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 
14 static 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 
31 static 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 
40 static 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 
47 static int bmp280_spi_probe(struct spi_device *spi)
48 {
49 	const struct spi_device_id *id = spi_get_device_id(spi);
50 	const struct bmp280_chip_info *chip_info;
51 	struct regmap *regmap;
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 	chip_info = device_get_match_data(&spi->dev);
62 	if (!chip_info)
63 		chip_info = (const struct bmp280_chip_info *) id->driver_data;
64 
65 	regmap = devm_regmap_init(&spi->dev,
66 				  &bmp280_regmap_bus,
67 				  &spi->dev,
68 				  chip_info->regmap_config);
69 	if (IS_ERR(regmap)) {
70 		dev_err(&spi->dev, "failed to allocate register map\n");
71 		return PTR_ERR(regmap);
72 	}
73 
74 	return bmp280_common_probe(&spi->dev,
75 				   regmap,
76 				   chip_info,
77 				   id->name,
78 				   spi->irq);
79 }
80 
81 static const struct of_device_id bmp280_of_spi_match[] = {
82 	{ .compatible = "bosch,bmp085", .data = &bmp180_chip_info },
83 	{ .compatible = "bosch,bmp180", .data = &bmp180_chip_info },
84 	{ .compatible = "bosch,bmp181", .data = &bmp180_chip_info },
85 	{ .compatible = "bosch,bmp280", .data = &bmp280_chip_info },
86 	{ .compatible = "bosch,bme280", .data = &bme280_chip_info },
87 	{ .compatible = "bosch,bmp380", .data = &bmp380_chip_info },
88 	{ .compatible = "bosch,bmp580", .data = &bmp580_chip_info },
89 	{ },
90 };
91 MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
92 
93 static const struct spi_device_id bmp280_spi_id[] = {
94 	{ "bmp085", (kernel_ulong_t)&bmp180_chip_info },
95 	{ "bmp180", (kernel_ulong_t)&bmp180_chip_info },
96 	{ "bmp181", (kernel_ulong_t)&bmp180_chip_info },
97 	{ "bmp280", (kernel_ulong_t)&bmp280_chip_info },
98 	{ "bme280", (kernel_ulong_t)&bme280_chip_info },
99 	{ "bmp380", (kernel_ulong_t)&bmp380_chip_info },
100 	{ "bmp580", (kernel_ulong_t)&bmp580_chip_info },
101 	{ }
102 };
103 MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
104 
105 static struct spi_driver bmp280_spi_driver = {
106 	.driver = {
107 		.name = "bmp280",
108 		.of_match_table = bmp280_of_spi_match,
109 		.pm = pm_ptr(&bmp280_dev_pm_ops),
110 	},
111 	.id_table = bmp280_spi_id,
112 	.probe = bmp280_spi_probe,
113 };
114 module_spi_driver(bmp280_spi_driver);
115 
116 MODULE_DESCRIPTION("BMP280 SPI bus driver");
117 MODULE_LICENSE("GPL");
118 MODULE_IMPORT_NS(IIO_BMP280);
119