similarity index 76%
rename from Documentation/devicetree/bindings/serial/atmel-usart.txt
rename to Documentation/devicetree/bindings/mfd/atmel-usart.txt
@@ -1,6 +1,6 @@
* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
-Required properties:
+Required properties for USART:
- compatible: Should be "atmel,<chip>-usart" or "atmel,<chip>-dbgu"
The compatible <chip> indicated will be the first SoC to support an
additional mode or an USART new feature.
@@ -11,7 +11,13 @@ Required properties:
Required elements: "usart"
- clocks: phandles to input clocks.
-Optional properties:
+Required properties for USART in SPI mode:
+- #size-cells : Must be <0>
+- #address-cells : Must be <1>
+- cs-gpios: chipselects (internal cs not supported)
+- atmel,usart-mode : Must be <USART_MODE_SPI> (found in dt-bindings/mfd/at91-usart.h)
+
+Optional properties in serial mode:
- atmel,use-dma-rx: use of PDC or DMA for receiving data
- atmel,use-dma-tx: use of PDC or DMA for transmitting data
- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively.
@@ -62,3 +68,18 @@ Example:
dma-names = "tx", "rx";
atmel,fifo-size = <32>;
};
+
+- SPI mode:
+ #include <dt-bindings/mfd/at91-usart.h>
+
+ spi0: spi@f001c000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "atmel,at91rm9200-usart", "atmel,at91sam9260-usart";
+ atmel,usart-mode = <USART_MODE_SPI>;
+ reg = <0xf001c000 0x100>;
+ interrupts = <12 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&usart0_clk>;
+ clock-names = "usart";
+ cs-gpios = <&pioB 3 0>;
+ };
new file mode 100644
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This header provides macros for AT91 USART DT bindings.
+ *
+ * Copyright (C) 2018 Microchip Technology
+ *
+ * Author: Radu Pirea <radu.pirea@microchip.com>
+ *
+ */
+
+#ifndef __DT_BINDINGS_AT91_USART_H__
+#define __DT_BINDINGS_AT91_USART_H__
+
+#define AT91_USART_MODE_SERIAL 0
+#define AT91_USART_MODE_SPI 1
+
+#endif /* __DT_BINDINGS_AT91_USART_H__ */