From 7d3aa342cef7aa3721bab5157a84bb3d6acce437 Mon Sep 17 00:00:00 2001
From: Radu Pirea <radu.pirea@microchip.com>
Date: Fri, 13 Jul 2018 19:47:33 +0300
Subject: 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>
---
 drivers/mfd/Kconfig      |  9 ++++++
 drivers/mfd/Makefile     |  1 +
 drivers/mfd/at91-usart.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100644 drivers/mfd/at91-usart.c

(limited to 'drivers/mfd')

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");
-- 
cgit v1.2.3


From 65b80dfffeabd4eb253b93d07eadde4d89c18511 Mon Sep 17 00:00:00 2001
From: Lee Jones <lee.jones@linaro.org>
Date: Tue, 11 Sep 2018 11:34:27 +0100
Subject: mfd: at91-usart: Include Device Tree header

Will ensure 'of_device_id' is declared.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/mfd/at91-usart.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'drivers/mfd')

diff --git a/drivers/mfd/at91-usart.c b/drivers/mfd/at91-usart.c
index a4b9929c156f..d20747f612c1 100644
--- a/drivers/mfd/at91-usart.c
+++ b/drivers/mfd/at91-usart.c
@@ -12,6 +12,7 @@
 
 #include <linux/module.h>
 #include <linux/mfd/core.h>
+#include <linux/of.h>
 #include <linux/property.h>
 
 static struct mfd_cell at91_usart_spi_subdev = {
-- 
cgit v1.2.3


From 9612f8f503804d2fd2f63aa6ba1e58bba4612d96 Mon Sep 17 00:00:00 2001
From: Alexandre Belloni <alexandre.belloni@bootlin.com>
Date: Sun, 9 Sep 2018 22:48:58 +0200
Subject: mfd: menelaus: Fix possible race condition and leak

The IRQ work is added before the struct rtc is allocated and registered,
but this struct is used in the IRQ handler. This may lead to a NULL pointer
dereference.

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before calling menelaus_add_irq_work.

Also, this solves a possible leak as the RTC is never released.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/mfd/menelaus.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

(limited to 'drivers/mfd')

diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c
index 29b7164a823b..d28ebe7ecd21 100644
--- a/drivers/mfd/menelaus.c
+++ b/drivers/mfd/menelaus.c
@@ -1094,6 +1094,7 @@ static void menelaus_rtc_alarm_work(struct menelaus_chip *m)
 static inline void menelaus_rtc_init(struct menelaus_chip *m)
 {
 	int	alarm = (m->client->irq > 0);
+	int	err;
 
 	/* assume 32KDETEN pin is pulled high */
 	if (!(menelaus_read_reg(MENELAUS_OSC_CTRL) & 0x80)) {
@@ -1101,6 +1102,12 @@ static inline void menelaus_rtc_init(struct menelaus_chip *m)
 		return;
 	}
 
+	m->rtc = devm_rtc_allocate_device(&m->client->dev);
+	if (IS_ERR(m->rtc))
+		return;
+
+	m->rtc->ops = &menelaus_rtc_ops;
+
 	/* support RTC alarm; it can issue wakeups */
 	if (alarm) {
 		if (menelaus_add_irq_work(MENELAUS_RTCALM_IRQ,
@@ -1125,10 +1132,8 @@ static inline void menelaus_rtc_init(struct menelaus_chip *m)
 		menelaus_write_reg(MENELAUS_RTC_CTRL, m->rtc_control);
 	}
 
-	m->rtc = rtc_device_register(DRIVER_NAME,
-			&m->client->dev,
-			&menelaus_rtc_ops, THIS_MODULE);
-	if (IS_ERR(m->rtc)) {
+	err = rtc_register_device(m->rtc);
+	if (err) {
 		if (alarm) {
 			menelaus_remove_irq_work(MENELAUS_RTCALM_IRQ);
 			device_init_wakeup(&m->client->dev, 0);
-- 
cgit v1.2.3