xref: /openbmc/linux/drivers/spi/spi-fsl-spi.c (revision 81d67439)
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  * This program is free software; you can redistribute  it and/or modify it
14  * under  the terms of  the GNU General  Public License as published by the
15  * Free Software Foundation;  either version 2 of the  License, or (at your
16  * option) any later version.
17  */
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/kernel.h>
21 #include <linux/interrupt.h>
22 #include <linux/delay.h>
23 #include <linux/irq.h>
24 #include <linux/spi/spi.h>
25 #include <linux/spi/spi_bitbang.h>
26 #include <linux/platform_device.h>
27 #include <linux/fsl_devices.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/mm.h>
30 #include <linux/mutex.h>
31 #include <linux/of.h>
32 #include <linux/of_platform.h>
33 #include <linux/gpio.h>
34 #include <linux/of_gpio.h>
35 
36 #include <sysdev/fsl_soc.h>
37 #include <asm/cpm.h>
38 #include <asm/qe.h>
39 
40 #include "spi-fsl-lib.h"
41 
42 /* CPM1 and CPM2 are mutually exclusive. */
43 #ifdef CONFIG_CPM1
44 #include <asm/cpm1.h>
45 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_CH_SPI, 0)
46 #else
47 #include <asm/cpm2.h>
48 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_SPI_PAGE, CPM_CR_SPI_SBLOCK, 0, 0)
49 #endif
50 
51 /* SPI Controller registers */
52 struct fsl_spi_reg {
53 	u8 res1[0x20];
54 	__be32 mode;
55 	__be32 event;
56 	__be32 mask;
57 	__be32 command;
58 	__be32 transmit;
59 	__be32 receive;
60 };
61 
62 /* SPI Controller mode register definitions */
63 #define	SPMODE_LOOP		(1 << 30)
64 #define	SPMODE_CI_INACTIVEHIGH	(1 << 29)
65 #define	SPMODE_CP_BEGIN_EDGECLK	(1 << 28)
66 #define	SPMODE_DIV16		(1 << 27)
67 #define	SPMODE_REV		(1 << 26)
68 #define	SPMODE_MS		(1 << 25)
69 #define	SPMODE_ENABLE		(1 << 24)
70 #define	SPMODE_LEN(x)		((x) << 20)
71 #define	SPMODE_PM(x)		((x) << 16)
72 #define	SPMODE_OP		(1 << 14)
73 #define	SPMODE_CG(x)		((x) << 7)
74 
75 /*
76  * Default for SPI Mode:
77  *	SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
78  */
79 #define	SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \
80 			 SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf))
81 
82 /* SPIE register values */
83 #define	SPIE_NE		0x00000200	/* Not empty */
84 #define	SPIE_NF		0x00000100	/* Not full */
85 
86 /* SPIM register values */
87 #define	SPIM_NE		0x00000200	/* Not empty */
88 #define	SPIM_NF		0x00000100	/* Not full */
89 
90 #define	SPIE_TXB	0x00000200	/* Last char is written to tx fifo */
91 #define	SPIE_RXB	0x00000100	/* Last char is written to rx buf */
92 
93 /* SPCOM register values */
94 #define	SPCOM_STR	(1 << 23)	/* Start transmit */
95 
96 #define	SPI_PRAM_SIZE	0x100
97 #define	SPI_MRBLR	((unsigned int)PAGE_SIZE)
98 
99 static void *fsl_dummy_rx;
100 static DEFINE_MUTEX(fsl_dummy_rx_lock);
101 static int fsl_dummy_rx_refcnt;
102 
103 static void fsl_spi_change_mode(struct spi_device *spi)
104 {
105 	struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
106 	struct spi_mpc8xxx_cs *cs = spi->controller_state;
107 	struct fsl_spi_reg *reg_base = mspi->reg_base;
108 	__be32 __iomem *mode = &reg_base->mode;
109 	unsigned long flags;
110 
111 	if (cs->hw_mode == mpc8xxx_spi_read_reg(mode))
112 		return;
113 
114 	/* Turn off IRQs locally to minimize time that SPI is disabled. */
115 	local_irq_save(flags);
116 
117 	/* Turn off SPI unit prior changing mode */
118 	mpc8xxx_spi_write_reg(mode, cs->hw_mode & ~SPMODE_ENABLE);
119 
120 	/* When in CPM mode, we need to reinit tx and rx. */
121 	if (mspi->flags & SPI_CPM_MODE) {
122 		if (mspi->flags & SPI_QE) {
123 			qe_issue_cmd(QE_INIT_TX_RX, mspi->subblock,
124 				     QE_CR_PROTOCOL_UNSPECIFIED, 0);
125 		} else {
126 			cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
127 			if (mspi->flags & SPI_CPM1) {
128 				out_be16(&mspi->pram->rbptr,
129 					 in_be16(&mspi->pram->rbase));
130 				out_be16(&mspi->pram->tbptr,
131 					 in_be16(&mspi->pram->tbase));
132 			}
133 		}
134 	}
135 	mpc8xxx_spi_write_reg(mode, cs->hw_mode);
136 	local_irq_restore(flags);
137 }
138 
139 static void fsl_spi_chipselect(struct spi_device *spi, int value)
140 {
141 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
142 	struct fsl_spi_platform_data *pdata = spi->dev.parent->platform_data;
143 	bool pol = spi->mode & SPI_CS_HIGH;
144 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
145 
146 	if (value == BITBANG_CS_INACTIVE) {
147 		if (pdata->cs_control)
148 			pdata->cs_control(spi, !pol);
149 	}
150 
151 	if (value == BITBANG_CS_ACTIVE) {
152 		mpc8xxx_spi->rx_shift = cs->rx_shift;
153 		mpc8xxx_spi->tx_shift = cs->tx_shift;
154 		mpc8xxx_spi->get_rx = cs->get_rx;
155 		mpc8xxx_spi->get_tx = cs->get_tx;
156 
157 		fsl_spi_change_mode(spi);
158 
159 		if (pdata->cs_control)
160 			pdata->cs_control(spi, pol);
161 	}
162 }
163 
164 static int mspi_apply_cpu_mode_quirks(struct spi_mpc8xxx_cs *cs,
165 				struct spi_device *spi,
166 				struct mpc8xxx_spi *mpc8xxx_spi,
167 				int bits_per_word)
168 {
169 	cs->rx_shift = 0;
170 	cs->tx_shift = 0;
171 	if (bits_per_word <= 8) {
172 		cs->get_rx = mpc8xxx_spi_rx_buf_u8;
173 		cs->get_tx = mpc8xxx_spi_tx_buf_u8;
174 		if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
175 			cs->rx_shift = 16;
176 			cs->tx_shift = 24;
177 		}
178 	} else if (bits_per_word <= 16) {
179 		cs->get_rx = mpc8xxx_spi_rx_buf_u16;
180 		cs->get_tx = mpc8xxx_spi_tx_buf_u16;
181 		if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
182 			cs->rx_shift = 16;
183 			cs->tx_shift = 16;
184 		}
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->flags & SPI_QE_CPU_MODE &&
192 	    spi->mode & SPI_LSB_FIRST) {
193 		cs->tx_shift = 0;
194 		if (bits_per_word <= 8)
195 			cs->rx_shift = 8;
196 		else
197 			cs->rx_shift = 0;
198 	}
199 	mpc8xxx_spi->rx_shift = cs->rx_shift;
200 	mpc8xxx_spi->tx_shift = cs->tx_shift;
201 	mpc8xxx_spi->get_rx = cs->get_rx;
202 	mpc8xxx_spi->get_tx = cs->get_tx;
203 
204 	return bits_per_word;
205 }
206 
207 static int mspi_apply_qe_mode_quirks(struct spi_mpc8xxx_cs *cs,
208 				struct spi_device *spi,
209 				int bits_per_word)
210 {
211 	/* QE uses Little Endian for words > 8
212 	 * so transform all words > 8 into 8 bits
213 	 * Unfortnatly that doesn't work for LSB so
214 	 * reject these for now */
215 	/* Note: 32 bits word, LSB works iff
216 	 * tfcr/rfcr is set to CPMFCR_GBL */
217 	if (spi->mode & SPI_LSB_FIRST &&
218 	    bits_per_word > 8)
219 		return -EINVAL;
220 	if (bits_per_word > 8)
221 		return 8; /* pretend its 8 bits */
222 	return bits_per_word;
223 }
224 
225 static int fsl_spi_setup_transfer(struct spi_device *spi,
226 					struct spi_transfer *t)
227 {
228 	struct mpc8xxx_spi *mpc8xxx_spi;
229 	int bits_per_word = 0;
230 	u8 pm;
231 	u32 hz = 0;
232 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
233 
234 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
235 
236 	if (t) {
237 		bits_per_word = t->bits_per_word;
238 		hz = t->speed_hz;
239 	}
240 
241 	/* spi_transfer level calls that work per-word */
242 	if (!bits_per_word)
243 		bits_per_word = spi->bits_per_word;
244 
245 	/* Make sure its a bit width we support [4..16, 32] */
246 	if ((bits_per_word < 4)
247 	    || ((bits_per_word > 16) && (bits_per_word != 32)))
248 		return -EINVAL;
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 
279 		WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
280 			  "Will use %d Hz instead.\n", dev_name(&spi->dev),
281 			  hz, mpc8xxx_spi->spibrg / 1024);
282 		if (pm > 16)
283 			pm = 16;
284 	} else {
285 		pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
286 	}
287 	if (pm)
288 		pm--;
289 
290 	cs->hw_mode |= SPMODE_PM(pm);
291 
292 	fsl_spi_change_mode(spi);
293 	return 0;
294 }
295 
296 static void fsl_spi_cpm_bufs_start(struct mpc8xxx_spi *mspi)
297 {
298 	struct cpm_buf_desc __iomem *tx_bd = mspi->tx_bd;
299 	struct cpm_buf_desc __iomem *rx_bd = mspi->rx_bd;
300 	unsigned int xfer_len = min(mspi->count, SPI_MRBLR);
301 	unsigned int xfer_ofs;
302 	struct fsl_spi_reg *reg_base = mspi->reg_base;
303 
304 	xfer_ofs = mspi->xfer_in_progress->len - mspi->count;
305 
306 	if (mspi->rx_dma == mspi->dma_dummy_rx)
307 		out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma);
308 	else
309 		out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma + xfer_ofs);
310 	out_be16(&rx_bd->cbd_datlen, 0);
311 	out_be16(&rx_bd->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT | BD_SC_WRAP);
312 
313 	if (mspi->tx_dma == mspi->dma_dummy_tx)
314 		out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma);
315 	else
316 		out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma + xfer_ofs);
317 	out_be16(&tx_bd->cbd_datlen, xfer_len);
318 	out_be16(&tx_bd->cbd_sc, BD_SC_READY | BD_SC_INTRPT | BD_SC_WRAP |
319 				 BD_SC_LAST);
320 
321 	/* start transfer */
322 	mpc8xxx_spi_write_reg(&reg_base->command, SPCOM_STR);
323 }
324 
325 static int fsl_spi_cpm_bufs(struct mpc8xxx_spi *mspi,
326 				struct spi_transfer *t, bool is_dma_mapped)
327 {
328 	struct device *dev = mspi->dev;
329 	struct fsl_spi_reg *reg_base = mspi->reg_base;
330 
331 	if (is_dma_mapped) {
332 		mspi->map_tx_dma = 0;
333 		mspi->map_rx_dma = 0;
334 	} else {
335 		mspi->map_tx_dma = 1;
336 		mspi->map_rx_dma = 1;
337 	}
338 
339 	if (!t->tx_buf) {
340 		mspi->tx_dma = mspi->dma_dummy_tx;
341 		mspi->map_tx_dma = 0;
342 	}
343 
344 	if (!t->rx_buf) {
345 		mspi->rx_dma = mspi->dma_dummy_rx;
346 		mspi->map_rx_dma = 0;
347 	}
348 
349 	if (mspi->map_tx_dma) {
350 		void *nonconst_tx = (void *)mspi->tx; /* shut up gcc */
351 
352 		mspi->tx_dma = dma_map_single(dev, nonconst_tx, t->len,
353 					      DMA_TO_DEVICE);
354 		if (dma_mapping_error(dev, mspi->tx_dma)) {
355 			dev_err(dev, "unable to map tx dma\n");
356 			return -ENOMEM;
357 		}
358 	} else if (t->tx_buf) {
359 		mspi->tx_dma = t->tx_dma;
360 	}
361 
362 	if (mspi->map_rx_dma) {
363 		mspi->rx_dma = dma_map_single(dev, mspi->rx, t->len,
364 					      DMA_FROM_DEVICE);
365 		if (dma_mapping_error(dev, mspi->rx_dma)) {
366 			dev_err(dev, "unable to map rx dma\n");
367 			goto err_rx_dma;
368 		}
369 	} else if (t->rx_buf) {
370 		mspi->rx_dma = t->rx_dma;
371 	}
372 
373 	/* enable rx ints */
374 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIE_RXB);
375 
376 	mspi->xfer_in_progress = t;
377 	mspi->count = t->len;
378 
379 	/* start CPM transfers */
380 	fsl_spi_cpm_bufs_start(mspi);
381 
382 	return 0;
383 
384 err_rx_dma:
385 	if (mspi->map_tx_dma)
386 		dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
387 	return -ENOMEM;
388 }
389 
390 static void fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi *mspi)
391 {
392 	struct device *dev = mspi->dev;
393 	struct spi_transfer *t = mspi->xfer_in_progress;
394 
395 	if (mspi->map_tx_dma)
396 		dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
397 	if (mspi->map_rx_dma)
398 		dma_unmap_single(dev, mspi->rx_dma, t->len, DMA_FROM_DEVICE);
399 	mspi->xfer_in_progress = NULL;
400 }
401 
402 static int fsl_spi_cpu_bufs(struct mpc8xxx_spi *mspi,
403 				struct spi_transfer *t, unsigned int len)
404 {
405 	u32 word;
406 	struct fsl_spi_reg *reg_base = mspi->reg_base;
407 
408 	mspi->count = len;
409 
410 	/* enable rx ints */
411 	mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
412 
413 	/* transmit word */
414 	word = mspi->get_tx(mspi);
415 	mpc8xxx_spi_write_reg(&reg_base->transmit, word);
416 
417 	return 0;
418 }
419 
420 static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t,
421 			    bool is_dma_mapped)
422 {
423 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
424 	struct fsl_spi_reg *reg_base;
425 	unsigned int len = t->len;
426 	u8 bits_per_word;
427 	int ret;
428 
429 	reg_base = mpc8xxx_spi->reg_base;
430 	bits_per_word = spi->bits_per_word;
431 	if (t->bits_per_word)
432 		bits_per_word = t->bits_per_word;
433 
434 	if (bits_per_word > 8) {
435 		/* invalid length? */
436 		if (len & 1)
437 			return -EINVAL;
438 		len /= 2;
439 	}
440 	if (bits_per_word > 16) {
441 		/* invalid length? */
442 		if (len & 1)
443 			return -EINVAL;
444 		len /= 2;
445 	}
446 
447 	mpc8xxx_spi->tx = t->tx_buf;
448 	mpc8xxx_spi->rx = t->rx_buf;
449 
450 	INIT_COMPLETION(mpc8xxx_spi->done);
451 
452 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
453 		ret = fsl_spi_cpm_bufs(mpc8xxx_spi, t, is_dma_mapped);
454 	else
455 		ret = fsl_spi_cpu_bufs(mpc8xxx_spi, t, len);
456 	if (ret)
457 		return ret;
458 
459 	wait_for_completion(&mpc8xxx_spi->done);
460 
461 	/* disable rx ints */
462 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
463 
464 	if (mpc8xxx_spi->flags & SPI_CPM_MODE)
465 		fsl_spi_cpm_bufs_complete(mpc8xxx_spi);
466 
467 	return mpc8xxx_spi->count;
468 }
469 
470 static void fsl_spi_do_one_msg(struct spi_message *m)
471 {
472 	struct spi_device *spi = m->spi;
473 	struct spi_transfer *t;
474 	unsigned int cs_change;
475 	const int nsecs = 50;
476 	int status;
477 
478 	cs_change = 1;
479 	status = 0;
480 	list_for_each_entry(t, &m->transfers, transfer_list) {
481 		if (t->bits_per_word || t->speed_hz) {
482 			/* Don't allow changes if CS is active */
483 			status = -EINVAL;
484 
485 			if (cs_change)
486 				status = fsl_spi_setup_transfer(spi, t);
487 			if (status < 0)
488 				break;
489 		}
490 
491 		if (cs_change) {
492 			fsl_spi_chipselect(spi, BITBANG_CS_ACTIVE);
493 			ndelay(nsecs);
494 		}
495 		cs_change = t->cs_change;
496 		if (t->len)
497 			status = fsl_spi_bufs(spi, t, m->is_dma_mapped);
498 		if (status) {
499 			status = -EMSGSIZE;
500 			break;
501 		}
502 		m->actual_length += t->len;
503 
504 		if (t->delay_usecs)
505 			udelay(t->delay_usecs);
506 
507 		if (cs_change) {
508 			ndelay(nsecs);
509 			fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
510 			ndelay(nsecs);
511 		}
512 	}
513 
514 	m->status = status;
515 	m->complete(m->context);
516 
517 	if (status || !cs_change) {
518 		ndelay(nsecs);
519 		fsl_spi_chipselect(spi, BITBANG_CS_INACTIVE);
520 	}
521 
522 	fsl_spi_setup_transfer(spi, NULL);
523 }
524 
525 static int fsl_spi_setup(struct spi_device *spi)
526 {
527 	struct mpc8xxx_spi *mpc8xxx_spi;
528 	struct fsl_spi_reg *reg_base;
529 	int retval;
530 	u32 hw_mode;
531 	struct spi_mpc8xxx_cs	*cs = spi->controller_state;
532 
533 	if (!spi->max_speed_hz)
534 		return -EINVAL;
535 
536 	if (!cs) {
537 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
538 		if (!cs)
539 			return -ENOMEM;
540 		spi->controller_state = cs;
541 	}
542 	mpc8xxx_spi = spi_master_get_devdata(spi->master);
543 
544 	reg_base = mpc8xxx_spi->reg_base;
545 
546 	hw_mode = cs->hw_mode; /* Save original settings */
547 	cs->hw_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
548 	/* mask out bits we are going to set */
549 	cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
550 			 | SPMODE_REV | SPMODE_LOOP);
551 
552 	if (spi->mode & SPI_CPHA)
553 		cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
554 	if (spi->mode & SPI_CPOL)
555 		cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
556 	if (!(spi->mode & SPI_LSB_FIRST))
557 		cs->hw_mode |= SPMODE_REV;
558 	if (spi->mode & SPI_LOOP)
559 		cs->hw_mode |= SPMODE_LOOP;
560 
561 	retval = fsl_spi_setup_transfer(spi, NULL);
562 	if (retval < 0) {
563 		cs->hw_mode = hw_mode; /* Restore settings */
564 		return retval;
565 	}
566 	return 0;
567 }
568 
569 static void fsl_spi_cpm_irq(struct mpc8xxx_spi *mspi, u32 events)
570 {
571 	u16 len;
572 	struct fsl_spi_reg *reg_base = mspi->reg_base;
573 
574 	dev_dbg(mspi->dev, "%s: bd datlen %d, count %d\n", __func__,
575 		in_be16(&mspi->rx_bd->cbd_datlen), mspi->count);
576 
577 	len = in_be16(&mspi->rx_bd->cbd_datlen);
578 	if (len > mspi->count) {
579 		WARN_ON(1);
580 		len = mspi->count;
581 	}
582 
583 	/* Clear the events */
584 	mpc8xxx_spi_write_reg(&reg_base->event, events);
585 
586 	mspi->count -= len;
587 	if (mspi->count)
588 		fsl_spi_cpm_bufs_start(mspi);
589 	else
590 		complete(&mspi->done);
591 }
592 
593 static void fsl_spi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
594 {
595 	struct fsl_spi_reg *reg_base = mspi->reg_base;
596 
597 	/* We need handle RX first */
598 	if (events & SPIE_NE) {
599 		u32 rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
600 
601 		if (mspi->rx)
602 			mspi->get_rx(rx_data, mspi);
603 	}
604 
605 	if ((events & SPIE_NF) == 0)
606 		/* spin until TX is done */
607 		while (((events =
608 			mpc8xxx_spi_read_reg(&reg_base->event)) &
609 						SPIE_NF) == 0)
610 			cpu_relax();
611 
612 	/* Clear the events */
613 	mpc8xxx_spi_write_reg(&reg_base->event, events);
614 
615 	mspi->count -= 1;
616 	if (mspi->count) {
617 		u32 word = mspi->get_tx(mspi);
618 
619 		mpc8xxx_spi_write_reg(&reg_base->transmit, word);
620 	} else {
621 		complete(&mspi->done);
622 	}
623 }
624 
625 static irqreturn_t fsl_spi_irq(s32 irq, void *context_data)
626 {
627 	struct mpc8xxx_spi *mspi = context_data;
628 	irqreturn_t ret = IRQ_NONE;
629 	u32 events;
630 	struct fsl_spi_reg *reg_base = mspi->reg_base;
631 
632 	/* Get interrupt events(tx/rx) */
633 	events = mpc8xxx_spi_read_reg(&reg_base->event);
634 	if (events)
635 		ret = IRQ_HANDLED;
636 
637 	dev_dbg(mspi->dev, "%s: events %x\n", __func__, events);
638 
639 	if (mspi->flags & SPI_CPM_MODE)
640 		fsl_spi_cpm_irq(mspi, events);
641 	else
642 		fsl_spi_cpu_irq(mspi, events);
643 
644 	return ret;
645 }
646 
647 static void *fsl_spi_alloc_dummy_rx(void)
648 {
649 	mutex_lock(&fsl_dummy_rx_lock);
650 
651 	if (!fsl_dummy_rx)
652 		fsl_dummy_rx = kmalloc(SPI_MRBLR, GFP_KERNEL);
653 	if (fsl_dummy_rx)
654 		fsl_dummy_rx_refcnt++;
655 
656 	mutex_unlock(&fsl_dummy_rx_lock);
657 
658 	return fsl_dummy_rx;
659 }
660 
661 static void fsl_spi_free_dummy_rx(void)
662 {
663 	mutex_lock(&fsl_dummy_rx_lock);
664 
665 	switch (fsl_dummy_rx_refcnt) {
666 	case 0:
667 		WARN_ON(1);
668 		break;
669 	case 1:
670 		kfree(fsl_dummy_rx);
671 		fsl_dummy_rx = NULL;
672 		/* fall through */
673 	default:
674 		fsl_dummy_rx_refcnt--;
675 		break;
676 	}
677 
678 	mutex_unlock(&fsl_dummy_rx_lock);
679 }
680 
681 static unsigned long fsl_spi_cpm_get_pram(struct mpc8xxx_spi *mspi)
682 {
683 	struct device *dev = mspi->dev;
684 	struct device_node *np = dev->of_node;
685 	const u32 *iprop;
686 	int size;
687 	void __iomem *spi_base;
688 	unsigned long pram_ofs = -ENOMEM;
689 
690 	/* Can't use of_address_to_resource(), QE muram isn't at 0. */
691 	iprop = of_get_property(np, "reg", &size);
692 
693 	/* QE with a fixed pram location? */
694 	if (mspi->flags & SPI_QE && iprop && size == sizeof(*iprop) * 4)
695 		return cpm_muram_alloc_fixed(iprop[2], SPI_PRAM_SIZE);
696 
697 	/* QE but with a dynamic pram location? */
698 	if (mspi->flags & SPI_QE) {
699 		pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
700 		qe_issue_cmd(QE_ASSIGN_PAGE_TO_DEVICE, mspi->subblock,
701 				QE_CR_PROTOCOL_UNSPECIFIED, pram_ofs);
702 		return pram_ofs;
703 	}
704 
705 	spi_base = of_iomap(np, 1);
706 	if (spi_base == NULL)
707 		return -EINVAL;
708 
709 	if (mspi->flags & SPI_CPM2) {
710 		pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
711 		out_be16(spi_base, pram_ofs);
712 	} else {
713 		struct spi_pram __iomem *pram = spi_base;
714 		u16 rpbase = in_be16(&pram->rpbase);
715 
716 		/* Microcode relocation patch applied? */
717 		if (rpbase)
718 			pram_ofs = rpbase;
719 		else {
720 			pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
721 			out_be16(spi_base, pram_ofs);
722 		}
723 	}
724 
725 	iounmap(spi_base);
726 	return pram_ofs;
727 }
728 
729 static int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi)
730 {
731 	struct device *dev = mspi->dev;
732 	struct device_node *np = dev->of_node;
733 	const u32 *iprop;
734 	int size;
735 	unsigned long pram_ofs;
736 	unsigned long bds_ofs;
737 
738 	if (!(mspi->flags & SPI_CPM_MODE))
739 		return 0;
740 
741 	if (!fsl_spi_alloc_dummy_rx())
742 		return -ENOMEM;
743 
744 	if (mspi->flags & SPI_QE) {
745 		iprop = of_get_property(np, "cell-index", &size);
746 		if (iprop && size == sizeof(*iprop))
747 			mspi->subblock = *iprop;
748 
749 		switch (mspi->subblock) {
750 		default:
751 			dev_warn(dev, "cell-index unspecified, assuming SPI1");
752 			/* fall through */
753 		case 0:
754 			mspi->subblock = QE_CR_SUBBLOCK_SPI1;
755 			break;
756 		case 1:
757 			mspi->subblock = QE_CR_SUBBLOCK_SPI2;
758 			break;
759 		}
760 	}
761 
762 	pram_ofs = fsl_spi_cpm_get_pram(mspi);
763 	if (IS_ERR_VALUE(pram_ofs)) {
764 		dev_err(dev, "can't allocate spi parameter ram\n");
765 		goto err_pram;
766 	}
767 
768 	bds_ofs = cpm_muram_alloc(sizeof(*mspi->tx_bd) +
769 				  sizeof(*mspi->rx_bd), 8);
770 	if (IS_ERR_VALUE(bds_ofs)) {
771 		dev_err(dev, "can't allocate bds\n");
772 		goto err_bds;
773 	}
774 
775 	mspi->dma_dummy_tx = dma_map_single(dev, empty_zero_page, PAGE_SIZE,
776 					    DMA_TO_DEVICE);
777 	if (dma_mapping_error(dev, mspi->dma_dummy_tx)) {
778 		dev_err(dev, "unable to map dummy tx buffer\n");
779 		goto err_dummy_tx;
780 	}
781 
782 	mspi->dma_dummy_rx = dma_map_single(dev, fsl_dummy_rx, SPI_MRBLR,
783 					    DMA_FROM_DEVICE);
784 	if (dma_mapping_error(dev, mspi->dma_dummy_rx)) {
785 		dev_err(dev, "unable to map dummy rx buffer\n");
786 		goto err_dummy_rx;
787 	}
788 
789 	mspi->pram = cpm_muram_addr(pram_ofs);
790 
791 	mspi->tx_bd = cpm_muram_addr(bds_ofs);
792 	mspi->rx_bd = cpm_muram_addr(bds_ofs + sizeof(*mspi->tx_bd));
793 
794 	/* Initialize parameter ram. */
795 	out_be16(&mspi->pram->tbase, cpm_muram_offset(mspi->tx_bd));
796 	out_be16(&mspi->pram->rbase, cpm_muram_offset(mspi->rx_bd));
797 	out_8(&mspi->pram->tfcr, CPMFCR_EB | CPMFCR_GBL);
798 	out_8(&mspi->pram->rfcr, CPMFCR_EB | CPMFCR_GBL);
799 	out_be16(&mspi->pram->mrblr, SPI_MRBLR);
800 	out_be32(&mspi->pram->rstate, 0);
801 	out_be32(&mspi->pram->rdp, 0);
802 	out_be16(&mspi->pram->rbptr, 0);
803 	out_be16(&mspi->pram->rbc, 0);
804 	out_be32(&mspi->pram->rxtmp, 0);
805 	out_be32(&mspi->pram->tstate, 0);
806 	out_be32(&mspi->pram->tdp, 0);
807 	out_be16(&mspi->pram->tbptr, 0);
808 	out_be16(&mspi->pram->tbc, 0);
809 	out_be32(&mspi->pram->txtmp, 0);
810 
811 	return 0;
812 
813 err_dummy_rx:
814 	dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
815 err_dummy_tx:
816 	cpm_muram_free(bds_ofs);
817 err_bds:
818 	cpm_muram_free(pram_ofs);
819 err_pram:
820 	fsl_spi_free_dummy_rx();
821 	return -ENOMEM;
822 }
823 
824 static void fsl_spi_cpm_free(struct mpc8xxx_spi *mspi)
825 {
826 	struct device *dev = mspi->dev;
827 
828 	dma_unmap_single(dev, mspi->dma_dummy_rx, SPI_MRBLR, DMA_FROM_DEVICE);
829 	dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
830 	cpm_muram_free(cpm_muram_offset(mspi->tx_bd));
831 	cpm_muram_free(cpm_muram_offset(mspi->pram));
832 	fsl_spi_free_dummy_rx();
833 }
834 
835 static void fsl_spi_remove(struct mpc8xxx_spi *mspi)
836 {
837 	iounmap(mspi->reg_base);
838 	fsl_spi_cpm_free(mspi);
839 }
840 
841 static struct spi_master * __devinit fsl_spi_probe(struct device *dev,
842 		struct resource *mem, unsigned int irq)
843 {
844 	struct fsl_spi_platform_data *pdata = dev->platform_data;
845 	struct spi_master *master;
846 	struct mpc8xxx_spi *mpc8xxx_spi;
847 	struct fsl_spi_reg *reg_base;
848 	u32 regval;
849 	int ret = 0;
850 
851 	master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
852 	if (master == NULL) {
853 		ret = -ENOMEM;
854 		goto err;
855 	}
856 
857 	dev_set_drvdata(dev, master);
858 
859 	ret = mpc8xxx_spi_probe(dev, mem, irq);
860 	if (ret)
861 		goto err_probe;
862 
863 	master->setup = fsl_spi_setup;
864 
865 	mpc8xxx_spi = spi_master_get_devdata(master);
866 	mpc8xxx_spi->spi_do_one_msg = fsl_spi_do_one_msg;
867 	mpc8xxx_spi->spi_remove = fsl_spi_remove;
868 
869 
870 	ret = fsl_spi_cpm_init(mpc8xxx_spi);
871 	if (ret)
872 		goto err_cpm_init;
873 
874 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
875 		mpc8xxx_spi->rx_shift = 16;
876 		mpc8xxx_spi->tx_shift = 24;
877 	}
878 
879 	mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
880 	if (mpc8xxx_spi->reg_base == NULL) {
881 		ret = -ENOMEM;
882 		goto err_ioremap;
883 	}
884 
885 	/* Register for SPI Interrupt */
886 	ret = request_irq(mpc8xxx_spi->irq, fsl_spi_irq,
887 			  0, "fsl_spi", mpc8xxx_spi);
888 
889 	if (ret != 0)
890 		goto free_irq;
891 
892 	reg_base = mpc8xxx_spi->reg_base;
893 
894 	/* SPI controller initializations */
895 	mpc8xxx_spi_write_reg(&reg_base->mode, 0);
896 	mpc8xxx_spi_write_reg(&reg_base->mask, 0);
897 	mpc8xxx_spi_write_reg(&reg_base->command, 0);
898 	mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
899 
900 	/* Enable SPI interface */
901 	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
902 	if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE)
903 		regval |= SPMODE_OP;
904 
905 	mpc8xxx_spi_write_reg(&reg_base->mode, regval);
906 
907 	ret = spi_register_master(master);
908 	if (ret < 0)
909 		goto unreg_master;
910 
911 	dev_info(dev, "at 0x%p (irq = %d), %s mode\n", reg_base,
912 		 mpc8xxx_spi->irq, mpc8xxx_spi_strmode(mpc8xxx_spi->flags));
913 
914 	return master;
915 
916 unreg_master:
917 	free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
918 free_irq:
919 	iounmap(mpc8xxx_spi->reg_base);
920 err_ioremap:
921 	fsl_spi_cpm_free(mpc8xxx_spi);
922 err_cpm_init:
923 err_probe:
924 	spi_master_put(master);
925 err:
926 	return ERR_PTR(ret);
927 }
928 
929 static void fsl_spi_cs_control(struct spi_device *spi, bool on)
930 {
931 	struct device *dev = spi->dev.parent;
932 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(dev->platform_data);
933 	u16 cs = spi->chip_select;
934 	int gpio = pinfo->gpios[cs];
935 	bool alow = pinfo->alow_flags[cs];
936 
937 	gpio_set_value(gpio, on ^ alow);
938 }
939 
940 static int of_fsl_spi_get_chipselects(struct device *dev)
941 {
942 	struct device_node *np = dev->of_node;
943 	struct fsl_spi_platform_data *pdata = dev->platform_data;
944 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
945 	unsigned int ngpios;
946 	int i = 0;
947 	int ret;
948 
949 	ngpios = of_gpio_count(np);
950 	if (!ngpios) {
951 		/*
952 		 * SPI w/o chip-select line. One SPI device is still permitted
953 		 * though.
954 		 */
955 		pdata->max_chipselect = 1;
956 		return 0;
957 	}
958 
959 	pinfo->gpios = kmalloc(ngpios * sizeof(*pinfo->gpios), GFP_KERNEL);
960 	if (!pinfo->gpios)
961 		return -ENOMEM;
962 	memset(pinfo->gpios, -1, ngpios * sizeof(*pinfo->gpios));
963 
964 	pinfo->alow_flags = kzalloc(ngpios * sizeof(*pinfo->alow_flags),
965 				    GFP_KERNEL);
966 	if (!pinfo->alow_flags) {
967 		ret = -ENOMEM;
968 		goto err_alloc_flags;
969 	}
970 
971 	for (; i < ngpios; i++) {
972 		int gpio;
973 		enum of_gpio_flags flags;
974 
975 		gpio = of_get_gpio_flags(np, i, &flags);
976 		if (!gpio_is_valid(gpio)) {
977 			dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
978 			ret = gpio;
979 			goto err_loop;
980 		}
981 
982 		ret = gpio_request(gpio, dev_name(dev));
983 		if (ret) {
984 			dev_err(dev, "can't request gpio #%d: %d\n", i, ret);
985 			goto err_loop;
986 		}
987 
988 		pinfo->gpios[i] = gpio;
989 		pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW;
990 
991 		ret = gpio_direction_output(pinfo->gpios[i],
992 					    pinfo->alow_flags[i]);
993 		if (ret) {
994 			dev_err(dev, "can't set output direction for gpio "
995 				"#%d: %d\n", i, ret);
996 			goto err_loop;
997 		}
998 	}
999 
1000 	pdata->max_chipselect = ngpios;
1001 	pdata->cs_control = fsl_spi_cs_control;
1002 
1003 	return 0;
1004 
1005 err_loop:
1006 	while (i >= 0) {
1007 		if (gpio_is_valid(pinfo->gpios[i]))
1008 			gpio_free(pinfo->gpios[i]);
1009 		i--;
1010 	}
1011 
1012 	kfree(pinfo->alow_flags);
1013 	pinfo->alow_flags = NULL;
1014 err_alloc_flags:
1015 	kfree(pinfo->gpios);
1016 	pinfo->gpios = NULL;
1017 	return ret;
1018 }
1019 
1020 static int of_fsl_spi_free_chipselects(struct device *dev)
1021 {
1022 	struct fsl_spi_platform_data *pdata = dev->platform_data;
1023 	struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
1024 	int i;
1025 
1026 	if (!pinfo->gpios)
1027 		return 0;
1028 
1029 	for (i = 0; i < pdata->max_chipselect; i++) {
1030 		if (gpio_is_valid(pinfo->gpios[i]))
1031 			gpio_free(pinfo->gpios[i]);
1032 	}
1033 
1034 	kfree(pinfo->gpios);
1035 	kfree(pinfo->alow_flags);
1036 	return 0;
1037 }
1038 
1039 static int __devinit of_fsl_spi_probe(struct platform_device *ofdev)
1040 {
1041 	struct device *dev = &ofdev->dev;
1042 	struct device_node *np = ofdev->dev.of_node;
1043 	struct spi_master *master;
1044 	struct resource mem;
1045 	struct resource irq;
1046 	int ret = -ENOMEM;
1047 
1048 	ret = of_mpc8xxx_spi_probe(ofdev);
1049 	if (ret)
1050 		return ret;
1051 
1052 	ret = of_fsl_spi_get_chipselects(dev);
1053 	if (ret)
1054 		goto err;
1055 
1056 	ret = of_address_to_resource(np, 0, &mem);
1057 	if (ret)
1058 		goto err;
1059 
1060 	ret = of_irq_to_resource(np, 0, &irq);
1061 	if (!ret) {
1062 		ret = -EINVAL;
1063 		goto err;
1064 	}
1065 
1066 	master = fsl_spi_probe(dev, &mem, irq.start);
1067 	if (IS_ERR(master)) {
1068 		ret = PTR_ERR(master);
1069 		goto err;
1070 	}
1071 
1072 	return 0;
1073 
1074 err:
1075 	of_fsl_spi_free_chipselects(dev);
1076 	return ret;
1077 }
1078 
1079 static int __devexit of_fsl_spi_remove(struct platform_device *ofdev)
1080 {
1081 	int ret;
1082 
1083 	ret = mpc8xxx_spi_remove(&ofdev->dev);
1084 	if (ret)
1085 		return ret;
1086 	of_fsl_spi_free_chipselects(&ofdev->dev);
1087 	return 0;
1088 }
1089 
1090 static const struct of_device_id of_fsl_spi_match[] = {
1091 	{ .compatible = "fsl,spi" },
1092 	{}
1093 };
1094 MODULE_DEVICE_TABLE(of, of_fsl_spi_match);
1095 
1096 static struct platform_driver of_fsl_spi_driver = {
1097 	.driver = {
1098 		.name = "fsl_spi",
1099 		.owner = THIS_MODULE,
1100 		.of_match_table = of_fsl_spi_match,
1101 	},
1102 	.probe		= of_fsl_spi_probe,
1103 	.remove		= __devexit_p(of_fsl_spi_remove),
1104 };
1105 
1106 #ifdef CONFIG_MPC832x_RDB
1107 /*
1108  * XXX XXX XXX
1109  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
1110  * only. The driver should go away soon, since newer MPC8323E-RDB's device
1111  * tree can work with OpenFirmware driver. But for now we support old trees
1112  * as well.
1113  */
1114 static int __devinit plat_mpc8xxx_spi_probe(struct platform_device *pdev)
1115 {
1116 	struct resource *mem;
1117 	int irq;
1118 	struct spi_master *master;
1119 
1120 	if (!pdev->dev.platform_data)
1121 		return -EINVAL;
1122 
1123 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1124 	if (!mem)
1125 		return -EINVAL;
1126 
1127 	irq = platform_get_irq(pdev, 0);
1128 	if (irq <= 0)
1129 		return -EINVAL;
1130 
1131 	master = fsl_spi_probe(&pdev->dev, mem, irq);
1132 	if (IS_ERR(master))
1133 		return PTR_ERR(master);
1134 	return 0;
1135 }
1136 
1137 static int __devexit plat_mpc8xxx_spi_remove(struct platform_device *pdev)
1138 {
1139 	return mpc8xxx_spi_remove(&pdev->dev);
1140 }
1141 
1142 MODULE_ALIAS("platform:mpc8xxx_spi");
1143 static struct platform_driver mpc8xxx_spi_driver = {
1144 	.probe = plat_mpc8xxx_spi_probe,
1145 	.remove = __devexit_p(plat_mpc8xxx_spi_remove),
1146 	.driver = {
1147 		.name = "mpc8xxx_spi",
1148 		.owner = THIS_MODULE,
1149 	},
1150 };
1151 
1152 static bool legacy_driver_failed;
1153 
1154 static void __init legacy_driver_register(void)
1155 {
1156 	legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
1157 }
1158 
1159 static void __exit legacy_driver_unregister(void)
1160 {
1161 	if (legacy_driver_failed)
1162 		return;
1163 	platform_driver_unregister(&mpc8xxx_spi_driver);
1164 }
1165 #else
1166 static void __init legacy_driver_register(void) {}
1167 static void __exit legacy_driver_unregister(void) {}
1168 #endif /* CONFIG_MPC832x_RDB */
1169 
1170 static int __init fsl_spi_init(void)
1171 {
1172 	legacy_driver_register();
1173 	return platform_driver_register(&of_fsl_spi_driver);
1174 }
1175 module_init(fsl_spi_init);
1176 
1177 static void __exit fsl_spi_exit(void)
1178 {
1179 	platform_driver_unregister(&of_fsl_spi_driver);
1180 	legacy_driver_unregister();
1181 }
1182 module_exit(fsl_spi_exit);
1183 
1184 MODULE_AUTHOR("Kumar Gala");
1185 MODULE_DESCRIPTION("Simple Freescale SPI Driver");
1186 MODULE_LICENSE("GPL");
1187