men_z188_adc.c 3.6 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176
  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * MEN 16z188 Analog to Digial Converter
  4. *
  5. * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
  6. * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
  7. */
  8. #include <linux/kernel.h>
  9. #include <linux/module.h>
  10. #include <linux/mcb.h>
  11. #include <linux/io.h>
  12. #include <linux/iio/iio.h>
  13. #define Z188_ADC_MAX_CHAN 8
  14. #define Z188_ADC_GAIN 0x0700000
  15. #define Z188_MODE_VOLTAGE BIT(27)
  16. #define Z188_CFG_AUTO 0x1
  17. #define Z188_CTRL_REG 0x40
  18. #define ADC_DATA(x) (((x) >> 2) & 0x7ffffc)
  19. #define ADC_OVR(x) ((x) & 0x1)
  20. struct z188_adc {
  21. struct resource *mem;
  22. void __iomem *base;
  23. };
  24. #define Z188_ADC_CHANNEL(idx) { \
  25. .type = IIO_VOLTAGE, \
  26. .indexed = 1, \
  27. .channel = (idx), \
  28. .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  29. }
  30. static const struct iio_chan_spec z188_adc_iio_channels[] = {
  31. Z188_ADC_CHANNEL(0),
  32. Z188_ADC_CHANNEL(1),
  33. Z188_ADC_CHANNEL(2),
  34. Z188_ADC_CHANNEL(3),
  35. Z188_ADC_CHANNEL(4),
  36. Z188_ADC_CHANNEL(5),
  37. Z188_ADC_CHANNEL(6),
  38. Z188_ADC_CHANNEL(7),
  39. };
  40. static int z188_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. struct z188_adc *adc = iio_priv(iio_dev);
  47. int ret;
  48. u16 tmp;
  49. switch (info) {
  50. case IIO_CHAN_INFO_RAW:
  51. tmp = readw(adc->base + chan->channel * 4);
  52. if (ADC_OVR(tmp)) {
  53. dev_info(&iio_dev->dev,
  54. "Oversampling error on ADC channel %d\n",
  55. chan->channel);
  56. return -EIO;
  57. }
  58. *val = ADC_DATA(tmp);
  59. ret = IIO_VAL_INT;
  60. break;
  61. default:
  62. ret = -EINVAL;
  63. break;
  64. }
  65. return ret;
  66. }
  67. static const struct iio_info z188_adc_info = {
  68. .read_raw = &z188_iio_read_raw,
  69. };
  70. static void men_z188_config_channels(void __iomem *addr)
  71. {
  72. int i;
  73. u32 cfg;
  74. u32 ctl;
  75. ctl = readl(addr + Z188_CTRL_REG);
  76. ctl |= Z188_CFG_AUTO;
  77. writel(ctl, addr + Z188_CTRL_REG);
  78. for (i = 0; i < Z188_ADC_MAX_CHAN; i++) {
  79. cfg = readl(addr + i);
  80. cfg &= ~Z188_ADC_GAIN;
  81. cfg |= Z188_MODE_VOLTAGE;
  82. writel(cfg, addr + i);
  83. }
  84. }
  85. static int men_z188_probe(struct mcb_device *dev,
  86. const struct mcb_device_id *id)
  87. {
  88. struct z188_adc *adc;
  89. struct iio_dev *indio_dev;
  90. struct resource *mem;
  91. int ret;
  92. indio_dev = devm_iio_device_alloc(&dev->dev, sizeof(struct z188_adc));
  93. if (!indio_dev)
  94. return -ENOMEM;
  95. adc = iio_priv(indio_dev);
  96. indio_dev->name = "z188-adc";
  97. indio_dev->info = &z188_adc_info;
  98. indio_dev->modes = INDIO_DIRECT_MODE;
  99. indio_dev->channels = z188_adc_iio_channels;
  100. indio_dev->num_channels = ARRAY_SIZE(z188_adc_iio_channels);
  101. mem = mcb_request_mem(dev, "z188-adc");
  102. if (IS_ERR(mem))
  103. return PTR_ERR(mem);
  104. adc->base = ioremap(mem->start, resource_size(mem));
  105. if (adc->base == NULL)
  106. goto err;
  107. men_z188_config_channels(adc->base);
  108. adc->mem = mem;
  109. mcb_set_drvdata(dev, indio_dev);
  110. ret = iio_device_register(indio_dev);
  111. if (ret)
  112. goto err_unmap;
  113. return 0;
  114. err_unmap:
  115. iounmap(adc->base);
  116. err:
  117. mcb_release_mem(mem);
  118. return -ENXIO;
  119. }
  120. static void men_z188_remove(struct mcb_device *dev)
  121. {
  122. struct iio_dev *indio_dev = mcb_get_drvdata(dev);
  123. struct z188_adc *adc = iio_priv(indio_dev);
  124. iio_device_unregister(indio_dev);
  125. iounmap(adc->base);
  126. mcb_release_mem(adc->mem);
  127. }
  128. static const struct mcb_device_id men_z188_ids[] = {
  129. { .device = 0xbc },
  130. { }
  131. };
  132. MODULE_DEVICE_TABLE(mcb, men_z188_ids);
  133. static struct mcb_driver men_z188_driver = {
  134. .driver = {
  135. .name = "z188-adc",
  136. .owner = THIS_MODULE,
  137. },
  138. .probe = men_z188_probe,
  139. .remove = men_z188_remove,
  140. .id_table = men_z188_ids,
  141. };
  142. module_mcb_driver(men_z188_driver);
  143. MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
  144. MODULE_LICENSE("GPL");
  145. MODULE_DESCRIPTION("IIO ADC driver for MEN 16z188 ADC Core");
  146. MODULE_ALIAS("mcb:16z188");
  147. MODULE_IMPORT_NS(MCB);