/* 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"


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;
};

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

	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 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;

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

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

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

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

	tuner_dbg("Reading firmware %s\n", fname);
	rc = request_firmware(&fw, fname, priv->i2c_props.adap->dev.parent);
	if (rc < 0) {
		if (rc == -ENOENT)
			tuner_err("Error: firmware %s not found.\n",
				   fname);
		else
			tuner_err("Error %d while requesting firmware %s \n",
				   rc, fname);

		return rc;
	}
	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",
			  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, fname, name,
		   priv->firm_version >> 8, priv->firm_version & 0xff);

	priv->firm = kzalloc(sizeof(*priv->firm) * n_array, 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:
	release_firmware(fw);
	if (rc == 0)
		tuner_dbg("Firmware files loaded.\n");

	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;
		}
	}
	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 = 0, is_retry = 0;
	u16			   version, hwmodel;
	v4l2_std_id		   std0;

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

	if (!priv->firm) {
		if (!priv->ctrl.fname) {
			tuner_info("xc2028/3028 firmware name not set!\n");
			return -EINVAL;
		}

		rc = load_all_firmwares(fe);
		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 */
	if (((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:
	memcpy(&priv->cur_fw, &new_fw, sizeof(priv->cur_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;

	return 0;

fail:
	memset(&priv->cur_fw, 0, sizeof(priv->cur_fw));
	if (!is_retry) {
		msleep(50);
		is_retry = 1;
		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;

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

	mutex_lock(&priv->lock);

	/* Sync Lock Indicator */
	rc = xc2028_get_reg(priv, 0x0002, &frq_lock);
	if (rc < 0)
		goto ret;

	/* Frequency is locked */
	if (frq_lock == 1)
		signal = 32768;

	/* Get SNR of the video signal */
	rc = xc2028_get_reg(priv, 0x0040, &signal);
	if (rc < 0)
		goto ret;

	/* Use both frq_lock and signal to generate the result */
	signal = signal || ((signal & 0x07) << 12);

ret:
	mutex_unlock(&priv->lock);

	*strength = signal;

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

	return rc;
}

#define DIV 15625

static int generic_set_freq(struct dvb_frontend *fe, u32 freq /* in HZ */,
			    enum tuner_mode new_mode,
			    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.
	 */
	if (new_mode == T_ANALOG_TV) {
		rc = send_seq(priv, {0x00, 0x00});

		/* Analog modes require offset = 0 */
	} else {
		/*
		 * 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
		 */
		if (priv->cur_fw.type & DTV6)
			offset = 1750000;
		else if (priv->cur_fw.type & DTV7)
			offset = 2250000;
		else	/* DTV8 or DTV78 */
			offset = 2750000;
		if ((priv->cur_fw.type & DTV78) && freq < 470000000)
			offset -= 500000;

		/*
		 * 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
		 */

#if 1
		/*
		 * 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 (priv->cur_fw.type & DTV7)
			offset += 500000;

#else
		/*
		 * 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, 0x02, 0x00, 0x00});
	else
		rc = send_seq(priv, {0x80, 0x02, 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= %02x %02x %02x %02x (freq=%d.%03d)\n",
	       buf[0], buf[1], buf[2], buf[3],
	       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,
				T_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,
				T_ANALOG_TV, type, p->std, 0);
}

static int xc2028_set_params(struct dvb_frontend *fe,
			     struct dvb_frontend_parameters *p)
{
	struct xc2028_data *priv = fe->tuner_priv;
	unsigned int       type=0;
	fe_bandwidth_t     bw = BANDWIDTH_8_MHZ;
	u16                demod = 0;

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

	switch(fe->ops.info.type) {
	case FE_OFDM:
		bw = p->u.ofdm.bandwidth;
		/*
		 * 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 == BANDWIDTH_6_MHZ)
			type |= QAM;
		break;
	case FE_ATSC:
		bw = BANDWIDTH_6_MHZ;
		/* 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;
	}

	switch (bw) {
	case BANDWIDTH_8_MHZ:
		if (p->frequency < 470000000)
			priv->ctrl.vhfbw7 = 0;
		else
			priv->ctrl.uhfbw8 = 1;
		type |= (priv->ctrl.vhfbw7 && priv->ctrl.uhfbw8) ? DTV78 : DTV8;
		type |= F8MHZ;
		break;
	case BANDWIDTH_7_MHZ:
		if (p->frequency < 470000000)
			priv->ctrl.vhfbw7 = 1;
		else
			priv->ctrl.uhfbw8 = 0;
		type |= (priv->ctrl.vhfbw7 && priv->ctrl.uhfbw8) ? DTV78 : DTV7;
		type |= F8MHZ;
		break;
	case BANDWIDTH_6_MHZ:
		type |= DTV6;
		priv->ctrl.vhfbw7 = 0;
		priv->ctrl.uhfbw8 = 0;
		break;
	default:
		tuner_err("error: bandwidth not supported.\n");
	};

	/*
	  Selects between D2633 or D2620 firmware.
	  It doesn't make sense for ATSC, since it should be D2633 on all cases
	 */
	if (fe->ops.info.type != FE_ATSC) {
		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;
		}
	}

	/* 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, p->frequency,
				T_DIGITAL_TV, type, 0, demod);
}

static int xc2028_sleep(struct dvb_frontend *fe)
{
	struct xc2028_data *priv = fe->tuner_priv;
	int rc = 0;

	/* 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, 0x08, 0x00, 0x00});
	else
		rc = send_seq(priv, {0x80, 0x08, 0x00, 0x00});

	priv->cur_fw.type = 0;	/* need firmware reload */

	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) {
		kfree(priv->ctrl.fname);
		free_firmware(priv);
	}

	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;

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

	*frequency = priv->frequency;

	return 0;
}

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);

	memcpy(&priv->ctrl, p, sizeof(priv->ctrl));
	if (priv->ctrl.max_len < 9)
		priv->ctrl.max_len = 13;

	if (p->fname) {
		if (priv->ctrl.fname && strcmp(p->fname, priv->ctrl.fname)) {
			kfree(priv->ctrl.fname);
			free_firmware(priv);
		}

		priv->ctrl.fname = kstrdup(p->fname, GFP_KERNEL);
		if (priv->ctrl.fname == NULL)
			rc = -ENOMEM;
	}

	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,
	.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");