1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Nano River Technologies viperboard IIO ADC driver |
4 | * |
5 | * (C) 2012 by Lemonage GmbH |
6 | * Author: Lars Poeschel <poeschel@lemonage.de> |
7 | * All rights reserved. |
8 | */ |
9 | |
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 | |
25 | struct vprbrd_adc_msg { |
26 | u8 cmd; |
27 | u8 chan; |
28 | u8 val; |
29 | } __packed; |
30 | |
31 | struct 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 | |
42 | static 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 | |
49 | static 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(indio_dev: 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(dev: vb->usb_dev, |
69 | usb_sndctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC, |
70 | VPRBRD_USB_TYPE_OUT, value: 0x0000, index: 0x0000, data: admsg, |
71 | size: 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(dev: vb->usb_dev, |
78 | usb_rcvctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC, |
79 | VPRBRD_USB_TYPE_IN, value: 0x0000, index: 0x0000, data: admsg, |
80 | size: sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS); |
81 | |
82 | *val = admsg->val; |
83 | |
84 | mutex_unlock(lock: &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 | } |
99 | error: |
100 | return error; |
101 | } |
102 | |
103 | static const struct iio_info vprbrd_adc_iio_info = { |
104 | .read_raw = &vprbrd_iio_read_raw, |
105 | }; |
106 | |
107 | static int vprbrd_adc_probe(struct platform_device *pdev) |
108 | { |
109 | struct vprbrd *vb = dev_get_drvdata(dev: pdev->dev.parent); |
110 | struct vprbrd_adc *adc; |
111 | struct iio_dev *indio_dev; |
112 | int ret; |
113 | |
114 | /* registering iio */ |
115 | indio_dev = devm_iio_device_alloc(parent: &pdev->dev, sizeof_priv: 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->info = &vprbrd_adc_iio_info; |
125 | indio_dev->modes = INDIO_DIRECT_MODE; |
126 | indio_dev->channels = vprbrd_adc_iio_channels; |
127 | indio_dev->num_channels = ARRAY_SIZE(vprbrd_adc_iio_channels); |
128 | |
129 | ret = devm_iio_device_register(&pdev->dev, indio_dev); |
130 | if (ret) { |
131 | dev_err(&pdev->dev, "could not register iio (adc)" ); |
132 | return ret; |
133 | } |
134 | |
135 | return 0; |
136 | } |
137 | |
138 | static struct platform_driver vprbrd_adc_driver = { |
139 | .driver = { |
140 | .name = "viperboard-adc" , |
141 | }, |
142 | .probe = vprbrd_adc_probe, |
143 | }; |
144 | |
145 | module_platform_driver(vprbrd_adc_driver); |
146 | |
147 | MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>" ); |
148 | MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard" ); |
149 | MODULE_LICENSE("GPL" ); |
150 | MODULE_ALIAS("platform:viperboard-adc" ); |
151 | |