path: root/drivers/gpio
diff options
authorAndrew Lunn <andrew@lunn.ch>2013-02-03 11:34:26 +0100
committerJason Cooper <jason@lakedaemon.net>2013-03-08 21:34:34 +0000
commitde88747f514a4e0cca416a8871de2302f4f77790 (patch)
treea0a44be0a4ca5f16784bed1ee835b9ec85ddda5a /drivers/gpio
parent7bf5b408b419fc849578e6e9fbd221bf43638eb6 (diff)
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@gmail.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Simon Baatz <gmbnomis@gmail.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Diffstat (limited to 'drivers/gpio')
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index 7472182967c..61a6fde6c08 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;