GPIO interrupts configuration and handling.

diff --git a/drivers/gpio.c b/drivers/gpio.c
index 351cd44..e5ba6c4 100644 (file)
--- a/drivers/gpio.c
+++ b/drivers/gpio.c
@@ -198,15 +198,184 @@ void set_gpio_pins(void)
        io_config_clk_off();
 }
 
-/* Handlers */
+
+static void (*gpio_calbacks_port0[PORT0_NB_PINS]) (uint32_t);
+static void (*gpio_calbacks_port1[PORT1_NB_PINS]) (uint32_t);
+static void (*gpio_calbacks_port2[PORT2_NB_PINS]) (uint32_t);
+
+
+int set_gpio_callback(void (*callback) (uint32_t), uint8_t port, uint8_t pin, uint8_t sense)
+{
+       struct lpc_gpio* gpio_port = NULL;
+       uint32_t irq = 0;
+
+       /* Register the callback */
+       /* FIXME : we should check that there were none registered for the selected pin */
+       switch (port) {
+               case 0:
+                       if (pin >= PORT0_NB_PINS)
+                               return -EINVAL;
+                       gpio_calbacks_port0[pin] = callback;
+                       gpio_port = LPC_GPIO_0;
+                       irq = PIO_0_IRQ;
+                       break;
+               case 1:
+                       if (pin >= PORT1_NB_PINS)
+                               return -EINVAL;
+                       gpio_calbacks_port1[pin] = callback;
+                       gpio_port = LPC_GPIO_1;
+                       irq = PIO_1_IRQ;
+                       break;
+               case 2:
+                       if (pin >= PORT2_NB_PINS)
+                               return -EINVAL;
+                       gpio_calbacks_port2[pin] = callback;
+                       gpio_port = LPC_GPIO_2;
+                       irq = PIO_2_IRQ;
+                       break;
+               default:
+                       return -EINVAL;
+       }
+
+       /* Configure the pin as interrupt source */
+       gpio_port->data_dir &= ~(1 << pin); /* Input */
+       config_gpio(port, pin, (LPC_IO_FUNC_ALT(0) | LPC_IO_DIGITAL));
+       switch (sense) {
+               case EDGES_BOTH:
+                       gpio_port->int_sense &= ~(1 << pin);
+                       gpio_port->int_both_edges |= (1 << pin);
+                       break;
+               case EDGE_RISING:
+                       gpio_port->int_sense &= ~(1 << pin);
+                       gpio_port->int_both_edges &= ~(1 << pin);
+                       gpio_port->int_event |= (1 << pin);
+                       break;
+               case EDGE_FALLING:
+                       gpio_port->int_sense &= ~(1 << pin);
+                       gpio_port->int_both_edges &= ~(1 << pin);
+                       gpio_port->int_event &= ~(1 << pin);
+                       break;
+               case LEVEL_LOW:
+                       gpio_port->int_sense |= (1 << pin);
+                       gpio_port->int_both_edges &= ~(1 << pin);
+                       gpio_port->int_event &= ~(1 << pin);
+                       break;
+               case LEVEL_HIGH:
+                       gpio_port->int_sense |= (1 << pin);
+                       gpio_port->int_both_edges &= ~(1 << pin);
+                       gpio_port->int_event |= (1 << pin);
+                       break;
+               default: /* Not handled, do not activate the interrupt */
+                       return -EINVAL;
+       }
+       gpio_port->int_enable |= (1 << pin);
+       NVIC_EnableIRQ(irq);
+       return 0;
+}
+void remove_gpio_callback(uint8_t port, uint8_t pin)
+{
+       struct lpc_gpio* gpio_port = NULL;
+       uint32_t irq = 0;
+
+       /* Remove the handler */
+       switch (port) {
+               case 0:
+                       if (pin >= PORT0_NB_PINS)
+                               return;
+                       gpio_calbacks_port0[pin] = NULL;
+                       gpio_port = LPC_GPIO_0;
+                       irq = PIO_0_IRQ;
+                       break;
+               case 1:
+                       if (pin >= PORT1_NB_PINS)
+                               return;
+                       gpio_calbacks_port1[pin] = NULL;
+                       gpio_port = LPC_GPIO_1;
+                       irq = PIO_1_IRQ;
+                       break;
+               case 2:
+                       if (pin >= PORT2_NB_PINS)
+                               return;
+                       gpio_calbacks_port2[pin] = NULL;
+                       gpio_port = LPC_GPIO_2;
+                       irq = PIO_2_IRQ;
+                       break;
+               default:
+                       return;
+       }
+       /* And disable the interrupt */
+       gpio_port->int_enable &= ~(1 << pin);
+       if (gpio_port->int_enable == 0) {
+               NVIC_DisableIRQ(irq);
+       }
+}
+
+
+/* Interrupt Handlers */
+/* Those handlers are far from the most effective if used without concertation
+ * with the people doing the electronic design.
+ * Use them if you place the signals generating interrupts on low numbered pins
+ */
+#include "drivers/serial.h"
 void PIO_0_Handler(void)
 {
+       struct lpc_gpio* gpio0 = LPC_GPIO_0;
+       uint32_t status = gpio0->masked_int_status;
+       uint32_t i = 0;
+
+       /* Call interrupt handlers */
+       while (status) {
+               if (status & 1) {
+                       /* Is there an handler for this one ? */
+                       if (gpio_calbacks_port0[i] != NULL) {
+                               gpio_calbacks_port0[i](i);
+                       }
+                       /* Clear edge detection logic */
+                       gpio0->int_clear |= (1 << i);
+               }
+               status >>= 1;
+               i++;
+       }
 }
 void PIO_1_Handler(void)
 {
+       struct lpc_gpio* gpio1 = LPC_GPIO_1;
+       uint32_t status = gpio1->masked_int_status;
+       uint32_t i = 0;
+
+       /* Call interrupt handlers */
+       while (status) {
+               if (status & 1) {
+                       /* Is there an handler for this one ? */
+                       if (gpio_calbacks_port1[i] != NULL) {
+                               gpio_calbacks_port1[i](i);
+                       }
+                       /* Clear pending interrupt */
+                       gpio1->int_clear |= (1 << i);
+               }
+               status >>= 1;
+               i++;
+       }
 }
 void PIO_2_Handler(void)
 {
+       struct lpc_gpio* gpio2 = LPC_GPIO_2;
+       uint32_t status = gpio2->masked_int_status;
+       uint32_t i = 0;
+
+       /* Call interrupt handlers */
+       while (status) {
+               if (status & 1) {
+                       /* Is there an handler for this one ? */
+                       if (gpio_calbacks_port2[i] != NULL) {
+                               gpio_calbacks_port2[i](i);
+                       }
+                       /* Clear pending interrupt */
+                       gpio2->int_clear |= (1 << i);
+               }
+               status >>= 1;
+               i++;
+       }
 }
 
 

diff --git a/include/drivers/gpio.h b/include/drivers/gpio.h
index cafd106..33a3cca 100644 (file)
--- a/include/drivers/gpio.h
+++ b/include/drivers/gpio.h
@@ -31,6 +31,17 @@
 
 void config_gpio(uint8_t port, uint8_t pin, uint32_t mode);
 
+enum gpio_interrupt_senses {
+       EDGES_BOTH = 0,
+       EDGE_FALLING,
+       EDGE_RISING,
+       LEVEL_HIGH,
+       LEVEL_LOW,
+};
+
+int set_gpio_callback(void (*callback) (uint32_t), uint8_t port, uint8_t pin, uint8_t sense);
+void remove_gpio_callback(uint8_t port, uint8_t pin);
+
 void gpio_on(void);
 void gpio_off(void);