Cleaned up GPIO code quite a bit.

1 files changed, 168 insertions, 0 deletions

diff --git a/src/gpio.c b/src/gpio.c
new file mode 100644
index 0000000..e016179
--- /dev/null
+++ b/src/gpio.c
@@ -0,0 +1,168 @@
+#include "gpio.h"
+
+#include "ch573/pfic.h"
+#include "isr_vector.h"
+
+void configure_gpio(gpio_pin_t pin, gpio_config_t cfg)
+{
+  int ipin = pin;
+  struct ch573_gpio__gpio_port_t* port;
+  if (pin & IS_PORT_B) {
+    port = GPIO_PORT_B;
+    ipin &= ~IS_PORT_B;
+  } else {
+    port = GPIO_PORT_A;
+  }
+
+  switch (cfg) {
+    case PIN_CFG_INPUT_FLOATING:
+      GPIO_PORT.dir.set(port, DIR_IN, ipin);
+      GPIO_PORT.pu.set(port, DISABLED, ipin);
+      GPIO_PORT.pd_drv.set(port, 0, ipin);
+      break;
+    case PIN_CFG_INPUT_PULL_UP:
+      GPIO_PORT.dir.set(port, DIR_IN, ipin);
+      GPIO_PORT.pu.set(port, ENABLED, ipin);
+      GPIO_PORT.pd_drv.set(port, 0, ipin);
+      break;
+    case PIN_CFG_INPUT_PULL_DOWN:
+      GPIO_PORT.dir.set(port, DIR_IN, ipin);
+      GPIO_PORT.pu.set(port, DISABLED, ipin);
+      GPIO_PORT.pd_drv.set(port, 1, ipin);
+      break;
+    case PIN_CFG_OUTPUT_5mA:
+      GPIO_PORT.dir.set(port, DIR_OUT, ipin);
+      GPIO_PORT.pu.set(port, DISABLED, ipin);
+      GPIO_PORT.pd_drv.set(port, 0, ipin);
+      break;
+    case PIN_CFG_OUTPUT_20mA:
+      GPIO_PORT.dir.set(port, DIR_OUT, ipin);
+      GPIO_PORT.pu.set(port, DISABLED, ipin);
+      GPIO_PORT.pd_drv.set(port, 1, ipin);
+      break;
+  }
+}
+
+int read_gpio(gpio_pin_t pin)
+{
+  int ipin = pin;
+  struct ch573_gpio__gpio_port_t* port;
+  if (pin & IS_PORT_B) {
+    port = GPIO_PORT_B;
+    ipin &= ~IS_PORT_B;
+  } else {
+    port = GPIO_PORT_A;
+  }
+
+  return !!GPIO_PORT.pin.in.get(port, ipin);
+}
+
+void set_gpio(gpio_pin_t pin, int high)
+{
+  int ipin = pin;
+  struct ch573_gpio__gpio_port_t* port;
+  if (pin & IS_PORT_B) {
+    port = GPIO_PORT_B;
+    ipin &= ~IS_PORT_B;
+  } else {
+    port = GPIO_PORT_A;
+  }
+
+  GPIO_PORT.out.set(port, !!high, ipin);
+}
+
+void enable_alternate_function(alternate_function_t afn)
+{
+  GPIO_I.pin_alternate.set(GPIO, 1 << afn);
+}
+
+#define PFIC ch573_pfic__pfic
+static void enable_gpio_pfic(int irq)
+{
+  PFIC->interrupt_priority_threshold = 0x10;
+  PFIC->interrupt_enable |= irq;
+}
+
+void enable_gpio_interrupt(gpio_pin_t pin, interrupt_mode_t int_mode)
+{
+  int ipin = pin;
+  struct ch573_gpio__gpio_port_t* port;
+
+  volatile uint16_t* port_int_mode;
+  volatile uint16_t* port_int_enable;
+  volatile uint16_t* port_int_flag;
+
+  if (pin & IS_PORT_B) {
+    port = GPIO_PORT_B;
+    ipin &= ~IS_PORT_B;
+    port_int_mode = &GPIO->pb_interrupt_mode;
+    port_int_flag = &GPIO->pb_interrupt_flag;
+    port_int_enable = &GPIO->pb_interrupt_enable;
+
+    enable_gpio_pfic(IRQ_GpioB);
+  } else {
+    port = GPIO_PORT_A;
+    port_int_mode = &GPIO->pa_interrupt_mode;
+    port_int_flag = &GPIO->pa_interrupt_flag;
+    port_int_enable = &GPIO->pa_interrupt_enable;
+
+    enable_gpio_pfic(IRQ_GpioA);
+  }
+
+  switch (int_mode) {
+    case INT_MODE_FALLING_EDGE:
+      *port_int_mode |= 1 << ipin;
+      GPIO_PORT.clr.set(port, 1 << ipin);
+      break;
+
+    case INT_MODE_RISING_EDGE:
+      *port_int_mode |= 1 << ipin;
+      GPIO_PORT.out.set(port, 1, ipin);
+      break;
+
+    case INT_MODE_LEVEL_HIGH:
+      *port_int_mode &= ~(1 << ipin);
+      GPIO_PORT.out.set(port, 1, ipin);
+      break;
+
+    case INT_MODE_LEVEL_LOW:
+      *port_int_mode &= ~(1 << ipin);
+      GPIO_PORT.clr.set(port, 1 << ipin);
+      break;
+  }
+
+  *port_int_flag = 1 << ipin;
+  *port_int_enable |= 1 << ipin;
+}
+
+extern gpio_callback_t GPIO_LISTENERS_START;
+extern gpio_callback_t GPIO_LISTENERS_END;
+void fire_irq(volatile uint16_t* int_flag_ptr, int is_port_b)
+{
+  gpio_callback_t* cur = &GPIO_LISTENERS_START;
+
+  uint16_t pin = 0;
+  uint16_t intflag = *int_flag_ptr;
+
+  for (pin = 0; pin < 16; ++pin) {
+    if (intflag & (1 << pin)) {
+      // If this pin triggered an interrupt, fire the GPIO listeners.
+      for (cur = &GPIO_LISTENERS_START; cur < &GPIO_LISTENERS_END; ++cur) {
+        (*cur)(pin | is_port_b);
+      }
+      *int_flag_ptr |= 1 << pin; // Clear the interrupt for this pin.
+    }
+  }
+
+  *int_flag_ptr = 0xffff;
+}
+
+IRQ(gpio_b)
+{
+  fire_irq(&GPIO->pb_interrupt_flag, IS_PORT_B);
+}
+
+IRQ(gpio_a)
+{
+  fire_irq(&GPIO->pa_interrupt_flag, 0);
+}