summaryrefslogtreecommitdiffstats
path: root/drivers/i2c/ppc4xx_i2c.c
blob: e7a15ba6448a7600ac5f8a077840e2e98533d2e3 (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
413
414
415
416
417
418
419
/*
 * (C) Copyright 2007-2009
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * based on work by Anne Sophie Harnois <anne-sophie.harnois@nextream.fr>
 *
 * (C) Copyright 2001
 * Bill Hunter,  Wave 7 Optics, williamhunter@mediaone.net
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <asm/ppc4xx.h>
#include <asm/ppc4xx-i2c.h>
#include <i2c.h>
#include <asm/io.h>

DECLARE_GLOBAL_DATA_PTR;

static inline struct ppc4xx_i2c *ppc4xx_get_i2c(int hwadapnr)
{
	unsigned long base;

#if defined(CONFIG_440EP) || defined(CONFIG_440GR) || \
	defined(CONFIG_440EPX) || defined(CONFIG_440GRX) || \
	defined(CONFIG_460EX) || defined(CONFIG_460GT)
	base = CONFIG_SYS_PERIPHERAL_BASE + 0x00000700 + (hwadapnr * 0x100);
#elif defined(CONFIG_440) || defined(CONFIG_405EX)
/* all remaining 440 variants */
	base = CONFIG_SYS_PERIPHERAL_BASE + 0x00000400 + (hwadapnr * 0x100);
#else
/* all 405 variants */
	base = 0xEF600500 + (hwadapnr * 0x100);
#endif
	return (struct ppc4xx_i2c *)base;
}

static void _i2c_bus_reset(struct i2c_adapter *adap)
{
	struct ppc4xx_i2c *i2c = ppc4xx_get_i2c(adap->hwadapnr);
	int i;
	u8 dc;

	/* Reset status register */
	/* write 1 in SCMP and IRQA to clear these fields */
	out_8(&i2c->sts, 0x0A);

	/* write 1 in IRQP IRQD LA ICT XFRA to clear these fields */
	out_8(&i2c->extsts, 0x8F);

	/* Place chip in the reset state */
	out_8(&i2c->xtcntlss, IIC_XTCNTLSS_SRST);

	/* Check if bus is free */
	dc = in_8(&i2c->directcntl);
	if (!DIRCTNL_FREE(dc)){
		/* Try to set bus free state */
		out_8(&i2c->directcntl, IIC_DIRCNTL_SDAC | IIC_DIRCNTL_SCC);

		/* Wait until we regain bus control */
		for (i = 0; i < 100; ++i) {
			dc = in_8(&i2c->directcntl);
			if (DIRCTNL_FREE(dc))
				break;

			/* Toggle SCL line */
			dc ^= IIC_DIRCNTL_SCC;
			out_8(&i2c->directcntl, dc);
			udelay(10);
			dc ^= IIC_DIRCNTL_SCC;
			out_8(&i2c->directcntl, dc);
		}
	}

	/* Remove reset */
	out_8(&i2c->xtcntlss, 0);
}

static void ppc4xx_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
{
	struct ppc4xx_i2c *i2c = ppc4xx_get_i2c(adap->hwadapnr);
	int val, divisor;

#ifdef CONFIG_SYS_I2C_INIT_BOARD
	/*
	 * Call board specific i2c bus reset routine before accessing the
	 * environment, which might be in a chip on that bus. For details
	 * about this problem see doc/I2C_Edge_Conditions.
	 */
	i2c_init_board();
#endif

	/* Handle possible failed I2C state */
	/* FIXME: put this into i2c_init_board()? */
	_i2c_bus_reset(adap);

	/* clear lo master address */
	out_8(&i2c->lmadr, 0);

	/* clear hi master address */
	out_8(&i2c->hmadr, 0);

	/* clear lo slave address */
	out_8(&i2c->lsadr, 0);

	/* clear hi slave address */
	out_8(&i2c->hsadr, 0);

	/* Clock divide Register */
	/* set divisor according to freq_opb */
	divisor = (get_OPB_freq() - 1) / 10000000;
	if (divisor == 0)
		divisor = 1;
	out_8(&i2c->clkdiv, divisor);

	/* no interrupts */
	out_8(&i2c->intrmsk, 0);

	/* clear transfer count */
	out_8(&i2c->xfrcnt, 0);

	/* clear extended control & stat */
	/* write 1 in SRC SRS SWC SWS to clear these fields */
	out_8(&i2c->xtcntlss, 0xF0);

	/* Mode Control Register
	   Flush Slave/Master data buffer */
	out_8(&i2c->mdcntl, IIC_MDCNTL_FSDB | IIC_MDCNTL_FMDB);

	val = in_8(&i2c->mdcntl);

	/* Ignore General Call, slave transfers are ignored,
	 * disable interrupts, exit unknown bus state, enable hold
	 * SCL 100kHz normaly or FastMode for 400kHz and above
	 */

	val |= IIC_MDCNTL_EUBS | IIC_MDCNTL_HSCL;
	if (speed >= 400000)
		val |= IIC_MDCNTL_FSM;
	out_8(&i2c->mdcntl, val);

	/* clear control reg */
	out_8(&i2c->cntl, 0x00);
}

/*
 * This code tries to use the features of the 405GP i2c
 * controller. It will transfer up to 4 bytes in one pass
 * on the loop. It only does out_8((u8 *)lbz) to the buffer when it
 * is possible to do out16(lhz) transfers.
 *
 * cmd_type is 0 for write 1 for read.
 *
 * addr_len can take any value from 0-255, it is only limited
 * by the char, we could make it larger if needed. If it is
 * 0 we skip the address write cycle.
 *
 * Typical case is a Write of an addr followd by a Read. The
 * IBM FAQ does not cover this. On the last byte of the write
 * we don't set the creg CHT bit, and on the first bytes of the
 * read we set the RPST bit.
 *
 * It does not support address only transfers, there must be
 * a data part. If you want to write the address yourself, put
 * it in the data pointer.
 *
 * It does not support transfer to/from address 0.
 *
 * It does not check XFRCNT.
 */
static int _i2c_transfer(struct i2c_adapter *adap,
			unsigned char cmd_type,
			unsigned char chip,
			unsigned char addr[],
			unsigned char addr_len,
			unsigned char data[],
			unsigned short data_len)
{
	struct ppc4xx_i2c *i2c = ppc4xx_get_i2c(adap->hwadapnr);
	u8 *ptr;
	int reading;
	int tran, cnt;
	int result;
	int status;
	int i;
	u8 creg;

	if (data == 0 || data_len == 0) {
		/* Don't support data transfer of no length or to address 0 */
		printf( "i2c_transfer: bad call\n" );
		return IIC_NOK;
	}
	if (addr && addr_len) {
		ptr = addr;
		cnt = addr_len;
		reading = 0;
	} else {
		ptr = data;
		cnt = data_len;
		reading = cmd_type;
	}

	/* Clear Stop Complete Bit */
	out_8(&i2c->sts, IIC_STS_SCMP);

	/* Check init */
	i = 10;
	do {
		/* Get status */
		status = in_8(&i2c->sts);
		i--;
	} while ((status & IIC_STS_PT) && (i > 0));

	if (status & IIC_STS_PT) {
		result = IIC_NOK_TOUT;
		return(result);
	}

	/* flush the Master/Slave Databuffers */
	out_8(&i2c->mdcntl, in_8(&i2c->mdcntl) |
	      IIC_MDCNTL_FMDB | IIC_MDCNTL_FSDB);

	/* need to wait 4 OPB clocks? code below should take that long */

	/* 7-bit adressing */
	out_8(&i2c->hmadr, 0);
	out_8(&i2c->lmadr, chip);

	tran = 0;
	result = IIC_OK;
	creg = 0;

	while (tran != cnt && (result == IIC_OK)) {
		int  bc,j;

		/*
		 * Control register =
		 * Normal transfer, 7-bits adressing, Transfer up to
		 * bc bytes, Normal start, Transfer is a sequence of transfers
		 */
		creg |= IIC_CNTL_PT;

		bc = (cnt - tran) > 4 ? 4 : cnt - tran;
		creg |= (bc - 1) << 4;
		/* if the real cmd type is write continue trans */
		if ((!cmd_type && (ptr == addr)) || ((tran + bc) != cnt))
			creg |= IIC_CNTL_CHT;

		if (reading) {
			creg |= IIC_CNTL_READ;
		} else {
			for(j = 0; j < bc; j++) {
				/* Set buffer */
				out_8(&i2c->mdbuf, ptr[tran + j]);
			}
		}
		out_8(&i2c->cntl, creg);

		/*
		 * Transfer is in progress
		 * we have to wait for upto 5 bytes of data
		 * 1 byte chip address+r/w bit then bc bytes
		 * of data.
		 * udelay(10) is 1 bit time at 100khz
		 * Doubled for slop. 20 is too small.
		 */
		i = 2 * 5 * 8;
		do {
			/* Get status */
			status = in_8(&i2c->sts);
			udelay(10);
			i--;
		} while ((status & IIC_STS_PT) && !(status & IIC_STS_ERR) &&
			 (i > 0));

		if (status & IIC_STS_ERR) {
			result = IIC_NOK;
			status = in_8(&i2c->extsts);
			/* Lost arbitration? */
			if (status & IIC_EXTSTS_LA)
				result = IIC_NOK_LA;
			/* Incomplete transfer? */
			if (status & IIC_EXTSTS_ICT)
				result = IIC_NOK_ICT;
			/* Transfer aborted? */
			if (status & IIC_EXTSTS_XFRA)
				result = IIC_NOK_XFRA;
		} else if ( status & IIC_STS_PT) {
			result = IIC_NOK_TOUT;
		}

		/* Command is reading => get buffer */
		if ((reading) && (result == IIC_OK)) {
			/* Are there data in buffer */
			if (status & IIC_STS_MDBS) {
				/*
				 * even if we have data we have to wait 4OPB
				 * clocks for it to hit the front of the FIFO,
				 * after that we can just read. We should check
				 * XFCNT here and if the FIFO is full there is
				 * no need to wait.
				 */
				udelay(1);
				for (j = 0; j < bc; j++)
					ptr[tran + j] = in_8(&i2c->mdbuf);
			} else
				result = IIC_NOK_DATA;
		}
		creg = 0;
		tran += bc;
		if (ptr == addr && tran == cnt) {
			ptr = data;
			cnt = data_len;
			tran = 0;
			reading = cmd_type;
			if (reading)
				creg = IIC_CNTL_RPST;
		}
	}
	return result;
}

static int ppc4xx_i2c_probe(struct i2c_adapter *adap, uchar chip)
{
	uchar buf[1];

	buf[0] = 0;

	/*
	 * What is needed is to send the chip address and verify that the
	 * address was <ACK>ed (i.e. there was a chip at that address which
	 * drove the data line low).
	 */
	return (_i2c_transfer(adap, 1, chip << 1, 0, 0, buf, 1) != 0);
}

static int ppc4xx_i2c_transfer(struct i2c_adapter *adap, uchar chip, uint addr,
			       int alen, uchar *buffer, int len, int read)
{
	uchar xaddr[4];
	int ret;

	if (alen > 4) {
		printf("I2C: addr len %d not supported\n", alen);
		return 1;
	}

	if (alen > 0) {
		xaddr[0] = (addr >> 24) & 0xFF;
		xaddr[1] = (addr >> 16) & 0xFF;
		xaddr[2] = (addr >> 8) & 0xFF;
		xaddr[3] = addr & 0xFF;
	}


#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
	/*
	 * EEPROM chips that implement "address overflow" are ones
	 * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
	 * address and the extra bits end up in the "chip address"
	 * bit slots. This makes a 24WC08 (1Kbyte) chip look like
	 * four 256 byte chips.
	 *
	 * Note that we consider the length of the address field to
	 * still be one byte because the extra address bits are
	 * hidden in the chip address.
	 */
	if (alen > 0)
		chip |= ((addr >> (alen * 8)) &
			 CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
#endif
	ret = _i2c_transfer(adap, read, chip << 1, &xaddr[4 - alen], alen,
			    buffer, len);
	if (ret) {
		printf("I2C %s: failed %d\n", read ? "read" : "write", ret);
		return 1;
	}

	return 0;
}

static int ppc4xx_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
			   int alen, uchar *buffer, int len)
{
	return ppc4xx_i2c_transfer(adap, chip, addr, alen, buffer, len, 1);
}

static int ppc4xx_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
			    int alen, uchar *buffer, int len)
{
	return ppc4xx_i2c_transfer(adap, chip, addr, alen, buffer, len, 0);
}

static unsigned int ppc4xx_i2c_set_bus_speed(struct i2c_adapter *adap,
					     unsigned int speed)
{
	if (speed != adap->speed)
		return -1;
	return speed;
}

/*
 * Register ppc4xx i2c adapters
 */
#ifdef CONFIG_SYS_I2C_PPC4XX_CH0
U_BOOT_I2C_ADAP_COMPLETE(ppc4xx_0, ppc4xx_i2c_init, ppc4xx_i2c_probe,
			 ppc4xx_i2c_read, ppc4xx_i2c_write,
			 ppc4xx_i2c_set_bus_speed,
			 CONFIG_SYS_I2C_PPC4XX_SPEED_0,
			 CONFIG_SYS_I2C_PPC4XX_SLAVE_0, 0)
#endif
#ifdef CONFIG_SYS_I2C_PPC4XX_CH1
U_BOOT_I2C_ADAP_COMPLETE(ppc4xx_1, ppc4xx_i2c_init, ppc4xx_i2c_probe,
			 ppc4xx_i2c_read, ppc4xx_i2c_write,
			 ppc4xx_i2c_set_bus_speed,
			 CONFIG_SYS_I2C_PPC4XX_SPEED_1,
			 CONFIG_SYS_I2C_PPC4XX_SLAVE_1, 1)
#endif
OpenPOWER on IntegriCloud