1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.
4 *
5 *  This is the core hwmon driver of the MEN 14F021P00 BMC.
6 *  The BMC monitors the board voltages which can be access with this
7 *  driver through sysfs.
8 *
9 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/platform_device.h>
15#include <linux/hwmon.h>
16#include <linux/hwmon-sysfs.h>
17#include <linux/jiffies.h>
18#include <linux/slab.h>
19#include <linux/i2c.h>
20#include <linux/err.h>
21
22#define DRV_NAME  "menf21bmc_hwmon"
23
24#define BMC_VOLT_COUNT	5
25#define MENF21BMC_V33	0
26#define MENF21BMC_V5	1
27#define MENF21BMC_V12	2
28#define MENF21BMC_V5_SB	3
29#define MENF21BMC_VBAT	4
30
31#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)
32#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)
33#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)
34
35struct menf21bmc_hwmon {
36	bool valid;
37	struct i2c_client *i2c_client;
38	unsigned long last_update;
39	int in_val[BMC_VOLT_COUNT];
40	int in_min[BMC_VOLT_COUNT];
41	int in_max[BMC_VOLT_COUNT];
42};
43
44static const char *const input_names[] = {
45	[MENF21BMC_V33]		= "MON_3_3V",
46	[MENF21BMC_V5]		= "MON_5V",
47	[MENF21BMC_V12]		= "MON_12V",
48	[MENF21BMC_V5_SB]	= "5V_STANDBY",
49	[MENF21BMC_VBAT]	= "VBAT"
50};
51
52static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)
53{
54	int i;
55	int val;
56	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
57	struct menf21bmc_hwmon *data_ret = drv_data;
58
59	if (time_after(jiffies, drv_data->last_update + HZ)
60	    || !drv_data->valid) {
61		for (i = 0; i < BMC_VOLT_COUNT; i++) {
62			val = i2c_smbus_read_word_data(drv_data->i2c_client,
63						       IDX_TO_VOLT_INP_CMD(i));
64			if (val < 0) {
65				data_ret = ERR_PTR(val);
66				goto abort;
67			}
68			drv_data->in_val[i] = val;
69		}
70		drv_data->last_update = jiffies;
71		drv_data->valid = true;
72	}
73abort:
74	return data_ret;
75}
76
77static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)
78{
79	int i, val;
80
81	for (i = 0; i < BMC_VOLT_COUNT; i++) {
82		val = i2c_smbus_read_word_data(drv_data->i2c_client,
83					       IDX_TO_VOLT_MIN_CMD(i));
84		if (val < 0)
85			return val;
86
87		drv_data->in_min[i] = val;
88
89		val = i2c_smbus_read_word_data(drv_data->i2c_client,
90					       IDX_TO_VOLT_MAX_CMD(i));
91		if (val < 0)
92			return val;
93
94		drv_data->in_max[i] = val;
95	}
96	return 0;
97}
98
99static ssize_t
100label_show(struct device *dev, struct device_attribute *devattr, char *buf)
101{
102	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
103
104	return sprintf(buf, "%s\n", input_names[attr->index]);
105}
106
107static ssize_t
108in_show(struct device *dev, struct device_attribute *devattr, char *buf)
109{
110	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
111	struct menf21bmc_hwmon *drv_data = menf21bmc_hwmon_update(dev);
112
113	if (IS_ERR(drv_data))
114		return PTR_ERR(drv_data);
115
116	return sprintf(buf, "%d\n", drv_data->in_val[attr->index]);
117}
118
119static ssize_t
120min_show(struct device *dev, struct device_attribute *devattr, char *buf)
121{
122	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
123	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
124
125	return sprintf(buf, "%d\n", drv_data->in_min[attr->index]);
126}
127
128static ssize_t
129max_show(struct device *dev, struct device_attribute *devattr, char *buf)
130{
131	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
132	struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);
133
134	return sprintf(buf, "%d\n", drv_data->in_max[attr->index]);
135}
136
137static SENSOR_DEVICE_ATTR_RO(in0_input, in, 0);
138static SENSOR_DEVICE_ATTR_RO(in0_min, min, 0);
139static SENSOR_DEVICE_ATTR_RO(in0_max, max, 0);
140static SENSOR_DEVICE_ATTR_RO(in0_label, label, 0);
141static SENSOR_DEVICE_ATTR_RO(in1_input, in, 1);
142static SENSOR_DEVICE_ATTR_RO(in1_min, min, 1);
143static SENSOR_DEVICE_ATTR_RO(in1_max, max, 1);
144static SENSOR_DEVICE_ATTR_RO(in1_label, label, 1);
145static SENSOR_DEVICE_ATTR_RO(in2_input, in, 2);
146static SENSOR_DEVICE_ATTR_RO(in2_min, min, 2);
147static SENSOR_DEVICE_ATTR_RO(in2_max, max, 2);
148static SENSOR_DEVICE_ATTR_RO(in2_label, label, 2);
149static SENSOR_DEVICE_ATTR_RO(in3_input, in, 3);
150static SENSOR_DEVICE_ATTR_RO(in3_min, min, 3);
151static SENSOR_DEVICE_ATTR_RO(in3_max, max, 3);
152static SENSOR_DEVICE_ATTR_RO(in3_label, label, 3);
153static SENSOR_DEVICE_ATTR_RO(in4_input, in, 4);
154static SENSOR_DEVICE_ATTR_RO(in4_min, min, 4);
155static SENSOR_DEVICE_ATTR_RO(in4_max, max, 4);
156static SENSOR_DEVICE_ATTR_RO(in4_label, label, 4);
157
158static struct attribute *menf21bmc_hwmon_attrs[] = {
159	&sensor_dev_attr_in0_input.dev_attr.attr,
160	&sensor_dev_attr_in0_min.dev_attr.attr,
161	&sensor_dev_attr_in0_max.dev_attr.attr,
162	&sensor_dev_attr_in0_label.dev_attr.attr,
163
164	&sensor_dev_attr_in1_input.dev_attr.attr,
165	&sensor_dev_attr_in1_min.dev_attr.attr,
166	&sensor_dev_attr_in1_max.dev_attr.attr,
167	&sensor_dev_attr_in1_label.dev_attr.attr,
168
169	&sensor_dev_attr_in2_input.dev_attr.attr,
170	&sensor_dev_attr_in2_min.dev_attr.attr,
171	&sensor_dev_attr_in2_max.dev_attr.attr,
172	&sensor_dev_attr_in2_label.dev_attr.attr,
173
174	&sensor_dev_attr_in3_input.dev_attr.attr,
175	&sensor_dev_attr_in3_min.dev_attr.attr,
176	&sensor_dev_attr_in3_max.dev_attr.attr,
177	&sensor_dev_attr_in3_label.dev_attr.attr,
178
179	&sensor_dev_attr_in4_input.dev_attr.attr,
180	&sensor_dev_attr_in4_min.dev_attr.attr,
181	&sensor_dev_attr_in4_max.dev_attr.attr,
182	&sensor_dev_attr_in4_label.dev_attr.attr,
183	NULL
184};
185
186ATTRIBUTE_GROUPS(menf21bmc_hwmon);
187
188static int menf21bmc_hwmon_probe(struct platform_device *pdev)
189{
190	int ret;
191	struct menf21bmc_hwmon *drv_data;
192	struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
193	struct device *hwmon_dev;
194
195	drv_data = devm_kzalloc(&pdev->dev, sizeof(struct menf21bmc_hwmon),
196				GFP_KERNEL);
197	if (!drv_data)
198		return -ENOMEM;
199
200	drv_data->i2c_client = i2c_client;
201
202	ret = menf21bmc_hwmon_get_volt_limits(drv_data);
203	if (ret) {
204		dev_err(&pdev->dev, "failed to read sensor limits");
205		return ret;
206	}
207
208	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev,
209						   "menf21bmc", drv_data,
210						   menf21bmc_hwmon_groups);
211	if (IS_ERR(hwmon_dev))
212		return PTR_ERR(hwmon_dev);
213
214	dev_info(&pdev->dev, "MEN 14F021P00 BMC hwmon device enabled");
215
216	return 0;
217}
218
219static struct platform_driver menf21bmc_hwmon = {
220	.probe		= menf21bmc_hwmon_probe,
221	.driver		= {
222		.name		= DRV_NAME,
223	},
224};
225
226module_platform_driver(menf21bmc_hwmon);
227
228MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
229MODULE_DESCRIPTION("MEN 14F021P00 BMC hwmon");
230MODULE_LICENSE("GPL v2");
231MODULE_ALIAS("platform:menf21bmc_hwmon");
232