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 <[email protected]>
Signed-off-by: Andrew Lunn <[email protected]>
Tested-by: Simon Baatz <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Cc: <[email protected]>
Signed-off-by: Jason Cooper <[email protected]>
This commit is contained in:
Andrew Lunn 2013-02-03 11:34:26 +01:00 • committed by Jason Cooper
commit de88747f51
2 changed files with 9 additions and 0 deletions

View file

@ -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;