Merge tag 'ib-mfd-spi-tty-v4.20' of git://git.kernel.org/pub/scm/linu…

…x/kernel/git/lee/mfd into tty-next

Immutable branch between MFD, SPI and TTY due for the v4.20 merge window

Documentation/devicetree/bindings/serial/atmel-usart.txt → 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 <AT91_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 = <AT91_USART_MODE_SPI>;
+		reg = <0xf001c000 0x100>;
+		interrupts = <12 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&usart0_clk>;
+		clock-names = "usart";
+		cs-gpios = <&pioB 3 0>;
+	};

MAINTAINERS

@@ -9503,6 +9503,7 @@ M:	Richard Genoud <richard.genoud@gmail.com>
 S:	Maintained
 F:	drivers/tty/serial/atmel_serial.c
 F:	drivers/tty/serial/atmel_serial.h
+F:	Documentation/devicetree/bindings/mfd/atmel-usart.txt
 
 MICROCHIP / ATMEL DMA DRIVER
 M:	Ludovic Desroches <ludovic.desroches@microchip.com>
@@ -9534,6 +9535,21 @@ S:	Supported
 F:	drivers/mtd/nand/raw/atmel/*
 F:	Documentation/devicetree/bindings/mtd/atmel-nand.txt
 
+MICROCHIP AT91 USART MFD DRIVER
+M:	Radu Pirea <radu.pirea@microchip.com>
+L:	linux-kernel@vger.kernel.org
+S:	Supported
+F:	drivers/mfd/at91-usart.c
+F:	include/dt-bindings/mfd/at91-usart.h
+F:	Documentation/devicetree/bindings/mfd/atmel-usart.txt
+
+MICROCHIP AT91 USART SPI DRIVER
+M:	Radu Pirea <radu.pirea@microchip.com>
+L:	linux-spi@vger.kernel.org
+S:	Supported
+F:	drivers/spi/spi-at91-usart.c
+F:	Documentation/devicetree/bindings/mfd/atmel-usart.txt
+
 MICROCHIP KSZ SERIES ETHERNET SWITCH DRIVER
 M:	Woojung Huh <Woojung.Huh@microchip.com>
 M:	Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>

drivers/mfd/Kconfig

@@ -99,6 +99,15 @@ config MFD_AAT2870_CORE
 	  additional drivers must be enabled in order to use the
 	  functionality of the device.
 
+config MFD_AT91_USART
+	tristate "AT91 USART Driver"
+	select MFD_CORE
+	help
+	  Select this to get support for AT91 USART IP. This is a wrapper
+	  over at91-usart-serial driver and usart-spi-driver. Only one function
+	  can be used at a time. The choice is done at boot time by the probe
+	  function of this MFD driver according to a device tree property.
+
 config MFD_ATMEL_FLEXCOM
 	tristate "Atmel Flexcom (Flexible Serial Communication Unit)"
 	select MFD_CORE

drivers/mfd/Makefile

@@ -196,6 +196,7 @@ obj-$(CONFIG_MFD_SPMI_PMIC)	+= qcom-spmi-pmic.o
 obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
 obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
 obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
+obj-$(CONFIG_MFD_AT91_USART)	+= at91-usart.o
 obj-$(CONFIG_MFD_ATMEL_FLEXCOM)	+= atmel-flexcom.o
 obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
 obj-$(CONFIG_MFD_ATMEL_SMC)	+= atmel-smc.o

drivers/mfd/at91-usart.c

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for AT91 USART
+ *
+ * Copyright (C) 2018 Microchip Technology
+ *
+ * Author: Radu Pirea <radu.pirea@microchip.com>
+ *
+ */
+
+#include <dt-bindings/mfd/at91-usart.h>
+
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/property.h>
+
+static struct mfd_cell at91_usart_spi_subdev = {
+		.name = "at91_usart_spi",
+		.of_compatible = "microchip,at91sam9g45-usart-spi",
+	};
+
+static struct mfd_cell at91_usart_serial_subdev = {
+		.name = "atmel_usart_serial",
+		.of_compatible = "atmel,at91rm9200-usart-serial",
+	};
+
+static int at91_usart_mode_probe(struct platform_device *pdev)
+{
+	struct mfd_cell cell;
+	u32 opmode = AT91_USART_MODE_SERIAL;
+
+	device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
+
+	switch (opmode) {
+	case AT91_USART_MODE_SPI:
+		cell = at91_usart_spi_subdev;
+		break;
+	case AT91_USART_MODE_SERIAL:
+		cell = at91_usart_serial_subdev;
+		break;
+	default:
+		dev_err(&pdev->dev, "atmel,usart-mode has an invalid value %u\n",
+			opmode);
+		return -EINVAL;
+	}
+
+	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, &cell, 1,
+			      NULL, 0, NULL);
+}
+
+static const struct of_device_id at91_usart_mode_of_match[] = {
+	{ .compatible = "atmel,at91rm9200-usart" },
+	{ .compatible = "atmel,at91sam9260-usart" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, at91_usart_mode_of_match);
+
+static struct platform_driver at91_usart_mfd = {
+	.probe	= at91_usart_mode_probe,
+	.driver	= {
+		.name		= "at91_usart_mode",
+		.of_match_table	= at91_usart_mode_of_match,
+	},
+};
+
+module_platform_driver(at91_usart_mfd);
+
+MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
+MODULE_DESCRIPTION("AT91 USART MFD driver");
+MODULE_LICENSE("GPL v2");

drivers/spi/Kconfig

@@ -83,6 +83,14 @@ config SPI_ATMEL
 	  This selects a driver for the Atmel SPI Controller, present on
 	  many AT91 ARM chips.
 
+config SPI_AT91_USART
+	tristate "Atmel USART Controller SPI driver"
+	depends on (ARCH_AT91 || COMPILE_TEST)
+	depends on MFD_AT91_USART
+	help
+	  This selects a driver for the AT91 USART Controller as SPI Master,
+	  present on AT91 and SAMA5 SoC series.
+
 config SPI_AU1550
 	tristate "Au1550/Au1200/Au1300 SPI Controller"
 	depends on MIPS_ALCHEMY

drivers/spi/Makefile

@@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_LOOPBACK_TEST)		+= spi-loopback-test.o
 obj-$(CONFIG_SPI_ALTERA)		+= spi-altera.o
 obj-$(CONFIG_SPI_ARMADA_3700)		+= spi-armada-3700.o
 obj-$(CONFIG_SPI_ATMEL)			+= spi-atmel.o
+obj-$(CONFIG_SPI_AT91_USART)		+= spi-at91-usart.o
 obj-$(CONFIG_SPI_ATH79)			+= spi-ath79.o
 obj-$(CONFIG_SPI_AU1550)		+= spi-au1550.o
 obj-$(CONFIG_SPI_AXI_SPI_ENGINE)	+= spi-axi-spi-engine.o