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Subject[PATCH v2] gpio: Device tree support for LPC32xx
Date
This patch adds device tree support for gpio-lpc32xx.c

Signed-off-by: Roland Stigge <stigge@antcom.de>

---
Applies to v3.4-rc1

Changes since last version:
* Documented property #address-cells (always 1)
* Documented property status="disabled"
* Removed gpio-lines property
* Removed #gpio-cells from the parent node
* Support both DT and non-DT to make patch less disruptive and independent
from DT switch of mach-lpc32xx
* Use module_platform_driver()

Thanks to Arnd Bergmann and Grant Likely for reviewing!

Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt | 65 ++++++++++++++++
arch/arm/mach-lpc32xx/include/mach/gpio.h | 9 +-
drivers/gpio/gpio-lpc32xx.c | 52 ++++++++++++
3 files changed, 123 insertions(+), 3 deletions(-)
--- /dev/null
+++ linux-2.6/Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt
@@ -0,0 +1,65 @@
+NXP LPC32xx SoC GPIO controller
+
+Required properties:
+- compatible: "nxp,lpc32xx-gpio"
+- reg: Physical base address and length of the controller's registers.
+- #address-cells: Always 1, for indexing of the subnodes (GPIO groups of the
+ SoC)
+- #size-cells: Always 0
+
+Required properties of sub-nodes which describe the GPIO groups of LPC32xx:
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells: Should be two. The first cell is the pin number and the
+ second cell is used to specify optional parameters:
+ - bit 0 specifies polarity (0 for normal, 1 for inverted)
+- reg: Index of the GPIO group
+
+Optional properties of sub-nodes which describe the GPIO groups of LPC32xx:
+- status: Set to "disabled" if you don't use the respective GPIO group
+ of the LPC32 SoC
+
+Example:
+
+ gpio: gpio@40028000 {
+ compatible = "nxp,lpc32xx-gpio";
+ reg = <0x40028000 0x1000>;
+ /* create a private address space for enumeration */
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ gpio_p0: gpio-bank@0 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0>;
+ };
+
+ gpio_p1: gpio-bank@1 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <1>;
+ };
+
+ gpio_p2: gpio-bank@2 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <2>;
+ };
+
+ gpio_p3: gpio-bank@3 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <3>;
+ };
+
+ gpi_p3: gpio-bank@4 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <4>;
+ };
+
+ gpo_p3: gpio-bank@5 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <5>;
+ };
+ };
--- linux-2.6.orig/arch/arm/mach-lpc32xx/include/mach/gpio.h
+++ linux-2.6/arch/arm/mach-lpc32xx/include/mach/gpio.h
@@ -1 +1,8 @@
-/* empty */
+#ifndef __MACH_GPIO_H
+#define __MACH_GPIO_H
+
+#include "gpio-lpc32xx.h"
+
+#define ARCH_NR_GPIOS (LPC32XX_GPO_P3_GRP + LPC32XX_GPO_P3_MAX)
+
+#endif /* __MACH_GPIO_H */
--- linux-2.6.orig/drivers/gpio/gpio-lpc32xx.c
+++ linux-2.6/drivers/gpio/gpio-lpc32xx.c
@@ -21,6 +21,9 @@
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>

#include <mach/hardware.h>
#include <mach/platform.h>
@@ -454,10 +457,55 @@ static struct lpc32xx_gpio_chip lpc32xx_
},
};

+/* Empty now, can be removed later when mach-lpc32xx is finally switched over
+ * to DT support
+ */
void __init lpc32xx_gpio_init(void)
{
+}
+
+static int __devinit lpc32xx_gpio_probe(struct platform_device *pdev)
+{
+ struct device_node *node;
int i;

- for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++)
- gpiochip_add(&lpc32xx_gpiochip[i].chip);
+ if (pdev->dev.of_node) {
+ for_each_child_of_node(pdev->dev.of_node, node) {
+ if (of_device_is_available(node)) {
+ u32 index;
+ struct gpio_chip *chip;
+ if (of_property_read_u32(node,
+ "reg", &index) < 0)
+ continue;
+ if (index >= ARRAY_SIZE(lpc32xx_gpiochip))
+ continue;
+ chip = &lpc32xx_gpiochip[index].chip;
+ chip->of_node = of_node_get(node);
+ gpiochip_add(chip);
+ }
+ }
+ } else {
+ for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++)
+ gpiochip_add(&lpc32xx_gpiochip[i].chip);
+ }
+
+ return 0;
}
+
+#ifdef CONFIG_OF
+static struct of_device_id lpc32xx_gpio_of_match[] __devinitdata = {
+ { .compatible = "nxp,lpc32xx-gpio", },
+ { },
+};
+#endif
+
+static struct platform_driver lpc32xx_gpio_driver = {
+ .driver = {
+ .name = "lpc32xx-gpio",
+ .owner = THIS_MODULE,
+ .of_match_table = lpc32xx_gpio_of_match,
+ },
+ .probe = lpc32xx_gpio_probe,
+};
+
+module_platform_driver(lpc32xx_gpio_driver);

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