mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-16 01:04:08 +08:00
d4584bbfcf
Add driver for serial-connected Mediatek-based GNSS receivers. These devices typically boot transmitting vendor specific NMEA output sequences. The serial port bit rate is read from the device tree "current-speed". Note that the driver uses the generic GNSS serial implementation and therefore essentially only manages power abstracted into three power states: ACTIVE, STANDBY, and OFF. For mediatek receivers with a main supply and no enable-gpios, this simply means that the main supply is disabled in STANDBY and OFF (the optional backup supply is kept enabled while the driver is bound). Note that the timepulse-support is left unimplemented. Signed-off-by: Loys Ollivier <lollivier@baylibre.com> [ johan: rename backup supply ] Signed-off-by: Johan Hovold <johan@kernel.org>
153 lines
3.0 KiB
C
153 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Mediatek GNSS receiver driver
|
|
*
|
|
* Copyright (C) 2018 Johan Hovold <johan@kernel.org>
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/gnss.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/regulator/consumer.h>
|
|
#include <linux/serdev.h>
|
|
|
|
#include "serial.h"
|
|
|
|
struct mtk_data {
|
|
struct regulator *vbackup;
|
|
struct regulator *vcc;
|
|
};
|
|
|
|
static int mtk_set_active(struct gnss_serial *gserial)
|
|
{
|
|
struct mtk_data *data = gnss_serial_get_drvdata(gserial);
|
|
int ret;
|
|
|
|
ret = regulator_enable(data->vcc);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtk_set_standby(struct gnss_serial *gserial)
|
|
{
|
|
struct mtk_data *data = gnss_serial_get_drvdata(gserial);
|
|
int ret;
|
|
|
|
ret = regulator_disable(data->vcc);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtk_set_power(struct gnss_serial *gserial,
|
|
enum gnss_serial_pm_state state)
|
|
{
|
|
switch (state) {
|
|
case GNSS_SERIAL_ACTIVE:
|
|
return mtk_set_active(gserial);
|
|
case GNSS_SERIAL_OFF:
|
|
case GNSS_SERIAL_STANDBY:
|
|
return mtk_set_standby(gserial);
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static const struct gnss_serial_ops mtk_gserial_ops = {
|
|
.set_power = mtk_set_power,
|
|
};
|
|
|
|
static int mtk_probe(struct serdev_device *serdev)
|
|
{
|
|
struct gnss_serial *gserial;
|
|
struct mtk_data *data;
|
|
int ret;
|
|
|
|
gserial = gnss_serial_allocate(serdev, sizeof(*data));
|
|
if (IS_ERR(gserial)) {
|
|
ret = PTR_ERR(gserial);
|
|
return ret;
|
|
}
|
|
|
|
gserial->ops = &mtk_gserial_ops;
|
|
|
|
gserial->gdev->type = GNSS_TYPE_MTK;
|
|
|
|
data = gnss_serial_get_drvdata(gserial);
|
|
|
|
data->vcc = devm_regulator_get(&serdev->dev, "vcc");
|
|
if (IS_ERR(data->vcc)) {
|
|
ret = PTR_ERR(data->vcc);
|
|
goto err_free_gserial;
|
|
}
|
|
|
|
data->vbackup = devm_regulator_get_optional(&serdev->dev, "vbackup");
|
|
if (IS_ERR(data->vbackup)) {
|
|
ret = PTR_ERR(data->vbackup);
|
|
if (ret == -ENODEV)
|
|
data->vbackup = NULL;
|
|
else
|
|
goto err_free_gserial;
|
|
}
|
|
|
|
if (data->vbackup) {
|
|
ret = regulator_enable(data->vbackup);
|
|
if (ret)
|
|
goto err_free_gserial;
|
|
}
|
|
|
|
ret = gnss_serial_register(gserial);
|
|
if (ret)
|
|
goto err_disable_vbackup;
|
|
|
|
return 0;
|
|
|
|
err_disable_vbackup:
|
|
if (data->vbackup)
|
|
regulator_disable(data->vbackup);
|
|
err_free_gserial:
|
|
gnss_serial_free(gserial);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void mtk_remove(struct serdev_device *serdev)
|
|
{
|
|
struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
|
|
struct mtk_data *data = gnss_serial_get_drvdata(gserial);
|
|
|
|
gnss_serial_deregister(gserial);
|
|
if (data->vbackup)
|
|
regulator_disable(data->vbackup);
|
|
gnss_serial_free(gserial);
|
|
};
|
|
|
|
#ifdef CONFIG_OF
|
|
static const struct of_device_id mtk_of_match[] = {
|
|
{ .compatible = "globaltop,pa6h" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, mtk_of_match);
|
|
#endif
|
|
|
|
static struct serdev_device_driver mtk_driver = {
|
|
.driver = {
|
|
.name = "gnss-mtk",
|
|
.of_match_table = of_match_ptr(mtk_of_match),
|
|
.pm = &gnss_serial_pm_ops,
|
|
},
|
|
.probe = mtk_probe,
|
|
.remove = mtk_remove,
|
|
};
|
|
module_serdev_device_driver(mtk_driver);
|
|
|
|
MODULE_AUTHOR("Loys Ollivier <lollivier@baylibre.com>");
|
|
MODULE_DESCRIPTION("Mediatek GNSS receiver driver");
|
|
MODULE_LICENSE("GPL v2");
|