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>

11 files changed, 85 insertions, 35 deletions

diff --git a/include/backlight.h b/include/backlight.h
index be905d0f47..4a11e15a4a 100644
--- a/include/backlight.h
+++ b/include/backlight.h
@@ -9,6 +9,7 @@
 #define __CROS_EC_BACKLIGHT_H
 
 #include "common.h"
+#include "gpio.h"
 
 /**
  * Interrupt handler for backlight.
@@ -18,7 +19,7 @@
 #ifdef CONFIG_BACKLIGHT_REQ_GPIO
 void backlight_interrupt(enum gpio_signal signal);
 #else
-#define backlight_interrupt NULL
-#endif
+static inline void backlight_interrupt(enum gpio_signal signal) { }
+#endif /* !CONFIG_BACKLIGHT_REQ_GPIO */
 
 #endif  /* __CROS_EC_BACKLIGHT_H */
diff --git a/include/chipset.h b/include/chipset.h
index 952c243663..0237767fbf 100644
--- a/include/chipset.h
+++ b/include/chipset.h
@@ -14,6 +14,7 @@
 #define __CROS_EC_CHIPSET_H
 
 #include "common.h"
+#include "gpio.h"
 
 /*
  * Chipset state mask
@@ -95,8 +96,7 @@ static inline void chipset_exit_hard_off(void) { }
 static inline void chipset_throttle_cpu(int throttle) { }
 static inline void chipset_force_shutdown(void) { }
 static inline void chipset_reset(int cold_reset) { }
-
-#define power_interrupt NULL
+static inline void power_interrupt(enum gpio_signal signal) { }
 
 #endif /* !HAS_TASK_CHIPSET */
 
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 */
diff --git a/include/gpio.wrap b/include/gpio.wrap
index cf4fbb319a..1eb9f3643e 100644
--- a/include/gpio.wrap
+++ b/include/gpio.wrap
@@ -8,15 +8,26 @@
 /*
  * The GPIO macro is used to define a new GPIO pin name and function.
  *
- * The name is used to populate the gpio_signal enum by first prepending GPIO_
- * to the name.  It is also used to construct the string name that is presented
- * in the shell interface.  Similarly, the port parameter has GPIO_ prepended to
- * it before it is used to initialize the port base address of a gpio_info
- * struct.  The pin number is used to create a bitmask.  The flags and signal
- * parameters are passed on to the gpio_info directly.
+ * The name is used to populate the gpio_signal enum by first
+ * prepending GPIO_ to the name.  It is also used to construct the
+ * string name that is presented in the shell interface.  Similarly,
+ * the port parameter has GPIO_ prepended to it before it is used to
+ * initialize the port base address of a gpio_info struct.  The pin
+ * number is used to create a bitmask.  The flags parameter is passed
+ * on to the gpio_info directly.
  */
 #ifndef GPIO
-#define GPIO(name, port, pin, flags, signal)
+#define GPIO(name, port, pin, flags)
+#endif
+
+/*
+ * The GPIO_INT macro is used to define a GPIOs that have an IRQ handler.
+ *
+ * The IRQ handler pointers are stored as elements in the gpio_irq_handlers
+ * array.
+ */
+#ifndef GPIO_INT
+#define GPIO_INT(name, port, pin, flags, signal)
 #endif
 
 /*
@@ -61,5 +72,6 @@
  * Once the gpio.inc file has been included these macros are no longer needed.
  */
 #undef GPIO
+#undef GPIO_INT
 #undef ALTERNATE
 #undef UNIMPLEMENTED
diff --git a/include/gpio_list.h b/include/gpio_list.h
index c7e2962747..c9bdd5668d 100644
--- a/include/gpio_list.h
+++ b/include/gpio_list.h
@@ -3,17 +3,21 @@
  * found in the LICENSE file.
  */
 
+#include "gpio_signal.h"
+
 #ifdef CONFIG_COMMON_GPIO_SHORTNAMES
-#define GPIO(name, port, pin, flags, signal) \
-	{#port#pin, GPIO_##port, (1 << pin), flags, signal},
+#define GPIO(name, port, pin, flags)			\
+	{#port#pin, GPIO_##port, (1 << pin), flags},
 #else
-#define GPIO(name, port, pin, flags, signal) \
-	{#name, GPIO_##port, (1 << pin), flags, signal},
+#define GPIO(name, port, pin, flags)			\
+	{#name, GPIO_##port, (1 << pin), flags},
 #endif
 
 #define UNIMPLEMENTED(name) \
-	{#name, DUMMY_GPIO_BANK, 0, GPIO_DEFAULT, NULL},
+	{#name, DUMMY_GPIO_BANK, 0, GPIO_DEFAULT},
 
+#define GPIO_INT(name, port, pin, flags, signal)	\
+	GPIO(name, port, pin, flags)
 /* GPIO signal list. */
 const struct gpio_info gpio_list[] = {
 	#include "gpio.wrap"
@@ -33,3 +37,18 @@ const struct gpio_alt_func gpio_alt_funcs[] = {
 };
 
 const int gpio_alt_funcs_count = ARRAY_SIZE(gpio_alt_funcs);
+
+/* GPIO Interrupt Handlers */
+#define GPIO_INT(name, port, pin, flags, signal) signal,
+void (* const gpio_irq_handlers[])(enum gpio_signal signal) = {
+	#include "gpio.wrap"
+};
+const int gpio_ih_count = ARRAY_SIZE(gpio_irq_handlers);
+
+/*
+ * ALL GPIOs with interrupt handlers must be declared at the top of the gpio.inc
+ * file.
+ */
+#define GPIO_INT(name, port, pin, flags, signal)	\
+	BUILD_ASSERT(GPIO_##name < ARRAY_SIZE(gpio_irq_handlers));
+#include "gpio.wrap"
diff --git a/include/gpio_signal.h b/include/gpio_signal.h
index 83e9dfe6fa..bcec1b522f 100644
--- a/include/gpio_signal.h
+++ b/include/gpio_signal.h
@@ -3,10 +3,16 @@
  * found in the LICENSE file.
  */
 
-#define GPIO(name, port, pin, flags, signal) GPIO_##name,
+#ifndef __CROS_EC_GPIO_SIGNAL_H
+#define __CROS_EC_GPIO_SIGNAL_H
+
+#define GPIO(name, port, pin, flags) GPIO_##name,
 #define UNIMPLEMENTED(name) GPIO_##name,
+#define GPIO_INT(name, port, pin, flags, signal) GPIO_##name,
 
 enum gpio_signal {
 	#include "gpio.wrap"
 	GPIO_COUNT
 };
+
+#endif /* __CROS_EC_GPIO_SIGNAL_H */
diff --git a/include/jtag.h b/include/jtag.h
index 9c7835dfd0..cf927c2e2d 100644
--- a/include/jtag.h
+++ b/include/jtag.h
@@ -9,6 +9,7 @@
 #define __CROS_EC_JTAG_H
 
 #include "common.h"
+#include "gpio.h"
 
 /**
  * Pre-initialize the JTAG module.
@@ -23,8 +24,7 @@ void jtag_pre_init(void);
  */
 void jtag_interrupt(enum gpio_signal signal);
 #else
-#define jtag_interrupt NULL
-#endif
-
+static inline void jtag_interrupt(enum gpio_signal signal) { }
+#endif /* !CONFIG_LOW_POWER_IDLE */
 
 #endif  /* __CROS_EC_JTAG_H */
diff --git a/include/keyboard_raw.h b/include/keyboard_raw.h
index 9bdd1cce8f..8591700b47 100644
--- a/include/keyboard_raw.h
+++ b/include/keyboard_raw.h
@@ -68,7 +68,7 @@ void keyboard_raw_enable_interrupt(int enable);
 void keyboard_raw_gpio_interrupt(enum gpio_signal signal);
 
 #else
-#define keyboard_raw_gpio_interrupt NULL
-#endif
+static inline void keyboard_raw_gpio_interrupt(enum gpio_signal signal) { }
+#endif /* !HAS_TASK_KEYSCAN */
 
 #endif  /* __CROS_EC_KEYBOARD_RAW_H */
diff --git a/include/power.h b/include/power.h
index 36054e8bd1..8f11c14868 100644
--- a/include/power.h
+++ b/include/power.h
@@ -100,7 +100,7 @@ enum power_state power_handle_state(enum power_state state);
 #ifdef HAS_TASK_CHIPSET
 void power_signal_interrupt(enum gpio_signal signal);
 #else
-#define power_signal_interrupt NULL
-#endif
+static inline void power_signal_interrupt(enum gpio_signal signal) { }
+#endif /* !HAS_TASK_CHIPSET */
 
 #endif  /* __CROS_EC_POWER_H */
diff --git a/include/switch.h b/include/switch.h
index f59e56df52..c2b67393d0 100644
--- a/include/switch.h
+++ b/include/switch.h
@@ -19,7 +19,7 @@
  */
 void switch_interrupt(enum gpio_signal signal);
 #else
-#define switch_interrupt NULL
-#endif  /* CONFIG_SWITCH */
+static inline void switch_interrupt(enum gpio_signal signal) { }
+#endif  /* !CONFIG_SWITCH */
 
 #endif  /* __CROS_EC_SWITCH_H */
diff --git a/include/uart.h b/include/uart.h
index 6128962726..6499eb9453 100644
--- a/include/uart.h
+++ b/include/uart.h
@@ -10,6 +10,7 @@
 
 #include <stdarg.h>  /* For va_list */
 #include "common.h"
+#include "gpio.h"
 
 /**
  * Initialize the UART module.
@@ -224,8 +225,8 @@ void uart_exit_dsleep(void);
  */
 void uart_deepsleep_interrupt(enum gpio_signal signal);
 #else
-#define uart_deepsleep_interrupt NULL
-#endif
+static inline void uart_deepsleep_interrupt(enum gpio_signal signal) { }
+#endif /* !CONFIG_LOW_POWER_IDLE */
 
 #ifdef CONFIG_UART_INPUT_FILTER
 /**