aboutsummaryrefslogtreecommitdiff
path: root/drivers/iio/adc/viperboard_adc.c
blob: 3be2e35721cc58f53c1691101553d952633b8126 (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
/*
 *  Nano River Technologies viperboard IIO ADC driver
 *
 *  (C) 2012 by Lemonage GmbH
 *  Author: Lars Poeschel <poeschel@lemonage.de>
 *  All rights reserved.
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the	License, or (at your
 *  option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>

#include <linux/usb.h>
#include <linux/iio/iio.h>

#include <linux/mfd/viperboard.h>

#define VPRBRD_ADC_CMD_GET		0x00

struct vprbrd_adc_msg {
	u8 cmd;
	u8 chan;
	u8 val;
} __packed;

struct vprbrd_adc {
	struct vprbrd *vb;
};

#define VPRBRD_ADC_CHANNEL(_index) {			\
	.type = IIO_VOLTAGE,				\
	.indexed = 1,					\
	.channel = _index,				\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
}

static struct iio_chan_spec const vprbrd_adc_iio_channels[] = {
	VPRBRD_ADC_CHANNEL(0),
	VPRBRD_ADC_CHANNEL(1),
	VPRBRD_ADC_CHANNEL(2),
	VPRBRD_ADC_CHANNEL(3),
};

static int vprbrd_iio_read_raw(struct iio_dev *iio_dev,
				struct iio_chan_spec const *chan,
				int *val,
				int *val2,
				long info)
{
	int ret, error = 0;
	struct vprbrd_adc *adc = iio_priv(iio_dev);
	struct vprbrd *vb = adc->vb;
	struct vprbrd_adc_msg *admsg = (struct vprbrd_adc_msg *)vb->buf;

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&vb->lock);

		admsg->cmd = VPRBRD_ADC_CMD_GET;
		admsg->chan = chan->channel;
		admsg->val = 0x00;

		ret = usb_control_msg(vb->usb_dev,
			usb_sndctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
			VPRBRD_USB_TYPE_OUT, 0x0000, 0x0000, admsg,
			sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
		if (ret != sizeof(struct vprbrd_adc_msg)) {
			dev_err(&iio_dev->dev, "usb send error on adc read\n");
			error = -EREMOTEIO;
		}

		ret = usb_control_msg(vb->usb_dev,
			usb_rcvctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
			VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, admsg,
			sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);

		*val = admsg->val;

		mutex_unlock(&vb->lock);

		if (ret != sizeof(struct vprbrd_adc_msg)) {
			dev_err(&iio_dev->dev, "usb recv error on adc read\n");
			error = -EREMOTEIO;
		}

		if (error)
			goto error;

		return IIO_VAL_INT;
	default:
		error = -EINVAL;
		break;
	}
error:
	return error;
}

static const struct iio_info vprbrd_adc_iio_info = {
	.read_raw = &vprbrd_iio_read_raw,
	.driver_module = THIS_MODULE,
};

static int vprbrd_adc_probe(struct platform_device *pdev)
{
	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
	struct vprbrd_adc *adc;
	struct iio_dev *indio_dev;
	int ret;

	/* registering iio */
	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
	if (!indio_dev) {
		dev_err(&pdev->dev, "failed allocating iio device\n");
		return -ENOMEM;
	}

	adc = iio_priv(indio_dev);
	adc->vb = vb;
	indio_dev->name = "viperboard adc";
	indio_dev->dev.parent = &pdev->dev;
	indio_dev->info = &vprbrd_adc_iio_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = vprbrd_adc_iio_channels;
	indio_dev->num_channels = ARRAY_SIZE(vprbrd_adc_iio_channels);

	ret = devm_iio_device_register(&pdev->dev, indio_dev);
	if (ret) {
		dev_err(&pdev->dev, "could not register iio (adc)");
		return ret;
	}

	return 0;
}

static struct platform_driver vprbrd_adc_driver = {
	.driver = {
		.name	= "viperboard-adc",
	},
	.probe		= vprbrd_adc_probe,
};

module_platform_driver(vprbrd_adc_driver);

MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:viperboard-adc");