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Commit 7d3aa342 authored by Radu Pirea's avatar Radu Pirea Committed by Lee Jones
Browse files

mfd: at91-usart: Add MFD driver for USART 



This MFD driver is just a wrapper over atmel_serial driver and
spi-at91-usart driver. Selection of one of the drivers is based on a
property from device tree. If the property is not specified, the default
driver is atmel_serial.

Signed-off-by: default avatarRadu Pirea <radu.pirea@microchip.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent a785ce4c

drivers/mfd/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -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

+1 −0
Original line number Diff line number Diff line
@@ -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 → 100644
+71 −0
Original line number Diff line number Diff line 
// 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");