xref: /linux/drivers/spi/spi-fsl-espi.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Freescale eSPI controller driver.
3  *
4  * Copyright 2010 Freescale Semiconductor, Inc.
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  */
11 #include <linux/module.h>
12 #include <linux/delay.h>
13 #include <linux/irq.h>
14 #include <linux/spi/spi.h>
15 #include <linux/platform_device.h>
16 #include <linux/fsl_devices.h>
17 #include <linux/mm.h>
18 #include <linux/of.h>
19 #include <linux/of_platform.h>
20 #include <linux/interrupt.h>
21 #include <linux/err.h>
22 #include <sysdev/fsl_soc.h>
23 
24 #include "spi-fsl-lib.h"
25 
26 /* eSPI Controller registers */
27 struct fsl_espi_reg {
28 	__be32 mode;		/* 0x000 - eSPI mode register */
29 	__be32 event;		/* 0x004 - eSPI event register */
30 	__be32 mask;		/* 0x008 - eSPI mask register */
31 	__be32 command;		/* 0x00c - eSPI command register */
32 	__be32 transmit;	/* 0x010 - eSPI transmit FIFO access register*/
33 	__be32 receive;		/* 0x014 - eSPI receive FIFO access register*/
34 	u8 res[8];		/* 0x018 - 0x01c reserved */
35 	__be32 csmode[4];	/* 0x020 - 0x02c eSPI cs mode register */
36 };
37 
38 struct fsl_espi_transfer {
39 	const void *tx_buf;
40 	void *rx_buf;
41 	unsigned len;
42 	unsigned n_tx;
43 	unsigned n_rx;
44 	unsigned actual_length;
45 	int status;
46 };
47 
48 /* eSPI Controller mode register definitions */
49 #define SPMODE_ENABLE		(1 << 31)
50 #define SPMODE_LOOP		(1 << 30)
51 #define SPMODE_TXTHR(x)		((x) << 8)
52 #define SPMODE_RXTHR(x)		((x) << 0)
53 
54 /* eSPI Controller CS mode register definitions */
55 #define CSMODE_CI_INACTIVEHIGH	(1 << 31)
56 #define CSMODE_CP_BEGIN_EDGECLK	(1 << 30)
57 #define CSMODE_REV		(1 << 29)
58 #define CSMODE_DIV16		(1 << 28)
59 #define CSMODE_PM(x)		((x) << 24)
60 #define CSMODE_POL_1		(1 << 20)
61 #define CSMODE_LEN(x)		((x) << 16)
62 #define CSMODE_BEF(x)		((x) << 12)
63 #define CSMODE_AFT(x)		((x) << 8)
64 #define CSMODE_CG(x)		((x) << 3)
65 
66 /* Default mode/csmode for eSPI controller */
67 #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3))
68 #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
69 		| CSMODE_AFT(0) | CSMODE_CG(1))
70 
71 /* SPIE register values */
72 #define	SPIE_NE		0x00000200	/* Not empty */
73 #define	SPIE_NF		0x00000100	/* Not full */
74 
75 /* SPIM register values */
76 #define	SPIM_NE		0x00000200	/* Not empty */
77 #define	SPIM_NF		0x00000100	/* Not full */
78 #define SPIE_RXCNT(reg)     ((reg >> 24) & 0x3F)
79 #define SPIE_TXCNT(reg)     ((reg >> 16) & 0x3F)
80 
81 /* SPCOM register values */
82 #define SPCOM_CS(x)		((x) << 30)
83 #define SPCOM_TRANLEN(x)	((x) << 0)
84 #define	SPCOM_TRANLEN_MAX	0xFFFF	/* Max transaction length */
85 
86 static void fsl_espi_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_espi_reg *reg_base = mspi->reg_base;
91 	__be32 __iomem *mode = &reg_base->csmode[spi->chip_select];
92 	__be32 __iomem *espi_mode = &reg_base->mode;
93 	u32 tmp;
94 	unsigned long flags;
95 
96 	/* Turn off IRQs locally to minimize time that SPI is disabled. */
97 	local_irq_save(flags);
98 
99 	/* Turn off SPI unit prior changing mode */
100 	tmp = mpc8xxx_spi_read_reg(espi_mode);
101 	mpc8xxx_spi_write_reg(espi_mode, tmp & ~SPMODE_ENABLE);
102 	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
103 	mpc8xxx_spi_write_reg(espi_mode, tmp);
104 
105 	local_irq_restore(flags);
106 }
107 
108 static u32 fsl_espi_tx_buf_lsb(struct mpc8xxx_spi *mpc8xxx_spi)
109 {
110 	u32 data;
111 	u16 data_h;
112 	u16 data_l;
113 	const u32 *tx = mpc8xxx_spi->tx;
114 
115 	if (!tx)
116 		return 0;
117 
118 	data = *tx++ << mpc8xxx_spi->tx_shift;
119 	data_l = data & 0xffff;
120 	data_h = (data >> 16) & 0xffff;
121 	swab16s(&data_l);
122 	swab16s(&data_h);
123 	data = data_h | data_l;
124 
125 	mpc8xxx_spi->tx = tx;
126 	return data;
127 }
128 
129 static int fsl_espi_setup_transfer(struct spi_device *spi,
130 					struct spi_transfer *t)
131 {
132 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
133 	int bits_per_word = 0;
134 	u8 pm;
135 	u32 hz = 0;
136 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
137 
138 	if (t) {
139 		bits_per_word = t->bits_per_word;
140 		hz = t->speed_hz;
141 	}
142 
143 	/* spi_transfer level calls that work per-word */
144 	if (!bits_per_word)
145 		bits_per_word = spi->bits_per_word;
146 
147 	/* Make sure its a bit width we support [4..16] */
148 	if ((bits_per_word < 4) || (bits_per_word > 16))
149 		return -EINVAL;
150 
151 	if (!hz)
152 		hz = spi->max_speed_hz;
153 
154 	cs->rx_shift = 0;
155 	cs->tx_shift = 0;
156 	cs->get_rx = mpc8xxx_spi_rx_buf_u32;
157 	cs->get_tx = mpc8xxx_spi_tx_buf_u32;
158 	if (bits_per_word <= 8) {
159 		cs->rx_shift = 8 - bits_per_word;
160 	} else if (bits_per_word <= 16) {
161 		cs->rx_shift = 16 - bits_per_word;
162 		if (spi->mode & SPI_LSB_FIRST)
163 			cs->get_tx = fsl_espi_tx_buf_lsb;
164 	} else {
165 		return -EINVAL;
166 	}
167 
168 	mpc8xxx_spi->rx_shift = cs->rx_shift;
169 	mpc8xxx_spi->tx_shift = cs->tx_shift;
170 	mpc8xxx_spi->get_rx = cs->get_rx;
171 	mpc8xxx_spi->get_tx = cs->get_tx;
172 
173 	bits_per_word = bits_per_word - 1;
174 
175 	/* mask out bits we are going to set */
176 	cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
177 
178 	cs->hw_mode |= CSMODE_LEN(bits_per_word);
179 
180 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
181 		cs->hw_mode |= CSMODE_DIV16;
182 		pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4);
183 
184 		WARN_ONCE(pm > 33, "%s: Requested speed is too low: %d Hz. "
185 			  "Will use %d Hz instead.\n", dev_name(&spi->dev),
186 				hz, mpc8xxx_spi->spibrg / (4 * 16 * (32 + 1)));
187 		if (pm > 33)
188 			pm = 33;
189 	} else {
190 		pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4);
191 	}
192 	if (pm)
193 		pm--;
194 	if (pm < 2)
195 		pm = 2;
196 
197 	cs->hw_mode |= CSMODE_PM(pm);
198 
199 	fsl_espi_change_mode(spi);
200 	return 0;
201 }
202 
203 static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t,
204 		unsigned int len)
205 {
206 	u32 word;
207 	struct fsl_espi_reg *reg_base = mspi->reg_base;
208 
209 	mspi->count = len;
210 
211 	/* enable rx ints */
212 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
213 
214 	/* transmit word */
215 	word = mspi->get_tx(mspi);
216 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
217 
218 	return 0;
219 }
220 
221 static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
222 {
223 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
224 	struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
225 	unsigned int len = t->len;
226 	u8 bits_per_word;
227 	int ret;
228 
229 	bits_per_word = spi->bits_per_word;
230 	if (t->bits_per_word)
231 		bits_per_word = t->bits_per_word;
232 
233 	mpc8xxx_spi->len = t->len;
234 	len = roundup(len, 4) / 4;
235 
236 	mpc8xxx_spi->tx = t->tx_buf;
237 	mpc8xxx_spi->rx = t->rx_buf;
238 
239 	INIT_COMPLETION(mpc8xxx_spi->done);
240 
241 	/* Set SPCOM[CS] and SPCOM[TRANLEN] field */
242 	if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
243 		dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
244 				" beyond the SPCOM[TRANLEN] field\n", t->len);
245 		return -EINVAL;
246 	}
247 	mpc8xxx_spi_write_reg(&reg_base->command,
248 		(SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1)));
249 
250 	ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len);
251 	if (ret)
252 		return ret;
253 
254 	wait_for_completion(&mpc8xxx_spi->done);
255 
256 	/* disable rx ints */
257 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
258 
259 	return mpc8xxx_spi->count;
260 }
261 
262 static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
263 {
264 	if (cmd) {
265 		cmd[1] = (u8)(addr >> 16);
266 		cmd[2] = (u8)(addr >> 8);
267 		cmd[3] = (u8)(addr >> 0);
268 	}
269 }
270 
271 static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
272 {
273 	if (cmd)
274 		return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
275 
276 	return 0;
277 }
278 
279 static void fsl_espi_do_trans(struct spi_message *m,
280 				struct fsl_espi_transfer *tr)
281 {
282 	struct spi_device *spi = m->spi;
283 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
284 	struct fsl_espi_transfer *espi_trans = tr;
285 	struct spi_message message;
286 	struct spi_transfer *t, *first, trans;
287 	int status = 0;
288 
289 	spi_message_init(&message);
290 	memset(&trans, 0, sizeof(trans));
291 
292 	first = list_first_entry(&m->transfers, struct spi_transfer,
293 			transfer_list);
294 	list_for_each_entry(t, &m->transfers, transfer_list) {
295 		if ((first->bits_per_word != t->bits_per_word) ||
296 			(first->speed_hz != t->speed_hz)) {
297 			espi_trans->status = -EINVAL;
298 			dev_err(mspi->dev, "bits_per_word/speed_hz should be"
299 					" same for the same SPI transfer\n");
300 			return;
301 		}
302 
303 		trans.speed_hz = t->speed_hz;
304 		trans.bits_per_word = t->bits_per_word;
305 		trans.delay_usecs = max(first->delay_usecs, t->delay_usecs);
306 	}
307 
308 	trans.len = espi_trans->len;
309 	trans.tx_buf = espi_trans->tx_buf;
310 	trans.rx_buf = espi_trans->rx_buf;
311 	spi_message_add_tail(&trans, &message);
312 
313 	list_for_each_entry(t, &message.transfers, transfer_list) {
314 		if (t->bits_per_word || t->speed_hz) {
315 			status = -EINVAL;
316 
317 			status = fsl_espi_setup_transfer(spi, t);
318 			if (status < 0)
319 				break;
320 		}
321 
322 		if (t->len)
323 			status = fsl_espi_bufs(spi, t);
324 
325 		if (status) {
326 			status = -EMSGSIZE;
327 			break;
328 		}
329 
330 		if (t->delay_usecs)
331 			udelay(t->delay_usecs);
332 	}
333 
334 	espi_trans->status = status;
335 	fsl_espi_setup_transfer(spi, NULL);
336 }
337 
338 static void fsl_espi_cmd_trans(struct spi_message *m,
339 				struct fsl_espi_transfer *trans, u8 *rx_buff)
340 {
341 	struct spi_transfer *t;
342 	u8 *local_buf;
343 	int i = 0;
344 	struct fsl_espi_transfer *espi_trans = trans;
345 
346 	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
347 	if (!local_buf) {
348 		espi_trans->status = -ENOMEM;
349 		return;
350 	}
351 
352 	list_for_each_entry(t, &m->transfers, transfer_list) {
353 		if (t->tx_buf) {
354 			memcpy(local_buf + i, t->tx_buf, t->len);
355 			i += t->len;
356 		}
357 	}
358 
359 	espi_trans->tx_buf = local_buf;
360 	espi_trans->rx_buf = local_buf + espi_trans->n_tx;
361 	fsl_espi_do_trans(m, espi_trans);
362 
363 	espi_trans->actual_length = espi_trans->len;
364 	kfree(local_buf);
365 }
366 
367 static void fsl_espi_rw_trans(struct spi_message *m,
368 				struct fsl_espi_transfer *trans, u8 *rx_buff)
369 {
370 	struct fsl_espi_transfer *espi_trans = trans;
371 	unsigned int n_tx = espi_trans->n_tx;
372 	unsigned int n_rx = espi_trans->n_rx;
373 	struct spi_transfer *t;
374 	u8 *local_buf;
375 	u8 *rx_buf = rx_buff;
376 	unsigned int trans_len;
377 	unsigned int addr;
378 	int i, pos, loop;
379 
380 	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
381 	if (!local_buf) {
382 		espi_trans->status = -ENOMEM;
383 		return;
384 	}
385 
386 	for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) {
387 		trans_len = n_rx - pos;
388 		if (trans_len > SPCOM_TRANLEN_MAX - n_tx)
389 			trans_len = SPCOM_TRANLEN_MAX - n_tx;
390 
391 		i = 0;
392 		list_for_each_entry(t, &m->transfers, transfer_list) {
393 			if (t->tx_buf) {
394 				memcpy(local_buf + i, t->tx_buf, t->len);
395 				i += t->len;
396 			}
397 		}
398 
399 		if (pos > 0) {
400 			addr = fsl_espi_cmd2addr(local_buf);
401 			addr += pos;
402 			fsl_espi_addr2cmd(addr, local_buf);
403 		}
404 
405 		espi_trans->n_tx = n_tx;
406 		espi_trans->n_rx = trans_len;
407 		espi_trans->len = trans_len + n_tx;
408 		espi_trans->tx_buf = local_buf;
409 		espi_trans->rx_buf = local_buf + n_tx;
410 		fsl_espi_do_trans(m, espi_trans);
411 
412 		memcpy(rx_buf + pos, espi_trans->rx_buf + n_tx, trans_len);
413 
414 		if (loop > 0)
415 			espi_trans->actual_length += espi_trans->len - n_tx;
416 		else
417 			espi_trans->actual_length += espi_trans->len;
418 	}
419 
420 	kfree(local_buf);
421 }
422 
423 static void fsl_espi_do_one_msg(struct spi_message *m)
424 {
425 	struct spi_transfer *t;
426 	u8 *rx_buf = NULL;
427 	unsigned int n_tx = 0;
428 	unsigned int n_rx = 0;
429 	struct fsl_espi_transfer espi_trans;
430 
431 	list_for_each_entry(t, &m->transfers, transfer_list) {
432 		if (t->tx_buf)
433 			n_tx += t->len;
434 		if (t->rx_buf) {
435 			n_rx += t->len;
436 			rx_buf = t->rx_buf;
437 		}
438 	}
439 
440 	espi_trans.n_tx = n_tx;
441 	espi_trans.n_rx = n_rx;
442 	espi_trans.len = n_tx + n_rx;
443 	espi_trans.actual_length = 0;
444 	espi_trans.status = 0;
445 
446 	if (!rx_buf)
447 		fsl_espi_cmd_trans(m, &espi_trans, NULL);
448 	else
449 		fsl_espi_rw_trans(m, &espi_trans, rx_buf);
450 
451 	m->actual_length = espi_trans.actual_length;
452 	m->status = espi_trans.status;
453 	m->complete(m->context);
454 }
455 
456 static int fsl_espi_setup(struct spi_device *spi)
457 {
458 	struct mpc8xxx_spi *mpc8xxx_spi;
459 	struct fsl_espi_reg *reg_base;
460 	int retval;
461 	u32 hw_mode;
462 	u32 loop_mode;
463 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
464 
465 	if (!spi->max_speed_hz)
466 		return -EINVAL;
467 
468 	if (!cs) {
469 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
470 		if (!cs)
471 			return -ENOMEM;
472 		spi->controller_state = cs;
473 	}
474 
475 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
476 	reg_base = mpc8xxx_spi->reg_base;
477 
478 	hw_mode = cs->hw_mode; /* Save original settings */
479 	cs->hw_mode = mpc8xxx_spi_read_reg(
480 			&reg_base->csmode[spi->chip_select]);
481 	/* mask out bits we are going to set */
482 	cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
483 			 | CSMODE_REV);
484 
485 	if (spi->mode & SPI_CPHA)
486 		cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
487 	if (spi->mode & SPI_CPOL)
488 		cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
489 	if (!(spi->mode & SPI_LSB_FIRST))
490 		cs->hw_mode |= CSMODE_REV;
491 
492 	/* Handle the loop mode */
493 	loop_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
494 	loop_mode &= ~SPMODE_LOOP;
495 	if (spi->mode & SPI_LOOP)
496 		loop_mode |= SPMODE_LOOP;
497 	mpc8xxx_spi_write_reg(&reg_base->mode, loop_mode);
498 
499 	retval = fsl_espi_setup_transfer(spi, NULL);
500 	if (retval < 0) {
501 		cs->hw_mode = hw_mode; /* Restore settings */
502 		return retval;
503 	}
504 	return 0;
505 }
506 
507 void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
508 {
509 	struct fsl_espi_reg *reg_base = mspi->reg_base;
510 
511 	/* We need handle RX first */
512 	if (events & SPIE_NE) {
513 		u32 rx_data, tmp;
514 		u8 rx_data_8;
515 
516 		/* Spin until RX is done */
517 		while (SPIE_RXCNT(events) < min(4, mspi->len)) {
518 			cpu_relax();
519 			events = mpc8xxx_spi_read_reg(&reg_base->event);
520 		}
521 
522 		if (mspi->len >= 4) {
523 			rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
524 		} else {
525 			tmp = mspi->len;
526 			rx_data = 0;
527 			while (tmp--) {
528 				rx_data_8 = in_8((u8 *)&reg_base->receive);
529 				rx_data |= (rx_data_8 << (tmp * 8));
530 			}
531 
532 			rx_data <<= (4 - mspi->len) * 8;
533 		}
534 
535 		mspi->len -= 4;
536 
537 		if (mspi->rx)
538 			mspi->get_rx(rx_data, mspi);
539 	}
540 
541 	if (!(events & SPIE_NF)) {
542 		int ret;
543 
544 		/* spin until TX is done */
545 		ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg(
546 				&reg_base->event)) & SPIE_NF) == 0, 1000, 0);
547 		if (!ret) {
548 			dev_err(mspi->dev, "tired waiting for SPIE_NF\n");
549 			return;
550 		}
551 	}
552 
553 	/* Clear the events */
554 	mpc8xxx_spi_write_reg(&reg_base->event, events);
555 
556 	mspi->count -= 1;
557 	if (mspi->count) {
558 		u32 word = mspi->get_tx(mspi);
559 
560 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
561 	} else {
562 		complete(&mspi->done);
563 	}
564 }
565 
566 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
567 {
568 	struct mpc8xxx_spi *mspi = context_data;
569 	struct fsl_espi_reg *reg_base = mspi->reg_base;
570 	irqreturn_t ret = IRQ_NONE;
571 	u32 events;
572 
573 	/* Get interrupt events(tx/rx) */
574 	events = mpc8xxx_spi_read_reg(&reg_base->event);
575 	if (events)
576 		ret = IRQ_HANDLED;
577 
578 	dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events);
579 
580 	fsl_espi_cpu_irq(mspi, events);
581 
582 	return ret;
583 }
584 
585 static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
586 {
587 	iounmap(mspi->reg_base);
588 }
589 
590 static struct spi_master * fsl_espi_probe(struct device *dev,
591 		struct resource *mem, unsigned int irq)
592 {
593 	struct fsl_spi_platform_data *pdata = dev->platform_data;
594 	struct spi_master *master;
595 	struct mpc8xxx_spi *mpc8xxx_spi;
596 	struct fsl_espi_reg *reg_base;
597 	u32 regval;
598 	int i, ret = 0;
599 
600 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
601 	if (!master) {
602 		ret = -ENOMEM;
603 		goto err;
604 	}
605 
606 	dev_set_drvdata(dev, master);
607 
608 	ret = mpc8xxx_spi_probe(dev, mem, irq);
609 	if (ret)
610 		goto err_probe;
611 
612 	master->setup = fsl_espi_setup;
613 
614 	mpc8xxx_spi = spi_master_get_devdata(master);
615 	mpc8xxx_spi->spi_do_one_msg = fsl_espi_do_one_msg;
616 	mpc8xxx_spi->spi_remove = fsl_espi_remove;
617 
618 	mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
619 	if (!mpc8xxx_spi->reg_base) {
620 		ret = -ENOMEM;
621 		goto err_probe;
622 	}
623 
624 	reg_base = mpc8xxx_spi->reg_base;
625 
626 	/* Register for SPI Interrupt */
627 	ret = request_irq(mpc8xxx_spi->irq, fsl_espi_irq,
628 			  0, "fsl_espi", mpc8xxx_spi);
629 	if (ret)
630 		goto free_irq;
631 
632 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
633 		mpc8xxx_spi->rx_shift = 16;
634 		mpc8xxx_spi->tx_shift = 24;
635 	}
636 
637 	/* SPI controller initializations */
638 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
639 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
640 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
641 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
642 
643 	/* Init eSPI CS mode register */
644 	for (i = 0; i < pdata->max_chipselect; i++)
645 		mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
646 
647 	/* Enable SPI interface */
648 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
649 
650 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
651 
652 	ret = spi_register_master(master);
653 	if (ret < 0)
654 		goto unreg_master;
655 
656 	dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq);
657 
658 	return master;
659 
660 unreg_master:
661 	free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
662 free_irq:
663 	iounmap(mpc8xxx_spi->reg_base);
664 err_probe:
665 	spi_master_put(master);
666 err:
667 	return ERR_PTR(ret);
668 }
669 
670 static int of_fsl_espi_get_chipselects(struct device *dev)
671 {
672 	struct device_node *np = dev->of_node;
673 	struct fsl_spi_platform_data *pdata = dev->platform_data;
674 	const u32 *prop;
675 	int len;
676 
677 	prop = of_get_property(np, "fsl,espi-num-chipselects", &len);
678 	if (!prop || len < sizeof(*prop)) {
679 		dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
680 		return -EINVAL;
681 	}
682 
683 	pdata->max_chipselect = *prop;
684 	pdata->cs_control = NULL;
685 
686 	return 0;
687 }
688 
689 static int of_fsl_espi_probe(struct platform_device *ofdev)
690 {
691 	struct device *dev = &ofdev->dev;
692 	struct device_node *np = ofdev->dev.of_node;
693 	struct spi_master *master;
694 	struct resource mem;
695 	struct resource irq;
696 	int ret = -ENOMEM;
697 
698 	ret = of_mpc8xxx_spi_probe(ofdev);
699 	if (ret)
700 		return ret;
701 
702 	ret = of_fsl_espi_get_chipselects(dev);
703 	if (ret)
704 		goto err;
705 
706 	ret = of_address_to_resource(np, 0, &mem);
707 	if (ret)
708 		goto err;
709 
710 	ret = of_irq_to_resource(np, 0, &irq);
711 	if (!ret) {
712 		ret = -EINVAL;
713 		goto err;
714 	}
715 
716 	master = fsl_espi_probe(dev, &mem, irq.start);
717 	if (IS_ERR(master)) {
718 		ret = PTR_ERR(master);
719 		goto err;
720 	}
721 
722 	return 0;
723 
724 err:
725 	return ret;
726 }
727 
728 static int of_fsl_espi_remove(struct platform_device *dev)
729 {
730 	return mpc8xxx_spi_remove(&dev->dev);
731 }
732 
733 static const struct of_device_id of_fsl_espi_match[] = {
734 	{ .compatible = "fsl,mpc8536-espi" },
735 	{}
736 };
737 MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
738 
739 static struct platform_driver fsl_espi_driver = {
740 	.driver = {
741 		.name = "fsl_espi",
742 		.owner = THIS_MODULE,
743 		.of_match_table = of_fsl_espi_match,
744 	},
745 	.probe		= of_fsl_espi_probe,
746 	.remove		= of_fsl_espi_remove,
747 };
748 module_platform_driver(fsl_espi_driver);
749 
750 MODULE_AUTHOR("Mingkai Hu");
751 MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
752 MODULE_LICENSE("GPL");
753