/*
 * bt856 - BT856A Digital Video Encoder (Rockwell Part)
 *
 * Copyright (C) 1999 Mike Bernson <mike@mlb.org>
 * Copyright (C) 1998 Dave Perks <dperks@ibm.net>
 *
 * Modifications for LML33/DC10plus unified driver
 * Copyright (C) 2000 Serguei Miridonov <mirsev@cicese.mx>
 *
 * This code was modify/ported from the saa7111 driver written
 * by Dave Perks.
 *
 * Changes by Ronald Bultje <rbultje@ronald.bitfreak.net>
 *   - moved over to linux>=2.4.x i2c protocol (9/9/2002)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/signal.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/video_encoder.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/uaccess.h>

#include <linux/videodev.h>

MODULE_DESCRIPTION("Brooktree-856A video encoder driver");
MODULE_AUTHOR("Mike Bernson & Dave Perks");
MODULE_LICENSE("GPL");


#define I2C_NAME(s) (s)->name


static int debug = 0;
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0-1)");

#define dprintk(num, format, args...) \
        do { \
                if (debug >= num) \
                        printk(format, ##args); \
        } while (0)

/* ----------------------------------------------------------------------- */

#define REG_OFFSET      0xDA
#define BT856_NR_REG    6

struct bt856 {
        unsigned char reg[BT856_NR_REG];

        int norm;
        int enable;
};

#define   I2C_BT856        0x88

/* ----------------------------------------------------------------------- */

static inline int
bt856_write (struct i2c_client *client,
             u8                 reg,
             u8                 value)
{
        struct bt856 *encoder = i2c_get_clientdata(client);

        encoder->reg[reg - REG_OFFSET] = value;
        return i2c_smbus_write_byte_data(client, reg, value);
}

static inline int
bt856_setbit (struct i2c_client *client,
              u8                 reg,
              u8                 bit,
              u8                 value)
{
        struct bt856 *encoder = i2c_get_clientdata(client);

        return bt856_write(client, reg,
                           (encoder->
                            reg[reg - REG_OFFSET] & ~(1 << bit)) |
                            (value ? (1 << bit) : 0));
}

static void
bt856_dump (struct i2c_client *client)
{
        int i;
        struct bt856 *encoder = i2c_get_clientdata(client);

        printk(KERN_INFO "%s: register dump:", I2C_NAME(client));
        for (i = 0; i < BT856_NR_REG; i += 2)
                printk(" %02x", encoder->reg[i]);
        printk("\n");
}

/* ----------------------------------------------------------------------- */

static int
bt856_command (struct i2c_client *client,
               unsigned int       cmd,
               void              *arg)
{
        struct bt856 *encoder = i2c_get_clientdata(client);

        switch (cmd) {

        case 0:
                /* This is just for testing!!! */
                dprintk(1, KERN_INFO "bt856: init\n");
                bt856_write(client, 0xdc, 0x18);
                bt856_write(client, 0xda, 0);
                bt856_write(client, 0xde, 0);

                bt856_setbit(client, 0xdc, 3, 1);
                //bt856_setbit(client, 0xdc, 6, 0);
                bt856_setbit(client, 0xdc, 4, 1);

                switch (encoder->norm) {

                case VIDEO_MODE_NTSC:
                        bt856_setbit(client, 0xdc, 2, 0);
                        break;

                case VIDEO_MODE_PAL:
                        bt856_setbit(client, 0xdc, 2, 1);
                        break;
                }

                bt856_setbit(client, 0xdc, 1, 1);
                bt856_setbit(client, 0xde, 4, 0);
                bt856_setbit(client, 0xde, 3, 1);
                if (debug != 0)
                        bt856_dump(client);
                break;

        case ENCODER_GET_CAPABILITIES:
        {
                struct video_encoder_capability *cap = arg;

                dprintk(1, KERN_INFO "%s: get capabilities\n",
                        I2C_NAME(client));

                cap->flags = VIDEO_ENCODER_PAL |
                             VIDEO_ENCODER_NTSC |
                             VIDEO_ENCODER_CCIR;
                cap->inputs = 2;
                cap->outputs = 1;
        }
                break;

        case ENCODER_SET_NORM:
        {
                int *iarg = arg;

                dprintk(1, KERN_INFO "%s: set norm %d\n", I2C_NAME(client),
                        *iarg);

                switch (*iarg) {

                case VIDEO_MODE_NTSC:
                        bt856_setbit(client, 0xdc, 2, 0);
                        break;

                case VIDEO_MODE_PAL:
                        bt856_setbit(client, 0xdc, 2, 1);
                        bt856_setbit(client, 0xda, 0, 0);
                        //bt856_setbit(client, 0xda, 0, 1);
                        break;

                default:
                        return -EINVAL;

                }
                encoder->norm = *iarg;
                if (debug != 0)
                        bt856_dump(client);
        }
                break;

        case ENCODER_SET_INPUT:
        {
                int *iarg = arg;

                dprintk(1, KERN_INFO "%s: set input %d\n", I2C_NAME(client),
                        *iarg);

                /* We only have video bus.
                 * iarg = 0: input is from bt819
                 * iarg = 1: input is from ZR36060 */

                switch (*iarg) {

                case 0:
                        bt856_setbit(client, 0xde, 4, 0);
                        bt856_setbit(client, 0xde, 3, 1);
                        bt856_setbit(client, 0xdc, 3, 1);
                        bt856_setbit(client, 0xdc, 6, 0);
                        break;
                case 1:
                        bt856_setbit(client, 0xde, 4, 0);
                        bt856_setbit(client, 0xde, 3, 1);
                        bt856_setbit(client, 0xdc, 3, 1);
                        bt856_setbit(client, 0xdc, 6, 1);
                        break;
                case 2: // Color bar
                        bt856_setbit(client, 0xdc, 3, 0);
                        bt856_setbit(client, 0xde, 4, 1);
                        break;
                default:
                        return -EINVAL;

                }

                if (debug != 0)
                        bt856_dump(client);
        }
                break;

        case ENCODER_SET_OUTPUT:
        {
                int *iarg = arg;

                dprintk(1, KERN_INFO "%s: set output %d\n", I2C_NAME(client),
                        *iarg);

                /* not much choice of outputs */
                if (*iarg != 0) {
                        return -EINVAL;
                }
        }
                break;

        case ENCODER_ENABLE_OUTPUT:
        {
                int *iarg = arg;

                encoder->enable = !!*iarg;

                dprintk(1, KERN_INFO "%s: enable output %d\n",
                        I2C_NAME(client), encoder->enable);
        }
                break;

        default:
                return -EINVAL;
        }

        return 0;
}

/* ----------------------------------------------------------------------- */

/*
 * Generic i2c probe
 * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
 */
static unsigned short normal_i2c[] = { I2C_BT856 >> 1, I2C_CLIENT_END };

static unsigned short ignore = I2C_CLIENT_END;

static struct i2c_client_address_data addr_data = {
        .normal_i2c             = normal_i2c,
        .probe                  = &ignore,
        .ignore                 = &ignore,
};

static struct i2c_driver i2c_driver_bt856;

static int
bt856_detect_client (struct i2c_adapter *adapter,
                     int                 address,
                     int                 kind)
{
        int i;
        struct i2c_client *client;
        struct bt856 *encoder;

        dprintk(1,
                KERN_INFO
                "bt856.c: detecting bt856 client on address 0x%x\n",
                address << 1);

        /* Check if the adapter supports the needed features */
        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return 0;

        client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
        if (client == 0)
                return -ENOMEM;
        client->addr = address;
        client->adapter = adapter;
        client->driver = &i2c_driver_bt856;
        strlcpy(I2C_NAME(client), "bt856", sizeof(I2C_NAME(client)));

        encoder = kzalloc(sizeof(struct bt856), GFP_KERNEL);
        if (encoder == NULL) {
                kfree(client);
                return -ENOMEM;
        }
        encoder->norm = VIDEO_MODE_NTSC;
        encoder->enable = 1;
        i2c_set_clientdata(client, encoder);

        i = i2c_attach_client(client);
        if (i) {
                kfree(client);
                kfree(encoder);
                return i;
        }

        bt856_write(client, 0xdc, 0x18);
        bt856_write(client, 0xda, 0);
        bt856_write(client, 0xde, 0);

        bt856_setbit(client, 0xdc, 3, 1);
        //bt856_setbit(client, 0xdc, 6, 0);
        bt856_setbit(client, 0xdc, 4, 1);

        switch (encoder->norm) {

        case VIDEO_MODE_NTSC:
                bt856_setbit(client, 0xdc, 2, 0);
                break;

        case VIDEO_MODE_PAL:
                bt856_setbit(client, 0xdc, 2, 1);
                break;
        }

        bt856_setbit(client, 0xdc, 1, 1);
        bt856_setbit(client, 0xde, 4, 0);
        bt856_setbit(client, 0xde, 3, 1);

        if (debug != 0)
                bt856_dump(client);

        dprintk(1, KERN_INFO "%s_attach: at address 0x%x\n", I2C_NAME(client),
                client->addr << 1);

        return 0;
}

static int
bt856_attach_adapter (struct i2c_adapter *adapter)
{
        dprintk(1,
                KERN_INFO
                "bt856.c: starting probe for adapter %s (0x%x)\n",
                I2C_NAME(adapter), adapter->id);
        return i2c_probe(adapter, &addr_data, &bt856_detect_client);
}

static int
bt856_detach_client (struct i2c_client *client)
{
        struct bt856 *encoder = i2c_get_clientdata(client);
        int err;

        err = i2c_detach_client(client);
        if (err) {
                return err;
        }

        kfree(encoder);
        kfree(client);

        return 0;
}

/* ----------------------------------------------------------------------- */

static struct i2c_driver i2c_driver_bt856 = {
        .driver = {
                .name = "bt856",
        },

        .id = I2C_DRIVERID_BT856,

        .attach_adapter = bt856_attach_adapter,
        .detach_client = bt856_detach_client,
        .command = bt856_command,
};

static int __init
bt856_init (void)
{
        return i2c_add_driver(&i2c_driver_bt856);
}

static void __exit
bt856_exit (void)
{
        i2c_del_driver(&i2c_driver_bt856);
}

module_init(bt856_init);
module_exit(bt856_exit);