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/mod_devicetable.h>
  27 #include <linux/hwmon.h>
  28 #include <linux/slab.h>
  29 #include <linux/init.h>
  30 #include <linux/err.h>
  31
  32 #define DRIVER_NAME     "mc13783-adc"
  33
  34 /* platform device id driver data */
  35 #define MC13783_ADC_16CHANS     1
  36 #define MC13783_ADC_BPDIV2      2
  37
  38 struct mc13783_adc_priv {
  39         struct mc13xxx *mc13xxx;
  40         struct device *hwmon_dev;
  41         char name[PLATFORM_NAME_SIZE];
  42 };
  43
  44 static ssize_t name_show(struct device *dev, struct device_attribute *devattr,
  45                          char *buf)
  46 {
  47         struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
  48
  49         return sprintf(buf, "%s\n", priv->name);
  50 }
  51
  52 static int mc13783_adc_read(struct device *dev,
  53                 struct device_attribute *devattr, unsigned int *val)
  54 {
  55         struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
  56         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  57         unsigned int channel = attr->index;
  58         unsigned int sample[4];
  59         int ret;
  60
  61         ret = mc13xxx_adc_do_conversion(priv->mc13xxx,
  62                         MC13XXX_ADC_MODE_MULT_CHAN,
  63                         channel, 0, 0, sample);
  64         if (ret)
  65                 return ret;
  66
  67         /* ADIN7 subchannels */
  68         if (channel >= 16)
  69                 channel = 7;
  70
  71         channel &= 0x7;
  72
  73         *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
  74
  75         return 0;
  76 }
  77
  78 static ssize_t mc13783_adc_read_bp(struct device *dev,
  79                 struct device_attribute *devattr, char *buf)
  80 {
  81         unsigned val;
  82         struct platform_device *pdev = to_platform_device(dev);
  83         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
  84         int ret = mc13783_adc_read(dev, devattr, &val);
  85
  86         if (ret)
  87                 return ret;
  88
  89         if (driver_data & MC13783_ADC_BPDIV2)
  90                 val = DIV_ROUND_CLOSEST(val * 9, 2);
  91         else
  92                 /*
  93                  * BP (channel 2) reports with offset 2.4V to the actual value
  94                  * to fit the input range of the ADC.  unit = 2.25mV = 9/4 mV.
  95                  */
  96                 val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;
  97
  98         return sprintf(buf, "%u\n", val);
  99 }
 100
 101 static ssize_t mc13783_adc_read_gp(struct device *dev,
 102                 struct device_attribute *devattr, char *buf)
 103 {
 104         unsigned val;
 105         int ret = mc13783_adc_read(dev, devattr, &val);
 106
 107         if (ret)
 108                 return ret;
 109
 110         /*
 111          * input range is [0, 2.3V], val has 10 bits, so each bit
 112          * is worth 9/4 mV.
 113          */
 114         val = DIV_ROUND_CLOSEST(val * 9, 4);
 115
 116         return sprintf(buf, "%u\n", val);
 117 }
 118
 119 static ssize_t mc13783_adc_read_uid(struct device *dev,
 120                 struct device_attribute *devattr, char *buf)
 121 {
 122         unsigned int val;
 123         struct platform_device *pdev = to_platform_device(dev);
 124         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
 125         int ret = mc13783_adc_read(dev, devattr, &val);
 126
 127         if (ret)
 128                 return ret;
 129
 130         if (driver_data & MC13783_ADC_BPDIV2)
 131                 /* MC13892 have 1/2 divider, input range is [0, 4.800V] */
 132                 val = DIV_ROUND_CLOSEST(val * 4800, 1024);
 133         else
 134                 /* MC13783 have 0.9 divider, input range is [0, 2.555V] */
 135                 val = DIV_ROUND_CLOSEST(val * 2555, 1024);
 136
 137         return sprintf(buf, "%u\n", val);
 138 }
 139
 140 static ssize_t mc13783_adc_read_temp(struct device *dev,
 141                 struct device_attribute *devattr, char *buf)
 142 {
 143         unsigned int val;
 144         struct platform_device *pdev = to_platform_device(dev);
 145         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
 146         int ret = mc13783_adc_read(dev, devattr, &val);
 147
 148         if (ret)
 149                 return ret;
 150
 151         if (driver_data & MC13783_ADC_BPDIV2) {
 152                 /*
 153                  * MC13892:
 154                  * Die Temperature Read Out Code at 25C 680
 155                  * Temperature change per LSB +0.4244C
 156                  */
 157                 ret = DIV_ROUND_CLOSEST(-2635920 + val * 4244, 10);
 158         } else {
 159                 /*
 160                  * MC13783:
 161                  * Die Temperature Read Out Code at 25C 282
 162                  * Temperature change per LSB -1.14C
 163                  */
 164                 ret = 346480 - 1140 * val;
 165         }
 166
 167         return sprintf(buf, "%d\n", ret);
 168 }
 169
 170 static DEVICE_ATTR_RO(name);
 171 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
 172 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
 173 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
 174 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
 175 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
 176 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
 177 static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
 178 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
 179 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
 180 static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
 181 static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
 182 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
 183 static SENSOR_DEVICE_ATTR(in16_input, S_IRUGO, mc13783_adc_read_uid, NULL, 16);
 184 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
 185                           mc13783_adc_read_temp, NULL, 17);
 186
 187 static struct attribute *mc13783_attr_base[] = {
 188         &dev_attr_name.attr,
 189         &sensor_dev_attr_in2_input.dev_attr.attr,
 190         &sensor_dev_attr_in5_input.dev_attr.attr,
 191         &sensor_dev_attr_in6_input.dev_attr.attr,
 192         &sensor_dev_attr_in7_input.dev_attr.attr,
 193         &sensor_dev_attr_in16_input.dev_attr.attr,
 194         &sensor_dev_attr_temp1_input.dev_attr.attr,
 195         NULL
 196 };
 197
 198 static const struct attribute_group mc13783_group_base = {
 199         .attrs = mc13783_attr_base,
 200 };
 201
 202 /* these are only used if MC13783_ADC_16CHANS is provided in driver data */
 203 static struct attribute *mc13783_attr_16chans[] = {
 204         &sensor_dev_attr_in8_input.dev_attr.attr,
 205         &sensor_dev_attr_in9_input.dev_attr.attr,
 206         &sensor_dev_attr_in10_input.dev_attr.attr,
 207         &sensor_dev_attr_in11_input.dev_attr.attr,
 208         NULL
 209 };
 210
 211 static const struct attribute_group mc13783_group_16chans = {
 212         .attrs = mc13783_attr_16chans,
 213 };
 214
 215 /* last four channels may be occupied by the touchscreen */
 216 static struct attribute *mc13783_attr_ts[] = {
 217         &sensor_dev_attr_in12_input.dev_attr.attr,
 218         &sensor_dev_attr_in13_input.dev_attr.attr,
 219         &sensor_dev_attr_in14_input.dev_attr.attr,
 220         &sensor_dev_attr_in15_input.dev_attr.attr,
 221         NULL
 222 };
 223
 224 static const struct attribute_group mc13783_group_ts = {
 225         .attrs = mc13783_attr_ts,
 226 };
 227
 228 static int mc13783_adc_use_touchscreen(struct platform_device *pdev)
 229 {
 230         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
 231         unsigned flags = mc13xxx_get_flags(priv->mc13xxx);
 232
 233         return flags & MC13XXX_USE_TOUCHSCREEN;
 234 }
 235
 236 static int __init mc13783_adc_probe(struct platform_device *pdev)
 237 {
 238         struct mc13783_adc_priv *priv;
 239         int ret;
 240         const struct platform_device_id *id = platform_get_device_id(pdev);
 241         char *dash;
 242
 243         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 244         if (!priv)
 245                 return -ENOMEM;
 246
 247         priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
 248         snprintf(priv->name, ARRAY_SIZE(priv->name), "%s", id->name);
 249         dash = strchr(priv->name, '-');
 250         if (dash)
 251                 *dash = '\0';
 252
 253         platform_set_drvdata(pdev, priv);
 254
 255         /* Register sysfs hooks */
 256         ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_base);
 257         if (ret)
 258                 return ret;
 259
 260         if (id->driver_data & MC13783_ADC_16CHANS) {
 261                 ret = sysfs_create_group(&pdev->dev.kobj,
 262                                 &mc13783_group_16chans);
 263                 if (ret)
 264                         goto out_err_create_16chans;
 265         }
 266
 267         if (!mc13783_adc_use_touchscreen(pdev)) {
 268                 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
 269                 if (ret)
 270                         goto out_err_create_ts;
 271         }
 272
 273         priv->hwmon_dev = hwmon_device_register(&pdev->dev);
 274         if (IS_ERR(priv->hwmon_dev)) {
 275                 ret = PTR_ERR(priv->hwmon_dev);
 276                 dev_err(&pdev->dev,
 277                                 "hwmon_device_register failed with %d.\n", ret);
 278                 goto out_err_register;
 279         }
 280
 281         return 0;
 282
 283 out_err_register:
 284
 285         if (!mc13783_adc_use_touchscreen(pdev))
 286                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
 287 out_err_create_ts:
 288
 289         if (id->driver_data & MC13783_ADC_16CHANS)
 290                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
 291 out_err_create_16chans:
 292
 293         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
 294         return ret;
 295 }
 296
 297 static int mc13783_adc_remove(struct platform_device *pdev)
 298 {
 299         struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
 300         kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
 301
 302         hwmon_device_unregister(priv->hwmon_dev);
 303
 304         if (!mc13783_adc_use_touchscreen(pdev))
 305                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
 306
 307         if (driver_data & MC13783_ADC_16CHANS)
 308                 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
 309
 310         sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
 311
 312         return 0;
 313 }
 314
 315 static const struct platform_device_id mc13783_adc_idtable[] = {
 316         {
 317                 .name = "mc13783-adc",
 318                 .driver_data = MC13783_ADC_16CHANS,
 319         }, {
 320                 .name = "mc13892-adc",
 321                 .driver_data = MC13783_ADC_BPDIV2,
 322         }, {
 323                 /* sentinel */
 324         }
 325 };
 326 MODULE_DEVICE_TABLE(platform, mc13783_adc_idtable);
 327
 328 static struct platform_driver mc13783_adc_driver = {
 329         .remove         = mc13783_adc_remove,
 330         .driver         = {
 331                 .name   = DRIVER_NAME,
 332         },
 333         .id_table       = mc13783_adc_idtable,
 334 };
 335
 336 module_platform_driver_probe(mc13783_adc_driver, mc13783_adc_probe);
 337
 338 MODULE_DESCRIPTION("MC13783 ADC driver");
 339 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
 340 MODULE_LICENSE("GPL");