drivers/amlogic/mtd_meson8b/aml_dtb.c - manifest_repos/kernel - Git at Google

 /*
  * drivers/amlogic/mtd/aml_dtb.c
  *
  * Copyright (C) 2017 Amlogic, Inc. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  */

 #include "aml_mtd.h"

 #ifndef AML_NAND_UBOOT
 #include<linux/cdev.h>
 #include <linux/device.h>

 #define DTB_NAME "dtb"
 static dev_t amlnf_dtb_no;
 struct cdev amlnf_dtb;
 struct device *dtb_dev_nand;
 struct class *amlnf_dtb_class;
 #endif  /* AML_NAND_UBOOT */

 int dtb_erase_blk = -1;

 struct aml_nand_chip *aml_chip_dtb;

 int amlnf_dtb_save(u8 *buf, int len)
 {
 	struct mtd_info *mtd = aml_chip_dtb->mtd;
 	u8 *dtb_buf = NULL;
 	int ret = 0;

 	pr_info("%s: ####\n", __func__);
 	if (aml_chip_dtb == NULL) {
 		pr_info("%s: amlnf not init yet!\n", __func__);
 		return -EFAULT;
 	}

 	if (len > aml_chip_dtb->dtbsize) {
 		pr_info("warnning!!! %s: length too much\n", __func__);
 		len = aml_chip_dtb->dtbsize;
 		/*return -EFAULT;*/
 	}
 	dtb_buf = vmalloc(aml_chip_dtb->dtbsize + mtd->writesize);
 	if (dtb_buf == NULL) {
 		ret = -1;
 		goto exit_err;
 	}
 	memset(dtb_buf, 0, aml_chip_dtb->dtbsize);
 	memcpy(dtb_buf, buf, len);
 	aml_nand_save_dtb(mtd, dtb_buf);

 exit_err:
 	if (dtb_buf) {
 		/* kfree(dtb_buf); */
 		vfree(dtb_buf);
 		dtb_buf = NULL;
 	}
 	return ret;
 }

 int amlnf_dtb_erase(void)
 {
 	int ret = 0;

 	if (aml_chip_dtb == NULL) {
 		pr_info("%s amlnf not ready yet!\n", __func__);
 		return -1;
 	}
 	return ret;
 }

 int amlnf_dtb_read(u8 *buf, int len)
 {
 	struct mtd_info *mtd = aml_chip_dtb->mtd;
 	size_t offset = 0;
 	u8 *dtb_buf = NULL;
 	int ret = 0;

 	pr_info("%s: ####\n", __func__);

 	if (len > aml_chip_dtb->dtbsize) {
 		pr_info("warnning!!! %s dtd length too much\n", __func__);
 		len = aml_chip_dtb->dtbsize;
 		/*return -EFAULT;*/
 	}
 	if (aml_chip_dtb == NULL) {
 		memset(buf, 0x0, len);
 		pr_info("%s amlnf not ready yet!\n", __func__);
 		return 0;
 	}

 	dtb_buf = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
 	if (dtb_buf == NULL) {
 		ret = -1;
 		goto exit_err;
 	}
 	memset(dtb_buf, 0, aml_chip_dtb->dtbsize);
 	aml_nand_read_dtb(mtd, offset, (u8 *)dtb_buf);
 	memcpy(buf, dtb_buf, len);
 exit_err:
 	if (dtb_buf) {
 		/* kfree(dtb_buf); */
 		kfree(dtb_buf);
 		dtb_buf = NULL;
 	}
 	return ret;
 }

 /* under kernel */
 #ifndef AML_NAND_UBOOT
 ssize_t dtb_show(struct class *class, struct class_attribute *attr,
 		char *buf)
 {
 	pr_info("dtb_show : #####\n");
 	/* fixme, read back and show in log! */
 	return 0;
 }

 ssize_t dtb_store(struct class *class, struct class_attribute *attr,
 		const char *buf, size_t count)
 {
 	int ret = 0;
 	u8 *dtb_ptr = NULL;

 	pr_info("dtb_store : #####\n");
 	dtb_ptr = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
 	if (dtb_ptr == NULL) {
 		pr_info("%s: malloc buf failed\n ", __func__);
 		return -ENOMEM;
 	}
 	/* fixme, why read back then write? */
 	ret = amlnf_dtb_read(dtb_ptr, aml_chip_dtb->dtbsize);
 	if (ret) {
 		pr_info("%s: read failed\n", __func__);
 		kfree(dtb_ptr);
 		return -EFAULT;
 	}

 	ret = amlnf_dtb_save(dtb_ptr, aml_chip_dtb->dtbsize);
 	if (ret) {
 		pr_info("%s: save failed\n", __func__);
 		kfree(dtb_ptr);
 		return -EFAULT;
 	}

 	pr_info("dtb_store : OK #####\n");
 	return count;
 }

 static CLASS_ATTR(nfdtb, 0644, dtb_show, dtb_store);

 int dtb_open(struct inode *node, struct file *file)
 {
 	return 0;
 }

 ssize_t dtb_read(struct file *file,
 		char __user *buf,
 		size_t count,
 		loff_t *ppos)
 {
 	u8 *dtb_ptr = NULL;
 	/*struct nand_flash *flash = &aml_chip_dtb->flash;*/
 	struct mtd_info *mtd = aml_chip_dtb->mtd;
 	ssize_t read_size = 0;
 	int ret = 0;

 	if (*ppos == aml_chip_dtb->dtbsize)
 		return 0;

 	if (*ppos >= aml_chip_dtb->dtbsize) {
 		pr_info("%s:data access out of space!\n", __func__);
 		return -EFAULT;
 	}

 	dtb_ptr = vmalloc(aml_chip_dtb->dtbsize + mtd->writesize);
 	if (dtb_ptr == NULL)
 		return -ENOMEM;

 	/*not need nand_get_device here, mtd->_read_xx will done with it*/
 	/*nand_get_device(mtd, FL_READING);*/
 	ret = amlnf_dtb_read((u8 *)dtb_ptr, aml_chip_dtb->dtbsize);
 	if (ret) {
 		pr_info("%s: read failed:%d\n", __func__, ret);
 		ret = -EFAULT;
 		goto exit;
 	}

 	if ((*ppos + count) > aml_chip_dtb->dtbsize)
 		read_size = aml_chip_dtb->dtbsize - *ppos;
 	else
 		read_size = count;

 	ret = copy_to_user(buf, (dtb_ptr + *ppos), read_size);
 	*ppos += read_size;
 exit:
 	/*nand_release_device(mtd);*/
 	/* kfree(dtb_ptr); */
 	vfree(dtb_ptr);
 	return read_size;
 }

 ssize_t dtb_write(struct file *file,
 		const char __user *buf,
 		size_t count, loff_t *ppos)
 {
 	u8 *dtb_ptr = NULL;
 	ssize_t write_size = 0;
 	/*struct nand_flash *flash = &aml_chip_dtb->flash;*/
 	struct mtd_info *mtd = aml_chip_dtb->mtd;
 	int ret = 0;

 	if (*ppos == aml_chip_dtb->dtbsize)
 		return 0;

 	if (*ppos >= aml_chip_dtb->dtbsize) {
 		pr_info("%s: data access out of space!\n", __func__);
 		return -EFAULT;
 	}

 	dtb_ptr = vmalloc(aml_chip_dtb->dtbsize + mtd->writesize);
 	if (dtb_ptr == NULL)
 		return -ENOMEM;

 	/*not need nand_get_device here, mtd->_read_xx will done with it*/
 	/*nand_get_device(mtd, FL_WRITING);*/
 	ret = amlnf_dtb_read((u8 *)dtb_ptr, aml_chip_dtb->dtbsize);
 	if (ret) {
 		pr_info("%s: read failed\n", __func__);
 		ret = -EFAULT;
 		goto exit;
 	}

 	if ((*ppos + count) > aml_chip_dtb->dtbsize)
 		write_size = aml_chip_dtb->dtbsize - *ppos;
 	else
 		write_size = count;

 	ret = copy_from_user((dtb_ptr + *ppos), buf, write_size);

 	ret = amlnf_dtb_save(dtb_ptr, aml_chip_dtb->dtbsize);
 	if (ret) {
 		pr_info("%s: read failed\n", __func__);
 		ret = -EFAULT;
 		goto exit;
 	}

 	*ppos += write_size;
 exit:
 	/*nand_release_device(mtd);*/
 	/* kfree(dtb_ptr); */
 	vfree(dtb_ptr);
 	return write_size;
 }

 long dtb_ioctl(struct file *file, u32 cmd, unsigned long args)
 {
 	return 0;
 }

 static const struct file_operations dtb_ops = {
 	.open = dtb_open,
 	.read = dtb_read,
 	.write = dtb_write,
 	.unlocked_ioctl = dtb_ioctl,
 };
 #endif /* AML_NAND_UBOOT */

 int amlnf_dtb_init(struct aml_nand_chip *aml_chip)
 {
 	int ret = 0;
 	u8 *dtb_buf = NULL;

 	aml_chip_dtb = aml_chip;

 	dtb_buf = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
 	if (dtb_buf == NULL) {
 		ret = -1;
 		goto exit_err;
 	}

 	memset(dtb_buf, 0x0, aml_chip_dtb->dtbsize);

 #ifndef AML_NAND_UBOOT
 	pr_info("%s: register dtb cdev\n", __func__);
 	ret = alloc_chrdev_region(&amlnf_dtb_no, 0, 1, DTB_NAME);
 	if (ret < 0) {
 		pr_info("%s alloc dtb dev_t number failed\n", __func__);
 		ret = -1;
 		goto exit_err;
 	}

 	cdev_init(&amlnf_dtb, &dtb_ops);
 	amlnf_dtb.owner = THIS_MODULE;
 	ret = cdev_add(&amlnf_dtb, amlnf_dtb_no, 1);
 	if (ret) {
 		pr_info("%s amlnf dtd dev add failed\n", __func__);
 		ret = -1;
 		goto exit_err1;
 	}

 	amlnf_dtb_class = class_create(THIS_MODULE, DTB_NAME);
 	if (IS_ERR(amlnf_dtb_class)) {
 		pr_info("%s: amlnf dtd class add failed\n", __func__);
 		ret = -1;
 		goto exit_err2;
 	}

 	ret = class_create_file(amlnf_dtb_class, &class_attr_nfdtb);
 	if (ret) {
 		pr_info("%s dev add failed\n", __func__);
 		ret = -1;
 		goto exit_err2;
 	}

 	dtb_dev_nand = device_create(amlnf_dtb_class,
 		NULL,
 		amlnf_dtb_no,
 		NULL,
 		DTB_NAME);
 	if (IS_ERR(dtb_dev_nand)) {
 		pr_info("%s: device_create failed\n", __func__);
 		ret = -1;
 		goto exit_err3;
 	}

 	pr_info("%s: register dtd cdev OK\n", __func__);
 	kfree(dtb_buf);
 	dtb_buf = NULL;

 	return ret;

 exit_err3:
 	class_remove_file(amlnf_dtb_class, &class_attr_nfdtb);
 	class_destroy(amlnf_dtb_class);
 exit_err2:
 	cdev_del(&amlnf_dtb);
 exit_err1:
 	unregister_chrdev_region(amlnf_dtb_no, 1);

 #endif /* AML_NAND_UBOOT */
 exit_err:
 	kfree(dtb_buf);
 	dtb_buf = NULL;
 	return ret;
 }

 #ifdef AML_NAND_UBOOT
 int amlnf_dtb_init_partitions(struct aml_nand_chip *aml_chip)
 {
 	int ret = 0;
 	u8 *dtb_buf = NULL;

 	aml_chip_dtb = aml_chip;

 	dtb_buf = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
 	if (dtb_buf == NULL) {
 		ret = -1;
 		goto exit_err;
 	}
 	memset(dtb_buf, 0x0, aml_chip_dtb->dtbsize);
 	/*parse partitions table */
 	ret = get_partition_from_dts(dtb_buf);
 	if (ret)
 		pr_info("%s get_partition_from_dts failed\n",  __func__);

 exit_err:
 	kfree(dtb_buf);
 	dtb_buf = NULL;

 	return ret;
 }


 /*****************************************************************************
  * Prototype    : amlnf_detect_dtb_partitions
  *Description  : if 'dtb, write the bad block, we can't erase this block.
  *		So we have to find the 'dtb' address in flash and flag it.
  *Input        : struct amlnand_chip *aml_chip
  *Output       : NULL
  *Return Value :	ret
  *Called By    : amlnand_get_partition_table

  *History        :
  *1.Date         : 2015/10/15
  *	Author       : Fly Mo
  *	Modification : Created function
  *****************************************************************************/
 int amlnf_detect_dtb_partitions(struct aml_nand_chip *aml_chip)
 {
 	return 0;
 }

 /* for blank positions... */
 int aml_nand_update_dtb(struct aml_nand_chip *aml_chip, char *dtb_ptr)
 {
 	return 0;
 }
 #endif
	/*
	* drivers/amlogic/mtd/aml_dtb.c
	*
	* Copyright (C) 2017 Amlogic, Inc. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	*/

	#include "aml_mtd.h"

	#ifndef AML_NAND_UBOOT
	#include<linux/cdev.h>
	#include <linux/device.h>

	#define DTB_NAME "dtb"
	static dev_t amlnf_dtb_no;
	struct cdev amlnf_dtb;
	struct device *dtb_dev_nand;
	struct class *amlnf_dtb_class;
	#endif /* AML_NAND_UBOOT */

	int dtb_erase_blk = -1;

	struct aml_nand_chip *aml_chip_dtb;

	int amlnf_dtb_save(u8 *buf, int len)
	{
	struct mtd_info *mtd = aml_chip_dtb->mtd;
	u8 *dtb_buf = NULL;
	int ret = 0;

	pr_info("%s: ####\n", __func__);
	if (aml_chip_dtb == NULL) {
	pr_info("%s: amlnf not init yet!\n", __func__);
	return -EFAULT;
	}

	if (len > aml_chip_dtb->dtbsize) {
	pr_info("warnning!!! %s: length too much\n", __func__);
	len = aml_chip_dtb->dtbsize;
	/return -EFAULT;/
	}
	dtb_buf = vmalloc(aml_chip_dtb->dtbsize + mtd->writesize);
	if (dtb_buf == NULL) {
	ret = -1;
	goto exit_err;
	}
	memset(dtb_buf, 0, aml_chip_dtb->dtbsize);
	memcpy(dtb_buf, buf, len);
	aml_nand_save_dtb(mtd, dtb_buf);

	exit_err:
	if (dtb_buf) {
	/* kfree(dtb_buf); */
	vfree(dtb_buf);
	dtb_buf = NULL;
	}
	return ret;
	}

	int amlnf_dtb_erase(void)
	{
	int ret = 0;

	if (aml_chip_dtb == NULL) {
	pr_info("%s amlnf not ready yet!\n", __func__);
	return -1;
	}
	return ret;
	}

	int amlnf_dtb_read(u8 *buf, int len)
	{
	struct mtd_info *mtd = aml_chip_dtb->mtd;
	size_t offset = 0;
	u8 *dtb_buf = NULL;
	int ret = 0;

	pr_info("%s: ####\n", __func__);

	if (len > aml_chip_dtb->dtbsize) {
	pr_info("warnning!!! %s dtd length too much\n", __func__);
	len = aml_chip_dtb->dtbsize;
	/return -EFAULT;/
	}
	if (aml_chip_dtb == NULL) {
	memset(buf, 0x0, len);
	pr_info("%s amlnf not ready yet!\n", __func__);
	return 0;
	}

	dtb_buf = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
	if (dtb_buf == NULL) {
	ret = -1;
	goto exit_err;
	}
	memset(dtb_buf, 0, aml_chip_dtb->dtbsize);
	aml_nand_read_dtb(mtd, offset, (u8 *)dtb_buf);
	memcpy(buf, dtb_buf, len);
	exit_err:
	if (dtb_buf) {
	/* kfree(dtb_buf); */
	kfree(dtb_buf);
	dtb_buf = NULL;
	}
	return ret;
	}

	/* under kernel */
	#ifndef AML_NAND_UBOOT
	ssize_t dtb_show(struct class class, struct class_attribute attr,
	char *buf)
	{
	pr_info("dtb_show : #####\n");
	/* fixme, read back and show in log! */
	return 0;
	}

	ssize_t dtb_store(struct class class, struct class_attribute attr,
	const char *buf, size_t count)
	{
	int ret = 0;
	u8 *dtb_ptr = NULL;

	pr_info("dtb_store : #####\n");
	dtb_ptr = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
	if (dtb_ptr == NULL) {
	pr_info("%s: malloc buf failed\n ", __func__);
	return -ENOMEM;
	}
	/* fixme, why read back then write? */
	ret = amlnf_dtb_read(dtb_ptr, aml_chip_dtb->dtbsize);
	if (ret) {
	pr_info("%s: read failed\n", __func__);
	kfree(dtb_ptr);
	return -EFAULT;
	}

	ret = amlnf_dtb_save(dtb_ptr, aml_chip_dtb->dtbsize);
	if (ret) {
	pr_info("%s: save failed\n", __func__);
	kfree(dtb_ptr);
	return -EFAULT;
	}

	pr_info("dtb_store : OK #####\n");
	return count;
	}

	static CLASS_ATTR(nfdtb, 0644, dtb_show, dtb_store);

	int dtb_open(struct inode node, struct file file)
	{
	return 0;
	}

	ssize_t dtb_read(struct file *file,
	char __user *buf,
	size_t count,
	loff_t *ppos)
	{
	u8 *dtb_ptr = NULL;
	/struct nand_flash flash = &aml_chip_dtb->flash;*/
	struct mtd_info *mtd = aml_chip_dtb->mtd;
	ssize_t read_size = 0;
	int ret = 0;

	if (*ppos == aml_chip_dtb->dtbsize)
	return 0;

	if (*ppos >= aml_chip_dtb->dtbsize) {
	pr_info("%s:data access out of space!\n", __func__);
	return -EFAULT;
	}

	dtb_ptr = vmalloc(aml_chip_dtb->dtbsize + mtd->writesize);
	if (dtb_ptr == NULL)
	return -ENOMEM;

	/not need nand_get_device here, mtd->_read_xx will done with it/
	/nand_get_device(mtd, FL_READING);/
	ret = amlnf_dtb_read((u8 *)dtb_ptr, aml_chip_dtb->dtbsize);
	if (ret) {
	pr_info("%s: read failed:%d\n", __func__, ret);
	ret = -EFAULT;
	goto exit;
	}

	if ((*ppos + count) > aml_chip_dtb->dtbsize)
	read_size = aml_chip_dtb->dtbsize - *ppos;
	else
	read_size = count;

	ret = copy_to_user(buf, (dtb_ptr + *ppos), read_size);
	*ppos += read_size;
	exit:
	/nand_release_device(mtd);/
	/* kfree(dtb_ptr); */
	vfree(dtb_ptr);
	return read_size;
	}

	ssize_t dtb_write(struct file *file,
	const char __user *buf,
	size_t count, loff_t *ppos)
	{
	u8 *dtb_ptr = NULL;
	ssize_t write_size = 0;
	/struct nand_flash flash = &aml_chip_dtb->flash;*/
	struct mtd_info *mtd = aml_chip_dtb->mtd;
	int ret = 0;

	if (*ppos == aml_chip_dtb->dtbsize)
	return 0;

	if (*ppos >= aml_chip_dtb->dtbsize) {
	pr_info("%s: data access out of space!\n", __func__);
	return -EFAULT;
	}

	dtb_ptr = vmalloc(aml_chip_dtb->dtbsize + mtd->writesize);
	if (dtb_ptr == NULL)
	return -ENOMEM;

	/not need nand_get_device here, mtd->_read_xx will done with it/
	/nand_get_device(mtd, FL_WRITING);/
	ret = amlnf_dtb_read((u8 *)dtb_ptr, aml_chip_dtb->dtbsize);
	if (ret) {
	pr_info("%s: read failed\n", __func__);
	ret = -EFAULT;
	goto exit;
	}

	if ((*ppos + count) > aml_chip_dtb->dtbsize)
	write_size = aml_chip_dtb->dtbsize - *ppos;
	else
	write_size = count;

	ret = copy_from_user((dtb_ptr + *ppos), buf, write_size);

	ret = amlnf_dtb_save(dtb_ptr, aml_chip_dtb->dtbsize);
	if (ret) {
	pr_info("%s: read failed\n", __func__);
	ret = -EFAULT;
	goto exit;
	}

	*ppos += write_size;
	exit:
	/nand_release_device(mtd);/
	/* kfree(dtb_ptr); */
	vfree(dtb_ptr);
	return write_size;
	}

	long dtb_ioctl(struct file *file, u32 cmd, unsigned long args)
	{
	return 0;
	}

	static const struct file_operations dtb_ops = {
	.open = dtb_open,
	.read = dtb_read,
	.write = dtb_write,
	.unlocked_ioctl = dtb_ioctl,
	};
	#endif /* AML_NAND_UBOOT */

	int amlnf_dtb_init(struct aml_nand_chip *aml_chip)
	{
	int ret = 0;
	u8 *dtb_buf = NULL;

	aml_chip_dtb = aml_chip;

	dtb_buf = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
	if (dtb_buf == NULL) {
	ret = -1;
	goto exit_err;
	}

	memset(dtb_buf, 0x0, aml_chip_dtb->dtbsize);

	#ifndef AML_NAND_UBOOT
	pr_info("%s: register dtb cdev\n", __func__);
	ret = alloc_chrdev_region(&amlnf_dtb_no, 0, 1, DTB_NAME);
	if (ret < 0) {
	pr_info("%s alloc dtb dev_t number failed\n", __func__);
	ret = -1;
	goto exit_err;
	}

	cdev_init(&amlnf_dtb, &dtb_ops);
	amlnf_dtb.owner = THIS_MODULE;
	ret = cdev_add(&amlnf_dtb, amlnf_dtb_no, 1);
	if (ret) {
	pr_info("%s amlnf dtd dev add failed\n", __func__);
	ret = -1;
	goto exit_err1;
	}

	amlnf_dtb_class = class_create(THIS_MODULE, DTB_NAME);
	if (IS_ERR(amlnf_dtb_class)) {
	pr_info("%s: amlnf dtd class add failed\n", __func__);
	ret = -1;
	goto exit_err2;
	}

	ret = class_create_file(amlnf_dtb_class, &class_attr_nfdtb);
	if (ret) {
	pr_info("%s dev add failed\n", __func__);
	ret = -1;
	goto exit_err2;
	}

	dtb_dev_nand = device_create(amlnf_dtb_class,
	NULL,
	amlnf_dtb_no,
	NULL,
	DTB_NAME);
	if (IS_ERR(dtb_dev_nand)) {
	pr_info("%s: device_create failed\n", __func__);
	ret = -1;
	goto exit_err3;
	}

	pr_info("%s: register dtd cdev OK\n", __func__);
	kfree(dtb_buf);
	dtb_buf = NULL;

	return ret;

	exit_err3:
	class_remove_file(amlnf_dtb_class, &class_attr_nfdtb);
	class_destroy(amlnf_dtb_class);
	exit_err2:
	cdev_del(&amlnf_dtb);
	exit_err1:
	unregister_chrdev_region(amlnf_dtb_no, 1);

	#endif /* AML_NAND_UBOOT */
	exit_err:
	kfree(dtb_buf);
	dtb_buf = NULL;
	return ret;
	}

	#ifdef AML_NAND_UBOOT
	int amlnf_dtb_init_partitions(struct aml_nand_chip *aml_chip)
	{
	int ret = 0;
	u8 *dtb_buf = NULL;

	aml_chip_dtb = aml_chip;

	dtb_buf = kzalloc(aml_chip_dtb->dtbsize, GFP_KERNEL);
	if (dtb_buf == NULL) {
	ret = -1;
	goto exit_err;
	}
	memset(dtb_buf, 0x0, aml_chip_dtb->dtbsize);
	/parse partitions table /
	ret = get_partition_from_dts(dtb_buf);
	if (ret)
	pr_info("%s get_partition_from_dts failed\n", __func__);

	exit_err:
	kfree(dtb_buf);
	dtb_buf = NULL;

	return ret;
	}


	/*****************************************************************************
	* Prototype : amlnf_detect_dtb_partitions
	*Description : if 'dtb, write the bad block, we can't erase this block.
	* So we have to find the 'dtb' address in flash and flag it.
	Input : struct amlnand_chip aml_chip
	*Output : NULL
	*Return Value : ret
	*Called By : amlnand_get_partition_table

	*History :
	*1.Date : 2015/10/15
	* Author : Fly Mo
	* Modification : Created function
	*****************************************************************************/
	int amlnf_detect_dtb_partitions(struct aml_nand_chip *aml_chip)
	{
	return 0;
	}

	/* for blank positions... */
	int aml_nand_update_dtb(struct aml_nand_chip aml_chip, char dtb_ptr)
	{
	return 0;
	}
	#endif