linux/drivers/hwmon/ad7418.c
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   1/*
   2 * An hwmon driver for the Analog Devices AD7416/17/18
   3 * Copyright (C) 2006-07 Tower Technologies
   4 *
   5 * Author: Alessandro Zummo <a.zummo@towertech.it>
   6 *
   7 * Based on lm75.c
   8 * Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License,
  12 * as published by the Free Software Foundation - version 2.
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/jiffies.h>
  17#include <linux/i2c.h>
  18#include <linux/hwmon.h>
  19#include <linux/hwmon-sysfs.h>
  20#include <linux/err.h>
  21#include <linux/mutex.h>
  22#include <linux/of_device.h>
  23#include <linux/delay.h>
  24#include <linux/slab.h>
  25
  26#include "lm75.h"
  27
  28#define DRV_VERSION "0.4"
  29
  30enum chips { ad7416, ad7417, ad7418 };
  31
  32/* AD7418 registers */
  33#define AD7418_REG_TEMP_IN      0x00
  34#define AD7418_REG_CONF         0x01
  35#define AD7418_REG_TEMP_HYST    0x02
  36#define AD7418_REG_TEMP_OS      0x03
  37#define AD7418_REG_ADC          0x04
  38#define AD7418_REG_CONF2        0x05
  39
  40#define AD7418_REG_ADC_CH(x)    ((x) << 5)
  41#define AD7418_CH_TEMP          AD7418_REG_ADC_CH(0)
  42
  43static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
  44                                        AD7418_REG_TEMP_HYST,
  45                                        AD7418_REG_TEMP_OS };
  46
  47struct ad7418_data {
  48        struct i2c_client       *client;
  49        enum chips              type;
  50        struct mutex            lock;
  51        int                     adc_max;        /* number of ADC channels */
  52        char                    valid;
  53        unsigned long           last_updated;   /* In jiffies */
  54        s16                     temp[3];        /* Register values */
  55        u16                     in[4];
  56};
  57
  58static int ad7418_update_device(struct device *dev)
  59{
  60        struct ad7418_data *data = dev_get_drvdata(dev);
  61        struct i2c_client *client = data->client;
  62        s32 val;
  63
  64        mutex_lock(&data->lock);
  65
  66        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
  67                || !data->valid) {
  68                u8 cfg;
  69                int i, ch;
  70
  71                /* read config register and clear channel bits */
  72                val = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
  73                if (val < 0)
  74                        goto abort;
  75
  76                cfg = val;
  77                cfg &= 0x1F;
  78
  79                val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
  80                                                cfg | AD7418_CH_TEMP);
  81                if (val < 0)
  82                        goto abort;
  83
  84                udelay(30);
  85
  86                for (i = 0; i < 3; i++) {
  87                        val = i2c_smbus_read_word_swapped(client,
  88                                                          AD7418_REG_TEMP[i]);
  89                        if (val < 0)
  90                                goto abort;
  91
  92                        data->temp[i] = val;
  93                }
  94
  95                for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
  96                        val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
  97                                        cfg | AD7418_REG_ADC_CH(ch));
  98                        if (val < 0)
  99                                goto abort;
 100
 101                        udelay(15);
 102                        val = i2c_smbus_read_word_swapped(client,
 103                                                          AD7418_REG_ADC);
 104                        if (val < 0)
 105                                goto abort;
 106
 107                        data->in[data->adc_max - 1 - i] = val;
 108                }
 109
 110                /* restore old configuration value */
 111                val = i2c_smbus_write_word_swapped(client, AD7418_REG_CONF,
 112                                                   cfg);
 113                if (val < 0)
 114                        goto abort;
 115
 116                data->last_updated = jiffies;
 117                data->valid = 1;
 118        }
 119
 120        mutex_unlock(&data->lock);
 121        return 0;
 122
 123abort:
 124        data->valid = 0;
 125        mutex_unlock(&data->lock);
 126        return val;
 127}
 128
 129static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
 130                         char *buf)
 131{
 132        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 133        struct ad7418_data *data = dev_get_drvdata(dev);
 134        int ret;
 135
 136        ret = ad7418_update_device(dev);
 137        if (ret < 0)
 138                return ret;
 139
 140        return sprintf(buf, "%d\n",
 141                LM75_TEMP_FROM_REG(data->temp[attr->index]));
 142}
 143
 144static ssize_t adc_show(struct device *dev, struct device_attribute *devattr,
 145                        char *buf)
 146{
 147        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 148        struct ad7418_data *data = dev_get_drvdata(dev);
 149        int ret;
 150
 151        ret = ad7418_update_device(dev);
 152        if (ret < 0)
 153                return ret;
 154
 155        return sprintf(buf, "%d\n",
 156                ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
 157}
 158
 159static ssize_t temp_store(struct device *dev,
 160                          struct device_attribute *devattr, const char *buf,
 161                          size_t count)
 162{
 163        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 164        struct ad7418_data *data = dev_get_drvdata(dev);
 165        struct i2c_client *client = data->client;
 166        long temp;
 167        int ret = kstrtol(buf, 10, &temp);
 168
 169        if (ret < 0)
 170                return ret;
 171
 172        mutex_lock(&data->lock);
 173        data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
 174        i2c_smbus_write_word_swapped(client,
 175                                     AD7418_REG_TEMP[attr->index],
 176                                     data->temp[attr->index]);
 177        mutex_unlock(&data->lock);
 178        return count;
 179}
 180
 181static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
 182static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp, 1);
 183static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);
 184
 185static SENSOR_DEVICE_ATTR_RO(in1_input, adc, 0);
 186static SENSOR_DEVICE_ATTR_RO(in2_input, adc, 1);
 187static SENSOR_DEVICE_ATTR_RO(in3_input, adc, 2);
 188static SENSOR_DEVICE_ATTR_RO(in4_input, adc, 3);
 189
 190static struct attribute *ad7416_attrs[] = {
 191        &sensor_dev_attr_temp1_max.dev_attr.attr,
 192        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 193        &sensor_dev_attr_temp1_input.dev_attr.attr,
 194        NULL
 195};
 196ATTRIBUTE_GROUPS(ad7416);
 197
 198static struct attribute *ad7417_attrs[] = {
 199        &sensor_dev_attr_temp1_max.dev_attr.attr,
 200        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 201        &sensor_dev_attr_temp1_input.dev_attr.attr,
 202        &sensor_dev_attr_in1_input.dev_attr.attr,
 203        &sensor_dev_attr_in2_input.dev_attr.attr,
 204        &sensor_dev_attr_in3_input.dev_attr.attr,
 205        &sensor_dev_attr_in4_input.dev_attr.attr,
 206        NULL
 207};
 208ATTRIBUTE_GROUPS(ad7417);
 209
 210static struct attribute *ad7418_attrs[] = {
 211        &sensor_dev_attr_temp1_max.dev_attr.attr,
 212        &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 213        &sensor_dev_attr_temp1_input.dev_attr.attr,
 214        &sensor_dev_attr_in1_input.dev_attr.attr,
 215        NULL
 216};
 217ATTRIBUTE_GROUPS(ad7418);
 218
 219static void ad7418_init_client(struct i2c_client *client)
 220{
 221        struct ad7418_data *data = i2c_get_clientdata(client);
 222
 223        int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
 224        if (reg < 0) {
 225                dev_err(&client->dev, "cannot read configuration register\n");
 226        } else {
 227                dev_info(&client->dev, "configuring for mode 1\n");
 228                i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);
 229
 230                if (data->type == ad7417 || data->type == ad7418)
 231                        i2c_smbus_write_byte_data(client,
 232                                                AD7418_REG_CONF2, 0x00);
 233        }
 234}
 235
 236static int ad7418_probe(struct i2c_client *client,
 237                         const struct i2c_device_id *id)
 238{
 239        struct device *dev = &client->dev;
 240        struct i2c_adapter *adapter = client->adapter;
 241        struct ad7418_data *data;
 242        struct device *hwmon_dev;
 243        const struct attribute_group **attr_groups = NULL;
 244
 245        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 246                                        I2C_FUNC_SMBUS_WORD_DATA))
 247                return -EOPNOTSUPP;
 248
 249        data = devm_kzalloc(dev, sizeof(struct ad7418_data), GFP_KERNEL);
 250        if (!data)
 251                return -ENOMEM;
 252
 253        i2c_set_clientdata(client, data);
 254
 255        mutex_init(&data->lock);
 256        data->client = client;
 257        if (dev->of_node)
 258                data->type = (enum chips)of_device_get_match_data(dev);
 259        else
 260                data->type = id->driver_data;
 261
 262        switch (data->type) {
 263        case ad7416:
 264                data->adc_max = 0;
 265                attr_groups = ad7416_groups;
 266                break;
 267
 268        case ad7417:
 269                data->adc_max = 4;
 270                attr_groups = ad7417_groups;
 271                break;
 272
 273        case ad7418:
 274                data->adc_max = 1;
 275                attr_groups = ad7418_groups;
 276                break;
 277        }
 278
 279        dev_info(dev, "%s chip found\n", client->name);
 280
 281        /* Initialize the AD7418 chip */
 282        ad7418_init_client(client);
 283
 284        hwmon_dev = devm_hwmon_device_register_with_groups(dev,
 285                                                           client->name,
 286                                                           data, attr_groups);
 287        return PTR_ERR_OR_ZERO(hwmon_dev);
 288}
 289
 290static const struct i2c_device_id ad7418_id[] = {
 291        { "ad7416", ad7416 },
 292        { "ad7417", ad7417 },
 293        { "ad7418", ad7418 },
 294        { }
 295};
 296MODULE_DEVICE_TABLE(i2c, ad7418_id);
 297
 298static const struct of_device_id ad7418_dt_ids[] = {
 299        { .compatible = "adi,ad7416", .data = (void *)ad7416, },
 300        { .compatible = "adi,ad7417", .data = (void *)ad7417, },
 301        { .compatible = "adi,ad7418", .data = (void *)ad7418, },
 302        { }
 303};
 304MODULE_DEVICE_TABLE(of, ad7418_dt_ids);
 305
 306static struct i2c_driver ad7418_driver = {
 307        .driver = {
 308                .name   = "ad7418",
 309                .of_match_table = ad7418_dt_ids,
 310        },
 311        .probe          = ad7418_probe,
 312        .id_table       = ad7418_id,
 313};
 314
 315module_i2c_driver(ad7418_driver);
 316
 317MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 318MODULE_DESCRIPTION("AD7416/17/18 driver");
 319MODULE_LICENSE("GPL");
 320MODULE_VERSION(DRV_VERSION);
 321