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 .scan_index = _index, \ 46 .scan_type = { \ 47 .sign = 'u', \ 48 .realbits = 8, \ 49 .storagebits = 8, \ 50 }, \ 51 } 52 53 static 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 60 static 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 } 110 error: 111 return error; 112 } 113 114 static const struct iio_info vprbrd_adc_iio_info = { 115 .read_raw = &vprbrd_iio_read_raw, 116 .driver_module = THIS_MODULE, 117 }; 118 119 static 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 /* registering iio */ 127 indio_dev = devm_iio_device_alloc(&pdev->dev, 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 return ret; 146 } 147 148 platform_set_drvdata(pdev, indio_dev); 149 150 return 0; 151 } 152 153 static int vprbrd_adc_remove(struct platform_device *pdev) 154 { 155 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 156 157 iio_device_unregister(indio_dev); 158 159 return 0; 160 } 161 162 static struct platform_driver vprbrd_adc_driver = { 163 .driver = { 164 .name = "viperboard-adc", 165 .owner = THIS_MODULE, 166 }, 167 .probe = vprbrd_adc_probe, 168 .remove = vprbrd_adc_remove, 169 }; 170 171 module_platform_driver(vprbrd_adc_driver); 172 173 MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>"); 174 MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard"); 175 MODULE_LICENSE("GPL"); 176 MODULE_ALIAS("platform:viperboard-adc"); 177