277 lines
6.2 KiB
C
277 lines
6.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Generic serial 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/pm.h>
|
|
#include <linux/pm_runtime.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/serdev.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "serial.h"
|
|
|
|
static int gnss_serial_open(struct gnss_device *gdev)
|
|
{
|
|
struct gnss_serial *gserial = gnss_get_drvdata(gdev);
|
|
struct serdev_device *serdev = gserial->serdev;
|
|
int ret;
|
|
|
|
ret = serdev_device_open(serdev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
serdev_device_set_baudrate(serdev, gserial->speed);
|
|
serdev_device_set_flow_control(serdev, false);
|
|
|
|
ret = pm_runtime_get_sync(&serdev->dev);
|
|
if (ret < 0) {
|
|
pm_runtime_put_noidle(&serdev->dev);
|
|
goto err_close;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_close:
|
|
serdev_device_close(serdev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void gnss_serial_close(struct gnss_device *gdev)
|
|
{
|
|
struct gnss_serial *gserial = gnss_get_drvdata(gdev);
|
|
struct serdev_device *serdev = gserial->serdev;
|
|
|
|
serdev_device_close(serdev);
|
|
|
|
pm_runtime_put(&serdev->dev);
|
|
}
|
|
|
|
static int gnss_serial_write_raw(struct gnss_device *gdev,
|
|
const unsigned char *buf, size_t count)
|
|
{
|
|
struct gnss_serial *gserial = gnss_get_drvdata(gdev);
|
|
struct serdev_device *serdev = gserial->serdev;
|
|
int ret;
|
|
|
|
/* write is only buffered synchronously */
|
|
ret = serdev_device_write(serdev, buf, count, MAX_SCHEDULE_TIMEOUT);
|
|
if (ret < 0 || ret < count)
|
|
return ret;
|
|
|
|
/* FIXME: determine if interrupted? */
|
|
serdev_device_wait_until_sent(serdev, 0);
|
|
|
|
return count;
|
|
}
|
|
|
|
static const struct gnss_operations gnss_serial_gnss_ops = {
|
|
.open = gnss_serial_open,
|
|
.close = gnss_serial_close,
|
|
.write_raw = gnss_serial_write_raw,
|
|
};
|
|
|
|
static int gnss_serial_receive_buf(struct serdev_device *serdev,
|
|
const unsigned char *buf, size_t count)
|
|
{
|
|
struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
|
|
struct gnss_device *gdev = gserial->gdev;
|
|
|
|
return gnss_insert_raw(gdev, buf, count);
|
|
}
|
|
|
|
static const struct serdev_device_ops gnss_serial_serdev_ops = {
|
|
.receive_buf = gnss_serial_receive_buf,
|
|
.write_wakeup = serdev_device_write_wakeup,
|
|
};
|
|
|
|
static int gnss_serial_set_power(struct gnss_serial *gserial,
|
|
enum gnss_serial_pm_state state)
|
|
{
|
|
if (!gserial->ops || !gserial->ops->set_power)
|
|
return 0;
|
|
|
|
return gserial->ops->set_power(gserial, state);
|
|
}
|
|
|
|
/*
|
|
* FIXME: need to provide subdriver defaults or separate dt parsing from
|
|
* allocation.
|
|
*/
|
|
static int gnss_serial_parse_dt(struct serdev_device *serdev)
|
|
{
|
|
struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
|
|
struct device_node *node = serdev->dev.of_node;
|
|
u32 speed = 4800;
|
|
|
|
of_property_read_u32(node, "current-speed", &speed);
|
|
|
|
gserial->speed = speed;
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct gnss_serial *gnss_serial_allocate(struct serdev_device *serdev,
|
|
size_t data_size)
|
|
{
|
|
struct gnss_serial *gserial;
|
|
struct gnss_device *gdev;
|
|
int ret;
|
|
|
|
gserial = kzalloc(sizeof(*gserial) + data_size, GFP_KERNEL);
|
|
if (!gserial)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
gdev = gnss_allocate_device(&serdev->dev);
|
|
if (!gdev) {
|
|
ret = -ENOMEM;
|
|
goto err_free_gserial;
|
|
}
|
|
|
|
gdev->ops = &gnss_serial_gnss_ops;
|
|
gnss_set_drvdata(gdev, gserial);
|
|
|
|
gserial->serdev = serdev;
|
|
gserial->gdev = gdev;
|
|
|
|
serdev_device_set_drvdata(serdev, gserial);
|
|
serdev_device_set_client_ops(serdev, &gnss_serial_serdev_ops);
|
|
|
|
ret = gnss_serial_parse_dt(serdev);
|
|
if (ret)
|
|
goto err_put_device;
|
|
|
|
return gserial;
|
|
|
|
err_put_device:
|
|
gnss_put_device(gserial->gdev);
|
|
err_free_gserial:
|
|
kfree(gserial);
|
|
|
|
return ERR_PTR(ret);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_serial_allocate);
|
|
|
|
void gnss_serial_free(struct gnss_serial *gserial)
|
|
{
|
|
gnss_put_device(gserial->gdev);
|
|
kfree(gserial);
|
|
};
|
|
EXPORT_SYMBOL_GPL(gnss_serial_free);
|
|
|
|
int gnss_serial_register(struct gnss_serial *gserial)
|
|
{
|
|
struct serdev_device *serdev = gserial->serdev;
|
|
int ret;
|
|
|
|
if (IS_ENABLED(CONFIG_PM)) {
|
|
pm_runtime_enable(&serdev->dev);
|
|
} else {
|
|
ret = gnss_serial_set_power(gserial, GNSS_SERIAL_ACTIVE);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
ret = gnss_register_device(gserial->gdev);
|
|
if (ret)
|
|
goto err_disable_rpm;
|
|
|
|
return 0;
|
|
|
|
err_disable_rpm:
|
|
if (IS_ENABLED(CONFIG_PM))
|
|
pm_runtime_disable(&serdev->dev);
|
|
else
|
|
gnss_serial_set_power(gserial, GNSS_SERIAL_OFF);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_serial_register);
|
|
|
|
void gnss_serial_deregister(struct gnss_serial *gserial)
|
|
{
|
|
struct serdev_device *serdev = gserial->serdev;
|
|
|
|
gnss_deregister_device(gserial->gdev);
|
|
|
|
if (IS_ENABLED(CONFIG_PM))
|
|
pm_runtime_disable(&serdev->dev);
|
|
else
|
|
gnss_serial_set_power(gserial, GNSS_SERIAL_OFF);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gnss_serial_deregister);
|
|
|
|
#ifdef CONFIG_PM
|
|
static int gnss_serial_runtime_suspend(struct device *dev)
|
|
{
|
|
struct gnss_serial *gserial = dev_get_drvdata(dev);
|
|
|
|
return gnss_serial_set_power(gserial, GNSS_SERIAL_STANDBY);
|
|
}
|
|
|
|
static int gnss_serial_runtime_resume(struct device *dev)
|
|
{
|
|
struct gnss_serial *gserial = dev_get_drvdata(dev);
|
|
|
|
return gnss_serial_set_power(gserial, GNSS_SERIAL_ACTIVE);
|
|
}
|
|
#endif /* CONFIG_PM */
|
|
|
|
static int gnss_serial_prepare(struct device *dev)
|
|
{
|
|
if (pm_runtime_suspended(dev))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int gnss_serial_suspend(struct device *dev)
|
|
{
|
|
struct gnss_serial *gserial = dev_get_drvdata(dev);
|
|
int ret = 0;
|
|
|
|
/*
|
|
* FIXME: serdev currently lacks support for managing the underlying
|
|
* device's wakeup settings. A workaround would be to close the serdev
|
|
* device here if it is open.
|
|
*/
|
|
|
|
if (!pm_runtime_suspended(dev))
|
|
ret = gnss_serial_set_power(gserial, GNSS_SERIAL_STANDBY);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int gnss_serial_resume(struct device *dev)
|
|
{
|
|
struct gnss_serial *gserial = dev_get_drvdata(dev);
|
|
int ret = 0;
|
|
|
|
if (!pm_runtime_suspended(dev))
|
|
ret = gnss_serial_set_power(gserial, GNSS_SERIAL_ACTIVE);
|
|
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_PM_SLEEP */
|
|
|
|
const struct dev_pm_ops gnss_serial_pm_ops = {
|
|
.prepare = gnss_serial_prepare,
|
|
SET_SYSTEM_SLEEP_PM_OPS(gnss_serial_suspend, gnss_serial_resume)
|
|
SET_RUNTIME_PM_OPS(gnss_serial_runtime_suspend, gnss_serial_runtime_resume, NULL)
|
|
};
|
|
EXPORT_SYMBOL_GPL(gnss_serial_pm_ops);
|
|
|
|
MODULE_AUTHOR("Johan Hovold <johan@kernel.org>");
|
|
MODULE_DESCRIPTION("Generic serial GNSS receiver driver");
|
|
MODULE_LICENSE("GPL v2");
|