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(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 } 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(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(&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 } 138 139 static struct platform_driver vprbrd_adc_driver = { 140 .driver = { 141 .name = "viperboard-adc", 142 }, 143 .probe = vprbrd_adc_probe, 144 }; 145 146 module_platform_driver(vprbrd_adc_driver); 147 148 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>"); 149 MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard"); 150 MODULE_LICENSE("GPL"); 151 MODULE_ALIAS("platform:viperboard-adc"); 152