diff --git a/drivers/net/wireless/silabs/wfx/bus_sdio.c b/drivers/net/wireless/silabs/wfx/bus_sdio.c
new file mode 100644
index 000000000000..55b6728416ba
--- /dev/null
+++ b/drivers/net/wireless/silabs/wfx/bus_sdio.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SDIO interface.
+ *
+ * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
+ * Copyright (c) 2010, ST-Ericsson
+ */
+#include <linux/module.h>
+#include <linux/mmc/sdio.h>
+#include <linux/mmc/sdio_func.h>
+#include <linux/mmc/sdio_ids.h>
+#include <linux/mmc/card.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/irq.h>
+
+#include "bus.h"
+#include "wfx.h"
+#include "hwio.h"
+#include "main.h"
+#include "bh.h"
+
+static const struct wfx_platform_data wfx_sdio_pdata = {
+	.file_fw = "wfm_wf200",
+	.file_pds = "wf200.pds",
+};
+
+struct wfx_sdio_priv {
+	struct sdio_func *func;
+	struct wfx_dev *core;
+	u8 buf_id_tx;
+	u8 buf_id_rx;
+	int of_irq;
+};
+
+static int wfx_sdio_copy_from_io(void *priv, unsigned int reg_id,
+				 void *dst, size_t count)
+{
+	struct wfx_sdio_priv *bus = priv;
+	unsigned int sdio_addr = reg_id << 2;
+	int ret;
+
+	WARN(reg_id > 7, "chip only has 7 registers");
+	WARN(((uintptr_t)dst) & 3, "unaligned buffer size");
+	WARN(count & 3, "unaligned buffer address");
+
+	/* Use queue mode buffers */
+	if (reg_id == WFX_REG_IN_OUT_QUEUE)
+		sdio_addr |= (bus->buf_id_rx + 1) << 7;
+	ret = sdio_memcpy_fromio(bus->func, dst, sdio_addr, count);
+	if (!ret && reg_id == WFX_REG_IN_OUT_QUEUE)
+		bus->buf_id_rx = (bus->buf_id_rx + 1) % 4;
+
+	return ret;
+}
+
+static int wfx_sdio_copy_to_io(void *priv, unsigned int reg_id,
+			       const void *src, size_t count)
+{
+	struct wfx_sdio_priv *bus = priv;
+	unsigned int sdio_addr = reg_id << 2;
+	int ret;
+
+	WARN(reg_id > 7, "chip only has 7 registers");
+	WARN(((uintptr_t)src) & 3, "unaligned buffer size");
+	WARN(count & 3, "unaligned buffer address");
+
+	/* Use queue mode buffers */
+	if (reg_id == WFX_REG_IN_OUT_QUEUE)
+		sdio_addr |= bus->buf_id_tx << 7;
+	/* FIXME: discards 'const' qualifier for src */
+	ret = sdio_memcpy_toio(bus->func, sdio_addr, (void *)src, count);
+	if (!ret && reg_id == WFX_REG_IN_OUT_QUEUE)
+		bus->buf_id_tx = (bus->buf_id_tx + 1) % 32;
+
+	return ret;
+}
+
+static void wfx_sdio_lock(void *priv)
+{
+	struct wfx_sdio_priv *bus = priv;
+
+	sdio_claim_host(bus->func);
+}
+
+static void wfx_sdio_unlock(void *priv)
+{
+	struct wfx_sdio_priv *bus = priv;
+
+	sdio_release_host(bus->func);
+}
+
+static void wfx_sdio_irq_handler(struct sdio_func *func)
+{
+	struct wfx_sdio_priv *bus = sdio_get_drvdata(func);
+
+	wfx_bh_request_rx(bus->core);
+}
+
+static irqreturn_t wfx_sdio_irq_handler_ext(int irq, void *priv)
+{
+	struct wfx_sdio_priv *bus = priv;
+
+	sdio_claim_host(bus->func);
+	wfx_bh_request_rx(bus->core);
+	sdio_release_host(bus->func);
+	return IRQ_HANDLED;
+}
+
+static int wfx_sdio_irq_subscribe(void *priv)
+{
+	struct wfx_sdio_priv *bus = priv;
+	u32 flags;
+	int ret;
+	u8 cccr;
+
+	if (!bus->of_irq) {
+		sdio_claim_host(bus->func);
+		ret = sdio_claim_irq(bus->func, wfx_sdio_irq_handler);
+		sdio_release_host(bus->func);
+		return ret;
+	}
+
+	sdio_claim_host(bus->func);
+	cccr = sdio_f0_readb(bus->func, SDIO_CCCR_IENx, NULL);
+	cccr |= BIT(0);
+	cccr |= BIT(bus->func->num);
+	sdio_f0_writeb(bus->func, cccr, SDIO_CCCR_IENx, NULL);
+	sdio_release_host(bus->func);
+	flags = irq_get_trigger_type(bus->of_irq);
+	if (!flags)
+		flags = IRQF_TRIGGER_HIGH;
+	flags |= IRQF_ONESHOT;
+	return devm_request_threaded_irq(&bus->func->dev, bus->of_irq, NULL,
+					 wfx_sdio_irq_handler_ext, flags,
+					 "wfx", bus);
+}
+
+static int wfx_sdio_irq_unsubscribe(void *priv)
+{
+	struct wfx_sdio_priv *bus = priv;
+	int ret;
+
+	if (bus->of_irq)
+		devm_free_irq(&bus->func->dev, bus->of_irq, bus);
+	sdio_claim_host(bus->func);
+	ret = sdio_release_irq(bus->func);
+	sdio_release_host(bus->func);
+	return ret;
+}
+
+static size_t wfx_sdio_align_size(void *priv, size_t size)
+{
+	struct wfx_sdio_priv *bus = priv;
+
+	return sdio_align_size(bus->func, size);
+}
+
+static const struct hwbus_ops wfx_sdio_hwbus_ops = {
+	.copy_from_io = wfx_sdio_copy_from_io,
+	.copy_to_io = wfx_sdio_copy_to_io,
+	.irq_subscribe = wfx_sdio_irq_subscribe,
+	.irq_unsubscribe = wfx_sdio_irq_unsubscribe,
+	.lock			= wfx_sdio_lock,
+	.unlock			= wfx_sdio_unlock,
+	.align_size		= wfx_sdio_align_size,
+};
+
+static const struct of_device_id wfx_sdio_of_match[] = {
+	{ .compatible = "silabs,wfx-sdio" },
+	{ .compatible = "silabs,wf200" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, wfx_sdio_of_match);
+
+static int wfx_sdio_probe(struct sdio_func *func,
+			  const struct sdio_device_id *id)
+{
+	struct device_node *np = func->dev.of_node;
+	struct wfx_sdio_priv *bus;
+	int ret;
+
+	if (func->num != 1) {
+		dev_err(&func->dev, "SDIO function number is %d while it should always be 1 (unsupported chip?)\n",
+			func->num);
+		return -ENODEV;
+	}
+
+	bus = devm_kzalloc(&func->dev, sizeof(*bus), GFP_KERNEL);
+	if (!bus)
+		return -ENOMEM;
+
+	if (!np || !of_match_node(wfx_sdio_of_match, np)) {
+		dev_warn(&func->dev, "no compatible device found in DT\n");
+		return -ENODEV;
+	}
+
+	bus->func = func;
+	bus->of_irq = irq_of_parse_and_map(np, 0);
+	sdio_set_drvdata(func, bus);
+	func->card->quirks |= MMC_QUIRK_LENIENT_FN0 |
+			      MMC_QUIRK_BLKSZ_FOR_BYTE_MODE |
+			      MMC_QUIRK_BROKEN_BYTE_MODE_512;
+
+	sdio_claim_host(func);
+	ret = sdio_enable_func(func);
+	/* Block of 64 bytes is more efficient than 512B for frame sizes < 4k */
+	sdio_set_block_size(func, 64);
+	sdio_release_host(func);
+	if (ret)
+		goto err0;
+
+	bus->core = wfx_init_common(&func->dev, &wfx_sdio_pdata,
+				    &wfx_sdio_hwbus_ops, bus);
+	if (!bus->core) {
+		ret = -EIO;
+		goto err1;
+	}
+
+	ret = wfx_probe(bus->core);
+	if (ret)
+		goto err1;
+
+	return 0;
+
+err1:
+	sdio_claim_host(func);
+	sdio_disable_func(func);
+	sdio_release_host(func);
+err0:
+	return ret;
+}
+
+static void wfx_sdio_remove(struct sdio_func *func)
+{
+	struct wfx_sdio_priv *bus = sdio_get_drvdata(func);
+
+	wfx_release(bus->core);
+	sdio_claim_host(func);
+	sdio_disable_func(func);
+	sdio_release_host(func);
+}
+
+static const struct sdio_device_id wfx_sdio_ids[] = {
+	{ SDIO_DEVICE(SDIO_VENDOR_ID_SILABS, SDIO_DEVICE_ID_SILABS_WF200) },
+	{ },
+};
+MODULE_DEVICE_TABLE(sdio, wfx_sdio_ids);
+
+struct sdio_driver wfx_sdio_driver = {
+	.name = "wfx-sdio",
+	.id_table = wfx_sdio_ids,
+	.probe = wfx_sdio_probe,
+	.remove = wfx_sdio_remove,
+	.drv = {
+		.owner = THIS_MODULE,
+		.of_match_table = wfx_sdio_of_match,
+	}
+};
