zephyr: add HOOKS task

Enable the HOOKS task so the periodic HOOK_TICK and HOOK_SECONDS are
called.

HOOK_TICK is required by the PWM LED support.

BUG=b:174851299
BRANCH=none
TEST=make buildall, zmake testall

Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: Id00f38833d05e32b921d92d2441831058294c994
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2636481
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>

7 files changed, 81 insertions, 1 deletions

diff --git a/zephyr/Kconfig.tasks b/zephyr/Kconfig.tasks
index 96795fbe94..bd10d35259 100644
--- a/zephyr/Kconfig.tasks
+++ b/zephyr/Kconfig.tasks
@@ -68,6 +68,26 @@ config TASK_CHIPSET_STACK_SIZE
 
 endif # HAS_TASK_CHIPSET
 
+config HAS_TASK_HOOKS
+	bool "Hooks task"
+	default y
+	help
+	  This required task runs periodic routines connected to the HOOK_TICK
+	  and HOOK_SECOND events. This task is responsible for running
+	  deferred routines.
+
+if HAS_TASK_HOOKS
+
+config TASK_HOOKS_STACK_SIZE
+	hex "Stack size"
+	default 0x400
+	help
+	  The stack size of the hooks task.
+
+	  See b/176180736 for checking these stack sizes.
+
+endif # HAS_TASK_HOOKS
+
 config HAS_TASK_HOSTCMD
 	bool "Host-command task"
 	depends on PLATFORM_EC_HOSTCMD
diff --git a/zephyr/app/ec/Kconfig b/zephyr/app/ec/Kconfig
index 44f8690f64..eed08f5b8d 100644
--- a/zephyr/app/ec/Kconfig
+++ b/zephyr/app/ec/Kconfig
@@ -42,6 +42,15 @@ config CROS_EC_ACTIVE_COPY
 	  When the active copy name is output to a console, this
 	  string will be displayed.
 
+config CROS_EC_HOOK_TICK_INTERVAL
+	int "The interval time for the HOOK_TICK"
+	default 250000
+	help
+	  Specificies the interval time for the HOOK_TICK, specified in
+	  microseconds. Modules register with HOOK_TICK to be called
+	  periodically by the HOOKS task. The interval must be shorter than
+	  1 second and is set according the EC chipset's sleep requirements.
+
 # When building for the host, we still need values for the various memory
 # sizes, though they aren't actually used, so just set some reasonable-looking
 # values and then ignore them.
diff --git a/zephyr/projects/volteer/boards/arm/volteer/volteer_defconfig b/zephyr/projects/volteer/boards/arm/volteer/volteer_defconfig
index 7670ba7228..608c7891af 100644
--- a/zephyr/projects/volteer/boards/arm/volteer/volteer_defconfig
+++ b/zephyr/projects/volteer/boards/arm/volteer/volteer_defconfig
@@ -1,4 +1,6 @@
-# SPDX-License-Identifier: Apache-2.0
+# Copyright 2021 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
 
 # Zephyr Kernel Configuration
 CONFIG_SOC_SERIES_NPCX7=y
@@ -52,3 +54,5 @@ CONFIG_CROS_EC_RW_MEM_OFF=0x40000
 # (CONFIG_CROS_EC_FLASH_SIZE - CONFIG_CROS_EC_RW_MEM_OFF -
 #  CONFIG_CROS_EC_RO_MEM_OFF)
 CONFIG_CROS_EC_RW_SIZE=0x40000
+
+CONFIG_CROS_EC_HOOK_TICK_INTERVAL=200000
diff --git a/zephyr/shim/include/config_chip.h b/zephyr/shim/include/config_chip.h
index 4d66c158b3..ce9063d4f9 100644
--- a/zephyr/shim/include/config_chip.h
+++ b/zephyr/shim/include/config_chip.h
@@ -21,6 +21,9 @@
 #define CONFIG_ZEPHYR
 #define CHROMIUM_EC
 
+/* EC chipset configuration */
+#define HOOK_TICK_INTERVAL	CONFIG_CROS_EC_HOOK_TICK_INTERVAL
+
 /* Chipset and power configuration */
 #ifdef CONFIG_AP_X86_INTEL_CML
 #define CONFIG_CHIPSET_COMETLAKE
diff --git a/zephyr/shim/include/shimmed_task_id.h b/zephyr/shim/include/shimmed_task_id.h
index f0999834cc..3b66c03168 100644
--- a/zephyr/shim/include/shimmed_task_id.h
+++ b/zephyr/shim/include/shimmed_task_id.h
@@ -40,6 +40,9 @@ typedef uint8_t task_id_t;
 	COND_CODE_1(HAS_TASK_MOTIONSENSE,                                     \
 		     (CROS_EC_TASK(MOTIONSENSE, motion_sense_task, 0,         \
 				   CONFIG_TASK_MOTIONSENSE_STACK_SIZE)), ())  \
+	COND_CODE_1(HAS_TASK_HOOKS,                                       \
+			(CROS_EC_TASK(HOOKS, hook_task, 0,                \
+				CONFIG_TASK_HOOKS_STACK_SIZE)), ())       \
 	COND_CODE_1(HAS_TASK_HOSTCMD,                                     \
 		     (CROS_EC_TASK(HOSTCMD, host_command_task, 0,         \
 				   CONFIG_TASK_HOSTCMD_STACK_SIZE)), ())  \
diff --git a/zephyr/shim/include/shimmed_tasks.h b/zephyr/shim/include/shimmed_tasks.h
index 4db1672a30..631b3fcb16 100644
--- a/zephyr/shim/include/shimmed_tasks.h
+++ b/zephyr/shim/include/shimmed_tasks.h
@@ -18,6 +18,10 @@
 #define HAS_TASK_CHIPSET 1
 #endif /* CONFIG_HAS_TASK_CHIPSET */
 
+#ifdef CONFIG_HAS_TASK_HOOKS
+#define HAS_TASK_HOOKS 1
+#endif /* CONFIG_HAS_TASK_HOOKS */
+
 #ifdef CONFIG_HAS_TASK_HOSTCMD
 #define HAS_TASK_HOSTCMD 1
 #define CONFIG_HOSTCMD_EVENTS
diff --git a/zephyr/shim/src/hooks.c b/zephyr/shim/src/hooks.c
index e4b1ea8791..179f35eef4 100644
--- a/zephyr/shim/src/hooks.c
+++ b/zephyr/shim/src/hooks.c
@@ -9,6 +9,8 @@
 #include "common.h"
 #include "console.h"
 #include "hooks.h"
+#include "task.h"
+#include "timer.h"
 
 #define DEFERRED_STACK_SIZE 1024
 
@@ -90,3 +92,38 @@ void hook_notify(enum hook_type type)
 	for (p = hook_registry[type]; p; p = p->next)
 		p->routine();
 }
+
+void hook_task(void *u)
+{
+	/* Periodic hooks will be called first time through the loop */
+	static uint64_t last_second = -SECOND;
+	static uint64_t last_tick = -HOOK_TICK_INTERVAL;
+
+	while (1) {
+		uint64_t t = get_time().val;
+		int next = 0;
+
+		if (t - last_tick >= HOOK_TICK_INTERVAL) {
+			hook_notify(HOOK_TICK);
+			last_tick = t;
+		}
+
+		if (t - last_second >= SECOND) {
+			hook_notify(HOOK_SECOND);
+			last_second = t;
+		}
+
+		/* Calculate when next tick needs to occur */
+		t = get_time().val;
+		if (last_tick + HOOK_TICK_INTERVAL > t)
+			next = last_tick + HOOK_TICK_INTERVAL - t;
+
+		/*
+		 * Sleep until next tick, unless we've already exceeded
+		 * HOOK_TICK_INTERVAL.
+		 */
+		if (next > 0)
+			task_wait_event(next);
+	}
+}
+