xref: /openbmc/linux/drivers/misc/isl29020.c (revision 4800cd83)
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 	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 static int __init sensor_isl29020_init(void)
234 {
235 	return i2c_add_driver(&isl29020_driver);
236 }
237 
238 static void  __exit sensor_isl29020_exit(void)
239 {
240 	i2c_del_driver(&isl29020_driver);
241 }
242 
243 module_init(sensor_isl29020_init);
244 module_exit(sensor_isl29020_exit);
245 
246 MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com>");
247 MODULE_DESCRIPTION("Intersil isl29020 ALS Driver");
248 MODULE_LICENSE("GPL v2");
249