1/*
2 * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
3 *             monitoring
4 * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
5 *                         Jean Delvare <jdelvare@suse.de>
6 *
7 * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
8 * It reports up to two temperatures (its own plus up to
9 * one external one). Complete datasheet can be
10 * obtained from Maxim's website at:
11 *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21 * GNU General Public License for more details.
22 */
23
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/jiffies.h>
28#include <linux/i2c.h>
29#include <linux/hwmon.h>
30#include <linux/hwmon-sysfs.h>
31#include <linux/err.h>
32#include <linux/mutex.h>
33#include <linux/sysfs.h>
34
35static const unsigned short normal_i2c[] = {
36	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
37
38/*
39 * The MAX1619 registers
40 */
41
42#define MAX1619_REG_R_MAN_ID		0xFE
43#define MAX1619_REG_R_CHIP_ID		0xFF
44#define MAX1619_REG_R_CONFIG		0x03
45#define MAX1619_REG_W_CONFIG		0x09
46#define MAX1619_REG_R_CONVRATE		0x04
47#define MAX1619_REG_W_CONVRATE		0x0A
48#define MAX1619_REG_R_STATUS		0x02
49#define MAX1619_REG_R_LOCAL_TEMP	0x00
50#define MAX1619_REG_R_REMOTE_TEMP	0x01
51#define MAX1619_REG_R_REMOTE_HIGH	0x07
52#define MAX1619_REG_W_REMOTE_HIGH	0x0D
53#define MAX1619_REG_R_REMOTE_LOW	0x08
54#define MAX1619_REG_W_REMOTE_LOW	0x0E
55#define MAX1619_REG_R_REMOTE_CRIT	0x10
56#define MAX1619_REG_W_REMOTE_CRIT	0x12
57#define MAX1619_REG_R_TCRIT_HYST	0x11
58#define MAX1619_REG_W_TCRIT_HYST	0x13
59
60/*
61 * Conversions
62 */
63
64static int temp_from_reg(int val)
65{
66	return (val & 0x80 ? val-0x100 : val) * 1000;
67}
68
69static int temp_to_reg(int val)
70{
71	return (val < 0 ? val+0x100*1000 : val) / 1000;
72}
73
74enum temp_index {
75	t_input1 = 0,
76	t_input2,
77	t_low2,
78	t_high2,
79	t_crit2,
80	t_hyst2,
81	t_num_regs
82};
83
84/*
85 * Client data (each client gets its own)
86 */
87
88struct max1619_data {
89	struct i2c_client *client;
90	struct mutex update_lock;
91	char valid; /* zero until following fields are valid */
92	unsigned long last_updated; /* in jiffies */
93
94	/* registers values */
95	u8 temp[t_num_regs];	/* index with enum temp_index */
96	u8 alarms;
97};
98
99static const u8 regs_read[t_num_regs] = {
100	[t_input1] = MAX1619_REG_R_LOCAL_TEMP,
101	[t_input2] = MAX1619_REG_R_REMOTE_TEMP,
102	[t_low2] = MAX1619_REG_R_REMOTE_LOW,
103	[t_high2] = MAX1619_REG_R_REMOTE_HIGH,
104	[t_crit2] = MAX1619_REG_R_REMOTE_CRIT,
105	[t_hyst2] = MAX1619_REG_R_TCRIT_HYST,
106};
107
108static const u8 regs_write[t_num_regs] = {
109	[t_low2] = MAX1619_REG_W_REMOTE_LOW,
110	[t_high2] = MAX1619_REG_W_REMOTE_HIGH,
111	[t_crit2] = MAX1619_REG_W_REMOTE_CRIT,
112	[t_hyst2] = MAX1619_REG_W_TCRIT_HYST,
113};
114
115static struct max1619_data *max1619_update_device(struct device *dev)
116{
117	struct max1619_data *data = dev_get_drvdata(dev);
118	struct i2c_client *client = data->client;
119	int config, i;
120
121	mutex_lock(&data->update_lock);
122
123	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
124		dev_dbg(&client->dev, "Updating max1619 data.\n");
125		for (i = 0; i < t_num_regs; i++)
126			data->temp[i] = i2c_smbus_read_byte_data(client,
127					regs_read[i]);
128		data->alarms = i2c_smbus_read_byte_data(client,
129					MAX1619_REG_R_STATUS);
130		/* If OVERT polarity is low, reverse alarm bit */
131		config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
132		if (!(config & 0x20))
133			data->alarms ^= 0x02;
134
135		data->last_updated = jiffies;
136		data->valid = 1;
137	}
138
139	mutex_unlock(&data->update_lock);
140
141	return data;
142}
143
144/*
145 * Sysfs stuff
146 */
147
148static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
149			 char *buf)
150{
151	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
152	struct max1619_data *data = max1619_update_device(dev);
153
154	return sprintf(buf, "%d\n", temp_from_reg(data->temp[attr->index]));
155}
156
157static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
158			   const char *buf, size_t count)
159{
160	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
161	struct max1619_data *data = dev_get_drvdata(dev);
162	struct i2c_client *client = data->client;
163	long val;
164	int err = kstrtol(buf, 10, &val);
165	if (err)
166		return err;
167
168	mutex_lock(&data->update_lock);
169	data->temp[attr->index] = temp_to_reg(val);
170	i2c_smbus_write_byte_data(client, regs_write[attr->index],
171				  data->temp[attr->index]);
172	mutex_unlock(&data->update_lock);
173	return count;
174}
175
176static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
177			   char *buf)
178{
179	struct max1619_data *data = max1619_update_device(dev);
180	return sprintf(buf, "%d\n", data->alarms);
181}
182
183static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
184			  char *buf)
185{
186	int bitnr = to_sensor_dev_attr(attr)->index;
187	struct max1619_data *data = max1619_update_device(dev);
188	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
189}
190
191static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input1);
192static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, t_input2);
193static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp, set_temp,
194			  t_low2);
195static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp, set_temp,
196			  t_high2);
197static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp, set_temp,
198			  t_crit2);
199static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp,
200			  set_temp, t_hyst2);
201
202static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
203static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
204static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
205static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
206static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
207
208static struct attribute *max1619_attrs[] = {
209	&sensor_dev_attr_temp1_input.dev_attr.attr,
210	&sensor_dev_attr_temp2_input.dev_attr.attr,
211	&sensor_dev_attr_temp2_min.dev_attr.attr,
212	&sensor_dev_attr_temp2_max.dev_attr.attr,
213	&sensor_dev_attr_temp2_crit.dev_attr.attr,
214	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
215
216	&dev_attr_alarms.attr,
217	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
218	&sensor_dev_attr_temp2_fault.dev_attr.attr,
219	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
220	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
221	NULL
222};
223ATTRIBUTE_GROUPS(max1619);
224
225/* Return 0 if detection is successful, -ENODEV otherwise */
226static int max1619_detect(struct i2c_client *client,
227			  struct i2c_board_info *info)
228{
229	struct i2c_adapter *adapter = client->adapter;
230	u8 reg_config, reg_convrate, reg_status, man_id, chip_id;
231
232	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
233		return -ENODEV;
234
235	/* detection */
236	reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
237	reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONVRATE);
238	reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_R_STATUS);
239	if ((reg_config & 0x03) != 0x00
240	 || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
241		dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
242			client->addr);
243		return -ENODEV;
244	}
245
246	/* identification */
247	man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_MAN_ID);
248	chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CHIP_ID);
249	if (man_id != 0x4D || chip_id != 0x04) {
250		dev_info(&adapter->dev,
251			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
252			 man_id, chip_id);
253		return -ENODEV;
254	}
255
256	strlcpy(info->type, "max1619", I2C_NAME_SIZE);
257
258	return 0;
259}
260
261static void max1619_init_client(struct i2c_client *client)
262{
263	u8 config;
264
265	/*
266	 * Start the conversions.
267	 */
268	i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
269				  5); /* 2 Hz */
270	config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
271	if (config & 0x40)
272		i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
273					  config & 0xBF); /* run */
274}
275
276static int max1619_probe(struct i2c_client *new_client,
277			 const struct i2c_device_id *id)
278{
279	struct max1619_data *data;
280	struct device *hwmon_dev;
281
282	data = devm_kzalloc(&new_client->dev, sizeof(struct max1619_data),
283			    GFP_KERNEL);
284	if (!data)
285		return -ENOMEM;
286
287	data->client = new_client;
288	mutex_init(&data->update_lock);
289
290	/* Initialize the MAX1619 chip */
291	max1619_init_client(new_client);
292
293	hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
294							   new_client->name,
295							   data,
296							   max1619_groups);
297	return PTR_ERR_OR_ZERO(hwmon_dev);
298}
299
300static const struct i2c_device_id max1619_id[] = {
301	{ "max1619", 0 },
302	{ }
303};
304MODULE_DEVICE_TABLE(i2c, max1619_id);
305
306static struct i2c_driver max1619_driver = {
307	.class		= I2C_CLASS_HWMON,
308	.driver = {
309		.name	= "max1619",
310	},
311	.probe		= max1619_probe,
312	.id_table	= max1619_id,
313	.detect		= max1619_detect,
314	.address_list	= normal_i2c,
315};
316
317module_i2c_driver(max1619_driver);
318
319MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
320MODULE_DESCRIPTION("MAX1619 sensor driver");
321MODULE_LICENSE("GPL");
322