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1 /*
2  * Freescale SPI controller driver.
3  *
4  * Maintainer: Kumar Gala
5  *
6  * Copyright (C) 2006 Polycom, Inc.
7  * Copyright 2010 Freescale Semiconductor, Inc.
8  *
9  * CPM SPI and QE buffer descriptors mode support:
10  * Copyright (c) 2009  MontaVista Software, Inc.
11  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
12  *
13  * GRLIB support:
14  * Copyright (c) 2012 Aeroflex Gaisler AB.
15  * Author: Andreas Larsson <andreas@gaisler.com>
16  *
17  * This program is free software; you can redistribute  it and/or modify it
18  * under  the terms of  the GNU General  Public License as published by the
19  * Free Software Foundation;  either version 2 of the  License, or (at your
20  * option) any later version.
21  */
22 #include <linux/delay.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/fsl_devices.h>
25 #include <linux/gpio.h>
26 #include <linux/interrupt.h>
27 #include <linux/irq.h>
28 #include <linux/kernel.h>
29 #include <linux/mm.h>
30 #include <linux/module.h>
31 #include <linux/mutex.h>
32 #include <linux/of.h>
33 #include <linux/of_address.h>
34 #include <linux/of_irq.h>
35 #include <linux/of_gpio.h>
36 #include <linux/of_platform.h>
37 #include <linux/platform_device.h>
38 #include <linux/spi/spi.h>
39 #include <linux/spi/spi_bitbang.h>
40 #include <linux/types.h>
41 
42 #include "spi-fsl-lib.h"
43 #include "spi-fsl-cpm.h"
44 #include "spi-fsl-spi.h"
45 
46 #define TYPE_FSL	0
47 #define TYPE_GRLIB	1
48 
49 struct fsl_spi_match_data {
50 	int type;
51 };
52 
53 static struct fsl_spi_match_data of_fsl_spi_fsl_config = {
54 	.type = TYPE_FSL,
55 };
56 
57 static struct fsl_spi_match_data of_fsl_spi_grlib_config = {
58 	.type = TYPE_GRLIB,
59 };
60 
61 static const struct of_device_id of_fsl_spi_match[] = {
62 	{
63 		.compatible = "fsl,spi",
64 		.data = &of_fsl_spi_fsl_config,
65 	},
66 	{
67 		.compatible = "aeroflexgaisler,spictrl",
68 		.data = &of_fsl_spi_grlib_config,
69 	},
70 	{}
71 };
72 MODULE_DEVICE_TABLE(of, of_fsl_spi_match);
73 
fsl_spi_get_type(struct device * dev)74 static int fsl_spi_get_type(struct device *dev)
75 {
76 	const struct of_device_id *match;
77 
78 	if (dev->of_node) {
79 		match = of_match_node(of_fsl_spi_match, dev->of_node);
80 		if (match && match->data)
81 			return ((struct fsl_spi_match_data *)match->data)->type;
82 	}
83 	return TYPE_FSL;
84 }
85 
fsl_spi_change_mode(struct spi_device * spi)86 static void fsl_spi_change_mode(struct spi_device *spi)
87 {
88 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
89 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
90 	struct fsl_spi_reg *reg_base = mspi->reg_base;
91 	__be32 __iomem *mode = &reg_base->mode;
92 	unsigned long flags;
93 
94 	if (cs->hw_mode == mpc8xxx_spi_read_reg(mode))
95 		return;
96 
97 	/* Turn off IRQs locally to minimize time that SPI is disabled. */
98 	local_irq_save(flags);
99 
100 	/* Turn off SPI unit prior changing mode */
101 	mpc8xxx_spi_write_reg(mode, cs->hw_mode & ~SPMODE_ENABLE);
102 
103 	/* When in CPM mode, we need to reinit tx and rx. */
104 	if (mspi->flags & SPI_CPM_MODE) {
105 		fsl_spi_cpm_reinit_txrx(mspi);
106 	}
107 	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
108 	local_irq_restore(flags);
109 }
110 
fsl_spi_chipselect(struct spi_device * spi,int value)111 static void fsl_spi_chipselect(struct spi_device *spi, int value)
112 {
113 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
114 	struct fsl_spi_platform_data *pdata;
115 	bool pol = spi->mode & SPI_CS_HIGH;
116 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
117 
118 	pdata = spi->dev.parent->parent->platform_data;
119 
120 	if (value == BITBANG_CS_INACTIVE) {
121 		if (pdata->cs_control)
122 			pdata->cs_control(spi, !pol);
123 	}
124 
125 	if (value == BITBANG_CS_ACTIVE) {
126 		mpc8xxx_spi->rx_shift = cs->rx_shift;
127 		mpc8xxx_spi->tx_shift = cs->tx_shift;
128 		mpc8xxx_spi->get_rx = cs->get_rx;
129 		mpc8xxx_spi->get_tx = cs->get_tx;
130 
131 		fsl_spi_change_mode(spi);
132 
133 		if (pdata->cs_control)
134 			pdata->cs_control(spi, pol);
135 	}
136 }
137 
fsl_spi_qe_cpu_set_shifts(u32 * rx_shift,u32 * tx_shift,int bits_per_word,int msb_first)138 static void fsl_spi_qe_cpu_set_shifts(u32 *rx_shift, u32 *tx_shift,
139 				      int bits_per_word, int msb_first)
140 {
141 	*rx_shift = 0;
142 	*tx_shift = 0;
143 	if (msb_first) {
144 		if (bits_per_word <= 8) {
145 			*rx_shift = 16;
146 			*tx_shift = 24;
147 		} else if (bits_per_word <= 16) {
148 			*rx_shift = 16;
149 			*tx_shift = 16;
150 		}
151 	} else {
152 		if (bits_per_word <= 8)
153 			*rx_shift = 8;
154 	}
155 }
156 
fsl_spi_grlib_set_shifts(u32 * rx_shift,u32 * tx_shift,int bits_per_word,int msb_first)157 static void fsl_spi_grlib_set_shifts(u32 *rx_shift, u32 *tx_shift,
158 				     int bits_per_word, int msb_first)
159 {
160 	*rx_shift = 0;
161 	*tx_shift = 0;
162 	if (bits_per_word <= 16) {
163 		if (msb_first) {
164 			*rx_shift = 16; /* LSB in bit 16 */
165 			*tx_shift = 32 - bits_per_word; /* MSB in bit 31 */
166 		} else {
167 			*rx_shift = 16 - bits_per_word; /* MSB in bit 15 */
168 		}
169 	}
170 }
171 
mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs * cs,struct spi_device * spi,struct mpc8xxx_spi * mpc8xxx_spi,int bits_per_word)172 static int mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs,
173 				struct spi_device *spi,
174 				struct mpc8xxx_spi *mpc8xxx_spi,
175 				int bits_per_word)
176 {
177 	cs->rx_shift = 0;
178 	cs->tx_shift = 0;
179 	if (bits_per_word <= 8) {
180 		cs->get_rx = mpc8xxx_spi_rx_buf_u8;
181 		cs->get_tx = mpc8xxx_spi_tx_buf_u8;
182 	} else if (bits_per_word <= 16) {
183 		cs->get_rx = mpc8xxx_spi_rx_buf_u16;
184 		cs->get_tx = mpc8xxx_spi_tx_buf_u16;
185 	} else if (bits_per_word <= 32) {
186 		cs->get_rx = mpc8xxx_spi_rx_buf_u32;
187 		cs->get_tx = mpc8xxx_spi_tx_buf_u32;
188 	} else
189 		return -EINVAL;
190 
191 	if (mpc8xxx_spi->set_shifts)
192 		mpc8xxx_spi->set_shifts(&cs->rx_shift, &cs->tx_shift,
193 					bits_per_word,
194 					!(spi->mode & SPI_LSB_FIRST));
195 
196 	mpc8xxx_spi->rx_shift = cs->rx_shift;
197 	mpc8xxx_spi->tx_shift = cs->tx_shift;
198 	mpc8xxx_spi->get_rx = cs->get_rx;
199 	mpc8xxx_spi->get_tx = cs->get_tx;
200 
201 	return bits_per_word;
202 }
203 
mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs * cs,struct spi_device * spi,int bits_per_word)204 static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
205 				struct spi_device *spi,
206 				int bits_per_word)
207 {
208 	/* QE uses Little Endian for words > 8
209 	 * so transform all words > 8 into 8 bits
210 	 * Unfortnatly that doesn't work for LSB so
211 	 * reject these for now */
212 	/* Note: 32 bits word, LSB works iff
213 	 * tfcr/rfcr is set to CPMFCR_GBL */
214 	if (spi->mode & SPI_LSB_FIRST &&
215 	    bits_per_word > 8)
216 		return -EINVAL;
217 	if (bits_per_word > 8)
218 		return 8; /* pretend its 8 bits */
219 	return bits_per_word;
220 }
221 
fsl_spi_setup_transfer(struct spi_device * spi,struct spi_transfer * t)222 static int fsl_spi_setup_transfer(struct spi_device *spi,
223 					struct spi_transfer *t)
224 {
225 	struct mpc8xxx_spi *mpc8xxx_spi;
226 	int bits_per_word = 0;
227 	u8 pm;
228 	u32 hz = 0;
229 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
230 
231 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
232 
233 	if (t) {
234 		bits_per_word = t->bits_per_word;
235 		hz = t->speed_hz;
236 	}
237 
238 	/* spi_transfer level calls that work per-word */
239 	if (!bits_per_word)
240 		bits_per_word = spi->bits_per_word;
241 
242 	if (!hz)
243 		hz = spi->max_speed_hz;
244 
245 	if (!(mpc8xxx_spi->flags & SPI_CPM_MODE))
246 		bits_per_word = mspi_apply_cpu_mode_quirks(cs, spi,
247 							   mpc8xxx_spi,
248 							   bits_per_word);
249 	else if (mpc8xxx_spi->flags & SPI_QE)
250 		bits_per_word = mspi_apply_qe_mode_quirks(cs, spi,
251 							  bits_per_word);
252 
253 	if (bits_per_word < 0)
254 		return bits_per_word;
255 
256 	if (bits_per_word == 32)
257 		bits_per_word = 0;
258 	else
259 		bits_per_word = bits_per_word - 1;
260 
261 	/* mask out bits we are going to set */
262 	cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
263 				  | SPMODE_PM(0xF));
264 
265 	cs->hw_mode |= SPMODE_LEN(bits_per_word);
266 
267 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
268 		cs->hw_mode |= SPMODE_DIV16;
269 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
270 
271 		WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
272 			  "Will use %d Hz instead.\n", dev_name(&spi->dev),
273 			  hz, mpc8xxx_spi->spibrg / 1024);
274 		if (pm > 16)
275 			pm = 16;
276 	} else {
277 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
278 	}
279 	if (pm)
280 		pm--;
281 
282 	cs->hw_mode |= SPMODE_PM(pm);
283 
284 	fsl_spi_change_mode(spi);
285 	return 0;
286 }
287 
fsl_spi_cpu_bufs(struct mpc8xxx_spi * mspi,struct spi_transfer * t,unsigned int len)288 static int fsl_spi_cpu_bufs(struct mpc8xxx_spi *mspi,
289 				struct spi_transfer *t, unsigned int len)
290 {
291 	u32 word;
292 	struct fsl_spi_reg *reg_base = mspi->reg_base;
293 
294 	mspi->count = len;
295 
296 	/* enable rx ints */
297 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
298 
299 	/* transmit word */
300 	word = mspi->get_tx(mspi);
301 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
302 
303 	return 0;
304 }
305 
fsl_spi_bufs(struct spi_device * spi,struct spi_transfer * t,bool is_dma_mapped)306 static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
307 			    bool is_dma_mapped)
308 {
309 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
310 	struct fsl_spi_reg *reg_base;
311 	unsigned int len = t->len;
312 	u8 bits_per_word;
313 	int ret;
314 
315 	reg_base = mpc8xxx_spi->reg_base;
316 	bits_per_word = spi->bits_per_word;
317 	if (t->bits_per_word)
318 		bits_per_word = t->bits_per_word;
319 
320 	if (bits_per_word > 8) {
321 		/* invalid length? */
322 		if (len & 1)
323 			return -EINVAL;
324 		len /= 2;
325 	}
326 	if (bits_per_word > 16) {
327 		/* invalid length? */
328 		if (len & 1)
329 			return -EINVAL;
330 		len /= 2;
331 	}
332 
333 	mpc8xxx_spi->tx = t->tx_buf;
334 	mpc8xxx_spi->rx = t->rx_buf;
335 
336 	reinit_completion(&mpc8xxx_spi->done);
337 
338 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
339 		ret = fsl_spi_cpm_bufs(mpc8xxx_spi, t, is_dma_mapped);
340 	else
341 		ret = fsl_spi_cpu_bufs(mpc8xxx_spi, t, len);
342 	if (ret)
343 		return ret;
344 
345 	wait_for_completion(&mpc8xxx_spi->done);
346 
347 	/* disable rx ints */
348 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
349 
350 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
351 		fsl_spi_cpm_bufs_complete(mpc8xxx_spi);
352 
353 	return mpc8xxx_spi->count;
354 }
355 
fsl_spi_do_one_msg(struct spi_master * master,struct spi_message * m)356 static int fsl_spi_do_one_msg(struct spi_master *master,
357 			      struct spi_message *m)
358 {
359 	struct spi_device *spi = m->spi;
360 	struct spi_transfer *t, *first;
361 	unsigned int cs_change;
362 	const int nsecs = 50;
363 	int status;
364 
365 	/* Don't allow changes if CS is active */
366 	first = list_first_entry(&m->transfers, struct spi_transfer,
367 			transfer_list);
368 	list_for_each_entry(t, &m->transfers, transfer_list) {
369 		if ((first->bits_per_word != t->bits_per_word) ||
370 			(first->speed_hz != t->speed_hz)) {
371 			dev_err(&spi->dev,
372 				"bits_per_word/speed_hz should be same for the same SPI transfer\n");
373 			return -EINVAL;
374 		}
375 	}
376 
377 	cs_change = 1;
378 	status = -EINVAL;
379 	list_for_each_entry(t, &m->transfers, transfer_list) {
380 		if (t->bits_per_word || t->speed_hz) {
381 			if (cs_change)
382 				status = fsl_spi_setup_transfer(spi, t);
383 			if (status < 0)
384 				break;
385 		}
386 
387 		if (cs_change) {
388 			fsl_spi_chipselect(spi, BITBANG_CS_ACTIVE);
389 			ndelay(nsecs);
390 		}
391 		cs_change = t->cs_change;
392 		if (t->len)
393 			status = fsl_spi_bufs(spi, t, m->is_dma_mapped);
394 		if (status) {
395 			status = -EMSGSIZE;
396 			break;
397 		}
398 		m->actual_length += t->len;
399 
400 		if (t->delay_usecs)
401 			udelay(t->delay_usecs);
402 
403 		if (cs_change) {
404 			ndelay(nsecs);
405 			fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
406 			ndelay(nsecs);
407 		}
408 	}
409 
410 	m->status = status;
411 	spi_finalize_current_message(master);
412 
413 	if (status || !cs_change) {
414 		ndelay(nsecs);
415 		fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
416 	}
417 
418 	fsl_spi_setup_transfer(spi, NULL);
419 	return 0;
420 }
421 
fsl_spi_setup(struct spi_device * spi)422 static int fsl_spi_setup(struct spi_device *spi)
423 {
424 	struct mpc8xxx_spi *mpc8xxx_spi;
425 	struct fsl_spi_reg *reg_base;
426 	int retval;
427 	u32 hw_mode;
428 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
429 
430 	if (!spi->max_speed_hz)
431 		return -EINVAL;
432 
433 	if (!cs) {
434 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
435 		if (!cs)
436 			return -ENOMEM;
437 		spi_set_ctldata(spi, cs);
438 	}
439 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
440 
441 	reg_base = mpc8xxx_spi->reg_base;
442 
443 	hw_mode = cs->hw_mode; /* Save original settings */
444 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
445 	/* mask out bits we are going to set */
446 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
447 			 | SPMODE_REV | SPMODE_LOOP);
448 
449 	if (spi->mode & SPI_CPHA)
450 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
451 	if (spi->mode & SPI_CPOL)
452 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
453 	if (!(spi->mode & SPI_LSB_FIRST))
454 		cs->hw_mode |= SPMODE_REV;
455 	if (spi->mode & SPI_LOOP)
456 		cs->hw_mode |= SPMODE_LOOP;
457 
458 	retval = fsl_spi_setup_transfer(spi, NULL);
459 	if (retval < 0) {
460 		cs->hw_mode = hw_mode; /* Restore settings */
461 		return retval;
462 	}
463 
464 	if (mpc8xxx_spi->type == TYPE_GRLIB) {
465 		if (gpio_is_valid(spi->cs_gpio)) {
466 			int desel;
467 
468 			retval = gpio_request(spi->cs_gpio,
469 					      dev_name(&spi->dev));
470 			if (retval)
471 				return retval;
472 
473 			desel = !(spi->mode & SPI_CS_HIGH);
474 			retval = gpio_direction_output(spi->cs_gpio, desel);
475 			if (retval) {
476 				gpio_free(spi->cs_gpio);
477 				return retval;
478 			}
479 		} else if (spi->cs_gpio != -ENOENT) {
480 			if (spi->cs_gpio < 0)
481 				return spi->cs_gpio;
482 			return -EINVAL;
483 		}
484 		/* When spi->cs_gpio == -ENOENT, a hole in the phandle list
485 		 * indicates to use native chipselect if present, or allow for
486 		 * an always selected chip
487 		 */
488 	}
489 
490 	/* Initialize chipselect - might be active for SPI_CS_HIGH mode */
491 	fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
492 
493 	return 0;
494 }
495 
fsl_spi_cleanup(struct spi_device * spi)496 static void fsl_spi_cleanup(struct spi_device *spi)
497 {
498 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
499 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
500 
501 	if (mpc8xxx_spi->type == TYPE_GRLIB && gpio_is_valid(spi->cs_gpio))
502 		gpio_free(spi->cs_gpio);
503 
504 	kfree(cs);
505 	spi_set_ctldata(spi, NULL);
506 }
507 
fsl_spi_cpu_irq(struct mpc8xxx_spi * mspi,u32 events)508 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
509 {
510 	struct fsl_spi_reg *reg_base = mspi->reg_base;
511 
512 	/* We need handle RX first */
513 	if (events & SPIE_NE) {
514 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
515 
516 		if (mspi->rx)
517 			mspi->get_rx(rx_data, mspi);
518 	}
519 
520 	if ((events & SPIE_NF) == 0)
521 		/* spin until TX is done */
522 		while (((events =
523 			mpc8xxx_spi_read_reg(&reg_base->event)) &
524 						SPIE_NF) == 0)
525 			cpu_relax();
526 
527 	/* Clear the events */
528 	mpc8xxx_spi_write_reg(&reg_base->event, events);
529 
530 	mspi->count -= 1;
531 	if (mspi->count) {
532 		u32 word = mspi->get_tx(mspi);
533 
534 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
535 	} else {
536 		complete(&mspi->done);
537 	}
538 }
539 
fsl_spi_irq(s32 irq,void * context_data)540 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
541 {
542 	struct mpc8xxx_spi *mspi = context_data;
543 	irqreturn_t ret = IRQ_NONE;
544 	u32 events;
545 	struct fsl_spi_reg *reg_base = mspi->reg_base;
546 
547 	/* Get interrupt events(tx/rx) */
548 	events = mpc8xxx_spi_read_reg(&reg_base->event);
549 	if (events)
550 		ret = IRQ_HANDLED;
551 
552 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
553 
554 	if (mspi->flags & SPI_CPM_MODE)
555 		fsl_spi_cpm_irq(mspi, events);
556 	else
557 		fsl_spi_cpu_irq(mspi, events);
558 
559 	return ret;
560 }
561 
fsl_spi_grlib_cs_control(struct spi_device * spi,bool on)562 static void fsl_spi_grlib_cs_control(struct spi_device *spi, bool on)
563 {
564 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
565 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
566 	u32 slvsel;
567 	u16 cs = spi->chip_select;
568 
569 	if (gpio_is_valid(spi->cs_gpio)) {
570 		gpio_set_value(spi->cs_gpio, on);
571 	} else if (cs < mpc8xxx_spi->native_chipselects) {
572 		slvsel = mpc8xxx_spi_read_reg(&reg_base->slvsel);
573 		slvsel = on ? (slvsel | (1 << cs)) : (slvsel & ~(1 << cs));
574 		mpc8xxx_spi_write_reg(&reg_base->slvsel, slvsel);
575 	}
576 }
577 
fsl_spi_grlib_probe(struct device * dev)578 static void fsl_spi_grlib_probe(struct device *dev)
579 {
580 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
581 	struct spi_master *master = dev_get_drvdata(dev);
582 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
583 	struct fsl_spi_reg *reg_base = mpc8xxx_spi->reg_base;
584 	int mbits;
585 	u32 capabilities;
586 
587 	capabilities = mpc8xxx_spi_read_reg(&reg_base->cap);
588 
589 	mpc8xxx_spi->set_shifts = fsl_spi_grlib_set_shifts;
590 	mbits = SPCAP_MAXWLEN(capabilities);
591 	if (mbits)
592 		mpc8xxx_spi->max_bits_per_word = mbits + 1;
593 
594 	mpc8xxx_spi->native_chipselects = 0;
595 	if (SPCAP_SSEN(capabilities)) {
596 		mpc8xxx_spi->native_chipselects = SPCAP_SSSZ(capabilities);
597 		mpc8xxx_spi_write_reg(&reg_base->slvsel, 0xffffffff);
598 	}
599 	master->num_chipselect = mpc8xxx_spi->native_chipselects;
600 	pdata->cs_control = fsl_spi_grlib_cs_control;
601 }
602 
fsl_spi_probe(struct device * dev,struct resource * mem,unsigned int irq)603 static struct spi_master * fsl_spi_probe(struct device *dev,
604 		struct resource *mem, unsigned int irq)
605 {
606 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
607 	struct spi_master *master;
608 	struct mpc8xxx_spi *mpc8xxx_spi;
609 	struct fsl_spi_reg *reg_base;
610 	u32 regval;
611 	int ret = 0;
612 
613 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
614 	if (master == NULL) {
615 		ret = -ENOMEM;
616 		goto err;
617 	}
618 
619 	dev_set_drvdata(dev, master);
620 
621 	mpc8xxx_spi_probe(dev, mem, irq);
622 
623 	master->setup = fsl_spi_setup;
624 	master->cleanup = fsl_spi_cleanup;
625 	master->transfer_one_message = fsl_spi_do_one_msg;
626 
627 	mpc8xxx_spi = spi_master_get_devdata(master);
628 	mpc8xxx_spi->max_bits_per_word = 32;
629 	mpc8xxx_spi->type = fsl_spi_get_type(dev);
630 
631 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
632 	if (ret)
633 		goto err_cpm_init;
634 
635 	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
636 	if (IS_ERR(mpc8xxx_spi->reg_base)) {
637 		ret = PTR_ERR(mpc8xxx_spi->reg_base);
638 		goto err_probe;
639 	}
640 
641 	if (mpc8xxx_spi->type == TYPE_GRLIB)
642 		fsl_spi_grlib_probe(dev);
643 
644 	master->bits_per_word_mask =
645 		(SPI_BPW_RANGE_MASK(4, 16) | SPI_BPW_MASK(32)) &
646 		SPI_BPW_RANGE_MASK(1, mpc8xxx_spi->max_bits_per_word);
647 
648 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
649 		mpc8xxx_spi->set_shifts = fsl_spi_qe_cpu_set_shifts;
650 
651 	if (mpc8xxx_spi->set_shifts)
652 		/* 8 bits per word and MSB first */
653 		mpc8xxx_spi->set_shifts(&mpc8xxx_spi->rx_shift,
654 					&mpc8xxx_spi->tx_shift, 8, 1);
655 
656 	/* Register for SPI Interrupt */
657 	ret = devm_request_irq(dev, mpc8xxx_spi->irq, fsl_spi_irq,
658 			       0, "fsl_spi", mpc8xxx_spi);
659 
660 	if (ret != 0)
661 		goto err_probe;
662 
663 	reg_base = mpc8xxx_spi->reg_base;
664 
665 	/* SPI controller initializations */
666 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
667 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
668 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
669 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
670 
671 	/* Enable SPI interface */
672 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
673 	if (mpc8xxx_spi->max_bits_per_word < 8) {
674 		regval &= ~SPMODE_LEN(0xF);
675 		regval |= SPMODE_LEN(mpc8xxx_spi->max_bits_per_word - 1);
676 	}
677 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
678 		regval |= SPMODE_OP;
679 
680 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
681 
682 	ret = devm_spi_register_master(dev, master);
683 	if (ret < 0)
684 		goto err_probe;
685 
686 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
687 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
688 
689 	return master;
690 
691 err_probe:
692 	fsl_spi_cpm_free(mpc8xxx_spi);
693 err_cpm_init:
694 	spi_master_put(master);
695 err:
696 	return ERR_PTR(ret);
697 }
698 
fsl_spi_cs_control(struct spi_device * spi,bool on)699 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
700 {
701 	struct device *dev = spi->dev.parent->parent;
702 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
703 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
704 	u16 cs = spi->chip_select;
705 	int gpio = pinfo->gpios[cs];
706 	bool alow = pinfo->alow_flags[cs];
707 
708 	gpio_set_value(gpio, on ^ alow);
709 }
710 
of_fsl_spi_get_chipselects(struct device * dev)711 static int of_fsl_spi_get_chipselects(struct device *dev)
712 {
713 	struct device_node *np = dev->of_node;
714 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
715 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
716 	int ngpios;
717 	int i = 0;
718 	int ret;
719 
720 	ngpios = of_gpio_count(np);
721 	if (ngpios <= 0) {
722 		/*
723 		 * SPI w/o chip-select line. One SPI device is still permitted
724 		 * though.
725 		 */
726 		pdata->max_chipselect = 1;
727 		return 0;
728 	}
729 
730 	pinfo->gpios = kmalloc(ngpios * sizeof(*pinfo->gpios), GFP_KERNEL);
731 	if (!pinfo->gpios)
732 		return -ENOMEM;
733 	memset(pinfo->gpios, -1, ngpios * sizeof(*pinfo->gpios));
734 
735 	pinfo->alow_flags = kzalloc(ngpios * sizeof(*pinfo->alow_flags),
736 				    GFP_KERNEL);
737 	if (!pinfo->alow_flags) {
738 		ret = -ENOMEM;
739 		goto err_alloc_flags;
740 	}
741 
742 	for (; i < ngpios; i++) {
743 		int gpio;
744 		enum of_gpio_flags flags;
745 
746 		gpio = of_get_gpio_flags(np, i, &flags);
747 		if (!gpio_is_valid(gpio)) {
748 			dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
749 			ret = gpio;
750 			goto err_loop;
751 		}
752 
753 		ret = gpio_request(gpio, dev_name(dev));
754 		if (ret) {
755 			dev_err(dev, "can't request gpio #%d: %d\n", i, ret);
756 			goto err_loop;
757 		}
758 
759 		pinfo->gpios[i] = gpio;
760 		pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW;
761 
762 		ret = gpio_direction_output(pinfo->gpios[i],
763 					    pinfo->alow_flags[i]);
764 		if (ret) {
765 			dev_err(dev, "can't set output direction for gpio "
766 				"#%d: %d\n", i, ret);
767 			goto err_loop;
768 		}
769 	}
770 
771 	pdata->max_chipselect = ngpios;
772 	pdata->cs_control = fsl_spi_cs_control;
773 
774 	return 0;
775 
776 err_loop:
777 	while (i >= 0) {
778 		if (gpio_is_valid(pinfo->gpios[i]))
779 			gpio_free(pinfo->gpios[i]);
780 		i--;
781 	}
782 
783 	kfree(pinfo->alow_flags);
784 	pinfo->alow_flags = NULL;
785 err_alloc_flags:
786 	kfree(pinfo->gpios);
787 	pinfo->gpios = NULL;
788 	return ret;
789 }
790 
of_fsl_spi_free_chipselects(struct device * dev)791 static int of_fsl_spi_free_chipselects(struct device *dev)
792 {
793 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
794 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
795 	int i;
796 
797 	if (!pinfo->gpios)
798 		return 0;
799 
800 	for (i = 0; i < pdata->max_chipselect; i++) {
801 		if (gpio_is_valid(pinfo->gpios[i]))
802 			gpio_free(pinfo->gpios[i]);
803 	}
804 
805 	kfree(pinfo->gpios);
806 	kfree(pinfo->alow_flags);
807 	return 0;
808 }
809 
of_fsl_spi_probe(struct platform_device * ofdev)810 static int of_fsl_spi_probe(struct platform_device *ofdev)
811 {
812 	struct device *dev = &ofdev->dev;
813 	struct device_node *np = ofdev->dev.of_node;
814 	struct spi_master *master;
815 	struct resource mem;
816 	int irq, type;
817 	int ret = -ENOMEM;
818 
819 	ret = of_mpc8xxx_spi_probe(ofdev);
820 	if (ret)
821 		return ret;
822 
823 	type = fsl_spi_get_type(&ofdev->dev);
824 	if (type == TYPE_FSL) {
825 		ret = of_fsl_spi_get_chipselects(dev);
826 		if (ret)
827 			goto err;
828 	}
829 
830 	ret = of_address_to_resource(np, 0, &mem);
831 	if (ret)
832 		goto err;
833 
834 	irq = irq_of_parse_and_map(np, 0);
835 	if (!irq) {
836 		ret = -EINVAL;
837 		goto err;
838 	}
839 
840 	master = fsl_spi_probe(dev, &mem, irq);
841 	if (IS_ERR(master)) {
842 		ret = PTR_ERR(master);
843 		goto err;
844 	}
845 
846 	return 0;
847 
848 err:
849 	if (type == TYPE_FSL)
850 		of_fsl_spi_free_chipselects(dev);
851 	return ret;
852 }
853 
of_fsl_spi_remove(struct platform_device * ofdev)854 static int of_fsl_spi_remove(struct platform_device *ofdev)
855 {
856 	struct spi_master *master = platform_get_drvdata(ofdev);
857 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
858 
859 	fsl_spi_cpm_free(mpc8xxx_spi);
860 	if (mpc8xxx_spi->type == TYPE_FSL)
861 		of_fsl_spi_free_chipselects(&ofdev->dev);
862 	return 0;
863 }
864 
865 static struct platform_driver of_fsl_spi_driver = {
866 	.driver = {
867 		.name = "fsl_spi",
868 		.of_match_table = of_fsl_spi_match,
869 	},
870 	.probe		= of_fsl_spi_probe,
871 	.remove		= of_fsl_spi_remove,
872 };
873 
874 #ifdef CONFIG_MPC832x_RDB
875 /*
876  * XXX XXX XXX
877  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
878  * only. The driver should go away soon, since newer MPC8323E-RDB's device
879  * tree can work with OpenFirmware driver. But for now we support old trees
880  * as well.
881  */
plat_mpc8xxx_spi_probe(struct platform_device * pdev)882 static int plat_mpc8xxx_spi_probe(struct platform_device *pdev)
883 {
884 	struct resource *mem;
885 	int irq;
886 	struct spi_master *master;
887 
888 	if (!dev_get_platdata(&pdev->dev))
889 		return -EINVAL;
890 
891 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
892 	if (!mem)
893 		return -EINVAL;
894 
895 	irq = platform_get_irq(pdev, 0);
896 	if (irq <= 0)
897 		return -EINVAL;
898 
899 	master = fsl_spi_probe(&pdev->dev, mem, irq);
900 	return PTR_ERR_OR_ZERO(master);
901 }
902 
plat_mpc8xxx_spi_remove(struct platform_device * pdev)903 static int plat_mpc8xxx_spi_remove(struct platform_device *pdev)
904 {
905 	struct spi_master *master = platform_get_drvdata(pdev);
906 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
907 
908 	fsl_spi_cpm_free(mpc8xxx_spi);
909 
910 	return 0;
911 }
912 
913 MODULE_ALIAS("platform:mpc8xxx_spi");
914 static struct platform_driver mpc8xxx_spi_driver = {
915 	.probe = plat_mpc8xxx_spi_probe,
916 	.remove = plat_mpc8xxx_spi_remove,
917 	.driver = {
918 		.name = "mpc8xxx_spi",
919 	},
920 };
921 
922 static bool legacy_driver_failed;
923 
legacy_driver_register(void)924 static void __init legacy_driver_register(void)
925 {
926 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
927 }
928 
legacy_driver_unregister(void)929 static void __exit legacy_driver_unregister(void)
930 {
931 	if (legacy_driver_failed)
932 		return;
933 	platform_driver_unregister(&mpc8xxx_spi_driver);
934 }
935 #else
legacy_driver_register(void)936 static void __init legacy_driver_register(void) {}
legacy_driver_unregister(void)937 static void __exit legacy_driver_unregister(void) {}
938 #endif /* CONFIG_MPC832x_RDB */
939 
fsl_spi_init(void)940 static int __init fsl_spi_init(void)
941 {
942 	legacy_driver_register();
943 	return platform_driver_register(&of_fsl_spi_driver);
944 }
945 module_init(fsl_spi_init);
946 
fsl_spi_exit(void)947 static void __exit fsl_spi_exit(void)
948 {
949 	platform_driver_unregister(&of_fsl_spi_driver);
950 	legacy_driver_unregister();
951 }
952 module_exit(fsl_spi_exit);
953 
954 MODULE_AUTHOR("Kumar Gala");
955 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
956 MODULE_LICENSE("GPL");
957