From 9330da939c87ab440a2c6aed9d1e2aff61c3f95c Mon Sep 17 00:00:00 2001
From: Venkata Rao Kakani <vkakani@codeaurora.org>
Date: Wed, 27 Jan 2021 19:56:05 +0530
Subject: [PATCH] drivers: soc: rename block device nodes

Rename block driver enables the renaming of block dev
nodes assigned by generic driver.

Change-Id: I40f966717683efb9800dcb34ed851f95cb22e3c8
Signed-off-by: Venkata Rao Kakani <vkakani@codeaurora.org>
---
 drivers/soc/qcom/Kconfig               |  9 ++++
 drivers/soc/qcom/Makefile              |  1 +
 drivers/soc/qcom/rename_block_device.c | 58 ++++++++++++++++++++++++++
 3 files changed, 68 insertions(+)
 create mode 100644 drivers/soc/qcom/rename_block_device.c

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index f12c44670896..9e4b3e29bf9d 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -1156,5 +1156,14 @@ config QCOM_RTIC
 	  will trigger RTIC kernel MP.s (measurement parameters) generation
 	  during the kernel build.
 
+config RENAME_BLOCK_DEVICE
+	tristate "Rename block device node in /dev"
+	default n
+	help
+	  Say 'Y' to to rename the block device node assigned by generic
+	  driver to a name that is needed. This is used for rename block
+	  device names created by default as sda1, sda2 etc. to the
+	  names system is needed.this is applicable for block devices only.
+
 source "drivers/soc/qcom/icnss2/Kconfig"
 endmenu
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 2bc2b758bc43..d37792330201 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -104,3 +104,4 @@ obj-$(CONFIG_QTI_HW_MEMLAT_SCMI_CLIENT)	+= memlat_scmi.o
 obj-$(CONFIG_QTI_HW_MEMLAT) += rimps_memlat.o
 obj-$(CONFIG_QTI_HW_MEMLAT_LOG)	+= rimps_log.o
 obj-$(CONFIG_QCOM_QFPROM_SYS) += qfprom-sys.o
+obj-$(CONFIG_RENAME_BLOCK_DEVICE) += rename_block_device.o
diff --git a/drivers/soc/qcom/rename_block_device.c b/drivers/soc/qcom/rename_block_device.c
new file mode 100644
index 000000000000..917482077b6b
--- /dev/null
+++ b/drivers/soc/qcom/rename_block_device.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/genhd.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#define PATH_SIZE	32
+
+static int rename_blk_dev_init(void)
+{
+	dev_t dev;
+	int index = 0, partno;
+	struct gendisk *disk;
+	struct device_node *node;
+	char dev_path[PATH_SIZE];
+	const char *actual_name, *modified_name;
+
+	node = of_find_compatible_node(NULL, NULL, "qcom,blkdev-rename");
+	if (!node) {
+		pr_err("qcom,blkdev-rename is missing\n");
+		goto out;
+	}
+	while (!of_property_read_string_index(node, "actual-dev", index,
+						&actual_name)) {
+		memset(dev_path, '\0', PATH_SIZE);
+		snprintf(dev_path, PATH_SIZE, "/dev/%s", actual_name);
+		dev = name_to_dev_t(dev_path);
+		if (!dev) {
+			pr_err("No device path : %s\n", dev_path);
+			return -EINVAL;
+		}
+		disk = get_gendisk(dev, &partno);
+		if (!disk) {
+			pr_err("No device with dev path : %s\n", dev_path);
+			return -ENXIO;
+		}
+		if (!of_property_read_string_index(node, "rename-dev", index,
+							&modified_name)) {
+			device_rename(disk_to_dev(disk), modified_name);
+		} else {
+			pr_err("rename-dev for actual-dev = %s is missing\n",
+								 actual_name);
+			return -ENXIO;
+		}
+		index++;
+	}
+out:
+	return  0;
+}
+
+late_initcall(rename_blk_dev_init);
+MODULE_DESCRIPTION("Rename block devices");
+MODULE_LICENSE("GPL v2");