LXR linux/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
  32static 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
  42static 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
  56static 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
  74static 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
  91WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
  92WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
  93WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
  94WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
  95
  96WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
  97WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
  98WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
  99WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
 100WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
 101
 102static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
 103                          WM831X_AUX_CHIP_TEMP);
 104static 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 */
 110static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
 111                          WM831X_AUX_BATT_TEMP);
 112static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
 113                          WM831X_AUX_BATT_TEMP);
 114
 115static 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
 140ATTRIBUTE_GROUPS(wm831x);
 141
 142static 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
 153static struct platform_driver wm831x_hwmon_driver = {
 154        .probe = wm831x_hwmon_probe,
 155        .driver = {
 156                .name = "wm831x-hwmon",
 157        },
 158};
 159
 160module_platform_driver(wm831x_hwmon_driver);
 161
 162MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 163MODULE_DESCRIPTION("WM831x Hardware Monitoring");
 164MODULE_LICENSE("GPL");
 165MODULE_ALIAS("platform:wm831x-hwmon");
 166