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11#include <linux/i2c.h>
12#include <linux/slab.h>
13#include <linux/platform_device.h>
14#include <linux/delay.h>
15#include <linux/module.h>
16#include <linux/mod_devicetable.h>
17#include <linux/pm_runtime.h>
18#include <linux/iio/iio.h>
19#include <linux/iio/sysfs.h>
20#include <linux/bitops.h>
21
22#define BH1780_CMD_BIT BIT(7)
23#define BH1780_REG_CONTROL 0x00
24#define BH1780_REG_PARTID 0x0A
25#define BH1780_REG_MANFID 0x0B
26#define BH1780_REG_DLOW 0x0C
27#define BH1780_REG_DHIGH 0x0D
28
29#define BH1780_REVMASK GENMASK(3,0)
30#define BH1780_POWMASK GENMASK(1,0)
31#define BH1780_POFF (0x0)
32#define BH1780_PON (0x3)
33
34
35#define BH1780_PON_DELAY 2
36
37#define BH1780_INTERVAL 250
38
39struct bh1780_data {
40 struct i2c_client *client;
41};
42
43static int bh1780_write(struct bh1780_data *bh1780, u8 reg, u8 val)
44{
45 int ret = i2c_smbus_write_byte_data(bh1780->client,
46 BH1780_CMD_BIT | reg,
47 val);
48 if (ret < 0)
49 dev_err(&bh1780->client->dev,
50 "i2c_smbus_write_byte_data failed error "
51 "%d, register %01x\n",
52 ret, reg);
53 return ret;
54}
55
56static int bh1780_read(struct bh1780_data *bh1780, u8 reg)
57{
58 int ret = i2c_smbus_read_byte_data(bh1780->client,
59 BH1780_CMD_BIT | reg);
60 if (ret < 0)
61 dev_err(&bh1780->client->dev,
62 "i2c_smbus_read_byte_data failed error "
63 "%d, register %01x\n",
64 ret, reg);
65 return ret;
66}
67
68static int bh1780_read_word(struct bh1780_data *bh1780, u8 reg)
69{
70 int ret = i2c_smbus_read_word_data(bh1780->client,
71 BH1780_CMD_BIT | reg);
72 if (ret < 0)
73 dev_err(&bh1780->client->dev,
74 "i2c_smbus_read_word_data failed error "
75 "%d, register %01x\n",
76 ret, reg);
77 return ret;
78}
79
80static int bh1780_debugfs_reg_access(struct iio_dev *indio_dev,
81 unsigned int reg, unsigned int writeval,
82 unsigned int *readval)
83{
84 struct bh1780_data *bh1780 = iio_priv(indio_dev);
85 int ret;
86
87 if (!readval)
88 return bh1780_write(bh1780, (u8)reg, (u8)writeval);
89
90 ret = bh1780_read(bh1780, (u8)reg);
91 if (ret < 0)
92 return ret;
93
94 *readval = ret;
95
96 return 0;
97}
98
99static int bh1780_read_raw(struct iio_dev *indio_dev,
100 struct iio_chan_spec const *chan,
101 int *val, int *val2, long mask)
102{
103 struct bh1780_data *bh1780 = iio_priv(indio_dev);
104 int value;
105
106 switch (mask) {
107 case IIO_CHAN_INFO_RAW:
108 switch (chan->type) {
109 case IIO_LIGHT:
110 pm_runtime_get_sync(&bh1780->client->dev);
111 value = bh1780_read_word(bh1780, BH1780_REG_DLOW);
112 if (value < 0)
113 return value;
114 pm_runtime_mark_last_busy(&bh1780->client->dev);
115 pm_runtime_put_autosuspend(&bh1780->client->dev);
116 *val = value;
117
118 return IIO_VAL_INT;
119 default:
120 return -EINVAL;
121 }
122 case IIO_CHAN_INFO_INT_TIME:
123 *val = 0;
124 *val2 = BH1780_INTERVAL * 1000;
125 return IIO_VAL_INT_PLUS_MICRO;
126 default:
127 return -EINVAL;
128 }
129}
130
131static const struct iio_info bh1780_info = {
132 .read_raw = bh1780_read_raw,
133 .debugfs_reg_access = bh1780_debugfs_reg_access,
134};
135
136static const struct iio_chan_spec bh1780_channels[] = {
137 {
138 .type = IIO_LIGHT,
139 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
140 BIT(IIO_CHAN_INFO_INT_TIME)
141 }
142};
143
144static int bh1780_probe(struct i2c_client *client,
145 const struct i2c_device_id *id)
146{
147 int ret;
148 struct bh1780_data *bh1780;
149 struct i2c_adapter *adapter = client->adapter;
150 struct iio_dev *indio_dev;
151
152 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
153 return -EIO;
154
155 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*bh1780));
156 if (!indio_dev)
157 return -ENOMEM;
158
159 bh1780 = iio_priv(indio_dev);
160 bh1780->client = client;
161 i2c_set_clientdata(client, indio_dev);
162
163
164 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
165 if (ret < 0)
166 return ret;
167 msleep(BH1780_PON_DELAY);
168 pm_runtime_get_noresume(&client->dev);
169 pm_runtime_set_active(&client->dev);
170 pm_runtime_enable(&client->dev);
171
172 ret = bh1780_read(bh1780, BH1780_REG_PARTID);
173 if (ret < 0)
174 goto out_disable_pm;
175 dev_info(&client->dev,
176 "Ambient Light Sensor, Rev : %lu\n",
177 (ret & BH1780_REVMASK));
178
179
180
181
182
183
184 pm_runtime_set_autosuspend_delay(&client->dev, 5000);
185 pm_runtime_use_autosuspend(&client->dev);
186 pm_runtime_put(&client->dev);
187
188 indio_dev->info = &bh1780_info;
189 indio_dev->name = "bh1780";
190 indio_dev->channels = bh1780_channels;
191 indio_dev->num_channels = ARRAY_SIZE(bh1780_channels);
192 indio_dev->modes = INDIO_DIRECT_MODE;
193
194 ret = iio_device_register(indio_dev);
195 if (ret)
196 goto out_disable_pm;
197 return 0;
198
199out_disable_pm:
200 pm_runtime_put_noidle(&client->dev);
201 pm_runtime_disable(&client->dev);
202 return ret;
203}
204
205static int bh1780_remove(struct i2c_client *client)
206{
207 struct iio_dev *indio_dev = i2c_get_clientdata(client);
208 struct bh1780_data *bh1780 = iio_priv(indio_dev);
209 int ret;
210
211 iio_device_unregister(indio_dev);
212 pm_runtime_get_sync(&client->dev);
213 pm_runtime_put_noidle(&client->dev);
214 pm_runtime_disable(&client->dev);
215 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
216 if (ret < 0) {
217 dev_err(&client->dev, "failed to power off\n");
218 return ret;
219 }
220
221 return 0;
222}
223
224#ifdef CONFIG_PM
225static int bh1780_runtime_suspend(struct device *dev)
226{
227 struct i2c_client *client = to_i2c_client(dev);
228 struct iio_dev *indio_dev = i2c_get_clientdata(client);
229 struct bh1780_data *bh1780 = iio_priv(indio_dev);
230 int ret;
231
232 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
233 if (ret < 0) {
234 dev_err(dev, "failed to runtime suspend\n");
235 return ret;
236 }
237
238 return 0;
239}
240
241static int bh1780_runtime_resume(struct device *dev)
242{
243 struct i2c_client *client = to_i2c_client(dev);
244 struct iio_dev *indio_dev = i2c_get_clientdata(client);
245 struct bh1780_data *bh1780 = iio_priv(indio_dev);
246 int ret;
247
248 ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
249 if (ret < 0) {
250 dev_err(dev, "failed to runtime resume\n");
251 return ret;
252 }
253
254
255 msleep(BH1780_PON_DELAY + BH1780_INTERVAL);
256
257 return 0;
258}
259#endif
260
261static const struct dev_pm_ops bh1780_dev_pm_ops = {
262 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
263 pm_runtime_force_resume)
264 SET_RUNTIME_PM_OPS(bh1780_runtime_suspend,
265 bh1780_runtime_resume, NULL)
266};
267
268static const struct i2c_device_id bh1780_id[] = {
269 { "bh1780", 0 },
270 { },
271};
272
273MODULE_DEVICE_TABLE(i2c, bh1780_id);
274
275static const struct of_device_id of_bh1780_match[] = {
276 { .compatible = "rohm,bh1780gli", },
277 {},
278};
279MODULE_DEVICE_TABLE(of, of_bh1780_match);
280
281static struct i2c_driver bh1780_driver = {
282 .probe = bh1780_probe,
283 .remove = bh1780_remove,
284 .id_table = bh1780_id,
285 .driver = {
286 .name = "bh1780",
287 .pm = &bh1780_dev_pm_ops,
288 .of_match_table = of_bh1780_match,
289 },
290};
291
292module_i2c_driver(bh1780_driver);
293
294MODULE_DESCRIPTION("ROHM BH1780GLI Ambient Light Sensor Driver");
295MODULE_LICENSE("GPL");
296MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
297
