bmi270_spi.c

 1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 2
 3#include <linux/iio/iio.h>
 4#include <linux/mod_devicetable.h>
 5#include <linux/module.h>
 6#include <linux/pm.h>
 7#include <linux/regmap.h>
 8#include <linux/spi/spi.h>
 9
10#include "bmi270.h"
11
12/*
13 * The following two functions are taken from the BMI323 spi driver code.
14 * In section 6.4 of the BMI270 data it specifies that after a read
15 * operation the first data byte from the device is a dummy byte
16 */
17static int bmi270_regmap_spi_read(void *spi, const void *reg_buf,
18				  size_t reg_size, void *val_buf,
19				  size_t val_size)
20{
21	return spi_write_then_read(spi, reg_buf, reg_size, val_buf, val_size);
22}
23
24static int bmi270_regmap_spi_write(void *spi, const void *data,
25				   size_t count)
26{
27	u8 *data_buff = (u8 *)data;
28
29	/*
30	 * Remove the extra pad byte since its only needed for the read
31	 * operation
32	 */
33	data_buff[1] = data_buff[0];
34	return spi_write_then_read(spi, data_buff + 1, count - 1, NULL, 0);
35}
36
37static const struct regmap_bus bmi270_regmap_bus = {
38	.read = bmi270_regmap_spi_read,
39	.write = bmi270_regmap_spi_write,
40};
41
42static const struct regmap_config bmi270_spi_regmap_config = {
43	.reg_bits = 8,
44	.val_bits = 8,
45	.pad_bits = 8,
46	.read_flag_mask = BIT(7),
47};
48
49static int bmi270_spi_probe(struct spi_device *spi)
50{
51	struct regmap *regmap;
52	struct device *dev = &spi->dev;
53	const struct bmi270_chip_info *chip_info;
54
55	chip_info = spi_get_device_match_data(spi);
56	if (!chip_info)
57		return -ENODEV;
58
59	regmap = devm_regmap_init(dev, &bmi270_regmap_bus, dev,
60				  &bmi270_spi_regmap_config);
61	if (IS_ERR(regmap))
62		return dev_err_probe(dev, PTR_ERR(regmap),
63				     "Failed to init spi regmap\n");
64
65	return bmi270_core_probe(dev, regmap, chip_info);
66}
67
68static const struct spi_device_id bmi270_spi_id[] = {
69	{ "bmi260", (kernel_ulong_t)&bmi260_chip_info },
70	{ "bmi270", (kernel_ulong_t)&bmi270_chip_info },
71	{ }
72};
73
74static const struct of_device_id bmi270_of_match[] = {
75	{ .compatible = "bosch,bmi260", .data = &bmi260_chip_info },
76	{ .compatible = "bosch,bmi270", .data = &bmi270_chip_info },
77	{ }
78};
79
80static struct spi_driver bmi270_spi_driver = {
81	.driver = {
82		.name = "bmi270",
83		.pm = pm_ptr(&bmi270_core_pm_ops),
84		.of_match_table = bmi270_of_match,
85	},
86	.probe = bmi270_spi_probe,
87	.id_table = bmi270_spi_id,
88};
89module_spi_driver(bmi270_spi_driver);
90
91MODULE_AUTHOR("Alex Lanzano");
92MODULE_DESCRIPTION("BMI270 driver");
93MODULE_LICENSE("GPL");
94MODULE_IMPORT_NS("IIO_BMI270");