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>

1 files changed, 69 insertions, 0 deletions

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,
+};