ichspi: add (partially) dead support code for Intel Hardware Sequencing

This was done to ease the review. Another patch will hook up (and
explain) this code later.

Corresponding to flashrom svn r1452.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
diff --git a/ich_descriptors.c b/ich_descriptors.c
index da1326e..125077c 100644
--- a/ich_descriptors.c
+++ b/ich_descriptors.c
@@ -213,6 +213,34 @@
 	msg_pdbg2("\n");
 }
 
+/** Returns the integer representation of the component density with index
+idx in bytes or 0 if a correct size can not be determined. */
+int getFCBA_component_density(const struct ich_descriptors *desc, uint8_t idx)
+{
+	uint8_t size_enc;
+	
+	switch(idx) {
+	case 0:
+		size_enc = desc->component.comp1_density;
+		break;
+	case 1:
+		if (desc->content.NC == 0)
+			return 0;
+		size_enc = desc->component.comp2_density;
+		break;
+	default:
+		msg_perr("Only ICH SPI component index 0 or 1 are supported "
+			 "yet.\n");
+		return 0;
+	}
+	if (size_enc > 5) {
+		msg_perr("Density of ICH SPI component with index %d is "
+			 "invalid. Encoded density is 0x%x.\n", idx, size_enc);
+		return 0;
+	}
+	return (1 << (19 + size_enc));
+}
+
 static uint32_t read_descriptor_reg(uint8_t section, uint16_t offset, void *spibar)
 {
 	uint32_t control = 0;