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From:   Jai Luthra <j-luthra@ti.com>
To:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
CC:     <linux-media@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Maxime Ripard <mripard@kernel.org>,
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        Benoit Parrot <bparrot@ti.com>,
        Vaishnav Achath <vaishnav.a@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>, <nm@ti.com>,
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        Martyn Welch <martyn.welch@collabora.com>,
        Julien Massot <julien.massot@collabora.com>
Subject: [PATCH v10 08/13] media: cadence: csi2rx: Set the STOP bit when stopping a stream
Date:   Mon, 9 Oct 2023 18:39:34 +0530
Message-ID: <20231009-upstream_csi-v10-8-330aaed24c5d@ti.com>
In-Reply-To: <20231009-upstream_csi-v10-0-330aaed24c5d@ti.com>
References: <20231009-upstream_csi-v10-0-330aaed24c5d@ti.com>
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From: Pratyush Yadav <p.yadav@ti.com>

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>
Tested-by: Julien Massot <julien.massot@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
---
 drivers/media/platform/cadence/cdns-csi2rx.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c
index 913f84c341f4..230c627ef1f4 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>
@@ -41,8 +42,12 @@
 
 #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)
@@ -310,13 +315,25 @@ 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);
 	reset_control_assert(csi2rx->sys_rst);
 	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 streaming on pad%u\n", i);
 
 		reset_control_assert(csi2rx->pixel_rst[i]);
 		clk_disable_unprepare(csi2rx->pixel_clk[i]);

-- 
2.42.0