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 * @disable_one: Will be called to disable a single channel after
41 * ad_sigma_delta_single_conversion(), may be NULL.
42 * Usage of this callback expects iio_chan_spec.address to contain
43 * the value required for the driver to identify the channel.
44 * @postprocess_sample: Is called for each sampled data word, can be used to
45 * modify or drop the sample data, it, may be NULL.
46 * @has_registers: true if the device has writable and readable registers, false
47 * if there is just one read-only sample data shift register.
48 * @addr_shift: Shift of the register address in the communications register.
49 * @read_mask: Mask for the communications register having the read bit set.
50 * @status_ch_mask: Mask for the channel number stored in status register.
51 * @data_reg: Address of the data register, if 0 the default address of 0x3 will
52 * be used.
53 * @irq_flags: flags for the interrupt used by the triggered buffer
54 * @num_slots: Number of sequencer slots
55 * @irq_line: IRQ for reading conversions. If 0, spi->irq will be used
56 */
57 struct ad_sigma_delta_info {
58 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
59 int (*append_status)(struct ad_sigma_delta *, bool append);
60 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
61 int (*disable_all)(struct ad_sigma_delta *);
62 int (*disable_one)(struct ad_sigma_delta *, unsigned int chan);
63 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
64 bool has_registers;
65 unsigned int addr_shift;
66 unsigned int read_mask;
67 unsigned int status_ch_mask;
68 unsigned int data_reg;
69 unsigned long irq_flags;
70 unsigned int num_slots;
71 int irq_line;
72 };
73
74 /**
75 * struct ad_sigma_delta - Sigma Delta device struct
76 * @spi: The spi device associated with the Sigma Delta device.
77 * @trig: The IIO trigger associated with the Sigma Delta device.
78 *
79 * Most of the fields are private to the sigma delta library code and should not
80 * be accessed by individual drivers.
81 */
82 struct ad_sigma_delta {
83 struct spi_device *spi;
84 struct iio_trigger *trig;
85
86 /* private: */
87 struct completion completion;
88 bool irq_dis;
89
90 bool bus_locked;
91 bool keep_cs_asserted;
92
93 uint8_t comm;
94
95 const struct ad_sigma_delta_info *info;
96 unsigned int active_slots;
97 unsigned int current_slot;
98 unsigned int num_slots;
99 int irq_line;
100 bool status_appended;
101 /* map slots to channels in order to know what to expect from devices */
102 unsigned int *slots;
103 uint8_t *samples_buf;
104
105 /*
106 * DMA (thus cache coherency maintenance) requires the
107 * transfer buffers to live in their own cache lines.
108 * 'tx_buf' is up to 32 bits.
109 * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp,
110 * rounded to 16 bytes to take into account padding.
111 */
112 uint8_t tx_buf[4] __aligned(IIO_DMA_MINALIGN);
113 uint8_t rx_buf[16] __aligned(8);
114 };
115
116 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
117 unsigned int channel)
118 {
119 if (sd->info->set_channel)
120 return sd->info->set_channel(sd, channel);
121
122 return 0;
123 }
124
125 static inline int ad_sigma_delta_append_status(struct ad_sigma_delta *sd, bool append)
126 {
127 int ret;
128
129 if (sd->info->append_status) {
130 ret = sd->info->append_status(sd, append);
131 if (ret < 0)
132 return ret;
133
134 sd->status_appended = append;
135 }
136
137 return 0;
138 }
139
140 static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd)
141 {
142 if (sd->info->disable_all)
143 return sd->info->disable_all(sd);
144
145 return 0;
146 }
147
148 static inline int ad_sigma_delta_disable_one(struct ad_sigma_delta *sd,
149 unsigned int chan)
150 {
151 if (sd->info->disable_one)
152 return sd->info->disable_one(sd, chan);
153
154 return 0;
155 }
156
157 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
158 unsigned int mode)
159 {
160 if (sd->info->set_mode)
161 return sd->info->set_mode(sd, mode);
162
163 return 0;
164 }
165
166 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
167 unsigned int raw_sample)
168 {
169 if (sd->info->postprocess_sample)
170 return sd->info->postprocess_sample(sd, raw_sample);
171
172 return 0;
173 }
174
175 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
176 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
177 unsigned int size, unsigned int val);
178 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
179 unsigned int size, unsigned int *val);
180
181 int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
182 unsigned int reset_length);
183
184 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
185 const struct iio_chan_spec *chan, int *val);
186 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
187 unsigned int mode, unsigned int channel);
188 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
189 const struct ad_sd_calib_data *cd, unsigned int n);
190 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
191 struct spi_device *spi, const struct ad_sigma_delta_info *info);
192
193 int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev);
194
195 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
196
197 #endif
198
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