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[EXT] Re: about DMA API updates proposal

Hake Huang
 

Hi Gala,

I will create a separated PR for DMA new API only.

and one question for below:
"use some of the generic devicetree properties in "dts/bindings/dma/dma-controller.yaml”. The number space allocation code seems pretty generic"

Do you mean, instead of just add API call but move below implement to common code?

static int dma_mcux_edma_request_channel(const struct device *dev,
enum dma_channel_filter filter)
{
int i = 0;
int channel = -EINVAL;

k_mutex_lock(&DEV_DATA(dev)->dma_mutex, K_FOREVER);

for (i = 0; i < DEV_CFG(dev)->dma_channels; i++) {
/* channel 0-3 is Period trigger enabled */
if (filter == DMA_CHANNEL_PERIODIC && i > 3) {
break;
}
if (!atomic_test_and_set_bit(DEV_DATA(dev)->dma_channels, i)) {
channel = i;
break;
}
}

k_mutex_unlock(&DEV_DATA(dev)->dma_mutex);

return channel;
}

If so the filter is hard to aligned, as different SOC has different filter setting.

Regards,
Hake

-----Original Message-----
From: Kumar Gala <kumar.gala@linaro.org>
Sent: 2021年3月3日 1:43
To: Hake Huang <hake.huang@nxp.com>
Cc: devel@lists.zephyrproject.org; Maureen Helm <maureen.helm@nxp.com>
Subject: [EXT] Re: about DMA API updates proposal

Caution: EXT Email

On Feb 26, 2021, at 5:46 AM, Hake Huang <hake.huang@nxp.com> wrote:

Hi All,

I am working on enable NXP EDMA drivers to Zephyr DMA framework, and I have two DMA API changes need to discussion.
1. https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fzephyrproject-rtos%2Fzephyr%2Fpull%2F28895&;data=04%7C01%7Chake.huang%40nxp.com%7C3753d08aba3a4799ddb008d8dda294b0%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637503037637028957%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=qvzAFWPYl0UqMQ1EXwcLV8RsfZafClxs5BqVRVjGwJE%3D&amp;reserved=0
in this PR, I add chain_link by using the dest_chaining_en(Major) and source_chaining_en(minor).
2.
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
ub.com%2Fzephyrproject-rtos%2Fzephyr%2Fpull%2F27737&amp;data=04%7C01%7
Chake.huang%40nxp.com%7C3753d08aba3a4799ddb008d8dda294b0%7C686ea1d3bc2
b4c6fa92cd99c5c301635%7C0%7C0%7C637503037637038943%7CUnknown%7CTWFpbGZ
sb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3
D%7C1000&amp;sdata=3QEP18IvoC9MS3C9o274Z0eMIdbIWTzaoZp18la0OzQ%3D&amp;
reserved=0 in this PR,
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
ub.com%2Fzephyrproject-rtos%2Fzephyr%2Fpull%2F27737%2Fcommits%2F25e19f
5b4e4ef07b1598104a02c4722386f2f17b&amp;data=04%7C01%7Chake.huang%40nxp
.com%7C3753d08aba3a4799ddb008d8dda294b0%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637503037637038943%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=wp3iDOFIDkcsLjHRqk9OMWe3yiDfBXko6SHkIDrjQeA%3D&amp;reserved=0 two helper APIs is added dma_api_request_channel request_channel; dma_api_release_channel release_channel; the two APIs are for DMA engine which is capable to dynamically allocate its channels to different DMA requests. and a filter is also added in case of special DMA channel features.

Slack topic discussion is here

Can this topic be scheduled in next API meeting? Thanks.


Regards,
Hake
I wonder if we should pull this into a separate PR. I think a fair amount of the code for these APIs could be generic.

For example I think we can use some of the generic devicetree properties in "dts/bindings/dma/dma-controller.yaml”. The number space allocation code seems pretty generic, even if it just library code used by all the drivers.

- k
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