commit: de88747f514a4e0cca416a8871de2302f4f77790
From: Andrew Lunn <andrew@xxxxxxx>
Date: Sun, 3 Feb 2013 11:34:26 +0100
Subject: gpio: mvebu: Add clk support to prevent lockup
The kirkwood SoC GPIO cores use the runit clock. Add code to
clk_prepare_enable() runit, otherwise there is a danger of locking up
the SoC by accessing the GPIO registers when runit clock is not
ticking.
Reported-by: Simon Baatz <gmbnomis@xxxxxxxxx>
Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
Tested-by: Simon Baatz <gmbnomis@xxxxxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jason Cooper <jason@xxxxxxxxxxxxxx>
---
arch/arm/boot/dts/kirkwood.dtsi | 2 ++
drivers/gpio/gpio-mvebu.c | 7 +++++++
2 files changed, 9 insertions(+)
diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi
index 19709fb..cf8e892 100644
--- a/arch/arm/boot/dts/kirkwood.dtsi
+++ b/arch/arm/boot/dts/kirkwood.dtsi
@@ -38,6 +38,7 @@
interrupt-controller;
#interrupt-cells = <2>;
interrupts = <35>, <36>, <37>, <38>;
+ clocks = <&gate_clk 7>;
};
gpio1: gpio@10140 {
@@ -49,6 +50,7 @@
interrupt-controller;
#interrupt-cells = <2>;
interrupts = <39>, <40>, <41>;
+ clocks = <&gate_clk 7>;
};
serial@12000 {
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index 7472182..61a6fde 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -42,6 +42,7 @@
#include <linux/io.h>
#include <linux/of_irq.h>
#include <linux/of_device.h>
+#include <linux/clk.h>
#include <linux/pinctrl/consumer.h>
/*
@@ -496,6 +497,7 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
struct resource *res;
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
+ struct clk *clk;
unsigned int ngpios;
int soc_variant;
int i, cpu, id;
@@ -529,6 +531,11 @@ static int mvebu_gpio_probe(struct platform_device *pdev)
return id;
}
+ clk = devm_clk_get(&pdev->dev, NULL);
+ /* Not all SoCs require a clock.*/
+ if (!IS_ERR(clk))
+ clk_prepare_enable(clk);
+
mvchip->soc_variant = soc_variant;
mvchip->chip.label = dev_name(&pdev->dev);
mvchip->chip.dev = &pdev->dev;
--
1.7.10.4
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