root/drivers/usb/typec/ucsi/ucsi_glink.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.
 * Copyright (c) 2023, Linaro Ltd
 */
#include <linux/auxiliary_bus.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/property.h>
#include <linux/soc/qcom/pdr.h>
#include <linux/usb/typec_mux.h>
#include <linux/gpio/consumer.h>
#include <linux/soc/qcom/pmic_glink.h>
#include "ucsi.h"

#define PMIC_GLINK_MAX_PORTS            3

#define UCSI_BUF_V1_SIZE                (UCSI_MESSAGE_OUT + (UCSI_MESSAGE_OUT - UCSI_MESSAGE_IN))
#define UCSI_BUF_V2_SIZE                (UCSIv2_MESSAGE_OUT + (UCSIv2_MESSAGE_OUT - UCSI_MESSAGE_IN))

#define MSG_TYPE_REQ_RESP               1

#define UC_NOTIFY_RECEIVER_UCSI         0x0
#define UC_UCSI_READ_BUF_REQ            0x11
#define UC_UCSI_WRITE_BUF_REQ           0x12
#define UC_UCSI_USBC_NOTIFY_IND         0x13

struct ucsi_read_buf_req_msg {
        struct pmic_glink_hdr   hdr;
};

struct __packed ucsi_read_buf_resp_msg {
        struct pmic_glink_hdr   hdr;
        union {
                u8 v2_buf[UCSI_BUF_V2_SIZE];
                u8 v1_buf[UCSI_BUF_V1_SIZE];
        } buf;
        u32                     ret_code;
};

struct __packed ucsi_write_buf_req_msg {
        struct pmic_glink_hdr   hdr;
        union {
                u8 v2_buf[UCSI_BUF_V2_SIZE];
                u8 v1_buf[UCSI_BUF_V1_SIZE];
        } buf;
        u32                     reserved;
};

struct __packed ucsi_write_buf_resp_msg {
        struct pmic_glink_hdr   hdr;
        u32                     ret_code;
};

struct __packed ucsi_notify_ind_msg {
        struct pmic_glink_hdr   hdr;
        u32                     notification;
        u32                     receiver;
        u32                     reserved;
};

struct pmic_glink_ucsi {
        struct device *dev;

        struct gpio_desc *port_orientation[PMIC_GLINK_MAX_PORTS];

        struct pmic_glink_client *client;

        struct ucsi *ucsi;
        struct completion read_ack;
        struct completion write_ack;
        struct mutex lock;      /* protects concurrent access to PMIC Glink interface */

        struct work_struct notify_work;
        struct work_struct register_work;
        spinlock_t state_lock;
        bool ucsi_registered;
        bool pd_running;

        u8 read_buf[UCSI_BUF_V2_SIZE];
};

static int pmic_glink_ucsi_read(struct ucsi *__ucsi, unsigned int offset,
                                void *val, size_t val_len)
{
        struct pmic_glink_ucsi *ucsi = ucsi_get_drvdata(__ucsi);
        struct ucsi_read_buf_req_msg req = {};
        unsigned long left;
        int ret;

        req.hdr.owner = PMIC_GLINK_OWNER_USBC;
        req.hdr.type = MSG_TYPE_REQ_RESP;
        req.hdr.opcode = UC_UCSI_READ_BUF_REQ;

        mutex_lock(&ucsi->lock);
        memset(ucsi->read_buf, 0, sizeof(ucsi->read_buf));
        reinit_completion(&ucsi->read_ack);

        ret = pmic_glink_send(ucsi->client, &req, sizeof(req));
        if (ret < 0) {
                dev_err(ucsi->dev, "failed to send UCSI read request: %d\n", ret);
                goto out_unlock;
        }

        left = wait_for_completion_timeout(&ucsi->read_ack, 5 * HZ);
        if (!left) {
                dev_err(ucsi->dev, "timeout waiting for UCSI read response\n");
                ret = -ETIMEDOUT;
                goto out_unlock;
        }

        memcpy(val, &ucsi->read_buf[offset], val_len);
        ret = 0;

out_unlock:
        mutex_unlock(&ucsi->lock);

        return ret;
}

static int pmic_glink_ucsi_read_version(struct ucsi *ucsi, u16 *version)
{
        return pmic_glink_ucsi_read(ucsi, UCSI_VERSION, version, sizeof(*version));
}

static int pmic_glink_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
{
        return pmic_glink_ucsi_read(ucsi, UCSI_CCI, cci, sizeof(*cci));
}

static int pmic_glink_ucsi_read_message_in(struct ucsi *ucsi, void *val, size_t val_len)
{
        return pmic_glink_ucsi_read(ucsi, UCSI_MESSAGE_IN, val, val_len);
}

static int pmic_glink_ucsi_locked_write(struct pmic_glink_ucsi *ucsi, unsigned int offset,
                                        const void *val, size_t val_len)
{
        struct ucsi_write_buf_req_msg req = {};
        size_t req_len, buf_len;
        unsigned long left;
        int ret;
        u8 *buf;

        req.hdr.owner = PMIC_GLINK_OWNER_USBC;
        req.hdr.type = MSG_TYPE_REQ_RESP;
        req.hdr.opcode = UC_UCSI_WRITE_BUF_REQ;

        if (ucsi->ucsi->version >= UCSI_VERSION_2_0) {
                buf_len = UCSI_BUF_V2_SIZE;
                buf = req.buf.v2_buf;
        } else if (ucsi->ucsi->version) {
                buf_len = UCSI_BUF_V1_SIZE;
                buf = req.buf.v1_buf;
        } else {
                dev_err(ucsi->dev, "UCSI version unknown\n");
                return -EINVAL;
        }
        req_len = sizeof(struct pmic_glink_hdr) + buf_len + sizeof(u32);

        if (offset + val_len > buf_len)
                return -EINVAL;

        memcpy(&buf[offset], val, val_len);

        reinit_completion(&ucsi->write_ack);

        ret = pmic_glink_send(ucsi->client, &req, req_len);
        if (ret < 0) {
                dev_err(ucsi->dev, "failed to send UCSI write request: %d\n", ret);
                return ret;
        }

        left = wait_for_completion_timeout(&ucsi->write_ack, 5 * HZ);
        if (!left) {
                dev_err(ucsi->dev, "timeout waiting for UCSI write response\n");
                return -ETIMEDOUT;
        }

        return 0;
}

static int pmic_glink_ucsi_async_control(struct ucsi *__ucsi, u64 command)
{
        struct pmic_glink_ucsi *ucsi = ucsi_get_drvdata(__ucsi);
        int ret;

        mutex_lock(&ucsi->lock);
        ret = pmic_glink_ucsi_locked_write(ucsi, UCSI_CONTROL, &command, sizeof(command));
        mutex_unlock(&ucsi->lock);

        return ret;
}

static void pmic_glink_ucsi_update_connector(struct ucsi_connector *con)
{
        struct pmic_glink_ucsi *ucsi = ucsi_get_drvdata(con->ucsi);

        if (con->num > PMIC_GLINK_MAX_PORTS ||
            !ucsi->port_orientation[con->num - 1])
                return;

        con->typec_cap.orientation_aware = true;
}

static void pmic_glink_ucsi_connector_status(struct ucsi_connector *con)
{
        struct pmic_glink_ucsi *ucsi = ucsi_get_drvdata(con->ucsi);
        int orientation;

        if (!UCSI_CONSTAT(con, CONNECTED)) {
                typec_set_orientation(con->port, TYPEC_ORIENTATION_NONE);
                return;
        }

        if (con->num > PMIC_GLINK_MAX_PORTS ||
            !ucsi->port_orientation[con->num - 1])
                return;

        orientation = gpiod_get_value(ucsi->port_orientation[con->num - 1]);
        if (orientation >= 0) {
                typec_set_orientation(con->port,
                                      orientation ?
                                      TYPEC_ORIENTATION_REVERSE :
                                      TYPEC_ORIENTATION_NORMAL);
        }
}

static const struct ucsi_operations pmic_glink_ucsi_ops = {
        .read_version = pmic_glink_ucsi_read_version,
        .read_cci = pmic_glink_ucsi_read_cci,
        .poll_cci = pmic_glink_ucsi_read_cci,
        .read_message_in = pmic_glink_ucsi_read_message_in,
        .sync_control = ucsi_sync_control_common,
        .async_control = pmic_glink_ucsi_async_control,
        .update_connector = pmic_glink_ucsi_update_connector,
        .connector_status = pmic_glink_ucsi_connector_status,
};

static void pmic_glink_ucsi_read_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
{
        u32 ret_code, resp_len, buf_len = 0;
        u8 *buf;

        if (ucsi->ucsi->version) {
                if (ucsi->ucsi->version >= UCSI_VERSION_2_0) {
                        buf = ((struct ucsi_read_buf_resp_msg *)data)->buf.v2_buf;
                        buf_len = UCSI_BUF_V2_SIZE;
                } else {
                        buf = ((struct ucsi_read_buf_resp_msg *)data)->buf.v1_buf;
                        buf_len = UCSI_BUF_V1_SIZE;
                }
        } else if (!ucsi->ucsi_registered) {
                /*
                 * If UCSI version is not known yet because device is not registered, choose buffer
                 * size which best fits incoming data
                 */
                if (len > sizeof(struct pmic_glink_hdr) + UCSI_BUF_V2_SIZE) {
                        buf = ((struct ucsi_read_buf_resp_msg *)data)->buf.v2_buf;
                        buf_len = UCSI_BUF_V2_SIZE;
                } else {
                        buf = ((struct ucsi_read_buf_resp_msg *)data)->buf.v1_buf;
                        buf_len = UCSI_BUF_V1_SIZE;
                }
        } else {
                dev_err(ucsi->dev, "Device has been registered but UCSI version is still unknown\n");
                return;
        }

        resp_len = sizeof(struct pmic_glink_hdr) + buf_len + sizeof(u32);

        if (len > resp_len)
                return;

        /* Ensure that buffer_len leaves space for ret_code to be read back from memory */
        if (buf_len > len - sizeof(struct pmic_glink_hdr) - sizeof(u32))
                buf_len = len - sizeof(struct pmic_glink_hdr) - sizeof(u32);

        memcpy(&ret_code, buf + buf_len, sizeof(u32));
        if (ret_code)
                return;

        memcpy(ucsi->read_buf, buf, buf_len);
        complete(&ucsi->read_ack);
}

static void pmic_glink_ucsi_write_ack(struct pmic_glink_ucsi *ucsi, const void *data, int len)
{
        const struct ucsi_write_buf_resp_msg *resp = data;

        if (resp->ret_code)
                return;

        complete(&ucsi->write_ack);
}

static void pmic_glink_ucsi_notify(struct work_struct *work)
{
        struct pmic_glink_ucsi *ucsi = container_of(work, struct pmic_glink_ucsi, notify_work);
        u32 cci;
        int ret;

        ret = pmic_glink_ucsi_read(ucsi->ucsi, UCSI_CCI, &cci, sizeof(cci));
        if (ret) {
                dev_err(ucsi->dev, "failed to read CCI on notification\n");
                return;
        }

        ucsi_notify_common(ucsi->ucsi, cci);
}

static void pmic_glink_ucsi_register(struct work_struct *work)
{
        struct pmic_glink_ucsi *ucsi = container_of(work, struct pmic_glink_ucsi, register_work);
        unsigned long flags;
        bool pd_running;

        spin_lock_irqsave(&ucsi->state_lock, flags);
        pd_running = ucsi->pd_running;
        spin_unlock_irqrestore(&ucsi->state_lock, flags);

        if (!ucsi->ucsi_registered && pd_running) {
                ucsi_register(ucsi->ucsi);
                ucsi->ucsi_registered = true;
        } else if (ucsi->ucsi_registered && !pd_running) {
                ucsi_unregister(ucsi->ucsi);
                ucsi->ucsi_registered = false;
        }
}

static void pmic_glink_ucsi_callback(const void *data, size_t len, void *priv)
{
        struct pmic_glink_ucsi *ucsi = priv;
        const struct pmic_glink_hdr *hdr = data;

        switch (le32_to_cpu(hdr->opcode)) {
        case UC_UCSI_READ_BUF_REQ:
                pmic_glink_ucsi_read_ack(ucsi, data, len);
                break;
        case UC_UCSI_WRITE_BUF_REQ:
                pmic_glink_ucsi_write_ack(ucsi, data, len);
                break;
        case UC_UCSI_USBC_NOTIFY_IND:
                schedule_work(&ucsi->notify_work);
                break;
        }
}

static void pmic_glink_ucsi_pdr_notify(void *priv, int state)
{
        struct pmic_glink_ucsi *ucsi = priv;
        unsigned long flags;

        spin_lock_irqsave(&ucsi->state_lock, flags);
        ucsi->pd_running = (state == SERVREG_SERVICE_STATE_UP);
        spin_unlock_irqrestore(&ucsi->state_lock, flags);
        schedule_work(&ucsi->register_work);
}

static void pmic_glink_ucsi_destroy(void *data)
{
        struct pmic_glink_ucsi *ucsi = data;

        /* Protect to make sure we're not in a middle of a transaction from a glink callback */
        mutex_lock(&ucsi->lock);
        ucsi_destroy(ucsi->ucsi);
        mutex_unlock(&ucsi->lock);
}

static unsigned long quirk_sc8180x = UCSI_NO_PARTNER_PDOS;
static unsigned long quirk_sc8280xp = UCSI_NO_PARTNER_PDOS | UCSI_DELAY_DEVICE_PDOS;
static unsigned long quirk_sm8450 = UCSI_DELAY_DEVICE_PDOS;

static const struct of_device_id pmic_glink_ucsi_of_quirks[] = {
        { .compatible = "qcom,qcm6490-pmic-glink", .data = &quirk_sc8280xp, },
        { .compatible = "qcom,sc8180x-pmic-glink", .data = &quirk_sc8180x, },
        { .compatible = "qcom,sc8280xp-pmic-glink", .data = &quirk_sc8280xp, },
        { .compatible = "qcom,sm8350-pmic-glink", .data = &quirk_sc8180x, },
        { .compatible = "qcom,sm8450-pmic-glink", .data = &quirk_sm8450, },
        { .compatible = "qcom,sm8550-pmic-glink", .data = &quirk_sm8450, },
        {}
};

static int pmic_glink_ucsi_probe(struct auxiliary_device *adev,
                                 const struct auxiliary_device_id *id)
{
        struct pmic_glink_ucsi *ucsi;
        struct device *dev = &adev->dev;
        const struct of_device_id *match;
        int ret;

        ucsi = devm_kzalloc(dev, sizeof(*ucsi), GFP_KERNEL);
        if (!ucsi)
                return -ENOMEM;

        ucsi->dev = dev;
        dev_set_drvdata(dev, ucsi);

        INIT_WORK(&ucsi->notify_work, pmic_glink_ucsi_notify);
        INIT_WORK(&ucsi->register_work, pmic_glink_ucsi_register);
        init_completion(&ucsi->read_ack);
        init_completion(&ucsi->write_ack);
        spin_lock_init(&ucsi->state_lock);
        mutex_init(&ucsi->lock);

        ucsi->ucsi = ucsi_create(dev, &pmic_glink_ucsi_ops);
        if (IS_ERR(ucsi->ucsi))
                return PTR_ERR(ucsi->ucsi);

        /* Make sure we destroy *after* pmic_glink unregister */
        ret = devm_add_action_or_reset(dev, pmic_glink_ucsi_destroy, ucsi);
        if (ret)
                return ret;

        match = of_match_device(pmic_glink_ucsi_of_quirks, dev->parent);
        if (match)
                ucsi->ucsi->quirks = *(unsigned long *)match->data;

        ucsi_set_drvdata(ucsi->ucsi, ucsi);

        device_for_each_child_node_scoped(dev, fwnode) {
                struct gpio_desc *desc;
                u32 port;

                ret = fwnode_property_read_u32(fwnode, "reg", &port);
                if (ret < 0) {
                        dev_err(dev, "missing reg property of %pOFn\n", fwnode);
                        return ret;
                }

                if (port >= PMIC_GLINK_MAX_PORTS) {
                        dev_warn(dev, "invalid connector number, ignoring\n");
                        continue;
                }

                desc = devm_gpiod_get_index_optional(&adev->dev, "orientation", port, GPIOD_IN);

                /* If GPIO isn't found, continue */
                if (!desc)
                        continue;

                if (IS_ERR(desc))
                        return dev_err_probe(dev, PTR_ERR(desc),
                                             "unable to acquire orientation gpio\n");

                ucsi->port_orientation[port] = desc;
        }

        ucsi->client = devm_pmic_glink_client_alloc(dev, PMIC_GLINK_OWNER_USBC,
                                                    pmic_glink_ucsi_callback,
                                                    pmic_glink_ucsi_pdr_notify,
                                                    ucsi);
        if (IS_ERR(ucsi->client))
                return PTR_ERR(ucsi->client);

        pmic_glink_client_register(ucsi->client);

        return 0;
}

static void pmic_glink_ucsi_remove(struct auxiliary_device *adev)
{
        struct pmic_glink_ucsi *ucsi = dev_get_drvdata(&adev->dev);

        /* Unregister first to stop having read & writes */
        ucsi_unregister(ucsi->ucsi);
}

static const struct auxiliary_device_id pmic_glink_ucsi_id_table[] = {
        { .name = "pmic_glink.ucsi", },
        {},
};
MODULE_DEVICE_TABLE(auxiliary, pmic_glink_ucsi_id_table);

static struct auxiliary_driver pmic_glink_ucsi_driver = {
        .name = "pmic_glink_ucsi",
        .probe = pmic_glink_ucsi_probe,
        .remove = pmic_glink_ucsi_remove,
        .id_table = pmic_glink_ucsi_id_table,
};

module_auxiliary_driver(pmic_glink_ucsi_driver);

MODULE_DESCRIPTION("Qualcomm PMIC GLINK UCSI driver");
MODULE_LICENSE("GPL");