stm32: Add optimized stm32h7_gpio.c

Add optimized gpio functions for stm32h7 - caching the ODR register
can notably improve the performance of the gpio_out_toggle() code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/src/stm32/gpio.h b/src/stm32/gpio.h
index 6a5f910c..0bfffc4b 100644
--- a/src/stm32/gpio.h
+++ b/src/stm32/gpio.h
@@ -5,7 +5,10 @@
 
 struct gpio_out {
     void *regs;
-    uint32_t bit;
+    union {
+        struct odr_cache *oc;  // stm32h7 uses 'oc'; all others use 'bit'
+        uint32_t bit;
+    };
 };
 struct gpio_out gpio_out_setup(uint32_t pin, uint32_t val);
 void gpio_out_reset(struct gpio_out g, uint32_t val);