drivers/hwmon/max1619.c

   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
  55 static int temp_from_reg(int val)
  56 {
  57         return (val & 0x80 ? val-0x100 : val) * 1000;
  58 }
  59
  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         char valid; /* zero 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
 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 = 1;
 128         }
 129
 130         mutex_unlock(&data->update_lock);
 131
 132         return data;
 133 }
 134
 135 /*
 136  * Sysfs stuff
 137  */
 138
 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
 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
 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
 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 */
 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         strlcpy(info->type, "max1619", I2C_NAME_SIZE);
 245
 246         return 0;
 247 }
 248
 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
 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");