lkml.org 
[lkml]   [2012]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] gpio: Device tree support for LPC32xx
Date
This patch adds device tree support for gpio-lpc32xx.c.

To register the various GPIO banks as (struct) gpio_chips via the same DT
gpio-controller, we utilize the adjusted of_xlate API to manipulate the
actually used struct gpio_chip.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

---
Thanks to Jean-Christophe PLAGNIOL-VILLARD, Grant Likely, Arnd Bergmann, Jon
Smirl, Mark Brown for reviewing!

You can also pull from:
git://git.antcom.de/linux-2.6.git dt/gpio
http://git.antcom.de/linux-2.6.git dt/gpio
http://git.antcom.de/?p=linux-2.6.git;a=shortlog;h=refs/heads/dt/gpio

Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt | 43 +++++++++++++
arch/arm/mach-lpc32xx/include/mach/gpio.h | 9 ++
drivers/gpio/gpio-lpc32xx.c | 52 +++++++++++++++-
3 files changed, 102 insertions(+), 2 deletions(-)
--- /dev/null
+++ linux-2.6/Documentation/devicetree/bindings/gpio/gpio_lpc32xx.txt
@@ -0,0 +1,43 @@
+NXP LPC32xx SoC GPIO controller
+
+Required properties:
+- compatible: must be "nxp,lpc3220-gpio"
+- reg: Physical base address and length of the controller's registers.
+- gpio-controller: Marks the device node as a GPIO controller.
+- #gpio-cells: Should be 3:
+ 1) bank:
+ 0: GPIO P0
+ 1: GPIO P1
+ 2: GPIO P2
+ 3: GPIO P3
+ 4: GPI P3
+ 5: GPO P3
+ 2) pin number
+ 3) optional parameters:
+ - bit 0 specifies polarity (0 for normal, 1 for inverted)
+- reg: Index of the GPIO group
+
+Example:
+
+ gpio: gpio@40028000 {
+ compatible = "nxp,lpc3220-gpio";
+ reg = <0x40028000 0x1000>;
+ gpio-controller;
+ #gpio-cells = <3>; /* bank, pin, flags */
+ };
+
+ leds {
+ compatible = "gpio-leds";
+
+ led0 {
+ gpios = <&gpio 5 1 1>; /* GPO_P3 1, active low */
+ linux,default-trigger = "heartbeat";
+ default-state = "off";
+ };
+
+ led1 {
+ gpios = <&gpio 5 14 1>; /* GPO_P3 14, active low */
+ linux,default-trigger = "timer";
+ default-state = "off";
+ };
+ };
--- 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 +457,57 @@ 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 lpc32xx_of_xlate(struct gpio_chip *gc,
+ const struct of_phandle_args *gpiospec, u32 *flags)
+{
+ /* Is this the correct bank? */
+ u32 bank = gpiospec->args[0];
+ if ((bank > ARRAY_SIZE(lpc32xx_gpiochip) ||
+ (gc != &lpc32xx_gpiochip[bank].chip)))
+ return -EINVAL;
+
+ if (flags)
+ *flags = gpiospec->args[2];
+ return gpiospec->args[1];
+}
+
+static int __devinit lpc32xx_gpio_probe(struct platform_device *pdev)
+{
int i;

- for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++)
+ for (i = 0; i < ARRAY_SIZE(lpc32xx_gpiochip); i++) {
+ if (pdev->dev.of_node) {
+ lpc32xx_gpiochip[i].chip.of_xlate = lpc32xx_of_xlate;
+ lpc32xx_gpiochip[i].chip.of_gpio_n_cells = 3;
+ lpc32xx_gpiochip[i].chip.of_node = pdev->dev.of_node;
+ }
gpiochip_add(&lpc32xx_gpiochip[i].chip);
+ }
+
+ return 0;
}
+
+#ifdef CONFIG_OF
+static struct of_device_id lpc32xx_gpio_of_match[] __devinitdata = {
+ { .compatible = "nxp,lpc3220-gpio", },
+ { },
+};
+#endif
+
+static struct platform_driver lpc32xx_gpio_driver = {
+ .driver = {
+ .name = "lpc32xx-gpio",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(lpc32xx_gpio_of_match),
+ },
+ .probe = lpc32xx_gpio_probe,
+};
+
+module_platform_driver(lpc32xx_gpio_driver);

\
 
 \ /
  Last update: 2012-05-18 11:01    [from the cache]
©2003-2011 Jasper Spaans