1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * SPI interface for the BMP280 driver
4 *
5 * Inspired by the older BMP085 driver drivers/misc/bmp085-spi.c
6 */
7#include <linux/module.h>
8#include <linux/spi/spi.h>
9#include <linux/err.h>
10#include <linux/regmap.h>
11
12#include "bmp280.h"
13
14static int bmp280_regmap_spi_write(void *context, const void *data,
15                                   size_t count)
16{
17	struct device *dev = context;
18	struct spi_device *spi = to_spi_device(dev);
19	u8 buf[2];
20
21	memcpy(buf, data, 2);
22	/*
23	 * The SPI register address (= full register address without bit 7) and
24	 * the write command (bit7 = RW = '0')
25	 */
26	buf[0] &= ~0x80;
27
28	return spi_write_then_read(spi, buf, 2, NULL, 0);
29}
30
31static int bmp280_regmap_spi_read(void *context, const void *reg,
32                                  size_t reg_size, void *val, size_t val_size)
33{
34	struct device *dev = context;
35	struct spi_device *spi = to_spi_device(dev);
36
37	return spi_write_then_read(spi, reg, reg_size, val, val_size);
38}
39
40static struct regmap_bus bmp280_regmap_bus = {
41	.write = bmp280_regmap_spi_write,
42	.read = bmp280_regmap_spi_read,
43	.reg_format_endian_default = REGMAP_ENDIAN_BIG,
44	.val_format_endian_default = REGMAP_ENDIAN_BIG,
45};
46
47static int bmp280_spi_probe(struct spi_device *spi)
48{
49	const struct spi_device_id *id = spi_get_device_id(spi);
50	struct regmap *regmap;
51	const struct regmap_config *regmap_config;
52	int ret;
53
54	spi->bits_per_word = 8;
55	ret = spi_setup(spi);
56	if (ret < 0) {
57		dev_err(&spi->dev, "spi_setup failed!\n");
58		return ret;
59	}
60
61	switch (id->driver_data) {
62	case BMP180_CHIP_ID:
63		regmap_config = &bmp180_regmap_config;
64		break;
65	case BMP280_CHIP_ID:
66	case BME280_CHIP_ID:
67		regmap_config = &bmp280_regmap_config;
68		break;
69	default:
70		return -EINVAL;
71	}
72
73	regmap = devm_regmap_init(&spi->dev,
74				  &bmp280_regmap_bus,
75				  &spi->dev,
76				  regmap_config);
77	if (IS_ERR(regmap)) {
78		dev_err(&spi->dev, "failed to allocate register map\n");
79		return PTR_ERR(regmap);
80	}
81
82	return bmp280_common_probe(&spi->dev,
83				   regmap,
84				   id->driver_data,
85				   id->name,
86				   spi->irq);
87}
88
89static const struct of_device_id bmp280_of_spi_match[] = {
90	{ .compatible = "bosch,bmp085", },
91	{ .compatible = "bosch,bmp180", },
92	{ .compatible = "bosch,bmp181", },
93	{ .compatible = "bosch,bmp280", },
94	{ .compatible = "bosch,bme280", },
95	{ },
96};
97MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
98
99static const struct spi_device_id bmp280_spi_id[] = {
100	{ "bmp180", BMP180_CHIP_ID },
101	{ "bmp181", BMP180_CHIP_ID },
102	{ "bmp280", BMP280_CHIP_ID },
103	{ "bme280", BME280_CHIP_ID },
104	{ }
105};
106MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
107
108static struct spi_driver bmp280_spi_driver = {
109	.driver = {
110		.name = "bmp280",
111		.of_match_table = bmp280_of_spi_match,
112		.pm = &bmp280_dev_pm_ops,
113	},
114	.id_table = bmp280_spi_id,
115	.probe = bmp280_spi_probe,
116};
117module_spi_driver(bmp280_spi_driver);
118
119MODULE_DESCRIPTION("BMP280 SPI bus driver");
120MODULE_LICENSE("GPL");
121