drm/amd/display: add gpio lock/unlock

[Why]
When querying HPD via GPIO flow,
it will create a new gpio object then free in the end of query.
There is a irql issue for HPD querying at ISR level.

[How]
Therefore, creating the HPD gpio object in dc_link and set it as unlcok in default.
1. reducing unnecessary malloc/free when HPD querying.
2. reducing init GPIO flow.
3. add lock/unlock to prevent multi gpio service running.

Signed-off-by: Chiawen Huang <chiawen.huang@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link.c

@@ -76,6 +76,12 @@ static void destruct(struct dc_link *link)
 {
 	int i;
 
+	if (link->hpd_gpio != NULL) {
+		dal_gpio_close(link->hpd_gpio);
+		dal_gpio_destroy_irq(&link->hpd_gpio);
+		link->hpd_gpio = NULL;
+	}
+
 	if (link->ddc)
 		dal_ddc_service_destroy(&link->ddc);
 
@@ -931,18 +937,11 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 
 bool dc_link_get_hpd_state(struct dc_link *dc_link)
 {
-	struct gpio *hpd_pin;
 	uint32_t state;
 
-	hpd_pin = get_hpd_gpio(dc_link->ctx->dc_bios,
+	dal_gpio_lock_pin(dc_link->hpd_gpio);
-					dc_link->link_id, dc_link->ctx->gpio_service);
+	dal_gpio_get_value(dc_link->hpd_gpio, &state);
-	if (hpd_pin == NULL)
+	dal_gpio_unlock_pin(dc_link->hpd_gpio);
-		ASSERT(false);
-
-	dal_gpio_open(hpd_pin, GPIO_MODE_INTERRUPT);
-	dal_gpio_get_value(hpd_pin, &state);
-	dal_gpio_close(hpd_pin);
-	dal_gpio_destroy_irq(&hpd_pin);
 
 	return state;
 }
@@ -1098,7 +1097,6 @@ static bool construct(
 	const struct link_init_data *init_params)
 {
 	uint8_t i;
-	struct gpio *hpd_gpio = NULL;
 	struct ddc_service_init_data ddc_service_init_data = { { 0 } };
 	struct dc_context *dc_ctx = init_params->ctx;
 	struct encoder_init_data enc_init_data = { 0 };
@@ -1128,10 +1126,11 @@ static bool construct(
 	if (link->dc->res_pool->funcs->link_init)
 		link->dc->res_pool->funcs->link_init(link);
 
-	hpd_gpio = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);
+	link->hpd_gpio = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);
-
+	dal_gpio_open(link->hpd_gpio, GPIO_MODE_INTERRUPT);
-	if (hpd_gpio != NULL)
+	dal_gpio_unlock_pin(link->hpd_gpio);
-		link->irq_source_hpd = dal_irq_get_source(hpd_gpio);
+	if (link->hpd_gpio != NULL)
+		link->irq_source_hpd = dal_irq_get_source(link->hpd_gpio);
 
 	switch (link->link_id.id) {
 	case CONNECTOR_ID_HDMI_TYPE_A:
@@ -1149,18 +1148,18 @@ static bool construct(
 	case CONNECTOR_ID_DISPLAY_PORT:
 		link->connector_signal =	SIGNAL_TYPE_DISPLAY_PORT;
 
-		if (hpd_gpio != NULL)
+		if (link->hpd_gpio != NULL)
 			link->irq_source_hpd_rx =
-					dal_irq_get_rx_source(hpd_gpio);
+					dal_irq_get_rx_source(link->hpd_gpio);
 
 		break;
 	case CONNECTOR_ID_EDP:
 		link->connector_signal = SIGNAL_TYPE_EDP;
 
-		if (hpd_gpio != NULL) {
+		if (link->hpd_gpio != NULL) {
 			link->irq_source_hpd = DC_IRQ_SOURCE_INVALID;
 			link->irq_source_hpd_rx =
-					dal_irq_get_rx_source(hpd_gpio);
+					dal_irq_get_rx_source(link->hpd_gpio);
 		}
 		break;
 	case CONNECTOR_ID_LVDS:
@@ -1171,10 +1170,7 @@ static bool construct(
 		goto create_fail;
 	}
 
-	if (hpd_gpio != NULL) {
+
-		dal_gpio_destroy_irq(&hpd_gpio);
-		hpd_gpio = NULL;
-	}
 
 	/* TODO: #DAL3 Implement id to str function.*/
 	LINK_INFO("Connector[%d] description:"
@@ -1277,8 +1273,9 @@ static bool construct(
 ddc_create_fail:
 create_fail:
 
-	if (hpd_gpio != NULL) {
+	if (link->hpd_gpio != NULL) {
-		dal_gpio_destroy_irq(&hpd_gpio);
+		dal_gpio_destroy_irq(&link->hpd_gpio);
+		link->hpd_gpio = NULL;
 	}
 
 	return false;

drivers/gpu/drm/amd/display/dc/dc_link.h

@@ -125,6 +125,7 @@ struct dc_link {
 	struct dc_link_status link_status;
 
 	struct link_trace link_trace;
+	struct gpio *hpd_gpio;
 };
 
 const struct dc_link_status *dc_link_get_status(const struct dc_link *dc_link);

drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c

@@ -101,6 +101,18 @@ enum gpio_mode dal_gpio_get_mode(
 	return gpio->mode;
 }
 
+enum gpio_result dal_gpio_lock_pin(
+	struct gpio *gpio)
+{
+	return dal_gpio_service_lock(gpio->service, gpio->id, gpio->en);
+}
+
+enum gpio_result dal_gpio_unlock_pin(
+	struct gpio *gpio)
+{
+	return dal_gpio_service_unlock(gpio->service, gpio->id, gpio->en);
+}
+
 enum gpio_result dal_gpio_change_mode(
 	struct gpio *gpio,
 	enum gpio_mode mode)

drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c

@@ -192,6 +192,34 @@ static void set_pin_free(
 	service->busyness[id][en] = false;
 }
 
+enum gpio_result dal_gpio_service_lock(
+	struct gpio_service *service,
+	enum gpio_id id,
+	uint32_t en)
+{
+	if (!service->busyness[id]) {
+		ASSERT_CRITICAL(false);
+		return GPIO_RESULT_OPEN_FAILED;
+	}
+
+	set_pin_busy(service, id, en);
+	return GPIO_RESULT_OK;
+}
+
+enum gpio_result dal_gpio_service_unlock(
+	struct gpio_service *service,
+	enum gpio_id id,
+	uint32_t en)
+{
+	if (!service->busyness[id]) {
+		ASSERT_CRITICAL(false);
+		return GPIO_RESULT_OPEN_FAILED;
+	}
+
+	set_pin_free(service, id, en);
+	return GPIO_RESULT_OK;
+}
+
 enum gpio_result dal_gpio_service_open(
 	struct gpio_service *service,
 	enum gpio_id id,

drivers/gpu/drm/amd/display/dc/gpio/gpio_service.h

@@ -52,4 +52,14 @@ void dal_gpio_service_close(
 	struct gpio_service *service,
 	struct hw_gpio_pin **ptr);
 
+enum gpio_result dal_gpio_service_lock(
+	struct gpio_service *service,
+	enum gpio_id id,
+	uint32_t en);
+
+enum gpio_result dal_gpio_service_unlock(
+	struct gpio_service *service,
+	enum gpio_id id,
+	uint32_t en);
+
 #endif

drivers/gpu/drm/amd/display/include/gpio_interface.h

@@ -59,6 +59,14 @@ enum gpio_result dal_gpio_change_mode(
 	struct gpio *gpio,
 	enum gpio_mode mode);
 
+/* Lock Pin */
+enum gpio_result dal_gpio_lock_pin(
+	struct gpio *gpio);
+
+/* Unlock Pin */
+enum gpio_result dal_gpio_unlock_pin(
+	struct gpio *gpio);
+
 /* Get the GPIO id */
 enum gpio_id dal_gpio_get_id(
 	const struct gpio *gpio);