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10#include <linux/kernel.h>
11#include <linux/errno.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/types.h>
15#include <linux/mutex.h>
16#include <linux/platform_device.h>
17
18#include <linux/usb.h>
19#include <linux/iio/iio.h>
20
21#include <linux/mfd/viperboard.h>
22
23#define VPRBRD_ADC_CMD_GET 0x00
24
25struct vprbrd_adc_msg {
26 u8 cmd;
27 u8 chan;
28 u8 val;
29} __packed;
30
31struct vprbrd_adc {
32 struct vprbrd *vb;
33};
34
35#define VPRBRD_ADC_CHANNEL(_index) { \
36 .type = IIO_VOLTAGE, \
37 .indexed = 1, \
38 .channel = _index, \
39 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
40}
41
42static struct iio_chan_spec const vprbrd_adc_iio_channels[] = {
43 VPRBRD_ADC_CHANNEL(0),
44 VPRBRD_ADC_CHANNEL(1),
45 VPRBRD_ADC_CHANNEL(2),
46 VPRBRD_ADC_CHANNEL(3),
47};
48
49static int vprbrd_iio_read_raw(struct iio_dev *iio_dev,
50 struct iio_chan_spec const *chan,
51 int *val,
52 int *val2,
53 long info)
54{
55 int ret, error = 0;
56 struct vprbrd_adc *adc = iio_priv(iio_dev);
57 struct vprbrd *vb = adc->vb;
58 struct vprbrd_adc_msg *admsg = (struct vprbrd_adc_msg *)vb->buf;
59
60 switch (info) {
61 case IIO_CHAN_INFO_RAW:
62 mutex_lock(&vb->lock);
63
64 admsg->cmd = VPRBRD_ADC_CMD_GET;
65 admsg->chan = chan->channel;
66 admsg->val = 0x00;
67
68 ret = usb_control_msg(vb->usb_dev,
69 usb_sndctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
70 VPRBRD_USB_TYPE_OUT, 0x0000, 0x0000, admsg,
71 sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
72 if (ret != sizeof(struct vprbrd_adc_msg)) {
73 dev_err(&iio_dev->dev, "usb send error on adc read\n");
74 error = -EREMOTEIO;
75 }
76
77 ret = usb_control_msg(vb->usb_dev,
78 usb_rcvctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
79 VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, admsg,
80 sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
81
82 *val = admsg->val;
83
84 mutex_unlock(&vb->lock);
85
86 if (ret != sizeof(struct vprbrd_adc_msg)) {
87 dev_err(&iio_dev->dev, "usb recv error on adc read\n");
88 error = -EREMOTEIO;
89 }
90
91 if (error)
92 goto error;
93
94 return IIO_VAL_INT;
95 default:
96 error = -EINVAL;
97 break;
98 }
99error:
100 return error;
101}
102
103static const struct iio_info vprbrd_adc_iio_info = {
104 .read_raw = &vprbrd_iio_read_raw,
105};
106
107static int vprbrd_adc_probe(struct platform_device *pdev)
108{
109 struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
110 struct vprbrd_adc *adc;
111 struct iio_dev *indio_dev;
112 int ret;
113
114
115 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
116 if (!indio_dev) {
117 dev_err(&pdev->dev, "failed allocating iio device\n");
118 return -ENOMEM;
119 }
120
121 adc = iio_priv(indio_dev);
122 adc->vb = vb;
123 indio_dev->name = "viperboard adc";
124 indio_dev->dev.parent = &pdev->dev;
125 indio_dev->info = &vprbrd_adc_iio_info;
126 indio_dev->modes = INDIO_DIRECT_MODE;
127 indio_dev->channels = vprbrd_adc_iio_channels;
128 indio_dev->num_channels = ARRAY_SIZE(vprbrd_adc_iio_channels);
129
130 ret = devm_iio_device_register(&pdev->dev, indio_dev);
131 if (ret) {
132 dev_err(&pdev->dev, "could not register iio (adc)");
133 return ret;
134 }
135
136 return 0;
137}
138
139static struct platform_driver vprbrd_adc_driver = {
140 .driver = {
141 .name = "viperboard-adc",
142 },
143 .probe = vprbrd_adc_probe,
144};
145
146module_platform_driver(vprbrd_adc_driver);
147
148MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
149MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard");
150MODULE_LICENSE("GPL");
151MODULE_ALIAS("platform:viperboard-adc");
152
