Re: [PATCH v4 04/11] media: cadence: csi2rx: Set the STOP bit when stopping a stream

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Pratyush Yadav <p.yadav@ti.com>
Cc: "Mauro Carvalho Chehab" <mchehab@kernel.org>,
	"Nikhil Devshatwar" <nikhil.nd@ti.com>,
	"Tomi Valkeinen" <tomi.valkeinen@ideasonboard.com>,
	"Vignesh Raghavendra" <vigneshr@ti.com>,
	"Benoit Parrot" <bparrot@ti.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Sakari Ailus" <sakari.ailus@linux.intel.com>,
	"Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-media@vger.kernel.org
Subject: Re: [PATCH v4 04/11] media: cadence: csi2rx: Set the STOP bit when stopping a stream
Date: Thu, 7 Oct 2021 02:42:30 +0300	[thread overview]
Message-ID: <YV40Zh9snnXqDIhn@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20210915120240.21572-5-p.yadav@ti.com>

Hi Pratyush,

Thank you for the patch.

On Wed, Sep 15, 2021 at 05:32:33PM +0530, Pratyush Yadav wrote:
> The stream stop procedure says that the STOP bit should be set when the
> stream is to be stopped, and then the ready bit in stream status
> register polled to make sure the STOP operation is finished.
> 
> Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> ---
> 
> (no changes since v1)
> 
>  drivers/media/platform/cadence/cdns-csi2rx.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
> index e05d76394cd6..3730e8beee48 100644
> --- a/drivers/media/platform/cadence/cdns-csi2rx.c
> +++ b/drivers/media/platform/cadence/cdns-csi2rx.c
> @@ -8,6 +8,7 @@
>  #include <linux/clk.h>
>  #include <linux/delay.h>
>  #include <linux/io.h>
> +#include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_graph.h>
> @@ -40,8 +41,12 @@
>  
>  #define CSI2RX_STREAM_CTRL_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x000)
>  #define CSI2RX_STREAM_CTRL_SOFT_RST			BIT(4)
> +#define CSI2RX_STREAM_CTRL_STOP				BIT(1)
>  #define CSI2RX_STREAM_CTRL_START			BIT(0)
>  
> +#define CSI2RX_STREAM_STATUS_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x004)
> +#define CSI2RX_STREAM_STATUS_RDY			BIT(31)
> +
>  #define CSI2RX_STREAM_DATA_CFG_REG(n)		(CSI2RX_STREAM_BASE(n) + 0x008)
>  #define CSI2RX_STREAM_DATA_CFG_EN_VC_SELECT		BIT(31)
>  #define CSI2RX_STREAM_DATA_CFG_VC_SELECT(n)		BIT((n) + 16)
> @@ -321,12 +326,23 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx)
>  static void csi2rx_stop(struct csi2rx_priv *csi2rx)
>  {
>  	unsigned int i;
> +	u32 val;
> +	int ret;
>  
>  	clk_prepare_enable(csi2rx->p_clk);
>  	clk_disable_unprepare(csi2rx->sys_clk);
>  
>  	for (i = 0; i < csi2rx->max_streams; i++) {
> -		writel(0, csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
> +		writel(CSI2RX_STREAM_CTRL_STOP,
> +		       csi2rx->base + CSI2RX_STREAM_CTRL_REG(i));
> +
> +		ret = readl_relaxed_poll_timeout(csi2rx->base +
> +						 CSI2RX_STREAM_STATUS_REG(i),
> +						 val,
> +						 (val & CSI2RX_STREAM_STATUS_RDY),
> +						 10, 10000);
> +		if (ret)
> +			dev_warn(csi2rx->dev, "Failed to stop stream%d\n", i);

%u for unsigned int.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

>  
>  		clk_disable_unprepare(csi2rx->pixel_clk[i]);
>  	}

-- 
Regards,

Laurent Pinchart