1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SPI driver for Bosch BMI323 6-Axis IMU.
4 *
5 * Copyright (C) 2023, Jagath Jog J <jagathjog1996@gmail.com>
6 */
7
8#include <linux/mod_devicetable.h>
9#include <linux/module.h>
10#include <linux/regmap.h>
11#include <linux/spi/spi.h>
12
13#include "bmi323.h"
14
15/*
16 * From BMI323 datasheet section 4: Notes on the Serial Interface Support.
17 * Each SPI register read operation requires to read one dummy byte before
18 * the actual payload.
19 */
20static int bmi323_regmap_spi_read(void *context, const void *reg_buf,
21				  size_t reg_size, void *val_buf,
22				  size_t val_size)
23{
24	struct spi_device *spi = context;
25
26	return spi_write_then_read(spi, reg_buf, reg_size, val_buf, val_size);
27}
28
29static int bmi323_regmap_spi_write(void *context, const void *data,
30				   size_t count)
31{
32	struct spi_device *spi = context;
33	u8 *data_buff = (u8 *)data;
34
35	data_buff[1] = data_buff[0];
36	return spi_write(spi, data_buff + 1, count - 1);
37}
38
39static struct regmap_bus bmi323_regmap_bus = {
40	.read = bmi323_regmap_spi_read,
41	.write = bmi323_regmap_spi_write,
42};
43
44static const struct regmap_config bmi323_spi_regmap_config = {
45	.reg_bits = 8,
46	.val_bits = 16,
47	.pad_bits = 8,
48	.read_flag_mask = BIT(7),
49	.max_register = BMI323_CFG_RES_REG,
50	.val_format_endian = REGMAP_ENDIAN_LITTLE,
51};
52
53static int bmi323_spi_probe(struct spi_device *spi)
54{
55	struct device *dev = &spi->dev;
56	struct regmap *regmap;
57
58	regmap = devm_regmap_init(dev, &bmi323_regmap_bus, dev,
59				  &bmi323_spi_regmap_config);
60	if (IS_ERR(regmap))
61		return dev_err_probe(dev, PTR_ERR(regmap),
62				     "Failed to initialize SPI Regmap\n");
63
64	return bmi323_core_probe(dev);
65}
66
67static const struct spi_device_id bmi323_spi_ids[] = {
68	{ "bmi323" },
69	{ }
70};
71MODULE_DEVICE_TABLE(spi, bmi323_spi_ids);
72
73static const struct of_device_id bmi323_of_spi_match[] = {
74	{ .compatible = "bosch,bmi323" },
75	{ }
76};
77MODULE_DEVICE_TABLE(of, bmi323_of_spi_match);
78
79static struct spi_driver bmi323_spi_driver = {
80	.driver = {
81		.name = "bmi323",
82		.of_match_table = bmi323_of_spi_match,
83	},
84	.probe = bmi323_spi_probe,
85	.id_table = bmi323_spi_ids,
86};
87module_spi_driver(bmi323_spi_driver);
88
89MODULE_DESCRIPTION("Bosch BMI323 IMU driver");
90MODULE_AUTHOR("Jagath Jog J <jagathjog1996@gmail.com>");
91MODULE_LICENSE("GPL");
92MODULE_IMPORT_NS(IIO_BMI323);
93