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/slab.h>
26 #include <linux/i2c.h>
27 #include <linux/err.h>
28 #include <linux/delay.h>
29 #include <linux/mutex.h>
30 #include <linux/sysfs.h>
31 #include <linux/pm_runtime.h>
32
33 #define ALS_MIN_RANGE_VAL 1
34 #define ALS_MAX_RANGE_VAL 2
35 #define POWER_STA_ENABLE 1
36 #define POWER_STA_DISABLE 0
37
38 #define DRIVER_NAME "apds9802als"
39
40 struct als_data {
41 struct mutex mutex;
42 };
43
als_sensing_range_show(struct device * dev,struct device_attribute * attr,char * buf)44 static ssize_t als_sensing_range_show(struct device *dev,
45 struct device_attribute *attr, char *buf)
46 {
47 struct i2c_client *client = to_i2c_client(dev);
48 int val;
49
50 val = i2c_smbus_read_byte_data(client, 0x81);
51 if (val < 0)
52 return val;
53 if (val & 1)
54 return sprintf(buf, "4095\n");
55 else
56 return sprintf(buf, "65535\n");
57 }
58
als_wait_for_data_ready(struct device * dev)59 static int als_wait_for_data_ready(struct device *dev)
60 {
61 struct i2c_client *client = to_i2c_client(dev);
62 int ret;
63 int retry = 10;
64
65 do {
66 msleep(30);
67 ret = i2c_smbus_read_byte_data(client, 0x86);
68 } while (!(ret & 0x80) && retry--);
69
70 if (retry < 0) {
71 dev_warn(dev, "timeout waiting for data ready\n");
72 return -ETIMEDOUT;
73 }
74
75 return 0;
76 }
77
als_lux0_input_data_show(struct device * dev,struct device_attribute * attr,char * buf)78 static ssize_t als_lux0_input_data_show(struct device *dev,
79 struct device_attribute *attr, char *buf)
80 {
81 struct i2c_client *client = to_i2c_client(dev);
82 struct als_data *data = i2c_get_clientdata(client);
83 int ret_val;
84 int temp;
85
86 /* Protect against parallel reads */
87 pm_runtime_get_sync(dev);
88 mutex_lock(&data->mutex);
89
90 /* clear EOC interrupt status */
91 i2c_smbus_write_byte(client, 0x40);
92 /* start measurement */
93 temp = i2c_smbus_read_byte_data(client, 0x81);
94 i2c_smbus_write_byte_data(client, 0x81, temp | 0x08);
95
96 ret_val = als_wait_for_data_ready(dev);
97 if (ret_val < 0)
98 goto failed;
99
100 temp = i2c_smbus_read_byte_data(client, 0x8C); /* LSB data */
101 if (temp < 0) {
102 ret_val = temp;
103 goto failed;
104 }
105 ret_val = i2c_smbus_read_byte_data(client, 0x8D); /* MSB data */
106 if (ret_val < 0)
107 goto failed;
108
109 mutex_unlock(&data->mutex);
110 pm_runtime_put_sync(dev);
111
112 temp = (ret_val << 8) | temp;
113 return sprintf(buf, "%d\n", temp);
114 failed:
115 mutex_unlock(&data->mutex);
116 pm_runtime_put_sync(dev);
117 return ret_val;
118 }
119
als_sensing_range_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)120 static ssize_t als_sensing_range_store(struct device *dev,
121 struct device_attribute *attr, const char *buf, size_t count)
122 {
123 struct i2c_client *client = to_i2c_client(dev);
124 struct als_data *data = i2c_get_clientdata(client);
125 int ret_val;
126 unsigned long val;
127
128 ret_val = kstrtoul(buf, 10, &val);
129 if (ret_val)
130 return ret_val;
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
als_set_power_state(struct i2c_client * client,bool on_off)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 const struct attribute_group m_als_gr = {
201 .name = "apds9802als",
202 .attrs = mid_att_als
203 };
204
als_set_default_config(struct i2c_client * client)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
apds9802als_probe(struct i2c_client * client,const struct i2c_device_id * id)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
apds9802als_remove(struct i2c_client * client)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
apds9802als_suspend(struct device * dev)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
apds9802als_resume(struct device * dev)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 const 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");
323