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 
26 static 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 
temp_from_reg(int val)55 static int temp_from_reg(int val)
56 {
57 	return (val & 0x80 ? val-0x100 : val) * 1000;
58 }
59 
temp_to_reg(int val)60 static int temp_to_reg(int val)
61 {
62 	return (val < 0 ? val+0x100*1000 : val) / 1000;
63 }
64 
65 enum 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 
79 struct 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 
90 static 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 
99 static 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 
max1619_update_device(struct device * dev)106 static 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 					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(&data->update_lock);
131 
132 	return data;
133 }
134 
135 /*
136  * Sysfs stuff
137  */
138 
temp_show(struct device * dev,struct device_attribute * devattr,char * buf)139 static 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, "%d\n", temp_from_reg(data->temp[attr->index]));
146 }
147 
temp_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)148 static 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(buf, 10, &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, regs_write[attr->index],
163 				  data->temp[attr->index]);
164 	mutex_unlock(&data->update_lock);
165 	return count;
166 }
167 
alarms_show(struct device * dev,struct device_attribute * attr,char * buf)168 static 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, "%d\n", data->alarms);
173 }
174 
alarm_show(struct device * dev,struct device_attribute * attr,char * buf)175 static 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, "%d\n", (data->alarms >> bitnr) & 1);
181 }
182 
183 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input1);
184 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, t_input2);
185 static SENSOR_DEVICE_ATTR_RW(temp2_min, temp, t_low2);
186 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, t_high2);
187 static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp, t_crit2);
188 static SENSOR_DEVICE_ATTR_RW(temp2_crit_hyst, temp, t_hyst2);
189 
190 static DEVICE_ATTR_RO(alarms);
191 static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 1);
192 static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 2);
193 static SENSOR_DEVICE_ATTR_RO(temp2_min_alarm, alarm, 3);
194 static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 4);
195 
196 static 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 };
211 ATTRIBUTE_GROUPS(max1619);
212 
213 /* Return 0 if detection is successful, -ENODEV otherwise */
max1619_detect(struct i2c_client * client,struct i2c_board_info * info)214 static 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(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(info->type, "max1619", I2C_NAME_SIZE);
245 
246 	return 0;
247 }
248 
max1619_init_client(struct i2c_client * client)249 static 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 				  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 					  config & 0xBF); /* run */
262 }
263 
max1619_probe(struct i2c_client * new_client)264 static int max1619_probe(struct i2c_client *new_client)
265 {
266 	struct max1619_data *data;
267 	struct device *hwmon_dev;
268 
269 	data = devm_kzalloc(&new_client->dev, 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(new_client);
279 
280 	hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
281 							   new_client->name,
282 							   data,
283 							   max1619_groups);
284 	return PTR_ERR_OR_ZERO(hwmon_dev);
285 }
286 
287 static const struct i2c_device_id max1619_id[] = {
288 	{ "max1619", 0 },
289 	{ }
290 };
291 MODULE_DEVICE_TABLE(i2c, max1619_id);
292 
293 #ifdef CONFIG_OF
294 static const struct of_device_id max1619_of_match[] = {
295 	{ .compatible = "maxim,max1619", },
296 	{},
297 };
298 
299 MODULE_DEVICE_TABLE(of, max1619_of_match);
300 #endif
301 
302 static 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_new	= max1619_probe,
309 	.id_table	= max1619_id,
310 	.detect		= max1619_detect,
311 	.address_list	= normal_i2c,
312 };
313 
314 module_i2c_driver(max1619_driver);
315 
316 MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
317 MODULE_DESCRIPTION("MAX1619 sensor driver");
318 MODULE_LICENSE("GPL");
319