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 * @append_status: Will be called to enable status append at the end of the sample, may be NULL.
36 * @set_mode: Will be called to select the current mode, may be NULL.
37 * @disable_all: Will be called to disable all channels, may be NULL.
38 * @postprocess_sample: Is called for each sampled data word, can be used to
39 * modify or drop the sample data, it, may be NULL.
40 * @has_registers: true if the device has writable and readable registers, false
41 * if there is just one read-only sample data shift register.
42 * @addr_shift: Shift of the register address in the communications register.
43 * @read_mask: Mask for the communications register having the read bit set.
44 * @status_ch_mask: Mask for the channel number stored in status register.
45 * @data_reg: Address of the data register, if 0 the default address of 0x3 will
46 * be used.
47 * @irq_flags: flags for the interrupt used by the triggered buffer
48 * @num_slots: Number of sequencer slots
49 */
50 struct ad_sigma_delta_info {
51 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
52 int (*append_status)(struct ad_sigma_delta *, bool append);
53 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
54 int (*disable_all)(struct ad_sigma_delta *);
55 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
56 bool has_registers;
57 unsigned int addr_shift;
58 unsigned int read_mask;
59 unsigned int status_ch_mask;
60 unsigned int data_reg;
61 unsigned long irq_flags;
62 unsigned int num_slots;
63 };
64
65 /**
66 * struct ad_sigma_delta - Sigma Delta device struct
67 * @spi: The spi device associated with the Sigma Delta device.
68 * @trig: The IIO trigger associated with the Sigma Delta device.
69 *
70 * Most of the fields are private to the sigma delta library code and should not
71 * be accessed by individual drivers.
72 */
73 struct ad_sigma_delta {
74 struct spi_device *spi;
75 struct iio_trigger *trig;
76
77 /* private: */
78 struct completion completion;
79 bool irq_dis;
80
81 bool bus_locked;
82 bool keep_cs_asserted;
83
84 uint8_t comm;
85
86 const struct ad_sigma_delta_info *info;
87 unsigned int active_slots;
88 unsigned int current_slot;
89 unsigned int num_slots;
90 bool status_appended;
91 /* map slots to channels in order to know what to expect from devices */
92 unsigned int *slots;
93 uint8_t *samples_buf;
94
95 /*
96 * DMA (thus cache coherency maintenance) requires the
97 * transfer buffers to live in their own cache lines.
98 * 'tx_buf' is up to 32 bits.
99 * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp,
100 * rounded to 16 bytes to take into account padding.
101 */
102 uint8_t tx_buf[4] ____cacheline_aligned;
103 uint8_t rx_buf[16] __aligned(8);
104 };
105
ad_sigma_delta_set_channel(struct ad_sigma_delta * sd,unsigned int channel)106 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
107 unsigned int channel)
108 {
109 if (sd->info->set_channel)
110 return sd->info->set_channel(sd, channel);
111
112 return 0;
113 }
114
ad_sigma_delta_append_status(struct ad_sigma_delta * sd,bool append)115 static inline int ad_sigma_delta_append_status(struct ad_sigma_delta *sd, bool append)
116 {
117 int ret;
118
119 if (sd->info->append_status) {
120 ret = sd->info->append_status(sd, append);
121 if (ret < 0)
122 return ret;
123
124 sd->status_appended = append;
125 }
126
127 return 0;
128 }
129
ad_sigma_delta_disable_all(struct ad_sigma_delta * sd)130 static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd)
131 {
132 if (sd->info->disable_all)
133 return sd->info->disable_all(sd);
134
135 return 0;
136 }
137
ad_sigma_delta_set_mode(struct ad_sigma_delta * sd,unsigned int mode)138 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
139 unsigned int mode)
140 {
141 if (sd->info->set_mode)
142 return sd->info->set_mode(sd, mode);
143
144 return 0;
145 }
146
ad_sigma_delta_postprocess_sample(struct ad_sigma_delta * sd,unsigned int raw_sample)147 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
148 unsigned int raw_sample)
149 {
150 if (sd->info->postprocess_sample)
151 return sd->info->postprocess_sample(sd, raw_sample);
152
153 return 0;
154 }
155
156 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
157 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
158 unsigned int size, unsigned int val);
159 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
160 unsigned int size, unsigned int *val);
161
162 int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
163 unsigned int reset_length);
164
165 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
166 const struct iio_chan_spec *chan, int *val);
167 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
168 unsigned int mode, unsigned int channel);
169 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
170 const struct ad_sd_calib_data *cd, unsigned int n);
171 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
172 struct spi_device *spi, const struct ad_sigma_delta_info *info);
173
174 int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev);
175
176 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
177
178 #endif
179