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isl29020.c
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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);
66  return temp;
67  }
68 
69  ret_val = i2c_smbus_read_byte_data(client, 0x01); /* LSB data */
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 <[email protected]>");
236 MODULE_DESCRIPTION("Intersil isl29020 ALS Driver");
237 MODULE_LICENSE("GPL v2");