[PATCH v4 3/6] efi_loader: Add SPI I/O protocol support

Paul Barker paul.barker at sancloud.com
Wed Oct 5 14:18:36 CEST 2022


This addition allows UEFI applications running under u-boot to access
peripherals on SPI busses. It is based on the UEFI Platform
Initialization (PI) Specification, Version 1.7 Errata A (April 2020).
Only the core functionality required to discover SPI peripherals and
communicate with them is currently implemented. Other functionality such
as the legacy SPI controller interface and the ability to update the SPI
peripheral object associated with a particular SPI I/O protocol object
is currently unimplemented.

The following protocols are defined:
* EFI_SPI_CONFIGURATION_PROTOCOL
* EFI_SPI_IO_PROTOCOL
* EFI_LEGACY_SPI_CONTROLLER_PROTOCOL

Since there are no open source implementations of these protocols to use
as an example, educated guesses/hacks have been made in cases where the
UEFI PI specification is unclear and these are documented in comments.

This implementation has been tested on the SanCloud BBE Lite and allowed
a UEFI test application to successfully communicate with a Micron
Authenta flash device connected via the SPI bus.

Signed-off-by: Paul Barker <paul.barker at sancloud.com>
---
 MAINTAINERS                       |   6 +
 include/efi_api.h                 |   4 +
 include/efi_loader.h              |   4 +
 include/efi_spi_protocol.h        | 166 +++++++++
 lib/efi_loader/Kconfig            |   8 +
 lib/efi_loader/Makefile           |   1 +
 lib/efi_loader/efi_setup.c        |   6 +
 lib/efi_loader/efi_spi_protocol.c | 590 ++++++++++++++++++++++++++++++
 lib/uuid.c                        |   4 +
 9 files changed, 789 insertions(+)
 create mode 100644 include/efi_spi_protocol.h
 create mode 100644 lib/efi_loader/efi_spi_protocol.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 83346183ee4b..40b3f1c80daa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -857,6 +857,12 @@ F:	tools/efivar.py
 F:	tools/file2include.c
 F:	tools/mkeficapsule.c
 
+EFI SPI SUPPORT
+M:	Paul Barker <paul.barker at sancloud.com>
+S:	Maintained
+F:	include/efi_spi_protocol.h
+F:	lib/efi_loader/efi_spi_protocol.c
+
 EFI VARIABLES VIA OP-TEE
 M:	Ilias Apalodimas <ilias.apalodimas at linaro.org>
 S:	Maintained
diff --git a/include/efi_api.h b/include/efi_api.h
index 9bb0d44ac8d5..eebefbe1585a 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -454,6 +454,10 @@ struct efi_runtime_services {
 	EFI_GUID(0x607f766c, 0x7455, 0x42be, 0x93, \
 		 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f)
 
+#define EFI_SPI_CONFIGURATION_GUID  \
+	EFI_GUID(0x85a6d3e6, 0xb65b, 0x4afc,     \
+		 0xb3, 0x8f, 0xc6, 0xd5, 0x4a, 0xf6, 0xdd, 0xc8)
+
 #define RISCV_EFI_BOOT_PROTOCOL_GUID \
 	EFI_GUID(0xccd15fec, 0x6f73, 0x4eec, 0x83, \
 		 0x95, 0x3e, 0x69, 0xe4, 0xb9, 0x40, 0xbf)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 4dbbb2d3a06c..18947ac6e94e 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -541,6 +541,10 @@ efi_status_t efi_rng_register(void);
 efi_status_t efi_tcg2_register(void);
 /* Called by efi_init_obj_list() to install RISCV_EFI_BOOT_PROTOCOL */
 efi_status_t efi_riscv_register(void);
+/* Called by efi_init_obj_list() to install EFI_SPI_CONFIGURATION_PROTOCOL &
+ * EFI_SPI_IO_PROTOCOL
+ */
+efi_status_t efi_spi_protocol_register(void);
 /* Called by efi_init_obj_list() to do initial measurement */
 efi_status_t efi_tcg2_do_initial_measurement(void);
 /* measure the pe-coff image, extend PCR and add Event Log */
diff --git a/include/efi_spi_protocol.h b/include/efi_spi_protocol.h
new file mode 100644
index 000000000000..1a247a6a6f85
--- /dev/null
+++ b/include/efi_spi_protocol.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: BSD-2-Clause-Patent */
+/*
+ * Copyright (c) 2017, Intel Corporation. All rights reserved.
+ * Copyright (c) 2022 Micron Technology, Inc.
+ *
+ * This header is based on code from EDK II, with modifications to match the
+ * u-boot coding style. It defines data structures for the following protocols
+ * found in the UEFI Platform Initialization (PI) Specification, version 1.7
+ * errata A:
+ *
+ *    - EFI_SPI_CONFIGURATION_PROTOCOL
+ *    - EFI_SPI_IO_PROTOCOL
+ *    - EFI_LEGACY_SPI_CONTROLLER_PROTOCOL (required by the I/O protocol as the
+ *      spec does not appear to allow the legacy_spi_protocol pointer to be NULL
+ *      in struct efi_spi_io_protocol)
+ */
+
+#ifndef _EFI_SPI_PROTOCOL_H
+#define _EFI_SPI_PROTOCOL_H
+
+#include <efi.h>
+#include <efi_api.h>
+
+struct efi_spi_peripheral;
+
+struct efi_spi_part {
+	efi_string_t vendor;
+	efi_string_t part_number;
+	u32 min_clock_hz;
+	u32 max_clock_hz;
+	bool chip_select_polarity;
+};
+
+struct efi_spi_bus {
+	efi_string_t friendly_name;
+	struct efi_spi_peripheral *peripheral_list;
+	struct efi_device_path *controller_path;
+
+	efi_status_t
+	(EFIAPI * clock)(const struct efi_spi_peripheral *spi_peripheral,
+		u32 *clock_hz);
+
+	void *clock_parameter;
+};
+
+struct efi_spi_peripheral {
+	struct efi_spi_peripheral *next_spi_peripheral;
+	efi_string_t friendly_name;
+	efi_guid_t *spi_peripheral_driver_guid;
+	struct efi_spi_part *spi_part;
+	u32 max_clock_hz;
+	bool clock_polarity;
+	bool clock_phase;
+	u32 attributes;
+	void *configuration_data;
+	struct efi_spi_bus *spi_bus;
+
+	efi_status_t
+	(EFIAPI * chip_select)(const struct efi_spi_peripheral *spi_peripheral,
+		bool pin_value);
+
+	void *chip_select_parameter;
+};
+
+struct efi_spi_configuration_protocol {
+	u32 bus_count;
+	struct efi_spi_bus **bus_list;
+};
+
+#define EFI_LEGACY_SPI_CONTROLLER_GUID  \
+	EFI_GUID(0x39136fc7, 0x1a11, 0x49de,         \
+		 0xbf, 0x35, 0x0e, 0x78, 0xdd, 0xb5, 0x24, 0xfc)
+
+struct efi_legacy_spi_controller_protocol;
+
+struct efi_legacy_spi_controller_protocol {
+	u32 maximum_offset;
+	u32 maximum_range_bytes;
+	u32 range_register_count;
+
+	efi_status_t
+	(EFIAPI * erase_block_opcode)(const struct efi_legacy_spi_controller_protocol *this,
+		u8 erase_block_opcode);
+
+	efi_status_t
+	(EFIAPI * write_status_prefix)(const struct efi_legacy_spi_controller_protocol *this,
+		u8 write_status_prefix);
+
+	efi_status_t
+	(EFIAPI * bios_base_address)(const struct efi_legacy_spi_controller_protocol *this,
+		u32 bios_base_address);
+
+	efi_status_t
+	(EFIAPI * clear_spi_protect)(const struct efi_legacy_spi_controller_protocol *this);
+
+	bool
+	(EFIAPI * is_range_protected)(const struct efi_legacy_spi_controller_protocol *this,
+		u32 bios_address,
+		u32 blocks_to_protect);
+
+	efi_status_t
+	(EFIAPI * protect_next_range)(const struct efi_legacy_spi_controller_protocol *this,
+		u32 bios_address,
+		u32 blocks_to_protect);
+
+	efi_status_t
+	(EFIAPI * lock_controller)(const struct efi_legacy_spi_controller_protocol *this);
+};
+
+struct efi_spi_io_protocol;
+
+enum efi_spi_transaction_type {
+	SPI_TRANSACTION_FULL_DUPLEX,
+	SPI_TRANSACTION_WRITE_ONLY,
+	SPI_TRANSACTION_READ_ONLY,
+	SPI_TRANSACTION_WRITE_THEN_READ
+};
+
+struct efi_spi_bus_transaction {
+	struct efi_spi_peripheral *spi_peripheral;
+	enum efi_spi_transaction_type transaction_type;
+	bool debug_transaction;
+	u32 bus_width;
+	u32 frame_size;
+	u32 write_bytes;
+	u8 *write_buffer;
+	u32 read_bytes;
+	u8 *read_buffer;
+};
+
+struct efi_spi_io_protocol {
+	struct efi_spi_peripheral *spi_peripheral;
+	struct efi_spi_peripheral *original_spi_peripheral;
+	u32 frame_size_support_mask;
+	u32 maximum_transfer_bytes;
+	u32 attributes;
+	struct efi_legacy_spi_controller_protocol *legacy_spi_protocol;
+
+	efi_status_t
+	(EFIAPI * transaction)(const struct efi_spi_io_protocol *this,
+		enum efi_spi_transaction_type transaction_type,
+		bool debug_transaction,
+		u32 clock_hz,
+		u32 bus_width,
+		u32 frame_size,
+		u32 write_bytes,
+		u8 *write_buffer,
+		u32 read_bytes,
+		u8 *read_buffer);
+
+	efi_status_t
+	(EFIAPI * update_spi_peripheral)(struct efi_spi_io_protocol *this,
+		struct efi_spi_peripheral *spi_peripheral);
+};
+
+struct efi_spi_peripheral_priv {
+	struct efi_spi_peripheral peripheral;
+	struct efi_spi_part part;
+	struct efi_spi_io_protocol io_protocol;
+	efi_handle_t handle;
+	struct spi_slave *target;
+};
+
+efi_status_t efi_spi_protocol_register(void);
+
+#endif
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index b8fb2701a74e..a9533eac4cbc 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -412,4 +412,12 @@ config EFI_RISCV_BOOT_PROTOCOL
 	  replace the transfer via the device-tree. The latter is not
 	  possible on systems using ACPI.
 
+config EFI_SPI_PROTOCOL
+	bool "EFI SPI protocol support"
+	depends on DM_SPI
+	help
+	  Provide implementations of EFI_SPI_CONFIGURATION_PROTOCOL and
+	  EFI_SPI_IO_PROTOCOL to allow UEFI applications to access devices
+	  connected via SPI bus.
+
 endif
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index e187d2a914f9..8b77dddfbb8e 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -74,6 +74,7 @@ obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += efi_smbios.o
 obj-$(CONFIG_EFI_RNG_PROTOCOL) += efi_rng.o
 obj-$(CONFIG_EFI_TCG2_PROTOCOL) += efi_tcg2.o
 obj-$(CONFIG_EFI_RISCV_BOOT_PROTOCOL) += efi_riscv.o
+obj-$(CONFIG_EFI_SPI_PROTOCOL) += efi_spi_protocol.o
 obj-$(CONFIG_EFI_LOAD_FILE2_INITRD) += efi_load_initrd.o
 obj-$(CONFIG_EFI_SIGNATURE_SUPPORT) += efi_signature.o
 obj-$(CONFIG_EFI_ECPT) += efi_conformance.o
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index c633fcd91e35..1fb7f6497b1a 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -309,6 +309,12 @@ efi_status_t efi_init_obj_list(void)
 			goto out;
 	}
 
+	if (IS_ENABLED(CONFIG_EFI_SPI_PROTOCOL)) {
+		ret = efi_spi_protocol_register();
+		if (ret != EFI_SUCCESS)
+			goto out;
+	}
+
 	/* Secure boot */
 	ret = efi_init_secure_boot();
 	if (ret != EFI_SUCCESS)
diff --git a/lib/efi_loader/efi_spi_protocol.c b/lib/efi_loader/efi_spi_protocol.c
new file mode 100644
index 000000000000..612772fce2a5
--- /dev/null
+++ b/lib/efi_loader/efi_spi_protocol.c
@@ -0,0 +1,590 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022 Micron Technology, Inc.
+ */
+
+#define LOG_CATEGORY LOGC_EFI
+
+#include <common.h>
+#include <dm/device.h>
+#include <dm/device-internal.h>
+#include <dm/read.h>
+#include <efi.h>
+#include <efi_loader.h>
+#include <efi_spi_protocol.h>
+#include <malloc.h>
+#include <spi.h>
+
+static void dump_buffer(const char *msg, u32 length, u8 *buffer)
+{
+	u32 i;
+	EFI_PRINT("%s %d bytes:", msg, length);
+	for (i = 0; i < length; i++)
+		EFI_PRINT(" %02x", buffer[i]);
+	EFI_PRINT("\n");
+}
+
+static efi_status_t EFIAPI
+efi_spi_bus_clock(const struct efi_spi_peripheral *spi_peripheral,
+		  u32 *clock_hz)
+{
+	EFI_ENTRY("%p, %p", spi_peripheral, clock_hz);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+efi_spi_peripheral_chip_select(const struct efi_spi_peripheral *spi_peripheral,
+			       bool pin_value)
+{
+	EFI_ENTRY("%p, %d", spi_peripheral, pin_value);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+legacy_erase_block_opcode(const struct efi_legacy_spi_controller_protocol *this,
+			  u8 erase_block_opcode)
+{
+	EFI_ENTRY("%p, %u", this, erase_block_opcode);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+legacy_write_status_prefix(const struct efi_legacy_spi_controller_protocol *this,
+			   u8 write_status_prefix)
+{
+	EFI_ENTRY("%p, %u", this, write_status_prefix);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+legacy_bios_base_address(const struct efi_legacy_spi_controller_protocol *this,
+			 u32 bios_base_address)
+{
+	EFI_ENTRY("%p, %u", this, bios_base_address);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+legacy_clear_spi_protect(const struct efi_legacy_spi_controller_protocol *this)
+{
+	EFI_ENTRY("%p", this);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static bool EFIAPI
+legacy_is_range_protected(const struct efi_legacy_spi_controller_protocol *this,
+			  u32 bios_address,
+			  u32 blocks_to_protect)
+{
+	EFI_ENTRY("%p, %u, %u", this, bios_address, blocks_to_protect);
+	return EFI_EXIT(false);
+}
+
+static efi_status_t EFIAPI
+legacy_protect_next_range(const struct efi_legacy_spi_controller_protocol *this,
+			  u32 bios_address,
+			  u32 blocks_to_protect)
+{
+	EFI_ENTRY("%p, %u, %u", this, bios_address, blocks_to_protect);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+legacy_lock_controller(const struct efi_legacy_spi_controller_protocol *this)
+{
+	EFI_ENTRY("%p", this);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+efi_spi_io_update_spi_peripheral(struct efi_spi_io_protocol *this,
+				 struct efi_spi_peripheral *spi_peripheral)
+{
+	EFI_ENTRY("%p, %p", this, spi_peripheral);
+	return EFI_EXIT(EFI_UNSUPPORTED);
+}
+
+static efi_status_t EFIAPI
+efi_spi_io_transaction(const struct efi_spi_io_protocol *this,
+		       enum efi_spi_transaction_type transaction_type,
+		       bool debug_transaction,
+		       u32 clock_hz,
+		       u32 bus_width,
+		       u32 frame_size,
+		       u32 write_bytes,
+		       u8 *write_buffer,
+		       u32 read_bytes,
+		       u8 *read_buffer)
+{
+	struct spi_slave *target;
+	efi_status_t status = EFI_SUCCESS;
+	int r;
+
+	/* We ignore the bus_width and frame_size arguments to this function as the
+	 * appropriate bus configuration for the connected device will be performed
+	 * during spi_claim_bus().
+	 */
+
+	/* TODO: Print transaction details if debug_transaction is true. */
+
+	EFI_ENTRY("%p, %u, %u, %u, %u, %u, %u, %p, %u, %p",
+		  this, transaction_type, debug_transaction,
+		  clock_hz, bus_width, frame_size,
+		  write_bytes, write_buffer, read_bytes, read_buffer);
+
+	if (!this)
+		return EFI_EXIT(EFI_INVALID_PARAMETER);
+
+	target = container_of(this, struct efi_spi_peripheral_priv, io_protocol)->target;
+
+	if (clock_hz > this->spi_peripheral->max_clock_hz)
+		return EFI_EXIT(EFI_UNSUPPORTED);
+
+	r = spi_claim_bus(target);
+	if (r != 0)
+		return EFI_EXIT(EFI_DEVICE_ERROR);
+	EFI_PRINT("SPI IO: Bus claimed\n");
+
+	if (clock_hz) {
+		EFI_PRINT("SPI IO: Setting clock rate to %u Hz\n", clock_hz);
+		spi_set_speed(target, clock_hz);
+	} else {
+		EFI_PRINT("SPI IO: Using default clock rate\n");
+	}
+
+	switch (transaction_type) {
+	case SPI_TRANSACTION_FULL_DUPLEX:
+		EFI_PRINT("SPI IO: Full-duplex\n");
+		if (write_bytes != read_bytes || !write_bytes || !write_buffer || !read_buffer) {
+			status = EFI_INVALID_PARAMETER;
+			break;
+		}
+		if (debug_transaction)
+			dump_buffer("SPI IO: write", write_bytes, write_buffer);
+		r = spi_xfer(target, 8 * write_bytes,
+			     write_buffer, read_buffer, SPI_XFER_ONCE);
+		EFI_PRINT("SPI IO: xfer returned %d\n", r);
+		if (debug_transaction)
+			dump_buffer("SPI IO: read", read_bytes, read_buffer);
+		status = (r == 0) ? EFI_SUCCESS : EFI_DEVICE_ERROR;
+		break;
+	case SPI_TRANSACTION_READ_ONLY:
+		EFI_PRINT("SPI IO: Read-only\n");
+		if (!read_bytes || !read_buffer) {
+			status = EFI_INVALID_PARAMETER;
+			break;
+		}
+		r = spi_xfer(target, 8 * read_bytes,
+			     NULL, read_buffer, SPI_XFER_ONCE);
+		EFI_PRINT("SPI IO: xfer returned %d\n", r);
+		if (debug_transaction)
+			dump_buffer("SPI IO: read", read_bytes, read_buffer);
+		status = (r == 0) ? EFI_SUCCESS : EFI_DEVICE_ERROR;
+		break;
+	case SPI_TRANSACTION_WRITE_ONLY:
+		EFI_PRINT("SPI IO: Write-only\n");
+		if (!write_bytes || !write_buffer) {
+			status = EFI_INVALID_PARAMETER;
+			break;
+		}
+		if (debug_transaction)
+			dump_buffer("SPI IO: write", write_bytes, write_buffer);
+		r = spi_xfer(target, 8 * write_bytes,
+			     write_buffer, NULL, SPI_XFER_ONCE);
+		EFI_PRINT("SPI IO: xfer returned %d\n", r);
+		status = (r == 0) ? EFI_SUCCESS : EFI_DEVICE_ERROR;
+		break;
+	case SPI_TRANSACTION_WRITE_THEN_READ:
+		EFI_PRINT("SPI IO: Write-then-read\n");
+		if (!write_bytes || !write_buffer || !read_bytes || !read_buffer) {
+			status = EFI_INVALID_PARAMETER;
+			break;
+		}
+		if (debug_transaction)
+			dump_buffer("SPI IO: write", write_bytes, write_buffer);
+		r = spi_xfer(target, 8 * write_bytes,
+			     write_buffer, NULL, SPI_XFER_BEGIN);
+		EFI_PRINT("SPI IO: xfer [1/2] returned %d\n", r);
+		if (r != 0) {
+			status = EFI_DEVICE_ERROR;
+			break;
+		}
+		r = spi_xfer(target, 8 * read_bytes,
+			     NULL, read_buffer, SPI_XFER_END);
+		EFI_PRINT("SPI IO: xfer [2/2] returned %d\n", r);
+		if (debug_transaction)
+			dump_buffer("SPI IO: read", read_bytes, read_buffer);
+		status = (r == 0) ? EFI_SUCCESS : EFI_DEVICE_ERROR;
+		break;
+	default:
+		status = EFI_INVALID_PARAMETER;
+		break;
+	}
+
+	spi_release_bus(target);
+	EFI_PRINT("SPI IO: Released bus\n");
+	return EFI_EXIT(status);
+}
+
+static struct efi_device_path null_device_path = {
+	.type     = DEVICE_PATH_TYPE_END,
+	.sub_type = DEVICE_PATH_SUB_TYPE_END,
+	.length   = 4
+};
+
+static struct efi_legacy_spi_controller_protocol
+dummy_legacy_spi_controller_protocol = {
+	.maximum_offset = 0,
+	.maximum_range_bytes = 0,
+	.range_register_count = 0,
+	.erase_block_opcode = legacy_erase_block_opcode,
+	.write_status_prefix = legacy_write_status_prefix,
+	.bios_base_address = legacy_bios_base_address,
+	.clear_spi_protect = legacy_clear_spi_protect,
+	.is_range_protected = legacy_is_range_protected,
+	.protect_next_range = legacy_protect_next_range,
+	.lock_controller = legacy_lock_controller
+};
+
+static efi_guid_t efi_spi_configuration_guid = EFI_SPI_CONFIGURATION_GUID;
+
+static void destroy_efi_spi_peripheral(struct efi_spi_peripheral *peripheral)
+{
+	struct efi_spi_peripheral_priv *priv =
+		container_of(peripheral,
+			     struct efi_spi_peripheral_priv,
+			     peripheral);
+	free(priv->peripheral.friendly_name);
+	free(priv->part.vendor);
+	free(priv->part.part_number);
+	free(priv);
+}
+
+static void destroy_efi_spi_bus(struct efi_spi_bus *bus)
+{
+	struct efi_spi_peripheral *peripheral = bus->peripheral_list;
+
+	while (peripheral) {
+		struct efi_spi_peripheral *next =
+			peripheral->next_spi_peripheral;
+		destroy_efi_spi_peripheral(peripheral);
+		peripheral = next;
+	}
+	free(bus->friendly_name);
+	free(bus);
+}
+
+static efi_status_t efi_spi_new_handle(const efi_guid_t *guid, void *proto)
+{
+	efi_status_t status;
+	efi_handle_t handle;
+
+	status = efi_create_handle(&handle);
+	if (status != EFI_SUCCESS) {
+		printf("Failed to create EFI handle\n");
+		goto fail_1;
+	}
+
+	status = efi_add_protocol(handle, guid, proto);
+	if (status != EFI_SUCCESS) {
+		printf("Failed to add protocol\n");
+		goto fail_2;
+	}
+
+	return EFI_SUCCESS;
+
+fail_2:
+	efi_delete_handle(handle);
+fail_1:
+	return status;
+}
+
+static void
+efi_spi_init_part(struct efi_spi_part *part,
+		  struct spi_slave *target,
+		  efi_string_t vendor_utf16,
+		  efi_string_t part_number_utf16
+)
+{
+	part->vendor = vendor_utf16;
+	part->part_number = part_number_utf16;
+	part->min_clock_hz = 0;
+	part->max_clock_hz = target->max_hz;
+	part->chip_select_polarity =
+		(target->mode & SPI_CS_HIGH) ? true : false;
+}
+
+static void
+efi_spi_init_peripheral(struct efi_spi_peripheral *peripheral,
+			struct efi_spi_part *part,
+			struct efi_spi_bus *bus,
+			struct spi_slave *target,
+			efi_guid_t *guid,
+			efi_string_t name_utf16
+)
+{
+	peripheral->friendly_name = name_utf16;
+	peripheral->spi_part = part;
+	peripheral->next_spi_peripheral = NULL;
+	peripheral->spi_peripheral_driver_guid = guid;
+	peripheral->max_clock_hz = target->max_hz;
+	peripheral->clock_polarity = (target->mode & SPI_CPOL) ? true : false;
+	peripheral->clock_phase = (target->mode & SPI_CPHA) ? true : false;
+	peripheral->attributes = 0;
+	peripheral->configuration_data = NULL;
+	peripheral->spi_bus = bus;
+	peripheral->chip_select = efi_spi_peripheral_chip_select;
+	peripheral->chip_select_parameter = NULL;
+}
+
+static void
+efi_spi_append_peripheral(struct efi_spi_peripheral *peripheral,
+			  struct efi_spi_bus *bus
+)
+{
+	if (bus->peripheral_list) {
+		struct efi_spi_peripheral *tmp = bus->peripheral_list;
+
+		while (tmp->next_spi_peripheral)
+			tmp = tmp->next_spi_peripheral;
+
+		tmp->next_spi_peripheral = peripheral;
+	} else {
+		bus->peripheral_list = peripheral;
+	}
+}
+
+static void
+efi_spi_init_io_protocol(struct efi_spi_io_protocol *io_protocol,
+			 struct efi_spi_peripheral *peripheral,
+			 struct spi_slave *target
+)
+{
+	u32 max_read, max_write;
+
+	io_protocol->spi_peripheral = peripheral;
+	io_protocol->original_spi_peripheral = peripheral;
+	io_protocol->legacy_spi_protocol = &dummy_legacy_spi_controller_protocol;
+	io_protocol->transaction = efi_spi_io_transaction;
+	io_protocol->update_spi_peripheral = efi_spi_io_update_spi_peripheral;
+
+	/* This is a bit of a hack. The EFI data structures do not allow us to
+	 * represent a frame size greater than 32 bits.
+	 */
+	if (target->wordlen <= 32)
+		io_protocol->frame_size_support_mask =
+			1 << (target->wordlen - 1);
+	else
+		io_protocol->frame_size_support_mask = 0;
+
+	/* Again, this is a bit of a hack. The EFI data structures only allow
+	 * for a single maximum transfer size whereas the u-boot spi_slave
+	 * structure records maximum read transfer size and maximum write
+	 * transfer size separately. So we need to take the minimum of these two
+	 * values.
+	 *
+	 * In u-boot, a value of zero for these fields means there is no limit
+	 * on the transfer size. However in the UEFI PI spec a value of zero is
+	 * invalid so we'll use 0xFFFFFFFF as a substitute unlimited value.
+	 */
+	max_write = target->max_write_size ? target->max_write_size : 0xFFFFFFFF;
+	max_read = target->max_read_size ? target->max_read_size : 0xFFFFFFFF;
+	io_protocol->maximum_transfer_bytes = (max_read > max_write) ? max_write : max_read;
+
+	/* Hack++. Leave attributes set to zero since the flags listed in the
+	 * UEFI PI spec have no defined numerical values and so cannot be used.
+	 */
+	io_protocol->attributes = 0;
+}
+
+static efi_status_t
+export_spi_peripheral(struct efi_spi_bus *bus, struct udevice *dev)
+{
+	efi_string_t name_utf16, vendor_utf16, part_number_utf16;
+	struct efi_spi_peripheral_priv *priv;
+	efi_status_t status;
+	struct udevice *dev_bus = dev->parent;
+	struct spi_slave *target;
+	const char *name = dev_read_name(dev);
+	const char *vendor = dev_read_string(dev, "uefi-spi-vendor");
+	const char *part_number = dev_read_string(dev, "uefi-spi-part-number");
+	efi_guid_t *guid =
+		(efi_guid_t *)dev_read_u8_array_ptr(dev, "uefi-spi-io-guid", 16);
+
+	if (device_get_uclass_id(dev) == UCLASS_SPI_EMUL) {
+		debug("Skipping emulated SPI peripheral %s\n", name);
+		goto fail_1;
+	}
+
+	if (!vendor || !part_number || !guid) {
+		debug("Skipping SPI peripheral %s\n", name);
+		status = EFI_UNSUPPORTED;
+		goto fail_1;
+	}
+
+	if (!device_active(dev)) {
+		int ret = device_probe(dev);
+		if (ret) {
+			debug("Skipping SPI peripheral %s, probe failed\n", name);
+			goto fail_1;
+		}
+	}
+
+	target = dev_get_parent_priv(dev);
+	if (!target) {
+		debug("Skipping uninitialized SPI peripheral %s\n", name);
+		status = EFI_UNSUPPORTED;
+		goto fail_1;
+	}
+
+	debug("Registering SPI dev %d:%d, name %s\n",
+	      dev_bus->seq_, spi_chip_select(dev), name);
+
+	priv = calloc(1, sizeof(*priv));
+	if (!priv) {
+		status = EFI_OUT_OF_RESOURCES;
+		goto fail_1;
+	}
+
+	vendor_utf16 = efi_convert_string(vendor);
+	if (!vendor_utf16) {
+		status = EFI_OUT_OF_RESOURCES;
+		goto fail_2;
+	}
+
+	part_number_utf16 = efi_convert_string(part_number);
+	if (!part_number_utf16) {
+		status = EFI_OUT_OF_RESOURCES;
+		goto fail_3;
+	}
+
+	name_utf16 = efi_convert_string(name);
+	if (!name_utf16) {
+		status = EFI_OUT_OF_RESOURCES;
+		goto fail_4;
+	}
+
+	priv->target = target;
+
+	efi_spi_init_part(&priv->part, target, vendor_utf16, part_number_utf16);
+
+	efi_spi_init_peripheral(&priv->peripheral, &priv->part,
+				bus, target, guid, name_utf16);
+
+	efi_spi_append_peripheral(&priv->peripheral, bus);
+
+	efi_spi_init_io_protocol(&priv->io_protocol, &priv->peripheral, target);
+
+	status = efi_spi_new_handle(guid, &priv->io_protocol);
+	if (status != EFI_SUCCESS)
+		goto fail_5;
+
+	debug("Added EFI_SPI_IO_PROTOCOL for %s with guid %pUl\n", name, guid);
+	return EFI_SUCCESS;
+
+fail_5:
+	free(name_utf16);
+fail_4:
+	free(part_number_utf16);
+fail_3:
+	free(vendor_utf16);
+fail_2:
+	free(priv);
+fail_1:
+	return status;
+}
+
+static struct efi_spi_bus *export_spi_bus(int i)
+{
+	struct efi_spi_bus *bus;
+	struct udevice *dev, *child;
+	const char *name;
+	int r;
+
+	r = uclass_get_device(UCLASS_SPI, i, &dev);
+	if (r < 0) {
+		printf("Failed to get SPI bus %d\n", i);
+		goto fail_1;
+	}
+
+	name = dev_read_name(dev);
+	debug("Registering SPI bus %d, name %s\n", i, name);
+
+	bus = calloc(1, sizeof(*bus));
+	if (!bus)
+		goto fail_1;
+
+	bus->friendly_name = efi_convert_string(name);
+	if (!bus->friendly_name)
+		goto fail_2;
+
+	bus->peripheral_list = NULL;
+	bus->clock = efi_spi_bus_clock;
+	bus->clock_parameter = NULL;
+
+	/* For the purposes of the current implementation, we do not need to expose
+	 * the hardware device path to users of the SPI I/O protocol.
+	 */
+	bus->controller_path = &null_device_path;
+
+	device_foreach_child(child, dev) {
+		efi_status_t status = export_spi_peripheral(bus, child);
+
+		if (status == EFI_OUT_OF_RESOURCES)
+			goto fail_3;
+	}
+
+	return bus;
+
+fail_3:
+	destroy_efi_spi_bus(bus);
+fail_2:
+	free(bus);
+fail_1:
+	return NULL;
+}
+
+efi_status_t efi_spi_protocol_register(void)
+{
+	efi_status_t status;
+	struct efi_spi_configuration_protocol *proto;
+	uint i;
+
+	printf("Registering EFI_SPI_CONFIGURATION_PROTOCOL\n");
+
+	proto = calloc(1, sizeof(*proto));
+	if (!proto) {
+		status = EFI_OUT_OF_RESOURCES;
+		goto fail_1;
+	}
+
+	proto->bus_count = uclass_id_count(UCLASS_SPI);
+	proto->bus_list = calloc(proto->bus_count, sizeof(*proto->bus_list));
+	if (!proto->bus_list) {
+		status = EFI_OUT_OF_RESOURCES;
+		goto fail_2;
+	}
+
+	for (i = 0; i < proto->bus_count; i++) {
+		proto->bus_list[i] = export_spi_bus(i);
+		if (!proto->bus_list[i])
+			goto fail_3;
+	}
+
+	status = efi_spi_new_handle(&efi_spi_configuration_guid, proto);
+	if (status != EFI_SUCCESS)
+		goto fail_3;
+
+	return EFI_SUCCESS;
+
+fail_3:
+	for (i = 0; i < proto->bus_count; i++) {
+		if (proto->bus_list[i])
+			destroy_efi_spi_bus(proto->bus_list[i]);
+	}
+	free(proto->bus_list);
+fail_2:
+	free(proto);
+fail_1:
+	return status;
+}
diff --git a/lib/uuid.c b/lib/uuid.c
index 465e1ac38f57..3f723b732588 100644
--- a/lib/uuid.c
+++ b/lib/uuid.c
@@ -187,6 +187,10 @@ static const struct {
 		"TCG2",
 		EFI_TCG2_PROTOCOL_GUID,
 		},
+	{
+		"SPI Protocol Stack",
+		EFI_SPI_CONFIGURATION_GUID
+	},
 	{
 		"System Partition",
 		PARTITION_SYSTEM_GUID
-- 
2.25.1



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