vi5: fix v4l2 VI driver channel open

unmap chan_id from DT with capture channel id.
Capture channel id is shared between isp capture
and v4l2. Find a free capture channel that does not
conflict with other clients

bug 3691031

Change-Id: If3cd887db6feb2a1817a7451249185de47d6e9ad
Signed-off-by: Anubhav Rai <arai@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2768753
(cherry picked from commit cf54cc587eba0854236c634b8ec0c1c2c98a3a5d)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2866951
Reviewed-by: svcacv <svcacv@nvidia.com>
Reviewed-by: Ankur Pawar <ankurp@nvidia.com>
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Ankur Pawar <ankurp@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

drivers/media/platform/tegra/camera/vi/vi5_fops.c

@@ -2,12 +2,15 @@
 /*
  * Tegra Video Input 5 device common APIs
  *
- * Copyright (c) 2016-2022, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2016-2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  */
 
+#include <linux/syscalls.h>
+#include <linux/fs.h>
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/nvhost.h>
+#include <linux/errno.h>
 #include <linux/semaphore.h>
 #include <media/tegra_camera_platform.h>
 #include <media/mc_common.h>
@@ -25,6 +28,9 @@
 #define PG_BITRATE		32
 #define SLVSEC_STREAM_MAIN	0U
 
+#define VI_CHANNEL_DEV "/dev/capture-vi-channel"
+#define VI_CHAN_PATH_MAX 40
+
 #define CAPTURE_TIMEOUT_MS	2500
 
 static const struct vi_capture_setup default_setup = {
@@ -213,6 +219,50 @@ static int vi5_add_ctrls(struct tegra_channel *chan)
 	return 0;
 }
 
+/*
+ * Find a free VI channel to open. Synchronize vi capture channel sharing
+ * with other clients.
+ */
+static int vi5_channel_open(struct tegra_channel *chan, u32 vi_port)
+{
+	bool found = false;
+	char chanFilePath[VI_CHAN_PATH_MAX];
+	int channel = 0;
+	struct file *filp = NULL;
+	long err = 0;
+
+	while (!found) {
+		sprintf(chanFilePath, "%s%u", VI_CHANNEL_DEV, channel);
+
+		filp = filp_open(chanFilePath, O_RDONLY, 0);
+
+		if (IS_ERR(filp)) {
+			err = PTR_ERR(filp);
+			/* Retry with the next available channel. Opening
+			 * a channel number greater than the ones supported
+			 * by the platform will trigger a ENODEV from the
+			 * VI capture channel driver
+			 */
+			if (err == -EBUSY)
+				channel++;
+			else {
+				dev_err(&chan->video->dev,
+					"Error opening VI capture channel node %s with err: %ld\n",
+					chanFilePath, err);
+				return -ENODEV;
+			}
+		} else
+			found = true;
+	}
+
+	err = 0;
+	chan->vi_channel_id[vi_port] = channel;
+
+	chan->tegra_vi_channel[vi_port] = filp->private_data;
+
+	return err;
+}
+
 static int vi5_channel_setup_queue(struct tegra_channel *chan,
 	unsigned int *nbuffers)
 {
@@ -534,7 +584,8 @@ static int vi5_channel_error_recover(struct tegra_channel *chan,
 			dev_err(&chan->video->dev, "vi capture release failed\n");
 			goto done;
 		}
-		vi_channel_close_ex(chan->id + vi_port, chan->tegra_vi_channel[vi_port]);
+		vi_channel_close_ex(chan->vi_channel_id[vi_port],
+					chan->tegra_vi_channel[vi_port]);
 		chan->tegra_vi_channel[vi_port] = NULL;
 	}
 
@@ -573,7 +624,7 @@ static int vi5_channel_error_recover(struct tegra_channel *chan,
 
 	/* restart vi channel */
 	for (vi_port = 0; vi_port < chan->valid_ports; vi_port++) {
-		chan->tegra_vi_channel[vi_port] = vi_channel_open_ex(chan->id + vi_port, false);
+		err = vi5_channel_open(chan, vi_port);
 		if (IS_ERR(chan->tegra_vi_channel[vi_port])) {
 			err = PTR_ERR(chan);
 			goto done;
@@ -766,12 +817,11 @@ static int vi5_channel_start_streaming(struct vb2_queue *vq, u32 count)
 	/* Skip in bypass mode */
 	if (!chan->bypass) {
 		for (vi_port = 0; vi_port < chan->valid_ports; vi_port++) {
-			chan->tegra_vi_channel[vi_port] =
+			int err = vi5_channel_open(chan, vi_port);
-					vi_channel_open_ex(chan->id + vi_port, false);
+
-			if (IS_ERR(chan->tegra_vi_channel[vi_port])) {
+			if (err)
-				ret = PTR_ERR(chan);
 				goto err_open_ex;
-			}
+
 			spin_lock_irqsave(&chan->capture_state_lock, flags);
 			chan->capture_state = CAPTURE_IDLE;
 			spin_unlock_irqrestore(&chan->capture_state_lock, flags);
@@ -880,7 +930,8 @@ err_start_kthreads:
 err_setup:
 	if (!chan->bypass)
 		for (vi_port = 0; vi_port < chan->valid_ports; vi_port++) {
-			vi_channel_close_ex(chan->id + vi_port, chan->tegra_vi_channel[vi_port]);
+			vi_channel_close_ex(chan->vi_channel_id[vi_port],
+						chan->tegra_vi_channel[vi_port]);
 			chan->tegra_vi_channel[vi_port] = NULL;
 		}
 
@@ -911,7 +962,8 @@ static int vi5_channel_stop_streaming(struct vb2_queue *vq)
 				dev_err(&chan->video->dev,
 					"vi capture release failed\n");
 
-			vi_channel_close_ex(chan->id + vi_port, chan->tegra_vi_channel[vi_port]);
+			vi_channel_close_ex(chan->vi_channel_id[vi_port],
+						chan->tegra_vi_channel[vi_port]);
 			chan->tegra_vi_channel[vi_port] = NULL;
 		}
 

include/media/mc_common.h

@@ -2,7 +2,7 @@
 /*
  * Tegra Media controller common APIs
  *
- * Copyright (c) 2012-2022, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2012-2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
  */
 
 #ifndef __CAMERA_MC_COMMON_H__
@@ -157,6 +157,7 @@ struct tegra_channel {
 	unsigned int num_video_formats;
 	struct mutex stop_kthread_lock;
 
+	unsigned int vi_channel_id[TEGRA_CSI_BLOCKS];
 	unsigned char port[TEGRA_CSI_BLOCKS];
 	unsigned int virtual_channel;
 	unsigned int syncpt[TEGRA_CSI_BLOCKS][MAX_SYNCPT_PER_CHANNEL];