Date:   Tue, 6 Sep 2016 10:56:12 +0300
From:   Peter Ujfalusi <peter.ujfalusi@...com>
To:     <laurent.pinchart@...asonboard.com>
CC:     <hans.verkuil@...co.com>, <linux-media@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <arnd@...db.de>,
        <linux@...linux.org.uk>
Subject: Re: [PATCH] [media] v4l: omap_vout: vrfb: Convert to dmaengine

Hi,

On 08/18/16 13:22, Peter Ujfalusi wrote:
> The dmaengine driver for sDMA now have support for interleaved transfer.
> This trasnfer type was open coded with the legacy omap-dma API, but now
> we can move it to dmaengine.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
> ---
> The dmaengine driver for sDMA now have support for interleaved transfer.
> This trasnfer type was open coded with the legacy omap-dma API, but now
> we can move it to dmaengine.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
> ---
> Hi,
> 
> I do not have access to any hardware where I could test if the conversion works
> correctly. I think it should. The dmaengine part looks fine to me - not that
> this means too much as I have written it ;)
> Based on debugging the code with starring at it I think the old and the new way
> would end up setting up the DMA in a same way. However the dmaengine driver will
> set CSDP_DST_PACKED | CSDP_SRC_PACKED.
> 
> Laurent: would you be able to test this?

I managed to test the dmaengine interleaved with:
https://github.com/omap-audio/linux-audio/blob/peter/linux-next-wip/drivers/misc/ovv_dmaengine.c

Basically I have ripped the relevant code from omap_vout_vrfb.c, added the
dmaengine implementation. Then:
0. allocate and init the three buffers
1. copy from buffer0 to buffer1 with legacy omap-dma
2. copy from buffer0 to buffer2 with legacy omap-dma
3. compare buffer1 and buffer2
4. reinit buffer2
5. copy from buffer0 to buffer2 with dmaengine
6. compare buffer1 and buffer2

The result is:
[  100.578943] ovv_init: ENTER
[  100.626871] ovv_setup_buffers: pattern is good
[  100.774526] ovv_setup_buffers: pattern is good
[  100.911386] ovv_setup_buffers: pattern is good
[  101.136397] ovv_get_legacy_dma: got channel: 6
[  101.140859] ovv_get_dmaengine_dma: got channel
[  101.160475] omap_vout_vrfb_dma_tx_callback: ENTER
[  101.180357] omap_vout_vrfb_dma_tx_callback: ENTER
[  101.470146] ovv_init: Legacy vs Legacy: they are identical
[  101.595408] ovv_init: pattern is good
[  101.599104] dmaengine_callback: ENTER
[  101.888070] ovv_init: Legacy vs dmaengine: they are identical

-- 
Péter

> 
> Regards,
> Peter
> 
>  drivers/media/platform/omap/omap_vout_vrfb.c | 133 ++++++++++++++++-----------
>  drivers/media/platform/omap/omap_voutdef.h   |   6 +-
>  2 files changed, 83 insertions(+), 56 deletions(-)
> 
> diff --git a/drivers/media/platform/omap/omap_vout_vrfb.c b/drivers/media/platform/omap/omap_vout_vrfb.c
> index b8638e4e1627..957ff7621652 100644
> --- a/drivers/media/platform/omap/omap_vout_vrfb.c
> +++ b/drivers/media/platform/omap/omap_vout_vrfb.c
> @@ -16,7 +16,6 @@
>  #include <media/videobuf-dma-contig.h>
>  #include <media/v4l2-device.h>
> 
> -#include <linux/omap-dma.h>
>  #include <video/omapvrfb.h>
> 
>  #include "omap_voutdef.h"
> @@ -63,7 +62,7 @@ static int omap_vout_allocate_vrfb_buffers(struct omap_vout_device *vout,
>  /*
>   * Wakes up the application once the DMA transfer to VRFB space is completed.
>   */
> -static void omap_vout_vrfb_dma_tx_callback(int lch, u16 ch_status, void *data)
> +static void omap_vout_vrfb_dma_tx_callback(void *data)
>  {
>  	struct vid_vrfb_dma *t = (struct vid_vrfb_dma *) data;
> 
> @@ -94,6 +93,7 @@ int omap_vout_setup_vrfb_bufs(struct platform_device *pdev, int vid_num,
>  	int ret = 0, i, j;
>  	struct omap_vout_device *vout;
>  	struct video_device *vfd;
> +	dma_cap_mask_t mask;
>  	int image_width, image_height;
>  	int vrfb_num_bufs = VRFB_NUM_BUFS;
>  	struct v4l2_device *v4l2_dev = platform_get_drvdata(pdev);
> @@ -131,17 +131,26 @@ int omap_vout_setup_vrfb_bufs(struct platform_device *pdev, int vid_num,
>  	/*
>  	 * Request and Initialize DMA, for DMA based VRFB transfer
>  	 */
> -	vout->vrfb_dma_tx.dev_id = OMAP_DMA_NO_DEVICE;
> -	vout->vrfb_dma_tx.dma_ch = -1;
> -	vout->vrfb_dma_tx.req_status = DMA_CHAN_ALLOTED;
> -	ret = omap_request_dma(vout->vrfb_dma_tx.dev_id, "VRFB DMA TX",
> -			omap_vout_vrfb_dma_tx_callback,
> -			(void *) &vout->vrfb_dma_tx, &vout->vrfb_dma_tx.dma_ch);
> -	if (ret < 0) {
> +	dma_cap_zero(mask);
> +	dma_cap_set(DMA_INTERLEAVE, mask);
> +	vout->vrfb_dma_tx.chan = dma_request_chan_by_mask(&mask);
> +	if (IS_ERR(vout->vrfb_dma_tx.chan)) {
>  		vout->vrfb_dma_tx.req_status = DMA_CHAN_NOT_ALLOTED;
> +	} else {
> +		size_t xt_size = sizeof(struct dma_interleaved_template) +
> +				 sizeof(struct data_chunk);
> +
> +		vout->vrfb_dma_tx.xt = kzalloc(xt_size, GFP_KERNEL);
> +		if (!vout->vrfb_dma_tx.xt) {
> +			dma_release_channel(vout->vrfb_dma_tx.chan);
> +			vout->vrfb_dma_tx.req_status = DMA_CHAN_NOT_ALLOTED;
> +		}
> +	}
> +
> +	if (vout->vrfb_dma_tx.req_status == DMA_CHAN_NOT_ALLOTED)
>  		dev_info(&pdev->dev, ": failed to allocate DMA Channel for"
>  				" video%d\n", vfd->minor);
> -	}
> +
>  	init_waitqueue_head(&vout->vrfb_dma_tx.wait);
> 
>  	/* statically allocated the VRFB buffer is done through
> @@ -176,7 +185,9 @@ void omap_vout_release_vrfb(struct omap_vout_device *vout)
> 
>  	if (vout->vrfb_dma_tx.req_status == DMA_CHAN_ALLOTED) {
>  		vout->vrfb_dma_tx.req_status = DMA_CHAN_NOT_ALLOTED;
> -		omap_free_dma(vout->vrfb_dma_tx.dma_ch);
> +		kfree(vout->vrfb_dma_tx.xt);
> +		dmaengine_terminate_sync(vout->vrfb_dma_tx.chan);
> +		dma_release_channel(vout->vrfb_dma_tx.chan);
>  	}
>  }
> 
> @@ -218,70 +229,84 @@ int omap_vout_vrfb_buffer_setup(struct omap_vout_device *vout,
>  }
> 
>  int omap_vout_prepare_vrfb(struct omap_vout_device *vout,
> -				struct videobuf_buffer *vb)
> +			   struct videobuf_buffer *vb)
>  {
> -	dma_addr_t dmabuf;
> -	struct vid_vrfb_dma *tx;
> +	struct dma_async_tx_descriptor *tx;
> +	enum dma_ctrl_flags flags;
> +	struct dma_chan *chan = vout->vrfb_dma_tx.chan;
> +	struct dma_device *dmadev = chan->device;
> +	struct dma_interleaved_template *xt = vout->vrfb_dma_tx.xt;
> +	dma_cookie_t cookie;
> +	enum dma_status status;
>  	enum dss_rotation rotation;
> -	u32 dest_frame_index = 0, src_element_index = 0;
> -	u32 dest_element_index = 0, src_frame_index = 0;
> -	u32 elem_count = 0, frame_count = 0, pixsize = 2;
> +	size_t dst_icg;
> +	u32 pixsize;
> 
>  	if (!is_rotation_enabled(vout))
>  		return 0;
> 
> -	dmabuf = vout->buf_phy_addr[vb->i];
>  	/* If rotation is enabled, copy input buffer into VRFB
>  	 * memory space using DMA. We are copying input buffer
>  	 * into VRFB memory space of desired angle and DSS will
>  	 * read image VRFB memory for 0 degree angle
>  	 */
> +
>  	pixsize = vout->bpp * vout->vrfb_bpp;
> -	/*
> -	 * DMA transfer in double index mode
> -	 */
> +	dst_icg = ((MAX_PIXELS_PER_LINE * pixsize) -
> +		  (vout->pix.width * vout->bpp)) + 1;
> +
> +	xt->src_start = vout->buf_phy_addr[vb->i];
> +	xt->dst_start = vout->vrfb_context[vb->i].paddr[0];
> +
> +	xt->numf = vout->pix.height;
> +	xt->frame_size = 1;
> +	xt->sgl[0].size = vout->pix.width * vout->bpp;
> +	xt->sgl[0].icg = dst_icg;
> +
> +	xt->dir = DMA_MEM_TO_MEM;
> +	xt->src_sgl = false;
> +	xt->src_inc = true;
> +	xt->dst_sgl = true;
> +	xt->dst_inc = true;
> +
> +	tx = dmadev->device_prep_interleaved_dma(chan, xt, flags);
> +	if (tx == NULL) {
> +		pr_err("%s: DMA interleaved prep error\n", __func__);
> +		return -EINVAL;
> +	}
> 
> -	/* Frame index */
> -	dest_frame_index = ((MAX_PIXELS_PER_LINE * pixsize) -
> -			(vout->pix.width * vout->bpp)) + 1;
> -
> -	/* Source and destination parameters */
> -	src_element_index = 0;
> -	src_frame_index = 0;
> -	dest_element_index = 1;
> -	/* Number of elements per frame */
> -	elem_count = vout->pix.width * vout->bpp;
> -	frame_count = vout->pix.height;
> -	tx = &vout->vrfb_dma_tx;
> -	tx->tx_status = 0;
> -	omap_set_dma_transfer_params(tx->dma_ch, OMAP_DMA_DATA_TYPE_S32,
> -			(elem_count / 4), frame_count, OMAP_DMA_SYNC_ELEMENT,
> -			tx->dev_id, 0x0);
> -	/* src_port required only for OMAP1 */
> -	omap_set_dma_src_params(tx->dma_ch, 0, OMAP_DMA_AMODE_POST_INC,
> -			dmabuf, src_element_index, src_frame_index);
> -	/*set dma source burst mode for VRFB */
> -	omap_set_dma_src_burst_mode(tx->dma_ch, OMAP_DMA_DATA_BURST_16);
> -	rotation = calc_rotation(vout);
> +	tx->callback = omap_vout_vrfb_dma_tx_callback;
> +	tx->callback_param = &vout->vrfb_dma_tx;
> +
> +	cookie = dmaengine_submit(tx);
> +	if (dma_submit_error(cookie)) {
> +		pr_err("%s: dmaengine_submit failed (%d)\n", __func__, cookie);
> +		return -EINVAL;
> +	}
> 
> -	/* dest_port required only for OMAP1 */
> -	omap_set_dma_dest_params(tx->dma_ch, 0, OMAP_DMA_AMODE_DOUBLE_IDX,
> -			vout->vrfb_context[vb->i].paddr[0], dest_element_index,
> -			dest_frame_index);
> -	/*set dma dest burst mode for VRFB */
> -	omap_set_dma_dest_burst_mode(tx->dma_ch, OMAP_DMA_DATA_BURST_16);
> -	omap_dma_set_global_params(DMA_DEFAULT_ARB_RATE, 0x20, 0);
> +	vout->vrfb_dma_tx.tx_status = 0;
> +	dma_async_issue_pending(chan);
> 
> -	omap_start_dma(tx->dma_ch);
> -	wait_event_interruptible_timeout(tx->wait, tx->tx_status == 1,
> +	wait_event_interruptible_timeout(vout->vrfb_dma_tx.wait,
> +					 vout->vrfb_dma_tx.tx_status == 1,
>  					 VRFB_TX_TIMEOUT);
> 
> -	if (tx->tx_status == 0) {
> -		omap_stop_dma(tx->dma_ch);
> +	status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
> +
> +	if (vout->vrfb_dma_tx.tx_status == 0) {
> +		pr_err("%s: Timeout while waiting for DMA\n", __func__);
> +		dmaengine_terminate_sync(chan);
> +		return -EINVAL;
> +	} else if (status != DMA_COMPLETE) {
> +		pr_err("%s: DMA completion %s status\n", __func__,
> +		       status == DMA_ERROR ? "error" : "busy");
> +		dmaengine_terminate_sync(chan);
>  		return -EINVAL;
>  	}
> +
>  	/* Store buffers physical address into an array. Addresses
>  	 * from this array will be used to configure DSS */
> +	rotation = calc_rotation(vout);
>  	vout->queued_buf_addr[vb->i] = (u8 *)
>  		vout->vrfb_context[vb->i].paddr[rotation];
>  	return 0;
> diff --git a/drivers/media/platform/omap/omap_voutdef.h b/drivers/media/platform/omap/omap_voutdef.h
> index 80c79fabdf95..56b630b1c8b4 100644
> --- a/drivers/media/platform/omap/omap_voutdef.h
> +++ b/drivers/media/platform/omap/omap_voutdef.h
> @@ -14,6 +14,7 @@
>  #include <media/v4l2-ctrls.h>
>  #include <video/omapfb_dss.h>
>  #include <video/omapvrfb.h>
> +#include <linux/dmaengine.h>
> 
>  #define YUYV_BPP        2
>  #define RGB565_BPP      2
> @@ -81,8 +82,9 @@ enum vout_rotaion_type {
>   * for VRFB hidden buffer
>   */
>  struct vid_vrfb_dma {
> -	int dev_id;
> -	int dma_ch;
> +	struct dma_chan *chan;
> +	struct dma_interleaved_template *xt;
> +
>  	int req_status;
>  	int tx_status;
>  	wait_queue_head_t wait;
> --
> 2.9.2
> 

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