drivers/hwmon/wm8350-hwmon.c

   1 /*
   2  * drivers/hwmon/wm8350-hwmon.c - Wolfson Microelectronics WM8350 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/err.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/hwmon.h>
  26 #include <linux/hwmon-sysfs.h>
  27
  28 #include <linux/mfd/wm8350/core.h>
  29 #include <linux/mfd/wm8350/comparator.h>
  30
  31 static ssize_t show_name(struct device *dev,
  32                          struct device_attribute *attr, char *buf)
  33 {
  34         return sprintf(buf, "wm8350\n");
  35 }
  36
  37 static const char * const input_names[] = {
  38         [WM8350_AUXADC_USB]  = "USB",
  39         [WM8350_AUXADC_LINE] = "Line",
  40         [WM8350_AUXADC_BATT] = "Battery",
  41 };
  42
  43
  44 static ssize_t show_voltage(struct device *dev,
  45                             struct device_attribute *attr, char *buf)
  46 {
  47         struct wm8350 *wm8350 = dev_get_drvdata(dev);
  48         int channel = to_sensor_dev_attr(attr)->index;
  49         int val;
  50
  51         val = wm8350_read_auxadc(wm8350, channel, 0, 0) * WM8350_AUX_COEFF;
  52         val = DIV_ROUND_CLOSEST(val, 1000);
  53
  54         return sprintf(buf, "%d\n", val);
  55 }
  56
  57 static ssize_t show_label(struct device *dev,
  58                           struct device_attribute *attr, char *buf)
  59 {
  60         int channel = to_sensor_dev_attr(attr)->index;
  61
  62         return sprintf(buf, "%s\n", input_names[channel]);
  63 }
  64
  65 #define WM8350_NAMED_VOLTAGE(id, name) \
  66         static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage,\
  67                                   NULL, name);          \
  68         static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
  69                                   NULL, name)
  70
  71 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
  72
  73 WM8350_NAMED_VOLTAGE(0, WM8350_AUXADC_USB);
  74 WM8350_NAMED_VOLTAGE(1, WM8350_AUXADC_BATT);
  75 WM8350_NAMED_VOLTAGE(2, WM8350_AUXADC_LINE);
  76
  77 static struct attribute *wm8350_attributes[] = {
  78         &dev_attr_name.attr,
  79
  80         &sensor_dev_attr_in0_input.dev_attr.attr,
  81         &sensor_dev_attr_in0_label.dev_attr.attr,
  82         &sensor_dev_attr_in1_input.dev_attr.attr,
  83         &sensor_dev_attr_in1_label.dev_attr.attr,
  84         &sensor_dev_attr_in2_input.dev_attr.attr,
  85         &sensor_dev_attr_in2_label.dev_attr.attr,
  86
  87         NULL,
  88 };
  89
  90 static const struct attribute_group wm8350_attr_group = {
  91         .attrs  = wm8350_attributes,
  92 };
  93
  94 static int wm8350_hwmon_probe(struct platform_device *pdev)
  95 {
  96         struct wm8350 *wm8350 = platform_get_drvdata(pdev);
  97         int ret;
  98
  99         ret = sysfs_create_group(&pdev->dev.kobj, &wm8350_attr_group);
 100         if (ret)
 101                 goto err;
 102
 103         wm8350->hwmon.classdev = hwmon_device_register(&pdev->dev);
 104         if (IS_ERR(wm8350->hwmon.classdev)) {
 105                 ret = PTR_ERR(wm8350->hwmon.classdev);
 106                 goto err_group;
 107         }
 108
 109         return 0;
 110
 111 err_group:
 112         sysfs_remove_group(&pdev->dev.kobj, &wm8350_attr_group);
 113 err:
 114         return ret;
 115 }
 116
 117 static int wm8350_hwmon_remove(struct platform_device *pdev)
 118 {
 119         struct wm8350 *wm8350 = platform_get_drvdata(pdev);
 120
 121         hwmon_device_unregister(wm8350->hwmon.classdev);
 122         sysfs_remove_group(&pdev->dev.kobj, &wm8350_attr_group);
 123
 124         return 0;
 125 }
 126
 127 static struct platform_driver wm8350_hwmon_driver = {
 128         .probe = wm8350_hwmon_probe,
 129         .remove = wm8350_hwmon_remove,
 130         .driver = {
 131                 .name = "wm8350-hwmon",
 132                 .owner = THIS_MODULE,
 133         },
 134 };
 135
 136 module_platform_driver(wm8350_hwmon_driver);
 137
 138 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 139 MODULE_DESCRIPTION("WM8350 Hardware Monitoring");
 140 MODULE_LICENSE("GPL");
 141 MODULE_ALIAS("platform:wm8350-hwmon");