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.h>
  23 #include <linux/of_device.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/vexpress.h>
  26
  27 struct vexpress_hwmon_data {
  28         struct device *hwmon_dev;
  29         struct vexpress_config_func *func;
  30 };
  31
  32 static ssize_t vexpress_hwmon_name_show(struct device *dev,
  33                 struct device_attribute *dev_attr, char *buffer)
  34 {
  35         const char *compatible = of_get_property(dev->of_node, "compatible",
  36                         NULL);
  37
  38         return sprintf(buffer, "%s\n", compatible);
  39 }
  40
  41 static ssize_t vexpress_hwmon_label_show(struct device *dev,
  42                 struct device_attribute *dev_attr, char *buffer)
  43 {
  44         const char *label = of_get_property(dev->of_node, "label", NULL);
  45
  46         if (!label)
  47                 return -ENOENT;
  48
  49         return snprintf(buffer, PAGE_SIZE, "%s\n", label);
  50 }
  51
  52 static ssize_t vexpress_hwmon_u32_show(struct device *dev,
  53                 struct device_attribute *dev_attr, char *buffer)
  54 {
  55         struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
  56         int err;
  57         u32 value;
  58
  59         err = vexpress_config_read(data->func, 0, &value);
  60         if (err)
  61                 return err;
  62
  63         return snprintf(buffer, PAGE_SIZE, "%u\n", value /
  64                         to_sensor_dev_attr(dev_attr)->index);
  65 }
  66
  67 static ssize_t vexpress_hwmon_u64_show(struct device *dev,
  68                 struct device_attribute *dev_attr, char *buffer)
  69 {
  70         struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
  71         int err;
  72         u32 value_hi, value_lo;
  73
  74         err = vexpress_config_read(data->func, 0, &value_lo);
  75         if (err)
  76                 return err;
  77
  78         err = vexpress_config_read(data->func, 1, &value_hi);
  79         if (err)
  80                 return err;
  81
  82         return snprintf(buffer, PAGE_SIZE, "%llu\n",
  83                         div_u64(((u64)value_hi << 32) | value_lo,
  84                         to_sensor_dev_attr(dev_attr)->index));
  85 }
  86
  87 static DEVICE_ATTR(name, S_IRUGO, vexpress_hwmon_name_show, NULL);
  88
  89 #define VEXPRESS_HWMON_ATTRS(_name, _label_attr, _input_attr)   \
  90 struct attribute *vexpress_hwmon_attrs_##_name[] = {            \
  91         &dev_attr_name.attr,                                    \
  92         &dev_attr_##_label_attr.attr,                           \
  93         &sensor_dev_attr_##_input_attr.dev_attr.attr,           \
  94         NULL                                                    \
  95 }
  96
  97 #if !defined(CONFIG_REGULATOR_VEXPRESS)
  98 static DEVICE_ATTR(in1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
  99 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
 100                 NULL, 1000);
 101 static VEXPRESS_HWMON_ATTRS(volt, in1_label, in1_input);
 102 static struct attribute_group vexpress_hwmon_group_volt = {
 103         .attrs = vexpress_hwmon_attrs_volt,
 104 };
 105 #endif
 106
 107 static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 108 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
 109                 NULL, 1000);
 110 static VEXPRESS_HWMON_ATTRS(amp, curr1_label, curr1_input);
 111 static struct attribute_group vexpress_hwmon_group_amp = {
 112         .attrs = vexpress_hwmon_attrs_amp,
 113 };
 114
 115 static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 116 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
 117                 NULL, 1000);
 118 static VEXPRESS_HWMON_ATTRS(temp, temp1_label, temp1_input);
 119 static struct attribute_group vexpress_hwmon_group_temp = {
 120         .attrs = vexpress_hwmon_attrs_temp,
 121 };
 122
 123 static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 124 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
 125                 NULL, 1);
 126 static VEXPRESS_HWMON_ATTRS(power, power1_label, power1_input);
 127 static struct attribute_group vexpress_hwmon_group_power = {
 128         .attrs = vexpress_hwmon_attrs_power,
 129 };
 130
 131 static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
 132 static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
 133                 NULL, 1);
 134 static VEXPRESS_HWMON_ATTRS(energy, energy1_label, energy1_input);
 135 static struct attribute_group vexpress_hwmon_group_energy = {
 136         .attrs = vexpress_hwmon_attrs_energy,
 137 };
 138
 139 static struct of_device_id vexpress_hwmon_of_match[] = {
 140 #if !defined(CONFIG_REGULATOR_VEXPRESS)
 141         {
 142                 .compatible = "arm,vexpress-volt",
 143                 .data = &vexpress_hwmon_group_volt,
 144         },
 145 #endif
 146         {
 147                 .compatible = "arm,vexpress-amp",
 148                 .data = &vexpress_hwmon_group_amp,
 149         }, {
 150                 .compatible = "arm,vexpress-temp",
 151                 .data = &vexpress_hwmon_group_temp,
 152         }, {
 153                 .compatible = "arm,vexpress-power",
 154                 .data = &vexpress_hwmon_group_power,
 155         }, {
 156                 .compatible = "arm,vexpress-energy",
 157                 .data = &vexpress_hwmon_group_energy,
 158         },
 159         {}
 160 };
 161 MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
 162
 163 static int vexpress_hwmon_probe(struct platform_device *pdev)
 164 {
 165         int err;
 166         const struct of_device_id *match;
 167         struct vexpress_hwmon_data *data;
 168
 169         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 170         if (!data)
 171                 return -ENOMEM;
 172         platform_set_drvdata(pdev, data);
 173
 174         match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
 175         if (!match)
 176                 return -ENODEV;
 177
 178         data->func = vexpress_config_func_get_by_dev(&pdev->dev);
 179         if (!data->func)
 180                 return -ENODEV;
 181
 182         err = sysfs_create_group(&pdev->dev.kobj, match->data);
 183         if (err)
 184                 goto error;
 185
 186         data->hwmon_dev = hwmon_device_register(&pdev->dev);
 187         if (IS_ERR(data->hwmon_dev)) {
 188                 err = PTR_ERR(data->hwmon_dev);
 189                 goto error;
 190         }
 191
 192         return 0;
 193
 194 error:
 195         sysfs_remove_group(&pdev->dev.kobj, match->data);
 196         vexpress_config_func_put(data->func);
 197         return err;
 198 }
 199
 200 static int vexpress_hwmon_remove(struct platform_device *pdev)
 201 {
 202         struct vexpress_hwmon_data *data = platform_get_drvdata(pdev);
 203         const struct of_device_id *match;
 204
 205         hwmon_device_unregister(data->hwmon_dev);
 206
 207         match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
 208         sysfs_remove_group(&pdev->dev.kobj, match->data);
 209
 210         vexpress_config_func_put(data->func);
 211
 212         return 0;
 213 }
 214
 215 static struct platform_driver vexpress_hwmon_driver = {
 216         .probe = vexpress_hwmon_probe,
 217         .remove = vexpress_hwmon_remove,
 218         .driver = {
 219                 .name = DRVNAME,
 220                 .owner = THIS_MODULE,
 221                 .of_match_table = vexpress_hwmon_of_match,
 222         },
 223 };
 224
 225 module_platform_driver(vexpress_hwmon_driver);
 226
 227 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
 228 MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
 229 MODULE_LICENSE("GPL");
 230 MODULE_ALIAS("platform:vexpress-hwmon");