Make "ti,tilcdc,slave" DT binding more sensible

These patches are needed for Beaglebone-back HDMI audio. There is no direct dependency between these patches and the other (dts and ASoC) changes needed for the HDMI audio so these changes can be merged independently. I also feel that these changes make sense even without the HDMI audio.

Best regards,
Jyri

Jyri Sarha (3):
drm: encoder_slave: Add drm_i2c_encoder_attach() drm/tilcdc: slave: Add support for "i2c-slave" DT-parameter
ARM: dts: am335x-boneblack: Use new binding in ti,tilcdc,slave node

 .../devicetree/bindings/drm/tilcdc/slave.txt       |    4 +-
 arch/arm/boot/dts/am335x-boneblack.dts             |    9 +++-
 drivers/gpu/drm/drm_encoder_slave.c                |   51 ++++++++++++++++++++
 drivers/gpu/drm/tilcdc/tilcdc_slave.c              |   50 +++++++++++--------
 include/drm/drm_encoder_slave.h                    |    3 ++
 5 files changed, 95 insertions(+), 22 deletions(-)

1.7.9.5

Add drm_i2c_encoder_attach() for attaching an already probed i2c encoder. This is needed for instance if the encoder is probed from device tree.

---
 drivers/gpu/drm/drm_encoder_slave.c |   51 +++++++++++++++++++++++++++++++++++
 include/drm/drm_encoder_slave.h     |    3 +++
 2 files changed, 54 insertions(+)

index d18b88b..ed627f7 100644
@@ -120,6 +120,57 @@ void drm_i2c_encoder_destroy(struct drm_encoder *drm_encoder)
 }
 EXPORT_SYMBOL(drm_i2c_encoder_destroy);
 
+/**
+ * drm_i2c_encoder_attach - Attach an I2C slave encoder
+ * @dev:	DRM device.
+ * @encoder:	Encoder to be attached to the I2C device. You aren't
+ *		required to have called drm_encoder_init() before.
+ * @client:	I2C encoder to be attached.
+ *
+ * Attach the I2C device specified to the specified &drm_encoder_slave.
+ * The @slave_funcs field will be initialized with the hooks provided by
+ * the slave driver.
+ *
+ * Returns 0 on success or a negative errno on failure, in particular,
+ * -ENODEV is returned when no matching driver is found.
+ */
+int drm_i2c_encoder_attach(struct drm_device *dev,
+			   struct drm_encoder_slave *encoder,
+			   struct i2c_client *client)
+{
+	struct drm_i2c_encoder_driver *encoder_drv;
+	struct module *module = NULL;
+	int err = 0;
+
+	if (!client->dev.driver) {
+		err = -ENODEV;
+		goto fail;
+	}
+
+	module = client->dev.driver->owner;
+	if (!try_module_get(module)) {
+		err = -ENODEV;
+		goto fail;
+	}
+
+	encoder->bus_priv = client;
+
+	encoder_drv =
+		to_drm_i2c_encoder_driver(to_i2c_driver(client->dev.driver));
+
+	err = encoder_drv->encoder_init(client, dev, encoder);
+	if (err)
+		goto fail_put;
+
+	return 0;
+
+fail_put:
+	module_put(module);
+fail:
+	return err;
+}
+EXPORT_SYMBOL(drm_i2c_encoder_attach);
+
 /*
  * Wrapper fxns which can be plugged in to drm_encoder_helper_funcs:
  */

index 8b9cc36..4f7f8d5 100644
@@ -106,6 +106,9 @@ int drm_i2c_encoder_init(struct drm_device *dev,
 			 struct i2c_adapter *adap,
 			 const struct i2c_board_info *info);
 
+int drm_i2c_encoder_attach(struct drm_device *dev,
+			   struct drm_encoder_slave *encoder,
+			   struct i2c_client *client);
 
 /**
  * struct drm_i2c_encoder_driver

1.7.9.5

It is more convenient to refer to the i2c slave encoder directly with phandle than to refer to the i2c bus and to create the device "manually".

---
 .../devicetree/bindings/drm/tilcdc/slave.txt       |    4 +-
 drivers/gpu/drm/tilcdc/tilcdc_slave.c              |   50 ++++++++++++--------
 2 files changed, 33 insertions(+), 21 deletions(-)

index 3d2c524..930550f 100644
@@ -2,6 +2,8 @@ Device-Tree bindings for tilcdc DRM encoder slave output driver
 
 Required properties:
  - compatible: value should be "ti,tilcdc,slave".
+ - i2c-slave: phandle for the encoder slave device
+ or
  - i2c: the phandle for the i2c device the encoder slave is connected to
 
 Recommended properties:

@@ -12,7 +14,7 @@ Example:
 
 	hdmi {
 		compatible = "ti,tilcdc,slave";
-		i2c = <&i2c0>;
+		i2c-slave = <&tda19988>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&nxp_hdmi_bonelt_pins>;
 	};

1.7.9.5

Add node for NXP TDA19988 encoder and refer to it in the hdmi node instead of referring to the i2c bus where the encoder is connected to.

---
 arch/arm/boot/dts/am335x-boneblack.dts |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

index 5c42d25..c0c8e4b 100644
@@ -70,10 +70,17 @@
 	status = "okay";
 };
 
+&i2c0 {
+	tda19988: tda19988@70 {
+		compatible = "nxp,tda998x";
+		reg = <0x70>;
+	};
+};
+
 / {
 	hdmi {
 		compatible = "ti,tilcdc,slave";
-		i2c = <&i2c0>;
+		i2c-slave = <&tda19988>;
 		pinctrl-names = "default", "off";
 		pinctrl-0 = <&nxp_hdmi_bonelt_pins>;
 		pinctrl-1 = <&nxp_hdmi_bonelt_off_pins>;

1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Instead of adding code to have the slave encoder working, it would be simpler to change the way tilcdc uses the tda998x.
I already proposed such a patch:

http://lists.freedesktop.org/archives/dri-devel/2014-March/056065.html

and the changes in the tda998x driver have been done by Russell:

commit: a8f4d4d63739e4bca459ff40636f1d9e4b7ef5e6
drm/i2c: tda998x: allow re-use of tda998x support code
and
commit: c707c3619ca81f499a5ce032021405e989a96ff0
drm/i2c: tda998x: add component support

Ken ar c'hentañ	|	      ** Breizh ha Linux atav! **
Jef		|		http://moinejf.free.fr/
_______________________________________________
dri-devel mailing list
[email protected]
http://lists.freedesktop.org/mailman/listinfo/dri-devel

Interesting. Would you still have the original branch somewhere? Manual applying the patches from the web-page is time consuming.

Best regards,
Jyri