drivers/misc/isl29020.c

   1 /*
   2  * isl29020.c - Intersil  ALS Driver
   3  *
   4  * Copyright (C) 2008 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  * Data sheet at: http://www.intersil.com/data/fn/fn6505.pdf
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/i2c.h>
  29 #include <linux/err.h>
  30 #include <linux/delay.h>
  31 #include <linux/sysfs.h>
  32 #include <linux/pm_runtime.h>
  33
  34 static DEFINE_MUTEX(mutex);
  35
  36 static ssize_t als_sensing_range_show(struct device *dev,
  37                         struct device_attribute *attr,  char *buf)
  38 {
  39         struct i2c_client *client = to_i2c_client(dev);
  40         int  val;
  41
  42         val = i2c_smbus_read_byte_data(client, 0x00);
  43
  44         if (val < 0)
  45                 return val;
  46         return sprintf(buf, "%d000\n", 1 << (2 * (val & 3)));
  47
  48 }
  49
  50 static ssize_t als_lux_input_data_show(struct device *dev,
  51                         struct device_attribute *attr, char *buf)
  52 {
  53         struct i2c_client *client = to_i2c_client(dev);
  54         int ret_val, val;
  55         unsigned long int lux;
  56         int temp;
  57
  58         pm_runtime_get_sync(dev);
  59         msleep(100);
  60
  61         mutex_lock(&mutex);
  62         temp = i2c_smbus_read_byte_data(client, 0x02); /* MSB data */
  63         if (temp < 0) {
  64                 pm_runtime_put_sync(dev);
  65                 mutex_unlock(&mutex);
  66                 return temp;
  67         }
  68
  69         ret_val = i2c_smbus_read_byte_data(client, 0x01); /* LSB data */
  70         mutex_unlock(&mutex);
  71
  72         if (ret_val < 0) {
  73                 pm_runtime_put_sync(dev);
  74                 return ret_val;
  75         }
  76
  77         ret_val |= temp << 8;
  78         val = i2c_smbus_read_byte_data(client, 0x00);
  79         pm_runtime_put_sync(dev);
  80         if (val < 0)
  81                 return val;
  82         lux = ((((1 << (2 * (val & 3))))*1000) * ret_val) / 65536;
  83         return sprintf(buf, "%ld\n", lux);
  84 }
  85
  86 static ssize_t als_sensing_range_store(struct device *dev,
  87                 struct device_attribute *attr, const  char *buf, size_t count)
  88 {
  89         struct i2c_client *client = to_i2c_client(dev);
  90         int ret_val;
  91         unsigned long val;
  92
  93         if (strict_strtoul(buf, 10, &val))
  94                 return -EINVAL;
  95         if (val < 1 || val > 64000)
  96                 return -EINVAL;
  97
  98         /* Pick the smallest sensor range that will meet our requirements */
  99         if (val <= 1000)
 100                 val = 1;
 101         else if (val <= 4000)
 102                 val = 2;
 103         else if (val <= 16000)
 104                 val = 3;
 105         else
 106                 val = 4;
 107
 108         ret_val = i2c_smbus_read_byte_data(client, 0x00);
 109         if (ret_val < 0)
 110                 return ret_val;
 111
 112         ret_val &= 0xFC; /*reset the bit before setting them */
 113         ret_val |= val - 1;
 114         ret_val = i2c_smbus_write_byte_data(client, 0x00, ret_val);
 115
 116         if (ret_val < 0)
 117                 return ret_val;
 118         return count;
 119 }
 120
 121 static void als_set_power_state(struct i2c_client *client, int enable)
 122 {
 123         int ret_val;
 124
 125         ret_val = i2c_smbus_read_byte_data(client, 0x00);
 126         if (ret_val < 0)
 127                 return;
 128
 129         if (enable)
 130                 ret_val |= 0x80;
 131         else
 132                 ret_val &= 0x7F;
 133
 134         i2c_smbus_write_byte_data(client, 0x00, ret_val);
 135 }
 136
 137 static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
 138         als_sensing_range_show, als_sensing_range_store);
 139 static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux_input_data_show, NULL);
 140
 141 static struct attribute *mid_att_als[] = {
 142         &dev_attr_lux0_sensor_range.attr,
 143         &dev_attr_lux0_input.attr,
 144         NULL
 145 };
 146
 147 static struct attribute_group m_als_gr = {
 148         .name = "isl29020",
 149         .attrs = mid_att_als
 150 };
 151
 152 static int als_set_default_config(struct i2c_client *client)
 153 {
 154         int retval;
 155
 156         retval = i2c_smbus_write_byte_data(client, 0x00, 0xc0);
 157         if (retval < 0) {
 158                 dev_err(&client->dev, "default write failed.");
 159                 return retval;
 160         }
 161         return 0;
 162 }
 163
 164 static int  isl29020_probe(struct i2c_client *client,
 165                                         const struct i2c_device_id *id)
 166 {
 167         int res;
 168
 169         res = als_set_default_config(client);
 170         if (res <  0)
 171                 return res;
 172
 173         res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
 174         if (res) {
 175                 dev_err(&client->dev, "isl29020: device create file failed\n");
 176                 return res;
 177         }
 178         dev_info(&client->dev, "%s isl29020: ALS chip found\n", client->name);
 179         als_set_power_state(client, 0);
 180         pm_runtime_enable(&client->dev);
 181         return res;
 182 }
 183
 184 static int isl29020_remove(struct i2c_client *client)
 185 {
 186         sysfs_remove_group(&client->dev.kobj, &m_als_gr);
 187         return 0;
 188 }
 189
 190 static struct i2c_device_id isl29020_id[] = {
 191         { "isl29020", 0 },
 192         { }
 193 };
 194
 195 MODULE_DEVICE_TABLE(i2c, isl29020_id);
 196
 197 #ifdef CONFIG_PM
 198
 199 static int isl29020_runtime_suspend(struct device *dev)
 200 {
 201         struct i2c_client *client = to_i2c_client(dev);
 202         als_set_power_state(client, 0);
 203         return 0;
 204 }
 205
 206 static int isl29020_runtime_resume(struct device *dev)
 207 {
 208         struct i2c_client *client = to_i2c_client(dev);
 209         als_set_power_state(client, 1);
 210         return 0;
 211 }
 212
 213 static const struct dev_pm_ops isl29020_pm_ops = {
 214         .runtime_suspend = isl29020_runtime_suspend,
 215         .runtime_resume = isl29020_runtime_resume,
 216 };
 217
 218 #define ISL29020_PM_OPS (&isl29020_pm_ops)
 219 #else   /* CONFIG_PM */
 220 #define ISL29020_PM_OPS NULL
 221 #endif  /* CONFIG_PM */
 222
 223 static struct i2c_driver isl29020_driver = {
 224         .driver = {
 225                 .name = "isl29020",
 226                 .pm = ISL29020_PM_OPS,
 227         },
 228         .probe = isl29020_probe,
 229         .remove = isl29020_remove,
 230         .id_table = isl29020_id,
 231 };
 232
 233 module_i2c_driver(isl29020_driver);
 234
 235 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com>");
 236 MODULE_DESCRIPTION("Intersil isl29020 ALS Driver");
 237 MODULE_LICENSE("GPL v2");