brcmfmac: assure USB dongle firmware is reset upon module unload

Upon unloading the brcmfmac module the USB firmware should be reset
as the device remains powered. The reset assures a known device
state when a new brcmfmac driver load is being done.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmfmac/dhd.h

@@ -39,6 +39,7 @@
 #define BRCMF_C_GET_BSSID			23
 #define BRCMF_C_GET_SSID			25
 #define BRCMF_C_SET_SSID			26
+#define BRCMF_C_TERMINATED			28
 #define BRCMF_C_GET_CHANNEL			29
 #define BRCMF_C_SET_CHANNEL			30
 #define BRCMF_C_GET_SRL				31

drivers/net/wireless/brcm80211/brcmfmac/dhd_bus.h

@@ -154,7 +154,8 @@ static inline void brcmf_rx_packet(struct device *dev, int ifidx,
 extern int brcmf_attach(uint bus_hdrlen, struct device *dev);
 /* Indication from bus module regarding removal/absence of dongle */
 extern void brcmf_detach(struct device *dev);
-
+/* Indication from bus module that dongle should be reset */
+extern void brcmf_dev_reset(struct device *dev);
 /* Indication from bus module to change flow-control state */
 extern void brcmf_txflowblock(struct device *dev, bool state);
 

drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c

@@ -845,6 +845,17 @@ static void brcmf_bus_detach(struct brcmf_pub *drvr)
 	}
 }
 
+void brcmf_dev_reset(struct device *dev)
+{
+	struct brcmf_bus *bus_if = dev_get_drvdata(dev);
+	struct brcmf_pub *drvr = bus_if->drvr;
+
+	if (drvr == NULL)
+		return;
+
+	brcmf_fil_cmd_int_set(drvr->iflist[0], BRCMF_C_TERMINATED, 1);
+}
+
 void brcmf_detach(struct device *dev)
 {
 	int i;

drivers/net/wireless/brcm80211/brcmfmac/usb.c

@@ -1524,10 +1524,23 @@ static void brcmf_release_fw(struct list_head *q)
 	}
 }
 
+static int brcmf_usb_reset_device(struct device *dev, void *notused)
+{
+	/* device past is the usb interface so we
+	 * need to use parent here.
+	 */
+	brcmf_dev_reset(dev->parent);
+	return 0;
+}
 
 void brcmf_usb_exit(void)
 {
+	struct device_driver *drv = &brcmf_usbdrvr.drvwrap.driver;
+	int ret;
+
 	brcmf_dbg(USB, "Enter\n");
+	ret = driver_for_each_device(drv, NULL, NULL,
+				     brcmf_usb_reset_device);
 	usb_deregister(&brcmf_usbdrvr);
 	brcmf_release_fw(&fw_image_list);
 }