/*
 * Copyright (c) 2016, Linaro Ltd.
 * Copyright (c) 2015, Sony Mobile Communications Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#include <linux/firmware.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/rpmsg.h>
#include <linux/soc/qcom/wcnss_ctrl.h>

#define WCNSS_REQUEST_TIMEOUT   (5 * HZ)
#define WCNSS_CBC_TIMEOUT       (10 * HZ)

#define WCNSS_ACK_DONE_BOOTING  1
#define WCNSS_ACK_COLD_BOOTING  2

#define NV_FRAGMENT_SIZE        3072
#define NVBIN_FILE              "wlan/prima/WCNSS_qcom_wlan_nv.bin"

/**
 * struct wcnss_ctrl - driver context
 * @dev:        device handle
 * @channel:    SMD channel handle
 * @ack:        completion for outstanding requests
 * @cbc:        completion for cbc complete indication
 * @ack_status: status of the outstanding request
 * @probe_work: worker for uploading nv binary
 */
struct wcnss_ctrl {
        struct device *dev;
        struct rpmsg_endpoint *channel;

        struct completion ack;
        struct completion cbc;
        int ack_status;

        struct work_struct probe_work;
};

/* message types */
enum {
        WCNSS_VERSION_REQ = 0x01000000,
        WCNSS_VERSION_RESP,
        WCNSS_DOWNLOAD_NV_REQ,
        WCNSS_DOWNLOAD_NV_RESP,
        WCNSS_UPLOAD_CAL_REQ,
        WCNSS_UPLOAD_CAL_RESP,
        WCNSS_DOWNLOAD_CAL_REQ,
        WCNSS_DOWNLOAD_CAL_RESP,
        WCNSS_VBAT_LEVEL_IND,
        WCNSS_BUILD_VERSION_REQ,
        WCNSS_BUILD_VERSION_RESP,
        WCNSS_PM_CONFIG_REQ,
        WCNSS_CBC_COMPLETE_IND,
};

/**
 * struct wcnss_msg_hdr - common packet header for requests and responses
 * @type:       packet message type
 * @len:        total length of the packet, including this header
 */
struct wcnss_msg_hdr {
        u32 type;
        u32 len;
} __packed;

/**
 * struct wcnss_version_resp - version request response
 * @hdr:        common packet wcnss_msg_hdr header
 */
struct wcnss_version_resp {
        struct wcnss_msg_hdr hdr;
        u8 major;
        u8 minor;
        u8 version;
        u8 revision;
} __packed;

/**
 * struct wcnss_download_nv_req - firmware fragment request
 * @hdr:        common packet wcnss_msg_hdr header
 * @seq:        sequence number of this fragment
 * @last:       boolean indicator of this being the last fragment of the binary
 * @frag_size:  length of this fragment
 * @fragment:   fragment data
 */
struct wcnss_download_nv_req {
        struct wcnss_msg_hdr hdr;
        u16 seq;
        u16 last;
        u32 frag_size;
        u8 fragment[];
} __packed;

/**
 * struct wcnss_download_nv_resp - firmware download response
 * @hdr:        common packet wcnss_msg_hdr header
 * @status:     boolean to indicate success of the download
 */
struct wcnss_download_nv_resp {
        struct wcnss_msg_hdr hdr;
        u8 status;
} __packed;

/**
 * wcnss_ctrl_smd_callback() - handler from SMD responses
 * @channel:    smd channel handle
 * @data:       pointer to the incoming data packet
 * @count:      size of the incoming data packet
 *
 * Handles any incoming packets from the remote WCNSS_CTRL service.
 */
static int wcnss_ctrl_smd_callback(struct rpmsg_device *rpdev,
                                   void *data,
                                   int count,
                                   void *priv,
                                   u32 addr)
{
        struct wcnss_ctrl *wcnss = dev_get_drvdata(&rpdev->dev);
        const struct wcnss_download_nv_resp *nvresp;
        const struct wcnss_version_resp *version;
        const struct wcnss_msg_hdr *hdr = data;

        switch (hdr->type) {
        case WCNSS_VERSION_RESP:
                if (count != sizeof(*version)) {
                        dev_err(wcnss->dev,
                                "invalid size of version response\n");
                        break;
                }

                version = data;
                dev_info(wcnss->dev, "WCNSS Version %d.%d %d.%d\n",
                         version->major, version->minor,
                         version->version, version->revision);

                complete(&wcnss->ack);
                break;
        case WCNSS_DOWNLOAD_NV_RESP:
                if (count != sizeof(*nvresp)) {
                        dev_err(wcnss->dev,
                                "invalid size of download response\n");
                        break;
                }

                nvresp = data;
                wcnss->ack_status = nvresp->status;
                complete(&wcnss->ack);
                break;
        case WCNSS_CBC_COMPLETE_IND:
                dev_dbg(wcnss->dev, "cold boot complete\n");
                complete(&wcnss->cbc);
                break;
        default:
                dev_info(wcnss->dev, "unknown message type %d\n", hdr->type);
                break;
        }

        return 0;
}

/**
 * wcnss_request_version() - send a version request to WCNSS
 * @wcnss:      wcnss ctrl driver context
 */
static int wcnss_request_version(struct wcnss_ctrl *wcnss)
{
        struct wcnss_msg_hdr msg;
        int ret;

        msg.type = WCNSS_VERSION_REQ;
        msg.len = sizeof(msg);
        ret = rpmsg_send(wcnss->channel, &msg, sizeof(msg));
        if (ret < 0)
                return ret;

        ret = wait_for_completion_timeout(&wcnss->ack, WCNSS_CBC_TIMEOUT);
        if (!ret) {
                dev_err(wcnss->dev, "timeout waiting for version response\n");
                return -ETIMEDOUT;
        }

        return 0;
}

/**
 * wcnss_download_nv() - send nv binary to WCNSS
 * @wcnss:      wcnss_ctrl state handle
 * @expect_cbc: indicator to caller that an cbc event is expected
 *
 * Returns 0 on success. Negative errno on failure.
 */
static int wcnss_download_nv(struct wcnss_ctrl *wcnss, bool *expect_cbc)
{
        struct wcnss_download_nv_req *req;
        const struct firmware *fw;
        const void *data;
        ssize_t left;
        int ret;

        req = kzalloc(sizeof(*req) + NV_FRAGMENT_SIZE, GFP_KERNEL);
        if (!req)
                return -ENOMEM;

        ret = request_firmware(&fw, NVBIN_FILE, wcnss->dev);
        if (ret < 0) {
                dev_err(wcnss->dev, "Failed to load nv file %s: %d\n",
                        NVBIN_FILE, ret);
                goto free_req;
        }

        data = fw->data;
        left = fw->size;

        req->hdr.type = WCNSS_DOWNLOAD_NV_REQ;
        req->hdr.len = sizeof(*req) + NV_FRAGMENT_SIZE;

        req->last = 0;
        req->frag_size = NV_FRAGMENT_SIZE;

        req->seq = 0;
        do {
                if (left <= NV_FRAGMENT_SIZE) {
                        req->last = 1;
                        req->frag_size = left;
                        req->hdr.len = sizeof(*req) + left;
                }

                memcpy(req->fragment, data, req->frag_size);

                ret = rpmsg_send(wcnss->channel, req, req->hdr.len);
                if (ret < 0) {
                        dev_err(wcnss->dev, "failed to send smd packet\n");
                        goto release_fw;
                }

                /* Increment for next fragment */
                req->seq++;

                data += NV_FRAGMENT_SIZE;
                left -= NV_FRAGMENT_SIZE;
        } while (left > 0);

        ret = wait_for_completion_timeout(&wcnss->ack, WCNSS_REQUEST_TIMEOUT);
        if (!ret) {
                dev_err(wcnss->dev, "timeout waiting for nv upload ack\n");
                ret = -ETIMEDOUT;
        } else {
                *expect_cbc = wcnss->ack_status == WCNSS_ACK_COLD_BOOTING;
                ret = 0;
        }

release_fw:
        release_firmware(fw);
free_req:
        kfree(req);

        return ret;
}

/**
 * qcom_wcnss_open_channel() - open additional SMD channel to WCNSS
 * @wcnss:      wcnss handle, retrieved from drvdata
 * @name:       SMD channel name
 * @cb:         callback to handle incoming data on the channel
 */
struct rpmsg_endpoint *qcom_wcnss_open_channel(void *wcnss, const char *name, rpmsg_rx_cb_t cb, void *priv)
{
        struct rpmsg_channel_info chinfo;
        struct wcnss_ctrl *_wcnss = wcnss;

        strncpy(chinfo.name, name, sizeof(chinfo.name));
        chinfo.src = RPMSG_ADDR_ANY;
        chinfo.dst = RPMSG_ADDR_ANY;

        return rpmsg_create_ept(_wcnss->channel->rpdev, cb, priv, chinfo);
}
EXPORT_SYMBOL(qcom_wcnss_open_channel);

static void wcnss_async_probe(struct work_struct *work)
{
        struct wcnss_ctrl *wcnss = container_of(work, struct wcnss_ctrl, probe_work);
        bool expect_cbc;
        int ret;

        ret = wcnss_request_version(wcnss);
        if (ret < 0)
                return;

        ret = wcnss_download_nv(wcnss, &expect_cbc);
        if (ret < 0)
                return;

        /* Wait for pending cold boot completion if indicated by the nv downloader */
        if (expect_cbc) {
                ret = wait_for_completion_timeout(&wcnss->cbc, WCNSS_REQUEST_TIMEOUT);
                if (!ret)
                        dev_err(wcnss->dev, "expected cold boot completion\n");
        }

        of_platform_populate(wcnss->dev->of_node, NULL, NULL, wcnss->dev);
}

static int wcnss_ctrl_probe(struct rpmsg_device *rpdev)
{
        struct wcnss_ctrl *wcnss;

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

        wcnss->dev = &rpdev->dev;
        wcnss->channel = rpdev->ept;

        init_completion(&wcnss->ack);
        init_completion(&wcnss->cbc);
        INIT_WORK(&wcnss->probe_work, wcnss_async_probe);

        dev_set_drvdata(&rpdev->dev, wcnss);

        schedule_work(&wcnss->probe_work);

        return 0;
}

static void wcnss_ctrl_remove(struct rpmsg_device *rpdev)
{
        struct wcnss_ctrl *wcnss = dev_get_drvdata(&rpdev->dev);

        cancel_work_sync(&wcnss->probe_work);
        of_platform_depopulate(&rpdev->dev);
}

static const struct of_device_id wcnss_ctrl_of_match[] = {
        { .compatible = "qcom,wcnss", },
        {}
};
MODULE_DEVICE_TABLE(of, wcnss_ctrl_of_match);

static struct rpmsg_driver wcnss_ctrl_driver = {
        .probe = wcnss_ctrl_probe,
        .remove = wcnss_ctrl_remove,
        .callback = wcnss_ctrl_smd_callback,
        .drv  = {
                .name  = "qcom_wcnss_ctrl",
                .owner = THIS_MODULE,
                .of_match_table = wcnss_ctrl_of_match,
        },
};

module_rpmsg_driver(wcnss_ctrl_driver);

MODULE_DESCRIPTION("Qualcomm WCNSS control driver");
MODULE_LICENSE("GPL v2");