1/* Texas Instruments TMP102 SMBus temperature sensor driver
  2 *
  3 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
  4 *
  5 * This program is free software; you can redistribute it and/or modify
  6 * it under the terms of the GNU General Public License as published by
  7 * the Free Software Foundation; either version 2 of the License, or
  8 * (at your option) any later version.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program; if not, write to the Free Software
 17 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
 18 */
 19
 20#include <linux/module.h>
 21#include <linux/init.h>
 22#include <linux/slab.h>
 23#include <linux/i2c.h>
 24#include <linux/hwmon.h>
 25#include <linux/hwmon-sysfs.h>
 26#include <linux/err.h>
 27#include <linux/mutex.h>
 28#include <linux/device.h>
 29#include <linux/jiffies.h>
 30#include <linux/thermal.h>
 31#include <linux/of.h>
 32
 33#define	DRIVER_NAME "tmp102"
 34
 35#define	TMP102_TEMP_REG			0x00
 36#define	TMP102_CONF_REG			0x01
 37/* note: these bit definitions are byte swapped */
 38#define		TMP102_CONF_SD		0x0100
 39#define		TMP102_CONF_TM		0x0200
 40#define		TMP102_CONF_POL		0x0400
 41#define		TMP102_CONF_F0		0x0800
 42#define		TMP102_CONF_F1		0x1000
 43#define		TMP102_CONF_R0		0x2000
 44#define		TMP102_CONF_R1		0x4000
 45#define		TMP102_CONF_OS		0x8000
 46#define		TMP102_CONF_EM		0x0010
 47#define		TMP102_CONF_AL		0x0020
 48#define		TMP102_CONF_CR0		0x0040
 49#define		TMP102_CONF_CR1		0x0080
 50#define	TMP102_TLOW_REG			0x02
 51#define	TMP102_THIGH_REG		0x03
 52
 53struct tmp102 {
 54	struct i2c_client *client;
 55	struct device *hwmon_dev;
 56	struct thermal_zone_device *tz;
 57	struct mutex lock;
 58	u16 config_orig;
 59	unsigned long last_update;
 60	int temp[3];
 61	bool first_time;
 62};
 63
 64/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
 65static inline int tmp102_reg_to_mC(s16 val)
 66{
 67	return ((val & ~0x01) * 1000) / 128;
 68}
 69
 70/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
 71static inline u16 tmp102_mC_to_reg(int val)
 72{
 73	return (val * 128) / 1000;
 74}
 75
 76static const u8 tmp102_reg[] = {
 77	TMP102_TEMP_REG,
 78	TMP102_TLOW_REG,
 79	TMP102_THIGH_REG,
 80};
 81
 82static struct tmp102 *tmp102_update_device(struct device *dev)
 83{
 84	struct tmp102 *tmp102 = dev_get_drvdata(dev);
 85	struct i2c_client *client = tmp102->client;
 86
 87	mutex_lock(&tmp102->lock);
 88	if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
 89		int i;
 90		for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
 91			int status = i2c_smbus_read_word_swapped(client,
 92								 tmp102_reg[i]);
 93			if (status > -1)
 94				tmp102->temp[i] = tmp102_reg_to_mC(status);
 95		}
 96		tmp102->last_update = jiffies;
 97		tmp102->first_time = false;
 98	}
 99	mutex_unlock(&tmp102->lock);
100	return tmp102;
101}
102
103static int tmp102_read_temp(void *dev, int *temp)
104{
105	struct tmp102 *tmp102 = tmp102_update_device(dev);
106
107	/* Is it too early even to return a conversion? */
108	if (tmp102->first_time) {
109		dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
110		return -EAGAIN;
111	}
112
113	*temp = tmp102->temp[0];
114
115	return 0;
116}
117
118static ssize_t tmp102_show_temp(struct device *dev,
119				struct device_attribute *attr,
120				char *buf)
121{
122	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
123	struct tmp102 *tmp102 = tmp102_update_device(dev);
124
125	/* Is it too early even to return a read? */
126	if (tmp102->first_time)
127		return -EAGAIN;
128
129	return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
130}
131
132static ssize_t tmp102_set_temp(struct device *dev,
133			       struct device_attribute *attr,
134			       const char *buf, size_t count)
135{
136	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
137	struct tmp102 *tmp102 = dev_get_drvdata(dev);
138	struct i2c_client *client = tmp102->client;
139	long val;
140	int status;
141
142	if (kstrtol(buf, 10, &val) < 0)
143		return -EINVAL;
144	val = clamp_val(val, -256000, 255000);
145
146	mutex_lock(&tmp102->lock);
147	tmp102->temp[sda->index] = val;
148	status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index],
149					      tmp102_mC_to_reg(val));
150	mutex_unlock(&tmp102->lock);
151	return status ? : count;
152}
153
154static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
155
156static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
157			  tmp102_set_temp, 1);
158
159static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
160			  tmp102_set_temp, 2);
161
162static struct attribute *tmp102_attrs[] = {
163	&sensor_dev_attr_temp1_input.dev_attr.attr,
164	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
165	&sensor_dev_attr_temp1_max.dev_attr.attr,
166	NULL
167};
168ATTRIBUTE_GROUPS(tmp102);
169
170#define TMP102_CONFIG  (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
171#define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
172
173static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = {
174	.get_temp = tmp102_read_temp,
175};
176
177static int tmp102_probe(struct i2c_client *client,
178				  const struct i2c_device_id *id)
179{
180	struct device *dev = &client->dev;
181	struct device *hwmon_dev;
182	struct tmp102 *tmp102;
183	int status;
184
185	if (!i2c_check_functionality(client->adapter,
186				     I2C_FUNC_SMBUS_WORD_DATA)) {
187		dev_err(dev,
188			"adapter doesn't support SMBus word transactions\n");
189		return -ENODEV;
190	}
191
192	tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
193	if (!tmp102)
194		return -ENOMEM;
195
196	i2c_set_clientdata(client, tmp102);
197	tmp102->client = client;
198
199	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
200	if (status < 0) {
201		dev_err(dev, "error reading config register\n");
202		return status;
203	}
204	tmp102->config_orig = status;
205	status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
206					      TMP102_CONFIG);
207	if (status < 0) {
208		dev_err(dev, "error writing config register\n");
209		goto fail_restore_config;
210	}
211	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
212	if (status < 0) {
213		dev_err(dev, "error reading config register\n");
214		goto fail_restore_config;
215	}
216	status &= ~TMP102_CONFIG_RD_ONLY;
217	if (status != TMP102_CONFIG) {
218		dev_err(dev, "config settings did not stick\n");
219		status = -ENODEV;
220		goto fail_restore_config;
221	}
222	tmp102->last_update = jiffies;
223	/* Mark that we are not ready with data until conversion is complete */
224	tmp102->first_time = true;
225	mutex_init(&tmp102->lock);
226
227	hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
228						      tmp102, tmp102_groups);
229	if (IS_ERR(hwmon_dev)) {
230		dev_dbg(dev, "unable to register hwmon device\n");
231		status = PTR_ERR(hwmon_dev);
232		goto fail_restore_config;
233	}
234	tmp102->hwmon_dev = hwmon_dev;
235	tmp102->tz = thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev,
236						     &tmp102_of_thermal_ops);
237	if (IS_ERR(tmp102->tz))
238		tmp102->tz = NULL;
239
240	dev_info(dev, "initialized\n");
241
242	return 0;
243
244fail_restore_config:
245	i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
246				     tmp102->config_orig);
247	return status;
248}
249
250static int tmp102_remove(struct i2c_client *client)
251{
252	struct tmp102 *tmp102 = i2c_get_clientdata(client);
253
254	thermal_zone_of_sensor_unregister(tmp102->hwmon_dev, tmp102->tz);
255	hwmon_device_unregister(tmp102->hwmon_dev);
256
257	/* Stop monitoring if device was stopped originally */
258	if (tmp102->config_orig & TMP102_CONF_SD) {
259		int config;
260
261		config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
262		if (config >= 0)
263			i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
264						     config | TMP102_CONF_SD);
265	}
266
267	return 0;
268}
269
270#ifdef CONFIG_PM_SLEEP
271static int tmp102_suspend(struct device *dev)
272{
273	struct i2c_client *client = to_i2c_client(dev);
274	int config;
275
276	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
277	if (config < 0)
278		return config;
279
280	config |= TMP102_CONF_SD;
281	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
282}
283
284static int tmp102_resume(struct device *dev)
285{
286	struct i2c_client *client = to_i2c_client(dev);
287	int config;
288
289	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
290	if (config < 0)
291		return config;
292
293	config &= ~TMP102_CONF_SD;
294	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
295}
296#endif /* CONFIG_PM */
297
298static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
299
300static const struct i2c_device_id tmp102_id[] = {
301	{ "tmp102", 0 },
302	{ }
303};
304MODULE_DEVICE_TABLE(i2c, tmp102_id);
305
306static struct i2c_driver tmp102_driver = {
307	.driver.name	= DRIVER_NAME,
308	.driver.pm	= &tmp102_dev_pm_ops,
309	.probe		= tmp102_probe,
310	.remove		= tmp102_remove,
311	.id_table	= tmp102_id,
312};
313
314module_i2c_driver(tmp102_driver);
315
316MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
317MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
318MODULE_LICENSE("GPL");

  1/* Texas Instruments TMP102 SMBus temperature sensor driver
  2 *
  3 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
  4 *
  5 * This program is free software; you can redistribute it and/or modify
  6 * it under the terms of the GNU General Public License as published by
  7 * the Free Software Foundation; either version 2 of the License, or
  8 * (at your option) any later version.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program; if not, write to the Free Software
 17 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
 18 */
 19
 20#include <linux/module.h>
 21#include <linux/init.h>
 22#include <linux/slab.h>
 23#include <linux/i2c.h>
 24#include <linux/hwmon.h>
 25#include <linux/hwmon-sysfs.h>
 26#include <linux/err.h>
 27#include <linux/mutex.h>
 28#include <linux/device.h>
 29#include <linux/jiffies.h>
 30#include <linux/thermal.h>
 31#include <linux/of.h>
 32
 33#define	DRIVER_NAME "tmp102"
 34
 35#define	TMP102_TEMP_REG			0x00
 36#define	TMP102_CONF_REG			0x01
 37/* note: these bit definitions are byte swapped */
 38#define		TMP102_CONF_SD		0x0100
 39#define		TMP102_CONF_TM		0x0200
 40#define		TMP102_CONF_POL		0x0400
 41#define		TMP102_CONF_F0		0x0800
 42#define		TMP102_CONF_F1		0x1000
 43#define		TMP102_CONF_R0		0x2000
 44#define		TMP102_CONF_R1		0x4000
 45#define		TMP102_CONF_OS		0x8000
 46#define		TMP102_CONF_EM		0x0010
 47#define		TMP102_CONF_AL		0x0020
 48#define		TMP102_CONF_CR0		0x0040
 49#define		TMP102_CONF_CR1		0x0080
 50#define	TMP102_TLOW_REG			0x02
 51#define	TMP102_THIGH_REG		0x03
 52
 53struct tmp102 {
 54	struct i2c_client *client;
 55	struct device *hwmon_dev;
 56	struct thermal_zone_device *tz;
 57	struct mutex lock;
 58	u16 config_orig;
 59	unsigned long last_update;
 60	int temp[3];
 61	bool first_time;
 62};
 63
 64/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
 65static inline int tmp102_reg_to_mC(s16 val)
 66{
 67	return ((val & ~0x01) * 1000) / 128;
 68}
 69
 70/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
 71static inline u16 tmp102_mC_to_reg(int val)
 72{
 73	return (val * 128) / 1000;
 74}
 75
 76static const u8 tmp102_reg[] = {
 77	TMP102_TEMP_REG,
 78	TMP102_TLOW_REG,
 79	TMP102_THIGH_REG,
 80};
 81
 82static struct tmp102 *tmp102_update_device(struct device *dev)
 83{
 84	struct tmp102 *tmp102 = dev_get_drvdata(dev);
 85	struct i2c_client *client = tmp102->client;
 86
 87	mutex_lock(&tmp102->lock);
 88	if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
 89		int i;
 90		for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
 91			int status = i2c_smbus_read_word_swapped(client,
 92								 tmp102_reg[i]);
 93			if (status > -1)
 94				tmp102->temp[i] = tmp102_reg_to_mC(status);
 95		}
 96		tmp102->last_update = jiffies;
 97		tmp102->first_time = false;
 98	}
 99	mutex_unlock(&tmp102->lock);
100	return tmp102;
101}
102
103static int tmp102_read_temp(void *dev, int *temp)
104{
105	struct tmp102 *tmp102 = tmp102_update_device(dev);
106
107	/* Is it too early even to return a conversion? */
108	if (tmp102->first_time) {
109		dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
110		return -EAGAIN;
111	}
112
113	*temp = tmp102->temp[0];
114
115	return 0;
116}
117
118static ssize_t tmp102_show_temp(struct device *dev,
119				struct device_attribute *attr,
120				char *buf)
121{
122	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
123	struct tmp102 *tmp102 = tmp102_update_device(dev);
124
125	/* Is it too early even to return a read? */
126	if (tmp102->first_time)
127		return -EAGAIN;
128
129	return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
130}
131
132static ssize_t tmp102_set_temp(struct device *dev,
133			       struct device_attribute *attr,
134			       const char *buf, size_t count)
135{
136	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
137	struct tmp102 *tmp102 = dev_get_drvdata(dev);
138	struct i2c_client *client = tmp102->client;
139	long val;
140	int status;
141
142	if (kstrtol(buf, 10, &val) < 0)
143		return -EINVAL;
144	val = clamp_val(val, -256000, 255000);
145
146	mutex_lock(&tmp102->lock);
147	tmp102->temp[sda->index] = val;
148	status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index],
149					      tmp102_mC_to_reg(val));
150	mutex_unlock(&tmp102->lock);
151	return status ? : count;
152}
153
154static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
155
156static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
157			  tmp102_set_temp, 1);
158
159static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
160			  tmp102_set_temp, 2);
161
162static struct attribute *tmp102_attrs[] = {
163	&sensor_dev_attr_temp1_input.dev_attr.attr,
164	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
165	&sensor_dev_attr_temp1_max.dev_attr.attr,
166	NULL
167};
168ATTRIBUTE_GROUPS(tmp102);
169
170#define TMP102_CONFIG  (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
171#define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
172
173static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops = {
174	.get_temp = tmp102_read_temp,
175};
176
177static int tmp102_probe(struct i2c_client *client,
178				  const struct i2c_device_id *id)
179{
180	struct device *dev = &client->dev;
181	struct device *hwmon_dev;
182	struct tmp102 *tmp102;
183	int status;
184
185	if (!i2c_check_functionality(client->adapter,
186				     I2C_FUNC_SMBUS_WORD_DATA)) {
187		dev_err(dev,
188			"adapter doesn't support SMBus word transactions\n");
189		return -ENODEV;
190	}
191
192	tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
193	if (!tmp102)
194		return -ENOMEM;
195
196	i2c_set_clientdata(client, tmp102);
197	tmp102->client = client;
198
199	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
200	if (status < 0) {
201		dev_err(dev, "error reading config register\n");
202		return status;
203	}
204	tmp102->config_orig = status;
205	status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
206					      TMP102_CONFIG);
207	if (status < 0) {
208		dev_err(dev, "error writing config register\n");
209		goto fail_restore_config;
210	}
211	status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
212	if (status < 0) {
213		dev_err(dev, "error reading config register\n");
214		goto fail_restore_config;
215	}
216	status &= ~TMP102_CONFIG_RD_ONLY;
217	if (status != TMP102_CONFIG) {
218		dev_err(dev, "config settings did not stick\n");
219		status = -ENODEV;
220		goto fail_restore_config;
221	}
222	tmp102->last_update = jiffies;
223	/* Mark that we are not ready with data until conversion is complete */
224	tmp102->first_time = true;
225	mutex_init(&tmp102->lock);
226
227	hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
228						      tmp102, tmp102_groups);
229	if (IS_ERR(hwmon_dev)) {
230		dev_dbg(dev, "unable to register hwmon device\n");
231		status = PTR_ERR(hwmon_dev);
232		goto fail_restore_config;
233	}
234	tmp102->hwmon_dev = hwmon_dev;
235	tmp102->tz = thermal_zone_of_sensor_register(hwmon_dev, 0, hwmon_dev,
236						     &tmp102_of_thermal_ops);
237	if (IS_ERR(tmp102->tz))
238		tmp102->tz = NULL;
239
240	dev_info(dev, "initialized\n");
241
242	return 0;
243
244fail_restore_config:
245	i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
246				     tmp102->config_orig);
247	return status;
248}
249
250static int tmp102_remove(struct i2c_client *client)
251{
252	struct tmp102 *tmp102 = i2c_get_clientdata(client);
253
254	thermal_zone_of_sensor_unregister(tmp102->hwmon_dev, tmp102->tz);
255	hwmon_device_unregister(tmp102->hwmon_dev);
256
257	/* Stop monitoring if device was stopped originally */
258	if (tmp102->config_orig & TMP102_CONF_SD) {
259		int config;
260
261		config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
262		if (config >= 0)
263			i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
264						     config | TMP102_CONF_SD);
265	}
266
267	return 0;
268}
269
270#ifdef CONFIG_PM_SLEEP
271static int tmp102_suspend(struct device *dev)
272{
273	struct i2c_client *client = to_i2c_client(dev);
274	int config;
275
276	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
277	if (config < 0)
278		return config;
279
280	config |= TMP102_CONF_SD;
281	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
282}
283
284static int tmp102_resume(struct device *dev)
285{
286	struct i2c_client *client = to_i2c_client(dev);
287	int config;
288
289	config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
290	if (config < 0)
291		return config;
292
293	config &= ~TMP102_CONF_SD;
294	return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
295}
296#endif /* CONFIG_PM */
297
298static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
299
300static const struct i2c_device_id tmp102_id[] = {
301	{ "tmp102", 0 },
302	{ }
303};
304MODULE_DEVICE_TABLE(i2c, tmp102_id);
305
306static struct i2c_driver tmp102_driver = {
307	.driver.name	= DRIVER_NAME,
308	.driver.pm	= &tmp102_dev_pm_ops,
309	.probe		= tmp102_probe,
310	.remove		= tmp102_remove,
311	.id_table	= tmp102_id,
312};
313
314module_i2c_driver(tmp102_driver);
315
316MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
317MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
318MODULE_LICENSE("GPL");