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/slab.h>
27#include <linux/i2c.h>
28#include <linux/err.h>
29#include <linux/delay.h>
30#include <linux/sysfs.h>
31#include <linux/pm_runtime.h>
32
33static DEFINE_MUTEX(mutex);
34
35static ssize_t als_sensing_range_show(struct device *dev,
36			struct device_attribute *attr,  char *buf)
37{
38	struct i2c_client *client = to_i2c_client(dev);
39	int  val;
40
41	val = i2c_smbus_read_byte_data(client, 0x00);
42
43	if (val < 0)
44		return val;
45	return sprintf(buf, "%d000\n", 1 << (2 * (val & 3)));
46
47}
48
49static ssize_t als_lux_input_data_show(struct device *dev,
50			struct device_attribute *attr, char *buf)
51{
52	struct i2c_client *client = to_i2c_client(dev);
53	int ret_val, val;
54	unsigned long int lux;
55	int temp;
56
57	pm_runtime_get_sync(dev);
58	msleep(100);
59
60	mutex_lock(&mutex);
61	temp = i2c_smbus_read_byte_data(client, 0x02); /* MSB data */
62	if (temp < 0) {
63		pm_runtime_put_sync(dev);
64		mutex_unlock(&mutex);
65		return temp;
66	}
67
68	ret_val = i2c_smbus_read_byte_data(client, 0x01); /* LSB data */
69	mutex_unlock(&mutex);
70
71	if (ret_val < 0) {
72		pm_runtime_put_sync(dev);
73		return ret_val;
74	}
75
76	ret_val |= temp << 8;
77	val = i2c_smbus_read_byte_data(client, 0x00);
78	pm_runtime_put_sync(dev);
79	if (val < 0)
80		return val;
81	lux = ((((1 << (2 * (val & 3))))*1000) * ret_val) / 65536;
82	return sprintf(buf, "%ld\n", lux);
83}
84
85static ssize_t als_sensing_range_store(struct device *dev,
86		struct device_attribute *attr, const  char *buf, size_t count)
87{
88	struct i2c_client *client = to_i2c_client(dev);
89	int ret_val;
90	unsigned long val;
91
92	ret_val = kstrtoul(buf, 10, &val);
93	if (ret_val)
94		return ret_val;
95
96	if (val < 1 || val > 64000)
97		return -EINVAL;
98
99	/* Pick the smallest sensor range that will meet our requirements */
100	if (val <= 1000)
101		val = 1;
102	else if (val <= 4000)
103		val = 2;
104	else if (val <= 16000)
105		val = 3;
106	else
107		val = 4;
108
109	ret_val = i2c_smbus_read_byte_data(client, 0x00);
110	if (ret_val < 0)
111		return ret_val;
112
113	ret_val &= 0xFC; /*reset the bit before setting them */
114	ret_val |= val - 1;
115	ret_val = i2c_smbus_write_byte_data(client, 0x00, ret_val);
116
117	if (ret_val < 0)
118		return ret_val;
119	return count;
120}
121
122static void als_set_power_state(struct i2c_client *client, int enable)
123{
124	int ret_val;
125
126	ret_val = i2c_smbus_read_byte_data(client, 0x00);
127	if (ret_val < 0)
128		return;
129
130	if (enable)
131		ret_val |= 0x80;
132	else
133		ret_val &= 0x7F;
134
135	i2c_smbus_write_byte_data(client, 0x00, ret_val);
136}
137
138static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
139	als_sensing_range_show, als_sensing_range_store);
140static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux_input_data_show, NULL);
141
142static struct attribute *mid_att_als[] = {
143	&dev_attr_lux0_sensor_range.attr,
144	&dev_attr_lux0_input.attr,
145	NULL
146};
147
148static struct attribute_group m_als_gr = {
149	.name = "isl29020",
150	.attrs = mid_att_als
151};
152
153static int als_set_default_config(struct i2c_client *client)
154{
155	int retval;
156
157	retval = i2c_smbus_write_byte_data(client, 0x00, 0xc0);
158	if (retval < 0) {
159		dev_err(&client->dev, "default write failed.");
160		return retval;
161	}
162	return 0;
163}
164
165static int  isl29020_probe(struct i2c_client *client,
166					const struct i2c_device_id *id)
167{
168	int res;
169
170	res = als_set_default_config(client);
171	if (res <  0)
172		return res;
173
174	res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
175	if (res) {
176		dev_err(&client->dev, "isl29020: device create file failed\n");
177		return res;
178	}
179	dev_info(&client->dev, "%s isl29020: ALS chip found\n", client->name);
180	als_set_power_state(client, 0);
181	pm_runtime_enable(&client->dev);
182	return res;
183}
184
185static int isl29020_remove(struct i2c_client *client)
186{
187	sysfs_remove_group(&client->dev.kobj, &m_als_gr);
188	return 0;
189}
190
191static struct i2c_device_id isl29020_id[] = {
192	{ "isl29020", 0 },
193	{ }
194};
195
196MODULE_DEVICE_TABLE(i2c, isl29020_id);
197
198#ifdef CONFIG_PM
199
200static int isl29020_runtime_suspend(struct device *dev)
201{
202	struct i2c_client *client = to_i2c_client(dev);
203	als_set_power_state(client, 0);
204	return 0;
205}
206
207static int isl29020_runtime_resume(struct device *dev)
208{
209	struct i2c_client *client = to_i2c_client(dev);
210	als_set_power_state(client, 1);
211	return 0;
212}
213
214static const struct dev_pm_ops isl29020_pm_ops = {
215	.runtime_suspend = isl29020_runtime_suspend,
216	.runtime_resume = isl29020_runtime_resume,
217};
218
219#define ISL29020_PM_OPS (&isl29020_pm_ops)
220#else	/* CONFIG_PM */
221#define ISL29020_PM_OPS NULL
222#endif	/* CONFIG_PM */
223
224static struct i2c_driver isl29020_driver = {
225	.driver = {
226		.name = "isl29020",
227		.pm = ISL29020_PM_OPS,
228	},
229	.probe = isl29020_probe,
230	.remove = isl29020_remove,
231	.id_table = isl29020_id,
232};
233
234module_i2c_driver(isl29020_driver);
235
236MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com>");
237MODULE_DESCRIPTION("Intersil isl29020 ALS Driver");
238MODULE_LICENSE("GPL v2");
239