tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/gpio/consumer.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/regulator/consumer.h>
16#include <linux/serdev.h>
17
18#include "serial.h"
19
20struct ubx_data {
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 gpio_desc *reset;
70 struct ubx_data *data;
71 int ret;
72
73 gserial = gnss_serial_allocate(serdev, sizeof(*data));
74 if (IS_ERR(gserial)) {
75 ret = PTR_ERR(gserial);
76 return ret;
77 }
78
79 gserial->ops = &ubx_gserial_ops;
80
81 gserial->gdev->type = GNSS_TYPE_UBX;
82
83 data = gnss_serial_get_drvdata(gserial);
84
85 data->vcc = devm_regulator_get(&serdev->dev, "vcc");
86 if (IS_ERR(data->vcc)) {
87 ret = PTR_ERR(data->vcc);
88 goto err_free_gserial;
89 }
90
91 ret = devm_regulator_get_enable_optional(&serdev->dev, "v-bckp");
92 if (ret < 0 && ret != -ENODEV)
93 goto err_free_gserial;
94
95 /* Deassert reset */
96 reset = devm_gpiod_get_optional(&serdev->dev, "reset", GPIOD_OUT_LOW);
97 if (IS_ERR(reset)) {
98 ret = PTR_ERR(reset);
99 goto err_free_gserial;
100 }
101
102 ret = gnss_serial_register(gserial);
103 if (ret)
104 goto err_free_gserial;
105
106 return 0;
107
108err_free_gserial:
109 gnss_serial_free(gserial);
110
111 return ret;
112}
113
114static void ubx_remove(struct serdev_device *serdev)
115{
116 struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
117
118 gnss_serial_deregister(gserial);
119 gnss_serial_free(gserial);
120}
121
122#ifdef CONFIG_OF
123static const struct of_device_id ubx_of_match[] = {
124 { .compatible = "u-blox,neo-6m" },
125 { .compatible = "u-blox,neo-8" },
126 { .compatible = "u-blox,neo-m8" },
127 {},
128};
129MODULE_DEVICE_TABLE(of, ubx_of_match);
130#endif
131
132static struct serdev_device_driver ubx_driver = {
133 .driver = {
134 .name = "gnss-ubx",
135 .of_match_table = of_match_ptr(ubx_of_match),
136 .pm = &gnss_serial_pm_ops,
137 },
138 .probe = ubx_probe,
139 .remove = ubx_remove,
140};
141module_serdev_device_driver(ubx_driver);
142
143MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
144MODULE_DESCRIPTION("u-blox GNSS receiver driver");
145MODULE_LICENSE("GPL v2");