drivers/staging/iio/adc/ad7298.h

   1 /*
   2  * AD7298 SPI ADC driver
   3  *
   4  * Copyright 2011 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2.
   7  */
   8
   9 #ifndef IIO_ADC_AD7298_H_
  10 #define IIO_ADC_AD7298_H_
  11
  12 #define AD7298_WRITE    (1 << 15) /* write to the control register */
  13 #define AD7298_REPEAT   (1 << 14) /* repeated conversion enable */
  14 #define AD7298_CH(x)    (1 << (13 - (x))) /* channel select */
  15 #define AD7298_TSENSE   (1 << 5) /* temperature conversion enable */
  16 #define AD7298_EXTREF   (1 << 2) /* external reference enable */
  17 #define AD7298_TAVG     (1 << 1) /* temperature sensor averaging enable */
  18 #define AD7298_PDD      (1 << 0) /* partial power down enable */
  19
  20 #define AD7298_MAX_CHAN         8
  21 #define AD7298_BITS             12
  22 #define AD7298_STORAGE_BITS     16
  23 #define AD7298_INTREF_mV        2500
  24
  25 #define AD7298_CH_TEMP          9
  26
  27 #define RES_MASK(bits)  ((1 << (bits)) - 1)
  28
  29 /*
  30  * TODO: struct ad7298_platform_data needs to go into include/linux/iio
  31  */
  32
  33 struct ad7298_platform_data {
  34         /* External Vref voltage applied */
  35         u16                             vref_mv;
  36 };
  37
  38 struct ad7298_state {
  39         struct spi_device               *spi;
  40         struct regulator                *reg;
  41         size_t                          d_size;
  42         u16                             int_vref_mv;
  43         unsigned                        ext_ref;
  44         struct spi_transfer             ring_xfer[10];
  45         struct spi_transfer             scan_single_xfer[3];
  46         struct spi_message              ring_msg;
  47         struct spi_message              scan_single_msg;
  48         /*
  49          * DMA (thus cache coherency maintenance) requires the
  50          * transfer buffers to live in their own cache lines.
  51          */
  52         unsigned short                  rx_buf[8] ____cacheline_aligned;
  53         unsigned short                  tx_buf[2];
  54 };
  55
  56 #ifdef CONFIG_IIO_RING_BUFFER
  57 int ad7298_scan_from_ring(struct iio_dev *indio_dev, long ch);
  58 int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev);
  59 void ad7298_ring_cleanup(struct iio_dev *indio_dev);
  60 #else /* CONFIG_IIO_RING_BUFFER */
  61 static inline int ad7298_scan_from_ring(struct iio_dev *indio_dev, long ch)
  62 {
  63         return 0;
  64 }
  65
  66 static inline int
  67 ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
  68 {
  69         return 0;
  70 }
  71
  72 static inline void ad7298_ring_cleanup(struct iio_dev *indio_dev)
  73 {
  74 }
  75 #endif /* CONFIG_IIO_RING_BUFFER */
  76 #endif /* IIO_ADC_AD7298_H_ */