usb: gadget: rndis: use rndis_params instead of configNr

RNDIS function has a limitation on the number of allowed instances.
So far it has been RNDIS_MAX_CONFIGS, which happens to be one.
In order to eliminate this kind of arbitrary limitation we should not
preallocate a predefined (RNDIS_MAX_CONFIGS) array of struct rndis_params
instances but instead allow allocating them on demand.

This patch prepares the elimination of the said limit by converting all the
functions which accept rndis config number to accept a pointer to the
actual struct rndis_params. Consequently, rndis_register() returns
a pointer to a corresponding struct rndis_params instance. The pointer
is then always used by f_rndis.c instead of config number when it talks
to rndis.c API.

A nice side-effect of the changes is that many lines of code in rndis.c
become shorter and fit in 80 columns.

If a function prototype changes in rndis.h a style cleanup is made
at the same time, otherwise checkpatch complains that the patch
has style problems.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/f_rndis.c

@@ -76,7 +76,7 @@ struct f_rndis {
 	u8				ethaddr[ETH_ALEN];
 	u32				vendorID;
 	const char			*manufacturer;
-	int				config;
+	struct rndis_params		*params;
 
 	struct usb_ep			*notify;
 	struct usb_request		*notify_req;
@@ -453,7 +453,7 @@ static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
 
 	/* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
 //	spin_lock(&dev->lock);
-	status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
+	status = rndis_msg_parser(rndis->params, (u8 *) req->buf);
 	if (status < 0)
 		pr_err("RNDIS command error %d, %d/%d\n",
 			status, req->actual, req->length);
@@ -499,12 +499,12 @@ rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 			u32 n;
 
 			/* return the result */
-			buf = rndis_get_next_response(rndis->config, &n);
+			buf = rndis_get_next_response(rndis->params, &n);
 			if (buf) {
 				memcpy(req->buf, buf, n);
 				req->complete = rndis_response_complete;
 				req->context = rndis;
-				rndis_free_response(rndis->config, buf);
+				rndis_free_response(rndis->params, buf);
 				value = n;
 			}
 			/* else stalls ... spec says to avoid that */
@@ -597,7 +597,7 @@ static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 		if (IS_ERR(net))
 			return PTR_ERR(net);
 
-		rndis_set_param_dev(rndis->config, net,
+		rndis_set_param_dev(rndis->params, net,
 				&rndis->port.cdc_filter);
 	} else
 		goto fail;
@@ -617,7 +617,7 @@ static void rndis_disable(struct usb_function *f)
 
 	DBG(cdev, "rndis deactivated\n");
 
-	rndis_uninit(rndis->config);
+	rndis_uninit(rndis->params);
 	gether_disconnect(&rndis->port);
 
 	usb_ep_disable(rndis->notify);
@@ -640,9 +640,9 @@ static void rndis_open(struct gether *geth)
 
 	DBG(cdev, "%s\n", __func__);
 
-	rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3,
+	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3,
 				bitrate(cdev->gadget) / 100);
-	rndis_signal_connect(rndis->config);
+	rndis_signal_connect(rndis->params);
 }
 
 static void rndis_close(struct gether *geth)
@@ -651,8 +651,8 @@ static void rndis_close(struct gether *geth)
 
 	DBG(geth->func.config->cdev, "%s\n", __func__);
 
-	rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
-	rndis_signal_disconnect(rndis->config);
+	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
+	rndis_signal_disconnect(rndis->params);
 }
 
 /*-------------------------------------------------------------------------*/
@@ -796,11 +796,11 @@ rndis_bind(struct usb_configuration *c, struct usb_function *f)
 	rndis->port.open = rndis_open;
 	rndis->port.close = rndis_close;
 
-	rndis_set_param_medium(rndis->config, RNDIS_MEDIUM_802_3, 0);
-	rndis_set_host_mac(rndis->config, rndis->ethaddr);
+	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
+	rndis_set_host_mac(rndis->params, rndis->ethaddr);
 
 	if (rndis->manufacturer && rndis->vendorID &&
-			rndis_set_param_vendor(rndis->config, rndis->vendorID,
+			rndis_set_param_vendor(rndis->params, rndis->vendorID,
 					       rndis->manufacturer)) {
 		status = -EINVAL;
 		goto fail_free_descs;
@@ -944,7 +944,7 @@ static void rndis_free(struct usb_function *f)
 	struct f_rndis_opts *opts;
 
 	rndis = func_to_rndis(f);
-	rndis_deregister(rndis->config);
+	rndis_deregister(rndis->params);
 	opts = container_of(f->fi, struct f_rndis_opts, func_inst);
 	kfree(rndis);
 	mutex_lock(&opts->lock);
@@ -968,7 +968,7 @@ static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
 {
 	struct f_rndis	*rndis;
 	struct f_rndis_opts *opts;
-	int status;
+	struct rndis_params *params;
 
 	/* allocate and initialize one new instance */
 	rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
@@ -1002,12 +1002,12 @@ static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
 	rndis->port.func.disable = rndis_disable;
 	rndis->port.func.free_func = rndis_free;
 
-	status = rndis_register(rndis_response_available, rndis);
-	if (status < 0) {
+	params = rndis_register(rndis_response_available, rndis);
+	if (IS_ERR(params)) {
 		kfree(rndis);
-		return ERR_PTR(status);
+		return ERR_CAST(params);
 	}
-	rndis->config = status;
+	rndis->params = params;
 
 	return &rndis->port.func;
 }

drivers/usb/gadget/function/rndis.h

@@ -197,24 +197,25 @@ typedef struct rndis_params
 } rndis_params;
 
 /* RNDIS Message parser and other useless functions */
-int  rndis_msg_parser (u8 configNr, u8 *buf);
-int  rndis_register(void (*resp_avail)(void *v), void *v);
-void rndis_deregister (int configNr);
-int  rndis_set_param_dev (u8 configNr, struct net_device *dev,
+int  rndis_msg_parser(struct rndis_params *params, u8 *buf);
+struct rndis_params *rndis_register(void (*resp_avail)(void *v), void *v);
+void rndis_deregister(struct rndis_params *params);
+int  rndis_set_param_dev(struct rndis_params *params, struct net_device *dev,
 			 u16 *cdc_filter);
-int  rndis_set_param_vendor (u8 configNr, u32 vendorID,
+int  rndis_set_param_vendor(struct rndis_params *params, u32 vendorID,
 			    const char *vendorDescr);
-int  rndis_set_param_medium (u8 configNr, u32 medium, u32 speed);
+int  rndis_set_param_medium(struct rndis_params *params, u32 medium,
+			     u32 speed);
 void rndis_add_hdr (struct sk_buff *skb);
 int rndis_rm_hdr(struct gether *port, struct sk_buff *skb,
 			struct sk_buff_head *list);
-u8   *rndis_get_next_response (int configNr, u32 *length);
-void rndis_free_response (int configNr, u8 *buf);
-
-void rndis_uninit (int configNr);
-int  rndis_signal_connect (int configNr);
-int  rndis_signal_disconnect (int configNr);
-int  rndis_state (int configNr);
-extern void rndis_set_host_mac (int configNr, const u8 *addr);
+u8   *rndis_get_next_response(struct rndis_params *params, u32 *length);
+void rndis_free_response(struct rndis_params *params, u8 *buf);
+
+void rndis_uninit(struct rndis_params *params);
+int  rndis_signal_connect(struct rndis_params *params);
+int  rndis_signal_disconnect(struct rndis_params *params);
+int  rndis_state(struct rndis_params *params);
+extern void rndis_set_host_mac(struct rndis_params *params, const u8 *addr);
 
 #endif  /* _LINUX_RNDIS_H */