1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright 2021 Google LLC.
  4 *
  5 * Code shared between most Semtech SAR sensor driver.
  6 */
  7
  8#ifndef IIO_SX_COMMON_H
  9#define IIO_SX_COMMON_H
 10
 11#include <linux/acpi.h>
 12#include <linux/iio/iio.h>
 13#include <linux/iio/types.h>
 14#include <linux/regulator/consumer.h>
 15#include <linux/types.h>
 16
 17struct device;
 18struct i2c_client;
 19struct regmap_config;
 20struct sx_common_data;
 21
 22#define SX_COMMON_REG_IRQ_SRC				0x00
 23
 24#define SX_COMMON_MAX_NUM_CHANNELS	4
 25static_assert(SX_COMMON_MAX_NUM_CHANNELS < BITS_PER_LONG);
 26
 27struct sx_common_reg_default {
 28	u8 reg;
 29	u8 def;
 30	const char *property;
 31};
 32
 33/**
 34 * struct sx_common_ops: function pointers needed by common code
 35 *
 36 * List functions needed by common code to gather information or configure
 37 * the sensor.
 38 *
 39 * @read_prox_data:	Function to read raw proximity data.
 40 * @check_whoami:	Set device name based on whoami register.
 41 * @init_compensation:	Function to set initial compensation.
 42 * @wait_for_sample:	When there are no physical IRQ, function to wait for a
 43 *			sample to be ready.
 44 * @get_default_reg:	Populate the initial value for a given register.
 45 */
 46struct sx_common_ops {
 47	int (*read_prox_data)(struct sx_common_data *data,
 48			      const struct iio_chan_spec *chan, __be16 *val);
 49	int (*check_whoami)(struct device *dev, struct iio_dev *indio_dev);
 50	int (*init_compensation)(struct iio_dev *indio_dev);
 51	int (*wait_for_sample)(struct sx_common_data *data);
 52	const struct sx_common_reg_default  *
 53		(*get_default_reg)(struct device *dev, int idx,
 54				   struct sx_common_reg_default *reg_def);
 55};
 56
 57/**
 58 * struct sx_common_chip_info: Semtech Sensor private chip information
 59 *
 60 * @reg_stat:		Main status register address.
 61 * @reg_irq_msk:	IRQ mask register address.
 62 * @reg_enable_chan:	Address to enable/disable channels.
 63 *			Each phase presented by the sensor is an IIO channel..
 64 * @reg_reset:		Reset register address.
 65 * @mask_enable_chan:	Mask over the channels bits in the enable channel
 66 *			register.
 67 * @stat_offset:	Offset to check phase status.
 68 * @irq_msk_offset:	Offset to enable interrupt in the IRQ mask
 69 *			register.
 70 * @num_channels:	Number of channels.
 71 * @num_default_regs:	Number of internal registers that can be configured.
 72 *
 73 * @ops:		Private functions pointers.
 74 * @iio_channels:	Description of exposed iio channels.
 75 * @num_iio_channels:	Number of iio_channels.
 76 * @iio_info:		iio_info structure for this driver.
 77 */
 78struct sx_common_chip_info {
 79	unsigned int reg_stat;
 80	unsigned int reg_irq_msk;
 81	unsigned int reg_enable_chan;
 82	unsigned int reg_reset;
 83
 84	unsigned int mask_enable_chan;
 85	unsigned int stat_offset;
 86	unsigned int irq_msk_offset;
 87	unsigned int num_channels;
 88	int num_default_regs;
 89
 90	struct sx_common_ops ops;
 91
 92	const struct iio_chan_spec *iio_channels;
 93	int num_iio_channels;
 94	struct iio_info iio_info;
 95};
 96
 97/**
 98 * struct sx_common_data: Semtech Sensor private data structure.
 99 *
100 * @chip_info:		Structure defining sensor internals.
101 * @mutex:		Serialize access to registers and channel configuration.
102 * @completion:		completion object to wait for data acquisition.
103 * @client:		I2C client structure.
104 * @trig:		IIO trigger object.
105 * @regmap:		Register map.
106 * @chan_prox_stat:	Last reading of the proximity status for each channel.
107 *			We only send an event to user space when this changes.
108 * @trigger_enabled:	True when the device trigger is enabled.
109 * @buffer:		Buffer to store raw samples.
110 * @suspend_ctrl:	Remember enabled channels and sample rate during suspend.
111 * @chan_read:		Bit field for each raw channel enabled.
112 * @chan_event:		Bit field for each event enabled.
113 */
114struct sx_common_data {
115	const struct sx_common_chip_info *chip_info;
116
117	struct mutex mutex;
118	struct completion completion;
119	struct i2c_client *client;
120	struct iio_trigger *trig;
121	struct regmap *regmap;
122
123	unsigned long chan_prox_stat;
124	bool trigger_enabled;
125
126	/* Ensure correct alignment of timestamp when present. */
127	struct {
128		__be16 channels[SX_COMMON_MAX_NUM_CHANNELS];
129		s64 ts __aligned(8);
130	} buffer;
131
132	unsigned int suspend_ctrl;
133	unsigned long chan_read;
134	unsigned long chan_event;
135};
136
137int sx_common_read_proximity(struct sx_common_data *data,
138			     const struct iio_chan_spec *chan, int *val);
139
140int sx_common_read_event_config(struct iio_dev *indio_dev,
141				const struct iio_chan_spec *chan,
142				enum iio_event_type type,
143				enum iio_event_direction dir);
144int sx_common_write_event_config(struct iio_dev *indio_dev,
145				 const struct iio_chan_spec *chan,
146				 enum iio_event_type type,
147				 enum iio_event_direction dir, int state);
148
149int sx_common_probe(struct i2c_client *client,
150		    const struct sx_common_chip_info *chip_info,
151		    const struct regmap_config *regmap_config);
152
153void sx_common_get_raw_register_config(struct device *dev,
154				       struct sx_common_reg_default *reg_def);
155
156/* 3 is the number of events defined by a single phase. */
157extern const struct iio_event_spec sx_common_events[3];
158
159#endif  /* IIO_SX_COMMON_H */