feat(plat/st/stm32mp1): add STM32MP_USB_PROGRAMMER target

Add a support of USB as serial boot devices for STM32MP15x platform:
the FIP file is provide by STM32CubeProgrammer with the DFU protocol,
loaded in DDR at DWL_BUFFER_BASE address and then the io memmap is used.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Change-Id: I272c17c458ff1e9d0780f8fa22330c8a35533d19
diff --git a/plat/st/stm32mp1/bl2_plat_setup.c b/plat/st/stm32mp1/bl2_plat_setup.c
index e87c529..7eaf0ed 100644
--- a/plat/st/stm32mp1/bl2_plat_setup.c
+++ b/plat/st/stm32mp1/bl2_plat_setup.c
@@ -490,5 +490,19 @@
 
 void bl2_el3_plat_prepare_exit(void)
 {
+	uint16_t boot_itf = stm32mp_get_boot_itf_selected();
+
+	switch (boot_itf) {
+#if STM32MP_USB_PROGRAMMER
+	case BOOT_API_CTX_BOOT_INTERFACE_SEL_SERIAL_USB:
+		/* Invalidate the downloaded buffer used with io_memmap */
+		inv_dcache_range(DWL_BUFFER_BASE, DWL_BUFFER_SIZE);
+		break;
+#endif
+	default:
+		/* Do nothing in default case */
+		break;
+	}
+
 	stm32mp1_security_setup();
 }
diff --git a/plat/st/stm32mp1/include/boot_api.h b/plat/st/stm32mp1/include/boot_api.h
index c16639a..52b1d1a 100644
--- a/plat/st/stm32mp1/include/boot_api.h
+++ b/plat/st/stm32mp1/include/boot_api.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019, STMicroelectronics - All Rights Reserved
+ * Copyright (c) 2017-2021, STMicroelectronics - All Rights Reserved
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -39,6 +39,9 @@
 /* Boot occurred on QSPI NOR */
 #define BOOT_API_CTX_BOOT_INTERFACE_SEL_FLASH_NOR_QSPI		0x4U
 
+/* Boot occurred on USB */
+#define BOOT_API_CTX_BOOT_INTERFACE_SEL_SERIAL_USB		0x6U
+
 /* Boot occurred on QSPI NAND */
 #define BOOT_API_CTX_BOOT_INTERFACE_SEL_FLASH_NAND_QSPI		0x7U
 
diff --git a/plat/st/stm32mp1/include/platform_def.h b/plat/st/stm32mp1/include/platform_def.h
index 8a065bf..1e9443e 100644
--- a/plat/st/stm32mp1/include/platform_def.h
+++ b/plat/st/stm32mp1/include/platform_def.h
@@ -92,6 +92,10 @@
  */
 #define PLAT_STM32MP_NS_IMAGE_OFFSET	BL33_BASE
 
+/* Needed by STM32CubeProgrammer support */
+#define DWL_BUFFER_BASE			(STM32MP_DDR_BASE + U(0x08000000))
+#define DWL_BUFFER_SIZE			U(0x08000000)
+
 /*
  * SSBL offset in case it's stored in eMMC boot partition.
  * We can fix it to 256K because TF-A size can't be bigger than SRAM
diff --git a/plat/st/stm32mp1/platform.mk b/plat/st/stm32mp1/platform.mk
index 14f90d4..c8c2e5f 100644
--- a/plat/st/stm32mp1/platform.mk
+++ b/plat/st/stm32mp1/platform.mk
@@ -53,6 +53,9 @@
 STM32MP_SPI_NOR		?=	0
 STM32MP_EMMC_BOOT	?=	0
 
+# Serial boot devices
+STM32MP_USB_PROGRAMMER	?=	0
+
 # Device tree
 DTB_FILE_NAME		?=	stm32mp157c-ev1.dtb
 ifeq ($(STM32MP_USE_STM32IMAGE),1)
@@ -127,6 +130,7 @@
 		STM32MP_SPI_NOR \
 		STM32MP_EMMC_BOOT \
 		PLAT_XLAT_TABLES_DYNAMIC \
+		STM32MP_USB_PROGRAMMER \
 		STM32MP_USE_STM32IMAGE \
 )))
 
@@ -147,6 +151,7 @@
 		PLAT_XLAT_TABLES_DYNAMIC \
 		STM32_TF_A_COPIES \
 		PLAT_PARTITION_MAX_ENTRIES \
+		STM32MP_USB_PROGRAMMER \
 		STM32MP_USE_STM32IMAGE \
 )))
 
@@ -251,6 +256,17 @@
 BL2_SOURCES		+=	plat/st/stm32mp1/stm32mp1_boot_device.c
 endif
 
+ifeq (${STM32MP_USB_PROGRAMMER},1)
+#The DFU stack uses only one end point, reduce the USB stack footprint
+$(eval $(call add_define_val,CONFIG_USBD_EP_NB,1U))
+BL2_SOURCES		+=	drivers/io/io_memmap.c					\
+				drivers/st/usb/stm32mp1_usb.c				\
+				drivers/usb/usb_device.c				\
+				plat/st/common/stm32cubeprogrammer_usb.c		\
+				plat/st/common/usb_dfu.c					\
+				plat/st/stm32mp1/stm32mp1_usb_dfu.c
+endif
+
 BL2_SOURCES		+=	drivers/st/ddr/stm32mp1_ddr.c				\
 				drivers/st/ddr/stm32mp1_ram.c
 
@@ -274,7 +290,8 @@
 	    [ ${STM32MP_SDMMC} != 1 ] && \
 	    [ ${STM32MP_RAW_NAND} != 1 ] && \
 	    [ ${STM32MP_SPI_NAND} != 1 ] && \
-	    [ ${STM32MP_SPI_NOR} != 1 ]; then \
+	    [ ${STM32MP_SPI_NOR} != 1 ] && \
+	    [ ${STM32MP_USB_PROGRAMMER} != 1 ]; then \
 		echo "No boot device driver is enabled"; \
 		false; \
 	fi