xref: /openbmc/linux/drivers/hwmon/tmp103.c (revision 9cfc5c90)
1 /*
2  * Texas Instruments TMP103 SMBus temperature sensor driver
3  * Copyright (C) 2014 Heiko Schocher <hs@denx.de>
4  *
5  * Based on:
6  * Texas Instruments TMP102 SMBus temperature sensor driver
7  *
8  * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  */
21 
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/i2c.h>
26 #include <linux/hwmon.h>
27 #include <linux/hwmon-sysfs.h>
28 #include <linux/err.h>
29 #include <linux/mutex.h>
30 #include <linux/device.h>
31 #include <linux/jiffies.h>
32 #include <linux/regmap.h>
33 
34 #define TMP103_TEMP_REG		0x00
35 #define TMP103_CONF_REG		0x01
36 #define TMP103_TLOW_REG		0x02
37 #define TMP103_THIGH_REG	0x03
38 
39 #define TMP103_CONF_M0		0x01
40 #define TMP103_CONF_M1		0x02
41 #define TMP103_CONF_LC		0x04
42 #define TMP103_CONF_FL		0x08
43 #define TMP103_CONF_FH		0x10
44 #define TMP103_CONF_CR0		0x20
45 #define TMP103_CONF_CR1		0x40
46 #define TMP103_CONF_ID		0x80
47 #define TMP103_CONF_SD		(TMP103_CONF_M1)
48 #define TMP103_CONF_SD_MASK	(TMP103_CONF_M0 | TMP103_CONF_M1)
49 
50 #define TMP103_CONFIG		(TMP103_CONF_CR1 | TMP103_CONF_M1)
51 #define TMP103_CONFIG_MASK	(TMP103_CONF_CR0 | TMP103_CONF_CR1 | \
52 				 TMP103_CONF_M0 | TMP103_CONF_M1)
53 
54 static inline int tmp103_reg_to_mc(s8 val)
55 {
56 	return val * 1000;
57 }
58 
59 static inline u8 tmp103_mc_to_reg(int val)
60 {
61 	return DIV_ROUND_CLOSEST(val, 1000);
62 }
63 
64 static ssize_t tmp103_show_temp(struct device *dev,
65 				struct device_attribute *attr,
66 				char *buf)
67 {
68 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
69 	struct regmap *regmap = dev_get_drvdata(dev);
70 	unsigned int regval;
71 	int ret;
72 
73 	ret = regmap_read(regmap, sda->index, &regval);
74 	if (ret < 0)
75 		return ret;
76 
77 	return sprintf(buf, "%d\n", tmp103_reg_to_mc(regval));
78 }
79 
80 static ssize_t tmp103_set_temp(struct device *dev,
81 			       struct device_attribute *attr,
82 			       const char *buf, size_t count)
83 {
84 	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
85 	struct regmap *regmap = dev_get_drvdata(dev);
86 	long val;
87 	int ret;
88 
89 	if (kstrtol(buf, 10, &val) < 0)
90 		return -EINVAL;
91 
92 	val = clamp_val(val, -55000, 127000);
93 	ret = regmap_write(regmap, sda->index, tmp103_mc_to_reg(val));
94 	return ret ? ret : count;
95 }
96 
97 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp103_show_temp, NULL ,
98 			  TMP103_TEMP_REG);
99 
100 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, tmp103_show_temp,
101 			  tmp103_set_temp, TMP103_TLOW_REG);
102 
103 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp103_show_temp,
104 			  tmp103_set_temp, TMP103_THIGH_REG);
105 
106 static struct attribute *tmp103_attrs[] = {
107 	&sensor_dev_attr_temp1_input.dev_attr.attr,
108 	&sensor_dev_attr_temp1_min.dev_attr.attr,
109 	&sensor_dev_attr_temp1_max.dev_attr.attr,
110 	NULL
111 };
112 ATTRIBUTE_GROUPS(tmp103);
113 
114 static bool tmp103_regmap_is_volatile(struct device *dev, unsigned int reg)
115 {
116 	return reg == TMP103_TEMP_REG;
117 }
118 
119 static const struct regmap_config tmp103_regmap_config = {
120 	.reg_bits = 8,
121 	.val_bits = 8,
122 	.max_register = TMP103_THIGH_REG,
123 	.volatile_reg = tmp103_regmap_is_volatile,
124 };
125 
126 static int tmp103_probe(struct i2c_client *client,
127 			const struct i2c_device_id *id)
128 {
129 	struct device *dev = &client->dev;
130 	struct device *hwmon_dev;
131 	struct regmap *regmap;
132 	int ret;
133 
134 	regmap = devm_regmap_init_i2c(client, &tmp103_regmap_config);
135 	if (IS_ERR(regmap)) {
136 		dev_err(dev, "failed to allocate register map\n");
137 		return PTR_ERR(regmap);
138 	}
139 
140 	ret = regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONFIG_MASK,
141 				 TMP103_CONFIG);
142 	if (ret < 0) {
143 		dev_err(&client->dev, "error writing config register\n");
144 		return ret;
145 	}
146 
147 	i2c_set_clientdata(client, regmap);
148 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
149 						      regmap, tmp103_groups);
150 	return PTR_ERR_OR_ZERO(hwmon_dev);
151 }
152 
153 #ifdef CONFIG_PM
154 static int tmp103_suspend(struct device *dev)
155 {
156 	struct regmap *regmap = dev_get_drvdata(dev);
157 
158 	return regmap_update_bits(regmap, TMP103_CONF_REG,
159 				  TMP103_CONF_SD_MASK, 0);
160 }
161 
162 static int tmp103_resume(struct device *dev)
163 {
164 	struct regmap *regmap = dev_get_drvdata(dev);
165 
166 	return regmap_update_bits(regmap, TMP103_CONF_REG,
167 				  TMP103_CONF_SD_MASK, TMP103_CONF_SD);
168 }
169 
170 static const struct dev_pm_ops tmp103_dev_pm_ops = {
171 	.suspend	= tmp103_suspend,
172 	.resume		= tmp103_resume,
173 };
174 
175 #define TMP103_DEV_PM_OPS (&tmp103_dev_pm_ops)
176 #else
177 #define	TMP103_DEV_PM_OPS NULL
178 #endif /* CONFIG_PM */
179 
180 static const struct i2c_device_id tmp103_id[] = {
181 	{ "tmp103", 0 },
182 	{ }
183 };
184 MODULE_DEVICE_TABLE(i2c, tmp103_id);
185 
186 static struct i2c_driver tmp103_driver = {
187 	.driver = {
188 		.name	= "tmp103",
189 		.pm	= TMP103_DEV_PM_OPS,
190 	},
191 	.probe		= tmp103_probe,
192 	.id_table	= tmp103_id,
193 };
194 
195 module_i2c_driver(tmp103_driver);
196 
197 MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
198 MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
199 MODULE_LICENSE("GPL");
200