drivers/misc/apds9802als.c

   1 /*
   2  * apds9802als.c - apds9802  ALS Driver
   3  *
   4  * Copyright (C) 2009 Intel Corp
   5  *
   6  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  20  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  21  *
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/i2c.h>
  28 #include <linux/err.h>
  29 #include <linux/delay.h>
  30 #include <linux/mutex.h>
  31 #include <linux/sysfs.h>
  32 #include <linux/pm_runtime.h>
  33
  34 #define ALS_MIN_RANGE_VAL 1
  35 #define ALS_MAX_RANGE_VAL 2
  36 #define POWER_STA_ENABLE 1
  37 #define POWER_STA_DISABLE 0
  38
  39 #define DRIVER_NAME "apds9802als"
  40
  41 struct als_data {
  42         struct mutex mutex;
  43 };
  44
  45 static ssize_t als_sensing_range_show(struct device *dev,
  46                         struct device_attribute *attr,  char *buf)
  47 {
  48         struct i2c_client *client = to_i2c_client(dev);
  49         int  val;
  50
  51         val = i2c_smbus_read_byte_data(client, 0x81);
  52         if (val < 0)
  53                 return val;
  54         if (val & 1)
  55                 return sprintf(buf, "4095\n");
  56         else
  57                 return sprintf(buf, "65535\n");
  58 }
  59
  60 static int als_wait_for_data_ready(struct device *dev)
  61 {
  62         struct i2c_client *client = to_i2c_client(dev);
  63         int ret;
  64         int retry = 10;
  65
  66         do {
  67                 msleep(30);
  68                 ret = i2c_smbus_read_byte_data(client, 0x86);
  69         } while (!(ret & 0x80) && retry--);
  70
  71         if (retry < 0) {
  72                 dev_warn(dev, "timeout waiting for data ready\n");
  73                 return -ETIMEDOUT;
  74         }
  75
  76         return 0;
  77 }
  78
  79 static ssize_t als_lux0_input_data_show(struct device *dev,
  80                         struct device_attribute *attr, char *buf)
  81 {
  82         struct i2c_client *client = to_i2c_client(dev);
  83         struct als_data *data = i2c_get_clientdata(client);
  84         int ret_val;
  85         int temp;
  86
  87         /* Protect against parallel reads */
  88         pm_runtime_get_sync(dev);
  89         mutex_lock(&data->mutex);
  90
  91         /* clear EOC interrupt status */
  92         i2c_smbus_write_byte(client, 0x40);
  93         /* start measurement */
  94         temp = i2c_smbus_read_byte_data(client, 0x81);
  95         i2c_smbus_write_byte_data(client, 0x81, temp | 0x08);
  96
  97         ret_val = als_wait_for_data_ready(dev);
  98         if (ret_val < 0)
  99                 goto failed;
 100
 101         temp = i2c_smbus_read_byte_data(client, 0x8C); /* LSB data */
 102         if (temp < 0) {
 103                 ret_val = temp;
 104                 goto failed;
 105         }
 106         ret_val = i2c_smbus_read_byte_data(client, 0x8D); /* MSB data */
 107         if (ret_val < 0)
 108                 goto failed;
 109
 110         mutex_unlock(&data->mutex);
 111         pm_runtime_put_sync(dev);
 112
 113         temp = (ret_val << 8) | temp;
 114         return sprintf(buf, "%d\n", temp);
 115 failed:
 116         mutex_unlock(&data->mutex);
 117         pm_runtime_put_sync(dev);
 118         return ret_val;
 119 }
 120
 121 static ssize_t als_sensing_range_store(struct device *dev,
 122                 struct device_attribute *attr, const  char *buf, size_t count)
 123 {
 124         struct i2c_client *client = to_i2c_client(dev);
 125         struct als_data *data = i2c_get_clientdata(client);
 126         int ret_val;
 127         unsigned long val;
 128
 129         ret_val = kstrtoul(buf, 10, &val);
 130         if (ret_val)
 131                 return ret_val;
 132
 133         if (val < 4096)
 134                 val = 1;
 135         else if (val < 65536)
 136                 val = 2;
 137         else
 138                 return -ERANGE;
 139
 140         pm_runtime_get_sync(dev);
 141
 142         /* Make sure nobody else reads/modifies/writes 0x81 while we
 143            are active */
 144         mutex_lock(&data->mutex);
 145
 146         ret_val = i2c_smbus_read_byte_data(client, 0x81);
 147         if (ret_val < 0)
 148                 goto fail;
 149
 150         /* Reset the bits before setting them */
 151         ret_val = ret_val & 0xFA;
 152
 153         if (val == 1) /* Setting detection range up to 4k LUX */
 154                 ret_val = (ret_val | 0x01);
 155         else /* Setting detection range up to 64k LUX*/
 156                 ret_val = (ret_val | 0x00);
 157
 158         ret_val = i2c_smbus_write_byte_data(client, 0x81, ret_val);
 159
 160         if (ret_val >= 0) {
 161                 /* All OK */
 162                 mutex_unlock(&data->mutex);
 163                 pm_runtime_put_sync(dev);
 164                 return count;
 165         }
 166 fail:
 167         mutex_unlock(&data->mutex);
 168         pm_runtime_put_sync(dev);
 169         return ret_val;
 170 }
 171
 172 static int als_set_power_state(struct i2c_client *client, bool on_off)
 173 {
 174         int ret_val;
 175         struct als_data *data = i2c_get_clientdata(client);
 176
 177         mutex_lock(&data->mutex);
 178         ret_val = i2c_smbus_read_byte_data(client, 0x80);
 179         if (ret_val < 0)
 180                 goto fail;
 181         if (on_off)
 182                 ret_val = ret_val | 0x01;
 183         else
 184                 ret_val = ret_val & 0xFE;
 185         ret_val = i2c_smbus_write_byte_data(client, 0x80, ret_val);
 186 fail:
 187         mutex_unlock(&data->mutex);
 188         return ret_val;
 189 }
 190
 191 static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
 192         als_sensing_range_show, als_sensing_range_store);
 193 static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux0_input_data_show, NULL);
 194
 195 static struct attribute *mid_att_als[] = {
 196         &dev_attr_lux0_sensor_range.attr,
 197         &dev_attr_lux0_input.attr,
 198         NULL
 199 };
 200
 201 static struct attribute_group m_als_gr = {
 202         .name = "apds9802als",
 203         .attrs = mid_att_als
 204 };
 205
 206 static int als_set_default_config(struct i2c_client *client)
 207 {
 208         int ret_val;
 209         /* Write the command and then switch on */
 210         ret_val = i2c_smbus_write_byte_data(client, 0x80, 0x01);
 211         if (ret_val < 0) {
 212                 dev_err(&client->dev, "failed default switch on write\n");
 213                 return ret_val;
 214         }
 215         /* detection range: 1~64K Lux, maunal measurement */
 216         ret_val = i2c_smbus_write_byte_data(client, 0x81, 0x08);
 217         if (ret_val < 0)
 218                 dev_err(&client->dev, "failed default LUX on write\n");
 219
 220         /*  We always get 0 for the 1st measurement after system power on,
 221          *  so make sure it is finished before user asks for data.
 222          */
 223         als_wait_for_data_ready(&client->dev);
 224
 225         return ret_val;
 226 }
 227
 228 static int apds9802als_probe(struct i2c_client *client,
 229                              const struct i2c_device_id *id)
 230 {
 231         int res;
 232         struct als_data *data;
 233
 234         data = kzalloc(sizeof(struct als_data), GFP_KERNEL);
 235         if (data == NULL) {
 236                 dev_err(&client->dev, "Memory allocation failed\n");
 237                 return -ENOMEM;
 238         }
 239         i2c_set_clientdata(client, data);
 240         res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
 241         if (res) {
 242                 dev_err(&client->dev, "device create file failed\n");
 243                 goto als_error1;
 244         }
 245         dev_info(&client->dev, "ALS chip found\n");
 246         als_set_default_config(client);
 247         mutex_init(&data->mutex);
 248
 249         pm_runtime_set_active(&client->dev);
 250         pm_runtime_enable(&client->dev);
 251
 252         return res;
 253 als_error1:
 254         kfree(data);
 255         return res;
 256 }
 257
 258 static int apds9802als_remove(struct i2c_client *client)
 259 {
 260         struct als_data *data = i2c_get_clientdata(client);
 261
 262         pm_runtime_get_sync(&client->dev);
 263
 264         als_set_power_state(client, false);
 265         sysfs_remove_group(&client->dev.kobj, &m_als_gr);
 266
 267         pm_runtime_disable(&client->dev);
 268         pm_runtime_set_suspended(&client->dev);
 269         pm_runtime_put_noidle(&client->dev);
 270
 271         kfree(data);
 272         return 0;
 273 }
 274
 275 #ifdef CONFIG_PM
 276
 277 static int apds9802als_suspend(struct device *dev)
 278 {
 279         struct i2c_client *client = to_i2c_client(dev);
 280
 281         als_set_power_state(client, false);
 282         return 0;
 283 }
 284
 285 static int apds9802als_resume(struct device *dev)
 286 {
 287         struct i2c_client *client = to_i2c_client(dev);
 288
 289         als_set_power_state(client, true);
 290         return 0;
 291 }
 292
 293 static UNIVERSAL_DEV_PM_OPS(apds9802als_pm_ops, apds9802als_suspend,
 294         apds9802als_resume, NULL);
 295
 296 #define APDS9802ALS_PM_OPS (&apds9802als_pm_ops)
 297
 298 #else   /* CONFIG_PM */
 299 #define APDS9802ALS_PM_OPS NULL
 300 #endif  /* CONFIG_PM */
 301
 302 static struct i2c_device_id apds9802als_id[] = {
 303         { DRIVER_NAME, 0 },
 304         { }
 305 };
 306
 307 MODULE_DEVICE_TABLE(i2c, apds9802als_id);
 308
 309 static struct i2c_driver apds9802als_driver = {
 310         .driver = {
 311                 .name = DRIVER_NAME,
 312                 .pm = APDS9802ALS_PM_OPS,
 313         },
 314         .probe = apds9802als_probe,
 315         .remove = apds9802als_remove,
 316         .id_table = apds9802als_id,
 317 };
 318
 319 module_i2c_driver(apds9802als_driver);
 320
 321 MODULE_AUTHOR("Anantha Narayanan <Anantha.Narayanan@intel.com");
 322 MODULE_DESCRIPTION("Avago apds9802als ALS Driver");
 323 MODULE_LICENSE("GPL v2");