The nicrealtek code uses magic constants, but they are not explained

That's OK if you know the datasheet well, but for casual readers some
comments are really helpful.

I'm not sure whether we want to disable hardware flash access forever
without enabling it again on shutdown. A few other places made me wonder
as well. I've added FIXME comments in those places.

Corresponding to flashrom svn r1046.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Andrew Morgan <ziltro@ziltro.com>
diff --git a/nicrealtek.c b/nicrealtek.c
index ad39eb2..6825c0c 100644
--- a/nicrealtek.c
+++ b/nicrealtek.c
@@ -65,6 +65,7 @@
 
 int nicrealtek_shutdown(void)
 {
+	/* FIXME: We forgot to disable software access again. */
 	free(programmer_param);
 	pci_cleanup(pacc);
 	release_io_perms();
@@ -73,8 +74,14 @@
 
 void nicrealtek_chip_writeb(uint8_t val, chipaddr addr)
 {
+	/* Output addr and data, set WE to 0, set OE to 1, set CS to 0,
+	 * enable software access.
+	 */
 	OUTL(((uint32_t)addr & 0x01FFFF) | 0x0A0000 | (val << 24),
 	     io_base_addr + BIOS_ROM_ADDR);
+	/* Output addr and data, set WE to 1, set OE to 1, set CS to 1,
+	 * enable software access.
+	 */
 	OUTL(((uint32_t)addr & 0x01FFFF) | 0x1E0000 | (val << 24),
 	     io_base_addr + BIOS_ROM_ADDR);
 }
@@ -83,11 +90,20 @@
 {
 	uint8_t val;
 
+	/* FIXME: Can we skip reading the old data and simply use 0? */
+	/* Read old data. */
 	val = INB(io_base_addr + BIOS_ROM_DATA);
+	/* Output new addr and old data, set WE to 1, set OE to 0, set CS to 0,
+	 * enable software access.
+	 */
 	OUTL(((uint32_t)addr & 0x01FFFF) | 0x060000 | (val << 24),
 	     io_base_addr + BIOS_ROM_ADDR);
 
+	/* Read new data. */
 	val = INB(io_base_addr + BIOS_ROM_DATA);
+	/* Output addr and new data, set WE to 1, set OE to 1, set CS to 1,
+	 * enable software access.
+	 */
 	OUTL(((uint32_t)addr & 0x01FFFF) | 0x1E0000 | (val << 24),
 	     io_base_addr + BIOS_ROM_ADDR);