179 lines
5.3 KiB
C
179 lines
5.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Support code for Analog Devices Sigma-Delta ADCs
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*
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* Copyright 2012 Analog Devices Inc.
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* Author: Lars-Peter Clausen <lars@metafoo.de>
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*/
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#ifndef __AD_SIGMA_DELTA_H__
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#define __AD_SIGMA_DELTA_H__
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enum ad_sigma_delta_mode {
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AD_SD_MODE_CONTINUOUS = 0,
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AD_SD_MODE_SINGLE = 1,
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AD_SD_MODE_IDLE = 2,
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AD_SD_MODE_POWERDOWN = 3,
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};
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/**
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* struct ad_sigma_delta_calib_data - Calibration data for Sigma Delta devices
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* @mode: Calibration mode.
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* @channel: Calibration channel.
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*/
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struct ad_sd_calib_data {
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unsigned int mode;
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unsigned int channel;
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};
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struct ad_sigma_delta;
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struct device;
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struct iio_dev;
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/**
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* struct ad_sigma_delta_info - Sigma Delta driver specific callbacks and options
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* @set_channel: Will be called to select the current channel, may be NULL.
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* @append_status: Will be called to enable status append at the end of the sample, may be NULL.
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* @set_mode: Will be called to select the current mode, may be NULL.
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* @disable_all: Will be called to disable all channels, may be NULL.
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* @postprocess_sample: Is called for each sampled data word, can be used to
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* modify or drop the sample data, it, may be NULL.
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* @has_registers: true if the device has writable and readable registers, false
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* if there is just one read-only sample data shift register.
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* @addr_shift: Shift of the register address in the communications register.
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* @read_mask: Mask for the communications register having the read bit set.
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* @status_ch_mask: Mask for the channel number stored in status register.
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* @data_reg: Address of the data register, if 0 the default address of 0x3 will
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* be used.
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* @irq_flags: flags for the interrupt used by the triggered buffer
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* @num_slots: Number of sequencer slots
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*/
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struct ad_sigma_delta_info {
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int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
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int (*append_status)(struct ad_sigma_delta *, bool append);
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int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
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int (*disable_all)(struct ad_sigma_delta *);
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int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
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bool has_registers;
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unsigned int addr_shift;
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unsigned int read_mask;
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unsigned int status_ch_mask;
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unsigned int data_reg;
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unsigned long irq_flags;
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unsigned int num_slots;
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};
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/**
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* struct ad_sigma_delta - Sigma Delta device struct
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* @spi: The spi device associated with the Sigma Delta device.
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* @trig: The IIO trigger associated with the Sigma Delta device.
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*
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* Most of the fields are private to the sigma delta library code and should not
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* be accessed by individual drivers.
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*/
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struct ad_sigma_delta {
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struct spi_device *spi;
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struct iio_trigger *trig;
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/* private: */
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struct completion completion;
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bool irq_dis;
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bool bus_locked;
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bool keep_cs_asserted;
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uint8_t comm;
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const struct ad_sigma_delta_info *info;
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unsigned int active_slots;
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unsigned int current_slot;
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unsigned int num_slots;
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bool status_appended;
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/* map slots to channels in order to know what to expect from devices */
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unsigned int *slots;
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uint8_t *samples_buf;
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/*
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* DMA (thus cache coherency maintenance) requires the
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* transfer buffers to live in their own cache lines.
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* 'tx_buf' is up to 32 bits.
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* 'rx_buf' is up to 32 bits per sample + 64 bit timestamp,
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* rounded to 16 bytes to take into account padding.
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*/
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uint8_t tx_buf[4] ____cacheline_aligned;
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uint8_t rx_buf[16] __aligned(8);
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};
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static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
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unsigned int channel)
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{
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if (sd->info->set_channel)
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return sd->info->set_channel(sd, channel);
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return 0;
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}
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static inline int ad_sigma_delta_append_status(struct ad_sigma_delta *sd, bool append)
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{
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int ret;
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if (sd->info->append_status) {
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ret = sd->info->append_status(sd, append);
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if (ret < 0)
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return ret;
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sd->status_appended = append;
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}
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return 0;
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}
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static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd)
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{
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if (sd->info->disable_all)
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return sd->info->disable_all(sd);
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return 0;
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}
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static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
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unsigned int mode)
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{
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if (sd->info->set_mode)
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return sd->info->set_mode(sd, mode);
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return 0;
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}
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static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
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unsigned int raw_sample)
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{
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if (sd->info->postprocess_sample)
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return sd->info->postprocess_sample(sd, raw_sample);
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return 0;
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}
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void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
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int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
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unsigned int size, unsigned int val);
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int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
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unsigned int size, unsigned int *val);
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int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
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unsigned int reset_length);
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int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan, int *val);
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int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
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unsigned int mode, unsigned int channel);
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int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
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const struct ad_sd_calib_data *cd, unsigned int n);
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int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
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struct spi_device *spi, const struct ad_sigma_delta_info *info);
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int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev);
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int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
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#endif
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