wifi: brcmfmac: add function to unbind device to bus layer api

Introduce a new bus callback .remove() which will unbind the device
from the driver. This allows the common driver layer to stop handling
a device.
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221129135446.151065-2-arend.vanspriel@broadcom.com

drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h

@@ -8,6 +8,7 @@
 
 #include <linux/kernel.h>
 #include <linux/firmware.h>
+#include <linux/device.h>
 #include "debug.h"
 
 /* IDs of the 6 default common rings of msgbuf protocol */
@@ -74,6 +75,7 @@ struct brcmf_bus_dcmd {
  * @get_ramsize: obtain size of device memory.
  * @get_memdump: obtain device memory dump in provided buffer.
  * @get_blob: obtain a firmware blob.
+ * @remove: initiate unbind of the device.
  *
  * This structure provides an abstract interface towards the
  * bus specific driver. For control messages to common driver
@@ -94,6 +96,7 @@ struct brcmf_bus_ops {
 			enum brcmf_blob_type type);
 	void (*debugfs_create)(struct device *dev);
 	int (*reset)(struct device *dev);
+	void (*remove)(struct device *dev);
 };
 
 
@@ -257,6 +260,16 @@ int brcmf_bus_reset(struct brcmf_bus *bus)
 	return bus->ops->reset(bus->dev);
 }
 
+static inline void brcmf_bus_remove(struct brcmf_bus *bus)
+{
+	if (!bus->ops->remove) {
+		device_release_driver(bus->dev);
+		return;
+	}
+
+	bus->ops->remove(bus->dev);
+}
+
 /*
  * interface functions from common layer
  */

drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c

@@ -4171,6 +4171,15 @@ static int brcmf_sdio_bus_reset(struct device *dev)
 	return 0;
 }
 
+static void brcmf_sdio_bus_remove(struct device *dev)
+{
+	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+	struct brcmf_sdio_dev *sdiod = bus_if->bus_priv.sdio;
+
+	device_release_driver(&sdiod->func2->dev);
+	device_release_driver(&sdiod->func1->dev);
+}
+
 static const struct brcmf_bus_ops brcmf_sdio_bus_ops = {
 	.stop = brcmf_sdio_bus_stop,
 	.preinit = brcmf_sdio_bus_preinit,
@@ -4183,7 +4192,8 @@ static const struct brcmf_bus_ops brcmf_sdio_bus_ops = {
 	.get_memdump = brcmf_sdio_bus_get_memdump,
 	.get_blob = brcmf_sdio_get_blob,
 	.debugfs_create = brcmf_sdio_debugfs_create,
-	.reset = brcmf_sdio_bus_reset
+	.reset = brcmf_sdio_bus_reset,
+	.remove = brcmf_sdio_bus_remove,
 };
 
 #define BRCMF_SDIO_FW_CODE	0