summaryrefslogtreecommitdiff
path: root/drivers/iio/light/cm3605.c
blob: c721b69d50950e37ddb4fe5796f2ac1d2dc386f1 (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
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
// SPDX-License-Identifier: GPL-2.0-only
/*
 * CM3605 Ambient Light and Proximity Sensor
 *
 * Copyright (C) 2016 Linaro Ltd.
 * Author: Linus Walleij <linus.walleij@linaro.org>
 *
 * This hardware was found in the very first Nexus One handset from Google/HTC
 * and an early endavour into mobile light and proximity sensors.
 */

#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/iio/consumer.h> /* To get our ADC channel */
#include <linux/iio/types.h> /* To deal with our ADC channel */
#include <linux/init.h>
#include <linux/leds.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/math64.h>
#include <linux/pm.h>

#define CM3605_PROX_CHANNEL 0
#define CM3605_ALS_CHANNEL 1
#define CM3605_AOUT_TYP_MAX_MV 1550
/* It should not go above 1.650V according to the data sheet */
#define CM3605_AOUT_MAX_MV 1650

/**
 * struct cm3605 - CM3605 state
 * @dev: pointer to parent device
 * @vdd: regulator controlling VDD
 * @aset: sleep enable GPIO, high = sleep
 * @aout: IIO ADC channel to convert the AOUT signal
 * @als_max: maximum LUX detection (depends on RSET)
 * @dir: proximity direction: start as FALLING
 * @led: trigger for the infrared LED used by the proximity sensor
 */
struct cm3605 {
	struct device *dev;
	struct regulator *vdd;
	struct gpio_desc *aset;
	struct iio_channel *aout;
	s32 als_max;
	enum iio_event_direction dir;
	struct led_trigger *led;
};

static irqreturn_t cm3605_prox_irq(int irq, void *d)
{
	struct iio_dev *indio_dev = d;
	struct cm3605 *cm3605 = iio_priv(indio_dev);
	u64 ev;

	ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, CM3605_PROX_CHANNEL,
				  IIO_EV_TYPE_THRESH, cm3605->dir);
	iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));

	/* Invert the edge for each event */
	if (cm3605->dir == IIO_EV_DIR_RISING)
		cm3605->dir = IIO_EV_DIR_FALLING;
	else
		cm3605->dir = IIO_EV_DIR_RISING;

	return IRQ_HANDLED;
}

static int cm3605_get_lux(struct cm3605 *cm3605)
{
	int ret, res;
	s64 lux;

	ret = iio_read_channel_processed(cm3605->aout, &res);
	if (ret < 0)
		return ret;

	dev_dbg(cm3605->dev, "read %d mV from ADC\n", res);

	/*
	 * AOUT has an offset of ~30mV then linear at dark
	 * then goes from 2.54 up to 650 LUX yielding 1.55V
	 * (1550 mV) so scale the returned value to this interval
	 * using simple linear interpolation.
	 */
	if (res < 30)
		return 0;
	if (res > CM3605_AOUT_MAX_MV)
		dev_err(cm3605->dev, "device out of range\n");

	/* Remove bias */
	lux = res - 30;

	/* Linear interpolation between 0 and ALS typ max */
	lux *= cm3605->als_max;
	lux = div64_s64(lux, CM3605_AOUT_TYP_MAX_MV);

	return lux;
}

static int cm3605_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val, int *val2, long mask)
{
	struct cm3605 *cm3605 = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		switch (chan->type) {
		case IIO_LIGHT:
			ret = cm3605_get_lux(cm3605);
			if (ret < 0)
				return ret;
			*val = ret;
			return IIO_VAL_INT;
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static const struct iio_info cm3605_info = {
	.read_raw = cm3605_read_raw,
};

static const struct iio_event_spec cm3605_events[] = {
	{
		.type = IIO_EV_TYPE_THRESH,
		.dir = IIO_EV_DIR_EITHER,
		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
	},
};

static const struct iio_chan_spec cm3605_channels[] = {
	{
		.type = IIO_PROXIMITY,
		.event_spec = cm3605_events,
		.num_event_specs = ARRAY_SIZE(cm3605_events),
	},
	{
		.type = IIO_LIGHT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.channel = CM3605_ALS_CHANNEL,
	},
};

static int cm3605_probe(struct platform_device *pdev)
{
	struct cm3605 *cm3605;
	struct iio_dev *indio_dev;
	struct device *dev = &pdev->dev;
	enum iio_chan_type ch_type;
	u32 rset;
	int irq;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*cm3605));
	if (!indio_dev)
		return -ENOMEM;
	platform_set_drvdata(pdev, indio_dev);

	cm3605 = iio_priv(indio_dev);
	cm3605->dev = dev;
	cm3605->dir = IIO_EV_DIR_FALLING;

	ret = device_property_read_u32(dev, "capella,aset-resistance-ohms", &rset);
	if (ret) {
		dev_info(dev, "no RSET specified, assuming 100K\n");
		rset = 100000;
	}
	switch (rset) {
	case 50000:
		cm3605->als_max = 650;
		break;
	case 100000:
		cm3605->als_max = 300;
		break;
	case 300000:
		cm3605->als_max = 100;
		break;
	case 600000:
		cm3605->als_max = 50;
		break;
	default:
		dev_info(dev, "non-standard resistance\n");
		return -EINVAL;
	}

	cm3605->aout = devm_iio_channel_get(dev, "aout");
	if (IS_ERR(cm3605->aout)) {
		ret = PTR_ERR(cm3605->aout);
		ret = (ret == -ENODEV) ? -EPROBE_DEFER : ret;
		return dev_err_probe(dev, ret, "failed to get AOUT ADC channel\n");
	}
	ret = iio_get_channel_type(cm3605->aout, &ch_type);
	if (ret < 0)
		return ret;
	if (ch_type != IIO_VOLTAGE) {
		dev_err(dev, "wrong type of IIO channel specified for AOUT\n");
		return -EINVAL;
	}

	cm3605->vdd = devm_regulator_get(dev, "vdd");
	if (IS_ERR(cm3605->vdd))
		return dev_err_probe(dev, PTR_ERR(cm3605->vdd),
				     "failed to get VDD regulator\n");

	ret = regulator_enable(cm3605->vdd);
	if (ret) {
		dev_err(dev, "failed to enable VDD regulator\n");
		return ret;
	}

	cm3605->aset = devm_gpiod_get(dev, "aset", GPIOD_OUT_HIGH);
	if (IS_ERR(cm3605->aset)) {
		ret = dev_err_probe(dev, PTR_ERR(cm3605->aset), "no ASET GPIO\n");
		goto out_disable_vdd;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return dev_err_probe(dev, irq, "failed to get irq\n");

	ret = devm_request_threaded_irq(dev, irq, cm3605_prox_irq,
					NULL, 0, "cm3605", indio_dev);
	if (ret) {
		dev_err(dev, "unable to request IRQ\n");
		goto out_disable_aset;
	}

	/* Just name the trigger the same as the driver */
	led_trigger_register_simple("cm3605", &cm3605->led);
	led_trigger_event(cm3605->led, LED_FULL);

	indio_dev->info = &cm3605_info;
	indio_dev->name = "cm3605";
	indio_dev->channels = cm3605_channels;
	indio_dev->num_channels = ARRAY_SIZE(cm3605_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = iio_device_register(indio_dev);
	if (ret)
		goto out_remove_trigger;
	dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n",
		 cm3605->als_max);

	return 0;

out_remove_trigger:
	led_trigger_event(cm3605->led, LED_OFF);
	led_trigger_unregister_simple(cm3605->led);
out_disable_aset:
	gpiod_set_value_cansleep(cm3605->aset, 0);
out_disable_vdd:
	regulator_disable(cm3605->vdd);
	return ret;
}

static int cm3605_remove(struct platform_device *pdev)
{
	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
	struct cm3605 *cm3605 = iio_priv(indio_dev);

	led_trigger_event(cm3605->led, LED_OFF);
	led_trigger_unregister_simple(cm3605->led);
	gpiod_set_value_cansleep(cm3605->aset, 0);
	iio_device_unregister(indio_dev);
	regulator_disable(cm3605->vdd);

	return 0;
}

static int cm3605_pm_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct cm3605 *cm3605 = iio_priv(indio_dev);

	led_trigger_event(cm3605->led, LED_OFF);
	regulator_disable(cm3605->vdd);

	return 0;
}

static int cm3605_pm_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct cm3605 *cm3605 = iio_priv(indio_dev);
	int ret;

	ret = regulator_enable(cm3605->vdd);
	if (ret)
		dev_err(dev, "failed to enable regulator in resume path\n");
	led_trigger_event(cm3605->led, LED_FULL);

	return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(cm3605_dev_pm_ops, cm3605_pm_suspend,
				cm3605_pm_resume);

static const struct of_device_id cm3605_of_match[] = {
	{.compatible = "capella,cm3605"},
	{ },
};
MODULE_DEVICE_TABLE(of, cm3605_of_match);

static struct platform_driver cm3605_driver = {
	.driver = {
		.name = "cm3605",
		.of_match_table = cm3605_of_match,
		.pm = pm_sleep_ptr(&cm3605_dev_pm_ops),
	},
	.probe = cm3605_probe,
	.remove = cm3605_remove,
};
module_platform_driver(cm3605_driver);

MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver");
MODULE_LICENSE("GPL");