xref: /linux/drivers/misc/isl29020.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 	ret_val = kstrtoul(buf, 10, &val);
94 	if (ret_val)
95 		return ret_val;
96 
97 	if (val < 1 || val > 64000)
98 		return -EINVAL;
99 
100 	/* Pick the smallest sensor range that will meet our requirements */
101 	if (val <= 1000)
102 		val = 1;
103 	else if (val <= 4000)
104 		val = 2;
105 	else if (val <= 16000)
106 		val = 3;
107 	else
108 		val = 4;
109 
110 	ret_val = i2c_smbus_read_byte_data(client, 0x00);
111 	if (ret_val < 0)
112 		return ret_val;
113 
114 	ret_val &= 0xFC; /*reset the bit before setting them */
115 	ret_val |= val - 1;
116 	ret_val = i2c_smbus_write_byte_data(client, 0x00, ret_val);
117 
118 	if (ret_val < 0)
119 		return ret_val;
120 	return count;
121 }
122 
123 static void als_set_power_state(struct i2c_client *client, int enable)
124 {
125 	int ret_val;
126 
127 	ret_val = i2c_smbus_read_byte_data(client, 0x00);
128 	if (ret_val < 0)
129 		return;
130 
131 	if (enable)
132 		ret_val |= 0x80;
133 	else
134 		ret_val &= 0x7F;
135 
136 	i2c_smbus_write_byte_data(client, 0x00, ret_val);
137 }
138 
139 static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
140 	als_sensing_range_show, als_sensing_range_store);
141 static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux_input_data_show, NULL);
142 
143 static struct attribute *mid_att_als[] = {
144 	&dev_attr_lux0_sensor_range.attr,
145 	&dev_attr_lux0_input.attr,
146 	NULL
147 };
148 
149 static struct attribute_group m_als_gr = {
150 	.name = "isl29020",
151 	.attrs = mid_att_als
152 };
153 
154 static int als_set_default_config(struct i2c_client *client)
155 {
156 	int retval;
157 
158 	retval = i2c_smbus_write_byte_data(client, 0x00, 0xc0);
159 	if (retval < 0) {
160 		dev_err(&client->dev, "default write failed.");
161 		return retval;
162 	}
163 	return 0;
164 }
165 
166 static int  isl29020_probe(struct i2c_client *client,
167 					const struct i2c_device_id *id)
168 {
169 	int res;
170 
171 	res = als_set_default_config(client);
172 	if (res <  0)
173 		return res;
174 
175 	res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
176 	if (res) {
177 		dev_err(&client->dev, "isl29020: device create file failed\n");
178 		return res;
179 	}
180 	dev_info(&client->dev, "%s isl29020: ALS chip found\n", client->name);
181 	als_set_power_state(client, 0);
182 	pm_runtime_enable(&client->dev);
183 	return res;
184 }
185 
186 static int isl29020_remove(struct i2c_client *client)
187 {
188 	sysfs_remove_group(&client->dev.kobj, &m_als_gr);
189 	return 0;
190 }
191 
192 static struct i2c_device_id isl29020_id[] = {
193 	{ "isl29020", 0 },
194 	{ }
195 };
196 
197 MODULE_DEVICE_TABLE(i2c, isl29020_id);
198 
199 #ifdef CONFIG_PM
200 
201 static int isl29020_runtime_suspend(struct device *dev)
202 {
203 	struct i2c_client *client = to_i2c_client(dev);
204 	als_set_power_state(client, 0);
205 	return 0;
206 }
207 
208 static int isl29020_runtime_resume(struct device *dev)
209 {
210 	struct i2c_client *client = to_i2c_client(dev);
211 	als_set_power_state(client, 1);
212 	return 0;
213 }
214 
215 static const struct dev_pm_ops isl29020_pm_ops = {
216 	.runtime_suspend = isl29020_runtime_suspend,
217 	.runtime_resume = isl29020_runtime_resume,
218 };
219 
220 #define ISL29020_PM_OPS (&isl29020_pm_ops)
221 #else	/* CONFIG_PM */
222 #define ISL29020_PM_OPS NULL
223 #endif	/* CONFIG_PM */
224 
225 static struct i2c_driver isl29020_driver = {
226 	.driver = {
227 		.name = "isl29020",
228 		.pm = ISL29020_PM_OPS,
229 	},
230 	.probe = isl29020_probe,
231 	.remove = isl29020_remove,
232 	.id_table = isl29020_id,
233 };
234 
235 module_i2c_driver(isl29020_driver);
236 
237 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com>");
238 MODULE_DESCRIPTION("Intersil isl29020 ALS Driver");
239 MODULE_LICENSE("GPL v2");
240