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
54static inline int tmp103_reg_to_mc(s8 val)
55{
56	return val * 1000;
57}
58
59static inline u8 tmp103_mc_to_reg(int val)
60{
61	return DIV_ROUND_CLOSEST(val, 1000);
62}
63
64static 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
80static 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
97static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp103_show_temp, NULL ,
98			  TMP103_TEMP_REG);
99
100static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, tmp103_show_temp,
101			  tmp103_set_temp, TMP103_TLOW_REG);
102
103static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp103_show_temp,
104			  tmp103_set_temp, TMP103_THIGH_REG);
105
106static 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};
112ATTRIBUTE_GROUPS(tmp103);
113
114static bool tmp103_regmap_is_volatile(struct device *dev, unsigned int reg)
115{
116	return reg == TMP103_TEMP_REG;
117}
118
119static 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
126static 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
154static 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
162static 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
170static 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
180static const struct i2c_device_id tmp103_id[] = {
181	{ "tmp103", 0 },
182	{ }
183};
184MODULE_DEVICE_TABLE(i2c, tmp103_id);
185
186static 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
195module_i2c_driver(tmp103_driver);
196
197MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
198MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
199MODULE_LICENSE("GPL");
200