drm/hisilicon/hibmc: Add MSI irq getting and requesting for HPD

To realize HPD feature, request irq for HPD , add its handler function.
We use pci_alloc_irq_vectors() to get our msi irq, because we have two
interrupts now.

Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20250331074212.3370287-9-shiyongbang@huawei.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h

@@ -99,6 +99,9 @@
 
 #define HIBMC_DP_TIMING_SYNC_CTRL		0xFF0
 
+#define HIBMC_DP_INTSTAT			0x1e0724
+#define HIBMC_DP_INTCLR				0x1e0728
+
 /* dp serdes reg */
 #define HIBMC_DP_HOST_OFFSET		0x10000
 #define HIBMC_DP_LANE0_RATE_OFFSET	0x4

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c

@@ -32,6 +32,8 @@
 
 DEFINE_DRM_GEM_FOPS(hibmc_fops);
 
+static const char *g_irqs_names_map[HIBMC_MAX_VECTORS] = { "vblank", "hpd" };
+
 static irqreturn_t hibmc_interrupt(int irq, void *arg)
 {
 	struct drm_device *dev = (struct drm_device *)arg;
@@ -49,6 +51,22 @@ static irqreturn_t hibmc_interrupt(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t hibmc_dp_interrupt(int irq, void *arg)
+{
+	struct drm_device *dev = (struct drm_device *)arg;
+	struct hibmc_drm_private *priv = to_hibmc_drm_private(dev);
+	u32 status;
+
+	status = readl(priv->mmio + HIBMC_DP_INTSTAT);
+	if (status) {
+		priv->dp.irq_status = status;
+		writel(status, priv->mmio + HIBMC_DP_INTCLR);
+		return IRQ_WAKE_THREAD;
+	}
+
+	return IRQ_HANDLED;
+}
+
 static int hibmc_dumb_create(struct drm_file *file, struct drm_device *dev,
 			     struct drm_mode_create_dumb *args)
 {
@@ -251,15 +269,48 @@ static int hibmc_hw_init(struct hibmc_drm_private *priv)
 	return 0;
 }
 
-static int hibmc_unload(struct drm_device *dev)
+static void hibmc_unload(struct drm_device *dev)
+{
+	drm_atomic_helper_shutdown(dev);
+}
+
+static int hibmc_msi_init(struct drm_device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
+	char name[32] = {0};
+	int valid_irq_num;
+	int irq;
+	int ret;
 
-	drm_atomic_helper_shutdown(dev);
+	ret = pci_alloc_irq_vectors(pdev, HIBMC_MIN_VECTORS,
+				    HIBMC_MAX_VECTORS, PCI_IRQ_MSI);
+	if (ret < 0) {
+		drm_err(dev, "enabling MSI failed: %d\n", ret);
+		return ret;
+	}
 
-	free_irq(pdev->irq, dev);
+	valid_irq_num = ret;
 
-	pci_disable_msi(to_pci_dev(dev->dev));
+	for (int i = 0; i < valid_irq_num; i++) {
+		snprintf(name, ARRAY_SIZE(name) - 1, "%s-%s-%s",
+			 dev->driver->name, pci_name(pdev), g_irqs_names_map[i]);
+
+		irq = pci_irq_vector(pdev, i);
+
+		if (i)
+			/* PCI devices require shared interrupts. */
+			ret = devm_request_threaded_irq(&pdev->dev, irq,
+							hibmc_dp_interrupt,
+							hibmc_dp_hpd_isr,
+							IRQF_SHARED, name, dev);
+		else
+			ret = devm_request_irq(&pdev->dev, irq, hibmc_interrupt,
+					       IRQF_SHARED, name, dev);
+		if (ret) {
+			drm_err(dev, "install irq failed: %d\n", ret);
+			return ret;
+		}
+	}
 
 	return 0;
 }
@@ -291,15 +342,10 @@ static int hibmc_load(struct drm_device *dev)
 		goto err;
 	}
 
-	ret = pci_enable_msi(pdev);
+	ret = hibmc_msi_init(dev);
 	if (ret) {
-		drm_warn(dev, "enabling MSI failed: %d\n", ret);
+		drm_err(dev, "hibmc msi init failed, ret:%d\n", ret);
-	} else {
+		goto err;
-		/* PCI devices require shared interrupts. */
-		ret = request_irq(pdev->irq, hibmc_interrupt, IRQF_SHARED,
-				  dev->driver->name, dev);
-		if (ret)
-			drm_warn(dev, "install irq failed: %d\n", ret);
 	}
 
 	/* reset all the states of crtc/plane/encoder/connector */
@@ -375,7 +421,7 @@ static void hibmc_pci_remove(struct pci_dev *pdev)
 
 static void hibmc_pci_shutdown(struct pci_dev *pdev)
 {
-	drm_atomic_helper_shutdown(pci_get_drvdata(pdev));
+	hibmc_pci_remove(pdev);
 }
 
 static const struct pci_device_id hibmc_pci_table[] = {

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h

@@ -22,6 +22,9 @@
 
 #include "dp/dp_hw.h"
 
+#define HIBMC_MIN_VECTORS	1
+#define HIBMC_MAX_VECTORS	2
+
 struct hibmc_vdac {
 	struct drm_device *dev;
 	struct drm_encoder encoder;