rt2x00: Add rt2800_wait_csr_ready

Similar to rt2800_wait_wpdma_ready() we can add a
function to waiting until the CSR is ready. This
centralizes some additional code into rt2800lib.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index 82ae58e..b1a8e94 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -122,22 +122,12 @@
 static int rt2800usb_init_registers(struct rt2x00_dev *rt2x00dev)
 {
 	u32 reg;
-	int i;
 
 	/*
 	 * Wait until BBP and RF are ready.
 	 */
-	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
-		rt2800_register_read(rt2x00dev, MAC_CSR0, &reg);
-		if (reg && reg != ~0)
-			break;
-		msleep(1);
-	}
-
-	if (i == REGISTER_BUSY_COUNT) {
-		ERROR(rt2x00dev, "Unstable hardware.\n");
+	if (rt2800_wait_csr_ready(rt2x00dev))
 		return -EBUSY;
-	}
 
 	rt2800_register_read(rt2x00dev, PBF_SYS_CTRL, &reg);
 	rt2800_register_write(rt2x00dev, PBF_SYS_CTRL, reg & ~0x00002000);