drivers/usb/typec/ucsi/ucsi_yoga_c630.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2022-2024, Linaro Ltd
 * Authors:
 *  Bjorn Andersson
 *  Dmitry Baryshkov
 */
#include <linux/auxiliary_bus.h>
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/container_of.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/string.h>
#include <linux/platform_data/lenovo-yoga-c630.h>

#include "ucsi.h"

struct yoga_c630_ucsi {
	struct yoga_c630_ec *ec;
	struct ucsi *ucsi;
	struct notifier_block nb;
	u16 version;
};

static int yoga_c630_ucsi_read_version(struct ucsi *ucsi, u16 *version)
{
	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);

	*version = uec->version;

	return 0;
}

static int yoga_c630_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
{
	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
	u8 buf[YOGA_C630_UCSI_READ_SIZE];
	int ret;

	ret = yoga_c630_ec_ucsi_read(uec->ec, buf);
	if (ret)
		return ret;

	memcpy(cci, buf, sizeof(*cci));

	return 0;
}

static int yoga_c630_ucsi_read_message_in(struct ucsi *ucsi,
					  void *val, size_t val_len)
{
	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
	u8 buf[YOGA_C630_UCSI_READ_SIZE];
	int ret;

	ret = yoga_c630_ec_ucsi_read(uec->ec, buf);
	if (ret)
		return ret;

	memcpy(val, buf + YOGA_C630_UCSI_CCI_SIZE,
	       min(val_len, YOGA_C630_UCSI_DATA_SIZE));

	return 0;
}

static int yoga_c630_ucsi_async_control(struct ucsi *ucsi, u64 command)
{
	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);

	return yoga_c630_ec_ucsi_write(uec->ec, (u8*)&command);
}

const struct ucsi_operations yoga_c630_ucsi_ops = {
	.read_version = yoga_c630_ucsi_read_version,
	.read_cci = yoga_c630_ucsi_read_cci,
	.read_message_in = yoga_c630_ucsi_read_message_in,
	.sync_control = ucsi_sync_control_common,
	.async_control = yoga_c630_ucsi_async_control,
};

static int yoga_c630_ucsi_notify(struct notifier_block *nb,
				 unsigned long action, void *data)
{
	struct yoga_c630_ucsi *uec = container_of(nb, struct yoga_c630_ucsi, nb);
	u32 cci;
	int ret;

	switch (action) {
	case LENOVO_EC_EVENT_USB:
	case LENOVO_EC_EVENT_HPD:
		ucsi_connector_change(uec->ucsi, 1);
		return NOTIFY_OK;

	case LENOVO_EC_EVENT_UCSI:
		ret = uec->ucsi->ops->read_cci(uec->ucsi, &cci);
		if (ret)
			return NOTIFY_DONE;

		ucsi_notify_common(uec->ucsi, cci);

		return NOTIFY_OK;

	default:
		return NOTIFY_DONE;
	}
}

static int yoga_c630_ucsi_probe(struct auxiliary_device *adev,
				const struct auxiliary_device_id *id)
{
	struct yoga_c630_ec *ec = adev->dev.platform_data;
	struct yoga_c630_ucsi *uec;
	int ret;

	uec = devm_kzalloc(&adev->dev, sizeof(*uec), GFP_KERNEL);
	if (!uec)
		return -ENOMEM;

	uec->ec = ec;
	uec->nb.notifier_call = yoga_c630_ucsi_notify;

	uec->ucsi = ucsi_create(&adev->dev, &yoga_c630_ucsi_ops);
	if (IS_ERR(uec->ucsi))
		return PTR_ERR(uec->ucsi);

	ucsi_set_drvdata(uec->ucsi, uec);

	uec->version = yoga_c630_ec_ucsi_get_version(uec->ec);

	auxiliary_set_drvdata(adev, uec);

	ret = yoga_c630_ec_register_notify(ec, &uec->nb);
	if (ret)
		return ret;

	return ucsi_register(uec->ucsi);
}

static void yoga_c630_ucsi_remove(struct auxiliary_device *adev)
{
	struct yoga_c630_ucsi *uec = auxiliary_get_drvdata(adev);

	yoga_c630_ec_unregister_notify(uec->ec, &uec->nb);
	ucsi_unregister(uec->ucsi);
}

static const struct auxiliary_device_id yoga_c630_ucsi_id_table[] = {
	{ .name = YOGA_C630_MOD_NAME "." YOGA_C630_DEV_UCSI, },
	{}
};
MODULE_DEVICE_TABLE(auxiliary, yoga_c630_ucsi_id_table);

static struct auxiliary_driver yoga_c630_ucsi_driver = {
	.name = YOGA_C630_DEV_UCSI,
	.id_table = yoga_c630_ucsi_id_table,
	.probe = yoga_c630_ucsi_probe,
	.remove = yoga_c630_ucsi_remove,
};

module_auxiliary_driver(yoga_c630_ucsi_driver);

MODULE_DESCRIPTION("Lenovo Yoga C630 UCSI");
MODULE_LICENSE("GPL");