linux/drivers/hwmon/max1619.c
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   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        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
  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                                        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
 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, "%d\n", temp_from_reg(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(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
 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, "%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, "%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(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
 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                                  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
 264static int max1619_probe(struct i2c_client *new_client,
 265                         const struct i2c_device_id *id)
 266{
 267        struct max1619_data *data;
 268        struct device *hwmon_dev;
 269
 270        data = devm_kzalloc(&new_client->dev, sizeof(struct max1619_data),
 271                            GFP_KERNEL);
 272        if (!data)
 273                return -ENOMEM;
 274
 275        data->client = new_client;
 276        mutex_init(&data->update_lock);
 277
 278        /* Initialize the MAX1619 chip */
 279        max1619_init_client(new_client);
 280
 281        hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
 282                                                           new_client->name,
 283                                                           data,
 284                                                           max1619_groups);
 285        return PTR_ERR_OR_ZERO(hwmon_dev);
 286}
 287
 288static const struct i2c_device_id max1619_id[] = {
 289        { "max1619", 0 },
 290        { }
 291};
 292MODULE_DEVICE_TABLE(i2c, max1619_id);
 293
 294#ifdef CONFIG_OF
 295static const struct of_device_id max1619_of_match[] = {
 296        { .compatible = "maxim,max1619", },
 297        {},
 298};
 299
 300MODULE_DEVICE_TABLE(of, max1619_of_match);
 301#endif
 302
 303static struct i2c_driver max1619_driver = {
 304        .class          = I2C_CLASS_HWMON,
 305        .driver = {
 306                .name   = "max1619",
 307                .of_match_table = of_match_ptr(max1619_of_match),
 308        },
 309        .probe          = max1619_probe,
 310        .id_table       = max1619_id,
 311        .detect         = max1619_detect,
 312        .address_list   = normal_i2c,
 313};
 314
 315module_i2c_driver(max1619_driver);
 316
 317MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
 318MODULE_DESCRIPTION("MAX1619 sensor driver");
 319MODULE_LICENSE("GPL");
 320