drivers/hwmon/mc13783-adc.c

   1 /*
   2  * Driver for the Freescale Semiconductor MC13783 adc.
   3  *
   4  * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
   5  * Copyright (C) 2009 Sascha Hauer, Pengutronix
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for 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., 51
  18  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <linux/mfd/mc13783-private.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/hwmon-sysfs.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/hwmon.h>
  27 #include <linux/init.h>
  28 #include <linux/err.h>
  29
  30 #define MC13783_ADC_NAME        "mc13783-adc"
  31
  32 struct mc13783_adc_priv {
  33         struct mc13783 *mc13783;
  34         struct device *hwmon_dev;
  35 };
  36
  37 static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute
  38                               *devattr, char *buf)
  39 {
  40         return sprintf(buf, "mc13783_adc\n");
  41 }
  42
  43 static unsigned int mc13783_adc_read(struct device *dev,
  44                 struct device_attribute *devattr)
  45 {
  46         struct platform_device *pdev = to_platform_device(dev);
  47         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
  48         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  49         unsigned int channel = attr->index;
  50         unsigned int sample[4];
  51
  52         mc13783_adc_do_conversion(priv->mc13783, MC13783_ADC_MODE_MULT_CHAN,
  53                         channel, sample);
  54
  55         channel &= 0x7;
  56
  57         return (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
  58 }
  59
  60 static ssize_t mc13783_adc_read_bp(struct device *dev,
  61                 struct device_attribute *devattr, char *buf)
  62 {
  63         unsigned res = mc13783_adc_read(dev, devattr);
  64
  65         /*
  66          * BP (channel 2) reports with offset 2.4V to the actual value to fit
  67          * the input range of the ADC.  unit = 2.25mV = 9/4 mV.
  68          */
  69         res = DIV_ROUND_CLOSEST(res * 9, 4) + 2400;
  70
  71         return sprintf(buf, "%u\n", res);
  72 }
  73
  74 static ssize_t mc13783_adc_read_gp(struct device *dev,
  75                 struct device_attribute *devattr, char *buf)
  76 {
  77         unsigned res = mc13783_adc_read(dev, devattr);
  78
  79         /*
  80          * input range is [0, 2.3V], res has 10 bits, so each bit
  81          * is worth 9/4 mV.
  82          */
  83         res = DIV_ROUND_CLOSEST(res * 9, 4);
  84
  85         return sprintf(buf, "%u\n", res);
  86 }
  87
  88 static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL);
  89 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
  90 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
  91 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
  92 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
  93 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
  94 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
  95 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
  96 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
  97 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
  98 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
  99 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
 100 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
 101
 102 static struct attribute *mc13783_attr[] =
 103 {
 104         &dev_attr_name.attr,
 105         &sensor_dev_attr_in2_input.dev_attr.attr,
 106         &sensor_dev_attr_in5_input.dev_attr.attr,
 107         &sensor_dev_attr_in6_input.dev_attr.attr,
 108         &sensor_dev_attr_in7_input.dev_attr.attr,
 109         &sensor_dev_attr_in8_input.dev_attr.attr,
 110         &sensor_dev_attr_in9_input.dev_attr.attr,
 111         &sensor_dev_attr_in10_input.dev_attr.attr,
 112         &sensor_dev_attr_in11_input.dev_attr.attr,
 113         NULL
 114 };
 115
 116 static const struct attribute_group mc13783_group = {
 117         .attrs = mc13783_attr,
 118 };
 119
 120 /* last four channels may be occupied by the touchscreen */
 121 static struct attribute *mc13783_attr_ts[] =
 122 {
 123         &sensor_dev_attr_in12_input.dev_attr.attr,
 124         &sensor_dev_attr_in13_input.dev_attr.attr,
 125         &sensor_dev_attr_in14_input.dev_attr.attr,
 126         &sensor_dev_attr_in15_input.dev_attr.attr,
 127         NULL
 128 };
 129
 130 static const struct attribute_group mc13783_group_ts = {
 131         .attrs = mc13783_attr_ts,
 132 };
 133
 134 static int __init mc13783_adc_probe(struct platform_device *pdev)
 135 {
 136         struct mc13783_adc_priv *priv;
 137         int ret;
 138
 139         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 140         if (!priv)
 141                 return -ENOMEM;
 142
 143         priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
 144
 145         platform_set_drvdata(pdev, priv);
 146
 147         /* Register sysfs hooks */
 148         ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group);
 149         if (ret)
 150                 goto out_err_create1;
 151
 152         if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
 153                 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
 154                 if (ret)
 155                         goto out_err_create2;
 156
 157         priv->hwmon_dev = hwmon_device_register(&pdev->dev);
 158         if (IS_ERR(priv->hwmon_dev)) {
 159                 ret = PTR_ERR(priv->hwmon_dev);
 160                 dev_err(&pdev->dev,
 161                                 "hwmon_device_register failed with %d.\n", ret);
 162                 goto out_err_register;
 163         }
 164
 165
 166         return 0;
 167
 168 out_err_register:
 169
 170         if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
 171                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
 172 out_err_create2:
 173
 174         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group);
 175 out_err_create1:
 176
 177         platform_set_drvdata(pdev, NULL);
 178         kfree(priv);
 179
 180         return ret;
 181 }
 182
 183 static int __devexit mc13783_adc_remove(struct platform_device *pdev)
 184 {
 185         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
 186
 187         hwmon_device_unregister(&pdev->dev);
 188
 189         if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
 190                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
 191
 192         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group);
 193
 194         platform_set_drvdata(pdev, NULL);
 195         kfree(priv);
 196
 197         return 0;
 198 }
 199
 200 static struct platform_driver mc13783_adc_driver = {
 201         .remove         = __devexit_p(mc13783_adc_remove),
 202         .driver         = {
 203                 .owner  = THIS_MODULE,
 204                 .name   = MC13783_ADC_NAME,
 205         },
 206 };
 207
 208 static int __init mc13783_adc_init(void)
 209 {
 210         return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe);
 211 }
 212
 213 static void __exit mc13783_adc_exit(void)
 214 {
 215         platform_driver_unregister(&mc13783_adc_driver);
 216 }
 217
 218 module_init(mc13783_adc_init);
 219 module_exit(mc13783_adc_exit);
 220
 221 MODULE_DESCRIPTION("MC13783 ADC driver");
 222 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 223 MODULE_LICENSE("GPL");
 224 MODULE_ALIAS("platform:" MC13783_ADC_NAME);