drivers/staging/iio/adc/ad7887.h

   1 /*
   2  * AD7887 SPI ADC driver
   3  *
   4  * Copyright 2010 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8 #ifndef IIO_ADC_AD7887_H_
   9 #define IIO_ADC_AD7887_H_
  10
  11 #define AD7887_REF_DIS          (1 << 5) /* on-chip reference disable */
  12 #define AD7887_DUAL             (1 << 4) /* dual-channel mode */
  13 #define AD7887_CH_AIN1          (1 << 3) /* convert on channel 1, DUAL=1 */
  14 #define AD7887_CH_AIN0          (0 << 3) /* convert on channel 0, DUAL=0,1 */
  15 #define AD7887_PM_MODE1         (0)      /* CS based shutdown */
  16 #define AD7887_PM_MODE2         (1)      /* full on */
  17 #define AD7887_PM_MODE3         (2)      /* auto shutdown after conversion */
  18 #define AD7887_PM_MODE4         (3)      /* standby mode */
  19
  20 enum ad7887_channels {
  21         AD7887_CH0,
  22         AD7887_CH0_CH1,
  23         AD7887_CH1,
  24 };
  25
  26 #define RES_MASK(bits)  ((1 << (bits)) - 1) /* TODO: move this into a common header */
  27
  28 /*
  29  * TODO: struct ad7887_platform_data needs to go into include/linux/iio
  30  */
  31
  32 struct ad7887_platform_data {
  33         /* External Vref voltage applied */
  34         u16                             vref_mv;
  35         /*
  36          * AD7887:
  37          * In single channel mode en_dual = flase, AIN1/Vref pins assumes its
  38          * Vref function. In dual channel mode en_dual = true, AIN1 becomes the
  39          * second input channel, and Vref is internally connected to Vdd.
  40          */
  41         bool                            en_dual;
  42         /*
  43          * AD7887:
  44          * use_onchip_ref = true, the Vref is internally connected to the 2.500V
  45          * Voltage reference. If use_onchip_ref = false, the reference voltage
  46          * is supplied by AIN1/Vref
  47          */
  48         bool                            use_onchip_ref;
  49 };
  50
  51 /**
  52  * struct ad7887_chip_info - chip specifc information
  53  * @int_vref_mv:        the internal reference voltage
  54  * @channel:            channel specification
  55  */
  56
  57 struct ad7887_chip_info {
  58         u16                             int_vref_mv;
  59         struct iio_chan_spec            channel[3];
  60 };
  61
  62 struct ad7887_state {
  63         struct spi_device               *spi;
  64         const struct ad7887_chip_info   *chip_info;
  65         struct regulator                *reg;
  66         size_t                          d_size;
  67         u16                             int_vref_mv;
  68         struct spi_transfer             xfer[4];
  69         struct spi_message              msg[3];
  70         struct spi_message              *ring_msg;
  71         unsigned char                   tx_cmd_buf[8];
  72
  73         /*
  74          * DMA (thus cache coherency maintenance) requires the
  75          * transfer buffers to live in their own cache lines.
  76          */
  77
  78         unsigned char                   data[4] ____cacheline_aligned;
  79 };
  80
  81 enum ad7887_supported_device_ids {
  82         ID_AD7887
  83 };
  84
  85 #ifdef CONFIG_IIO_BUFFER
  86 int ad7887_scan_from_ring(struct ad7887_state *st, int channum);
  87 int ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev);
  88 void ad7887_ring_cleanup(struct iio_dev *indio_dev);
  89 #else /* CONFIG_IIO_BUFFER */
  90 static inline int ad7887_scan_from_ring(struct ad7887_state *st, int channum)
  91 {
  92         return 0;
  93 }
  94
  95 static inline int
  96 ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev)
  97 {
  98         return 0;
  99 }
 100
 101 static inline void ad7887_ring_cleanup(struct iio_dev *indio_dev)
 102 {
 103 }
 104 #endif /* CONFIG_IIO_BUFFER */
 105 #endif /* IIO_ADC_AD7887_H_ */