1/* 2 * Support code for Analog Devices Sigma-Delta ADCs 3 * 4 * Copyright 2012 Analog Devices Inc. 5 * Author: Lars-Peter Clausen <lars@metafoo.de> 6 * 7 * Licensed under the GPL-2. 8 */ 9#ifndef __AD_SIGMA_DELTA_H__ 10#define __AD_SIGMA_DELTA_H__ 11 12enum ad_sigma_delta_mode { 13 AD_SD_MODE_CONTINUOUS = 0, 14 AD_SD_MODE_SINGLE = 1, 15 AD_SD_MODE_IDLE = 2, 16 AD_SD_MODE_POWERDOWN = 3, 17}; 18 19/** 20 * struct ad_sigma_delta_calib_data - Calibration data for Sigma Delta devices 21 * @mode: Calibration mode. 22 * @channel: Calibration channel. 23 */ 24struct ad_sd_calib_data { 25 unsigned int mode; 26 unsigned int channel; 27}; 28 29struct ad_sigma_delta; 30struct iio_dev; 31 32/** 33 * struct ad_sigma_delta_info - Sigma Delta driver specific callbacks and options 34 * @set_channel: Will be called to select the current channel, may be NULL. 35 * @set_mode: Will be called to select the current mode, may be NULL. 36 * @postprocess_sample: Is called for each sampled data word, can be used to 37 * modify or drop the sample data, it, may be NULL. 38 * @has_registers: true if the device has writable and readable registers, false 39 * if there is just one read-only sample data shift register. 40 * @addr_shift: Shift of the register address in the communications register. 41 * @read_mask: Mask for the communications register having the read bit set. 42 */ 43struct ad_sigma_delta_info { 44 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel); 45 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode); 46 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample); 47 bool has_registers; 48 unsigned int addr_shift; 49 unsigned int read_mask; 50}; 51 52/** 53 * struct ad_sigma_delta - Sigma Delta device struct 54 * @spi: The spi device associated with the Sigma Delta device. 55 * @trig: The IIO trigger associated with the Sigma Delta device. 56 * 57 * Most of the fields are private to the sigma delta library code and should not 58 * be accessed by individual drivers. 59 */ 60struct ad_sigma_delta { 61 struct spi_device *spi; 62 struct iio_trigger *trig; 63 64/* private: */ 65 struct completion completion; 66 bool irq_dis; 67 68 bool bus_locked; 69 70 uint8_t comm; 71 72 const struct ad_sigma_delta_info *info; 73 74 /* 75 * DMA (thus cache coherency maintenance) requires the 76 * transfer buffers to live in their own cache lines. 77 */ 78 uint8_t data[4] ____cacheline_aligned; 79}; 80 81static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd, 82 unsigned int channel) 83{ 84 if (sd->info->set_channel) 85 return sd->info->set_channel(sd, channel); 86 87 return 0; 88} 89 90static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd, 91 unsigned int mode) 92{ 93 if (sd->info->set_mode) 94 return sd->info->set_mode(sd, mode); 95 96 return 0; 97} 98 99static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd, 100 unsigned int raw_sample) 101{ 102 if (sd->info->postprocess_sample) 103 return sd->info->postprocess_sample(sd, raw_sample); 104 105 return 0; 106} 107 108void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm); 109int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, 110 unsigned int size, unsigned int val); 111int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, 112 unsigned int size, unsigned int *val); 113 114int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, 115 const struct iio_chan_spec *chan, int *val); 116int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, 117 const struct ad_sd_calib_data *cd, unsigned int n); 118int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, 119 struct spi_device *spi, const struct ad_sigma_delta_info *info); 120 121int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev); 122void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev); 123 124int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig); 125 126#define __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ 127 _storagebits, _shift, _extend_name, _type) \ 128 { \ 129 .type = (_type), \ 130 .differential = (_channel2 == -1 ? 0 : 1), \ 131 .indexed = 1, \ 132 .channel = (_channel1), \ 133 .channel2 = (_channel2), \ 134 .address = (_address), \ 135 .extend_name = (_extend_name), \ 136 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 137 BIT(IIO_CHAN_INFO_OFFSET), \ 138 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 139 .scan_index = (_si), \ 140 .scan_type = { \ 141 .sign = 'u', \ 142 .realbits = (_bits), \ 143 .storagebits = (_storagebits), \ 144 .shift = (_shift), \ 145 .endianness = IIO_BE, \ 146 }, \ 147 } 148 149#define AD_SD_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ 150 _storagebits, _shift) \ 151 __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \ 152 _storagebits, _shift, NULL, IIO_VOLTAGE) 153 154#define AD_SD_SHORTED_CHANNEL(_si, _channel, _address, _bits, \ 155 _storagebits, _shift) \ 156 __AD_SD_CHANNEL(_si, _channel, _channel, _address, _bits, \ 157 _storagebits, _shift, "shorted", IIO_VOLTAGE) 158 159#define AD_SD_CHANNEL(_si, _channel, _address, _bits, \ 160 _storagebits, _shift) \ 161 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \ 162 _storagebits, _shift, NULL, IIO_VOLTAGE) 163 164#define AD_SD_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \ 165 __AD_SD_CHANNEL(_si, 0, -1, _address, _bits, \ 166 _storagebits, _shift, NULL, IIO_TEMP) 167 168#define AD_SD_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \ 169 _shift) \ 170 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \ 171 _storagebits, _shift, "supply", IIO_VOLTAGE) 172 173#endif 174