drivers/hwmon/mc13783-adc.c

   1 /*
   2  * Driver for the ADC on Freescale Semiconductor MC13783 and MC13892 PMICs.
   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/mc13xxx.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/slab.h>
  28 #include <linux/init.h>
  29 #include <linux/err.h>
  30
  31 #define DRIVER_NAME     "mc13783-adc"
  32
  33 /* platform device id driver data */
  34 #define MC13783_ADC_16CHANS     1
  35 #define MC13783_ADC_BPDIV2      2
  36
  37 struct mc13783_adc_priv {
  38         struct mc13xxx *mc13xxx;
  39         struct device *hwmon_dev;
  40         char name[PLATFORM_NAME_SIZE];
  41 };
  42
  43 static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute
  44                               *devattr, char *buf)
  45 {
  46         struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
  47
  48         return sprintf(buf, "%s\n", priv->name);
  49 }
  50
  51 static int mc13783_adc_read(struct device *dev,
  52                 struct device_attribute *devattr, unsigned int *val)
  53 {
  54         struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
  55         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  56         unsigned int channel = attr->index;
  57         unsigned int sample[4];
  58         int ret;
  59
  60         ret = mc13xxx_adc_do_conversion(priv->mc13xxx,
  61                         MC13XXX_ADC_MODE_MULT_CHAN,
  62                         channel, 0, 0, sample);
  63         if (ret)
  64                 return ret;
  65
  66         channel &= 0x7;
  67
  68         *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
  69
  70         return 0;
  71 }
  72
  73 static ssize_t mc13783_adc_read_bp(struct device *dev,
  74                 struct device_attribute *devattr, char *buf)
  75 {
  76         unsigned val;
  77         struct platform_device *pdev = to_platform_device(dev);
  78         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
  79         int ret = mc13783_adc_read(dev, devattr, &val);
  80
  81         if (ret)
  82                 return ret;
  83
  84         if (driver_data & MC13783_ADC_BPDIV2)
  85                 val = DIV_ROUND_CLOSEST(val * 9, 2);
  86         else
  87                 /*
  88                  * BP (channel 2) reports with offset 2.4V to the actual value
  89                  * to fit the input range of the ADC.  unit = 2.25mV = 9/4 mV.
  90                  */
  91                 val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;
  92
  93         return sprintf(buf, "%u\n", val);
  94 }
  95
  96 static ssize_t mc13783_adc_read_gp(struct device *dev,
  97                 struct device_attribute *devattr, char *buf)
  98 {
  99         unsigned val;
 100         int ret = mc13783_adc_read(dev, devattr, &val);
 101
 102         if (ret)
 103                 return ret;
 104
 105         /*
 106          * input range is [0, 2.3V], val has 10 bits, so each bit
 107          * is worth 9/4 mV.
 108          */
 109         val = DIV_ROUND_CLOSEST(val * 9, 4);
 110
 111         return sprintf(buf, "%u\n", val);
 112 }
 113
 114 static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL);
 115 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
 116 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
 117 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
 118 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
 119 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
 120 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
 121 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
 122 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
 123 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
 124 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
 125 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
 126 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
 127
 128 static struct attribute *mc13783_attr_base[] = {
 129         &dev_attr_name.attr,
 130         &sensor_dev_attr_in2_input.dev_attr.attr,
 131         &sensor_dev_attr_in5_input.dev_attr.attr,
 132         &sensor_dev_attr_in6_input.dev_attr.attr,
 133         &sensor_dev_attr_in7_input.dev_attr.attr,
 134         NULL
 135 };
 136
 137 static const struct attribute_group mc13783_group_base = {
 138         .attrs = mc13783_attr_base,
 139 };
 140
 141 /* these are only used if MC13783_ADC_16CHANS is provided in driver data */
 142 static struct attribute *mc13783_attr_16chans[] = {
 143         &sensor_dev_attr_in8_input.dev_attr.attr,
 144         &sensor_dev_attr_in9_input.dev_attr.attr,
 145         &sensor_dev_attr_in10_input.dev_attr.attr,
 146         &sensor_dev_attr_in11_input.dev_attr.attr,
 147         NULL
 148 };
 149
 150 static const struct attribute_group mc13783_group_16chans = {
 151         .attrs = mc13783_attr_16chans,
 152 };
 153
 154 /* last four channels may be occupied by the touchscreen */
 155 static struct attribute *mc13783_attr_ts[] = {
 156         &sensor_dev_attr_in12_input.dev_attr.attr,
 157         &sensor_dev_attr_in13_input.dev_attr.attr,
 158         &sensor_dev_attr_in14_input.dev_attr.attr,
 159         &sensor_dev_attr_in15_input.dev_attr.attr,
 160         NULL
 161 };
 162
 163 static const struct attribute_group mc13783_group_ts = {
 164         .attrs = mc13783_attr_ts,
 165 };
 166
 167 static int mc13783_adc_use_touchscreen(struct platform_device *pdev)
 168 {
 169         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
 170         unsigned flags = mc13xxx_get_flags(priv->mc13xxx);
 171
 172         return flags & MC13XXX_USE_TOUCHSCREEN;
 173 }
 174
 175 static int __init mc13783_adc_probe(struct platform_device *pdev)
 176 {
 177         struct mc13783_adc_priv *priv;
 178         int ret;
 179         const struct platform_device_id *id = platform_get_device_id(pdev);
 180         char *dash;
 181
 182         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 183         if (!priv)
 184                 return -ENOMEM;
 185
 186         priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
 187         snprintf(priv->name, ARRAY_SIZE(priv->name), "%s", id->name);
 188         dash = strchr(priv->name, '-');
 189         if (dash)
 190                 *dash = '\0';
 191
 192         platform_set_drvdata(pdev, priv);
 193
 194         /* Register sysfs hooks */
 195         ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_base);
 196         if (ret)
 197                 return ret;
 198
 199         if (id->driver_data & MC13783_ADC_16CHANS) {
 200                 ret = sysfs_create_group(&pdev->dev.kobj,
 201                                 &mc13783_group_16chans);
 202                 if (ret)
 203                         goto out_err_create_16chans;
 204         }
 205
 206         if (!mc13783_adc_use_touchscreen(pdev)) {
 207                 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
 208                 if (ret)
 209                         goto out_err_create_ts;
 210         }
 211
 212         priv->hwmon_dev = hwmon_device_register(&pdev->dev);
 213         if (IS_ERR(priv->hwmon_dev)) {
 214                 ret = PTR_ERR(priv->hwmon_dev);
 215                 dev_err(&pdev->dev,
 216                                 "hwmon_device_register failed with %d.\n", ret);
 217                 goto out_err_register;
 218         }
 219
 220         return 0;
 221
 222 out_err_register:
 223
 224         if (!mc13783_adc_use_touchscreen(pdev))
 225                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
 226 out_err_create_ts:
 227
 228         if (id->driver_data & MC13783_ADC_16CHANS)
 229                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
 230 out_err_create_16chans:
 231
 232         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
 233         return ret;
 234 }
 235
 236 static int mc13783_adc_remove(struct platform_device *pdev)
 237 {
 238         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
 239         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
 240
 241         hwmon_device_unregister(priv->hwmon_dev);
 242
 243         if (!mc13783_adc_use_touchscreen(pdev))
 244                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
 245
 246         if (driver_data & MC13783_ADC_16CHANS)
 247                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
 248
 249         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
 250
 251         return 0;
 252 }
 253
 254 static const struct platform_device_id mc13783_adc_idtable[] = {
 255         {
 256                 .name = "mc13783-adc",
 257                 .driver_data = MC13783_ADC_16CHANS,
 258         }, {
 259                 .name = "mc13892-adc",
 260                 .driver_data = MC13783_ADC_BPDIV2,
 261         }, {
 262                 /* sentinel */
 263         }
 264 };
 265 MODULE_DEVICE_TABLE(platform, mc13783_adc_idtable);
 266
 267 static struct platform_driver mc13783_adc_driver = {
 268         .remove         = mc13783_adc_remove,
 269         .driver         = {
 270                 .name   = DRIVER_NAME,
 271         },
 272         .id_table       = mc13783_adc_idtable,
 273 };
 274
 275 module_platform_driver_probe(mc13783_adc_driver, mc13783_adc_probe);
 276
 277 MODULE_DESCRIPTION("MC13783 ADC driver");
 278 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 279 MODULE_LICENSE("GPL");