1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Support code for Analog Devices Sigma-Delta ADCs
4 *
5 * Copyright 2012 Analog Devices Inc.
6 * Author: Lars-Peter Clausen <lars@metafoo.de>
7 */
8 #ifndef __AD_SIGMA_DELTA_H__
9 #define __AD_SIGMA_DELTA_H__
10
11 enum ad_sigma_delta_mode {
12 AD_SD_MODE_CONTINUOUS = 0,
13 AD_SD_MODE_SINGLE = 1,
14 AD_SD_MODE_IDLE = 2,
15 AD_SD_MODE_POWERDOWN = 3,
16 };
17
18 /**
19 * struct ad_sigma_delta_calib_data - Calibration data for Sigma Delta devices
20 * @mode: Calibration mode.
21 * @channel: Calibration channel.
22 */
23 struct ad_sd_calib_data {
24 unsigned int mode;
25 unsigned int channel;
26 };
27
28 struct ad_sigma_delta;
29 struct iio_dev;
30
31 /**
32 * struct ad_sigma_delta_info - Sigma Delta driver specific callbacks and options
33 * @set_channel: Will be called to select the current channel, may be NULL.
34 * @set_mode: Will be called to select the current mode, may be NULL.
35 * @postprocess_sample: Is called for each sampled data word, can be used to
36 * modify or drop the sample data, it, may be NULL.
37 * @has_registers: true if the device has writable and readable registers, false
38 * if there is just one read-only sample data shift register.
39 * @addr_shift: Shift of the register address in the communications register.
40 * @read_mask: Mask for the communications register having the read bit set.
41 * @data_reg: Address of the data register, if 0 the default address of 0x3 will
42 * be used.
43 */
44 struct ad_sigma_delta_info {
45 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
46 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
47 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
48 bool has_registers;
49 unsigned int addr_shift;
50 unsigned int read_mask;
51 unsigned int data_reg;
52 };
53
54 /**
55 * struct ad_sigma_delta - Sigma Delta device struct
56 * @spi: The spi device associated with the Sigma Delta device.
57 * @trig: The IIO trigger associated with the Sigma Delta device.
58 *
59 * Most of the fields are private to the sigma delta library code and should not
60 * be accessed by individual drivers.
61 */
62 struct ad_sigma_delta {
63 struct spi_device *spi;
64 struct iio_trigger *trig;
65
66 /* private: */
67 struct completion completion;
68 bool irq_dis;
69
70 bool bus_locked;
71 bool keep_cs_asserted;
72
73 uint8_t comm;
74
75 const struct ad_sigma_delta_info *info;
76
77 /*
78 * DMA (thus cache coherency maintenance) requires the
79 * transfer buffers to live in their own cache lines.
80 */
81 uint8_t data[4] ____cacheline_aligned;
82 };
83
ad_sigma_delta_set_channel(struct ad_sigma_delta * sd,unsigned int channel)84 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
85 unsigned int channel)
86 {
87 if (sd->info->set_channel)
88 return sd->info->set_channel(sd, channel);
89
90 return 0;
91 }
92
ad_sigma_delta_set_mode(struct ad_sigma_delta * sd,unsigned int mode)93 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
94 unsigned int mode)
95 {
96 if (sd->info->set_mode)
97 return sd->info->set_mode(sd, mode);
98
99 return 0;
100 }
101
ad_sigma_delta_postprocess_sample(struct ad_sigma_delta * sd,unsigned int raw_sample)102 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
103 unsigned int raw_sample)
104 {
105 if (sd->info->postprocess_sample)
106 return sd->info->postprocess_sample(sd, raw_sample);
107
108 return 0;
109 }
110
111 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
112 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
113 unsigned int size, unsigned int val);
114 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
115 unsigned int size, unsigned int *val);
116
117 int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
118 unsigned int reset_length);
119
120 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
121 const struct iio_chan_spec *chan, int *val);
122 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
123 const struct ad_sd_calib_data *cd, unsigned int n);
124 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
125 struct spi_device *spi, const struct ad_sigma_delta_info *info);
126
127 int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev);
128 void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev);
129
130 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
131
132 #define __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
133 _storagebits, _shift, _extend_name, _type, _mask_all) \
134 { \
135 .type = (_type), \
136 .differential = (_channel2 == -1 ? 0 : 1), \
137 .indexed = 1, \
138 .channel = (_channel1), \
139 .channel2 = (_channel2), \
140 .address = (_address), \
141 .extend_name = (_extend_name), \
142 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
143 BIT(IIO_CHAN_INFO_OFFSET), \
144 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
145 .info_mask_shared_by_all = _mask_all, \
146 .scan_index = (_si), \
147 .scan_type = { \
148 .sign = 'u', \
149 .realbits = (_bits), \
150 .storagebits = (_storagebits), \
151 .shift = (_shift), \
152 .endianness = IIO_BE, \
153 }, \
154 }
155
156 #define AD_SD_DIFF_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
157 _storagebits, _shift) \
158 __AD_SD_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
159 _storagebits, _shift, NULL, IIO_VOLTAGE, \
160 BIT(IIO_CHAN_INFO_SAMP_FREQ))
161
162 #define AD_SD_SHORTED_CHANNEL(_si, _channel, _address, _bits, \
163 _storagebits, _shift) \
164 __AD_SD_CHANNEL(_si, _channel, _channel, _address, _bits, \
165 _storagebits, _shift, "shorted", IIO_VOLTAGE, \
166 BIT(IIO_CHAN_INFO_SAMP_FREQ))
167
168 #define AD_SD_CHANNEL(_si, _channel, _address, _bits, \
169 _storagebits, _shift) \
170 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
171 _storagebits, _shift, NULL, IIO_VOLTAGE, \
172 BIT(IIO_CHAN_INFO_SAMP_FREQ))
173
174 #define AD_SD_CHANNEL_NO_SAMP_FREQ(_si, _channel, _address, _bits, \
175 _storagebits, _shift) \
176 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
177 _storagebits, _shift, NULL, IIO_VOLTAGE, 0)
178
179 #define AD_SD_TEMP_CHANNEL(_si, _address, _bits, _storagebits, _shift) \
180 __AD_SD_CHANNEL(_si, 0, -1, _address, _bits, \
181 _storagebits, _shift, NULL, IIO_TEMP, \
182 BIT(IIO_CHAN_INFO_SAMP_FREQ))
183
184 #define AD_SD_SUPPLY_CHANNEL(_si, _channel, _address, _bits, _storagebits, \
185 _shift) \
186 __AD_SD_CHANNEL(_si, _channel, -1, _address, _bits, \
187 _storagebits, _shift, "supply", IIO_VOLTAGE, \
188 BIT(IIO_CHAN_INFO_SAMP_FREQ))
189
190 #endif
191
