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         if (strict_strtoul(buf, 10, &val))
 130                 return -EINVAL;
 131
 132         if (val < 4096)
 133                 val = 1;
 134         else if (val < 65536)
 135                 val = 2;
 136         else
 137                 return -ERANGE;
 138
 139         pm_runtime_get_sync(dev);
 140
 141         /* Make sure nobody else reads/modifies/writes 0x81 while we
 142            are active */
 143         mutex_lock(&data->mutex);
 144
 145         ret_val = i2c_smbus_read_byte_data(client, 0x81);
 146         if (ret_val < 0)
 147                 goto fail;
 148
 149         /* Reset the bits before setting them */
 150         ret_val = ret_val & 0xFA;
 151
 152         if (val == 1) /* Setting detection range up to 4k LUX */
 153                 ret_val = (ret_val | 0x01);
 154         else /* Setting detection range up to 64k LUX*/
 155                 ret_val = (ret_val | 0x00);
 156
 157         ret_val = i2c_smbus_write_byte_data(client, 0x81, ret_val);
 158
 159         if (ret_val >= 0) {
 160                 /* All OK */
 161                 mutex_unlock(&data->mutex);
 162                 pm_runtime_put_sync(dev);
 163                 return count;
 164         }
 165 fail:
 166         mutex_unlock(&data->mutex);
 167         pm_runtime_put_sync(dev);
 168         return ret_val;
 169 }
 170
 171 static int als_set_power_state(struct i2c_client *client, bool on_off)
 172 {
 173         int ret_val;
 174         struct als_data *data = i2c_get_clientdata(client);
 175
 176         mutex_lock(&data->mutex);
 177         ret_val = i2c_smbus_read_byte_data(client, 0x80);
 178         if (ret_val < 0)
 179                 goto fail;
 180         if (on_off)
 181                 ret_val = ret_val | 0x01;
 182         else
 183                 ret_val = ret_val & 0xFE;
 184         ret_val = i2c_smbus_write_byte_data(client, 0x80, ret_val);
 185 fail:
 186         mutex_unlock(&data->mutex);
 187         return ret_val;
 188 }
 189
 190 static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
 191         als_sensing_range_show, als_sensing_range_store);
 192 static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux0_input_data_show, NULL);
 193
 194 static struct attribute *mid_att_als[] = {
 195         &dev_attr_lux0_sensor_range.attr,
 196         &dev_attr_lux0_input.attr,
 197         NULL
 198 };
 199
 200 static struct attribute_group m_als_gr = {
 201         .name = "apds9802als",
 202         .attrs = mid_att_als
 203 };
 204
 205 static int als_set_default_config(struct i2c_client *client)
 206 {
 207         int ret_val;
 208         /* Write the command and then switch on */
 209         ret_val = i2c_smbus_write_byte_data(client, 0x80, 0x01);
 210         if (ret_val < 0) {
 211                 dev_err(&client->dev, "failed default switch on write\n");
 212                 return ret_val;
 213         }
 214         /* detection range: 1~64K Lux, maunal measurement */
 215         ret_val = i2c_smbus_write_byte_data(client, 0x81, 0x08);
 216         if (ret_val < 0)
 217                 dev_err(&client->dev, "failed default LUX on write\n");
 218
 219         /*  We always get 0 for the 1st measurement after system power on,
 220          *  so make sure it is finished before user asks for data.
 221          */
 222         als_wait_for_data_ready(&client->dev);
 223
 224         return ret_val;
 225 }
 226
 227 static int apds9802als_probe(struct i2c_client *client,
 228                              const struct i2c_device_id *id)
 229 {
 230         int res;
 231         struct als_data *data;
 232
 233         data = kzalloc(sizeof(struct als_data), GFP_KERNEL);
 234         if (data == NULL) {
 235                 dev_err(&client->dev, "Memory allocation failed\n");
 236                 return -ENOMEM;
 237         }
 238         i2c_set_clientdata(client, data);
 239         res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
 240         if (res) {
 241                 dev_err(&client->dev, "device create file failed\n");
 242                 goto als_error1;
 243         }
 244         dev_info(&client->dev, "ALS chip found\n");
 245         als_set_default_config(client);
 246         mutex_init(&data->mutex);
 247
 248         pm_runtime_set_active(&client->dev);
 249         pm_runtime_enable(&client->dev);
 250
 251         return res;
 252 als_error1:
 253         kfree(data);
 254         return res;
 255 }
 256
 257 static int apds9802als_remove(struct i2c_client *client)
 258 {
 259         struct als_data *data = i2c_get_clientdata(client);
 260
 261         pm_runtime_get_sync(&client->dev);
 262
 263         als_set_power_state(client, false);
 264         sysfs_remove_group(&client->dev.kobj, &m_als_gr);
 265
 266         pm_runtime_disable(&client->dev);
 267         pm_runtime_set_suspended(&client->dev);
 268         pm_runtime_put_noidle(&client->dev);
 269
 270         kfree(data);
 271         return 0;
 272 }
 273
 274 #ifdef CONFIG_PM
 275
 276 static int apds9802als_suspend(struct device *dev)
 277 {
 278         struct i2c_client *client = to_i2c_client(dev);
 279
 280         als_set_power_state(client, false);
 281         return 0;
 282 }
 283
 284 static int apds9802als_resume(struct device *dev)
 285 {
 286         struct i2c_client *client = to_i2c_client(dev);
 287
 288         als_set_power_state(client, true);
 289         return 0;
 290 }
 291
 292 static UNIVERSAL_DEV_PM_OPS(apds9802als_pm_ops, apds9802als_suspend,
 293         apds9802als_resume, NULL);
 294
 295 #define APDS9802ALS_PM_OPS (&apds9802als_pm_ops)
 296
 297 #else   /* CONFIG_PM */
 298 #define APDS9802ALS_PM_OPS NULL
 299 #endif  /* CONFIG_PM */
 300
 301 static struct i2c_device_id apds9802als_id[] = {
 302         { DRIVER_NAME, 0 },
 303         { }
 304 };
 305
 306 MODULE_DEVICE_TABLE(i2c, apds9802als_id);
 307
 308 static struct i2c_driver apds9802als_driver = {
 309         .driver = {
 310                 .name = DRIVER_NAME,
 311                 .pm = APDS9802ALS_PM_OPS,
 312         },
 313         .probe = apds9802als_probe,
 314         .remove = apds9802als_remove,
 315         .id_table = apds9802als_id,
 316 };
 317
 318 module_i2c_driver(apds9802als_driver);
 319
 320 MODULE_AUTHOR("Anantha Narayanan <Anantha.Narayanan@intel.com");
 321 MODULE_DESCRIPTION("Avago apds9802als ALS Driver");
 322 MODULE_LICENSE("GPL v2");