Re: [PATCH v18 6/6] soc: mediatek: mutex: add functions that operate registers by CMDQ

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

Hi, Moudy:

On Thu, 2022-05-12 at 16:41 +0800, Moudy Ho wrote:
> Due to HW limitations, MDP3 is necessary to enable MUTEX in each
> frame
> for SOF triggering and cooperate with CMDQ control to reduce the
> amount
> of interrupts generated(also, reduce frame latency).
> 
> In response to the above situation, a new interface
> "mtk_mutex_enable_by_cmdq" has been added to achieve the purpose.
> 
> Signed-off-by: Moudy Ho <moudy.ho@mediatek.com>
> Reviewed-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> ---
>  drivers/soc/mediatek/mtk-mutex.c       | 47
> +++++++++++++++++++++++++-
>  include/linux/soc/mediatek/mtk-mutex.h |  2 ++
>  2 files changed, 48 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-mutex.c
> b/drivers/soc/mediatek/mtk-mutex.c
> index 92afdee14d43..4ec2954f2f43 100644
> --- a/drivers/soc/mediatek/mtk-mutex.c
> +++ b/drivers/soc/mediatek/mtk-mutex.c
> @@ -7,10 +7,12 @@
>  #include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
> +#include <linux/of_address.h>
>  #include <linux/platform_device.h>
>  #include <linux/regmap.h>
>  #include <linux/soc/mediatek/mtk-mmsys.h>
>  #include <linux/soc/mediatek/mtk-mutex.h>
> +#include <linux/soc/mediatek/mtk-cmdq.h>
>  
>  #define MT2701_MUTEX0_MOD0			0x2c
>  #define MT2701_MUTEX0_SOF0			0x30
> @@ -176,6 +178,9 @@ struct mtk_mutex_ctx {
>  	void __iomem			*regs;
>  	struct mtk_mutex		mutex[10];
>  	const struct mtk_mutex_data	*data;
> +	phys_addr_t			addr;
> +	struct cmdq_client_reg		cmdq_reg;
> +	bool				has_gce_client_reg;

I think this is not necessary. If cmdq_reg.size == 0, that would imply
cmdq_reg is invalid.

>  };
>  
>  static const unsigned int mt2701_mutex_mod[DDP_COMPONENT_ID_MAX] = {
> @@ -531,6 +536,30 @@ void mtk_mutex_enable(struct mtk_mutex *mutex)
>  }
>  EXPORT_SYMBOL_GPL(mtk_mutex_enable);
>  
> +int mtk_mutex_enable_by_cmdq(struct mtk_mutex *mutex, void *pkt)
> +{
> +	struct mtk_mutex_ctx *mtx = container_of(mutex, struct
> mtk_mutex_ctx,
> +						 mutex[mutex->id]);
> +#if IS_REACHABLE(CONFIG_MTK_CMDQ)
> +	struct cmdq_pkt *cmdq_pkt = (struct cmdq_pkt *)pkt;
> +
> +	WARN_ON(&mtx->mutex[mutex->id] != mutex);
> +
> +	if (!mtx->has_gce_client_reg) {
> +		dev_err(mtx->dev, "mediatek,gce-client-reg hasn't been
> set in dts");
> +		return -EINVAL;
> +	}
> +
> +	cmdq_pkt_write(cmdq_pkt, mtx->cmdq_reg.subsys,
> +		       mtx->addr + DISP_REG_MUTEX_EN(mutex->id), 1);
> +	return 0;
> +#else
> +	dev_err(mtx->dev, "Not support for enable MUTEX by CMDQ");
> +	return -ENODEV;
> +#endif
> +}
> +EXPORT_SYMBOL_GPL(mtk_mutex_enable_by_cmdq);
> +
>  void mtk_mutex_disable(struct mtk_mutex *mutex)
>  {
>  	struct mtk_mutex_ctx *mtx = container_of(mutex, struct
> mtk_mutex_ctx,
> @@ -655,8 +684,11 @@ static int mtk_mutex_probe(struct
> platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct mtk_mutex_ctx *mtx;
> -	struct resource *regs;
> +	struct resource *regs, addr;
>  	int i;
> +#if IS_REACHABLE(CONFIG_MTK_CMDQ)
> +	int ret;
> +#endif
>  
>  	mtx = devm_kzalloc(dev, sizeof(*mtx), GFP_KERNEL);
>  	if (!mtx)
> @@ -676,6 +708,19 @@ static int mtk_mutex_probe(struct
> platform_device *pdev)
>  		}
>  	}
>  
> +	if (of_address_to_resource(dev->of_node, 0, &addr) < 0)
> +		mtx->addr = 0L;

You may return error, or you should check mtx->addr when use it.

Regards,
CK

> +	else
> +		mtx->addr = addr.start;
> +
> +#if IS_REACHABLE(CONFIG_MTK_CMDQ)
> +	ret = cmdq_dev_get_client_reg(dev, &mtx->cmdq_reg, 0);
> +	if (ret)
> +		dev_dbg(dev, "No mediatek,gce-client-reg!\n");
> +	else
> +		mtx->has_gce_client_reg = true;
> +#endif
> +
>  	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	mtx->regs = devm_ioremap_resource(dev, regs);
>  	if (IS_ERR(mtx->regs)) {
> diff --git a/include/linux/soc/mediatek/mtk-mutex.h
> b/include/linux/soc/mediatek/mtk-mutex.h
> index f174452212d6..80425ae19fb7 100644
> --- a/include/linux/soc/mediatek/mtk-mutex.h
> +++ b/include/linux/soc/mediatek/mtk-mutex.h
> @@ -29,6 +29,8 @@ int mtk_mutex_prepare(struct mtk_mutex *mutex);
>  void mtk_mutex_add_comp(struct mtk_mutex *mutex,
>  			enum mtk_ddp_comp_id id);
>  void mtk_mutex_enable(struct mtk_mutex *mutex);
> +int mtk_mutex_enable_by_cmdq(struct mtk_mutex *mutex,
> +			     void *pkt);
>  void mtk_mutex_disable(struct mtk_mutex *mutex);
>  void mtk_mutex_remove_comp(struct mtk_mutex *mutex,
>  			   enum mtk_ddp_comp_id id);