Re: [PATCH v17 4/4] media: platform: mtk-mdp3: add Mediatek MDP3 driver

[CK Hu <ck.hu@mediatek.com>]

Hi, Moudy:

On Tue, 2022-05-31 at 14:13 +0800, Moudy Ho wrote:
> This patch adds driver for Mediatek's Media Data Path ver.3 (MDP3).
> It provides the following functions:
>   color transform, format conversion, resize, crop, rotate, flip
>   and additional image quality enhancement.
> 
> The MDP3 driver is mainly used for Google Chromebook products to
> import the new architecture to set the HW settings as shown below:
>   User -> V4L2 framework
>     -> MDP3 driver -> SCP (setting calculations)
>       -> MDP3 driver -> CMDQ (GCE driver) -> HW
> 
> Each modules' related operation control is sited in mtk-mdp3-comp.c
> Each modules' register table is defined in file with "mdp_reg_"
> prefix
> GCE related API, operation control  sited in mtk-mdp3-cmdq.c
> V4L2 m2m device functions are implemented in mtk-mdp3-m2m.c
> Probe, power, suspend/resume, system level functions are defined in
> mtk-mdp3-core.c
> 

[snip]

> 
> +int mdp_cmdq_send(struct mdp_dev *mdp, struct mdp_cmdq_param *param)
> +{
> +	struct mdp_cmdq_cmd cmd;
> +	struct mdp_path *path = NULL;
> +	struct mdp_cmdq_cb_param *cb_param = NULL;
> +	struct mdp_comp *comps = NULL;
> +	struct device *dev = &mdp->pdev->dev;
> +	int i, ret;
> +
> +	atomic_inc(&mdp->job_count);
> +	if (atomic_read(&mdp->suspended)) {
> +		atomic_dec(&mdp->job_count);
> +		return -ECANCELED;
> +	}
> +
> +	cb_param = kzalloc(sizeof(*cb_param), GFP_KERNEL);
> +	if (!cb_param) {
> +		ret = -ENOMEM;
> +		goto err_cmdq_data;
> +	}
> +
> +	cmd.pkt = cmdq_pkt_create(mdp->cmdq_clt, SZ_16K);
> +	if (IS_ERR(cmd.pkt)) {
> +		ret = PTR_ERR(cmd.pkt);
> +		goto err_cmdq_data;
> +	}
> +
> +	comps = kcalloc(param->config->num_components, sizeof(*comps),
> +			GFP_KERNEL);
> +	if (!comps) {
> +		ret = -ENOMEM;
> +		goto err_cmdq_data;
> +	}
> +
> +	path = kzalloc(sizeof(*path), GFP_KERNEL);
> +	if (!path) {
> +		ret = -ENOMEM;
> +		goto err_cmdq_data;
> +	}
> +
> +	path->mdp_dev = mdp;
> +	path->config = param->config;
> +	path->param = param->param;
> +	for (i = 0; i < param->param->num_outputs; i++) {
> +		path->bounds[i].left = 0;
> +		path->bounds[i].top = 0;
> +		path->bounds[i].width =
> +			param->param->outputs[i].buffer.format.width;
> +		path->bounds[i].height =
> +			param->param->outputs[i].buffer.format.height;
> +		path->composes[i] = param->composes[i] ?
> +			param->composes[i] : &path->bounds[i];
> +	}
> +
> +	ret = mdp_path_ctx_init(mdp, path);
> +	if (ret) {
> +		dev_err(dev, "mdp_path_ctx_init error\n");
> +		goto err_cmdq_data;
> +	}
> +
> +	cmd.event = &mdp->event[0];
> +	ret = mdp_path_config(mdp, &cmd, path);
> +	if (ret) {
> +		dev_err(dev, "mdp_path_config error\n");
> +		goto err_cmdq_data;
> +	}
> +	cmdq_pkt_finalize(cmd.pkt);
> +
> +	for (i = 0; i < param->config->num_components; i++)
> +		memcpy(&comps[i], path->comps[i].comp,
> +		       sizeof(struct mdp_comp));
> +
> +	cb_param->mdp = mdp;
> +	cb_param->user_cmdq_cb = param->cmdq_cb;
> +	cb_param->user_cb_data = param->cb_data;
> +	cb_param->pkt = cmd.pkt;
> +	cb_param->comps = comps;
> +	cb_param->num_comps = param->config->num_components;
> +	cb_param->mdp_ctx = param->mdp_ctx;
> +
> +	cmd.pkt->async_cb.data = (void *)cb_param;

async_cb is part of proprietary callback mechanism and I'm replacing
the proprietary one with standard one. My final patch is [1] (not
upstreamed yet) and 'data' would be removed. The way to get data
related to pkt:

strutc mdp_data {
    struct cmdq_pkt pkt;
    /* Other data such as mdp, user_cmdq_cb, ... */
}

The callback function would callback with pkt and you could use pkt to
find struct mdp_data{}.

[1] 
https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/commit/?h=mediatek-cmdq6&id=a35f642aa89f02b7307725cdaa3bfb348b26d093

Regards,
CK


> +	mdp->cmdq_clt->client.rx_callback = mdp_handle_cmdq_callback;
> +
> +	mtk_mutex_prepare(mdp->mdp_mutex[MDP_PIPE_RDMA0]);
> +	for (i = 0; i < param->config->num_components; i++)
> +		mdp_comp_clock_on(&mdp->pdev->dev, path-
> >comps[i].comp);
> +
> +	dma_sync_single_for_device(mdp->cmdq_clt->chan->mbox->dev,
> +				   cmd.pkt->pa_base, cmd.pkt-
> >cmd_buf_size,
> +				   DMA_TO_DEVICE);
> +	ret = mbox_send_message(mdp->cmdq_clt->chan, cmd.pkt);
> +	if (ret < 0) {
> +		dev_err(dev, "mbox send message fail %d!\n", ret);
> +		goto err_clock_off;
> +	}
> +	mbox_client_txdone(mdp->cmdq_clt->chan, 0);
> +
> +	kfree(path);
> +	return 0;
> +
> +err_clock_off:
> +	mtk_mutex_unprepare(mdp->mdp_mutex[MDP_PIPE_RDMA0]);
> +	mdp_comp_clocks_off(&mdp->pdev->dev, cb_param->comps,
> +			    cb_param->num_comps);
> +err_cmdq_data:
> +	kfree(path);
> +	atomic_dec(&mdp->job_count);
> +	wake_up(&mdp->callback_wq);
> +	if (cmd.pkt)
> +		cmdq_pkt_destroy(cmd.pkt);
> +	kfree(comps);
> +	kfree(cb_param);
> +	return ret;
> +}