1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
4 * monitoring
5 * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
6 * Jean Delvare <jdelvare@suse.de>
7 *
8 * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
9 * It reports up to two temperatures (its own plus up to
10 * one external one). Complete datasheet can be
11 * obtained from Maxim's website at:
12 * http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
13 */
14
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/jiffies.h>
19#include <linux/i2c.h>
20#include <linux/hwmon.h>
21#include <linux/hwmon-sysfs.h>
22#include <linux/err.h>
23#include <linux/mutex.h>
24#include <linux/sysfs.h>
25
26static const unsigned short normal_i2c[] = {
27 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
28
29/*
30 * The MAX1619 registers
31 */
32
33#define MAX1619_REG_R_MAN_ID 0xFE
34#define MAX1619_REG_R_CHIP_ID 0xFF
35#define MAX1619_REG_R_CONFIG 0x03
36#define MAX1619_REG_W_CONFIG 0x09
37#define MAX1619_REG_R_CONVRATE 0x04
38#define MAX1619_REG_W_CONVRATE 0x0A
39#define MAX1619_REG_R_STATUS 0x02
40#define MAX1619_REG_R_LOCAL_TEMP 0x00
41#define MAX1619_REG_R_REMOTE_TEMP 0x01
42#define MAX1619_REG_R_REMOTE_HIGH 0x07
43#define MAX1619_REG_W_REMOTE_HIGH 0x0D
44#define MAX1619_REG_R_REMOTE_LOW 0x08
45#define MAX1619_REG_W_REMOTE_LOW 0x0E
46#define MAX1619_REG_R_REMOTE_CRIT 0x10
47#define MAX1619_REG_W_REMOTE_CRIT 0x12
48#define MAX1619_REG_R_TCRIT_HYST 0x11
49#define MAX1619_REG_W_TCRIT_HYST 0x13
50
51/*
52 * Conversions
53 */
54
55static int temp_from_reg(int val)
56{
57 return (val & 0x80 ? val-0x100 : val) * 1000;
58}
59
60static int temp_to_reg(int val)
61{
62 return (val < 0 ? val+0x100*1000 : val) / 1000;
63}
64
65enum temp_index {
66 t_input1 = 0,
67 t_input2,
68 t_low2,
69 t_high2,
70 t_crit2,
71 t_hyst2,
72 t_num_regs
73};
74
75/*
76 * Client data (each client gets its own)
77 */
78
79struct max1619_data {
80 struct i2c_client *client;
81 struct mutex update_lock;
82 bool valid; /* false until following fields are valid */
83 unsigned long last_updated; /* in jiffies */
84
85 /* registers values */
86 u8 temp[t_num_regs]; /* index with enum temp_index */
87 u8 alarms;
88};
89
90static const u8 regs_read[t_num_regs] = {
91 [t_input1] = MAX1619_REG_R_LOCAL_TEMP,
92 [t_input2] = MAX1619_REG_R_REMOTE_TEMP,
93 [t_low2] = MAX1619_REG_R_REMOTE_LOW,
94 [t_high2] = MAX1619_REG_R_REMOTE_HIGH,
95 [t_crit2] = MAX1619_REG_R_REMOTE_CRIT,
96 [t_hyst2] = MAX1619_REG_R_TCRIT_HYST,
97};
98
99static const u8 regs_write[t_num_regs] = {
100 [t_low2] = MAX1619_REG_W_REMOTE_LOW,
101 [t_high2] = MAX1619_REG_W_REMOTE_HIGH,
102 [t_crit2] = MAX1619_REG_W_REMOTE_CRIT,
103 [t_hyst2] = MAX1619_REG_W_TCRIT_HYST,
104};
105
106static struct max1619_data *max1619_update_device(struct device *dev)
107{
108 struct max1619_data *data = dev_get_drvdata(dev);
109 struct i2c_client *client = data->client;
110 int config, i;
111
112 mutex_lock(&data->update_lock);
113
114 if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
115 dev_dbg(&client->dev, "Updating max1619 data.\n");
116 for (i = 0; i < t_num_regs; i++)
117 data->temp[i] = i2c_smbus_read_byte_data(client,
118 command: regs_read[i]);
119 data->alarms = i2c_smbus_read_byte_data(client,
120 MAX1619_REG_R_STATUS);
121 /* If OVERT polarity is low, reverse alarm bit */
122 config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
123 if (!(config & 0x20))
124 data->alarms ^= 0x02;
125
126 data->last_updated = jiffies;
127 data->valid = true;
128 }
129
130 mutex_unlock(lock: &data->update_lock);
131
132 return data;
133}
134
135/*
136 * Sysfs stuff
137 */
138
139static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
140 char *buf)
141{
142 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
143 struct max1619_data *data = max1619_update_device(dev);
144
145 return sprintf(buf, fmt: "%d\n", temp_from_reg(val: data->temp[attr->index]));
146}
147
148static ssize_t temp_store(struct device *dev,
149 struct device_attribute *devattr, const char *buf,
150 size_t count)
151{
152 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
153 struct max1619_data *data = dev_get_drvdata(dev);
154 struct i2c_client *client = data->client;
155 long val;
156 int err = kstrtol(s: buf, base: 10, res: &val);
157 if (err)
158 return err;
159
160 mutex_lock(&data->update_lock);
161 data->temp[attr->index] = temp_to_reg(val);
162 i2c_smbus_write_byte_data(client, command: regs_write[attr->index],
163 value: data->temp[attr->index]);
164 mutex_unlock(lock: &data->update_lock);
165 return count;
166}
167
168static ssize_t alarms_show(struct device *dev, struct device_attribute *attr,
169 char *buf)
170{
171 struct max1619_data *data = max1619_update_device(dev);
172 return sprintf(buf, fmt: "%d\n", data->alarms);
173}
174
175static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
176 char *buf)
177{
178 int bitnr = to_sensor_dev_attr(attr)->index;
179 struct max1619_data *data = max1619_update_device(dev);
180 return sprintf(buf, fmt: "%d\n", (data->alarms >> bitnr) & 1);
181}
182
183static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input1);
184static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, t_input2);
185static SENSOR_DEVICE_ATTR_RW(temp2_min, temp, t_low2);
186static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, t_high2);
187static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp, t_crit2);
188static SENSOR_DEVICE_ATTR_RW(temp2_crit_hyst, temp, t_hyst2);
189
190static DEVICE_ATTR_RO(alarms);
191static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 1);
192static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2);
193static SENSOR_DEVICE_ATTR_RO(temp2_min_alarm, alarm, 3);
194static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4);
195
196static struct attribute *max1619_attrs[] = {
197 &sensor_dev_attr_temp1_input.dev_attr.attr,
198 &sensor_dev_attr_temp2_input.dev_attr.attr,
199 &sensor_dev_attr_temp2_min.dev_attr.attr,
200 &sensor_dev_attr_temp2_max.dev_attr.attr,
201 &sensor_dev_attr_temp2_crit.dev_attr.attr,
202 &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
203
204 &dev_attr_alarms.attr,
205 &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
206 &sensor_dev_attr_temp2_fault.dev_attr.attr,
207 &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
208 &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
209 NULL
210};
211ATTRIBUTE_GROUPS(max1619);
212
213/* Return 0 if detection is successful, -ENODEV otherwise */
214static int max1619_detect(struct i2c_client *client,
215 struct i2c_board_info *info)
216{
217 struct i2c_adapter *adapter = client->adapter;
218 u8 reg_config, reg_convrate, reg_status, man_id, chip_id;
219
220 if (!i2c_check_functionality(adap: adapter, I2C_FUNC_SMBUS_BYTE_DATA))
221 return -ENODEV;
222
223 /* detection */
224 reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
225 reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONVRATE);
226 reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_R_STATUS);
227 if ((reg_config & 0x03) != 0x00
228 || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
229 dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
230 client->addr);
231 return -ENODEV;
232 }
233
234 /* identification */
235 man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_MAN_ID);
236 chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CHIP_ID);
237 if (man_id != 0x4D || chip_id != 0x04) {
238 dev_info(&adapter->dev,
239 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
240 man_id, chip_id);
241 return -ENODEV;
242 }
243
244 strscpy(p: info->type, q: "max1619", I2C_NAME_SIZE);
245
246 return 0;
247}
248
249static void max1619_init_client(struct i2c_client *client)
250{
251 u8 config;
252
253 /*
254 * Start the conversions.
255 */
256 i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
257 value: 5); /* 2 Hz */
258 config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
259 if (config & 0x40)
260 i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
261 value: config & 0xBF); /* run */
262}
263
264static int max1619_probe(struct i2c_client *new_client)
265{
266 struct max1619_data *data;
267 struct device *hwmon_dev;
268
269 data = devm_kzalloc(dev: &new_client->dev, size: sizeof(struct max1619_data),
270 GFP_KERNEL);
271 if (!data)
272 return -ENOMEM;
273
274 data->client = new_client;
275 mutex_init(&data->update_lock);
276
277 /* Initialize the MAX1619 chip */
278 max1619_init_client(client: new_client);
279
280 hwmon_dev = devm_hwmon_device_register_with_groups(dev: &new_client->dev,
281 name: new_client->name,
282 drvdata: data,
283 groups: max1619_groups);
284 return PTR_ERR_OR_ZERO(ptr: hwmon_dev);
285}
286
287static const struct i2c_device_id max1619_id[] = {
288 { "max1619", 0 },
289 { }
290};
291MODULE_DEVICE_TABLE(i2c, max1619_id);
292
293#ifdef CONFIG_OF
294static const struct of_device_id max1619_of_match[] = {
295 { .compatible = "maxim,max1619", },
296 {},
297};
298
299MODULE_DEVICE_TABLE(of, max1619_of_match);
300#endif
301
302static struct i2c_driver max1619_driver = {
303 .class = I2C_CLASS_HWMON,
304 .driver = {
305 .name = "max1619",
306 .of_match_table = of_match_ptr(max1619_of_match),
307 },
308 .probe = max1619_probe,
309 .id_table = max1619_id,
310 .detect = max1619_detect,
311 .address_list = normal_i2c,
312};
313
314module_i2c_driver(max1619_driver);
315
316MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
317MODULE_DESCRIPTION("MAX1619 sensor driver");
318MODULE_LICENSE("GPL");
319

source code of linux/drivers/hwmon/max1619.c