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7efe15f2 H |
1 | /* |
2 | * bh1780gli.c | |
3 | * ROHM Ambient Light Sensor Driver | |
4 | * | |
5 | * Copyright (C) 2010 Texas Instruments | |
6 | * Author: Hemanth V <hemanthv@ti.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License version 2 as published by | |
10 | * the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
15 | * more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along with | |
18 | * this program. If not, see <http://www.gnu.org/licenses/>. | |
19 | */ | |
20 | #include <linux/i2c.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/mutex.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/delay.h> | |
25 | ||
26 | #define BH1780_REG_CONTROL 0x80 | |
27 | #define BH1780_REG_PARTID 0x8A | |
28 | #define BH1780_REG_MANFID 0x8B | |
29 | #define BH1780_REG_DLOW 0x8C | |
30 | #define BH1780_REG_DHIGH 0x8D | |
31 | ||
32 | #define BH1780_REVMASK (0xf) | |
33 | #define BH1780_POWMASK (0x3) | |
34 | #define BH1780_POFF (0x0) | |
35 | #define BH1780_PON (0x3) | |
36 | ||
37 | /* power on settling time in ms */ | |
38 | #define BH1780_PON_DELAY 2 | |
39 | ||
40 | struct bh1780_data { | |
41 | struct i2c_client *client; | |
42 | int power_state; | |
43 | /* lock for sysfs operations */ | |
44 | struct mutex lock; | |
45 | }; | |
46 | ||
47 | static int bh1780_write(struct bh1780_data *ddata, u8 reg, u8 val, char *msg) | |
48 | { | |
49 | int ret = i2c_smbus_write_byte_data(ddata->client, reg, val); | |
50 | if (ret < 0) | |
51 | dev_err(&ddata->client->dev, | |
52 | "i2c_smbus_write_byte_data failed error %d\ | |
53 | Register (%s)\n", ret, msg); | |
54 | return ret; | |
55 | } | |
56 | ||
57 | static int bh1780_read(struct bh1780_data *ddata, u8 reg, char *msg) | |
58 | { | |
59 | int ret = i2c_smbus_read_byte_data(ddata->client, reg); | |
60 | if (ret < 0) | |
61 | dev_err(&ddata->client->dev, | |
62 | "i2c_smbus_read_byte_data failed error %d\ | |
63 | Register (%s)\n", ret, msg); | |
64 | return ret; | |
65 | } | |
66 | ||
67 | static ssize_t bh1780_show_lux(struct device *dev, | |
68 | struct device_attribute *attr, char *buf) | |
69 | { | |
70 | struct platform_device *pdev = to_platform_device(dev); | |
71 | struct bh1780_data *ddata = platform_get_drvdata(pdev); | |
72 | int lsb, msb; | |
73 | ||
74 | lsb = bh1780_read(ddata, BH1780_REG_DLOW, "DLOW"); | |
75 | if (lsb < 0) | |
76 | return lsb; | |
77 | ||
78 | msb = bh1780_read(ddata, BH1780_REG_DHIGH, "DHIGH"); | |
79 | if (msb < 0) | |
80 | return msb; | |
81 | ||
82 | return sprintf(buf, "%d\n", (msb << 8) | lsb); | |
83 | } | |
84 | ||
85 | static ssize_t bh1780_show_power_state(struct device *dev, | |
86 | struct device_attribute *attr, | |
87 | char *buf) | |
88 | { | |
89 | struct platform_device *pdev = to_platform_device(dev); | |
90 | struct bh1780_data *ddata = platform_get_drvdata(pdev); | |
91 | int state; | |
92 | ||
93 | state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL"); | |
94 | if (state < 0) | |
95 | return state; | |
96 | ||
97 | return sprintf(buf, "%d\n", state & BH1780_POWMASK); | |
98 | } | |
99 | ||
100 | static ssize_t bh1780_store_power_state(struct device *dev, | |
101 | struct device_attribute *attr, | |
102 | const char *buf, size_t count) | |
103 | { | |
104 | struct platform_device *pdev = to_platform_device(dev); | |
105 | struct bh1780_data *ddata = platform_get_drvdata(pdev); | |
106 | unsigned long val; | |
107 | int error; | |
108 | ||
109 | error = strict_strtoul(buf, 0, &val); | |
110 | if (error) | |
111 | return error; | |
112 | ||
113 | if (val < BH1780_POFF || val > BH1780_PON) | |
114 | return -EINVAL; | |
115 | ||
116 | mutex_lock(&ddata->lock); | |
117 | ||
118 | error = bh1780_write(ddata, BH1780_REG_CONTROL, val, "CONTROL"); | |
119 | if (error < 0) { | |
120 | mutex_unlock(&ddata->lock); | |
121 | return error; | |
122 | } | |
123 | ||
124 | msleep(BH1780_PON_DELAY); | |
125 | ddata->power_state = val; | |
126 | mutex_unlock(&ddata->lock); | |
127 | ||
128 | return count; | |
129 | } | |
130 | ||
131 | static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL); | |
132 | ||
133 | static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, | |
134 | bh1780_show_power_state, bh1780_store_power_state); | |
135 | ||
136 | static struct attribute *bh1780_attributes[] = { | |
137 | &dev_attr_power_state.attr, | |
138 | &dev_attr_lux.attr, | |
139 | NULL | |
140 | }; | |
141 | ||
142 | static const struct attribute_group bh1780_attr_group = { | |
143 | .attrs = bh1780_attributes, | |
144 | }; | |
145 | ||
146 | static int __devinit bh1780_probe(struct i2c_client *client, | |
147 | const struct i2c_device_id *id) | |
148 | { | |
149 | int ret; | |
150 | struct bh1780_data *ddata = NULL; | |
151 | struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); | |
152 | ||
153 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) { | |
154 | ret = -EIO; | |
155 | goto err_op_failed; | |
156 | } | |
157 | ||
158 | ddata = kzalloc(sizeof(struct bh1780_data), GFP_KERNEL); | |
159 | if (ddata == NULL) { | |
160 | ret = -ENOMEM; | |
161 | goto err_op_failed; | |
162 | } | |
163 | ||
164 | ddata->client = client; | |
165 | i2c_set_clientdata(client, ddata); | |
166 | ||
167 | ret = bh1780_read(ddata, BH1780_REG_PARTID, "PART ID"); | |
168 | if (ret < 0) | |
169 | goto err_op_failed; | |
170 | ||
171 | dev_info(&client->dev, "Ambient Light Sensor, Rev : %d\n", | |
172 | (ret & BH1780_REVMASK)); | |
173 | ||
174 | mutex_init(&ddata->lock); | |
175 | ||
176 | ret = sysfs_create_group(&client->dev.kobj, &bh1780_attr_group); | |
177 | if (ret) | |
178 | goto err_op_failed; | |
179 | ||
180 | return 0; | |
181 | ||
182 | err_op_failed: | |
183 | kfree(ddata); | |
184 | return ret; | |
185 | } | |
186 | ||
187 | static int __devexit bh1780_remove(struct i2c_client *client) | |
188 | { | |
189 | struct bh1780_data *ddata; | |
190 | ||
191 | ddata = i2c_get_clientdata(client); | |
192 | sysfs_remove_group(&client->dev.kobj, &bh1780_attr_group); | |
7efe15f2 H |
193 | kfree(ddata); |
194 | ||
195 | return 0; | |
196 | } | |
197 | ||
198 | #ifdef CONFIG_PM | |
199 | static int bh1780_suspend(struct i2c_client *client, pm_message_t mesg) | |
200 | { | |
201 | struct bh1780_data *ddata; | |
202 | int state, ret; | |
203 | ||
204 | ddata = i2c_get_clientdata(client); | |
205 | state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL"); | |
206 | if (state < 0) | |
207 | return state; | |
208 | ||
209 | ddata->power_state = state & BH1780_POWMASK; | |
210 | ||
211 | ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF, | |
212 | "CONTROL"); | |
213 | ||
214 | if (ret < 0) | |
215 | return ret; | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
220 | static int bh1780_resume(struct i2c_client *client) | |
221 | { | |
222 | struct bh1780_data *ddata; | |
223 | int state, ret; | |
224 | ||
225 | ddata = i2c_get_clientdata(client); | |
226 | state = ddata->power_state; | |
227 | ||
228 | ret = bh1780_write(ddata, BH1780_REG_CONTROL, state, | |
229 | "CONTROL"); | |
230 | ||
231 | if (ret < 0) | |
232 | return ret; | |
233 | ||
234 | return 0; | |
235 | } | |
236 | #else | |
237 | #define bh1780_suspend NULL | |
238 | #define bh1780_resume NULL | |
239 | #endif /* CONFIG_PM */ | |
240 | ||
241 | static const struct i2c_device_id bh1780_id[] = { | |
242 | { "bh1780", 0 }, | |
243 | { }, | |
244 | }; | |
245 | ||
246 | static struct i2c_driver bh1780_driver = { | |
247 | .probe = bh1780_probe, | |
248 | .remove = bh1780_remove, | |
249 | .id_table = bh1780_id, | |
250 | .suspend = bh1780_suspend, | |
251 | .resume = bh1780_resume, | |
252 | .driver = { | |
253 | .name = "bh1780" | |
254 | }, | |
255 | }; | |
256 | ||
257 | static int __init bh1780_init(void) | |
258 | { | |
259 | return i2c_add_driver(&bh1780_driver); | |
260 | } | |
261 | ||
262 | static void __exit bh1780_exit(void) | |
263 | { | |
264 | i2c_del_driver(&bh1780_driver); | |
265 | } | |
266 | ||
267 | module_init(bh1780_init) | |
268 | module_exit(bh1780_exit) | |
269 | ||
270 | MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver"); | |
271 | MODULE_LICENSE("GPL"); | |
272 | MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>"); |