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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#include <linux/module.h>
26#include <linux/of.h>
27
28#define BH1780_REG_CONTROL 0x80
29#define BH1780_REG_PARTID 0x8A
30#define BH1780_REG_MANFID 0x8B
31#define BH1780_REG_DLOW 0x8C
32#define BH1780_REG_DHIGH 0x8D
33
34#define BH1780_REVMASK (0xf)
35#define BH1780_POWMASK (0x3)
36#define BH1780_POFF (0x0)
37#define BH1780_PON (0x3)
38
39/* power on settling time in ms */
40#define BH1780_PON_DELAY 2
41
42struct bh1780_data {
43 struct i2c_client *client;
44 int power_state;
45 /* lock for sysfs operations */
46 struct mutex lock;
47};
48
49static int bh1780_write(struct bh1780_data *ddata, u8 reg, u8 val, char *msg)
50{
51 int ret = i2c_smbus_write_byte_data(ddata->client, reg, val);
52 if (ret < 0)
53 dev_err(&ddata->client->dev,
54 "i2c_smbus_write_byte_data failed error %d Register (%s)\n",
55 ret, msg);
56 return ret;
57}
58
59static int bh1780_read(struct bh1780_data *ddata, u8 reg, char *msg)
60{
61 int ret = i2c_smbus_read_byte_data(ddata->client, reg);
62 if (ret < 0)
63 dev_err(&ddata->client->dev,
64 "i2c_smbus_read_byte_data failed error %d Register (%s)\n",
65 ret, msg);
66 return ret;
67}
68
69static ssize_t bh1780_show_lux(struct device *dev,
70 struct device_attribute *attr, char *buf)
71{
72 struct platform_device *pdev = to_platform_device(dev);
73 struct bh1780_data *ddata = platform_get_drvdata(pdev);
74 int lsb, msb;
75
76 lsb = bh1780_read(ddata, BH1780_REG_DLOW, "DLOW");
77 if (lsb < 0)
78 return lsb;
79
80 msb = bh1780_read(ddata, BH1780_REG_DHIGH, "DHIGH");
81 if (msb < 0)
82 return msb;
83
84 return sprintf(buf, "%d\n", (msb << 8) | lsb);
85}
86
87static ssize_t bh1780_show_power_state(struct device *dev,
88 struct device_attribute *attr,
89 char *buf)
90{
91 struct platform_device *pdev = to_platform_device(dev);
92 struct bh1780_data *ddata = platform_get_drvdata(pdev);
93 int state;
94
95 state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
96 if (state < 0)
97 return state;
98
99 return sprintf(buf, "%d\n", state & BH1780_POWMASK);
100}
101
102static ssize_t bh1780_store_power_state(struct device *dev,
103 struct device_attribute *attr,
104 const char *buf, size_t count)
105{
106 struct platform_device *pdev = to_platform_device(dev);
107 struct bh1780_data *ddata = platform_get_drvdata(pdev);
108 unsigned long val;
109 int error;
110
111 error = kstrtoul(buf, 0, &val);
112 if (error)
113 return error;
114
115 if (val < BH1780_POFF || val > BH1780_PON)
116 return -EINVAL;
117
118 mutex_lock(&ddata->lock);
119
120 error = bh1780_write(ddata, BH1780_REG_CONTROL, val, "CONTROL");
121 if (error < 0) {
122 mutex_unlock(&ddata->lock);
123 return error;
124 }
125
126 msleep(BH1780_PON_DELAY);
127 ddata->power_state = val;
128 mutex_unlock(&ddata->lock);
129
130 return count;
131}
132
133static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL);
134
135static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
136 bh1780_show_power_state, bh1780_store_power_state);
137
138static struct attribute *bh1780_attributes[] = {
139 &dev_attr_power_state.attr,
140 &dev_attr_lux.attr,
141 NULL
142};
143
144static const struct attribute_group bh1780_attr_group = {
145 .attrs = bh1780_attributes,
146};
147
148static int bh1780_probe(struct i2c_client *client,
149 const struct i2c_device_id *id)
150{
151 int ret;
152 struct bh1780_data *ddata;
153 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
154
155 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
156 return -EIO;
157
158 ddata = devm_kzalloc(&client->dev, sizeof(struct bh1780_data),
159 GFP_KERNEL);
160 if (ddata == NULL)
161 return -ENOMEM;
162
163 ddata->client = client;
164 i2c_set_clientdata(client, ddata);
165
166 ret = bh1780_read(ddata, BH1780_REG_PARTID, "PART ID");
167 if (ret < 0)
168 return ret;
169
170 dev_info(&client->dev, "Ambient Light Sensor, Rev : %d\n",
171 (ret & BH1780_REVMASK));
172
173 mutex_init(&ddata->lock);
174
175 return sysfs_create_group(&client->dev.kobj, &bh1780_attr_group);
176}
177
178static int bh1780_remove(struct i2c_client *client)
179{
180 sysfs_remove_group(&client->dev.kobj, &bh1780_attr_group);
181
182 return 0;
183}
184
185#ifdef CONFIG_PM_SLEEP
186static int bh1780_suspend(struct device *dev)
187{
188 struct bh1780_data *ddata;
189 int state, ret;
190 struct i2c_client *client = to_i2c_client(dev);
191
192 ddata = i2c_get_clientdata(client);
193 state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
194 if (state < 0)
195 return state;
196
197 ddata->power_state = state & BH1780_POWMASK;
198
199 ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF,
200 "CONTROL");
201
202 if (ret < 0)
203 return ret;
204
205 return 0;
206}
207
208static int bh1780_resume(struct device *dev)
209{
210 struct bh1780_data *ddata;
211 int state, ret;
212 struct i2c_client *client = to_i2c_client(dev);
213
214 ddata = i2c_get_clientdata(client);
215 state = ddata->power_state;
216 ret = bh1780_write(ddata, BH1780_REG_CONTROL, state,
217 "CONTROL");
218
219 if (ret < 0)
220 return ret;
221
222 return 0;
223}
224#endif /* CONFIG_PM_SLEEP */
225
226static SIMPLE_DEV_PM_OPS(bh1780_pm, bh1780_suspend, bh1780_resume);
227
228static const struct i2c_device_id bh1780_id[] = {
229 { "bh1780", 0 },
230 { },
231};
232
233MODULE_DEVICE_TABLE(i2c, bh1780_id);
234
235#ifdef CONFIG_OF
236static const struct of_device_id of_bh1780_match[] = {
237 { .compatible = "rohm,bh1780gli", },
238 {},
239};
240
241MODULE_DEVICE_TABLE(of, of_bh1780_match);
242#endif
243
244static struct i2c_driver bh1780_driver = {
245 .probe = bh1780_probe,
246 .remove = bh1780_remove,
247 .id_table = bh1780_id,
248 .driver = {
249 .name = "bh1780",
250 .pm = &bh1780_pm,
251 .of_match_table = of_match_ptr(of_bh1780_match),
252 },
253};
254
255module_i2c_driver(bh1780_driver);
256
257MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
258MODULE_LICENSE("GPL");
259MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");
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
40struct bh1780_data {
41 struct i2c_client *client;
42 int power_state;
43 /* lock for sysfs operations */
44 struct mutex lock;
45};
46
47static 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 Register (%s)\n",
53 ret, msg);
54 return ret;
55}
56
57static 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 Register (%s)\n",
63 ret, msg);
64 return ret;
65}
66
67static 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
85static 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
100static 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
131static DEVICE_ATTR(lux, S_IRUGO, bh1780_show_lux, NULL);
132
133static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
134 bh1780_show_power_state, bh1780_store_power_state);
135
136static struct attribute *bh1780_attributes[] = {
137 &dev_attr_power_state.attr,
138 &dev_attr_lux.attr,
139 NULL
140};
141
142static const struct attribute_group bh1780_attr_group = {
143 .attrs = bh1780_attributes,
144};
145
146static 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
182err_op_failed:
183 kfree(ddata);
184 return ret;
185}
186
187static 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);
193 kfree(ddata);
194
195 return 0;
196}
197
198#ifdef CONFIG_PM
199static int bh1780_suspend(struct device *dev)
200{
201 struct bh1780_data *ddata;
202 int state, ret;
203 struct i2c_client *client = to_i2c_client(dev);
204
205 ddata = i2c_get_clientdata(client);
206 state = bh1780_read(ddata, BH1780_REG_CONTROL, "CONTROL");
207 if (state < 0)
208 return state;
209
210 ddata->power_state = state & BH1780_POWMASK;
211
212 ret = bh1780_write(ddata, BH1780_REG_CONTROL, BH1780_POFF,
213 "CONTROL");
214
215 if (ret < 0)
216 return ret;
217
218 return 0;
219}
220
221static int bh1780_resume(struct device *dev)
222{
223 struct bh1780_data *ddata;
224 int state, ret;
225 struct i2c_client *client = to_i2c_client(dev);
226
227 ddata = i2c_get_clientdata(client);
228 state = ddata->power_state;
229 ret = bh1780_write(ddata, BH1780_REG_CONTROL, state,
230 "CONTROL");
231
232 if (ret < 0)
233 return ret;
234
235 return 0;
236}
237static SIMPLE_DEV_PM_OPS(bh1780_pm, bh1780_suspend, bh1780_resume);
238#define BH1780_PMOPS (&bh1780_pm)
239#else
240#define BH1780_PMOPS NULL
241#endif /* CONFIG_PM */
242
243static const struct i2c_device_id bh1780_id[] = {
244 { "bh1780", 0 },
245 { },
246};
247
248static struct i2c_driver bh1780_driver = {
249 .probe = bh1780_probe,
250 .remove = bh1780_remove,
251 .id_table = bh1780_id,
252 .driver = {
253 .name = "bh1780",
254 .pm = BH1780_PMOPS,
255},
256};
257
258static int __init bh1780_init(void)
259{
260 return i2c_add_driver(&bh1780_driver);
261}
262
263static void __exit bh1780_exit(void)
264{
265 i2c_del_driver(&bh1780_driver);
266}
267
268module_init(bh1780_init)
269module_exit(bh1780_exit)
270
271MODULE_DESCRIPTION("BH1780GLI Ambient Light Sensor Driver");
272MODULE_LICENSE("GPL");
273MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");