diff --git a/sys/arm/broadcom/bcm2835/bcm2835_spi.c b/sys/arm/broadcom/bcm2835/bcm2835_spi.c
--- a/sys/arm/broadcom/bcm2835/bcm2835_spi.c
+++ b/sys/arm/broadcom/bcm2835/bcm2835_spi.c
@@ -388,8 +388,10 @@
 	/* Check for end of transfer. */
 	if (sc->sc_written == sc->sc_len && sc->sc_read == sc->sc_len) {
 		/* Disable interrupts and the SPI engine. */
-		bcm_spi_modifyreg(sc, SPI_CS,
-		    SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0);
+		if ((sc->sc_flags & BCM_SPI_KEEP_CS) == 0) {
+			bcm_spi_modifyreg(sc, SPI_CS,
+			    SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0);
+		}
 		wakeup(sc->sc_dev);
 	}
 
@@ -438,16 +440,23 @@
 
 	/* If the controller is in use wait until it is available. */
 	BCM_SPI_LOCK(sc);
-	while (sc->sc_flags & BCM_SPI_BUSY)
-		mtx_sleep(dev, &sc->sc_mtx, 0, "bcm_spi", 0);
+	if (sc->sc_thread != curthread)
+		while (sc->sc_flags & BCM_SPI_BUSY)
+			mtx_sleep(dev, &sc->sc_mtx, 0, "bcm_spi", 0);
 
 	/* Now we have control over SPI controller. */
 	sc->sc_flags = BCM_SPI_BUSY;
 
+	if ((cmd->flags & SPI_FLAG_KEEP_CS) != 0)
+		sc->sc_flags |= BCM_SPI_KEEP_CS;
+
 	/* Clear the FIFO. */
-	bcm_spi_modifyreg(sc, SPI_CS,
-	    SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO,
-	    SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO);
+	if (sc->sc_thread != curthread)
+		bcm_spi_modifyreg(sc, SPI_CS,
+		    SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO,
+		    SPI_CS_CLEAR_RXFIFO | SPI_CS_CLEAR_TXFIFO);
+
+	sc->sc_thread = curthread;
 
 	/* Save a pointer to the SPI command. */
 	sc->sc_cmd = cmd;
@@ -517,11 +526,15 @@
 	err = mtx_sleep(dev, &sc->sc_mtx, 0, "bcm_spi", hz * 2);
 
 	/* Make sure the SPI engine and interrupts are disabled. */
-	bcm_spi_modifyreg(sc, SPI_CS, SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0);
+	if (!(cmd->flags & SPI_FLAG_KEEP_CS)) {
+		bcm_spi_modifyreg(sc,
+		    SPI_CS, SPI_CS_TA | SPI_CS_INTR | SPI_CS_INTD, 0);
+		sc->sc_thread = 0;
+	}
 
-	/* Release the controller and wakeup the next thread waiting for it. */
-	sc->sc_flags = 0;
 	wakeup_one(dev);
+	sc->sc_flags &= ~BCM_SPI_BUSY;
+	/* Release the controller and wakeup the next thread waiting for it. */
 	BCM_SPI_UNLOCK(sc);
 
 	/*
diff --git a/sys/arm/broadcom/bcm2835/bcm2835_spivar.h b/sys/arm/broadcom/bcm2835/bcm2835_spivar.h
--- a/sys/arm/broadcom/bcm2835/bcm2835_spivar.h
+++ b/sys/arm/broadcom/bcm2835/bcm2835_spivar.h
@@ -36,6 +36,7 @@
 	struct resource *	sc_mem_res;
 	struct resource *	sc_irq_res;
 	struct spi_command	*sc_cmd;
+	struct thread		*sc_thread;
 	bus_space_tag_t		sc_bst;
 	bus_space_handle_t	sc_bsh;
 	uint32_t		sc_len;
@@ -46,6 +47,7 @@
 };
 
 #define	BCM_SPI_BUSY		0x1
+#define	BCM_SPI_KEEP_CS		0x2
 
 #define BCM_SPI_WRITE(_sc, _off, _val)		\
     bus_space_write_4(_sc->sc_bst, _sc->sc_bsh, _off, _val)