From: Peter Ujfalusi <peter.ujfalusi@ti.com>
To: Vinod Koul <vkoul@kernel.org>
Cc: <dmaengine@vger.kernel.org>, Rob Herring <robh+dt@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
<linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 2/3] dmaengine: add peripheral configuration
Date: Fri, 9 Oct 2020 13:45:55 +0300 [thread overview]
Message-ID: <a44af464-7d13-1254-54dd-f7783ccfaa0f@ti.com> (raw)
In-Reply-To: <20201009103019.GD2968@vkoul-mobl>
Hi Vinod,
On 09/10/2020 13.30, Vinod Koul wrote:
> Hi Peter,
>
> On 09-10-20, 12:04, Peter Ujfalusi wrote:
>> On 08/10/2020 15.31, Vinod Koul wrote:
>>> Some complex dmaengine controllers have capability to program the
>>> peripheral device, so pass on the peripheral configuration as part of
>>> dma_slave_config
>>>
>>> Signed-off-by: Vinod Koul <vkoul@kernel.org>
>>> ---
>>> include/linux/dmaengine.h | 5 +++++
>>> 1 file changed, 5 insertions(+)
>>>
>>> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
>>> index 6fbd5c99e30c..a15dc2960f6d 100644
>>> --- a/include/linux/dmaengine.h
>>> +++ b/include/linux/dmaengine.h
>>> @@ -418,6 +418,9 @@ enum dma_slave_buswidth {
>>> * @slave_id: Slave requester id. Only valid for slave channels. The dma
>>> * slave peripheral will have unique id as dma requester which need to be
>>> * pass as slave config.
>>> + * @peripheral_config: peripheral configuration for programming peripheral
>>> + * for dmaengine transfer
>>> + * @peripheral_size: peripheral configuration buffer size
>>> *
>>> * This struct is passed in as configuration data to a DMA engine
>>> * in order to set up a certain channel for DMA transport at runtime.
>>> @@ -443,6 +446,8 @@ struct dma_slave_config {
>>> u32 dst_port_window_size;
>>> bool device_fc;
>>> unsigned int slave_id;
>>> + void *peripheral_config;
>>> + size_t peripheral_size;
>>
>> Do you foresee a need of src/dst pair of these?
>> If we do DEV_TO_DEV with different type of peripherals it is going to
>> cause issues.
>
> Not really as the channel already has direction and this is per channel.
Yes, in case of DEV_TO_MEM or MEM_TO_DEV.
> If for any any reason subsequent txn is for different direction, I would
> expect that parameters are set again before prep_ calls
But in DEV_TO_DEV?
If we have two peripherals, both needs config:
p1_config and p2_config
What and how would one use the single peripheral_config?
If only one of them needs config, then sure, the driver can pin-point
which one the single config might apply to.
Or you chain the same type of peripheral and you would need different
config for tx and rx?
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
next prev parent reply other threads:[~2020-10-09 10:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 12:31 [PATCH v4 0/3] dmaengine: Add support for QCOM GSI dma controller Vinod Koul
2020-10-08 12:31 ` [PATCH v4 1/3] dt-bindings: dmaengine: Document qcom,gpi dma binding Vinod Koul
2020-10-12 18:57 ` Rob Herring
2020-10-13 7:02 ` Vinod Koul
2020-10-08 12:31 ` [PATCH v4 2/3] dmaengine: add peripheral configuration Vinod Koul
2020-10-09 9:04 ` Peter Ujfalusi
2020-10-09 10:30 ` Vinod Koul
2020-10-09 10:45 ` Peter Ujfalusi [this message]
2020-10-09 11:15 ` Vinod Koul
2020-10-09 11:29 ` Peter Ujfalusi
2020-10-12 6:09 ` Vinod Koul
2020-10-12 12:05 ` Peter Ujfalusi
2020-10-08 12:31 ` [PATCH v4 3/3] dmaengine: qcom: Add GPI dma driver Vinod Koul
2020-10-09 9:00 ` Peter Ujfalusi
2020-10-09 10:31 ` Vinod Koul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=a44af464-7d13-1254-54dd-f7783ccfaa0f@ti.com \
--to=peter.ujfalusi@ti.com \
--cc=bjorn.andersson@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=dmaengine@vger.kernel.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=robh+dt@kernel.org \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).