summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/menf21bmc_hwmon.c
blob: c92229d321c92c24c5686fd2a4beefd5d4baf6cf (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
/*
 *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
 *
 *  This is the core hwmon driver of the MEN 14F021P00 BMC.
 *  The BMC monitors the board voltages which can be access with this
 *  driver through sysfs.
 *
 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
 *
 *  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.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/i2c.h>

#define DRV_NAME  "menf21bmc_hwmon"

#define BMC_VOLT_COUNT	5
#define MENF21BMC_V33	0
#define MENF21BMC_V5	1
#define MENF21BMC_V12	2
#define MENF21BMC_V5_SB	3
#define MENF21BMC_VBAT	4

#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)

struct menf21bmc_hwmon {
	bool valid;
	struct i2c_client *i2c_client;
	unsigned long last_update;
	int in_val[BMC_VOLT_COUNT];
	int in_min[BMC_VOLT_COUNT];
	int in_max[BMC_VOLT_COUNT];
};

static const char *const input_names[] = {
	[MENF21BMC_V33]		= "MON_3_3V",
	[MENF21BMC_V5]		= "MON_5V",
	[MENF21BMC_V12]		= "MON_12V",
	[MENF21BMC_V5_SB]	= "5V_STANDBY",
	[MENF21BMC_VBAT]	= "VBAT"
};

static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
{
	int i;
	int val;
	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
	struct menf21bmc_hwmon *data_ret = drv_data;

	if (time_after(jiffies, drv_data->last_update + HZ)
	    || !drv_data->valid) {
		for (i = 0; i < BMC_VOLT_COUNT; i++) {
			val = i2c_smbus_read_word_data(drv_data->i2c_client,
						       IDX_TO_VOLT_INP_CMD(i));
			if (val < 0) {
				data_ret = ERR_PTR(val);
				goto abort;
			}
			drv_data->in_val[i] = val;
		}
		drv_data->last_update = jiffies;
		drv_data->valid = true;
	}
abort:
	return data_ret;
}

static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
{
	int i, val;

	for (i = 0; i < BMC_VOLT_COUNT; i++) {
		val = i2c_smbus_read_word_data(drv_data->i2c_client,
					       IDX_TO_VOLT_MIN_CMD(i));
		if (val < 0)
			return val;

		drv_data->in_min[i] = val;

		val = i2c_smbus_read_word_data(drv_data->i2c_client,
					       IDX_TO_VOLT_MAX_CMD(i));
		if (val < 0)
			return val;

		drv_data->in_max[i] = val;
	}
	return 0;
}

static ssize_t
show_label(struct device *dev, struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	return sprintf(buf, "%s\n", input_names[attr->index]);
}

static ssize_t
show_in(struct device *dev, struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);

	if (IS_ERR(drv_data))
		return PTR_ERR(drv_data);

	return sprintf(buf, "%d\n", drv_data->in_val[attr->index]);
}

static ssize_t
show_min(struct device *dev, struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
}

static ssize_t
show_max(struct device *dev, struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
}

#define create_voltage_sysfs(idx)			\
static SENSOR_DEVICE_ATTR(in##idx##_input, S_IRUGO,	\
			show_in, NULL, idx);		\
static SENSOR_DEVICE_ATTR(in##idx##_min, S_IRUGO,	\
			show_min, NULL, idx);		\
static SENSOR_DEVICE_ATTR(in##idx##_max, S_IRUGO,	\
			show_max, NULL, idx);		\
static SENSOR_DEVICE_ATTR(in##idx##_label, S_IRUGO,	\
			show_label, NULL, idx);

create_voltage_sysfs(0);
create_voltage_sysfs(1);
create_voltage_sysfs(2);
create_voltage_sysfs(3);
create_voltage_sysfs(4);

static struct attribute *menf21bmc_hwmon_attrs[] = {
	&sensor_dev_attr_in0_input.dev_attr.attr,
	&sensor_dev_attr_in0_min.dev_attr.attr,
	&sensor_dev_attr_in0_max.dev_attr.attr,
	&sensor_dev_attr_in0_label.dev_attr.attr,

	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in1_min.dev_attr.attr,
	&sensor_dev_attr_in1_max.dev_attr.attr,
	&sensor_dev_attr_in1_label.dev_attr.attr,

	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in2_min.dev_attr.attr,
	&sensor_dev_attr_in2_max.dev_attr.attr,
	&sensor_dev_attr_in2_label.dev_attr.attr,

	&sensor_dev_attr_in3_input.dev_attr.attr,
	&sensor_dev_attr_in3_min.dev_attr.attr,
	&sensor_dev_attr_in3_max.dev_attr.attr,
	&sensor_dev_attr_in3_label.dev_attr.attr,

	&sensor_dev_attr_in4_input.dev_attr.attr,
	&sensor_dev_attr_in4_min.dev_attr.attr,
	&sensor_dev_attr_in4_max.dev_attr.attr,
	&sensor_dev_attr_in4_label.dev_attr.attr,
	NULL
};

ATTRIBUTE_GROUPS(menf21bmc_hwmon);

static int menf21bmc_hwmon_probe(struct platform_device *pdev)
{
	int ret;
	struct menf21bmc_hwmon *drv_data;
	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
	struct device *hwmon_dev;

	drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
				GFP_KERNEL);
	if (!drv_data)
		return -ENOMEM;

	drv_data->i2c_client = i2c_client;

	ret = menf21bmc_hwmon_get_volt_limits(drv_data);
	if (ret) {
		dev_err(&pdev->dev, "failed to read sensor limits");
		return ret;
	}

	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
						   "menf21bmc", drv_data,
						   menf21bmc_hwmon_groups);
	if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);

	dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");

	return 0;
}

static struct platform_driver menf21bmc_hwmon = {
	.probe		= menf21bmc_hwmon_probe,
	.driver		= {
		.name		= DRV_NAME,
		.owner		= THIS_MODULE,
	},
};

module_platform_driver(menf21bmc_hwmon);

MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:menf21bmc_hwmon");