summaryrefslogtreecommitdiff
path: root/drivers/spi/omap3_spi.c
blob: 9346c0b5b4af679d3015af0bbb35b78eecbc005d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
/*
 * Copyright (C) 2010 Dirk Behme <dirk.behme@googlemail.com>
 *
 * Driver for McSPI controller on OMAP3. Based on davinci_spi.c
 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/
 *
 * Copyright (C) 2007 Atmel Corporation
 *
 * Parts taken from linux/drivers/spi/omap2_mcspi.c
 * Copyright (C) 2005, 2006 Nokia Corporation
 *
 * Modified by Ruslan Araslanov <ruslan.araslanov@vitecmm.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 */

#include <common.h>
#include <spi.h>
#include <malloc.h>
#include <asm/io.h>
#include "omap3_spi.h"

#define WORD_LEN	8
#define SPI_WAIT_TIMEOUT 3000000;

static void spi_reset(struct omap3_spi_slave *ds)
{
	unsigned int tmp;

	writel(OMAP3_MCSPI_SYSCONFIG_SOFTRESET, &ds->regs->sysconfig);
	do {
		tmp = readl(&ds->regs->sysstatus);
	} while (!(tmp & OMAP3_MCSPI_SYSSTATUS_RESETDONE));

	writel(OMAP3_MCSPI_SYSCONFIG_AUTOIDLE |
				 OMAP3_MCSPI_SYSCONFIG_ENAWAKEUP |
				 OMAP3_MCSPI_SYSCONFIG_SMARTIDLE,
				 &ds->regs->sysconfig);

	writel(OMAP3_MCSPI_WAKEUPENABLE_WKEN, &ds->regs->wakeupenable);
}

void spi_init()
{
	/* do nothing */
}

struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
				  unsigned int max_hz, unsigned int mode)
{
	struct omap3_spi_slave	*ds;

	ds = malloc(sizeof(struct omap3_spi_slave));
	if (!ds) {
		printf("SPI error: malloc of SPI structure failed\n");
		return NULL;
	}

	/*
	 * OMAP3 McSPI (MultiChannel SPI) has 4 busses (modules)
	 * with different number of chip selects (CS, channels):
	 * McSPI1 has 4 CS (bus 0, cs 0 - 3)
	 * McSPI2 has 2 CS (bus 1, cs 0 - 1)
	 * McSPI3 has 2 CS (bus 2, cs 0 - 1)
	 * McSPI4 has 1 CS (bus 3, cs 0)
	 */

	switch (bus) {
	case 0:
		ds->regs = (struct mcspi *)OMAP3_MCSPI1_BASE;
		break;
	case 1:
		ds->regs = (struct mcspi *)OMAP3_MCSPI2_BASE;
		break;
	case 2:
		ds->regs = (struct mcspi *)OMAP3_MCSPI3_BASE;
		break;
	case 3:
		ds->regs = (struct mcspi *)OMAP3_MCSPI4_BASE;
		break;
	default:
		printf("SPI error: unsupported bus %i. \
			Supported busses 0 - 3\n", bus);
		return NULL;
	}
	ds->slave.bus = bus;

	if (((bus == 0) && (cs > 3)) ||
			((bus == 1) && (cs > 1)) ||
			((bus == 2) && (cs > 1)) ||
			((bus == 3) && (cs > 0))) {
		printf("SPI error: unsupported chip select %i \
			on bus %i\n", cs, bus);
		return NULL;
	}
	ds->slave.cs = cs;

	if (max_hz > OMAP3_MCSPI_MAX_FREQ) {
		printf("SPI error: unsupported frequency %i Hz. \
			Max frequency is 48 Mhz\n", max_hz);
		return NULL;
	}
	ds->freq = max_hz;

	if (mode > SPI_MODE_3) {
		printf("SPI error: unsupported SPI mode %i\n", mode);
		return NULL;
	}
	ds->mode = mode;

	return &ds->slave;
}

void spi_free_slave(struct spi_slave *slave)
{
	struct omap3_spi_slave *ds = to_omap3_spi(slave);

	free(ds);
}

int spi_claim_bus(struct spi_slave *slave)
{
	struct omap3_spi_slave *ds = to_omap3_spi(slave);
	unsigned int conf, div = 0;

	/* McSPI global module configuration */

	/*
	 * setup when switching from (reset default) slave mode
	 * to single-channel master mode
	 */
	spi_reset(ds);
	conf = readl(&ds->regs->modulctrl);
	conf &= ~(OMAP3_MCSPI_MODULCTRL_STEST | OMAP3_MCSPI_MODULCTRL_MS);
	conf |= OMAP3_MCSPI_MODULCTRL_SINGLE;
	writel(conf, &ds->regs->modulctrl);

	/* McSPI individual channel configuration */

	/* Calculate clock divisor. Valid range: 0x0 - 0xC ( /1 - /4096 ) */
	if (ds->freq) {
		while (div <= 0xC && (OMAP3_MCSPI_MAX_FREQ / (1 << div))
					 > ds->freq)
			div++;
	} else
		div = 0xC;

	conf = readl(&ds->regs->channel[ds->slave.cs].chconf);

	/* standard 4-wire master mode:	SCK, MOSI/out, MISO/in, nCS
	 * REVISIT: this controller could support SPI_3WIRE mode.
	 */
	conf &= ~(OMAP3_MCSPI_CHCONF_IS|OMAP3_MCSPI_CHCONF_DPE1);
	conf |= OMAP3_MCSPI_CHCONF_DPE0;

	/* wordlength */
	conf &= ~OMAP3_MCSPI_CHCONF_WL_MASK;
	conf |= (WORD_LEN - 1) << 7;

	/* set chipselect polarity; manage with FORCE */
	if (!(ds->mode & SPI_CS_HIGH))
		conf |= OMAP3_MCSPI_CHCONF_EPOL; /* active-low; normal */
	else
		conf &= ~OMAP3_MCSPI_CHCONF_EPOL;

	/* set clock divisor */
	conf &= ~OMAP3_MCSPI_CHCONF_CLKD_MASK;
	conf |= div << 2;

	/* set SPI mode 0..3 */
	if (ds->mode & SPI_CPOL)
		conf |= OMAP3_MCSPI_CHCONF_POL;
	else
		conf &= ~OMAP3_MCSPI_CHCONF_POL;
	if (ds->mode & SPI_CPHA)
		conf |= OMAP3_MCSPI_CHCONF_PHA;
	else
		conf &= ~OMAP3_MCSPI_CHCONF_PHA;

	/* Transmit & receive mode */
	conf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;

	writel(conf, &ds->regs->channel[ds->slave.cs].chconf);

	return 0;
}

void spi_release_bus(struct spi_slave *slave)
{
	struct omap3_spi_slave *ds = to_omap3_spi(slave);

	/* Reset the SPI hardware */
	spi_reset(ds);
}

int omap3_spi_write(struct spi_slave *slave, unsigned int len, const u8 *txp,
		    unsigned long flags)
{
	struct omap3_spi_slave *ds = to_omap3_spi(slave);
	int i;
	int timeout = SPI_WAIT_TIMEOUT;
	int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);

	if (flags & SPI_XFER_BEGIN)
		writel(OMAP3_MCSPI_CHCTRL_EN,
		       &ds->regs->channel[ds->slave.cs].chctrl);

	chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;
	chconf |= OMAP3_MCSPI_CHCONF_TRM_TX_ONLY;
	chconf |= OMAP3_MCSPI_CHCONF_FORCE;
	writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);

	for (i = 0; i < len; i++) {
		/* wait till TX register is empty (TXS == 1) */
		while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
			 OMAP3_MCSPI_CHSTAT_TXS)) {
			if (--timeout <= 0) {
				printf("SPI TXS timed out, status=0x%08x\n",
				       readl(&ds->regs->channel[ds->slave.cs].chstat));
				return -1;
			}
		}
		/* Write the data */
		writel(txp[i], &ds->regs->channel[ds->slave.cs].tx);
	}

	if (flags & SPI_XFER_END) {
		/* wait to finish of transfer */
		while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
			 OMAP3_MCSPI_CHSTAT_EOT));

		chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
		writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);

		writel(0, &ds->regs->channel[ds->slave.cs].chctrl);
	}
	return 0;
}

int omap3_spi_read(struct spi_slave *slave, unsigned int len, u8 *rxp,
		   unsigned long flags)
{
	struct omap3_spi_slave *ds = to_omap3_spi(slave);
	int i;
	int timeout = SPI_WAIT_TIMEOUT;
	int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);

	if (flags & SPI_XFER_BEGIN)
		writel(OMAP3_MCSPI_CHCTRL_EN,
		       &ds->regs->channel[ds->slave.cs].chctrl);

	chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;
	chconf |= OMAP3_MCSPI_CHCONF_TRM_RX_ONLY;
	chconf |= OMAP3_MCSPI_CHCONF_FORCE;
	writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);

	writel(0, &ds->regs->channel[ds->slave.cs].tx);

	for (i = 0; i < len; i++) {
		/* Wait till RX register contains data (RXS == 1) */
		while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
			 OMAP3_MCSPI_CHSTAT_RXS)) {
			if (--timeout <= 0) {
				printf("SPI RXS timed out, status=0x%08x\n",
				       readl(&ds->regs->channel[ds->slave.cs].chstat));
				return -1;
			}
		}
		/* Read the data */
		rxp[i] = readl(&ds->regs->channel[ds->slave.cs].rx);
	}

	if (flags & SPI_XFER_END) {
		chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
		writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);

		writel(0, &ds->regs->channel[ds->slave.cs].chctrl);
	}

	return 0;
}

/*McSPI Transmit Receive Mode*/
int omap3_spi_txrx(struct spi_slave *slave,
		unsigned int len, const u8 *txp, u8 *rxp, unsigned long flags)
{
	struct omap3_spi_slave *ds = to_omap3_spi(slave);
	int timeout = SPI_WAIT_TIMEOUT;
	int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);
	int irqstatus = readl(&ds->regs->irqstatus);
	int i=0;

	/*Enable SPI channel*/
	if (flags & SPI_XFER_BEGIN)
		writel(OMAP3_MCSPI_CHCTRL_EN,
		       &ds->regs->channel[ds->slave.cs].chctrl);

	/*set TRANSMIT-RECEIVE Mode*/
	chconf &= ~OMAP3_MCSPI_CHCONF_TRM_MASK;
	chconf |= OMAP3_MCSPI_CHCONF_FORCE;
	writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);

	/*Shift in and out 1 byte at time*/
	for (i=0; i < len; i++){
		/* Write: wait for TX empty (TXS == 1)*/
		irqstatus |= (1<< (4*(ds->slave.bus)));
		while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
			 OMAP3_MCSPI_CHSTAT_TXS)) {
			if (--timeout <= 0) {
				printf("SPI TXS timed out, status=0x%08x\n",
				       readl(&ds->regs->channel[ds->slave.cs].chstat));
				return -1;
			}
		}
		/* Write the data */
		writel(txp[i], &ds->regs->channel[ds->slave.cs].tx);

		/*Read: wait for RX containing data (RXS == 1)*/
		while (!(readl(&ds->regs->channel[ds->slave.cs].chstat) &
			 OMAP3_MCSPI_CHSTAT_RXS)) {
			if (--timeout <= 0) {
				printf("SPI RXS timed out, status=0x%08x\n",
				       readl(&ds->regs->channel[ds->slave.cs].chstat));
				return -1;
			}
		}
		/* Read the data */
		rxp[i] = readl(&ds->regs->channel[ds->slave.cs].rx);
	}

	/*if transfer must be terminated disable the channel*/
	if (flags & SPI_XFER_END) {
		chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
		writel(chconf, &ds->regs->channel[ds->slave.cs].chconf);

		writel(0, &ds->regs->channel[ds->slave.cs].chctrl);
	}

	return 0;
}

int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
	     const void *dout, void *din, unsigned long flags)
{
	struct omap3_spi_slave *ds = to_omap3_spi(slave);
	unsigned int	len;
	const u8	*txp = dout;
	u8		*rxp = din;
	int ret = -1;

	if (bitlen % 8)
		return -1;

	len = bitlen / 8;

	if (bitlen == 0) {	 /* only change CS */
		int chconf = readl(&ds->regs->channel[ds->slave.cs].chconf);

		if (flags & SPI_XFER_BEGIN) {
			writel(OMAP3_MCSPI_CHCTRL_EN,
			       &ds->regs->channel[ds->slave.cs].chctrl);
			chconf |= OMAP3_MCSPI_CHCONF_FORCE;
			writel(chconf,
			       &ds->regs->channel[ds->slave.cs].chconf);
		}
		if (flags & SPI_XFER_END) {
			chconf &= ~OMAP3_MCSPI_CHCONF_FORCE;
			writel(chconf,
			       &ds->regs->channel[ds->slave.cs].chconf);
			writel(0, &ds->regs->channel[ds->slave.cs].chctrl);
		}
		ret = 0;
	} else {
		if (dout != NULL && din != NULL)
			ret = omap3_spi_txrx(slave, len, txp, rxp, flags);
		else if (dout != NULL)
			ret = omap3_spi_write(slave, len, txp, flags);
		else if (din != NULL)
			ret = omap3_spi_read(slave, len, rxp, flags);
	}
	return ret;
}

int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
	return 1;
}

void spi_cs_activate(struct spi_slave *slave)
{
}

void spi_cs_deactivate(struct spi_slave *slave)
{
}