1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Mediatek 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
19 struct mtk_data {
20 struct regulator *vbackup;
21 struct regulator *vcc;
22 };
23
mtk_set_active(struct gnss_serial * gserial)24 static int mtk_set_active(struct gnss_serial *gserial)
25 {
26 struct mtk_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
mtk_set_standby(struct gnss_serial * gserial)36 static int mtk_set_standby(struct gnss_serial *gserial)
37 {
38 struct mtk_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
mtk_set_power(struct gnss_serial * gserial,enum gnss_serial_pm_state state)48 static int mtk_set_power(struct gnss_serial *gserial,
49 enum gnss_serial_pm_state state)
50 {
51 switch (state) {
52 case GNSS_SERIAL_ACTIVE:
53 return mtk_set_active(gserial);
54 case GNSS_SERIAL_OFF:
55 case GNSS_SERIAL_STANDBY:
56 return mtk_set_standby(gserial);
57 }
58
59 return -EINVAL;
60 }
61
62 static const struct gnss_serial_ops mtk_gserial_ops = {
63 .set_power = mtk_set_power,
64 };
65
mtk_probe(struct serdev_device * serdev)66 static int mtk_probe(struct serdev_device *serdev)
67 {
68 struct gnss_serial *gserial;
69 struct mtk_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 = &mtk_gserial_ops;
79
80 gserial->gdev->type = GNSS_TYPE_MTK;
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->vbackup = devm_regulator_get_optional(&serdev->dev, "vbackup");
91 if (IS_ERR(data->vbackup)) {
92 ret = PTR_ERR(data->vbackup);
93 if (ret == -ENODEV)
94 data->vbackup = NULL;
95 else
96 goto err_free_gserial;
97 }
98
99 if (data->vbackup) {
100 ret = regulator_enable(data->vbackup);
101 if (ret)
102 goto err_free_gserial;
103 }
104
105 ret = gnss_serial_register(gserial);
106 if (ret)
107 goto err_disable_vbackup;
108
109 return 0;
110
111 err_disable_vbackup:
112 if (data->vbackup)
113 regulator_disable(data->vbackup);
114 err_free_gserial:
115 gnss_serial_free(gserial);
116
117 return ret;
118 }
119
mtk_remove(struct serdev_device * serdev)120 static void mtk_remove(struct serdev_device *serdev)
121 {
122 struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
123 struct mtk_data *data = gnss_serial_get_drvdata(gserial);
124
125 gnss_serial_deregister(gserial);
126 if (data->vbackup)
127 regulator_disable(data->vbackup);
128 gnss_serial_free(gserial);
129 }
130
131 #ifdef CONFIG_OF
132 static const struct of_device_id mtk_of_match[] = {
133 { .compatible = "globaltop,pa6h" },
134 {},
135 };
136 MODULE_DEVICE_TABLE(of, mtk_of_match);
137 #endif
138
139 static struct serdev_device_driver mtk_driver = {
140 .driver = {
141 .name = "gnss-mtk",
142 .of_match_table = of_match_ptr(mtk_of_match),
143 .pm = &gnss_serial_pm_ops,
144 },
145 .probe = mtk_probe,
146 .remove = mtk_remove,
147 };
148 module_serdev_device_driver(mtk_driver);
149
150 MODULE_AUTHOR("Loys Ollivier <lollivier@baylibre.com>");
151 MODULE_DESCRIPTION("Mediatek GNSS receiver driver");
152 MODULE_LICENSE("GPL v2");
153