From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 1/2] dmaengine: add Qualcomm BAM dma driver
Date: Fri, 17 Jan 2014 23:49:27 +0100 [thread overview]
Message-ID: <201401172349.28229.arnd@arndb.de> (raw)
In-Reply-To: <1389380874-22753-2-git-send-email-agross@codeaurora.org>
On Friday 10 January 2014, Andy Gross wrote:
> +static bool bam_dma_filter(struct dma_chan *chan, void *data)
> +{
> + struct bam_filter_args *args = data;
> + struct bam_chan *bchan = to_bam_chan(chan);
> +
> + if (args->dev == chan->device &&
> + args->id == bchan->id) {
> +
> + /* we found the channel, so lets set the EE and dir */
> + bchan->ee = args->ee;
> + bchan->slave.direction = args->dir ?
> + DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
> + return true;
> + }
> +
> + return false;
> +}
A filter function should no longer be needed.
> +static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
> + struct of_dma *of)
> +{
> + struct bam_filter_args args;
> + dma_cap_mask_t cap;
> +
> + if (dma_spec->args_count != 3)
> + return NULL;
> +
> + args.dev = of->of_dma_data;
> + args.id = dma_spec->args[0];
> + args.ee = dma_spec->args[1];
> + args.dir = dma_spec->args[2];
> +
> + dma_cap_zero(cap);
> + dma_cap_set(DMA_SLAVE, cap);
> +
> + return dma_request_channel(cap, bam_dma_filter, &args);
> +}
Instead, call dma_get_slave_channel() with the right channel that you already know
here.
> + if (pdev->dev.of_node) {
> + ret = of_dma_controller_register(pdev->dev.of_node,
> + bam_dma_xlate, &bdev->common);
> +
> + if (ret) {
> + dev_err(bdev->dev, "failed to register of_dma\n");
> + goto err_unregister_dma;
> + }
> + }
No need to check for pdev->dev.of_node when that is the only mode of probing.
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id bam_of_match[] = {
> + { .compatible = "qcom,bam-v1.4.0", },
> + { .compatible = "qcom,bam-v1.4.1", },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, bam_of_match);
> +#endif
Also, you can remove the #ifdef here and the of_match_ptr() below.
> +
> +static struct platform_driver bam_dma_driver = {
> + .probe = bam_dma_probe,
> + .remove = bam_dma_remove,
> + .driver = {
> + .name = "bam-dma-engine",
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(bam_of_match),
> + },
> +};
> +
> +static int __init bam_dma_init(void)
> +{
> + return platform_driver_register(&bam_dma_driver);
> +}
> +
> +static void __exit bam_dma_exit(void)
> +{
> + return platform_driver_unregister(&bam_dma_driver);
> +}
> +
module_platform_driver()
> diff --git a/drivers/dma/qcom_bam_dma.h b/drivers/dma/qcom_bam_dma.h
> new file mode 100644
> index 0000000..2cb3b5f
> --- /dev/null
> +++ b/drivers/dma/qcom_bam_dma.h
> @@ -0,0 +1,268 @@
> +#ifndef __QCOM_BAM_DMA_H__
> +#define __QCOM_BAM_DMA_H__
> +
> +#include <linux/dmaengine.h>
> +#include "virt-dma.h"
> +
> +enum bam_channel_dir {
> + BAM_PIPE_CONSUMER = 0, /* channel reads from data-fifo or memory */
> + BAM_PIPE_PRODUCER, /* channel writes to data-fifo or memory */
> +};
Since the header does not serve as an interface, just move all the contents
into the driver directly.
> +struct bam_desc_hw {
> + u32 addr; /* Buffer physical address */
> + u16 size; /* Buffer size in bytes */
> + u16 flags;
> +} __packed;
Remove __packed here, it only makes the access less efficient but does not change
the layout, which is already packed.
Arnd
next prev parent reply other threads:[~2014-01-17 22:49 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-10 19:07 [PATCH v2 0/2] Add Qualcomm BAM dmaengine driver Andy Gross
2014-01-10 19:07 ` [PATCH v2 1/2] dmaengine: add Qualcomm BAM dma driver Andy Gross
2014-01-13 10:31 ` Shevchenko, Andriy
2014-01-20 23:31 ` Andy Gross
2014-01-14 19:43 ` Stephen Boyd
2014-01-20 23:20 ` Andy Gross
2014-01-17 22:49 ` Arnd Bergmann [this message]
2014-01-20 22:52 ` Andy Gross
2014-01-21 8:03 ` Arnd Bergmann
2014-01-21 23:01 ` Andy Gross
2014-01-21 23:12 ` Arnd Bergmann
2014-01-23 20:17 ` Kumar Gala
2014-01-23 22:50 ` Andy Gross
2014-01-10 19:07 ` [PATCH v2 2/2] dmaengine: qcom_bam_dma: Add device tree binding Andy Gross
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