xref: /linux/drivers/spi/spi-fsl-spi.c (revision 7fc7f25419f5a6b09199ba4b5026b94ef184fa79)
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 
337 	/*
338 	 * In CPU mode, optimize large byte transfers to use larger
339 	 * bits_per_word values to reduce number of interrupts taken.
340 	 */
341 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) {
342 		list_for_each_entry(t, &m->transfers, transfer_list) {
343 			if (t->len < 256 || t->bits_per_word != 8)
344 				continue;
345 			if ((t->len & 3) == 0)
346 				t->bits_per_word = 32;
347 			else if ((t->len & 1) == 0)
348 				t->bits_per_word = 16;
349 		}
350 	}
351 	return 0;
352 }
353 
354 static int fsl_spi_transfer_one(struct spi_controller *controller,
355 				struct spi_device *spi,
356 				struct spi_transfer *t)
357 {
358 	int status;
359 
360 	status = fsl_spi_setup_transfer(spi, t);
361 	if (status < 0)
362 		return status;
363 	if (t->len)
364 		status = fsl_spi_bufs(spi, t, !!t->tx_dma || !!t->rx_dma);
365 	if (status > 0)
366 		return -EMSGSIZE;
367 
368 	return status;
369 }
370 
371 static int fsl_spi_unprepare_message(struct spi_controller *controller,
372 				     struct spi_message *msg)
373 {
374 	return fsl_spi_setup_transfer(msg->spi, NULL);
375 }
376 
377 static int fsl_spi_setup(struct spi_device *spi)
378 {
379 	struct mpc8xxx_spi *mpc8xxx_spi;
380 	struct fsl_spi_reg __iomem *reg_base;
381 	bool initial_setup = false;
382 	int retval;
383 	u32 hw_mode;
384 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
385 
386 	if (!spi->max_speed_hz)
387 		return -EINVAL;
388 
389 	if (!cs) {
390 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
391 		if (!cs)
392 			return -ENOMEM;
393 		spi_set_ctldata(spi, cs);
394 		initial_setup = true;
395 	}
396 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
397 
398 	reg_base = mpc8xxx_spi->reg_base;
399 
400 	hw_mode = cs->hw_mode; /* Save original settings */
401 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
402 	/* mask out bits we are going to set */
403 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
404 			 | SPMODE_REV | SPMODE_LOOP);
405 
406 	if (spi->mode & SPI_CPHA)
407 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
408 	if (spi->mode & SPI_CPOL)
409 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
410 	if (!(spi->mode & SPI_LSB_FIRST))
411 		cs->hw_mode |= SPMODE_REV;
412 	if (spi->mode & SPI_LOOP)
413 		cs->hw_mode |= SPMODE_LOOP;
414 
415 	retval = fsl_spi_setup_transfer(spi, NULL);
416 	if (retval < 0) {
417 		cs->hw_mode = hw_mode; /* Restore settings */
418 		if (initial_setup)
419 			kfree(cs);
420 		return retval;
421 	}
422 
423 	return 0;
424 }
425 
426 static void fsl_spi_cleanup(struct spi_device *spi)
427 {
428 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
429 
430 	kfree(cs);
431 	spi_set_ctldata(spi, NULL);
432 }
433 
434 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
435 {
436 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
437 
438 	/* We need handle RX first */
439 	if (events & SPIE_NE) {
440 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
441 
442 		if (mspi->rx)
443 			mspi->get_rx(rx_data, mspi);
444 	}
445 
446 	if ((events & SPIE_NF) == 0)
447 		/* spin until TX is done */
448 		while (((events =
449 			mpc8xxx_spi_read_reg(&reg_base->event)) &
450 						SPIE_NF) == 0)
451 			cpu_relax();
452 
453 	/* Clear the events */
454 	mpc8xxx_spi_write_reg(&reg_base->event, events);
455 
456 	mspi->count -= 1;
457 	if (mspi->count) {
458 		u32 word = mspi->get_tx(mspi);
459 
460 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
461 	} else {
462 		complete(&mspi->done);
463 	}
464 }
465 
466 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
467 {
468 	struct mpc8xxx_spi *mspi = context_data;
469 	irqreturn_t ret = IRQ_NONE;
470 	u32 events;
471 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
472 
473 	/* Get interrupt events(tx/rx) */
474 	events = mpc8xxx_spi_read_reg(&reg_base->event);
475 	if (events)
476 		ret = IRQ_HANDLED;
477 
478 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
479 
480 	if (mspi->flags & SPI_CPM_MODE)
481 		fsl_spi_cpm_irq(mspi, events);
482 	else
483 		fsl_spi_cpu_irq(mspi, events);
484 
485 	return ret;
486 }
487 
488 static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
489 {
490 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
491 	struct fsl_spi_reg __iomem *reg_base = mpc8xxx_spi->reg_base;
492 	u32 slvsel;
493 	u16 cs = spi->chip_select;
494 
495 	if (cs < mpc8xxx_spi->native_chipselects) {
496 		slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
497 		slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
498 		mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
499 	}
500 }
501 
502 static void fsl_spi_grlib_probe(struct device *dev)
503 {
504 	struct spi_master *master = dev_get_drvdata(dev);
505 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
506 	struct fsl_spi_reg __iomem *reg_base = mpc8xxx_spi->reg_base;
507 	int mbits;
508 	u32 capabilities;
509 
510 	capabilities = mpc8xxx_spi_read_reg(&reg_base->cap);
511 
512 	mpc8xxx_spi->set_shifts = fsl_spi_grlib_set_shifts;
513 	mbits = SPCAP_MAXWLEN(capabilities);
514 	if (mbits)
515 		mpc8xxx_spi->max_bits_per_word = mbits + 1;
516 
517 	mpc8xxx_spi->native_chipselects = 0;
518 	if (SPCAP_SSEN(capabilities)) {
519 		mpc8xxx_spi->native_chipselects = SPCAP_SSSZ(capabilities);
520 		mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
521 	}
522 	master->num_chipselect = mpc8xxx_spi->native_chipselects;
523 	master->set_cs = fsl_spi_grlib_cs_control;
524 }
525 
526 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
527 {
528 	struct device *dev = spi->dev.parent->parent;
529 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
530 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
531 
532 	if (WARN_ON_ONCE(!pinfo->immr_spi_cs))
533 		return;
534 	iowrite32be(on ? 0 : SPI_BOOT_SEL_BIT, pinfo->immr_spi_cs);
535 }
536 
537 static struct spi_master *fsl_spi_probe(struct device *dev,
538 		struct resource *mem, unsigned int irq)
539 {
540 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
541 	struct spi_master *master;
542 	struct mpc8xxx_spi *mpc8xxx_spi;
543 	struct fsl_spi_reg __iomem *reg_base;
544 	u32 regval;
545 	int ret = 0;
546 
547 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
548 	if (master == NULL) {
549 		ret = -ENOMEM;
550 		goto err;
551 	}
552 
553 	dev_set_drvdata(dev, master);
554 
555 	mpc8xxx_spi_probe(dev, mem, irq);
556 
557 	master->setup = fsl_spi_setup;
558 	master->cleanup = fsl_spi_cleanup;
559 	master->prepare_message = fsl_spi_prepare_message;
560 	master->transfer_one = fsl_spi_transfer_one;
561 	master->unprepare_message = fsl_spi_unprepare_message;
562 	master->use_gpio_descriptors = true;
563 	master->set_cs = fsl_spi_cs_control;
564 
565 	mpc8xxx_spi = spi_master_get_devdata(master);
566 	mpc8xxx_spi->max_bits_per_word = 32;
567 	mpc8xxx_spi->type = fsl_spi_get_type(dev);
568 
569 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
570 	if (ret)
571 		goto err_cpm_init;
572 
573 	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
574 	if (IS_ERR(mpc8xxx_spi->reg_base)) {
575 		ret = PTR_ERR(mpc8xxx_spi->reg_base);
576 		goto err_probe;
577 	}
578 
579 	if (mpc8xxx_spi->type == TYPE_GRLIB)
580 		fsl_spi_grlib_probe(dev);
581 
582 	master->bits_per_word_mask =
583 		(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32)) &
584 		SPI_BPW_RANGE_MASK(1, mpc8xxx_spi->max_bits_per_word);
585 
586 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
587 		mpc8xxx_spi->set_shifts = fsl_spi_qe_cpu_set_shifts;
588 
589 	if (mpc8xxx_spi->set_shifts)
590 		/* 8 bits per word and MSB first */
591 		mpc8xxx_spi->set_shifts(&mpc8xxx_spi->rx_shift,
592 					&mpc8xxx_spi->tx_shift, 8, 1);
593 
594 	/* Register for SPI Interrupt */
595 	ret = devm_request_irq(dev, mpc8xxx_spi->irq, fsl_spi_irq,
596 			       0, "fsl_spi", mpc8xxx_spi);
597 
598 	if (ret != 0)
599 		goto err_probe;
600 
601 	reg_base = mpc8xxx_spi->reg_base;
602 
603 	/* SPI controller initializations */
604 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
605 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
606 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
607 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
608 
609 	/* Enable SPI interface */
610 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
611 	if (mpc8xxx_spi->max_bits_per_word < 8) {
612 		regval &= ~SPMODE_LEN(0xF);
613 		regval |= SPMODE_LEN(mpc8xxx_spi->max_bits_per_word - 1);
614 	}
615 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
616 		regval |= SPMODE_OP;
617 
618 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
619 
620 	ret = devm_spi_register_master(dev, master);
621 	if (ret < 0)
622 		goto err_probe;
623 
624 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
625 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
626 
627 	return master;
628 
629 err_probe:
630 	fsl_spi_cpm_free(mpc8xxx_spi);
631 err_cpm_init:
632 	spi_master_put(master);
633 err:
634 	return ERR_PTR(ret);
635 }
636 
637 static int of_fsl_spi_probe(struct platform_device *ofdev)
638 {
639 	struct device *dev = &ofdev->dev;
640 	struct device_node *np = ofdev->dev.of_node;
641 	struct spi_master *master;
642 	struct resource mem;
643 	int irq, type;
644 	int ret;
645 	bool spisel_boot = false;
646 #if IS_ENABLED(CONFIG_FSL_SOC)
647 	struct mpc8xxx_spi_probe_info *pinfo = NULL;
648 #endif
649 
650 
651 	ret = of_mpc8xxx_spi_probe(ofdev);
652 	if (ret)
653 		return ret;
654 
655 	type = fsl_spi_get_type(&ofdev->dev);
656 	if (type == TYPE_FSL) {
657 		struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
658 #if IS_ENABLED(CONFIG_FSL_SOC)
659 		pinfo = to_of_pinfo(pdata);
660 
661 		spisel_boot = of_property_read_bool(np, "fsl,spisel_boot");
662 		if (spisel_boot) {
663 			pinfo->immr_spi_cs = ioremap(get_immrbase() + IMMR_SPI_CS_OFFSET, 4);
664 			if (!pinfo->immr_spi_cs)
665 				return -ENOMEM;
666 		}
667 #endif
668 		/*
669 		 * Handle the case where we have one hardwired (always selected)
670 		 * device on the first "chipselect". Else we let the core code
671 		 * handle any GPIOs or native chip selects and assign the
672 		 * appropriate callback for dealing with the CS lines. This isn't
673 		 * supported on the GRLIB variant.
674 		 */
675 		ret = gpiod_count(dev, "cs");
676 		if (ret < 0)
677 			ret = 0;
678 		if (ret == 0 && !spisel_boot)
679 			pdata->max_chipselect = 1;
680 		else
681 			pdata->max_chipselect = ret + spisel_boot;
682 	}
683 
684 	ret = of_address_to_resource(np, 0, &mem);
685 	if (ret)
686 		goto unmap_out;
687 
688 	irq = platform_get_irq(ofdev, 0);
689 	if (irq < 0) {
690 		ret = irq;
691 		goto unmap_out;
692 	}
693 
694 	master = fsl_spi_probe(dev, &mem, irq);
695 
696 	return PTR_ERR_OR_ZERO(master);
697 
698 unmap_out:
699 #if IS_ENABLED(CONFIG_FSL_SOC)
700 	if (spisel_boot)
701 		iounmap(pinfo->immr_spi_cs);
702 #endif
703 	return ret;
704 }
705 
706 static int of_fsl_spi_remove(struct platform_device *ofdev)
707 {
708 	struct spi_master *master = platform_get_drvdata(ofdev);
709 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
710 
711 	fsl_spi_cpm_free(mpc8xxx_spi);
712 	return 0;
713 }
714 
715 static struct platform_driver of_fsl_spi_driver = {
716 	.driver = {
717 		.name = "fsl_spi",
718 		.of_match_table = of_fsl_spi_match,
719 	},
720 	.probe		= of_fsl_spi_probe,
721 	.remove		= of_fsl_spi_remove,
722 };
723 
724 #ifdef CONFIG_MPC832x_RDB
725 /*
726  * XXX XXX XXX
727  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
728  * only. The driver should go away soon, since newer MPC8323E-RDB's device
729  * tree can work with OpenFirmware driver. But for now we support old trees
730  * as well.
731  */
732 static int plat_mpc8xxx_spi_probe(struct platform_device *pdev)
733 {
734 	struct resource *mem;
735 	int irq;
736 	struct spi_master *master;
737 
738 	if (!dev_get_platdata(&pdev->dev))
739 		return -EINVAL;
740 
741 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
742 	if (!mem)
743 		return -EINVAL;
744 
745 	irq = platform_get_irq(pdev, 0);
746 	if (irq <= 0)
747 		return -EINVAL;
748 
749 	master = fsl_spi_probe(&pdev->dev, mem, irq);
750 	return PTR_ERR_OR_ZERO(master);
751 }
752 
753 static int plat_mpc8xxx_spi_remove(struct platform_device *pdev)
754 {
755 	struct spi_master *master = platform_get_drvdata(pdev);
756 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
757 
758 	fsl_spi_cpm_free(mpc8xxx_spi);
759 
760 	return 0;
761 }
762 
763 MODULE_ALIAS("platform:mpc8xxx_spi");
764 static struct platform_driver mpc8xxx_spi_driver = {
765 	.probe = plat_mpc8xxx_spi_probe,
766 	.remove = plat_mpc8xxx_spi_remove,
767 	.driver = {
768 		.name = "mpc8xxx_spi",
769 	},
770 };
771 
772 static bool legacy_driver_failed;
773 
774 static void __init legacy_driver_register(void)
775 {
776 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
777 }
778 
779 static void __exit legacy_driver_unregister(void)
780 {
781 	if (legacy_driver_failed)
782 		return;
783 	platform_driver_unregister(&mpc8xxx_spi_driver);
784 }
785 #else
786 static void __init legacy_driver_register(void) {}
787 static void __exit legacy_driver_unregister(void) {}
788 #endif /* CONFIG_MPC832x_RDB */
789 
790 static int __init fsl_spi_init(void)
791 {
792 	legacy_driver_register();
793 	return platform_driver_register(&of_fsl_spi_driver);
794 }
795 module_init(fsl_spi_init);
796 
797 static void __exit fsl_spi_exit(void)
798 {
799 	platform_driver_unregister(&of_fsl_spi_driver);
800 	legacy_driver_unregister();
801 }
802 module_exit(fsl_spi_exit);
803 
804 MODULE_AUTHOR("Kumar Gala");
805 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
806 MODULE_LICENSE("GPL");
807