1/*
  2 * SPI bus via the Blackfin SPORT peripheral
  3 *
  4 * Enter bugs at http://blackfin.uclinux.org/
  5 *
  6 * Copyright 2009-2011 Analog Devices Inc.
  7 *
  8 * Licensed under the GPL-2 or later.
  9 */
 10
 11#include <linux/init.h>
 12#include <linux/module.h>
 13#include <linux/delay.h>
 14#include <linux/device.h>
 15#include <linux/gpio.h>
 16#include <linux/io.h>
 17#include <linux/ioport.h>
 18#include <linux/irq.h>
 19#include <linux/errno.h>
 20#include <linux/interrupt.h>
 21#include <linux/platform_device.h>
 22#include <linux/spi/spi.h>
 23#include <linux/workqueue.h>
 24
 25#include <asm/portmux.h>
 26#include <asm/bfin5xx_spi.h>
 27#include <asm/blackfin.h>
 28#include <asm/bfin_sport.h>
 29#include <asm/cacheflush.h>
 30
 31#define DRV_NAME	"bfin-sport-spi"
 32#define DRV_DESC	"SPI bus via the Blackfin SPORT"
 33
 34MODULE_AUTHOR("Cliff Cai");
 35MODULE_DESCRIPTION(DRV_DESC);
 36MODULE_LICENSE("GPL");
 37MODULE_ALIAS("platform:bfin-sport-spi");
 38
 39enum bfin_sport_spi_state {
 40	START_STATE,
 41	RUNNING_STATE,
 42	DONE_STATE,
 43	ERROR_STATE,
 44};
 45
 46struct bfin_sport_spi_master_data;
 47
 48struct bfin_sport_transfer_ops {
 49	void (*write) (struct bfin_sport_spi_master_data *);
 50	void (*read) (struct bfin_sport_spi_master_data *);
 51	void (*duplex) (struct bfin_sport_spi_master_data *);
 52};
 53
 54struct bfin_sport_spi_master_data {
 55	/* Driver model hookup */
 56	struct device *dev;
 57
 58	/* SPI framework hookup */
 59	struct spi_master *master;
 60
 61	/* Regs base of SPI controller */
 62	struct sport_register __iomem *regs;
 63	int err_irq;
 64
 65	/* Pin request list */
 66	u16 *pin_req;
 67
 68	/* Driver message queue */
 69	struct workqueue_struct *workqueue;
 70	struct work_struct pump_messages;
 71	spinlock_t lock;
 72	struct list_head queue;
 73	int busy;
 74	bool run;
 75
 76	/* Message Transfer pump */
 77	struct tasklet_struct pump_transfers;
 78
 79	/* Current message transfer state info */
 80	enum bfin_sport_spi_state state;
 81	struct spi_message *cur_msg;
 82	struct spi_transfer *cur_transfer;
 83	struct bfin_sport_spi_slave_data *cur_chip;
 84	union {
 85		void *tx;
 86		u8 *tx8;
 87		u16 *tx16;
 88	};
 89	void *tx_end;
 90	union {
 91		void *rx;
 92		u8 *rx8;
 93		u16 *rx16;
 94	};
 95	void *rx_end;
 96
 97	int cs_change;
 98	struct bfin_sport_transfer_ops *ops;
 99};
100
101struct bfin_sport_spi_slave_data {
102	u16 ctl_reg;
103	u16 baud;
104	u16 cs_chg_udelay;	/* Some devices require > 255usec delay */
105	u32 cs_gpio;
106	u16 idle_tx_val;
107	struct bfin_sport_transfer_ops *ops;
108};
109
110static void
111bfin_sport_spi_enable(struct bfin_sport_spi_master_data *drv_data)
112{
113	bfin_write_or(&drv_data->regs->tcr1, TSPEN);
114	bfin_write_or(&drv_data->regs->rcr1, TSPEN);
115	SSYNC();
116}
117
118static void
119bfin_sport_spi_disable(struct bfin_sport_spi_master_data *drv_data)
120{
121	bfin_write_and(&drv_data->regs->tcr1, ~TSPEN);
122	bfin_write_and(&drv_data->regs->rcr1, ~TSPEN);
123	SSYNC();
124}
125
126/* Caculate the SPI_BAUD register value based on input HZ */
127static u16
128bfin_sport_hz_to_spi_baud(u32 speed_hz)
129{
130	u_long clk, sclk = get_sclk();
131	int div = (sclk / (2 * speed_hz)) - 1;
132
133	if (div < 0)
134		div = 0;
135
136	clk = sclk / (2 * (div + 1));
137
138	if (clk > speed_hz)
139		div++;
140
141	return div;
142}
143
144/* Chip select operation functions for cs_change flag */
145static void
146bfin_sport_spi_cs_active(struct bfin_sport_spi_slave_data *chip)
147{
148	gpio_direction_output(chip->cs_gpio, 0);
149}
150
151static void
152bfin_sport_spi_cs_deactive(struct bfin_sport_spi_slave_data *chip)
153{
154	gpio_direction_output(chip->cs_gpio, 1);
155	/* Move delay here for consistency */
156	if (chip->cs_chg_udelay)
157		udelay(chip->cs_chg_udelay);
158}
159
160static void
161bfin_sport_spi_stat_poll_complete(struct bfin_sport_spi_master_data *drv_data)
162{
163	unsigned long timeout = jiffies + HZ;
164	while (!(bfin_read(&drv_data->regs->stat) & RXNE)) {
165		if (!time_before(jiffies, timeout))
166			break;
167	}
168}
169
170static void
171bfin_sport_spi_u8_writer(struct bfin_sport_spi_master_data *drv_data)
172{
173	u16 dummy;
174
175	while (drv_data->tx < drv_data->tx_end) {
176		bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
177		bfin_sport_spi_stat_poll_complete(drv_data);
178		dummy = bfin_read(&drv_data->regs->rx16);
179	}
180}
181
182static void
183bfin_sport_spi_u8_reader(struct bfin_sport_spi_master_data *drv_data)
184{
185	u16 tx_val = drv_data->cur_chip->idle_tx_val;
186
187	while (drv_data->rx < drv_data->rx_end) {
188		bfin_write(&drv_data->regs->tx16, tx_val);
189		bfin_sport_spi_stat_poll_complete(drv_data);
190		*drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
191	}
192}
193
194static void
195bfin_sport_spi_u8_duplex(struct bfin_sport_spi_master_data *drv_data)
196{
197	while (drv_data->rx < drv_data->rx_end) {
198		bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
199		bfin_sport_spi_stat_poll_complete(drv_data);
200		*drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
201	}
202}
203
204static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u8 = {
205	.write  = bfin_sport_spi_u8_writer,
206	.read   = bfin_sport_spi_u8_reader,
207	.duplex = bfin_sport_spi_u8_duplex,
208};
209
210static void
211bfin_sport_spi_u16_writer(struct bfin_sport_spi_master_data *drv_data)
212{
213	u16 dummy;
214
215	while (drv_data->tx < drv_data->tx_end) {
216		bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
217		bfin_sport_spi_stat_poll_complete(drv_data);
218		dummy = bfin_read(&drv_data->regs->rx16);
219	}
220}
221
222static void
223bfin_sport_spi_u16_reader(struct bfin_sport_spi_master_data *drv_data)
224{
225	u16 tx_val = drv_data->cur_chip->idle_tx_val;
226
227	while (drv_data->rx < drv_data->rx_end) {
228		bfin_write(&drv_data->regs->tx16, tx_val);
229		bfin_sport_spi_stat_poll_complete(drv_data);
230		*drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
231	}
232}
233
234static void
235bfin_sport_spi_u16_duplex(struct bfin_sport_spi_master_data *drv_data)
236{
237	while (drv_data->rx < drv_data->rx_end) {
238		bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
239		bfin_sport_spi_stat_poll_complete(drv_data);
240		*drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
241	}
242}
243
244static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u16 = {
245	.write  = bfin_sport_spi_u16_writer,
246	.read   = bfin_sport_spi_u16_reader,
247	.duplex = bfin_sport_spi_u16_duplex,
248};
249
250/* stop controller and re-config current chip */
251static void
252bfin_sport_spi_restore_state(struct bfin_sport_spi_master_data *drv_data)
253{
254	struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;
255	unsigned int bits = (drv_data->ops == &bfin_sport_transfer_ops_u8 ? 7 : 15);
256
257	bfin_sport_spi_disable(drv_data);
258	dev_dbg(drv_data->dev, "restoring spi ctl state\n");
259
260	bfin_write(&drv_data->regs->tcr1, chip->ctl_reg);
261	bfin_write(&drv_data->regs->tcr2, bits);
262	bfin_write(&drv_data->regs->tclkdiv, chip->baud);
263	bfin_write(&drv_data->regs->tfsdiv, bits);
264	SSYNC();
265
266	bfin_write(&drv_data->regs->rcr1, chip->ctl_reg & ~(ITCLK | ITFS));
267	bfin_write(&drv_data->regs->rcr2, bits);
268	SSYNC();
269
270	bfin_sport_spi_cs_active(chip);
271}
272
273/* test if there is more transfer to be done */
274static enum bfin_sport_spi_state
275bfin_sport_spi_next_transfer(struct bfin_sport_spi_master_data *drv_data)
276{
277	struct spi_message *msg = drv_data->cur_msg;
278	struct spi_transfer *trans = drv_data->cur_transfer;
279
280	/* Move to next transfer */
281	if (trans->transfer_list.next != &msg->transfers) {
282		drv_data->cur_transfer =
283		    list_entry(trans->transfer_list.next,
284			       struct spi_transfer, transfer_list);
285		return RUNNING_STATE;
286	}
287
288	return DONE_STATE;
289}
290
291/*
292 * caller already set message->status;
293 * dma and pio irqs are blocked give finished message back
294 */
295static void
296bfin_sport_spi_giveback(struct bfin_sport_spi_master_data *drv_data)
297{
298	struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;
299	unsigned long flags;
300	struct spi_message *msg;
301
302	spin_lock_irqsave(&drv_data->lock, flags);
303	msg = drv_data->cur_msg;
304	drv_data->state = START_STATE;
305	drv_data->cur_msg = NULL;
306	drv_data->cur_transfer = NULL;
307	drv_data->cur_chip = NULL;
308	queue_work(drv_data->workqueue, &drv_data->pump_messages);
309	spin_unlock_irqrestore(&drv_data->lock, flags);
310
311	if (!drv_data->cs_change)
312		bfin_sport_spi_cs_deactive(chip);
313
314	if (msg->complete)
315		msg->complete(msg->context);
316}
317
318static irqreturn_t
319sport_err_handler(int irq, void *dev_id)
320{
321	struct bfin_sport_spi_master_data *drv_data = dev_id;
322	u16 status;
323
324	dev_dbg(drv_data->dev, "%s enter\n", __func__);
325	status = bfin_read(&drv_data->regs->stat) & (TOVF | TUVF | ROVF | RUVF);
326
327	if (status) {
328		bfin_write(&drv_data->regs->stat, status);
329		SSYNC();
330
331		bfin_sport_spi_disable(drv_data);
332		dev_err(drv_data->dev, "status error:%s%s%s%s\n",
333			status & TOVF ? " TOVF" : "",
334			status & TUVF ? " TUVF" : "",
335			status & ROVF ? " ROVF" : "",
336			status & RUVF ? " RUVF" : "");
337	}
338
339	return IRQ_HANDLED;
340}
341
342static void
343bfin_sport_spi_pump_transfers(unsigned long data)
344{
345	struct bfin_sport_spi_master_data *drv_data = (void *)data;
346	struct spi_message *message = NULL;
347	struct spi_transfer *transfer = NULL;
348	struct spi_transfer *previous = NULL;
349	struct bfin_sport_spi_slave_data *chip = NULL;
350	unsigned int bits_per_word;
351	u32 tranf_success = 1;
352	u32 transfer_speed;
353	u8 full_duplex = 0;
354
355	/* Get current state information */
356	message = drv_data->cur_msg;
357	transfer = drv_data->cur_transfer;
358	chip = drv_data->cur_chip;
359
360	if (transfer->speed_hz)
361		transfer_speed = bfin_sport_hz_to_spi_baud(transfer->speed_hz);
362	else
363		transfer_speed = chip->baud;
364	bfin_write(&drv_data->regs->tclkdiv, transfer_speed);
365	SSYNC();
366
367	/*
368	 * if msg is error or done, report it back using complete() callback
369	 */
370
371	 /* Handle for abort */
372	if (drv_data->state == ERROR_STATE) {
373		dev_dbg(drv_data->dev, "transfer: we've hit an error\n");
374		message->status = -EIO;
375		bfin_sport_spi_giveback(drv_data);
376		return;
377	}
378
379	/* Handle end of message */
380	if (drv_data->state == DONE_STATE) {
381		dev_dbg(drv_data->dev, "transfer: all done!\n");
382		message->status = 0;
383		bfin_sport_spi_giveback(drv_data);
384		return;
385	}
386
387	/* Delay if requested at end of transfer */
388	if (drv_data->state == RUNNING_STATE) {
389		dev_dbg(drv_data->dev, "transfer: still running ...\n");
390		previous = list_entry(transfer->transfer_list.prev,
391				      struct spi_transfer, transfer_list);
392		if (previous->delay_usecs)
393			udelay(previous->delay_usecs);
394	}
395
396	if (transfer->len == 0) {
397		/* Move to next transfer of this msg */
398		drv_data->state = bfin_sport_spi_next_transfer(drv_data);
399		/* Schedule next transfer tasklet */
400		tasklet_schedule(&drv_data->pump_transfers);
401	}
402
403	if (transfer->tx_buf != NULL) {
404		drv_data->tx = (void *)transfer->tx_buf;
405		drv_data->tx_end = drv_data->tx + transfer->len;
406		dev_dbg(drv_data->dev, "tx_buf is %p, tx_end is %p\n",
407			transfer->tx_buf, drv_data->tx_end);
408	} else
409		drv_data->tx = NULL;
410
411	if (transfer->rx_buf != NULL) {
412		full_duplex = transfer->tx_buf != NULL;
413		drv_data->rx = transfer->rx_buf;
414		drv_data->rx_end = drv_data->rx + transfer->len;
415		dev_dbg(drv_data->dev, "rx_buf is %p, rx_end is %p\n",
416			transfer->rx_buf, drv_data->rx_end);
417	} else
418		drv_data->rx = NULL;
419
420	drv_data->cs_change = transfer->cs_change;
421
422	/* Bits per word setup */
423	bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word;
424	if (bits_per_word == 8)
425		drv_data->ops = &bfin_sport_transfer_ops_u8;
426	else
427		drv_data->ops = &bfin_sport_transfer_ops_u16;
 
 
 
 
 
428
429	drv_data->state = RUNNING_STATE;
430
431	if (drv_data->cs_change)
432		bfin_sport_spi_cs_active(chip);
433
434	dev_dbg(drv_data->dev,
435		"now pumping a transfer: width is %d, len is %d\n",
436		bits_per_word, transfer->len);
437
438	/* PIO mode write then read */
439	dev_dbg(drv_data->dev, "doing IO transfer\n");
440
441	bfin_sport_spi_enable(drv_data);
442	if (full_duplex) {
443		/* full duplex mode */
444		BUG_ON((drv_data->tx_end - drv_data->tx) !=
445		       (drv_data->rx_end - drv_data->rx));
446		drv_data->ops->duplex(drv_data);
447
448		if (drv_data->tx != drv_data->tx_end)
449			tranf_success = 0;
450	} else if (drv_data->tx != NULL) {
451		/* write only half duplex */
452
453		drv_data->ops->write(drv_data);
454
455		if (drv_data->tx != drv_data->tx_end)
456			tranf_success = 0;
457	} else if (drv_data->rx != NULL) {
458		/* read only half duplex */
459
460		drv_data->ops->read(drv_data);
461		if (drv_data->rx != drv_data->rx_end)
462			tranf_success = 0;
463	}
464	bfin_sport_spi_disable(drv_data);
465
466	if (!tranf_success) {
467		dev_dbg(drv_data->dev, "IO write error!\n");
468		drv_data->state = ERROR_STATE;
469	} else {
470		/* Update total byte transfered */
471		message->actual_length += transfer->len;
472		/* Move to next transfer of this msg */
473		drv_data->state = bfin_sport_spi_next_transfer(drv_data);
474		if (drv_data->cs_change)
475			bfin_sport_spi_cs_deactive(chip);
476	}
477
478	/* Schedule next transfer tasklet */
479	tasklet_schedule(&drv_data->pump_transfers);
480}
481
482/* pop a msg from queue and kick off real transfer */
483static void
484bfin_sport_spi_pump_messages(struct work_struct *work)
485{
486	struct bfin_sport_spi_master_data *drv_data;
487	unsigned long flags;
488	struct spi_message *next_msg;
489
490	drv_data = container_of(work, struct bfin_sport_spi_master_data, pump_messages);
491
492	/* Lock queue and check for queue work */
493	spin_lock_irqsave(&drv_data->lock, flags);
494	if (list_empty(&drv_data->queue) || !drv_data->run) {
495		/* pumper kicked off but no work to do */
496		drv_data->busy = 0;
497		spin_unlock_irqrestore(&drv_data->lock, flags);
498		return;
499	}
500
501	/* Make sure we are not already running a message */
502	if (drv_data->cur_msg) {
503		spin_unlock_irqrestore(&drv_data->lock, flags);
504		return;
505	}
506
507	/* Extract head of queue */
508	next_msg = list_entry(drv_data->queue.next,
509		struct spi_message, queue);
510
511	drv_data->cur_msg = next_msg;
512
513	/* Setup the SSP using the per chip configuration */
514	drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
515
516	list_del_init(&drv_data->cur_msg->queue);
517
518	/* Initialize message state */
519	drv_data->cur_msg->state = START_STATE;
520	drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
521					    struct spi_transfer, transfer_list);
522	bfin_sport_spi_restore_state(drv_data);
523	dev_dbg(drv_data->dev, "got a message to pump, "
524		"state is set to: baud %d, cs_gpio %i, ctl 0x%x\n",
525		drv_data->cur_chip->baud, drv_data->cur_chip->cs_gpio,
526		drv_data->cur_chip->ctl_reg);
527
528	dev_dbg(drv_data->dev,
529		"the first transfer len is %d\n",
530		drv_data->cur_transfer->len);
531
532	/* Mark as busy and launch transfers */
533	tasklet_schedule(&drv_data->pump_transfers);
534
535	drv_data->busy = 1;
536	spin_unlock_irqrestore(&drv_data->lock, flags);
537}
538
539/*
540 * got a msg to transfer, queue it in drv_data->queue.
541 * And kick off message pumper
542 */
543static int
544bfin_sport_spi_transfer(struct spi_device *spi, struct spi_message *msg)
545{
546	struct bfin_sport_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
547	unsigned long flags;
548
549	spin_lock_irqsave(&drv_data->lock, flags);
550
551	if (!drv_data->run) {
552		spin_unlock_irqrestore(&drv_data->lock, flags);
553		return -ESHUTDOWN;
554	}
555
556	msg->actual_length = 0;
557	msg->status = -EINPROGRESS;
558	msg->state = START_STATE;
559
560	dev_dbg(&spi->dev, "adding an msg in transfer()\n");
561	list_add_tail(&msg->queue, &drv_data->queue);
562
563	if (drv_data->run && !drv_data->busy)
564		queue_work(drv_data->workqueue, &drv_data->pump_messages);
565
566	spin_unlock_irqrestore(&drv_data->lock, flags);
567
568	return 0;
569}
570
571/* Called every time common spi devices change state */
572static int
573bfin_sport_spi_setup(struct spi_device *spi)
574{
575	struct bfin_sport_spi_slave_data *chip, *first = NULL;
576	int ret;
577
578	/* Only alloc (or use chip_info) on first setup */
579	chip = spi_get_ctldata(spi);
580	if (chip == NULL) {
581		struct bfin5xx_spi_chip *chip_info;
582
583		chip = first = kzalloc(sizeof(*chip), GFP_KERNEL);
584		if (!chip)
585			return -ENOMEM;
586
587		/* platform chip_info isn't required */
588		chip_info = spi->controller_data;
589		if (chip_info) {
590			/*
591			 * DITFS and TDTYPE are only thing we don't set, but
592			 * they probably shouldn't be changed by people.
593			 */
594			if (chip_info->ctl_reg || chip_info->enable_dma) {
595				ret = -EINVAL;
596				dev_err(&spi->dev, "don't set ctl_reg/enable_dma fields");
597				goto error;
598			}
599			chip->cs_chg_udelay = chip_info->cs_chg_udelay;
600			chip->idle_tx_val = chip_info->idle_tx_val;
601			spi->bits_per_word = chip_info->bits_per_word;
602		}
603	}
604
605	if (spi->bits_per_word != 8 && spi->bits_per_word != 16) {
 
 
606		ret = -EINVAL;
607		goto error;
608	}
609
610	/* translate common spi framework into our register
611	 * following configure contents are same for tx and rx.
612	 */
613
614	if (spi->mode & SPI_CPHA)
615		chip->ctl_reg &= ~TCKFE;
616	else
617		chip->ctl_reg |= TCKFE;
618
619	if (spi->mode & SPI_LSB_FIRST)
620		chip->ctl_reg |= TLSBIT;
621	else
622		chip->ctl_reg &= ~TLSBIT;
623
624	/* Sport in master mode */
625	chip->ctl_reg |= ITCLK | ITFS | TFSR | LATFS | LTFS;
626
627	chip->baud = bfin_sport_hz_to_spi_baud(spi->max_speed_hz);
628
629	chip->cs_gpio = spi->chip_select;
630	ret = gpio_request(chip->cs_gpio, spi->modalias);
631	if (ret)
632		goto error;
633
634	dev_dbg(&spi->dev, "setup spi chip %s, width is %d\n",
635			spi->modalias, spi->bits_per_word);
636	dev_dbg(&spi->dev, "ctl_reg is 0x%x, GPIO is %i\n",
637			chip->ctl_reg, spi->chip_select);
638
639	spi_set_ctldata(spi, chip);
640
641	bfin_sport_spi_cs_deactive(chip);
642
643	return ret;
644
645 error:
646	kfree(first);
647	return ret;
648}
649
650/*
651 * callback for spi framework.
652 * clean driver specific data
653 */
654static void
655bfin_sport_spi_cleanup(struct spi_device *spi)
656{
657	struct bfin_sport_spi_slave_data *chip = spi_get_ctldata(spi);
658
659	if (!chip)
660		return;
661
662	gpio_free(chip->cs_gpio);
663
664	kfree(chip);
665}
666
667static int
668bfin_sport_spi_init_queue(struct bfin_sport_spi_master_data *drv_data)
669{
670	INIT_LIST_HEAD(&drv_data->queue);
671	spin_lock_init(&drv_data->lock);
672
673	drv_data->run = false;
674	drv_data->busy = 0;
675
676	/* init transfer tasklet */
677	tasklet_init(&drv_data->pump_transfers,
678		     bfin_sport_spi_pump_transfers, (unsigned long)drv_data);
679
680	/* init messages workqueue */
681	INIT_WORK(&drv_data->pump_messages, bfin_sport_spi_pump_messages);
682	drv_data->workqueue =
683	    create_singlethread_workqueue(dev_name(drv_data->master->dev.parent));
684	if (drv_data->workqueue == NULL)
685		return -EBUSY;
686
687	return 0;
688}
689
690static int
691bfin_sport_spi_start_queue(struct bfin_sport_spi_master_data *drv_data)
692{
693	unsigned long flags;
694
695	spin_lock_irqsave(&drv_data->lock, flags);
696
697	if (drv_data->run || drv_data->busy) {
698		spin_unlock_irqrestore(&drv_data->lock, flags);
699		return -EBUSY;
700	}
701
702	drv_data->run = true;
703	drv_data->cur_msg = NULL;
704	drv_data->cur_transfer = NULL;
705	drv_data->cur_chip = NULL;
706	spin_unlock_irqrestore(&drv_data->lock, flags);
707
708	queue_work(drv_data->workqueue, &drv_data->pump_messages);
709
710	return 0;
711}
712
713static inline int
714bfin_sport_spi_stop_queue(struct bfin_sport_spi_master_data *drv_data)
715{
716	unsigned long flags;
717	unsigned limit = 500;
718	int status = 0;
719
720	spin_lock_irqsave(&drv_data->lock, flags);
721
722	/*
723	 * This is a bit lame, but is optimized for the common execution path.
724	 * A wait_queue on the drv_data->busy could be used, but then the common
725	 * execution path (pump_messages) would be required to call wake_up or
726	 * friends on every SPI message. Do this instead
727	 */
728	drv_data->run = false;
729	while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
730		spin_unlock_irqrestore(&drv_data->lock, flags);
731		msleep(10);
732		spin_lock_irqsave(&drv_data->lock, flags);
733	}
734
735	if (!list_empty(&drv_data->queue) || drv_data->busy)
736		status = -EBUSY;
737
738	spin_unlock_irqrestore(&drv_data->lock, flags);
739
740	return status;
741}
742
743static inline int
744bfin_sport_spi_destroy_queue(struct bfin_sport_spi_master_data *drv_data)
745{
746	int status;
747
748	status = bfin_sport_spi_stop_queue(drv_data);
749	if (status)
750		return status;
751
752	destroy_workqueue(drv_data->workqueue);
753
754	return 0;
755}
756
757static int __devinit
758bfin_sport_spi_probe(struct platform_device *pdev)
759{
760	struct device *dev = &pdev->dev;
761	struct bfin5xx_spi_master *platform_info;
762	struct spi_master *master;
763	struct resource *res, *ires;
764	struct bfin_sport_spi_master_data *drv_data;
765	int status;
766
767	platform_info = dev->platform_data;
768
769	/* Allocate master with space for drv_data */
770	master = spi_alloc_master(dev, sizeof(*master) + 16);
771	if (!master) {
772		dev_err(dev, "cannot alloc spi_master\n");
773		return -ENOMEM;
774	}
775
776	drv_data = spi_master_get_devdata(master);
777	drv_data->master = master;
778	drv_data->dev = dev;
779	drv_data->pin_req = platform_info->pin_req;
780
781	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
782	master->bus_num = pdev->id;
783	master->num_chipselect = platform_info->num_chipselect;
784	master->cleanup = bfin_sport_spi_cleanup;
785	master->setup = bfin_sport_spi_setup;
786	master->transfer = bfin_sport_spi_transfer;
787
788	/* Find and map our resources */
789	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
790	if (res == NULL) {
791		dev_err(dev, "cannot get IORESOURCE_MEM\n");
792		status = -ENOENT;
793		goto out_error_get_res;
794	}
795
796	drv_data->regs = ioremap(res->start, resource_size(res));
797	if (drv_data->regs == NULL) {
798		dev_err(dev, "cannot map registers\n");
799		status = -ENXIO;
800		goto out_error_ioremap;
801	}
802
803	ires = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
804	if (!ires) {
805		dev_err(dev, "cannot get IORESOURCE_IRQ\n");
806		status = -ENODEV;
807		goto out_error_get_ires;
808	}
809	drv_data->err_irq = ires->start;
810
811	/* Initial and start queue */
812	status = bfin_sport_spi_init_queue(drv_data);
813	if (status) {
814		dev_err(dev, "problem initializing queue\n");
815		goto out_error_queue_alloc;
816	}
817
818	status = bfin_sport_spi_start_queue(drv_data);
819	if (status) {
820		dev_err(dev, "problem starting queue\n");
821		goto out_error_queue_alloc;
822	}
823
824	status = request_irq(drv_data->err_irq, sport_err_handler,
825		0, "sport_spi_err", drv_data);
826	if (status) {
827		dev_err(dev, "unable to request sport err irq\n");
828		goto out_error_irq;
829	}
830
831	status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
832	if (status) {
833		dev_err(dev, "requesting peripherals failed\n");
834		goto out_error_peripheral;
835	}
836
837	/* Register with the SPI framework */
838	platform_set_drvdata(pdev, drv_data);
839	status = spi_register_master(master);
840	if (status) {
841		dev_err(dev, "problem registering spi master\n");
842		goto out_error_master;
843	}
844
845	dev_info(dev, "%s, regs_base@%p\n", DRV_DESC, drv_data->regs);
846	return 0;
847
848 out_error_master:
849	peripheral_free_list(drv_data->pin_req);
850 out_error_peripheral:
851	free_irq(drv_data->err_irq, drv_data);
852 out_error_irq:
853 out_error_queue_alloc:
854	bfin_sport_spi_destroy_queue(drv_data);
855 out_error_get_ires:
856	iounmap(drv_data->regs);
857 out_error_ioremap:
858 out_error_get_res:
859	spi_master_put(master);
860
861	return status;
862}
863
864/* stop hardware and remove the driver */
865static int __devexit
866bfin_sport_spi_remove(struct platform_device *pdev)
867{
868	struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
869	int status = 0;
870
871	if (!drv_data)
872		return 0;
873
874	/* Remove the queue */
875	status = bfin_sport_spi_destroy_queue(drv_data);
876	if (status)
877		return status;
878
879	/* Disable the SSP at the peripheral and SOC level */
880	bfin_sport_spi_disable(drv_data);
881
882	/* Disconnect from the SPI framework */
883	spi_unregister_master(drv_data->master);
884
885	peripheral_free_list(drv_data->pin_req);
886
887	/* Prevent double remove */
888	platform_set_drvdata(pdev, NULL);
889
890	return 0;
891}
892
893#ifdef CONFIG_PM
894static int
895bfin_sport_spi_suspend(struct platform_device *pdev, pm_message_t state)
896{
897	struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
898	int status;
899
900	status = bfin_sport_spi_stop_queue(drv_data);
901	if (status)
902		return status;
903
904	/* stop hardware */
905	bfin_sport_spi_disable(drv_data);
906
907	return status;
908}
909
910static int
911bfin_sport_spi_resume(struct platform_device *pdev)
912{
913	struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
914	int status;
915
916	/* Enable the SPI interface */
917	bfin_sport_spi_enable(drv_data);
918
919	/* Start the queue running */
920	status = bfin_sport_spi_start_queue(drv_data);
921	if (status)
922		dev_err(drv_data->dev, "problem resuming queue\n");
923
924	return status;
925}
926#else
927# define bfin_sport_spi_suspend NULL
928# define bfin_sport_spi_resume  NULL
929#endif
930
931static struct platform_driver bfin_sport_spi_driver = {
932	.driver	= {
933		.name = DRV_NAME,
934		.owner = THIS_MODULE,
935	},
936	.probe   = bfin_sport_spi_probe,
937	.remove  = __devexit_p(bfin_sport_spi_remove),
938	.suspend = bfin_sport_spi_suspend,
939	.resume  = bfin_sport_spi_resume,
940};
941
942static int __init bfin_sport_spi_init(void)
943{
944	return platform_driver_register(&bfin_sport_spi_driver);
945}
946module_init(bfin_sport_spi_init);
947
948static void __exit bfin_sport_spi_exit(void)
949{
950	platform_driver_unregister(&bfin_sport_spi_driver);
951}
952module_exit(bfin_sport_spi_exit);