/* tuner-xc2028
 *
 * Copyright (c) 2007-2008 Mauro Carvalho Chehab (mchehab@infradead.org)
 *
 * Copyright (c) 2007 Michel Ludwig (michel.ludwig@gmail.com)
 *       - frontend interface
 *
 * This code is placed under the terms of the GNU General Public License v2
 */

#include <linux/i2c.h>
#include <asm/div64.h>
#include <linux/firmware.h>
#include <linux/videodev2.h>
#include <linux/delay.h>
#include <media/tuner.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
#include "tuner-i2c.h"
#include "tuner-xc2028.h"
#include "tuner-xc2028-types.h"

#include <linux/dvb/frontend.h>
#include "dvb_frontend.h"

/* Registers (Write-only) */
#define XREG_INIT         0x00
#define XREG_RF_FREQ      0x02
#define XREG_POWER_DOWN   0x08

/* Registers (Read-only) */
#define XREG_FREQ_ERROR   0x01
#define XREG_LOCK         0x02
#define XREG_VERSION      0x04
#define XREG_PRODUCT_ID   0x08
#define XREG_HSYNC_FREQ   0x10
#define XREG_FRAME_LINES  0x20
#define XREG_SNR          0x40

#define XREG_ADC_ENV      0x0100

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "enable verbose debug messages");

static int no_poweroff;
module_param(no_poweroff, int, 0644);
MODULE_PARM_DESC(no_poweroff, "0 (default) powers device off when not used.\n"
        "1 keep device energized and with tuner ready all the times.\n"
        "  Faster, but consumes more power and keeps the device hotter\n");

static char audio_std[8];
module_param_string(audio_std, audio_std, sizeof(audio_std), 0);
MODULE_PARM_DESC(audio_std,
        "Audio standard. XC3028 audio decoder explicitly "
        "needs to know what audio\n"
        "standard is needed for some video standards with audio A2 or NICAM.\n"
        "The valid values are:\n"
        "A2\n"
        "A2/A\n"
        "A2/B\n"
        "NICAM\n"
        "NICAM/A\n"
        "NICAM/B\n");

static char firmware_name[30];
module_param_string(firmware_name, firmware_name, sizeof(firmware_name), 0);
MODULE_PARM_DESC(firmware_name, "Firmware file name. Allows overriding the "
                                "default firmware name\n");

static LIST_HEAD(hybrid_tuner_instance_list);
static DEFINE_MUTEX(xc2028_list_mutex);

/* struct for storing firmware table */
struct firmware_description {
        unsigned int  type;
        v4l2_std_id   id;
        __u16         int_freq;
        unsigned char *ptr;
        unsigned int  size;
};

struct firmware_properties {
        unsigned int    type;
        v4l2_std_id     id;
        v4l2_std_id     std_req;
        __u16           int_freq;
        unsigned int    scode_table;
        int             scode_nr;
};

enum xc2028_state {
        XC2028_NO_FIRMWARE = 0,
        XC2028_WAITING_FIRMWARE,
        XC2028_ACTIVE,
        XC2028_SLEEP,
        XC2028_NODEV,
};

struct xc2028_data {
        struct list_head        hybrid_tuner_instance_list;
        struct tuner_i2c_props  i2c_props;
        __u32                   frequency;

        enum xc2028_state       state;
        const char              *fname;

        struct firmware_description *firm;
        int                     firm_size;
        __u16                   firm_version;

        __u16                   hwmodel;
        __u16                   hwvers;

        struct xc2028_ctrl      ctrl;

        struct firmware_properties cur_fw;

        struct mutex lock;
};

#define i2c_send(priv, buf, size) ({                                    \
        int _rc;                                                        \
        _rc = tuner_i2c_xfer_send(&priv->i2c_props, buf, size);         \
        if (size != _rc)                                                \
                tuner_info("i2c output error: rc = %d (should be %d)\n",\
                           _rc, (int)size);                             \
        if (priv->ctrl.msleep)                                          \
                msleep(priv->ctrl.msleep);                              \
        _rc;                                                            \
})

#define i2c_rcv(priv, buf, size) ({                                     \
        int _rc;                                                        \
        _rc = tuner_i2c_xfer_recv(&priv->i2c_props, buf, size);         \
        if (size != _rc)                                                \
                tuner_err("i2c input error: rc = %d (should be %d)\n",  \
                           _rc, (int)size);                             \
        _rc;                                                            \
})

#define i2c_send_recv(priv, obuf, osize, ibuf, isize) ({                \
        int _rc;                                                        \
        _rc = tuner_i2c_xfer_send_recv(&priv->i2c_props, obuf, osize,   \
                                       ibuf, isize);                    \
        if (isize != _rc)                                               \
                tuner_err("i2c input error: rc = %d (should be %d)\n",  \
                           _rc, (int)isize);                            \
        if (priv->ctrl.msleep)                                          \
                msleep(priv->ctrl.msleep);                              \
        _rc;                                                            \
})

#define send_seq(priv, data...) ({                                      \
        static u8 _val[] = data;                                        \
        int _rc;                                                        \
        if (sizeof(_val) !=                                             \
                        (_rc = tuner_i2c_xfer_send(&priv->i2c_props,    \
                                                _val, sizeof(_val)))) { \
                tuner_err("Error on line %d: %d\n", __LINE__, _rc);     \
        } else if (priv->ctrl.msleep)                                   \
                msleep(priv->ctrl.msleep);                              \
        _rc;                                                            \
})

static int xc2028_get_reg(struct xc2028_data *priv, u16 reg, u16 *val)
{
        unsigned char buf[2];
        unsigned char ibuf[2];

        tuner_dbg("%s %04x called\n", __func__, reg);

        buf[0] = reg >> 8;
        buf[1] = (unsigned char) reg;

        if (i2c_send_recv(priv, buf, 2, ibuf, 2) != 2)
                return -EIO;

        *val = (ibuf[1]) | (ibuf[0] << 8);
        return 0;
}

#define dump_firm_type(t)       dump_firm_type_and_int_freq(t, 0)
static void dump_firm_type_and_int_freq(unsigned int type, u16 int_freq)
{
         if (type & BASE)
                printk("BASE ");
         if (type & INIT1)
                printk("INIT1 ");
         if (type & F8MHZ)
                printk("F8MHZ ");
         if (type & MTS)
                printk("MTS ");
         if (type & D2620)
                printk("D2620 ");
         if (type & D2633)
                printk("D2633 ");
         if (type & DTV6)
                printk("DTV6 ");
         if (type & QAM)
                printk("QAM ");
         if (type & DTV7)
                printk("DTV7 ");
         if (type & DTV78)
                printk("DTV78 ");
         if (type & DTV8)
                printk("DTV8 ");
         if (type & FM)
                printk("FM ");
         if (type & INPUT1)
                printk("INPUT1 ");
         if (type & LCD)
                printk("LCD ");
         if (type & NOGD)
                printk("NOGD ");
         if (type & MONO)
                printk("MONO ");
         if (type & ATSC)
                printk("ATSC ");
         if (type & IF)
                printk("IF ");
         if (type & LG60)
                printk("LG60 ");
         if (type & ATI638)
                printk("ATI638 ");
         if (type & OREN538)
                printk("OREN538 ");
         if (type & OREN36)
                printk("OREN36 ");
         if (type & TOYOTA388)
                printk("TOYOTA388 ");
         if (type & TOYOTA794)
                printk("TOYOTA794 ");
         if (type & DIBCOM52)
                printk("DIBCOM52 ");
         if (type & ZARLINK456)
                printk("ZARLINK456 ");
         if (type & CHINA)
                printk("CHINA ");
         if (type & F6MHZ)
                printk("F6MHZ ");
         if (type & INPUT2)
                printk("INPUT2 ");
         if (type & SCODE)
                printk("SCODE ");
         if (type & HAS_IF)
                printk("HAS_IF_%d ", int_freq);
}

static  v4l2_std_id parse_audio_std_option(void)
{
        if (strcasecmp(audio_std, "A2") == 0)
                return V4L2_STD_A2;
        if (strcasecmp(audio_std, "A2/A") == 0)
                return V4L2_STD_A2_A;
        if (strcasecmp(audio_std, "A2/B") == 0)
                return V4L2_STD_A2_B;
        if (strcasecmp(audio_std, "NICAM") == 0)
                return V4L2_STD_NICAM;
        if (strcasecmp(audio_std, "NICAM/A") == 0)
                return V4L2_STD_NICAM_A;
        if (strcasecmp(audio_std, "NICAM/B") == 0)
                return V4L2_STD_NICAM_B;

        return 0;
}

static int check_device_status(struct xc2028_data *priv)
{
        switch (priv->state) {
        case XC2028_NO_FIRMWARE:
        case XC2028_WAITING_FIRMWARE:
                return -EAGAIN;
        case XC2028_ACTIVE:
        case XC2028_SLEEP:
                return 0;
        case XC2028_NODEV:
                return -ENODEV;
        }
        return 0;
}

static void free_firmware(struct xc2028_data *priv)
{
        int i;
        tuner_dbg("%s called\n", __func__);

        if (!priv->firm)
                return;

        for (i = 0; i < priv->firm_size; i++)
                kfree(priv->firm[i].ptr);

        kfree(priv->firm);

        priv->firm = NULL;
        priv->firm_size = 0;
        priv->state = XC2028_NO_FIRMWARE;

        memset(&priv->cur_fw, 0, sizeof(priv->cur_fw));
}

static int load_all_firmwares(struct dvb_frontend *fe,
                              const struct firmware *fw)
{
        struct xc2028_data    *priv = fe->tuner_priv;
        const unsigned char   *p, *endp;
        int                   rc = 0;
        int                   n, n_array;
        char                  name[33];

        tuner_dbg("%s called\n", __func__);

        p = fw->data;
        endp = p + fw->size;

        if (fw->size < sizeof(name) - 1 + 2 + 2) {
                tuner_err("Error: firmware file %s has invalid size!\n",
                          priv->fname);
                goto corrupt;
        }

        memcpy(name, p, sizeof(name) - 1);
        name[sizeof(name) - 1] = 0;
        p += sizeof(name) - 1;

        priv->firm_version = get_unaligned_le16(p);
        p += 2;

        n_array = get_unaligned_le16(p);
        p += 2;

        tuner_info("Loading %d firmware images from %s, type: %s, ver %d.%d\n",
                   n_array, priv->fname, name,
                   priv->firm_version >> 8, priv->firm_version & 0xff);

        priv->firm = kcalloc(n_array, sizeof(*priv->firm), GFP_KERNEL);
        if (priv->firm == NULL) {
                tuner_err("Not enough memory to load firmware file.\n");
                rc = -ENOMEM;
                goto err;
        }
        priv->firm_size = n_array;

        n = -1;
        while (p < endp) {
                __u32 type, size;
                v4l2_std_id id;
                __u16 int_freq = 0;

                n++;
                if (n >= n_array) {
                        tuner_err("More firmware images in file than "
                                  "were expected!\n");
                        goto corrupt;
                }

                /* Checks if there's enough bytes to read */
                if (endp - p < sizeof(type) + sizeof(id) + sizeof(size))
                        goto header;

                type = get_unaligned_le32(p);
                p += sizeof(type);

                id = get_unaligned_le64(p);
                p += sizeof(id);

                if (type & HAS_IF) {
                        int_freq = get_unaligned_le16(p);
                        p += sizeof(int_freq);
                        if (endp - p < sizeof(size))
                                goto header;
                }

                size = get_unaligned_le32(p);
                p += sizeof(size);

                if (!size || size > endp - p) {
                        tuner_err("Firmware type ");
                        dump_firm_type(type);
                        printk("(%x), id %llx is corrupted "
                               "(size=%d, expected %d)\n",
                               type, (unsigned long long)id,
                               (unsigned)(endp - p), size);
                        goto corrupt;
                }

                priv->firm[n].ptr = kzalloc(size, GFP_KERNEL);
                if (priv->firm[n].ptr == NULL) {
                        tuner_err("Not enough memory to load firmware file.\n");
                        rc = -ENOMEM;
                        goto err;
                }
                tuner_dbg("Reading firmware type ");
                if (debug) {
                        dump_firm_type_and_int_freq(type, int_freq);
                        printk("(%x), id %llx, size=%d.\n",
                               type, (unsigned long long)id, size);
                }

                memcpy(priv->firm[n].ptr, p, size);
                priv->firm[n].type = type;
                priv->firm[n].id   = id;
                priv->firm[n].size = size;
                priv->firm[n].int_freq = int_freq;

                p += size;
        }

        if (n + 1 != priv->firm_size) {
                tuner_err("Firmware file is incomplete!\n");
                goto corrupt;
        }

        goto done;

header:
        tuner_err("Firmware header is incomplete!\n");
corrupt:
        rc = -EINVAL;
        tuner_err("Error: firmware file is corrupted!\n");

err:
        tuner_info("Releasing partially loaded firmware file.\n");
        free_firmware(priv);

done:
        if (rc == 0)
                tuner_dbg("Firmware files loaded.\n");
        else
                priv->state = XC2028_NODEV;

        return rc;
}

static int seek_firmware(struct dvb_frontend *fe, unsigned int type,
                         v4l2_std_id *id)
{
        struct xc2028_data *priv = fe->tuner_priv;
        int                 i, best_i = -1, best_nr_matches = 0;
        unsigned int        type_mask = 0;

        tuner_dbg("%s called, want type=", __func__);
        if (debug) {
                dump_firm_type(type);
                printk("(%x), id %016llx.\n", type, (unsigned long long)*id);
        }

        if (!priv->firm) {
                tuner_err("Error! firmware not loaded\n");
                return -EINVAL;
        }

        if (((type & ~SCODE) == 0) && (*id == 0))
                *id = V4L2_STD_PAL;

        if (type & BASE)
                type_mask = BASE_TYPES;
        else if (type & SCODE) {
                type &= SCODE_TYPES;
                type_mask = SCODE_TYPES & ~HAS_IF;
        } else if (type & DTV_TYPES)
                type_mask = DTV_TYPES;
        else if (type & STD_SPECIFIC_TYPES)
                type_mask = STD_SPECIFIC_TYPES;

        type &= type_mask;

        if (!(type & SCODE))
                type_mask = ~0;

        /* Seek for exact match */
        for (i = 0; i < priv->firm_size; i++) {
                if ((type == (priv->firm[i].type & type_mask)) &&
                    (*id == priv->firm[i].id))
                        goto found;
        }

        /* Seek for generic video standard match */
        for (i = 0; i < priv->firm_size; i++) {
                v4l2_std_id match_mask;
                int nr_matches;

                if (type != (priv->firm[i].type & type_mask))
                        continue;

                match_mask = *id & priv->firm[i].id;
                if (!match_mask)
                        continue;

                if ((*id & match_mask) == *id)
                        goto found; /* Supports all the requested standards */

                nr_matches = hweight64(match_mask);
                if (nr_matches > best_nr_matches) {
                        best_nr_matches = nr_matches;
                        best_i = i;
                }
        }

        if (best_nr_matches > 0) {
                tuner_dbg("Selecting best matching firmware (%d bits) for "
                          "type=", best_nr_matches);
                dump_firm_type(type);
                printk("(%x), id %016llx:\n", type, (unsigned long long)*id);
                i = best_i;
                goto found;
        }

        /*FIXME: Would make sense to seek for type "hint" match ? */

        i = -ENOENT;
        goto ret;

found:
        *id = priv->firm[i].id;

ret:
        tuner_dbg("%s firmware for type=", (i < 0) ? "Can't find" : "Found");
        if (debug) {
                dump_firm_type(type);
                printk("(%x), id %016llx.\n", type, (unsigned long long)*id);
        }
        return i;
}

static inline int do_tuner_callback(struct dvb_frontend *fe, int cmd, int arg)
{
        struct xc2028_data *priv = fe->tuner_priv;

        /* analog side (tuner-core) uses i2c_adap->algo_data.
         * digital side is not guaranteed to have algo_data defined.
         *
         * digital side will always have fe->dvb defined.
         * analog side (tuner-core) doesn't (yet) define fe->dvb.
         */

        return (!fe->callback) ? -EINVAL :
                fe->callback(((fe->dvb) && (fe->dvb->priv)) ?
                                fe->dvb->priv : priv->i2c_props.adap->algo_data,
                             DVB_FRONTEND_COMPONENT_TUNER, cmd, arg);
}

static int load_firmware(struct dvb_frontend *fe, unsigned int type,
                         v4l2_std_id *id)
{
        struct xc2028_data *priv = fe->tuner_priv;
        int                pos, rc;
        unsigned char      *p, *endp, buf[priv->ctrl.max_len];

        tuner_dbg("%s called\n", __func__);

        pos = seek_firmware(fe, type, id);
        if (pos < 0)
                return pos;

        tuner_info("Loading firmware for type=");
        dump_firm_type(priv->firm[pos].type);
        printk("(%x), id %016llx.\n", priv->firm[pos].type,
               (unsigned long long)*id);

        p = priv->firm[pos].ptr;
        endp = p + priv->firm[pos].size;

        while (p < endp) {
                __u16 size;

                /* Checks if there's enough bytes to read */
                if (p + sizeof(size) > endp) {
                        tuner_err("Firmware chunk size is wrong\n");
                        return -EINVAL;
                }

                size = le16_to_cpu(*(__u16 *) p);
                p += sizeof(size);

                if (size == 0xffff)
                        return 0;

                if (!size) {
                        /* Special callback command received */
                        rc = do_tuner_callback(fe, XC2028_TUNER_RESET, 0);
                        if (rc < 0) {
                                tuner_err("Error at RESET code %d\n",
                                           (*p) & 0x7f);
                                return -EINVAL;
                        }
                        continue;
                }
                if (size >= 0xff00) {
                        switch (size) {
                        case 0xff00:
                                rc = do_tuner_callback(fe, XC2028_RESET_CLK, 0);
                                if (rc < 0) {
                                        tuner_err("Error at RESET code %d\n",
                                                  (*p) & 0x7f);
                                        return -EINVAL;
                                }
                                break;
                        default:
                                tuner_info("Invalid RESET code %d\n",
                                           size & 0x7f);
                                return -EINVAL;

                        }
                        continue;
                }

                /* Checks for a sleep command */
                if (size & 0x8000) {
                        msleep(size & 0x7fff);
                        continue;
                }

                if ((size + p > endp)) {
                        tuner_err("missing bytes: need %d, have %d\n",
                                   size, (int)(endp - p));
                        return -EINVAL;
                }

                buf[0] = *p;
                p++;
                size--;

                /* Sends message chunks */
                while (size > 0) {
                        int len = (size < priv->ctrl.max_len - 1) ?
                                   size : priv->ctrl.max_len - 1;

                        memcpy(buf + 1, p, len);

                        rc = i2c_send(priv, buf, len + 1);
                        if (rc < 0) {
                                tuner_err("%d returned from send\n", rc);
                                return -EINVAL;
                        }

                        p += len;
                        size -= len;
                }

                /* silently fail if the frontend doesn't support I2C flush */
                rc = do_tuner_callback(fe, XC2028_I2C_FLUSH, 0);
                if ((rc < 0) && (rc != -EINVAL)) {
                        tuner_err("error executing flush: %d\n", rc);
                        return rc;
                }
        }
        return 0;
}

static int load_scode(struct dvb_frontend *fe, unsigned int type,
                         v4l2_std_id *id, __u16 int_freq, int scode)
{
        struct xc2028_data *priv = fe->tuner_priv;
        int                pos, rc;
        unsigned char      *p;

        tuner_dbg("%s called\n", __func__);

        if (!int_freq) {
                pos = seek_firmware(fe, type, id);
                if (pos < 0)
                        return pos;
        } else {
                for (pos = 0; pos < priv->firm_size; pos++) {
                        if ((priv->firm[pos].int_freq == int_freq) &&
                            (priv->firm[pos].type & HAS_IF))
                                break;
                }
                if (pos == priv->firm_size)
                        return -ENOENT;
        }

        p = priv->firm[pos].ptr;

        if (priv->firm[pos].type & HAS_IF) {
                if (priv->firm[pos].size != 12 * 16 || scode >= 16)
                        return -EINVAL;
                p += 12 * scode;
        } else {
                /* 16 SCODE entries per file; each SCODE entry is 12 bytes and
                 * has a 2-byte size header in the firmware format. */
                if (priv->firm[pos].size != 14 * 16 || scode >= 16 ||
                    le16_to_cpu(*(__u16 *)(p + 14 * scode)) != 12)
                        return -EINVAL;
                p += 14 * scode + 2;
        }

        tuner_info("Loading SCODE for type=");
        dump_firm_type_and_int_freq(priv->firm[pos].type,
                                    priv->firm[pos].int_freq);
        printk("(%x), id %016llx.\n", priv->firm[pos].type,
               (unsigned long long)*id);

        if (priv->firm_version < 0x0202)
                rc = send_seq(priv, {0x20, 0x00, 0x00, 0x00});
        else
                rc = send_seq(priv, {0xa0, 0x00, 0x00, 0x00});
        if (rc < 0)
                return -EIO;

        rc = i2c_send(priv, p, 12);
        if (rc < 0)
                return -EIO;

        rc = send_seq(priv, {0x00, 0x8c});
        if (rc < 0)
                return -EIO;

        return 0;
}

static int check_firmware(struct dvb_frontend *fe, unsigned int type,
                          v4l2_std_id std, __u16 int_freq)
{
        struct xc2028_data         *priv = fe->tuner_priv;
        struct firmware_properties new_fw;
        int                        rc, retry_count = 0;
        u16                        version, hwmodel;
        v4l2_std_id                std0;

        tuner_dbg("%s called\n", __func__);

        rc = check_device_status(priv);
        if (rc < 0)
                return rc;

        if (priv->ctrl.mts && !(type & FM))
                type |= MTS;

retry:
        new_fw.type = type;
        new_fw.id = std;
        new_fw.std_req = std;
        new_fw.scode_table = SCODE | priv->ctrl.scode_table;
        new_fw.scode_nr = 0;
        new_fw.int_freq = int_freq;

        tuner_dbg("checking firmware, user requested type=");
        if (debug) {
                dump_firm_type(new_fw.type);
                printk("(%x), id %016llx, ", new_fw.type,
                       (unsigned long long)new_fw.std_req);
                if (!int_freq) {
                        printk("scode_tbl ");
                        dump_firm_type(priv->ctrl.scode_table);
                        printk("(%x), ", priv->ctrl.scode_table);
                } else
                        printk("int_freq %d, ", new_fw.int_freq);
                printk("scode_nr %d\n", new_fw.scode_nr);
        }

        /*
         * No need to reload base firmware if it matches and if the tuner
         * is not at sleep mode
         */
        if ((priv->state == XC2028_ACTIVE) &&
            (((BASE | new_fw.type) & BASE_TYPES) ==
            (priv->cur_fw.type & BASE_TYPES))) {
                tuner_dbg("BASE firmware not changed.\n");
                goto skip_base;
        }

        /* Updating BASE - forget about all currently loaded firmware */
        memset(&priv->cur_fw, 0, sizeof(priv->cur_fw));

        /* Reset is needed before loading firmware */
        rc = do_tuner_callback(fe, XC2028_TUNER_RESET, 0);
        if (rc < 0)
                goto fail;

        /* BASE firmwares are all std0 */
        std0 = 0;
        rc = load_firmware(fe, BASE | new_fw.type, &std0);
        if (rc < 0) {
                tuner_err("Error %d while loading base firmware\n",
                          rc);
                goto fail;
        }

        /* Load INIT1, if needed */
        tuner_dbg("Load init1 firmware, if exists\n");

        rc = load_firmware(fe, BASE | INIT1 | new_fw.type, &std0);
        if (rc == -ENOENT)
                rc = load_firmware(fe, (BASE | INIT1 | new_fw.type) & ~F8MHZ,
                                   &std0);
        if (rc < 0 && rc != -ENOENT) {
                tuner_err("Error %d while loading init1 firmware\n",
                          rc);
                goto fail;
        }

skip_base:
        /*
         * No need to reload standard specific firmware if base firmware
         * was not reloaded and requested video standards have not changed.
         */
        if (priv->cur_fw.type == (BASE | new_fw.type) &&
            priv->cur_fw.std_req == std) {
                tuner_dbg("Std-specific firmware already loaded.\n");
                goto skip_std_specific;
        }

        /* Reloading std-specific firmware forces a SCODE update */
        priv->cur_fw.scode_table = 0;

        rc = load_firmware(fe, new_fw.type, &new_fw.id);
        if (rc == -ENOENT)
                rc = load_firmware(fe, new_fw.type & ~F8MHZ, &new_fw.id);

        if (rc < 0)
                goto fail;

skip_std_specific:
        if (priv->cur_fw.scode_table == new_fw.scode_table &&
            priv->cur_fw.scode_nr == new_fw.scode_nr) {
                tuner_dbg("SCODE firmware already loaded.\n");
                goto check_device;
        }

        if (new_fw.type & FM)
                goto check_device;

        /* Load SCODE firmware, if exists */
        tuner_dbg("Trying to load scode %d\n", new_fw.scode_nr);

        rc = load_scode(fe, new_fw.type | new_fw.scode_table, &new_fw.id,
                        new_fw.int_freq, new_fw.scode_nr);

check_device:
        if (xc2028_get_reg(priv, 0x0004, &version) < 0 ||
            xc2028_get_reg(priv, 0x0008, &hwmodel) < 0) {
                tuner_err("Unable to read tuner registers.\n");
                goto fail;
        }

        tuner_dbg("Device is Xceive %d version %d.%d, "
                  "firmware version %d.%d\n",
                  hwmodel, (version & 0xf000) >> 12, (version & 0xf00) >> 8,
                  (version & 0xf0) >> 4, version & 0xf);


        if (priv->ctrl.read_not_reliable)
                goto read_not_reliable;

        /* Check firmware version against what we downloaded. */
        if (priv->firm_version != ((version & 0xf0) << 4 | (version & 0x0f))) {
                if (!priv->ctrl.read_not_reliable) {
                        tuner_err("Incorrect readback of firmware version.\n");
                        goto fail;
                } else {
                        tuner_err("Returned an incorrect version. However, "
                                  "read is not reliable enough. Ignoring it.\n");
                        hwmodel = 3028;
                }
        }

        /* Check that the tuner hardware model remains consistent over time. */
        if (priv->hwmodel == 0 && (hwmodel == 2028 || hwmodel == 3028)) {
                priv->hwmodel = hwmodel;
                priv->hwvers  = version & 0xff00;
        } else if (priv->hwmodel == 0 || priv->hwmodel != hwmodel ||
                   priv->hwvers != (version & 0xff00)) {
                tuner_err("Read invalid device hardware information - tuner "
                          "hung?\n");
                goto fail;
        }

read_not_reliable:
        priv->cur_fw = new_fw;

        /*
         * By setting BASE in cur_fw.type only after successfully loading all
         * firmwares, we can:
         * 1. Identify that BASE firmware with type=0 has been loaded;
         * 2. Tell whether BASE firmware was just changed the next time through.
         */
        priv->cur_fw.type |= BASE;
        priv->state = XC2028_ACTIVE;

        return 0;

fail:
        priv->state = XC2028_SLEEP;

        memset(&priv->cur_fw, 0, sizeof(priv->cur_fw));
        if (retry_count < 8) {
                msleep(50);
                retry_count++;
                tuner_dbg("Retrying firmware load\n");
                goto retry;
        }

        if (rc == -ENOENT)
                rc = -EINVAL;
        return rc;
}

static int xc2028_signal(struct dvb_frontend *fe, u16 *strength)
{
        struct xc2028_data *priv = fe->tuner_priv;
        u16                 frq_lock, signal = 0;
        int                 rc, i;

        tuner_dbg("%s called\n", __func__);

        rc = check_device_status(priv);
        if (rc < 0)
                return rc;

        mutex_lock(&priv->lock);

        /* Sync Lock Indicator */
        for (i = 0; i < 3; i++) {
                rc = xc2028_get_reg(priv, XREG_LOCK, &frq_lock);
                if (rc < 0)
                        goto ret;

                if (frq_lock)
                        break;
                msleep(6);
        }

        /* Frequency didn't lock */
        if (frq_lock == 2)
                goto ret;

        /* Get SNR of the video signal */
        rc = xc2028_get_reg(priv, XREG_SNR, &signal);
        if (rc < 0)
                goto ret;

        /* Signal level is 3 bits only */

        signal = ((1 << 12) - 1) | ((signal & 0x07) << 12);

ret:
        mutex_unlock(&priv->lock);

        *strength = signal;

        tuner_dbg("signal strength is %d\n", signal);

        return rc;
}

static int xc2028_get_afc(struct dvb_frontend *fe, s32 *afc)
{
        struct xc2028_data *priv = fe->tuner_priv;
        int i, rc;
        u16 frq_lock = 0;
        s16 afc_reg = 0;

        rc = check_device_status(priv);
        if (rc < 0)
                return rc;

        mutex_lock(&priv->lock);

        /* Sync Lock Indicator */
        for (i = 0; i < 3; i++) {
                rc = xc2028_get_reg(priv, XREG_LOCK, &frq_lock);
                if (rc < 0)
                        goto ret;

                if (frq_lock)
                        break;
                msleep(6);
        }

        /* Frequency didn't lock */
        if (frq_lock == 2)
                goto ret;

        /* Get AFC */
        rc = xc2028_get_reg(priv, XREG_FREQ_ERROR, &afc_reg);
        if (rc < 0)
                goto ret;

        *afc = afc_reg * 15625; /* Hz */

        tuner_dbg("AFC is %d Hz\n", *afc);

ret:
        mutex_unlock(&priv->lock);

        return rc;
}

#define DIV 15625

static int generic_set_freq(struct dvb_frontend *fe, u32 freq /* in HZ */,
                            enum v4l2_tuner_type new_type,
                            unsigned int type,
                            v4l2_std_id std,
                            u16 int_freq)
{

        struct xc2028_data *priv = fe->tuner_priv;
        int                rc = -EINVAL;
        unsigned char      buf[4];
        u32                div, offset = 0;

        tuner_dbg("%s called\n", __func__);

        mutex_lock(&priv->lock);

        tuner_dbg("should set frequency %d kHz\n", freq / 1000);

        if (check_firmware(fe, type, std, int_freq) < 0)
                goto ret;

        /* On some cases xc2028 can disable video output, if
         * very weak signals are received. By sending a soft
         * reset, this is re-enabled. So, it is better to always
         * send a soft reset before changing channels, to be sure
         * that xc2028 will be in a safe state.
         * Maybe this might also be needed for DTV.
         */
        switch (new_type) {
        case V4L2_TUNER_ANALOG_TV:
                rc = send_seq(priv, {0x00, 0x00});

                /* Analog mode requires offset = 0 */
                break;
        case V4L2_TUNER_RADIO:
                /* Radio mode requires offset = 0 */
                break;
        case V4L2_TUNER_DIGITAL_TV:
                /*
                 * Digital modes require an offset to adjust to the
                 * proper frequency. The offset depends on what
                 * firmware version is used.
                 */

                /*
                 * Adjust to the center frequency. This is calculated by the
                 * formula: offset = 1.25MHz - BW/2
                 * For DTV 7/8, the firmware uses BW = 8000, so it needs a
                 * further adjustment to get the frequency center on VHF
                 */

                /*
                 * The firmware DTV78 used to work fine in UHF band (8 MHz
                 * bandwidth) but not at all in VHF band (7 MHz bandwidth).
                 * The real problem was connected to the formula used to
                 * calculate the center frequency offset in VHF band.
                 * In fact, removing the 500KHz adjustment fixed the problem.
                 * This is coherent to what was implemented for the DTV7
                 * firmware.
                 * In the end, now the center frequency is the same for all 3
                 * firmwares (DTV7, DTV8, DTV78) and doesn't depend on channel
                 * bandwidth.
                 */

                if (priv->cur_fw.type & DTV6)
                        offset = 1750000;
                else    /* DTV7 or DTV8 or DTV78 */
                        offset = 2750000;

                /*
                 * xc3028 additional "magic"
                 * Depending on the firmware version, it needs some adjustments
                 * to properly centralize the frequency. This seems to be
                 * needed to compensate the SCODE table adjustments made by
                 * newer firmwares
                 */

                /*
                 * The proper adjustment would be to do it at s-code table.
                 * However, this didn't work, as reported by
                 * Robert Lowery <rglowery@exemail.com.au>
                 */

#if 0
                /*
                 * Still need tests for XC3028L (firmware 3.2 or upper)
                 * So, for now, let's just comment the per-firmware
                 * version of this change. Reports with xc3028l working
                 * with and without the lines bellow are welcome
                 */

                if (priv->firm_version < 0x0302) {
                        if (priv->cur_fw.type & DTV7)
                                offset += 500000;
                } else {
                        if (priv->cur_fw.type & DTV7)
                                offset -= 300000;
                        else if (type != ATSC) /* DVB @6MHz, DTV 8 and DTV 7/8 */
                                offset += 200000;
                }
#endif
        }

        div = (freq - offset + DIV / 2) / DIV;

        /* CMD= Set frequency */
        if (priv->firm_version < 0x0202)
                rc = send_seq(priv, {0x00, XREG_RF_FREQ, 0x00, 0x00});
        else
                rc = send_seq(priv, {0x80, XREG_RF_FREQ, 0x00, 0x00});
        if (rc < 0)
                goto ret;

        /* Return code shouldn't be checked.
           The reset CLK is needed only with tm6000.
           Driver should work fine even if this fails.
         */
        if (priv->ctrl.msleep)
                msleep(priv->ctrl.msleep);
        do_tuner_callback(fe, XC2028_RESET_CLK, 1);

        msleep(10);

        buf[0] = 0xff & (div >> 24);
        buf[1] = 0xff & (div >> 16);
        buf[2] = 0xff & (div >> 8);
        buf[3] = 0xff & (div);

        rc = i2c_send(priv, buf, sizeof(buf));
        if (rc < 0)
                goto ret;
        msleep(100);

        priv->frequency = freq;

        tuner_dbg("divisor= %*ph (freq=%d.%03d)\n", 4, buf,
               freq / 1000000, (freq % 1000000) / 1000);

        rc = 0;

ret:
        mutex_unlock(&priv->lock);

        return rc;
}

static int xc2028_set_analog_freq(struct dvb_frontend *fe,
                              struct analog_parameters *p)
{
        struct xc2028_data *priv = fe->tuner_priv;
        unsigned int       type=0;

        tuner_dbg("%s called\n", __func__);

        if (p->mode == V4L2_TUNER_RADIO) {
                type |= FM;
                if (priv->ctrl.input1)
                        type |= INPUT1;
                return generic_set_freq(fe, (625l * p->frequency) / 10,
                                V4L2_TUNER_RADIO, type, 0, 0);
        }

        /* if std is not defined, choose one */
        if (!p->std)
                p->std = V4L2_STD_MN;

        /* PAL/M, PAL/N, PAL/Nc and NTSC variants should use 6MHz firmware */
        if (!(p->std & V4L2_STD_MN))
                type |= F8MHZ;

        /* Add audio hack to std mask */
        p->std |= parse_audio_std_option();

        return generic_set_freq(fe, 62500l * p->frequency,
                                V4L2_TUNER_ANALOG_TV, type, p->std, 0);
}

static int xc2028_set_params(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 delsys = c->delivery_system;
        u32 bw = c->bandwidth_hz;
        struct xc2028_data *priv = fe->tuner_priv;
        int rc;
        unsigned int       type = 0;
        u16                demod = 0;

        tuner_dbg("%s called\n", __func__);

        rc = check_device_status(priv);
        if (rc < 0)
                return rc;

        switch (delsys) {
        case SYS_DVBT:
        case SYS_DVBT2:
                /*
                 * The only countries with 6MHz seem to be Taiwan/Uruguay.
                 * Both seem to require QAM firmware for OFDM decoding
                 * Tested in Taiwan by Terry Wu <terrywu2009@gmail.com>
                 */
                if (bw <= 6000000)
                        type |= QAM;

                switch (priv->ctrl.type) {
                case XC2028_D2633:
                        type |= D2633;
                        break;
                case XC2028_D2620:
                        type |= D2620;
                        break;
                case XC2028_AUTO:
                default:
                        /* Zarlink seems to need D2633 */
                        if (priv->ctrl.demod == XC3028_FE_ZARLINK456)
                                type |= D2633;
                        else
                                type |= D2620;
                }
                break;
        case SYS_ATSC:
                /* The only ATSC firmware (at least on v2.7) is D2633 */
                type |= ATSC | D2633;
                break;
        /* DVB-S and pure QAM (FE_QAM) are not supported */
        default:
                return -EINVAL;
        }

        if (bw <= 6000000) {
                type |= DTV6;
                priv->ctrl.vhfbw7 = 0;
                priv->ctrl.uhfbw8 = 0;
        } else if (bw <= 7000000) {
                if (c->frequency < 470000000)
                        priv->ctrl.vhfbw7 = 1;
                else
                        priv->ctrl.uhfbw8 = 0;
                type |= (priv->ctrl.vhfbw7 && priv->ctrl.uhfbw8) ? DTV78 : DTV7;
                type |= F8MHZ;
        } else {
                if (c->frequency < 470000000)
                        priv->ctrl.vhfbw7 = 0;
                else
                        priv->ctrl.uhfbw8 = 1;
                type |= (priv->ctrl.vhfbw7 && priv->ctrl.uhfbw8) ? DTV78 : DTV8;
                type |= F8MHZ;
        }

        /* All S-code tables need a 200kHz shift */
        if (priv->ctrl.demod) {
                demod = priv->ctrl.demod;

                /*
                 * Newer firmwares require a 200 kHz offset only for ATSC
                 */
                if (type == ATSC || priv->firm_version < 0x0302)
                        demod += 200;
                /*
                 * The DTV7 S-code table needs a 700 kHz shift.
                 *
                 * DTV7 is only used in Australia.  Germany or Italy may also
                 * use this firmware after initialization, but a tune to a UHF
                 * channel should then cause DTV78 to be used.
                 *
                 * Unfortunately, on real-field tests, the s-code offset
                 * didn't work as expected, as reported by
                 * Robert Lowery <rglowery@exemail.com.au>
                 */
        }

        return generic_set_freq(fe, c->frequency,
                                V4L2_TUNER_DIGITAL_TV, type, 0, demod);
}

static int xc2028_sleep(struct dvb_frontend *fe)
{
        struct xc2028_data *priv = fe->tuner_priv;
        int rc;

        rc = check_device_status(priv);
        if (rc < 0)
                return rc;

        /* Avoid firmware reload on slow devices or if PM disabled */
        if (no_poweroff || priv->ctrl.disable_power_mgmt)
                return 0;

        tuner_dbg("Putting xc2028/3028 into poweroff mode.\n");
        if (debug > 1) {
                tuner_dbg("Printing sleep stack trace:\n");
                dump_stack();
        }

        mutex_lock(&priv->lock);

        if (priv->firm_version < 0x0202)
                rc = send_seq(priv, {0x00, XREG_POWER_DOWN, 0x00, 0x00});
        else
                rc = send_seq(priv, {0x80, XREG_POWER_DOWN, 0x00, 0x00});

        priv->state = XC2028_SLEEP;

        mutex_unlock(&priv->lock);

        return rc;
}

static int xc2028_dvb_release(struct dvb_frontend *fe)
{
        struct xc2028_data *priv = fe->tuner_priv;

        tuner_dbg("%s called\n", __func__);

        mutex_lock(&xc2028_list_mutex);

        /* only perform final cleanup if this is the last instance */
        if (hybrid_tuner_report_instance_count(priv) == 1) {
                free_firmware(priv);
                kfree(priv->ctrl.fname);
                priv->ctrl.fname = NULL;
        }

        if (priv)
                hybrid_tuner_release_state(priv);

        mutex_unlock(&xc2028_list_mutex);

        fe->tuner_priv = NULL;

        return 0;
}

static int xc2028_get_frequency(struct dvb_frontend *fe, u32 *frequency)
{
        struct xc2028_data *priv = fe->tuner_priv;
        int rc;

        tuner_dbg("%s called\n", __func__);

        rc = check_device_status(priv);
        if (rc < 0)
                return rc;

        *frequency = priv->frequency;

        return 0;
}

static void load_firmware_cb(const struct firmware *fw,
                             void *context)
{
        struct dvb_frontend *fe = context;
        struct xc2028_data *priv = fe->tuner_priv;
        int rc;

        tuner_dbg("request_firmware_nowait(): %s\n", fw ? "OK" : "error");
        if (!fw) {
                tuner_err("Could not load firmware %s.\n", priv->fname);
                priv->state = XC2028_NODEV;
                return;
        }

        rc = load_all_firmwares(fe, fw);

        release_firmware(fw);

        if (rc < 0)
                return;
        priv->state = XC2028_SLEEP;
}

static int xc2028_set_config(struct dvb_frontend *fe, void *priv_cfg)
{
        struct xc2028_data *priv = fe->tuner_priv;
        struct xc2028_ctrl *p    = priv_cfg;
        int                 rc   = 0;

        tuner_dbg("%s called\n", __func__);

        mutex_lock(&priv->lock);

        /*
         * Copy the config data.
         * For the firmware name, keep a local copy of the string,
         * in order to avoid troubles during device release.
         */
        kfree(priv->ctrl.fname);
        memcpy(&priv->ctrl, p, sizeof(priv->ctrl));
        if (p->fname) {
                priv->ctrl.fname = kstrdup(p->fname, GFP_KERNEL);
                if (priv->ctrl.fname == NULL)
                        rc = -ENOMEM;
        }

        /*
         * If firmware name changed, frees firmware. As free_firmware will
         * reset the status to NO_FIRMWARE, this forces a new request_firmware
         */
        if (!firmware_name[0] && p->fname &&
            priv->fname && strcmp(p->fname, priv->fname))
                free_firmware(priv);

        if (priv->ctrl.max_len < 9)
                priv->ctrl.max_len = 13;

        if (priv->state == XC2028_NO_FIRMWARE) {
                if (!firmware_name[0])
                        priv->fname = priv->ctrl.fname;
                else
                        priv->fname = firmware_name;

                rc = request_firmware_nowait(THIS_MODULE, 1,
                                             priv->fname,
                                             priv->i2c_props.adap->dev.parent,
                                             GFP_KERNEL,
                                             fe, load_firmware_cb);
                if (rc < 0) {
                        tuner_err("Failed to request firmware %s\n",
                                  priv->fname);
                        priv->state = XC2028_NODEV;
                } else
                        priv->state = XC2028_WAITING_FIRMWARE;
        }
        mutex_unlock(&priv->lock);

        return rc;
}

static const struct dvb_tuner_ops xc2028_dvb_tuner_ops = {
        .info = {
                 .name = "Xceive XC3028",
                 .frequency_min = 42000000,
                 .frequency_max = 864000000,
                 .frequency_step = 50000,
                 },

        .set_config        = xc2028_set_config,
        .set_analog_params = xc2028_set_analog_freq,
        .release           = xc2028_dvb_release,
        .get_frequency     = xc2028_get_frequency,
        .get_rf_strength   = xc2028_signal,
        .get_afc           = xc2028_get_afc,
        .set_params        = xc2028_set_params,
        .sleep             = xc2028_sleep,
};

struct dvb_frontend *xc2028_attach(struct dvb_frontend *fe,
                                   struct xc2028_config *cfg)
{
        struct xc2028_data *priv;
        int instance;

        if (debug)
                printk(KERN_DEBUG "xc2028: Xcv2028/3028 init called!\n");

        if (NULL == cfg)
                return NULL;

        if (!fe) {
                printk(KERN_ERR "xc2028: No frontend!\n");
                return NULL;
        }

        mutex_lock(&xc2028_list_mutex);

        instance = hybrid_tuner_request_state(struct xc2028_data, priv,
                                              hybrid_tuner_instance_list,
                                              cfg->i2c_adap, cfg->i2c_addr,
                                              "xc2028");
        switch (instance) {
        case 0:
                /* memory allocation failure */
                goto fail;
                break;
        case 1:
                /* new tuner instance */
                priv->ctrl.max_len = 13;

                mutex_init(&priv->lock);

                fe->tuner_priv = priv;
                break;
        case 2:
                /* existing tuner instance */
                fe->tuner_priv = priv;
                break;
        }

        memcpy(&fe->ops.tuner_ops, &xc2028_dvb_tuner_ops,
               sizeof(xc2028_dvb_tuner_ops));

        tuner_info("type set to %s\n", "XCeive xc2028/xc3028 tuner");

        if (cfg->ctrl)
                xc2028_set_config(fe, cfg->ctrl);

        mutex_unlock(&xc2028_list_mutex);

        return fe;
fail:
        mutex_unlock(&xc2028_list_mutex);

        xc2028_dvb_release(fe);
        return NULL;
}

EXPORT_SYMBOL(xc2028_attach);

MODULE_DESCRIPTION("Xceive xc2028/xc3028 tuner driver");
MODULE_AUTHOR("Michel Ludwig <michel.ludwig@gmail.com>");
MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
MODULE_LICENSE("GPL");
MODULE_FIRMWARE(XC2028_DEFAULT_FIRMWARE);
MODULE_FIRMWARE(XC3028L_DEFAULT_FIRMWARE);