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 | #include <linux/iio/iio.h> |
12 | |
13 | enum ad_sigma_delta_mode { |
14 | AD_SD_MODE_CONTINUOUS = 0, |
15 | AD_SD_MODE_SINGLE = 1, |
16 | AD_SD_MODE_IDLE = 2, |
17 | AD_SD_MODE_POWERDOWN = 3, |
18 | }; |
19 | |
20 | /** |
21 | * struct ad_sigma_delta_calib_data - Calibration data for Sigma Delta devices |
22 | * @mode: Calibration mode. |
23 | * @channel: Calibration channel. |
24 | */ |
25 | struct ad_sd_calib_data { |
26 | unsigned int mode; |
27 | unsigned int channel; |
28 | }; |
29 | |
30 | struct ad_sigma_delta; |
31 | struct device; |
32 | struct iio_dev; |
33 | |
34 | /** |
35 | * struct ad_sigma_delta_info - Sigma Delta driver specific callbacks and options |
36 | * @set_channel: Will be called to select the current channel, may be NULL. |
37 | * @append_status: Will be called to enable status append at the end of the sample, may be NULL. |
38 | * @set_mode: Will be called to select the current mode, may be NULL. |
39 | * @disable_all: Will be called to disable all channels, may be NULL. |
40 | * @postprocess_sample: Is called for each sampled data word, can be used to |
41 | * modify or drop the sample data, it, may be NULL. |
42 | * @has_registers: true if the device has writable and readable registers, false |
43 | * if there is just one read-only sample data shift register. |
44 | * @addr_shift: Shift of the register address in the communications register. |
45 | * @read_mask: Mask for the communications register having the read bit set. |
46 | * @status_ch_mask: Mask for the channel number stored in status register. |
47 | * @data_reg: Address of the data register, if 0 the default address of 0x3 will |
48 | * be used. |
49 | * @irq_flags: flags for the interrupt used by the triggered buffer |
50 | * @num_slots: Number of sequencer slots |
51 | */ |
52 | struct ad_sigma_delta_info { |
53 | int (*set_channel)(struct ad_sigma_delta *, unsigned int channel); |
54 | int (*append_status)(struct ad_sigma_delta *, bool append); |
55 | int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode); |
56 | int (*disable_all)(struct ad_sigma_delta *); |
57 | int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample); |
58 | bool has_registers; |
59 | unsigned int addr_shift; |
60 | unsigned int read_mask; |
61 | unsigned int status_ch_mask; |
62 | unsigned int data_reg; |
63 | unsigned long irq_flags; |
64 | unsigned int num_slots; |
65 | }; |
66 | |
67 | /** |
68 | * struct ad_sigma_delta - Sigma Delta device struct |
69 | * @spi: The spi device associated with the Sigma Delta device. |
70 | * @trig: The IIO trigger associated with the Sigma Delta device. |
71 | * |
72 | * Most of the fields are private to the sigma delta library code and should not |
73 | * be accessed by individual drivers. |
74 | */ |
75 | struct ad_sigma_delta { |
76 | struct spi_device *spi; |
77 | struct iio_trigger *trig; |
78 | |
79 | /* private: */ |
80 | struct completion completion; |
81 | bool irq_dis; |
82 | |
83 | bool bus_locked; |
84 | bool keep_cs_asserted; |
85 | |
86 | uint8_t comm; |
87 | |
88 | const struct ad_sigma_delta_info *info; |
89 | unsigned int active_slots; |
90 | unsigned int current_slot; |
91 | unsigned int num_slots; |
92 | bool status_appended; |
93 | /* map slots to channels in order to know what to expect from devices */ |
94 | unsigned int *slots; |
95 | uint8_t *samples_buf; |
96 | |
97 | /* |
98 | * DMA (thus cache coherency maintenance) requires the |
99 | * transfer buffers to live in their own cache lines. |
100 | * 'tx_buf' is up to 32 bits. |
101 | * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp, |
102 | * rounded to 16 bytes to take into account padding. |
103 | */ |
104 | uint8_t tx_buf[4] __aligned(IIO_DMA_MINALIGN); |
105 | uint8_t rx_buf[16] __aligned(8); |
106 | }; |
107 | |
108 | static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd, |
109 | unsigned int channel) |
110 | { |
111 | if (sd->info->set_channel) |
112 | return sd->info->set_channel(sd, channel); |
113 | |
114 | return 0; |
115 | } |
116 | |
117 | static inline int ad_sigma_delta_append_status(struct ad_sigma_delta *sd, bool append) |
118 | { |
119 | int ret; |
120 | |
121 | if (sd->info->append_status) { |
122 | ret = sd->info->append_status(sd, append); |
123 | if (ret < 0) |
124 | return ret; |
125 | |
126 | sd->status_appended = append; |
127 | } |
128 | |
129 | return 0; |
130 | } |
131 | |
132 | static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd) |
133 | { |
134 | if (sd->info->disable_all) |
135 | return sd->info->disable_all(sd); |
136 | |
137 | return 0; |
138 | } |
139 | |
140 | static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd, |
141 | unsigned int mode) |
142 | { |
143 | if (sd->info->set_mode) |
144 | return sd->info->set_mode(sd, mode); |
145 | |
146 | return 0; |
147 | } |
148 | |
149 | static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd, |
150 | unsigned int raw_sample) |
151 | { |
152 | if (sd->info->postprocess_sample) |
153 | return sd->info->postprocess_sample(sd, raw_sample); |
154 | |
155 | return 0; |
156 | } |
157 | |
158 | void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm); |
159 | int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, |
160 | unsigned int size, unsigned int val); |
161 | int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, |
162 | unsigned int size, unsigned int *val); |
163 | |
164 | int ad_sd_reset(struct ad_sigma_delta *sigma_delta, |
165 | unsigned int reset_length); |
166 | |
167 | int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, |
168 | const struct iio_chan_spec *chan, int *val); |
169 | int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, |
170 | unsigned int mode, unsigned int channel); |
171 | int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, |
172 | const struct ad_sd_calib_data *cd, unsigned int n); |
173 | int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, |
174 | struct spi_device *spi, const struct ad_sigma_delta_info *info); |
175 | |
176 | int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev); |
177 | |
178 | int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig); |
179 | |
180 | #endif |
181 | |