summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/pmbus/zl6100.c
blob: 48c7b4a716ae49dfec79a51ff3ac0362849973cd (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
/*
 * Hardware monitoring driver for ZL6100 and compatibles
 *
 * Copyright (c) 2011 Ericsson AB.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/ktime.h>
#include <linux/delay.h>
#include "pmbus.h"

enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105 };

struct zl6100_data {
	int id;
	ktime_t access;		/* chip access time */
	struct pmbus_driver_info info;
};

#define to_zl6100_data(x)  container_of(x, struct zl6100_data, info)

#define ZL6100_MFR_CONFIG		0xd0
#define ZL6100_DEVICE_ID		0xe4

#define ZL6100_MFR_XTEMP_ENABLE		(1 << 7)

#define ZL6100_WAIT_TIME		1000	/* uS	*/

static ushort delay = ZL6100_WAIT_TIME;
module_param(delay, ushort, 0644);
MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");

/* Some chips need a delay between accesses */
static inline void zl6100_wait(const struct zl6100_data *data)
{
	if (delay) {
		s64 delta = ktime_us_delta(ktime_get(), data->access);
		if (delta < delay)
			udelay(delay - delta);
	}
}

static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret;

	if (page || reg >= PMBUS_VIRT_BASE)
		return -ENXIO;

	if (data->id == zl2005) {
		/*
		 * Limit register detection is not reliable on ZL2005.
		 * Make sure registers are not erroneously detected.
		 */
		switch (reg) {
		case PMBUS_VOUT_OV_WARN_LIMIT:
		case PMBUS_VOUT_UV_WARN_LIMIT:
		case PMBUS_IOUT_OC_WARN_LIMIT:
			return -ENXIO;
		}
	}

	zl6100_wait(data);
	ret = pmbus_read_word_data(client, page, reg);
	data->access = ktime_get();

	return ret;
}

static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret;

	if (page > 0)
		return -ENXIO;

	zl6100_wait(data);
	ret = pmbus_read_byte_data(client, page, reg);
	data->access = ktime_get();

	return ret;
}

static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
				  u16 word)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret;

	if (page || reg >= PMBUS_VIRT_BASE)
		return -ENXIO;

	zl6100_wait(data);
	ret = pmbus_write_word_data(client, page, reg, word);
	data->access = ktime_get();

	return ret;
}

static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret;

	if (page > 0)
		return -ENXIO;

	zl6100_wait(data);
	ret = pmbus_write_byte(client, page, value);
	data->access = ktime_get();

	return ret;
}

static const struct i2c_device_id zl6100_id[] = {
	{"bmr450", zl2005},
	{"bmr451", zl2005},
	{"bmr462", zl2008},
	{"bmr463", zl2008},
	{"bmr464", zl2008},
	{"zl2004", zl2004},
	{"zl2005", zl2005},
	{"zl2006", zl2006},
	{"zl2008", zl2008},
	{"zl2105", zl2105},
	{"zl2106", zl2106},
	{"zl6100", zl6100},
	{"zl6105", zl6105},
	{ }
};
MODULE_DEVICE_TABLE(i2c, zl6100_id);

static int zl6100_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	int ret;
	struct zl6100_data *data;
	struct pmbus_driver_info *info;
	u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
	const struct i2c_device_id *mid;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_READ_WORD_DATA
				     | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
		return -ENODEV;

	ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
					device_id);
	if (ret < 0) {
		dev_err(&client->dev, "Failed to read device ID\n");
		return ret;
	}
	device_id[ret] = '\0';
	dev_info(&client->dev, "Device ID %s\n", device_id);

	mid = NULL;
	for (mid = zl6100_id; mid->name[0]; mid++) {
		if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
			break;
	}
	if (!mid->name[0]) {
		dev_err(&client->dev, "Unsupported device\n");
		return -ENODEV;
	}
	if (id->driver_data != mid->driver_data)
		dev_notice(&client->dev,
			   "Device mismatch: Configured %s, detected %s\n",
			   id->name, mid->name);

	data = kzalloc(sizeof(struct zl6100_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->id = mid->driver_data;

	/*
	 * ZL2005, ZL2008, ZL2105, and ZL6100 are known to require a wait time
	 * between I2C accesses. ZL2004 and ZL6105 are known to be safe.
	 * Other chips have not yet been tested.
	 *
	 * Only clear the wait time for chips known to be safe. The wait time
	 * can be cleared later for additional chips if tests show that it
	 * is not needed (in other words, better be safe than sorry).
	 */
	if (data->id == zl2004 || data->id == zl6105)
		delay = 0;

	/*
	 * Since there was a direct I2C device access above, wait before
	 * accessing the chip again.
	 */
	data->access = ktime_get();
	zl6100_wait(data);

	info = &data->info;

	info->pages = 1;
	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
	  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
	  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
	  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;

	ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
	if (ret < 0)
		goto err_mem;
	if (ret & ZL6100_MFR_XTEMP_ENABLE)
		info->func[0] |= PMBUS_HAVE_TEMP2;

	data->access = ktime_get();
	zl6100_wait(data);

	info->read_word_data = zl6100_read_word_data;
	info->read_byte_data = zl6100_read_byte_data;
	info->write_word_data = zl6100_write_word_data;
	info->write_byte = zl6100_write_byte;

	ret = pmbus_do_probe(client, mid, info);
	if (ret)
		goto err_mem;
	return 0;

err_mem:
	kfree(data);
	return ret;
}

static int zl6100_remove(struct i2c_client *client)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	const struct zl6100_data *data = to_zl6100_data(info);

	pmbus_do_remove(client);
	kfree(data);
	return 0;
}

static struct i2c_driver zl6100_driver = {
	.driver = {
		   .name = "zl6100",
		   },
	.probe = zl6100_probe,
	.remove = zl6100_remove,
	.id_table = zl6100_id,
};

static int __init zl6100_init(void)
{
	return i2c_add_driver(&zl6100_driver);
}

static void __exit zl6100_exit(void)
{
	i2c_del_driver(&zl6100_driver);
}

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
MODULE_LICENSE("GPL");
module_init(zl6100_init);
module_exit(zl6100_exit);