drm/i2c: adv7511: ADV7533 support

From: Lars-Peter Clausen <[email protected]>

drivers/gpu/drm/i2c/adv7511.c +0 -0

drivers/gpu/drm/i2c/adv7511.c +1 -0

+
 static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
 {
 	struct adv7511_link_config link_config;

drivers/gpu/drm/i2c/adv7511.c +5 -0

+		adv7511->type = (enum adv7511_type) of_id->data;
+	} else {
+		adv7511->type = id->driver_data;
+	}
+

static const struct i2c_device_id adv7511_i2c_ids[] = {

drivers/gpu/drm/i2c/adv7511.c +4 -3

-	{ "adv7511", 0 },
-	{ "adv7511w", 0 },
-	{ "adv7513", 0 },
+	{ "adv7511", ADV7511 },
+	{ "adv7511w", ADV7511 },
+	{ "adv7513", ADV7511 },
+	{ "adv7533", ADV7533 },
 	{ }
 };

Quoted 2 lines · Archit Taneja

From: Lars-Peter Clausen <[email protected]>

[..]

Quoted 1 line

drivers/gpu/drm/i2c/adv7511.c +0 -0

[..]

drivers/gpu/drm/i2c/adv7511.c static const int edid_i2c_addr = 0x7e; · line 921

Quoted 9 lines

drivers/gpu/drm/i2c/adv7511.c +8 -0

+static const struct of_device_id adv7511_of_ids[] = {
+	{ .compatible = "adi,adv7511", .data = (void *) ADV7511 },
+	{ .compatible = "adi,adv7511w", .data = (void *) ADV7511 },
+	{ .compatible = "adi,adv7513", .data = (void *) ADV7511 },
+	{ .compatible = "adi,adv7533", .data = (void *) ADV7533 },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, adv7511_of_ids);

Please leave this at the bottom.

Quoted 8 lines

drivers/gpu/drm/i2c/adv7511.c +1 -0

+
  static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
  {
  	struct adv7511_link_config link_config;

@@ -871,9 +938,22 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
  	adv7511->powered = false;
  	adv7511->status = connector_status_disconnected;
 

drivers/gpu/drm/i2c/adv7511.c static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id) · line 944

Quoted 7 lines

drivers/gpu/drm/i2c/adv7511.c +4 -3

-	ret = adv7511_parse_dt(dev->of_node, &link_config);
-	if (ret)
-		return ret;
+	if (dev->of_node) {
+		const struct of_device_id *of_id;
+
+		of_id = of_match_node(adv7511_of_ids, dev->of_node);

If you use of_device_get_match_data() instead you don't need to move the of_device_id table.

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Move the code in encoder slave functions to generate helpers that are agnostic to the drm object type. These helpers will later also be used by bridge and connecter helper functions.

Signed-off-by Archit Taneja <[email protected]>

---
 drivers/gpu/drm/i2c/adv7511.c | 80 +++++++++++++++++++++++++++------------
 1 file changed, 57 insertions(+), 23 deletions(-)

drivers/gpu/drm/i2c/adv7511.c +56 -28

index 63a3d20..46fb24d 100644
@@ -612,13 +612,11 @@ static int adv7511_get_edid_block(void *data, u8 *buf,
 unsigned int block, }
 
 /*
---------------------------------------------------------------------------
-- - * Encoder operations
+ * ADV75xx helpers
  */
-
-static int adv7511_get_modes(struct drm_encoder *encoder,
-			     struct drm_connector *connector)
+static int adv7511_get_modes(struct adv7511 *adv7511,
+		struct drm_connector *connector)
 {
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
 	struct edid *edid;
 	unsigned int count;

@@ -656,21 +654,10 @@ static int adv7511_get_modes(struct drm_encoder
 *encoder, return count;
 }
 
-static void adv7511_encoder_dpms(struct drm_encoder *encoder, int mode)
-{
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
-
-	if (mode == DRM_MODE_DPMS_ON)
-		adv7511_power_on(adv7511);
-	else
-		adv7511_power_off(adv7511);
-}
-
 static enum drm_connector_status
-adv7511_encoder_detect(struct drm_encoder *encoder,
+adv7511_detect(struct adv7511 *adv7511,
 		       struct drm_connector *connector)
 {
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
 	enum drm_connector_status status;
 	unsigned int val;
 	bool hpd;

@@ -694,7 +681,7 @@ adv7511_encoder_detect(struct drm_encoder *encoder,
 	if (status == connector_status_connected && hpd && adv7511->powered) {
 		regcache_mark_dirty(adv7511->regmap);
 		adv7511_power_on(adv7511);
-		adv7511_get_modes(encoder, connector);
+		adv7511_get_modes(adv7511, connector);
 		if (adv7511->status == connector_status_connected)
 			status = connector_status_disconnected;
 	} else {

@@ -708,8 +695,8 @@ adv7511_encoder_detect(struct drm_encoder *encoder,
 	return status;
 }
 
-static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
-				      struct drm_display_mode *mode)
+static int adv7511_mode_valid(struct adv7511 *adv7511,
+				     const struct drm_display_mode *mode)
 {
 	if (mode->clock > 165000)
 		return MODE_CLOCK_HIGH;

@@ -717,11 +704,10 @@ static int adv7511_encoder_mode_valid(struct
 drm_encoder *encoder, return MODE_OK;
 }
 
-static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
+static void adv7511_mode_set(struct adv7511 *adv7511,
 				     struct drm_display_mode *mode,
 				     struct drm_display_mode *adj_mode)
 {
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
 	unsigned int low_refresh_rate;
 	unsigned int hsync_polarity = 0;
 	unsigned int vsync_polarity = 0;

@@ -812,12 +798,60 @@ static void adv7511_encoder_mode_set(struct
 drm_encoder *encoder, adv7511->f_tmds = mode->clock;
 }
 
+/*
---------------------------------------------------------------------------
-- + * Encoder operations
+ */
+
+static int adv7511_encoder_get_modes(struct drm_encoder *encoder,
+			     struct drm_connector *connector)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	return adv7511_get_modes(adv7511, connector);
+}
+
+static void adv7511_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	if (mode == DRM_MODE_DPMS_ON)
+		adv7511_power_on(adv7511);
+	else
+		adv7511_power_off(adv7511);
+}
+
+static enum drm_connector_status
+adv7511_encoder_detect(struct drm_encoder *encoder,
+		       struct drm_connector *connector)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	return adv7511_detect(adv7511, connector);
+}
+
+static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
+				      struct drm_display_mode *mode)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	return adv7511_mode_valid(adv7511, mode);
+}
+
+static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
+				     struct drm_display_mode *mode,
+				     struct drm_display_mode *adj_mode)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	adv7511_mode_set(adv7511, mode, adj_mode);
+}
+
 static struct drm_encoder_slave_funcs adv7511_encoder_funcs = {
 	.dpms = adv7511_encoder_dpms,
 	.mode_valid = adv7511_encoder_mode_valid,
 	.mode_set = adv7511_encoder_mode_set,
 	.detect = adv7511_encoder_detect,
-	.get_modes = adv7511_get_modes,
+	.get_modes = adv7511_encoder_get_modes,
 };
 
 /*
---------------------------------------------------------------------------
--

Hi Archit,

(CC'ing Boris Brezillon)

Thank you for the patch.

On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

Quoted 3 lines

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

Boris, I know you were experimenting with that, do you have anything to report ?

Quoted 152 lines

Move the code in encoder slave functions to generate helpers that are agnostic to the drm object type. These helpers will later also be used by bridge and connecter helper functions.

Signed-off-by Archit Taneja <[email protected]>

---
  drivers/gpu/drm/i2c/adv7511.c | 80 +++++++++++++++++++++++++++------------
  1 file changed, 57 insertions(+), 23 deletions(-)

drivers/gpu/drm/i2c/adv7511.c +56 -28

index 63a3d20..46fb24d 100644
@@ -612,13 +612,11 @@ static int adv7511_get_edid_block(void *data, u8 *buf,
 unsigned int block, }
 
  /*
---------------------------------------------------------------------------
-- - * Encoder operations
+ * ADV75xx helpers
   */
-
-static int adv7511_get_modes(struct drm_encoder *encoder,
-			     struct drm_connector *connector)
+static int adv7511_get_modes(struct adv7511 *adv7511,
+		struct drm_connector *connector)
  {
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
  	struct edid *edid;
  	unsigned int count;

@@ -656,21 +654,10 @@ static int adv7511_get_modes(struct drm_encoder
 *encoder, return count;
  }
 
-static void adv7511_encoder_dpms(struct drm_encoder *encoder, int mode)
-{
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
-
-	if (mode == DRM_MODE_DPMS_ON)
-		adv7511_power_on(adv7511);
-	else
-		adv7511_power_off(adv7511);
-}
-
  static enum drm_connector_status
-adv7511_encoder_detect(struct drm_encoder *encoder,
+adv7511_detect(struct adv7511 *adv7511,
  		       struct drm_connector *connector)
  {
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
  	enum drm_connector_status status;
  	unsigned int val;
  	bool hpd;

@@ -694,7 +681,7 @@ adv7511_encoder_detect(struct drm_encoder *encoder,
  	if (status == connector_status_connected && hpd && adv7511->powered) {
  		regcache_mark_dirty(adv7511->regmap);
  		adv7511_power_on(adv7511);
-		adv7511_get_modes(encoder, connector);
+		adv7511_get_modes(adv7511, connector);
  		if (adv7511->status == connector_status_connected)
  			status = connector_status_disconnected;
  	} else {

@@ -708,8 +695,8 @@ adv7511_encoder_detect(struct drm_encoder *encoder,
  	return status;
  }
 
-static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
-				      struct drm_display_mode *mode)
+static int adv7511_mode_valid(struct adv7511 *adv7511,
+				     const struct drm_display_mode *mode)
  {
  	if (mode->clock > 165000)
  		return MODE_CLOCK_HIGH;

@@ -717,11 +704,10 @@ static int adv7511_encoder_mode_valid(struct
 drm_encoder *encoder, return MODE_OK;
  }
 
-static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
+static void adv7511_mode_set(struct adv7511 *adv7511,
  				     struct drm_display_mode *mode,
  				     struct drm_display_mode *adj_mode)
  {
-	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
  	unsigned int low_refresh_rate;
  	unsigned int hsync_polarity = 0;
  	unsigned int vsync_polarity = 0;

@@ -812,12 +798,60 @@ static void adv7511_encoder_mode_set(struct
 drm_encoder *encoder, adv7511->f_tmds = mode->clock;
  }
 
+/*
---------------------------------------------------------------------------
-- + * Encoder operations
+ */
+
+static int adv7511_encoder_get_modes(struct drm_encoder *encoder,
+			     struct drm_connector *connector)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	return adv7511_get_modes(adv7511, connector);
+}
+
+static void adv7511_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	if (mode == DRM_MODE_DPMS_ON)
+		adv7511_power_on(adv7511);
+	else
+		adv7511_power_off(adv7511);
+}
+
+static enum drm_connector_status
+adv7511_encoder_detect(struct drm_encoder *encoder,
+		       struct drm_connector *connector)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	return adv7511_detect(adv7511, connector);
+}
+
+static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
+				      struct drm_display_mode *mode)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	return adv7511_mode_valid(adv7511, mode);
+}
+
+static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
+				     struct drm_display_mode *mode,
+				     struct drm_display_mode *adj_mode)
+{
+	struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+	adv7511_mode_set(adv7511, mode, adj_mode);
+}
+
  static struct drm_encoder_slave_funcs adv7511_encoder_funcs = {
  	.dpms = adv7511_encoder_dpms,
  	.mode_valid = adv7511_encoder_mode_valid,
  	.mode_set = adv7511_encoder_mode_set,
  	.detect = adv7511_encoder_detect,
-	.get_modes = adv7511_get_modes,
+	.get_modes = adv7511_encoder_get_modes,
  };
 
  /*
---------------------------------------------------------------------------
--

Hi,

Quoted 7 lines · Laurent Pinchart

Hi Archit,

(CC'ing Boris Brezillon)

Thank you for the patch.

On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

Quoted 8 lines

Quoted 3 lines

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

i2c slave encoders and bridges aren't exactly the same. slave encoders are used when the there is no real 'encoder' in the display chain. bridges are used when there is already an encoder available, and the bridge entity represents another encoder in the chain.

ADV7511 takes in RGB/MIPI DPI data, which is generally the output of a crtc for drm drivers.

ADV7533 takes in MIPI DSI data, which is generally the output of an encoder for drm drivers.

Therefore, having i2c slave encoder for the former and bridge for the latter made sense to me.

I do agree that it would be better if they were somehow merged. It would prevent the fragmentation we currently have among encoder chips.

One possible way would be to convert slave encoder to bridge. With this, an i2c slave encoder would be a 'dummy encoder' and a bridge. i2c slave encoders even now just tie the slave encoder helper funcs to encoder helper funcs. So it's not really any different.

Merging these 2 entities would be nice, but we're still shying away from the larger problem of creating generic encoder chains. The ideal solution would be for bridges and slave encoders to just be 'encoders', and the facility to connect on encoder output to the input of another. I don't know how easy it is to do this, and whether it'll break userspace.

Archit

Quoted 3 lines

Boris, I know you were experimenting with that, do you have anything to report ?

Archit, Laurent,

Quoted 42 lines · On Tue, 28 Jul 2015 13:47:37 +0530 Archit Taneja <[email protected]> wrote:

Hi,

Quoted 7 lines · Laurent Pinchart

Hi Archit,

(CC'ing Boris Brezillon)

Thank you for the patch.

On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

Quoted 8 lines

Quoted 3 lines

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

i2c slave encoders and bridges aren't exactly the same. slave encoders are used when the there is no real 'encoder' in the display chain. bridges are used when there is already an encoder available, and the bridge entity represents another encoder in the chain.

ADV7511 takes in RGB/MIPI DPI data, which is generally the output of a crtc for drm drivers.

ADV7533 takes in MIPI DSI data, which is generally the output of an encoder for drm drivers.

Therefore, having i2c slave encoder for the former and bridge for the latter made sense to me.

I do agree that it would be better if they were somehow merged. It would prevent the fragmentation we currently have among encoder chips.

One possible way would be to convert slave encoder to bridge. With this, an i2c slave encoder would be a 'dummy encoder' and a bridge. i2c slave encoders even now just tie the slave encoder helper funcs to encoder helper funcs. So it's not really any different.

Quoted 6 lines

Merging these 2 entities would be nice, but we're still shying away from the larger problem of creating generic encoder chains. The ideal solution would be for bridges and slave encoders to just be 'encoders', and the facility to connect on encoder output to the input of another. I don't know how easy it is to do this, and whether it'll break userspace.

Yes, that's pretty much what I was trying to do.
I'd also like to ease display pipelines creation by providing helper functions, so that display controller don't have to worry about encoders and connectors creation if these ones are attached to external encoders.

Quoted 1 line

Quoted 5 lines

Archit

Quoted 3 lines

Boris, I know you were experimenting with that, do you have anything to report ?

Nope, I didn't work on it since last time we talked about it. I pushed my work here if you want to have a look [1].

Best Regards,

Boris

[1]https://github.com/bbrezillon/linux-at91/tree/drm-encoder-chain-WIP

Hi Boris, Laurent,

Quoted 60 lines · Boris Brezillon

Archit, Laurent,

Quoted 42 lines · On Tue, 28 Jul 2015 13:47:37 +0530 Archit Taneja <[email protected]> wrote:

Hi,

Quoted 7 lines · Laurent Pinchart

Hi Archit,

(CC'ing Boris Brezillon)

Thank you for the patch.

On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

Quoted 8 lines

Quoted 3 lines

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

i2c slave encoders and bridges aren't exactly the same. slave encoders are used when the there is no real 'encoder' in the display chain. bridges are used when there is already an encoder available, and the bridge entity represents another encoder in the chain.

ADV7511 takes in RGB/MIPI DPI data, which is generally the output of a crtc for drm drivers.

ADV7533 takes in MIPI DSI data, which is generally the output of an encoder for drm drivers.

Therefore, having i2c slave encoder for the former and bridge for the latter made sense to me.

I do agree that it would be better if they were somehow merged. It would prevent the fragmentation we currently have among encoder chips.

One possible way would be to convert slave encoder to bridge. With this, an i2c slave encoder would be a 'dummy encoder' and a bridge. i2c slave encoders even now just tie the slave encoder helper funcs to encoder helper funcs. So it's not really any different.

Quoted 6 lines

Merging these 2 entities would be nice, but we're still shying away from the larger problem of creating generic encoder chains. The ideal solution would be for bridges and slave encoders to just be 'encoders', and the facility to connect on encoder output to the input of another. I don't know how easy it is to do this, and whether it'll break userspace.

Yes, that's pretty much what I was trying to do.
I'd also like to ease display pipelines creation by providing helper functions, so that display controller don't have to worry about encoders and connectors creation if these ones are attached to external encoders.

Quoted 1 line

Quoted 8 lines

Quoted 5 lines

Archit

Quoted 3 lines

Boris, I know you were experimenting with that, do you have anything to report ?

Nope, I didn't work on it since last time we talked about it. I pushed my work here if you want to have a look [1].

I went through the branch you shared. From what I understood, the encoder chain comprises of one 'real' encoder object (drm_encoder) in the 'drm_encoder_chain' struct. This drm_encoder encapsulates all the 'encoder elements' forming the chain.

I'm guessing the various dridge/slave encoder drivers would have to be changed to now create a drm_encoder_element object, replacing drm_bridge/drm_i2c_slave_encoder objects.

One problem I see with this approach is that we can't use this when the display controller already exposes a drm_encoder. I.e, it already creates a drm_encoder object. If we want the encoder chain to be connected to the output of this encoder, we'll need to link the 2 drm_encoders together, which isn't possible at the moment.

I guess we have two ways to go about this:

1) Have an approach like this where all the entities in the encoder chain connect to just one encoder. We define the sequence in which they are connected. The drm kms framework acts as if this chain doesn't exist, and assumes that this is what the encoder is outputting.

2) Make each element in the chain be a 'drm_encoder' object in itself. This would be a more intrusive change, since drm_encoders are expected to receive an input from crtc, and output to a connector. Furthermore, it may confuse userspace what encoder to chose.

For 1), we could either work more on your approach, or use drm_bridges. drm_bridges can already be chained to each other, and bridge ops of each bridge in the chain are called successively. It still relies on the device drivers to form the chain, which is something your approach takes care of by itself. But that's something that can be extended for bridges too.

Laurent,

Merging i2c slave encoders and bridges is possible, but there is no guarantee that the new solution would be future proof and work well with encoder chains. We needed more consensus from folks on dri-devel.

Hi Archit,

Quoted 81 lines · On Fri, 31 Jul 2015 10:56:20 +0530 Archit Taneja <[email protected]> wrote:

Hi Boris, Laurent,

Quoted 60 lines · Boris Brezillon

Archit, Laurent,

Quoted 42 lines · On Tue, 28 Jul 2015 13:47:37 +0530 Archit Taneja <[email protected]> wrote:

Hi,

Quoted 7 lines · Laurent Pinchart

Hi Archit,

(CC'ing Boris Brezillon)

Thank you for the patch.

On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

Quoted 8 lines

Quoted 3 lines

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

i2c slave encoders and bridges aren't exactly the same. slave encoders are used when the there is no real 'encoder' in the display chain. bridges are used when there is already an encoder available, and the bridge entity represents another encoder in the chain.

ADV7511 takes in RGB/MIPI DPI data, which is generally the output of a crtc for drm drivers.

ADV7533 takes in MIPI DSI data, which is generally the output of an encoder for drm drivers.

Therefore, having i2c slave encoder for the former and bridge for the latter made sense to me.

I do agree that it would be better if they were somehow merged. It would prevent the fragmentation we currently have among encoder chips.

One possible way would be to convert slave encoder to bridge. With this, an i2c slave encoder would be a 'dummy encoder' and a bridge. i2c slave encoders even now just tie the slave encoder helper funcs to encoder helper funcs. So it's not really any different.

Quoted 6 lines

Merging these 2 entities would be nice, but we're still shying away from the larger problem of creating generic encoder chains. The ideal solution would be for bridges and slave encoders to just be 'encoders', and the facility to connect on encoder output to the input of another. I don't know how easy it is to do this, and whether it'll break userspace.

Yes, that's pretty much what I was trying to do.
I'd also like to ease display pipelines creation by providing helper functions, so that display controller don't have to worry about encoders and connectors creation if these ones are attached to external encoders.

Quoted 1 line

Quoted 8 lines

Quoted 5 lines

Archit

Quoted 3 lines

Boris, I know you were experimenting with that, do you have anything to report ?

Nope, I didn't work on it since last time we talked about it. I pushed my work here if you want to have a look [1].

I went through the branch you shared. From what I understood, the encoder chain comprises of one 'real' encoder object (drm_encoder) in the 'drm_encoder_chain' struct. This drm_encoder encapsulates all the 'encoder elements' forming the chain.

I'm guessing the various dridge/slave encoder drivers would have to be changed to now create a drm_encoder_element object, replacing drm_bridge/drm_i2c_slave_encoder objects.

Quoted 5 lines

One problem I see with this approach is that we can't use this when the display controller already exposes a drm_encoder. I.e, it already creates a drm_encoder object. If we want the encoder chain to be connected to the output of this encoder, we'll need to link the 2 drm_encoders together, which isn't possible at the moment.

Actually my goal was to move everybody to the drm_encoder_element model, even the encoder directly provided by the display controller IP. If the internal encoder is actually directly connected to a connector, then the encoder chain will just contain one element, but everything should work fine.

Quoted 9 lines

I guess we have two ways to go about this:

1) Have an approach like this where all the entities in the encoder chain connect to just one encoder. We define the sequence in which they are connected. The drm kms framework acts as if this chain doesn't exist, and assumes that this is what the encoder is outputting.

Yep, that's pretty much what I've done. The main reason for doing that is to keep the interface with the userspace unchanged.

Quoted 5 lines

2) Make each element in the chain be a 'drm_encoder' object in itself. This would be a more intrusive change, since drm_encoders are expected to receive an input from crtc, and output to a connector. Furthermore, it may confuse userspace what encoder to chose.

That's why Laurent suggested to go for the 1st approach.

Quoted 1 line

Quoted 6 lines

For 1), we could either work more on your approach, or use drm_bridges. drm_bridges can already be chained to each other, and bridge ops of each bridge in the chain are called successively. It still relies on the device drivers to form the chain, which is something your approach takes care of by itself. But that's something that can be extended for bridges too.

Can we really chain several bridges ?

Also note that I plan to automate the encoder chain creation, or at least provide helper functions so that in standard cases the display controller does not have to bother creating its encoder chain. This is particularly true for platforms supporting DT, the encoder chain + connector can be declared in a generic way, and the core could provide helper functions to parse and create the encoder chain and the endpoint connector.

Quoted 4 lines

Laurent,

Quoted 4 lines

Merging i2c slave encoders and bridges is possible, but there is no guarantee that the new solution would be future proof and work well with encoder chains. We needed more consensus from folks on dri-devel.

I'll let Laurent correct me if I'm wrong, but I think the plan was to move all slave encoders and bridges to the encoder element representation.

Hi Archit,

Quoted 81 lines · On Fri, 31 Jul 2015 10:56:20 +0530 Archit Taneja <[email protected]> wrote:

Hi Boris, Laurent,

Quoted 60 lines · Boris Brezillon

Archit, Laurent,

Quoted 42 lines · On Tue, 28 Jul 2015 13:47:37 +0530 Archit Taneja <[email protected]> wrote:

Hi,

Quoted 7 lines · Laurent Pinchart

Hi Archit,

(CC'ing Boris Brezillon)

Thank you for the patch.

On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

Quoted 8 lines

Quoted 3 lines

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

i2c slave encoders and bridges aren't exactly the same. slave encoders are used when the there is no real 'encoder' in the display chain. bridges are used when there is already an encoder available, and the bridge entity represents another encoder in the chain.

ADV7511 takes in RGB/MIPI DPI data, which is generally the output of a crtc for drm drivers.

ADV7533 takes in MIPI DSI data, which is generally the output of an encoder for drm drivers.

Therefore, having i2c slave encoder for the former and bridge for the latter made sense to me.

I do agree that it would be better if they were somehow merged. It would prevent the fragmentation we currently have among encoder chips.

One possible way would be to convert slave encoder to bridge. With this, an i2c slave encoder would be a 'dummy encoder' and a bridge. i2c slave encoders even now just tie the slave encoder helper funcs to encoder helper funcs. So it's not really any different.

Quoted 6 lines

Merging these 2 entities would be nice, but we're still shying away from the larger problem of creating generic encoder chains. The ideal solution would be for bridges and slave encoders to just be 'encoders', and the facility to connect on encoder output to the input of another. I don't know how easy it is to do this, and whether it'll break userspace.

Yes, that's pretty much what I was trying to do.
I'd also like to ease display pipelines creation by providing helper functions, so that display controller don't have to worry about encoders and connectors creation if these ones are attached to external encoders.

Quoted 1 line

Quoted 8 lines

Quoted 5 lines

Archit

Quoted 3 lines

Boris, I know you were experimenting with that, do you have anything to report ?

Nope, I didn't work on it since last time we talked about it. I pushed my work here if you want to have a look [1].

I went through the branch you shared. From what I understood, the encoder chain comprises of one 'real' encoder object (drm_encoder) in the 'drm_encoder_chain' struct. This drm_encoder encapsulates all the 'encoder elements' forming the chain.

I'm guessing the various dridge/slave encoder drivers would have to be changed to now create a drm_encoder_element object, replacing drm_bridge/drm_i2c_slave_encoder objects.

Quoted 5 lines

One problem I see with this approach is that we can't use this when the display controller already exposes a drm_encoder. I.e, it already creates a drm_encoder object. If we want the encoder chain to be connected to the output of this encoder, we'll need to link the 2 drm_encoders together, which isn't possible at the moment.

Actually my goal was to move everybody to the drm_encoder_element model, even the encoder directly provided by the display controller IP. If the internal encoder is actually directly connected to a connector, then the encoder chain will just contain one element, but everything should work fine.

Quoted 8 lines

I guess we have two ways to go about this:

1) Have an approach like this where all the entities in the encoder chain connect to just one encoder. We define the sequence in which they are connected. The drm kms framework acts as if this chain doesn't exist, and assumes that this is what the encoder is outputting.

Yep, that's pretty much what I've done. The main reason for doing that is to keep the interface with the userspace unchanged.

Quoted 5 lines

2) Make each element in the chain be a 'drm_encoder' object in itself. This would be a more intrusive change, since drm_encoders are expected to receive an input from crtc, and output to a connector. Furthermore, it may confuse userspace what encoder to chose.

That's why Laurent suggested to go for the 1st approach.

Quoted 7 lines

For 1), we could either work more on your approach, or use drm_bridges. drm_bridges can already be chained to each other, and bridge ops of each bridge in the chain are called successively. It still relies on the device drivers to form the chain, which is something your approach takes care of by itself. But that's something that can be extended for bridges too.

Can we really chain several bridges ?

Also note that I plan to automate the encoder chain creation, or at least provide helper functions so that in standard cases the display controller does not have to bother creating its encoder chain. This is particularly true for platforms supporting DT, the encoder chain + connector can be declared in a generic way, and the core could provide helper functions to parse and create the encoder chain and the endpoint connector.

Quoted 7 lines

Laurent,

Merging i2c slave encoders and bridges is possible, but there is no guarantee that the new solution would be future proof and work well with encoder chains. We needed more consensus from folks on dri-devel.

I'll let Laurent correct me if I'm wrong, but I think the plan was to move all slave encoders and bridges to the encoder element representation.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
_______________________________________________
dri-devel mailing list
[email protected]
http://lists.freedesktop.org/mailman/listinfo/dri-devel

Quoted 16 lines

Quoted 15 lines

I went through the branch you shared. From what I understood, the encoder chain comprises of one 'real' encoder object (drm_encoder) in the 'drm_encoder_chain' struct. This drm_encoder encapsulates all the 'encoder elements' forming the chain.

I'm guessing the various dridge/slave encoder drivers would have to be changed to now create a drm_encoder_element object, replacing drm_bridge/drm_i2c_slave_encoder objects.

One problem I see with this approach is that we can't use this when the display controller already exposes a drm_encoder. I.e, it already creates a drm_encoder object. If we want the encoder chain to be connected to the output of this encoder, we'll need to link the 2 drm_encoders together, which isn't possible at the moment.

Quoted 5 lines

Actually my goal was to move everybody to the drm_encoder_element model, even the encoder directly provided by the display controller IP. If the internal encoder is actually directly connected to a connector, then the encoder chain will just contain one element, but everything should work fine.

so.. I'd be careful about changing the role of drm_encoder, as it does play a small role in the interface exposed to userspace.

If you do anything, I think you need to make i2c-encoder-slave stuff look like a drm_bridge + drm_connector, since bridge is not visible to userspace and can already be chained... which I think ends up making it more like how adv7533 looks w/ archit's patches.

That said, the adv7511 type case (raw parallel output) is kind of a better fit for the existing i2c-slave-encoder model, vs adv7533 where you already have a dsi encoder and is a better fit for the drm_bridge model. So maybe there is still a place for both.

At any rate, if we do unify, I think we should go towards the drm_bridge + drm_connector approach and migrate i2c-encoder users over to that. Which would make Archit's approach a reasonable transition step. We just drop the i2c-encoder part of it when none of the adv7511 users still depend on that.

Hi Rob,

Quoted 16 lines · On Fri, 31 Jul 2015 08:13:59 -0400 Rob Clark <[email protected]> wrote:

Quoted 16 lines

Quoted 15 lines

I went through the branch you shared. From what I understood, the encoder chain comprises of one 'real' encoder object (drm_encoder) in the 'drm_encoder_chain' struct. This drm_encoder encapsulates all the 'encoder elements' forming the chain.

I'm guessing the various dridge/slave encoder drivers would have to be changed to now create a drm_encoder_element object, replacing drm_bridge/drm_i2c_slave_encoder objects.

One problem I see with this approach is that we can't use this when the display controller already exposes a drm_encoder. I.e, it already creates a drm_encoder object. If we want the encoder chain to be connected to the output of this encoder, we'll need to link the 2 drm_encoders together, which isn't possible at the moment.

Quoted 8 lines

Quoted 5 lines

Actually my goal was to move everybody to the drm_encoder_element model, even the encoder directly provided by the display controller IP. If the internal encoder is actually directly connected to a connector, then the encoder chain will just contain one element, but everything should work fine.

so.. I'd be careful about changing the role of drm_encoder, as it does play a small role in the interface exposed to userspace.

I don't think I changed the role of the drm_encoder in my approach. Actually I'm only exposing one encoder for the whole encoder chain. The encoder chain is containing one or several encoder elements, which are not exposed to userspace.

Quoted 5 lines

If you do anything, I think you need to make i2c-encoder-slave stuff look like a drm_bridge + drm_connector, since bridge is not visible to userspace and can already be chained... which I think ends up making it more like how adv7533 looks w/ archit's patches.

Okay, maybe we can do the same with drm bridges (I wasn't aware that these ones could be chained before Archit mentioned it).
I remember that I was missing a few features in the DRM bridge implementation (like the possibility to negotiate the format passed on the link between 2 encoders), but that's probably something we can add.

Quoted 5 lines

That said, the adv7511 type case (raw parallel output) is kind of a better fit for the existing i2c-slave-encoder model, vs adv7533 where you already have a dsi encoder and is a better fit for the drm_bridge model. So maybe there is still a place for both.

Excuse my ignorance, but I still don't get why the RGB/MIPI DPI are not represented as encoders. They are dummy encoders which just forwards the output of the display controller in raw RGB format, but still. IMHO, representing them as encoders in the chain would ease the whole thing.

Moreover, by doing that we would be able to link this RGB/DPI encoder to a bridge, and we wouldn't have to differentiate the encoder-slave and bridge elements.

Quoted 6 lines

At any rate, if we do unify, I think we should go towards the drm_bridge + drm_connector approach and migrate i2c-encoder users over to that. Which would make Archit's approach a reasonable transition step. We just drop the i2c-encoder part of it when none of the adv7511 users still depend on that.

Another problem I've seen with some drm bridge drivers is that they directly create their own connector, which, as Archit stated, is wrong if you decide to chain this bridge with another bridge. The other

reason why the bridge should not create the connector by its own is that in some case the encoder supports different types of connectors (a TDMS encoder can be used to output HDMI or DVI), and thus, selecting the connector type should be left to the part responsible for creating the display pipelines.

This being said, I'm definitely not an expert in this area, so don't hesitate to show me where I'm wrong.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Quoted 5 lines · Boris Brezillon

Hi Rob,

On Fri, 31 Jul 2015 08:13:59 -0400
Rob Clark <[email protected]> wrote:

Quoted 4 lines

Another problem I've seen with some drm bridge drivers is that they directly create their own connector, which, as Archit stated, is wrong if you decide to chain this bridge with another bridge. The other

I agree with Archit on this. He took this approach w/ msm support for external bridges, and it seems sensible that the last bridge constructs the connector. (Plus presumably that is where hpd, ddc probing, etc, is happing)

Quoted 6 lines

reason why the bridge should not create the connector by its own is that in some case the encoder supports different types of connectors (a TDMS encoder can be used to output HDMI or DVI), and thus, selecting the connector type should be left to the part responsible for creating the display pipelines.

did you mean "should" instead of "should not"? Otherwise I don't think I understand..

BR,
-R

Quoted 11 lines

This being said, I'm definitely not an expert in this area, so don't hesitate to show me where I'm wrong.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Hi,

Quoted 7 lines · Rob Clark

Quoted 5 lines · Boris Brezillon

Hi Rob,

On Fri, 31 Jul 2015 08:13:59 -0400
Rob Clark <[email protected]> wrote:

(...)

Quoted 9 lines

Quoted 4 lines

Another problem I've seen with some drm bridge drivers is that they directly create their own connector, which, as Archit stated, is wrong if you decide to chain this bridge with another bridge. The other

I agree with Archit on this. He took this approach w/ msm support for external bridges, and it seems sensible that the last bridge constructs the connector. (Plus presumably that is where hpd, ddc probing, etc, is happing)

With this approach many bridges should construct connector conditionally, depending if there is something behind them in pipeline (the same is true for encoders and even crtcs). It works, but for me there is lot of unnecessary code and all those conditional paths make things less friendly for development. Wouldn't be better to move creation of the connector to the main drm driver, it would require probably adding some opses/fields to drm_bridges but the drivers would be simpler, I guess.

Regards
Andrzej

Quoted 24 lines

Quoted 6 lines

reason why the bridge should not create the connector by its own is that in some case the encoder supports different types of connectors (a TDMS encoder can be used to output HDMI or DVI), and thus, selecting the connector type should be left to the part responsible for creating the display pipelines.

did you mean "should" instead of "should not"? Otherwise I don't think I understand..

BR,
-R

Quoted 11 lines

This being said, I'm definitely not an expert in this area, so don't hesitate to show me where I'm wrong.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Quoted 19 lines · Andrzej Hajda

Hi,

Quoted 7 lines · Rob Clark

Quoted 5 lines · Boris Brezillon

Hi Rob,

On Fri, 31 Jul 2015 08:13:59 -0400
Rob Clark <[email protected]> wrote:

(...)

Quoted 7 lines

Quoted 3 lines

Another problem I've seen with some drm bridge drivers is that they directly create their own connector, which, as Archit stated, is wrong if you decide to chain this bridge with another bridge. The other

I agree with Archit on this. He took this approach w/ msm support for external bridges, and it seems sensible that the last bridge constructs the connector. (Plus presumably that is where hpd, ddc probing, etc, is happing)

Quoted 7 lines

With this approach many bridges should construct connector conditionally, depending if there is something behind them in pipeline (the same is true for encoders and even crtcs). It works, but for me there is lot of unnecessary code and all those conditional paths make things less friendly for development. Wouldn't be better to move creation of the connector to the main drm driver, it would require probably adding some opses/fields to drm_bridges but the drivers would be simpler, I guess.

six of one, half dozen of the other.. you'd still need to implement
the hpd and ddc probe bits, and that sort of thing *somewhere*. Whether it is directly by implementing drm_connector in the bridge, or indirectly via some extra drm_bridge op's called by a shim connector in the main drm driver, doesn't really seem to change things..

BR,
-R

Quoted 25 lines

Regards
Andrzej

Quoted 22 lines

Quoted 5 lines

reason why the bridge should not create the connector by its own is that in some case the encoder supports different types of connectors (a TDMS encoder can be used to output HDMI or DVI), and thus, selecting the connector type should be left to the part responsible for creating the display pipelines.

did you mean "should" instead of "should not"? Otherwise I don't think I understand..

BR,
-R

Quoted 11 lines

This being said, I'm definitely not an expert in this area, so don't hesitate to show me where I'm wrong.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Quoted 27 lines · Rob Clark

Quoted 26 lines · Andrzej Hajda

Hi,

Quoted 7 lines · Rob Clark

Quoted 5 lines · Boris Brezillon

Hi Rob,

On Fri, 31 Jul 2015 08:13:59 -0400
Rob Clark <[email protected]> wrote:

(...)

Quoted 7 lines

Quoted 3 lines

Another problem I've seen with some drm bridge drivers is that they directly create their own connector, which, as Archit stated, is wrong if you decide to chain this bridge with another bridge. The other

I agree with Archit on this. He took this approach w/ msm support for external bridges, and it seems sensible that the last bridge constructs the connector. (Plus presumably that is where hpd, ddc probing, etc, is happing)

With this approach many bridges should construct connector conditionally, depending if there is something behind them in pipeline (the same is true for encoders and even crtcs). It works, but for me there is lot of unnecessary code and all those conditional paths make things less friendly for development. Wouldn't be better to move creation of the connector to the main drm driver, it would require probably adding some opses/fields to drm_bridges but the drivers would be simpler, I guess.

Quoted 5 lines

six of one, half dozen of the other.. you'd still need to implement
the hpd and ddc probe bits, and that sort of thing *somewhere*. Whether it is directly by implementing drm_connector in the bridge, or indirectly via some extra drm_bridge op's called by a shim connector in the main drm driver, doesn't really seem to change things..

The difference is that instead of duplicating connector related code in every driver you will call one helper from the main drm driver/core.

Regards
Andrzej

Quoted 29 lines

BR,
-R

Quoted 25 lines

Regards
Andrzej

Quoted 22 lines

Quoted 5 lines

reason why the bridge should not create the connector by its own is that in some case the encoder supports different types of connectors (a TDMS encoder can be used to output HDMI or DVI), and thus, selecting the connector type should be left to the part responsible for creating the display pipelines.

did you mean "should" instead of "should not"? Otherwise I don't think I understand..

BR,
-R

Quoted 11 lines

This being said, I'm definitely not an expert in this area, so don't hesitate to show me where I'm wrong.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Quoted 34 lines · Andrzej Hajda

Quoted 32 lines · Rob Clark

Quoted 19 lines · Andrzej Hajda

Hi,

Quoted 7 lines · Rob Clark

Quoted 5 lines · Boris Brezillon

Hi Rob,

On Fri, 31 Jul 2015 08:13:59 -0400
Rob Clark <[email protected]> wrote:

(...)

Quoted 7 lines

Quoted 3 lines

Another problem I've seen with some drm bridge drivers is that they directly create their own connector, which, as Archit stated, is wrong if you decide to chain this bridge with another bridge. The other

I agree with Archit on this. He took this approach w/ msm support for external bridges, and it seems sensible that the last bridge constructs the connector. (Plus presumably that is where hpd, ddc probing, etc, is happing)

Quoted 7 lines

With this approach many bridges should construct connector conditionally, depending if there is something behind them in pipeline (the same is true for encoders and even crtcs). It works, but for me there is lot of unnecessary code and all those conditional paths make things less friendly for development. Wouldn't be better to move creation of the connector to the main drm driver, it would require probably adding some opses/fields to drm_bridges but the drivers would be simpler, I guess.

six of one, half dozen of the other.. you'd still need to implement
the hpd and ddc probe bits, and that sort of thing *somewhere*. Whether it is directly by implementing drm_connector in the bridge, or indirectly via some extra drm_bridge op's called by a shim connector in the main drm driver, doesn't really seem to change things..

Quoted 2 lines

The difference is that instead of duplicating connector related code in every driver you will call one helper from the main drm driver/core.

Which isn't more than a few lines of code.. I mean, looking at a couple connectors, the bulk of the code is hpd and ddc related. That doesn't magically go away. There isn't that many lines of boilerplate, so meh.

BR,
-R

Quoted 33 lines

Regards
Andrzej

Quoted 29 lines

BR,
-R

Quoted 25 lines

Regards
Andrzej

Quoted 22 lines

Quoted 5 lines

reason why the bridge should not create the connector by its own is that in some case the encoder supports different types of connectors (a TDMS encoder can be used to output HDMI or DVI), and thus, selecting the connector type should be left to the part responsible for creating the display pipelines.

did you mean "should" instead of "should not"? Otherwise I don't think I understand..

BR,
-R

Quoted 11 lines

This being said, I'm definitely not an expert in this area, so don't hesitate to show me where I'm wrong.

Best Regards,

Boris

--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Hi Archit,

(CC'ing Boris Brezillon)

Thank you for the patch.

On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

Quoted 3 lines

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

Boris, I know you were experimenting with that, do you have anything to report ?

Quoted 142 lines

Move the code in encoder slave functions to generate helpers that are agnostic to the drm object type. These helpers will later also be used by bridge and connecter helper functions.

Signed-off-by Archit Taneja <[email protected]>

---
 drivers/gpu/drm/i2c/adv7511.c | 80 +++++++++++++++++++++++++++------------
 1 file changed, 57 insertions(+), 23 deletions(-)

drivers/gpu/drm/i2c/adv7511.c +55 -25

index 63a3d20..46fb24d 100644
@@ -612,13 +612,11 @@ static int adv7511_get_edid_block(void *data, u8 *buf,
 unsigned int block, }
 
 /*
---------------------------------------------------------------------------
-- - * Encoder operations
+ * ADV75xx helpers
  */
-
-static int adv7511_get_modes(struct drm_encoder *encoder,
-                          struct drm_connector *connector)
+static int adv7511_get_modes(struct adv7511 *adv7511,
+             struct drm_connector *connector)
 {
-     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
      struct edid *edid;
      unsigned int count;

@@ -656,21 +654,10 @@ static int adv7511_get_modes(struct drm_encoder
 *encoder, return count;
 }
 
-static void adv7511_encoder_dpms(struct drm_encoder *encoder, int mode)
-{
-     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
-
-     if (mode == DRM_MODE_DPMS_ON)
-             adv7511_power_on(adv7511);
-     else
-             adv7511_power_off(adv7511);
-}
-
 static enum drm_connector_status
-adv7511_encoder_detect(struct drm_encoder *encoder,
+adv7511_detect(struct adv7511 *adv7511,
                     struct drm_connector *connector)
 {
-     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
      enum drm_connector_status status;
      unsigned int val;
      bool hpd;

@@ -694,7 +681,7 @@ adv7511_encoder_detect(struct drm_encoder *encoder,
      if (status == connector_status_connected && hpd && adv7511->powered) {
              regcache_mark_dirty(adv7511->regmap);
              adv7511_power_on(adv7511);
-             adv7511_get_modes(encoder, connector);
+             adv7511_get_modes(adv7511, connector);
              if (adv7511->status == connector_status_connected)
                      status = connector_status_disconnected;
      } else {

@@ -708,8 +695,8 @@ adv7511_encoder_detect(struct drm_encoder *encoder,
      return status;
 }
 
-static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
-                                   struct drm_display_mode *mode)
+static int adv7511_mode_valid(struct adv7511 *adv7511,
+                                  const struct drm_display_mode *mode)
 {
      if (mode->clock > 165000)
              return MODE_CLOCK_HIGH;

@@ -717,11 +704,10 @@ static int adv7511_encoder_mode_valid(struct
 drm_encoder *encoder, return MODE_OK;
 }
 
-static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
+static void adv7511_mode_set(struct adv7511 *adv7511,
                                   struct drm_display_mode *mode,
                                   struct drm_display_mode *adj_mode)
 {
-     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
      unsigned int low_refresh_rate;
      unsigned int hsync_polarity = 0;
      unsigned int vsync_polarity = 0;

@@ -812,12 +798,60 @@ static void adv7511_encoder_mode_set(struct
 drm_encoder *encoder, adv7511->f_tmds = mode->clock;
 }
 
+/*
---------------------------------------------------------------------------
-- + * Encoder operations
+ */
+
+static int adv7511_encoder_get_modes(struct drm_encoder *encoder,
+                          struct drm_connector *connector)
+{
+     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+     return adv7511_get_modes(adv7511, connector);
+}
+
+static void adv7511_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+     if (mode == DRM_MODE_DPMS_ON)
+             adv7511_power_on(adv7511);
+     else
+             adv7511_power_off(adv7511);
+}
+
+static enum drm_connector_status
+adv7511_encoder_detect(struct drm_encoder *encoder,
+                    struct drm_connector *connector)
+{
+     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+     return adv7511_detect(adv7511, connector);
+}
+
+static int adv7511_encoder_mode_valid(struct drm_encoder *encoder,
+                                   struct drm_display_mode *mode)
+{
+     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+     return adv7511_mode_valid(adv7511, mode);
+}
+
+static void adv7511_encoder_mode_set(struct drm_encoder *encoder,
+                                  struct drm_display_mode *mode,
+                                  struct drm_display_mode *adj_mode)
+{
+     struct adv7511 *adv7511 = encoder_to_adv7511(encoder);
+
+     adv7511_mode_set(adv7511, mode, adj_mode);
+}
+
 static struct drm_encoder_slave_funcs adv7511_encoder_funcs = {
      .dpms = adv7511_encoder_dpms,

drivers/gpu/drm/i2c/adv7511.c static void adv7511_encoder_mode_set(struct

Quoted 10 lines

drivers/gpu/drm/i2c/adv7511.c +1 -3

      .mode_valid = adv7511_encoder_mode_valid,
      .mode_set = adv7511_encoder_mode_set,
      .detect = adv7511_encoder_detect,
-     .get_modes = adv7511_get_modes,
+     .get_modes = adv7511_encoder_get_modes,
 };
 
 /*
---------------------------------------------------------------------------
--

--
Regards,

Laurent Pinchart

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Quoted 9 lines · Laurent Pinchart

Quoted 3 lines · On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

btw, what is the status here? I'd kind of lost track of the discussion, but I'm getting impatient that it is somehow taking ridiculously long to get adv7533 support merged. (It's good thing the x86/desktop folks don't bikeshed so much.. I'd hate to wait a year for my new laptop to be supported..)

Anyways, if needed, just copy/paste the adv7511/7533 code into a separate bridge-only driver, and we'll use that. Once the i2c-slave-encoder users for adv7511 are converted over, we can delete the original slave encoder driver. That seems like a sane transition plan to a bridge-only world.

Quoted 11 lines · On Thursday 03 December 2015 10:02:02 Rob Clark wrote:

Quoted 9 lines · Laurent Pinchart

Quoted 3 lines · On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

Quoted 5 lines

btw, what is the status here? I'd kind of lost track of the discussion, but I'm getting impatient that it is somehow taking ridiculously long to get adv7533 support merged. (It's good thing the x86/desktop folks don't bikeshed so much.. I'd hate to wait a year for my new laptop to be supported..)

I'd hardly call the overall architecture on which drivers rely a bikeshed (and maybe if x86/desktop folks cared more about embedded there would be more willingness to make the framework evolve in an embedded-friendly way).

Quoted 5 lines

Anyways, if needed, just copy/paste the adv7511/7533 code into a separate bridge-only driver, and we'll use that. Once the i2c-slave-encoder users for adv7511 are converted over, we can delete the original slave encoder driver. That seems like a sane transition plan to a bridge-only world.

It's a very sane way to make sure nobody will do the work and keep two copies of the same code for a long time, yes.

The path forward is pretty clear, the issue is to find someone who can do the work.

--
Regards,

Laurent Pinchart

Quoted 18 lines · Laurent Pinchart

Quoted 16 lines · On Thursday 03 December 2015 10:02:02 Rob Clark wrote:

Quoted 9 lines · Laurent Pinchart

Quoted 3 lines · On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

btw, what is the status here? I'd kind of lost track of the discussion, but I'm getting impatient that it is somehow taking ridiculously long to get adv7533 support merged. (It's good thing the x86/desktop folks don't bikeshed so much.. I'd hate to wait a year for my new laptop to be supported..)

Quoted 4 lines

I'd hardly call the overall architecture on which drivers rely a bikeshed (and maybe if x86/desktop folks cared more about embedded there would be more willingness to make the framework evolve in an embedded-friendly way).

I don't know that we can blame this on the desktop folks like that..

after all i2c-slave was sufficient for embedded devices for some time, and it was an improvement over what came before when it comes to sharing external encoder support (ie. nothing)

But, as was the case with atomic, the framework evolves. And as atomic roll-out has shown, it doesn't require a flag-day if you accept some duplication.

Quoted 6 lines

Quoted 5 lines

Anyways, if needed, just copy/paste the adv7511/7533 code into a separate bridge-only driver, and we'll use that. Once the i2c-slave-encoder users for adv7511 are converted over, we can delete the original slave encoder driver. That seems like a sane transition plan to a bridge-only world.

Quoted 2 lines

It's a very sane way to make sure nobody will do the work and keep two copies of the same code for a long time, yes.

As opposed to a change everything at once approach, and corresponding updates to drivers for hw you don't have. That sounds like a *much* saner plan</sarcasm>

Seriously, the cost of duplicating a bit of code is low. Especially when the code you are duplicating is low churn. Duplicating lets other drivers that use adv75xx via slave-encoder migrate over at their own pace. Similar to how atomic was rolled out. To me that sounds like the much more practical way forward.

Quoted 2 lines

The path forward is pretty clear, the issue is to find someone who can do the work.

Maybe the end goal is clear. But apparently the path forward less so.

Quoted 18 lines · Laurent Pinchart

Quoted 11 lines · On Thursday 03 December 2015 10:02:02 Rob Clark wrote:

Quoted 9 lines · Laurent Pinchart

Quoted 3 lines · On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on the other hand, is going be a normal i2c client device creating bridge and connector entities.

Please, no. It's really time to stop piling hacks and fix the problem properly. There's no reason to have separate APIs for I2C slave encoders and DRM bridges. Those two APIs need to be merged, and then you'll find it much easier to implement ADV7533 support.

Quoted 5 lines

btw, what is the status here? I'd kind of lost track of the discussion, but I'm getting impatient that it is somehow taking ridiculously long to get adv7533 support merged. (It's good thing the x86/desktop folks don't bikeshed so much.. I'd hate to wait a year for my new laptop to be supported..)

Quoted 3 lines

I'd hardly call the overall architecture on which drivers rely a bikeshed (and maybe if x86/desktop folks cared more about embedded there would be more willingness to make the framework evolve in an embedded-friendly way).

I don't know that we can blame this on the desktop folks like that.. after all i2c-slave was sufficient for embedded devices for some time, and it was an improvement over what came before when it comes to sharing external encoder support (ie. nothing)

But, as was the case with atomic, the framework evolves. And as atomic roll-out has shown, it doesn't require a flag-day if you accept some duplication.

Quoted 8 lines

Quoted 5 lines

Anyways, if needed, just copy/paste the adv7511/7533 code into a separate bridge-only driver, and we'll use that. Once the i2c-slave-encoder users for adv7511 are converted over, we can delete the original slave encoder driver. That seems like a sane transition plan to a bridge-only world.

It's a very sane way to make sure nobody will do the work and keep two copies of the same code for a long time, yes.

As opposed to a change everything at once approach, and corresponding updates to drivers for hw you don't have. That sounds like a *much* saner plan</sarcasm>

Seriously, the cost of duplicating a bit of code is low. Especially when the code you are duplicating is low churn. Duplicating lets other drivers that use adv75xx via slave-encoder migrate over at their own pace. Similar to how atomic was rolled out. To me that sounds like the much more practical way forward.

Quoted 2 lines

The path forward is pretty clear, the issue is to find someone who can do the work.

Maybe the end goal is clear. But apparently the path forward less so.

BR,
-R

Quoted 5 lines

--
Regards,

Laurent Pinchart

Quoted 10 lines · Rob Clark

Quoted 8 lines · Laurent Pinchart

Quoted 7 lines · On Thursday 03 December 2015 10:02:02 Rob Clark wrote:

Quoted 6 lines · Laurent Pinchart

Quoted 5 lines · On Monday 27 July 2015 11:46:57 Archit Taneja wrote:

ADV7511 is represented as an i2c drm slave encoder device. ADV7533, on
the other hand, is going be a normal i2c client device creating bridge
and connector entities.

Laurent, as we'd discussed in the past, I did an initial study of how we could map bridge ops to the encoder slave ops, and change it for the rcar kms driver (and others) that might use adv7511.

The drm_encoder_slave_funcs ops are a superset of bridge ops. The rcar-du driver uses a subset of these ops (encoder-like ops) to implement the hdmi encoder (rcar_du_hdmienc.c) and the other (connector-like ops)for implementing the hdmi connector (rcar_du_hdmicon.c)

We have two options:

1. If we want to use drm_bridge as it is, the rcar driver shouldn't create a hdmi connector anymore, and rely on the adv7511 driver to make a connector for it. This is the easiest way, but it will break the nice representation of the hardware in DT.

2. We add more drm_bridge ops (the ones that implement the connector ops), and make the hdmi connector created by rcar-du use these bridge ops.

Both these options have issues. The 2) one is the probably the better of the two, but I don't know if adding more ops to the bridge is the right way to go.

Therefore, I don't know how we can solve this straight away. If there is more debate needed on this, then it is probably easier to get adv7533 support in, and then figure out how two merge the two.

Quoted 10 lines

BR,
-R

Quoted 5 lines

--
Regards,

Laurent Pinchart