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authorRadu Pirea <radu.pirea@microchip.com>2018-07-13 19:47:33 +0300
committerLee Jones <lee.jones@linaro.org>2018-09-10 16:07:24 +0100
commit7d3aa342cef7aa3721bab5157a84bb3d6acce437 (patch)
tree17aafc20ced7522af0cda151fb0b0e3cf938ce51 /drivers/mfd
parenta785ce4c6d6c1e8e120a13a100edbb31b447675a (diff)
downloadlinux-7d3aa342cef7aa3721bab5157a84bb3d6acce437.tar.bz2
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>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/Kconfig9
-rw-r--r--drivers/mfd/Makefile1
-rw-r--r--drivers/mfd/at91-usart.c71
3 files changed, 81 insertions, 0 deletions
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 11841f4b7b2b..0b79c5d04cc9 100644
--- a/drivers/mfd/Kconfig
+++ b/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
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 5856a9489cbd..12980a4ad460 100644
--- a/drivers/mfd/Makefile
+++ b/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
diff --git a/drivers/mfd/at91-usart.c b/drivers/mfd/at91-usart.c
new file mode 100644
index 000000000000..a4b9929c156f
--- /dev/null
+++ b/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");