x86: qemu: move QFW to its own uclass

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).

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

Signed-off-by: Asherah Connor <ashe@kivikakk.ee>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/common/Makefile b/common/Makefile
index 215b8b2..0952ae2 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -138,3 +138,5 @@
 
 obj-$(CONFIG_AVB_VERIFY) += avb_verify.o
 obj-$(CONFIG_SCP03) += scp03.o
+
+obj-$(CONFIG_QFW) += qfw.o
diff --git a/common/qfw.c b/common/qfw.c
new file mode 100644
index 0000000..90cbb8c
--- /dev/null
+++ b/common/qfw.c
@@ -0,0 +1,104 @@
+// 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;
+}