drivers: gpio: make reset of TLE9104 optional

In some hardware designs it might happen that the reset signal
for the TLE9104 is not used only for this purpose, but instead for
instance to reset other devices at the same time. For such a hardware
design it is then necessary to make the reset GPIO optional. The reset
will have to be triggered earlier on.

Signed-off-by: Benedikt Schmidt <[email protected]>

drivers/gpio/gpio_tle9104.c

@@ -440,16 +440,18 @@ static int tle9104_init(const struct device *dev)
 		}
 	}
 
-	result = gpio_pin_configure_dt(&config->gpio_reset, GPIO_OUTPUT_ACTIVE);
-	if (result != 0) {
-		LOG_ERR("failed to initialize GPIO for reset");
-		return result;
-	}
+	if (config->gpio_reset.port != NULL) {
+		result = gpio_pin_configure_dt(&config->gpio_reset, GPIO_OUTPUT_ACTIVE);
+		if (result != 0) {
+			LOG_ERR("failed to initialize GPIO for reset");
+			return result;
+		}
 
-	k_busy_wait(TLE9104_RESET_DURATION_TIME_US);
-	gpio_pin_set_dt(&config->gpio_reset, 0);
-	k_busy_wait(TLE9104_RESET_DURATION_WAIT_TIME_US +
-		    TLE9104_RESET_DURATION_WAIT_TIME_SAFETY_MARGIN_US);
+		k_busy_wait(TLE9104_RESET_DURATION_TIME_US);
+		gpio_pin_set_dt(&config->gpio_reset, 0);
+		k_busy_wait(TLE9104_RESET_DURATION_WAIT_TIME_US +
+			    TLE9104_RESET_DURATION_WAIT_TIME_SAFETY_MARGIN_US);
+	}
 
 	/*
 	 * The first read value should be the ICVID, this acts also as the setup of the
@@ -525,7 +527,7 @@ BUILD_ASSERT(CONFIG_GPIO_TLE9104_INIT_PRIORITY > CONFIG_SPI_INIT_PRIORITY,
 		.bus = SPI_DT_SPEC_INST_GET(                                                       \
 			inst, SPI_OP_MODE_MASTER | SPI_MODE_CPHA | SPI_WORD_SET(8), 0),            \
 		.gpio_enable = TLE9104_INIT_GPIO_FIELDS(inst, en_gpios),                           \
-		.gpio_reset = GPIO_DT_SPEC_GET_BY_IDX(DT_DRV_INST(inst), resn_gpios, 0),           \
+		.gpio_reset = TLE9104_INIT_GPIO_FIELDS(inst, resn_gpios),                          \
 		.gpio_control = {                                                                  \
 				TLE9104_INIT_GPIO_FIELDS(inst, in1_gpios),                         \
 				TLE9104_INIT_GPIO_FIELDS(inst, in2_gpios),                         \

dts/bindings/gpio/infineon,tle9104.yaml

@@ -26,7 +26,6 @@ properties:
 
   resn-gpios:
     type: phandle-array
-    required: true
     description: "GPIO for reset"
 
   in1-gpios: