diff mbox

Multiple codecs on one sound card for multi-channel sound card

Message ID 55FA7F05.4020001@invoxia.com (mailing list archive)
State New, archived
Headers show

Commit Message

Arnaud Mouiche Sept. 17, 2015, 8:51 a.m. UTC
Hello Caleb,

freescale SSI is fine with more than 2 channels.
I have planed to publish a set of patch in this direction but we still 
have some corner cases to fix first (rare issues with channels alignment)

Yet, this following is far enough to have it working.
And since the max/min rate is at the end the intersection of what the 
SSI, the codec and the card are declaring, it will not change anything 
until you connect the SSI to a codec with more than 2 channels, or a 
multi-codec solution.

Arnaud

         },


Le 17/09/2015 00:07, Caleb Crome a écrit :
> Ah Ha!  thank you Arnaud!  I'll understand this stuff eventually.
> I'll implement as you've shown and see how it goes.
>
> I see that you have 'fsl,imx-audio-foo', using an SSI.  from what I
> can see the SSIs only support channels_max=2.  How do you get
> multi-channel TDM to work with the freescale SSI port?  I need to get
> this TDM working on both TI & Freescale, and the freescale has been
> quite problematic because the multi-channel doesn't seem to be
> supported in the driver.
>
> I have just checked out and verified that
>
> http://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/
>
> sound/soc/fsl/*ssi*
>
> all have channels_max = 2
>
> We're very motivated to get this working on the freescale MX6, and
> getting it to work sure does not seem as simple as changing 2 to a
> bigger number :-)
>
>
> Thanks,
>    -Caleb
>
>
> On Wed, Sep 16, 2015 at 2:57 AM, arnaud.mouiche@invoxia.com
> <arnaud.mouiche@invoxia.com> wrote:
>> Hello Caleb,
>>
>> Multi-codec support is now working fine the current linux releases.
>> for previous releases, check if commit
>>      [PATCH] ASoC: dapm: Don't add prefix to widget stream name
>> is included. I remember this is the last required patch.
>>
>> After that, I don't know if the "simple-card" can be configured for multi
>> codec support as you wish.
>>
>> On my side, I cooked a particular sound card for the purpose.
>> here is some tips:
>>
>>
>>      struct snd_soc_dai_link_component codecs[2];
>>      struct snd_soc_codec_conf codecs_conf[2];
>> [...]
>>      for (num_codecs=0; num_codecs<2; num_codecs++) {
>>          struct device_node *of_node;
>>          of_node = of_parse_phandle(pdev->dev.of_node, "audio-codec",
>> num_codecs);
>>          if (!of_node) break;
>>          data->codecs[num_codecs].of_node = of_node;
>>          data->codecs[num_codecs].dai_name = "tlv320aic3x-foo";
>>
>>          /* add a "C2" name prefix for every control of the 2nd codec */
>>          data->codecs_conf[num_codecs].of_node = of_node;
>>          if (num_codecs == 1) {
>>              data->codecs_conf[num_codecs].name_prefix = "C2";
>>          }
>>      }
>> [...]
>>      data->dai.codecs = data->codecs;
>>      data->dai.num_codecs = num_codecs;
>>      data->card.dai_link = &data->dai;
>>      data->card.codec_conf = data->codecs_conf;
>>      data->card.num_configs = num_codecs;
>> [...]
>>
>>
>> On DTS side, I have something like
>>
>>      sound@0 {
>>          compatible = "fsl,imx-audio-foo";
>>          model = "foo-audio";
>>          ssi-controller = <&ssi1>;
>>
>>          /*
>>           * list phandles for the 2 codecs used in the same TDM network
>>           */
>>          audio-codec = <&codec1>, <&codec2>;
>>
>>          [...]
>>
>>      };
>>
>>
>> You also need to have a particular hw_params() method to dispatch the TDM
>> and sysclk configuration to your codecs, making the difference between your
>> first codec (your bus master) and the others.
>>
>>
>> Arnaud
>>
>>
>> Le 15/09/2015 03:07, Caleb Crome a écrit :
>>> (re-sending hope it's not a duplicate -- I think I must have had HTML
>>> in my previous email and it was ignored)
>>>
>>>    Hi all,
>>>       What are the current best practices to specify multiple codecs on
>>> one sound card, with all codecs sharing a single TDM bus?
>>>
>>>    I have a card with up to 32 TLV320AIC33 codecs on it.  For the
>>> moment, we can limit the discussion to only 16 codecs, so we don't
>>> have to get extra serializers involved...
>>>
>>>    I currently have something like this in my am335x-boneblack.dts file:
>>>
>>>    (i.e. attempting to set tdm slot width and num in the i2c codec)
>>>
>>>    but it doesn't seem to be picking up the fact that I want all the
>>> codecs linked together as one.
>>>
>>>    (FYI, the first codec, i.e. tlv32aic3x_a should be the master, and
>>> all others including the CPU will be slaves).
>>>
>>>    Thanks for any help!
>>>
>>>    BTW, I'm happy to use whatever kernel will support me with the
>>> minimal amount of effort, currently using 4.1
>>>
>>>
>>>
>>> Thank you!
>>>      -Caleb
>>>
>>> &i2c1 {
>>>    ...
>>> tlv320aic3x_a: tlv320aic3x@18 {
>>> #sound-dai-cells = <1>;
>>> compatible = "ti,tlv320aic3x";
>>> reg = <0x18>;
>>> tdm-offset = <0>;
>>> status = "okay";
>>> };
>>> tlv320aic3x_b: tlv320aic3x@19 {
>>> #sound-dai-cells = <1>;
>>> compatible = "ti,tlv320aic3x";
>>> reg = <0x19>;
>>> tdm-offset = <32>;
>>> status = "okay";
>>> };
>>> tlv320aic3x_c: tlv320aic3x@1a {
>>> #sound-dai-cells = <1>;
>>> compatible = "ti,tlv320aic3x";
>>> reg = <0x1a>;
>>> tdm-offset = <64>;
>>> status = "okay";
>>> };
>>> tlv320aic3x_d: tlv320aic3x@1b {
>>> #sound-dai-cells = <1>;
>>> compatible = "ti,tlv320aic3x";
>>> reg = <0x1b>;
>>> tdm-offset = <96>;
>>> status = "okay";
>>> };
>>> };
>>>
>>> &mcasp0 {
>>> #sound-dai-cells = <0>;
>>> pinctrl-names = "default";
>>> pinctrl-0 = <&mcasp_0_pins_default>;
>>> status = "okay";
>>>
>>> op-mode = <0>;          /* MCASP_IIS_MODE */
>>> tdm-slots = <16>;
>>> num-serializer = <16>;
>>> serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
>>> 0 0 1 2
>>> 0 0 0 0
>>> 0 0 0 0
>>> 0 0 0 0
>>>> ;
>>> tx-num-evt = <1>;
>>> rx-num-evt = <1>;
>>> };
>>>
>>> / {
>>> sound {
>>> compatible = "simple-audio-card";
>>> simple-audio-card,name = "puppy-audio";
>>> simple-audio-card,mclk-fs = <256>;
>>> system-clock-frequency = <12288000>;
>>> status = "okay";
>>> simple-audio-card,bitclock-master = <&tlv320aic3x_a>;
>>>         simple-audio-card,frame-master    = <&tlv320aic3x_a>;
>>> simple-audio-card,widgets =
>>> "Line", "Line Out",
>>> "Line", "Line In";
>>> simple-audio-card,routing =
>>> "Line Out",       "HPLOUT",
>>> "Line Out",       "HPROUT",
>>> "Line In",        "LINE1L",
>>> "Line In",        "LINE1R";
>>>
>>> simple-audio-card,dai-link@0 {
>>> format = "left_j";
>>> cpu {
>>> sound-dai = <&mcasp0>;
>>> };
>>> codec {
>>> sound-dai = <&tlv320aic3x_a 0>;
>>> dai-tdm-slot-num = <0>;
>>> dai-tdm-slot-width = <16>;
>>> };
>>> };
>>> /**** The stuff below doesn't work -- I can't figure out how to get
>>> the name_prefixes set
>>>    on each codec... .How do I set up so that each codec gets its own name
>>> prfix
>>> and so that the soc core thinks all codecs are on the same DAI?
>>> **** */
>>>
>>> // simple-audio-card,dai-link@1 {
>>> // format = "left_j";
>>> // cpu {
>>> // sound-dai = <&mcasp0>;
>>> // };
>>> // codec {
>>> // sound-dai = <&tlv320aic3x_b 0>;
>>> // dai-tdm-slot-num = <2>;
>>> // dai-tdm-slot-width = <16>;
>>> // };
>>> // };
>>> // simple-audio-card,dai-link@2 {
>>> // format = "left_j";
>>> // cpu {
>>> // sound-dai = <&mcasp0>;
>>> // };
>>> // codec {
>>> // sound-dai = <&tlv320aic3x_c>;
>>> // dai-tdm-slot-num = <4>;
>>> // dai-tdm-slot-width = <16>;
>>> // };
>>> // };
>>> // simple-audio-card,dai-link@3 {
>>> // format = "left_j";
>>> // cpu {
>>> // sound-dai = <&mcasp0>;
>>> // };
>>> // codec {
>>> // sound-dai = <&tlv320aic3x_d>;
>>> // dai-tdm-slot-num = <6>;
>>> // dai-tdm-slot-width = <16>;
>>> // };
>>> // };
>>> };
>>> };
>>> _______________________________________________
>>> Alsa-devel mailing list
>>> Alsa-devel@alsa-project.org
>>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>>
>> _______________________________________________
>> Alsa-devel mailing list
>> Alsa-devel@alsa-project.org
>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Comments

Caleb Crome Sept. 17, 2015, 1:38 p.m. UTC | #1
On Thu, Sep 17, 2015 at 1:51 AM, arnaud.mouiche@invoxia.com
<arnaud.mouiche@invoxia.com> wrote:
> Hello Caleb,
>
> freescale SSI is fine with more than 2 channels.
> I have planed to publish a set of patch in this direction but we still have
> some corner cases to fix first (rare issues with channels alignment)
>

I'd love to see anything you're willing to show :-)

> Yet, this following is far enough to have it working.
> And since the max/min rate is at the end the intersection of what the SSI,
> the codec and the card are declaring, it will not change anything until you
> connect the SSI to a codec with more than 2 channels, or a multi-codec
> solution.

What if I change channels_max to 16 for capture and playback?  Last
time I tried, it would not keep the channels synchronized on the TDM
bus.  I tried playing with the FIFO settings, which helped, but it
still would not start each channel in the right slot reliably.
Perhaps I was using an older kernel.

I'll give it a try again.  Like I said, we'd love to get our
16-channel board up and running on the MX6, so I'm definitely
motivated to put some work in to get it reliable.

Thanks,
 -Caleb


>
> Arnaud
>
> diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
> index c25a1e8..26e980b 100644
> --- a/sound/soc/fsl/fsl_ssi.c
> +++ b/sound/soc/fsl/fsl_ssi.c
> @@ -1082,14 +1082,14 @@ static struct snd_soc_dai_driver
> fsl_ssi_dai_template = {
>         .playback = {
>                 .stream_name = "CPU-Playback",
>                 .channels_min = 1,
> -               .channels_max = 2,
> +               .channels_max = 4,
>                 .rates = FSLSSI_I2S_RATES,
>                 .formats = FSLSSI_I2S_FORMATS,
>         },
>         .capture = {
>                 .stream_name = "CPU-Capture",
>                 .channels_min = 1,
> -               .channels_max = 2,
> +               .channels_max = 4,
>                 .rates = FSLSSI_I2S_RATES,
>                 .formats = FSLSSI_I2S_FORMATS,
>         },
>
>
>
> Le 17/09/2015 00:07, Caleb Crome a écrit :
>>
>> Ah Ha!  thank you Arnaud!  I'll understand this stuff eventually.
>> I'll implement as you've shown and see how it goes.
>>
>> I see that you have 'fsl,imx-audio-foo', using an SSI.  from what I
>> can see the SSIs only support channels_max=2.  How do you get
>> multi-channel TDM to work with the freescale SSI port?  I need to get
>> this TDM working on both TI & Freescale, and the freescale has been
>> quite problematic because the multi-channel doesn't seem to be
>> supported in the driver.
>>
>> I have just checked out and verified that
>>
>> http://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git/
>>
>> sound/soc/fsl/*ssi*
>>
>> all have channels_max = 2
>>
>> We're very motivated to get this working on the freescale MX6, and
>> getting it to work sure does not seem as simple as changing 2 to a
>> bigger number :-)
>>
>>
>> Thanks,
>>    -Caleb
>>
>>
>> On Wed, Sep 16, 2015 at 2:57 AM, arnaud.mouiche@invoxia.com
>> <arnaud.mouiche@invoxia.com> wrote:
>>>
>>> Hello Caleb,
>>>
>>> Multi-codec support is now working fine the current linux releases.
>>> for previous releases, check if commit
>>>      [PATCH] ASoC: dapm: Don't add prefix to widget stream name
>>> is included. I remember this is the last required patch.
>>>
>>> After that, I don't know if the "simple-card" can be configured for multi
>>> codec support as you wish.
>>>
>>> On my side, I cooked a particular sound card for the purpose.
>>> here is some tips:
>>>
>>>
>>>      struct snd_soc_dai_link_component codecs[2];
>>>      struct snd_soc_codec_conf codecs_conf[2];
>>> [...]
>>>      for (num_codecs=0; num_codecs<2; num_codecs++) {
>>>          struct device_node *of_node;
>>>          of_node = of_parse_phandle(pdev->dev.of_node, "audio-codec",
>>> num_codecs);
>>>          if (!of_node) break;
>>>          data->codecs[num_codecs].of_node = of_node;
>>>          data->codecs[num_codecs].dai_name = "tlv320aic3x-foo";
>>>
>>>          /* add a "C2" name prefix for every control of the 2nd codec */
>>>          data->codecs_conf[num_codecs].of_node = of_node;
>>>          if (num_codecs == 1) {
>>>              data->codecs_conf[num_codecs].name_prefix = "C2";
>>>          }
>>>      }
>>> [...]
>>>      data->dai.codecs = data->codecs;
>>>      data->dai.num_codecs = num_codecs;
>>>      data->card.dai_link = &data->dai;
>>>      data->card.codec_conf = data->codecs_conf;
>>>      data->card.num_configs = num_codecs;
>>> [...]
>>>
>>>
>>> On DTS side, I have something like
>>>
>>>      sound@0 {
>>>          compatible = "fsl,imx-audio-foo";
>>>          model = "foo-audio";
>>>          ssi-controller = <&ssi1>;
>>>
>>>          /*
>>>           * list phandles for the 2 codecs used in the same TDM network
>>>           */
>>>          audio-codec = <&codec1>, <&codec2>;
>>>
>>>          [...]
>>>
>>>      };
>>>
>>>
>>> You also need to have a particular hw_params() method to dispatch the TDM
>>> and sysclk configuration to your codecs, making the difference between
>>> your
>>> first codec (your bus master) and the others.
>>>
>>>
>>> Arnaud
>>>
>>>
>>> Le 15/09/2015 03:07, Caleb Crome a écrit :
>>>>
>>>> (re-sending hope it's not a duplicate -- I think I must have had HTML
>>>> in my previous email and it was ignored)
>>>>
>>>>    Hi all,
>>>>       What are the current best practices to specify multiple codecs on
>>>> one sound card, with all codecs sharing a single TDM bus?
>>>>
>>>>    I have a card with up to 32 TLV320AIC33 codecs on it.  For the
>>>> moment, we can limit the discussion to only 16 codecs, so we don't
>>>> have to get extra serializers involved...
>>>>
>>>>    I currently have something like this in my am335x-boneblack.dts file:
>>>>
>>>>    (i.e. attempting to set tdm slot width and num in the i2c codec)
>>>>
>>>>    but it doesn't seem to be picking up the fact that I want all the
>>>> codecs linked together as one.
>>>>
>>>>    (FYI, the first codec, i.e. tlv32aic3x_a should be the master, and
>>>> all others including the CPU will be slaves).
>>>>
>>>>    Thanks for any help!
>>>>
>>>>    BTW, I'm happy to use whatever kernel will support me with the
>>>> minimal amount of effort, currently using 4.1
>>>>
>>>>
>>>>
>>>> Thank you!
>>>>      -Caleb
>>>>
>>>> &i2c1 {
>>>>    ...
>>>> tlv320aic3x_a: tlv320aic3x@18 {
>>>> #sound-dai-cells = <1>;
>>>> compatible = "ti,tlv320aic3x";
>>>> reg = <0x18>;
>>>> tdm-offset = <0>;
>>>> status = "okay";
>>>> };
>>>> tlv320aic3x_b: tlv320aic3x@19 {
>>>> #sound-dai-cells = <1>;
>>>> compatible = "ti,tlv320aic3x";
>>>> reg = <0x19>;
>>>> tdm-offset = <32>;
>>>> status = "okay";
>>>> };
>>>> tlv320aic3x_c: tlv320aic3x@1a {
>>>> #sound-dai-cells = <1>;
>>>> compatible = "ti,tlv320aic3x";
>>>> reg = <0x1a>;
>>>> tdm-offset = <64>;
>>>> status = "okay";
>>>> };
>>>> tlv320aic3x_d: tlv320aic3x@1b {
>>>> #sound-dai-cells = <1>;
>>>> compatible = "ti,tlv320aic3x";
>>>> reg = <0x1b>;
>>>> tdm-offset = <96>;
>>>> status = "okay";
>>>> };
>>>> };
>>>>
>>>> &mcasp0 {
>>>> #sound-dai-cells = <0>;
>>>> pinctrl-names = "default";
>>>> pinctrl-0 = <&mcasp_0_pins_default>;
>>>> status = "okay";
>>>>
>>>> op-mode = <0>;          /* MCASP_IIS_MODE */
>>>> tdm-slots = <16>;
>>>> num-serializer = <16>;
>>>> serial-dir = <  /* 0: INACTIVE, 1: TX, 2: RX */
>>>> 0 0 1 2
>>>> 0 0 0 0
>>>> 0 0 0 0
>>>> 0 0 0 0
>>>>>
>>>>> ;
>>>>
>>>> tx-num-evt = <1>;
>>>> rx-num-evt = <1>;
>>>> };
>>>>
>>>> / {
>>>> sound {
>>>> compatible = "simple-audio-card";
>>>> simple-audio-card,name = "puppy-audio";
>>>> simple-audio-card,mclk-fs = <256>;
>>>> system-clock-frequency = <12288000>;
>>>> status = "okay";
>>>> simple-audio-card,bitclock-master = <&tlv320aic3x_a>;
>>>>         simple-audio-card,frame-master    = <&tlv320aic3x_a>;
>>>> simple-audio-card,widgets =
>>>> "Line", "Line Out",
>>>> "Line", "Line In";
>>>> simple-audio-card,routing =
>>>> "Line Out",       "HPLOUT",
>>>> "Line Out",       "HPROUT",
>>>> "Line In",        "LINE1L",
>>>> "Line In",        "LINE1R";
>>>>
>>>> simple-audio-card,dai-link@0 {
>>>> format = "left_j";
>>>> cpu {
>>>> sound-dai = <&mcasp0>;
>>>> };
>>>> codec {
>>>> sound-dai = <&tlv320aic3x_a 0>;
>>>> dai-tdm-slot-num = <0>;
>>>> dai-tdm-slot-width = <16>;
>>>> };
>>>> };
>>>> /**** The stuff below doesn't work -- I can't figure out how to get
>>>> the name_prefixes set
>>>>    on each codec... .How do I set up so that each codec gets its own
>>>> name
>>>> prfix
>>>> and so that the soc core thinks all codecs are on the same DAI?
>>>> **** */
>>>>
>>>> // simple-audio-card,dai-link@1 {
>>>> // format = "left_j";
>>>> // cpu {
>>>> // sound-dai = <&mcasp0>;
>>>> // };
>>>> // codec {
>>>> // sound-dai = <&tlv320aic3x_b 0>;
>>>> // dai-tdm-slot-num = <2>;
>>>> // dai-tdm-slot-width = <16>;
>>>> // };
>>>> // };
>>>> // simple-audio-card,dai-link@2 {
>>>> // format = "left_j";
>>>> // cpu {
>>>> // sound-dai = <&mcasp0>;
>>>> // };
>>>> // codec {
>>>> // sound-dai = <&tlv320aic3x_c>;
>>>> // dai-tdm-slot-num = <4>;
>>>> // dai-tdm-slot-width = <16>;
>>>> // };
>>>> // };
>>>> // simple-audio-card,dai-link@3 {
>>>> // format = "left_j";
>>>> // cpu {
>>>> // sound-dai = <&mcasp0>;
>>>> // };
>>>> // codec {
>>>> // sound-dai = <&tlv320aic3x_d>;
>>>> // dai-tdm-slot-num = <6>;
>>>> // dai-tdm-slot-width = <16>;
>>>> // };
>>>> // };
>>>> };
>>>> };
>>>> _______________________________________________
>>>> Alsa-devel mailing list
>>>> Alsa-devel@alsa-project.org
>>>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>>>
>>>
>>> _______________________________________________
>>> Alsa-devel mailing list
>>> Alsa-devel@alsa-project.org
>>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
>
>
Arnaud Mouiche Sept. 17, 2015, 2:33 p.m. UTC | #2
hello,

Le 17/09/2015 15:38, Caleb Crome a écrit :
> On Thu, Sep 17, 2015 at 1:51 AM, arnaud.mouiche@invoxia.com
> <arnaud.mouiche@invoxia.com> wrote:
>> Hello Caleb,
>>
>> freescale SSI is fine with more than 2 channels.
>> I have planed to publish a set of patch in this direction but we still have
>> some corner cases to fix first (rare issues with channels alignment)
>>
> I'd love to see anything you're willing to show :-)
>
>> Yet, this following is far enough to have it working.
>> And since the max/min rate is at the end the intersection of what the SSI,
>> the codec and the card are declaring, it will not change anything until you
>> connect the SSI to a codec with more than 2 channels, or a multi-codec
>> solution.
> What if I change channels_max to 16 for capture and playback?  Last
> time I tried, it would not keep the channels synchronized on the TDM
> bus.  I tried playing with the FIFO settings, which helped, but it
> still would not start each channel in the right slot reliably.
> Perhaps I was using an older kernel.
you put the finger on what's hurting !  ;)

In fact, we made 8 channels working in reliable way on imx50, with 
predictive latency  ... with an old kernel (3.17) ... based on freescale 
BSP... on sound/soc/imx/imx-ssi.c (something that doesn't exist outside 
freescale BSP)

Well, just to say it is doable on any recent imx since the hardware is 
not the issue. But the job was a set of awful hacks.

My plan was to re-do all this job on an upstream kernel, in a way it can 
be accepted.
Unfortunately you will have to wait, I'm under pressure for other stuff 
right now.

Regards,
arnaud

>
> I'll give it a try again.  Like I said, we'd love to get our
> 16-channel board up and running on the MX6, so I'm definitely
> motivated to put some work in to get it reliable.
>
> Thanks,
>   -Caleb
>
Caleb Crome Sept. 17, 2015, 3:34 p.m. UTC | #3
On Thu, Sep 17, 2015 at 7:33 AM, arnaud.mouiche@invoxia.com
<arnaud.mouiche@invoxia.com> wrote:
> hello,
>
> Le 17/09/2015 15:38, Caleb Crome a écrit :
>>
>> On Thu, Sep 17, 2015 at 1:51 AM, arnaud.mouiche@invoxia.com
>> <arnaud.mouiche@invoxia.com> wrote:
>>>
>>> Hello Caleb,
>>>
>>> freescale SSI is fine with more than 2 channels.
>>> I have planed to publish a set of patch in this direction but we still
>>> have
>>> some corner cases to fix first (rare issues with channels alignment)
>>>
>> I'd love to see anything you're willing to show :-)
>>
>>> Yet, this following is far enough to have it working.
>>> And since the max/min rate is at the end the intersection of what the
>>> SSI,
>>> the codec and the card are declaring, it will not change anything until
>>> you
>>> connect the SSI to a codec with more than 2 channels, or a multi-codec
>>> solution.
>>
>> What if I change channels_max to 16 for capture and playback?  Last
>> time I tried, it would not keep the channels synchronized on the TDM
>> bus.  I tried playing with the FIFO settings, which helped, but it
>> still would not start each channel in the right slot reliably.
>> Perhaps I was using an older kernel.
>
> you put the finger on what's hurting !  ;)
>
> In fact, we made 8 channels working in reliable way on imx50, with
> predictive latency  ... with an old kernel (3.17) ... based on freescale
> BSP... on sound/soc/imx/imx-ssi.c (something that doesn't exist outside
> freescale BSP)
>
> Well, just to say it is doable on any recent imx since the hardware is not
> the issue. But the job was a set of awful hacks.

Sorry, I don't quite understand.  Are you saying that on a recent
kernel (say 4.1 or 4.2), you think it will just work.  Or are yo
saying that even on a modern kernel it's a set of awful hacks?  And
should I use fsl_ssi.c or imx-ssi.c (device tree/non device tree)
version?

In short, what's your best current recommendation to get it working today?

>
> My plan was to re-do all this job on an upstream kernel, in a way it can be
> accepted.
> Unfortunately you will have to wait, I'm under pressure for other stuff
> right now.

Heh, understood.  If there's anything I can do to help, let me know.

Thanks,
-Caleb

> Regards,
> arnaud
>
>
>>
>> I'll give it a try again.  Like I said, we'd love to get our
>> 16-channel board up and running on the MX6, so I'm definitely
>> motivated to put some work in to get it reliable.
>>
>> Thanks,
>>   -Caleb
>>
>
Arnaud Mouiche Sept. 17, 2015, 4:09 p.m. UTC | #4
Le 17/09/2015 17:34, Caleb Crome a écrit :
> On Thu, Sep 17, 2015 at 7:33 AM, arnaud.mouiche@invoxia.com
> <arnaud.mouiche@invoxia.com> wrote:
>> hello,
>>
>> Le 17/09/2015 15:38, Caleb Crome a écrit :
>>> On Thu, Sep 17, 2015 at 1:51 AM, arnaud.mouiche@invoxia.com
>>> <arnaud.mouiche@invoxia.com> wrote:
>>>> Hello Caleb,
>>>>
>>>> freescale SSI is fine with more than 2 channels.
>>>> I have planed to publish a set of patch in this direction but we still
>>>> have
>>>> some corner cases to fix first (rare issues with channels alignment)
>>>>
>>> I'd love to see anything you're willing to show :-)
>>>
>>>> Yet, this following is far enough to have it working.
>>>> And since the max/min rate is at the end the intersection of what the
>>>> SSI,
>>>> the codec and the card are declaring, it will not change anything until
>>>> you
>>>> connect the SSI to a codec with more than 2 channels, or a multi-codec
>>>> solution.
>>> What if I change channels_max to 16 for capture and playback?  Last
>>> time I tried, it would not keep the channels synchronized on the TDM
>>> bus.  I tried playing with the FIFO settings, which helped, but it
>>> still would not start each channel in the right slot reliably.
>>> Perhaps I was using an older kernel.
>> you put the finger on what's hurting !  ;)
>>
>> In fact, we made 8 channels working in reliable way on imx50, with
>> predictive latency  ... with an old kernel (3.17) ... based on freescale
>> BSP... on sound/soc/imx/imx-ssi.c (something that doesn't exist outside
>> freescale BSP)
>>
>> Well, just to say it is doable on any recent imx since the hardware is not
>> the issue. But the job was a set of awful hacks.
> Sorry, I don't quite understand.  Are you saying that on a recent
> kernel (say 4.1 or 4.2), you think it will just work.  Or are yo
> saying that even on a modern kernel it's a set of awful hacks?  And
> should I use fsl_ssi.c or imx-ssi.c (device tree/non device tree)
> version?
- I'm saying it is working on recent upstream kernel, using 
sound/soc/fsl/fsl_ssi.c, but with
some channel sync issues in rare conditions (at least 4 channels case, 
opening multiple SSI at the same time).
So, you should test on your side with you setup, and simply be prepared 
to not see it working as a charm.

- we made it work perfectly, but on an old freescale BSP, where 
freescale rewrites a SSI driver different from the already 2 drivers 
(device tree/non device tree) available today in upstream + lot of awful 
hacks => so, this is not a hardware issue.

- when I will have time, I will start from the upstream driver, and make 
it work correctly with 8 channels (or more)

arnaud
>
> In short, what's your best current recommendation to get it working today?
>
>> My plan was to re-do all this job on an upstream kernel, in a way it can be
>> accepted.
>> Unfortunately you will have to wait, I'm under pressure for other stuff
>> right now.
> Heh, understood.  If there's anything I can do to help, let me know.
>
> Thanks,
> -Caleb
>
>> Regards,
>> arnaud
>>
>>
>>> I'll give it a try again.  Like I said, we'd love to get our
>>> 16-channel board up and running on the MX6, so I'm definitely
>>> motivated to put some work in to get it reliable.
>>>
>>> Thanks,
>>>    -Caleb
>>>
Caleb Crome Sept. 17, 2015, 5:39 p.m. UTC | #5
Got it.  Thanks Arnaud.

-Caleb


On Thu, Sep 17, 2015 at 9:09 AM, arnaud.mouiche@invoxia.com
<arnaud.mouiche@invoxia.com> wrote:
>
>
> Le 17/09/2015 17:34, Caleb Crome a écrit :
>>
>> On Thu, Sep 17, 2015 at 7:33 AM, arnaud.mouiche@invoxia.com
>> <arnaud.mouiche@invoxia.com> wrote:
>>>
>>> hello,
>>>
>>> Le 17/09/2015 15:38, Caleb Crome a écrit :
>>>>
>>>> On Thu, Sep 17, 2015 at 1:51 AM, arnaud.mouiche@invoxia.com
>>>> <arnaud.mouiche@invoxia.com> wrote:
>>>>>
>>>>> Hello Caleb,
>>>>>
>>>>> freescale SSI is fine with more than 2 channels.
>>>>> I have planed to publish a set of patch in this direction but we still
>>>>> have
>>>>> some corner cases to fix first (rare issues with channels alignment)
>>>>>
>>>> I'd love to see anything you're willing to show :-)
>>>>
>>>>> Yet, this following is far enough to have it working.
>>>>> And since the max/min rate is at the end the intersection of what the
>>>>> SSI,
>>>>> the codec and the card are declaring, it will not change anything until
>>>>> you
>>>>> connect the SSI to a codec with more than 2 channels, or a multi-codec
>>>>> solution.
>>>>
>>>> What if I change channels_max to 16 for capture and playback?  Last
>>>> time I tried, it would not keep the channels synchronized on the TDM
>>>> bus.  I tried playing with the FIFO settings, which helped, but it
>>>> still would not start each channel in the right slot reliably.
>>>> Perhaps I was using an older kernel.
>>>
>>> you put the finger on what's hurting !  ;)
>>>
>>> In fact, we made 8 channels working in reliable way on imx50, with
>>> predictive latency  ... with an old kernel (3.17) ... based on freescale
>>> BSP... on sound/soc/imx/imx-ssi.c (something that doesn't exist outside
>>> freescale BSP)
>>>
>>> Well, just to say it is doable on any recent imx since the hardware is
>>> not
>>> the issue. But the job was a set of awful hacks.
>>
>> Sorry, I don't quite understand.  Are you saying that on a recent
>> kernel (say 4.1 or 4.2), you think it will just work.  Or are yo
>> saying that even on a modern kernel it's a set of awful hacks?  And
>> should I use fsl_ssi.c or imx-ssi.c (device tree/non device tree)
>> version?
>
> - I'm saying it is working on recent upstream kernel, using
> sound/soc/fsl/fsl_ssi.c, but with
> some channel sync issues in rare conditions (at least 4 channels case,
> opening multiple SSI at the same time).
> So, you should test on your side with you setup, and simply be prepared to
> not see it working as a charm.
>
> - we made it work perfectly, but on an old freescale BSP, where freescale
> rewrites a SSI driver different from the already 2 drivers (device tree/non
> device tree) available today in upstream + lot of awful hacks => so, this is
> not a hardware issue.
>
> - when I will have time, I will start from the upstream driver, and make it
> work correctly with 8 channels (or more)
>
> arnaud
>
>>
>> In short, what's your best current recommendation to get it working today?
>>
>>> My plan was to re-do all this job on an upstream kernel, in a way it can
>>> be
>>> accepted.
>>> Unfortunately you will have to wait, I'm under pressure for other stuff
>>> right now.
>>
>> Heh, understood.  If there's anything I can do to help, let me know.
>>
>> Thanks,
>> -Caleb
>>
>>> Regards,
>>> arnaud
>>>
>>>
>>>> I'll give it a try again.  Like I said, we'd love to get our
>>>> 16-channel board up and running on the MX6, so I'm definitely
>>>> motivated to put some work in to get it reliable.
>>>>
>>>> Thanks,
>>>>    -Caleb
>>>>
>
diff mbox

Patch

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index c25a1e8..26e980b 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -1082,14 +1082,14 @@  static struct snd_soc_dai_driver 
fsl_ssi_dai_template = {
         .playback = {
                 .stream_name = "CPU-Playback",
                 .channels_min = 1,
-               .channels_max = 2,
+               .channels_max = 4,
                 .rates = FSLSSI_I2S_RATES,
                 .formats = FSLSSI_I2S_FORMATS,
         },
         .capture = {
                 .stream_name = "CPU-Capture",
                 .channels_min = 1,
-               .channels_max = 2,
+               .channels_max = 4,
                 .rates = FSLSSI_I2S_RATES,
                 .formats = FSLSSI_I2S_FORMATS,