drm/nouveau/disp/dp: maintain receiver caps in response to hpd signal

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

2 files changed, 68 insertions, 8 deletions

diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
index ea6483d066c1..7f5588755436 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.c
@@ -26,21 +26,73 @@
 
 #include "outpdp.h"
 #include "conn.h"
+#include "dport.h"
 
-static int
-nvkm_output_dp_service(void *data, u32 type, int index)
+static void
+nvkm_output_dp_enable(struct nvkm_output_dp *outp, bool present)
 {
-        struct nvkm_output_dp *outp = data;
-        DBG("IRQ: %d\n", type);
-        return NVKM_EVENT_KEEP;
+        struct nouveau_i2c_port *port = outp->base.edid;
+        if (present) {
+                if (!outp->present) {
+                        nouveau_i2c(port)->acquire_pad(port, 0);
+                        DBG("aux power -> always\n");
+                        outp->present = true;
+                }
+        } else {
+                if (outp->present) {
+                        nouveau_i2c(port)->release_pad(port);
+                        DBG("aux power -> demand\n");
+                        outp->present = false;
+                }
+        }
+}
+
+static void
+nvkm_output_dp_detect(struct nvkm_output_dp *outp)
+{
+        struct nouveau_i2c_port *port = outp->base.edid;
+        int ret = nouveau_i2c(port)->acquire_pad(port, 0);
+        if (ret == 0) {
+                ret = nv_rdaux(outp->base.edid, DPCD_RC00_DPCD_REV,
+                               outp->dpcd, sizeof(outp->dpcd));
+                nvkm_output_dp_enable(outp, ret == 0);
+                nouveau_i2c(port)->release_pad(port);
+        }
+}
+
+static void
+nvkm_output_dp_service_work(struct work_struct *work)
+{
+        struct nvkm_output_dp *outp = container_of(work, typeof(*outp), work);
+        struct nouveau_disp *disp = nouveau_disp(outp);
+        int type = atomic_xchg(&outp->pending, 0);
+        u32 send = 0;
+
+        if (type & (NVKM_I2C_PLUG | NVKM_I2C_UNPLUG)) {
+                nvkm_output_dp_detect(outp);
+                if (type & NVKM_I2C_UNPLUG)
+                        send |= NVKM_HPD_UNPLUG;
+                if (type & NVKM_I2C_PLUG)
+                        send |= NVKM_HPD_PLUG;
+                nouveau_event_get(outp->base.conn->hpd.event);
+        }
+
+        if (type & NVKM_I2C_IRQ) {
+                nouveau_event_get(outp->irq);
+                send |= NVKM_HPD_IRQ;
+        }
+
+        nouveau_event_trigger(disp->hpd, send, outp->base.info.connector);
 }
 
 static int
-nvkm_output_dp_hotplug(void *data, u32 type, int index)
+nvkm_output_dp_service(void *data, u32 type, int index)
 {
         struct nvkm_output_dp *outp = data;
         DBG("HPD: %d\n", type);
-        return NVKM_EVENT_KEEP;
+        atomic_or(type, &outp->pending);
+        schedule_work(&outp->work);
+        return NVKM_EVENT_DROP;
 }
 
 int
@@ -48,6 +100,7 @@ _nvkm_output_dp_fini(struct nouveau_object *object, bool suspend)
 {
         struct nvkm_output_dp *outp = (void *)object;
         nouveau_event_put(outp->irq);
+        nvkm_output_dp_enable(outp, false);
         return nvkm_output_fini(&outp->base, suspend);
 }
 
@@ -55,6 +108,7 @@ int
 _nvkm_output_dp_init(struct nouveau_object *object)
 {
         struct nvkm_output_dp *outp = (void *)object;
+        nvkm_output_dp_detect(outp);
         return nvkm_output_init(&outp->base);
 }
 
@@ -113,10 +167,12 @@ nvkm_output_dp_create_(struct nouveau_object *parent,
                 return ret;
         }
 
+        INIT_WORK(&outp->work, nvkm_output_dp_service_work);
+
         /* hotplug detect, replaces gpio-based mechanism with aux events */
         ret = nouveau_event_new(i2c->ntfy, NVKM_I2C_PLUG | NVKM_I2C_UNPLUG,
                                 outp->base.edid->index,
-                                nvkm_output_dp_hotplug, outp,
+                                nvkm_output_dp_service, outp,
                                &outp->base.conn->hpd.event);
         if (ret) {
                 ERR("error monitoring aux hpd events: %d\n", ret);
diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h
index 22f692da1b1d..228b5d845640 100644
--- a/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/outpdp.h
@@ -14,6 +14,10 @@ struct nvkm_output_dp {
 
         struct nouveau_eventh *irq;
         struct nouveau_eventh *hpd;
+        struct work_struct work;
+        atomic_t pending;
+        bool present;
+        u8 dpcd[16];
 };
 
 #define nvkm_output_dp_create(p,e,c,b,i,d)                                     \