summaryrefslogtreecommitdiff
path: root/drivers/i2c/busses/i2c-powermac.c
blob: 60a53c169ed2b3c8d3803411a310b752d8e1631b (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
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
/*
    i2c Support for Apple SMU Controller

    Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
                       <benh@kernel.crashing.org>

    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.

*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/of_irq.h>
#include <asm/prom.h>
#include <asm/pmac_low_i2c.h>

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
MODULE_LICENSE("GPL");

/*
 * SMBUS-type transfer entrypoint
 */
static s32 i2c_powermac_smbus_xfer(	struct i2c_adapter*	adap,
					u16			addr,
					unsigned short		flags,
					char			read_write,
					u8			command,
					int			size,
					union i2c_smbus_data*	data)
{
	struct pmac_i2c_bus	*bus = i2c_get_adapdata(adap);
	int			rc = 0;
	int			read = (read_write == I2C_SMBUS_READ);
	int			addrdir = (addr << 1) | read;
	int			mode, subsize, len;
	u32			subaddr;
	u8			*buf;
	u8			local[2];

	if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {
		mode = pmac_i2c_mode_std;
		subsize = 0;
		subaddr = 0;
	} else {
		mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;
		subsize = 1;
		subaddr = command;
	}

	switch (size) {
        case I2C_SMBUS_QUICK:
		buf = NULL;
		len = 0;
	    	break;
        case I2C_SMBUS_BYTE:
        case I2C_SMBUS_BYTE_DATA:
		buf = &data->byte;
		len = 1;
	    	break;
        case I2C_SMBUS_WORD_DATA:
		if (!read) {
			local[0] = data->word & 0xff;
			local[1] = (data->word >> 8) & 0xff;
		}
		buf = local;
		len = 2;
	    	break;

	/* Note that these are broken vs. the expected smbus API where
	 * on reads, the length is actually returned from the function,
	 * but I think the current API makes no sense and I don't want
	 * any driver that I haven't verified for correctness to go
	 * anywhere near a pmac i2c bus anyway ...
	 *
	 * I'm also not completely sure what kind of phases to do between
	 * the actual command and the data (what I am _supposed_ to do that
	 * is). For now, I assume writes are a single stream and reads have
	 * a repeat start/addr phase (but not stop in between)
	 */
        case I2C_SMBUS_BLOCK_DATA:
		buf = data->block;
		len = data->block[0] + 1;
		break;
	case I2C_SMBUS_I2C_BLOCK_DATA:
		buf = &data->block[1];
		len = data->block[0];
		break;

        default:
		return -EINVAL;
	}

	rc = pmac_i2c_open(bus, 0);
	if (rc) {
		dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
		return rc;
	}

	rc = pmac_i2c_setmode(bus, mode);
	if (rc) {
		dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
			mode, rc);
		goto bail;
	}

	rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
	if (rc) {
		if (rc == -ENXIO)
			dev_dbg(&adap->dev,
				"I2C transfer at 0x%02x failed, size %d, "
				"err %d\n", addrdir >> 1, size, rc);
		else
			dev_err(&adap->dev,
				"I2C transfer at 0x%02x failed, size %d, "
				"err %d\n", addrdir >> 1, size, rc);
		goto bail;
	}

	if (size == I2C_SMBUS_WORD_DATA && read) {
		data->word = ((u16)local[1]) << 8;
		data->word |= local[0];
	}

 bail:
	pmac_i2c_close(bus);
	return rc;
}

/*
 * Generic i2c master transfer entrypoint. This driver only support single
 * messages (for "lame i2c" transfers). Anything else should use the smbus
 * entry point
 */
static int i2c_powermac_master_xfer(	struct i2c_adapter *adap,
					struct i2c_msg *msgs,
					int num)
{
	struct pmac_i2c_bus	*bus = i2c_get_adapdata(adap);
	int			rc = 0;
	int			read;
	int			addrdir;

	if (num != 1) {
		dev_err(&adap->dev,
			"Multi-message I2C transactions not supported\n");
		return -EOPNOTSUPP;
	}

	if (msgs->flags & I2C_M_TEN)
		return -EINVAL;
	read = (msgs->flags & I2C_M_RD) != 0;
	addrdir = (msgs->addr << 1) | read;

	rc = pmac_i2c_open(bus, 0);
	if (rc) {
		dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
		return rc;
	}
	rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
	if (rc) {
		dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
			pmac_i2c_mode_std, rc);
		goto bail;
	}
	rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
	if (rc < 0) {
		if (rc == -ENXIO)
			dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
				addrdir & 1 ? "read from" : "write to",
				addrdir >> 1, rc);
		else
			dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
				addrdir & 1 ? "read from" : "write to",
				addrdir >> 1, rc);
	}
 bail:
	pmac_i2c_close(bus);
	return rc < 0 ? rc : 1;
}

static u32 i2c_powermac_func(struct i2c_adapter * adapter)
{
	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
}

/* For now, we only handle smbus */
static const struct i2c_algorithm i2c_powermac_algorithm = {
	.smbus_xfer	= i2c_powermac_smbus_xfer,
	.master_xfer	= i2c_powermac_master_xfer,
	.functionality	= i2c_powermac_func,
};


static int i2c_powermac_remove(struct platform_device *dev)
{
	struct i2c_adapter	*adapter = platform_get_drvdata(dev);

	i2c_del_adapter(adapter);
	memset(adapter, 0, sizeof(*adapter));

	return 0;
}

static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
					   struct pmac_i2c_bus *bus,
					   struct device_node *node)
{
	const __be32 *prop;
	int len;

	/* First check for valid "reg" */
	prop = of_get_property(node, "reg", &len);
	if (prop && (len >= sizeof(int)))
		return (be32_to_cpup(prop) & 0xff) >> 1;

	/* Then check old-style "i2c-address" */
	prop = of_get_property(node, "i2c-address", &len);
	if (prop && (len >= sizeof(int)))
		return (be32_to_cpup(prop) & 0xff) >> 1;

	/* Now handle some devices with missing "reg" properties */
	if (!strcmp(node->name, "cereal"))
		return 0x60;
	else if (!strcmp(node->name, "deq"))
		return 0x34;

	dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);

	return 0xffffffff;
}

static void i2c_powermac_create_one(struct i2c_adapter *adap,
					      const char *type,
					      u32 addr)
{
	struct i2c_board_info info = {};
	struct i2c_client *newdev;

	strncpy(info.type, type, sizeof(info.type));
	info.addr = addr;
	newdev = i2c_new_device(adap, &info);
	if (!newdev)
		dev_err(&adap->dev,
			"i2c-powermac: Failure to register missing %s\n",
			type);
}

static void i2c_powermac_add_missing(struct i2c_adapter *adap,
					       struct pmac_i2c_bus *bus,
					       bool found_onyx)
{
	struct device_node *busnode = pmac_i2c_get_bus_node(bus);
	int rc;

	/* Check for the onyx audio codec */
#define ONYX_REG_CONTROL		67
	if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
		union i2c_smbus_data data;

		rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
				    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
				    &data);
		if (rc >= 0)
			i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);

		rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
				    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
				    &data);
		if (rc >= 0)
			i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
	}
}

static bool i2c_powermac_get_type(struct i2c_adapter *adap,
					    struct device_node *node,
					    u32 addr, char *type, int type_size)
{
	char tmp[16];

	/* Note: we to _NOT_ want the standard
	 * i2c drivers to match with any of our powermac stuff
	 * unless they have been specifically modified to handle
	 * it on a case by case basis. For example, for thermal
	 * control, things like lm75 etc... shall match with their
	 * corresponding windfarm drivers, _NOT_ the generic ones,
	 * so we force a prefix of AAPL, onto the modalias to
	 * make that happen
	 */

	/* First try proper modalias */
	if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
		snprintf(type, type_size, "MAC,%s", tmp);
		return true;
	}

	/* Now look for known workarounds */
	if (!strcmp(node->name, "deq")) {
		/* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
		if (addr == 0x34) {
			snprintf(type, type_size, "MAC,tas3001");
			return true;
		} else if (addr == 0x35) {
			snprintf(type, type_size, "MAC,tas3004");
			return true;
		}
	}

	dev_err(&adap->dev, "i2c-powermac: modalias failure"
		" on %s\n", node->full_name);
	return false;
}

static void i2c_powermac_register_devices(struct i2c_adapter *adap,
						    struct pmac_i2c_bus *bus)
{
	struct i2c_client *newdev;
	struct device_node *node;
	bool found_onyx = 0;

	/*
	 * In some cases we end up with the via-pmu node itself, in this
	 * case we skip this function completely as the device-tree will
	 * not contain anything useful.
	 */
	if (!strcmp(adap->dev.of_node->name, "via-pmu"))
		return;

	for_each_child_of_node(adap->dev.of_node, node) {
		struct i2c_board_info info = {};
		u32 addr;

		/* Get address & channel */
		addr = i2c_powermac_get_addr(adap, bus, node);
		if (addr == 0xffffffff)
			continue;

		/* Multibus setup, check channel */
		if (!pmac_i2c_match_adapter(node, adap))
			continue;

		dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
			node->full_name);

		/*
		 * Keep track of some device existence to handle
		 * workarounds later.
		 */
		if (of_device_is_compatible(node, "pcm3052"))
			found_onyx = true;

		/* Make up a modalias */
		if (!i2c_powermac_get_type(adap, node, addr,
					   info.type, sizeof(info.type))) {
			continue;
		}

		/* Fill out the rest of the info structure */
		info.addr = addr;
		info.irq = irq_of_parse_and_map(node, 0);
		info.of_node = of_node_get(node);

		newdev = i2c_new_device(adap, &info);
		if (!newdev) {
			dev_err(&adap->dev, "i2c-powermac: Failure to register"
				" %s\n", node->full_name);
			of_node_put(node);
			/* We do not dispose of the interrupt mapping on
			 * purpose. It's not necessary (interrupt cannot be
			 * re-used) and somebody else might have grabbed it
			 * via direct DT lookup so let's not bother
			 */
			continue;
		}
	}

	/* Additional workarounds */
	i2c_powermac_add_missing(adap, bus, found_onyx);
}

static int i2c_powermac_probe(struct platform_device *dev)
{
	struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
	struct device_node *parent = NULL;
	struct i2c_adapter *adapter;
	const char *basename;
	int rc;

	if (bus == NULL)
		return -EINVAL;
	adapter = pmac_i2c_get_adapter(bus);

	/* Ok, now we need to make up a name for the interface that will
	 * match what we used to do in the past, that is basically the
	 * controller's parent device node for keywest. PMU didn't have a
	 * naming convention and SMU has a different one
	 */
	switch(pmac_i2c_get_type(bus)) {
	case pmac_i2c_bus_keywest:
		parent = of_get_parent(pmac_i2c_get_controller(bus));
		if (parent == NULL)
			return -EINVAL;
		basename = parent->name;
		break;
	case pmac_i2c_bus_pmu:
		basename = "pmu";
		break;
	case pmac_i2c_bus_smu:
		/* This is not what we used to do but I'm fixing drivers at
		 * the same time as this change
		 */
		basename = "smu";
		break;
	default:
		return -EINVAL;
	}
	snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
		 pmac_i2c_get_channel(bus));
	of_node_put(parent);

	platform_set_drvdata(dev, adapter);
	adapter->algo = &i2c_powermac_algorithm;
	i2c_set_adapdata(adapter, bus);
	adapter->dev.parent = &dev->dev;

	/* Clear of_node to skip automatic registration of i2c child nodes */
	adapter->dev.of_node = NULL;
	rc = i2c_add_adapter(adapter);
	if (rc) {
		printk(KERN_ERR "i2c-powermac: Adapter %s registration "
		       "failed\n", adapter->name);
		memset(adapter, 0, sizeof(*adapter));
		return rc;
	}

	printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);

	/* Use custom child registration due to Apple device-tree funkyness */
	adapter->dev.of_node = dev->dev.of_node;
	i2c_powermac_register_devices(adapter, bus);

	return 0;
}

static struct platform_driver i2c_powermac_driver = {
	.probe = i2c_powermac_probe,
	.remove = i2c_powermac_remove,
	.driver = {
		.name = "i2c-powermac",
		.bus = &platform_bus_type,
	},
};

module_platform_driver(i2c_powermac_driver);

MODULE_ALIAS("platform:i2c-powermac");