1 /* 2 * Nano River Technologies viperboard IIO ADC driver 3 * 4 * (C) 2012 by Lemonage GmbH 5 * Author: Lars Poeschel <poeschel@lemonage.de> 6 * All rights reserved. 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 * 13 */ 14 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 30 struct vprbrd_adc_msg { 31 u8 cmd; 32 u8 chan; 33 u8 val; 34 } __packed; 35 36 struct 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 } 46 47 static struct iio_chan_spec const vprbrd_adc_iio_channels[] = { 48 VPRBRD_ADC_CHANNEL(0), 49 VPRBRD_ADC_CHANNEL(1), 50 VPRBRD_ADC_CHANNEL(2), 51 VPRBRD_ADC_CHANNEL(3), 52 }; 53 54 static int vprbrd_iio_read_raw(struct iio_dev *iio_dev, 55 struct iio_chan_spec const *chan, 56 int *val, 57 int *val2, 58 long info) 59 { 60 int ret, error = 0; 61 struct vprbrd_adc *adc = iio_priv(iio_dev); 62 struct vprbrd *vb = adc->vb; 63 struct vprbrd_adc_msg *admsg = (struct vprbrd_adc_msg *)vb->buf; 64 65 switch (info) { 66 case IIO_CHAN_INFO_RAW: 67 mutex_lock(&vb->lock); 68 69 admsg->cmd = VPRBRD_ADC_CMD_GET; 70 admsg->chan = chan->channel; 71 admsg->val = 0x00; 72 73 ret = usb_control_msg(vb->usb_dev, 74 usb_sndctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC, 75 VPRBRD_USB_TYPE_OUT, 0x0000, 0x0000, admsg, 76 sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS); 77 if (ret != sizeof(struct vprbrd_adc_msg)) { 78 dev_err(&iio_dev->dev, "usb send error on adc read\n"); 79 error = -EREMOTEIO; 80 } 81 82 ret = usb_control_msg(vb->usb_dev, 83 usb_rcvctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC, 84 VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, admsg, 85 sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS); 86 87 *val = admsg->val; 88 89 mutex_unlock(&vb->lock); 90 91 if (ret != sizeof(struct vprbrd_adc_msg)) { 92 dev_err(&iio_dev->dev, "usb recv error on adc read\n"); 93 error = -EREMOTEIO; 94 } 95 96 if (error) 97 goto error; 98 99 return IIO_VAL_INT; 100 default: 101 error = -EINVAL; 102 break; 103 } 104 error: 105 return error; 106 } 107 108 static const struct iio_info vprbrd_adc_iio_info = { 109 .read_raw = &vprbrd_iio_read_raw, 110 .driver_module = THIS_MODULE, 111 }; 112 113 static int vprbrd_adc_probe(struct platform_device *pdev) 114 { 115 struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent); 116 struct vprbrd_adc *adc; 117 struct iio_dev *indio_dev; 118 int ret; 119 120 /* registering iio */ 121 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); 122 if (!indio_dev) { 123 dev_err(&pdev->dev, "failed allocating iio device\n"); 124 return -ENOMEM; 125 } 126 127 adc = iio_priv(indio_dev); 128 adc->vb = vb; 129 indio_dev->name = "viperboard adc"; 130 indio_dev->dev.parent = &pdev->dev; 131 indio_dev->info = &vprbrd_adc_iio_info; 132 indio_dev->modes = INDIO_DIRECT_MODE; 133 indio_dev->channels = vprbrd_adc_iio_channels; 134 indio_dev->num_channels = ARRAY_SIZE(vprbrd_adc_iio_channels); 135 136 ret = devm_iio_device_register(&pdev->dev, indio_dev); 137 if (ret) { 138 dev_err(&pdev->dev, "could not register iio (adc)"); 139 return ret; 140 } 141 142 platform_set_drvdata(pdev, indio_dev); 143 144 return 0; 145 } 146 147 static struct platform_driver vprbrd_adc_driver = { 148 .driver = { 149 .name = "viperboard-adc", 150 .owner = THIS_MODULE, 151 }, 152 .probe = vprbrd_adc_probe, 153 }; 154 155 module_platform_driver(vprbrd_adc_driver); 156 157 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>"); 158 MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard"); 159 MODULE_LICENSE("GPL"); 160 MODULE_ALIAS("platform:viperboard-adc"); 161