zephyr: support shared PD interrupts

Some boards share an interrupt line between multiple PD ports by running
pd_shared_alert_task in a task instead of individual per-port tasks.
Add support for that by adding USB-C options for shared interrupts and
using those to enable the shared interrupt task for the chosen ports.

BUG=b:204860054
TEST=builds
BRANCH=none

Signed-off-by: Peter Marheine <pmarheine@chromium.org>
Change-Id: Ice67a6a74b0a2f42982de6e19aa1a478c0a4e068
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3263604
Reviewed-by: Keith Short <keithshort@chromium.org>

3 files changed, 65 insertions, 0 deletions

diff --git a/zephyr/Kconfig.tasks b/zephyr/Kconfig.tasks
index 1c4e50fa84..457a911d18 100644
--- a/zephyr/Kconfig.tasks
+++ b/zephyr/Kconfig.tasks
@@ -230,9 +230,16 @@ config HAS_TASK_PD_C3
 	help
 	  This turns on the PD_C3 task for devices with 4 ports.
 
+config HAS_TASK_PD_INT_SHARED
+	bool # Selected by PLATFORM_EC_USB_PD_INT_SHARED
+	help
+	  This turns on the PD_INT_SHARED task which services PD message
+	  interrupts for any port which has a shared IRQ enabled.
+
 config HAS_TASK_PD_INT_C0
 	bool
 	depends on PLATFORM_EC_USB_POWER_DELIVERY
+	depends on !PLATFORM_EC_USB_PD_PORT_0_SHARED
 	default y if PLATFORM_EC_USB_PD_PORT_MAX_COUNT > 0
 	help
 	  This turns on the PD_INT_C0 task which handles servicing of Power
@@ -243,6 +250,7 @@ config HAS_TASK_PD_INT_C0
 config HAS_TASK_PD_INT_C1
 	bool
 	depends on PLATFORM_EC_USB_POWER_DELIVERY
+	depends on !PLATFORM_EC_USB_PD_PORT_1_SHARED
 	default y if PLATFORM_EC_USB_PD_PORT_MAX_COUNT > 1
 	help
 	  This turns on the PD_INT_C1 task for devices with >=2 ports.
@@ -250,6 +258,7 @@ config HAS_TASK_PD_INT_C1
 config HAS_TASK_PD_INT_C2
 	bool
 	depends on PLATFORM_EC_USB_POWER_DELIVERY
+	depends on !PLATFORM_EC_USB_PD_PORT_2_SHARED
 	default y if PLATFORM_EC_USB_PD_PORT_MAX_COUNT > 2
 	help
 	  This turns on the PD_INT_C2 task for devices with >=3 ports.
@@ -257,6 +266,7 @@ config HAS_TASK_PD_INT_C2
 config HAS_TASK_PD_INT_C3
 	bool
 	depends on PLATFORM_EC_USB_POWER_DELIVERY
+	depends on !PLATFORM_EC_USB_PD_PORT_2_SHARED
 	default y if PLATFORM_EC_USB_PD_PORT_MAX_COUNT > 3
 	help
 	  This turns on the PD_INT_C3 task for devices with 4 ports.
diff --git a/zephyr/Kconfig.usbc b/zephyr/Kconfig.usbc
index 67f3fbcc33..343de8b4a7 100644
--- a/zephyr/Kconfig.usbc
+++ b/zephyr/Kconfig.usbc
@@ -250,6 +250,45 @@ menuconfig PLATFORM_EC_USB_POWER_DELIVERY
 
 if PLATFORM_EC_USB_POWER_DELIVERY
 
+menuconfig PLATFORM_EC_USB_PD_INT_SHARED
+	bool "USB-C ports share PD interrupts"
+	select HAS_TASK_PD_INT_SHARED
+	help
+	  This enables processing of shared interrupts where multiple ports
+	  share a single IRQ on the EC. Only one shared IRQ is supported,
+	  but any combination of ports can be serviced by that one IRQ.
+
+if PLATFORM_EC_USB_PD_INT_SHARED
+
+config PLATFORM_EC_USB_PD_PORT_0_SHARED
+	bool "Port 0 IRQ is shared"
+	help
+	  Enable handling of port 0 PD interrupts signalled by an IRQ that is
+	  shared by every other port enabled in this section.
+
+config PLATFORM_EC_USB_PD_PORT_1_SHARED
+	bool "Port 1 IRQ is shared"
+	depends on PLATFORM_EC_USB_PD_PORT_MAX_COUNT > 1
+	help
+	  Enable handling of port 1 PD interrupts signalled by an IRQ that is
+	  shared by every other port enabled in this section.
+
+config PLATFORM_EC_USB_PD_PORT_2_SHARED
+	bool "Port 2 IRQ is shared"
+	depends on PLATFORM_EC_USB_PD_PORT_MAX_COUNT > 2
+	help
+	  Enable handling of port 2 PD interrupts signalled by an IRQ that is
+	  shared by every other port enabled in this section.
+
+config PLATFORM_EC_USB_PD_PORT_3_SHARED
+	bool "Port 3 IRQ is shared"
+	depends on PLATFORM_EC_USB_PD_PORT_MAX_COUNT > 3
+	help
+	  Enable handling of port 3 PD interrupts signalled by an IRQ that is
+	  shared by every other port enabled in this section.
+
+endif # PLATFORM_EC_USB_PD_INT_SHARED
+
 config PLATFORM_EC_USB_PD_HOST_CMD
 	bool "Host commands related to USB Power Delivery"
 	default y
diff --git a/zephyr/shim/include/shimmed_task_id.h b/zephyr/shim/include/shimmed_task_id.h
index f56edf0806..082c305cca 100644
--- a/zephyr/shim/include/shimmed_task_id.h
+++ b/zephyr/shim/include/shimmed_task_id.h
@@ -12,6 +12,18 @@
 typedef uint8_t task_id_t;
 
 /*
+ * Bitmask of port enable bits, expanding to a value like `BIT(0) | BIT(2) | 0`.
+ */
+#define PD_INT_SHARED_PORT_MASK ( \
+	FOR_EACH_NONEMPTY_TERM(BIT, (|),		\
+		IF_ENABLED(CONFIG_PLATFORM_EC_USB_PD_PORT_0_SHARED, (0)),	\
+		IF_ENABLED(CONFIG_PLATFORM_EC_USB_PD_PORT_1_SHARED, (1)),	\
+		IF_ENABLED(CONFIG_PLATFORM_EC_USB_PD_PORT_2_SHARED, (2)),	\
+		IF_ENABLED(CONFIG_PLATFORM_EC_USB_PD_PORT_3_SHARED, (3)),	\
+	) 0 \
+)
+
+/*
  * Highest priority on bottom -- same as in platform/ec. List of CROS_EC_TASK
  * items. See CONFIG_TASK_LIST in platform/ec's config.h for more information.
  * For tests that want their own custom tasks, use CONFIG_HAS_TEST_TASKS and not
@@ -67,6 +79,10 @@ typedef uint8_t task_id_t;
 	COND_CODE_1(HAS_TASK_PD_C3,                                       \
 		     (CROS_EC_TASK(PD_C3, pd_task, 0,                     \
 				   CONFIG_TASK_PD_STACK_SIZE)), ())       \
+	IF_ENABLED(CONFIG_HAS_TASK_PD_INT_SHARED,			  \
+		   (CROS_EC_TASK(PD_INT_SHARED, pd_shared_alert_task,	  \
+				 PD_INT_SHARED_PORT_MASK,		  \
+				 CONFIG_TASK_PD_INT_STACK_SIZE)))	  \
 	COND_CODE_1(HAS_TASK_PD_INT_C0,                                   \
 		     (CROS_EC_TASK(PD_INT_C0, pd_interrupt_handler_task, 0, \
 				   CONFIG_TASK_PD_INT_STACK_SIZE)), ())   \