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Hemanth V7efe15f2010-08-09 17:20:25 -07001/*
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>
Paul Gortmakereb12a672011-07-03 15:14:56 -040025#include <linux/module.h>
Hemanth V7efe15f2010-08-09 17:20:25 -070026
27#define BH1780_REG_CONTROL 0x80
28#define BH1780_REG_PARTID 0x8A
29#define BH1780_REG_MANFID 0x8B
30#define BH1780_REG_DLOW 0x8C
31#define BH1780_REG_DHIGH 0x8D
32
33#define BH1780_REVMASK (0xf)
34#define BH1780_POWMASK (0x3)
35#define BH1780_POFF (0x0)
36#define BH1780_PON (0x3)
37
38/* power on settling time in ms */
39#define BH1780_PON_DELAY 2
40
41struct bh1780_data {
42 struct i2c_client *client;
43 int power_state;
44 /* lock for sysfs operations */
45 struct mutex lock;
46};
47
48static int bh1780_write(struct bh1780_data *ddata, u8 reg, u8 val, char *msg)
49{
50 int ret = i2c_smbus_write_byte_data(ddata->client, reg, val);
51 if (ret < 0)
52 dev_err(&ddata->client->dev,
Joe Perches85ee7a12011-04-23 20:38:19 -070053 "i2c_smbus_write_byte_data failed error %d Register (%s)\n",
54 ret, msg);
Hemanth V7efe15f2010-08-09 17:20:25 -070055 return ret;
56}
57
58static int bh1780_read(struct bh1780_data *ddata, u8 reg, char *msg)
59{
60 int ret = i2c_smbus_read_byte_data(ddata->client, reg);
61 if (ret < 0)
62 dev_err(&ddata->client->dev,
Joe Perches85ee7a12011-04-23 20:38:19 -070063 "i2c_smbus_read_byte_data failed error %d Register (%s)\n",
64 ret, msg);
Hemanth V7efe15f2010-08-09 17:20:25 -070065 return ret;
66}
67
68static ssize_t bh1780_show_lux(struct device *dev,
69 struct device_attribute *attr, char *buf)
70{
71 struct platform_device *pdev = to_platform_device(dev);
72 struct bh1780_data *ddata = platform_get_drvdata(pdev);
73 int lsb, msb;
74
75 lsb = bh1780_read(ddata, BH1780_REG_DLOW, "DLOW");
76 if (lsb < 0)
77 return lsb;
78
79 msb = bh1780_read(ddata, BH1780_REG_DHIGH, "DHIGH");
80 if (msb < 0)
81 return msb;
82
83 return sprintf(buf, "%d\n", (msb << 8) | lsb);
84}
85
86static ssize_t bh1780_show_power_state(struct device *dev,
87 struct device_attribute *attr,
88 char *buf)
89{
90 struct platform_device *pdev = to_platform_device(dev);
91 struct bh1780_data *ddata = platform_get_drvdata(pdev);
92 int state;
93
94 state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
95 if (state < 0)
96 return state;
97
98 return sprintf(buf, "%d\n", state & BH1780_POWMASK);
99}
100
101static ssize_t bh1780_store_power_state(struct device *dev,
102 struct device_attribute *attr,
103 const char *buf, size_t count)
104{
105 struct platform_device *pdev = to_platform_device(dev);
106 struct bh1780_data *ddata = platform_get_drvdata(pdev);
107 unsigned long val;
108 int error;
109
110 error = strict_strtoul(buf, 0, &val);
111 if (error)
112 return error;
113
114 if (val < BH1780_POFF || val > BH1780_PON)
115 return -EINVAL;
116
117 mutex_lock(&ddata->lock);
118
119 error = bh1780_write(ddata, BH1780_REG_CONTROL, val, "CONTROL");
120 if (error < 0) {
121 mutex_unlock(&ddata->lock);
122 return error;
123 }
124
125 msleep(BH1780_PON_DELAY);
126 ddata->power_state = val;
127 mutex_unlock(&ddata->lock);
128
129 return count;
130}
131
132static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL);
133
134static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
135 bh1780_show_power_state, bh1780_store_power_state);
136
137static struct attribute *bh1780_attributes[] = {
138 &dev_attr_power_state.attr,
139 &dev_attr_lux.attr,
140 NULL
141};
142
143static const struct attribute_group bh1780_attr_group = {
144 .attrs = bh1780_attributes,
145};
146
147static int __devinit bh1780_probe(struct i2c_client *client,
148 const struct i2c_device_id *id)
149{
150 int ret;
151 struct bh1780_data *ddata = NULL;
152 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
153
154 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) {
155 ret = -EIO;
156 goto err_op_failed;
157 }
158
159 ddata = kzalloc(sizeof(struct bh1780_data), GFP_KERNEL);
160 if (ddata == NULL) {
161 ret = -ENOMEM;
162 goto err_op_failed;
163 }
164
165 ddata->client = client;
166 i2c_set_clientdata(client, ddata);
167
168 ret = bh1780_read(ddata, BH1780_REG_PARTID, "PART ID");
169 if (ret < 0)
170 goto err_op_failed;
171
172 dev_info(&client->dev, "Ambient Light Sensor, Rev : %d\n",
173 (ret & BH1780_REVMASK));
174
175 mutex_init(&ddata->lock);
176
177 ret = sysfs_create_group(&client->dev.kobj, &bh1780_attr_group);
178 if (ret)
179 goto err_op_failed;
180
181 return 0;
182
183err_op_failed:
184 kfree(ddata);
185 return ret;
186}
187
188static int __devexit bh1780_remove(struct i2c_client *client)
189{
190 struct bh1780_data *ddata;
191
192 ddata = i2c_get_clientdata(client);
193 sysfs_remove_group(&client->dev.kobj, &bh1780_attr_group);
Hemanth V7efe15f2010-08-09 17:20:25 -0700194 kfree(ddata);
195
196 return 0;
197}
198
199#ifdef CONFIG_PM
Shubhrajyoti Datta4a7de632011-03-22 16:33:57 -0700200static int bh1780_suspend(struct device *dev)
Hemanth V7efe15f2010-08-09 17:20:25 -0700201{
202 struct bh1780_data *ddata;
203 int state, ret;
Shubhrajyoti Datta4a7de632011-03-22 16:33:57 -0700204 struct i2c_client *client = to_i2c_client(dev);
Hemanth V7efe15f2010-08-09 17:20:25 -0700205
206 ddata = i2c_get_clientdata(client);
207 state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
208 if (state < 0)
209 return state;
210
211 ddata->power_state = state & BH1780_POWMASK;
212
213 ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF,
214 "CONTROL");
215
216 if (ret < 0)
217 return ret;
218
219 return 0;
220}
221
Shubhrajyoti Datta4a7de632011-03-22 16:33:57 -0700222static int bh1780_resume(struct device *dev)
Hemanth V7efe15f2010-08-09 17:20:25 -0700223{
224 struct bh1780_data *ddata;
225 int state, ret;
Shubhrajyoti Datta4a7de632011-03-22 16:33:57 -0700226 struct i2c_client *client = to_i2c_client(dev);
Hemanth V7efe15f2010-08-09 17:20:25 -0700227
228 ddata = i2c_get_clientdata(client);
229 state = ddata->power_state;
Hemanth V7efe15f2010-08-09 17:20:25 -0700230 ret = bh1780_write(ddata, BH1780_REG_CONTROL, state,
231 "CONTROL");
232
233 if (ret < 0)
234 return ret;
235
236 return 0;
237}
Shubhrajyoti Datta4a7de632011-03-22 16:33:57 -0700238static SIMPLE_DEV_PM_OPS(bh1780_pm, bh1780_suspend, bh1780_resume);
239#define BH1780_PMOPS (&bh1780_pm)
Hemanth V7efe15f2010-08-09 17:20:25 -0700240#else
Shubhrajyoti Datta4a7de632011-03-22 16:33:57 -0700241#define BH1780_PMOPS NULL
Hemanth V7efe15f2010-08-09 17:20:25 -0700242#endif /* CONFIG_PM */
243
244static const struct i2c_device_id bh1780_id[] = {
245 { "bh1780", 0 },
246 { },
247};
248
249static struct i2c_driver bh1780_driver = {
250 .probe = bh1780_probe,
251 .remove = bh1780_remove,
252 .id_table = bh1780_id,
Hemanth V7efe15f2010-08-09 17:20:25 -0700253 .driver = {
Shubhrajyoti Datta4a7de632011-03-22 16:33:57 -0700254 .name = "bh1780",
255 .pm = BH1780_PMOPS,
Axel Lina64fe2e2012-01-22 15:36:45 +0800256 },
Hemanth V7efe15f2010-08-09 17:20:25 -0700257};
258
Axel Lina64fe2e2012-01-22 15:36:45 +0800259module_i2c_driver(bh1780_driver);
Hemanth V7efe15f2010-08-09 17:20:25 -0700260
261MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
262MODULE_LICENSE("GPL");
263MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");