3.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andrew Lunn <and...@lunn.ch>
commit de88747f514a4e0cca416a8871de2302f4f77790 upstream.
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 <gmbno...@gmail.com>
Signed-off-by: Andrew Lunn <and...@lunn.ch>
Tested-by: Simon Baatz <gmbno...@gmail.com>
Acked-by: Linus Walleij <linus.wall...@linaro.org>
Signed-off-by: Jason Cooper <ja...@lakedaemon.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/arm/boot/dts/kirkwood.dtsi | 2 ++
drivers/gpio/gpio-mvebu.c | 7 +++++++
2 files changed, 9 insertions(+)
--- 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 {
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -41,6 +41,7 @@
#include <linux/io.h>
#include <linux/of_irq.h>
#include <linux/of_device.h>
+#include <linux/clk.h>
#include <linux/pinctrl/consumer.h>
/*
@@ -495,6 +496,7 @@ static int mvebu_gpio_probe(struct platf
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;
@@ -528,6 +530,11 @@ static int mvebu_gpio_probe(struct platf
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;
--
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