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
40struct als_data {
41	struct mutex mutex;
42};
43
44static 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
59static 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
78static 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);
114failed:
115	mutex_unlock(&data->mutex);
116	pm_runtime_put_sync(dev);
117	return ret_val;
118}
119
120static 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	}
165fail:
166	mutex_unlock(&data->mutex);
167	pm_runtime_put_sync(dev);
168	return ret_val;
169}
170
171static 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);
185fail:
186	mutex_unlock(&data->mutex);
187	return ret_val;
188}
189
190static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
191	als_sensing_range_show, als_sensing_range_store);
192static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux0_input_data_show, NULL);
193
194static struct attribute *mid_att_als[] = {
195	&dev_attr_lux0_sensor_range.attr,
196	&dev_attr_lux0_input.attr,
197	NULL
198};
199
200static struct attribute_group m_als_gr = {
201	.name = "apds9802als",
202	.attrs = mid_att_als
203};
204
205static 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
227static 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;
252als_error1:
253	kfree(data);
254	return res;
255}
256
257static 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
276static 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
284static 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
292static 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
301static struct i2c_device_id apds9802als_id[] = {
302	{ DRIVER_NAME, 0 },
303	{ }
304};
305
306MODULE_DEVICE_TABLE(i2c, apds9802als_id);
307
308static 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
318module_i2c_driver(apds9802als_driver);
319
320MODULE_AUTHOR("Anantha Narayanan <Anantha.Narayanan@intel.com");
321MODULE_DESCRIPTION("Avago apds9802als ALS Driver");
322MODULE_LICENSE("GPL v2");
323