viperboard_adc.c 3.4 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150
  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. #include <linux/kernel.h>
  10. #include <linux/errno.h>
  11. #include <linux/module.h>
  12. #include <linux/slab.h>
  13. #include <linux/types.h>
  14. #include <linux/mutex.h>
  15. #include <linux/platform_device.h>
  16. #include <linux/usb.h>
  17. #include <linux/iio/iio.h>
  18. #include <linux/mfd/viperboard.h>
  19. #define VPRBRD_ADC_CMD_GET 0x00
  20. struct vprbrd_adc_msg {
  21. u8 cmd;
  22. u8 chan;
  23. u8 val;
  24. } __packed;
  25. struct vprbrd_adc {
  26. struct vprbrd *vb;
  27. };
  28. #define VPRBRD_ADC_CHANNEL(_index) { \
  29. .type = IIO_VOLTAGE, \
  30. .indexed = 1, \
  31. .channel = _index, \
  32. .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  33. }
  34. static struct iio_chan_spec const vprbrd_adc_iio_channels[] = {
  35. VPRBRD_ADC_CHANNEL(0),
  36. VPRBRD_ADC_CHANNEL(1),
  37. VPRBRD_ADC_CHANNEL(2),
  38. VPRBRD_ADC_CHANNEL(3),
  39. };
  40. static int vprbrd_iio_read_raw(struct iio_dev *iio_dev,
  41. struct iio_chan_spec const *chan,
  42. int *val,
  43. int *val2,
  44. long info)
  45. {
  46. int ret, error = 0;
  47. struct vprbrd_adc *adc = iio_priv(iio_dev);
  48. struct vprbrd *vb = adc->vb;
  49. struct vprbrd_adc_msg *admsg = (struct vprbrd_adc_msg *)vb->buf;
  50. switch (info) {
  51. case IIO_CHAN_INFO_RAW:
  52. mutex_lock(&vb->lock);
  53. admsg->cmd = VPRBRD_ADC_CMD_GET;
  54. admsg->chan = chan->channel;
  55. admsg->val = 0x00;
  56. ret = usb_control_msg(vb->usb_dev,
  57. usb_sndctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
  58. VPRBRD_USB_TYPE_OUT, 0x0000, 0x0000, admsg,
  59. sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
  60. if (ret != sizeof(struct vprbrd_adc_msg)) {
  61. dev_err(&iio_dev->dev, "usb send error on adc read\n");
  62. error = -EREMOTEIO;
  63. }
  64. ret = usb_control_msg(vb->usb_dev,
  65. usb_rcvctrlpipe(vb->usb_dev, 0), VPRBRD_USB_REQUEST_ADC,
  66. VPRBRD_USB_TYPE_IN, 0x0000, 0x0000, admsg,
  67. sizeof(struct vprbrd_adc_msg), VPRBRD_USB_TIMEOUT_MS);
  68. *val = admsg->val;
  69. mutex_unlock(&vb->lock);
  70. if (ret != sizeof(struct vprbrd_adc_msg)) {
  71. dev_err(&iio_dev->dev, "usb recv error on adc read\n");
  72. error = -EREMOTEIO;
  73. }
  74. if (error)
  75. goto error;
  76. return IIO_VAL_INT;
  77. default:
  78. error = -EINVAL;
  79. break;
  80. }
  81. error:
  82. return error;
  83. }
  84. static const struct iio_info vprbrd_adc_iio_info = {
  85. .read_raw = &vprbrd_iio_read_raw,
  86. };
  87. static int vprbrd_adc_probe(struct platform_device *pdev)
  88. {
  89. struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
  90. struct vprbrd_adc *adc;
  91. struct iio_dev *indio_dev;
  92. int ret;
  93. /* registering iio */
  94. indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
  95. if (!indio_dev) {
  96. dev_err(&pdev->dev, "failed allocating iio device\n");
  97. return -ENOMEM;
  98. }
  99. adc = iio_priv(indio_dev);
  100. adc->vb = vb;
  101. indio_dev->name = "viperboard adc";
  102. indio_dev->info = &vprbrd_adc_iio_info;
  103. indio_dev->modes = INDIO_DIRECT_MODE;
  104. indio_dev->channels = vprbrd_adc_iio_channels;
  105. indio_dev->num_channels = ARRAY_SIZE(vprbrd_adc_iio_channels);
  106. ret = devm_iio_device_register(&pdev->dev, indio_dev);
  107. if (ret) {
  108. dev_err(&pdev->dev, "could not register iio (adc)");
  109. return ret;
  110. }
  111. return 0;
  112. }
  113. static struct platform_driver vprbrd_adc_driver = {
  114. .driver = {
  115. .name = "viperboard-adc",
  116. },
  117. .probe = vprbrd_adc_probe,
  118. };
  119. module_platform_driver(vprbrd_adc_driver);
  120. MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
  121. MODULE_DESCRIPTION("IIO ADC driver for Nano River Techs Viperboard");
  122. MODULE_LICENSE("GPL");
  123. MODULE_ALIAS("platform:viperboard-adc");