drivers: usb: rename UDC buffer to USB buffer

doc/connectivity/usb/device_next/api/udc.rst

@@ -17,4 +17,4 @@ API reference
 
 .. doxygengroup:: udc_api
 
-.. doxygengroup:: udc_buf
+.. doxygengroup:: usb_buf

drivers/usb/Kconfig

@@ -3,6 +3,13 @@
 # Copyright (c) 2016 Wind River Systems, Inc.
 # SPDX-License-Identifier: Apache-2.0
 
+config USB_BUF_FORCE_NOCACHE
+	bool
+	depends on NOCACHE_MEMORY && DCACHE && (UDC_DRIVER || UHC_DRIVER)
+	help
+	  Place the buffer pools in the nocache memory region if the driver
+	  cannot handle buffers in cached memory.
+
 source "drivers/usb/bc12/Kconfig"
 source "drivers/usb/udc/Kconfig"
 source "drivers/usb/uhc/Kconfig"

drivers/usb/common/CMakeLists.txt

@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_subdirectory_ifdef(CONFIG_HAS_NRFX nrf_usbd_common)
+add_subdirectory(buf)

drivers/usb/common/buf/CMakeLists.txt

@@ -0,0 +1,5 @@
+# Copyright Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+zephyr_library_sources_ifdef(CONFIG_UDC_DRIVER usb_buf.c)

drivers/usb/common/buf/usb_buf.c

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/net_buf.h>
+#include <zephyr/drivers/usb/usb_buf.h>
+
+static inline uint8_t *usb_pool_data_alloc(struct net_buf *const buf,
+					   size_t *const size, k_timeout_t timeout)
+{
+	struct net_buf_pool *const buf_pool = net_buf_pool_get(buf->pool_id);
+	struct k_heap *const pool = buf_pool->alloc->alloc_data;
+	void *b;
+
+	*size = USB_BUF_ROUND_UP(*size);
+	b = k_heap_aligned_alloc(pool, USB_BUF_ALIGN, *size, timeout);
+	if (b == NULL) {
+		*size = 0;
+		return NULL;
+	}
+
+	return b;
+}
+
+static inline void usb_pool_data_unref(struct net_buf *buf, uint8_t *const data)
+{
+	struct net_buf_pool *buf_pool = net_buf_pool_get(buf->pool_id);
+	struct k_heap *pool = buf_pool->alloc->alloc_data;
+
+	k_heap_free(pool, data);
+}
+
+const struct net_buf_data_cb net_buf_dma_cb = {
+	.alloc = usb_pool_data_alloc,
+	.unref = usb_pool_data_unref,
+};

drivers/usb/device/CMakeLists.txt

@@ -3,7 +3,7 @@
 if(CONFIG_USB_DEVICE_DRIVER)
 
 zephyr_library()
-zephyr_library_include_directories(${ZEPHYR_BASE}/drivers/usb/common/)
+zephyr_library_include_directories(${ZEPHYR_BASE}/drivers/usb/common/include)
 
 zephyr_library_sources_ifdef(CONFIG_USB_DW           usb_dc_dw.c)
 zephyr_library_sources_ifdef(CONFIG_USB_DC_RPI_PICO  usb_dc_rpi_pico.c)

drivers/usb/udc/CMakeLists.txt

@@ -4,7 +4,7 @@
 zephyr_library()
 
 zephyr_library_sources(udc_common.c)
-zephyr_library_include_directories(${ZEPHYR_BASE}/drivers/usb/common/)
+zephyr_library_include_directories(${ZEPHYR_BASE}/drivers/usb/common/include)
 
 zephyr_library_sources_ifdef(CONFIG_UDC_DWC2 udc_dwc2.c)
 zephyr_library_sources_ifdef(CONFIG_UDC_NRF udc_nrf.c)

drivers/usb/udc/Kconfig

@@ -25,13 +25,6 @@ config UDC_BUF_POOL_SIZE
 	help
 	  Total amount of memory available for UDC requests.
 
-config UDC_BUF_FORCE_NOCACHE
-	bool "Place the buffer pools in the nocache memory region"
-	depends on NOCACHE_MEMORY && DCACHE
-	help
-	  Place the buffer pools in the nocache memory region if the driver
-	  cannot handle buffers in cached memory.
-
 config UDC_WORKQUEUE
 	bool "Use a dedicate work queue for UDC drivers"
 	help

drivers/usb/udc/Kconfig.mcux

@@ -7,7 +7,7 @@ config UDC_NXP_EHCI
 	depends on DT_HAS_NXP_EHCI_ENABLED
 	select PINCTRL
 	select NOCACHE_MEMORY if CPU_HAS_DCACHE
-	imply UDC_BUF_FORCE_NOCACHE
+	imply USB_BUF_FORCE_NOCACHE
 	imply UDC_WORKQUEUE
 	help
 	  NXP MCUX USB Device Controller Driver for EHCI.

drivers/usb/udc/udc_common.c

@@ -10,7 +10,7 @@
 #include <zephyr/sys/byteorder.h>
 #include <zephyr/sys/__assert.h>
 #include <zephyr/usb/usb_ch9.h>
-#include <zephyr/drivers/usb/udc_buf.h>
+#include <zephyr/drivers/usb/usb_buf.h>
 #include "udc_common.h"
 
 #include <zephyr/logging/log.h>
@@ -21,36 +21,6 @@
 #endif
 LOG_MODULE_REGISTER(udc, CONFIG_UDC_DRIVER_LOG_LEVEL);
 
-static inline uint8_t *udc_pool_data_alloc(struct net_buf *const buf,
-					   size_t *const size, k_timeout_t timeout)
-{
-	struct net_buf_pool *const buf_pool = net_buf_pool_get(buf->pool_id);
-	struct k_heap *const pool = buf_pool->alloc->alloc_data;
-	void *b;
-
-	*size = ROUND_UP(*size, UDC_BUF_GRANULARITY);
-	b = k_heap_aligned_alloc(pool, UDC_BUF_ALIGN, *size, timeout);
-	if (b == NULL) {
-		*size = 0;
-		return NULL;
-	}
-
-	return b;
-}
-
-static inline void udc_pool_data_unref(struct net_buf *buf, uint8_t *const data)
-{
-	struct net_buf_pool *buf_pool = net_buf_pool_get(buf->pool_id);
-	struct k_heap *pool = buf_pool->alloc->alloc_data;
-
-	k_heap_free(pool, data);
-}
-
-const struct net_buf_data_cb net_buf_dma_cb = {
-	.alloc = udc_pool_data_alloc,
-	.unref = udc_pool_data_unref,
-};
-
 static inline void udc_buf_destroy(struct net_buf *buf);
 
 UDC_BUF_POOL_VAR_DEFINE(udc_ep_pool,

drivers/usb/uhc/uhc_common.c

@@ -14,11 +14,10 @@ LOG_MODULE_REGISTER(uhc, CONFIG_UHC_DRIVER_LOG_LEVEL);
 K_MEM_SLAB_DEFINE_STATIC(uhc_xfer_pool, sizeof(struct uhc_transfer),
 			 CONFIG_UHC_XFER_COUNT, sizeof(void *));
 
-NET_BUF_POOL_VAR_DEFINE(uhc_ep_pool,
+USB_BUF_POOL_VAR_DEFINE(uhc_ep_pool,
 			CONFIG_UHC_BUF_COUNT, CONFIG_UHC_BUF_POOL_SIZE,
 			0, NULL);
 
-
 int uhc_submit_event(const struct device *dev,
 		     const enum uhc_event_type type,
 		     const int status)

include/zephyr/drivers/usb/udc.h

@@ -14,7 +14,7 @@
 
 #include <zephyr/kernel.h>
 #include <zephyr/device.h>
-#include <zephyr/drivers/usb/udc_buf.h>
+#include <zephyr/drivers/usb/usb_buf.h>
 #include <zephyr/sys/atomic.h>
 #include <zephyr/usb/usb_ch9.h>
 

include/zephyr/drivers/usb/uhc.h

@@ -15,6 +15,7 @@
 #include <zephyr/kernel.h>
 #include <zephyr/device.h>
 #include <zephyr/net_buf.h>
+#include <zephyr/drivers/usb/usb_buf.h>
 #include <zephyr/usb/usb_ch9.h>
 #include <zephyr/sys/dlist.h>
 

include/zephyr/drivers/usb/udc_buf.h → include/zephyr/drivers/usb/usb_buf.h

@@ -9,55 +9,58 @@
  * @brief Buffers for USB device support
  */
 
-#ifndef ZEPHYR_INCLUDE_UDC_BUF_H
-#define ZEPHYR_INCLUDE_UDC_BUF_H
+#ifndef ZEPHYR_INCLUDE_USB_BUF_H
+#define ZEPHYR_INCLUDE_USB_BUF_H
 
 #include <zephyr/kernel.h>
 #include <zephyr/net_buf.h>
 
-#if defined(CONFIG_DCACHE) && !defined(CONFIG_UDC_BUF_FORCE_NOCACHE)
+#if defined(CONFIG_DCACHE) && !defined(CONFIG_USB_BUF_FORCE_NOCACHE)
 /*
  * Here we try to get DMA-safe buffers, but we lack a consistent source of
  * information about data cache properties, such as line cache size, and a
  * consistent source of information about what part of memory is DMA'able.
  * For now, we simply assume that all available memory is DMA'able and use
  * Kconfig option DCACHE_LINE_SIZE for alignment and granularity.
  */
-#define Z_UDC_BUF_ALIGN		CONFIG_DCACHE_LINE_SIZE
-#define Z_UDC_BUF_GRANULARITY	CONFIG_DCACHE_LINE_SIZE
+#define Z_USB_BUF_ALIGN		CONFIG_DCACHE_LINE_SIZE
+#define Z_USB_BUF_GRANULARITY	CONFIG_DCACHE_LINE_SIZE
 #else
 /*
  * Default alignment and granularity to pointer size if the platform does not
  * have a data cache or buffers are placed in nocache memory region.
  */
-#define Z_UDC_BUF_ALIGN		sizeof(void *)
-#define Z_UDC_BUF_GRANULARITY	sizeof(void *)
+#define Z_USB_BUF_ALIGN		sizeof(void *)
+#define Z_USB_BUF_GRANULARITY	sizeof(void *)
 #endif
 
 
-#if defined(CONFIG_UDC_BUF_FORCE_NOCACHE)
+#if defined(CONFIG_USB_BUF_FORCE_NOCACHE)
 /*
  * The usb transfer buffer needs to be in __nocache section
  */
-#define Z_UDC_BUF_SECTION	__nocache
+#define Z_USB_BUF_SECTION	__nocache
 #else
-#define Z_UDC_BUF_SECTION
+#define Z_USB_BUF_SECTION
 #endif
 
 /**
- * @brief Buffer macros and definitions used in USB device support
- * @defgroup udc_buf Buffer macros and definitions used in USB device support
+ * @brief USB buffer macros and definitions
+ * @defgroup usb_buf USB buffer macros and definitions
  * @ingroup usb
  * @since 4.0
- * @version 0.1.0
+ * @version 0.1.1
  * @{
  */
 
 /** Buffer alignment required by the UDC driver */
-#define UDC_BUF_ALIGN		Z_UDC_BUF_ALIGN
+#define USB_BUF_ALIGN		Z_USB_BUF_ALIGN
 
 /** Buffer granularity required by the UDC driver */
-#define UDC_BUF_GRANULARITY	Z_UDC_BUF_GRANULARITY
+#define USB_BUF_GRANULARITY	Z_USB_BUF_GRANULARITY
+
+/** Round up to the granularity required by the UDC driver */
+#define USB_BUF_ROUND_UP(size)	ROUND_UP(size, Z_USB_BUF_GRANULARITY)
 
 /**
  * @brief Define a UDC driver-compliant static buffer
@@ -68,9 +71,9 @@
  * @param name Buffer name
  * @param size Buffer size
  */
-#define UDC_STATIC_BUF_DEFINE(name, size)					\
-	static uint8_t Z_UDC_BUF_SECTION __aligned(UDC_BUF_ALIGN)		\
-	name[ROUND_UP(size, UDC_BUF_GRANULARITY)];
+#define USB_STATIC_BUF_DEFINE(name, size)					\
+	static uint8_t Z_USB_BUF_SECTION __aligned(USB_BUF_ALIGN)		\
+	name[USB_BUF_ROUND_UP(size)];
 
 /**
  * @brief Verify that the buffer is aligned as required by the UDC driver
@@ -79,13 +82,13 @@
  *
  * @param buf Buffer pointer
  */
-#define IS_UDC_ALIGNED(buf) IS_ALIGNED(buf, UDC_BUF_ALIGN)
+#define IS_USB_BUF_ALIGNED(buf) IS_ALIGNED(buf, USB_BUF_ALIGN)
 
 /**
  * @cond INTERNAL_HIDDEN
  */
-#define UDC_HEAP_DEFINE(name, bytes, in_section)				\
-	uint8_t in_section __aligned(UDC_BUF_ALIGN)				\
+#define USB_BUF_HEAP_DEFINE(name, bytes, in_section)				\
+	uint8_t in_section __aligned(USB_BUF_ALIGN)				\
 		kheap_##name[MAX(bytes, Z_HEAP_MIN_SIZE)];			\
 	STRUCT_SECTION_ITERABLE(k_heap, name) = {				\
 		.heap = {							\
@@ -94,10 +97,10 @@
 		 },								\
 	}
 
-#define UDC_K_HEAP_DEFINE(name, size)						\
-	COND_CODE_1(CONFIG_UDC_BUF_FORCE_NOCACHE,				\
-		    (UDC_HEAP_DEFINE(name, size, __nocache)),			\
-		    (UDC_HEAP_DEFINE(name, size, __noinit)))
+#define USB_BUF_K_HEAP_DEFINE(name, size)					\
+	COND_CODE_1(CONFIG_USB_BUF_FORCE_NOCACHE,				\
+		    (USB_BUF_HEAP_DEFINE(name, size, __nocache)),		\
+		    (USB_BUF_HEAP_DEFINE(name, size, __noinit)))
 
 extern const struct net_buf_data_cb net_buf_dma_cb;
 /** @endcond */
@@ -116,9 +119,9 @@ extern const struct net_buf_data_cb net_buf_dma_cb;
  * @param ud_size    User data space to reserve per buffer.
  * @param fdestroy   Optional destroy callback when buffer is freed.
  */
-#define UDC_BUF_POOL_VAR_DEFINE(pname, count, size, ud_size, fdestroy)		\
+#define USB_BUF_POOL_VAR_DEFINE(pname, count, size, ud_size, fdestroy)		\
 	_NET_BUF_ARRAY_DEFINE(pname, count, ud_size);				\
-	UDC_K_HEAP_DEFINE(net_buf_mem_pool_##pname, size);			\
+	USB_BUF_K_HEAP_DEFINE(net_buf_mem_pool_##pname, size);			\
 	static const struct net_buf_data_alloc net_buf_data_alloc_##pname = {	\
 		.cb = &net_buf_dma_cb,						\
 		.alloc_data = &net_buf_mem_pool_##pname,			\
@@ -143,25 +146,68 @@ extern const struct net_buf_data_cb net_buf_dma_cb;
  * @param ud_size    User data space to reserve per buffer.
  * @param fdestroy   Optional destroy callback when buffer is freed.
  */
-#define UDC_BUF_POOL_DEFINE(pname, count, size, ud_size, fdestroy)		\
+#define USB_BUF_POOL_DEFINE(pname, count, size, ud_size, fdestroy)		\
 	_NET_BUF_ARRAY_DEFINE(pname, count, ud_size);				\
-	BUILD_ASSERT((UDC_BUF_GRANULARITY) % (UDC_BUF_ALIGN) == 0,		\
+	BUILD_ASSERT((USB_BUF_GRANULARITY) % (USB_BUF_ALIGN) == 0,		\
 		     "Code assumes granurality is multiple of alignment");	\
-	static uint8_t Z_UDC_BUF_SECTION __aligned(UDC_BUF_ALIGN)		\
-		net_buf_data_##pname[count][ROUND_UP(size, UDC_BUF_GRANULARITY)];\
+	static uint8_t Z_USB_BUF_SECTION __aligned(USB_BUF_ALIGN)		\
+		net_buf_data_##pname[count][USB_BUF_ROUND_UP(size)];		\
 	static const struct net_buf_pool_fixed net_buf_fixed_##pname = {	\
 		.data_pool = (uint8_t *)net_buf_data_##pname,			\
 	};									\
 	static const struct net_buf_data_alloc net_buf_fixed_alloc_##pname = {	\
 		.cb = &net_buf_fixed_cb,					\
 		.alloc_data = (void *)&net_buf_fixed_##pname,			\
-		.max_alloc_size = ROUND_UP(size, UDC_BUF_GRANULARITY),		\
+		.max_alloc_size = USB_BUF_ROUND_UP(size),			\
 	};									\
 	static STRUCT_SECTION_ITERABLE(net_buf_pool, pname) =			\
 		NET_BUF_POOL_INITIALIZER(pname, &net_buf_fixed_alloc_##pname,	\
 					 _net_buf_##pname, count, ud_size,	\
 					 fdestroy)
 
+/**
+ * @brief Buffer alignment required by the UDC driver
+ * @see USB_BUF_ALIGN
+ */
+#define UDC_BUF_ALIGN		USB_BUF_ALIGN
+
+/**
+ * @brief Buffer granularity required by the UDC driver
+ * @see USB_BUF_GRANULARITY
+ */
+#define UDC_BUF_GRANULARITY	USB_BUF_GRANULARITY
+
+/**
+ * @brief Round up to the granularity required by the UDC driver
+ * @see USB_BUF_ROUND_UP
+ */
+#define UDC_ROUND_UP(size)	USB_BUF_ROUND_UP(size)
+
+/**
+ * @brief Define a UDC driver-compliant static buffer
+ * @see USB_STATIC_BUF_DEFINE
+ */
+#define UDC_STATIC_BUF_DEFINE(name, size) USB_STATIC_BUF_DEFINE(name, size)
+
+/**
+ * @brief Verify that the buffer is aligned as required by the UDC driver
+ * @see IS_UDC_ALIGNED
+ */
+#define IS_UDC_ALIGNED(buf)	IS_USB_BUF_ALIGNED(buf)
+
+/**
+ * @brief Define a new pool for UDC buffers based on fixed-size data
+ * @see USB_BUF_POOL_VAR_DEFINE
+ */
+#define UDC_BUF_POOL_VAR_DEFINE(pname, count, size, ud_size, fdestroy)		\
+	USB_BUF_POOL_VAR_DEFINE(pname, count, size, ud_size, fdestroy)
+
+/**
+ * @brief Define a new pool for UDC buffers based on fixed-size data
+ * @see USB_BUF_POOL_DEFINE
+ */
+#define UDC_BUF_POOL_DEFINE(pname, count, size, ud_size, fdestroy)		\
+	USB_BUF_POOL_DEFINE(pname, count, size, ud_size, fdestroy)
 /**
  * @}
  */