stepper: Introduce and use gpio_out_toggle_noirq()

The gpio_out_toggle() function in the sam3x8e and stm32f1 code was
only valid if it was called with irqs disabled.

Commits 018c5daa and 9c52ad43 enabled the lcd code which called
gpio_out_toggle() with irqs enabled.  This could cause corruption of
the gpio state.

Introduce a gpio_out_toggle_noirq() function that will only be invoked
with irqs disabled, and fix gpio_out_toggle() on sam3x8e and stm32f1
so that it safe to call even if irqs are enabled.

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

2 files changed, 8 insertions, 1 deletions

diff --git a/src/pru/gpio.c b/src/pru/gpio.c
index ba4ba935..dfa7567b 100644
--- a/src/pru/gpio.c
+++ b/src/pru/gpio.c
@@ -104,12 +104,18 @@ fail:
 }
 
 void
-gpio_out_toggle(struct gpio_out g)
+gpio_out_toggle_noirq(struct gpio_out g)
 {
     gpio_out_write(g, !(*g.reg & g.bit));
 }
 
 void
+gpio_out_toggle(struct gpio_out g)
+{
+    gpio_out_toggle_noirq(g);
+}
+
+void
 gpio_out_write(struct gpio_out g, uint8_t val)
 {
     volatile uint32_t *reg = g.reg;
diff --git a/src/pru/gpio.h b/src/pru/gpio.h
index fc5e16b9..b3dd5508 100644
--- a/src/pru/gpio.h
+++ b/src/pru/gpio.h
@@ -9,6 +9,7 @@ struct gpio_out {
     uint32_t bit;
 };
 struct gpio_out gpio_out_setup(uint8_t pin, uint8_t val);
+void gpio_out_toggle_noirq(struct gpio_out g);
 void gpio_out_toggle(struct gpio_out g);
 void gpio_out_write(struct gpio_out g, uint8_t val);