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 device;
30 struct iio_dev;
31
32 /**
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
43 * be used.
44 * @irq_flags: flags for the interrupt used by the triggered buffer
45 */
46 struct ad_sigma_delta_info {
47 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
48 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
49 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
50 bool has_registers;
51 unsigned int addr_shift;
52 unsigned int read_mask;
53 unsigned int data_reg;
54 unsigned long irq_flags;
55 };
56
57 /**
58 * struct ad_sigma_delta - Sigma Delta device struct
59 * @spi: The spi device associated with the Sigma Delta device.
60 * @trig: The IIO trigger associated with the Sigma Delta device.
61 *
62 * Most of the fields are private to the sigma delta library code and should not
63 * be accessed by individual drivers.
64 */
65 struct ad_sigma_delta {
66 struct spi_device *spi;
67 struct iio_trigger *trig;
68
69 /* private: */
70 struct completion completion;
71 bool irq_dis;
72
73 bool bus_locked;
74 bool keep_cs_asserted;
75
76 uint8_t comm;
77
78 const struct ad_sigma_delta_info *info;
79
80 /*
81 * DMA (thus cache coherency maintenance) requires the
82 * transfer buffers to live in their own cache lines.
83 * 'tx_buf' is up to 32 bits.
84 * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp,
85 * rounded to 16 bytes to take into account padding.
86 */
87 uint8_t tx_buf[4] ____cacheline_aligned;
88 uint8_t rx_buf[16] __aligned(8);
89 };
90
ad_sigma_delta_set_channel(struct ad_sigma_delta * sd,unsigned int channel)91 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
92 unsigned int channel)
93 {
94 if (sd->info->set_channel)
95 return sd->info->set_channel(sd, channel);
96
97 return 0;
98 }
99
ad_sigma_delta_set_mode(struct ad_sigma_delta * sd,unsigned int mode)100 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
101 unsigned int mode)
102 {
103 if (sd->info->set_mode)
104 return sd->info->set_mode(sd, mode);
105
106 return 0;
107 }
108
ad_sigma_delta_postprocess_sample(struct ad_sigma_delta * sd,unsigned int raw_sample)109 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
110 unsigned int raw_sample)
111 {
112 if (sd->info->postprocess_sample)
113 return sd->info->postprocess_sample(sd, raw_sample);
114
115 return 0;
116 }
117
118 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
119 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
120 unsigned int size, unsigned int val);
121 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
122 unsigned int size, unsigned int *val);
123
124 int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
125 unsigned int reset_length);
126
127 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
128 const struct iio_chan_spec *chan, int *val);
129 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
130 unsigned int mode, unsigned int channel);
131 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
132 const struct ad_sd_calib_data *cd, unsigned int n);
133 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
134 struct spi_device *spi, const struct ad_sigma_delta_info *info);
135
136 int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev);
137
138 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
139
140 #endif
141