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 
16 struct device;
17 struct i2c_client;
18 struct regmap_config;
19 struct sx_common_data;
20 
21 #define SX_COMMON_REG_IRQ_SRC				0x00
22 
23 #define SX_COMMON_MAX_NUM_CHANNELS	4
24 static_assert(SX_COMMON_MAX_NUM_CHANNELS < BITS_PER_LONG);
25 
26 struct sx_common_reg_default {
27 	u8 reg;
28 	u8 def;
29 };
30 
31 /**
32  * struct sx_common_ops: function pointers needed by common code
33  *
34  * List functions needed by common code to gather information or configure
35  * the sensor.
36  *
37  * @read_prox_data:	Function to read raw proximity data.
38  * @check_whoami:	Set device name based on whoami register.
39  * @init_compensation:	Function to set initial compensation.
40  * @wait_for_sample:	When there are no physical IRQ, function to wait for a
41  *			sample to be ready.
42  * @get_default_reg:	Populate the initial value for a given register.
43  */
44 struct sx_common_ops {
45 	int (*read_prox_data)(struct sx_common_data *data,
46 			      const struct iio_chan_spec *chan, __be16 *val);
47 	int (*check_whoami)(struct device *dev, struct iio_dev *indio_dev);
48 	int (*init_compensation)(struct iio_dev *indio_dev);
49 	int (*wait_for_sample)(struct sx_common_data *data);
50 	const struct sx_common_reg_default  *
51 		(*get_default_reg)(struct device *dev, int idx,
52 				   struct sx_common_reg_default *reg_def);
53 };
54 
55 /**
56  * struct sx_common_chip_info: Semtech Sensor private chip information
57  *
58  * @reg_stat:		Main status register address.
59  * @reg_irq_msk:	IRQ mask register address.
60  * @reg_enable_chan:	Address to enable/disable channels.
61  *			Each phase presented by the sensor is an IIO channel..
62  * @reg_reset:		Reset register address.
63  * @mask_enable_chan:	Mask over the channels bits in the enable channel
64  *			register.
65  * @stat_offset:	Offset to check phase status.
66  * @irq_msk_offset:	Offset to enable interrupt in the IRQ mask
67  *			register.
68  * @num_channels:	Number of channels.
69  * @num_default_regs:	Number of internal registers that can be configured.
70  *
71  * @ops:		Private functions pointers.
72  * @iio_channels:	Description of exposed iio channels.
73  * @num_iio_channels:	Number of iio_channels.
74  * @iio_info:		iio_info structure for this driver.
75  */
76 struct sx_common_chip_info {
77 	unsigned int reg_stat;
78 	unsigned int reg_irq_msk;
79 	unsigned int reg_enable_chan;
80 	unsigned int reg_reset;
81 
82 	unsigned int mask_enable_chan;
83 	unsigned int stat_offset;
84 	unsigned int irq_msk_offset;
85 	unsigned int num_channels;
86 	int num_default_regs;
87 
88 	struct sx_common_ops ops;
89 
90 	const struct iio_chan_spec *iio_channels;
91 	int num_iio_channels;
92 	struct iio_info iio_info;
93 };
94 
95 /**
96  * struct sx_common_data: Semtech Sensor private data structure.
97  *
98  * @chip_info:		Structure defining sensor internals.
99  * @mutex:		Serialize access to registers and channel configuration.
100  * @completion:		completion object to wait for data acquisition.
101  * @client:		I2C client structure.
102  * @trig:		IIO trigger object.
103  * @regmap:		Register map.
104  * @num_default_regs:	Number of default registers to set at init.
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  */
113 struct 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 		s64 ts __aligned(8);
129 	} buffer;
130 
131 	unsigned int suspend_ctrl;
132 	unsigned long chan_read;
133 	unsigned long chan_event;
134 };
135 
136 int sx_common_read_proximity(struct sx_common_data *data,
137 			     const struct iio_chan_spec *chan, int *val);
138 
139 int 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);
143 int 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, int state);
147 
148 int 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. */
153 extern const struct iio_event_spec sx_common_events[3];
154 
155 #endif  /* IIO_SX_COMMON_H */
156