Change in flashrom[master]: [v4, 3/6] ENE EDI - add dummy read to ensure proper detection of ENE c...

[Mike Banon (Code Review)]

Mike Banon has uploaded this change for review. ( https://review.coreboot.org/23260

Change subject: [v4,3/6] ENE EDI - add dummy read to ensure proper detection of ENE chips
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[v4,3/6] ENE EDI - add dummy read to ensure proper detection of ENE chips

ENE chips enable EDI by detecting a clock frequency between 1 MHz and 8 MHz.
In many cases, the chip won't be able to both detect the clock signal and
serve the associated request at the same time.

Thus, a dummy read has to be added to ensure that EDI is enabled and
operational starting from the next request.

Original patch has been created by Paul Kocialkowski, the previous version:
http://git.code.paulk.fr/gitweb/?p=flashrom.git;a=shortlog;h=refs/heads/next
Now it has been ported to the latest source code of flashrom master branch

Change-Id: I69ee71674649cd8ba4fc635f889cb39a1cd204b9
Signed-off-by: Mike Banon 
---
M edi.c
1 file changed, 18 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/60/23260/1

diff --git a/edi.c b/edi.c
index 0ca1704..fde5ff1 100644
--- a/edi.c
+++ b/edi.c
@@ -163,6 +163,14 @@
    return 0;
 }

+static void edi_detect(struct flashctx *flash)
+{
+	unsigned char hwversion;
+
+	/* This dummy read ensures proper detection of EDI. */
+	edi_read(flash, ENE_EC_HWVERSION, &hwversion);
+}
+
 static int edi_spi_enable(struct flashctx *flash)
 {
    unsigned char buffer;
@@ -481,6 +489,16 @@
    int probe;
    int rc;

+	/*
+	 * ENE chips enable EDI by detecting a clock frequency between 1 MHz and
+	 * 8 MHz. In many cases, the chip won't be able to both detect the clock
+	 * signal and serve the associated request at the same time.
+	 *
+	 * Thus, a dummy read has to be added to ensure that EDI is enabled and
+	 * operational starting from the next request.
+	 */
+	edi_detect(flash);
+
    probe = edi_chip_probe(flash, &ene_kb9012);
    if (!probe)
    	return 0;