drivers/gnss/ubx.c

   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
  19 struct ubx_data {
  20         struct regulator *vcc;
  21 };
  22
  23 static int ubx_set_active(struct gnss_serial *gserial)
  24 {
  25         struct ubx_data *data = gnss_serial_get_drvdata(gserial);
  26         int ret;
  27
  28         ret = regulator_enable(data->vcc);
  29         if (ret)
  30                 return ret;
  31
  32         return 0;
  33 }
  34
  35 static int ubx_set_standby(struct gnss_serial *gserial)
  36 {
  37         struct ubx_data *data = gnss_serial_get_drvdata(gserial);
  38         int ret;
  39
  40         ret = regulator_disable(data->vcc);
  41         if (ret)
  42                 return ret;
  43
  44         return 0;
  45 }
  46
  47 static int ubx_set_power(struct gnss_serial *gserial,
  48                                 enum gnss_serial_pm_state state)
  49 {
  50         switch (state) {
  51         case GNSS_SERIAL_ACTIVE:
  52                 return ubx_set_active(gserial);
  53         case GNSS_SERIAL_OFF:
  54         case GNSS_SERIAL_STANDBY:
  55                 return ubx_set_standby(gserial);
  56         }
  57
  58         return -EINVAL;
  59 }
  60
  61 static const struct gnss_serial_ops ubx_gserial_ops = {
  62         .set_power = ubx_set_power,
  63 };
  64
  65 static int ubx_probe(struct serdev_device *serdev)
  66 {
  67         struct gnss_serial *gserial;
  68         struct ubx_data *data;
  69         int ret;
  70
  71         gserial = gnss_serial_allocate(serdev, sizeof(*data));
  72         if (IS_ERR(gserial)) {
  73                 ret = PTR_ERR(gserial);
  74                 return ret;
  75         }
  76
  77         gserial->ops = &ubx_gserial_ops;
  78
  79         gserial->gdev->type = GNSS_TYPE_UBX;
  80
  81         data = gnss_serial_get_drvdata(gserial);
  82
  83         data->vcc = devm_regulator_get(&serdev->dev, "vcc");
  84         if (IS_ERR(data->vcc)) {
  85                 ret = PTR_ERR(data->vcc);
  86                 goto err_free_gserial;
  87         }
  88
  89         ret = devm_regulator_get_enable_optional(&serdev->dev, "v-bckp");
  90         if (ret < 0 && ret != -ENODEV)
  91                 goto err_free_gserial;
  92
  93         ret = gnss_serial_register(gserial);
  94         if (ret)
  95                 goto err_free_gserial;
  96
  97         return 0;
  98
  99 err_free_gserial:
 100         gnss_serial_free(gserial);
 101
 102         return ret;
 103 }
 104
 105 static void ubx_remove(struct serdev_device *serdev)
 106 {
 107         struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
 108
 109         gnss_serial_deregister(gserial);
 110         gnss_serial_free(gserial);
 111 }
 112
 113 #ifdef CONFIG_OF
 114 static const struct of_device_id ubx_of_match[] = {
 115         { .compatible = "u-blox,neo-6m" },
 116         { .compatible = "u-blox,neo-8" },
 117         { .compatible = "u-blox,neo-m8" },
 118         {},
 119 };
 120 MODULE_DEVICE_TABLE(of, ubx_of_match);
 121 #endif
 122
 123 static struct serdev_device_driver ubx_driver = {
 124         .driver = {
 125                 .name           = "gnss-ubx",
 126                 .of_match_table = of_match_ptr(ubx_of_match),
 127                 .pm             = &gnss_serial_pm_ops,
 128         },
 129         .probe  = ubx_probe,
 130         .remove = ubx_remove,
 131 };
 132 module_serdev_device_driver(ubx_driver);
 133
 134 MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
 135 MODULE_DESCRIPTION("u-blox GNSS receiver driver");
 136 MODULE_LICENSE("GPL v2");