From: Arnd Bergmann <arnd@arndb•de>
To: Alexander Popov <a13xp0p0v88@gmail•com>
Cc: devicetree@vger•kernel.org, Lars-Peter Clausen <lars@metafoo•de>,
Vinod Koul <vinod.koul@intel•com>, Gerhard Sittig <gsi@denx•de>,
Dan Williams <dan.j.williams@intel•com>,
Anatolij Gustschin <agust@denx•de>,
linuxppc-dev@lists•ozlabs.org
Subject: Re: [PATCH RFC v5 3/5] dma: of: Add common xlate function for matching by channel id
Date: Fri, 1 Nov 2013 08:52:05 +0100 [thread overview]
Message-ID: <201311010852.05709.arnd@arndb.de> (raw)
In-Reply-To: <1383290374-17484-4-git-send-email-a13xp0p0v88@gmail.com>
On Friday 01 November 2013, Alexander Popov wrote:
> + * of_dma_xlate_by_chan_id - Translate dt property to DMA channel by channel id
> + * @dma_spec: pointer to DMA specifier as found in the device tree
> + * @of_dma: pointer to DMA controller data
> + *
> + * This function can be used as the of xlate callback for DMA driver which wants
> + * to match the channel based on the channel id. When using this xlate function
> + * the #dma-cells propety of the DMA controller dt node needs to be set to 1.
> + * The data parameter of of_dma_controller_register must be a pointer to the
> + * dma_device struct the function should match upon.
> + *
> + * Returns pointer to appropriate dma channel on success or NULL on error.
> + */
> +struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec,
> + struct of_dma *ofdma)
> +{
> + struct of_dma_filter_by_chan_id_args args;
> + dma_cap_mask_t cap;
> +
> + args.dev = ofdma->of_dma_data;
> + if (!args.dev)
> + return NULL;
> +
> + if (dma_spec->args_count != 1)
> + return NULL;
> +
> + dma_cap_zero(cap);
> + dma_cap_set(DMA_SLAVE, cap);
> +
> + args.chan_id = dma_spec->args[0];
> +
> + return dma_request_channel(cap, of_dma_filter_by_chan_id, &args);
> +}
> +EXPORT_SYMBOL_GPL(of_dma_xlate_by_chan_id);
This seems rather clumsy, now that we have added the dma_get_slave_channel interface.
Can you try using that instead of dma_request_channel() now?
next prev parent reply other threads:[~2013-11-01 7:57 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-01 7:19 [PATCH RFC v5 0/5] MPC512x DMA slave s/g support, OF DMA lookup Alexander Popov
2013-11-01 7:19 ` [PATCH RFC v5 1/5] dma: mpc512x: reorder mpc8308 specific instructions Alexander Popov
2013-11-01 10:04 ` Anatolij Gustschin
2013-11-11 20:01 ` Gerhard Sittig
2013-11-01 7:19 ` [PATCH RFC v5 2/5] dma: mpc512x: add support for peripheral transfers Alexander Popov
2013-11-11 20:10 ` Gerhard Sittig
2013-11-12 12:23 ` Alexander Popov
2013-11-14 20:58 ` Gerhard Sittig
2013-11-20 6:49 ` Alexander Popov
2013-11-01 7:19 ` [PATCH RFC v5 3/5] dma: of: Add common xlate function for matching by channel id Alexander Popov
2013-11-01 7:52 ` Arnd Bergmann [this message]
2013-11-07 11:33 ` Alexander Popov
2013-11-01 7:19 ` [PATCH RFC v5 4/5] dma: mpc512x: register for device tree channel lookup Alexander Popov
2013-11-18 12:09 ` Mark Rutland
2013-11-18 14:31 ` Arnd Bergmann
2013-11-18 15:23 ` Mark Rutland
2013-11-01 7:19 ` [PATCH RFC v5 5/5] HACK mmc: mxcmmc: enable clocks for the MPC512x Alexander Popov
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=201311010852.05709.arnd@arndb.de \
--to=arnd@arndb$(echo .)de \
--cc=a13xp0p0v88@gmail$(echo .)com \
--cc=agust@denx$(echo .)de \
--cc=dan.j.williams@intel$(echo .)com \
--cc=devicetree@vger$(echo .)kernel.org \
--cc=gsi@denx$(echo .)de \
--cc=lars@metafoo$(echo .)de \
--cc=linuxppc-dev@lists$(echo .)ozlabs.org \
--cc=vinod.koul@intel$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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