gpio/lpc32xx: Add device tree support

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>

1 files changed, 51 insertions, 1 deletions

diff --git a/drivers/gpio/gpio-lpc32xx.c b/drivers/gpio/gpio-lpc32xx.c
index 61c2d08d37b6..c2199beca98a 100644
--- a/drivers/gpio/gpio-lpc32xx.c
+++ b/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_gpiochip[] = {
         },
 };
 
+/* 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);