver_data;
317 	tty_port_close(&ifx_dev->tty_port, tty, filp);
318 	/* FIXME: should we do an ifx_spi_reset here ? */
319 }
320 
321 /**
322  *	ifx_decode_spi_header	-	decode received header
323  *	@buffer: the received data
324  *	@length: decoded length
325  *	@more: decoded more flag
326  *	@received_cts: status of cts we received
327  *
328  *	Note how received_cts is handled -- if header is all F it is left
329  *	the same as it was, if header is all 0 it is set to 0 otherwise it is
330  *	taken from the incoming header.
331  *
332  *	FIXME: endianness
333  */
ifx_spi_decode_spi_header(unsigned char * buffer,int * length,unsigned char * more,unsigned char * received_cts)334 static int ifx_spi_decode_spi_header(unsigned char *buffer, int *length,
335 			unsigned char *more, unsigned char *received_cts)
336 {
337 	u16 h1;
338 	u16 h2;
339 	u16 *in_buffer = (u16 *)buffer;
340 
341 	h1 = *in_buffer;
342 	h2 = *(in_buffer+1);
343 
344 	if (h1 == 0 && h2 == 0) {
345 		*received_cts = 0;
346 		return IFX_SPI_HEADER_0;
347 	} else if (h1 == 0xffff && h2 == 0xffff) {
348 		/* spi_slave_cts remains as it was */
349 		return IFX_SPI_HEADER_F;
350 	}
351 
352 	*length = h1 & 0xfff;	/* upper bits of byte are flags */
353 	*more = (buffer[1] >> IFX_SPI_MORE_BIT) & 1;
354 	*received_cts = (buffer[3] >> IFX_SPI_CTS_BIT) & 1;
355 	return 0;
356 }
357 
358 /**
359  *	ifx_setup_spi_header	-	set header fields
360  *	@txbuffer: pointer to start of SPI buffer
361  *	@tx_count: bytes
362  *	@more: indicate if more to follow
363  *
364  *	Format up an SPI header for a transfer
365  *
366  *	FIXME: endianness?
367  */
ifx_spi_setup_spi_header(unsigned char * txbuffer,int tx_count,unsigned char more)368 static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count,
369 					unsigned char more)
370 {
371 	*(u16 *)(txbuffer) = tx_count;
372 	*(u16 *)(txbuffer+2) = IFX_SPI_PAYLOAD_SIZE;
373 	txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK;
374 }
375 
376 /**
377  *	ifx_spi_wakeup_serial	-	SPI space made
378  *	@port_data: our SPI device
379  *
380  *	We have emptied the FIFO enough that we want to get more data
381  *	queued into it. Poke the line discipline via tty_wakeup so that
382  *	it will feed us more bits
383  */
ifx_spi_wakeup_serial(struct ifx_spi_device * ifx_dev)384 static void ifx_spi_wakeup_serial(struct ifx_spi_device *ifx_dev)
385 {
386 	struct tty_struct *tty;
387 
388 	tty = tty_port_tty_get(&ifx_dev->tty_port);
389 	if (!tty)
390 		return;
391 	tty_wakeup(tty);
392 	tty_kref_put(tty);
393 }
394 
395 /**
396  *	ifx_spi_prepare_tx_buffer	-	prepare transmit frame
397  *	@ifx_dev: our SPI device
398  *
399  *	The transmit buffr needs a header and various other bits of
400  *	information followed by as much data as we can pull from the FIFO
401  *	and transfer. This function formats up a suitable buffer in the
402  *	ifx_dev->tx_buffer
403  *
404  *	FIXME: performance - should we wake the tty when the queue is half
405  *			     empty ?
406  */
ifx_spi_prepare_tx_buffer(struct ifx_spi_device * ifx_dev)407 static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
408 {
409 	int temp_count;
410 	int queue_length;
411 	int tx_count;
412 	unsigned char *tx_buffer;
413 
414 	tx_buffer = ifx_dev->tx_buffer;
415 	memset(tx_buffer, 0, IFX_SPI_TRANSFER_SIZE);
416 
417 	/* make room for required SPI header */
418 	tx_buffer += IFX_SPI_HEADER_OVERHEAD;
419 	tx_count = IFX_SPI_HEADER_OVERHEAD;
420 
421 	/* clear to signal no more data if this turns out to be the
422 	 * last buffer sent in a sequence */
423 	ifx_dev->spi_more = 0;
424 
425 	/* if modem cts is set, just send empty buffer */
426 	if (!ifx_dev->spi_slave_cts) {
427 		/* see if there's tx data */
428 		queue_length = kfifo_len(&ifx_dev->tx_fifo);
429 		if (queue_length != 0) {
430 			/* data to mux -- see if there's room for it */
431 			temp_count = min(queue_length, IFX_SPI_PAYLOAD_SIZE);
432 			temp_count = kfifo_out_locked(&ifx_dev->tx_fifo,
433 					tx_buffer, temp_count,
434 					&ifx_dev->fifo_lock);
435 
436 			/* update buffer pointer and data count in message */
437 			tx_buffer += temp_count;
438 			tx_count += temp_count;
439 			if (temp_count == queue_length)
440 				/* poke port to get more data */
441 				ifx_spi_wakeup_serial(ifx_dev);
442 			else /* more data in port, use next SPI message */
443 				ifx_dev->spi_more = 1;
444 		}
445 	}
446 	/* have data and info for header -- set up SPI header in buffer */
447 	/* spi header needs payload size, not entire buffer size */
448 	ifx_spi_setup_spi_header(ifx_dev->tx_buffer,
449 					tx_count-IFX_SPI_HEADER_OVERHEAD,
450 					ifx_dev->spi_more);
451 	/* swap actual data in the buffer */
452 	swap_buf((u16 *)(ifx_dev->tx_buffer), tx_count,
453 		&ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]);
454 	return tx_count;
455 }
456 
457 /**
458  *	ifx_spi_write		-	line discipline write
459  *	@tty: our tty device
460  *	@buf: pointer to buffer to write (kernel space)
461  *	@count: size of buffer
462  *
463  *	Write the characters we have been given into the FIFO. If the device
464  *	is not active then activate it, when the SRDY line is asserted back
465  *	this will commence I/O
466  */
ifx_spi_write(struct tty_struct * tty,const unsigned char * buf,int count)467 static int ifx_spi_write(struct tty_struct *tty, const unsigned char *buf,
468 			 int count)
469 {
470 	struct ifx_spi_device *ifx_dev = tty->driver_data;
471 	unsigned char *tmp_buf = (unsigned char *)buf;
472 	int tx_count = kfifo_in_locked(&ifx_dev->tx_fifo, tmp_buf, count,
473 				   &ifx_dev->fifo_lock);
474 	mrdy_assert(ifx_dev);
475 	return tx_count;
476 }
477 
478 /**
479  *	ifx_spi_chars_in_buffer	-	line discipline helper
480  *	@tty: our tty device
481  *
482  *	Report how much data we can accept before we drop bytes. As we use
483  *	a simple FIFO this is nice and easy.
484  */
ifx_spi_write_room(struct tty_struct * tty)485 static int ifx_spi_write_room(struct tty_struct *tty)
486 {
487 	struct ifx_spi_device *ifx_dev = tty->driver_data;
488 	return IFX_SPI_FIFO_SIZE - kfifo_len(&ifx_dev->tx_fifo);
489 }
490 
491 /**
492  *	ifx_spi_chars_in_buffer	-	line discipline helper
493  *	@tty: our tty device
494  *
495  *	Report how many characters we have buffered. In our case this is the
496  *	number of bytes sitting in our transmit FIFO.
497  */
ifx_spi_chars_in_buffer(struct tty_struct * tty)498 static int ifx_spi_chars_in_buffer(struct tty_struct *tty)
499 {
500 	struct ifx_spi_device *ifx_dev = tty->driver_data;
501 	return kfifo_len(&ifx_dev->tx_fifo);
502 }
503 
504 /**
505  *	ifx_port_hangup
506  *	@port: our tty port
507  *
508  *	tty port hang up. Called when tty_hangup processing is invoked either
509  *	by loss of carrier, or by software (eg vhangup). Serialized against
510  *	activate/shutdown by the tty layer.
511  */
ifx_spi_hangup(struct tty_struct * tty)512 static void ifx_spi_hangup(struct tty_struct *tty)
513 {
514 	struct ifx_spi_device *ifx_dev = tty->driver_data;
515 	tty_port_hangup(&ifx_dev->tty_port);
516 }
517 
518 /**
519  *	ifx_port_activate
520  *	@port: our tty port
521  *
522  *	tty port activate method - called for first open. Serialized
523  *	with hangup and shutdown by the tty layer.
524  */
ifx_port_activate(struct tty_port * port,struct tty_struct * tty)525 static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty)
526 {
527 	struct ifx_spi_device *ifx_dev =
528 		container_of(port, struct ifx_spi_device, tty_port);
529 
530 	/* clear any old data; can't do this in 'close' */
531 	kfifo_reset(&ifx_dev->tx_fifo);
532 
533 	/* put port data into this tty */
534 	tty->driver_data = ifx_dev;
535 
536 	/* allows flip string push from int context */
537 	tty->low_latency = 1;
538 
539 	return 0;
540 }
541 
542 /**
543  *	ifx_port_shutdown
544  *	@port: our tty port
545  *
546  *	tty port shutdown method - called for last port close. Serialized
547  *	with hangup and activate by the tty layer.
548  */
ifx_port_shutdown(struct tty_port * port)549 static void ifx_port_shutdown(struct tty_port *port)
550 {
551 	struct ifx_spi_device *ifx_dev =
552 		container_of(port, struct ifx_spi_device, tty_port);
553 
554 	mrdy_set_low(ifx_dev);
555 	clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
556 	tasklet_kill(&ifx_dev->io_work_tasklet);
557 }
558 
559 static const struct tty_port_operations ifx_tty_port_ops = {
560 	.activate = ifx_port_activate,
561 	.shutdown = ifx_port_shutdown,
562 };
563 
564 static const struct tty_operations ifx_spi_serial_ops = {
565 	.open = ifx_spi_open,
566 	.close = ifx_spi_close,
567 	.write = ifx_spi_write,
568 	.hangup = ifx_spi_hangup,
569 	.write_room = ifx_spi_write_room,
570 	.chars_in_buffer = ifx_spi_chars_in_buffer,
571 	.tiocmget = ifx_spi_tiocmget,
572 	.tiocmset = ifx_spi_tiocmset,
573 };
574 
575 /**
576  *	ifx_spi_insert_fip_string	-	queue received data
577  *	@ifx_ser: our SPI device
578  *	@chars: buffer we have received
579  *	@size: number of chars reeived
580  *
581  *	Queue bytes to the tty assuming the tty side is currently open. If
582  *	not the discard the data.
583  */
ifx_spi_insert_flip_string(struct ifx_spi_device * ifx_dev,unsigned char * chars,size_t size)584 static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev,
585 				    unsigned char *chars, size_t size)
586 {
587 	struct tty_struct *tty = tty_port_tty_get(&ifx_dev->tty_port);
588 	if (!tty)
589 		return;
590 	tty_insert_flip_string(tty, chars, size);
591 	tty_flip_buffer_push(tty);
592 	tty_kref_put(tty);
593 }
594 
595 /**
596  *	ifx_spi_complete	-	SPI transfer completed
597  *	@ctx: our SPI device
598  *
599  *	An SPI transfer has completed. Process any received data and kick off
600  *	any further transmits we can commence.
601  */
ifx_spi_complete(void * ctx)602 static void ifx_spi_complete(void *ctx)
603 {
604 	struct ifx_spi_device *ifx_dev = ctx;
605 	struct tty_struct *tty;
606 	struct tty_ldisc *ldisc = NULL;
607 	int length;
608 	int actual_length;
609 	unsigned char more;
610 	unsigned char cts;
611 	int local_write_pending = 0;
612 	int queue_length;
613 	int srdy;
614 	int decode_result;
615 
616 	mrdy_set_low(ifx_dev);
617 
618 	if (!ifx_dev->spi_msg.status) {
619 		/* check header validity, get comm flags */
620 		swap_buf((u16 *)ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
621 			&ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]);
622 		decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer,
623 				&length, &more, &cts);
624 		if (decode_result == IFX_SPI_HEADER_0) {
625 			dev_dbg(&ifx_dev->spi_dev->dev,
626 				"ignore input: invalid header 0");
627 			ifx_dev->spi_slave_cts = 0;
628 			goto complete_exit;
629 		} else if (decode_result == IFX_SPI_HEADER_F) {
630 			dev_dbg(&ifx_dev->spi_dev->dev,
631 				"ignore input: invalid header F");
632 			goto complete_exit;
633 		}
634 
635 		ifx_dev->spi_slave_cts = cts;
636 
637 		actual_length = min((unsigned int)length,
638 					ifx_dev->spi_msg.actual_length);
639 		swap_buf((u16 *)(ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
640 			 actual_length,
641 			 &ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]);
642 		ifx_spi_insert_flip_string(
643 			ifx_dev,
644 			ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD,
645 			(size_t)actual_length);
646 	} else {
647 		dev_dbg(&ifx_dev->spi_dev->dev, "SPI transfer error %d",
648 		       ifx_dev->spi_msg.status);
649 	}
650 
651 complete_exit:
652 	if (ifx_dev->write_pending) {
653 		ifx_dev->write_pending = 0;
654 		local_write_pending = 1;
655 	}
656 
657 	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags));
658 
659 	queue_length = kfifo_len(&ifx_dev->tx_fifo);
660 	srdy = gpio_get_value(ifx_dev->gpio.srdy);
661 	if (!srdy)
662 		ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY);
663 
664 	/* schedule output if there is more to do */
665 	if (test_and_clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags))
666 		tasklet_schedule(&ifx_dev->io_work_tasklet);
667 	else {
668 		if (more || ifx_dev->spi_more || queue_length > 0 ||
669 			local_write_pending) {
670 			if (ifx_dev->spi_slave_cts) {
671 				if (more)
672 					mrdy_assert(ifx_dev);
673 			} else
674 				mrdy_assert(ifx_dev);
675 		} else {
676 			/*
677 			 * poke line discipline driver if any for more data
678 			 * may or may not get more data to write
679 			 * for now, say not busy
680 			 */
681 			ifx_spi_power_state_clear(ifx_dev,
682 						  IFX_SPI_POWER_DATA_PENDING);
683 			tty = tty_port_tty_get(&ifx_dev->tty_port);
684 			if (tty) {
685 				ldisc = tty_ldisc_ref(tty);
686 				if (ldisc) {
687 					ldisc->ops->write_wakeup(tty);
688 					tty_ldisc_deref(ldisc);
689 				}
690 				tty_kref_put(tty);
691 			}
692 		}
693 	}
694 }
695 
696 /**
697  *	ifx_spio_io		-	I/O tasklet
698  *	@data: our SPI device
699  *
700  *	Queue data for transmission if possible and then kick off the
701  *	transfer.
702  */
ifx_spi_io(unsigned long data)703 static void ifx_spi_io(unsigned long data)
704 {
705 	int retval;
706 	struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *) data;
707 
708 	if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags)) {
709 		if (ifx_dev->gpio.unack_srdy_int_nb > 0)
710 			ifx_dev->gpio.unack_srdy_int_nb--;
711 
712 		ifx_spi_prepare_tx_buffer(ifx_dev);
713 
714 		spi_message_init(&ifx_dev->spi_msg);
715 		INIT_LIST_HEAD(&ifx_dev->spi_msg.queue);
716 
717 		ifx_dev->spi_msg.context = ifx_dev;
718 		ifx_dev->spi_msg.complete = ifx_spi_complete;
719 
720 		/* set up our spi transfer */
721 		/* note len is BYTES, not transfers */
722 		ifx_dev->spi_xfer.len = IFX_SPI_TRANSFER_SIZE;
723 		ifx_dev->spi_xfer.cs_change = 0;
724 		ifx_dev->spi_xfer.speed_hz = ifx_dev->spi_dev->max_speed_hz;
725 		/* ifx_dev->spi_xfer.speed_hz = 390625; */
726 		ifx_dev->spi_xfer.bits_per_word = spi_bpw;
727 
728 		ifx_dev->spi_xfer.tx_buf = ifx_dev->tx_buffer;
729 		ifx_dev->spi_xfer.rx_buf = ifx_dev->rx_buffer;
730 
731 		/*
732 		 * setup dma pointers
733 		 */
734 		if (ifx_dev->use_dma) {
735 			ifx_dev->spi_msg.is_dma_mapped = 1;
736 			ifx_dev->tx_dma = ifx_dev->tx_bus;
737 			ifx_dev->rx_dma = ifx_dev->rx_bus;
738 			ifx_dev->spi_xfer.tx_dma = ifx_dev->tx_dma;
739 			ifx_dev->spi_xfer.rx_dma = ifx_dev->rx_dma;
740 		} else {
741 			ifx_dev->spi_msg.is_dma_mapped = 0;
742 			ifx_dev->tx_dma = (dma_addr_t)0;
743 			ifx_dev->rx_dma = (dma_addr_t)0;
744 			ifx_dev->spi_xfer.tx_dma = (dma_addr_t)0;
745 			ifx_dev->spi_xfer.rx_dma = (dma_addr_t)0;
746 		}
747 
748 		spi_message_add_tail(&ifx_dev->spi_xfer, &ifx_dev->spi_msg);
749 
750 		/* Assert MRDY. This may have already been done by the write
751 		 * routine.
752 		 */
753 		mrdy_assert(ifx_dev);
754 
755 		retval = spi_async(ifx_dev->spi_dev, &ifx_dev->spi_msg);
756 		if (retval) {
757 			clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS,
758 				  &ifx_dev->flags);
759 			tasklet_schedule(&ifx_dev->io_work_tasklet);
760 			return;
761 		}
762 	} else
763 		ifx_dev->write_pending = 1;
764 }
765 
766 /**
767  *	ifx_spi_free_port	-	free up the tty side
768  *	@ifx_dev: IFX device going away
769  *
770  *	Unregister and free up a port when the device goes away
771  */
ifx_spi_free_port(struct ifx_spi_device * ifx_dev)772 static void ifx_spi_free_port(struct ifx_spi_device *ifx_dev)
773 {
774 	if (ifx_dev->tty_dev)
775 		tty_unregister_device(tty_drv, ifx_dev->minor);
776 	kfifo_free(&ifx_dev->tx_fifo);
777 }
778 
779 /**
780  *	ifx_spi_create_port	-	create a new port
781  *	@ifx_dev: our spi device
782  *
783  *	Allocate and initialise the tty port that goes with this interface
784  *	and add it to the tty layer so that it can be opened.
785  */
ifx_spi_create_port(struct ifx_spi_device * ifx_dev)786 static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev)
787 {
788 	int ret = 0;
789 	struct tty_port *pport = &ifx_dev->tty_port;
790 
791 	spin_lock_init(&ifx_dev->fifo_lock);
792 	lockdep_set_class_and_subclass(&ifx_dev->fifo_lock,
793 		&ifx_spi_key, 0);
794 
795 	if (kfifo_alloc(&ifx_dev->tx_fifo, IFX_SPI_FIFO_SIZE, GFP_KERNEL)) {
796 		ret = -ENOMEM;
797 		goto error_ret;
798 	}
799 
800 	tty_port_init(pport);
801 	pport->ops = &ifx_tty_port_ops;
802 	ifx_dev->minor = IFX_SPI_TTY_ID;
803 	ifx_dev->tty_dev = tty_register_device(tty_drv, ifx_dev->minor,
804 					       &ifx_dev->spi_dev->dev);
805 	if (IS_ERR(ifx_dev->tty_dev)) {
806 		dev_dbg(&ifx_dev->spi_dev->dev,
807 			"%s: registering tty device failed", __func__);
808 		ret = PTR_ERR(ifx_dev->tty_dev);
809 		goto error_ret;
810 	}
811 	return 0;
812 
813 error_ret:
814 	ifx_spi_free_port(ifx_dev);
815 	return ret;
816 }
817 
818 /**
819  *	ifx_spi_handle_srdy		-	handle SRDY
820  *	@ifx_dev: device asserting SRDY
821  *
822  *	Check our device state and see what we need to kick off when SRDY
823  *	is asserted. This usually means killing the timer and firing off the
824  *	I/O processing.
825  */
ifx_spi_handle_srdy(struct ifx_spi_device * ifx_dev)826 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev)
827 {
828 	if (test_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) {
829 		del_timer_sync(&ifx_dev->spi_timer);
830 		clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
831 	}
832 
833 	ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_SRDY);
834 
835 	if (!test_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags))
836 		tasklet_schedule(&ifx_dev->io_work_tasklet);
837 	else
838 		set_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
839 }
840 
841 /**
842  *	ifx_spi_srdy_interrupt	-	SRDY asserted
843  *	@irq: our IRQ number
844  *	@dev: our ifx device
845  *
846  *	The modem asserted SRDY. Handle the srdy event
847  */
ifx_spi_srdy_interrupt(int irq,void * dev)848 static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev)
849 {
850 	struct ifx_spi_device *ifx_dev = dev;
851 	ifx_dev->gpio.unack_srdy_int_nb++;
852 	ifx_spi_handle_srdy(ifx_dev);
853 	return IRQ_HANDLED;
854 }
855 
856 /**
857  *	ifx_spi_reset_interrupt	-	Modem has changed reset state
858  *	@irq: interrupt number
859  *	@dev: our device pointer
860  *
861  *	The modem has either entered or left reset state. Check the GPIO
862  *	line to see which.
863  *
864  *	FIXME: review locking on MR_INPROGRESS versus
865  *	parallel unsolicited reset/solicited reset
866  */
ifx_spi_reset_interrupt(int irq,void * dev)867 static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
868 {
869 	struct ifx_spi_device *ifx_dev = dev;
870 	int val = gpio_get_value(ifx_dev->gpio.reset_out);
871 	int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state);
872 
873 	if (val == 0) {
874 		/* entered reset */
875 		set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
876 		if (!solreset) {
877 			/* unsolicited reset  */
878 			ifx_spi_ttyhangup(ifx_dev);
879 		}
880 	} else {
881 		/* exited reset */
882 		clear_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
883 		if (solreset) {
884 			set_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state);
885 			wake_up(&ifx_dev->mdm_reset_wait);
886 		}
887 	}
888 	return IRQ_HANDLED;
889 }
890 
891 /**
892  *	ifx_spi_free_device - free device
893  *	@ifx_dev: device to free
894  *
895  *	Free the IFX device
896  */
ifx_spi_free_device(struct ifx_spi_device * ifx_dev)897 static void ifx_spi_free_device(struct ifx_spi_device *ifx_dev)
898 {
899 	ifx_spi_free_port(ifx_dev);
900 	dma_free_coherent(&ifx_dev->spi_dev->dev,
901 				IFX_SPI_TRANSFER_SIZE,
902 				ifx_dev->tx_buffer,
903 				ifx_dev->tx_bus);
904 	dma_free_coherent(&ifx_dev->spi_dev->dev,
905 				IFX_SPI_TRANSFER_SIZE,
906 				ifx_dev->rx_buffer,
907 				ifx_dev->rx_bus);
908 }
909 
910 /**
911  *	ifx_spi_reset	-	reset modem
912  *	@ifx_dev: modem to reset
913  *
914  *	Perform a reset on the modem
915  */
ifx_spi_reset(struct ifx_spi_device * ifx_dev)916 static int ifx_spi_reset(struct ifx_spi_device *ifx_dev)
917 {
918 	int ret;
919 	/*
920 	 * set up modem power, reset
921 	 *
922 	 * delays are required on some platforms for the modem
923 	 * to reset properly
924 	 */
925 	set_bit(MR_START, &ifx_dev->mdm_reset_state);
926 	gpio_set_value(ifx_dev->gpio.po, 0);
927 	gpio_set_value(ifx_dev->gpio.reset, 0);
928 	msleep(25);
929 	gpio_set_value(ifx_dev->gpio.reset, 1);
930 	msleep(1);
931 	gpio_set_value(ifx_dev->gpio.po, 1);
932 	msleep(1);
933 	gpio_set_value(ifx_dev->gpio.po, 0);
934 	ret = wait_event_timeout(ifx_dev->mdm_reset_wait,
935 				 test_bit(MR_COMPLETE,
936 					  &ifx_dev->mdm_reset_state),
937 				 IFX_RESET_TIMEOUT);
938 	if (!ret)
939 		dev_warn(&ifx_dev->spi_dev->dev, "Modem reset timeout: (state:%lx)",
940 			 ifx_dev->mdm_reset_state);
941 
942 	ifx_dev->mdm_reset_state = 0;
943 	return ret;
944 }
945 
946 /**
947  *	ifx_spi_spi_probe	-	probe callback
948  *	@spi: our possible matching SPI device
949  *
950  *	Probe for a 6x60 modem on SPI bus. Perform any needed device and
951  *	GPIO setup.
952  *
953  *	FIXME:
954  *	-	Support for multiple devices
955  *	-	Split out MID specific GPIO handling eventually
956  */
957 
ifx_spi_spi_probe(struct spi_device * spi)958 static int ifx_spi_spi_probe(struct spi_device *spi)
959 {
960 	int ret;
961 	int srdy;
962 	struct ifx_modem_platform_data *pl_data;
963 	struct ifx_spi_device *ifx_dev;
964 
965 	if (saved_ifx_dev) {
966 		dev_dbg(&spi->dev, "ignoring subsequent detection");
967 		return -ENODEV;
968 	}
969 
970 	pl_data = (struct ifx_modem_platform_data *)spi->dev.platform_data;
971 	if (!pl_data) {
972 		dev_err(&spi->dev, "missing platform data!");
973 		return -ENODEV;
974 	}
975 
976 	/* initialize structure to hold our device variables */
977 	ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL);
978 	if (!ifx_dev) {
979 		dev_err(&spi->dev, "spi device allocation failed");
980 		return -ENOMEM;
981 	}
982 	saved_ifx_dev = ifx_dev;
983 	ifx_dev->spi_dev = spi;
984 	clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
985 	spin_lock_init(&ifx_dev->write_lock);
986 	spin_lock_init(&ifx_dev->power_lock);
987 	ifx_dev->power_status = 0;
988 	init_timer(&ifx_dev->spi_timer);
989 	ifx_dev->spi_timer.function = ifx_spi_timeout;
990 	ifx_dev->spi_timer.data = (unsigned long)ifx_dev;
991 	ifx_dev->modem = pl_data->modem_type;
992 	ifx_dev->use_dma = pl_data->use_dma;
993 	ifx_dev->max_hz = pl_data->max_hz;
994 	/* initialize spi mode, etc */
995 	spi->max_speed_hz = ifx_dev->max_hz;
996 	spi->mode = IFX_SPI_MODE | (SPI_LOOP & spi->mode);
997 	spi->bits_per_word = spi_bpw;
998 	ret = spi_setup(spi);
999 	if (ret) {
1000 		dev_err(&spi->dev, "SPI setup wasn't successful %d", ret);
1001 		return -ENODEV;
1002 	}
1003 
1004 	/* ensure SPI protocol flags are initialized to enable transfer */
1005 	ifx_dev->spi_more = 0;
1006 	ifx_dev->spi_slave_cts = 0;
1007 
1008 	/*initialize transfer and dma buffers */
1009 	ifx_dev->tx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1010 				IFX_SPI_TRANSFER_SIZE,
1011 				&ifx_dev->tx_bus,
1012 				GFP_KERNEL);
1013 	if (!ifx_dev->tx_buffer) {
1014 		dev_err(&spi->dev, "DMA-TX buffer allocation failed");
1015 		ret = -ENOMEM;
1016 		goto error_ret;
1017 	}
1018 	ifx_dev->rx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1019 				IFX_SPI_TRANSFER_SIZE,
1020 				&ifx_dev->rx_bus,
1021 				GFP_KERNEL);
1022 	if (!ifx_dev->rx_buffer) {
1023 		dev_err(&spi->dev, "DMA-RX buffer allocation failed");
1024 		ret = -ENOMEM;
1025 		goto error_ret;
1026 	}
1027 
1028 	/* initialize waitq for modem reset */
1029 	init_waitqueue_head(&ifx_dev->mdm_reset_wait);
1030 
1031 	spi_set_drvdata(spi, ifx_dev);
1032 	tasklet_init(&ifx_dev->io_work_tasklet, ifx_spi_io,
1033 						(unsigned long)ifx_dev);
1034 
1035 	set_bit(IFX_SPI_STATE_PRESENT, &ifx_dev->flags);
1036 
1037 	/* create our tty port */
1038 	ret = ifx_spi_create_port(ifx_dev);
1039 	if (ret != 0) {
1040 		dev_err(&spi->dev, "create default tty port failed");
1041 		goto error_ret;
1042 	}
1043 
1044 	ifx_dev->gpio.reset = pl_data->rst_pmu;
1045 	ifx_dev->gpio.po = pl_data->pwr_on;
1046 	ifx_dev->gpio.mrdy = pl_data->mrdy;
1047 	ifx_dev->gpio.srdy = pl_data->srdy;
1048 	ifx_dev->gpio.reset_out = pl_data->rst_out;
1049 
1050 	dev_info(&spi->dev, "gpios %d, %d, %d, %d, %d",
1051 		 ifx_dev->gpio.reset, ifx_dev->gpio.po, ifx_dev->gpio.mrdy,
1052 		 ifx_dev->gpio.srdy, ifx_dev->gpio.reset_out);
1053 
1054 	/* Configure gpios */
1055 	ret = gpio_request(ifx_dev->gpio.reset, "ifxModem");
1056 	if (ret < 0) {
1057 		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET)",
1058 			ifx_dev->gpio.reset);
1059 		goto error_ret;
1060 	}
1061 	ret += gpio_direction_output(ifx_dev->gpio.reset, 0);
1062 	ret += gpio_export(ifx_dev->gpio.reset, 1);
1063 	if (ret) {
1064 		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET)",
1065 			ifx_dev->gpio.reset);
1066 		ret = -EBUSY;
1067 		goto error_ret2;
1068 	}
1069 
1070 	ret = gpio_request(ifx_dev->gpio.po, "ifxModem");
1071 	ret += gpio_direction_output(ifx_dev->gpio.po, 0);
1072 	ret += gpio_export(ifx_dev->gpio.po, 1);
1073 	if (ret) {
1074 		dev_err(&spi->dev, "Unable to configure GPIO%d (ON)",
1075 			ifx_dev->gpio.po);
1076 		ret = -EBUSY;
1077 		goto error_ret3;
1078 	}
1079 
1080 	ret = gpio_request(ifx_dev->gpio.mrdy, "ifxModem");
1081 	if (ret < 0) {
1082 		dev_err(&spi->dev, "Unable to allocate GPIO%d (MRDY)",
1083 			ifx_dev->gpio.mrdy);
1084 		goto error_ret3;
1085 	}
1086 	ret += gpio_export(ifx_dev->gpio.mrdy, 1);
1087 	ret += gpio_direction_output(ifx_dev->gpio.mrdy, 0);
1088 	if (ret) {
1089 		dev_err(&spi->dev, "Unable to configure GPIO%d (MRDY)",
1090 			ifx_dev->gpio.mrdy);
1091 		ret = -EBUSY;
1092 		goto error_ret4;
1093 	}
1094 
1095 	ret = gpio_request(ifx_dev->gpio.srdy, "ifxModem");
1096 	if (ret < 0) {
1097 		dev_err(&spi->dev, "Unable to allocate GPIO%d (SRDY)",
1098 			ifx_dev->gpio.srdy);
1099 		ret = -EBUSY;
1100 		goto error_ret4;
1101 	}
1102 	ret += gpio_export(ifx_dev->gpio.srdy, 1);
1103 	ret += gpio_direction_input(ifx_dev->gpio.srdy);
1104 	if (ret) {
1105 		dev_err(&spi->dev, "Unable to configure GPIO%d (SRDY)",
1106 			ifx_dev->gpio.srdy);
1107 		ret = -EBUSY;
1108 		goto error_ret5;
1109 	}
1110 
1111 	ret = gpio_request(ifx_dev->gpio.reset_out, "ifxModem");
1112 	if (ret < 0) {
1113 		dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET_OUT)",
1114 			ifx_dev->gpio.reset_out);
1115 		goto error_ret5;
1116 	}
1117 	ret += gpio_export(ifx_dev->gpio.reset_out, 1);
1118 	ret += gpio_direction_input(ifx_dev->gpio.reset_out);
1119 	if (ret) {
1120 		dev_err(&spi->dev, "Unable to configure GPIO%d (RESET_OUT)",
1121 			ifx_dev->gpio.reset_out);
1122 		ret = -EBUSY;
1123 		goto error_ret6;
1124 	}
1125 
1126 	ret = request_irq(gpio_to_irq(ifx_dev->gpio.reset_out),
1127 			  ifx_spi_reset_interrupt,
1128 			  IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME,
1129 		(void *)ifx_dev);
1130 	if (ret) {
1131 		dev_err(&spi->dev, "Unable to get irq %x\n",
1132 			gpio_to_irq(ifx_dev->gpio.reset_out));
1133 		goto error_ret6;
1134 	}
1135 
1136 	ret = ifx_spi_reset(ifx_dev);
1137 
1138 	ret = request_irq(gpio_to_irq(ifx_dev->gpio.srdy),
1139 			  ifx_spi_srdy_interrupt,
1140 			  IRQF_TRIGGER_RISING, DRVNAME,
1141 			  (void *)ifx_dev);
1142 	if (ret) {
1143 		dev_err(&spi->dev, "Unable to get irq %x",
1144 			gpio_to_irq(ifx_dev->gpio.srdy));
1145 		goto error_ret7;
1146 	}
1147 
1148 	/* set pm runtime power state and register with power system */
1149 	pm_runtime_set_active(&spi->dev);
1150 	pm_runtime_enable(&spi->dev);
1151 
1152 	/* handle case that modem is already signaling SRDY */
1153 	/* no outgoing tty open at this point, this just satisfies the
1154 	 * modem's read and should reset communication properly
1155 	 */
1156 	srdy = gpio_get_value(ifx_dev->gpio.srdy);
1157 
1158 	if (srdy) {
1159 		mrdy_assert(ifx_dev);
1160 		ifx_spi_handle_srdy(ifx_dev);
1161 	} else
1162 		mrdy_set_low(ifx_dev);
1163 	return 0;
1164 
1165 error_ret7:
1166 	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev);
1167 error_ret6:
1168 	gpio_free(ifx_dev->gpio.srdy);
1169 error_ret5:
1170 	gpio_free(ifx_dev->gpio.mrdy);
1171 error_ret4:
1172 	gpio_free(ifx_dev->gpio.reset);
1173 error_ret3:
1174 	gpio_free(ifx_dev->gpio.po);
1175 error_ret2:
1176 	gpio_free(ifx_dev->gpio.reset_out);
1177 error_ret:
1178 	ifx_spi_free_device(ifx_dev);
1179 	saved_ifx_dev = NULL;
1180 	return ret;
1181 }
1182 
1183 /**
1184  *	ifx_spi_spi_remove	-	SPI device was removed
1185  *	@spi: SPI device
1186  *
1187  *	FIXME: We should be shutting the device down here not in
1188  *	the module unload path.
1189  */
1190 
ifx_spi_spi_remove(struct spi_device * spi)1191 static int ifx_spi_spi_remove(struct spi_device *spi)
1192 {
1193 	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1194 	/* stop activity */
1195 	tasklet_kill(&ifx_dev->io_work_tasklet);
1196 	/* free irq */
1197 	free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev);
1198 	free_irq(gpio_to_irq(ifx_dev->gpio.srdy), (void *)ifx_dev);
1199 
1200 	gpio_free(ifx_dev->gpio.srdy);
1201 	gpio_free(ifx_dev->gpio.mrdy);
1202 	gpio_free(ifx_dev->gpio.reset);
1203 	gpio_free(ifx_dev->gpio.po);
1204 	gpio_free(ifx_dev->gpio.reset_out);
1205 
1206 	/* free allocations */
1207 	ifx_spi_free_device(ifx_dev);
1208 
1209 	saved_ifx_dev = NULL;
1210 	return 0;
1211 }
1212 
1213 /**
1214  *	ifx_spi_spi_shutdown	-	called on SPI shutdown
1215  *	@spi: SPI device
1216  *
1217  *	No action needs to be taken here
1218  */
1219 
ifx_spi_spi_shutdown(struct spi_device * spi)1220 static void ifx_spi_spi_shutdown(struct spi_device *spi)
1221 {
1222 }
1223 
1224 /*
1225  * various suspends and resumes have nothing to do
1226  * no hardware to save state for
1227  */
1228 
1229 /**
1230  *	ifx_spi_spi_suspend	-	suspend SPI on system suspend
1231  *	@dev: device being suspended
1232  *
1233  *	Suspend the SPI side. No action needed on Intel MID platforms, may
1234  *	need extending for other systems.
1235  */
ifx_spi_spi_suspend(struct spi_device * spi,pm_message_t msg)1236 static int ifx_spi_spi_suspend(struct spi_device *spi, pm_message_t msg)
1237 {
1238 	return 0;
1239 }
1240 
1241 /**
1242  *	ifx_spi_spi_resume	-	resume SPI side on system resume
1243  *	@dev: device being suspended
1244  *
1245  *	Suspend the SPI side. No action needed on Intel MID platforms, may
1246  *	need extending for other systems.
1247  */
ifx_spi_spi_resume(struct spi_device * spi)1248 static int ifx_spi_spi_resume(struct spi_device *spi)
1249 {
1250 	return 0;
1251 }
1252 
1253 /**
1254  *	ifx_spi_pm_suspend	-	suspend modem on system suspend
1255  *	@dev: device being suspended
1256  *
1257  *	Suspend the modem. No action needed on Intel MID platforms, may
1258  *	need extending for other systems.
1259  */
ifx_spi_pm_suspend(struct device * dev)1260 static int ifx_spi_pm_suspend(struct device *dev)
1261 {
1262 	return 0;
1263 }
1264 
1265 /**
1266  *	ifx_spi_pm_resume	-	resume modem on system resume
1267  *	@dev: device being suspended
1268  *
1269  *	Allow the modem to resume. No action needed.
1270  *
1271  *	FIXME: do we need to reset anything here ?
1272  */
ifx_spi_pm_resume(struct device * dev)1273 static int ifx_spi_pm_resume(struct device *dev)
1274 {
1275 	return 0;
1276 }
1277 
1278 /**
1279  *	ifx_spi_pm_runtime_resume	-	suspend modem
1280  *	@dev: device being suspended
1281  *
1282  *	Allow the modem to resume. No action needed.
1283  */
ifx_spi_pm_runtime_resume(struct device * dev)1284 static int ifx_spi_pm_runtime_resume(struct device *dev)
1285 {
1286 	return 0;
1287 }
1288 
1289 /**
1290  *	ifx_spi_pm_runtime_suspend	-	suspend modem
1291  *	@dev: device being suspended
1292  *
1293  *	Allow the modem to suspend and thus suspend to continue up the
1294  *	device tree.
1295  */
ifx_spi_pm_runtime_suspend(struct device * dev)1296 static int ifx_spi_pm_runtime_suspend(struct device *dev)
1297 {
1298 	return 0;
1299 }
1300 
1301 /**
1302  *	ifx_spi_pm_runtime_idle		-	check if modem idle
1303  *	@dev: our device
1304  *
1305  *	Check conditions and queue runtime suspend if idle.
1306  */
ifx_spi_pm_runtime_idle(struct device * dev)1307 static int ifx_spi_pm_runtime_idle(struct device *dev)
1308 {
1309 	struct spi_device *spi = to_spi_device(dev);
1310 	struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1311 
1312 	if (!ifx_dev->power_status)
1313 		pm_runtime_suspend(dev);
1314 
1315 	return 0;
1316 }
1317 
1318 static const struct dev_pm_ops ifx_spi_pm = {
1319 	.resume = ifx_spi_pm_resume,
1320 	.suspend = ifx_spi_pm_suspend,
1321 	.runtime_resume = ifx_spi_pm_runtime_resume,
1322 	.runtime_suspend = ifx_spi_pm_runtime_suspend,
1323 	.runtime_idle = ifx_spi_pm_runtime_idle
1324 };
1325 
1326 static const struct spi_device_id ifx_id_table[] = {
1327 	{"ifx6160", 0},
1328 	{"ifx6260", 0},
1329 	{ }
1330 };
1331 MODULE_DEVICE_TABLE(spi, ifx_id_table);
1332 
1333 /* spi operations */
1334 static const struct spi_driver ifx_spi_driver = {
1335 	.driver = {
1336 		.name = DRVNAME,
1337 		.pm = &ifx_spi_pm,
1338 		.owner = THIS_MODULE},
1339 	.probe = ifx_spi_spi_probe,
1340 	.shutdown = ifx_spi_spi_shutdown,
1341 	.remove = __devexit_p(ifx_spi_spi_remove),
1342 	.suspend = ifx_spi_spi_suspend,
1343 	.resume = ifx_spi_spi_resume,
1344 	.id_table = ifx_id_table
1345 };
1346 
1347 /**
1348  *	ifx_spi_exit	-	module exit
1349  *
1350  *	Unload the module.
1351  */
1352 
ifx_spi_exit(void)1353 static void __exit ifx_spi_exit(void)
1354 {
1355 	/* unregister */
1356 	tty_unregister_driver(tty_drv);
1357 	spi_unregister_driver((void *)&ifx_spi_driver);
1358 }
1359 
1360 /**
1361  *	ifx_spi_init		-	module entry point
1362  *
1363  *	Initialise the SPI and tty interfaces for the IFX SPI driver
1364  *	We need to initialize upper-edge spi driver after the tty
1365  *	driver because otherwise the spi probe will race
1366  */
1367 
ifx_spi_init(void)1368 static int __init ifx_spi_init(void)
1369 {
1370 	int result;
1371 
1372 	tty_drv = alloc_tty_driver(1);
1373 	if (!tty_drv) {
1374 		pr_err("%s: alloc_tty_driver failed", DRVNAME);
1375 		return -ENOMEM;
1376 	}
1377 
1378 	tty_drv->magic = TTY_DRIVER_MAGIC;
1379 	tty_drv->owner = THIS_MODULE;
1380 	tty_drv->driver_name = DRVNAME;
1381 	tty_drv->name = TTYNAME;
1382 	tty_drv->minor_start = IFX_SPI_TTY_ID;
1383 	tty_drv->num = 1;
1384 	tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1385 	tty_drv->subtype = SERIAL_TYPE_NORMAL;
1386 	tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1387 	tty_drv->init_termios = tty_std_termios;
1388 
1389 	tty_set_operations(tty_drv, &ifx_spi_serial_ops);
1390 
1391 	result = tty_register_driver(tty_drv);
1392 	if (result) {
1393 		pr_err("%s: tty_register_driver failed(%d)",
1394 			DRVNAME, result);
1395 		put_tty_driver(tty_drv);
1396 		return result;
1397 	}
1398 
1399 	result = spi_register_driver((void *)&ifx_spi_driver);
1400 	if (result) {
1401 		pr_err("%s: spi_register_driver failed(%d)",
1402 			DRVNAME, result);
1403 		tty_unregister_driver(tty_drv);
1404 	}
1405 	return result;
1406 }
1407 
1408 module_init(ifx_spi_init);
1409 module_exit(ifx_spi_exit);
1410 
1411 MODULE_AUTHOR("Intel");
1412 MODULE_DESCRIPTION("IFX6x60 spi driver");
1413 MODULE_LICENSE("GPL");
1414 MODULE_INFO(Version, "0.1-IFX6x60");
1415