From:   Vaishnav Achath <vaishnav.a@ti.com>
To:     <linux-media@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <mripard@kernel.org>, <mchehab@kernel.org>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>,
        <laurent.pinchart@ideasonboard.com>,
        <sakari.ailus@linux.intel.com>, <tomi.valkeinen@ideasonboard.com>
CC:     <linux-kernel@vger.kernel.org>, <bparrot@ti.com>,
        <niklas.soderlund+renesas@ragnatech.se>, <j-luthra@ti.com>,
        <devarsht@ti.com>, <praneeth@ti.com>, <u-kumar1@ti.com>,
        <vigneshr@ti.com>, <nm@ti.com>, <martyn.welch@collabora.com>,
        <vaishnav.a@ti.com>
Subject: [PATCH v7 06/13] media: cadence: csi2rx: Set the STOP bit when stopping a stream
Date:   Tue, 14 Mar 2023 17:25:09 +0530
Message-ID: <20230314115516.667-7-vaishnav.a@ti.com>
In-Reply-To: <20230314115516.667-1-vaishnav.a@ti.com>
References: <20230314115516.667-1-vaishnav.a@ti.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

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>
Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

(no changes since v5)

Changes in v5:
- Change %d to %u
- Add Laurent's R-by.

 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 8ecd889690b7..e80220840e93 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)
@@ -304,12 +309,23 @@ 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%u\n", i);
 
 		clk_disable_unprepare(csi2rx->pixel_clk[i]);
 	}
-- 
2.17.1