// SPDX-License-Identifier: ISC
/*
 * Copyright (c) 2013 Broadcom Corporation
 */

#include <linux/efi.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/firmware.h>
#include <linux/module.h>
#include <linux/bcm47xx_nvram.h>

#include "debug.h"
#include "firmware.h"
#include "core.h"
#include "common.h"
#include "chip.h"

#define BRCMF_FW_MAX_NVRAM_SIZE                 64000
#define BRCMF_FW_NVRAM_DEVPATH_LEN              19      /* devpath0=pcie/1/4/ */
#define BRCMF_FW_NVRAM_PCIEDEV_LEN              10      /* pcie/1/4/ + \0 */
#define BRCMF_FW_DEFAULT_BOARDREV               "boardrev=0xff"

enum nvram_parser_state {
        IDLE,
        KEY,
        VALUE,
        COMMENT,
        END
};

/**
 * struct nvram_parser - internal info for parser.
 *
 * @state: current parser state.
 * @data: input buffer being parsed.
 * @nvram: output buffer with parse result.
 * @nvram_len: length of parse result.
 * @line: current line.
 * @column: current column in line.
 * @pos: byte offset in input buffer.
 * @entry: start position of key,value entry.
 * @multi_dev_v1: detect pcie multi device v1 (compressed).
 * @multi_dev_v2: detect pcie multi device v2.
 * @boardrev_found: nvram contains boardrev information.
 */
struct nvram_parser {
        enum nvram_parser_state state;
        const u8 *data;
        u8 *nvram;
        u32 nvram_len;
        u32 line;
        u32 column;
        u32 pos;
        u32 entry;
        bool multi_dev_v1;
        bool multi_dev_v2;
        bool boardrev_found;
};

/*
 * is_nvram_char() - check if char is a valid one for NVRAM entry
 *
 * It accepts all printable ASCII chars except for '#' which opens a comment.
 * Please note that ' ' (space) while accepted is not a valid key name char.
 */
static bool is_nvram_char(char c)
{
        /* comment marker excluded */
        if (c == '#')
                return false;

        /* key and value may have any other readable character */
        return (c >= 0x20 && c < 0x7f);
}

static bool is_whitespace(char c)
{
        return (c == ' ' || c == '\r' || c == '\n' || c == '\t');
}

static enum nvram_parser_state brcmf_nvram_handle_idle(struct nvram_parser *nvp)
{
        char c;

        c = nvp->data[nvp->pos];
        if (c == '\n')
                return COMMENT;
        if (is_whitespace(c) || c == '\0')
                goto proceed;
        if (c == '#')
                return COMMENT;
        if (is_nvram_char(c)) {
                nvp->entry = nvp->pos;
                return KEY;
        }
        brcmf_dbg(INFO, "warning: ln=%d:col=%d: ignoring invalid character\n",
                  nvp->line, nvp->column);
proceed:
        nvp->column++;
        nvp->pos++;
        return IDLE;
}

static enum nvram_parser_state brcmf_nvram_handle_key(struct nvram_parser *nvp)
{
        enum nvram_parser_state st = nvp->state;
        char c;

        c = nvp->data[nvp->pos];
        if (c == '=') {
                /* ignore RAW1 by treating as comment */
                if (strncmp(&nvp->data[nvp->entry], "RAW1", 4) == 0)
                        st = COMMENT;
                else
                        st = VALUE;
                if (strncmp(&nvp->data[nvp->entry], "devpath", 7) == 0)
                        nvp->multi_dev_v1 = true;
                if (strncmp(&nvp->data[nvp->entry], "pcie/", 5) == 0)
                        nvp->multi_dev_v2 = true;
                if (strncmp(&nvp->data[nvp->entry], "boardrev", 8) == 0)
                        nvp->boardrev_found = true;
        } else if (!is_nvram_char(c) || c == ' ') {
                brcmf_dbg(INFO, "warning: ln=%d:col=%d: '=' expected, skip invalid key entry\n",
                          nvp->line, nvp->column);
                return COMMENT;
        }

        nvp->column++;
        nvp->pos++;
        return st;
}

static enum nvram_parser_state
brcmf_nvram_handle_value(struct nvram_parser *nvp)
{
        char c;
        char *skv;
        char *ekv;
        u32 cplen;

        c = nvp->data[nvp->pos];
        if (!is_nvram_char(c)) {
                /* key,value pair complete */
                ekv = (u8 *)&nvp->data[nvp->pos];
                skv = (u8 *)&nvp->data[nvp->entry];
                cplen = ekv - skv;
                if (nvp->nvram_len + cplen + 1 >= BRCMF_FW_MAX_NVRAM_SIZE)
                        return END;
                /* copy to output buffer */
                memcpy(&nvp->nvram[nvp->nvram_len], skv, cplen);
                nvp->nvram_len += cplen;
                nvp->nvram[nvp->nvram_len] = '\0';
                nvp->nvram_len++;
                return IDLE;
        }
        nvp->pos++;
        nvp->column++;
        return VALUE;
}

static enum nvram_parser_state
brcmf_nvram_handle_comment(struct nvram_parser *nvp)
{
        char *eoc, *sol;

        sol = (char *)&nvp->data[nvp->pos];
        eoc = strchr(sol, '\n');
        if (!eoc) {
                eoc = strchr(sol, '\0');
                if (!eoc)
                        return END;
        }

        /* eat all moving to next line */
        nvp->line++;
        nvp->column = 1;
        nvp->pos += (eoc - sol) + 1;
        return IDLE;
}

static enum nvram_parser_state brcmf_nvram_handle_end(struct nvram_parser *nvp)
{
        /* final state */
        return END;
}

static enum nvram_parser_state
(*nv_parser_states[])(struct nvram_parser *nvp) = {
        brcmf_nvram_handle_idle,
        brcmf_nvram_handle_key,
        brcmf_nvram_handle_value,
        brcmf_nvram_handle_comment,
        brcmf_nvram_handle_end
};

static int brcmf_init_nvram_parser(struct nvram_parser *nvp,
                                   const u8 *data, size_t data_len)
{
        size_t size;

        memset(nvp, 0, sizeof(*nvp));
        nvp->data = data;
        /* Limit size to MAX_NVRAM_SIZE, some files contain lot of comment */
        if (data_len > BRCMF_FW_MAX_NVRAM_SIZE)
                size = BRCMF_FW_MAX_NVRAM_SIZE;
        else
                size = data_len;
        /* Alloc for extra 0 byte + roundup by 4 + length field */
        size += 1 + 3 + sizeof(u32);
        nvp->nvram = kzalloc(size, GFP_KERNEL);
        if (!nvp->nvram)
                return -ENOMEM;

        nvp->line = 1;
        nvp->column = 1;
        return 0;
}

/* brcmf_fw_strip_multi_v1 :Some nvram files contain settings for multiple
 * devices. Strip it down for one device, use domain_nr/bus_nr to determine
 * which data is to be returned. v1 is the version where nvram is stored
 * compressed and "devpath" maps to index for valid entries.
 */
static void brcmf_fw_strip_multi_v1(struct nvram_parser *nvp, u16 domain_nr,
                                    u16 bus_nr)
{
        /* Device path with a leading '=' key-value separator */
        char pci_path[] = "=pci/?/?";
        size_t pci_len;
        char pcie_path[] = "=pcie/?/?";
        size_t pcie_len;

        u32 i, j;
        bool found;
        u8 *nvram;
        u8 id;

        nvram = kzalloc(nvp->nvram_len + 1 + 3 + sizeof(u32), GFP_KERNEL);
        if (!nvram)
                goto fail;

        /* min length: devpath0=pcie/1/4/ + 0:x=y */
        if (nvp->nvram_len < BRCMF_FW_NVRAM_DEVPATH_LEN + 6)
                goto fail;

        /* First search for the devpathX and see if it is the configuration
         * for domain_nr/bus_nr. Search complete nvp
         */
        snprintf(pci_path, sizeof(pci_path), "=pci/%d/%d", domain_nr,
                 bus_nr);
        pci_len = strlen(pci_path);
        snprintf(pcie_path, sizeof(pcie_path), "=pcie/%d/%d", domain_nr,
                 bus_nr);
        pcie_len = strlen(pcie_path);
        found = false;
        i = 0;
        while (i < nvp->nvram_len - BRCMF_FW_NVRAM_DEVPATH_LEN) {
                /* Format: devpathX=pcie/Y/Z/
                 * Y = domain_nr, Z = bus_nr, X = virtual ID
                 */
                if (strncmp(&nvp->nvram[i], "devpath", 7) == 0 &&
                    (!strncmp(&nvp->nvram[i + 8], pci_path, pci_len) ||
                     !strncmp(&nvp->nvram[i + 8], pcie_path, pcie_len))) {
                        id = nvp->nvram[i + 7] - '0';
                        found = true;
                        break;
                }
                while (nvp->nvram[i] != 0)
                        i++;
                i++;
        }
        if (!found)
                goto fail;

        /* Now copy all valid entries, release old nvram and assign new one */
        i = 0;
        j = 0;
        while (i < nvp->nvram_len) {
                if ((nvp->nvram[i] - '0' == id) && (nvp->nvram[i + 1] == ':')) {
                        i += 2;
                        if (strncmp(&nvp->nvram[i], "boardrev", 8) == 0)
                                nvp->boardrev_found = true;
                        while (nvp->nvram[i] != 0) {
                                nvram[j] = nvp->nvram[i];
                                i++;
                                j++;
                        }
                        nvram[j] = 0;
                        j++;
                }
                while (nvp->nvram[i] != 0)
                        i++;
                i++;
        }
        kfree(nvp->nvram);
        nvp->nvram = nvram;
        nvp->nvram_len = j;
        return;

fail:
        kfree(nvram);
        nvp->nvram_len = 0;
}

/* brcmf_fw_strip_multi_v2 :Some nvram files contain settings for multiple
 * devices. Strip it down for one device, use domain_nr/bus_nr to determine
 * which data is to be returned. v2 is the version where nvram is stored
 * uncompressed, all relevant valid entries are identified by
 * pcie/domain_nr/bus_nr:
 */
static void brcmf_fw_strip_multi_v2(struct nvram_parser *nvp, u16 domain_nr,
                                    u16 bus_nr)
{
        char prefix[BRCMF_FW_NVRAM_PCIEDEV_LEN];
        size_t len;
        u32 i, j;
        u8 *nvram;

        nvram = kzalloc(nvp->nvram_len + 1 + 3 + sizeof(u32), GFP_KERNEL);
        if (!nvram) {
                nvp->nvram_len = 0;
                return;
        }

        /* Copy all valid entries, release old nvram and assign new one.
         * Valid entries are of type pcie/X/Y/ where X = domain_nr and
         * Y = bus_nr.
         */
        snprintf(prefix, sizeof(prefix), "pcie/%d/%d/", domain_nr, bus_nr);
        len = strlen(prefix);
        i = 0;
        j = 0;
        while (i < nvp->nvram_len - len) {
                if (strncmp(&nvp->nvram[i], prefix, len) == 0) {
                        i += len;
                        if (strncmp(&nvp->nvram[i], "boardrev", 8) == 0)
                                nvp->boardrev_found = true;
                        while (nvp->nvram[i] != 0) {
                                nvram[j] = nvp->nvram[i];
                                i++;
                                j++;
                        }
                        nvram[j] = 0;
                        j++;
                }
                while (nvp->nvram[i] != 0)
                        i++;
                i++;
        }
        kfree(nvp->nvram);
        nvp->nvram = nvram;
        nvp->nvram_len = j;
}

static void brcmf_fw_add_defaults(struct nvram_parser *nvp)
{
        if (nvp->boardrev_found)
                return;

        memcpy(&nvp->nvram[nvp->nvram_len], &BRCMF_FW_DEFAULT_BOARDREV,
               strlen(BRCMF_FW_DEFAULT_BOARDREV));
        nvp->nvram_len += strlen(BRCMF_FW_DEFAULT_BOARDREV);
        nvp->nvram[nvp->nvram_len] = '\0';
        nvp->nvram_len++;
}

/* brcmf_nvram_strip :Takes a buffer of "<var>=<value>\n" lines read from a fil
 * and ending in a NUL. Removes carriage returns, empty lines, comment lines,
 * and converts newlines to NULs. Shortens buffer as needed and pads with NULs.
 * End of buffer is completed with token identifying length of buffer.
 */
static void *brcmf_fw_nvram_strip(const u8 *data, size_t data_len,
                                  u32 *new_length, u16 domain_nr, u16 bus_nr)
{
        struct nvram_parser nvp;
        u32 pad;
        u32 token;
        __le32 token_le;

        if (brcmf_init_nvram_parser(&nvp, data, data_len) < 0)
                return NULL;

        while (nvp.pos < data_len) {
                nvp.state = nv_parser_states[nvp.state](&nvp);
                if (nvp.state == END)
                        break;
        }
        if (nvp.multi_dev_v1) {
                nvp.boardrev_found = false;
                brcmf_fw_strip_multi_v1(&nvp, domain_nr, bus_nr);
        } else if (nvp.multi_dev_v2) {
                nvp.boardrev_found = false;
                brcmf_fw_strip_multi_v2(&nvp, domain_nr, bus_nr);
        }

        if (nvp.nvram_len == 0) {
                kfree(nvp.nvram);
                return NULL;
        }

        brcmf_fw_add_defaults(&nvp);

        pad = nvp.nvram_len;
        *new_length = roundup(nvp.nvram_len + 1, 4);
        while (pad != *new_length) {
                nvp.nvram[pad] = 0;
                pad++;
        }

        token = *new_length / 4;
        token = (~token << 16) | (token & 0x0000FFFF);
        token_le = cpu_to_le32(token);

        memcpy(&nvp.nvram[*new_length], &token_le, sizeof(token_le));
        *new_length += sizeof(token_le);

        return nvp.nvram;
}

void brcmf_fw_nvram_free(void *nvram)
{
        kfree(nvram);
}

struct brcmf_fw {
        struct device *dev;
        struct brcmf_fw_request *req;
        u32 curpos;
        void (*done)(struct device *dev, int err, struct brcmf_fw_request *req);
};

#ifdef CONFIG_EFI
/* In some cases the EFI-var stored nvram contains "ccode=ALL" or "ccode=XV"
 * to specify "worldwide" compatible settings, but these 2 ccode-s do not work
 * properly. "ccode=ALL" causes channels 12 and 13 to not be available,
 * "ccode=XV" causes all 5GHz channels to not be available. So we replace both
 * with "ccode=X2" which allows channels 12+13 and 5Ghz channels in
 * no-Initiate-Radiation mode. This means that we will never send on these
 * channels without first having received valid wifi traffic on the channel.
 */
static void brcmf_fw_fix_efi_nvram_ccode(char *data, unsigned long data_len)
{
        char *ccode;

        ccode = strnstr((char *)data, "ccode=ALL", data_len);
        if (!ccode)
                ccode = strnstr((char *)data, "ccode=XV\r", data_len);
        if (!ccode)
                return;

        ccode[6] = 'X';
        ccode[7] = '2';
        ccode[8] = '\r';
}

static u8 *brcmf_fw_nvram_from_efi(size_t *data_len_ret)
{
        const u16 name[] = { 'n', 'v', 'r', 'a', 'm', 0 };
        struct efivar_entry *nvram_efivar;
        unsigned long data_len = 0;
        u8 *data = NULL;
        int err;

        nvram_efivar = kzalloc(sizeof(*nvram_efivar), GFP_KERNEL);
        if (!nvram_efivar)
                return NULL;

        memcpy(&nvram_efivar->var.VariableName, name, sizeof(name));
        nvram_efivar->var.VendorGuid = EFI_GUID(0x74b00bd9, 0x805a, 0x4d61,
                                                0xb5, 0x1f, 0x43, 0x26,
                                                0x81, 0x23, 0xd1, 0x13);

        err = efivar_entry_size(nvram_efivar, &data_len);
        if (err)
                goto fail;

        data = kmalloc(data_len, GFP_KERNEL);
        if (!data)
                goto fail;

        err = efivar_entry_get(nvram_efivar, NULL, &data_len, data);
        if (err)
                goto fail;

        brcmf_fw_fix_efi_nvram_ccode(data, data_len);
        brcmf_info("Using nvram EFI variable\n");

        kfree(nvram_efivar);
        *data_len_ret = data_len;
        return data;

fail:
        kfree(data);
        kfree(nvram_efivar);
        return NULL;
}
#else
static inline u8 *brcmf_fw_nvram_from_efi(size_t *data_len) { return NULL; }
#endif

static void brcmf_fw_free_request(struct brcmf_fw_request *req)
{
        struct brcmf_fw_item *item;
        int i;

        for (i = 0, item = &req->items[0]; i < req->n_items; i++, item++) {
                if (item->type == BRCMF_FW_TYPE_BINARY)
                        release_firmware(item->binary);
                else if (item->type == BRCMF_FW_TYPE_NVRAM)
                        brcmf_fw_nvram_free(item->nv_data.data);
        }
        kfree(req);
}

static int brcmf_fw_request_nvram_done(const struct firmware *fw, void *ctx)
{
        struct brcmf_fw *fwctx = ctx;
        struct brcmf_fw_item *cur;
        bool free_bcm47xx_nvram = false;
        bool kfree_nvram = false;
        u32 nvram_length = 0;
        void *nvram = NULL;
        u8 *data = NULL;
        size_t data_len;

        brcmf_dbg(TRACE, "enter: dev=%s\n", dev_name(fwctx->dev));

        cur = &fwctx->req->items[fwctx->curpos];

        if (fw && fw->data) {
                data = (u8 *)fw->data;
                data_len = fw->size;
        } else {
                if ((data = bcm47xx_nvram_get_contents(&data_len)))
                        free_bcm47xx_nvram = true;
                else if ((data = brcmf_fw_nvram_from_efi(&data_len)))
                        kfree_nvram = true;
                else if (!(cur->flags & BRCMF_FW_REQF_OPTIONAL))
                        goto fail;
        }

        if (data)
                nvram = brcmf_fw_nvram_strip(data, data_len, &nvram_length,
                                             fwctx->req->domain_nr,
                                             fwctx->req->bus_nr);

        if (free_bcm47xx_nvram)
                bcm47xx_nvram_release_contents(data);
        if (kfree_nvram)
                kfree(data);

        release_firmware(fw);
        if (!nvram && !(cur->flags & BRCMF_FW_REQF_OPTIONAL))
                goto fail;

        brcmf_dbg(TRACE, "nvram %p len %d\n", nvram, nvram_length);
        cur->nv_data.data = nvram;
        cur->nv_data.len = nvram_length;
        return 0;

fail:
        return -ENOENT;
}

static int brcmf_fw_complete_request(const struct firmware *fw,
                                     struct brcmf_fw *fwctx)
{
        struct brcmf_fw_item *cur = &fwctx->req->items[fwctx->curpos];
        int ret = 0;

        brcmf_dbg(TRACE, "firmware %s %sfound\n", cur->path, fw ? "" : "not ");

        switch (cur->type) {
        case BRCMF_FW_TYPE_NVRAM:
                ret = brcmf_fw_request_nvram_done(fw, fwctx);
                break;
        case BRCMF_FW_TYPE_BINARY:
                if (fw)
                        cur->binary = fw;
                else
                        ret = -ENOENT;
                break;
        default:
                /* something fishy here so bail out early */
                brcmf_err("unknown fw type: %d\n", cur->type);
                release_firmware(fw);
                ret = -EINVAL;
        }

        return (cur->flags & BRCMF_FW_REQF_OPTIONAL) ? 0 : ret;
}

static char *brcm_alt_fw_path(const char *path, const char *board_type)
{
        char alt_path[BRCMF_FW_NAME_LEN];
        char suffix[5];

        strscpy(alt_path, path, BRCMF_FW_NAME_LEN);
        /* At least one character + suffix */
        if (strlen(alt_path) < 5)
                return NULL;

        /* strip .txt or .bin at the end */
        strscpy(suffix, alt_path + strlen(alt_path) - 4, 5);
        alt_path[strlen(alt_path) - 4] = 0;
        strlcat(alt_path, ".", BRCMF_FW_NAME_LEN);
        strlcat(alt_path, board_type, BRCMF_FW_NAME_LEN);
        strlcat(alt_path, suffix, BRCMF_FW_NAME_LEN);

        return kstrdup(alt_path, GFP_KERNEL);
}

static int brcmf_fw_request_firmware(const struct firmware **fw,
                                     struct brcmf_fw *fwctx)
{
        struct brcmf_fw_item *cur = &fwctx->req->items[fwctx->curpos];
        int ret;

        /* Files can be board-specific, first try a board-specific path */
        if (cur->type == BRCMF_FW_TYPE_NVRAM && fwctx->req->board_type) {
                char *alt_path;

                alt_path = brcm_alt_fw_path(cur->path, fwctx->req->board_type);
                if (!alt_path)
                        goto fallback;

                ret = request_firmware(fw, alt_path, fwctx->dev);
                kfree(alt_path);
                if (ret == 0)
                        return ret;
        }

fallback:
        return request_firmware(fw, cur->path, fwctx->dev);
}

static void brcmf_fw_request_done(const struct firmware *fw, void *ctx)
{
        struct brcmf_fw *fwctx = ctx;
        int ret;

        ret = brcmf_fw_complete_request(fw, fwctx);

        while (ret == 0 && ++fwctx->curpos < fwctx->req->n_items) {
                brcmf_fw_request_firmware(&fw, fwctx);
                ret = brcmf_fw_complete_request(fw, ctx);
        }

        if (ret) {
                brcmf_fw_free_request(fwctx->req);
                fwctx->req = NULL;
        }
        fwctx->done(fwctx->dev, ret, fwctx->req);
        kfree(fwctx);
}

static void brcmf_fw_request_done_alt_path(const struct firmware *fw, void *ctx)
{
        struct brcmf_fw *fwctx = ctx;
        struct brcmf_fw_item *first = &fwctx->req->items[0];
        int ret = 0;

        /* Fall back to canonical path if board firmware not found */
        if (!fw)
                ret = request_firmware_nowait(THIS_MODULE, true, first->path,
                                              fwctx->dev, GFP_KERNEL, fwctx,
                                              brcmf_fw_request_done);

        if (fw || ret < 0)
                brcmf_fw_request_done(fw, ctx);
}

static bool brcmf_fw_request_is_valid(struct brcmf_fw_request *req)
{
        struct brcmf_fw_item *item;
        int i;

        if (!req->n_items)
                return false;

        for (i = 0, item = &req->items[0]; i < req->n_items; i++, item++) {
                if (!item->path)
                        return false;
        }
        return true;
}

int brcmf_fw_get_firmwares(struct device *dev, struct brcmf_fw_request *req,
                           void (*fw_cb)(struct device *dev, int err,
                                         struct brcmf_fw_request *req))
{
        struct brcmf_fw_item *first = &req->items[0];
        struct brcmf_fw *fwctx;
        char *alt_path;
        int ret;

        brcmf_dbg(TRACE, "enter: dev=%s\n", dev_name(dev));
        if (!fw_cb)
                return -EINVAL;

        if (!brcmf_fw_request_is_valid(req))
                return -EINVAL;

        fwctx = kzalloc(sizeof(*fwctx), GFP_KERNEL);
        if (!fwctx)
                return -ENOMEM;

        fwctx->dev = dev;
        fwctx->req = req;
        fwctx->done = fw_cb;

        /* First try alternative board-specific path if any */
        alt_path = brcm_alt_fw_path(first->path, fwctx->req->board_type);
        if (alt_path) {
                ret = request_firmware_nowait(THIS_MODULE, true, alt_path,
                                              fwctx->dev, GFP_KERNEL, fwctx,
                                              brcmf_fw_request_done_alt_path);
                kfree(alt_path);
        } else {
                ret = request_firmware_nowait(THIS_MODULE, true, first->path,
                                              fwctx->dev, GFP_KERNEL, fwctx,
                                              brcmf_fw_request_done);
        }
        if (ret < 0)
                brcmf_fw_request_done(NULL, fwctx);

        return 0;
}

struct brcmf_fw_request *
brcmf_fw_alloc_request(u32 chip, u32 chiprev,
                       const struct brcmf_firmware_mapping mapping_table[],
                       u32 table_size, struct brcmf_fw_name *fwnames,
                       u32 n_fwnames)
{
        struct brcmf_fw_request *fwreq;
        char chipname[12];
        const char *mp_path;
        size_t mp_path_len;
        u32 i, j;
        char end = '\0';

        for (i = 0; i < table_size; i++) {
                if (mapping_table[i].chipid == chip &&
                    mapping_table[i].revmask & BIT(chiprev))
                        break;
        }

        brcmf_chip_name(chip, chiprev, chipname, sizeof(chipname));

        if (i == table_size) {
                brcmf_err("Unknown chip %s\n", chipname);
                return NULL;
        }

        fwreq = kzalloc(struct_size(fwreq, items, n_fwnames), GFP_KERNEL);
        if (!fwreq)
                return NULL;

        brcmf_info("using %s for chip %s\n",
                   mapping_table[i].fw_base, chipname);

        mp_path = brcmf_mp_global.firmware_path;
        mp_path_len = strnlen(mp_path, BRCMF_FW_ALTPATH_LEN);
        if (mp_path_len)
                end = mp_path[mp_path_len - 1];

        fwreq->n_items = n_fwnames;

        for (j = 0; j < n_fwnames; j++) {
                fwreq->items[j].path = fwnames[j].path;
                fwnames[j].path[0] = '\0';
                /* check if firmware path is provided by module parameter */
                if (brcmf_mp_global.firmware_path[0] != '\0') {
                        strlcpy(fwnames[j].path, mp_path,
                                BRCMF_FW_NAME_LEN);

                        if (end != '/') {
                                strlcat(fwnames[j].path, "/",
                                        BRCMF_FW_NAME_LEN);
                        }
                }
                strlcat(fwnames[j].path, mapping_table[i].fw_base,
                        BRCMF_FW_NAME_LEN);
                strlcat(fwnames[j].path, fwnames[j].extension,
                        BRCMF_FW_NAME_LEN);
                fwreq->items[j].path = fwnames[j].path;
        }

        return fwreq;
}