ad7887.h

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/*
 * AD7887 SPI ADC driver
 *
 * Copyright 2010 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */
#ifndef IIO_ADC_AD7887_H_
#define IIO_ADC_AD7887_H_

#define AD7887_REF_DIS      (1 << 5) /* on-chip reference disable */
#define AD7887_DUAL     (1 << 4) /* dual-channel mode */
#define AD7887_CH_AIN1      (1 << 3) /* convert on channel 1, DUAL=1 */
#define AD7887_CH_AIN0      (0 << 3) /* convert on channel 0, DUAL=0,1 */
#define AD7887_PM_MODE1     (0)  /* CS based shutdown */
#define AD7887_PM_MODE2     (1)  /* full on */
#define AD7887_PM_MODE3     (2)  /* auto shutdown after conversion */
#define AD7887_PM_MODE4     (3)  /* standby mode */

enum ad7887_channels {
    AD7887_CH0,
    AD7887_CH0_CH1,
    AD7887_CH1,
};

#define RES_MASK(bits)  ((1 << (bits)) - 1) /* TODO: move this into a common header */

/*
 * TODO: struct ad7887_platform_data needs to go into include/linux/iio
 */

struct ad7887_platform_data {
    /* External Vref voltage applied */
    u16             vref_mv;
    /*
     * AD7887:
     * In single channel mode en_dual = flase, AIN1/Vref pins assumes its
     * Vref function. In dual channel mode en_dual = true, AIN1 becomes the
     * second input channel, and Vref is internally connected to Vdd.
     */
    bool                en_dual;
    /*
     * AD7887:
     * use_onchip_ref = true, the Vref is internally connected to the 2.500V
     * Voltage reference. If use_onchip_ref = false, the reference voltage
     * is supplied by AIN1/Vref
     */
    bool                use_onchip_ref;
};

struct ad7887_chip_info {
    u16             int_vref_mv;
    struct iio_chan_spec        channel[3];
};

struct ad7887_state {
    struct spi_device       *spi;
    const struct ad7887_chip_info   *chip_info;
    struct regulator        *reg;
    u16             int_vref_mv;
    struct spi_transfer     xfer[4];
    struct spi_message      msg[3];
    struct spi_message      *ring_msg;
    unsigned char           tx_cmd_buf[8];

    /*
     * DMA (thus cache coherency maintenance) requires the
     * transfer buffers to live in their own cache lines.
     */

    unsigned char           data[4] ____cacheline_aligned;
};

enum ad7887_supported_device_ids {
    ID_AD7887
};

#ifdef CONFIG_IIO_BUFFER
int ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev);
void ad7887_ring_cleanup(struct iio_dev *indio_dev);
#else /* CONFIG_IIO_BUFFER */

static inline int
ad7887_register_ring_funcs_and_init(struct iio_dev *indio_dev)
{
    return 0;
}

static inline void ad7887_ring_cleanup(struct iio_dev *indio_dev)
{
}
#endif /* CONFIG_IIO_BUFFER */
#endif /* IIO_ADC_AD7887_H_ */