xref: /openbmc/linux/drivers/spi/spi-fsl-spi.c (revision 6d99a79c)
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/delay.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/fsl_devices.h>
25 #include <linux/gpio.h>
26 #include <linux/interrupt.h>
27 #include <linux/irq.h>
28 #include <linux/kernel.h>
29 #include <linux/mm.h>
30 #include <linux/module.h>
31 #include <linux/mutex.h>
32 #include <linux/of.h>
33 #include <linux/of_address.h>
34 #include <linux/of_irq.h>
35 #include <linux/of_gpio.h>
36 #include <linux/of_platform.h>
37 #include <linux/platform_device.h>
38 #include <linux/spi/spi.h>
39 #include <linux/spi/spi_bitbang.h>
40 #include <linux/types.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 const 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 	if (!hz)
243 		hz = spi->max_speed_hz;
244 
245 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE))
246 		bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi,
247 							   mpc8xxx_spi,
248 							   bits_per_word);
249 	else if (mpc8xxx_spi->flags & SPI_QE)
250 		bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
251 							  bits_per_word);
252 
253 	if (bits_per_word < 0)
254 		return bits_per_word;
255 
256 	if (bits_per_word == 32)
257 		bits_per_word = 0;
258 	else
259 		bits_per_word = bits_per_word - 1;
260 
261 	/* mask out bits we are going to set */
262 	cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
263 				  | SPMODE_PM(0xF));
264 
265 	cs->hw_mode |= SPMODE_LEN(bits_per_word);
266 
267 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
268 		cs->hw_mode |= SPMODE_DIV16;
269 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
270 		WARN_ONCE(pm > 16,
271 			  "%s: Requested speed is too low: %d Hz. Will use %d Hz instead.\n",
272 			  dev_name(&spi->dev), hz, mpc8xxx_spi->spibrg / 1024);
273 		if (pm > 16)
274 			pm = 16;
275 	} else {
276 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
277 	}
278 	if (pm)
279 		pm--;
280 
281 	cs->hw_mode |= SPMODE_PM(pm);
282 
283 	fsl_spi_change_mode(spi);
284 	return 0;
285 }
286 
287 static int fsl_spi_cpu_bufs(struct mpc8xxx_spi *mspi,
288 				struct spi_transfer *t, unsigned int len)
289 {
290 	u32 word;
291 	struct fsl_spi_reg *reg_base = mspi->reg_base;
292 
293 	mspi->count = len;
294 
295 	/* enable rx ints */
296 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
297 
298 	/* transmit word */
299 	word = mspi->get_tx(mspi);
300 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
301 
302 	return 0;
303 }
304 
305 static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
306 			    bool is_dma_mapped)
307 {
308 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
309 	struct fsl_spi_reg *reg_base;
310 	unsigned int len = t->len;
311 	u8 bits_per_word;
312 	int ret;
313 
314 	reg_base = mpc8xxx_spi->reg_base;
315 	bits_per_word = spi->bits_per_word;
316 	if (t->bits_per_word)
317 		bits_per_word = t->bits_per_word;
318 
319 	if (bits_per_word > 8) {
320 		/* invalid length? */
321 		if (len & 1)
322 			return -EINVAL;
323 		len /= 2;
324 	}
325 	if (bits_per_word > 16) {
326 		/* invalid length? */
327 		if (len & 1)
328 			return -EINVAL;
329 		len /= 2;
330 	}
331 
332 	mpc8xxx_spi->tx = t->tx_buf;
333 	mpc8xxx_spi->rx = t->rx_buf;
334 
335 	reinit_completion(&mpc8xxx_spi->done);
336 
337 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
338 		ret = fsl_spi_cpm_bufs(mpc8xxx_spi, t, is_dma_mapped);
339 	else
340 		ret = fsl_spi_cpu_bufs(mpc8xxx_spi, t, len);
341 	if (ret)
342 		return ret;
343 
344 	wait_for_completion(&mpc8xxx_spi->done);
345 
346 	/* disable rx ints */
347 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
348 
349 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
350 		fsl_spi_cpm_bufs_complete(mpc8xxx_spi);
351 
352 	return mpc8xxx_spi->count;
353 }
354 
355 static int fsl_spi_do_one_msg(struct spi_master *master,
356 			      struct spi_message *m)
357 {
358 	struct spi_device *spi = m->spi;
359 	struct spi_transfer *t, *first;
360 	unsigned int cs_change;
361 	const int nsecs = 50;
362 	int status;
363 
364 	/* Don't allow changes if CS is active */
365 	first = list_first_entry(&m->transfers, struct spi_transfer,
366 			transfer_list);
367 	list_for_each_entry(t, &m->transfers, transfer_list) {
368 		if ((first->bits_per_word != t->bits_per_word) ||
369 			(first->speed_hz != t->speed_hz)) {
370 			dev_err(&spi->dev,
371 				"bits_per_word/speed_hz should be same for the same SPI transfer\n");
372 			return -EINVAL;
373 		}
374 	}
375 
376 	cs_change = 1;
377 	status = -EINVAL;
378 	list_for_each_entry(t, &m->transfers, transfer_list) {
379 		if (t->bits_per_word || t->speed_hz) {
380 			if (cs_change)
381 				status = fsl_spi_setup_transfer(spi, t);
382 			if (status < 0)
383 				break;
384 		}
385 
386 		if (cs_change) {
387 			fsl_spi_chipselect(spi, BITBANG_CS_ACTIVE);
388 			ndelay(nsecs);
389 		}
390 		cs_change = t->cs_change;
391 		if (t->len)
392 			status = fsl_spi_bufs(spi, t, m->is_dma_mapped);
393 		if (status) {
394 			status = -EMSGSIZE;
395 			break;
396 		}
397 		m->actual_length += t->len;
398 
399 		if (t->delay_usecs)
400 			udelay(t->delay_usecs);
401 
402 		if (cs_change) {
403 			ndelay(nsecs);
404 			fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
405 			ndelay(nsecs);
406 		}
407 	}
408 
409 	m->status = status;
410 	spi_finalize_current_message(master);
411 
412 	if (status || !cs_change) {
413 		ndelay(nsecs);
414 		fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
415 	}
416 
417 	fsl_spi_setup_transfer(spi, NULL);
418 	return 0;
419 }
420 
421 static int fsl_spi_setup(struct spi_device *spi)
422 {
423 	struct mpc8xxx_spi *mpc8xxx_spi;
424 	struct fsl_spi_reg *reg_base;
425 	int retval;
426 	u32 hw_mode;
427 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
428 
429 	if (!spi->max_speed_hz)
430 		return -EINVAL;
431 
432 	if (!cs) {
433 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
434 		if (!cs)
435 			return -ENOMEM;
436 		spi_set_ctldata(spi, cs);
437 	}
438 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
439 
440 	reg_base = mpc8xxx_spi->reg_base;
441 
442 	hw_mode = cs->hw_mode; /* Save original settings */
443 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
444 	/* mask out bits we are going to set */
445 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
446 			 | SPMODE_REV | SPMODE_LOOP);
447 
448 	if (spi->mode & SPI_CPHA)
449 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
450 	if (spi->mode & SPI_CPOL)
451 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
452 	if (!(spi->mode & SPI_LSB_FIRST))
453 		cs->hw_mode |= SPMODE_REV;
454 	if (spi->mode & SPI_LOOP)
455 		cs->hw_mode |= SPMODE_LOOP;
456 
457 	retval = fsl_spi_setup_transfer(spi, NULL);
458 	if (retval < 0) {
459 		cs->hw_mode = hw_mode; /* Restore settings */
460 		return retval;
461 	}
462 
463 	if (mpc8xxx_spi->type == TYPE_GRLIB) {
464 		if (gpio_is_valid(spi->cs_gpio)) {
465 			int desel;
466 
467 			retval = gpio_request(spi->cs_gpio,
468 					      dev_name(&spi->dev));
469 			if (retval)
470 				return retval;
471 
472 			desel = !(spi->mode & SPI_CS_HIGH);
473 			retval = gpio_direction_output(spi->cs_gpio, desel);
474 			if (retval) {
475 				gpio_free(spi->cs_gpio);
476 				return retval;
477 			}
478 		} else if (spi->cs_gpio != -ENOENT) {
479 			if (spi->cs_gpio < 0)
480 				return spi->cs_gpio;
481 			return -EINVAL;
482 		}
483 		/* When spi->cs_gpio == -ENOENT, a hole in the phandle list
484 		 * indicates to use native chipselect if present, or allow for
485 		 * an always selected chip
486 		 */
487 	}
488 
489 	/* Initialize chipselect - might be active for SPI_CS_HIGH mode */
490 	fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
491 
492 	return 0;
493 }
494 
495 static void fsl_spi_cleanup(struct spi_device *spi)
496 {
497 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
498 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
499 
500 	if (mpc8xxx_spi->type == TYPE_GRLIB && gpio_is_valid(spi->cs_gpio))
501 		gpio_free(spi->cs_gpio);
502 
503 	kfree(cs);
504 	spi_set_ctldata(spi, NULL);
505 }
506 
507 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
508 {
509 	struct fsl_spi_reg *reg_base = mspi->reg_base;
510 
511 	/* We need handle RX first */
512 	if (events & SPIE_NE) {
513 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
514 
515 		if (mspi->rx)
516 			mspi->get_rx(rx_data, mspi);
517 	}
518 
519 	if ((events & SPIE_NF) == 0)
520 		/* spin until TX is done */
521 		while (((events =
522 			mpc8xxx_spi_read_reg(&reg_base->event)) &
523 						SPIE_NF) == 0)
524 			cpu_relax();
525 
526 	/* Clear the events */
527 	mpc8xxx_spi_write_reg(&reg_base->event, events);
528 
529 	mspi->count -= 1;
530 	if (mspi->count) {
531 		u32 word = mspi->get_tx(mspi);
532 
533 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
534 	} else {
535 		complete(&mspi->done);
536 	}
537 }
538 
539 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
540 {
541 	struct mpc8xxx_spi *mspi = context_data;
542 	irqreturn_t ret = IRQ_NONE;
543 	u32 events;
544 	struct fsl_spi_reg *reg_base = mspi->reg_base;
545 
546 	/* Get interrupt events(tx/rx) */
547 	events = mpc8xxx_spi_read_reg(&reg_base->event);
548 	if (events)
549 		ret = IRQ_HANDLED;
550 
551 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
552 
553 	if (mspi->flags & SPI_CPM_MODE)
554 		fsl_spi_cpm_irq(mspi, events);
555 	else
556 		fsl_spi_cpu_irq(mspi, events);
557 
558 	return ret;
559 }
560 
561 static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
562 {
563 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
564 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
565 	u32 slvsel;
566 	u16 cs = spi->chip_select;
567 
568 	if (gpio_is_valid(spi->cs_gpio)) {
569 		gpio_set_value(spi->cs_gpio, on);
570 	} else if (cs < mpc8xxx_spi->native_chipselects) {
571 		slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
572 		slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
573 		mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
574 	}
575 }
576 
577 static void fsl_spi_grlib_probe(struct device *dev)
578 {
579 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
580 	struct spi_master *master = dev_get_drvdata(dev);
581 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
582 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
583 	int mbits;
584 	u32 capabilities;
585 
586 	capabilities = mpc8xxx_spi_read_reg(&reg_base->cap);
587 
588 	mpc8xxx_spi->set_shifts = fsl_spi_grlib_set_shifts;
589 	mbits = SPCAP_MAXWLEN(capabilities);
590 	if (mbits)
591 		mpc8xxx_spi->max_bits_per_word = mbits + 1;
592 
593 	mpc8xxx_spi->native_chipselects = 0;
594 	if (SPCAP_SSEN(capabilities)) {
595 		mpc8xxx_spi->native_chipselects = SPCAP_SSSZ(capabilities);
596 		mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
597 	}
598 	master->num_chipselect = mpc8xxx_spi->native_chipselects;
599 	pdata->cs_control = fsl_spi_grlib_cs_control;
600 }
601 
602 static struct spi_master * fsl_spi_probe(struct device *dev,
603 		struct resource *mem, unsigned int irq)
604 {
605 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
606 	struct spi_master *master;
607 	struct mpc8xxx_spi *mpc8xxx_spi;
608 	struct fsl_spi_reg *reg_base;
609 	u32 regval;
610 	int ret = 0;
611 
612 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
613 	if (master == NULL) {
614 		ret = -ENOMEM;
615 		goto err;
616 	}
617 
618 	dev_set_drvdata(dev, master);
619 
620 	mpc8xxx_spi_probe(dev, mem, irq);
621 
622 	master->setup = fsl_spi_setup;
623 	master->cleanup = fsl_spi_cleanup;
624 	master->transfer_one_message = fsl_spi_do_one_msg;
625 
626 	mpc8xxx_spi = spi_master_get_devdata(master);
627 	mpc8xxx_spi->max_bits_per_word = 32;
628 	mpc8xxx_spi->type = fsl_spi_get_type(dev);
629 
630 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
631 	if (ret)
632 		goto err_cpm_init;
633 
634 	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
635 	if (IS_ERR(mpc8xxx_spi->reg_base)) {
636 		ret = PTR_ERR(mpc8xxx_spi->reg_base);
637 		goto err_probe;
638 	}
639 
640 	if (mpc8xxx_spi->type == TYPE_GRLIB)
641 		fsl_spi_grlib_probe(dev);
642 
643 	master->bits_per_word_mask =
644 		(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32)) &
645 		SPI_BPW_RANGE_MASK(1, mpc8xxx_spi->max_bits_per_word);
646 
647 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
648 		mpc8xxx_spi->set_shifts = fsl_spi_qe_cpu_set_shifts;
649 
650 	if (mpc8xxx_spi->set_shifts)
651 		/* 8 bits per word and MSB first */
652 		mpc8xxx_spi->set_shifts(&mpc8xxx_spi->rx_shift,
653 					&mpc8xxx_spi->tx_shift, 8, 1);
654 
655 	/* Register for SPI Interrupt */
656 	ret = devm_request_irq(dev, mpc8xxx_spi->irq, fsl_spi_irq,
657 			       0, "fsl_spi", mpc8xxx_spi);
658 
659 	if (ret != 0)
660 		goto err_probe;
661 
662 	reg_base = mpc8xxx_spi->reg_base;
663 
664 	/* SPI controller initializations */
665 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
666 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
667 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
668 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
669 
670 	/* Enable SPI interface */
671 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
672 	if (mpc8xxx_spi->max_bits_per_word < 8) {
673 		regval &= ~SPMODE_LEN(0xF);
674 		regval |= SPMODE_LEN(mpc8xxx_spi->max_bits_per_word - 1);
675 	}
676 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
677 		regval |= SPMODE_OP;
678 
679 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
680 
681 	ret = devm_spi_register_master(dev, master);
682 	if (ret < 0)
683 		goto err_probe;
684 
685 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
686 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
687 
688 	return master;
689 
690 err_probe:
691 	fsl_spi_cpm_free(mpc8xxx_spi);
692 err_cpm_init:
693 	spi_master_put(master);
694 err:
695 	return ERR_PTR(ret);
696 }
697 
698 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
699 {
700 	struct device *dev = spi->dev.parent->parent;
701 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
702 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
703 	u16 cs = spi->chip_select;
704 	int gpio = pinfo->gpios[cs];
705 	bool alow = pinfo->alow_flags[cs];
706 
707 	gpio_set_value(gpio, on ^ alow);
708 }
709 
710 static int of_fsl_spi_get_chipselects(struct device *dev)
711 {
712 	struct device_node *np = dev->of_node;
713 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
714 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
715 	int ngpios;
716 	int i = 0;
717 	int ret;
718 
719 	ngpios = of_gpio_count(np);
720 	if (ngpios <= 0) {
721 		/*
722 		 * SPI w/o chip-select line. One SPI device is still permitted
723 		 * though.
724 		 */
725 		pdata->max_chipselect = 1;
726 		return 0;
727 	}
728 
729 	pinfo->gpios = kmalloc_array(ngpios, sizeof(*pinfo->gpios),
730 				     GFP_KERNEL);
731 	if (!pinfo->gpios)
732 		return -ENOMEM;
733 	memset(pinfo->gpios, -1, ngpios * sizeof(*pinfo->gpios));
734 
735 	pinfo->alow_flags = kcalloc(ngpios, sizeof(*pinfo->alow_flags),
736 				    GFP_KERNEL);
737 	if (!pinfo->alow_flags) {
738 		ret = -ENOMEM;
739 		goto err_alloc_flags;
740 	}
741 
742 	for (; i < ngpios; i++) {
743 		int gpio;
744 		enum of_gpio_flags flags;
745 
746 		gpio = of_get_gpio_flags(np, i, &flags);
747 		if (!gpio_is_valid(gpio)) {
748 			dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
749 			ret = gpio;
750 			goto err_loop;
751 		}
752 
753 		ret = gpio_request(gpio, dev_name(dev));
754 		if (ret) {
755 			dev_err(dev, "can't request gpio #%d: %d\n", i, ret);
756 			goto err_loop;
757 		}
758 
759 		pinfo->gpios[i] = gpio;
760 		pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW;
761 
762 		ret = gpio_direction_output(pinfo->gpios[i],
763 					    pinfo->alow_flags[i]);
764 		if (ret) {
765 			dev_err(dev,
766 				"can't set output direction for gpio #%d: %d\n",
767 				i, ret);
768 			goto err_loop;
769 		}
770 	}
771 
772 	pdata->max_chipselect = ngpios;
773 	pdata->cs_control = fsl_spi_cs_control;
774 
775 	return 0;
776 
777 err_loop:
778 	while (i >= 0) {
779 		if (gpio_is_valid(pinfo->gpios[i]))
780 			gpio_free(pinfo->gpios[i]);
781 		i--;
782 	}
783 
784 	kfree(pinfo->alow_flags);
785 	pinfo->alow_flags = NULL;
786 err_alloc_flags:
787 	kfree(pinfo->gpios);
788 	pinfo->gpios = NULL;
789 	return ret;
790 }
791 
792 static int of_fsl_spi_free_chipselects(struct device *dev)
793 {
794 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
795 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
796 	int i;
797 
798 	if (!pinfo->gpios)
799 		return 0;
800 
801 	for (i = 0; i < pdata->max_chipselect; i++) {
802 		if (gpio_is_valid(pinfo->gpios[i]))
803 			gpio_free(pinfo->gpios[i]);
804 	}
805 
806 	kfree(pinfo->gpios);
807 	kfree(pinfo->alow_flags);
808 	return 0;
809 }
810 
811 static int of_fsl_spi_probe(struct platform_device *ofdev)
812 {
813 	struct device *dev = &ofdev->dev;
814 	struct device_node *np = ofdev->dev.of_node;
815 	struct spi_master *master;
816 	struct resource mem;
817 	int irq = 0, type;
818 	int ret = -ENOMEM;
819 
820 	ret = of_mpc8xxx_spi_probe(ofdev);
821 	if (ret)
822 		return ret;
823 
824 	type = fsl_spi_get_type(&ofdev->dev);
825 	if (type == TYPE_FSL) {
826 		ret = of_fsl_spi_get_chipselects(dev);
827 		if (ret)
828 			goto err;
829 	}
830 
831 	ret = of_address_to_resource(np, 0, &mem);
832 	if (ret)
833 		goto err;
834 
835 	irq = irq_of_parse_and_map(np, 0);
836 	if (!irq) {
837 		ret = -EINVAL;
838 		goto err;
839 	}
840 
841 	master = fsl_spi_probe(dev, &mem, irq);
842 	if (IS_ERR(master)) {
843 		ret = PTR_ERR(master);
844 		goto err;
845 	}
846 
847 	return 0;
848 
849 err:
850 	irq_dispose_mapping(irq);
851 	if (type == TYPE_FSL)
852 		of_fsl_spi_free_chipselects(dev);
853 	return ret;
854 }
855 
856 static int of_fsl_spi_remove(struct platform_device *ofdev)
857 {
858 	struct spi_master *master = platform_get_drvdata(ofdev);
859 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
860 
861 	fsl_spi_cpm_free(mpc8xxx_spi);
862 	if (mpc8xxx_spi->type == TYPE_FSL)
863 		of_fsl_spi_free_chipselects(&ofdev->dev);
864 	return 0;
865 }
866 
867 static struct platform_driver of_fsl_spi_driver = {
868 	.driver = {
869 		.name = "fsl_spi",
870 		.of_match_table = of_fsl_spi_match,
871 	},
872 	.probe		= of_fsl_spi_probe,
873 	.remove		= of_fsl_spi_remove,
874 };
875 
876 #ifdef CONFIG_MPC832x_RDB
877 /*
878  * XXX XXX XXX
879  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
880  * only. The driver should go away soon, since newer MPC8323E-RDB's device
881  * tree can work with OpenFirmware driver. But for now we support old trees
882  * as well.
883  */
884 static int plat_mpc8xxx_spi_probe(struct platform_device *pdev)
885 {
886 	struct resource *mem;
887 	int irq;
888 	struct spi_master *master;
889 
890 	if (!dev_get_platdata(&pdev->dev))
891 		return -EINVAL;
892 
893 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
894 	if (!mem)
895 		return -EINVAL;
896 
897 	irq = platform_get_irq(pdev, 0);
898 	if (irq <= 0)
899 		return -EINVAL;
900 
901 	master = fsl_spi_probe(&pdev->dev, mem, irq);
902 	return PTR_ERR_OR_ZERO(master);
903 }
904 
905 static int plat_mpc8xxx_spi_remove(struct platform_device *pdev)
906 {
907 	struct spi_master *master = platform_get_drvdata(pdev);
908 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
909 
910 	fsl_spi_cpm_free(mpc8xxx_spi);
911 
912 	return 0;
913 }
914 
915 MODULE_ALIAS("platform:mpc8xxx_spi");
916 static struct platform_driver mpc8xxx_spi_driver = {
917 	.probe = plat_mpc8xxx_spi_probe,
918 	.remove = plat_mpc8xxx_spi_remove,
919 	.driver = {
920 		.name = "mpc8xxx_spi",
921 	},
922 };
923 
924 static bool legacy_driver_failed;
925 
926 static void __init legacy_driver_register(void)
927 {
928 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
929 }
930 
931 static void __exit legacy_driver_unregister(void)
932 {
933 	if (legacy_driver_failed)
934 		return;
935 	platform_driver_unregister(&mpc8xxx_spi_driver);
936 }
937 #else
938 static void __init legacy_driver_register(void) {}
939 static void __exit legacy_driver_unregister(void) {}
940 #endif /* CONFIG_MPC832x_RDB */
941 
942 static int __init fsl_spi_init(void)
943 {
944 	legacy_driver_register();
945 	return platform_driver_register(&of_fsl_spi_driver);
946 }
947 module_init(fsl_spi_init);
948 
949 static void __exit fsl_spi_exit(void)
950 {
951 	platform_driver_unregister(&of_fsl_spi_driver);
952 	legacy_driver_unregister();
953 }
954 module_exit(fsl_spi_exit);
955 
956 MODULE_AUTHOR("Kumar Gala");
957 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
958 MODULE_LICENSE("GPL");
959