samd21: Restore pin cfg when exti is disabled

Instead of clearing the pmux, set it back to the previous value as is
needed by ms5607.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/samd21/ao_exti_samd21.c b/src/samd21/ao_exti_samd21.c
index 962197837713975d0950d9e7db048fe0ae0f5050..d8109483a83a1e6a3c61de4097c69b507d3cda00 100644 (file)
--- a/src/samd21/ao_exti_samd21.c
+++ b/src/samd21/ao_exti_samd21.c
@@ -21,8 +21,8 @@
 
 struct ao_samd21_exti {
        void                    (*callback)(void);
-       struct samd21_port      *port;
-       uint8_t                 pin;
+       uint8_t                 pmux;
+       uint8_t                 pincfg;
 };
 
 static struct ao_samd21_exti ao_samd21_exti[SAMD21_NUM_EIC];
@@ -87,16 +87,21 @@ ao_exti_setup (struct samd21_port *port, uint8_t pin, uint8_t mode, void (*callb
        uint8_t                 id = pin_id(port,pin);
        struct ao_samd21_exti   *exti = &ao_samd21_exti[id];
 
-       if (exti->port)
+       if (exti->callback)
                ao_panic(AO_PANIC_EXTI);
 
-       if (!(mode & AO_EXTI_PIN_NOCONFIGURE))
+       if (mode & AO_EXTI_PIN_NOCONFIGURE) {
+               ao_enable_port(port);
+               samd21_port_dir_set(port, pin, SAMD21_PORT_DIR_IN);
+               samd21_port_pincfg_set(port, pin,
+                                      (1 << SAMD21_PORT_PINCFG_INEN),
+                                      (1 << SAMD21_PORT_PINCFG_INEN));
+       } else {
                ao_enable_input(port, pin, mode);
+       }
 
        ao_arch_block_interrupts();
 
-       exti->port = port;
-       exti->pin = pin;
        exti->callback = callback;
 
        /* Set edge triggered */
@@ -133,6 +138,8 @@ ao_exti_enable(struct samd21_port *port, uint8_t pin)
        ao_arch_block_interrupts();
        samd21_eic.intenset = 1 << id;
        /* configure gpio to interrupt routing */
+       ao_samd21_exti[id].pmux = samd21_port_pmux_get(port, pin);
+       ao_samd21_exti[id].pincfg = samd21_port_pincfg_get(port, pin);
        samd21_port_pmux_set(port, pin, SAMD21_PORT_PMUX_FUNC_A);
        ao_arch_release_interrupts();
 }
@@ -144,8 +151,11 @@ ao_exti_disable(struct samd21_port *port, uint8_t pin)
 
        ao_arch_block_interrupts();
        samd21_eic.intenclr = 1 << id;
-       /* configure gpio to interrupt routing */
-       samd21_port_pmux_clr(port, pin);
+       /* restore gpio config */
+       if (ao_samd21_exti[id].pincfg & (1 << SAMD21_PORT_PINCFG_PMUXEN))
+               samd21_port_pmux_set(port, pin, ao_samd21_exti[id].pmux);
+       else
+               samd21_port_pmux_clr(port, pin);
        ao_arch_release_interrupts();
 }