xref: /linux/drivers/spi/spi-fsl-spi.c (revision 447b0c7b939f1d9e4024edf07a471ce7b1bcf002)
1 /*
2  * Freescale SPI controller driver.
3  *
4  * Maintainer: Kumar Gala
5  *
6  * Copyright (C) 2006 Polycom, Inc.
7  * Copyright 2010 Freescale Semiconductor, Inc.
8  *
9  * CPM SPI and QE buffer descriptors mode support:
10  * Copyright (c) 2009  MontaVista Software, Inc.
11  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
12  *
13  * GRLIB support:
14  * Copyright (c) 2012 Aeroflex Gaisler AB.
15  * Author: Andreas Larsson <andreas@gaisler.com>
16  *
17  * This program is free software; you can redistribute  it and/or modify it
18  * under  the terms of  the GNU General  Public License as published by the
19  * Free Software Foundation;  either version 2 of the  License, or (at your
20  * option) any later version.
21  */
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/kernel.h>
25 #include <linux/interrupt.h>
26 #include <linux/delay.h>
27 #include <linux/irq.h>
28 #include <linux/spi/spi.h>
29 #include <linux/spi/spi_bitbang.h>
30 #include <linux/platform_device.h>
31 #include <linux/fsl_devices.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/mm.h>
34 #include <linux/mutex.h>
35 #include <linux/of.h>
36 #include <linux/of_platform.h>
37 #include <linux/of_address.h>
38 #include <linux/of_irq.h>
39 #include <linux/gpio.h>
40 #include <linux/of_gpio.h>
41 
42 #include "spi-fsl-lib.h"
43 #include "spi-fsl-cpm.h"
44 #include "spi-fsl-spi.h"
45 
46 #define TYPE_FSL	0
47 #define TYPE_GRLIB	1
48 
49 struct fsl_spi_match_data {
50 	int type;
51 };
52 
53 static struct fsl_spi_match_data of_fsl_spi_fsl_config = {
54 	.type = TYPE_FSL,
55 };
56 
57 static struct fsl_spi_match_data of_fsl_spi_grlib_config = {
58 	.type = TYPE_GRLIB,
59 };
60 
61 static struct of_device_id of_fsl_spi_match[] = {
62 	{
63 		.compatible = "fsl,spi",
64 		.data = &of_fsl_spi_fsl_config,
65 	},
66 	{
67 		.compatible = "aeroflexgaisler,spictrl",
68 		.data = &of_fsl_spi_grlib_config,
69 	},
70 	{}
71 };
72 MODULE_DEVICE_TABLE(of, of_fsl_spi_match);
73 
74 static int fsl_spi_get_type(struct device *dev)
75 {
76 	const struct of_device_id *match;
77 
78 	if (dev->of_node) {
79 		match = of_match_node(of_fsl_spi_match, dev->of_node);
80 		if (match && match->data)
81 			return ((struct fsl_spi_match_data *)match->data)->type;
82 	}
83 	return TYPE_FSL;
84 }
85 
86 static void fsl_spi_change_mode(struct spi_device *spi)
87 {
88 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
89 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
90 	struct fsl_spi_reg *reg_base = mspi->reg_base;
91 	__be32 __iomem *mode = &reg_base->mode;
92 	unsigned long flags;
93 
94 	if (cs->hw_mode == mpc8xxx_spi_read_reg(mode))
95 		return;
96 
97 	/* Turn off IRQs locally to minimize time that SPI is disabled. */
98 	local_irq_save(flags);
99 
100 	/* Turn off SPI unit prior changing mode */
101 	mpc8xxx_spi_write_reg(mode, cs->hw_mode & ~SPMODE_ENABLE);
102 
103 	/* When in CPM mode, we need to reinit tx and rx. */
104 	if (mspi->flags & SPI_CPM_MODE) {
105 		fsl_spi_cpm_reinit_txrx(mspi);
106 	}
107 	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
108 	local_irq_restore(flags);
109 }
110 
111 static void fsl_spi_chipselect(struct spi_device *spi, int value)
112 {
113 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
114 	struct fsl_spi_platform_data *pdata;
115 	bool pol = spi->mode & SPI_CS_HIGH;
116 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
117 
118 	pdata = spi->dev.parent->parent->platform_data;
119 
120 	if (value == BITBANG_CS_INACTIVE) {
121 		if (pdata->cs_control)
122 			pdata->cs_control(spi, !pol);
123 	}
124 
125 	if (value == BITBANG_CS_ACTIVE) {
126 		mpc8xxx_spi->rx_shift = cs->rx_shift;
127 		mpc8xxx_spi->tx_shift = cs->tx_shift;
128 		mpc8xxx_spi->get_rx = cs->get_rx;
129 		mpc8xxx_spi->get_tx = cs->get_tx;
130 
131 		fsl_spi_change_mode(spi);
132 
133 		if (pdata->cs_control)
134 			pdata->cs_control(spi, pol);
135 	}
136 }
137 
138 static void fsl_spi_qe_cpu_set_shifts(u32 *rx_shift, u32 *tx_shift,
139 				      int bits_per_word, int msb_first)
140 {
141 	*rx_shift = 0;
142 	*tx_shift = 0;
143 	if (msb_first) {
144 		if (bits_per_word <= 8) {
145 			*rx_shift = 16;
146 			*tx_shift = 24;
147 		} else if (bits_per_word <= 16) {
148 			*rx_shift = 16;
149 			*tx_shift = 16;
150 		}
151 	} else {
152 		if (bits_per_word <= 8)
153 			*rx_shift = 8;
154 	}
155 }
156 
157 static void fsl_spi_grlib_set_shifts(u32 *rx_shift, u32 *tx_shift,
158 				     int bits_per_word, int msb_first)
159 {
160 	*rx_shift = 0;
161 	*tx_shift = 0;
162 	if (bits_per_word <= 16) {
163 		if (msb_first) {
164 			*rx_shift = 16; /* LSB in bit 16 */
165 			*tx_shift = 32 - bits_per_word; /* MSB in bit 31 */
166 		} else {
167 			*rx_shift = 16 - bits_per_word; /* MSB in bit 15 */
168 		}
169 	}
170 }
171 
172 static int mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs,
173 				struct spi_device *spi,
174 				struct mpc8xxx_spi *mpc8xxx_spi,
175 				int bits_per_word)
176 {
177 	cs->rx_shift = 0;
178 	cs->tx_shift = 0;
179 	if (bits_per_word <= 8) {
180 		cs->get_rx = mpc8xxx_spi_rx_buf_u8;
181 		cs->get_tx = mpc8xxx_spi_tx_buf_u8;
182 	} else if (bits_per_word <= 16) {
183 		cs->get_rx = mpc8xxx_spi_rx_buf_u16;
184 		cs->get_tx = mpc8xxx_spi_tx_buf_u16;
185 	} else if (bits_per_word <= 32) {
186 		cs->get_rx = mpc8xxx_spi_rx_buf_u32;
187 		cs->get_tx = mpc8xxx_spi_tx_buf_u32;
188 	} else
189 		return -EINVAL;
190 
191 	if (mpc8xxx_spi->set_shifts)
192 		mpc8xxx_spi->set_shifts(&cs->rx_shift, &cs->tx_shift,
193 					bits_per_word,
194 					!(spi->mode & SPI_LSB_FIRST));
195 
196 	mpc8xxx_spi->rx_shift = cs->rx_shift;
197 	mpc8xxx_spi->tx_shift = cs->tx_shift;
198 	mpc8xxx_spi->get_rx = cs->get_rx;
199 	mpc8xxx_spi->get_tx = cs->get_tx;
200 
201 	return bits_per_word;
202 }
203 
204 static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
205 				struct spi_device *spi,
206 				int bits_per_word)
207 {
208 	/* QE uses Little Endian for words > 8
209 	 * so transform all words > 8 into 8 bits
210 	 * Unfortnatly that doesn't work for LSB so
211 	 * reject these for now */
212 	/* Note: 32 bits word, LSB works iff
213 	 * tfcr/rfcr is set to CPMFCR_GBL */
214 	if (spi->mode & SPI_LSB_FIRST &&
215 	    bits_per_word > 8)
216 		return -EINVAL;
217 	if (bits_per_word > 8)
218 		return 8; /* pretend its 8 bits */
219 	return bits_per_word;
220 }
221 
222 static int fsl_spi_setup_transfer(struct spi_device *spi,
223 					struct spi_transfer *t)
224 {
225 	struct mpc8xxx_spi *mpc8xxx_spi;
226 	int bits_per_word = 0;
227 	u8 pm;
228 	u32 hz = 0;
229 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
230 
231 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
232 
233 	if (t) {
234 		bits_per_word = t->bits_per_word;
235 		hz = t->speed_hz;
236 	}
237 
238 	/* spi_transfer level calls that work per-word */
239 	if (!bits_per_word)
240 		bits_per_word = spi->bits_per_word;
241 
242 	/* Make sure its a bit width we support [4..16, 32] */
243 	if ((bits_per_word < 4)
244 	    || ((bits_per_word > 16) && (bits_per_word != 32))
245 	    || (bits_per_word > mpc8xxx_spi->max_bits_per_word))
246 		return -EINVAL;
247 
248 	if (!hz)
249 		hz = spi->max_speed_hz;
250 
251 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE))
252 		bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi,
253 							   mpc8xxx_spi,
254 							   bits_per_word);
255 	else if (mpc8xxx_spi->flags & SPI_QE)
256 		bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
257 							  bits_per_word);
258 
259 	if (bits_per_word < 0)
260 		return bits_per_word;
261 
262 	if (bits_per_word == 32)
263 		bits_per_word = 0;
264 	else
265 		bits_per_word = bits_per_word - 1;
266 
267 	/* mask out bits we are going to set */
268 	cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
269 				  | SPMODE_PM(0xF));
270 
271 	cs->hw_mode |= SPMODE_LEN(bits_per_word);
272 
273 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
274 		cs->hw_mode |= SPMODE_DIV16;
275 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
276 
277 		WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
278 			  "Will use %d Hz instead.\n", dev_name(&spi->dev),
279 			  hz, mpc8xxx_spi->spibrg / 1024);
280 		if (pm > 16)
281 			pm = 16;
282 	} else {
283 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
284 	}
285 	if (pm)
286 		pm--;
287 
288 	cs->hw_mode |= SPMODE_PM(pm);
289 
290 	fsl_spi_change_mode(spi);
291 	return 0;
292 }
293 
294 static int fsl_spi_cpu_bufs(struct mpc8xxx_spi *mspi,
295 				struct spi_transfer *t, unsigned int len)
296 {
297 	u32 word;
298 	struct fsl_spi_reg *reg_base = mspi->reg_base;
299 
300 	mspi->count = len;
301 
302 	/* enable rx ints */
303 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
304 
305 	/* transmit word */
306 	word = mspi->get_tx(mspi);
307 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
308 
309 	return 0;
310 }
311 
312 static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
313 			    bool is_dma_mapped)
314 {
315 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
316 	struct fsl_spi_reg *reg_base;
317 	unsigned int len = t->len;
318 	u8 bits_per_word;
319 	int ret;
320 
321 	reg_base = mpc8xxx_spi->reg_base;
322 	bits_per_word = spi->bits_per_word;
323 	if (t->bits_per_word)
324 		bits_per_word = t->bits_per_word;
325 
326 	if (bits_per_word > 8) {
327 		/* invalid length? */
328 		if (len & 1)
329 			return -EINVAL;
330 		len /= 2;
331 	}
332 	if (bits_per_word > 16) {
333 		/* invalid length? */
334 		if (len & 1)
335 			return -EINVAL;
336 		len /= 2;
337 	}
338 
339 	mpc8xxx_spi->tx = t->tx_buf;
340 	mpc8xxx_spi->rx = t->rx_buf;
341 
342 	INIT_COMPLETION(mpc8xxx_spi->done);
343 
344 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
345 		ret = fsl_spi_cpm_bufs(mpc8xxx_spi, t, is_dma_mapped);
346 	else
347 		ret = fsl_spi_cpu_bufs(mpc8xxx_spi, t, len);
348 	if (ret)
349 		return ret;
350 
351 	wait_for_completion(&mpc8xxx_spi->done);
352 
353 	/* disable rx ints */
354 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
355 
356 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
357 		fsl_spi_cpm_bufs_complete(mpc8xxx_spi);
358 
359 	return mpc8xxx_spi->count;
360 }
361 
362 static void fsl_spi_do_one_msg(struct spi_message *m)
363 {
364 	struct spi_device *spi = m->spi;
365 	struct spi_transfer *t;
366 	unsigned int cs_change;
367 	const int nsecs = 50;
368 	int status;
369 
370 	cs_change = 1;
371 	status = 0;
372 	list_for_each_entry(t, &m->transfers, transfer_list) {
373 		if (t->bits_per_word || t->speed_hz) {
374 			/* Don't allow changes if CS is active */
375 			status = -EINVAL;
376 
377 			if (cs_change)
378 				status = fsl_spi_setup_transfer(spi, t);
379 			if (status < 0)
380 				break;
381 		}
382 
383 		if (cs_change) {
384 			fsl_spi_chipselect(spi, BITBANG_CS_ACTIVE);
385 			ndelay(nsecs);
386 		}
387 		cs_change = t->cs_change;
388 		if (t->len)
389 			status = fsl_spi_bufs(spi, t, m->is_dma_mapped);
390 		if (status) {
391 			status = -EMSGSIZE;
392 			break;
393 		}
394 		m->actual_length += t->len;
395 
396 		if (t->delay_usecs)
397 			udelay(t->delay_usecs);
398 
399 		if (cs_change) {
400 			ndelay(nsecs);
401 			fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
402 			ndelay(nsecs);
403 		}
404 	}
405 
406 	m->status = status;
407 	m->complete(m->context);
408 
409 	if (status || !cs_change) {
410 		ndelay(nsecs);
411 		fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
412 	}
413 
414 	fsl_spi_setup_transfer(spi, NULL);
415 }
416 
417 static int fsl_spi_setup(struct spi_device *spi)
418 {
419 	struct mpc8xxx_spi *mpc8xxx_spi;
420 	struct fsl_spi_reg *reg_base;
421 	int retval;
422 	u32 hw_mode;
423 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
424 
425 	if (!spi->max_speed_hz)
426 		return -EINVAL;
427 
428 	if (!cs) {
429 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
430 		if (!cs)
431 			return -ENOMEM;
432 		spi->controller_state = cs;
433 	}
434 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
435 
436 	reg_base = mpc8xxx_spi->reg_base;
437 
438 	hw_mode = cs->hw_mode; /* Save original settings */
439 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
440 	/* mask out bits we are going to set */
441 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
442 			 | SPMODE_REV | SPMODE_LOOP);
443 
444 	if (spi->mode & SPI_CPHA)
445 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
446 	if (spi->mode & SPI_CPOL)
447 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
448 	if (!(spi->mode & SPI_LSB_FIRST))
449 		cs->hw_mode |= SPMODE_REV;
450 	if (spi->mode & SPI_LOOP)
451 		cs->hw_mode |= SPMODE_LOOP;
452 
453 	retval = fsl_spi_setup_transfer(spi, NULL);
454 	if (retval < 0) {
455 		cs->hw_mode = hw_mode; /* Restore settings */
456 		return retval;
457 	}
458 
459 	/* Initialize chipselect - might be active for SPI_CS_HIGH mode */
460 	fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
461 
462 	return 0;
463 }
464 
465 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
466 {
467 	struct fsl_spi_reg *reg_base = mspi->reg_base;
468 
469 	/* We need handle RX first */
470 	if (events & SPIE_NE) {
471 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
472 
473 		if (mspi->rx)
474 			mspi->get_rx(rx_data, mspi);
475 	}
476 
477 	if ((events & SPIE_NF) == 0)
478 		/* spin until TX is done */
479 		while (((events =
480 			mpc8xxx_spi_read_reg(&reg_base->event)) &
481 						SPIE_NF) == 0)
482 			cpu_relax();
483 
484 	/* Clear the events */
485 	mpc8xxx_spi_write_reg(&reg_base->event, events);
486 
487 	mspi->count -= 1;
488 	if (mspi->count) {
489 		u32 word = mspi->get_tx(mspi);
490 
491 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
492 	} else {
493 		complete(&mspi->done);
494 	}
495 }
496 
497 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
498 {
499 	struct mpc8xxx_spi *mspi = context_data;
500 	irqreturn_t ret = IRQ_NONE;
501 	u32 events;
502 	struct fsl_spi_reg *reg_base = mspi->reg_base;
503 
504 	/* Get interrupt events(tx/rx) */
505 	events = mpc8xxx_spi_read_reg(&reg_base->event);
506 	if (events)
507 		ret = IRQ_HANDLED;
508 
509 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
510 
511 	if (mspi->flags & SPI_CPM_MODE)
512 		fsl_spi_cpm_irq(mspi, events);
513 	else
514 		fsl_spi_cpu_irq(mspi, events);
515 
516 	return ret;
517 }
518 
519 static void fsl_spi_remove(struct mpc8xxx_spi *mspi)
520 {
521 	iounmap(mspi->reg_base);
522 	fsl_spi_cpm_free(mspi);
523 }
524 
525 static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
526 {
527 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
528 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
529 	u32 slvsel;
530 	u16 cs = spi->chip_select;
531 
532 	slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
533 	slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
534 	mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
535 }
536 
537 static void fsl_spi_grlib_probe(struct device *dev)
538 {
539 	struct fsl_spi_platform_data *pdata = dev->platform_data;
540 	struct spi_master *master = dev_get_drvdata(dev);
541 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
542 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
543 	int mbits;
544 	u32 capabilities;
545 
546 	capabilities = mpc8xxx_spi_read_reg(&reg_base->cap);
547 
548 	mpc8xxx_spi->set_shifts = fsl_spi_grlib_set_shifts;
549 	mbits = SPCAP_MAXWLEN(capabilities);
550 	if (mbits)
551 		mpc8xxx_spi->max_bits_per_word = mbits + 1;
552 
553 	master->num_chipselect = 1; /* Allow for an always selected chip */
554 	if (SPCAP_SSEN(capabilities)) {
555 		master->num_chipselect = SPCAP_SSSZ(capabilities);
556 		mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
557 	}
558 	pdata->cs_control = fsl_spi_grlib_cs_control;
559 }
560 
561 static struct spi_master * fsl_spi_probe(struct device *dev,
562 		struct resource *mem, unsigned int irq)
563 {
564 	struct fsl_spi_platform_data *pdata = dev->platform_data;
565 	struct spi_master *master;
566 	struct mpc8xxx_spi *mpc8xxx_spi;
567 	struct fsl_spi_reg *reg_base;
568 	u32 regval;
569 	int ret = 0;
570 
571 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
572 	if (master == NULL) {
573 		ret = -ENOMEM;
574 		goto err;
575 	}
576 
577 	dev_set_drvdata(dev, master);
578 
579 	ret = mpc8xxx_spi_probe(dev, mem, irq);
580 	if (ret)
581 		goto err_probe;
582 
583 	master->setup = fsl_spi_setup;
584 
585 	mpc8xxx_spi = spi_master_get_devdata(master);
586 	mpc8xxx_spi->spi_do_one_msg = fsl_spi_do_one_msg;
587 	mpc8xxx_spi->spi_remove = fsl_spi_remove;
588 	mpc8xxx_spi->max_bits_per_word = 32;
589 	mpc8xxx_spi->type = fsl_spi_get_type(dev);
590 
591 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
592 	if (ret)
593 		goto err_cpm_init;
594 
595 	mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
596 	if (mpc8xxx_spi->reg_base == NULL) {
597 		ret = -ENOMEM;
598 		goto err_ioremap;
599 	}
600 
601 	if (mpc8xxx_spi->type == TYPE_GRLIB)
602 		fsl_spi_grlib_probe(dev);
603 
604 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
605 		mpc8xxx_spi->set_shifts = fsl_spi_qe_cpu_set_shifts;
606 
607 	if (mpc8xxx_spi->set_shifts)
608 		/* 8 bits per word and MSB first */
609 		mpc8xxx_spi->set_shifts(&mpc8xxx_spi->rx_shift,
610 					&mpc8xxx_spi->tx_shift, 8, 1);
611 
612 	/* Register for SPI Interrupt */
613 	ret = request_irq(mpc8xxx_spi->irq, fsl_spi_irq,
614 			  0, "fsl_spi", mpc8xxx_spi);
615 
616 	if (ret != 0)
617 		goto free_irq;
618 
619 	reg_base = mpc8xxx_spi->reg_base;
620 
621 	/* SPI controller initializations */
622 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
623 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
624 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
625 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
626 
627 	/* Enable SPI interface */
628 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
629 	if (mpc8xxx_spi->max_bits_per_word < 8) {
630 		regval &= ~SPMODE_LEN(0xF);
631 		regval |= SPMODE_LEN(mpc8xxx_spi->max_bits_per_word - 1);
632 	}
633 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
634 		regval |= SPMODE_OP;
635 
636 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
637 
638 	ret = spi_register_master(master);
639 	if (ret < 0)
640 		goto unreg_master;
641 
642 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
643 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
644 
645 	return master;
646 
647 unreg_master:
648 	free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
649 free_irq:
650 	iounmap(mpc8xxx_spi->reg_base);
651 err_ioremap:
652 	fsl_spi_cpm_free(mpc8xxx_spi);
653 err_cpm_init:
654 err_probe:
655 	spi_master_put(master);
656 err:
657 	return ERR_PTR(ret);
658 }
659 
660 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
661 {
662 	struct device *dev = spi->dev.parent->parent;
663 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(dev->platform_data);
664 	u16 cs = spi->chip_select;
665 	int gpio = pinfo->gpios[cs];
666 	bool alow = pinfo->alow_flags[cs];
667 
668 	gpio_set_value(gpio, on ^ alow);
669 }
670 
671 static int of_fsl_spi_get_chipselects(struct device *dev)
672 {
673 	struct device_node *np = dev->of_node;
674 	struct fsl_spi_platform_data *pdata = dev->platform_data;
675 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
676 	int ngpios;
677 	int i = 0;
678 	int ret;
679 
680 	ngpios = of_gpio_count(np);
681 	if (ngpios <= 0) {
682 		/*
683 		 * SPI w/o chip-select line. One SPI device is still permitted
684 		 * though.
685 		 */
686 		pdata->max_chipselect = 1;
687 		return 0;
688 	}
689 
690 	pinfo->gpios = kmalloc(ngpios * sizeof(*pinfo->gpios), GFP_KERNEL);
691 	if (!pinfo->gpios)
692 		return -ENOMEM;
693 	memset(pinfo->gpios, -1, ngpios * sizeof(*pinfo->gpios));
694 
695 	pinfo->alow_flags = kzalloc(ngpios * sizeof(*pinfo->alow_flags),
696 				    GFP_KERNEL);
697 	if (!pinfo->alow_flags) {
698 		ret = -ENOMEM;
699 		goto err_alloc_flags;
700 	}
701 
702 	for (; i < ngpios; i++) {
703 		int gpio;
704 		enum of_gpio_flags flags;
705 
706 		gpio = of_get_gpio_flags(np, i, &flags);
707 		if (!gpio_is_valid(gpio)) {
708 			dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
709 			ret = gpio;
710 			goto err_loop;
711 		}
712 
713 		ret = gpio_request(gpio, dev_name(dev));
714 		if (ret) {
715 			dev_err(dev, "can't request gpio #%d: %d\n", i, ret);
716 			goto err_loop;
717 		}
718 
719 		pinfo->gpios[i] = gpio;
720 		pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW;
721 
722 		ret = gpio_direction_output(pinfo->gpios[i],
723 					    pinfo->alow_flags[i]);
724 		if (ret) {
725 			dev_err(dev, "can't set output direction for gpio "
726 				"#%d: %d\n", i, ret);
727 			goto err_loop;
728 		}
729 	}
730 
731 	pdata->max_chipselect = ngpios;
732 	pdata->cs_control = fsl_spi_cs_control;
733 
734 	return 0;
735 
736 err_loop:
737 	while (i >= 0) {
738 		if (gpio_is_valid(pinfo->gpios[i]))
739 			gpio_free(pinfo->gpios[i]);
740 		i--;
741 	}
742 
743 	kfree(pinfo->alow_flags);
744 	pinfo->alow_flags = NULL;
745 err_alloc_flags:
746 	kfree(pinfo->gpios);
747 	pinfo->gpios = NULL;
748 	return ret;
749 }
750 
751 static int of_fsl_spi_free_chipselects(struct device *dev)
752 {
753 	struct fsl_spi_platform_data *pdata = dev->platform_data;
754 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
755 	int i;
756 
757 	if (!pinfo->gpios)
758 		return 0;
759 
760 	for (i = 0; i < pdata->max_chipselect; i++) {
761 		if (gpio_is_valid(pinfo->gpios[i]))
762 			gpio_free(pinfo->gpios[i]);
763 	}
764 
765 	kfree(pinfo->gpios);
766 	kfree(pinfo->alow_flags);
767 	return 0;
768 }
769 
770 static int of_fsl_spi_probe(struct platform_device *ofdev)
771 {
772 	struct device *dev = &ofdev->dev;
773 	struct device_node *np = ofdev->dev.of_node;
774 	struct spi_master *master;
775 	struct resource mem;
776 	int irq, type;
777 	int ret = -ENOMEM;
778 
779 	ret = of_mpc8xxx_spi_probe(ofdev);
780 	if (ret)
781 		return ret;
782 
783 	type = fsl_spi_get_type(&ofdev->dev);
784 	if (type == TYPE_FSL) {
785 		ret = of_fsl_spi_get_chipselects(dev);
786 		if (ret)
787 			goto err;
788 	}
789 
790 	ret = of_address_to_resource(np, 0, &mem);
791 	if (ret)
792 		goto err;
793 
794 	irq = irq_of_parse_and_map(np, 0);
795 	if (!irq) {
796 		ret = -EINVAL;
797 		goto err;
798 	}
799 
800 	master = fsl_spi_probe(dev, &mem, irq);
801 	if (IS_ERR(master)) {
802 		ret = PTR_ERR(master);
803 		goto err;
804 	}
805 
806 	return 0;
807 
808 err:
809 	if (type == TYPE_FSL)
810 		of_fsl_spi_free_chipselects(dev);
811 	return ret;
812 }
813 
814 static int of_fsl_spi_remove(struct platform_device *ofdev)
815 {
816 	struct spi_master *master = dev_get_drvdata(&ofdev->dev);
817 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
818 	int ret;
819 
820 	ret = mpc8xxx_spi_remove(&ofdev->dev);
821 	if (ret)
822 		return ret;
823 	if (mpc8xxx_spi->type == TYPE_FSL)
824 		of_fsl_spi_free_chipselects(&ofdev->dev);
825 	return 0;
826 }
827 
828 static struct platform_driver of_fsl_spi_driver = {
829 	.driver = {
830 		.name = "fsl_spi",
831 		.owner = THIS_MODULE,
832 		.of_match_table = of_fsl_spi_match,
833 	},
834 	.probe		= of_fsl_spi_probe,
835 	.remove		= of_fsl_spi_remove,
836 };
837 
838 #ifdef CONFIG_MPC832x_RDB
839 /*
840  * XXX XXX XXX
841  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
842  * only. The driver should go away soon, since newer MPC8323E-RDB's device
843  * tree can work with OpenFirmware driver. But for now we support old trees
844  * as well.
845  */
846 static int plat_mpc8xxx_spi_probe(struct platform_device *pdev)
847 {
848 	struct resource *mem;
849 	int irq;
850 	struct spi_master *master;
851 
852 	if (!pdev->dev.platform_data)
853 		return -EINVAL;
854 
855 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
856 	if (!mem)
857 		return -EINVAL;
858 
859 	irq = platform_get_irq(pdev, 0);
860 	if (irq <= 0)
861 		return -EINVAL;
862 
863 	master = fsl_spi_probe(&pdev->dev, mem, irq);
864 	return PTR_RET(master);
865 }
866 
867 static int plat_mpc8xxx_spi_remove(struct platform_device *pdev)
868 {
869 	return mpc8xxx_spi_remove(&pdev->dev);
870 }
871 
872 MODULE_ALIAS("platform:mpc8xxx_spi");
873 static struct platform_driver mpc8xxx_spi_driver = {
874 	.probe = plat_mpc8xxx_spi_probe,
875 	.remove = plat_mpc8xxx_spi_remove,
876 	.driver = {
877 		.name = "mpc8xxx_spi",
878 		.owner = THIS_MODULE,
879 	},
880 };
881 
882 static bool legacy_driver_failed;
883 
884 static void __init legacy_driver_register(void)
885 {
886 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
887 }
888 
889 static void __exit legacy_driver_unregister(void)
890 {
891 	if (legacy_driver_failed)
892 		return;
893 	platform_driver_unregister(&mpc8xxx_spi_driver);
894 }
895 #else
896 static void __init legacy_driver_register(void) {}
897 static void __exit legacy_driver_unregister(void) {}
898 #endif /* CONFIG_MPC832x_RDB */
899 
900 static int __init fsl_spi_init(void)
901 {
902 	legacy_driver_register();
903 	return platform_driver_register(&of_fsl_spi_driver);
904 }
905 module_init(fsl_spi_init);
906 
907 static void __exit fsl_spi_exit(void)
908 {
909 	platform_driver_unregister(&of_fsl_spi_driver);
910 	legacy_driver_unregister();
911 }
912 module_exit(fsl_spi_exit);
913 
914 MODULE_AUTHOR("Kumar Gala");
915 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
916 MODULE_LICENSE("GPL");
917