drivers/hwmon/vexpress.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License version 2 as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * Copyright (C) 2012 ARM Limited
  12  */
  13
  14 #define DRVNAME "vexpress-hwmon"
  15 #define pr_fmt(fmt) DRVNAME ": " fmt
  16
  17 #include <linux/device.h>
  18 #include <linux/err.h>
  19 #include <linux/hwmon.h>
  20 #include <linux/hwmon-sysfs.h>
  21 #include <linux/module.h>
  22 #include <linux/of_device.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/vexpress.h>
  25
  26 struct vexpress_hwmon_data {
  27         struct device *hwmon_dev;
  28         struct vexpress_config_func *func;
  29 };
  30
  31 static ssize_t vexpress_hwmon_name_show(struct device *dev,
  32                 struct device_attribute *dev_attr, char *buffer)
  33 {
  34         const char *compatible = of_get_property(dev->of_node, "compatible",
  35                         NULL);
  36
  37         return sprintf(buffer, "%s\n", compatible);
  38 }
  39
  40 static ssize_t vexpress_hwmon_label_show(struct device *dev,
  41                 struct device_attribute *dev_attr, char *buffer)
  42 {
  43         const char *label = of_get_property(dev->of_node, "label", NULL);
  44
  45         if (!label)
  46                 return -ENOENT;
  47
  48         return snprintf(buffer, PAGE_SIZE, "%s\n", label);
  49 }
  50
  51 static ssize_t vexpress_hwmon_u32_show(struct device *dev,
  52                 struct device_attribute *dev_attr, char *buffer)
  53 {
  54         struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
  55         int err;
  56         u32 value;
  57
  58         err = vexpress_config_read(data->func, 0, &value);
  59         if (err)
  60                 return err;
  61
  62         return snprintf(buffer, PAGE_SIZE, "%u\n", value /
  63                         to_sensor_dev_attr(dev_attr)->index);
  64 }
  65
  66 static ssize_t vexpress_hwmon_u64_show(struct device *dev,
  67                 struct device_attribute *dev_attr, char *buffer)
  68 {
  69         struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
  70         int err;
  71         u32 value_hi, value_lo;
  72
  73         err = vexpress_config_read(data->func, 0, &value_lo);
  74         if (err)
  75                 return err;
  76
  77         err = vexpress_config_read(data->func, 1, &value_hi);
  78         if (err)
  79                 return err;
  80
  81         return snprintf(buffer, PAGE_SIZE, "%llu\n",
  82                         div_u64(((u64)value_hi << 32) | value_lo,
  83                         to_sensor_dev_attr(dev_attr)->index));
  84 }
  85
  86 static DEVICE_ATTR(name, S_IRUGO, vexpress_hwmon_name_show, NULL);
  87
  88 #define VEXPRESS_HWMON_ATTRS(_name, _label_attr, _input_attr)   \
  89 struct attribute *vexpress_hwmon_attrs_##_name[] = {            \
  90         &dev_attr_name.attr,                                    \
  91         &dev_attr_##_label_attr.attr,                           \
  92         &sensor_dev_attr_##_input_attr.dev_attr.attr,           \
  93         NULL                                                    \
  94 }
  95
  96 #if !defined(CONFIG_REGULATOR_VEXPRESS)
  97 static DEVICE_ATTR(in1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
  98 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
  99                 NULL, 1000);
 100 static VEXPRESS_HWMON_ATTRS(volt, in1_label, in1_input);
 101 static struct attribute_group vexpress_hwmon_group_volt = {
 102         .attrs = vexpress_hwmon_attrs_volt,
 103 };
 104 #endif
 105
 106 static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 107 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
 108                 NULL, 1000);
 109 static VEXPRESS_HWMON_ATTRS(amp, curr1_label, curr1_input);
 110 static struct attribute_group vexpress_hwmon_group_amp = {
 111         .attrs = vexpress_hwmon_attrs_amp,
 112 };
 113
 114 static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 115 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
 116                 NULL, 1000);
 117 static VEXPRESS_HWMON_ATTRS(temp, temp1_label, temp1_input);
 118 static struct attribute_group vexpress_hwmon_group_temp = {
 119         .attrs = vexpress_hwmon_attrs_temp,
 120 };
 121
 122 static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 123 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
 124                 NULL, 1);
 125 static VEXPRESS_HWMON_ATTRS(power, power1_label, power1_input);
 126 static struct attribute_group vexpress_hwmon_group_power = {
 127         .attrs = vexpress_hwmon_attrs_power,
 128 };
 129
 130 static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 131 static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
 132                 NULL, 1);
 133 static VEXPRESS_HWMON_ATTRS(energy, energy1_label, energy1_input);
 134 static struct attribute_group vexpress_hwmon_group_energy = {
 135         .attrs = vexpress_hwmon_attrs_energy,
 136 };
 137
 138 static struct of_device_id vexpress_hwmon_of_match[] = {
 139 #if !defined(CONFIG_REGULATOR_VEXPRESS)
 140         {
 141                 .compatible = "arm,vexpress-volt",
 142                 .data = &vexpress_hwmon_group_volt,
 143         },
 144 #endif
 145         {
 146                 .compatible = "arm,vexpress-amp",
 147                 .data = &vexpress_hwmon_group_amp,
 148         }, {
 149                 .compatible = "arm,vexpress-temp",
 150                 .data = &vexpress_hwmon_group_temp,
 151         }, {
 152                 .compatible = "arm,vexpress-power",
 153                 .data = &vexpress_hwmon_group_power,
 154         }, {
 155                 .compatible = "arm,vexpress-energy",
 156                 .data = &vexpress_hwmon_group_energy,
 157         },
 158         {}
 159 };
 160 MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
 161
 162 static int vexpress_hwmon_probe(struct platform_device *pdev)
 163 {
 164         int err;
 165         const struct of_device_id *match;
 166         struct vexpress_hwmon_data *data;
 167
 168         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 169         if (!data)
 170                 return -ENOMEM;
 171         platform_set_drvdata(pdev, data);
 172
 173         match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
 174         if (!match)
 175                 return -ENODEV;
 176
 177         data->func = vexpress_config_func_get_by_dev(&pdev->dev);
 178         if (!data->func)
 179                 return -ENODEV;
 180
 181         err = sysfs_create_group(&pdev->dev.kobj, match->data);
 182         if (err)
 183                 goto error;
 184
 185         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 186         if (IS_ERR(data->hwmon_dev)) {
 187                 err = PTR_ERR(data->hwmon_dev);
 188                 goto error;
 189         }
 190
 191         return 0;
 192
 193 error:
 194         sysfs_remove_group(&pdev->dev.kobj, match->data);
 195         vexpress_config_func_put(data->func);
 196         return err;
 197 }
 198
 199 static int vexpress_hwmon_remove(struct platform_device *pdev)
 200 {
 201         struct vexpress_hwmon_data *data = platform_get_drvdata(pdev);
 202         const struct of_device_id *match;
 203
 204         hwmon_device_unregister(data->hwmon_dev);
 205
 206         match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
 207         sysfs_remove_group(&pdev->dev.kobj, match->data);
 208
 209         vexpress_config_func_put(data->func);
 210
 211         return 0;
 212 }
 213
 214 static struct platform_driver vexpress_hwmon_driver = {
 215         .probe = vexpress_hwmon_probe,
 216         .remove = vexpress_hwmon_remove,
 217         .driver = {
 218                 .name = DRVNAME,
 219                 .owner = THIS_MODULE,
 220                 .of_match_table = vexpress_hwmon_of_match,
 221         },
 222 };
 223
 224 module_platform_driver(vexpress_hwmon_driver);
 225
 226 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
 227 MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
 228 MODULE_LICENSE("GPL");
 229 MODULE_ALIAS("platform:vexpress-hwmon");