xref: /openbmc/linux/drivers/spi/spi-fsl-espi.c (revision 9cfc5c90)
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/delay.h>
12 #include <linux/err.h>
13 #include <linux/fsl_devices.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/module.h>
17 #include <linux/mm.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/spi/spi.h>
24 #include <linux/pm_runtime.h>
25 #include <sysdev/fsl_soc.h>
26 
27 #include "spi-fsl-lib.h"
28 
29 /* eSPI Controller registers */
30 struct fsl_espi_reg {
31 	__be32 mode;		/* 0x000 - eSPI mode register */
32 	__be32 event;		/* 0x004 - eSPI event register */
33 	__be32 mask;		/* 0x008 - eSPI mask register */
34 	__be32 command;		/* 0x00c - eSPI command register */
35 	__be32 transmit;	/* 0x010 - eSPI transmit FIFO access register*/
36 	__be32 receive;		/* 0x014 - eSPI receive FIFO access register*/
37 	u8 res[8];		/* 0x018 - 0x01c reserved */
38 	__be32 csmode[4];	/* 0x020 - 0x02c eSPI cs mode register */
39 };
40 
41 struct fsl_espi_transfer {
42 	const void *tx_buf;
43 	void *rx_buf;
44 	unsigned len;
45 	unsigned n_tx;
46 	unsigned n_rx;
47 	unsigned actual_length;
48 	int status;
49 };
50 
51 /* eSPI Controller mode register definitions */
52 #define SPMODE_ENABLE		(1 << 31)
53 #define SPMODE_LOOP		(1 << 30)
54 #define SPMODE_TXTHR(x)		((x) << 8)
55 #define SPMODE_RXTHR(x)		((x) << 0)
56 
57 /* eSPI Controller CS mode register definitions */
58 #define CSMODE_CI_INACTIVEHIGH	(1 << 31)
59 #define CSMODE_CP_BEGIN_EDGECLK	(1 << 30)
60 #define CSMODE_REV		(1 << 29)
61 #define CSMODE_DIV16		(1 << 28)
62 #define CSMODE_PM(x)		((x) << 24)
63 #define CSMODE_POL_1		(1 << 20)
64 #define CSMODE_LEN(x)		((x) << 16)
65 #define CSMODE_BEF(x)		((x) << 12)
66 #define CSMODE_AFT(x)		((x) << 8)
67 #define CSMODE_CG(x)		((x) << 3)
68 
69 /* Default mode/csmode for eSPI controller */
70 #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3))
71 #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
72 		| CSMODE_AFT(0) | CSMODE_CG(1))
73 
74 /* SPIE register values */
75 #define	SPIE_NE		0x00000200	/* Not empty */
76 #define	SPIE_NF		0x00000100	/* Not full */
77 
78 /* SPIM register values */
79 #define	SPIM_NE		0x00000200	/* Not empty */
80 #define	SPIM_NF		0x00000100	/* Not full */
81 #define SPIE_RXCNT(reg)     ((reg >> 24) & 0x3F)
82 #define SPIE_TXCNT(reg)     ((reg >> 16) & 0x3F)
83 
84 /* SPCOM register values */
85 #define SPCOM_CS(x)		((x) << 30)
86 #define SPCOM_TRANLEN(x)	((x) << 0)
87 #define	SPCOM_TRANLEN_MAX	0xFFFF	/* Max transaction length */
88 
89 #define AUTOSUSPEND_TIMEOUT 2000
90 
91 static void fsl_espi_change_mode(struct spi_device *spi)
92 {
93 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
94 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
95 	struct fsl_espi_reg *reg_base = mspi->reg_base;
96 	__be32 __iomem *mode = &reg_base->csmode[spi->chip_select];
97 	__be32 __iomem *espi_mode = &reg_base->mode;
98 	u32 tmp;
99 	unsigned long flags;
100 
101 	/* Turn off IRQs locally to minimize time that SPI is disabled. */
102 	local_irq_save(flags);
103 
104 	/* Turn off SPI unit prior changing mode */
105 	tmp = mpc8xxx_spi_read_reg(espi_mode);
106 	mpc8xxx_spi_write_reg(espi_mode, tmp & ~SPMODE_ENABLE);
107 	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
108 	mpc8xxx_spi_write_reg(espi_mode, tmp);
109 
110 	local_irq_restore(flags);
111 }
112 
113 static u32 fsl_espi_tx_buf_lsb(struct mpc8xxx_spi *mpc8xxx_spi)
114 {
115 	u32 data;
116 	u16 data_h;
117 	u16 data_l;
118 	const u32 *tx = mpc8xxx_spi->tx;
119 
120 	if (!tx)
121 		return 0;
122 
123 	data = *tx++ << mpc8xxx_spi->tx_shift;
124 	data_l = data & 0xffff;
125 	data_h = (data >> 16) & 0xffff;
126 	swab16s(&data_l);
127 	swab16s(&data_h);
128 	data = data_h | data_l;
129 
130 	mpc8xxx_spi->tx = tx;
131 	return data;
132 }
133 
134 static int fsl_espi_setup_transfer(struct spi_device *spi,
135 					struct spi_transfer *t)
136 {
137 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
138 	int bits_per_word = 0;
139 	u8 pm;
140 	u32 hz = 0;
141 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
142 
143 	if (t) {
144 		bits_per_word = t->bits_per_word;
145 		hz = t->speed_hz;
146 	}
147 
148 	/* spi_transfer level calls that work per-word */
149 	if (!bits_per_word)
150 		bits_per_word = spi->bits_per_word;
151 
152 	if (!hz)
153 		hz = spi->max_speed_hz;
154 
155 	cs->rx_shift = 0;
156 	cs->tx_shift = 0;
157 	cs->get_rx = mpc8xxx_spi_rx_buf_u32;
158 	cs->get_tx = mpc8xxx_spi_tx_buf_u32;
159 	if (bits_per_word <= 8) {
160 		cs->rx_shift = 8 - bits_per_word;
161 	} else {
162 		cs->rx_shift = 16 - bits_per_word;
163 		if (spi->mode & SPI_LSB_FIRST)
164 			cs->get_tx = fsl_espi_tx_buf_lsb;
165 	}
166 
167 	mpc8xxx_spi->rx_shift = cs->rx_shift;
168 	mpc8xxx_spi->tx_shift = cs->tx_shift;
169 	mpc8xxx_spi->get_rx = cs->get_rx;
170 	mpc8xxx_spi->get_tx = cs->get_tx;
171 
172 	bits_per_word = bits_per_word - 1;
173 
174 	/* mask out bits we are going to set */
175 	cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
176 
177 	cs->hw_mode |= CSMODE_LEN(bits_per_word);
178 
179 	if ((mpc8xxx_spi->spibrg / hz) > 64) {
180 		cs->hw_mode |= CSMODE_DIV16;
181 		pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4);
182 
183 		WARN_ONCE(pm > 33, "%s: Requested speed is too low: %d Hz. "
184 			  "Will use %d Hz instead.\n", dev_name(&spi->dev),
185 				hz, mpc8xxx_spi->spibrg / (4 * 16 * (32 + 1)));
186 		if (pm > 33)
187 			pm = 33;
188 	} else {
189 		pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4);
190 	}
191 	if (pm)
192 		pm--;
193 	if (pm < 2)
194 		pm = 2;
195 
196 	cs->hw_mode |= CSMODE_PM(pm);
197 
198 	fsl_espi_change_mode(spi);
199 	return 0;
200 }
201 
202 static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t,
203 		unsigned int len)
204 {
205 	u32 word;
206 	struct fsl_espi_reg *reg_base = mspi->reg_base;
207 
208 	mspi->count = len;
209 
210 	/* enable rx ints */
211 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
212 
213 	/* transmit word */
214 	word = mspi->get_tx(mspi);
215 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
216 
217 	return 0;
218 }
219 
220 static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
221 {
222 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
223 	struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
224 	unsigned int len = t->len;
225 	int ret;
226 
227 	mpc8xxx_spi->len = t->len;
228 	len = roundup(len, 4) / 4;
229 
230 	mpc8xxx_spi->tx = t->tx_buf;
231 	mpc8xxx_spi->rx = t->rx_buf;
232 
233 	reinit_completion(&mpc8xxx_spi->done);
234 
235 	/* Set SPCOM[CS] and SPCOM[TRANLEN] field */
236 	if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
237 		dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
238 				" beyond the SPCOM[TRANLEN] field\n", t->len);
239 		return -EINVAL;
240 	}
241 	mpc8xxx_spi_write_reg(&reg_base->command,
242 		(SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1)));
243 
244 	ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len);
245 	if (ret)
246 		return ret;
247 
248 	wait_for_completion(&mpc8xxx_spi->done);
249 
250 	/* disable rx ints */
251 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
252 
253 	return mpc8xxx_spi->count;
254 }
255 
256 static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
257 {
258 	if (cmd) {
259 		cmd[1] = (u8)(addr >> 16);
260 		cmd[2] = (u8)(addr >> 8);
261 		cmd[3] = (u8)(addr >> 0);
262 	}
263 }
264 
265 static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
266 {
267 	if (cmd)
268 		return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
269 
270 	return 0;
271 }
272 
273 static void fsl_espi_do_trans(struct spi_message *m,
274 				struct fsl_espi_transfer *tr)
275 {
276 	struct spi_device *spi = m->spi;
277 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
278 	struct fsl_espi_transfer *espi_trans = tr;
279 	struct spi_message message;
280 	struct spi_transfer *t, *first, trans;
281 	int status = 0;
282 
283 	spi_message_init(&message);
284 	memset(&trans, 0, sizeof(trans));
285 
286 	first = list_first_entry(&m->transfers, struct spi_transfer,
287 			transfer_list);
288 	list_for_each_entry(t, &m->transfers, transfer_list) {
289 		if ((first->bits_per_word != t->bits_per_word) ||
290 			(first->speed_hz != t->speed_hz)) {
291 			espi_trans->status = -EINVAL;
292 			dev_err(mspi->dev,
293 				"bits_per_word/speed_hz should be same for the same SPI transfer\n");
294 			return;
295 		}
296 
297 		trans.speed_hz = t->speed_hz;
298 		trans.bits_per_word = t->bits_per_word;
299 		trans.delay_usecs = max(first->delay_usecs, t->delay_usecs);
300 	}
301 
302 	trans.len = espi_trans->len;
303 	trans.tx_buf = espi_trans->tx_buf;
304 	trans.rx_buf = espi_trans->rx_buf;
305 	spi_message_add_tail(&trans, &message);
306 
307 	list_for_each_entry(t, &message.transfers, transfer_list) {
308 		if (t->bits_per_word || t->speed_hz) {
309 			status = -EINVAL;
310 
311 			status = fsl_espi_setup_transfer(spi, t);
312 			if (status < 0)
313 				break;
314 		}
315 
316 		if (t->len)
317 			status = fsl_espi_bufs(spi, t);
318 
319 		if (status) {
320 			status = -EMSGSIZE;
321 			break;
322 		}
323 
324 		if (t->delay_usecs)
325 			udelay(t->delay_usecs);
326 	}
327 
328 	espi_trans->status = status;
329 	fsl_espi_setup_transfer(spi, NULL);
330 }
331 
332 static void fsl_espi_cmd_trans(struct spi_message *m,
333 				struct fsl_espi_transfer *trans, u8 *rx_buff)
334 {
335 	struct spi_transfer *t;
336 	u8 *local_buf;
337 	int i = 0;
338 	struct fsl_espi_transfer *espi_trans = trans;
339 
340 	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
341 	if (!local_buf) {
342 		espi_trans->status = -ENOMEM;
343 		return;
344 	}
345 
346 	list_for_each_entry(t, &m->transfers, transfer_list) {
347 		if (t->tx_buf) {
348 			memcpy(local_buf + i, t->tx_buf, t->len);
349 			i += t->len;
350 		}
351 	}
352 
353 	espi_trans->tx_buf = local_buf;
354 	espi_trans->rx_buf = local_buf;
355 	fsl_espi_do_trans(m, espi_trans);
356 
357 	espi_trans->actual_length = espi_trans->len;
358 	kfree(local_buf);
359 }
360 
361 static void fsl_espi_rw_trans(struct spi_message *m,
362 				struct fsl_espi_transfer *trans, u8 *rx_buff)
363 {
364 	struct fsl_espi_transfer *espi_trans = trans;
365 	unsigned int total_len = espi_trans->len;
366 	struct spi_transfer *t;
367 	u8 *local_buf;
368 	u8 *rx_buf = rx_buff;
369 	unsigned int trans_len;
370 	unsigned int addr;
371 	unsigned int tx_only;
372 	unsigned int rx_pos = 0;
373 	unsigned int pos;
374 	int i, loop;
375 
376 	local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
377 	if (!local_buf) {
378 		espi_trans->status = -ENOMEM;
379 		return;
380 	}
381 
382 	for (pos = 0, loop = 0; pos < total_len; pos += trans_len, loop++) {
383 		trans_len = total_len - pos;
384 
385 		i = 0;
386 		tx_only = 0;
387 		list_for_each_entry(t, &m->transfers, transfer_list) {
388 			if (t->tx_buf) {
389 				memcpy(local_buf + i, t->tx_buf, t->len);
390 				i += t->len;
391 				if (!t->rx_buf)
392 					tx_only += t->len;
393 			}
394 		}
395 
396 		/* Add additional TX bytes to compensate SPCOM_TRANLEN_MAX */
397 		if (loop > 0)
398 			trans_len += tx_only;
399 
400 		if (trans_len > SPCOM_TRANLEN_MAX)
401 			trans_len = SPCOM_TRANLEN_MAX;
402 
403 		/* Update device offset */
404 		if (pos > 0) {
405 			addr = fsl_espi_cmd2addr(local_buf);
406 			addr += rx_pos;
407 			fsl_espi_addr2cmd(addr, local_buf);
408 		}
409 
410 		espi_trans->len = trans_len;
411 		espi_trans->tx_buf = local_buf;
412 		espi_trans->rx_buf = local_buf;
413 		fsl_espi_do_trans(m, espi_trans);
414 
415 		/* If there is at least one RX byte then copy it to rx_buf */
416 		if (tx_only < SPCOM_TRANLEN_MAX)
417 			memcpy(rx_buf + rx_pos, espi_trans->rx_buf + tx_only,
418 					trans_len - tx_only);
419 
420 		rx_pos += trans_len - tx_only;
421 
422 		if (loop > 0)
423 			espi_trans->actual_length += espi_trans->len - tx_only;
424 		else
425 			espi_trans->actual_length += espi_trans->len;
426 	}
427 
428 	kfree(local_buf);
429 }
430 
431 static int fsl_espi_do_one_msg(struct spi_master *master,
432 			       struct spi_message *m)
433 {
434 	struct spi_transfer *t;
435 	u8 *rx_buf = NULL;
436 	unsigned int n_tx = 0;
437 	unsigned int n_rx = 0;
438 	unsigned int xfer_len = 0;
439 	struct fsl_espi_transfer espi_trans;
440 
441 	list_for_each_entry(t, &m->transfers, transfer_list) {
442 		if (t->tx_buf)
443 			n_tx += t->len;
444 		if (t->rx_buf) {
445 			n_rx += t->len;
446 			rx_buf = t->rx_buf;
447 		}
448 		if ((t->tx_buf) || (t->rx_buf))
449 			xfer_len += t->len;
450 	}
451 
452 	espi_trans.n_tx = n_tx;
453 	espi_trans.n_rx = n_rx;
454 	espi_trans.len = xfer_len;
455 	espi_trans.actual_length = 0;
456 	espi_trans.status = 0;
457 
458 	if (!rx_buf)
459 		fsl_espi_cmd_trans(m, &espi_trans, NULL);
460 	else
461 		fsl_espi_rw_trans(m, &espi_trans, rx_buf);
462 
463 	m->actual_length = espi_trans.actual_length;
464 	m->status = espi_trans.status;
465 	spi_finalize_current_message(master);
466 	return 0;
467 }
468 
469 static int fsl_espi_setup(struct spi_device *spi)
470 {
471 	struct mpc8xxx_spi *mpc8xxx_spi;
472 	struct fsl_espi_reg *reg_base;
473 	int retval;
474 	u32 hw_mode;
475 	u32 loop_mode;
476 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
477 
478 	if (!spi->max_speed_hz)
479 		return -EINVAL;
480 
481 	if (!cs) {
482 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
483 		if (!cs)
484 			return -ENOMEM;
485 		spi_set_ctldata(spi, cs);
486 	}
487 
488 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
489 	reg_base = mpc8xxx_spi->reg_base;
490 
491 	pm_runtime_get_sync(mpc8xxx_spi->dev);
492 
493 	hw_mode = cs->hw_mode; /* Save original settings */
494 	cs->hw_mode = mpc8xxx_spi_read_reg(
495 			&reg_base->csmode[spi->chip_select]);
496 	/* mask out bits we are going to set */
497 	cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
498 			 | CSMODE_REV);
499 
500 	if (spi->mode & SPI_CPHA)
501 		cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
502 	if (spi->mode & SPI_CPOL)
503 		cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
504 	if (!(spi->mode & SPI_LSB_FIRST))
505 		cs->hw_mode |= CSMODE_REV;
506 
507 	/* Handle the loop mode */
508 	loop_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
509 	loop_mode &= ~SPMODE_LOOP;
510 	if (spi->mode & SPI_LOOP)
511 		loop_mode |= SPMODE_LOOP;
512 	mpc8xxx_spi_write_reg(&reg_base->mode, loop_mode);
513 
514 	retval = fsl_espi_setup_transfer(spi, NULL);
515 
516 	pm_runtime_mark_last_busy(mpc8xxx_spi->dev);
517 	pm_runtime_put_autosuspend(mpc8xxx_spi->dev);
518 
519 	if (retval < 0) {
520 		cs->hw_mode = hw_mode; /* Restore settings */
521 		return retval;
522 	}
523 	return 0;
524 }
525 
526 static void fsl_espi_cleanup(struct spi_device *spi)
527 {
528 	struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
529 
530 	kfree(cs);
531 	spi_set_ctldata(spi, NULL);
532 }
533 
534 void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
535 {
536 	struct fsl_espi_reg *reg_base = mspi->reg_base;
537 
538 	/* We need handle RX first */
539 	if (events & SPIE_NE) {
540 		u32 rx_data, tmp;
541 		u8 rx_data_8;
542 
543 		/* Spin until RX is done */
544 		while (SPIE_RXCNT(events) < min(4, mspi->len)) {
545 			cpu_relax();
546 			events = mpc8xxx_spi_read_reg(&reg_base->event);
547 		}
548 
549 		if (mspi->len >= 4) {
550 			rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
551 		} else {
552 			tmp = mspi->len;
553 			rx_data = 0;
554 			while (tmp--) {
555 				rx_data_8 = in_8((u8 *)&reg_base->receive);
556 				rx_data |= (rx_data_8 << (tmp * 8));
557 			}
558 
559 			rx_data <<= (4 - mspi->len) * 8;
560 		}
561 
562 		mspi->len -= 4;
563 
564 		if (mspi->rx)
565 			mspi->get_rx(rx_data, mspi);
566 	}
567 
568 	if (!(events & SPIE_NF)) {
569 		int ret;
570 
571 		/* spin until TX is done */
572 		ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg(
573 				&reg_base->event)) & SPIE_NF), 1000, 0);
574 		if (!ret) {
575 			dev_err(mspi->dev, "tired waiting for SPIE_NF\n");
576 
577 			/* Clear the SPIE bits */
578 			mpc8xxx_spi_write_reg(&reg_base->event, events);
579 			complete(&mspi->done);
580 			return;
581 		}
582 	}
583 
584 	/* Clear the events */
585 	mpc8xxx_spi_write_reg(&reg_base->event, events);
586 
587 	mspi->count -= 1;
588 	if (mspi->count) {
589 		u32 word = mspi->get_tx(mspi);
590 
591 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
592 	} else {
593 		complete(&mspi->done);
594 	}
595 }
596 
597 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
598 {
599 	struct mpc8xxx_spi *mspi = context_data;
600 	struct fsl_espi_reg *reg_base = mspi->reg_base;
601 	irqreturn_t ret = IRQ_NONE;
602 	u32 events;
603 
604 	/* Get interrupt events(tx/rx) */
605 	events = mpc8xxx_spi_read_reg(&reg_base->event);
606 	if (events)
607 		ret = IRQ_HANDLED;
608 
609 	dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events);
610 
611 	fsl_espi_cpu_irq(mspi, events);
612 
613 	return ret;
614 }
615 
616 #ifdef CONFIG_PM
617 static int fsl_espi_runtime_suspend(struct device *dev)
618 {
619 	struct spi_master *master = dev_get_drvdata(dev);
620 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
621 	struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
622 	u32 regval;
623 
624 	regval = mpc8xxx_spi_read_reg(&reg_base->mode);
625 	regval &= ~SPMODE_ENABLE;
626 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
627 
628 	return 0;
629 }
630 
631 static int fsl_espi_runtime_resume(struct device *dev)
632 {
633 	struct spi_master *master = dev_get_drvdata(dev);
634 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(master);
635 	struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
636 	u32 regval;
637 
638 	regval = mpc8xxx_spi_read_reg(&reg_base->mode);
639 	regval |= SPMODE_ENABLE;
640 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
641 
642 	return 0;
643 }
644 #endif
645 
646 static struct spi_master * fsl_espi_probe(struct device *dev,
647 		struct resource *mem, unsigned int irq)
648 {
649 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
650 	struct spi_master *master;
651 	struct mpc8xxx_spi *mpc8xxx_spi;
652 	struct fsl_espi_reg *reg_base;
653 	struct device_node *nc;
654 	const __be32 *prop;
655 	u32 regval, csmode;
656 	int i, len, ret = 0;
657 
658 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
659 	if (!master) {
660 		ret = -ENOMEM;
661 		goto err;
662 	}
663 
664 	dev_set_drvdata(dev, master);
665 
666 	mpc8xxx_spi_probe(dev, mem, irq);
667 
668 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
669 	master->setup = fsl_espi_setup;
670 	master->cleanup = fsl_espi_cleanup;
671 	master->transfer_one_message = fsl_espi_do_one_msg;
672 	master->auto_runtime_pm = true;
673 
674 	mpc8xxx_spi = spi_master_get_devdata(master);
675 
676 	mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
677 	if (IS_ERR(mpc8xxx_spi->reg_base)) {
678 		ret = PTR_ERR(mpc8xxx_spi->reg_base);
679 		goto err_probe;
680 	}
681 
682 	reg_base = mpc8xxx_spi->reg_base;
683 
684 	/* Register for SPI Interrupt */
685 	ret = devm_request_irq(dev, mpc8xxx_spi->irq, fsl_espi_irq,
686 			  0, "fsl_espi", mpc8xxx_spi);
687 	if (ret)
688 		goto err_probe;
689 
690 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
691 		mpc8xxx_spi->rx_shift = 16;
692 		mpc8xxx_spi->tx_shift = 24;
693 	}
694 
695 	/* SPI controller initializations */
696 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
697 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
698 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
699 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
700 
701 	/* Init eSPI CS mode register */
702 	for_each_available_child_of_node(master->dev.of_node, nc) {
703 		/* get chip select */
704 		prop = of_get_property(nc, "reg", &len);
705 		if (!prop || len < sizeof(*prop))
706 			continue;
707 		i = be32_to_cpup(prop);
708 		if (i < 0 || i >= pdata->max_chipselect)
709 			continue;
710 
711 		csmode = CSMODE_INIT_VAL;
712 		/* check if CSBEF is set in device tree */
713 		prop = of_get_property(nc, "fsl,csbef", &len);
714 		if (prop && len >= sizeof(*prop)) {
715 			csmode &= ~(CSMODE_BEF(0xf));
716 			csmode |= CSMODE_BEF(be32_to_cpup(prop));
717 		}
718 		/* check if CSAFT is set in device tree */
719 		prop = of_get_property(nc, "fsl,csaft", &len);
720 		if (prop && len >= sizeof(*prop)) {
721 			csmode &= ~(CSMODE_AFT(0xf));
722 			csmode |= CSMODE_AFT(be32_to_cpup(prop));
723 		}
724 		mpc8xxx_spi_write_reg(&reg_base->csmode[i], csmode);
725 
726 		dev_info(dev, "cs=%d, init_csmode=0x%x\n", i, csmode);
727 	}
728 
729 	/* Enable SPI interface */
730 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
731 
732 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
733 
734 	pm_runtime_set_autosuspend_delay(dev, AUTOSUSPEND_TIMEOUT);
735 	pm_runtime_use_autosuspend(dev);
736 	pm_runtime_set_active(dev);
737 	pm_runtime_enable(dev);
738 	pm_runtime_get_sync(dev);
739 
740 	ret = devm_spi_register_master(dev, master);
741 	if (ret < 0)
742 		goto err_pm;
743 
744 	dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq);
745 
746 	pm_runtime_mark_last_busy(dev);
747 	pm_runtime_put_autosuspend(dev);
748 
749 	return master;
750 
751 err_pm:
752 	pm_runtime_put_noidle(dev);
753 	pm_runtime_disable(dev);
754 	pm_runtime_set_suspended(dev);
755 err_probe:
756 	spi_master_put(master);
757 err:
758 	return ERR_PTR(ret);
759 }
760 
761 static int of_fsl_espi_get_chipselects(struct device *dev)
762 {
763 	struct device_node *np = dev->of_node;
764 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
765 	const u32 *prop;
766 	int len;
767 
768 	prop = of_get_property(np, "fsl,espi-num-chipselects", &len);
769 	if (!prop || len < sizeof(*prop)) {
770 		dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
771 		return -EINVAL;
772 	}
773 
774 	pdata->max_chipselect = *prop;
775 	pdata->cs_control = NULL;
776 
777 	return 0;
778 }
779 
780 static int of_fsl_espi_probe(struct platform_device *ofdev)
781 {
782 	struct device *dev = &ofdev->dev;
783 	struct device_node *np = ofdev->dev.of_node;
784 	struct spi_master *master;
785 	struct resource mem;
786 	unsigned int irq;
787 	int ret = -ENOMEM;
788 
789 	ret = of_mpc8xxx_spi_probe(ofdev);
790 	if (ret)
791 		return ret;
792 
793 	ret = of_fsl_espi_get_chipselects(dev);
794 	if (ret)
795 		goto err;
796 
797 	ret = of_address_to_resource(np, 0, &mem);
798 	if (ret)
799 		goto err;
800 
801 	irq = irq_of_parse_and_map(np, 0);
802 	if (!irq) {
803 		ret = -EINVAL;
804 		goto err;
805 	}
806 
807 	master = fsl_espi_probe(dev, &mem, irq);
808 	if (IS_ERR(master)) {
809 		ret = PTR_ERR(master);
810 		goto err;
811 	}
812 
813 	return 0;
814 
815 err:
816 	return ret;
817 }
818 
819 static int of_fsl_espi_remove(struct platform_device *dev)
820 {
821 	pm_runtime_disable(&dev->dev);
822 
823 	return 0;
824 }
825 
826 #ifdef CONFIG_PM_SLEEP
827 static int of_fsl_espi_suspend(struct device *dev)
828 {
829 	struct spi_master *master = dev_get_drvdata(dev);
830 	int ret;
831 
832 	ret = spi_master_suspend(master);
833 	if (ret) {
834 		dev_warn(dev, "cannot suspend master\n");
835 		return ret;
836 	}
837 
838 	ret = pm_runtime_force_suspend(dev);
839 	if (ret < 0)
840 		return ret;
841 
842 	return 0;
843 }
844 
845 static int of_fsl_espi_resume(struct device *dev)
846 {
847 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
848 	struct spi_master *master = dev_get_drvdata(dev);
849 	struct mpc8xxx_spi *mpc8xxx_spi;
850 	struct fsl_espi_reg *reg_base;
851 	u32 regval;
852 	int i, ret;
853 
854 	mpc8xxx_spi = spi_master_get_devdata(master);
855 	reg_base = mpc8xxx_spi->reg_base;
856 
857 	/* SPI controller initializations */
858 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
859 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
860 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
861 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
862 
863 	/* Init eSPI CS mode register */
864 	for (i = 0; i < pdata->max_chipselect; i++)
865 		mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
866 
867 	/* Enable SPI interface */
868 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
869 
870 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
871 
872 	ret = pm_runtime_force_resume(dev);
873 	if (ret < 0)
874 		return ret;
875 
876 	return spi_master_resume(master);
877 }
878 #endif /* CONFIG_PM_SLEEP */
879 
880 static const struct dev_pm_ops espi_pm = {
881 	SET_RUNTIME_PM_OPS(fsl_espi_runtime_suspend,
882 			   fsl_espi_runtime_resume, NULL)
883 	SET_SYSTEM_SLEEP_PM_OPS(of_fsl_espi_suspend, of_fsl_espi_resume)
884 };
885 
886 static const struct of_device_id of_fsl_espi_match[] = {
887 	{ .compatible = "fsl,mpc8536-espi" },
888 	{}
889 };
890 MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
891 
892 static struct platform_driver fsl_espi_driver = {
893 	.driver = {
894 		.name = "fsl_espi",
895 		.of_match_table = of_fsl_espi_match,
896 		.pm = &espi_pm,
897 	},
898 	.probe		= of_fsl_espi_probe,
899 	.remove		= of_fsl_espi_remove,
900 };
901 module_platform_driver(fsl_espi_driver);
902 
903 MODULE_AUTHOR("Mingkai Hu");
904 MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
905 MODULE_LICENSE("GPL");
906