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 <[email protected]>
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 gpio_desc;
33 struct iio_dev;
34
35 /**
36 * struct ad_sigma_delta_info - Sigma Delta driver specific callbacks and options
37 * @set_channel: Will be called to select the current channel, may be NULL.
38 * @append_status: Will be called to enable status append at the end of the sample, may be NULL.
39 * @set_mode: Will be called to select the current mode, may be NULL.
40 * @disable_all: Will be called to disable all channels, may be NULL.
41 * @disable_one: Will be called to disable a single channel after
42 * ad_sigma_delta_single_conversion(), may be NULL.
43 * Usage of this callback expects iio_chan_spec.address to contain
44 * the value required for the driver to identify the channel.
45 * @postprocess_sample: Is called for each sampled data word, can be used to
46 * modify or drop the sample data, it, may be NULL.
47 * @has_registers: true if the device has writable and readable registers, false
48 * if there is just one read-only sample data shift register.
49 * @addr_shift: Shift of the register address in the communications register.
50 * @read_mask: Mask for the communications register having the read bit set.
51 * @status_ch_mask: Mask for the channel number stored in status register.
52 * @data_reg: Address of the data register, if 0 the default address of 0x3 will
53 * be used.
54 * @irq_flags: flags for the interrupt used by the triggered buffer
55 * @num_slots: Number of sequencer slots
56 * @irq_line: IRQ for reading conversions. If 0, spi->irq will be used
57 * @num_resetclks: Number of SPI clk cycles with MOSI=1 to reset the chip.
58 */
59 struct ad_sigma_delta_info {
60 int (*set_channel)(struct ad_sigma_delta *, unsigned int channel);
61 int (*append_status)(struct ad_sigma_delta *, bool append);
62 int (*set_mode)(struct ad_sigma_delta *, enum ad_sigma_delta_mode mode);
63 int (*disable_all)(struct ad_sigma_delta *);
64 int (*disable_one)(struct ad_sigma_delta *, unsigned int chan);
65 int (*postprocess_sample)(struct ad_sigma_delta *, unsigned int raw_sample);
66 bool has_registers;
67 unsigned int addr_shift;
68 unsigned int read_mask;
69 unsigned int status_ch_mask;
70 unsigned int data_reg;
71 unsigned long irq_flags;
72 unsigned int num_slots;
73 int irq_line;
74 unsigned int num_resetclks;
75 };
76
77 /**
78 * struct ad_sigma_delta - Sigma Delta device struct
79 * @spi: The spi device associated with the Sigma Delta device.
80 * @trig: The IIO trigger associated with the Sigma Delta device.
81 *
82 * Most of the fields are private to the sigma delta library code and should not
83 * be accessed by individual drivers.
84 */
85 struct ad_sigma_delta {
86 struct spi_device *spi;
87 struct iio_trigger *trig;
88
89 /* private: */
90 struct completion completion;
91 spinlock_t irq_lock; /* protects .irq_dis and irq en/disable state */
92 bool irq_dis;
93
94 bool bus_locked;
95 bool keep_cs_asserted;
96
97 uint8_t comm;
98
99 const struct ad_sigma_delta_info *info;
100 unsigned int active_slots;
101 unsigned int current_slot;
102 unsigned int num_slots;
103 struct gpio_desc *rdy_gpiod;
104 int irq_line;
105 bool status_appended;
106 /* map slots to channels in order to know what to expect from devices */
107 unsigned int *slots;
108 uint8_t *samples_buf;
109
110 /*
111 * DMA (thus cache coherency maintenance) requires the
112 * transfer buffers to live in their own cache lines.
113 * 'tx_buf' is up to 32 bits.
114 * 'rx_buf' is up to 32 bits per sample + 64 bit timestamp,
115 * rounded to 16 bytes to take into account padding.
116 */
117 uint8_t tx_buf[4] __aligned(IIO_DMA_MINALIGN);
118 uint8_t rx_buf[16] __aligned(8);
119 };
120
ad_sigma_delta_set_channel(struct ad_sigma_delta * sd,unsigned int channel)121 static inline int ad_sigma_delta_set_channel(struct ad_sigma_delta *sd,
122 unsigned int channel)
123 {
124 if (sd->info->set_channel)
125 return sd->info->set_channel(sd, channel);
126
127 return 0;
128 }
129
ad_sigma_delta_append_status(struct ad_sigma_delta * sd,bool append)130 static inline int ad_sigma_delta_append_status(struct ad_sigma_delta *sd, bool append)
131 {
132 int ret;
133
134 if (sd->info->append_status) {
135 ret = sd->info->append_status(sd, append);
136 if (ret < 0)
137 return ret;
138
139 sd->status_appended = append;
140 }
141
142 return 0;
143 }
144
ad_sigma_delta_disable_all(struct ad_sigma_delta * sd)145 static inline int ad_sigma_delta_disable_all(struct ad_sigma_delta *sd)
146 {
147 if (sd->info->disable_all)
148 return sd->info->disable_all(sd);
149
150 return 0;
151 }
152
ad_sigma_delta_disable_one(struct ad_sigma_delta * sd,unsigned int chan)153 static inline int ad_sigma_delta_disable_one(struct ad_sigma_delta *sd,
154 unsigned int chan)
155 {
156 if (sd->info->disable_one)
157 return sd->info->disable_one(sd, chan);
158
159 return 0;
160 }
161
ad_sigma_delta_set_mode(struct ad_sigma_delta * sd,unsigned int mode)162 static inline int ad_sigma_delta_set_mode(struct ad_sigma_delta *sd,
163 unsigned int mode)
164 {
165 if (sd->info->set_mode)
166 return sd->info->set_mode(sd, mode);
167
168 return 0;
169 }
170
ad_sigma_delta_postprocess_sample(struct ad_sigma_delta * sd,unsigned int raw_sample)171 static inline int ad_sigma_delta_postprocess_sample(struct ad_sigma_delta *sd,
172 unsigned int raw_sample)
173 {
174 if (sd->info->postprocess_sample)
175 return sd->info->postprocess_sample(sd, raw_sample);
176
177 return 0;
178 }
179
180 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm);
181 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
182 unsigned int size, unsigned int val);
183 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
184 unsigned int size, unsigned int *val);
185
186 int ad_sd_reset(struct ad_sigma_delta *sigma_delta);
187
188 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
189 const struct iio_chan_spec *chan, int *val);
190 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
191 unsigned int mode, unsigned int channel);
192 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
193 const struct ad_sd_calib_data *cd, unsigned int n);
194 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
195 struct spi_device *spi, const struct ad_sigma_delta_info *info);
196
197 int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev);
198
199 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig);
200
201 #endif
202