drm/tilcdc: Add support for external tda998x encoder

Add support for an external compontised DRM encoder. The external
encoder can be connected to tilcdc trough device tree graph binding.
The binding document for tilcdc has been updated. The current
implementation supports only tda998x encoder.

To be able to filter out the unsupported video modes the tilcdc driver
needs to hijack the external connectors helper functions. The tilcdc
installes new helper functions that are otherwise identical to
orignals, but the mode_valid() call-back check the mode first localy,
before calling the original call-back. The tilcdc dirver restores the
original helper functions before it is unbound from the external
device.

I got the idea and some lines of code from Jean-Francois Moine's
"drm/tilcdc: Change the interface with the tda998x driver"-patch.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 72 insertions, 13 deletions

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 0f1e09986f56..fcc0508c58c0 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -17,10 +17,13 @@
 
 /* LCDC DRM driver, based on da8xx-fb */
 
+#include <linux/component.h>
+
 #include "tilcdc_drv.h"
 #include "tilcdc_regs.h"
 #include "tilcdc_tfp410.h"
 #include "tilcdc_panel.h"
+#include "tilcdc_external.h"
 
 #include "drm_fb_helper.h"
 
@@ -73,13 +76,6 @@ static int modeset_init(struct drm_device *dev)
 		mod->funcs->modeset_init(mod, dev);
 	}
 
-	if ((priv->num_encoders == 0) || (priv->num_connectors == 0)) {
-		/* oh nos! */
-		dev_err(dev->dev, "no encoders/connectors found\n");
-		drm_mode_config_cleanup(dev);
-		return -ENXIO;
-	}
-
 	dev->mode_config.min_width = 0;
 	dev->mode_config.min_height = 0;
 	dev->mode_config.max_width = tilcdc_crtc_max_width(priv->crtc);
@@ -114,6 +110,8 @@ static int tilcdc_unload(struct drm_device *dev)
 {
 	struct tilcdc_drm_private *priv = dev->dev_private;
 
+	tilcdc_remove_external_encoders(dev);
+
 	drm_fbdev_cma_fini(priv->fbdev);
 	drm_kms_helper_poll_fini(dev);
 	drm_mode_config_cleanup(dev);
@@ -164,6 +162,9 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 
 	dev->dev_private = priv;
 
+	priv->is_componentized =
+		tilcdc_get_external_components(dev->dev, NULL) > 0;
+
 	priv->wq = alloc_ordered_workqueue("tilcdc", 0);
 	if (!priv->wq) {
 		ret = -ENOMEM;
@@ -253,10 +254,28 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 		goto fail_cpufreq_unregister;
 	}
 
+	platform_set_drvdata(pdev, dev);
+
+	if (priv->is_componentized) {
+		ret = component_bind_all(dev->dev, dev);
+		if (ret < 0)
+			goto fail_mode_config_cleanup;
+
+		ret = tilcdc_add_external_encoders(dev, &bpp);
+		if (ret < 0)
+			goto fail_component_cleanup;
+	}
+
+	if ((priv->num_encoders == 0) || (priv->num_connectors == 0)) {
+		dev_err(dev->dev, "no encoders/connectors found\n");
+		ret = -ENXIO;
+		goto fail_external_cleanup;
+	}
+
 	ret = drm_vblank_init(dev, 1);
 	if (ret < 0) {
 		dev_err(dev->dev, "failed to initialize vblank\n");
-		goto fail_mode_config_cleanup;
+		goto fail_external_cleanup;
 	}
 
 	pm_runtime_get_sync(dev->dev);
@@ -267,9 +286,6 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
 		goto fail_vblank_cleanup;
 	}
 
-	platform_set_drvdata(pdev, dev);
-
-
 	list_for_each_entry(mod, &module_list, list) {
 		DBG("%s: preferred_bpp: %d", mod->name, mod->preferred_bpp);
 		bpp = mod->preferred_bpp;
@@ -300,6 +316,13 @@ fail_vblank_cleanup:
 fail_mode_config_cleanup:
 	drm_mode_config_cleanup(dev);
 
+fail_component_cleanup:
+	if (priv->is_componentized)
+		component_unbind_all(dev->dev, dev);
+
+fail_external_cleanup:
+	tilcdc_remove_external_encoders(dev);
+
 fail_cpufreq_unregister:
 	pm_runtime_disable(dev->dev);
 #ifdef CONFIG_CPU_FREQ
@@ -605,20 +628,56 @@ static const struct dev_pm_ops tilcdc_pm_ops = {
  * Platform driver:
  */
 
+static int tilcdc_bind(struct device *dev)
+{
+	return drm_platform_init(&tilcdc_driver, to_platform_device(dev));
+}
+
+static void tilcdc_unbind(struct device *dev)
+{
+	drm_put_dev(dev_get_drvdata(dev));
+}
+
+static const struct component_master_ops tilcdc_comp_ops = {
+	.bind = tilcdc_bind,
+	.unbind = tilcdc_unbind,
+};
+
 static int tilcdc_pdev_probe(struct platform_device *pdev)
 {
+	struct component_match *match = NULL;
+	int ret;
+
 	/* bail out early if no DT data: */
 	if (!pdev->dev.of_node) {
 		dev_err(&pdev->dev, "device-tree data is missing\n");
 		return -ENXIO;
 	}
 
-	return drm_platform_init(&tilcdc_driver, pdev);
+	ret = tilcdc_get_external_components(&pdev->dev, &match);
+	if (ret < 0)
+		return ret;
+	else if (ret == 0)
+		return drm_platform_init(&tilcdc_driver, pdev);
+	else
+		return component_master_add_with_match(&pdev->dev,
+						       &tilcdc_comp_ops,
+						       match);
 }
 
 static int tilcdc_pdev_remove(struct platform_device *pdev)
 {
-	drm_put_dev(platform_get_drvdata(pdev));
+	struct drm_device *ddev = dev_get_drvdata(&pdev->dev);
+	struct tilcdc_drm_private *priv = ddev->dev_private;
+
+	/* Check if a subcomponent has already triggered the unloading. */
+	if (!priv)
+		return 0;
+
+	if (priv->is_componentized)
+		component_master_del(&pdev->dev, &tilcdc_comp_ops);
+	else
+		drm_put_dev(platform_get_drvdata(pdev));
 
 	return 0;
 }