[PATCH] gpio: mvebu: Add clk support to prevent lockup
From: andrew@lunn.ch (Andrew Lunn)
Date: 2013-02-03 09:55:39
Subsystem:
gpio subsystem, the rest · Maintainers:
Linus Walleij, Bartosz Golaszewski, Linus Torvalds
The kirkwood SoC GPIO cores use the tclk. Add code to clk_prepare_enable() tclk, otherwise there is a danger of locking up the SoC by accessing the GPIO registers when tclk is not ticking. Reported-by: Simon Baatz <redacted> Signed-off-by: Andrew Lunn <andrew@lunn.ch> --- 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 d6ab442..6c5d75f 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 at 10140 {
@@ -49,6 +50,7 @@ interrupt-controller; #interrupt-cells = <2>; interrupts = <39>, <40>, <41>; + clocks = <&gate_clk 7>; }; serial at 12000 {
diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index 6819d63..456663c 100644
--- 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 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;
@@ -528,6 +530,11 @@ 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