greybus: es2: clean up CDSI CPort reservation

Clean up the CDSI CPort reservation by adding a host-device helper and
CPort defines.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/es2.c

@@ -18,6 +18,11 @@
 #include "connection.h"
 #include "greybus_trace.h"
 
+
+/* Fixed CPort numbers */
+#define ES2_CPORT_CDSI0		16
+#define ES2_CPORT_CDSI1		17
+
 /* Memory sizes for the buffers sent to/from the ES2 controller */
 #define ES2_GBUF_MSG_SIZE_MAX	2048
 
@@ -941,7 +946,6 @@ static int ap_probe(struct usb_interface *interface,
 	int retval;
 	int i;
 	int num_cports;
-	int cport_id;
 
 	udev = usb_get_dev(interface_to_usbdev(interface));
 
@@ -960,14 +964,6 @@ static int ap_probe(struct usb_interface *interface,
 		return PTR_ERR(hd);
 	}
 
-	/*
-	 * CPorts 16 and 17 are reserved for CDSI0 and CDSI1, make sure they
-	 * won't be allocated dynamically.
-	 */
-	do {
-		cport_id = ida_simple_get(&hd->cport_id_map, 16, 18, GFP_KERNEL);
-	} while (cport_id > 0);
-
 	es2 = hd_to_es2(hd);
 	es2->hd = hd;
 	es2->usb_intf = interface;
@@ -976,6 +972,17 @@ static int ap_probe(struct usb_interface *interface,
 	INIT_KFIFO(es2->apb_log_fifo);
 	usb_set_intfdata(interface, es2);
 
+	/*
+	 * Reserve the CDSI0 and CDSI1 CPorts so they won't be allocated
+	 * dynamically.
+	 */
+	retval = gb_hd_cport_reserve(hd, ES2_CPORT_CDSI0);
+	if (retval)
+		goto error;
+	retval = gb_hd_cport_reserve(hd, ES2_CPORT_CDSI1);
+	if (retval)
+		goto error;
+
 	es2->cport_to_ep = kcalloc(hd->num_cports, sizeof(*es2->cport_to_ep),
 				   GFP_KERNEL);
 	if (!es2->cport_to_ep) {

drivers/staging/greybus/hd.c

@@ -39,6 +39,21 @@ static struct attribute *bus_attrs[] = {
 };
 ATTRIBUTE_GROUPS(bus);
 
+int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id)
+{
+	struct ida *id_map = &hd->cport_id_map;
+	int ret;
+
+	ret = ida_simple_get(id_map, cport_id, cport_id + 1, GFP_KERNEL);
+	if (ret < 0) {
+		dev_err(&hd->dev, "failed to reserve cport %u\n", cport_id);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gb_hd_cport_reserve);
+
 /* Locking: Caller guarantees serialisation */
 int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id)
 {

drivers/staging/greybus/hd.h

@@ -50,6 +50,7 @@ struct gb_host_device {
 };
 #define to_gb_host_device(d) container_of(d, struct gb_host_device, dev)
 
+int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id);
 int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id);
 void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id);