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mtd: Add MTD VFS wrapper for use with DevFS

pr/rotary
Joakim Nohlgård 6 years ago committed by Vincent Dupont
parent
commit
6d3304f52c
  1. 10
      drivers/include/mtd.h
  2. 139
      drivers/mtd/mtd-vfs.c

10
drivers/include/mtd.h

@ -23,6 +23,9 @@
#define MTD_H
#include <stdint.h>
#if MODULE_VFS
#include "vfs.h"
#endif
#ifdef __cplusplus
extern "C" {
@ -225,6 +228,13 @@ int mtd_erase(mtd_dev_t *mtd, uint32_t addr, uint32_t count);
*/
int mtd_power(mtd_dev_t *mtd, enum mtd_power_state power);
#if defined(MODULE_VFS) || defined(DOXYGEN)
/**
* @brief MTD driver for VFS
*/
extern const vfs_file_ops_t mtd_vfs_ops;
#endif
#ifdef __cplusplus
}
#endif

139
drivers/mtd/mtd-vfs.c

@ -0,0 +1,139 @@
/*
* Copyright (C) 2016 Eistec AB
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
#if MODULE_VFS
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include "mtd.h"
#include "vfs.h"
/**
* @ingroup mtd
* @{
*
* @file
*
* @brief MTD generic VFS operations
*
* This allows the MTD driver to register as a node on DevFS
*
* See boards/mulle or tests/unittests/tests-devfs for examples on how to use.
*
* Tested with mtd_spi_nor on Mulle
*
* @author Joakim Nohlgård <joakim.nohlgard@eistec.se>
*/
static int mtd_vfs_fstat(vfs_file_t *filp, struct stat *buf);
static off_t mtd_vfs_lseek(vfs_file_t *filp, off_t off, int whence);
static ssize_t mtd_vfs_read(vfs_file_t *filp, void *dest, size_t nbytes);
static ssize_t mtd_vfs_write(vfs_file_t *filp, const void *src, size_t nbytes);
const vfs_file_ops_t mtd_vfs_ops = {
.fstat = mtd_vfs_fstat,
.lseek = mtd_vfs_lseek,
.read = mtd_vfs_read,
.write = mtd_vfs_write,
};
static int mtd_vfs_fstat(vfs_file_t *filp, struct stat *buf)
{
if (buf == NULL) {
return -EFAULT;
}
mtd_dev_t *mtd = filp->private_data.ptr;
if (mtd == NULL) {
return -EFAULT;
}
buf->st_nlink = 1;
buf->st_size = mtd->page_size * mtd->sector_count * mtd->pages_per_sector;
return 0;
}
static off_t mtd_vfs_lseek(vfs_file_t *filp, off_t off, int whence)
{
mtd_dev_t *mtd = filp->private_data.ptr;
if (mtd == NULL) {
return -EFAULT;
}
switch (whence) {
case SEEK_SET:
break;
case SEEK_CUR:
off += filp->pos;
break;
case SEEK_END:
off += mtd->page_size * mtd->sector_count * mtd->pages_per_sector;
break;
default:
return -EINVAL;
}
if (off < 0) {
/* the resulting file offset would be negative */
return -EINVAL;
}
/* POSIX allows seeking past the end of the file */
filp->pos = off;
return off;
}
static ssize_t mtd_vfs_read(vfs_file_t *filp, void *dest, size_t nbytes)
{
mtd_dev_t *mtd = filp->private_data.ptr;
if (mtd == NULL) {
return -EFAULT;
}
uint32_t size = mtd->page_size * mtd->sector_count * mtd->pages_per_sector;
uint32_t src = filp->pos;
if (src >= size) {
return 0;
}
if ((src + nbytes) > size) {
nbytes = size - src;
}
int res = mtd_read(mtd, dest, src, nbytes);
if (res < 0) {
return res;
}
/* Advance file position */
filp->pos += res;
return res;
}
static ssize_t mtd_vfs_write(vfs_file_t *filp, const void *src, size_t nbytes)
{
mtd_dev_t *mtd = filp->private_data.ptr;
if (mtd == NULL) {
return -EFAULT;
}
uint32_t size = mtd->page_size * mtd->sector_count * mtd->pages_per_sector;
uint32_t dest = filp->pos;
if (dest >= size) {
/* attempt to write outside the device memory */
return -ENOSPC;
}
if ((dest + nbytes) > size) {
nbytes = size - dest;
}
int res = mtd_write(mtd, src, dest, nbytes);
if (res < 0) {
return res;
}
/* Advance file position */
filp->pos += res;
return res;
}
/** @} */
#else
typedef int dont_be_pedantic;
#endif /* MODULE_VFS */
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