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
bmp280_regmap_spi_write(void * context,const void * data,size_t count)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
bmp280_regmap_spi_read(void * context,const void * reg,size_t reg_size,void * val,size_t val_size)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
bmp280_spi_probe(struct spi_device * spi)47 static 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 case BMP380_CHIP_ID:
70 regmap_config = &bmp380_regmap_config;
71 break;
72 default:
73 return -EINVAL;
74 }
75
76 regmap = devm_regmap_init(&spi->dev,
77 &bmp280_regmap_bus,
78 &spi->dev,
79 regmap_config);
80 if (IS_ERR(regmap)) {
81 dev_err(&spi->dev, "failed to allocate register map\n");
82 return PTR_ERR(regmap);
83 }
84
85 return bmp280_common_probe(&spi->dev,
86 regmap,
87 id->driver_data,
88 id->name,
89 spi->irq);
90 }
91
92 static const struct of_device_id bmp280_of_spi_match[] = {
93 { .compatible = "bosch,bmp085", },
94 { .compatible = "bosch,bmp180", },
95 { .compatible = "bosch,bmp181", },
96 { .compatible = "bosch,bmp280", },
97 { .compatible = "bosch,bme280", },
98 { .compatible = "bosch,bmp380", },
99 { },
100 };
101 MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
102
103 static const struct spi_device_id bmp280_spi_id[] = {
104 { "bmp180", BMP180_CHIP_ID },
105 { "bmp181", BMP180_CHIP_ID },
106 { "bmp280", BMP280_CHIP_ID },
107 { "bme280", BME280_CHIP_ID },
108 { "bmp380", BMP380_CHIP_ID },
109 { }
110 };
111 MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
112
113 static struct spi_driver bmp280_spi_driver = {
114 .driver = {
115 .name = "bmp280",
116 .of_match_table = bmp280_of_spi_match,
117 .pm = pm_ptr(&bmp280_dev_pm_ops),
118 },
119 .id_table = bmp280_spi_id,
120 .probe = bmp280_spi_probe,
121 };
122 module_spi_driver(bmp280_spi_driver);
123
124 MODULE_DESCRIPTION("BMP280 SPI bus driver");
125 MODULE_LICENSE("GPL");
126 MODULE_IMPORT_NS(IIO_BMP280);
127