1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Murata ZPA2326 SPI pressure and temperature sensor driver
4 *
5 * Copyright (c) 2016 Parrot S.A.
6 *
7 * Author: Gregor Boirie <gregor.boirie@parrot.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/regmap.h>
12 #include <linux/spi/spi.h>
13 #include <linux/mod_devicetable.h>
14 #include "zpa2326.h"
15
16 /*
17 * read_flag_mask:
18 * - address bit 7 must be set to request a register read operation
19 * - address bit 6 must be set to request register address auto increment
20 */
21 static const struct regmap_config zpa2326_regmap_spi_config = {
22 .reg_bits = 8,
23 .val_bits = 8,
24 .writeable_reg = zpa2326_isreg_writeable,
25 .readable_reg = zpa2326_isreg_readable,
26 .precious_reg = zpa2326_isreg_precious,
27 .max_register = ZPA2326_TEMP_OUT_H_REG,
28 .read_flag_mask = BIT(7) | BIT(6),
29 };
30
zpa2326_probe_spi(struct spi_device * spi)31 static int zpa2326_probe_spi(struct spi_device *spi)
32 {
33 struct regmap *regmap;
34 int err;
35
36 regmap = devm_regmap_init_spi(spi, &zpa2326_regmap_spi_config);
37 if (IS_ERR(regmap)) {
38 dev_err(&spi->dev, "failed to init registers map");
39 return PTR_ERR(regmap);
40 }
41
42 /*
43 * Enforce SPI slave settings to prevent from DT misconfiguration.
44 *
45 * Clock is idle high. Sampling happens on trailing edge, i.e., rising
46 * edge. Maximum bus frequency is 1 MHz. Registers are 8 bits wide.
47 */
48 spi->mode = SPI_MODE_3;
49 spi->max_speed_hz = min(spi->max_speed_hz, 1000000U);
50 spi->bits_per_word = 8;
51 err = spi_setup(spi);
52 if (err < 0)
53 return err;
54
55 return zpa2326_probe(&spi->dev, spi_get_device_id(spi)->name,
56 spi->irq, ZPA2326_DEVICE_ID, regmap);
57 }
58
zpa2326_remove_spi(struct spi_device * spi)59 static void zpa2326_remove_spi(struct spi_device *spi)
60 {
61 zpa2326_remove(&spi->dev);
62 }
63
64 static const struct spi_device_id zpa2326_spi_ids[] = {
65 { "zpa2326", 0 },
66 { },
67 };
68 MODULE_DEVICE_TABLE(spi, zpa2326_spi_ids);
69
70 static const struct of_device_id zpa2326_spi_matches[] = {
71 { .compatible = "murata,zpa2326" },
72 { }
73 };
74 MODULE_DEVICE_TABLE(of, zpa2326_spi_matches);
75
76 static struct spi_driver zpa2326_spi_driver = {
77 .driver = {
78 .name = "zpa2326-spi",
79 .of_match_table = zpa2326_spi_matches,
80 .pm = ZPA2326_PM_OPS,
81 },
82 .probe = zpa2326_probe_spi,
83 .remove = zpa2326_remove_spi,
84 .id_table = zpa2326_spi_ids,
85 };
86 module_spi_driver(zpa2326_spi_driver);
87
88 MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
89 MODULE_DESCRIPTION("SPI driver for Murata ZPA2326 pressure sensor");
90 MODULE_LICENSE("GPL v2");
91 MODULE_IMPORT_NS("IIO_ZPA2326");
92