2 * Support code for Analog Devices Sigma-Delta ADCs
4 * Copyright 2012 Analog Devices Inc.
5 * Author: Lars-Peter Clausen <lars@metafoo.de>
7 * Licensed under the GPL-2.
9 #ifndef __AD_SIGMA_DELTA_H__
10 #define __AD_SIGMA_DELTA_H__
12 enum ad_sigma_delta_mode {
13 AD_SD_MODE_CONTINUOUS = 0,
14 AD_SD_MODE_SINGLE = 1,
16 AD_SD_MODE_POWERDOWN = 3,
20 * struct ad_sigma_delta_calib_data - Calibration data for Sigma Delta devices
21 * @mode: Calibration mode.
22 * @channel: Calibration channel.
24 struct ad_sd_calib_data {
29 struct ad_sigma_delta;
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.
43 struct 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);
48 unsigned int addr_shift;
49 unsigned int read_mask;
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.
57 * Most of the fields are private to the sigma delta library code and should not
58 * be accessed by individual drivers.
60 struct ad_sigma_delta {
61 struct spi_device *spi;
62 struct iio_trigger *trig;
65 struct completion completion;
72 const struct ad_sigma_delta_info *info;
75 * DMA (thus cache coherency maintenance) requires the
76 * transfer buffers to live in their own cache lines.
78 uint8_t data[4] ____cacheline_aligned;
81 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
84 if (sd->info->set_channel)
85 return sd->info->set_channel(sd, channel);
90 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
93 if (sd->info->set_mode)
94 return sd->info->set_mode(sd, mode);
99 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
100 unsigned int raw_sample)
102 if (sd->info->postprocess_sample)
103 return sd->info->postprocess_sample(sd, raw_sample);
108 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
109 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
110 unsigned int size, unsigned int val);
111 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
112 unsigned int size, unsigned int *val);
114 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
115 const struct iio_chan_spec *chan, int *val);
116 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
117 const struct ad_sd_calib_data *cd, unsigned int n);
118 int 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);
121 int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev);
122 void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev);
124 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
126 #define __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
127 _storagebits, _shift, _extend_name, _type) \
130 .differential = (_channel2 == -1 ? 0 : 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), \
142 .realbits = (_bits), \
143 .storagebits = (_storagebits), \
145 .endianness = IIO_BE, \
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)
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)
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)
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)
168 #define AD_SD_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
170 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
171 _storagebits, _shift, "supply", IIO_VOLTAGE)