spi: sam0: use Device Tree for configuration.

Switch the SoC device tree to define a single entry per SERCOM instead
of one per mode.

Define a Device Tree binding for the SAM0 SPI and use it instead of
Kconfig for enabling / disabaling instances

Switch the Arduino Zero, Adafruit Feather M0 Basic Proto, and
Trinket M0 to use the new defintion.

Add the APA102 LED that's on the Trinket as a test.

Signed-off-by: Michael Hope <mlhx@google.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>

arch/arm/soc/atmel_sam0/samd21/dts.fixup

@@ -45,6 +45,24 @@
 #define CONFIG_UART_SAM0_SERCOM5_LABEL ATMEL_SAM0_UART_42001C00_LABEL
 #define CONFIG_UART_SAM0_SERCOM5_BASE_ADDRESS ATMEL_SAM0_UART_42001C00_BASE_ADDRESS
 
+#define CONFIG_SPI_SAM0_SERCOM0_LABEL ATMEL_SAM0_SPI_42000800_LABEL
+#define CONFIG_SPI_SAM0_SERCOM0_BASE_ADDRESS ATMEL_SAM0_SPI_42000800_BASE_ADDRESS
+
+#define CONFIG_SPI_SAM0_SERCOM1_LABEL ATMEL_SAM0_SPI_42000C00_LABEL
+#define CONFIG_SPI_SAM0_SERCOM1_BASE_ADDRESS ATMEL_SAM0_SPI_42000C00_BASE_ADDRESS
+
+#define CONFIG_SPI_SAM0_SERCOM2_LABEL ATMEL_SAM0_SPI_42001000_LABEL
+#define CONFIG_SPI_SAM0_SERCOM2_BASE_ADDRESS ATMEL_SAM0_SPI_42001000_BASE_ADDRESS
+
+#define CONFIG_SPI_SAM0_SERCOM3_LABEL ATMEL_SAM0_SPI_42001400_LABEL
+#define CONFIG_SPI_SAM0_SERCOM3_BASE_ADDRESS ATMEL_SAM0_SPI_42001400_BASE_ADDRESS
+
+#define CONFIG_SPI_SAM0_SERCOM4_LABEL ATMEL_SAM0_SPI_42001800_LABEL
+#define CONFIG_SPI_SAM0_SERCOM4_BASE_ADDRESS ATMEL_SAM0_SPI_42001800_BASE_ADDRESS
+
+#define CONFIG_SPI_SAM0_SERCOM5_LABEL ATMEL_SAM0_SPI_42001C00_LABEL
+#define CONFIG_SPI_SAM0_SERCOM5_BASE_ADDRESS ATMEL_SAM0_SPI_42001C00_BASE_ADDRESS
+
 #define CONFIG_WDT_SAM0_IRQ ATMEL_SAM0_WATCHDOG_40001000_IRQ_0
 #define CONFIG_WDT_SAM0_IRQ_PRIORITY ATMEL_SAM0_WATCHDOG_40001000_IRQ_0_PRIORITY
 #define CONFIG_WDT_SAM0_LABEL ATMEL_SAM0_WATCHDOG_40001000_LABEL

boards/arm/adafruit_feather_m0_basic_proto/adafruit_feather_m0_basic_proto.dts

@@ -22,11 +22,15 @@
 
 &sercom0 {
 	status = "ok";
+	compatible = "atmel,sam0-uart";
 	current-speed = <115200>;
 };
 
-&spi4 {
+&sercom4 {
 	status = "ok";
+	compatible = "atmel,sam0-spi";
+	#address-cells = <1>;
+	#size-cells = <0>;
 };
 
 &flash0 {

boards/arm/adafruit_feather_m0_basic_proto/adafruit_feather_m0_basic_proto_defconfig

@@ -17,7 +17,5 @@ CONFIG_SOC_ATMEL_SAMD_XOSC32K=y
 CONFIG_SOC_ATMEL_SAMD_XOSC32K_AS_MAIN=y
 CONFIG_SPI=y
 CONFIG_SPI_SAM0=y
-CONFIG_SPI_4=y
-CONFIG_SPI_LEGACY_API=n
 CONFIG_PINMUX=y
 CONFIG_PINMUX_SAM0=y

boards/arm/adafruit_trinket_m0/adafruit_trinket_m0.dts

@@ -21,17 +21,29 @@
 
 &sercom0 {
 	status = "ok";
+	compatible = "atmel,sam0-uart";
 	current-speed = <115200>;
 };
 
 &sercom2 {
 	status = "ok";
+	compatible = "atmel,sam0-uart";
 	current-speed = <115200>;
 };
 
 /* Drives the on-board DotStar LED */
-&spi1 {
+&sercom1 {
 	status = "ok";
+	compatible = "atmel,sam0-spi";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	led1: apa102@0 {
+		compatible = "apa,apa102";
+		reg = <0>;
+		spi-max-frequency = <24000000>;
+		label = "LED1";
+	};
 };
 
 &flash0 {

boards/arm/adafruit_trinket_m0/adafruit_trinket_m0_defconfig

@@ -16,8 +16,6 @@ CONFIG_WATCHDOG=y
 CONFIG_WDT_SAM0=y
 CONFIG_SPI=y
 CONFIG_SPI_SAM0=y
-CONFIG_SPI_1=y
-CONFIG_SPI_1_IRQ_PRI=0
 CONFIG_SPI_LEGACY_API=n
 CONFIG_PINMUX=y
 CONFIG_PINMUX_SAM0=y

boards/arm/arduino_zero/arduino_zero.dts

@@ -18,15 +18,23 @@
 	};
 };
 
-&sercom5 {
+&sercom0 {
 	status = "ok";
+	compatible = "atmel,sam0-uart";
 	current-speed = <115200>;
 };
-&sercom0 {
+
+&sercom5 {
 	status = "ok";
+	compatible = "atmel,sam0-uart";
 	current-speed = <115200>;
 };
 
+&sercom4 {
+	status = "ok";
+	compatible = "atmel,sam0-spi";
+};
+
 &flash0 {
 	partitions {
 		compatible = "fixed-partitions";

boards/arm/arduino_zero/arduino_zero_defconfig

@@ -17,7 +17,6 @@ CONFIG_SOC_ATMEL_SAMD_XOSC32K=y
 CONFIG_SOC_ATMEL_SAMD_XOSC32K_AS_MAIN=y
 CONFIG_SPI=y
 CONFIG_SPI_SAM0=y
-CONFIG_SPI_4=y
 CONFIG_SPI_LEGACY_API=n
 CONFIG_PINMUX=y
 CONFIG_PINMUX_SAM0=y

drivers/spi/Kconfig.sam0

@@ -6,6 +6,7 @@
 menuconfig SPI_SAM0
 	bool "Atmel SAM0 series SERCOM SPI driver"
 	depends on SOC_FAMILY_SAM0
+	select HAS_DTS_SPI
 	default n
 	help
 	  Enable support for the SAM0 SERCOM SPI driver.

drivers/spi/spi_sam0.c

@@ -436,7 +436,7 @@ static const struct spi_driver_api spi_sam0_driver_api = {
 
 #define SPI_SAM0_DEFINE_CONFIG(n)                                            \
 	static const struct spi_sam0_config spi_sam0_config_##n = {          \
-		.regs = &SERCOM##n->SPI,                                     \
+		.regs = (SercomSpi *)CONFIG_SPI_SAM0_SERCOM##n##_BASE_ADDRESS, \
 		.pm_apbcmask = PM_APBCMASK_SERCOM##n,                        \
 		.gclk_clkctrl_id = GCLK_CLKCTRL_ID_SERCOM##n##_CORE,         \
 		.pads = CONFIG_SPI_SAM0_SERCOM##n##_PADS                     \
@@ -448,31 +448,32 @@ static const struct spi_driver_api spi_sam0_driver_api = {
 		SPI_CONTEXT_INIT_LOCK(spi_sam0_dev_data_##n, ctx),           \
 		SPI_CONTEXT_INIT_SYNC(spi_sam0_dev_data_##n, ctx),           \
 	};                                                                   \
-	DEVICE_AND_API_INIT(spi_sam0_##n, CONFIG_SPI_##n##_NAME,             \
+	DEVICE_AND_API_INIT(spi_sam0_##n, \
+			    CONFIG_SPI_SAM0_SERCOM##n##_LABEL,               \
 			    &spi_sam0_init, &spi_sam0_dev_data_##n,          \
 			    &spi_sam0_config_##n, POST_KERNEL,               \
 			    CONFIG_SPI_INIT_PRIORITY, &spi_sam0_driver_api)
 
-#if CONFIG_SPI_0
+#if CONFIG_SPI_SAM0_SERCOM0_BASE_ADDRESS
 SPI_SAM0_DEVICE_INIT(0);
 #endif
 
-#if CONFIG_SPI_1
+#if CONFIG_SPI_SAM0_SERCOM1_BASE_ADDRESS
 SPI_SAM0_DEVICE_INIT(1);
 #endif
 
-#if CONFIG_SPI_2
+#if CONFIG_SPI_SAM0_SERCOM2_BASE_ADDRESS
 SPI_SAM0_DEVICE_INIT(2);
 #endif
 
-#if CONFIG_SPI_3
+#if CONFIG_SPI_SAM0_SERCOM3_BASE_ADDRESS
 SPI_SAM0_DEVICE_INIT(3);
 #endif
 
-#if CONFIG_SPI_4
+#if CONFIG_SPI_SAM0_SERCOM4_BASE_ADDRESS
 SPI_SAM0_DEVICE_INIT(4);
 #endif
 
-#if CONFIG_SPI_5
+#if CONFIG_SPI_SAM0_SERCOM5_BASE_ADDRESS
 SPI_SAM0_DEVICE_INIT(5);
 #endif

dts/arm/atmel/samd21.dtsi

@@ -61,96 +61,54 @@
 			label = "WATCHDOG_0";
 		};
 
-		sercom0: uart@42000800 {
+		sercom0: sercom@42000800 {
-			compatible = "atmel,sam0-uart";
+			compatible = "atmel,sam0-sercom";
 			reg = <0x42000800 0x40>;
 			interrupts = <9 0>;
 			status = "disabled";
 			label = "SERCOM0";
 		};
 
-		sercom1: uart@42000c00 {
+		sercom1: sercom@42000c00 {
-			compatible = "atmel,sam0-uart";
+			compatible = "atmel,sam0-sercom";
 			reg = <0x42000c00 0x40>;
 			interrupts = <10 0>;
 			status = "disabled";
 			label = "SERCOM1";
 		};
 
-		sercom2: uart@42001000 {
+		sercom2: sercom@42001000 {
-			compatible = "atmel,sam0-uart";
+			compatible = "atmel,sam0-sercom";
 			reg = <0x42001000 0x40>;
 			interrupts = <11 0>;
 			status = "disabled";
 			label = "SERCOM2";
 		};
 
-		sercom3: uart@42001400 {
+		sercom3: sercom@42001400 {
-			compatible = "atmel,sam0-uart";
+			compatible = "atmel,sam0-sercom";
 			reg = <0x42001400 0x40>;
 			interrupts = <12 0>;
 			status = "disabled";
 			label = "SERCOM3";
 		};
 
-		sercom4: uart@42001800 {
+		sercom4: sercom@42001800 {
-			compatible = "atmel,sam0-uart";
+			compatible = "atmel,sam0-sercom";
 			reg = <0x42001800 0x40>;
 			interrupts = <13 0>;
 			status = "disabled";
 			label = "SERCOM4";
 		};
 
-		sercom5: uart@42001C00 {
+		sercom5: sercom@42001C00 {
-			compatible = "atmel,sam0-uart";
+			compatible = "atmel,sam0-sercom";
 			reg = <0x42001C00 0x40>;
 			interrupts = <14 0>;
 			status = "disabled";
 			label = "SERCOM5";
 		};
 
-		spi0: spi@42000800 {
-			compatible = "atmel,sam0-spi";
-			reg = <0x42000800 0x40>;
-			status = "disabled";
-			label = "SPI0";
-		};
-
-		spi1: spi@42000c00 {
-			compatible = "atmel,sam0-spi";
-			reg = <0x42000c00 0x40>;
-			status = "disabled";
-			label = "SPI1";
-		};
-
-		spi2: spi@42001000 {
-			compatible = "atmel,sam0-spi";
-			reg = <0x42001000 0x40>;
-			status = "disabled";
-			label = "SPI2";
-		};
-
-		spi3: spi@42001400 {
-			compatible = "atmel,sam0-spi";
-			reg = <0x42001400 0x40>;
-			status = "disabled";
-			label = "SPI3";
-		};
-
-		spi4: spi@42001800 {
-			compatible = "atmel,sam0-spi";
-			reg = <0x42001800 0x40>;
-			status = "disabled";
-			label = "SPI4";
-		};
-
-		spi5: spi@42001C00 {
-			compatible = "atmel,sam0-spi";
-			reg = <0x42001C00 0x40>;
-			status = "disabled";
-			label = "SPI5";
-		};
-
 		porta: gpio@41004400 {
 			compatible = "atmel,sam0-gpio";
 			reg = <0x41004400 0x80>;

dts/bindings/arm/atmel,sam0-sercom.yaml

@@ -0,0 +1,27 @@
+---
+title: Atmel SERCOM binding
+id: atmel,sam0-sercom
+version: 0.1
+
+description: >
+    Binding for the Atmel SAM0 multi-protocol (UART, SPI, I2C) SERCOM unit.
+
+properties:
+    compatible:
+      type: string
+      category: required
+      description: compatible strings
+      constraint: "atmel,sam0-sercom"
+
+    reg:
+      type: array
+      description: mmio register space
+      generation: define
+      category: required
+
+    interrupts:
+      type: array
+      category: required
+      description: required interrupts
+      generation: define
+...

dts/bindings/spi/atmel,sam0-spi.yaml

@@ -0,0 +1,29 @@
+#
+# Copyright (c) 2018, Google LLC.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+---
+title: Atmel SAM0 SERCOM SPI driver
+id: atmel,sam0-spi
+version: 0.1
+
+description: >
+    This binding gives a base representation of the Atmel SAM0 SERCOM SPI controller
+
+inherits:
+    !include spi.yaml
+
+properties:
+    compatible:
+      type: string
+      category: required
+      description: compatible strings
+      constraint: "atmel,sam0-spi"
+
+    reg:
+      type: array
+      description: mmio register space
+      generation: define
+      category: required
+...