xref: /openbmc/linux/drivers/spi/spi-fsl-spi.c (revision 6de298ff)
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 void 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 	}
165 
166 	if (mpc8xxx_spi->set_shifts)
167 		mpc8xxx_spi->set_shifts(&cs->rx_shift, &cs->tx_shift,
168 					bits_per_word,
169 					!(spi->mode & SPI_LSB_FIRST));
170 
171 	mpc8xxx_spi->rx_shift = cs->rx_shift;
172 	mpc8xxx_spi->tx_shift = cs->tx_shift;
173 	mpc8xxx_spi->get_rx = cs->get_rx;
174 	mpc8xxx_spi->get_tx = cs->get_tx;
175 }
176 
177 static int fsl_spi_setup_transfer(struct spi_device *spi,
178 					struct spi_transfer *t)
179 {
180 	struct mpc8xxx_spi *mpc8xxx_spi;
181 	int bits_per_word = 0;
182 	u8 pm;
183 	u32 hz = 0;
184 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
185 
186 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
187 
188 	if (t) {
189 		bits_per_word = t->bits_per_word;
190 		hz = t->speed_hz;
191 	}
192 
193 	/* spi_transfer level calls that work per-word */
194 	if (!bits_per_word)
195 		bits_per_word = spi->bits_per_word;
196 
197 	if (!hz)
198 		hz = spi->max_speed_hz;
199 
200 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE))
201 		mspi_apply_cpu_mode_quirks(cs, spi, mpc8xxx_spi, bits_per_word);
202 
203 	if (bits_per_word == 32)
204 		bits_per_word = 0;
205 	else
206 		bits_per_word = bits_per_word - 1;
207 
208 	/* mask out bits we are going to set */
209 	cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
210 				  | SPMODE_PM(0xF));
211 
212 	cs->hw_mode |= SPMODE_LEN(bits_per_word);
213 
214 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
215 		cs->hw_mode |= SPMODE_DIV16;
216 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
217 		WARN_ONCE(pm > 16,
218 			  "%s: Requested speed is too low: %d Hz. Will use %d Hz instead.\n",
219 			  dev_name(&spi->dev), hz, mpc8xxx_spi->spibrg / 1024);
220 		if (pm > 16)
221 			pm = 16;
222 	} else {
223 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
224 	}
225 	if (pm)
226 		pm--;
227 
228 	cs->hw_mode |= SPMODE_PM(pm);
229 
230 	fsl_spi_change_mode(spi);
231 	return 0;
232 }
233 
234 static int fsl_spi_cpu_bufs(struct mpc8xxx_spi *mspi,
235 				struct spi_transfer *t, unsigned int len)
236 {
237 	u32 word;
238 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
239 
240 	mspi->count = len;
241 
242 	/* enable rx ints */
243 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
244 
245 	/* transmit word */
246 	word = mspi->get_tx(mspi);
247 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
248 
249 	return 0;
250 }
251 
252 static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
253 			    bool is_dma_mapped)
254 {
255 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
256 	struct fsl_spi_reg __iomem *reg_base;
257 	unsigned int len = t->len;
258 	u8 bits_per_word;
259 	int ret;
260 
261 	reg_base = mpc8xxx_spi->reg_base;
262 	bits_per_word = spi->bits_per_word;
263 	if (t->bits_per_word)
264 		bits_per_word = t->bits_per_word;
265 
266 	if (bits_per_word > 8)
267 		len /= 2;
268 	if (bits_per_word > 16)
269 		len /= 2;
270 
271 	mpc8xxx_spi->tx = t->tx_buf;
272 	mpc8xxx_spi->rx = t->rx_buf;
273 
274 	reinit_completion(&mpc8xxx_spi->done);
275 
276 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
277 		ret = fsl_spi_cpm_bufs(mpc8xxx_spi, t, is_dma_mapped);
278 	else
279 		ret = fsl_spi_cpu_bufs(mpc8xxx_spi, t, len);
280 	if (ret)
281 		return ret;
282 
283 	wait_for_completion(&mpc8xxx_spi->done);
284 
285 	/* disable rx ints */
286 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
287 
288 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
289 		fsl_spi_cpm_bufs_complete(mpc8xxx_spi);
290 
291 	return mpc8xxx_spi->count;
292 }
293 
294 static int fsl_spi_prepare_message(struct spi_controller *ctlr,
295 				   struct spi_message *m)
296 {
297 	struct mpc8xxx_spi *mpc8xxx_spi = spi_controller_get_devdata(ctlr);
298 	struct spi_transfer *t;
299 	struct spi_transfer *first;
300 
301 	first = list_first_entry(&m->transfers, struct spi_transfer,
302 				 transfer_list);
303 
304 	/*
305 	 * In CPU mode, optimize large byte transfers to use larger
306 	 * bits_per_word values to reduce number of interrupts taken.
307 	 *
308 	 * Some glitches can appear on the SPI clock when the mode changes.
309 	 * Check that there is no speed change during the transfer and set it up
310 	 * now to change the mode without having a chip-select asserted.
311 	 */
312 	list_for_each_entry(t, &m->transfers, transfer_list) {
313 		if (t->speed_hz != first->speed_hz) {
314 			dev_err(&m->spi->dev,
315 				"speed_hz cannot change during message.\n");
316 			return -EINVAL;
317 		}
318 		if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) {
319 			if (t->len < 256 || t->bits_per_word != 8)
320 				continue;
321 			if ((t->len & 3) == 0)
322 				t->bits_per_word = 32;
323 			else if ((t->len & 1) == 0)
324 				t->bits_per_word = 16;
325 		} else {
326 			/*
327 			 * CPM/QE uses Little Endian for words > 8
328 			 * so transform 16 and 32 bits words into 8 bits
329 			 * Unfortnatly that doesn't work for LSB so
330 			 * reject these for now
331 			 * Note: 32 bits word, LSB works iff
332 			 * tfcr/rfcr is set to CPMFCR_GBL
333 			 */
334 			if (m->spi->mode & SPI_LSB_FIRST && t->bits_per_word > 8)
335 				return -EINVAL;
336 			if (t->bits_per_word == 16 || t->bits_per_word == 32)
337 				t->bits_per_word = 8; /* pretend its 8 bits */
338 			if (t->bits_per_word == 8 && t->len >= 256 &&
339 			    (mpc8xxx_spi->flags & SPI_CPM1))
340 				t->bits_per_word = 16;
341 		}
342 	}
343 	return fsl_spi_setup_transfer(m->spi, first);
344 }
345 
346 static int fsl_spi_transfer_one(struct spi_controller *controller,
347 				struct spi_device *spi,
348 				struct spi_transfer *t)
349 {
350 	int status;
351 
352 	status = fsl_spi_setup_transfer(spi, t);
353 	if (status < 0)
354 		return status;
355 	if (t->len)
356 		status = fsl_spi_bufs(spi, t, !!t->tx_dma || !!t->rx_dma);
357 	if (status > 0)
358 		return -EMSGSIZE;
359 
360 	return status;
361 }
362 
363 static int fsl_spi_unprepare_message(struct spi_controller *controller,
364 				     struct spi_message *msg)
365 {
366 	return fsl_spi_setup_transfer(msg->spi, NULL);
367 }
368 
369 static int fsl_spi_setup(struct spi_device *spi)
370 {
371 	struct mpc8xxx_spi *mpc8xxx_spi;
372 	struct fsl_spi_reg __iomem *reg_base;
373 	bool initial_setup = false;
374 	int retval;
375 	u32 hw_mode;
376 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
377 
378 	if (!spi->max_speed_hz)
379 		return -EINVAL;
380 
381 	if (!cs) {
382 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
383 		if (!cs)
384 			return -ENOMEM;
385 		spi_set_ctldata(spi, cs);
386 		initial_setup = true;
387 	}
388 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
389 
390 	reg_base = mpc8xxx_spi->reg_base;
391 
392 	hw_mode = cs->hw_mode; /* Save original settings */
393 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
394 	/* mask out bits we are going to set */
395 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
396 			 | SPMODE_REV | SPMODE_LOOP);
397 
398 	if (spi->mode & SPI_CPHA)
399 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
400 	if (spi->mode & SPI_CPOL)
401 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
402 	if (!(spi->mode & SPI_LSB_FIRST))
403 		cs->hw_mode |= SPMODE_REV;
404 	if (spi->mode & SPI_LOOP)
405 		cs->hw_mode |= SPMODE_LOOP;
406 
407 	retval = fsl_spi_setup_transfer(spi, NULL);
408 	if (retval < 0) {
409 		cs->hw_mode = hw_mode; /* Restore settings */
410 		if (initial_setup)
411 			kfree(cs);
412 		return retval;
413 	}
414 
415 	return 0;
416 }
417 
418 static void fsl_spi_cleanup(struct spi_device *spi)
419 {
420 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
421 
422 	kfree(cs);
423 	spi_set_ctldata(spi, NULL);
424 }
425 
426 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
427 {
428 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
429 
430 	/* We need handle RX first */
431 	if (events & SPIE_NE) {
432 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
433 
434 		if (mspi->rx)
435 			mspi->get_rx(rx_data, mspi);
436 	}
437 
438 	if ((events & SPIE_NF) == 0)
439 		/* spin until TX is done */
440 		while (((events =
441 			mpc8xxx_spi_read_reg(&reg_base->event)) &
442 						SPIE_NF) == 0)
443 			cpu_relax();
444 
445 	/* Clear the events */
446 	mpc8xxx_spi_write_reg(&reg_base->event, events);
447 
448 	mspi->count -= 1;
449 	if (mspi->count) {
450 		u32 word = mspi->get_tx(mspi);
451 
452 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
453 	} else {
454 		complete(&mspi->done);
455 	}
456 }
457 
458 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
459 {
460 	struct mpc8xxx_spi *mspi = context_data;
461 	irqreturn_t ret = IRQ_NONE;
462 	u32 events;
463 	struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
464 
465 	/* Get interrupt events(tx/rx) */
466 	events = mpc8xxx_spi_read_reg(&reg_base->event);
467 	if (events)
468 		ret = IRQ_HANDLED;
469 
470 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
471 
472 	if (mspi->flags & SPI_CPM_MODE)
473 		fsl_spi_cpm_irq(mspi, events);
474 	else
475 		fsl_spi_cpu_irq(mspi, events);
476 
477 	return ret;
478 }
479 
480 static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
481 {
482 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
483 	struct fsl_spi_reg __iomem *reg_base = mpc8xxx_spi->reg_base;
484 	u32 slvsel;
485 	u16 cs = spi_get_chipselect(spi, 0);
486 
487 	if (cs < mpc8xxx_spi->native_chipselects) {
488 		slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
489 		slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
490 		mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
491 	}
492 }
493 
494 static void fsl_spi_grlib_probe(struct device *dev)
495 {
496 	struct spi_master *master = dev_get_drvdata(dev);
497 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
498 	struct fsl_spi_reg __iomem *reg_base = mpc8xxx_spi->reg_base;
499 	int mbits;
500 	u32 capabilities;
501 
502 	capabilities = mpc8xxx_spi_read_reg(&reg_base->cap);
503 
504 	mpc8xxx_spi->set_shifts = fsl_spi_grlib_set_shifts;
505 	mbits = SPCAP_MAXWLEN(capabilities);
506 	if (mbits)
507 		mpc8xxx_spi->max_bits_per_word = mbits + 1;
508 
509 	mpc8xxx_spi->native_chipselects = 0;
510 	if (SPCAP_SSEN(capabilities)) {
511 		mpc8xxx_spi->native_chipselects = SPCAP_SSSZ(capabilities);
512 		mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
513 	}
514 	master->num_chipselect = mpc8xxx_spi->native_chipselects;
515 	master->set_cs = fsl_spi_grlib_cs_control;
516 }
517 
518 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
519 {
520 	struct device *dev = spi->dev.parent->parent;
521 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
522 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
523 
524 	if (WARN_ON_ONCE(!pinfo->immr_spi_cs))
525 		return;
526 	iowrite32be(on ? 0 : SPI_BOOT_SEL_BIT, pinfo->immr_spi_cs);
527 }
528 
529 static struct spi_master *fsl_spi_probe(struct device *dev,
530 		struct resource *mem, unsigned int irq)
531 {
532 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
533 	struct spi_master *master;
534 	struct mpc8xxx_spi *mpc8xxx_spi;
535 	struct fsl_spi_reg __iomem *reg_base;
536 	u32 regval;
537 	int ret = 0;
538 
539 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
540 	if (master == NULL) {
541 		ret = -ENOMEM;
542 		goto err;
543 	}
544 
545 	dev_set_drvdata(dev, master);
546 
547 	mpc8xxx_spi_probe(dev, mem, irq);
548 
549 	master->setup = fsl_spi_setup;
550 	master->cleanup = fsl_spi_cleanup;
551 	master->prepare_message = fsl_spi_prepare_message;
552 	master->transfer_one = fsl_spi_transfer_one;
553 	master->unprepare_message = fsl_spi_unprepare_message;
554 	master->use_gpio_descriptors = true;
555 	master->set_cs = fsl_spi_cs_control;
556 
557 	mpc8xxx_spi = spi_master_get_devdata(master);
558 	mpc8xxx_spi->max_bits_per_word = 32;
559 	mpc8xxx_spi->type = fsl_spi_get_type(dev);
560 
561 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
562 	if (ret)
563 		goto err_cpm_init;
564 
565 	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
566 	if (IS_ERR(mpc8xxx_spi->reg_base)) {
567 		ret = PTR_ERR(mpc8xxx_spi->reg_base);
568 		goto err_probe;
569 	}
570 
571 	if (mpc8xxx_spi->type == TYPE_GRLIB)
572 		fsl_spi_grlib_probe(dev);
573 
574 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
575 		master->bits_per_word_mask =
576 			(SPI_BPW_RANGE_MASK(4, 8) | SPI_BPW_MASK(16) | SPI_BPW_MASK(32));
577 	else
578 		master->bits_per_word_mask =
579 			(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32));
580 
581 	master->bits_per_word_mask &=
582 		SPI_BPW_RANGE_MASK(1, mpc8xxx_spi->max_bits_per_word);
583 
584 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
585 		mpc8xxx_spi->set_shifts = fsl_spi_qe_cpu_set_shifts;
586 
587 	if (mpc8xxx_spi->set_shifts)
588 		/* 8 bits per word and MSB first */
589 		mpc8xxx_spi->set_shifts(&mpc8xxx_spi->rx_shift,
590 					&mpc8xxx_spi->tx_shift, 8, 1);
591 
592 	/* Register for SPI Interrupt */
593 	ret = devm_request_irq(dev, mpc8xxx_spi->irq, fsl_spi_irq,
594 			       0, "fsl_spi", mpc8xxx_spi);
595 
596 	if (ret != 0)
597 		goto err_probe;
598 
599 	reg_base = mpc8xxx_spi->reg_base;
600 
601 	/* SPI controller initializations */
602 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
603 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
604 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
605 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
606 
607 	/* Enable SPI interface */
608 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
609 	if (mpc8xxx_spi->max_bits_per_word < 8) {
610 		regval &= ~SPMODE_LEN(0xF);
611 		regval |= SPMODE_LEN(mpc8xxx_spi->max_bits_per_word - 1);
612 	}
613 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
614 		regval |= SPMODE_OP;
615 
616 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
617 
618 	ret = devm_spi_register_master(dev, master);
619 	if (ret < 0)
620 		goto err_probe;
621 
622 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
623 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
624 
625 	return master;
626 
627 err_probe:
628 	fsl_spi_cpm_free(mpc8xxx_spi);
629 err_cpm_init:
630 	spi_master_put(master);
631 err:
632 	return ERR_PTR(ret);
633 }
634 
635 static int of_fsl_spi_probe(struct platform_device *ofdev)
636 {
637 	struct device *dev = &ofdev->dev;
638 	struct device_node *np = ofdev->dev.of_node;
639 	struct spi_master *master;
640 	struct resource mem;
641 	int irq, type;
642 	int ret;
643 	bool spisel_boot = false;
644 #if IS_ENABLED(CONFIG_FSL_SOC)
645 	struct mpc8xxx_spi_probe_info *pinfo = NULL;
646 #endif
647 
648 
649 	ret = of_mpc8xxx_spi_probe(ofdev);
650 	if (ret)
651 		return ret;
652 
653 	type = fsl_spi_get_type(&ofdev->dev);
654 	if (type == TYPE_FSL) {
655 		struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
656 #if IS_ENABLED(CONFIG_FSL_SOC)
657 		pinfo = to_of_pinfo(pdata);
658 
659 		spisel_boot = of_property_read_bool(np, "fsl,spisel_boot");
660 		if (spisel_boot) {
661 			pinfo->immr_spi_cs = ioremap(get_immrbase() + IMMR_SPI_CS_OFFSET, 4);
662 			if (!pinfo->immr_spi_cs)
663 				return -ENOMEM;
664 		}
665 #endif
666 		/*
667 		 * Handle the case where we have one hardwired (always selected)
668 		 * device on the first "chipselect". Else we let the core code
669 		 * handle any GPIOs or native chip selects and assign the
670 		 * appropriate callback for dealing with the CS lines. This isn't
671 		 * supported on the GRLIB variant.
672 		 */
673 		ret = gpiod_count(dev, "cs");
674 		if (ret < 0)
675 			ret = 0;
676 		if (ret == 0 && !spisel_boot)
677 			pdata->max_chipselect = 1;
678 		else
679 			pdata->max_chipselect = ret + spisel_boot;
680 	}
681 
682 	ret = of_address_to_resource(np, 0, &mem);
683 	if (ret)
684 		goto unmap_out;
685 
686 	irq = platform_get_irq(ofdev, 0);
687 	if (irq < 0) {
688 		ret = irq;
689 		goto unmap_out;
690 	}
691 
692 	master = fsl_spi_probe(dev, &mem, irq);
693 
694 	return PTR_ERR_OR_ZERO(master);
695 
696 unmap_out:
697 #if IS_ENABLED(CONFIG_FSL_SOC)
698 	if (spisel_boot)
699 		iounmap(pinfo->immr_spi_cs);
700 #endif
701 	return ret;
702 }
703 
704 static void of_fsl_spi_remove(struct platform_device *ofdev)
705 {
706 	struct spi_master *master = platform_get_drvdata(ofdev);
707 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
708 
709 	fsl_spi_cpm_free(mpc8xxx_spi);
710 }
711 
712 static struct platform_driver of_fsl_spi_driver = {
713 	.driver = {
714 		.name = "fsl_spi",
715 		.of_match_table = of_fsl_spi_match,
716 	},
717 	.probe		= of_fsl_spi_probe,
718 	.remove_new	= of_fsl_spi_remove,
719 };
720 
721 #ifdef CONFIG_MPC832x_RDB
722 /*
723  * XXX XXX XXX
724  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
725  * only. The driver should go away soon, since newer MPC8323E-RDB's device
726  * tree can work with OpenFirmware driver. But for now we support old trees
727  * as well.
728  */
729 static int plat_mpc8xxx_spi_probe(struct platform_device *pdev)
730 {
731 	struct resource *mem;
732 	int irq;
733 	struct spi_master *master;
734 
735 	if (!dev_get_platdata(&pdev->dev))
736 		return -EINVAL;
737 
738 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
739 	if (!mem)
740 		return -EINVAL;
741 
742 	irq = platform_get_irq(pdev, 0);
743 	if (irq <= 0)
744 		return -EINVAL;
745 
746 	master = fsl_spi_probe(&pdev->dev, mem, irq);
747 	return PTR_ERR_OR_ZERO(master);
748 }
749 
750 static void plat_mpc8xxx_spi_remove(struct platform_device *pdev)
751 {
752 	struct spi_master *master = platform_get_drvdata(pdev);
753 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
754 
755 	fsl_spi_cpm_free(mpc8xxx_spi);
756 }
757 
758 MODULE_ALIAS("platform:mpc8xxx_spi");
759 static struct platform_driver mpc8xxx_spi_driver = {
760 	.probe = plat_mpc8xxx_spi_probe,
761 	.remove_new = plat_mpc8xxx_spi_remove,
762 	.driver = {
763 		.name = "mpc8xxx_spi",
764 	},
765 };
766 
767 static bool legacy_driver_failed;
768 
769 static void __init legacy_driver_register(void)
770 {
771 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
772 }
773 
774 static void __exit legacy_driver_unregister(void)
775 {
776 	if (legacy_driver_failed)
777 		return;
778 	platform_driver_unregister(&mpc8xxx_spi_driver);
779 }
780 #else
781 static void __init legacy_driver_register(void) {}
782 static void __exit legacy_driver_unregister(void) {}
783 #endif /* CONFIG_MPC832x_RDB */
784 
785 static int __init fsl_spi_init(void)
786 {
787 	legacy_driver_register();
788 	return platform_driver_register(&of_fsl_spi_driver);
789 }
790 module_init(fsl_spi_init);
791 
792 static void __exit fsl_spi_exit(void)
793 {
794 	platform_driver_unregister(&of_fsl_spi_driver);
795 	legacy_driver_unregister();
796 }
797 module_exit(fsl_spi_exit);
798 
799 MODULE_AUTHOR("Kumar Gala");
800 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
801 MODULE_LICENSE("GPL");
802