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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 
 32 struct wm831x_hwmon {
 33         struct wm831x *wm831x;
 34         struct device *classdev;
 35 };
 36 
 37 static ssize_t show_name(struct device *dev,
 38                          struct device_attribute *attr, char *buf)
 39 {
 40         return sprintf(buf, "wm831x\n");
 41 }
 42 
 43 static const char * const input_names[] = {
 44         [WM831X_AUX_SYSVDD]    = "SYSVDD",
 45         [WM831X_AUX_USB]       = "USB",
 46         [WM831X_AUX_BKUP_BATT] = "Backup battery",
 47         [WM831X_AUX_BATT]      = "Battery",
 48         [WM831X_AUX_WALL]      = "WALL",
 49         [WM831X_AUX_CHIP_TEMP] = "PMIC",
 50         [WM831X_AUX_BATT_TEMP] = "Battery",
 51 };
 52 
 53 
 54 static ssize_t show_voltage(struct device *dev,
 55                             struct device_attribute *attr, char *buf)
 56 {
 57         struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
 58         int channel = to_sensor_dev_attr(attr)->index;
 59         int ret;
 60 
 61         ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel);
 62         if (ret < 0)
 63                 return ret;
 64 
 65         return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
 66 }
 67 
 68 static ssize_t show_chip_temp(struct device *dev,
 69                               struct device_attribute *attr, char *buf)
 70 {
 71         struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
 72         int channel = to_sensor_dev_attr(attr)->index;
 73         int ret;
 74 
 75         ret = wm831x_auxadc_read(hwmon->wm831x, channel);
 76         if (ret < 0)
 77                 return ret;
 78 
 79         /* Degrees celsius = (512.18-ret) / 1.0983 */
 80         ret = 512180 - (ret * 1000);
 81         ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
 82 
 83         return sprintf(buf, "%d\n", ret);
 84 }
 85 
 86 static ssize_t show_label(struct device *dev,
 87                           struct device_attribute *attr, char *buf)
 88 {
 89         int channel = to_sensor_dev_attr(attr)->index;
 90 
 91         return sprintf(buf, "%s\n", input_names[channel]);
 92 }
 93 
 94 #define WM831X_VOLTAGE(id, name) \
 95         static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
 96                                   NULL, name)
 97 
 98 #define WM831X_NAMED_VOLTAGE(id, name) \
 99         WM831X_VOLTAGE(id, name); \
100         static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
101                                   NULL, name)
102 
103 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
104 
105 WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
106 WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
107 WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
108 WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
109 
110 WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
111 WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
112 WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
113 WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
114 WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
115 
116 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
117                           WM831X_AUX_CHIP_TEMP);
118 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
119                           WM831X_AUX_CHIP_TEMP);
120 /*
121  * Report as a voltage since conversion depends on external components
122  * and that's what the ABI wants.
123  */
124 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
125                           WM831X_AUX_BATT_TEMP);
126 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
127                           WM831X_AUX_BATT_TEMP);
128 
129 static struct attribute *wm831x_attributes[] = {
130         &dev_attr_name.attr,
131 
132         &sensor_dev_attr_in0_input.dev_attr.attr,
133         &sensor_dev_attr_in1_input.dev_attr.attr,
134         &sensor_dev_attr_in2_input.dev_attr.attr,
135         &sensor_dev_attr_in3_input.dev_attr.attr,
136 
137         &sensor_dev_attr_in4_input.dev_attr.attr,
138         &sensor_dev_attr_in4_label.dev_attr.attr,
139         &sensor_dev_attr_in5_input.dev_attr.attr,
140         &sensor_dev_attr_in5_label.dev_attr.attr,
141         &sensor_dev_attr_in6_input.dev_attr.attr,
142         &sensor_dev_attr_in6_label.dev_attr.attr,
143         &sensor_dev_attr_in7_input.dev_attr.attr,
144         &sensor_dev_attr_in7_label.dev_attr.attr,
145         &sensor_dev_attr_in8_input.dev_attr.attr,
146         &sensor_dev_attr_in8_label.dev_attr.attr,
147 
148         &sensor_dev_attr_temp1_input.dev_attr.attr,
149         &sensor_dev_attr_temp1_label.dev_attr.attr,
150         &sensor_dev_attr_temp2_input.dev_attr.attr,
151         &sensor_dev_attr_temp2_label.dev_attr.attr,
152 
153         NULL
154 };
155 
156 static const struct attribute_group wm831x_attr_group = {
157         .attrs  = wm831x_attributes,
158 };
159 
160 static int wm831x_hwmon_probe(struct platform_device *pdev)
161 {
162         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
163         struct wm831x_hwmon *hwmon;
164         int ret;
165 
166         hwmon = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_hwmon),
167                              GFP_KERNEL);
168         if (!hwmon)
169                 return -ENOMEM;
170 
171         hwmon->wm831x = wm831x;
172 
173         ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group);
174         if (ret)
175                 return ret;
176 
177         hwmon->classdev = hwmon_device_register(&pdev->dev);
178         if (IS_ERR(hwmon->classdev)) {
179                 ret = PTR_ERR(hwmon->classdev);
180                 goto err_sysfs;
181         }
182 
183         platform_set_drvdata(pdev, hwmon);
184 
185         return 0;
186 
187 err_sysfs:
188         sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
189         return ret;
190 }
191 
192 static int wm831x_hwmon_remove(struct platform_device *pdev)
193 {
194         struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev);
195 
196         hwmon_device_unregister(hwmon->classdev);
197         sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
198 
199         return 0;
200 }
201 
202 static struct platform_driver wm831x_hwmon_driver = {
203         .probe = wm831x_hwmon_probe,
204         .remove = wm831x_hwmon_remove,
205         .driver = {
206                 .name = "wm831x-hwmon",
207                 .owner = THIS_MODULE,
208         },
209 };
210 
211 module_platform_driver(wm831x_hwmon_driver);
212 
213 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
214 MODULE_DESCRIPTION("WM831x Hardware Monitoring");
215 MODULE_LICENSE("GPL");
216 MODULE_ALIAS("platform:wm831x-hwmon");
217 

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