Change in flashrom[master]: buspirate: Add psus option

[Jeremy Kerr (Code Review)]

Jeremy Kerr has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/54887 )

Change subject: buspirate: Add psus option
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buspirate: Add psus option

This change adds a 'psus=<on|off>' option, to control the external Vcc
state of the bus pirate, allowing hardware where the SPI flash chip is
powered by the 3V3/5V lines directly.

Change-Id: I8a7d4b40c0f7f04f6976f6757f05b61f2c9958f9
Signed-off-by: Jeremy Kerr 
---
M buspirate_spi.c
1 file changed, 16 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/87/54887/1

diff --git a/buspirate_spi.c b/buspirate_spi.c
index 96e9673..2024458 100644
--- a/buspirate_spi.c
+++ b/buspirate_spi.c
@@ -316,6 +316,7 @@
    int serialspeed_index = -1;
    int ret = 0;
    int pullup = 0;
+	int psu = 0;

dev = extract_programmer_param("dev");
    if (dev && !strlen(dev)) {
@@ -365,6 +366,17 @@
    }
    free(tmp);

+	tmp = extract_programmer_param("psus");
+	if (tmp) {
+		if (strcasecmp("on", tmp) == 0)
+			psu = 1;
+		else if (strcasecmp("off", tmp) == 0)
+			; // ignore
+		else
+			msg_perr("Invalid psus state, not enabling.\n");
+	}
+	free(tmp);
+
    /* Default buffer size is 19: 16 bytes data, 3 bytes control. */
 #define DEFAULT_BUFSIZE (16 + 3)
    bp_commbuf = malloc(DEFAULT_BUFSIZE);
@@ -613,6 +625,10 @@
    	bp_commbuf[0] |= (1 << 2);
    	msg_pdbg("Enabling pull-up resistors.\n");
    }
+	if (psu == 1) {
+		bp_commbuf[0] |= (1 << 3);
+		msg_pdbg("Enabling PSUs.\n");
+	}
    ret = buspirate_sendrecv(bp_commbuf, 1, 1);
    if (ret)
    	return 1;