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
153static int __maybe_unused tmp103_suspend(struct device *dev)
154{
155	struct regmap *regmap = dev_get_drvdata(dev);
156
157	return regmap_update_bits(regmap, TMP103_CONF_REG,
158				  TMP103_CONF_SD_MASK, 0);
159}
160
161static int __maybe_unused tmp103_resume(struct device *dev)
162{
163	struct regmap *regmap = dev_get_drvdata(dev);
164
165	return regmap_update_bits(regmap, TMP103_CONF_REG,
166				  TMP103_CONF_SD_MASK, TMP103_CONF_SD);
167}
168
169static SIMPLE_DEV_PM_OPS(tmp103_dev_pm_ops, tmp103_suspend, tmp103_resume);
170
171static const struct i2c_device_id tmp103_id[] = {
172	{ "tmp103", 0 },
173	{ }
174};
175MODULE_DEVICE_TABLE(i2c, tmp103_id);
176
177static const struct of_device_id tmp103_of_match[] = {
178	{ .compatible = "ti,tmp103" },
179	{ },
180};
181MODULE_DEVICE_TABLE(of, tmp103_of_match);
182
183static struct i2c_driver tmp103_driver = {
184	.driver = {
185		.name	= "tmp103",
186		.of_match_table = of_match_ptr(tmp103_of_match),
187		.pm	= &tmp103_dev_pm_ops,
188	},
189	.probe		= tmp103_probe,
190	.id_table	= tmp103_id,
191};
192
193module_i2c_driver(tmp103_driver);
194
195MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
196MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
197MODULE_LICENSE("GPL");