drivers/hwmon/wm831x-hwmon.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x PMIC
   4  *                                hardware monitoring features.
   5  *
   6  * Copyright (C) 2009 Wolfson Microelectronics plc
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/err.h>
  13 #include <linux/hwmon.h>
  14 #include <linux/hwmon-sysfs.h>
  15 #include <linux/slab.h>
  16
  17 #include <linux/mfd/wm831x/core.h>
  18 #include <linux/mfd/wm831x/auxadc.h>
  19
  20 static const char * const input_names[] = {
  21         [WM831X_AUX_SYSVDD]    = "SYSVDD",
  22         [WM831X_AUX_USB]       = "USB",
  23         [WM831X_AUX_BKUP_BATT] = "Backup battery",
  24         [WM831X_AUX_BATT]      = "Battery",
  25         [WM831X_AUX_WALL]      = "WALL",
  26         [WM831X_AUX_CHIP_TEMP] = "PMIC",
  27         [WM831X_AUX_BATT_TEMP] = "Battery",
  28 };
  29
  30 static ssize_t show_voltage(struct device *dev,
  31                             struct device_attribute *attr, char *buf)
  32 {
  33         struct wm831x *wm831x = dev_get_drvdata(dev);
  34         int channel = to_sensor_dev_attr(attr)->index;
  35         int ret;
  36
  37         ret = wm831x_auxadc_read_uv(wm831x, channel);
  38         if (ret < 0)
  39                 return ret;
  40
  41         return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
  42 }
  43
  44 static ssize_t show_chip_temp(struct device *dev,
  45                               struct device_attribute *attr, char *buf)
  46 {
  47         struct wm831x *wm831x = dev_get_drvdata(dev);
  48         int channel = to_sensor_dev_attr(attr)->index;
  49         int ret;
  50
  51         ret = wm831x_auxadc_read(wm831x, channel);
  52         if (ret < 0)
  53                 return ret;
  54
  55         /* Degrees celsius = (512.18-ret) / 1.0983 */
  56         ret = 512180 - (ret * 1000);
  57         ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
  58
  59         return sprintf(buf, "%d\n", ret);
  60 }
  61
  62 static ssize_t show_label(struct device *dev,
  63                           struct device_attribute *attr, char *buf)
  64 {
  65         int channel = to_sensor_dev_attr(attr)->index;
  66
  67         return sprintf(buf, "%s\n", input_names[channel]);
  68 }
  69
  70 #define WM831X_VOLTAGE(id, name) \
  71         static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
  72                                   NULL, name)
  73
  74 #define WM831X_NAMED_VOLTAGE(id, name) \
  75         WM831X_VOLTAGE(id, name); \
  76         static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
  77                                   NULL, name)
  78
  79 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
  80 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
  81 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
  82 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
  83
  84 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
  85 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
  86 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
  87 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
  88 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
  89
  90 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
  91                           WM831X_AUX_CHIP_TEMP);
  92 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
  93                           WM831X_AUX_CHIP_TEMP);
  94 /*
  95  * Report as a voltage since conversion depends on external components
  96  * and that's what the ABI wants.
  97  */
  98 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
  99                           WM831X_AUX_BATT_TEMP);
 100 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
 101                           WM831X_AUX_BATT_TEMP);
 102
 103 static struct attribute *wm831x_attrs[] = {
 104         &sensor_dev_attr_in0_input.dev_attr.attr,
 105         &sensor_dev_attr_in1_input.dev_attr.attr,
 106         &sensor_dev_attr_in2_input.dev_attr.attr,
 107         &sensor_dev_attr_in3_input.dev_attr.attr,
 108
 109         &sensor_dev_attr_in4_input.dev_attr.attr,
 110         &sensor_dev_attr_in4_label.dev_attr.attr,
 111         &sensor_dev_attr_in5_input.dev_attr.attr,
 112         &sensor_dev_attr_in5_label.dev_attr.attr,
 113         &sensor_dev_attr_in6_input.dev_attr.attr,
 114         &sensor_dev_attr_in6_label.dev_attr.attr,
 115         &sensor_dev_attr_in7_input.dev_attr.attr,
 116         &sensor_dev_attr_in7_label.dev_attr.attr,
 117         &sensor_dev_attr_in8_input.dev_attr.attr,
 118         &sensor_dev_attr_in8_label.dev_attr.attr,
 119
 120         &sensor_dev_attr_temp1_input.dev_attr.attr,
 121         &sensor_dev_attr_temp1_label.dev_attr.attr,
 122         &sensor_dev_attr_temp2_input.dev_attr.attr,
 123         &sensor_dev_attr_temp2_label.dev_attr.attr,
 124
 125         NULL
 126 };
 127
 128 ATTRIBUTE_GROUPS(wm831x);
 129
 130 static int wm831x_hwmon_probe(struct platform_device *pdev)
 131 {
 132         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 133         struct device *hwmon_dev;
 134
 135         hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, "wm831x",
 136                                                            wm831x,
 137                                                            wm831x_groups);
 138         return PTR_ERR_OR_ZERO(hwmon_dev);
 139 }
 140
 141 static struct platform_driver wm831x_hwmon_driver = {
 142         .probe = wm831x_hwmon_probe,
 143         .driver = {
 144                 .name = "wm831x-hwmon",
 145         },
 146 };
 147
 148 module_platform_driver(wm831x_hwmon_driver);
 149
 150 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 151 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
 152 MODULE_LICENSE("GPL");
 153 MODULE_ALIAS("platform:wm831x-hwmon");