drivers: gpio: mcp23xxx: support single-edge interrupts

An interrupt is triggered for every edge, but only the desired edges cause a callback to be called. Signed-off-by: Armin Brauns <[email protected]>
albayenes · Mar 20, 2023 · 07af23c · 07af23c
1 parent 0db9785
commit 07af23c
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Showing 2 changed files with 17 additions and 3 deletions.
diff --git a/drivers/gpio/gpio_mcp23xxx.c b/drivers/gpio/gpio_mcp23xxx.c
@@ -330,11 +330,16 @@ static int mcp23xxx_pin_interrupt_configure(const struct device *dev, gpio_pin_t
 
 		switch (trig) {
 		case GPIO_INT_TRIG_LOW:
+			drv_data->rising_edge_ints &= ~BIT(pin);
+			drv_data->falling_edge_ints |= BIT(pin);
+			break;
 		case GPIO_INT_TRIG_HIGH:
-			LOG_ERR("mcp23xxx does not support single-edge interrupts");
-			ret = -ENOTSUP;
-			goto done;
+			drv_data->rising_edge_ints |= BIT(pin);
+			drv_data->falling_edge_ints &= ~BIT(pin);
+			break;
 		case GPIO_INT_TRIG_BOTH:
+			drv_data->rising_edge_ints |= BIT(pin);
+			drv_data->falling_edge_ints |= BIT(pin);
 			break;
 		}
 		break;
@@ -421,6 +426,12 @@ static void mcp23xxx_work_handler(struct k_work *work)
 		goto done;
 	}
 
+	/* mcp23xxx does not support single-edge interrupts in hardware, filter them out manually */
+	uint16_t level_ints = drv_data->reg_cache.gpinten & drv_data->reg_cache.intcon;
+
+	intf &= level_ints | (intcap & drv_data->rising_edge_ints) |
+		(~intcap & drv_data->falling_edge_ints);
+
 	gpio_fire_callbacks(&drv_data->callbacks, dev, intf);
 done:
 	k_sem_give(&drv_data->lock);

diff --git a/drivers/gpio/gpio_mcp23xxx.h b/drivers/gpio/gpio_mcp23xxx.h
@@ -76,6 +76,9 @@ struct mcp23xxx_drv_data {
 	struct gpio_callback int_gpio_cb;
 	struct k_work work;
 
+	uint16_t rising_edge_ints;
+	uint16_t falling_edge_ints;
+
 	struct {
 		uint16_t iodir;
 		uint16_t ipol;