[flashrom] [PATCH] IT87* SPI unallocated port recovery

[Carl-Daniel Hailfinger]

For Ward Vandewege.

IT87* SPI unallocated port recovery.
Some coreboot versions forget to set the correct SPI flash port. This in
turn causes the port range to stay unallocated and thus not passed
through to the device.
Since the serial port at 0x3f8 is always enabled, disable the serial
port, set its address to zero, then allow the user to set the SPI flash
port to 0x3f8.

Not intended for merging yet, we need a proper user interface for this

How to use this:
Boot a kernel with modular serial port, load the serial module and test
it with minicom/whatever, run
# lspci -nnvvvxxxx >lspci_loaded.txt
# superiotool -d >superiotool_loaded.txt
Unload the serial module, then run
# lspci -nnvvvxxxx >lspci_unloaded.txt
# superiotool -d >superiotool_unloaded.txt
# flashrom -p it87spi=port=0x3f8
# lspci -nnvvvxxxx >lspci_modified.txt
# superiotool -d >superiotool_modified.txt

The above sequence needs to happen right after a cold boot and after
testing the serial port. The flashrom step will alter some registers
until the next cold boot, so running it twice will not yield useful results.

Signed-off-by: Carl-Daniel Hailfinger

Index: flashrom-it87spi_emergency_serial_replacement/it87spi.c
===================================================================
--- flashrom-it87spi_emergency_serial_replacement/it87spi.c	(Revision 653)
+++ flashrom-it87spi_emergency_serial_replacement/it87spi.c	(Arbeitskopie)
@@ -90,7 +90,7 @@
    		sio_write(port, 0x24, tmp);
    	}
    	printf("Serial flash pin %i\n", (tmp & 1 << 5) ? 87 : 29);
-		/* LDN 0x7, reg 0x64/0x65 */
+		/* LDN 0x7 */
    	sio_write(port, 0x07, 0x7);
    	flashport = sio_read(port, 0x64) << 8;
    	flashport |= sio_read(port, 0x65);
@@ -102,6 +102,16 @@
    	if (it87opts && (portpos = strstr(it87opts, "port="))) {
    		portpos += 5;
    		flashport = strtol(portpos, (char **)NULL, 0);
+			tmp = sio_read(port, 0x2b);
+			printf("Logical block lock is %02x\n", tmp);
+			printf("Disabling serial port\n");
+			/* LDN 0x1 */
+			sio_write(port, 0x07, 0x1);
+			sio_write(port, 0x30, 0x00);
+			sio_write(port, 0x60, 0x00);
+			sio_write(port, 0x61, 0x00);
+			/* LDN 0x7 */
+			sio_write(port, 0x07, 0x7);
    		printf("Forcing serial flash port 0x%04x\n", flashport);
    		sio_write(port, 0x64, (flashport >> 8));
    		sio_write(port, 0x65, (flashport & 0xff));