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_CH_MASK  (AD7298_CH0 | AD7298_CH1 | AD7298_CH2 | AD7298_CH3 | \
  21                         AD7298_CH4 | AD7298_CH5 | AD7298_CH6 | AD7298_CH7)
  22
  23 #define AD7298_MAX_CHAN         8
  24 #define AD7298_BITS             12
  25 #define AD7298_STORAGE_BITS     16
  26 #define AD7298_INTREF_mV        2500
  27
  28 #define RES_MASK(bits)  ((1 << (bits)) - 1)
  29
  30 /*
  31  * TODO: struct ad7298_platform_data needs to go into include/linux/iio
  32  */
  33
  34 struct ad7298_platform_data {
  35         /* External Vref voltage applied */
  36         u16                             vref_mv;
  37 };
  38
  39 struct ad7298_state {
  40         struct iio_dev                  *indio_dev;
  41         struct spi_device               *spi;
  42         struct regulator                *reg;
  43         struct work_struct              poll_work;
  44         atomic_t                        protect_ring;
  45         size_t                          d_size;
  46         u16                             int_vref_mv;
  47         unsigned                        ext_ref;
  48         struct spi_transfer             ring_xfer[10];
  49         struct spi_transfer             scan_single_xfer[3];
  50         struct spi_message              ring_msg;
  51         struct spi_message              scan_single_msg;
  52         /*
  53          * DMA (thus cache coherency maintenance) requires the
  54          * transfer buffers to live in their own cache lines.
  55          */
  56         unsigned short                  rx_buf[8] ____cacheline_aligned;
  57         unsigned short                  tx_buf[2];
  58 };
  59
  60 #ifdef CONFIG_IIO_RING_BUFFER
  61 int ad7298_scan_from_ring(struct ad7298_state *st, long ch);
  62 int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev);
  63 void ad7298_ring_cleanup(struct iio_dev *indio_dev);
  64 #else /* CONFIG_IIO_RING_BUFFER */
  65 static inline int ad7298_scan_from_ring(struct ad7298_state *st, long ch)
  66 {
  67         return 0;
  68 }
  69
  70 static inline int
  71 ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
  72 {
  73         return 0;
  74 }
  75
  76 static inline void ad7298_ring_cleanup(struct iio_dev *indio_dev)
  77 {
  78 }
  79 #endif /* CONFIG_IIO_RING_BUFFER */
  80 #endif /* IIO_ADC_AD7298_H_ */