diff options
| author | David Hendricks <dhendrix@chromium.org> | 2014-11-06 15:05:35 -0800 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2015-04-10 11:59:30 +0200 |
| commit | 21db62eb0e900b031cf7398149a76a3dfa6ceb5f (patch) | |
| tree | fb7550374f3412d6ee6fa75875a0a2f155a46dc7 | |
| parent | 3fc6368e1cb6800159acb769557d22a542c9bb93 (diff) | |
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 <pgeorgi@chromium.org>
Original-Commit-Id: 27873b7a9ea237d13f0cbafd10033a8d0f821cbe
Original-Change-Id: Ia7ffc16eb60e93413c0812573b9cf0999b92828e
Original-Signed-off-by: David Hendricks <dhendrix@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/228323
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: http://review.coreboot.org/9412
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>
| -rw-r--r-- | src/include/gpio.h | 9 | ||||
| -rw-r--r-- | src/lib/gpio.c | 12 |
2 files changed, 21 insertions, 0 deletions
diff --git a/src/include/gpio.h b/src/include/gpio.h index e54b156ce7..7b64ebfe80 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 3a646e0d1d..0875538bae 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) { /* |