microblaze: Support both levels for reset

Till this patch reset always perform writen to 1.
Now we can use negative logic and perform reset write to 0.

It is opposite level than is currently read from that pin
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/kernel/reset.c

@@ -17,6 +17,7 @@
 #include <linux/of_gpio.h>
 
 static int handle; /* reset pin handle */
+static unsigned int reset_val;
 
 static int of_reset_gpio_handle(void)
 {
@@ -75,9 +76,9 @@ void of_platform_reset_gpio_probe(void)
 	}
 
 	/* get current setup value */
-	ret = gpio_get_value(handle);
+	reset_val = gpio_get_value(handle);
 	/* FIXME maybe worth to perform any action */
-	pr_debug("Reset: Gpio output state: 0x%x\n", ret);
+	pr_debug("Reset: Gpio output state: 0x%x\n", reset_val);
 
 	/* Setup GPIO as output */
 	ret = gpio_direction_output(handle, 0);
@@ -87,7 +88,8 @@ void of_platform_reset_gpio_probe(void)
 	/* Setup output direction */
 	gpio_set_value(handle, 0);
 
-	printk(KERN_INFO "RESET: Registered gpio device: %d\n", handle);
+	printk(KERN_INFO "RESET: Registered gpio device: %d, current val: %d\n",
+							handle, reset_val);
 	return;
 err:
 	gpio_free(handle);
@@ -97,7 +99,7 @@ void of_platform_reset_gpio_probe(void)
 
 static void gpio_system_reset(void)
 {
-	gpio_set_value(handle, 1);
+	gpio_set_value(handle, 1 - reset_val);
 }
 #else
 #define gpio_system_reset() do {} while (0)