adxl345_spi.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * ADXL345 3-Axis Digital Accelerometer SPI driver
 4 *
 5 * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
 6 */
 7
 8#include <linux/module.h>
 9#include <linux/regmap.h>
10#include <linux/spi/spi.h>
11
12#include "adxl345.h"
13
14#define ADXL345_MAX_SPI_FREQ_HZ		5000000
15#define ADXL345_MAX_FREQ_NO_FIFO_DELAY	1500000
16
17static const struct regmap_config adxl345_spi_regmap_config = {
18	.reg_bits = 8,
19	.val_bits = 8,
20	 /* Setting bits 7 and 6 enables multiple-byte read */
21	.read_flag_mask = BIT(7) | BIT(6),
22	.volatile_reg = adxl345_is_volatile_reg,
23	.cache_type = REGCACHE_MAPLE,
24};
25
26static int adxl345_spi_setup(struct device *dev, struct regmap *regmap)
27{
28	return regmap_write(regmap, ADXL345_REG_DATA_FORMAT, ADXL345_DATA_FORMAT_SPI_3WIRE);
29}
30
31static int adxl345_spi_probe(struct spi_device *spi)
32{
33	struct regmap *regmap;
34	bool needs_delay;
35
36	/* Bail out if max_speed_hz exceeds 5 MHz */
37	if (spi->max_speed_hz > ADXL345_MAX_SPI_FREQ_HZ)
38		return dev_err_probe(&spi->dev, -EINVAL, "SPI CLK, %d Hz exceeds 5 MHz\n",
39				     spi->max_speed_hz);
40
41	regmap = devm_regmap_init_spi(spi, &adxl345_spi_regmap_config);
42	if (IS_ERR(regmap))
43		return dev_err_probe(&spi->dev, PTR_ERR(regmap), "Error initializing regmap\n");
44
45	needs_delay = spi->max_speed_hz > ADXL345_MAX_FREQ_NO_FIFO_DELAY;
46	if (spi->mode & SPI_3WIRE)
47		return adxl345_core_probe(&spi->dev, regmap, needs_delay, adxl345_spi_setup);
48	else
49		return adxl345_core_probe(&spi->dev, regmap, needs_delay, NULL);
50}
51
52static const struct adxl345_chip_info adxl345_spi_info = {
53	.name = "adxl345",
54	.uscale = ADXL345_USCALE,
55};
56
57static const struct adxl345_chip_info adxl375_spi_info = {
58	.name = "adxl375",
59	.uscale = ADXL375_USCALE,
60};
61
62static const struct spi_device_id adxl345_spi_id[] = {
63	{ "adxl345", (kernel_ulong_t)&adxl345_spi_info },
64	{ "adxl375", (kernel_ulong_t)&adxl375_spi_info },
65	{ }
66};
67MODULE_DEVICE_TABLE(spi, adxl345_spi_id);
68
69static const struct of_device_id adxl345_of_match[] = {
70	{ .compatible = "adi,adxl345", .data = &adxl345_spi_info },
71	{ .compatible = "adi,adxl375", .data = &adxl375_spi_info },
72	{ }
73};
74MODULE_DEVICE_TABLE(of, adxl345_of_match);
75
76static const struct acpi_device_id adxl345_acpi_match[] = {
77	{ "ADS0345", (kernel_ulong_t)&adxl345_spi_info },
78	{ }
79};
80MODULE_DEVICE_TABLE(acpi, adxl345_acpi_match);
81
82static struct spi_driver adxl345_spi_driver = {
83	.driver = {
84		.name	= "adxl345_spi",
85		.of_match_table = adxl345_of_match,
86		.acpi_match_table = adxl345_acpi_match,
87	},
88	.probe		= adxl345_spi_probe,
89	.id_table	= adxl345_spi_id,
90};
91module_spi_driver(adxl345_spi_driver);
92
93MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
94MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer SPI driver");
95MODULE_LICENSE("GPL v2");
96MODULE_IMPORT_NS("IIO_ADXL345");