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.
42 * @data_reg: Address of the data register, if 0 the default address of 0x3 will
45 struct ad_sigma_delta_info {
46 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
47 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
48 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
50 unsigned int addr_shift;
51 unsigned int read_mask;
52 unsigned int data_reg;
56 * struct ad_sigma_delta - Sigma Delta device struct
57 * @spi: The spi device associated with the Sigma Delta device.
58 * @trig: The IIO trigger associated with the Sigma Delta device.
60 * Most of the fields are private to the sigma delta library code and should not
61 * be accessed by individual drivers.
63 struct ad_sigma_delta {
64 struct spi_device *spi;
65 struct iio_trigger *trig;
68 struct completion completion;
72 bool keep_cs_asserted;
76 const struct ad_sigma_delta_info *info;
79 * DMA (thus cache coherency maintenance) requires the
80 * transfer buffers to live in their own cache lines.
82 uint8_t data[4] ____cacheline_aligned;
85 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
88 if (sd->info->set_channel)
89 return sd->info->set_channel(sd, channel);
94 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
97 if (sd->info->set_mode)
98 return sd->info->set_mode(sd, mode);
103 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
104 unsigned int raw_sample)
106 if (sd->info->postprocess_sample)
107 return sd->info->postprocess_sample(sd, raw_sample);
112 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
113 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
114 unsigned int size, unsigned int val);
115 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
116 unsigned int size, unsigned int *val);
118 int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
119 unsigned int reset_length);
121 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
122 const struct iio_chan_spec *chan, int *val);
123 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
124 const struct ad_sd_calib_data *cd, unsigned int n);
125 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
126 struct spi_device *spi, const struct ad_sigma_delta_info *info);
128 int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev);
129 void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev);
131 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
133 #define __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
134 _storagebits, _shift, _extend_name, _type, _mask_all) \
137 .differential = (_channel2 == -1 ? 0 : 1), \
139 .channel = (_channel1), \
140 .channel2 = (_channel2), \
141 .address = (_address), \
142 .extend_name = (_extend_name), \
143 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
144 BIT(IIO_CHAN_INFO_OFFSET), \
145 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
146 .info_mask_shared_by_all = _mask_all, \
147 .scan_index = (_si), \
150 .realbits = (_bits), \
151 .storagebits = (_storagebits), \
153 .endianness = IIO_BE, \
157 #define AD_SD_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
158 _storagebits, _shift) \
159 __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
160 _storagebits, _shift, NULL, IIO_VOLTAGE, \
161 BIT(IIO_CHAN_INFO_SAMP_FREQ))
163 #define AD_SD_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
164 _storagebits, _shift) \
165 __AD_SD_CHANNEL(_si, _channel, _channel, _address, _bits, \
166 _storagebits, _shift, "shorted", IIO_VOLTAGE, \
167 BIT(IIO_CHAN_INFO_SAMP_FREQ))
169 #define AD_SD_CHANNEL(_si, _channel, _address, _bits, \
170 _storagebits, _shift) \
171 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
172 _storagebits, _shift, NULL, IIO_VOLTAGE, \
173 BIT(IIO_CHAN_INFO_SAMP_FREQ))
175 #define AD_SD_CHANNEL_NO_SAMP_FREQ(_si, _channel, _address, _bits, \
176 _storagebits, _shift) \
177 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
178 _storagebits, _shift, NULL, IIO_VOLTAGE, 0)
180 #define AD_SD_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \
181 __AD_SD_CHANNEL(_si, 0, -1, _address, _bits, \
182 _storagebits, _shift, NULL, IIO_TEMP, \
183 BIT(IIO_CHAN_INFO_SAMP_FREQ))
185 #define AD_SD_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
187 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
188 _storagebits, _shift, "supply", IIO_VOLTAGE, \
189 BIT(IIO_CHAN_INFO_SAMP_FREQ))