Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <3bb2114c-cd0c-f176-c837-90a665a25343@linux.intel.com>
Date:   Fri, 13 Jan 2023 11:05:54 -0600
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Firefox/102.0 Thunderbird/102.4.2
Subject: Re: [PATCH 08/19] ASoC: amd: ps: add soundwire dma driver dma ops
Content-Language: en-US
To:     "Mukunda,Vijendar" <vijendar.mukunda@amd.com>, broonie@kernel.org,
        vkoul@kernel.org, alsa-devel@alsa-project.org
Cc:     Mastan.Katragadda@amd.com, Sunil-kumar.Dommati@amd.com,
        open list <linux-kernel@vger.kernel.org>,
        Basavaraj.Hiregoudar@amd.com, Takashi Iwai <tiwai@suse.com>,
        Liam Girdwood <lgirdwood@gmail.com>, Mario.Limonciello@amd.com,
        arungopal.kondaveeti@amd.com,
        Syed Saba Kareem <Syed.SabaKareem@amd.com>
References: <20230111090222.2016499-1-Vijendar.Mukunda@amd.com>
 <20230111090222.2016499-9-Vijendar.Mukunda@amd.com>
 <77e35f54-323e-42d0-9e74-be984eebc0fe@linux.intel.com>
 <6bb9b13c-2829-d7c3-872b-6e9586189300@amd.com>
From:   Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
In-Reply-To: <6bb9b13c-2829-d7c3-872b-6e9586189300@amd.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk


>>> +	sdw_data->sdw_stream[stream_id] = substream;
>>> +	size = params_buffer_bytes(params);
>>> +	period_bytes = params_period_bytes(params);
>>> +	sdw_stream_data->dma_addr = substream->runtime->dma_addr;
>>> +	sdw_stream_data->num_pages = (PAGE_ALIGN(size) >> PAGE_SHIFT);
>>> +	acp63_config_dma(sdw_stream_data, stream_id);
>>> +	ret = acp63_configure_sdw_ringbuffer(sdw_stream_data->acp_base, stream_id, size);
>>> +	if (ret) {
>>> +		dev_err(component->dev, "Invalid channel type\n");
>>> +		return -EINVAL;
>>> +	}
>>> +	switch (stream_id) {
>>> +	case ACP_SDW_AUDIO_TX:
>>> +		water_mark_size_reg = ACP_AUDIO_TX_INTR_WATERMARK_SIZE;
>>> +		irq_mask = BIT(ACP_AUDIO_TX_THRESHOLD);
>>> +		acp_ext_intr_cntl_reg = ACP_EXTERNAL_INTR_CNTL;
>>> +		break;
>> so there's ONE resource to deal with external codecs? How does this work
>> if you have a headset codec and an amplifier?
> Are you referring to playing a same stream over headset codec and
> amplifier?
> It's all about channel selection from DMA perspective.
> We have tested speaker aggregation and headset playback use cases.

No, I wasn't asking about playing the same content to different sinks.

I was referring to playing/recording different content to/from different
devices.

Even when interfacing with a single device, there are interesting
topologies in the SDCA spec that would require multiple DMA transfers
conveying unrelated content (or processed content from the same source).