aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/pmbus/ucd9200.c
blob: ffcc1cf3609d60d8cf56b4e767eed6292bb653c8 (plain) (blame)
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
/*
 * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers
 *
 * 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/i2c/pmbus.h>
#include "pmbus.h"

#define UCD9200_PHASE_INFO	0xd2
#define UCD9200_DEVICE_ID	0xfd

enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,
	     ucd9248 };

static const struct i2c_device_id ucd9200_id[] = {
	{"ucd9200", ucd9200},
	{"ucd9220", ucd9220},
	{"ucd9222", ucd9222},
	{"ucd9224", ucd9224},
	{"ucd9240", ucd9240},
	{"ucd9244", ucd9244},
	{"ucd9246", ucd9246},
	{"ucd9248", ucd9248},
	{}
};
MODULE_DEVICE_TABLE(i2c, ucd9200_id);

static int ucd9200_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
	struct pmbus_driver_info *info;
	const struct i2c_device_id *mid;
	int i, j, ret;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_BYTE_DATA |
				     I2C_FUNC_SMBUS_BLOCK_DATA))
		return -ENODEV;

	ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,
					block_buffer);
	if (ret < 0) {
		dev_err(&client->dev, "Failed to read device ID\n");
		return ret;
	}
	block_buffer[ret] = '\0';
	dev_info(&client->dev, "Device ID %s\n", block_buffer);

	mid = NULL;
	for (i = 0; i < ARRAY_SIZE(ucd9200_id); i++) {
		mid = &ucd9200_id[i];
		if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
			break;
	}
	if (!mid || !strlen(mid->name)) {
		dev_err(&client->dev, "Unsupported device\n");
		return -ENODEV;
	}
	if (id->driver_data != ucd9200 && id->driver_data != mid->driver_data)
		dev_notice(&client->dev,
			   "Device mismatch: Configured %s, detected %s\n",
			   id->name, mid->name);

	info = kzalloc(sizeof(struct pmbus_driver_info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
					block_buffer);
	if (ret < 0) {
		dev_err(&client->dev, "Failed to read phase information\n");
		goto out;
	}

	/*
	 * Calculate number of configured pages (rails) from PHASE_INFO
	 * register.
	 * Rails have to be sequential, so we can abort after finding
	 * the first unconfigured rail.
	 */
	info->pages = 0;
	for (i = 0; i < ret; i++) {
		if (!block_buffer[i])
			break;
		info->pages++;
	}
	if (!info->pages) {
		dev_err(&client->dev, "No rails configured\n");
		ret = -ENODEV;
		goto out;
	}
	dev_info(&client->dev, "%d rails configured\n", info->pages);

	/*
	 * Set PHASE registers on all pages to 0xff to ensure that phase
	 * specific commands will apply to all phases of a given page (rail).
	 * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
	 * READ_IOUT will return the sum of currents of all phases of a rail,
	 * and READ_TEMPERATURE2 will return the maximum temperature detected
	 * for the the phases of the rail.
	 */
	for (i = 0; i < info->pages; i++) {
		/*
		 * Setting PAGE & PHASE fails once in a while for no obvious
		 * reason, so we need to retry a couple of times.
		 */
		for (j = 0; j < 3; j++) {
			ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
			if (ret < 0)
				continue;
			ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
							0xff);
			if (ret < 0)
				continue;
			break;
		}
		if (ret < 0) {
			dev_err(&client->dev,
				"Failed to initialize PHASE registers\n");
			goto out;
		}
	}
	if (info->pages > 1)
		i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);

	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
			PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
			PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;

	for (i = 1; i < info->pages; i++)
		info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
			PMBUS_HAVE_POUT |
			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;

	/* ucd9240 supports a single fan */
	if (mid->driver_data == ucd9240)
		info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;

	ret = pmbus_do_probe(client, mid, info);
	if (ret < 0)
		goto out;
	return 0;
out:
	kfree(info);
	return ret;
}

static int ucd9200_remove(struct i2c_client *client)
{
	int ret;
	const struct pmbus_driver_info *info;

	info = pmbus_get_driver_info(client);
	ret = pmbus_do_remove(client);
	kfree(info);
	return ret;
}


/* This is the driver that will be inserted */
static struct i2c_driver ucd9200_driver = {
	.driver = {
		.name = "ucd9200",
	},
	.probe = ucd9200_probe,
	.remove = ucd9200_remove,
	.id_table = ucd9200_id,
};

static int __init ucd9200_init(void)
{
	return i2c_add_driver(&ucd9200_driver);
}

static void __exit ucd9200_exit(void)
{
	i2c_del_driver(&ucd9200_driver);
}

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
MODULE_LICENSE("GPL");
module_init(ucd9200_init);
module_exit(ucd9200_exit);