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 temp_show(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 temp_store(struct device *dev,
158 struct device_attribute *devattr, const char *buf,
159 size_t count)
160{
161 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
162 struct max1619_data *data = dev_get_drvdata(dev);
163 struct i2c_client *client = data->client;
164 long val;
165 int err = kstrtol(buf, 10, &val);
166 if (err)
167 return err;
168
169 mutex_lock(&data->update_lock);
170 data->temp[attr->index] = temp_to_reg(val);
171 i2c_smbus_write_byte_data(client, regs_write[attr->index],
172 data->temp[attr->index]);
173 mutex_unlock(&data->update_lock);
174 return count;
175}
176
177static ssize_t alarms_show(struct device *dev, struct device_attribute *attr,
178 char *buf)
179{
180 struct max1619_data *data = max1619_update_device(dev);
181 return sprintf(buf, "%d\n", data->alarms);
182}
183
184static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
185 char *buf)
186{
187 int bitnr = to_sensor_dev_attr(attr)->index;
188 struct max1619_data *data = max1619_update_device(dev);
189 return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
190}
191
192static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input1);
193static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, t_input2);
194static SENSOR_DEVICE_ATTR_RW(temp2_min, temp, t_low2);
195static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, t_high2);
196static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp, t_crit2);
197static SENSOR_DEVICE_ATTR_RW(temp2_crit_hyst, temp, t_hyst2);
198
199static DEVICE_ATTR_RO(alarms);
200static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 1);
201static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2);
202static SENSOR_DEVICE_ATTR_RO(temp2_min_alarm, alarm, 3);
203static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4);
204
205static struct attribute *max1619_attrs[] = {
206 &sensor_dev_attr_temp1_input.dev_attr.attr,
207 &sensor_dev_attr_temp2_input.dev_attr.attr,
208 &sensor_dev_attr_temp2_min.dev_attr.attr,
209 &sensor_dev_attr_temp2_max.dev_attr.attr,
210 &sensor_dev_attr_temp2_crit.dev_attr.attr,
211 &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
212
213 &dev_attr_alarms.attr,
214 &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
215 &sensor_dev_attr_temp2_fault.dev_attr.attr,
216 &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
217 &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
218 NULL
219};
220ATTRIBUTE_GROUPS(max1619);
221
222/* Return 0 if detection is successful, -ENODEV otherwise */
223static int max1619_detect(struct i2c_client *client,
224 struct i2c_board_info *info)
225{
226 struct i2c_adapter *adapter = client->adapter;
227 u8 reg_config, reg_convrate, reg_status, man_id, chip_id;
228
229 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
230 return -ENODEV;
231
232 /* detection */
233 reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
234 reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONVRATE);
235 reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_R_STATUS);
236 if ((reg_config & 0x03) != 0x00
237 || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
238 dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
239 client->addr);
240 return -ENODEV;
241 }
242
243 /* identification */
244 man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_MAN_ID);
245 chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CHIP_ID);
246 if (man_id != 0x4D || chip_id != 0x04) {
247 dev_info(&adapter->dev,
248 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
249 man_id, chip_id);
250 return -ENODEV;
251 }
252
253 strlcpy(info->type, "max1619", I2C_NAME_SIZE);
254
255 return 0;
256}
257
258static void max1619_init_client(struct i2c_client *client)
259{
260 u8 config;
261
262 /*
263 * Start the conversions.
264 */
265 i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
266 5); /* 2 Hz */
267 config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
268 if (config & 0x40)
269 i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
270 config & 0xBF); /* run */
271}
272
273static int max1619_probe(struct i2c_client *new_client,
274 const struct i2c_device_id *id)
275{
276 struct max1619_data *data;
277 struct device *hwmon_dev;
278
279 data = devm_kzalloc(&new_client->dev, sizeof(struct max1619_data),
280 GFP_KERNEL);
281 if (!data)
282 return -ENOMEM;
283
284 data->client = new_client;
285 mutex_init(&data->update_lock);
286
287 /* Initialize the MAX1619 chip */
288 max1619_init_client(new_client);
289
290 hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
291 new_client->name,
292 data,
293 max1619_groups);
294 return PTR_ERR_OR_ZERO(hwmon_dev);
295}
296
297static const struct i2c_device_id max1619_id[] = {
298 { "max1619", 0 },
299 { }
300};
301MODULE_DEVICE_TABLE(i2c, max1619_id);
302
303#ifdef CONFIG_OF
304static const struct of_device_id max1619_of_match[] = {
305 { .compatible = "maxim,max1619", },
306 {},
307};
308
309MODULE_DEVICE_TABLE(of, max1619_of_match);
310#endif
311
312static struct i2c_driver max1619_driver = {
313 .class = I2C_CLASS_HWMON,
314 .driver = {
315 .name = "max1619",
316 .of_match_table = of_match_ptr(max1619_of_match),
317 },
318 .probe = max1619_probe,
319 .id_table = max1619_id,
320 .detect = max1619_detect,
321 .address_list = normal_i2c,
322};
323
324module_i2c_driver(max1619_driver);
325
326MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
327MODULE_DESCRIPTION("MAX1619 sensor driver");
328MODULE_LICENSE("GPL");
329