[AVR32] Introduce at32_reserve_pin()
at32_reserve_pin() can be used for reserving portmux pins without
altering their configuration. Useful for e.g. SDRAM pins where we
really don't want to change the bootloader-provided configuration.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/mach-at32ap/pio.c b/arch/avr32/mach-at32ap/pio.c
index c3f596c..9ba5654 100644
--- a/arch/avr32/mach-at32ap/pio.c
+++ b/arch/avr32/mach-at32ap/pio.c
@@ -135,7 +135,28 @@
dump_stack();
}
-/*--------------------------------------------------------------------------*/
+/* Reserve a pin, preventing anyone else from changing its configuration. */
+void __init at32_reserve_pin(unsigned int pin)
+{
+ struct pio_device *pio;
+ unsigned int pin_index = pin & 0x1f;
+
+ pio = gpio_to_pio(pin);
+ if (unlikely(!pio)) {
+ printk("pio: invalid pin %u\n", pin);
+ goto fail;
+ }
+
+ if (unlikely(test_and_set_bit(pin_index, &pio->pinmux_mask))) {
+ printk("%s: pin %u is busy\n", pio->name, pin_index);
+ goto fail;
+ }
+
+ return;
+
+fail:
+ dump_stack();
+}
/*--------------------------------------------------------------------------*/
diff --git a/include/asm-avr32/arch-at32ap/portmux.h b/include/asm-avr32/arch-at32ap/portmux.h
index 2ba611e..9930871 100644
--- a/include/asm-avr32/arch-at32ap/portmux.h
+++ b/include/asm-avr32/arch-at32ap/portmux.h
@@ -23,5 +23,6 @@
void at32_select_periph(unsigned int pin, unsigned int periph,
unsigned long flags);
void at32_select_gpio(unsigned int pin, unsigned long flags);
+void at32_reserve_pin(unsigned int pin);
#endif /* __ASM_ARCH_PORTMUX_H__ */