/* Firmware file reading and download helpers
 *
 * See copyright notice in main.c
 */
#include <linux/kernel.h>
#include <linux/firmware.h>
#include <linux/device.h>

#include "hermes.h"
#include "hermes_dld.h"
#include "orinoco.h"

#include "fw.h"

/* End markers (for Symbol firmware only) */
#define TEXT_END        0x1A            /* End of text header */

struct fw_info {
        char *pri_fw;
        char *sta_fw;
        char *ap_fw;
        u32 pda_addr;
        u16 pda_size;
};

static const struct fw_info orinoco_fw[] = {
        { NULL, "agere_sta_fw.bin", "agere_ap_fw.bin", 0x00390000, 1000 },
        { NULL, "prism_sta_fw.bin", "prism_ap_fw.bin", 0, 1024 },
        { "symbol_sp24t_prim_fw", "symbol_sp24t_sec_fw", NULL, 0x00003100, 512 }
};

/* Structure used to access fields in FW
 * Make sure LE decoding macros are used
 */
struct orinoco_fw_header {
        char hdr_vers[6];       /* ASCII string for header version */
        __le16 headersize;      /* Total length of header */
        __le32 entry_point;     /* NIC entry point */
        __le32 blocks;          /* Number of blocks to program */
        __le32 block_offset;    /* Offset of block data from eof header */
        __le32 pdr_offset;      /* Offset to PDR data from eof header */
        __le32 pri_offset;      /* Offset to primary plug data */
        __le32 compat_offset;   /* Offset to compatibility data*/
        char signature[0];      /* FW signature length headersize-20 */
} __attribute__ ((packed));

/* Check the range of various header entries. Return a pointer to a
 * description of the problem, or NULL if everything checks out. */
static const char *validate_fw(const struct orinoco_fw_header *hdr, size_t len)
{
        u16 hdrsize;

        if (len < sizeof(*hdr))
                return "image too small";
        if (memcmp(hdr->hdr_vers, "HFW", 3) != 0)
                return "format not recognised";

        hdrsize = le16_to_cpu(hdr->headersize);
        if (hdrsize > len)
                return "bad headersize";
        if ((hdrsize + le32_to_cpu(hdr->block_offset)) > len)
                return "bad block offset";
        if ((hdrsize + le32_to_cpu(hdr->pdr_offset)) > len)
                return "bad PDR offset";
        if ((hdrsize + le32_to_cpu(hdr->pri_offset)) > len)
                return "bad PRI offset";
        if ((hdrsize + le32_to_cpu(hdr->compat_offset)) > len)
                return "bad compat offset";

        /* TODO: consider adding a checksum or CRC to the firmware format */
        return NULL;
}

#if defined(CONFIG_HERMES_CACHE_FW_ON_INIT) || defined(CONFIG_PM_SLEEP)
static inline const struct firmware *
orinoco_cached_fw_get(struct orinoco_private *priv, bool primary)
{
        if (primary)
                return priv->cached_pri_fw;
        else
                return priv->cached_fw;
}
#else
#define orinoco_cached_fw_get(priv, primary) (NULL)
#endif

/* Download either STA or AP firmware into the card. */
static int
orinoco_dl_firmware(struct orinoco_private *priv,
                    const struct fw_info *fw,
                    int ap)
{
        /* Plug Data Area (PDA) */
        __le16 *pda;

        hermes_t *hw = &priv->hw;
        const struct firmware *fw_entry;
        const struct orinoco_fw_header *hdr;
        const unsigned char *first_block;
        const void *end;
        const char *firmware;
        const char *fw_err;
        struct device *dev = priv->dev;
        int err = 0;

        pda = kzalloc(fw->pda_size, GFP_KERNEL);
        if (!pda)
                return -ENOMEM;

        if (ap)
                firmware = fw->ap_fw;
        else
                firmware = fw->sta_fw;

        dev_dbg(dev, "Attempting to download firmware %s\n", firmware);

        /* Read current plug data */
        err = hermes_read_pda(hw, pda, fw->pda_addr, fw->pda_size, 0);
        dev_dbg(dev, "Read PDA returned %d\n", err);
        if (err)
                goto free;

        if (!orinoco_cached_fw_get(priv, false)) {
                err = request_firmware(&fw_entry, firmware, priv->dev);

                if (err) {
                        dev_err(dev, "Cannot find firmware %s\n", firmware);
                        err = -ENOENT;
                        goto free;
                }
        } else
                fw_entry = orinoco_cached_fw_get(priv, false);

        hdr = (const struct orinoco_fw_header *) fw_entry->data;

        fw_err = validate_fw(hdr, fw_entry->size);
        if (fw_err) {
                dev_warn(dev, "Invalid firmware image detected (%s). "
                         "Aborting download\n", fw_err);
                err = -EINVAL;
                goto abort;
        }

        /* Enable aux port to allow programming */
        err = hermesi_program_init(hw, le32_to_cpu(hdr->entry_point));
        dev_dbg(dev, "Program init returned %d\n", err);
        if (err != 0)
                goto abort;

        /* Program data */
        first_block = (fw_entry->data +
                       le16_to_cpu(hdr->headersize) +
                       le32_to_cpu(hdr->block_offset));
        end = fw_entry->data + fw_entry->size;

        err = hermes_program(hw, first_block, end);
        dev_dbg(dev, "Program returned %d\n", err);
        if (err != 0)
                goto abort;

        /* Update production data */
        first_block = (fw_entry->data +
                       le16_to_cpu(hdr->headersize) +
                       le32_to_cpu(hdr->pdr_offset));

        err = hermes_apply_pda_with_defaults(hw, first_block, end, pda,
                                             &pda[fw->pda_size / sizeof(*pda)]);
        dev_dbg(dev, "Apply PDA returned %d\n", err);
        if (err)
                goto abort;

        /* Tell card we've finished */
        err = hermesi_program_end(hw);
        dev_dbg(dev, "Program end returned %d\n", err);
        if (err != 0)
                goto abort;

        /* Check if we're running */
        dev_dbg(dev, "hermes_present returned %d\n", hermes_present(hw));

abort:
        /* If we requested the firmware, release it. */
        if (!orinoco_cached_fw_get(priv, false))
                release_firmware(fw_entry);

free:
        kfree(pda);
        return err;
}

/*
 * Process a firmware image - stop the card, load the firmware, reset
 * the card and make sure it responds.  For the secondary firmware take
 * care of the PDA - read it and then write it on top of the firmware.
 */
static int
symbol_dl_image(struct orinoco_private *priv, const struct fw_info *fw,
                const unsigned char *image, const void *end,
                int secondary)
{
        hermes_t *hw = &priv->hw;
        int ret = 0;
        const unsigned char *ptr;
        const unsigned char *first_block;

        /* Plug Data Area (PDA) */
        __le16 *pda = NULL;

        /* Binary block begins after the 0x1A marker */
        ptr = image;
        while (*ptr++ != TEXT_END);
        first_block = ptr;

        /* Read the PDA from EEPROM */
        if (secondary) {
                pda = kzalloc(fw->pda_size, GFP_KERNEL);
                if (!pda)
                        return -ENOMEM;

                ret = hermes_read_pda(hw, pda, fw->pda_addr, fw->pda_size, 1);
                if (ret)
                        goto free;
        }

        /* Stop the firmware, so that it can be safely rewritten */
        if (priv->stop_fw) {
                ret = priv->stop_fw(priv, 1);
                if (ret)
                        goto free;
        }

        /* Program the adapter with new firmware */
        ret = hermes_program(hw, first_block, end);
        if (ret)
                goto free;

        /* Write the PDA to the adapter */
        if (secondary) {
                size_t len = hermes_blocks_length(first_block, end);
                ptr = first_block + len;
                ret = hermes_apply_pda(hw, ptr, end, pda,
                                       &pda[fw->pda_size / sizeof(*pda)]);
                kfree(pda);
                if (ret)
                        return ret;
        }

        /* Run the firmware */
        if (priv->stop_fw) {
                ret = priv->stop_fw(priv, 0);
                if (ret)
                        return ret;
        }

        /* Reset hermes chip and make sure it responds */
        ret = hermes_init(hw);

        /* hermes_reset() should return 0 with the secondary firmware */
        if (secondary && ret != 0)
                return -ENODEV;

        /* And this should work with any firmware */
        if (!hermes_present(hw))
                return -ENODEV;

        return 0;

free:
        kfree(pda);
        return ret;
}


/*
 * Download the firmware into the card, this also does a PCMCIA soft
 * reset on the card, to make sure it's in a sane state.
 */
static int
symbol_dl_firmware(struct orinoco_private *priv,
                   const struct fw_info *fw)
{
        struct device *dev = priv->dev;
        int ret;
        const struct firmware *fw_entry;

        if (!orinoco_cached_fw_get(priv, true)) {
                if (request_firmware(&fw_entry, fw->pri_fw, priv->dev) != 0) {
                        dev_err(dev, "Cannot find firmware: %s\n", fw->pri_fw);
                        return -ENOENT;
                }
        } else
                fw_entry = orinoco_cached_fw_get(priv, true);

        /* Load primary firmware */
        ret = symbol_dl_image(priv, fw, fw_entry->data,
                              fw_entry->data + fw_entry->size, 0);

        if (!orinoco_cached_fw_get(priv, true))
                release_firmware(fw_entry);
        if (ret) {
                dev_err(dev, "Primary firmware download failed\n");
                return ret;
        }

        if (!orinoco_cached_fw_get(priv, false)) {
                if (request_firmware(&fw_entry, fw->sta_fw, priv->dev) != 0) {
                        dev_err(dev, "Cannot find firmware: %s\n", fw->sta_fw);
                        return -ENOENT;
                }
        } else
                fw_entry = orinoco_cached_fw_get(priv, false);

        /* Load secondary firmware */
        ret = symbol_dl_image(priv, fw, fw_entry->data,
                              fw_entry->data + fw_entry->size, 1);
        if (!orinoco_cached_fw_get(priv, false))
                release_firmware(fw_entry);
        if (ret) {
                dev_err(dev, "Secondary firmware download failed\n");
        }

        return ret;
}

int orinoco_download(struct orinoco_private *priv)
{
        int err = 0;
        /* Reload firmware */
        switch (priv->firmware_type) {
        case FIRMWARE_TYPE_AGERE:
                /* case FIRMWARE_TYPE_INTERSIL: */
                err = orinoco_dl_firmware(priv,
                                          &orinoco_fw[priv->firmware_type], 0);
                break;

        case FIRMWARE_TYPE_SYMBOL:
                err = symbol_dl_firmware(priv,
                                         &orinoco_fw[priv->firmware_type]);
                break;
        case FIRMWARE_TYPE_INTERSIL:
                break;
        }
        /* TODO: if we fail we probably need to reinitialise
         * the driver */

        return err;
}

#if defined(CONFIG_HERMES_CACHE_FW_ON_INIT) || defined(CONFIG_PM_SLEEP)
void orinoco_cache_fw(struct orinoco_private *priv, int ap)
{
        const struct firmware *fw_entry = NULL;
        const char *pri_fw;
        const char *fw;

        pri_fw = orinoco_fw[priv->firmware_type].pri_fw;
        if (ap)
                fw = orinoco_fw[priv->firmware_type].ap_fw;
        else
                fw = orinoco_fw[priv->firmware_type].sta_fw;

        if (pri_fw) {
                if (request_firmware(&fw_entry, pri_fw, priv->dev) == 0)
                        priv->cached_pri_fw = fw_entry;
        }

        if (fw) {
                if (request_firmware(&fw_entry, fw, priv->dev) == 0)
                        priv->cached_fw = fw_entry;
        }
}

void orinoco_uncache_fw(struct orinoco_private *priv)
{
        if (priv->cached_pri_fw)
                release_firmware(priv->cached_pri_fw);
        if (priv->cached_fw)
                release_firmware(priv->cached_fw);

        priv->cached_pri_fw = NULL;
        priv->cached_fw = NULL;
}
#endif