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: Radu Pirea <radu.pirea@microchip.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Radu Pirea 2018-07-13 19:47:33 +03:00 committed by Lee Jones
parent a785ce4c6d
commit 7d3aa342ce
3 changed files with 81 additions and 0 deletions

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@ -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

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@ -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

71
drivers/mfd/at91-usart.c Normal file
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@ -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");