firmware/br-ext-chip-ingenic/board/t40/kernel/patches/00000-drivers_misc_rmem.c.patch

diff -drupN a/drivers/misc/rmem.c b/drivers/misc/rmem.c
--- a/drivers/misc/rmem.c	1970-01-01 03:00:00.000000000 +0300
+++ b/drivers/misc/rmem.c	2022-06-09 05:02:30.000000000 +0300
@@ -0,0 +1,165 @@
+/*
+ * rmem.c - Reserved memory driver for libimp.
+ *
+ * Copyright (C) 2012 Ingenic Semiconductor Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/miscdevice.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/syscalls.h>
+
+#define RMEM_MAGIC			'r'
+#define RMEM_CMD_FLUSH_CACHE		_IOWR(RMEM_MAGIC, 0, struct rmem_flush_cache_info)
+#define RMEM_CMD_RMEM_INFO	    	_IOWR(RMEM_MAGIC, 1, struct rmem_info)
+
+struct  rmem_info {
+    unsigned int vaddr;
+    unsigned int paddr;
+};
+static struct rmem_info rmem_addr;
+
+
+static struct miscdevice	mdev;
+
+struct rmem_flush_cache_info {
+	unsigned int	addr;
+	unsigned int	len;
+	unsigned int	dir;
+};
+
+static int rmem_open(struct inode *inode, struct file *filp)
+{
+	pr_debug("[%d:%d] %s\n", current->tgid, current->pid, __func__);
+	return 0;
+}
+
+static int rmem_release(struct inode *inode, struct file *filp)
+{
+	pr_debug("[%d:%d] %s\n", current->tgid, current->pid, __func__);
+	return 0;
+}
+
+static long rmem_cmd_flush_cache(long arg)
+{
+	struct rmem_flush_cache_info info;
+	long ret = 0;
+	if (copy_from_user(&info, (void *)arg, sizeof(info))) {
+		return -EFAULT;
+	}
+
+	dma_cache_sync(NULL, (void *)info.addr, info.len, info.dir);
+
+	return ret;
+}
+
+static long rmem_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case RMEM_CMD_FLUSH_CACHE:
+		return rmem_cmd_flush_cache(arg);
+	case RMEM_CMD_RMEM_INFO:
+	    if (copy_to_user((void *)arg, &rmem_addr, sizeof(struct rmem_info))) {
+		    return -EFAULT;
+	    }
+		break;
+	default:
+		pr_err("Unknown ioctl: 0x%.8X\n", cmd);
+		return -EINVAL;
+	}
+}
+
+static int rmem_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	vma->vm_flags |= VM_IO;
+
+	pgprot_val(vma->vm_page_prot) &= ~_CACHE_MASK;
+	pgprot_val(vma->vm_page_prot) |= _CACHE_CACHABLE_NONCOHERENT;
+
+	if (io_remap_pfn_range(vma,vma->vm_start,
+			       vma->vm_pgoff,
+			       vma->vm_end - vma->vm_start,
+			       vma->vm_page_prot))
+		return -EAGAIN;
+    rmem_addr.vaddr = vma->vm_start;
+    rmem_addr.paddr = vma->vm_pgoff * PAGE_SIZE;
+
+
+	return 0;
+}
+
+static struct file_operations rmem_misc_fops = {
+	.open		= rmem_open,
+	.release	= rmem_release,
+	.unlocked_ioctl	= rmem_ioctl,
+	.mmap		= rmem_mmap,
+};
+
+static int rmem_probe(struct platform_device *pdev)
+{
+	int ret;
+
+
+	mdev.minor = MISC_DYNAMIC_MINOR;
+	mdev.name =  "rmem";
+	mdev.fops = &rmem_misc_fops;
+
+	ret = misc_register(&mdev);
+	if (ret < 0) {
+		pr_err("rmem register failed\n");
+		return -1;
+	}
+
+    rmem_addr.vaddr = 0;
+    rmem_addr.paddr = 0;
+
+	return 0;
+}
+
+static int rmem_remove(struct platform_device *dev)
+{
+	return 0;
+}
+
+static struct platform_driver rmem_driver = {
+	.probe		= rmem_probe,
+	.remove		= rmem_remove,
+	.driver		= {
+		.name	= "rmem",
+	},
+};
+
+struct platform_device rmem_device = {
+	.name = "rmem",
+	.id = -1,
+	.resource = NULL,
+	.num_resources = 0,
+};
+
+static int __init rmem_init(void)
+{
+	platform_device_register(&rmem_device);
+	return platform_driver_register(&rmem_driver);
+}
+
+static void __exit rmem_exit(void)
+{
+	platform_device_unregister(&rmem_device);
+	platform_driver_unregister(&rmem_driver);
+}
+
+module_init(rmem_init);
+module_exit(rmem_exit);
+
+MODULE_LICENSE("GPL v2");