drm/omap: Add PM capabilities

Added power management capabilities into the omapdrm and DMM drivers.
During suspend, we don't need to do anything to maintain the state of
the LUT.  We have all the necessary information to recreate the mappings
of the GEM object list maintained by the omapdrm driver.

On resume, the DMM resume handler will first reprogram the LUT to point
to the dummy page.  The subsequent resume handler in the omapdrm will call
into the DMM and reprogram each of the buffer objects.  This will ensure
that all of the necessary objects will be pinned into the DMM properly.

Order of suspend/resume handlers is done by device creation.  We create
the DMM device before the omapdrm, so the correct order is maintained.

Signed-off-by: Andy Gross <andy.gross@ti.com>
Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 80 insertions, 0 deletions

diff --git a/drivers/staging/omapdrm/omap_dmm_tiler.c b/drivers/staging/omapdrm/omap_dmm_tiler.c
index 59bf43899fc0..c42c5e500e02 100644
--- a/drivers/staging/omapdrm/omap_dmm_tiler.c
+++ b/drivers/staging/omapdrm/omap_dmm_tiler.c
@@ -903,12 +903,46 @@ error:
 }
 #endif
 
+#ifdef CONFIG_PM
+static int omap_dmm_resume(struct device *dev)
+{
+	struct tcm_area area;
+	int i;
+
+	if (!omap_dmm)
+		return -ENODEV;
+
+	area = (struct tcm_area) {
+		.is2d = true,
+		.tcm = NULL,
+		.p1.x = omap_dmm->container_width - 1,
+		.p1.y = omap_dmm->container_height - 1,
+	};
+
+	/* initialize all LUTs to dummy page entries */
+	for (i = 0; i < omap_dmm->num_lut; i++) {
+		area.tcm = omap_dmm->tcm[i];
+		if (fill(&area, NULL, 0, 0, true))
+			dev_err(dev, "refill failed");
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops omap_dmm_pm_ops = {
+	.resume = omap_dmm_resume,
+};
+#endif
+
 struct platform_driver omap_dmm_driver = {
 	.probe = omap_dmm_probe,
 	.remove = omap_dmm_remove,
 	.driver = {
 		.owner = THIS_MODULE,
 		.name = DMM_DRIVER_NAME,
+#ifdef CONFIG_PM
+		.pm = &omap_dmm_pm_ops,
+#endif
 	},
 };
 
diff --git a/drivers/staging/omapdrm/omap_drv.c b/drivers/staging/omapdrm/omap_drv.c
index dfdb4ba1e7c6..9d6a584113d2 100644
--- a/drivers/staging/omapdrm/omap_drv.c
+++ b/drivers/staging/omapdrm/omap_drv.c
@@ -368,6 +368,9 @@ static int dev_load(struct drm_device *dev, unsigned long flags)
 		/* well, limp along without an fbdev.. maybe X11 will work? */
 	}
 
+	/* store off drm_device for use in pm ops */
+	dev_set_drvdata(dev->dev, dev);
+
 	drm_kms_helper_poll_init(dev);
 
 	return 0;
@@ -393,6 +396,8 @@ static int dev_unload(struct drm_device *dev)
 	kfree(dev->dev_private);
 	dev->dev_private = NULL;
 
+	dev_set_drvdata(dev->dev, NULL);
+
 	return 0;
 }
 
@@ -558,10 +563,19 @@ static int pdev_remove(struct platform_device *device)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static const struct dev_pm_ops omapdrm_pm_ops = {
+	.resume = omap_gem_resume,
+};
+#endif
+
 struct platform_driver pdev = {
 		.driver = {
 			.name = DRIVER_NAME,
 			.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+			.pm = &omapdrm_pm_ops,
+#endif
 		},
 		.probe = pdev_probe,
 		.remove = pdev_remove,
diff --git a/drivers/staging/omapdrm/omap_drv.h b/drivers/staging/omapdrm/omap_drv.h
index cd1f22b0b124..f921027e7500 100644
--- a/drivers/staging/omapdrm/omap_drv.h
+++ b/drivers/staging/omapdrm/omap_drv.h
@@ -135,6 +135,10 @@ void omap_gem_describe(struct drm_gem_object *obj, struct seq_file *m);
 void omap_gem_describe_objects(struct list_head *list, struct seq_file *m);
 #endif
 
+#ifdef CONFIG_PM
+int omap_gem_resume(struct device *dev);
+#endif
+
 int omap_irq_enable_vblank(struct drm_device *dev, int crtc);
 void omap_irq_disable_vblank(struct drm_device *dev, int crtc);
 irqreturn_t omap_irq_handler(DRM_IRQ_ARGS);
diff --git a/drivers/staging/omapdrm/omap_gem.c b/drivers/staging/omapdrm/omap_gem.c
index c38992b76fc9..08f1e292ed20 100644
--- a/drivers/staging/omapdrm/omap_gem.c
+++ b/drivers/staging/omapdrm/omap_gem.c
@@ -964,6 +964,34 @@ void *omap_gem_vaddr(struct drm_gem_object *obj)
 	return omap_obj->vaddr;
 }
 
+#ifdef CONFIG_PM
+/* re-pin objects in DMM in resume path: */
+int omap_gem_resume(struct device *dev)
+{
+	struct drm_device *drm_dev = dev_get_drvdata(dev);
+	struct omap_drm_private *priv = drm_dev->dev_private;
+	struct omap_gem_object *omap_obj;
+	int ret = 0;
+
+	list_for_each_entry(omap_obj, &priv->obj_list, mm_list) {
+		if (omap_obj->block) {
+			struct drm_gem_object *obj = &omap_obj->base;
+			uint32_t npages = obj->size >> PAGE_SHIFT;
+			WARN_ON(!omap_obj->pages);  /* this can't happen */
+			ret = tiler_pin(omap_obj->block,
+					omap_obj->pages, npages,
+					omap_obj->roll, true);
+			if (ret) {
+				dev_err(dev, "could not repin: %d\n", ret);
+				return ret;
+			}
+		}
+	}
+
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_DEBUG_FS
 void omap_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 {