xref: /openbmc/linux/drivers/spi/spi-fsl-spi.c (revision 752beb5e)
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 #ifdef CONFIG_FSL_SOC
43 #include <sysdev/fsl_soc.h>
44 #endif
45 
46 /* Specific to the MPC8306/MPC8309 */
47 #define IMMR_SPI_CS_OFFSET 0x14c
48 #define SPI_BOOT_SEL_BIT   0x80000000
49 
50 #include "spi-fsl-lib.h"
51 #include "spi-fsl-cpm.h"
52 #include "spi-fsl-spi.h"
53 
54 #define TYPE_FSL	0
55 #define TYPE_GRLIB	1
56 
57 struct fsl_spi_match_data {
58 	int type;
59 };
60 
61 static struct fsl_spi_match_data of_fsl_spi_fsl_config = {
62 	.type = TYPE_FSL,
63 };
64 
65 static struct fsl_spi_match_data of_fsl_spi_grlib_config = {
66 	.type = TYPE_GRLIB,
67 };
68 
69 static const struct of_device_id of_fsl_spi_match[] = {
70 	{
71 		.compatible = "fsl,spi",
72 		.data = &of_fsl_spi_fsl_config,
73 	},
74 	{
75 		.compatible = "aeroflexgaisler,spictrl",
76 		.data = &of_fsl_spi_grlib_config,
77 	},
78 	{}
79 };
80 MODULE_DEVICE_TABLE(of, of_fsl_spi_match);
81 
82 static int fsl_spi_get_type(struct device *dev)
83 {
84 	const struct of_device_id *match;
85 
86 	if (dev->of_node) {
87 		match = of_match_node(of_fsl_spi_match, dev->of_node);
88 		if (match && match->data)
89 			return ((struct fsl_spi_match_data *)match->data)->type;
90 	}
91 	return TYPE_FSL;
92 }
93 
94 static void fsl_spi_change_mode(struct spi_device *spi)
95 {
96 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
97 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
98 	struct fsl_spi_reg *reg_base = mspi->reg_base;
99 	__be32 __iomem *mode = &reg_base->mode;
100 	unsigned long flags;
101 
102 	if (cs->hw_mode == mpc8xxx_spi_read_reg(mode))
103 		return;
104 
105 	/* Turn off IRQs locally to minimize time that SPI is disabled. */
106 	local_irq_save(flags);
107 
108 	/* Turn off SPI unit prior changing mode */
109 	mpc8xxx_spi_write_reg(mode, cs->hw_mode & ~SPMODE_ENABLE);
110 
111 	/* When in CPM mode, we need to reinit tx and rx. */
112 	if (mspi->flags & SPI_CPM_MODE) {
113 		fsl_spi_cpm_reinit_txrx(mspi);
114 	}
115 	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
116 	local_irq_restore(flags);
117 }
118 
119 static void fsl_spi_chipselect(struct spi_device *spi, int value)
120 {
121 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
122 	struct fsl_spi_platform_data *pdata;
123 	bool pol = spi->mode & SPI_CS_HIGH;
124 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
125 
126 	pdata = spi->dev.parent->parent->platform_data;
127 
128 	if (value == BITBANG_CS_INACTIVE) {
129 		if (pdata->cs_control)
130 			pdata->cs_control(spi, !pol);
131 	}
132 
133 	if (value == BITBANG_CS_ACTIVE) {
134 		mpc8xxx_spi->rx_shift = cs->rx_shift;
135 		mpc8xxx_spi->tx_shift = cs->tx_shift;
136 		mpc8xxx_spi->get_rx = cs->get_rx;
137 		mpc8xxx_spi->get_tx = cs->get_tx;
138 
139 		fsl_spi_change_mode(spi);
140 
141 		if (pdata->cs_control)
142 			pdata->cs_control(spi, pol);
143 	}
144 }
145 
146 static void fsl_spi_qe_cpu_set_shifts(u32 *rx_shift, u32 *tx_shift,
147 				      int bits_per_word, int msb_first)
148 {
149 	*rx_shift = 0;
150 	*tx_shift = 0;
151 	if (msb_first) {
152 		if (bits_per_word <= 8) {
153 			*rx_shift = 16;
154 			*tx_shift = 24;
155 		} else if (bits_per_word <= 16) {
156 			*rx_shift = 16;
157 			*tx_shift = 16;
158 		}
159 	} else {
160 		if (bits_per_word <= 8)
161 			*rx_shift = 8;
162 	}
163 }
164 
165 static void fsl_spi_grlib_set_shifts(u32 *rx_shift, u32 *tx_shift,
166 				     int bits_per_word, int msb_first)
167 {
168 	*rx_shift = 0;
169 	*tx_shift = 0;
170 	if (bits_per_word <= 16) {
171 		if (msb_first) {
172 			*rx_shift = 16; /* LSB in bit 16 */
173 			*tx_shift = 32 - bits_per_word; /* MSB in bit 31 */
174 		} else {
175 			*rx_shift = 16 - bits_per_word; /* MSB in bit 15 */
176 		}
177 	}
178 }
179 
180 static int mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs,
181 				struct spi_device *spi,
182 				struct mpc8xxx_spi *mpc8xxx_spi,
183 				int bits_per_word)
184 {
185 	cs->rx_shift = 0;
186 	cs->tx_shift = 0;
187 	if (bits_per_word <= 8) {
188 		cs->get_rx = mpc8xxx_spi_rx_buf_u8;
189 		cs->get_tx = mpc8xxx_spi_tx_buf_u8;
190 	} else if (bits_per_word <= 16) {
191 		cs->get_rx = mpc8xxx_spi_rx_buf_u16;
192 		cs->get_tx = mpc8xxx_spi_tx_buf_u16;
193 	} else if (bits_per_word <= 32) {
194 		cs->get_rx = mpc8xxx_spi_rx_buf_u32;
195 		cs->get_tx = mpc8xxx_spi_tx_buf_u32;
196 	} else
197 		return -EINVAL;
198 
199 	if (mpc8xxx_spi->set_shifts)
200 		mpc8xxx_spi->set_shifts(&cs->rx_shift, &cs->tx_shift,
201 					bits_per_word,
202 					!(spi->mode & SPI_LSB_FIRST));
203 
204 	mpc8xxx_spi->rx_shift = cs->rx_shift;
205 	mpc8xxx_spi->tx_shift = cs->tx_shift;
206 	mpc8xxx_spi->get_rx = cs->get_rx;
207 	mpc8xxx_spi->get_tx = cs->get_tx;
208 
209 	return bits_per_word;
210 }
211 
212 static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
213 				struct spi_device *spi,
214 				int bits_per_word)
215 {
216 	/* QE uses Little Endian for words > 8
217 	 * so transform all words > 8 into 8 bits
218 	 * Unfortnatly that doesn't work for LSB so
219 	 * reject these for now */
220 	/* Note: 32 bits word, LSB works iff
221 	 * tfcr/rfcr is set to CPMFCR_GBL */
222 	if (spi->mode & SPI_LSB_FIRST &&
223 	    bits_per_word > 8)
224 		return -EINVAL;
225 	if (bits_per_word > 8)
226 		return 8; /* pretend its 8 bits */
227 	return bits_per_word;
228 }
229 
230 static int fsl_spi_setup_transfer(struct spi_device *spi,
231 					struct spi_transfer *t)
232 {
233 	struct mpc8xxx_spi *mpc8xxx_spi;
234 	int bits_per_word = 0;
235 	u8 pm;
236 	u32 hz = 0;
237 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
238 
239 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
240 
241 	if (t) {
242 		bits_per_word = t->bits_per_word;
243 		hz = t->speed_hz;
244 	}
245 
246 	/* spi_transfer level calls that work per-word */
247 	if (!bits_per_word)
248 		bits_per_word = spi->bits_per_word;
249 
250 	if (!hz)
251 		hz = spi->max_speed_hz;
252 
253 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE))
254 		bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi,
255 							   mpc8xxx_spi,
256 							   bits_per_word);
257 	else if (mpc8xxx_spi->flags & SPI_QE)
258 		bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
259 							  bits_per_word);
260 
261 	if (bits_per_word < 0)
262 		return bits_per_word;
263 
264 	if (bits_per_word == 32)
265 		bits_per_word = 0;
266 	else
267 		bits_per_word = bits_per_word - 1;
268 
269 	/* mask out bits we are going to set */
270 	cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
271 				  | SPMODE_PM(0xF));
272 
273 	cs->hw_mode |= SPMODE_LEN(bits_per_word);
274 
275 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
276 		cs->hw_mode |= SPMODE_DIV16;
277 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
278 		WARN_ONCE(pm > 16,
279 			  "%s: Requested speed is too low: %d Hz. Will use %d Hz instead.\n",
280 			  dev_name(&spi->dev), hz, mpc8xxx_spi->spibrg / 1024);
281 		if (pm > 16)
282 			pm = 16;
283 	} else {
284 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
285 	}
286 	if (pm)
287 		pm--;
288 
289 	cs->hw_mode |= SPMODE_PM(pm);
290 
291 	fsl_spi_change_mode(spi);
292 	return 0;
293 }
294 
295 static int fsl_spi_cpu_bufs(struct mpc8xxx_spi *mspi,
296 				struct spi_transfer *t, unsigned int len)
297 {
298 	u32 word;
299 	struct fsl_spi_reg *reg_base = mspi->reg_base;
300 
301 	mspi->count = len;
302 
303 	/* enable rx ints */
304 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
305 
306 	/* transmit word */
307 	word = mspi->get_tx(mspi);
308 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
309 
310 	return 0;
311 }
312 
313 static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
314 			    bool is_dma_mapped)
315 {
316 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
317 	struct fsl_spi_reg *reg_base;
318 	unsigned int len = t->len;
319 	u8 bits_per_word;
320 	int ret;
321 
322 	reg_base = mpc8xxx_spi->reg_base;
323 	bits_per_word = spi->bits_per_word;
324 	if (t->bits_per_word)
325 		bits_per_word = t->bits_per_word;
326 
327 	if (bits_per_word > 8) {
328 		/* invalid length? */
329 		if (len & 1)
330 			return -EINVAL;
331 		len /= 2;
332 	}
333 	if (bits_per_word > 16) {
334 		/* invalid length? */
335 		if (len & 1)
336 			return -EINVAL;
337 		len /= 2;
338 	}
339 
340 	mpc8xxx_spi->tx = t->tx_buf;
341 	mpc8xxx_spi->rx = t->rx_buf;
342 
343 	reinit_completion(&mpc8xxx_spi->done);
344 
345 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
346 		ret = fsl_spi_cpm_bufs(mpc8xxx_spi, t, is_dma_mapped);
347 	else
348 		ret = fsl_spi_cpu_bufs(mpc8xxx_spi, t, len);
349 	if (ret)
350 		return ret;
351 
352 	wait_for_completion(&mpc8xxx_spi->done);
353 
354 	/* disable rx ints */
355 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
356 
357 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
358 		fsl_spi_cpm_bufs_complete(mpc8xxx_spi);
359 
360 	return mpc8xxx_spi->count;
361 }
362 
363 static int fsl_spi_do_one_msg(struct spi_master *master,
364 			      struct spi_message *m)
365 {
366 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
367 	struct spi_device *spi = m->spi;
368 	struct spi_transfer *t, *first;
369 	unsigned int cs_change;
370 	const int nsecs = 50;
371 	int status, last_bpw;
372 
373 	/*
374 	 * In CPU mode, optimize large byte transfers to use larger
375 	 * bits_per_word values to reduce number of interrupts taken.
376 	 */
377 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) {
378 		list_for_each_entry(t, &m->transfers, transfer_list) {
379 			if (t->len < 256 || t->bits_per_word != 8)
380 				continue;
381 			if ((t->len & 3) == 0)
382 				t->bits_per_word = 32;
383 			else if ((t->len & 1) == 0)
384 				t->bits_per_word = 16;
385 		}
386 	}
387 
388 	/* Don't allow changes if CS is active */
389 	cs_change = 1;
390 	list_for_each_entry(t, &m->transfers, transfer_list) {
391 		if (cs_change)
392 			first = t;
393 		cs_change = t->cs_change;
394 		if (first->speed_hz != t->speed_hz) {
395 			dev_err(&spi->dev,
396 				"speed_hz cannot change while CS is active\n");
397 			return -EINVAL;
398 		}
399 	}
400 
401 	last_bpw = -1;
402 	cs_change = 1;
403 	status = -EINVAL;
404 	list_for_each_entry(t, &m->transfers, transfer_list) {
405 		if (cs_change || last_bpw != t->bits_per_word)
406 			status = fsl_spi_setup_transfer(spi, t);
407 		if (status < 0)
408 			break;
409 		last_bpw = t->bits_per_word;
410 
411 		if (cs_change) {
412 			fsl_spi_chipselect(spi, BITBANG_CS_ACTIVE);
413 			ndelay(nsecs);
414 		}
415 		cs_change = t->cs_change;
416 		if (t->len)
417 			status = fsl_spi_bufs(spi, t, m->is_dma_mapped);
418 		if (status) {
419 			status = -EMSGSIZE;
420 			break;
421 		}
422 		m->actual_length += t->len;
423 
424 		if (t->delay_usecs)
425 			udelay(t->delay_usecs);
426 
427 		if (cs_change) {
428 			ndelay(nsecs);
429 			fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
430 			ndelay(nsecs);
431 		}
432 	}
433 
434 	m->status = status;
435 	spi_finalize_current_message(master);
436 
437 	if (status || !cs_change) {
438 		ndelay(nsecs);
439 		fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
440 	}
441 
442 	fsl_spi_setup_transfer(spi, NULL);
443 	return 0;
444 }
445 
446 static int fsl_spi_setup(struct spi_device *spi)
447 {
448 	struct mpc8xxx_spi *mpc8xxx_spi;
449 	struct fsl_spi_reg *reg_base;
450 	int retval;
451 	u32 hw_mode;
452 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
453 
454 	if (!spi->max_speed_hz)
455 		return -EINVAL;
456 
457 	if (!cs) {
458 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
459 		if (!cs)
460 			return -ENOMEM;
461 		spi_set_ctldata(spi, cs);
462 	}
463 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
464 
465 	reg_base = mpc8xxx_spi->reg_base;
466 
467 	hw_mode = cs->hw_mode; /* Save original settings */
468 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
469 	/* mask out bits we are going to set */
470 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
471 			 | SPMODE_REV | SPMODE_LOOP);
472 
473 	if (spi->mode & SPI_CPHA)
474 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
475 	if (spi->mode & SPI_CPOL)
476 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
477 	if (!(spi->mode & SPI_LSB_FIRST))
478 		cs->hw_mode |= SPMODE_REV;
479 	if (spi->mode & SPI_LOOP)
480 		cs->hw_mode |= SPMODE_LOOP;
481 
482 	retval = fsl_spi_setup_transfer(spi, NULL);
483 	if (retval < 0) {
484 		cs->hw_mode = hw_mode; /* Restore settings */
485 		return retval;
486 	}
487 
488 	if (mpc8xxx_spi->type == TYPE_GRLIB) {
489 		if (gpio_is_valid(spi->cs_gpio)) {
490 			int desel;
491 
492 			retval = gpio_request(spi->cs_gpio,
493 					      dev_name(&spi->dev));
494 			if (retval)
495 				return retval;
496 
497 			desel = !(spi->mode & SPI_CS_HIGH);
498 			retval = gpio_direction_output(spi->cs_gpio, desel);
499 			if (retval) {
500 				gpio_free(spi->cs_gpio);
501 				return retval;
502 			}
503 		} else if (spi->cs_gpio != -ENOENT) {
504 			if (spi->cs_gpio < 0)
505 				return spi->cs_gpio;
506 			return -EINVAL;
507 		}
508 		/* When spi->cs_gpio == -ENOENT, a hole in the phandle list
509 		 * indicates to use native chipselect if present, or allow for
510 		 * an always selected chip
511 		 */
512 	}
513 
514 	/* Initialize chipselect - might be active for SPI_CS_HIGH mode */
515 	fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
516 
517 	return 0;
518 }
519 
520 static void fsl_spi_cleanup(struct spi_device *spi)
521 {
522 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
523 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
524 
525 	if (mpc8xxx_spi->type == TYPE_GRLIB && gpio_is_valid(spi->cs_gpio))
526 		gpio_free(spi->cs_gpio);
527 
528 	kfree(cs);
529 	spi_set_ctldata(spi, NULL);
530 }
531 
532 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
533 {
534 	struct fsl_spi_reg *reg_base = mspi->reg_base;
535 
536 	/* We need handle RX first */
537 	if (events & SPIE_NE) {
538 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
539 
540 		if (mspi->rx)
541 			mspi->get_rx(rx_data, mspi);
542 	}
543 
544 	if ((events & SPIE_NF) == 0)
545 		/* spin until TX is done */
546 		while (((events =
547 			mpc8xxx_spi_read_reg(&reg_base->event)) &
548 						SPIE_NF) == 0)
549 			cpu_relax();
550 
551 	/* Clear the events */
552 	mpc8xxx_spi_write_reg(&reg_base->event, events);
553 
554 	mspi->count -= 1;
555 	if (mspi->count) {
556 		u32 word = mspi->get_tx(mspi);
557 
558 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
559 	} else {
560 		complete(&mspi->done);
561 	}
562 }
563 
564 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
565 {
566 	struct mpc8xxx_spi *mspi = context_data;
567 	irqreturn_t ret = IRQ_NONE;
568 	u32 events;
569 	struct fsl_spi_reg *reg_base = mspi->reg_base;
570 
571 	/* Get interrupt events(tx/rx) */
572 	events = mpc8xxx_spi_read_reg(&reg_base->event);
573 	if (events)
574 		ret = IRQ_HANDLED;
575 
576 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
577 
578 	if (mspi->flags & SPI_CPM_MODE)
579 		fsl_spi_cpm_irq(mspi, events);
580 	else
581 		fsl_spi_cpu_irq(mspi, events);
582 
583 	return ret;
584 }
585 
586 static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
587 {
588 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
589 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
590 	u32 slvsel;
591 	u16 cs = spi->chip_select;
592 
593 	if (gpio_is_valid(spi->cs_gpio)) {
594 		gpio_set_value(spi->cs_gpio, on);
595 	} else if (cs < mpc8xxx_spi->native_chipselects) {
596 		slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
597 		slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
598 		mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
599 	}
600 }
601 
602 static void fsl_spi_grlib_probe(struct device *dev)
603 {
604 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
605 	struct spi_master *master = dev_get_drvdata(dev);
606 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
607 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
608 	int mbits;
609 	u32 capabilities;
610 
611 	capabilities = mpc8xxx_spi_read_reg(&reg_base->cap);
612 
613 	mpc8xxx_spi->set_shifts = fsl_spi_grlib_set_shifts;
614 	mbits = SPCAP_MAXWLEN(capabilities);
615 	if (mbits)
616 		mpc8xxx_spi->max_bits_per_word = mbits + 1;
617 
618 	mpc8xxx_spi->native_chipselects = 0;
619 	if (SPCAP_SSEN(capabilities)) {
620 		mpc8xxx_spi->native_chipselects = SPCAP_SSSZ(capabilities);
621 		mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
622 	}
623 	master->num_chipselect = mpc8xxx_spi->native_chipselects;
624 	pdata->cs_control = fsl_spi_grlib_cs_control;
625 }
626 
627 static struct spi_master * fsl_spi_probe(struct device *dev,
628 		struct resource *mem, unsigned int irq)
629 {
630 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
631 	struct spi_master *master;
632 	struct mpc8xxx_spi *mpc8xxx_spi;
633 	struct fsl_spi_reg *reg_base;
634 	u32 regval;
635 	int ret = 0;
636 
637 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
638 	if (master == NULL) {
639 		ret = -ENOMEM;
640 		goto err;
641 	}
642 
643 	dev_set_drvdata(dev, master);
644 
645 	mpc8xxx_spi_probe(dev, mem, irq);
646 
647 	master->setup = fsl_spi_setup;
648 	master->cleanup = fsl_spi_cleanup;
649 	master->transfer_one_message = fsl_spi_do_one_msg;
650 
651 	mpc8xxx_spi = spi_master_get_devdata(master);
652 	mpc8xxx_spi->max_bits_per_word = 32;
653 	mpc8xxx_spi->type = fsl_spi_get_type(dev);
654 
655 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
656 	if (ret)
657 		goto err_cpm_init;
658 
659 	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
660 	if (IS_ERR(mpc8xxx_spi->reg_base)) {
661 		ret = PTR_ERR(mpc8xxx_spi->reg_base);
662 		goto err_probe;
663 	}
664 
665 	if (mpc8xxx_spi->type == TYPE_GRLIB)
666 		fsl_spi_grlib_probe(dev);
667 
668 	master->bits_per_word_mask =
669 		(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32)) &
670 		SPI_BPW_RANGE_MASK(1, mpc8xxx_spi->max_bits_per_word);
671 
672 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
673 		mpc8xxx_spi->set_shifts = fsl_spi_qe_cpu_set_shifts;
674 
675 	if (mpc8xxx_spi->set_shifts)
676 		/* 8 bits per word and MSB first */
677 		mpc8xxx_spi->set_shifts(&mpc8xxx_spi->rx_shift,
678 					&mpc8xxx_spi->tx_shift, 8, 1);
679 
680 	/* Register for SPI Interrupt */
681 	ret = devm_request_irq(dev, mpc8xxx_spi->irq, fsl_spi_irq,
682 			       0, "fsl_spi", mpc8xxx_spi);
683 
684 	if (ret != 0)
685 		goto err_probe;
686 
687 	reg_base = mpc8xxx_spi->reg_base;
688 
689 	/* SPI controller initializations */
690 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
691 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
692 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
693 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
694 
695 	/* Enable SPI interface */
696 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
697 	if (mpc8xxx_spi->max_bits_per_word < 8) {
698 		regval &= ~SPMODE_LEN(0xF);
699 		regval |= SPMODE_LEN(mpc8xxx_spi->max_bits_per_word - 1);
700 	}
701 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
702 		regval |= SPMODE_OP;
703 
704 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
705 
706 	ret = devm_spi_register_master(dev, master);
707 	if (ret < 0)
708 		goto err_probe;
709 
710 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
711 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
712 
713 	return master;
714 
715 err_probe:
716 	fsl_spi_cpm_free(mpc8xxx_spi);
717 err_cpm_init:
718 	spi_master_put(master);
719 err:
720 	return ERR_PTR(ret);
721 }
722 
723 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
724 {
725 	struct device *dev = spi->dev.parent->parent;
726 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
727 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
728 	u16 cs = spi->chip_select;
729 
730 	if (cs < pinfo->ngpios) {
731 		int gpio = pinfo->gpios[cs];
732 		bool alow = pinfo->alow_flags[cs];
733 
734 		gpio_set_value(gpio, on ^ alow);
735 	} else {
736 		if (WARN_ON_ONCE(cs > pinfo->ngpios || !pinfo->immr_spi_cs))
737 			return;
738 		iowrite32be(on ? SPI_BOOT_SEL_BIT : 0, pinfo->immr_spi_cs);
739 	}
740 }
741 
742 static int of_fsl_spi_get_chipselects(struct device *dev)
743 {
744 	struct device_node *np = dev->of_node;
745 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
746 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
747 	bool spisel_boot = IS_ENABLED(CONFIG_FSL_SOC) &&
748 		of_property_read_bool(np, "fsl,spisel_boot");
749 	int ngpios;
750 	int i = 0;
751 	int ret;
752 
753 	ngpios = of_gpio_count(np);
754 	ngpios = max(ngpios, 0);
755 	if (ngpios == 0 && !spisel_boot) {
756 		/*
757 		 * SPI w/o chip-select line. One SPI device is still permitted
758 		 * though.
759 		 */
760 		pdata->max_chipselect = 1;
761 		return 0;
762 	}
763 
764 	pinfo->ngpios = ngpios;
765 	pinfo->gpios = kmalloc_array(ngpios, sizeof(*pinfo->gpios),
766 				     GFP_KERNEL);
767 	if (!pinfo->gpios)
768 		return -ENOMEM;
769 	memset(pinfo->gpios, -1, ngpios * sizeof(*pinfo->gpios));
770 
771 	pinfo->alow_flags = kcalloc(ngpios, sizeof(*pinfo->alow_flags),
772 				    GFP_KERNEL);
773 	if (!pinfo->alow_flags) {
774 		ret = -ENOMEM;
775 		goto err_alloc_flags;
776 	}
777 
778 	for (; i < ngpios; i++) {
779 		int gpio;
780 		enum of_gpio_flags flags;
781 
782 		gpio = of_get_gpio_flags(np, i, &flags);
783 		if (!gpio_is_valid(gpio)) {
784 			dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
785 			ret = gpio;
786 			goto err_loop;
787 		}
788 
789 		ret = gpio_request(gpio, dev_name(dev));
790 		if (ret) {
791 			dev_err(dev, "can't request gpio #%d: %d\n", i, ret);
792 			goto err_loop;
793 		}
794 
795 		pinfo->gpios[i] = gpio;
796 		pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW;
797 
798 		ret = gpio_direction_output(pinfo->gpios[i],
799 					    pinfo->alow_flags[i]);
800 		if (ret) {
801 			dev_err(dev,
802 				"can't set output direction for gpio #%d: %d\n",
803 				i, ret);
804 			goto err_loop;
805 		}
806 	}
807 
808 #if IS_ENABLED(CONFIG_FSL_SOC)
809 	if (spisel_boot) {
810 		pinfo->immr_spi_cs = ioremap(get_immrbase() + IMMR_SPI_CS_OFFSET, 4);
811 		if (!pinfo->immr_spi_cs) {
812 			ret = -ENOMEM;
813 			i = ngpios - 1;
814 			goto err_loop;
815 		}
816 	}
817 #endif
818 
819 	pdata->max_chipselect = ngpios + spisel_boot;
820 	pdata->cs_control = fsl_spi_cs_control;
821 
822 	return 0;
823 
824 err_loop:
825 	while (i >= 0) {
826 		if (gpio_is_valid(pinfo->gpios[i]))
827 			gpio_free(pinfo->gpios[i]);
828 		i--;
829 	}
830 
831 	kfree(pinfo->alow_flags);
832 	pinfo->alow_flags = NULL;
833 err_alloc_flags:
834 	kfree(pinfo->gpios);
835 	pinfo->gpios = NULL;
836 	return ret;
837 }
838 
839 static int of_fsl_spi_free_chipselects(struct device *dev)
840 {
841 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
842 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
843 	int i;
844 
845 	if (!pinfo->gpios)
846 		return 0;
847 
848 	for (i = 0; i < pdata->max_chipselect; i++) {
849 		if (gpio_is_valid(pinfo->gpios[i]))
850 			gpio_free(pinfo->gpios[i]);
851 	}
852 
853 	kfree(pinfo->gpios);
854 	kfree(pinfo->alow_flags);
855 	return 0;
856 }
857 
858 static int of_fsl_spi_probe(struct platform_device *ofdev)
859 {
860 	struct device *dev = &ofdev->dev;
861 	struct device_node *np = ofdev->dev.of_node;
862 	struct spi_master *master;
863 	struct resource mem;
864 	int irq = 0, type;
865 	int ret = -ENOMEM;
866 
867 	ret = of_mpc8xxx_spi_probe(ofdev);
868 	if (ret)
869 		return ret;
870 
871 	type = fsl_spi_get_type(&ofdev->dev);
872 	if (type == TYPE_FSL) {
873 		ret = of_fsl_spi_get_chipselects(dev);
874 		if (ret)
875 			goto err;
876 	}
877 
878 	ret = of_address_to_resource(np, 0, &mem);
879 	if (ret)
880 		goto err;
881 
882 	irq = irq_of_parse_and_map(np, 0);
883 	if (!irq) {
884 		ret = -EINVAL;
885 		goto err;
886 	}
887 
888 	master = fsl_spi_probe(dev, &mem, irq);
889 	if (IS_ERR(master)) {
890 		ret = PTR_ERR(master);
891 		goto err;
892 	}
893 
894 	return 0;
895 
896 err:
897 	irq_dispose_mapping(irq);
898 	if (type == TYPE_FSL)
899 		of_fsl_spi_free_chipselects(dev);
900 	return ret;
901 }
902 
903 static int of_fsl_spi_remove(struct platform_device *ofdev)
904 {
905 	struct spi_master *master = platform_get_drvdata(ofdev);
906 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
907 
908 	fsl_spi_cpm_free(mpc8xxx_spi);
909 	if (mpc8xxx_spi->type == TYPE_FSL)
910 		of_fsl_spi_free_chipselects(&ofdev->dev);
911 	return 0;
912 }
913 
914 static struct platform_driver of_fsl_spi_driver = {
915 	.driver = {
916 		.name = "fsl_spi",
917 		.of_match_table = of_fsl_spi_match,
918 	},
919 	.probe		= of_fsl_spi_probe,
920 	.remove		= of_fsl_spi_remove,
921 };
922 
923 #ifdef CONFIG_MPC832x_RDB
924 /*
925  * XXX XXX XXX
926  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
927  * only. The driver should go away soon, since newer MPC8323E-RDB's device
928  * tree can work with OpenFirmware driver. But for now we support old trees
929  * as well.
930  */
931 static int plat_mpc8xxx_spi_probe(struct platform_device *pdev)
932 {
933 	struct resource *mem;
934 	int irq;
935 	struct spi_master *master;
936 
937 	if (!dev_get_platdata(&pdev->dev))
938 		return -EINVAL;
939 
940 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
941 	if (!mem)
942 		return -EINVAL;
943 
944 	irq = platform_get_irq(pdev, 0);
945 	if (irq <= 0)
946 		return -EINVAL;
947 
948 	master = fsl_spi_probe(&pdev->dev, mem, irq);
949 	return PTR_ERR_OR_ZERO(master);
950 }
951 
952 static int plat_mpc8xxx_spi_remove(struct platform_device *pdev)
953 {
954 	struct spi_master *master = platform_get_drvdata(pdev);
955 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
956 
957 	fsl_spi_cpm_free(mpc8xxx_spi);
958 
959 	return 0;
960 }
961 
962 MODULE_ALIAS("platform:mpc8xxx_spi");
963 static struct platform_driver mpc8xxx_spi_driver = {
964 	.probe = plat_mpc8xxx_spi_probe,
965 	.remove = plat_mpc8xxx_spi_remove,
966 	.driver = {
967 		.name = "mpc8xxx_spi",
968 	},
969 };
970 
971 static bool legacy_driver_failed;
972 
973 static void __init legacy_driver_register(void)
974 {
975 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
976 }
977 
978 static void __exit legacy_driver_unregister(void)
979 {
980 	if (legacy_driver_failed)
981 		return;
982 	platform_driver_unregister(&mpc8xxx_spi_driver);
983 }
984 #else
985 static void __init legacy_driver_register(void) {}
986 static void __exit legacy_driver_unregister(void) {}
987 #endif /* CONFIG_MPC832x_RDB */
988 
989 static int __init fsl_spi_init(void)
990 {
991 	legacy_driver_register();
992 	return platform_driver_register(&of_fsl_spi_driver);
993 }
994 module_init(fsl_spi_init);
995 
996 static void __exit fsl_spi_exit(void)
997 {
998 	platform_driver_unregister(&of_fsl_spi_driver);
999 	legacy_driver_unregister();
1000 }
1001 module_exit(fsl_spi_exit);
1002 
1003 MODULE_AUTHOR("Kumar Gala");
1004 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
1005 MODULE_LICENSE("GPL");
1006