+#if defined(CONFIG_AVR32)
+
+static void toggle_bias(int is_on)
+{
+}
+
+#elif defined(CONFIG_ARCH_AT91)
+
+#include <asm/arch/at91_pmc.h>
+
+static void toggle_bias(int is_on)
+{
+ unsigned int uckr = at91_sys_read(AT91_CKGR_UCKR);
+
+ if (is_on)
+ at91_sys_write(AT91_CKGR_UCKR, uckr | AT91_PMC_BIASEN);
+ else
+ at91_sys_write(AT91_CKGR_UCKR, uckr & ~(AT91_PMC_BIASEN));
+}
+
+#endif /* CONFIG_ARCH_AT91 */
+