1/*
2 *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
3 *
4 *  Copyright (C) 2008, 2010 Pengutronix
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License version 2 as
8 *  published by the Free Software Foundation.
9 *
10 *  TODO: SPI, support for external temperature sensor
11 *	  use power-down mode for suspend?, interrupt handling?
12 */
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/err.h>
18#include <linux/mutex.h>
19#include <linux/jiffies.h>
20#include <linux/i2c.h>
21#include <linux/hwmon.h>
22#include <linux/hwmon-sysfs.h>
23#include <linux/slab.h>
24
25#define ADT7411_REG_INT_TEMP_VDD_LSB		0x03
26#define ADT7411_REG_EXT_TEMP_AIN14_LSB		0x04
27#define ADT7411_REG_VDD_MSB			0x06
28#define ADT7411_REG_INT_TEMP_MSB		0x07
29#define ADT7411_REG_EXT_TEMP_AIN1_MSB		0x08
30
31#define ADT7411_REG_CFG1			0x18
32#define ADT7411_CFG1_START_MONITOR		(1 << 0)
33
34#define ADT7411_REG_CFG2			0x19
35#define ADT7411_CFG2_DISABLE_AVG		(1 << 5)
36
37#define ADT7411_REG_CFG3			0x1a
38#define ADT7411_CFG3_ADC_CLK_225		(1 << 0)
39#define ADT7411_CFG3_REF_VDD			(1 << 4)
40
41#define ADT7411_REG_DEVICE_ID			0x4d
42#define ADT7411_REG_MANUFACTURER_ID		0x4e
43
44#define ADT7411_DEVICE_ID			0x2
45#define ADT7411_MANUFACTURER_ID			0x41
46
47static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
48
49struct adt7411_data {
50	struct mutex device_lock;	/* for "atomic" device accesses */
51	struct mutex update_lock;
52	unsigned long next_update;
53	int vref_cached;
54	struct i2c_client *client;
55};
56
57/*
58 * When reading a register containing (up to 4) lsb, all associated
59 * msb-registers get locked by the hardware. After _one_ of those msb is read,
60 * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
61 * is protected here with a mutex, too.
62 */
63static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
64				u8 msb_reg, u8 lsb_shift)
65{
66	struct adt7411_data *data = i2c_get_clientdata(client);
67	int val, tmp;
68
69	mutex_lock(&data->device_lock);
70
71	val = i2c_smbus_read_byte_data(client, lsb_reg);
72	if (val < 0)
73		goto exit_unlock;
74
75	tmp = (val >> lsb_shift) & 3;
76	val = i2c_smbus_read_byte_data(client, msb_reg);
77
78	if (val >= 0)
79		val = (val << 2) | tmp;
80
81 exit_unlock:
82	mutex_unlock(&data->device_lock);
83
84	return val;
85}
86
87static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
88				bool flag)
89{
90	struct adt7411_data *data = i2c_get_clientdata(client);
91	int ret, val;
92
93	mutex_lock(&data->device_lock);
94
95	ret = i2c_smbus_read_byte_data(client, reg);
96	if (ret < 0)
97		goto exit_unlock;
98
99	if (flag)
100		val = ret | bit;
101	else
102		val = ret & ~bit;
103
104	ret = i2c_smbus_write_byte_data(client, reg, val);
105
106 exit_unlock:
107	mutex_unlock(&data->device_lock);
108	return ret;
109}
110
111static ssize_t adt7411_show_vdd(struct device *dev,
112				struct device_attribute *attr, char *buf)
113{
114	struct adt7411_data *data = dev_get_drvdata(dev);
115	struct i2c_client *client = data->client;
116	int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
117			ADT7411_REG_VDD_MSB, 2);
118
119	return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
120}
121
122static ssize_t adt7411_show_temp(struct device *dev,
123			struct device_attribute *attr, char *buf)
124{
125	struct adt7411_data *data = dev_get_drvdata(dev);
126	struct i2c_client *client = data->client;
127	int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
128			ADT7411_REG_INT_TEMP_MSB, 0);
129
130	if (val < 0)
131		return val;
132
133	val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
134
135	return sprintf(buf, "%d\n", val * 250);
136}
137
138static ssize_t adt7411_show_input(struct device *dev,
139				  struct device_attribute *attr, char *buf)
140{
141	int nr = to_sensor_dev_attr(attr)->index;
142	struct adt7411_data *data = dev_get_drvdata(dev);
143	struct i2c_client *client = data->client;
144	int val;
145	u8 lsb_reg, lsb_shift;
146
147	mutex_lock(&data->update_lock);
148	if (time_after_eq(jiffies, data->next_update)) {
149		val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
150		if (val < 0)
151			goto exit_unlock;
152
153		if (val & ADT7411_CFG3_REF_VDD) {
154			val = adt7411_read_10_bit(client,
155					ADT7411_REG_INT_TEMP_VDD_LSB,
156					ADT7411_REG_VDD_MSB, 2);
157			if (val < 0)
158				goto exit_unlock;
159
160			data->vref_cached = val * 7000 / 1024;
161		} else {
162			data->vref_cached = 2250;
163		}
164
165		data->next_update = jiffies + HZ;
166	}
167
168	lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
169	lsb_shift = 2 * (nr & 0x03);
170	val = adt7411_read_10_bit(client, lsb_reg,
171			ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
172	if (val < 0)
173		goto exit_unlock;
174
175	val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
176 exit_unlock:
177	mutex_unlock(&data->update_lock);
178	return val;
179}
180
181static ssize_t adt7411_show_bit(struct device *dev,
182				struct device_attribute *attr, char *buf)
183{
184	struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
185	struct adt7411_data *data = dev_get_drvdata(dev);
186	struct i2c_client *client = data->client;
187	int ret = i2c_smbus_read_byte_data(client, attr2->index);
188
189	return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
190}
191
192static ssize_t adt7411_set_bit(struct device *dev,
193			       struct device_attribute *attr, const char *buf,
194			       size_t count)
195{
196	struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
197	struct adt7411_data *data = dev_get_drvdata(dev);
198	struct i2c_client *client = data->client;
199	int ret;
200	unsigned long flag;
201
202	ret = kstrtoul(buf, 0, &flag);
203	if (ret || flag > 1)
204		return -EINVAL;
205
206	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
207
208	/* force update */
209	mutex_lock(&data->update_lock);
210	data->next_update = jiffies;
211	mutex_unlock(&data->update_lock);
212
213	return ret < 0 ? ret : count;
214}
215
216#define ADT7411_BIT_ATTR(__name, __reg, __bit) \
217	SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
218	adt7411_set_bit, __bit, __reg)
219
220static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
221static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
222static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
223static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
224static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
225static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
226static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
227static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
228static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
229static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
230static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
231static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
232static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
233
234static struct attribute *adt7411_attrs[] = {
235	&dev_attr_temp1_input.attr,
236	&dev_attr_in0_input.attr,
237	&sensor_dev_attr_in1_input.dev_attr.attr,
238	&sensor_dev_attr_in2_input.dev_attr.attr,
239	&sensor_dev_attr_in3_input.dev_attr.attr,
240	&sensor_dev_attr_in4_input.dev_attr.attr,
241	&sensor_dev_attr_in5_input.dev_attr.attr,
242	&sensor_dev_attr_in6_input.dev_attr.attr,
243	&sensor_dev_attr_in7_input.dev_attr.attr,
244	&sensor_dev_attr_in8_input.dev_attr.attr,
245	&sensor_dev_attr_no_average.dev_attr.attr,
246	&sensor_dev_attr_fast_sampling.dev_attr.attr,
247	&sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
248	NULL
249};
250
251ATTRIBUTE_GROUPS(adt7411);
252
253static int adt7411_detect(struct i2c_client *client,
254			  struct i2c_board_info *info)
255{
256	int val;
257
258	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
259		return -ENODEV;
260
261	val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
262	if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
263		dev_dbg(&client->dev,
264			"Wrong manufacturer ID. Got %d, expected %d\n",
265			val, ADT7411_MANUFACTURER_ID);
266		return -ENODEV;
267	}
268
269	val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
270	if (val < 0 || val != ADT7411_DEVICE_ID) {
271		dev_dbg(&client->dev,
272			"Wrong device ID. Got %d, expected %d\n",
273			val, ADT7411_DEVICE_ID);
274		return -ENODEV;
275	}
276
277	strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
278
279	return 0;
280}
281
282static int adt7411_probe(struct i2c_client *client,
283				   const struct i2c_device_id *id)
284{
285	struct device *dev = &client->dev;
286	struct adt7411_data *data;
287	struct device *hwmon_dev;
288	int ret;
289
290	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
291	if (!data)
292		return -ENOMEM;
293
294	i2c_set_clientdata(client, data);
295	data->client = client;
296	mutex_init(&data->device_lock);
297	mutex_init(&data->update_lock);
298
299	ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
300				 ADT7411_CFG1_START_MONITOR, 1);
301	if (ret < 0)
302		return ret;
303
304	/* force update on first occasion */
305	data->next_update = jiffies;
306
307	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
308							   data,
309							   adt7411_groups);
310	return PTR_ERR_OR_ZERO(hwmon_dev);
311}
312
313static const struct i2c_device_id adt7411_id[] = {
314	{ "adt7411", 0 },
315	{ }
316};
317MODULE_DEVICE_TABLE(i2c, adt7411_id);
318
319static struct i2c_driver adt7411_driver = {
320	.driver		= {
321		.name		= "adt7411",
322	},
323	.probe  = adt7411_probe,
324	.id_table = adt7411_id,
325	.detect = adt7411_detect,
326	.address_list = normal_i2c,
327	.class = I2C_CLASS_HWMON,
328};
329
330module_i2c_driver(adt7411_driver);
331
332MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
333	"Wolfram Sang <w.sang@pengutronix.de>");
334MODULE_DESCRIPTION("ADT7411 driver");
335MODULE_LICENSE("GPL v2");
336