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 * @irq_line: IRQ for reading conversions. If 0, spi->irq will be used
52 */
53 struct ad_sigma_delta_info {
54 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
55 int (*append_status)(struct ad_sigma_delta *, bool append);
56 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
57 int (*disable_all)(struct ad_sigma_delta *);
58 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
59 bool has_registers;
60 unsigned int addr_shift;
61 unsigned int read_mask;
62 unsigned int status_ch_mask;
63 unsigned int data_reg;
64 unsigned long irq_flags;
65 unsigned int num_slots;
66 int irq_line;
67 };
68
69 /**
70 * struct ad_sigma_delta - Sigma Delta device struct
71 * @spi: The spi device associated with the Sigma Delta device.
72 * @trig: The IIO trigger associated with the Sigma Delta device.
73 *
74 * Most of the fields are private to the sigma delta library code and should not
75 * be accessed by individual drivers.
76 */
77 struct ad_sigma_delta {
78 struct spi_device *spi;
79 struct iio_trigger *trig;
80
81 /* private: */
82 struct completion completion;
83 bool irq_dis;
84
85 bool bus_locked;
86 bool keep_cs_asserted;
87
88 uint8_t comm;
89
90 const struct ad_sigma_delta_info *info;
91 unsigned int active_slots;
92 unsigned int current_slot;
93 unsigned int num_slots;
94 int irq_line;
95 bool status_appended;
96 /* map slots to channels in order to know what to expect from devices */
97 unsigned int *slots;
98 uint8_t *samples_buf;
99
100 /*
101 * DMA (thus cache coherency maintenance) requires the
102 * transfer buffers to live in their own cache lines.
103 * 'tx_buf' is up to 32 bits.
104 * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp,
105 * rounded to 16 bytes to take into account padding.
106 */
107 uint8_t tx_buf[4] __aligned(IIO_DMA_MINALIGN);
108 uint8_t rx_buf[16] __aligned(8);
109 };
110
ad_sigma_delta_set_channel(struct ad_sigma_delta * sd,unsigned int channel)111 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
112 unsigned int channel)
113 {
114 if (sd->info->set_channel)
115 return sd->info->set_channel(sd, channel);
116
117 return 0;
118 }
119
ad_sigma_delta_append_status(struct ad_sigma_delta * sd,bool append)120 static inline int ad_sigma_delta_append_status(struct ad_sigma_delta *sd, bool append)
121 {
122 int ret;
123
124 if (sd->info->append_status) {
125 ret = sd->info->append_status(sd, append);
126 if (ret < 0)
127 return ret;
128
129 sd->status_appended = append;
130 }
131
132 return 0;
133 }
134
ad_sigma_delta_disable_all(struct ad_sigma_delta * sd)135 static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd)
136 {
137 if (sd->info->disable_all)
138 return sd->info->disable_all(sd);
139
140 return 0;
141 }
142
ad_sigma_delta_set_mode(struct ad_sigma_delta * sd,unsigned int mode)143 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
144 unsigned int mode)
145 {
146 if (sd->info->set_mode)
147 return sd->info->set_mode(sd, mode);
148
149 return 0;
150 }
151
ad_sigma_delta_postprocess_sample(struct ad_sigma_delta * sd,unsigned int raw_sample)152 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
153 unsigned int raw_sample)
154 {
155 if (sd->info->postprocess_sample)
156 return sd->info->postprocess_sample(sd, raw_sample);
157
158 return 0;
159 }
160
161 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
162 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
163 unsigned int size, unsigned int val);
164 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
165 unsigned int size, unsigned int *val);
166
167 int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
168 unsigned int reset_length);
169
170 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
171 const struct iio_chan_spec *chan, int *val);
172 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
173 unsigned int mode, unsigned int channel);
174 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
175 const struct ad_sd_calib_data *cd, unsigned int n);
176 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
177 struct spi_device *spi, const struct ad_sigma_delta_info *info);
178
179 int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev);
180
181 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
182
183 #endif
184