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 * @irq_flags: flags for the interrupt used by the triggered buffer
44 */
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);
49 bool has_registers;
50 unsigned int addr_shift;
51 unsigned int read_mask;
52 unsigned int data_reg;
53 unsigned long irq_flags;
54 };
55
56 /**
57 * struct ad_sigma_delta - Sigma Delta device struct
58 * @spi: The spi device associated with the Sigma Delta device.
59 * @trig: The IIO trigger associated with the Sigma Delta device.
60 *
61 * Most of the fields are private to the sigma delta library code and should not
62 * be accessed by individual drivers.
63 */
64 struct ad_sigma_delta {
65 struct spi_device *spi;
66 struct iio_trigger *trig;
67
68 /* private: */
69 struct completion completion;
70 bool irq_dis;
71
72 bool bus_locked;
73 bool keep_cs_asserted;
74
75 uint8_t comm;
76
77 const struct ad_sigma_delta_info *info;
78
79 /*
80 * DMA (thus cache coherency maintenance) requires the
81 * transfer buffers to live in their own cache lines.
82 */
83 uint8_t data[4] ____cacheline_aligned;
84 };
85
ad_sigma_delta_set_channel(struct ad_sigma_delta * sd,unsigned int channel)86 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
87 unsigned int channel)
88 {
89 if (sd->info->set_channel)
90 return sd->info->set_channel(sd, channel);
91
92 return 0;
93 }
94
ad_sigma_delta_set_mode(struct ad_sigma_delta * sd,unsigned int mode)95 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
96 unsigned int mode)
97 {
98 if (sd->info->set_mode)
99 return sd->info->set_mode(sd, mode);
100
101 return 0;
102 }
103
ad_sigma_delta_postprocess_sample(struct ad_sigma_delta * sd,unsigned int raw_sample)104 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
105 unsigned int raw_sample)
106 {
107 if (sd->info->postprocess_sample)
108 return sd->info->postprocess_sample(sd, raw_sample);
109
110 return 0;
111 }
112
113 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
114 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
115 unsigned int size, unsigned int val);
116 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
117 unsigned int size, unsigned int *val);
118
119 int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
120 unsigned int reset_length);
121
122 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
123 const struct iio_chan_spec *chan, int *val);
124 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
125 unsigned int mode, unsigned int channel);
126 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
127 const struct ad_sd_calib_data *cd, unsigned int n);
128 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
129 struct spi_device *spi, const struct ad_sigma_delta_info *info);
130
131 int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev);
132 void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev);
133
134 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
135
136 #endif
137
