New patch to review for coreboot: 6a1a0c7 gpio: add a function to read GPIO array as base-2 value

[Patrick Georgi]

Patrick Georgi ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9412

-gerrit

commit 6a1a0c78fa762b1a81d3378f96d7af61c93b745e
Author: David Hendricks 
Date:   Thu Nov 6 15:05:35 2014 -0800

gpio: add a function to read GPIO array as base-2 value

This adds gpio_base2_value() which reads an array of 2-state
    GPIOs and returns a base-2 value, where gpio[0] represents the
    least significant bit.

BUG=none
    BRANCH=none
    TEST=tested with follow-up patches for pinky

Change-Id: I0d6bfac369da0d68079a38de0988c7b59d269a97
    Signed-off-by: Patrick Georgi 
    Original-Commit-Id: 27873b7a9ea237d13f0cbafd10033a8d0f821cbe
    Original-Change-Id: Ia7ffc16eb60e93413c0812573b9cf0999b92828e
    Original-Signed-off-by: David Hendricks 
    Original-Reviewed-on: https://chromium-review.googlesource.com/228323
    Original-Reviewed-by: Julius Werner 
---
 src/include/gpio.h |  9 +++++++++
 src/lib/gpio.c     | 12 ++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/src/include/gpio.h b/src/include/gpio.h
index e54b156..7b64ebf 100644
--- a/src/include/gpio.h
+++ b/src/include/gpio.h
@@ -36,6 +36,15 @@ void gpio_output(gpio_t gpio, int value);

/*
  * Read the value presented by the set of GPIOs, when each pin is interpreted
+ * as a base-2 digit (LOW = 0, HIGH = 1).
+ *
+ * gpio[]: pin positions to read. gpio[0] is less significant than gpio[1].
+ * num_gpio: number of pins to read.
+ */
+int gpio_base2_value(gpio_t gpio[], int num_gpio);
+
+/*
+ * Read the value presented by the set of GPIOs, when each pin is interpreted
  * as a base-3 digit (LOW = 0, HIGH = 1, Z/floating = 2).
  * Example: X1 = Z, X2 = 1 -> gpio_base3_value({GPIO(X1), GPIO(X2)}) = 5
  * BASE3() from <base3.h> can generate numbers to compare the result to.
diff --git a/src/lib/gpio.c b/src/lib/gpio.c
index 3a646e0..0875538 100644
--- a/src/lib/gpio.c
+++ b/src/lib/gpio.c
@@ -22,6 +22,18 @@
 #include <delay.h>
 #include <gpio.h>

+int gpio_base2_value(gpio_t gpio[], int num_gpio)
+{
+	int i, result = 0;
+
+	for (i = 0; i < num_gpio; i++) {
+		gpio_input(gpio[i]);
+		result |= gpio_get(gpio[i]) << i;
+	}
+
+	return result;
+}
+
 int gpio_base3_value(gpio_t gpio[], int num_gpio)
 {
    /*