xref: /kernel/linux/linux-6.6/drivers/gnss/ubx.c (revision 62306a36) 
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * u-blox GNSS receiver driver
4 *
5 * Copyright (C) 2018 Johan Hovold <johan@kernel.org>
6 */
7
8#include <linux/errno.h>
9#include <linux/gnss.h>
10#include <linux/init.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/regulator/consumer.h>
15#include <linux/serdev.h>
16
17#include "serial.h"
18
19struct ubx_data {
20	struct regulator *v_bckp;
21	struct regulator *vcc;
22};
23
24static int ubx_set_active(struct gnss_serial *gserial)
25{
26	struct ubx_data *data = gnss_serial_get_drvdata(gserial);
27	int ret;
28
29	ret = regulator_enable(data->vcc);
30	if (ret)
31		return ret;
32
33	return 0;
34}
35
36static int ubx_set_standby(struct gnss_serial *gserial)
37{
38	struct ubx_data *data = gnss_serial_get_drvdata(gserial);
39	int ret;
40
41	ret = regulator_disable(data->vcc);
42	if (ret)
43		return ret;
44
45	return 0;
46}
47
48static int ubx_set_power(struct gnss_serial *gserial,
49				enum gnss_serial_pm_state state)
50{
51	switch (state) {
52	case GNSS_SERIAL_ACTIVE:
53		return ubx_set_active(gserial);
54	case GNSS_SERIAL_OFF:
55	case GNSS_SERIAL_STANDBY:
56		return ubx_set_standby(gserial);
57	}
58
59	return -EINVAL;
60}
61
62static const struct gnss_serial_ops ubx_gserial_ops = {
63	.set_power = ubx_set_power,
64};
65
66static int ubx_probe(struct serdev_device *serdev)
67{
68	struct gnss_serial *gserial;
69	struct ubx_data *data;
70	int ret;
71
72	gserial = gnss_serial_allocate(serdev, sizeof(*data));
73	if (IS_ERR(gserial)) {
74		ret = PTR_ERR(gserial);
75		return ret;
76	}
77
78	gserial->ops = &ubx_gserial_ops;
79
80	gserial->gdev->type = GNSS_TYPE_UBX;
81
82	data = gnss_serial_get_drvdata(gserial);
83
84	data->vcc = devm_regulator_get(&serdev->dev, "vcc");
85	if (IS_ERR(data->vcc)) {
86		ret = PTR_ERR(data->vcc);
87		goto err_free_gserial;
88	}
89
90	data->v_bckp = devm_regulator_get_optional(&serdev->dev, "v-bckp");
91	if (IS_ERR(data->v_bckp)) {
92		ret = PTR_ERR(data->v_bckp);
93		if (ret == -ENODEV)
94			data->v_bckp = NULL;
95		else
96			goto err_free_gserial;
97	}
98
99	if (data->v_bckp) {
100		ret = regulator_enable(data->v_bckp);
101		if (ret)
102			goto err_free_gserial;
103	}
104
105	ret = gnss_serial_register(gserial);
106	if (ret)
107		goto err_disable_v_bckp;
108
109	return 0;
110
111err_disable_v_bckp:
112	if (data->v_bckp)
113		regulator_disable(data->v_bckp);
114err_free_gserial:
115	gnss_serial_free(gserial);
116
117	return ret;
118}
119
120static void ubx_remove(struct serdev_device *serdev)
121{
122	struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
123	struct ubx_data *data = gnss_serial_get_drvdata(gserial);
124
125	gnss_serial_deregister(gserial);
126	if (data->v_bckp)
127		regulator_disable(data->v_bckp);
128	gnss_serial_free(gserial);
129}
130
131#ifdef CONFIG_OF
132static const struct of_device_id ubx_of_match[] = {
133	{ .compatible = "u-blox,neo-6m" },
134	{ .compatible = "u-blox,neo-8" },
135	{ .compatible = "u-blox,neo-m8" },
136	{},
137};
138MODULE_DEVICE_TABLE(of, ubx_of_match);
139#endif
140
141static struct serdev_device_driver ubx_driver = {
142	.driver	= {
143		.name		= "gnss-ubx",
144		.of_match_table	= of_match_ptr(ubx_of_match),
145		.pm		= &gnss_serial_pm_ops,
146	},
147	.probe	= ubx_probe,
148	.remove	= ubx_remove,
149};
150module_serdev_device_driver(ubx_driver);
151
152MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
153MODULE_DESCRIPTION("u-blox GNSS receiver driver");
154MODULE_LICENSE("GPL v2");
155