summaryrefslogtreecommitdiffstats
path: root/drivers/iio/light/bh1780.c
blob: 790d3d6139796c0b5e65e11a9e50ddde258fea08 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ROHM 1780GLI Ambient Light Sensor Driver
 *
 * Copyright (C) 2016 Linaro Ltd.
 * Author: Linus Walleij <linus.walleij@linaro.org>
 * Loosely based on the previous BH1780 ALS misc driver
 * Copyright (C) 2010 Texas Instruments
 * Author: Hemanth V <hemanthv@ti.com>
 */
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/bitops.h>

#define BH1780_CMD_BIT		BIT(7)
#define BH1780_REG_CONTROL	0x00
#define BH1780_REG_PARTID	0x0A
#define BH1780_REG_MANFID	0x0B
#define BH1780_REG_DLOW		0x0C
#define BH1780_REG_DHIGH	0x0D

#define BH1780_REVMASK		GENMASK(3,0)
#define BH1780_POWMASK		GENMASK(1,0)
#define BH1780_POFF		(0x0)
#define BH1780_PON		(0x3)

/* power on settling time in ms */
#define BH1780_PON_DELAY	2
/* max time before value available in ms */
#define BH1780_INTERVAL		250

struct bh1780_data {
	struct i2c_client *client;
};

static int bh1780_write(struct bh1780_data *bh1780, u8 reg, u8 val)
{
	int ret = i2c_smbus_write_byte_data(bh1780->client,
					    BH1780_CMD_BIT | reg,
					    val);
	if (ret < 0)
		dev_err(&bh1780->client->dev,
			"i2c_smbus_write_byte_data failed error "
			"%d, register %01x\n",
			ret, reg);
	return ret;
}

static int bh1780_read(struct bh1780_data *bh1780, u8 reg)
{
	int ret = i2c_smbus_read_byte_data(bh1780->client,
					   BH1780_CMD_BIT | reg);
	if (ret < 0)
		dev_err(&bh1780->client->dev,
			"i2c_smbus_read_byte_data failed error "
			"%d, register %01x\n",
			ret, reg);
	return ret;
}

static int bh1780_read_word(struct bh1780_data *bh1780, u8 reg)
{
	int ret = i2c_smbus_read_word_data(bh1780->client,
					   BH1780_CMD_BIT | reg);
	if (ret < 0)
		dev_err(&bh1780->client->dev,
			"i2c_smbus_read_word_data failed error "
			"%d, register %01x\n",
			ret, reg);
	return ret;
}

static int bh1780_debugfs_reg_access(struct iio_dev *indio_dev,
			      unsigned int reg, unsigned int writeval,
			      unsigned int *readval)
{
	struct bh1780_data *bh1780 = iio_priv(indio_dev);
	int ret;

	if (!readval)
		return bh1780_write(bh1780, (u8)reg, (u8)writeval);

	ret = bh1780_read(bh1780, (u8)reg);
	if (ret < 0)
		return ret;

	*readval = ret;

	return 0;
}

static int bh1780_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val, int *val2, long mask)
{
	struct bh1780_data *bh1780 = iio_priv(indio_dev);
	int value;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		switch (chan->type) {
		case IIO_LIGHT:
			pm_runtime_get_sync(&bh1780->client->dev);
			value = bh1780_read_word(bh1780, BH1780_REG_DLOW);
			if (value < 0)
				return value;
			pm_runtime_mark_last_busy(&bh1780->client->dev);
			pm_runtime_put_autosuspend(&bh1780->client->dev);
			*val = value;

			return IIO_VAL_INT;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_INT_TIME:
		*val = 0;
		*val2 = BH1780_INTERVAL * 1000;
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		return -EINVAL;
	}
}

static const struct iio_info bh1780_info = {
	.read_raw = bh1780_read_raw,
	.debugfs_reg_access = bh1780_debugfs_reg_access,
};

static const struct iio_chan_spec bh1780_channels[] = {
	{
		.type = IIO_LIGHT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_INT_TIME)
	}
};

static int bh1780_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	int ret;
	struct bh1780_data *bh1780;
	struct i2c_adapter *adapter = client->adapter;
	struct iio_dev *indio_dev;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
		return -EIO;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*bh1780));
	if (!indio_dev)
		return -ENOMEM;

	bh1780 = iio_priv(indio_dev);
	bh1780->client = client;
	i2c_set_clientdata(client, indio_dev);

	/* Power up the device */
	ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
	if (ret < 0)
		return ret;
	msleep(BH1780_PON_DELAY);
	pm_runtime_get_noresume(&client->dev);
	pm_runtime_set_active(&client->dev);
	pm_runtime_enable(&client->dev);

	ret = bh1780_read(bh1780, BH1780_REG_PARTID);
	if (ret < 0)
		goto out_disable_pm;
	dev_info(&client->dev,
		 "Ambient Light Sensor, Rev : %lu\n",
		 (ret & BH1780_REVMASK));

	/*
	 * As the device takes 250 ms to even come up with a fresh
	 * measurement after power-on, do not shut it down unnecessarily.
	 * Set autosuspend to a five seconds.
	 */
	pm_runtime_set_autosuspend_delay(&client->dev, 5000);
	pm_runtime_use_autosuspend(&client->dev);
	pm_runtime_put(&client->dev);

	indio_dev->info = &bh1780_info;
	indio_dev->name = "bh1780";
	indio_dev->channels = bh1780_channels;
	indio_dev->num_channels = ARRAY_SIZE(bh1780_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = iio_device_register(indio_dev);
	if (ret)
		goto out_disable_pm;
	return 0;

out_disable_pm:
	pm_runtime_put_noidle(&client->dev);
	pm_runtime_disable(&client->dev);
	return ret;
}

static int bh1780_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct bh1780_data *bh1780 = iio_priv(indio_dev);
	int ret;

	iio_device_unregister(indio_dev);
	pm_runtime_get_sync(&client->dev);
	pm_runtime_put_noidle(&client->dev);
	pm_runtime_disable(&client->dev);
	ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
	if (ret < 0) {
		dev_err(&client->dev, "failed to power off\n");
		return ret;
	}

	return 0;
}

static int bh1780_runtime_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct bh1780_data *bh1780 = iio_priv(indio_dev);
	int ret;

	ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_POFF);
	if (ret < 0) {
		dev_err(dev, "failed to runtime suspend\n");
		return ret;
	}

	return 0;
}

static int bh1780_runtime_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct bh1780_data *bh1780 = iio_priv(indio_dev);
	int ret;

	ret = bh1780_write(bh1780, BH1780_REG_CONTROL, BH1780_PON);
	if (ret < 0) {
		dev_err(dev, "failed to runtime resume\n");
		return ret;
	}

	/* Wait for power on, then for a value to be available */
	msleep(BH1780_PON_DELAY + BH1780_INTERVAL);

	return 0;
}

static DEFINE_RUNTIME_DEV_PM_OPS(bh1780_dev_pm_ops, bh1780_runtime_suspend,
				bh1780_runtime_resume, NULL);

static const struct i2c_device_id bh1780_id[] = {
	{ "bh1780", 0 },
	{ },
};

MODULE_DEVICE_TABLE(i2c, bh1780_id);

static const struct of_device_id of_bh1780_match[] = {
	{ .compatible = "rohm,bh1780gli", },
	{},
};
MODULE_DEVICE_TABLE(of, of_bh1780_match);

static struct i2c_driver bh1780_driver = {
	.probe		= bh1780_probe,
	.remove		= bh1780_remove,
	.id_table	= bh1780_id,
	.driver = {
		.name = "bh1780",
		.pm = pm_ptr(&bh1780_dev_pm_ops),
		.of_match_table = of_bh1780_match,
	},
};

module_i2c_driver(bh1780_driver);

MODULE_DESCRIPTION("ROHM BH1780GLI Ambient Light Sensor Driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");