[PATCH v5 0/3] Move qfw to DM, add Arm support

[PATCH v5 0/3] Move qfw to DM, add Arm support

[Asherah Connor]

This series moves the QFW driver into a uclass, UCLASS_QFW, and splits
the driver into qfw_pio and qfw_mmio.  Each driver is selected on the
appropriate QEMU board.  A sandbox driver is also added, and a DM unit
test against that driver.  The qfw command is tested in QEMU, and
documentation added.

Version 5 reworks the series into three patches:
1. Do the DM conversion of existing QFW on x86
2. Add MMIO driver
3. Add the MMIO driver to qemu-arm

To view the changes online, see:
https://git.src.kameliya.ee/~kameliya/u-boot/log/qfw-priv

Changes in v5:
* Split conversion of existing x86-only QFW to DM into its own patch.
* Split MMIO driver into its own commit.
* Split adding MMIO driver to QEMU arm/64 into own commit.

Asherah Connor (3):
  x86: qemu: move QFW to its own uclass
  qemu: add MMIO driver for QFW
  qemu: arm: select QFW, MMIO on qemu-arm

 arch/x86/cpu/qemu/cpu.c          |   9 +-
 arch/x86/cpu/qemu/qemu.c         |  49 +------
 arch/x86/cpu/qfw_cpu.c           |  11 +-
 board/emulation/qemu-arm/Kconfig |   2 +
 board/emulation/qemu-x86/Kconfig |   1 +
 cmd/qfw.c                        |  56 ++++---
 common/Makefile                  |   2 +
 common/qfw.c                     | 105 +++++++++++++
 drivers/misc/Kconfig             |  18 ++-
 drivers/misc/Makefile            |   7 +-
 drivers/misc/qfw.c               | 243 +++++++++++--------------------
 drivers/misc/qfw_mmio.c          | 119 +++++++++++++++
 drivers/misc/qfw_pio.c           |  69 +++++++++
 drivers/misc/qfw_sandbox.c       | 128 ++++++++++++++++
 include/dm/uclass-id.h           |   1 +
 include/qfw.h                    | 200 +++++++++++++++++++++----
 test/dm/Makefile                 |   1 +
 test/dm/qfw.c                    |  42 ++++++
 test/py/tests/test_qfw.py        |  21 +++
 19 files changed, 812 insertions(+), 272 deletions(-)
 create mode 100644 common/qfw.c
 create mode 100644 drivers/misc/qfw_mmio.c
 create mode 100644 drivers/misc/qfw_pio.c
 create mode 100644 drivers/misc/qfw_sandbox.c
 create mode 100644 test/dm/qfw.c
 create mode 100644 test/py/tests/test_qfw.py

-- 
2.20.1

[PATCH v5 1/3] x86: qemu: move QFW to its own uclass

[Asherah Connor]

We move qfw into its own uclass and split the PIO functions into a
specific driver for that uclass.  The PIO driver is selected in the
qemu-x86 board config (this covers x86 and x86_64).

A sandbox driver and test are added for the uclass, and a test in QEMU
added for qfw functionality to confirm it doesn't break in real world
use.

include/qfw.h is cleaned up and documentation added.

Signed-off-by: Asherah Connor <ashe@kivikakk.ee>

---

Changes in v5:
* Split conversion of existing x86-only QFW to DM into its own patch.
* Fix qfw_get_dev() so it actually returns -ENODEV when device is
  missing.
* Add CONFIG_QFW_PIO.
* Choose CONFIG_QFW_PIO in board/emulation/qemu-x86/Kconfig.
* QFW sandbox driver no longer inserts itself from device tree; wasn't
  relevant to implementation and the ``compatible'' string was too
  made-up.  Use U_BOOT_DRVINFO like the other QFW driver in this patch.
* Relevant documentation and sandbox/qemu tests are now here.

 arch/x86/cpu/qemu/cpu.c          |   9 +-
 arch/x86/cpu/qemu/qemu.c         |  49 +------
 arch/x86/cpu/qfw_cpu.c           |  11 +-
 board/emulation/qemu-x86/Kconfig |   1 +
 cmd/qfw.c                        |  56 ++++---
 common/Makefile                  |   2 +
 common/qfw.c                     | 105 +++++++++++++
 drivers/misc/Kconfig             |  11 +-
 drivers/misc/Makefile            |   6 +-
 drivers/misc/qfw.c               | 243 +++++++++++--------------------
 drivers/misc/qfw_pio.c           |  69 +++++++++
 drivers/misc/qfw_sandbox.c       | 128 ++++++++++++++++
 include/dm/uclass-id.h           |   1 +
 include/qfw.h                    | 200 +++++++++++++++++++++----
 test/dm/Makefile                 |   1 +
 test/dm/qfw.c                    |  42 ++++++
 test/py/tests/test_qfw.py        |  21 +++
 17 files changed, 683 insertions(+), 272 deletions(-)
 create mode 100644 common/qfw.c
 create mode 100644 drivers/misc/qfw_pio.c
 create mode 100644 drivers/misc/qfw_sandbox.c
 create mode 100644 test/dm/qfw.c
 create mode 100644 test/py/tests/test_qfw.py

diff --git a/arch/x86/cpu/qemu/cpu.c b/arch/x86/cpu/qemu/cpu.c
index 9ce86b379c..735b656084 100644
--- a/arch/x86/cpu/qemu/cpu.c
+++ b/arch/x86/cpu/qemu/cpu.c
@@ -22,7 +22,14 @@ int cpu_qemu_get_desc(const struct udevice *dev, char *buf, int size)
 
 static int cpu_qemu_get_count(const struct udevice *dev)
 {
-	return qemu_fwcfg_online_cpus();
+	int ret;
+	struct udevice *qfw_dev;
+
+	ret = qfw_get_dev(&qfw_dev);
+	if (ret)
+		return ret;
+
+	return qfw_online_cpus(qfw_dev);
 }
 
 static const struct cpu_ops cpu_qemu_ops = {
diff --git a/arch/x86/cpu/qemu/qemu.c b/arch/x86/cpu/qemu/qemu.c
index 044a429c13..e54082df7f 100644
--- a/arch/x86/cpu/qemu/qemu.c
+++ b/arch/x86/cpu/qemu/qemu.c
@@ -8,6 +8,7 @@
 #include <init.h>
 #include <pci.h>
 #include <qfw.h>
+#include <dm/platdata.h>
 #include <asm/irq.h>
 #include <asm/post.h>
 #include <asm/processor.h>
@@ -16,47 +17,9 @@
 
 static bool i440fx;
 
-#ifdef CONFIG_QFW
-
-/* on x86, the qfw registers are all IO ports */
-#define FW_CONTROL_PORT	0x510
-#define FW_DATA_PORT		0x511
-#define FW_DMA_PORT_LOW	0x514
-#define FW_DMA_PORT_HIGH	0x518
-
-static void qemu_x86_fwcfg_read_entry_pio(uint16_t entry,
-		uint32_t size, void *address)
-{
-	uint32_t i = 0;
-	uint8_t *data = address;
-
-	/*
-	 * writting FW_CFG_INVALID will cause read operation to resume at
-	 * last offset, otherwise read will start at offset 0
-	 *
-	 * Note: on platform where the control register is IO port, the
-	 * endianness is little endian.
-	 */
-	if (entry != FW_CFG_INVALID)
-		outw(cpu_to_le16(entry), FW_CONTROL_PORT);
-
-	/* the endianness of data register is string-preserving */
-	while (size--)
-		data[i++] = inb(FW_DATA_PORT);
-}
-
-static void qemu_x86_fwcfg_read_entry_dma(struct fw_cfg_dma_access *dma)
-{
-	/* the DMA address register is big endian */
-	outl(cpu_to_be32((uintptr_t)dma), FW_DMA_PORT_HIGH);
-
-	while (be32_to_cpu(dma->control) & ~FW_CFG_DMA_ERROR)
-		__asm__ __volatile__ ("pause");
-}
-
-static struct fw_cfg_arch_ops fwcfg_x86_ops = {
-	.arch_read_pio = qemu_x86_fwcfg_read_entry_pio,
-	.arch_read_dma = qemu_x86_fwcfg_read_entry_dma
+#if CONFIG_IS_ENABLED(QFW_PIO)
+U_BOOT_DRVINFO(x86_qfw_pio) = {
+	.name = "qfw_pio",
 };
 #endif
 
@@ -132,10 +95,6 @@ static void qemu_chipset_init(void)
 
 		enable_pm_ich9();
 	}
-
-#ifdef CONFIG_QFW
-	qemu_fwcfg_init(&fwcfg_x86_ops);
-#endif
 }
 
 #if !CONFIG_IS_ENABLED(SPL_X86_32BIT_INIT)
diff --git a/arch/x86/cpu/qfw_cpu.c b/arch/x86/cpu/qfw_cpu.c
index b959eaddde..ee00b8fe73 100644
--- a/arch/x86/cpu/qfw_cpu.c
+++ b/arch/x86/cpu/qfw_cpu.c
@@ -18,7 +18,7 @@ int qemu_cpu_fixup(void)
 	int cpu_num;
 	int cpu_online;
 	struct uclass *uc;
-	struct udevice *dev, *pdev;
+	struct udevice *dev, *pdev, *qfwdev;
 	struct cpu_plat *plat;
 	char *cpu;
 
@@ -39,6 +39,13 @@ int qemu_cpu_fixup(void)
 		return -ENODEV;
 	}
 
+	/* get qfw dev */
+	ret = qfw_get_dev(&qfwdev);
+	if (ret) {
+		printf("unable to find qfw device\n");
+		return ret;
+	}
+
 	/* calculate cpus that are already bound */
 	cpu_num = 0;
 	for (uclass_find_first_device(UCLASS_CPU, &dev);
@@ -48,7 +55,7 @@ int qemu_cpu_fixup(void)
 	}
 
 	/* get actual cpu number */
-	cpu_online = qemu_fwcfg_online_cpus();
+	cpu_online = qfw_online_cpus(qfwdev);
 	if (cpu_online < 0) {
 		printf("unable to get online cpu number: %d\n", cpu_online);
 		return cpu_online;
diff --git a/board/emulation/qemu-x86/Kconfig b/board/emulation/qemu-x86/Kconfig
index 6d19299d8b..9bb8a726ed 100644
--- a/board/emulation/qemu-x86/Kconfig
+++ b/board/emulation/qemu-x86/Kconfig
@@ -20,6 +20,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select X86_RESET_VECTOR
 	select QEMU
+	select QFW_PIO
 	select BOARD_ROMSIZE_KB_1024
 	imply VIRTIO_PCI
 	imply VIRTIO_NET
diff --git a/cmd/qfw.c b/cmd/qfw.c
index bb571487f0..e6a9fdb2af 100644
--- a/cmd/qfw.c
+++ b/cmd/qfw.c
@@ -8,19 +8,22 @@
 #include <env.h>
 #include <errno.h>
 #include <qfw.h>
+#include <dm.h>
+
+static struct udevice *qfw_dev;
 
 /*
  * This function prepares kernel for zboot. It loads kernel data
  * to 'load_addr', initrd to 'initrd_addr' and kernel command
  * line using qemu fw_cfg interface.
  */
-static int qemu_fwcfg_setup_kernel(void *load_addr, void *initrd_addr)
+static int qemu_fwcfg_cmd_setup_kernel(void *load_addr, void *initrd_addr)
 {
 	char *data_addr;
 	uint32_t setup_size, kernel_size, cmdline_size, initrd_size;
 
-	qemu_fwcfg_read_entry(FW_CFG_SETUP_SIZE, 4, &setup_size);
-	qemu_fwcfg_read_entry(FW_CFG_KERNEL_SIZE, 4, &kernel_size);
+	qfw_read_entry(qfw_dev, FW_CFG_SETUP_SIZE, 4, &setup_size);
+	qfw_read_entry(qfw_dev, FW_CFG_KERNEL_SIZE, 4, &kernel_size);
 
 	if (setup_size == 0 || kernel_size == 0) {
 		printf("warning: no kernel available\n");
@@ -28,28 +31,28 @@ static int qemu_fwcfg_setup_kernel(void *load_addr, void *initrd_addr)
 	}
 
 	data_addr = load_addr;
-	qemu_fwcfg_read_entry(FW_CFG_SETUP_DATA,
-			      le32_to_cpu(setup_size), data_addr);
+	qfw_read_entry(qfw_dev, FW_CFG_SETUP_DATA,
+		       le32_to_cpu(setup_size), data_addr);
 	data_addr += le32_to_cpu(setup_size);
 
-	qemu_fwcfg_read_entry(FW_CFG_KERNEL_DATA,
-			      le32_to_cpu(kernel_size), data_addr);
+	qfw_read_entry(qfw_dev, FW_CFG_KERNEL_DATA,
+		       le32_to_cpu(kernel_size), data_addr);
 	data_addr += le32_to_cpu(kernel_size);
 
 	data_addr = initrd_addr;
-	qemu_fwcfg_read_entry(FW_CFG_INITRD_SIZE, 4, &initrd_size);
+	qfw_read_entry(qfw_dev, FW_CFG_INITRD_SIZE, 4, &initrd_size);
 	if (initrd_size == 0) {
 		printf("warning: no initrd available\n");
 	} else {
-		qemu_fwcfg_read_entry(FW_CFG_INITRD_DATA,
-				      le32_to_cpu(initrd_size), data_addr);
+		qfw_read_entry(qfw_dev, FW_CFG_INITRD_DATA,
+			       le32_to_cpu(initrd_size), data_addr);
 		data_addr += le32_to_cpu(initrd_size);
 	}
 
-	qemu_fwcfg_read_entry(FW_CFG_CMDLINE_SIZE, 4, &cmdline_size);
+	qfw_read_entry(qfw_dev, FW_CFG_CMDLINE_SIZE, 4, &cmdline_size);
 	if (cmdline_size) {
-		qemu_fwcfg_read_entry(FW_CFG_CMDLINE_DATA,
-				      le32_to_cpu(cmdline_size), data_addr);
+		qfw_read_entry(qfw_dev, FW_CFG_CMDLINE_DATA,
+			       le32_to_cpu(cmdline_size), data_addr);
 		/*
 		 * if kernel cmdline only contains '\0', (e.g. no -append
 		 * when invoking qemu), do not update bootargs
@@ -72,21 +75,20 @@ static int qemu_fwcfg_setup_kernel(void *load_addr, void *initrd_addr)
 	return 0;
 }
 
-static int qemu_fwcfg_list_firmware(void)
+static int qemu_fwcfg_cmd_list_firmware(void)
 {
 	int ret;
 	struct fw_cfg_file_iter iter;
 	struct fw_file *file;
 
 	/* make sure fw_list is loaded */
-	ret = qemu_fwcfg_read_firmware_list();
+	ret = qfw_read_firmware_list(qfw_dev);
 	if (ret)
 		return ret;
 
-
-	for (file = qemu_fwcfg_file_iter_init(&iter);
-	     !qemu_fwcfg_file_iter_end(&iter);
-	     file = qemu_fwcfg_file_iter_next(&iter)) {
+	for (file = qfw_file_iter_init(qfw_dev, &iter);
+	     !qfw_file_iter_end(&iter);
+	     file = qfw_file_iter_next(&iter)) {
 		printf("%-56s\n", file->cfg.name);
 	}
 
@@ -96,7 +98,7 @@ static int qemu_fwcfg_list_firmware(void)
 static int qemu_fwcfg_do_list(struct cmd_tbl *cmdtp, int flag,
 			      int argc, char *const argv[])
 {
-	if (qemu_fwcfg_list_firmware() < 0)
+	if (qemu_fwcfg_cmd_list_firmware() < 0)
 		return CMD_RET_FAILURE;
 
 	return 0;
@@ -105,14 +107,7 @@ static int qemu_fwcfg_do_list(struct cmd_tbl *cmdtp, int flag,
 static int qemu_fwcfg_do_cpus(struct cmd_tbl *cmdtp, int flag,
 			      int argc, char *const argv[])
 {
-	int ret = qemu_fwcfg_online_cpus();
-	if (ret < 0) {
-		printf("QEMU fw_cfg interface not found\n");
-		return CMD_RET_FAILURE;
-	}
-
-	printf("%d cpu(s) online\n", qemu_fwcfg_online_cpus());
-
+	printf("%d cpu(s) online\n", qfw_online_cpus(qfw_dev));
 	return 0;
 }
 
@@ -153,7 +148,7 @@ static int qemu_fwcfg_do_load(struct cmd_tbl *cmdtp, int flag,
 		return CMD_RET_FAILURE;
 	}
 
-	return qemu_fwcfg_setup_kernel(load_addr, initrd_addr);
+	return qemu_fwcfg_cmd_setup_kernel(load_addr, initrd_addr);
 }
 
 static struct cmd_tbl fwcfg_commands[] = {
@@ -168,7 +163,8 @@ static int do_qemu_fw(struct cmd_tbl *cmdtp, int flag, int argc,
 	int ret;
 	struct cmd_tbl *fwcfg_cmd;
 
-	if (!qemu_fwcfg_present()) {
+	ret = qfw_get_dev(&qfw_dev);
+	if (ret) {
 		printf("QEMU fw_cfg interface not found\n");
 		return CMD_RET_USAGE;
 	}
diff --git a/common/Makefile b/common/Makefile
index daeea67cf2..f174a06c33 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -137,3 +137,5 @@ obj-$(CONFIG_CMD_LOADB) += xyzModem.o
 obj-$(CONFIG_$(SPL_TPL_)YMODEM_SUPPORT) += xyzModem.o
 
 obj-$(CONFIG_AVB_VERIFY) += avb_verify.o
+
+obj-$(CONFIG_QFW) += qfw.o
diff --git a/common/qfw.c b/common/qfw.c
new file mode 100644
index 0000000000..9a1d1eda5f
--- /dev/null
+++ b/common/qfw.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
+ */
+
+#include <dm.h>
+#include <dm/uclass.h>
+#include <qfw.h>
+#include <stdlib.h>
+
+int qfw_get_dev(struct udevice **devp)
+{
+	return uclass_first_device_err(UCLASS_QFW, devp);
+}
+
+int qfw_online_cpus(struct udevice *dev)
+{
+	u16 nb_cpus;
+
+	qfw_read_entry(dev, FW_CFG_NB_CPUS, 2, &nb_cpus);
+
+	return le16_to_cpu(nb_cpus);
+}
+
+int qfw_read_firmware_list(struct udevice *dev)
+{
+	int i;
+	u32 count;
+	struct fw_file *file;
+	struct list_head *entry;
+
+	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
+
+	/* don't read it twice */
+	if (!list_empty(&qdev->fw_list))
+		return 0;
+
+	qfw_read_entry(dev, FW_CFG_FILE_DIR, 4, &count);
+	if (!count)
+		return 0;
+
+	count = be32_to_cpu(count);
+	for (i = 0; i < count; i++) {
+		file = malloc(sizeof(*file));
+		if (!file) {
+			printf("error: allocating resource\n");
+			goto err;
+		}
+		qfw_read_entry(dev, FW_CFG_INVALID,
+			       sizeof(struct fw_cfg_file), &file->cfg);
+		file->addr = 0;
+		list_add_tail(&file->list, &qdev->fw_list);
+	}
+
+	return 0;
+
+err:
+	list_for_each(entry, &qdev->fw_list) {
+		file = list_entry(entry, struct fw_file, list);
+		free(file);
+	}
+
+	return -ENOMEM;
+}
+
+struct fw_file *qfw_find_file(struct udevice *dev, const char *name)
+{
+	struct list_head *entry;
+	struct fw_file *file;
+
+	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
+
+	list_for_each(entry, &qdev->fw_list) {
+		file = list_entry(entry, struct fw_file, list);
+		if (!strcmp(file->cfg.name, name))
+			return file;
+	}
+
+	return NULL;
+}
+
+struct fw_file *qfw_file_iter_init(struct udevice *dev,
+				   struct fw_cfg_file_iter *iter)
+{
+	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
+
+	iter->entry = qdev->fw_list.next;
+	iter->end = &qdev->fw_list;
+	return list_entry((struct list_head *)iter->entry,
+			  struct fw_file, list);
+}
+
+struct fw_file *qfw_file_iter_next(struct fw_cfg_file_iter *iter)
+{
+	iter->entry = ((struct list_head *)iter->entry)->next;
+	return list_entry((struct list_head *)iter->entry,
+			  struct fw_file, list);
+}
+
+bool qfw_file_iter_end(struct fw_cfg_file_iter *iter)
+{
+	return iter->entry == iter->end;
+}
+
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 7d2a299779..3a254eba4b 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -368,8 +368,15 @@ config WINBOND_W83627
 config QFW
 	bool
 	help
-	  Hidden option to enable QEMU fw_cfg interface. This will be selected by
-	  either CONFIG_CMD_QFW or CONFIG_GENERATE_ACPI_TABLE.
+	  Hidden option to enable QEMU fw_cfg interface and uclass. This will
+	  be selected by either CONFIG_CMD_QFW or CONFIG_GENERATE_ACPI_TABLE.
+
+config QFW_PIO
+	bool
+	depends on QFW
+	help
+	  Hidden option to enable PIO QEMU fw_cfg interface. This will be
+	  selected by the appropriate QEMU board.
 
 config I2C_EEPROM
 	bool "Enable driver for generic I2C-attached EEPROMs"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 1a49396007..2864b84af9 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -55,7 +55,11 @@ obj-$(CONFIG_NUVOTON_NCT6102D) += nuvoton_nct6102d.o
 obj-$(CONFIG_P2SB) += p2sb-uclass.o
 obj-$(CONFIG_PCA9551_LED) += pca9551_led.o
 obj-$(CONFIG_$(SPL_)PWRSEQ) += pwrseq-uclass.o
-obj-$(CONFIG_QFW) += qfw.o
+ifdef CONFIG_QFW
+obj-y += qfw.o
+obj-$(CONFIG_QFW_PIO) += qfw_pio.o
+obj-$(CONFIG_SANDBOX) += qfw_sandbox.o
+endif
 obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
 obj-$(CONFIG_ROCKCHIP_OTP) += rockchip-otp.o
 obj-$(CONFIG_SANDBOX) += syscon_sandbox.o misc_sandbox.o
diff --git a/drivers/misc/qfw.c b/drivers/misc/qfw.c
index f6eb6583ed..ea00be88a8 100644
--- a/drivers/misc/qfw.c
+++ b/drivers/misc/qfw.c
@@ -1,25 +1,22 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
  */
 
+#define LOG_CATEGORY UCLASS_QFW
+
 #include <common.h>
 #include <command.h>
 #include <errno.h>
 #include <log.h>
 #include <malloc.h>
 #include <qfw.h>
-#include <asm/io.h>
+#include <dm.h>
+#include <misc.h>
 #ifdef CONFIG_GENERATE_ACPI_TABLE
 #include <asm/tables.h>
 #endif
-#include <linux/list.h>
-
-static bool fwcfg_present;
-static bool fwcfg_dma_present;
-static struct fw_cfg_arch_ops *fwcfg_arch_ops;
-
-static LIST_HEAD(fw_list);
 
 #ifdef CONFIG_GENERATE_ACPI_TABLE
 /*
@@ -32,7 +29,8 @@ static LIST_HEAD(fw_list);
  *          be ignored.
  * @return: 0 on success, or negative value on failure
  */
-static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
+static int bios_linker_allocate(struct udevice *dev,
+				struct bios_linker_entry *entry, ulong *addr)
 {
 	uint32_t size, align;
 	struct fw_file *file;
@@ -45,7 +43,7 @@ static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
 		return -EINVAL;
 	}
 
-	file = qemu_fwcfg_find_file(entry->alloc.file);
+	file = qfw_find_file(dev, entry->alloc.file);
 	if (!file) {
 		printf("error: can't find file %s\n", entry->alloc.file);
 		return -ENOENT;
@@ -75,8 +73,8 @@ static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
 	debug("bios_linker_allocate: allocate file %s, size %u, zone %d, align %u, addr 0x%lx\n",
 	      file->cfg.name, size, entry->alloc.zone, align, aligned_addr);
 
-	qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select),
-			      size, (void *)aligned_addr);
+	qfw_read_entry(dev, be16_to_cpu(file->cfg.select), size,
+		       (void *)aligned_addr);
 	file->addr = aligned_addr;
 
 	/* adjust address for low memory allocation */
@@ -94,16 +92,17 @@ static int bios_linker_allocate(struct bios_linker_entry *entry, ulong *addr)
  *          ACPI tables
  * @return: 0 on success, or negative value on failure
  */
-static int bios_linker_add_pointer(struct bios_linker_entry *entry)
+static int bios_linker_add_pointer(struct udevice *dev,
+				   struct bios_linker_entry *entry)
 {
 	struct fw_file *dest, *src;
 	uint32_t offset = le32_to_cpu(entry->pointer.offset);
 	uint64_t pointer = 0;
 
-	dest = qemu_fwcfg_find_file(entry->pointer.dest_file);
+	dest = qfw_find_file(dev, entry->pointer.dest_file);
 	if (!dest || !dest->addr)
 		return -ENOENT;
-	src = qemu_fwcfg_find_file(entry->pointer.src_file);
+	src = qfw_find_file(dev, entry->pointer.src_file);
 	if (!src || !src->addr)
 		return -ENOENT;
 
@@ -127,13 +126,14 @@ static int bios_linker_add_pointer(struct bios_linker_entry *entry)
  *          checksums
  * @return: 0 on success, or negative value on failure
  */
-static int bios_linker_add_checksum(struct bios_linker_entry *entry)
+static int bios_linker_add_checksum(struct udevice *dev,
+				    struct bios_linker_entry *entry)
 {
 	struct fw_file *file;
 	uint8_t *data, cksum = 0;
 	uint8_t *cksum_start;
 
-	file = qemu_fwcfg_find_file(entry->cksum.file);
+	file = qfw_find_file(dev, entry->cksum.file);
 	if (!file || !file->addr)
 		return -ENOENT;
 
@@ -149,20 +149,27 @@ static int bios_linker_add_checksum(struct bios_linker_entry *entry)
 /* This function loads and patches ACPI tables provided by QEMU */
 ulong write_acpi_tables(ulong addr)
 {
-	int i, ret = 0;
+	int i, ret;
 	struct fw_file *file;
 	struct bios_linker_entry *table_loader;
 	struct bios_linker_entry *entry;
 	uint32_t size;
+	struct udevice *dev;
+
+	ret = qfw_get_dev(&dev);
+	if (ret) {
+		printf("error: no qfw\n");
+		return addr;
+	}
 
 	/* make sure fw_list is loaded */
-	ret = qemu_fwcfg_read_firmware_list();
+	ret = qfw_read_firmware_list(dev);
 	if (ret) {
 		printf("error: can't read firmware file list\n");
 		return addr;
 	}
 
-	file = qemu_fwcfg_find_file("etc/table-loader");
+	file = qfw_find_file(dev, "etc/table-loader");
 	if (!file) {
 		printf("error: can't find etc/table-loader\n");
 		return addr;
@@ -180,24 +187,23 @@ ulong write_acpi_tables(ulong addr)
 		return addr;
 	}
 
-	qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select),
-			      size, table_loader);
+	qfw_read_entry(dev, be16_to_cpu(file->cfg.select), size, table_loader);
 
 	for (i = 0; i < (size / sizeof(*entry)); i++) {
 		entry = table_loader + i;
 		switch (le32_to_cpu(entry->command)) {
 		case BIOS_LINKER_LOADER_COMMAND_ALLOCATE:
-			ret = bios_linker_allocate(entry, &addr);
+			ret = bios_linker_allocate(dev, entry, &addr);
 			if (ret)
 				goto out;
 			break;
 		case BIOS_LINKER_LOADER_COMMAND_ADD_POINTER:
-			ret = bios_linker_add_pointer(entry);
+			ret = bios_linker_add_pointer(dev, entry);
 			if (ret)
 				goto out;
 			break;
 		case BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM:
-			ret = bios_linker_add_checksum(entry);
+			ret = bios_linker_add_checksum(dev, entry);
 			if (ret)
 				goto out;
 			break;
@@ -209,9 +215,9 @@ ulong write_acpi_tables(ulong addr)
 out:
 	if (ret) {
 		struct fw_cfg_file_iter iter;
-		for (file = qemu_fwcfg_file_iter_init(&iter);
-		     !qemu_fwcfg_file_iter_end(&iter);
-		     file = qemu_fwcfg_file_iter_next(&iter)) {
+		for (file = qfw_file_iter_init(dev, &iter);
+		     !qfw_file_iter_end(&iter);
+		     file = qfw_file_iter_next(&iter)) {
 			if (file->addr) {
 				free((void *)file->addr);
 				file->addr = 0;
@@ -225,170 +231,89 @@ out:
 
 ulong acpi_get_rsdp_addr(void)
 {
+	int ret;
 	struct fw_file *file;
+	struct udevice *dev;
 
-	file = qemu_fwcfg_find_file("etc/acpi/rsdp");
+	ret = qfw_get_dev(&dev);
+	if (ret) {
+		printf("error: no qfw\n");
+		return 0;
+	}
+
+	file = qfw_find_file(dev, "etc/acpi/rsdp");
 	return file->addr;
 }
 #endif
 
-/* Read configuration item using fw_cfg PIO interface */
-static void qemu_fwcfg_read_entry_pio(uint16_t entry,
-		uint32_t size, void *address)
+static void qfw_read_entry_io(struct qfw_dev *qdev, u16 entry, u32 size,
+			      void *address)
 {
-	debug("qemu_fwcfg_read_entry_pio: entry 0x%x, size %u address %p\n",
-	      entry, size, address);
+	struct dm_qfw_ops *ops = dm_qfw_get_ops(qdev->dev);
 
-	return fwcfg_arch_ops->arch_read_pio(entry, size, address);
+	debug("%s: entry 0x%x, size %u address %p\n", __func__, entry, size,
+	      address);
+
+	ops->read_entry_io(qdev->dev, entry, size, address);
 }
 
-/* Read configuration item using fw_cfg DMA interface */
-static void qemu_fwcfg_read_entry_dma(uint16_t entry,
-		uint32_t size, void *address)
+static void qfw_read_entry_dma(struct qfw_dev *qdev, u16 entry, u32 size,
+			       void *address)
 {
-	struct fw_cfg_dma_access dma;
+	struct dm_qfw_ops *ops = dm_qfw_get_ops(qdev->dev);
 
-	dma.length = cpu_to_be32(size);
-	dma.address = cpu_to_be64((uintptr_t)address);
-	dma.control = cpu_to_be32(FW_CFG_DMA_READ);
+	struct qfw_dma dma = {
+		.length = cpu_to_be32(size),
+		.address = cpu_to_be64((uintptr_t)address),
+		.control = cpu_to_be32(FW_CFG_DMA_READ),
+	};
 
 	/*
-	 * writting FW_CFG_INVALID will cause read operation to resume at
-	 * last offset, otherwise read will start at offset 0
+	 * writing FW_CFG_INVALID will cause read operation to resume at last
+	 * offset, otherwise read will start at offset 0
 	 */
 	if (entry != FW_CFG_INVALID)
 		dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16));
 
-	barrier();
-
-	debug("qemu_fwcfg_read_entry_dma: entry 0x%x, size %u address %p, control 0x%x\n",
+	debug("%s: entry 0x%x, size %u address %p, control 0x%x\n", __func__,
 	      entry, size, address, be32_to_cpu(dma.control));
 
-	fwcfg_arch_ops->arch_read_dma(&dma);
-}
+	barrier();
 
-bool qemu_fwcfg_present(void)
-{
-	return fwcfg_present;
+	ops->read_entry_dma(qdev->dev, &dma);
 }
 
-bool qemu_fwcfg_dma_present(void)
+void qfw_read_entry(struct udevice *dev, u16 entry, u32 size, void *address)
 {
-	return fwcfg_dma_present;
-}
+	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
 
-void qemu_fwcfg_read_entry(uint16_t entry, uint32_t length, void *address)
-{
-	if (fwcfg_dma_present)
-		qemu_fwcfg_read_entry_dma(entry, length, address);
+	if (qdev->dma_present)
+		qfw_read_entry_dma(qdev, entry, size, address);
 	else
-		qemu_fwcfg_read_entry_pio(entry, length, address);
+		qfw_read_entry_io(qdev, entry, size, address);
 }
 
-int qemu_fwcfg_online_cpus(void)
+int qfw_register(struct udevice *dev)
 {
-	uint16_t nb_cpus;
+	struct qfw_dev *qdev = dev_get_uclass_priv(dev);
+	u32 qemu, dma_enabled;
 
-	if (!fwcfg_present)
+	qdev->dev = dev;
+	INIT_LIST_HEAD(&qdev->fw_list);
+
+	qfw_read_entry_io(qdev, FW_CFG_SIGNATURE, 4, &qemu);
+	if (be32_to_cpu(qemu) != QEMU_FW_CFG_SIGNATURE)
 		return -ENODEV;
 
-	qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus);
-
-	return le16_to_cpu(nb_cpus);
-}
-
-int qemu_fwcfg_read_firmware_list(void)
-{
-	int i;
-	uint32_t count;
-	struct fw_file *file;
-	struct list_head *entry;
-
-	/* don't read it twice */
-	if (!list_empty(&fw_list))
-		return 0;
-
-	qemu_fwcfg_read_entry(FW_CFG_FILE_DIR, 4, &count);
-	if (!count)
-		return 0;
-
-	count = be32_to_cpu(count);
-	for (i = 0; i < count; i++) {
-		file = malloc(sizeof(*file));
-		if (!file) {
-			printf("error: allocating resource\n");
-			goto err;
-		}
-		qemu_fwcfg_read_entry(FW_CFG_INVALID,
-				      sizeof(struct fw_cfg_file), &file->cfg);
-		file->addr = 0;
-		list_add_tail(&file->list, &fw_list);
-	}
+	qfw_read_entry_io(qdev, FW_CFG_ID, 1, &dma_enabled);
+	if (dma_enabled & FW_CFG_DMA_ENABLED)
+		qdev->dma_present = true;
 
 	return 0;
-
-err:
-	list_for_each(entry, &fw_list) {
-		file = list_entry(entry, struct fw_file, list);
-		free(file);
-	}
-
-	return -ENOMEM;
 }
 
-struct fw_file *qemu_fwcfg_find_file(const char *name)
-{
-	struct list_head *entry;
-	struct fw_file *file;
-
-	list_for_each(entry, &fw_list) {
-		file = list_entry(entry, struct fw_file, list);
-		if (!strcmp(file->cfg.name, name))
-			return file;
-	}
-
-	return NULL;
-}
-
-struct fw_file *qemu_fwcfg_file_iter_init(struct fw_cfg_file_iter *iter)
-{
-	iter->entry = fw_list.next;
-	return list_entry((struct list_head *)iter->entry,
-			  struct fw_file, list);
-}
-
-struct fw_file *qemu_fwcfg_file_iter_next(struct fw_cfg_file_iter *iter)
-{
-	iter->entry = ((struct list_head *)iter->entry)->next;
-	return list_entry((struct list_head *)iter->entry,
-			  struct fw_file, list);
-}
-
-bool qemu_fwcfg_file_iter_end(struct fw_cfg_file_iter *iter)
-{
-	return iter->entry == &fw_list;
-}
-
-void qemu_fwcfg_init(struct fw_cfg_arch_ops *ops)
-{
-	uint32_t qemu;
-	uint32_t dma_enabled;
-
-	fwcfg_present = false;
-	fwcfg_dma_present = false;
-	fwcfg_arch_ops = NULL;
-
-	if (!ops || !ops->arch_read_pio || !ops->arch_read_dma)
-		return;
-	fwcfg_arch_ops = ops;
-
-	qemu_fwcfg_read_entry_pio(FW_CFG_SIGNATURE, 4, &qemu);
-	if (be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE)
-		fwcfg_present = true;
-
-	if (fwcfg_present) {
-		qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled);
-		if (dma_enabled & FW_CFG_DMA_ENABLED)
-			fwcfg_dma_present = true;
-	}
-}
+UCLASS_DRIVER(qfw) = {
+	.id		= UCLASS_QFW,
+	.name		= "qfw",
+	.per_device_auto	= sizeof(struct qfw_dev),
+};
diff --git a/drivers/misc/qfw_pio.c b/drivers/misc/qfw_pio.c
new file mode 100644
index 0000000000..e2f628d338
--- /dev/null
+++ b/drivers/misc/qfw_pio.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PIO interface for QFW
+ *
+ * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
+ */
+
+#define LOG_CATEGORY UCLASS_QFW
+
+#include <asm/io.h>
+#include <dm/device.h>
+#include <qfw.h>
+
+/*
+ * PIO ports are correct for x86, which appears to be the only arch that uses
+ * PIO.
+ */
+#define FW_CONTROL_PORT      0x510
+#define FW_DATA_PORT         0x511
+#define FW_DMA_PORT_LOW      0x514
+#define FW_DMA_PORT_HIGH     0x518
+
+static void qfw_pio_read_entry_io(struct udevice *dev, u16 entry, u32 size,
+				  void *address)
+{
+	/*
+	 * writing FW_CFG_INVALID will cause read operation to resume at last
+	 * offset, otherwise read will start at offset 0
+	 *
+	 * Note: on platform where the control register is IO port, the
+	 * endianness is little endian.
+	 */
+	if (entry != FW_CFG_INVALID)
+		outw(cpu_to_le16(entry), FW_CONTROL_PORT);
+
+	/* the endianness of data register is string-preserving */
+	u32 i = 0;
+	u8 *data = address;
+
+	while (size--)
+		data[i++] = inb(FW_DATA_PORT);
+}
+
+/* Read configuration item using fw_cfg DMA interface */
+static void qfw_pio_read_entry_dma(struct udevice *dev, struct qfw_dma *dma)
+{
+	/* the DMA address register is big-endian */
+	outl(cpu_to_be32((uintptr_t)dma), FW_DMA_PORT_HIGH);
+
+	while (be32_to_cpu(dma->control) & ~FW_CFG_DMA_ERROR);
+}
+
+static int qfw_pio_probe(struct udevice *dev)
+{
+	return qfw_register(dev);
+}
+
+static struct dm_qfw_ops qfw_pio_ops = {
+	.read_entry_io = qfw_pio_read_entry_io,
+	.read_entry_dma = qfw_pio_read_entry_dma,
+};
+
+U_BOOT_DRIVER(qfw_pio) = {
+	.name	= "qfw_pio",
+	.id	= UCLASS_QFW,
+	.probe	= qfw_pio_probe,
+	.ops	= &qfw_pio_ops,
+};
diff --git a/drivers/misc/qfw_sandbox.c b/drivers/misc/qfw_sandbox.c
new file mode 100644
index 0000000000..7ce532310f
--- /dev/null
+++ b/drivers/misc/qfw_sandbox.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Sandbox interface for QFW
+ *
+ * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
+ */
+
+#define LOG_CATEGORY UCLASS_QFW
+
+#include <asm/types.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <dm/device.h>
+#include <qfw.h>
+
+struct qfw_sandbox_plat {
+	u8 file_dir_offset;
+};
+
+static void qfw_sandbox_read_entry_io(struct udevice *dev, u16 entry, u32 size,
+				      void *address)
+{
+	debug("%s: entry 0x%x size %u address %p\n", __func__, entry, size,
+	      address);
+
+	switch (entry) {
+	case FW_CFG_SIGNATURE:
+		if (size == 4)
+			*((u32 *)address) = cpu_to_be32(QEMU_FW_CFG_SIGNATURE);
+		break;
+	case FW_CFG_ID:
+		/* Advertise DMA support */
+		if (size == 1)
+			*((u8 *)address) = FW_CFG_DMA_ENABLED;
+		break;
+	default:
+		debug("%s got unsupported entry 0x%x\n", __func__, entry);
+	/*
+	 * Sandbox driver doesn't support other entries here, assume we use DMA
+	 * to read them -- the uclass driver will exclusively use it when
+	 * advertised.
+	 */
+	}
+}
+
+static void qfw_sandbox_read_entry_dma(struct udevice *dev, struct qfw_dma *dma)
+{
+	u16 entry;
+	u32 control = be32_to_cpu(dma->control);
+	void *address = (void *)be64_to_cpu(dma->address);
+	u32 length = be32_to_cpu(dma->length);
+	struct qfw_sandbox_plat *plat = dev_get_plat(dev);
+	struct fw_cfg_file *file;
+
+	debug("%s\n", __func__);
+
+	if (!(control & FW_CFG_DMA_READ))
+		return;
+
+	if (control & FW_CFG_DMA_SELECT) {
+		/* Start new read. */
+		entry = control >> 16;
+
+		/* Arbitrary values to be used by tests. */
+		switch (entry) {
+		case FW_CFG_NB_CPUS:
+			if (length == 2)
+				*((u16 *)address) = cpu_to_le16(5);
+			break;
+		case FW_CFG_FILE_DIR:
+			if (length == 4) {
+				*((u32 *)address) = cpu_to_be32(2);
+				plat->file_dir_offset = 1;
+			}
+			break;
+		default:
+			debug("%s got unsupported entry 0x%x\n", __func__,
+			      entry);
+		}
+	} else if (plat->file_dir_offset && length == 64) {
+		file = address;
+		switch (plat->file_dir_offset) {
+		case 1:
+			file->size = cpu_to_be32(8);
+			file->select = cpu_to_be16(FW_CFG_FILE_FIRST);
+			strcpy(file->name, "test-one");
+			plat->file_dir_offset++;
+			break;
+		case 2:
+			file->size = cpu_to_be32(8);
+			file->select = cpu_to_be16(FW_CFG_FILE_FIRST + 1);
+			strcpy(file->name, "test-two");
+			plat->file_dir_offset++;
+			break;
+		}
+	}
+
+	/*
+	 * Signal that we are finished. No-one checks this in sandbox --
+	 * normally the platform-specific driver looks for it -- but let's
+	 * replicate the behaviour in case someone relies on it later.
+	 */
+	dma->control = 0;
+}
+
+static int qfw_sandbox_probe(struct udevice *dev)
+{
+	return qfw_register(dev);
+}
+
+static struct dm_qfw_ops qfw_sandbox_ops = {
+	.read_entry_io = qfw_sandbox_read_entry_io,
+	.read_entry_dma = qfw_sandbox_read_entry_dma,
+};
+
+U_BOOT_DRIVER(qfw_sandbox) = {
+	.name	= "qfw_sandbox",
+	.id	= UCLASS_QFW,
+	.plat_auto	= sizeof(struct qfw_sandbox_plat),
+	.probe	= qfw_sandbox_probe,
+	.ops	= &qfw_sandbox_ops,
+};
+
+U_BOOT_DRVINFO(qfw_sandbox) = {
+	.name = "qfw_sandbox",
+};
+
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index d75de368c5..d800f679d5 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -90,6 +90,7 @@ enum uclass_id {
 	UCLASS_POWER_DOMAIN,	/* (SoC) Power domains */
 	UCLASS_PWM,		/* Pulse-width modulator */
 	UCLASS_PWRSEQ,		/* Power sequence device */
+	UCLASS_QFW,		/* QEMU firmware config device */
 	UCLASS_RAM,		/* RAM controller */
 	UCLASS_REGULATOR,	/* Regulator device */
 	UCLASS_REMOTEPROC,	/* Remote Processor device */
diff --git a/include/qfw.h b/include/qfw.h
index cea8e11d44..7ca132e66a 100644
--- a/include/qfw.h
+++ b/include/qfw.h
@@ -8,7 +8,12 @@
 
 #include <linux/list.h>
 
-enum qemu_fwcfg_items {
+/*
+ * List of firmware configuration item selectors. The official source of truth
+ * for these is the QEMU source itself; see
+ * https://github.com/qemu/qemu/blob/master/hw/nvram/fw_cfg.c
+ */
+enum {
 	FW_CFG_SIGNATURE	= 0x00,
 	FW_CFG_ID		= 0x01,
 	FW_CFG_UUID		= 0x02,
@@ -66,8 +71,10 @@ enum {
 #define FW_CFG_DMA_SKIP	(1 << 2)
 #define FW_CFG_DMA_SELECT	(1 << 3)
 
+/* Bit set in FW_CFG_ID response to indicate DMA interface availability. */
 #define FW_CFG_DMA_ENABLED	(1 << 1)
 
+/* Structs read from FW_CFG_FILE_DIR. */
 struct fw_cfg_file {
 	__be32 size;
 	__be16 select;
@@ -82,19 +89,7 @@ struct fw_file {
 };
 
 struct fw_cfg_file_iter {
-	struct list_head *entry; /* structure to iterate file list */
-};
-
-struct fw_cfg_dma_access {
-	__be32 control;
-	__be32 length;
-	__be64 address;
-};
-
-struct fw_cfg_arch_ops {
-	void (*arch_read_pio)(uint16_t selector, uint32_t size,
-			void *address);
-	void (*arch_read_dma)(struct fw_cfg_dma_access *dma);
+	struct list_head *entry, *end; /* structures to iterate file list */
 };
 
 struct bios_linker_entry {
@@ -146,37 +141,178 @@ struct bios_linker_entry {
 	};
 } __packed;
 
+/* DMA transfer control data between UCLASS_QFW and QEMU. */
+struct qfw_dma {
+	__be32 control;
+	__be32 length;
+	__be64 address;
+};
+
+/* uclass per-device configuration information */
+struct qfw_dev {
+	struct udevice *dev;		/* Transport device */
+	bool dma_present;		/* DMA interface usable? */
+	struct list_head fw_list;	/* Cached firmware file list */
+};
+
+/* Ops used internally between UCLASS_QFW and its driver implementations. */
+struct dm_qfw_ops {
+	/**
+	 * read_entry_io() - Read a firmware config entry using the regular
+	 * IO interface for the platform (either PIO or MMIO)
+	 *
+	 * Supply %FW_CFG_INVALID as the entry to continue a previous read.  In
+	 * this case, no selector will be issued before reading.
+	 *
+	 * @dev: Device to use
+	 * @entry: Firmware config entry number (e.g. %FW_CFG_SIGNATURE)
+	 * @size: Number of bytes to read
+	 * @address: Target location for read
+	 */
+	void (*read_entry_io)(struct udevice *dev, u16 entry, u32 size,
+			      void *address);
+
+	/**
+	 * read_entry_dma() - Read a firmware config entry using the DMA
+	 * interface
+	 *
+	 * Supply FW_CFG_INVALID as the entry to continue a previous read.  In
+	 * this case, no selector will be issued before reading.
+	 *
+	 * This method assumes DMA availability has already been confirmed.
+	 *
+	 * @dev: Device to use
+	 * @dma: DMA transfer control struct
+	 */
+	void (*read_entry_dma)(struct udevice *dev, struct qfw_dma *dma);
+};
+
+#define dm_qfw_get_ops(dev) \
+		((struct dm_qfw_ops *)(dev)->driver->ops)
+
 /**
- * Initialize QEMU fw_cfg interface
+ * qfw_register() - Called by a qfw driver after successful probe.
+ * @dev: Device registering itself with the uclass.
+ *
+ * Used internally by driver implementations on successful probe.
  *
- * @ops: arch specific read operations
+ * Return: 0 on success, negative otherwise.
  */
-void qemu_fwcfg_init(struct fw_cfg_arch_ops *ops);
+int qfw_register(struct udevice *dev);
 
-void qemu_fwcfg_read_entry(uint16_t entry, uint32_t length, void *address);
-int qemu_fwcfg_read_firmware_list(void);
-struct fw_file *qemu_fwcfg_find_file(const char *name);
+struct udevice;
+
+/**
+ * qfw_get_dev() - Get QEMU firmware config device.
+ * @devp: Pointer to be filled with address of the qfw device.
+ *
+ * Gets the active QEMU firmware config device, for use with qfw_read_entry()
+ * and others.
+ *
+ * Return: 0 on success, -ENODEV if the device is not available.
+ */
+int qfw_get_dev(struct udevice **devp);
 
 /**
- * Get system cpu number
+ * qfw_read_entry() - Read a QEMU firmware config entry
+ * @dev: QFW device to use.
+ * @entry: Firmware config entry number (e.g. %FW_CFG_SIGNATURE).
+ * @size: Number of bytes to read.
+ * @address: Target location for read.
  *
- * @return:   cpu number in system
+ * Reads a QEMU firmware config entry using @dev.  DMA will be used if the QEMU
+ * machine supports it, otherwise PIO/MMIO.
  */
-int qemu_fwcfg_online_cpus(void);
+void qfw_read_entry(struct udevice *dev, u16 entry, u32 size, void *address);
 
-/* helper functions to iterate firmware file list */
-struct fw_file *qemu_fwcfg_file_iter_init(struct fw_cfg_file_iter *iter);
-struct fw_file *qemu_fwcfg_file_iter_next(struct fw_cfg_file_iter *iter);
-bool qemu_fwcfg_file_iter_end(struct fw_cfg_file_iter *iter);
+/**
+ * qfw_read_firmware_list() - Read and cache the QEMU firmware config file
+ * list.
+ * @dev: QFW device to use.
+ *
+ * Reads the QEMU firmware config file list, caching it against @dev for later
+ * use with qfw_find_file().
+ *
+ * If the list has already been read, does nothing and returns 0 (success).
+ *
+ * Return: 0 on success, -ENOMEM if unable to allocate.
+ */
+int qfw_read_firmware_list(struct udevice *dev);
+
+/**
+ * qfw_find_file() - Find a file by name in the QEMU firmware config file
+ * list.
+ * @dev: QFW device to use.
+ * @name: Name of file to locate (e.g. "etc/table-loader").
+ *
+ * Finds a file by name in the QEMU firmware config file list cached against
+ * @dev.  You must call qfw_read_firmware_list() successfully first for this to
+ * succeed.
+ *
+ * Return: Pointer to &struct fw_file if found, %NULL if not present.
+ */
+struct fw_file *qfw_find_file(struct udevice *dev, const char *name);
 
-bool qemu_fwcfg_present(void);
-bool qemu_fwcfg_dma_present(void);
+/**
+ * qfw_online_cpus() - Get number of CPUs in system from QEMU firmware config.
+ * @dev: QFW device to use.
+ *
+ * Asks QEMU to report how many CPUs it is emulating for the machine.
+ *
+ * Return: Number of CPUs in the system.
+ */
+int qfw_online_cpus(struct udevice *dev);
+
+/**
+ * qfw_file_iter_init() - Start iterating cached firmware file list.
+ * @dev: QFW device to use.
+ * @iter: Iterator to be initialised.
+ *
+ * Starts iterating the cached firmware file list in @dev.  You must call
+ * qfw_read_firmware_list() successfully first, otherwise you will always get
+ * an empty list.
+ *
+ * qfw_file_iter_init() returns the first &struct fw_file, but it may be
+ * invalid if the list is empty.  Check that ``!qfw_file_iter_end(&iter)``
+ * first.
+ *
+ * Return: The first &struct fw_file item in the firmware file list, if any.
+ * Only valid when qfw_file_iter_end() is not true after the call.
+ */
+struct fw_file *qfw_file_iter_init(struct udevice *dev,
+				   struct fw_cfg_file_iter *iter);
+
+/**
+ * qfw_file_iter_next() - Iterate cached firmware file list.
+ * @iter: Iterator to use.
+ *
+ * Continues iterating the cached firmware file list in @dev.  You must call
+ * qfw_file_iter_init() first to initialise it.  Check that
+ * ``!qfw_file_iter_end(&iter)`` before using the return value of this
+ * function.
+ *
+ * Return: The next &struct fw_file item in the firmware file list.  Only valid
+ * when qfw_file_iter_end() is not true after the call.
+ */
+struct fw_file *qfw_file_iter_next(struct fw_cfg_file_iter *iter);
+
+/**
+ * qfw_file_iter_end() - Check if iter is at end of list.
+ * @iter: Iterator to use.
+ *
+ * Checks whether or not the iterator is at its end position.  If so, the
+ * qfw_file_iter_init() or qfw_file_iter_next() call that immediately preceded
+ * returned invalid data.
+ *
+ * Return: True if the iterator is at its end; false otherwise.
+ */
+bool qfw_file_iter_end(struct fw_cfg_file_iter *iter);
 
 /**
- * qemu_cpu_fixup() - Fix up the CPUs for QEMU
+ * qemu_cpu_fixup() - Fix up the CPUs for QEMU.
  *
- * @return 0 if OK, -ENODEV if no CPUs, -ENOMEM if out of memory, other -ve on
- *	on other error
+ * Return: 0 on success, -ENODEV if no CPUs, -ENOMEM if out of memory, other <
+ * 0 on on other error.
  */
 int qemu_cpu_fixup(void);
 
diff --git a/test/dm/Makefile b/test/dm/Makefile
index fd1455109d..fc2902a3ea 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -98,5 +98,6 @@ endif
 ifneq ($(CONFIG_EFI_PARTITION),)
 obj-$(CONFIG_FASTBOOT_FLASH_MMC) += fastboot.o
 endif
+obj-$(CONFIG_QFW) += qfw.o
 endif
 endif # !SPL
diff --git a/test/dm/qfw.c b/test/dm/qfw.c
new file mode 100644
index 0000000000..f3f3568983
--- /dev/null
+++ b/test/dm/qfw.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
+ */
+
+#include <common.h>
+#include <qfw.h>
+#include <dm.h>
+#include <asm/test.h>
+#include <dm/test.h>
+#include <test/ut.h>
+
+/*
+ * Exercise the device enough to be satisfied the initialisation and DMA
+ * interfaces work.
+ */
+
+static int dm_test_qfw_cpus(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_first_device_err(UCLASS_QFW, &dev));
+	ut_asserteq(5, qfw_online_cpus(dev));
+
+	return 0;
+}
+
+DM_TEST(dm_test_qfw_cpus, UT_TESTF_SCAN_PDATA);
+
+static int dm_test_qfw_firmware_list(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+	struct fw_file *file;
+
+	ut_assertok(uclass_first_device_err(UCLASS_QFW, &dev));
+	ut_assertok(qfw_read_firmware_list(dev));
+	ut_assertok_ptr((file = qfw_find_file(dev, "test-one")));
+
+	return 0;
+}
+
+DM_TEST(dm_test_qfw_firmware_list, UT_TESTF_SCAN_PDATA);
diff --git a/test/py/tests/test_qfw.py b/test/py/tests/test_qfw.py
new file mode 100644
index 0000000000..a2631a0fa6
--- /dev/null
+++ b/test/py/tests/test_qfw.py
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (c) 2021, Asherah Connor <ashe@kivikakk.ee>
+
+# Test qfw command implementation
+
+import pytest
+
+ at pytest.mark.buildconfigspec('cmd_qfw')
+def test_qfw_cpus(u_boot_console):
+    "Test QEMU firmware config reports the CPU count correctly."
+
+    output = u_boot_console.run_command('qfw cpus')
+    assert '1 cpu(s) online' in output
+
+ at pytest.mark.buildconfigspec('cmd_qfw')
+def test_qfw_list(u_boot_console):
+    "Test QEMU firmware config lists devices."
+
+    output = u_boot_console.run_command('qfw list')
+    assert 'bootorder' in output
+    assert 'etc/table-loader' in output
-- 
2.20.1

[PATCH v5 1/3] x86: qemu: move QFW to its own uclass

[Simon Glass]

Hi Asherah,

On Mon, 1 Mar 2021 at 01:35, Asherah Connor <ashe@kivikakk.ee> wrote:
>
> We move qfw into its own uclass and split the PIO functions into a
> specific driver for that uclass.  The PIO driver is selected in the
> qemu-x86 board config (this covers x86 and x86_64).
>
> A sandbox driver and test are added for the uclass, and a test in QEMU
> added for qfw functionality to confirm it doesn't break in real world
> use.
>
> include/qfw.h is cleaned up and documentation added.
>
> Signed-off-by: Asherah Connor <ashe@kivikakk.ee>
>
> ---
>
> Changes in v5:
> * Split conversion of existing x86-only QFW to DM into its own patch.
> * Fix qfw_get_dev() so it actually returns -ENODEV when device is
>   missing.
> * Add CONFIG_QFW_PIO.
> * Choose CONFIG_QFW_PIO in board/emulation/qemu-x86/Kconfig.
> * QFW sandbox driver no longer inserts itself from device tree; wasn't
>   relevant to implementation and the ``compatible'' string was too
>   made-up.  Use U_BOOT_DRVINFO like the other QFW driver in this patch.
> * Relevant documentation and sandbox/qemu tests are now here.
>
>  arch/x86/cpu/qemu/cpu.c          |   9 +-
>  arch/x86/cpu/qemu/qemu.c         |  49 +------
>  arch/x86/cpu/qfw_cpu.c           |  11 +-
>  board/emulation/qemu-x86/Kconfig |   1 +
>  cmd/qfw.c                        |  56 ++++---
>  common/Makefile                  |   2 +
>  common/qfw.c                     | 105 +++++++++++++
>  drivers/misc/Kconfig             |  11 +-
>  drivers/misc/Makefile            |   6 +-
>  drivers/misc/qfw.c               | 243 +++++++++++--------------------
>  drivers/misc/qfw_pio.c           |  69 +++++++++
>  drivers/misc/qfw_sandbox.c       | 128 ++++++++++++++++
>  include/dm/uclass-id.h           |   1 +
>  include/qfw.h                    | 200 +++++++++++++++++++++----
>  test/dm/Makefile                 |   1 +
>  test/dm/qfw.c                    |  42 ++++++
>  test/py/tests/test_qfw.py        |  21 +++
>  17 files changed, 683 insertions(+), 272 deletions(-)
>  create mode 100644 common/qfw.c
>  create mode 100644 drivers/misc/qfw_pio.c
>  create mode 100644 drivers/misc/qfw_sandbox.c
>  create mode 100644 test/dm/qfw.c
>  create mode 100644 test/py/tests/test_qfw.py

This looks sensible but it really is a huge patch. Can it be split up a bit?

Regards,
Simon

[PATCH v5 1/3] x86: qemu: move QFW to its own uclass

[Asherah Connor]

Hi Simon,

On 21/03/04 11:03:p, Simon Glass wrote:
> This looks sensible but it really is a huge patch. Can it be split up a bit?

This is a rejig of v4 previously Reviewed-by: you, see
https://patchwork.ozlabs.org/project/uboot/list/?series=230778&state=%2a.

Bin Meng suggested the patch be reworked along these lines so that MMIO
and Arm support were added separately, see
https://patchwork.ozlabs.org/project/uboot/patch/20210224032323.15798-2-ashe at kivikakk.ee/#2637897.

I'm happy to rework it further but it's not clear to me what the best
way to do that is.  Perhaps separating out the qfw.h Sphinx
documentation and sandbox driver/tests?  Let me know, I would like to
get it right.

Thanks,

Asherah

[PATCH v5 1/3] x86: qemu: move QFW to its own uclass

[Simon Glass]

Hi Asherah,

On Thu, 4 Mar 2021 at 21:16, Asherah Connor <ashe@kivikakk.ee> wrote:
>
> Hi Simon,
>
> On 21/03/04 11:03:p, Simon Glass wrote:
> > This looks sensible but it really is a huge patch. Can it be split up a bit?
>
> This is a rejig of v4 previously Reviewed-by: you, see
> https://patchwork.ozlabs.org/project/uboot/list/?series=230778&state=%2a.

If I previously reviewed it you can add my tag.

>
> Bin Meng suggested the patch be reworked along these lines so that MMIO
> and Arm support were added separately, see
> https://patchwork.ozlabs.org/project/uboot/patch/20210224032323.15798-2-ashe at kivikakk.ee/#2637897.
>
> I'm happy to rework it further but it's not clear to me what the best
> way to do that is.  Perhaps separating out the qfw.h Sphinx
> documentation and sandbox driver/tests?  Let me know, I would like to
> get it right.

I think sandbox driver/tests being separate is a good idea.

Regards,
Simon

[PATCH v5 1/3] x86: qemu: move QFW to its own uclass

[Bin Meng]

Hi Asherah,

On Fri, Mar 5, 2021 at 10:31 PM Simon Glass <sjg@chromium.org> wrote:
>
> Hi Asherah,
>
> On Thu, 4 Mar 2021 at 21:16, Asherah Connor <ashe@kivikakk.ee> wrote:
> >
> > Hi Simon,
> >
> > On 21/03/04 11:03:p, Simon Glass wrote:
> > > This looks sensible but it really is a huge patch. Can it be split up a bit?
> >
> > This is a rejig of v4 previously Reviewed-by: you, see
> > https://patchwork.ozlabs.org/project/uboot/list/?series=230778&state=%2a.
>
> If I previously reviewed it you can add my tag.
>
> >
> > Bin Meng suggested the patch be reworked along these lines so that MMIO
> > and Arm support were added separately, see
> > https://patchwork.ozlabs.org/project/uboot/patch/20210224032323.15798-2-ashe at kivikakk.ee/#2637897.
> >

Thanks for making the split.

> > I'm happy to rework it further but it's not clear to me what the best
> > way to do that is.  Perhaps separating out the qfw.h Sphinx
> > documentation and sandbox driver/tests?  Let me know, I would like to
> > get it right.
>
> I think sandbox driver/tests being separate is a good idea.

Yes, as Simon said, sandbox driver/test should be a separate patch.

Regards,
Bin

[PATCH v5 1/3] x86: qemu: move QFW to its own uclass

[Asherah Connor]

Hi Bin, Simon,

On 21/03/05 10:03:p, Bin Meng wrote:
> On Fri, Mar 5, 2021 at 10:31 PM Simon Glass <sjg@chromium.org> wrote:
> > If I previously reviewed it you can add my tag.

I wasn't sure of the correct etiquette when a large rearrangement of the
patches had been done; I'll keep this in mind.

> > I think sandbox driver/tests being separate is a good idea.
> 
> Yes, as Simon said, sandbox driver/test should be a separate patch.

This will be sent along shortly.  The initial rework commit email is
still fairly sizeable (+490 -272), but I've compared this series with v4
(which had sjg's Reviewed-by: on all initially) and confirmed nothing
new has crept in other than:

* part 1:
  * adding config QFW_PIO to select the PIO driver
  * completing documentation to Sphinx standard
* part 2:
  * nothing new
* part 3:
  * adding config QFW_MMIO to select the driver
* part 4:
  * just adds two `select's to Kconfig

So there should be only these parts of the patch needing careful review.
Given parts 1, 3 and 4 are still at least partly unreviewed, I will not
carry the Reviewed-by: over.  2 is good to go.

Best,

Asherah

[PATCH v5 2/3] qemu: add MMIO driver for QFW

[Asherah Connor]

Add MMIO driver for QFW.

Note that there is no consumer as of this patch.

Signed-off-by: Asherah Connor <ashe@kivikakk.ee>
---

Changes in v5:
* Split MMIO driver into its own commit.
* Add CONFIG_QFW_MMIO for selection by arch/board.

 drivers/misc/Kconfig    |   7 +++
 drivers/misc/Makefile   |   1 +
 drivers/misc/qfw_mmio.c | 119 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 127 insertions(+)
 create mode 100644 drivers/misc/qfw_mmio.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 3a254eba4b..c650471ff7 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -378,6 +378,13 @@ config QFW_PIO
 	  Hidden option to enable PIO QEMU fw_cfg interface. This will be
 	  selected by the appropriate QEMU board.
 
+config QFW_MMIO
+	bool
+	depends on QFW
+	help
+	  Hidden option to enable MMIO QEMU fw_cfg interface. This will be
+	  selected by the appropriate QEMU board.
+
 config I2C_EEPROM
 	bool "Enable driver for generic I2C-attached EEPROMs"
 	depends on MISC
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 2864b84af9..0c67d43a5d 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_$(SPL_)PWRSEQ) += pwrseq-uclass.o
 ifdef CONFIG_QFW
 obj-y += qfw.o
 obj-$(CONFIG_QFW_PIO) += qfw_pio.o
+obj-$(CONFIG_QFW_MMIO) += qfw_mmio.o
 obj-$(CONFIG_SANDBOX) += qfw_sandbox.o
 endif
 obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
diff --git a/drivers/misc/qfw_mmio.c b/drivers/misc/qfw_mmio.c
new file mode 100644
index 0000000000..f397384054
--- /dev/null
+++ b/drivers/misc/qfw_mmio.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MMIO interface for QFW
+ *
+ * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ * (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
+ */
+
+#define LOG_CATEGORY UCLASS_QFW
+
+#include <asm/types.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <dm/device.h>
+#include <qfw.h>
+
+struct qfw_mmio {
+	/*
+	 * Each access to the 64-bit data register can be 8/16/32/64 bits wide.
+	 */
+	union {
+		u8 data8;
+		u16 data16;
+		u32 data32;
+		u64 data64;
+	};
+	u16 selector;
+	u8 padding[6];
+	u64 dma;
+};
+
+struct qfw_mmio_plat {
+	volatile struct qfw_mmio *mmio;
+};
+
+static void qfw_mmio_read_entry_io(struct udevice *dev, u16 entry, u32 size,
+				   void *address)
+{
+	struct qfw_mmio_plat *plat = dev_get_plat(dev);
+
+	/*
+	 * writing FW_CFG_INVALID will cause read operation to resume at last
+	 * offset, otherwise read will start at offset 0
+	 *
+	 * Note: on platform where the control register is MMIO, the register
+	 * is big endian.
+	 */
+	if (entry != FW_CFG_INVALID)
+		plat->mmio->selector = cpu_to_be16(entry);
+
+	/* the endianness of data register is string-preserving */
+	while (size >= 8) {
+		*(u64 *)address = plat->mmio->data64;
+		address += 8;
+		size -= 8;
+	}
+	while (size >= 4) {
+		*(u32 *)address = plat->mmio->data32;
+		address += 4;
+		size -= 4;
+	}
+	while (size >= 2) {
+		*(u16 *)address = plat->mmio->data16;
+		address += 2;
+		size -= 2;
+	}
+	while (size >= 1) {
+		*(u8 *)address = plat->mmio->data8;
+		address += 1;
+		size -= 1;
+	}
+}
+
+/* Read configuration item using fw_cfg DMA interface */
+static void qfw_mmio_read_entry_dma(struct udevice *dev, struct qfw_dma *dma)
+{
+	struct qfw_mmio_plat *plat = dev_get_plat(dev);
+
+	/* the DMA address register is big-endian */
+	plat->mmio->dma = cpu_to_be64((uintptr_t)dma);
+
+	while (be32_to_cpu(dma->control) & ~FW_CFG_DMA_ERROR);
+}
+
+static int qfw_mmio_of_to_plat(struct udevice *dev)
+{
+	struct qfw_mmio_plat *plat = dev_get_plat(dev);
+
+	plat->mmio = map_physmem(dev_read_addr(dev),
+				 sizeof(struct qfw_mmio),
+				 MAP_NOCACHE);
+
+	return 0;
+}
+
+static int qfw_mmio_probe(struct udevice *dev)
+{
+	return qfw_register(dev);
+}
+
+static struct dm_qfw_ops qfw_mmio_ops = {
+	.read_entry_io = qfw_mmio_read_entry_io,
+	.read_entry_dma = qfw_mmio_read_entry_dma,
+};
+
+static const struct udevice_id qfw_mmio_ids[] = {
+	{ .compatible = "qemu,fw-cfg-mmio" },
+	{}
+};
+
+U_BOOT_DRIVER(qfw_mmio) = {
+	.name	= "qfw_mmio",
+	.id	= UCLASS_QFW,
+	.of_match	= qfw_mmio_ids,
+	.plat_auto	= sizeof(struct qfw_mmio_plat),
+	.of_to_plat	= qfw_mmio_of_to_plat,
+	.probe	= qfw_mmio_probe,
+	.ops	= &qfw_mmio_ops,
+};
-- 
2.20.1

[PATCH v5 3/3] qemu: arm: select QFW, MMIO on qemu-arm

[Asherah Connor]

Select CMD_QFW and QFW_MMIO in the qemu-arm board (covers arm and
arm64).

Signed-off-by: Asherah Connor <ashe@kivikakk.ee>

---

Changes in v5:
* Split adding MMIO driver to QEMU arm/64 into own commit.
* Use the generic qemu-arm board config rather than adding to multiple
  defconfigs.

 board/emulation/qemu-arm/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/board/emulation/qemu-arm/Kconfig b/board/emulation/qemu-arm/Kconfig
index fb8d38f5b8..95dbefa78b 100644
--- a/board/emulation/qemu-arm/Kconfig
+++ b/board/emulation/qemu-arm/Kconfig
@@ -5,6 +5,8 @@ config SYS_TEXT_BASE
 
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
+	select CMD_QFW
+	select QFW_MMIO
 	imply VIRTIO_MMIO
 	imply VIRTIO_PCI
 	imply VIRTIO_NET
-- 
2.20.1