projects/linux·blob master · refs

153 lines · 3.1 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * u-blox GNSS receiver driver
4 *
5 * Copyright (C) 2018 Johan Hovold <[email protected]>
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 *safeboot;
70 struct gpio_desc *reset;
71 struct ubx_data *data;
72 int ret;
73
74 gserial = gnss_serial_allocate(serdev, sizeof(*data));
75 if (IS_ERR(gserial)) {
76 ret = PTR_ERR(gserial);
77 return ret;
78 }
79
80 gserial->ops = &ubx_gserial_ops;
81
82 gserial->gdev->type = GNSS_TYPE_UBX;
83
84 data = gnss_serial_get_drvdata(gserial);
85
86 data->vcc = devm_regulator_get(&serdev->dev, "vcc");
87 if (IS_ERR(data->vcc)) {
88 ret = PTR_ERR(data->vcc);
89 goto err_free_gserial;
90 }
91
92 ret = devm_regulator_get_enable_optional(&serdev->dev, "v-bckp");
93 if (ret < 0 && ret != -ENODEV)
94 goto err_free_gserial;
95
96 /* Deassert safeboot */
97 safeboot = devm_gpiod_get_optional(&serdev->dev, "safeboot", GPIOD_OUT_LOW);
98 if (IS_ERR(safeboot)) {
99 ret = PTR_ERR(safeboot);
100 goto err_free_gserial;
101 }
102
103 /* Deassert reset */
104 reset = devm_gpiod_get_optional(&serdev->dev, "reset", GPIOD_OUT_LOW);
105 if (IS_ERR(reset)) {
106 ret = PTR_ERR(reset);
107 goto err_free_gserial;
108 }
109
110 ret = gnss_serial_register(gserial);
111 if (ret)
112 goto err_free_gserial;
113
114 return 0;
115
116err_free_gserial:
117 gnss_serial_free(gserial);
118
119 return ret;
120}
121
122static void ubx_remove(struct serdev_device *serdev)
123{
124 struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
125
126 gnss_serial_deregister(gserial);
127 gnss_serial_free(gserial);
128}
129
130#ifdef CONFIG_OF
131static const struct of_device_id ubx_of_match[] = {
132 { .compatible = "u-blox,neo-6m" },
133 { .compatible = "u-blox,neo-8" },
134 { .compatible = "u-blox,neo-m8" },
135 {},
136};
137MODULE_DEVICE_TABLE(of, ubx_of_match);
138#endif
139
140static struct serdev_device_driver ubx_driver = {
141 .driver = {
142 .name = "gnss-ubx",
143 .of_match_table = of_match_ptr(ubx_of_match),
144 .pm = &gnss_serial_pm_ops,
145 },
146 .probe = ubx_probe,
147 .remove = ubx_remove,
148};
149module_serdev_device_driver(ubx_driver);
150
151MODULE_AUTHOR("Johan Hovold <[email protected]>");
152MODULE_DESCRIPTION("u-blox GNSS receiver driver");
153MODULE_LICENSE("GPL v2");