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