[MTD] MAPS: Add parameter to amd76xrom to override rom window size

#include <linux/module.h>

#include <linux/types.h>

#include <linux/version.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <asm/io.h>

	char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];

};

/* The 2 bits controlling the window size are often set to allow reading

 * the BIOS, but too small to allow writing, since the lock registers are

 * 4MiB lower in the address space than the data.

 *

 * This is intended to prevent flashing the bios, perhaps accidentally.

 *

 * This parameter allows the normal driver to over-ride the BIOS settings.

 *

 * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.

 * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a

 * 64KiB window.

 *

 */

static uint win_size_bits;

module_param(win_size_bits, uint, 0);

MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");

static struct amd76xrom_window amd76xrom_window = {

	.maps = LIST_HEAD_INIT(amd76xrom_window.maps),

};

	/* Remember the pci dev I find the window in - already have a ref */

	window->pdev = pdev;

	/* Enable the selected rom window.  This is often incorrectly

	 * set up by the BIOS, and the 4MiB offset for the lock registers

	 * requires the full 5MiB of window space.

	 *

	 * This 'write, then read' approach leaves the bits for

	 * other uses of the hardware info.

	 */

	pci_read_config_byte(pdev, 0x43, &byte);

	pci_write_config_byte(pdev, 0x43, byte | win_size_bits );

	/* Assume the rom window is properly setup, and find it's size */

	pci_read_config_byte(pdev, 0x43, &byte);

	if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {

			(unsigned long long)window->rsrc.end);

	}

#if 0

	/* Enable the selected rom window */

	pci_read_config_byte(pdev, 0x43, &byte);

	pci_write_config_byte(pdev, 0x43, byte | rwindow->segen_bits);

#endif

	/* Enable writes through the rom window */

	pci_read_config_byte(pdev, 0x40, &byte);