Change in flashrom[master]: ft2232_spi: prevent use of reserved pins on some programmers

[Nico Huber (Code Review)]

Nico Huber has submitted this change. ( https://review.coreboot.org/c/flashrom/+/57809 )

Change subject: ft2232_spi: prevent use of reserved pins on some programmers
......................................................................

ft2232_spi: prevent use of reserved pins on some programmers

On some programmers an output buffer needs to be enabled by pulling a
gpio high/low. This gpio can not be used for `csgpiol`. Prevent this by
printing an error.

Change-Id: Ied450fa5ef358153adefec3beabc63a62c9f60cd
Signed-off-by: Michael Niewöhner 
Reviewed-on: https://review.coreboot.org/c/flashrom/+/57809
Reviewed-by: Nico Huber 
Reviewed-by: Angel Pons 
Tested-by: build bot (Jenkins) 
---
M ft2232_spi.c
1 file changed, 12 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Nico Huber: Looks good to me, approved
  Angel Pons: Looks good to me, but someone else must approve

diff --git a/ft2232_spi.c b/ft2232_spi.c
index df156d6..110bdec 100644
--- a/ft2232_spi.c
+++ b/ft2232_spi.c
@@ -419,6 +419,9 @@
    }
    free(arg);

+	/* Remember reserved pins before pindir gets modified. */
+	const uint8_t rsv_bits = pindir & 0xf0;
+
    arg = extract_programmer_param("port");
    if (arg) {
    	switch (toupper((unsigned char)*arg)) {
@@ -478,6 +481,15 @@
    		return -2;
    	}
    	unsigned int pin = temp + 4;
+
+		if (rsv_bits & 1 << pin) {
+			msg_perr("Error: Invalid GPIOL specified: "%s".\n"
+				 "The pin is reserved on this programmer.\n",
+				 arg);
+			free(arg);
+			return -2;
+		}
+
    	cs_bits |= 1 << pin;
    	pindir |= 1 << pin;
    }