drivers/hwmon/wm831x-hwmon.c

   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
  32 struct wm831x_hwmon {
  33         struct wm831x *wm831x;
  34         struct device *classdev;
  35 };
  36
  37 static ssize_t show_name(struct device *dev,
  38                          struct device_attribute *attr, char *buf)
  39 {
  40         return sprintf(buf, "wm831x\n");
  41 }
  42
  43 static 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
  54 static 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
  68 static 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
  86 static 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
 103 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 104
 105 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
 106 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
 107 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
 108 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
 109
 110 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
 111 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
 112 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
 113 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
 114 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
 115
 116 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
 117                           WM831X_AUX_CHIP_TEMP);
 118 static 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  */
 124 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
 125                           WM831X_AUX_BATT_TEMP);
 126 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
 127                           WM831X_AUX_BATT_TEMP);
 128
 129 static 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
 156 static const struct attribute_group wm831x_attr_group = {
 157         .attrs  = wm831x_attributes,
 158 };
 159
 160 static 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
 187 err_sysfs:
 188         sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
 189         return ret;
 190 }
 191
 192 static 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
 202 static 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
 211 module_platform_driver(wm831x_hwmon_driver);
 212
 213 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 214 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
 215 MODULE_LICENSE("GPL");
 216 MODULE_ALIAS("platform:wm831x-hwmon");