On 13.06.2012 14:34, Richard Zhao wrote:
Sometimes, boards have gpios that don't own by any driver or owner
by a generic driver that don't like hacks. Such gpios is normally
output and need setup once on boot. So I introduce the config-on-boot
gpios.
Signed-off-by: Richard Zhao <richard.zhao@xxxxxxxxxxxxx>
Cc: Shawn Guo <shawn.guo@xxxxxxxxxx>
Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
---
.../devicetree/bindings/arm/config-on-boot.txt | 12 +++++++
arch/arm/boot/dts/imx6q-sabrelite.dts | 7 ++++
arch/arm/mach-imx/mach-imx6q.c | 35 ++++++++++++++++++++
3 files changed, 54 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/config-on-boot.txt
diff --git a/Documentation/devicetree/bindings/arm/config-on-boot.txt b/Documentation/devicetree/bindings/arm/config-on-boot.txt
new file mode 100644
index 0000000..f98ed74
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/config-on-boot.txt
@@ -0,0 +1,12 @@
+* Configure on Boot
+
+Node name: config-on-boot
+ It must be in root node. config-on-boot means to describe settings that needs
+ to be set one time on boot but aren't owned by any driver, or the owned driver
+ is too generic to handle such settings. For example, usb hub uses generic
+ driver in usb core code, a on-board usb may need deassert reset pin.
+
+Optional properties:
+- output-gpios: Output gpio array that needs to set.
+- output-gpio-values: This property is required if output-gpios is set.
+ The value is a array of 0 or 1. Total count eaquals the number of gpios.
diff --git a/arch/arm/boot/dts/imx6q-sabrelite.dts b/arch/arm/boot/dts/imx6q-sabrelite.dts
index e0ec929..1dd2261 100644
--- a/arch/arm/boot/dts/imx6q-sabrelite.dts
+++ b/arch/arm/boot/dts/imx6q-sabrelite.dts
@@ -17,6 +17,13 @@
model = "Freescale i.MX6 Quad SABRE Lite Board";
compatible = "fsl,imx6q-sabrelite", "fsl,imx6q";
+ config-on-boot {
+ output-gpios = <
+ &gpio3 22 0>; /* vbus reset */
+ output-gpio-values = <
+ 1>; /* vbus reset */
+ };
+
memory {
reg = <0x10000000 0x40000000>;
};
diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index b47e98b..577cf19 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -19,6 +19,7 @@
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_address.h>
+#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/pinctrl/machine.h>
@@ -113,6 +114,38 @@ static void __init imx6q_sabrelite_init(void)
imx6q_sabrelite_cko1_setup();
}
+static void __init imx6q_config_on_boot(void)
+{
+ struct device_node *np;
+ struct property *pp;
+ int cnt, len, i;
+ int gpio;
+
+ np = of_find_node_by_path("/config-on-boot");
+ if (!np)
+ return;
+ cnt = of_gpio_named_count(np, "output-gpios");
+ pp = of_find_property(np, "output-gpio-values", &len);
+ if (!pp || cnt != len / sizeof(u32)) {
+ pr_err("Invalid config-on-boot gpios!\n");
+ of_node_put(np);
+ return;
+ }
+ for (i = 0; i < cnt; i++) {
+ gpio = of_get_named_gpio(np, "output-gpios", i);
+ if (gpio_is_valid(gpio))
+ gpio_request_one(gpio, GPIOF_OUT_INIT_HIGH,
+ "config-on-boot");
While trying to use this code: Is there a special reason why all pins
are set to HIGH here? The contents of 'output-gpio-values' seem to be
ignored?
Best regards
Dirk
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