ft2232_spi: add an ability to use GPIO for chip selection

Change-Id: I6db05619e0d69ad18549c8556ef69225337b1532
Signed-off-by: Sergey Alirzaev <zl29ah@gmail.com>
Reviewed-on: https://review.coreboot.org/28911
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/flashrom.8.tmpl b/flashrom.8.tmpl
index 70af395..f882dc6 100644
--- a/flashrom.8.tmpl
+++ b/flashrom.8.tmpl
@@ -722,9 +722,9 @@
 Multi-Protocol Adapter (TUMPA), TUMPA Lite, GOEPEL PicoTAP and Google Servo v1/v2.
 .sp
 An optional parameter specifies the controller
-type and channel/interface/port it should support. For that you have to use the
+type, channel/interface/port and GPIO-based chip select it should support. For that you have to use the
 .sp
-.B "  flashrom \-p ft2232_spi:type=model,port=interface"
+.B "  flashrom \-p ft2232_spi:type=model,port=interface,csgpiol=gpio"
 .sp
 syntax where
 .B model
@@ -733,14 +733,17 @@
 arm-usb-tiny ", " arm-usb-tiny-h ", " arm-usb-ocd ", " arm-usb-ocd-h \
 ", " tumpa ", " tumpalite ", " picotap ", " google-servo ", " google-servo-v2 \
 " or " google-servo-v2-legacy
-and
 .B interface
 can be
-.BR A ", " B ", " C ", or " D .
+.BR A ", " B ", " C ", or " D
+and
+.B csgpiol
+can be a number between 0 and 3, denoting GPIOL0-GPIOL3 correspondingly.
 The default model is
 .B 4232H
-and the default interface is
-.BR A .
+the default interface is
+.BR A
+and GPIO is not used by default.
 .sp
 If there is more than one ft2232_spi-compatible device connected, you can select which one should be used by
 specifying its serial number with the