OMAPDSS: output: Add set/unset device ops for omap_dss_output

An output entity represented by the struct omap_dss_output connects to a
omap_dss_device entity. Add functions to set or unset an output's device. This
is similar to how managers and devices were connected previously. An output can
connect to a device without being connected to a manager. However, the output
needs to eventually connect to a manager so that the connected panel can be
enabled.

Keep the omap_overlay_manager pointer in omap_dss_device for now to prevent
breaking things. This will be removed later when outputs are supported
completely.

Signed-off-by: Archit Taneja <archit@ti.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/drivers/video/omap2/dss/output.c b/drivers/video/omap2/dss/output.c
index 388a6c997b9c..1a84b79d5580 100644
--- a/drivers/video/omap2/dss/output.c
+++ b/drivers/video/omap2/dss/output.c
@@ -16,6 +16,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
@@ -24,6 +25,72 @@
 #include "dss.h"
 
 static LIST_HEAD(output_list);
+static DEFINE_MUTEX(output_lock);
+
+int omapdss_output_set_device(struct omap_dss_output *out,
+                struct omap_dss_device *dssdev)
+{
+        int r;
+
+        mutex_lock(&output_lock);
+
+        if (out->device) {
+                DSSERR("output already has device %s connected to it\n",
+                        out->device->name);
+                r = -EINVAL;
+                goto err;
+        }
+
+        if (out->type != dssdev->type) {
+                DSSERR("output type and display type don't match\n");
+                r = -EINVAL;
+                goto err;
+        }
+
+        out->device = dssdev;
+        dssdev->output = out;
+
+        mutex_unlock(&output_lock);
+
+        return 0;
+err:
+        mutex_unlock(&output_lock);
+
+        return r;
+}
+EXPORT_SYMBOL(omapdss_output_set_device);
+
+int omapdss_output_unset_device(struct omap_dss_output *out)
+{
+        int r;
+
+        mutex_lock(&output_lock);
+
+        if (!out->device) {
+                DSSERR("output doesn't have a device connected to it\n");
+                r = -EINVAL;
+                goto err;
+        }
+
+        if (out->device->state != OMAP_DSS_DISPLAY_DISABLED) {
+                DSSERR("device %s is not disabled, cannot unset device\n",
+                                out->device->name);
+                r = -EINVAL;
+                goto err;
+        }
+
+        out->device->output = NULL;
+        out->device = NULL;
+
+        mutex_unlock(&output_lock);
+
+        return 0;
+err:
+        mutex_unlock(&output_lock);
+
+        return r;
+}
+EXPORT_SYMBOL(omapdss_output_unset_device);
 
 void dss_register_output(struct omap_dss_output *out)
 {