ad7298.h

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/*
 * AD7298 SPI ADC driver
 *
 * Copyright 2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2.
 */

#ifndef IIO_ADC_AD7298_H_
#define IIO_ADC_AD7298_H_

#define AD7298_WRITE    (1 << 15) /* write to the control register */
#define AD7298_REPEAT   (1 << 14) /* repeated conversion enable */
#define AD7298_CH(x)    (1 << (13 - (x))) /* channel select */
#define AD7298_TSENSE   (1 << 5) /* temperature conversion enable */
#define AD7298_EXTREF   (1 << 2) /* external reference enable */
#define AD7298_TAVG (1 << 1) /* temperature sensor averaging enable */
#define AD7298_PDD  (1 << 0) /* partial power down enable */

#define AD7298_MAX_CHAN     8
#define AD7298_BITS     12
#define AD7298_STORAGE_BITS 16
#define AD7298_INTREF_mV    2500

#define AD7298_CH_TEMP      9

#define RES_MASK(bits)  ((1 << (bits)) - 1)

/*
 * TODO: struct ad7298_platform_data needs to go into include/linux/iio
 */

struct ad7298_platform_data {
    /* External Vref voltage applied */
    u16             vref_mv;
};

struct ad7298_state {
    struct spi_device       *spi;
    struct regulator        *reg;
    u16             int_vref_mv;
    unsigned            ext_ref;
    struct spi_transfer     ring_xfer[10];
    struct spi_transfer     scan_single_xfer[3];
    struct spi_message      ring_msg;
    struct spi_message      scan_single_msg;
    /*
     * DMA (thus cache coherency maintenance) requires the
     * transfer buffers to live in their own cache lines.
     */
    unsigned short          rx_buf[8] ____cacheline_aligned;
    unsigned short          tx_buf[2];
};

#ifdef CONFIG_IIO_BUFFER
int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev);
void ad7298_ring_cleanup(struct iio_dev *indio_dev);
int ad7298_update_scan_mode(struct iio_dev *indio_dev,
    const unsigned long *active_scan_mask);
#else /* CONFIG_IIO_BUFFER */

static inline int
ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)
{
    return 0;
}

static inline void ad7298_ring_cleanup(struct iio_dev *indio_dev)
{
}

#define ad7298_update_scan_mode NULL

#endif /* CONFIG_IIO_BUFFER */
#endif /* IIO_ADC_AD7298_H_ */