pinctrl: generic: dump pin configuration

Add the support of dumping pin configuration.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/pinctrl/pinconf-generic.c b/drivers/pinctrl/pinconf-generic.c
index 06c304a..9c43685 100644
--- a/drivers/pinctrl/pinconf-generic.c
+++ b/drivers/pinctrl/pinconf-generic.c
@@ -12,6 +12,7 @@
 #define pr_fmt(fmt) "generic pinconfig core: " fmt
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/slab.h>
@@ -120,4 +121,17 @@
 	}
 }
 
+void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
+				 struct seq_file *s, unsigned long config)
+{
+	int i;
+
+	for(i = 0; i < ARRAY_SIZE(conf_items); i++) {
+		if (pinconf_to_config_param(config) != conf_items[i].param)
+			continue;
+		seq_printf(s, "%s: 0x%x", conf_items[i].display,
+			   pinconf_to_config_argument(config));
+	}
+}
+EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
 #endif