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From:   Pratyush Yadav <p.yadav@ti.com>
To:     Mauro Carvalho Chehab <mchehab@kernel.org>
CC:     Pratyush Yadav <p.yadav@ti.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        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>,
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        <linux-media@vger.kernel.org>
Subject: [PATCH v4 04/11] media: cadence: csi2rx: Set the STOP bit when stopping a stream
Date:   Wed, 15 Sep 2021 17:32:33 +0530
Message-ID: <20210915120240.21572-5-p.yadav@ti.com>
In-Reply-To: <20210915120240.21572-1-p.yadav@ti.com>
References: <20210915120240.21572-1-p.yadav@ti.com>
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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);
 
 		clk_disable_unprepare(csi2rx->pixel_clk[i]);
 	}
-- 
2.33.0