drivers: misc: Add an Ethos-U NPU driver

Add a driver for the Arm Ethos-U NPU, including a Devicetree entry for
the mps3_an547 platform.

Signed-off-by: Kristofer Jonsson <kristofer.jonsson@arm.com>
Signed-off-by: Fredrik Knutsson <fredrik.knutsson@arm.com>

boards/arm/mps3_an547/mps3_an547.dts

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018-2021 Linaro Limited
+ * Copyright 2022 Arm Limited and/or its affiliates <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -85,6 +86,21 @@
 		};
 	};
 
+	ethosu {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupt-parent = <&nvic>;
+
+		ethosu0: ethosu@48102000 {
+			compatible = "arm,ethos-u";
+			reg = <0x48102000>;
+			interrupts = <56 3>;
+			secure-enable;
+			privilege-enable;
+			status = "okay";
+		};
+	};
+
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;

drivers/misc/CMakeLists.txt

@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
 
+add_subdirectory_ifdef(CONFIG_ARM_ETHOS_U ethos_u)
 add_subdirectory_ifdef(CONFIG_FT800 ft8xx)
 add_subdirectory_ifdef(CONFIG_GROVE_LCD_RGB grove_lcd_rgb)

drivers/misc/ethos_u/CMakeLists.txt

@@ -0,0 +1,6 @@
+# Copyright 2022 Arm Limited and/or its affiliates <open-source-office@arm.com>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+zephyr_library_sources(init.c)

drivers/misc/ethos_u/init.c

@@ -0,0 +1,158 @@
+/*
+ * Copyright 2021-2022 Arm Limited and/or its affiliates <open-source-office@arm.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/init.h>
+#include <zephyr/kernel.h>
+#include <zephyr/irq.h>
+#include <zephyr/sys/util.h>
+
+#include <ethosu_driver.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(ethos_u, CONFIG_ARM_ETHOS_U_LOG_LEVEL);
+
+#define DT_DRV_COMPAT arm_ethos_u
+
+/*******************************************************************************
+ * Re-implementation/Overrides __((weak)) symbol functions from ethosu_driver.c
+ * To handle mutex and semaphores
+ *******************************************************************************/
+
+void *ethosu_mutex_create(void)
+{
+	struct k_mutex *mutex;
+
+	mutex = k_malloc(sizeof(*mutex));
+	if (mutex == NULL) {
+		LOG_ERR("Failed allocate mutex");
+		return NULL;
+	}
+
+	k_mutex_init(mutex);
+
+	return (void *)mutex;
+}
+
+int ethosu_mutex_lock(void *mutex)
+{
+	int status;
+
+	status = k_mutex_lock((struct k_mutex *)mutex, K_FOREVER);
+	if (status != 0) {
+		LOG_ERR("Failed to lock mutex with error - %d", status);
+		return -1;
+	}
+
+	return 0;
+}
+
+int ethosu_mutex_unlock(void *mutex)
+{
+	k_mutex_unlock((struct k_mutex *)mutex);
+	return 0;
+}
+
+void *ethosu_semaphore_create(void)
+{
+	struct k_sem *sem;
+
+	sem = k_malloc(sizeof(*sem));
+	if (sem == NULL) {
+		LOG_ERR("Failed to allocate semaphore");
+		return NULL;
+	}
+
+	k_sem_init(sem, 0, 100);
+
+	return (void *)sem;
+}
+
+int ethosu_semaphore_take(void *sem)
+{
+	int status;
+
+	status = k_sem_take((struct k_sem *)sem, K_FOREVER);
+	if (status != 0) {
+		LOG_ERR("Failed to take semaphore with error - %d", status);
+		return -1;
+	}
+
+	return 0;
+}
+
+int ethosu_semaphore_give(void *sem)
+{
+	k_sem_give((struct k_sem *)sem);
+	return 0;
+}
+
+struct ethosu_dts_info {
+	void *base_addr;
+	bool secure_enable;
+	bool privilege_enable;
+	void (*irq_config)(void);
+};
+
+struct ethosu_data {
+	struct ethosu_driver drv;
+};
+
+static int ethosu_zephyr_init(const struct device *dev)
+{
+	const struct ethosu_dts_info *config = dev->config;
+	struct ethosu_data *data = dev->data;
+	struct ethosu_driver *drv = &data->drv;
+	struct ethosu_driver_version version;
+
+	LOG_DBG("Ethos-U DTS info. base_address=0x%p, secure_enable=%u, privilege_enable=%u",
+		config->base_addr, config->secure_enable, config->privilege_enable);
+
+	ethosu_get_driver_version(&version);
+
+	LOG_DBG("Version. major=%u, minor=%u, patch=%u", version.major, version.minor,
+		version.patch);
+
+	if (ethosu_init(drv, config->base_addr, NULL, 0, config->secure_enable,
+			config->privilege_enable)) {
+		LOG_ERR("Failed to initialize NPU with ethosu_init().");
+		return -EINVAL;
+	}
+
+	config->irq_config();
+
+	return 0;
+}
+
+#define ETHOSU_DEVICE_INIT(n)									   \
+	static struct ethosu_data ethosu_data_##n;						   \
+												   \
+	static void ethosu_zephyr_irq_handler_##n(void)						   \
+	{											   \
+		struct ethosu_driver *drv = &ethosu_data_##n.drv;				   \
+		ethosu_irq_handler(drv);							   \
+	}											   \
+												   \
+	static void ethosu_zephyr_irq_config_##n(void)						   \
+	{											   \
+		IRQ_DIRECT_CONNECT(DT_INST_IRQN(n),						   \
+				   DT_INST_IRQ(n, priority),					   \
+				   ethosu_zephyr_irq_handler_##n, 0);				   \
+		irq_enable(DT_INST_IRQN(n));							   \
+	}											   \
+												   \
+	static const struct ethosu_dts_info ethosu_dts_info_##n = {				   \
+		.base_addr = (void *)DT_INST_REG_ADDR(n),					   \
+		.secure_enable = DT_INST_PROP(n, secure_enable),				   \
+		.privilege_enable = DT_INST_PROP(n, privilege_enable),				   \
+		.irq_config = &ethosu_zephyr_irq_config_##n,					   \
+	};											   \
+												   \
+	DEVICE_DT_INST_DEFINE(n, ethosu_zephyr_init, NULL, &ethosu_data_##n, &ethosu_dts_info_##n, \
+			      POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(ETHOSU_DEVICE_INIT);