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15#include <linux/kernel.h>
16#include <linux/errno.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/types.h>
20#include <linux/mutex.h>
21#include <linux/platform_device.h>
22
23#include <linux/usb.h>
24#include <linux/iio/iio.h>
25
26#include <linux/mfd/viperboard.h>
27
28#define VPRBRD_ADC_CMD_GET 0x00
29
30struct vprbrd_adc_msg {
31 u8 cmd;
32 u8 chan;
33 u8 val;
34} __packed;
35
36struct vprbrd_adc {
37 struct vprbrd *vb;
38};
39
40#define VPRBRD_ADC_CHANNEL(_index) { \
41 .type = IIO_VOLTAGE, \
42 .indexed = 1, \
43 .channel = _index, \
44 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
45 .scan_index = _index, \
46 .scan_type = { \
47 .sign = 'u', \
48 .realbits = 8, \
49 .storagebits = 8, \
50 }, \
51}
52
53static struct iio_chan_spec const vprbrd_adc_iio_channels[] = {
54 VPRBRD_ADC_CHANNEL(0),
55 VPRBRD_ADC_CHANNEL(1),
56 VPRBRD_ADC_CHANNEL(2),
57 VPRBRD_ADC_CHANNEL(3),
58};
59
60static int vprbrd_iio_read_raw(struct iio_dev *iio_dev,
61 struct iio_chan_spec const *chan,
62 int *val,
63 int *val2,
64 long info)
65{
66 int ret, error = 0;
67 struct vprbrd_adc *adc = iio_priv(iio_dev);
68 struct vprbrd *vb = adc->vb;
69 struct vprbrd_adc_msg *admsg = (struct vprbrd_adc_msg *)vb->buf;
70
71 switch (info) {
72 case IIO_CHAN_INFO_RAW:
73 mutex_lock(&vb->lock);
74
75 admsg->cmd = VPRBRD_ADC_CMD_GET;
76 admsg->chan = chan->scan_index;
77 admsg->val = 0x00;
78
79 ret = usb_control_msg(vb->usb_dev,
80 usb_sndctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
81 VPRBRD_USB_TYPE_OUT, 0x0000, 0x0000, admsg,
82 sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
83 if (ret != sizeof(struct vprbrd_adc_msg)) {
84 dev_err(&iio_dev->dev, "usb send error on adc read\n");
85 error = -EREMOTEIO;
86 }
87
88 ret = usb_control_msg(vb->usb_dev,
89 usb_rcvctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
90 VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, admsg,
91 sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
92
93 *val = admsg->val;
94
95 mutex_unlock(&vb->lock);
96
97 if (ret != sizeof(struct vprbrd_adc_msg)) {
98 dev_err(&iio_dev->dev, "usb recv error on adc read\n");
99 error = -EREMOTEIO;
100 }
101
102 if (error)
103 goto error;
104
105 return IIO_VAL_INT;
106 default:
107 error = -EINVAL;
108 break;
109 }
110error:
111 return error;
112}
113
114static const struct iio_info vprbrd_adc_iio_info = {
115 .read_raw = &vprbrd_iio_read_raw,
116 .driver_module = THIS_MODULE,
117};
118
119static int vprbrd_adc_probe(struct platform_device *pdev)
120{
121 struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
122 struct vprbrd_adc *adc;
123 struct iio_dev *indio_dev;
124 int ret;
125
126
127 indio_dev = iio_device_alloc(sizeof(*adc));
128 if (!indio_dev) {
129 dev_err(&pdev->dev, "failed allocating iio device\n");
130 return -ENOMEM;
131 }
132
133 adc = iio_priv(indio_dev);
134 adc->vb = vb;
135 indio_dev->name = "viperboard adc";
136 indio_dev->dev.parent = &pdev->dev;
137 indio_dev->info = &vprbrd_adc_iio_info;
138 indio_dev->modes = INDIO_DIRECT_MODE;
139 indio_dev->channels = vprbrd_adc_iio_channels;
140 indio_dev->num_channels = ARRAY_SIZE(vprbrd_adc_iio_channels);
141
142 ret = iio_device_register(indio_dev);
143 if (ret) {
144 dev_err(&pdev->dev, "could not register iio (adc)");
145 goto error;
146 }
147
148 platform_set_drvdata(pdev, indio_dev);
149
150 return 0;
151
152error:
153 iio_device_free(indio_dev);
154 return ret;
155}
156
157static int vprbrd_adc_remove(struct platform_device *pdev)
158{
159 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
160
161 iio_device_unregister(indio_dev);
162 iio_device_free(indio_dev);
163
164 return 0;
165}
166
167static struct platform_driver vprbrd_adc_driver = {
168 .driver = {
169 .name = "viperboard-adc",
170 .owner = THIS_MODULE,
171 },
172 .probe = vprbrd_adc_probe,
173 .remove = vprbrd_adc_remove,
174};
175
176module_platform_driver(vprbrd_adc_driver);
177
178MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
179MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard");
180MODULE_LICENSE("GPL");
181MODULE_ALIAS("platform:viperboard-adc");
182
