[Patch v5 08/13] ARM: imx6q: add config-on-boot gpios

[Richard Zhao]

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 at freescale.com>
Cc: Shawn Guo <shawn.guo at linaro.org>
Cc: Rob Herring <rob.herring at calxeda.com>
Cc: Grant Likely <grant.likely at secretlab.ca>
---
 .../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");
+	}
+
+	of_node_put(np);
+}
+
+static void __init imx6q_post_populate(void)
+{
+	imx6q_config_on_boot();
+}
+
 static void __init imx6q_init_machine(void)
 {
 	/*
@@ -126,6 +159,8 @@ static void __init imx6q_init_machine(void)
 
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 
+	imx6q_post_populate();
+
 	imx6q_pm_init();
 }
 
-- 
1.7.9.5