root/drivers/usb/typec/ucsi/ucsi_acpi.c
// SPDX-License-Identifier: GPL-2.0
/*
 * UCSI ACPI driver
 *
 * Copyright (C) 2017, Intel Corporation
 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
 */

#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/dmi.h>

#include "ucsi.h"

#define UCSI_DSM_UUID           "6f8398c2-7ca4-11e4-ad36-631042b5008f"
#define UCSI_DSM_FUNC_WRITE     1
#define UCSI_DSM_FUNC_READ      2

struct ucsi_acpi {
        struct device *dev;
        struct ucsi *ucsi;
        void *base;
        bool check_bogus_event;
        guid_t guid;
        u64 cmd;
};

static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func)
{
        union acpi_object *obj;

        obj = acpi_evaluate_dsm(ACPI_HANDLE(ua->dev), &ua->guid, 1, func,
                                NULL);
        if (!obj) {
                dev_err(ua->dev, "%s: failed to evaluate _DSM %d\n",
                        __func__, func);
                return -EIO;
        }

        ACPI_FREE(obj);
        return 0;
}

static int ucsi_acpi_read_version(struct ucsi *ucsi, u16 *version)
{
        struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
        int ret;

        ret = ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
        if (ret)
                return ret;

        memcpy(version, ua->base + UCSI_VERSION, sizeof(*version));

        return 0;
}

static int ucsi_acpi_read_cci(struct ucsi *ucsi, u32 *cci)
{
        struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);

        memcpy(cci, ua->base + UCSI_CCI, sizeof(*cci));

        return 0;
}

static int ucsi_acpi_poll_cci(struct ucsi *ucsi, u32 *cci)
{
        struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
        int ret;

        ret = ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
        if (ret)
                return ret;

        return ucsi_acpi_read_cci(ucsi, cci);
}

static int ucsi_acpi_read_message_in(struct ucsi *ucsi, void *val, size_t val_len)
{
        struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);

        memcpy(val, ua->base + UCSI_MESSAGE_IN, val_len);

        return 0;
}

static int ucsi_acpi_async_control(struct ucsi *ucsi, u64 command)
{
        struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);

        memcpy(ua->base + UCSI_CONTROL, &command, sizeof(command));
        ua->cmd = command;

        return ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_WRITE);
}

static const struct ucsi_operations ucsi_acpi_ops = {
        .read_version = ucsi_acpi_read_version,
        .read_cci = ucsi_acpi_read_cci,
        .poll_cci = ucsi_acpi_poll_cci,
        .read_message_in = ucsi_acpi_read_message_in,
        .sync_control = ucsi_sync_control_common,
        .async_control = ucsi_acpi_async_control
};

static int ucsi_gram_sync_control(struct ucsi *ucsi, u64 command, u32 *cci,
                                  void *val, size_t len)
{
        u16 bogus_change = UCSI_CONSTAT_POWER_LEVEL_CHANGE |
                           UCSI_CONSTAT_PDOS_CHANGE;
        struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
        int ret;

        ret = ucsi_sync_control_common(ucsi, command, cci, val, len);
        if (ret < 0)
                return ret;

        if (UCSI_COMMAND(ua->cmd) == UCSI_GET_PDOS &&
            ua->cmd & UCSI_GET_PDOS_PARTNER_PDO(1) &&
            ua->cmd & UCSI_GET_PDOS_SRC_PDOS)
                ua->check_bogus_event = true;

        if (UCSI_COMMAND(ua->cmd) == UCSI_GET_CONNECTOR_STATUS &&
            ua->check_bogus_event) {
                /* Clear the bogus change */
                if (*(u16 *)val == bogus_change)
                        *(u16 *)val = 0;

                ua->check_bogus_event = false;
        }

        return ret;
}

static const struct ucsi_operations ucsi_gram_ops = {
        .read_version = ucsi_acpi_read_version,
        .read_cci = ucsi_acpi_read_cci,
        .poll_cci = ucsi_acpi_poll_cci,
        .read_message_in = ucsi_acpi_read_message_in,
        .sync_control = ucsi_gram_sync_control,
        .async_control = ucsi_acpi_async_control
};

static const struct dmi_system_id ucsi_acpi_quirks[] = {
        {
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LG Electronics"),
                        DMI_MATCH(DMI_PRODUCT_FAMILY, "LG gram PC"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "90Q"),
                },
                .driver_data = (void *)&ucsi_gram_ops,
        },
        { }
};

static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
{
        struct ucsi_acpi *ua = data;
        u32 cci;
        int ret;

        ret = ua->ucsi->ops->read_cci(ua->ucsi, &cci);
        if (ret)
                return;

        ucsi_notify_common(ua->ucsi, cci);
}

static int ucsi_acpi_probe(struct platform_device *pdev)
{
        struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
        const struct ucsi_operations *ops = &ucsi_acpi_ops;
        const struct dmi_system_id *id;
        struct ucsi_acpi *ua;
        struct resource *res;
        acpi_status status;
        int ret;

        if (adev->dep_unmet)
                return -EPROBE_DEFER;

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

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                dev_err(&pdev->dev, "missing memory resource\n");
                return -ENODEV;
        }

        ua->base = devm_memremap(&pdev->dev, res->start, resource_size(res), MEMREMAP_WB);
        if (IS_ERR(ua->base))
                return PTR_ERR(ua->base);

        ret = guid_parse(UCSI_DSM_UUID, &ua->guid);
        if (ret)
                return ret;

        ua->dev = &pdev->dev;

        id = dmi_first_match(ucsi_acpi_quirks);
        if (id)
                ops = id->driver_data;

        ua->ucsi = ucsi_create(&pdev->dev, ops);
        if (IS_ERR(ua->ucsi))
                return PTR_ERR(ua->ucsi);

        ucsi_set_drvdata(ua->ucsi, ua);

        status = acpi_install_notify_handler(ACPI_HANDLE(&pdev->dev),
                                             ACPI_DEVICE_NOTIFY,
                                             ucsi_acpi_notify, ua);
        if (ACPI_FAILURE(status)) {
                dev_err(&pdev->dev, "failed to install notify handler\n");
                ucsi_destroy(ua->ucsi);
                return -ENODEV;
        }

        ret = ucsi_register(ua->ucsi);
        if (ret) {
                acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev),
                                           ACPI_DEVICE_NOTIFY,
                                           ucsi_acpi_notify);
                ucsi_destroy(ua->ucsi);
                return ret;
        }

        platform_set_drvdata(pdev, ua);

        return 0;
}

static void ucsi_acpi_remove(struct platform_device *pdev)
{
        struct ucsi_acpi *ua = platform_get_drvdata(pdev);

        ucsi_unregister(ua->ucsi);
        ucsi_destroy(ua->ucsi);

        acpi_remove_notify_handler(ACPI_HANDLE(&pdev->dev), ACPI_DEVICE_NOTIFY,
                                   ucsi_acpi_notify);
}

static int ucsi_acpi_resume(struct device *dev)
{
        struct ucsi_acpi *ua = dev_get_drvdata(dev);

        return ucsi_resume(ua->ucsi);
}

static DEFINE_SIMPLE_DEV_PM_OPS(ucsi_acpi_pm_ops, NULL, ucsi_acpi_resume);

static const struct acpi_device_id ucsi_acpi_match[] = {
        { "PNP0CA0", 0 },
        { },
};
MODULE_DEVICE_TABLE(acpi, ucsi_acpi_match);

static struct platform_driver ucsi_acpi_platform_driver = {
        .driver = {
                .name = "ucsi_acpi",
                .pm = pm_ptr(&ucsi_acpi_pm_ops),
                .acpi_match_table = ACPI_PTR(ucsi_acpi_match),
        },
        .probe = ucsi_acpi_probe,
        .remove = ucsi_acpi_remove,
};

module_platform_driver(ucsi_acpi_platform_driver);

MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("UCSI ACPI driver");