Add support for reading EDID over Display Data Channel. If no DDC
adapter is available, falls back to hardcoded EDID or display-timings
node as before.
Signed-off-by: Steve Longerbeam
---
drivers/staging/imx-drm/imx-ldb.c | 39 +
1 file changed, 31 insertions(+), 8 deletions(-)
diff --git a/drivers/staging/imx-drm/imx-ldb.c
b/drivers/staging/imx-drm/imx-ldb.c
index 1eb632f..6c16cf2 100644
--- a/drivers/staging/imx-drm/imx-ldb.c
+++ b/drivers/staging/imx-drm/imx-ldb.c
@@ -61,6 +61,7 @@ struct imx_ldb_channel {
struct drm_connector connector;
struct drm_encoder encoder;
struct device_node *child;
+ struct i2c_adapter *ddc;
int chno;
void *edid;
int edid_len;
@@ -103,6 +104,9 @@ static int imx_ldb_connector_get_modes(struct drm_connector
*connector)
imx_ldb_entry_dbg(imx_ldb_ch);
+ if (!imx_ldb_ch->edid && imx_ldb_ch->ddc)
+ imx_ldb_ch->edid = drm_get_edid(connector, imx_ldb_ch->ddc);
+
if (imx_ldb_ch->edid) {
drm_mode_connector_update_edid_property(connector,
imx_ldb_ch->edid);
@@ -529,6 +533,7 @@ static int imx_ldb_bind(struct device *dev, struct device
*master, void *data)
for_each_child_of_node(np, child) {
struct imx_ldb_channel *channel;
+ struct device_node *ddc_node;
ret = of_property_read_u32(child, "reg", &i);
if (ret || i < 0 || i > 1)
@@ -547,14 +552,30 @@ static int imx_ldb_bind(struct device *dev, struct device
*master, void *data)
channel->chno = i;
channel->child = child;
- edidp = of_get_property(child, "edid", &channel->edid_len);
- if (edidp) {
- channel->edid = kmemdup(edidp, channel->edid_len,
- GFP_KERNEL);
- } else {
- ret = of_get_drm_display_mode(child, &channel->mode, 0);
- if (!ret)
- channel->mode_valid = 1;
+ ddc_node = of_parse_phandle(child, "ddc-i2c-bus", 0);
+ if (ddc_node) {
+ channel->ddc = of_find_i2c_adapter_by_node(ddc_node);
+ of_node_put(ddc_node);
+ }
+
+ if (!channel->ddc) {
+ /* if no DDC available, fallback to hardcoded EDID */
+ dev_dbg(dev, "no ddc available\n");
+
+ edidp = of_get_property(child, "edid",
+ &channel->edid_len);
+ if (edidp) {
+ channel->edid = kmemdup(edidp,
+ channel->edid_len,
+ GFP_KERNEL);
+ } else {
+ /* fallback to display-timings node */
+ ret = of_get_drm_display_mode(child,
+ &channel->mode,
+ 0);
+ if (!ret)
+ channel->mode_valid = 1;
+ }
}
ret = of_property_read_u32(child, "fsl,data-width", &datawidth);
@@ -616,6 +637,8 @@ static void imx_ldb_unbind(struct device *dev, struct
device *master,
channel->connector.funcs->destroy(&channel->connector);
channel->encoder.funcs->destroy(&channel->encoder);
+
+ i2c_put_adapter(channel->ddc);
}
}
--
1.7.9.5
