path: root/drivers/tty/serdev/core.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2016-2017 Linaro Ltd., Rob Herring <robh@kernel.org>
 *
 * Based on drivers/spmi/spmi.c:
 * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
 */

#include <linux/acpi.h>
#include <linux/errno.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/sched.h>
#include <linux/serdev.h>
#include <linux/slab.h>

#include <linux/platform_data/x86/apple.h>

static bool is_registered;
static DEFINE_IDA(ctrl_ida);

static ssize_t modalias_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{
	int len;

	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
	if (len != -ENODEV)
		return len;

	return of_device_modalias(dev, buf, PAGE_SIZE);
}
static DEVICE_ATTR_RO(modalias);

static struct attribute *serdev_device_attrs[] = {
	&dev_attr_modalias.attr,
	NULL,
};
ATTRIBUTE_GROUPS(serdev_device);

static int serdev_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
	int rc;

	/* TODO: platform modalias */

	rc = acpi_device_uevent_modalias(dev, env);
	if (rc != -ENODEV)
		return rc;

	return of_device_uevent_modalias(dev, env);
}

static void serdev_device_release(struct device *dev)
{
	struct serdev_device *serdev = to_serdev_device(dev);
	kfree(serdev);
}

static const struct device_type serdev_device_type = {
	.groups		= serdev_device_groups,
	.uevent		= serdev_device_uevent,
	.release	= serdev_device_release,
};

static bool is_serdev_device(const struct device *dev)
{
	return dev->type == &serdev_device_type;
}

static void serdev_ctrl_release(struct device *dev)
{
	struct serdev_controller *ctrl = to_serdev_controller(dev);
	ida_free(&ctrl_ida, ctrl->nr);
	kfree(ctrl);
}

static const struct device_type serdev_ctrl_type = {
	.release	= serdev_ctrl_release,
};

static int serdev_device_match(struct device *dev, const struct device_driver *drv)
{
	if (!is_serdev_device(dev))
		return 0;

	/* TODO: platform matching */
	if (acpi_driver_match_device(dev, drv))
		return 1;

	return of_driver_match_device(dev, drv);
}

/**
 * serdev_device_add() - add a device previously constructed via serdev_device_alloc()
 * @serdev:	serdev_device to be added
 */
int serdev_device_add(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;
	struct device *parent = serdev->dev.parent;
	int err;

	dev_set_name(&serdev->dev, "%s-%d", dev_name(parent), serdev->nr);

	/* Only a single slave device is currently supported. */
	if (ctrl->serdev) {
		dev_err(&serdev->dev, "controller busy\n");
		return -EBUSY;
	}
	ctrl->serdev = serdev;

	err = device_add(&serdev->dev);
	if (err < 0) {
		dev_err(&serdev->dev, "Failed to add serdev: %d\n", err);
		goto err_clear_serdev;
	}

	dev_dbg(&serdev->dev, "serdev registered successfully\n");

	return 0;

err_clear_serdev:
	ctrl->serdev = NULL;
	return err;
}
EXPORT_SYMBOL_GPL(serdev_device_add);

/**
 * serdev_device_remove(): remove an serdev device
 * @serdev:	serdev_device to be removed
 */
void serdev_device_remove(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	device_unregister(&serdev->dev);
	ctrl->serdev = NULL;
}
EXPORT_SYMBOL_GPL(serdev_device_remove);

int serdev_device_open(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;
	int ret;

	if (!ctrl || !ctrl->ops->open)
		return -EINVAL;

	ret = ctrl->ops->open(ctrl);
	if (ret)
		return ret;

	ret = pm_runtime_get_sync(&ctrl->dev);
	if (ret < 0) {
		pm_runtime_put_noidle(&ctrl->dev);
		goto err_close;
	}

	return 0;

err_close:
	if (ctrl->ops->close)
		ctrl->ops->close(ctrl);

	return ret;
}
EXPORT_SYMBOL_GPL(serdev_device_open);

void serdev_device_close(struct serdev_device *serdev)
{
	struct serdev_controller *ctrl = serdev->ctrl;

	if (!ctrl || !ctrl->ops->close)
		return;

	pm_runtime_put(&ctrl->dev);

	ctrl->ops->close(ctrl);
}
EXPORT_SYMBOL_GPL(serdev_device_close);

static void devm_serdev_device_close(void *serdev)
{
	serdev_device_close(serdev);
}

int devm_serdev_device_open(struct device *