platform/raspberrypi: Destage VCHIQ interface

Destage the VCHIQ interface driver to drivers/platform/raspberrypi.

There is still the remaining TODO item of improving the documentation,
which can be handled post destaging.

Secondly, multimedia drivers like codec and ISP that rely on this
interface need to be upstreamed. And lastly, the drivers that facilitate
the shared memory between VideoCore and Linux, like the vc-sm-cma driver
and vc_mem char driver also need to be upstreamed.

Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
Link: https://patch.msgid.link/20251029-vchiq-destage-v3-6-da8d6c83c2c5@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 157 insertions, 0 deletions

diff --git a/drivers/platform/raspberrypi/vchiq-interface/vchiq_debugfs.c b/drivers/platform/raspberrypi/vchiq-interface/vchiq_debugfs.c
new file mode 100644
index 000000000000..c82326a9b6d9
--- /dev/null
+++ b/drivers/platform/raspberrypi/vchiq-interface/vchiq_debugfs.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.
+ * Copyright (c) 2010-2012 Broadcom. All rights reserved.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/raspberrypi/vchiq_core.h>
+#include <linux/raspberrypi/vchiq_arm.h>
+#include <linux/raspberrypi/vchiq_debugfs.h>
+
+#ifdef CONFIG_DEBUG_FS
+
+#define DEBUGFS_WRITE_BUF_SIZE 256
+
+/* Global 'vchiq' debugfs and clients entry used by all instances */
+static struct dentry *vchiq_dbg_dir;
+static struct dentry *vchiq_dbg_clients;
+
+static int debugfs_usecount_show(struct seq_file *f, void *offset)
+{
+	struct vchiq_instance *instance = f->private;
+	int use_count;
+
+	use_count = vchiq_instance_get_use_count(instance);
+	seq_printf(f, "%d\n", use_count);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(debugfs_usecount);
+
+static int debugfs_trace_show(struct seq_file *f, void *offset)
+{
+	struct vchiq_instance *instance = f->private;
+	int trace;
+
+	trace = vchiq_instance_get_trace(instance);
+	seq_printf(f, "%s\n", trace ? "Y" : "N");
+
+	return 0;
+}
+
+static int vchiq_dump_show(struct seq_file *f, void *offset)
+{
+	struct vchiq_state *state = f->private;
+
+	vchiq_dump_state(f, state);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(vchiq_dump);
+
+static int debugfs_trace_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, debugfs_trace_show, inode->i_private);
+}
+
+static ssize_t debugfs_trace_write(struct file *file,
+	const char __user *buffer,
+	size_t count, loff_t *ppos)
+{
+	struct seq_file *f = (struct seq_file *)file->private_data;
+	struct vchiq_instance *instance = f->private;
+	char firstchar;
+
+	if (copy_from_user(&firstchar, buffer, 1))
+		return -EFAULT;
+
+	switch (firstchar) {
+	case 'Y':
+	case 'y':
+	case '1':
+		vchiq_instance_set_trace(instance, 1);
+		break;
+	case 'N':
+	case 'n':
+	case '0':
+		vchiq_instance_set_trace(instance, 0);
+		break;
+	default:
+		break;
+	}
+
+	*ppos += count;
+
+	return count;
+}
+
+static const struct file_operations debugfs_trace_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debugfs_trace_open,
+	.write		= debugfs_trace_write,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+/* add an instance (process) to the debugfs entries */
+void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
+{
+	char pidstr[16];
+	struct dentry *top;
+
+	snprintf(pidstr, sizeof(pidstr), "%d",
+		 vchiq_instance_get_pid(instance));
+
+	top = debugfs_create_dir(pidstr, vchiq_dbg_clients);
+
+	debugfs_create_file("use_count", 0444, top, instance,
+			    &debugfs_usecount_fops);
+	debugfs_create_file("trace", 0644, top, instance, &debugfs_trace_fops);
+
+	vchiq_instance_get_debugfs_node(instance)->dentry = top;
+}
+
+void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
+{
+	struct vchiq_debugfs_node *node =
+				vchiq_instance_get_debugfs_node(instance);
+
+	debugfs_remove_recursive(node->dentry);
+}
+
+void vchiq_debugfs_init(struct vchiq_state *state)
+{
+	vchiq_dbg_dir = debugfs_create_dir("vchiq", NULL);
+	vchiq_dbg_clients = debugfs_create_dir("clients", vchiq_dbg_dir);
+
+	debugfs_create_file("state", S_IFREG | 0444, vchiq_dbg_dir, state,
+			    &vchiq_dump_fops);
+}
+
+/* remove all the debugfs entries */
+void vchiq_debugfs_deinit(void)
+{
+	debugfs_remove_recursive(vchiq_dbg_dir);
+}
+
+#else /* CONFIG_DEBUG_FS */
+
+void vchiq_debugfs_init(struct vchiq_state *state)
+{
+}
+
+void vchiq_debugfs_deinit(void)
+{
+}
+
+void vchiq_debugfs_add_instance(struct vchiq_instance *instance)
+{
+}
+
+void vchiq_debugfs_remove_instance(struct vchiq_instance *instance)
+{
+}
+
+#endif /* CONFIG_DEBUG_FS */