// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * NCI based driver for Samsung S3FWRN5 NFC chip
 *
 * Copyright (C) 2015 Samsung Electronics
 * Robert Baldyga <r.baldyga@samsung.com>
 */

#include <linux/completion.h>
#include <linux/firmware.h>
#include <crypto/sha1.h>

#include "s3fwrn5.h"
#include "firmware.h"

struct s3fwrn5_fw_version {
        __u8 major;
        __u8 build1;
        __u8 build2;
        __u8 target;
};

static int s3fwrn5_fw_send_msg(struct s3fwrn5_fw_info *fw_info,
        struct sk_buff *msg, struct sk_buff **rsp)
{
        struct s3fwrn5_info *info =
                container_of(fw_info, struct s3fwrn5_info, fw_info);
        long ret;

        reinit_completion(&fw_info->completion);

        ret = s3fwrn5_write(info, msg);
        if (ret < 0)
                return ret;

        ret = wait_for_completion_interruptible_timeout(
                &fw_info->completion, msecs_to_jiffies(1000));
        if (ret < 0)
                return ret;
        else if (ret == 0)
                return -ENXIO;

        if (!fw_info->rsp)
                return -EINVAL;

        *rsp = fw_info->rsp;
        fw_info->rsp = NULL;

        return 0;
}

static int s3fwrn5_fw_prep_msg(struct s3fwrn5_fw_info *fw_info,
        struct sk_buff **msg, u8 type, u8 code, const void *data, u16 len)
{
        struct s3fwrn5_fw_header hdr;
        struct sk_buff *skb;

        hdr.type = type | fw_info->parity;
        fw_info->parity ^= 0x80;
        hdr.code = code;
        hdr.len = len;

        skb = alloc_skb(S3FWRN5_FW_HDR_SIZE + len, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;

        skb_put_data(skb, &hdr, S3FWRN5_FW_HDR_SIZE);
        if (len)
                skb_put_data(skb, data, len);

        *msg = skb;

        return 0;
}

static int s3fwrn5_fw_get_bootinfo(struct s3fwrn5_fw_info *fw_info,
        struct s3fwrn5_fw_cmd_get_bootinfo_rsp *bootinfo)
{
        struct sk_buff *msg, *rsp = NULL;
        struct s3fwrn5_fw_header *hdr;
        int ret;

        /* Send GET_BOOTINFO command */

        ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
                S3FWRN5_FW_CMD_GET_BOOTINFO, NULL, 0);
        if (ret < 0)
                return ret;

        ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
        kfree_skb(msg);
        if (ret < 0)
                return ret;

        hdr = (struct s3fwrn5_fw_header *) rsp->data;
        if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
                ret = -EINVAL;
                goto out;
        }

        memcpy(bootinfo, rsp->data + S3FWRN5_FW_HDR_SIZE, 10);

out:
        kfree_skb(rsp);
        return ret;
}

static int s3fwrn5_fw_enter_update_mode(struct s3fwrn5_fw_info *fw_info,
        const void *hash_data, u16 hash_size,
        const void *sig_data, u16 sig_size)
{
        struct s3fwrn5_fw_cmd_enter_updatemode args;
        struct sk_buff *msg, *rsp = NULL;
        struct s3fwrn5_fw_header *hdr;
        int ret;

        /* Send ENTER_UPDATE_MODE command */

        args.hashcode_size = hash_size;
        args.signature_size = sig_size;

        ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
                S3FWRN5_FW_CMD_ENTER_UPDATE_MODE, &args, sizeof(args));
        if (ret < 0)
                return ret;

        ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
        kfree_skb(msg);
        if (ret < 0)
                return ret;

        hdr = (struct s3fwrn5_fw_header *) rsp->data;
        if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
                ret = -EPROTO;
                goto out;
        }

        kfree_skb(rsp);

        /* Send hashcode data */

        ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_DATA, 0,
                hash_data, hash_size);
        if (ret < 0)
                return ret;

        ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
        kfree_skb(msg);
        if (ret < 0)
                return ret;

        hdr = (struct s3fwrn5_fw_header *) rsp->data;
        if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
                ret = -EPROTO;
                goto out;
        }

        kfree_skb(rsp);

        /* Send signature data */

        ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_DATA, 0,
                sig_data, sig_size);
        if (ret < 0)
                return ret;

        ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
        kfree_skb(msg);
        if (ret < 0)
                return ret;

        hdr = (struct s3fwrn5_fw_header *) rsp->data;
        if (hdr->code != S3FWRN5_FW_RET_SUCCESS)
                ret = -EPROTO;

out:
        kfree_skb(rsp);
        return ret;
}

static int s3fwrn5_fw_update_sector(struct s3fwrn5_fw_info *fw_info,
        u32 base_addr, const void *data)
{
        struct s3fwrn5_fw_cmd_update_sector args;
        struct sk_buff *msg, *rsp = NULL;
        struct s3fwrn5_fw_header *hdr;
        int ret, i;

        /* Send UPDATE_SECTOR command */

        args.base_address = base_addr;

        ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
                S3FWRN5_FW_CMD_UPDATE_SECTOR, &args, sizeof(args));
        if (ret < 0)
                return ret;

        ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
        kfree_skb(msg);
        if (ret < 0)
                return ret;

        hdr = (struct s3fwrn5_fw_header *) rsp->data;
        if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
                ret = -EPROTO;
                goto err;
        }

        kfree_skb(rsp);

        /* Send data split into 256-byte packets */

        for (i = 0; i < 16; ++i) {
                ret = s3fwrn5_fw_prep_msg(fw_info, &msg,
                        S3FWRN5_FW_MSG_DATA, 0, data+256*i, 256);
                if (ret < 0)
                        break;

                ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
                kfree_skb(msg);
                if (ret < 0)
                        break;

                hdr = (struct s3fwrn5_fw_header *) rsp->data;
                if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
                        ret = -EPROTO;
                        goto err;
                }

                kfree_skb(rsp);
        }

        return ret;

err:
        kfree_skb(rsp);
        return ret;
}

static int s3fwrn5_fw_complete_update_mode(struct s3fwrn5_fw_info *fw_info)
{
        struct sk_buff *msg, *rsp = NULL;
        struct s3fwrn5_fw_header *hdr;
        int ret;

        /* Send COMPLETE_UPDATE_MODE command */

        ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
                S3FWRN5_FW_CMD_COMPLETE_UPDATE_MODE, NULL, 0);
        if (ret < 0)
                return ret;

        ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
        kfree_skb(msg);
        if (ret < 0)
                return ret;

        hdr = (struct s3fwrn5_fw_header *) rsp->data;
        if (hdr->code != S3FWRN5_FW_RET_SUCCESS)
                ret = -EPROTO;

        kfree_skb(rsp);

        return ret;
}

/*
 * Firmware header structure:
 *
 * 0x00 - 0x0B : Date and time string (w/o NUL termination)
 * 0x10 - 0x13 : Firmware version
 * 0x14 - 0x17 : Signature address
 * 0x18 - 0x1B : Signature size
 * 0x1C - 0x1F : Firmware image address
 * 0x20 - 0x23 : Firmware sectors count
 * 0x24 - 0x27 : Custom signature address
 * 0x28 - 0x2B : Custom signature size
 */

#define S3FWRN5_FW_IMAGE_HEADER_SIZE 44

int s3fwrn5_fw_request_firmware(struct s3fwrn5_fw_info *fw_info)
{
        struct s3fwrn5_fw_image *fw = &fw_info->fw;
        u32 sig_off;
        u32 image_off;
        u32 custom_sig_off;
        int ret;

        ret = request_firmware(&fw->fw, fw_info->fw_name,
                &fw_info->ndev->nfc_dev->dev);
        if (ret < 0)
                return ret;

        if (fw->fw->size < S3FWRN5_FW_IMAGE_HEADER_SIZE) {
                release_firmware(fw->fw);
                return -EINVAL;
        }

        memcpy(fw->date, fw->fw->data + 0x00, 12);
        fw->date[12] = '\0';

        memcpy(&fw->version, fw->fw->data + 0x10, 4);

        memcpy(&sig_off, fw->fw->data + 0x14, 4);
        fw->sig = fw->fw->data + sig_off;
        memcpy(&fw->sig_size, fw->fw->data + 0x18, 4);

        memcpy(&image_off, fw->fw->data + 0x1C, 4);
        fw->image = fw->fw->data + image_off;
        memcpy(&fw->image_sectors, fw->fw->data + 0x20, 4);

        memcpy(&custom_sig_off, fw->fw->data + 0x24, 4);
        fw->custom_sig = fw->fw->data + custom_sig_off;
        memcpy(&fw->custom_sig_size, fw->fw->data + 0x28, 4);

        return 0;
}

static void s3fwrn5_fw_release_firmware(struct s3fwrn5_fw_info *fw_info)
{
        release_firmware(fw_info->fw.fw);
}

static int s3fwrn5_fw_get_base_addr(
        struct s3fwrn5_fw_cmd_get_bootinfo_rsp *bootinfo, u32 *base_addr)
{
        int i;
        static const struct {
                u8 version[4];
                u32 base_addr;
        } match[] = {
                {{0x05, 0x00, 0x00, 0x00}, 0x00005000},
                {{0x05, 0x00, 0x00, 0x01}, 0x00003000},
                {{0x05, 0x00, 0x00, 0x02}, 0x00003000},
                {{0x05, 0x00, 0x00, 0x03}, 0x00003000},
                {{0x05, 0x00, 0x00, 0x05}, 0x00003000}
        };

        for (i = 0; i < ARRAY_SIZE(match); ++i)
                if (bootinfo->hw_version[0] == match[i].version[0] &&
                        bootinfo->hw_version[1] == match[i].version[1] &&
                        bootinfo->hw_version[3] == match[i].version[3]) {
                        *base_addr = match[i].base_addr;
                        return 0;
                }

        return -EINVAL;
}

static inline bool
s3fwrn5_fw_is_custom(const struct s3fwrn5_fw_cmd_get_bootinfo_rsp *bootinfo)
{
        return !!bootinfo->hw_version[2];
}

int s3fwrn5_fw_setup(struct s3fwrn5_fw_info *fw_info)
{
        struct device *dev = &fw_info->ndev->nfc_dev->dev;
        struct s3fwrn5_fw_cmd_get_bootinfo_rsp bootinfo;
        int ret;

        /* Get bootloader info */

        ret = s3fwrn5_fw_get_bootinfo(fw_info, &bootinfo);
        if (ret < 0) {
                dev_err(dev, "Failed to get bootinfo, ret=%02x\n", ret);
                goto err;
        }

        /* Match hardware version to obtain firmware base address */

        ret = s3fwrn5_fw_get_base_addr(&bootinfo, &fw_info->base_addr);
        if (ret < 0) {
                dev_err(dev, "Unknown hardware version\n");
                goto err;
        }

        fw_info->sector_size = bootinfo.sector_size;

        fw_info->sig_size = s3fwrn5_fw_is_custom(&bootinfo) ?
                fw_info->fw.custom_sig_size : fw_info->fw.sig_size;
        fw_info->sig = s3fwrn5_fw_is_custom(&bootinfo) ?
                fw_info->fw.custom_sig : fw_info->fw.sig;

        return 0;

err:
        s3fwrn5_fw_release_firmware(fw_info);
        return ret;
}

bool s3fwrn5_fw_check_version(const struct s3fwrn5_fw_info *fw_info, u32 version)
{
        struct s3fwrn5_fw_version *new = (void *) &fw_info->fw.version;
        struct s3fwrn5_fw_version *old = (void *) &version;

        if (new->major > old->major)
                return true;
        if (new->build1 > old->build1)
                return true;
        if (new->build2 > old->build2)
                return true;

        return false;
}

int s3fwrn5_fw_download(struct s3fwrn5_fw_info *fw_info)
{
        struct device *dev = &fw_info->ndev->nfc_dev->dev;
        struct s3fwrn5_fw_image *fw = &fw_info->fw;
        u8 hash_data[SHA1_DIGEST_SIZE];
        u32 image_size, off;
        int ret;

        image_size = fw_info->sector_size * fw->image_sectors;

        /* Compute SHA of firmware data */
        sha1(fw->image, image_size, hash_data);

        /* Firmware update process */

        dev_info(dev, "Firmware update: %s\n", fw_info->fw_name);

        ret = s3fwrn5_fw_enter_update_mode(fw_info, hash_data,
                SHA1_DIGEST_SIZE, fw_info->sig, fw_info->sig_size);
        if (ret < 0) {
                dev_err(dev, "Unable to enter update mode\n");
                return ret;
        }

        for (off = 0; off < image_size; off += fw_info->sector_size) {
                ret = s3fwrn5_fw_update_sector(fw_info,
                        fw_info->base_addr + off, fw->image + off);
                if (ret < 0) {
                        dev_err(dev, "Firmware update error (code=%d)\n", ret);
                        return ret;
                }
        }

        ret = s3fwrn5_fw_complete_update_mode(fw_info);
        if (ret < 0) {
                dev_err(dev, "Unable to complete update mode\n");
                return ret;
        }

        dev_info(dev, "Firmware update: success\n");

        return ret;
}

void s3fwrn5_fw_init(struct s3fwrn5_fw_info *fw_info, const char *fw_name)
{
        fw_info->parity = 0x00;
        fw_info->rsp = NULL;
        fw_info->fw.fw = NULL;
        strcpy(fw_info->fw_name, fw_name);
        init_completion(&fw_info->completion);
}

void s3fwrn5_fw_cleanup(struct s3fwrn5_fw_info *fw_info)
{
        s3fwrn5_fw_release_firmware(fw_info);
}

int s3fwrn5_fw_recv_frame(struct nci_dev *ndev, struct sk_buff *skb)
{
        struct s3fwrn5_info *info = nci_get_drvdata(ndev);
        struct s3fwrn5_fw_info *fw_info = &info->fw_info;

        if (WARN_ON(fw_info->rsp)) {
                kfree_skb(skb);
                return -EINVAL;
        }

        fw_info->rsp = skb;

        complete(&fw_info->completion);

        return 0;
}