rpi-sound cards and upstreaming

[msperl]

@clivem: let us discuss these sound card things here...

I have tried the following upstream, but the card is not recognized:

/ {
    pcm5102a_codec: pcm5102a_codec {
        #sound-dai-cells = <0>;
        compatible = "ti,pcm5102a";
        status = "okay";
    };

    sound {
        compatible = "simple-audio-card";
        simple-audio-card,format = "i2s";
        simple-audio-card,name = "pcm5102a";
        status = "okay";
        simple-audio-card,cpu {
            sound-dai = <&i2s>;
        };
        simple-audio-card,codec {
            sound-dai = <&pcm5102a_codec>;
        };
    };
};
/* for some reasons this is required - simple-sound-card complains otherwise */
&i2s {
    #sound-dai-cells = <0>;
};

If I can make this work we can take things further from here...

As for the extension: we can look into it if we know how to parametrise things...

[clivem]

I didn't need that sound-dai-cells=<0> for i2s def. I am using the simple-pcm5102a-dac overlay config that I showed in the gist....

https://gist.github.com/clivem/9d1da750f666dc1d1ede4df761079742

dtoverlay=simple-pcm5102a-dac,card-name="snd_rpi_hifiberry_dac"

asoc-simple-card soc:sound: New simple-card: snd_rpi_hifiberry_dac
asoc-simple-card soc:sound: Revert to legacy daifmt parsing
asoc-simple-card soc:sound:         name : bcm2835-i2s-pcm5102a-hifi
asoc-simple-card soc:sound:         format : 4001
asoc-simple-card soc:sound:         cpu : bcm2835-i2s / 0
asoc-simple-card soc:sound:         codec : pcm5102a-hifi / 0
asoc-simple-card soc:sound: pcm5102a-hifi <-> 20203000.i2s mapping ok

[msperl]

At least upstream 4.6 requires it - or you get:

[   70.787180] [591] asoc-simple-card sound: New simple-card: HifiBerry DAC
[   70.787255] [591] asoc-simple-card sound: Revert to legacy daifmt parsing
[   70.787316] /sound/simple-audio-card,cpu: could not get #sound-dai-cells for /soc/i2s@7e203000
[   70.787342] asoc-simple-card sound: parse error -22
[   70.787401] asoc-simple-card: probe of sound failed with error -22

with this defined the driver loads...

[   60.427500] [589] asoc-simple-card sound: New simple-card: HifiBerry DAC
[   60.427584] [589] asoc-simple-card sound: Revert to legacy daifmt parsing
[   60.427701] [589] asoc-simple-card sound:    name : bcm2835-i2s-pcm5102a-hifi
[   60.427727] [589] asoc-simple-card sound:    format : 4001
[   60.427746] [589] asoc-simple-card sound:    cpu : bcm2835-i2s / 0
[   60.427765] [589] asoc-simple-card sound:    codec : pcm5102a-hifi / 0
[   60.429111] asoc-simple-card sound: pcm5102a-hifi <-> 20203000.i2s mapping ok

I still have no sound, but that is probably related to the *2 issue

[msperl]

So going further: the snd_soc_dai_set_bclk_ratio(cpu_dai, sample_bits * 2)
is not really needed, as that is the default set in i2s_bcm2835 if nothing is set.

So we are actually covered there...

This mostly leaves the custom bclk settings...

[clivem]

Sorry, not in front of computer at moment. ISTR only difference without card driver setting bclk ratio, is for 24 bit, where bclk_ratio from i2s driver will be 48. ie. 24 bits * 2 channels. Card driver uses physical width of bits, so S24_LE = 32 bits * 2 channels = 64.

hifiberry_dac card driver will request bclk_ratio of 32 for 16 bit and 64 for 24 and 32 bit. I2S driver will use 32 for 16 bit, 48 for 24 bit, and 64 for 32 bit.

[msperl]

here an example that - i guess - I got to work:

        hw-params-rule@0 {
            match@0 {
                method = "asoc_generic_hw_params_match_sample_bits";
                value = <32>;
            };
            match@1 {
                method = "asoc_generic_hw_params_match_rate";
                value = <48000>;
            };
            match@2 {
                method = "asoc_generic_hw_params_match_channels";
                value = <2>;
            };
            action@0 {
                method = "asoc_generic_hw_params_set_fixed_bclk_size";
                value = <80>;
            };
        };

And then playing: speaker-test -c 2 -r 48000 -F S32_LE -f 440 -t sine
I get the following pcm clock:

root@raspcm:~# cat /sys/kernel/debug/clk/pcm/regdump
ctl = 0x00000001
div = 0x00005000

so parent clock 1 = OSC and a divider of 5.

Here the debug messages:

[root@raspcm:~# speaker-test -c 2 -r 48000 -F S32_LE -f 440 -t sine -l 1
speaker-test 1.0.28

Playback device is default
Stream parameters are 48000Hz, S32_LE, 2 channels
Sine wave rate is 440.0000Hz
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 64 to 65536
Period size range from 32 to 32768
Using max buffer size 65536
Periods = 4
was set period_size = 16384
was set buffer_size = 65536
 0 - Front Left
 1 - Front Right
Time per period = 4.196302
root@raspcm:~# cat /sys/kernel/debug/clk/pcm/regdump ctl = 0x00000001
div = 0x00005000
root@raspcm:~# dmesg
[  113.390048] [623] asoc-simple-card sound: New simple-card: HifiBerry DAC
[  113.390138] [623] asoc-simple-card sound: Revert to legacy daifmt parsing
[  113.390264] [623] asoc-simple-card sound:    name : bcm2835-i2s-pcm5102a-hifi
[  113.390291] [623] asoc-simple-card sound:    format : 4001
[  113.390312] [623] asoc-simple-card sound:    cpu : bcm2835-i2s / 3840000
[  113.390333] [623] asoc-simple-card sound:    codec : pcm5102a-hifi / 0
[  113.390380] [623] asoc-simple-card sound:    adding Rule: /sound/hw-params-rule@0
[  113.390454] [623] asoc-simple-card sound:        added match: /sound/hw-params-rule@0/match@0 - asoc_generic_hw_params_match_sample_bits [snd_soc_simple_card](00000020)
[  113.390512] [623] asoc-simple-card sound:        added match: /sound/hw-params-rule@0/match@1 - asoc_generic_hw_params_match_rate [snd_soc_simple_card](0000bb80)
[  113.390585] [623] asoc-simple-card sound:        added match: /sound/hw-params-rule@0/match@2 - asoc_generic_hw_params_match_channels [snd_soc_simple_card](00000002)
[  113.390655] [623] asoc-simple-card sound:        added action: /sound/hw-params-rule@0/action@0 - asoc_generic_hw_params_set_fixed_bclk_size [snd_soc_simple_card](00000050)
[  113.391991] asoc-simple-card sound: pcm5102a-hifi <-> 20203000.i2s mapping ok
--- here the speaker test ---
[  119.048124] [627]  bcm2835-i2s-pcm5102a-hifi: Trying to apply rule: /sound/hw-params-rule@0
[  119.048217] [627]  bcm2835-i2s-pcm5102a-hifi:    Running match asoc_generic_hw_params_match_sample_bits [snd_soc_simple_card](00000020)
[  119.048257] [627]  bcm2835-i2s-pcm5102a-hifi:    Running match asoc_generic_hw_params_match_rate [snd_soc_simple_card](0000bb80)
[  119.048309] [627]  bcm2835-i2s-pcm5102a-hifi:    Running match asoc_generic_hw_params_match_channels [snd_soc_simple_card](00000002)
[  119.048345] [627]  bcm2835-i2s-pcm5102a-hifi:    Running action asoc_generic_hw_params_set_fixed_bclk_size [snd_soc_simple_card](00000050)

So now in principle you can define (almost) any choice.

The way it is written this can easily get applied to any driver:

diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index 2389ab4..6b95ea1 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -8,6 +8,7 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
+#include "hw-params-rules.h"
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/gpio.h>
@@ -33,6 +34,7 @@ struct simple_card_data {
        int gpio_hp_det_invert;
        int gpio_mic_det;
        int gpio_mic_det_invert;
+       struct list_head hw_params_rules;
        struct snd_soc_dai_link dai_link[];     /* dynamically allocated */
 };

@@ -51,7 +53,7 @@ static int asoc_simple_card_startup(struct snd_pcm_substream *substream)
        ret = clk_prepare_enable(dai_props->cpu_dai.clk);
        if (ret)
                return ret;
-
+
        ret = clk_prepare_enable(dai_props->codec_dai.clk);
        if (ret)
                clk_disable_unprepare(dai_props->cpu_dai.clk);
@@ -99,7 +101,9 @@ static int asoc_simple_card_hw_params(struct snd_pcm_substream *substream,
                if (ret && ret != -ENOTSUPP)
                        goto err;
        }
-       return 0;
+
+       return asoc_generic_hw_params_process_rules(
+               &priv->hw_params_rules, substream, params);
 err:
        return ret;
 }
@@ -509,7 +513,8 @@ static int asoc_simple_card_parse_of(struct device_node *node,
        if (!priv->snd_card.name)
                priv->snd_card.name = priv->snd_card.dai_link->name;

-       return 0;
+       return asoc_generic_hw_params_rules_parse_of(
+               dev, node, &priv->hw_params_rules);
 }

 /* Decrease the reference count of the device nodes */

[msperl]

If you are interested look at my approach at:

• msperl/linux-upstream@e9d87a9 basic framework
• msperl/linux-upstream@9887b23 extending it to simple-sound

[clivem]

If you are interested look at my approach at:

Yes, more than interested, but at the moment I'm having to deal with a security breach issue, which means I won't get around to looking until this evening.

[msperl]

extensions for other "matches" or "actions" can get easily get added.

I really would like to use kallsyms_lookup_name, but that comes with some implications and could get abused, so it is not included yet, but the static mapping is used.

With that one could also add those "choose clock" things of the pcm51xx into that driver and use it with simple-config...

[clivem]

@msperl Martin, just thinking out loud, because I haven't even looked closely yet, are the match values, single values, or can be a list? Otherwise will have to have a hw-params-rule for every single sample rate at every single bit depth we want to cover. I'm thinking, something like this would result in the least lines of config needed in dts.....

        hw-params-rule@0 {
                match@0 {
                        method = "asoc_generic_hw_params_match_sample_bits";
                        value = <16>;
                };
                match@1 {
                        method = "asoc_generic_hw_params_match_rate";
                        value = <8000 16000 32000 48000 64000 96000>;
                };
                match@2 {
                        method = "asoc_generic_hw_params_match_channels";
                        value = <2>;
                };
                action@0 {
                        method = "asoc_generic_hw_params_set_fixed_bclk_size";
                        value = <50>;
                };
        };
        hw-params-rule@1 {
                match@0 {
                        method = "asoc_generic_hw_params_match_sample_bits";
                        value = <24 32>;
                };
                match@1 {
                        method = "asoc_generic_hw_params_match_rate";
                        value = <8000 16000 32000 48000 64000 96000>;
                };
                match@2 {
                        method = "asoc_generic_hw_params_match_channels";
                        value = <2>;
                };
                action@0 {
                        method = "asoc_generic_hw_params_set_fixed_bclk_size";
                        value = <100>;
                };
        };

[clivem]

@msperl When you tested the of parsing code, did you have more than a single rule in your dt config????

msperl.txt

[msperl]

@clivem I have only implemented single value matchers for now - an array is certainly feasible...
Afair I have tested 2 rules at some point...

[clivem]

Afair I have tested 2 rules at some point...

This doesn't look right to me. It looks like matches/actions for rules 0,1,2 and 3 are being added to the list for rule 3.

Rule: /soc/sound/hw-params-rule@3
 added match: /soc/sound/hw-params-rule@3/match@2
 added match: /soc/sound/hw-params-rule@3/match@1
 added match: /soc/sound/hw-params-rule@3/match@0
 added match: /soc/sound/hw-params-rule@2/match@2
 added match: /soc/sound/hw-params-rule@2/match@1
 added match: /soc/sound/hw-params-rule@2/match@0
 added match: /soc/sound/hw-params-rule@1/match@2
 added match: /soc/sound/hw-params-rule@1/match@1
 added match: /soc/sound/hw-params-rule@1/match@0
 added match: /soc/sound/hw-params-rule@0/match@2
 added match: /soc/sound/hw-params-rule@0/match@1
 added match: /soc/sound/hw-params-rule@0/match@0
 added action: /soc/sound/hw-params-rule@3/action@0
 added action: /soc/sound/hw-params-rule@2/action@0
 added action: /soc/sound/hw-params-rule@1/action@0
 added action: /soc/sound/hw-params-rule@0/action@0

[msperl]

i know - i guess I did not read the fine details when testing the first rule...
Working on the values thing right now and I guess that of_find_node_by_name does not stay within one parent and so I have to write my own matcher (and I had issue when i wrote that initially)...

[clivem]

Working on the values thing right now

OK, great. I'll come back to this later today. I think if you can make those matches takes arrays of u32's rather than a single value, and the logic is that if any value in the array is matched...... and the of parsing gets a tweak, we have a winner..... The question is, will upstream take it, or is there going to be the usual sharp intake of breath, followed by a "why do you even need this".... LOL.

As far as this framework is concerned, leaving aside clock selection again for the moment.... I wonder if you can find a few mins to think about this, and how we could make this sort of need to initialise things work via the same sort of framework on top of simple-card, so something like this PR submitted yesterday could use simple-card and not require a dedicated machine/card driver.......

raspberrypi#1476 (comment)

I still have concerns that "simple" is going to end up being "complicated".... But as @pelwell said yesterday, "Yes, once again simple-card proves to be slightly too simple to be useful."

[msperl]

well - as for initialization we could in principle use the same interface - just:

sound {
  init@0 { method = "..."; values = "..."; };
};

It just depends on what is needed - but actually, as 4.6 just went out, i want to try to get those clock changes in so I would like to focus on those...

I will send that initial "patch" for hw_param hopefully today...