[PATCH v9 08/13] media: cadence: csi2rx: Set the STOP bit when stopping a stream

[Jai Luthra <j-luthra@xxxxxx>]

From: Pratyush Yadav <p.yadav@xxxxxx>

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@xxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
Reviewed-by: Maxime Ripard <mripard@xxxxxxxxxx>
Signed-off-by: Jai Luthra <j-luthra@xxxxxx>
---
Changes from v8:
    - Better log message to avoid confusion between cadence streams and v4l2 
    streams

 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 b57e0c3b1944..f8205c3a28c0 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]);

-- 
2.41.0