sx_common.h

  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/iio/iio.h>
 12#include <linux/iio/types.h>
 13#include <linux/regulator/consumer.h>
 14#include <linux/types.h>
 15
 16struct device;
 17struct i2c_client;
 18struct regmap_config;
 19struct sx_common_data;
 20
 21#define SX_COMMON_REG_IRQ_SRC				0x00
 22
 23#define SX_COMMON_MAX_NUM_CHANNELS	4
 24static_assert(SX_COMMON_MAX_NUM_CHANNELS < BITS_PER_LONG);
 25
 26struct sx_common_reg_default {
 27	u8 reg;
 28	u8 def;
 29	const char *property;
 30};
 31
 32/**
 33 * struct sx_common_ops: function pointers needed by common code
 34 *
 35 * List functions needed by common code to gather information or configure
 36 * the sensor.
 37 *
 38 * @read_prox_data:	Function to read raw proximity data.
 39 * @check_whoami:	Set device name based on whoami register.
 40 * @init_compensation:	Function to set initial compensation.
 41 * @wait_for_sample:	When there are no physical IRQ, function to wait for a
 42 *			sample to be ready.
 43 * @get_default_reg:	Populate the initial value for a given register.
 44 */
 45struct sx_common_ops {
 46	int (*read_prox_data)(struct sx_common_data *data,
 47			      const struct iio_chan_spec *chan, __be16 *val);
 48	int (*check_whoami)(struct device *dev, struct iio_dev *indio_dev);
 49	int (*init_compensation)(struct iio_dev *indio_dev);
 50	int (*wait_for_sample)(struct sx_common_data *data);
 51	const struct sx_common_reg_default  *
 52		(*get_default_reg)(struct device *dev, int idx,
 53				   struct sx_common_reg_default *reg_def);
 54};
 55
 56/**
 57 * struct sx_common_chip_info: Semtech Sensor private chip information
 58 *
 59 * @reg_stat:		Main status register address.
 60 * @reg_irq_msk:	IRQ mask register address.
 61 * @reg_enable_chan:	Address to enable/disable channels.
 62 *			Each phase presented by the sensor is an IIO channel..
 63 * @reg_reset:		Reset register address.
 64 * @mask_enable_chan:	Mask over the channels bits in the enable channel
 65 *			register.
 66 * @stat_offset:	Offset to check phase status.
 67 * @irq_msk_offset:	Offset to enable interrupt in the IRQ mask
 68 *			register.
 69 * @num_channels:	Number of channels.
 70 * @num_default_regs:	Number of internal registers that can be configured.
 71 *
 72 * @ops:		Private functions pointers.
 73 * @iio_channels:	Description of exposed iio channels.
 74 * @num_iio_channels:	Number of iio_channels.
 75 * @iio_info:		iio_info structure for this driver.
 76 */
 77struct sx_common_chip_info {
 78	unsigned int reg_stat;
 79	unsigned int reg_irq_msk;
 80	unsigned int reg_enable_chan;
 81	unsigned int reg_reset;
 82
 83	unsigned int mask_enable_chan;
 84	unsigned int stat_offset;
 85	unsigned int irq_msk_offset;
 86	unsigned int num_channels;
 87	int num_default_regs;
 88
 89	struct sx_common_ops ops;
 90
 91	const struct iio_chan_spec *iio_channels;
 92	int num_iio_channels;
 93	struct iio_info iio_info;
 94};
 95
 96/**
 97 * struct sx_common_data: Semtech Sensor private data structure.
 98 *
 99 * @chip_info:		Structure defining sensor internals.
100 * @mutex:		Serialize access to registers and channel configuration.
101 * @completion:		completion object to wait for data acquisition.
102 * @client:		I2C client structure.
103 * @trig:		IIO trigger object.
104 * @regmap:		Register map.
105 * @chan_prox_stat:	Last reading of the proximity status for each channel.
106 *			We only send an event to user space when this changes.
107 * @trigger_enabled:	True when the device trigger is enabled.
108 * @buffer:		Buffer to store raw samples.
109 * @suspend_ctrl:	Remember enabled channels and sample rate during suspend.
110 * @chan_read:		Bit field for each raw channel enabled.
111 * @chan_event:		Bit field for each event enabled.
112 */
113struct sx_common_data {
114	const struct sx_common_chip_info *chip_info;
115
116	struct mutex mutex;
117	struct completion completion;
118	struct i2c_client *client;
119	struct iio_trigger *trig;
120	struct regmap *regmap;
121
122	unsigned long chan_prox_stat;
123	bool trigger_enabled;
124
125	/* Ensure correct alignment of timestamp when present. */
126	struct {
127		__be16 channels[SX_COMMON_MAX_NUM_CHANNELS];
128		aligned_s64 ts;
129	} buffer;
130
131	unsigned int suspend_ctrl;
132	unsigned long chan_read;
133	unsigned long chan_event;
134};
135
136int sx_common_read_proximity(struct sx_common_data *data,
137			     const struct iio_chan_spec *chan, int *val);
138
139int sx_common_read_event_config(struct iio_dev *indio_dev,
140				const struct iio_chan_spec *chan,
141				enum iio_event_type type,
142				enum iio_event_direction dir);
143int sx_common_write_event_config(struct iio_dev *indio_dev,
144				 const struct iio_chan_spec *chan,
145				 enum iio_event_type type,
146				 enum iio_event_direction dir, bool state);
147
148int sx_common_probe(struct i2c_client *client,
149		    const struct sx_common_chip_info *chip_info,
150		    const struct regmap_config *regmap_config);
151
152/* 3 is the number of events defined by a single phase. */
153extern const struct iio_event_spec sx_common_events[3];
154
155#endif  /* IIO_SX_COMMON_H */