gpio: Refactor IRQ handler pointer out of gpio_list

In the gpio_info struct, we had a irq_handler pointer defined even
though a majority of the GPIOs did not have irq handlers associated. By
removing the irq_handler pointer out of the struct, we can save some
space with some targets saving more than others. (For example, ~260
bytes for samus_pd).

This change also brings about a new define:

     GPIO_INT(name, port, pin, flags, signal)

And the existing GPIO macro has had the signal parameter removed since
they were just NULL.

     GPIO(name, port, pin, flags)

In each of the gpio.inc files, all the GPIOs with irq handlers must be
defined at the top of the file. This is because their enum values from
gpio_signal are used as the index to the gpio_irq_handlers table.

BUG=chromium:471331
BRANCH=none
TEST=Flashed ec to samus and samus_pd, verified lightbar tap, lid, power
button, keyboard, charging, all still working.
TEST=Moved a GPIO_INT declaration after a GPIO declaration and watched the build
fail.
TEST=make -j BOARD=peppy tests
TEST=make -j BOARD=auron tests
TEST=make -j BOARD=link tests

Change-Id: Id6e261b0a3cd63223ca92f2e96a80c95e85cdefb
Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Reviewed-on: https://chromium-review.googlesource.com/263973
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Tested-by: Aseda Aboagye <aaboagye@chromium.org>
Commit-Queue: Aseda Aboagye <aaboagye@chromium.org>
Trybot-Ready: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Alec Berg <alecaberg@chromium.org>

1 files changed, 18 insertions, 7 deletions

diff --git a/include/gpio.h b/include/gpio.h
index f71622dfe6..0441ff6096 100644
--- a/include/gpio.h
+++ b/include/gpio.h
@@ -45,6 +45,15 @@
 #define GPIO_INT_ANY        (GPIO_INT_BOTH | GPIO_INT_LEVEL)
 #define GPIO_INT_BOTH_DSLEEP (GPIO_INT_BOTH | GPIO_INT_DSLEEP)
 
+/* NOTE: This is normally included from board.h, thru config.h and common.h But,
+ * some boards and unit tests don't have a gpio_signal enum defined, so we
+ * define an emtpy one here.*/
+#ifndef __CROS_EC_GPIO_SIGNAL_H
+enum gpio_signal {
+	NULL
+};
+#endif /* __CROS_EC_GPIO_SIGNAL_H */
+
 /* GPIO signal definition structure, for use by board.c */
 struct gpio_info {
 	/* Signal name */
@@ -58,18 +67,20 @@ struct gpio_info {
 
 	/* Flags (GPIO_*; see above) */
 	uint32_t flags;
-
-	/*
-	 * Interrupt handler.  If non-NULL, and the signal's interrupt is
-	 * enabled, this will be called in the context of the GPIO interrupt
-	 * handler.
-	 */
-	void (*irq_handler)(enum gpio_signal signal);
 };
 
 /* Signal information from board.c.  Must match order from enum gpio_signal. */
 extern const struct gpio_info gpio_list[];
 
+/* Interrupt handler table for those GPIOs which have IRQ handlers.
+ *
+ * If the signal's interrupt is enabled, this will be called in the
+ * context of the GPIO interrupt handler.
+ */
+extern void (* const gpio_irq_handlers[])(enum gpio_signal signal);
+extern const int gpio_ih_count;
+#define GPIO_IH_COUNT gpio_ih_count
+
 /* GPIO alternate function structure, for use by board.c */
 struct gpio_alt_func {
 	/* Port base address */