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 static const char * const input_names[] = {
  33         [WM831X_AUX_SYSVDD]    = "SYSVDD",
  34         [WM831X_AUX_USB]       = "USB",
  35         [WM831X_AUX_BKUP_BATT] = "Backup battery",
  36         [WM831X_AUX_BATT]      = "Battery",
  37         [WM831X_AUX_WALL]      = "WALL",
  38         [WM831X_AUX_CHIP_TEMP] = "PMIC",
  39         [WM831X_AUX_BATT_TEMP] = "Battery",
  40 };
  41
  42 static ssize_t show_voltage(struct device *dev,
  43                             struct device_attribute *attr, char *buf)
  44 {
  45         struct wm831x *wm831x = dev_get_drvdata(dev);
  46         int channel = to_sensor_dev_attr(attr)->index;
  47         int ret;
  48
  49         ret = wm831x_auxadc_read_uv(wm831x, channel);
  50         if (ret < 0)
  51                 return ret;
  52
  53         return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
  54 }
  55
  56 static ssize_t show_chip_temp(struct device *dev,
  57                               struct device_attribute *attr, char *buf)
  58 {
  59         struct wm831x *wm831x = dev_get_drvdata(dev);
  60         int channel = to_sensor_dev_attr(attr)->index;
  61         int ret;
  62
  63         ret = wm831x_auxadc_read(wm831x, channel);
  64         if (ret < 0)
  65                 return ret;
  66
  67         /* Degrees celsius = (512.18-ret) / 1.0983 */
  68         ret = 512180 - (ret * 1000);
  69         ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
  70
  71         return sprintf(buf, "%d\n", ret);
  72 }
  73
  74 static ssize_t show_label(struct device *dev,
  75                           struct device_attribute *attr, char *buf)
  76 {
  77         int channel = to_sensor_dev_attr(attr)->index;
  78
  79         return sprintf(buf, "%s\n", input_names[channel]);
  80 }
  81
  82 #define WM831X_VOLTAGE(id, name) \
  83         static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
  84                                   NULL, name)
  85
  86 #define WM831X_NAMED_VOLTAGE(id, name) \
  87         WM831X_VOLTAGE(id, name); \
  88         static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
  89                                   NULL, name)
  90
  91 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
  92 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
  93 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
  94 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
  95
  96 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
  97 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
  98 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
  99 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
 100 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
 101
 102 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
 103                           WM831X_AUX_CHIP_TEMP);
 104 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
 105                           WM831X_AUX_CHIP_TEMP);
 106 /*
 107  * Report as a voltage since conversion depends on external components
 108  * and that's what the ABI wants.
 109  */
 110 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
 111                           WM831X_AUX_BATT_TEMP);
 112 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
 113                           WM831X_AUX_BATT_TEMP);
 114
 115 static struct attribute *wm831x_attrs[] = {
 116         &sensor_dev_attr_in0_input.dev_attr.attr,
 117         &sensor_dev_attr_in1_input.dev_attr.attr,
 118         &sensor_dev_attr_in2_input.dev_attr.attr,
 119         &sensor_dev_attr_in3_input.dev_attr.attr,
 120
 121         &sensor_dev_attr_in4_input.dev_attr.attr,
 122         &sensor_dev_attr_in4_label.dev_attr.attr,
 123         &sensor_dev_attr_in5_input.dev_attr.attr,
 124         &sensor_dev_attr_in5_label.dev_attr.attr,
 125         &sensor_dev_attr_in6_input.dev_attr.attr,
 126         &sensor_dev_attr_in6_label.dev_attr.attr,
 127         &sensor_dev_attr_in7_input.dev_attr.attr,
 128         &sensor_dev_attr_in7_label.dev_attr.attr,
 129         &sensor_dev_attr_in8_input.dev_attr.attr,
 130         &sensor_dev_attr_in8_label.dev_attr.attr,
 131
 132         &sensor_dev_attr_temp1_input.dev_attr.attr,
 133         &sensor_dev_attr_temp1_label.dev_attr.attr,
 134         &sensor_dev_attr_temp2_input.dev_attr.attr,
 135         &sensor_dev_attr_temp2_label.dev_attr.attr,
 136
 137         NULL
 138 };
 139
 140 ATTRIBUTE_GROUPS(wm831x);
 141
 142 static int wm831x_hwmon_probe(struct platform_device *pdev)
 143 {
 144         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 145         struct device *hwmon_dev;
 146
 147         hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, "wm831x",
 148                                                            wm831x,
 149                                                            wm831x_groups);
 150         return PTR_ERR_OR_ZERO(hwmon_dev);
 151 }
 152
 153 static struct platform_driver wm831x_hwmon_driver = {
 154         .probe = wm831x_hwmon_probe,
 155         .driver = {
 156                 .name = "wm831x-hwmon",
 157         },
 158 };
 159
 160 module_platform_driver(wm831x_hwmon_driver);
 161
 162 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 163 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
 164 MODULE_LICENSE("GPL");
 165 MODULE_ALIAS("platform:wm831x-hwmon");