/* cx25840 firmware functions
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <linux/firmware.h>
#include <media/v4l2-common.h>

#include "cx25840.h"

#define FWFILE "v4l-cx25840.fw"
#define FWSEND 1024

#define FWDEV(x) &((x)->adapter->dev)

static int fastfw = 1;
static char *firmware = FWFILE;

module_param(fastfw, bool, 0444);
module_param(firmware, charp, 0444);

MODULE_PARM_DESC(fastfw, "Load firmware fast [0=100MHz 1=333MHz (default)]");
MODULE_PARM_DESC(firmware, "Firmware image [default: " FWFILE "]");

static void set_i2c_delay(struct i2c_client *client, int delay)
{
	struct i2c_algo_bit_data *algod = client->adapter->algo_data;

	/* We aren't guaranteed to be using algo_bit,
	 * so avoid the null pointer dereference
	 * and disable the 'fast firmware load' */
	if (algod) {
		algod->udelay = delay;
	} else {
		fastfw = 0;
	}
}

static void start_fw_load(struct i2c_client *client)
{
	/* DL_ADDR_LB=0 DL_ADDR_HB=0 */
	cx25840_write(client, 0x800, 0x00);
	cx25840_write(client, 0x801, 0x00);
	// DL_MAP=3 DL_AUTO_INC=0 DL_ENABLE=1
	cx25840_write(client, 0x803, 0x0b);
	/* AUTO_INC_DIS=1 */
	cx25840_write(client, 0x000, 0x20);

	if (fastfw)
		set_i2c_delay(client, 3);
}

static void end_fw_load(struct i2c_client *client)
{
	if (fastfw)
		set_i2c_delay(client, 10);

	/* AUTO_INC_DIS=0 */
	cx25840_write(client, 0x000, 0x00);
	/* DL_ENABLE=0 */
	cx25840_write(client, 0x803, 0x03);
}

static int check_fw_load(struct i2c_client *client, int size)
{
	/* DL_ADDR_HB DL_ADDR_LB */
	int s = cx25840_read(client, 0x801) << 8;
	s |= cx25840_read(client, 0x800);

	if (size != s) {
		v4l_err(client, "firmware %s load failed\n", firmware);
		return -EINVAL;
	}

	v4l_info(client, "loaded %s firmware (%d bytes)\n", firmware, size);
	return 0;
}

static int fw_write(struct i2c_client *client, u8 * data, int size)
{
	int sent;

	if ((sent = i2c_master_send(client, data, size)) < size) {

		if (fastfw) {
			v4l_err(client, "333MHz i2c firmware load failed\n");
			fastfw = 0;
			set_i2c_delay(client, 10);

			if (sent > 2) {
				u16 dl_addr = cx25840_read(client, 0x801) << 8;
				dl_addr |= cx25840_read(client, 0x800);
				dl_addr -= sent - 2;
				cx25840_write(client, 0x801, dl_addr >> 8);
				cx25840_write(client, 0x800, dl_addr & 0xff);
			}

			if (i2c_master_send(client, data, size) < size) {
				v4l_err(client, "100MHz i2c firmware load failed\n");
				return -ENOSYS;
			}

		} else {
			v4l_err(client, "firmware load i2c failure\n");
			return -ENOSYS;
		}

	}

	return 0;
}

int cx25840_loadfw(struct i2c_client *client)
{
	const struct firmware *fw = NULL;
	u8 buffer[4], *ptr;
	int size, send, retval;

	if (request_firmware(&fw, firmware, FWDEV(client)) != 0) {
		v4l_err(client, "unable to open firmware %s\n", firmware);
		return -EINVAL;
	}

	start_fw_load(client);

	buffer[0] = 0x08;
	buffer[1] = 0x02;
	buffer[2] = fw->data[0];
	buffer[3] = fw->data[1];
	retval = fw_write(client, buffer, 4);

	if (retval < 0) {
		release_firmware(fw);
		return retval;
	}

	size = fw->size - 2;
	ptr = fw->data;
	while (size > 0) {
		ptr[0] = 0x08;
		ptr[1] = 0x02;
		send = size > (FWSEND - 2) ? FWSEND : size + 2;
		retval = fw_write(client, ptr, send);

		if (retval < 0) {
			release_firmware(fw);
			return retval;
		}

		size -= FWSEND - 2;
		ptr += FWSEND - 2;
	}

	end_fw_load(client);

	size = fw->size;
	release_firmware(fw);

	return check_fw_load(client, size);
}