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 */
21static 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	.cache_type     = REGCACHE_NONE,
30};
31
32static int zpa2326_probe_spi(struct spi_device *spi)
33{
34	struct regmap *regmap;
35	int            err;
36
37	regmap = devm_regmap_init_spi(spi, &zpa2326_regmap_spi_config);
38	if (IS_ERR(regmap)) {
39		dev_err(&spi->dev, "failed to init registers map");
40		return PTR_ERR(regmap);
41	}
42
43	/*
44	 * Enforce SPI slave settings to prevent from DT misconfiguration.
45	 *
46	 * Clock is idle high. Sampling happens on trailing edge, i.e., rising
47	 * edge. Maximum bus frequency is 1 MHz. Registers are 8 bits wide.
48	 */
49	spi->mode = SPI_MODE_3;
50	spi->max_speed_hz = min(spi->max_speed_hz, 1000000U);
51	spi->bits_per_word = 8;
52	err = spi_setup(spi);
53	if (err < 0)
54		return err;
55
56	return zpa2326_probe(&spi->dev, spi_get_device_id(spi)->name,
57			     spi->irq, ZPA2326_DEVICE_ID, regmap);
58}
59
60static int zpa2326_remove_spi(struct spi_device *spi)
61{
62	zpa2326_remove(&spi->dev);
63
64	return 0;
65}
66
67static const struct spi_device_id zpa2326_spi_ids[] = {
68	{ "zpa2326", 0 },
69	{ },
70};
71MODULE_DEVICE_TABLE(spi, zpa2326_spi_ids);
72
73static const struct of_device_id zpa2326_spi_matches[] = {
74	{ .compatible = "murata,zpa2326" },
75	{ }
76};
77MODULE_DEVICE_TABLE(of, zpa2326_spi_matches);
78
79static struct spi_driver zpa2326_spi_driver = {
80	.driver = {
81		.name           = "zpa2326-spi",
82		.of_match_table = zpa2326_spi_matches,
83		.pm             = ZPA2326_PM_OPS,
84	},
85	.probe    = zpa2326_probe_spi,
86	.remove   = zpa2326_remove_spi,
87	.id_table = zpa2326_spi_ids,
88};
89module_spi_driver(zpa2326_spi_driver);
90
91MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
92MODULE_DESCRIPTION("SPI driver for Murata ZPA2326 pressure sensor");
93MODULE_LICENSE("GPL v2");
94