drm/msm/mdp5: use irqdomains

For mdp5, the irqs of hdmi/eDP/dsi0/dsi1 blocks get routed through the
mdp block.  In order to decouple hdmi/eDP/etc, register an irq domain
in mdp5.  When hdmi/dsi/etc are used with mdp4, they can directly setup
their irqs in their DT nodes as normal.  When used with mdp5, instead
set the mdp device as the interrupt-parent, as in:

	mdp: qcom,mdss_mdp@fd900000 {
		compatible = "qcom,mdss_mdp";
		interrupt-controller;
		#interrupt-cells = <1>;
		...
	};

	hdmi: qcom,hdmi_tx@fd922100 {
		compatible = "qcom,hdmi-tx-8074";
		interrupt-parent = <&mdp>;
		interrupts = <8 0>;   /* MDP5_HW_INTR_STATUS.INTR_HDMI */
		...
	};

There is a slight awkwardness, in that we cannot disable child irqs
at the mdp level, they can only be cleared in the child block.  So
you must not use threaded irq handlers in the child.  I'm not sure
if there is a better way to deal with that.

Signed-off-by: Rob Clark <robdclark@gmail.com>

3 files changed, 107 insertions, 4 deletions

diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_irq.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_irq.c
index 812c59bbaf7..70ac81edd40 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_irq.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_irq.c
@@ -15,6 +15,8 @@
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
 
 #include "msm_drv.h"
 #include "mdp5_kms.h"
@@ -82,18 +84,23 @@ irqreturn_t mdp5_irq(struct msm_kms *kms)
 {
 	struct mdp_kms *mdp_kms = to_mdp_kms(kms);
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(mdp_kms);
-	struct msm_drm_private *priv = mdp5_kms->dev->dev_private;
 	uint32_t intr;
 
 	intr = mdp5_read(mdp5_kms, REG_MDP5_HW_INTR_STATUS);
 
 	VERB("intr=%08x", intr);
 
-	if (intr & MDP5_HW_INTR_STATUS_INTR_MDP)
+	if (intr & MDP5_HW_INTR_STATUS_INTR_MDP) {
 		mdp5_irq_mdp(mdp_kms);
+		intr &= ~MDP5_HW_INTR_STATUS_INTR_MDP;
+	}
 
-	if (intr & MDP5_HW_INTR_STATUS_INTR_HDMI)
-		hdmi_irq(0, priv->hdmi);
+	while (intr) {
+		irq_hw_number_t hwirq = fls(intr) - 1;
+		generic_handle_irq(irq_find_mapping(
+				mdp5_kms->irqcontroller.domain, hwirq));
+		intr &= ~(1 << hwirq);
+	}
 
 	return IRQ_HANDLED;
 }
@@ -110,3 +117,82 @@ void mdp5_disable_vblank(struct msm_kms *kms, struct drm_crtc *crtc)
 	mdp_update_vblank_mask(to_mdp_kms(kms),
 			mdp5_crtc_vblank(crtc), false);
 }
+
+/*
+ * interrupt-controller implementation, so sub-blocks (hdmi/eDP/dsi/etc)
+ * can register to get their irq's delivered
+ */
+
+#define VALID_IRQS  (MDP5_HW_INTR_STATUS_INTR_DSI0 | \
+		MDP5_HW_INTR_STATUS_INTR_DSI1 | \
+		MDP5_HW_INTR_STATUS_INTR_HDMI | \
+		MDP5_HW_INTR_STATUS_INTR_EDP)
+
+static void mdp5_hw_mask_irq(struct irq_data *irqd)
+{
+	struct mdp5_kms *mdp5_kms = irq_data_get_irq_chip_data(irqd);
+	smp_mb__before_atomic();
+	clear_bit(irqd->hwirq, &mdp5_kms->irqcontroller.enabled_mask);
+	smp_mb__after_atomic();
+}
+
+static void mdp5_hw_unmask_irq(struct irq_data *irqd)
+{
+	struct mdp5_kms *mdp5_kms = irq_data_get_irq_chip_data(irqd);
+	smp_mb__before_atomic();
+	set_bit(irqd->hwirq, &mdp5_kms->irqcontroller.enabled_mask);
+	smp_mb__after_atomic();
+}
+
+static struct irq_chip mdp5_hw_irq_chip = {
+	.name		= "mdp5",
+	.irq_mask	= mdp5_hw_mask_irq,
+	.irq_unmask	= mdp5_hw_unmask_irq,
+};
+
+static int mdp5_hw_irqdomain_map(struct irq_domain *d,
+		unsigned int irq, irq_hw_number_t hwirq)
+{
+	struct mdp5_kms *mdp5_kms = d->host_data;
+
+	if (!(VALID_IRQS & (1 << hwirq)))
+		return -EPERM;
+
+	irq_set_chip_and_handler(irq, &mdp5_hw_irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, mdp5_kms);
+	set_irq_flags(irq, IRQF_VALID);
+
+	return 0;
+}
+
+static struct irq_domain_ops mdp5_hw_irqdomain_ops = {
+	.map = mdp5_hw_irqdomain_map,
+	.xlate = irq_domain_xlate_onecell,
+};
+
+
+int mdp5_irq_domain_init(struct mdp5_kms *mdp5_kms)
+{
+	struct device *dev = mdp5_kms->dev->dev;
+	struct irq_domain *d;
+
+	d = irq_domain_add_linear(dev->of_node, 32,
+			&mdp5_hw_irqdomain_ops, mdp5_kms);
+	if (!d) {
+		dev_err(dev, "mdp5 irq domain add failed\n");
+		return -ENXIO;
+	}
+
+	mdp5_kms->irqcontroller.enabled_mask = 0;
+	mdp5_kms->irqcontroller.domain = d;
+
+	return 0;
+}
+
+void mdp5_irq_domain_fini(struct mdp5_kms *mdp5_kms)
+{
+	if (mdp5_kms->irqcontroller.domain) {
+		irq_domain_remove(mdp5_kms->irqcontroller.domain);
+		mdp5_kms->irqcontroller.domain = NULL;
+	}
+}
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
index ce0308124a7..6c414db6ff0 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
@@ -221,10 +221,13 @@ static void mdp5_destroy(struct msm_kms *kms)
 	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
 	struct msm_mmu *mmu = mdp5_kms->mmu;
 
+	mdp5_irq_domain_fini(mdp5_kms);
+
 	if (mmu) {
 		mmu->funcs->detach(mmu, iommu_ports, ARRAY_SIZE(iommu_ports));
 		mmu->funcs->destroy(mmu);
 	}
+
 	kfree(mdp5_kms);
 }
 
@@ -279,6 +282,13 @@ static int modeset_init(struct mdp5_kms *mdp5_kms)
 	struct drm_encoder *encoder;
 	int i, ret;
 
+	/* register our interrupt-controller for hdmi/eDP/dsi/etc
+	 * to use for irqs routed through mdp:
+	 */
+	ret = mdp5_irq_domain_init(mdp5_kms);
+	if (ret)
+		goto fail;
+
 	/* construct CRTCs: */
 	for (i = 0; i < mdp5_kms->hw_cfg->pipe_rgb.count; i++) {
 		struct drm_plane *plane;
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
index c91101d5ac0..0e9e3f7f4e9 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
@@ -72,6 +72,11 @@ struct mdp5_kms {
 	struct clk *vsync_clk;
 
 	struct mdp_irq error_handler;
+
+	struct {
+		volatile unsigned long enabled_mask;
+		struct irq_domain *domain;
+	} irqcontroller;
 };
 #define to_mdp5_kms(x) container_of(x, struct mdp5_kms, base)
 
@@ -195,6 +200,8 @@ void mdp5_irq_uninstall(struct msm_kms *kms);
 irqreturn_t mdp5_irq(struct msm_kms *kms);
 int mdp5_enable_vblank(struct msm_kms *kms, struct drm_crtc *crtc);
 void mdp5_disable_vblank(struct msm_kms *kms, struct drm_crtc *crtc);
+int mdp5_irq_domain_init(struct mdp5_kms *mdp5_kms);
+void mdp5_irq_domain_fini(struct mdp5_kms *mdp5_kms);
 
 static inline
 uint32_t mdp5_get_formats(enum mdp5_pipe pipe, uint32_t *pixel_formats,