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
  28 #include <linux/mfd/wm831x/core.h>
  29 #include <linux/mfd/wm831x/auxadc.h>
  30
  31 struct wm831x_hwmon {
  32         struct wm831x *wm831x;
  33         struct device *classdev;
  34 };
  35
  36 static ssize_t show_name(struct device *dev,
  37                          struct device_attribute *attr, char *buf)
  38 {
  39         return sprintf(buf, "wm831x\n");
  40 }
  41
  42 static const char *input_names[] = {
  43         [WM831X_AUX_SYSVDD]    = "SYSVDD",
  44         [WM831X_AUX_USB]       = "USB",
  45         [WM831X_AUX_BKUP_BATT] = "Backup battery",
  46         [WM831X_AUX_BATT]      = "Battery",
  47         [WM831X_AUX_WALL]      = "WALL",
  48         [WM831X_AUX_CHIP_TEMP] = "PMIC",
  49         [WM831X_AUX_BATT_TEMP] = "Battery",
  50 };
  51
  52
  53 static ssize_t show_voltage(struct device *dev,
  54                             struct device_attribute *attr, char *buf)
  55 {
  56         struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
  57         int channel = to_sensor_dev_attr(attr)->index;
  58         int ret;
  59
  60         ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel);
  61         if (ret < 0)
  62                 return ret;
  63
  64         return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
  65 }
  66
  67 static ssize_t show_chip_temp(struct device *dev,
  68                               struct device_attribute *attr, char *buf)
  69 {
  70         struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
  71         int channel = to_sensor_dev_attr(attr)->index;
  72         int ret;
  73
  74         ret = wm831x_auxadc_read(hwmon->wm831x, channel);
  75         if (ret < 0)
  76                 return ret;
  77
  78         /* Degrees celsius = (512.18-ret) / 1.0983 */
  79         ret = 512180 - (ret * 1000);
  80         ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
  81
  82         return sprintf(buf, "%d\n", ret);
  83 }
  84
  85 static ssize_t show_label(struct device *dev,
  86                           struct device_attribute *attr, char *buf)
  87 {
  88         int channel = to_sensor_dev_attr(attr)->index;
  89
  90         return sprintf(buf, "%s\n", input_names[channel]);
  91 }
  92
  93 #define WM831X_VOLTAGE(id, name) \
  94         static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
  95                                   NULL, name)
  96
  97 #define WM831X_NAMED_VOLTAGE(id, name) \
  98         WM831X_VOLTAGE(id, name); \
  99         static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
 100                                   NULL, name)
 101
 102 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 103
 104 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
 105 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
 106 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
 107 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
 108
 109 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
 110 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
 111 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
 112 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
 113 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
 114
 115 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
 116                           WM831X_AUX_CHIP_TEMP);
 117 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
 118                           WM831X_AUX_CHIP_TEMP);
 119 /* Report as a voltage since conversion depends on external components
 120  * and that's what the ABI wants. */
 121 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
 122                           WM831X_AUX_BATT_TEMP);
 123 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
 124                           WM831X_AUX_BATT_TEMP);
 125
 126 static struct attribute *wm831x_attributes[] = {
 127         &dev_attr_name.attr,
 128
 129         &sensor_dev_attr_in0_input.dev_attr.attr,
 130         &sensor_dev_attr_in1_input.dev_attr.attr,
 131         &sensor_dev_attr_in2_input.dev_attr.attr,
 132         &sensor_dev_attr_in3_input.dev_attr.attr,
 133
 134         &sensor_dev_attr_in4_input.dev_attr.attr,
 135         &sensor_dev_attr_in4_label.dev_attr.attr,
 136         &sensor_dev_attr_in5_input.dev_attr.attr,
 137         &sensor_dev_attr_in5_label.dev_attr.attr,
 138         &sensor_dev_attr_in6_input.dev_attr.attr,
 139         &sensor_dev_attr_in6_label.dev_attr.attr,
 140         &sensor_dev_attr_in7_input.dev_attr.attr,
 141         &sensor_dev_attr_in7_label.dev_attr.attr,
 142         &sensor_dev_attr_in8_input.dev_attr.attr,
 143         &sensor_dev_attr_in8_label.dev_attr.attr,
 144
 145         &sensor_dev_attr_temp1_input.dev_attr.attr,
 146         &sensor_dev_attr_temp1_label.dev_attr.attr,
 147         &sensor_dev_attr_temp2_input.dev_attr.attr,
 148         &sensor_dev_attr_temp2_label.dev_attr.attr,
 149
 150         NULL
 151 };
 152
 153 static const struct attribute_group wm831x_attr_group = {
 154         .attrs  = wm831x_attributes,
 155 };
 156
 157 static int __devinit wm831x_hwmon_probe(struct platform_device *pdev)
 158 {
 159         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 160         struct wm831x_hwmon *hwmon;
 161         int ret;
 162
 163         hwmon = kzalloc(sizeof(struct wm831x_hwmon), GFP_KERNEL);
 164         if (!hwmon)
 165                 return -ENOMEM;
 166
 167         hwmon->wm831x = wm831x;
 168
 169         ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group);
 170         if (ret)
 171                 goto err;
 172
 173         hwmon->classdev = hwmon_device_register(&pdev->dev);
 174         if (IS_ERR(hwmon->classdev)) {
 175                 ret = PTR_ERR(hwmon->classdev);
 176                 goto err_sysfs;
 177         }
 178
 179         platform_set_drvdata(pdev, hwmon);
 180
 181         return 0;
 182
 183 err_sysfs:
 184         sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
 185 err:
 186         kfree(hwmon);
 187         return ret;
 188 }
 189
 190 static int __devexit wm831x_hwmon_remove(struct platform_device *pdev)
 191 {
 192         struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev);
 193
 194         hwmon_device_unregister(hwmon->classdev);
 195         sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
 196         platform_set_drvdata(pdev, NULL);
 197         kfree(hwmon);
 198
 199         return 0;
 200 }
 201
 202 static struct platform_driver wm831x_hwmon_driver = {
 203         .probe = wm831x_hwmon_probe,
 204         .remove = __devexit_p(wm831x_hwmon_remove),
 205         .driver = {
 206                 .name = "wm831x-hwmon",
 207                 .owner = THIS_MODULE,
 208         },
 209 };
 210
 211 static int __init wm831x_hwmon_init(void)
 212 {
 213         return platform_driver_register(&wm831x_hwmon_driver);
 214 }
 215 module_init(wm831x_hwmon_init);
 216
 217 static void __exit wm831x_hwmon_exit(void)
 218 {
 219         platform_driver_unregister(&wm831x_hwmon_driver);
 220 }
 221 module_exit(wm831x_hwmon_exit);
 222
 223 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 224 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
 225 MODULE_LICENSE("GPL");
 226 MODULE_ALIAS("platform:wm831x-hwmon");