xref: /linux/drivers/spi/spi-fsl-spi.c (revision f22f9aaf6c3d92ebd5ad9e67acc03afebaaeb289)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Freescale SPI controller driver.
4  *
5  * Maintainer: Kumar Gala
6  *
7  * Copyright (C) 2006 Polycom, Inc.
8  * Copyright 2010 Freescale Semiconductor, Inc.
9  *
10  * CPM SPI and QE buffer descriptors mode support:
11  * Copyright (c) 2009  MontaVista Software, Inc.
12  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
13  *
14  * GRLIB support:
15  * Copyright (c) 2012 Aeroflex Gaisler AB.
16  * Author: Andreas Larsson <andreas@gaisler.com>
17  */
18 #include <linux/delay.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/fsl_devices.h>
21 #include <linux/gpio/consumer.h>
22 #include <linux/interrupt.h>
23 #include <linux/irq.h>
24 #include <linux/kernel.h>
25 #include <linux/mm.h>
26 #include <linux/module.h>
27 #include <linux/mutex.h>
28 #include <linux/of.h>
29 #include <linux/of_address.h>
30 #include <linux/of_irq.h>
31 #include <linux/of_platform.h>
32 #include <linux/platform_device.h>
33 #include <linux/spi/spi.h>
34 #include <linux/spi/spi_bitbang.h>
35 #include <linux/types.h>
36 
37 #ifdef CONFIG_FSL_SOC
38 #include <sysdev/fsl_soc.h>
39 #endif
40 
41 /* Specific to the MPC8306/MPC8309 */
42 #define IMMR_SPI_CS_OFFSET 0x14c
43 #define SPI_BOOT_SEL_BIT   0x80000000
44 
45 #include "spi-fsl-lib.h"
46 #include "spi-fsl-cpm.h"
47 #include "spi-fsl-spi.h"
48 
49 #define TYPE_FSL	0
50 #define TYPE_GRLIB	1
51 
52 struct fsl_spi_match_data {
53 	int type;
54 };
55 
56 static struct fsl_spi_match_data of_fsl_spi_fsl_config = {
57 	.type = TYPE_FSL,
58 };
59 
60 static struct fsl_spi_match_data of_fsl_spi_grlib_config = {
61 	.type = TYPE_GRLIB,
62 };
63 
64 static const struct of_device_id of_fsl_spi_match[] = {
65 	{
66 		.compatible = "fsl,spi",
67 		.data = &of_fsl_spi_fsl_config,
68 	},
69 	{
70 		.compatible = "aeroflexgaisler,spictrl",
71 		.data = &of_fsl_spi_grlib_config,
72 	},
73 	{}
74 };
75 MODULE_DEVICE_TABLE(of, of_fsl_spi_match);
76 
77 static int fsl_spi_get_type(struct device *dev)
78 {
79 	const struct of_device_id *match;
80 
81 	if (dev->of_node) {
82 		match = of_match_node(of_fsl_spi_match, dev->of_node);
83 		if (match && match->data)
84 			return ((struct fsl_spi_match_data *)match->data)->type;
85 	}
86 	return TYPE_FSL;
87 }
88 
89 static void fsl_spi_change_mode(struct spi_device *spi)
90 {
91 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
92 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
93 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
94 	__be32 __iomem *mode = &reg_base->mode;
95 	unsigned long flags;
96 
97 	if (cs->hw_mode == mpc8xxx_spi_read_reg(mode))
98 		return;
99 
100 	/* Turn off IRQs locally to minimize time that SPI is disabled. */
101 	local_irq_save(flags);
102 
103 	/* Turn off SPI unit prior changing mode */
104 	mpc8xxx_spi_write_reg(mode, cs->hw_mode & ~SPMODE_ENABLE);
105 
106 	/* When in CPM mode, we need to reinit tx and rx. */
107 	if (mspi->flags & SPI_CPM_MODE) {
108 		fsl_spi_cpm_reinit_txrx(mspi);
109 	}
110 	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
111 	local_irq_restore(flags);
112 }
113 
114 static void fsl_spi_qe_cpu_set_shifts(u32 *rx_shift, u32 *tx_shift,
115 				      int bits_per_word, int msb_first)
116 {
117 	*rx_shift = 0;
118 	*tx_shift = 0;
119 	if (msb_first) {
120 		if (bits_per_word <= 8) {
121 			*rx_shift = 16;
122 			*tx_shift = 24;
123 		} else if (bits_per_word <= 16) {
124 			*rx_shift = 16;
125 			*tx_shift = 16;
126 		}
127 	} else {
128 		if (bits_per_word <= 8)
129 			*rx_shift = 8;
130 	}
131 }
132 
133 static void fsl_spi_grlib_set_shifts(u32 *rx_shift, u32 *tx_shift,
134 				     int bits_per_word, int msb_first)
135 {
136 	*rx_shift = 0;
137 	*tx_shift = 0;
138 	if (bits_per_word <= 16) {
139 		if (msb_first) {
140 			*rx_shift = 16; /* LSB in bit 16 */
141 			*tx_shift = 32 - bits_per_word; /* MSB in bit 31 */
142 		} else {
143 			*rx_shift = 16 - bits_per_word; /* MSB in bit 15 */
144 		}
145 	}
146 }
147 
148 static int mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs,
149 				struct spi_device *spi,
150 				struct mpc8xxx_spi *mpc8xxx_spi,
151 				int bits_per_word)
152 {
153 	cs->rx_shift = 0;
154 	cs->tx_shift = 0;
155 	if (bits_per_word <= 8) {
156 		cs->get_rx = mpc8xxx_spi_rx_buf_u8;
157 		cs->get_tx = mpc8xxx_spi_tx_buf_u8;
158 	} else if (bits_per_word <= 16) {
159 		cs->get_rx = mpc8xxx_spi_rx_buf_u16;
160 		cs->get_tx = mpc8xxx_spi_tx_buf_u16;
161 	} else if (bits_per_word <= 32) {
162 		cs->get_rx = mpc8xxx_spi_rx_buf_u32;
163 		cs->get_tx = mpc8xxx_spi_tx_buf_u32;
164 	} else
165 		return -EINVAL;
166 
167 	if (mpc8xxx_spi->set_shifts)
168 		mpc8xxx_spi->set_shifts(&cs->rx_shift, &cs->tx_shift,
169 					bits_per_word,
170 					!(spi->mode & SPI_LSB_FIRST));
171 
172 	mpc8xxx_spi->rx_shift = cs->rx_shift;
173 	mpc8xxx_spi->tx_shift = cs->tx_shift;
174 	mpc8xxx_spi->get_rx = cs->get_rx;
175 	mpc8xxx_spi->get_tx = cs->get_tx;
176 
177 	return bits_per_word;
178 }
179 
180 static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
181 				struct spi_device *spi,
182 				int bits_per_word)
183 {
184 	/* QE uses Little Endian for words > 8
185 	 * so transform all words > 8 into 8 bits
186 	 * Unfortnatly that doesn't work for LSB so
187 	 * reject these for now */
188 	/* Note: 32 bits word, LSB works iff
189 	 * tfcr/rfcr is set to CPMFCR_GBL */
190 	if (spi->mode & SPI_LSB_FIRST &&
191 	    bits_per_word > 8)
192 		return -EINVAL;
193 	if (bits_per_word > 8)
194 		return 8; /* pretend its 8 bits */
195 	return bits_per_word;
196 }
197 
198 static int fsl_spi_setup_transfer(struct spi_device *spi,
199 					struct spi_transfer *t)
200 {
201 	struct mpc8xxx_spi *mpc8xxx_spi;
202 	int bits_per_word = 0;
203 	u8 pm;
204 	u32 hz = 0;
205 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
206 
207 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
208 
209 	if (t) {
210 		bits_per_word = t->bits_per_word;
211 		hz = t->speed_hz;
212 	}
213 
214 	/* spi_transfer level calls that work per-word */
215 	if (!bits_per_word)
216 		bits_per_word = spi->bits_per_word;
217 
218 	if (!hz)
219 		hz = spi->max_speed_hz;
220 
221 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE))
222 		bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi,
223 							   mpc8xxx_spi,
224 							   bits_per_word);
225 	else if (mpc8xxx_spi->flags & SPI_QE)
226 		bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
227 							  bits_per_word);
228 
229 	if (bits_per_word < 0)
230 		return bits_per_word;
231 
232 	if (bits_per_word == 32)
233 		bits_per_word = 0;
234 	else
235 		bits_per_word = bits_per_word - 1;
236 
237 	/* mask out bits we are going to set */
238 	cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
239 				  | SPMODE_PM(0xF));
240 
241 	cs->hw_mode |= SPMODE_LEN(bits_per_word);
242 
243 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
244 		cs->hw_mode |= SPMODE_DIV16;
245 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
246 		WARN_ONCE(pm > 16,
247 			  "%s: Requested speed is too low: %d Hz. Will use %d Hz instead.\n",
248 			  dev_name(&spi->dev), hz, mpc8xxx_spi->spibrg / 1024);
249 		if (pm > 16)
250 			pm = 16;
251 	} else {
252 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
253 	}
254 	if (pm)
255 		pm--;
256 
257 	cs->hw_mode |= SPMODE_PM(pm);
258 
259 	fsl_spi_change_mode(spi);
260 	return 0;
261 }
262 
263 static int fsl_spi_cpu_bufs(struct mpc8xxx_spi *mspi,
264 				struct spi_transfer *t, unsigned int len)
265 {
266 	u32 word;
267 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
268 
269 	mspi->count = len;
270 
271 	/* enable rx ints */
272 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
273 
274 	/* transmit word */
275 	word = mspi->get_tx(mspi);
276 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
277 
278 	return 0;
279 }
280 
281 static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
282 			    bool is_dma_mapped)
283 {
284 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
285 	struct fsl_spi_reg __iomem *reg_base;
286 	unsigned int len = t->len;
287 	u8 bits_per_word;
288 	int ret;
289 
290 	reg_base = mpc8xxx_spi->reg_base;
291 	bits_per_word = spi->bits_per_word;
292 	if (t->bits_per_word)
293 		bits_per_word = t->bits_per_word;
294 
295 	if (bits_per_word > 8) {
296 		/* invalid length? */
297 		if (len & 1)
298 			return -EINVAL;
299 		len /= 2;
300 	}
301 	if (bits_per_word > 16) {
302 		/* invalid length? */
303 		if (len & 1)
304 			return -EINVAL;
305 		len /= 2;
306 	}
307 
308 	mpc8xxx_spi->tx = t->tx_buf;
309 	mpc8xxx_spi->rx = t->rx_buf;
310 
311 	reinit_completion(&mpc8xxx_spi->done);
312 
313 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
314 		ret = fsl_spi_cpm_bufs(mpc8xxx_spi, t, is_dma_mapped);
315 	else
316 		ret = fsl_spi_cpu_bufs(mpc8xxx_spi, t, len);
317 	if (ret)
318 		return ret;
319 
320 	wait_for_completion(&mpc8xxx_spi->done);
321 
322 	/* disable rx ints */
323 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
324 
325 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
326 		fsl_spi_cpm_bufs_complete(mpc8xxx_spi);
327 
328 	return mpc8xxx_spi->count;
329 }
330 
331 static int fsl_spi_prepare_message(struct spi_controller *ctlr,
332 				   struct spi_message *m)
333 {
334 	struct mpc8xxx_spi *mpc8xxx_spi = spi_controller_get_devdata(ctlr);
335 	struct spi_transfer *t;
336 	struct spi_transfer *first;
337 
338 	first = list_first_entry(&m->transfers, struct spi_transfer,
339 				 transfer_list);
340 
341 	/*
342 	 * In CPU mode, optimize large byte transfers to use larger
343 	 * bits_per_word values to reduce number of interrupts taken.
344 	 *
345 	 * Some glitches can appear on the SPI clock when the mode changes.
346 	 * Check that there is no speed change during the transfer and set it up
347 	 * now to change the mode without having a chip-select asserted.
348 	 */
349 	list_for_each_entry(t, &m->transfers, transfer_list) {
350 		if (t->speed_hz != first->speed_hz) {
351 			dev_err(&m->spi->dev,
352 				"speed_hz cannot change during message.\n");
353 			return -EINVAL;
354 		}
355 		if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) {
356 			if (t->len < 256 || t->bits_per_word != 8)
357 				continue;
358 			if ((t->len & 3) == 0)
359 				t->bits_per_word = 32;
360 			else if ((t->len & 1) == 0)
361 				t->bits_per_word = 16;
362 		}
363 	}
364 	return fsl_spi_setup_transfer(m->spi, first);
365 }
366 
367 static int fsl_spi_transfer_one(struct spi_controller *controller,
368 				struct spi_device *spi,
369 				struct spi_transfer *t)
370 {
371 	int status;
372 
373 	status = fsl_spi_setup_transfer(spi, t);
374 	if (status < 0)
375 		return status;
376 	if (t->len)
377 		status = fsl_spi_bufs(spi, t, !!t->tx_dma || !!t->rx_dma);
378 	if (status > 0)
379 		return -EMSGSIZE;
380 
381 	return status;
382 }
383 
384 static int fsl_spi_unprepare_message(struct spi_controller *controller,
385 				     struct spi_message *msg)
386 {
387 	return fsl_spi_setup_transfer(msg->spi, NULL);
388 }
389 
390 static int fsl_spi_setup(struct spi_device *spi)
391 {
392 	struct mpc8xxx_spi *mpc8xxx_spi;
393 	struct fsl_spi_reg __iomem *reg_base;
394 	bool initial_setup = false;
395 	int retval;
396 	u32 hw_mode;
397 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
398 
399 	if (!spi->max_speed_hz)
400 		return -EINVAL;
401 
402 	if (!cs) {
403 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
404 		if (!cs)
405 			return -ENOMEM;
406 		spi_set_ctldata(spi, cs);
407 		initial_setup = true;
408 	}
409 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
410 
411 	reg_base = mpc8xxx_spi->reg_base;
412 
413 	hw_mode = cs->hw_mode; /* Save original settings */
414 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
415 	/* mask out bits we are going to set */
416 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
417 			 | SPMODE_REV | SPMODE_LOOP);
418 
419 	if (spi->mode & SPI_CPHA)
420 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
421 	if (spi->mode & SPI_CPOL)
422 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
423 	if (!(spi->mode & SPI_LSB_FIRST))
424 		cs->hw_mode |= SPMODE_REV;
425 	if (spi->mode & SPI_LOOP)
426 		cs->hw_mode |= SPMODE_LOOP;
427 
428 	retval = fsl_spi_setup_transfer(spi, NULL);
429 	if (retval < 0) {
430 		cs->hw_mode = hw_mode; /* Restore settings */
431 		if (initial_setup)
432 			kfree(cs);
433 		return retval;
434 	}
435 
436 	return 0;
437 }
438 
439 static void fsl_spi_cleanup(struct spi_device *spi)
440 {
441 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
442 
443 	kfree(cs);
444 	spi_set_ctldata(spi, NULL);
445 }
446 
447 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
448 {
449 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
450 
451 	/* We need handle RX first */
452 	if (events & SPIE_NE) {
453 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
454 
455 		if (mspi->rx)
456 			mspi->get_rx(rx_data, mspi);
457 	}
458 
459 	if ((events & SPIE_NF) == 0)
460 		/* spin until TX is done */
461 		while (((events =
462 			mpc8xxx_spi_read_reg(&reg_base->event)) &
463 						SPIE_NF) == 0)
464 			cpu_relax();
465 
466 	/* Clear the events */
467 	mpc8xxx_spi_write_reg(&reg_base->event, events);
468 
469 	mspi->count -= 1;
470 	if (mspi->count) {
471 		u32 word = mspi->get_tx(mspi);
472 
473 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
474 	} else {
475 		complete(&mspi->done);
476 	}
477 }
478 
479 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
480 {
481 	struct mpc8xxx_spi *mspi = context_data;
482 	irqreturn_t ret = IRQ_NONE;
483 	u32 events;
484 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
485 
486 	/* Get interrupt events(tx/rx) */
487 	events = mpc8xxx_spi_read_reg(&reg_base->event);
488 	if (events)
489 		ret = IRQ_HANDLED;
490 
491 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
492 
493 	if (mspi->flags & SPI_CPM_MODE)
494 		fsl_spi_cpm_irq(mspi, events);
495 	else
496 		fsl_spi_cpu_irq(mspi, events);
497 
498 	return ret;
499 }
500 
501 static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
502 {
503 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
504 	struct fsl_spi_reg __iomem *reg_base = mpc8xxx_spi->reg_base;
505 	u32 slvsel;
506 	u16 cs = spi->chip_select;
507 
508 	if (cs < mpc8xxx_spi->native_chipselects) {
509 		slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
510 		slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
511 		mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
512 	}
513 }
514 
515 static void fsl_spi_grlib_probe(struct device *dev)
516 {
517 	struct spi_master *master = dev_get_drvdata(dev);
518 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
519 	struct fsl_spi_reg __iomem *reg_base = mpc8xxx_spi->reg_base;
520 	int mbits;
521 	u32 capabilities;
522 
523 	capabilities = mpc8xxx_spi_read_reg(&reg_base->cap);
524 
525 	mpc8xxx_spi->set_shifts = fsl_spi_grlib_set_shifts;
526 	mbits = SPCAP_MAXWLEN(capabilities);
527 	if (mbits)
528 		mpc8xxx_spi->max_bits_per_word = mbits + 1;
529 
530 	mpc8xxx_spi->native_chipselects = 0;
531 	if (SPCAP_SSEN(capabilities)) {
532 		mpc8xxx_spi->native_chipselects = SPCAP_SSSZ(capabilities);
533 		mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
534 	}
535 	master->num_chipselect = mpc8xxx_spi->native_chipselects;
536 	master->set_cs = fsl_spi_grlib_cs_control;
537 }
538 
539 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
540 {
541 	struct device *dev = spi->dev.parent->parent;
542 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
543 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
544 
545 	if (WARN_ON_ONCE(!pinfo->immr_spi_cs))
546 		return;
547 	iowrite32be(on ? 0 : SPI_BOOT_SEL_BIT, pinfo->immr_spi_cs);
548 }
549 
550 static struct spi_master *fsl_spi_probe(struct device *dev,
551 		struct resource *mem, unsigned int irq)
552 {
553 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
554 	struct spi_master *master;
555 	struct mpc8xxx_spi *mpc8xxx_spi;
556 	struct fsl_spi_reg __iomem *reg_base;
557 	u32 regval;
558 	int ret = 0;
559 
560 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
561 	if (master == NULL) {
562 		ret = -ENOMEM;
563 		goto err;
564 	}
565 
566 	dev_set_drvdata(dev, master);
567 
568 	mpc8xxx_spi_probe(dev, mem, irq);
569 
570 	master->setup = fsl_spi_setup;
571 	master->cleanup = fsl_spi_cleanup;
572 	master->prepare_message = fsl_spi_prepare_message;
573 	master->transfer_one = fsl_spi_transfer_one;
574 	master->unprepare_message = fsl_spi_unprepare_message;
575 	master->use_gpio_descriptors = true;
576 	master->set_cs = fsl_spi_cs_control;
577 
578 	mpc8xxx_spi = spi_master_get_devdata(master);
579 	mpc8xxx_spi->max_bits_per_word = 32;
580 	mpc8xxx_spi->type = fsl_spi_get_type(dev);
581 
582 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
583 	if (ret)
584 		goto err_cpm_init;
585 
586 	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
587 	if (IS_ERR(mpc8xxx_spi->reg_base)) {
588 		ret = PTR_ERR(mpc8xxx_spi->reg_base);
589 		goto err_probe;
590 	}
591 
592 	if (mpc8xxx_spi->type == TYPE_GRLIB)
593 		fsl_spi_grlib_probe(dev);
594 
595 	master->bits_per_word_mask =
596 		(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32)) &
597 		SPI_BPW_RANGE_MASK(1, mpc8xxx_spi->max_bits_per_word);
598 
599 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
600 		mpc8xxx_spi->set_shifts = fsl_spi_qe_cpu_set_shifts;
601 
602 	if (mpc8xxx_spi->set_shifts)
603 		/* 8 bits per word and MSB first */
604 		mpc8xxx_spi->set_shifts(&mpc8xxx_spi->rx_shift,
605 					&mpc8xxx_spi->tx_shift, 8, 1);
606 
607 	/* Register for SPI Interrupt */
608 	ret = devm_request_irq(dev, mpc8xxx_spi->irq, fsl_spi_irq,
609 			       0, "fsl_spi", mpc8xxx_spi);
610 
611 	if (ret != 0)
612 		goto err_probe;
613 
614 	reg_base = mpc8xxx_spi->reg_base;
615 
616 	/* SPI controller initializations */
617 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
618 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
619 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
620 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
621 
622 	/* Enable SPI interface */
623 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
624 	if (mpc8xxx_spi->max_bits_per_word < 8) {
625 		regval &= ~SPMODE_LEN(0xF);
626 		regval |= SPMODE_LEN(mpc8xxx_spi->max_bits_per_word - 1);
627 	}
628 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
629 		regval |= SPMODE_OP;
630 
631 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
632 
633 	ret = devm_spi_register_master(dev, master);
634 	if (ret < 0)
635 		goto err_probe;
636 
637 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
638 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
639 
640 	return master;
641 
642 err_probe:
643 	fsl_spi_cpm_free(mpc8xxx_spi);
644 err_cpm_init:
645 	spi_master_put(master);
646 err:
647 	return ERR_PTR(ret);
648 }
649 
650 static int of_fsl_spi_probe(struct platform_device *ofdev)
651 {
652 	struct device *dev = &ofdev->dev;
653 	struct device_node *np = ofdev->dev.of_node;
654 	struct spi_master *master;
655 	struct resource mem;
656 	int irq, type;
657 	int ret;
658 	bool spisel_boot = false;
659 #if IS_ENABLED(CONFIG_FSL_SOC)
660 	struct mpc8xxx_spi_probe_info *pinfo = NULL;
661 #endif
662 
663 
664 	ret = of_mpc8xxx_spi_probe(ofdev);
665 	if (ret)
666 		return ret;
667 
668 	type = fsl_spi_get_type(&ofdev->dev);
669 	if (type == TYPE_FSL) {
670 		struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
671 #if IS_ENABLED(CONFIG_FSL_SOC)
672 		pinfo = to_of_pinfo(pdata);
673 
674 		spisel_boot = of_property_read_bool(np, "fsl,spisel_boot");
675 		if (spisel_boot) {
676 			pinfo->immr_spi_cs = ioremap(get_immrbase() + IMMR_SPI_CS_OFFSET, 4);
677 			if (!pinfo->immr_spi_cs)
678 				return -ENOMEM;
679 		}
680 #endif
681 		/*
682 		 * Handle the case where we have one hardwired (always selected)
683 		 * device on the first "chipselect". Else we let the core code
684 		 * handle any GPIOs or native chip selects and assign the
685 		 * appropriate callback for dealing with the CS lines. This isn't
686 		 * supported on the GRLIB variant.
687 		 */
688 		ret = gpiod_count(dev, "cs");
689 		if (ret < 0)
690 			ret = 0;
691 		if (ret == 0 && !spisel_boot)
692 			pdata->max_chipselect = 1;
693 		else
694 			pdata->max_chipselect = ret + spisel_boot;
695 	}
696 
697 	ret = of_address_to_resource(np, 0, &mem);
698 	if (ret)
699 		goto unmap_out;
700 
701 	irq = platform_get_irq(ofdev, 0);
702 	if (irq < 0) {
703 		ret = irq;
704 		goto unmap_out;
705 	}
706 
707 	master = fsl_spi_probe(dev, &mem, irq);
708 
709 	return PTR_ERR_OR_ZERO(master);
710 
711 unmap_out:
712 #if IS_ENABLED(CONFIG_FSL_SOC)
713 	if (spisel_boot)
714 		iounmap(pinfo->immr_spi_cs);
715 #endif
716 	return ret;
717 }
718 
719 static int of_fsl_spi_remove(struct platform_device *ofdev)
720 {
721 	struct spi_master *master = platform_get_drvdata(ofdev);
722 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
723 
724 	fsl_spi_cpm_free(mpc8xxx_spi);
725 	return 0;
726 }
727 
728 static struct platform_driver of_fsl_spi_driver = {
729 	.driver = {
730 		.name = "fsl_spi",
731 		.of_match_table = of_fsl_spi_match,
732 	},
733 	.probe		= of_fsl_spi_probe,
734 	.remove		= of_fsl_spi_remove,
735 };
736 
737 #ifdef CONFIG_MPC832x_RDB
738 /*
739  * XXX XXX XXX
740  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
741  * only. The driver should go away soon, since newer MPC8323E-RDB's device
742  * tree can work with OpenFirmware driver. But for now we support old trees
743  * as well.
744  */
745 static int plat_mpc8xxx_spi_probe(struct platform_device *pdev)
746 {
747 	struct resource *mem;
748 	int irq;
749 	struct spi_master *master;
750 
751 	if (!dev_get_platdata(&pdev->dev))
752 		return -EINVAL;
753 
754 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
755 	if (!mem)
756 		return -EINVAL;
757 
758 	irq = platform_get_irq(pdev, 0);
759 	if (irq <= 0)
760 		return -EINVAL;
761 
762 	master = fsl_spi_probe(&pdev->dev, mem, irq);
763 	return PTR_ERR_OR_ZERO(master);
764 }
765 
766 static int plat_mpc8xxx_spi_remove(struct platform_device *pdev)
767 {
768 	struct spi_master *master = platform_get_drvdata(pdev);
769 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
770 
771 	fsl_spi_cpm_free(mpc8xxx_spi);
772 
773 	return 0;
774 }
775 
776 MODULE_ALIAS("platform:mpc8xxx_spi");
777 static struct platform_driver mpc8xxx_spi_driver = {
778 	.probe = plat_mpc8xxx_spi_probe,
779 	.remove = plat_mpc8xxx_spi_remove,
780 	.driver = {
781 		.name = "mpc8xxx_spi",
782 	},
783 };
784 
785 static bool legacy_driver_failed;
786 
787 static void __init legacy_driver_register(void)
788 {
789 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
790 }
791 
792 static void __exit legacy_driver_unregister(void)
793 {
794 	if (legacy_driver_failed)
795 		return;
796 	platform_driver_unregister(&mpc8xxx_spi_driver);
797 }
798 #else
799 static void __init legacy_driver_register(void) {}
800 static void __exit legacy_driver_unregister(void) {}
801 #endif /* CONFIG_MPC832x_RDB */
802 
803 static int __init fsl_spi_init(void)
804 {
805 	legacy_driver_register();
806 	return platform_driver_register(&of_fsl_spi_driver);
807 }
808 module_init(fsl_spi_init);
809 
810 static void __exit fsl_spi_exit(void)
811 {
812 	platform_driver_unregister(&of_fsl_spi_driver);
813 	legacy_driver_unregister();
814 }
815 module_exit(fsl_spi_exit);
816 
817 MODULE_AUTHOR("Kumar Gala");
818 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
819 MODULE_LICENSE("GPL");
820