linux/drivers/hwmon/wm831x-hwmon.c
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   1/*
   2 * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x PMIC
   3 *                                hardware monitoring features.
   4 *
   5 * Copyright (C) 2009 Wolfson Microelectronics plc
   6 *
   7 * This program is free software; you can redistribute it and/or modify it
   8 * under the terms of the GNU General Public License v2 as published by the
   9 * Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but WITHOUT
  12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14 * more details.
  15 *
  16 * You should have received a copy of the GNU General Public License along with
  17 * this program; if not, write to the Free Software Foundation, Inc.,
  18 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  19 */
  20
  21#include <linux/kernel.h>
  22#include <linux/module.h>
  23#include <linux/platform_device.h>
  24#include <linux/err.h>
  25#include <linux/hwmon.h>
  26#include <linux/hwmon-sysfs.h>
  27#include <linux/slab.h>
  28
  29#include <linux/mfd/wm831x/core.h>
  30#include <linux/mfd/wm831x/auxadc.h>
  31
  32struct wm831x_hwmon {
  33        struct wm831x *wm831x;
  34        struct device *classdev;
  35};
  36
  37static ssize_t show_name(struct device *dev,
  38                         struct device_attribute *attr, char *buf)
  39{
  40        return sprintf(buf, "wm831x\n");
  41}
  42
  43static const char * const input_names[] = {
  44        [WM831X_AUX_SYSVDD]    = "SYSVDD",
  45        [WM831X_AUX_USB]       = "USB",
  46        [WM831X_AUX_BKUP_BATT] = "Backup battery",
  47        [WM831X_AUX_BATT]      = "Battery",
  48        [WM831X_AUX_WALL]      = "WALL",
  49        [WM831X_AUX_CHIP_TEMP] = "PMIC",
  50        [WM831X_AUX_BATT_TEMP] = "Battery",
  51};
  52
  53
  54static ssize_t show_voltage(struct device *dev,
  55                            struct device_attribute *attr, char *buf)
  56{
  57        struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
  58        int channel = to_sensor_dev_attr(attr)->index;
  59        int ret;
  60
  61        ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel);
  62        if (ret < 0)
  63                return ret;
  64
  65        return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
  66}
  67
  68static ssize_t show_chip_temp(struct device *dev,
  69                              struct device_attribute *attr, char *buf)
  70{
  71        struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
  72        int channel = to_sensor_dev_attr(attr)->index;
  73        int ret;
  74
  75        ret = wm831x_auxadc_read(hwmon->wm831x, channel);
  76        if (ret < 0)
  77                return ret;
  78
  79        /* Degrees celsius = (512.18-ret) / 1.0983 */
  80        ret = 512180 - (ret * 1000);
  81        ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
  82
  83        return sprintf(buf, "%d\n", ret);
  84}
  85
  86static ssize_t show_label(struct device *dev,
  87                          struct device_attribute *attr, char *buf)
  88{
  89        int channel = to_sensor_dev_attr(attr)->index;
  90
  91        return sprintf(buf, "%s\n", input_names[channel]);
  92}
  93
  94#define WM831X_VOLTAGE(id, name) \
  95        static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
  96                                  NULL, name)
  97
  98#define WM831X_NAMED_VOLTAGE(id, name) \
  99        WM831X_VOLTAGE(id, name); \
 100        static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
 101                                  NULL, name)
 102
 103static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 104
 105WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
 106WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
 107WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
 108WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
 109
 110WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
 111WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
 112WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
 113WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
 114WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
 115
 116static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
 117                          WM831X_AUX_CHIP_TEMP);
 118static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
 119                          WM831X_AUX_CHIP_TEMP);
 120/*
 121 * Report as a voltage since conversion depends on external components
 122 * and that's what the ABI wants.
 123 */
 124static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
 125                          WM831X_AUX_BATT_TEMP);
 126static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
 127                          WM831X_AUX_BATT_TEMP);
 128
 129static struct attribute *wm831x_attributes[] = {
 130        &dev_attr_name.attr,
 131
 132        &sensor_dev_attr_in0_input.dev_attr.attr,
 133        &sensor_dev_attr_in1_input.dev_attr.attr,
 134        &sensor_dev_attr_in2_input.dev_attr.attr,
 135        &sensor_dev_attr_in3_input.dev_attr.attr,
 136
 137        &sensor_dev_attr_in4_input.dev_attr.attr,
 138        &sensor_dev_attr_in4_label.dev_attr.attr,
 139        &sensor_dev_attr_in5_input.dev_attr.attr,
 140        &sensor_dev_attr_in5_label.dev_attr.attr,
 141        &sensor_dev_attr_in6_input.dev_attr.attr,
 142        &sensor_dev_attr_in6_label.dev_attr.attr,
 143        &sensor_dev_attr_in7_input.dev_attr.attr,
 144        &sensor_dev_attr_in7_label.dev_attr.attr,
 145        &sensor_dev_attr_in8_input.dev_attr.attr,
 146        &sensor_dev_attr_in8_label.dev_attr.attr,
 147
 148        &sensor_dev_attr_temp1_input.dev_attr.attr,
 149        &sensor_dev_attr_temp1_label.dev_attr.attr,
 150        &sensor_dev_attr_temp2_input.dev_attr.attr,
 151        &sensor_dev_attr_temp2_label.dev_attr.attr,
 152
 153        NULL
 154};
 155
 156static const struct attribute_group wm831x_attr_group = {
 157        .attrs  = wm831x_attributes,
 158};
 159
 160static int wm831x_hwmon_probe(struct platform_device *pdev)
 161{
 162        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 163        struct wm831x_hwmon *hwmon;
 164        int ret;
 165
 166        hwmon = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_hwmon),
 167                             GFP_KERNEL);
 168        if (!hwmon)
 169                return -ENOMEM;
 170
 171        hwmon->wm831x = wm831x;
 172
 173        ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group);
 174        if (ret)
 175                return ret;
 176
 177        hwmon->classdev = hwmon_device_register(&pdev->dev);
 178        if (IS_ERR(hwmon->classdev)) {
 179                ret = PTR_ERR(hwmon->classdev);
 180                goto err_sysfs;
 181        }
 182
 183        platform_set_drvdata(pdev, hwmon);
 184
 185        return 0;
 186
 187err_sysfs:
 188        sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
 189        return ret;
 190}
 191
 192static int wm831x_hwmon_remove(struct platform_device *pdev)
 193{
 194        struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev);
 195
 196        hwmon_device_unregister(hwmon->classdev);
 197        sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
 198
 199        return 0;
 200}
 201
 202static struct platform_driver wm831x_hwmon_driver = {
 203        .probe = wm831x_hwmon_probe,
 204        .remove = wm831x_hwmon_remove,
 205        .driver = {
 206                .name = "wm831x-hwmon",
 207                .owner = THIS_MODULE,
 208        },
 209};
 210
 211module_platform_driver(wm831x_hwmon_driver);
 212
 213MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 214MODULE_DESCRIPTION("WM831x Hardware Monitoring");
 215MODULE_LICENSE("GPL");
 216MODULE_ALIAS("platform:wm831x-hwmon");
 217
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