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/****************************************************************************
* drivers/mtd/at25.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/signal.h>
#include <nuttx/fs/ioctl.h>
#include <nuttx/spi/spi.h>
#include <nuttx/mtd/mtd.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_AT25_SPIMODE
# define CONFIG_AT25_SPIMODE SPIDEV_MODE0
#endif
#ifndef CONFIG_AT25_SPIFREQUENCY
# define CONFIG_AT25_SPIFREQUENCY 20000000
#endif
/* AT25 Registers ***********************************************************/
/* Identification register values */
#define AT25_MANUFACTURER 0x1f
#define AT25_AT25DF081A_TYPE 0x45 /* 8 M-bit */
#define AT25_AT25DF321_TYPE 0x47 /* 32 M-bit */
/* AT25DF081A capacity is 1,048,575 bytes:
* (16 sectors) * (65,536 bytes per sector)
* (4096 pages) * (256 bytes per page)
*/
#define AT25_AT25DF081A_SECTOR_SHIFT 12 /* Sector size 1 << 12 = 4096 */
#define AT25_AT25DF081A_NSECTORS 256
#define AT25_AT25DF081A_PAGE_SHIFT 9 /* Page size 1 << 8 = 256 */
#define AT25_AT25DF081A_NPAGES 2048
/* AT25DF321 capacity is 4,194,304 bytes:
* (64 sectors) * (65,536 bytes per sector)
* (16384 pages) * (256 bytes per page)
*/
#define AT25_AT25DF321_SECTOR_SHIFT 12 /* Sector size 1 << 12 = 4096 */
#define AT25_AT25DF321_NSECTORS 1024
#define AT25_AT25DF321_PAGE_SHIFT 9 /* Page size 1 << 9 = 512 */
#define AT25_AT25DF321_NPAGES 8192
/* Instructions */
/* Command Value N Description Addr Dummy Data */
#define AT25_WREN 0x06 /* 1 Write Enable 0 0 0 */
#define AT25_WRDI 0x04 /* 1 Write Disable 0 0 0 */
#define AT25_RDID 0x9f /* 1 Read Identification 0 0 1-3 */
#define AT25_RDSR 0x05 /* 1 Read Status Register 0 0 >=1 */
#define AT25_WRSR 0x01 /* 1 Write Status Register 0 0 1 */
#define AT25_READ 0x03 /* 1 Read Data Bytes 3 0 >=1 */
#define AT25_FAST_READ 0x0b /* 1 Higher speed read 3 1 >=1 */
#define AT25_PP 0x02 /* 1 Page Program 3 0 1-256 */
#define AT25_SE 0x20 /* 1 Sector Erase 3 0 0 */
#define AT25_BE 0xc7 /* 1 Bulk Erase 0 0 0 */
#define AT25_DP 0xb9 /* 2 Deep power down 0 0 0 */
#define AT25_RES 0xab /* 2 Read Electronic Signature 0 3 >=1 */
/* Status register bit definitions */
#define AT25_SR_BUSY (1 << 0) /* Bit 0: Ready/Busy Status */
#define AT25_SR_WEL (1 << 1) /* Bit 1: Write enable latch bit */
#define AT25_SR_SWP_SHIFT (2) /* Bits 2-3: Software protection */
#define AT25_SR_SWP_MASK (3 << AT25_SR_SWP_SHIFT)
#define AT25_SR_WPP (1 << 4) /* Bit 4: Write Protect (/WP) Pin Status */
#define AT25_SR_EPE (1 << 5) /* Bit 5: Erase/program error */
/* Bit 6: Reserved */
#define AT25_SR_SPRL (1 << 7) /* Bit 7: Sector Protection Registers Locked */
#define AT25_SR_UNPROT 0x00 /* Global unprotect command */
#define AT25_DUMMY 0xa5
/****************************************************************************
* Private Types
****************************************************************************/
/* This type represents the state of the MTD device. The struct mtd_dev_s
* must appear at the beginning of the definition so that you can freely
* cast between pointers to struct mtd_dev_s and struct at25_dev_s.
*/
struct at25_dev_s
{
struct mtd_dev_s mtd; /* MTD interface */
FAR struct spi_dev_s *dev; /* Saved SPI interface instance */
uint8_t sectorshift; /* 16 or 18 */
uint8_t pageshift; /* 8 */
uint16_t nsectors; /* 128 or 64 */
uint32_t npages; /* 32,768 or 65,536 */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Helpers */
static void at25_lock(FAR struct spi_dev_s *dev);
static inline void at25_unlock(FAR struct spi_dev_s *dev);
static inline int at25_readid(struct at25_dev_s *priv);
static void at25_waitwritecomplete(struct at25_dev_s *priv);
static void at25_writeenable(struct at25_dev_s *priv);
static inline void at25_sectorerase(struct at25_dev_s *priv,
off_t offset);
static inline int at25_bulkerase(struct at25_dev_s *priv);
static inline void at25_pagewrite(struct at25_dev_s *priv,
FAR const uint8_t *buffer,
off_t offset);
/* MTD driver methods */
static int at25_erase(FAR struct mtd_dev_s *dev,
off_t startblock,
size_t nblocks);
static ssize_t at25_bread(FAR struct mtd_dev_s *dev,
off_t startblock,
size_t nblocks,
FAR uint8_t *buf);
static ssize_t at25_bwrite(FAR struct mtd_dev_s *dev,
off_t startblock,
size_t nblocks,
FAR const uint8_t *buf);
static ssize_t at25_read(FAR struct mtd_dev_s *dev,
off_t offset,
size_t nbytes,
FAR uint8_t *buffer);
static int at25_ioctl(FAR struct mtd_dev_s *dev,
int cmd,
unsigned long arg);
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: at25_lock
****************************************************************************/
static void at25_lock(FAR struct spi_dev_s *dev)
{
/* On SPI buses where there are multiple devices, it will be necessary to
* lock SPI to have exclusive access to the buses for a sequence of
* transfers. The bus should be locked before the chip is selected.
*
* This is a blocking call and will not return until we have exclusive
* access to the SPI bus.
* We will retain that exclusive access until the bus is unlocked.
*/
SPI_LOCK(dev, true);
/* After locking the SPI bus, the we also need call the setfrequency,
* setbits, and setmode methods to make sure that the SPI is properly
* configured for the device.
* If the SPI bus is being shared, then it may have been left in an
* incompatible state.
*/
SPI_SETMODE(dev, CONFIG_AT25_SPIMODE);
SPI_SETBITS(dev, 8);
SPI_HWFEATURES(dev, 0);
SPI_SETFREQUENCY(dev, CONFIG_AT25_SPIFREQUENCY);
}
/****************************************************************************
* Name: at25_unlock
****************************************************************************/
static inline void at25_unlock(FAR struct spi_dev_s *dev)
{
SPI_LOCK(dev, false);
}
/****************************************************************************
* Name: at25_readid
****************************************************************************/
static inline int at25_readid(struct at25_dev_s *priv)
{
uint16_t manufacturer;
uint16_t memory;
finfo("priv: %p\n", priv);
/* Lock the SPI bus, configure the bus, and select this FLASH part. */
at25_lock(priv->dev);
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send the "Read ID (RDID)" command and read the first three ID bytes */
SPI_SEND(priv->dev, AT25_RDID);
manufacturer = SPI_SEND(priv->dev, AT25_DUMMY);
memory = SPI_SEND(priv->dev, AT25_DUMMY);
/* Deselect the FLASH and unlock the bus */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
at25_unlock(priv->dev);
finfo("manufacturer: %02x memory: %02x\n",
manufacturer, memory);
/* Check for a valid manufacturer and memory type */
if (manufacturer == AT25_MANUFACTURER &&
memory == AT25_AT25DF081A_TYPE)
{
priv->sectorshift = AT25_AT25DF081A_SECTOR_SHIFT;
priv->nsectors = AT25_AT25DF081A_NSECTORS;
priv->pageshift = AT25_AT25DF081A_PAGE_SHIFT;
priv->npages = AT25_AT25DF081A_NPAGES;
return OK;
}
else if (manufacturer == AT25_MANUFACTURER &&
memory == AT25_AT25DF321_TYPE)
{
priv->sectorshift = AT25_AT25DF321_SECTOR_SHIFT;
priv->nsectors = AT25_AT25DF321_NSECTORS;
priv->pageshift = AT25_AT25DF321_PAGE_SHIFT;
priv->npages = AT25_AT25DF321_NPAGES;
return OK;
}
return -ENODEV;
}
/****************************************************************************
* Name: at25_waitwritecomplete
****************************************************************************/
static void at25_waitwritecomplete(struct at25_dev_s *priv)
{
uint8_t status;
/* Loop as long as the memory is busy with a write cycle */
do
{
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send "Read Status Register (RDSR)" command */
SPI_SEND(priv->dev, AT25_RDSR);
/* Send a dummy byte to generate the clock needed to shift out
* the status
*/
status = SPI_SEND(priv->dev, AT25_DUMMY);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
/* Given that writing could take up to few tens of milliseconds,
* and erasing could take more.
* The following short delay in the "busy" case will allow other
* peripherals to access the SPI bus.
*/
if ((status & AT25_SR_BUSY) != 0)
{
at25_unlock(priv->dev);
nxsched_usleep(10000);
at25_lock(priv->dev);
}
}
while ((status & AT25_SR_BUSY) != 0);
if (status & AT25_SR_EPE)
{
ferr("ERROR: Write error, status: 0x%02x\n", status);
}
finfo("Complete, status: 0x%02x\n", status);
}
/****************************************************************************
* Name: at25_writeenable
****************************************************************************/
static void at25_writeenable(struct at25_dev_s *priv)
{
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
SPI_SEND(priv->dev, AT25_WREN);
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
finfo("Enabled\n");
}
/****************************************************************************
* Name: at25_sectorerase
****************************************************************************/
static inline void at25_sectorerase(struct at25_dev_s *priv, off_t sector)
{
off_t offset = sector << priv->sectorshift;
finfo("sector: %08lx\n", (long)sector);
/* Wait for any preceding write to complete. We could simplify things by
* perform this wait at the end of each write operation (rather than at
* the beginning of ALL operations), but have the wait first will slightly
* improve performance.
*/
at25_waitwritecomplete(priv);
/* Send write enable instruction */
at25_writeenable(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send the "Sector Erase (SE)" instruction */
SPI_SEND(priv->dev, AT25_SE);
/* Send the sector offset high byte first. For all of the supported
* parts, the sector number is completely contained in the first byte
* and the values used in the following two bytes don't really matter.
*/
SPI_SEND(priv->dev, (offset >> 16) & 0xff);
SPI_SEND(priv->dev, (offset >> 8) & 0xff);
SPI_SEND(priv->dev, offset & 0xff);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
finfo("Erased\n");
}
/****************************************************************************
* Name: at25_bulkerase
****************************************************************************/
static inline int at25_bulkerase(struct at25_dev_s *priv)
{
finfo("priv: %p\n", priv);
/* Wait for any preceding write to complete. We could simplify things by
* perform this wait at the end of each write operation (rather than at
* the beginning of ALL operations), but have the wait first will slightly
* improve performance.
*/
at25_waitwritecomplete(priv);
/* Send write enable instruction */
at25_writeenable(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send the "Bulk Erase (BE)" instruction */
SPI_SEND(priv->dev, AT25_BE);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
finfo("Return: OK\n");
return OK;
}
/****************************************************************************
* Name: at25_pagewrite
****************************************************************************/
static inline void at25_pagewrite(struct at25_dev_s *priv,
FAR const uint8_t *buffer,
off_t page)
{
off_t offset = page << 8;
finfo("page: %08lx offset: %08lx\n", (long)page, (long)offset);
/* Wait for any preceding write to complete. We could simplify things by
* perform this wait at the end of each write operation (rather than at
* the beginning of ALL operations), but have the wait first will slightly
* improve performance.
*/
at25_waitwritecomplete(priv);
/* Enable the write access to the FLASH */
at25_writeenable(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send "Page Program (PP)" command */
SPI_SEND(priv->dev, AT25_PP);
/* Send the page offset high byte first. */
SPI_SEND(priv->dev, (offset >> 16) & 0xff);
SPI_SEND(priv->dev, (offset >> 8) & 0xff);
SPI_SEND(priv->dev, offset & 0xff);
/* Then write the specified number of bytes */
SPI_SNDBLOCK(priv->dev, buffer, 256);
/* Deselect the FLASH: Chip Select high */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
finfo("Written\n");
}
/****************************************************************************
* Name: at25_erase
****************************************************************************/
static int at25_erase(FAR struct mtd_dev_s *dev,
off_t startblock,
size_t nblocks)
{
FAR struct at25_dev_s *priv = (FAR struct at25_dev_s *)dev;
size_t blocksleft = nblocks;
finfo("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks);
/* Lock access to the SPI bus until we complete the erase */
at25_lock(priv->dev);
while (blocksleft-- > 0)
{
/* Erase each sector */
at25_sectorerase(priv, startblock);
startblock++;
}
at25_unlock(priv->dev);
return (int)nblocks;
}
/****************************************************************************
* Name: at25_bread
****************************************************************************/
static ssize_t at25_bread(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks,
FAR uint8_t *buffer)
{
FAR struct at25_dev_s *priv = (FAR struct at25_dev_s *)dev;
ssize_t nbytes;
finfo("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks);
/* On this device, we can handle the block read just like the byte-oriented
* read
*/
nbytes = at25_read(dev, startblock << priv->pageshift,
nblocks << priv->pageshift, buffer);
if (nbytes > 0)
{
return nbytes >> priv->pageshift;
}
return (int)nbytes;
}
/****************************************************************************
* Name: at25_bwrite
****************************************************************************/
static ssize_t at25_bwrite(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR const uint8_t *buffer)
{
FAR struct at25_dev_s *priv = (FAR struct at25_dev_s *)dev;
size_t blocksleft = nblocks;
finfo("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks);
/* Lock the SPI bus and write each page to FLASH */
at25_lock(priv->dev);
while (blocksleft-- > 0)
{
at25_pagewrite(priv, buffer, startblock * 2);
at25_pagewrite(priv, buffer + 256, startblock * 2 + 1);
buffer += 1 << priv->pageshift;
startblock++;
}
at25_unlock(priv->dev);
return nblocks;
}
/****************************************************************************
* Name: at25_read
****************************************************************************/
static ssize_t at25_read(FAR struct mtd_dev_s *dev,
off_t offset,
size_t nbytes,
FAR uint8_t *buffer)
{
FAR struct at25_dev_s *priv = (FAR struct at25_dev_s *)dev;
finfo("offset: %08lx nbytes: %d\n", (long)offset, (int)nbytes);
/* Lock the SPI bus NOW because the following call must be executed with
* the bus locked.
*/
at25_lock(priv->dev);
/* Wait for any preceding write to complete. We could simplify things by
* perform this wait at the end of each write operation (rather than at
* the beginning of ALL operations), but have the wait first will slightly
* improve performance.
*/
at25_waitwritecomplete(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send "Read from Memory " instruction */
SPI_SEND(priv->dev, AT25_READ);
/* Send the page offset high byte first. */
SPI_SEND(priv->dev, (offset >> 16) & 0xff);
SPI_SEND(priv->dev, (offset >> 8) & 0xff);
SPI_SEND(priv->dev, offset & 0xff);
/* Then read all of the requested bytes */
SPI_RECVBLOCK(priv->dev, buffer, nbytes);
/* Deselect the FLASH and unlock the SPI bus */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
at25_unlock(priv->dev);
finfo("return nbytes: %d\n", (int)nbytes);
return nbytes;
}
/****************************************************************************
* Name: at25_ioctl
****************************************************************************/
static int at25_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
{
FAR struct at25_dev_s *priv = (FAR struct at25_dev_s *)dev;
int ret = -EINVAL; /* Assume good command with bad parameters */
finfo("cmd: %d\n", cmd);
switch (cmd)
{
case MTDIOC_GEOMETRY:
{
FAR struct mtd_geometry_s *geo =
(FAR struct mtd_geometry_s *)((uintptr_t)arg);
if (geo != NULL)
{
memset(geo, 0, sizeof(*geo));
/* Populate the geometry structure with information need to
* know the capacity and how to access the device.
*
* NOTE:
* that the device is treated as though it where just an array
* of fixed size blocks.
* That is most likely not true, but the client will expect the
* device logic to do whatever is necessary to make it appear
* so.
*/
geo->blocksize = (1 << priv->pageshift);
geo->erasesize = (1 << priv->sectorshift);
geo->neraseblocks = priv->nsectors;
ret = OK;
finfo("blocksize: %" PRId32 " erasesize: %" PRId32
" neraseblocks: %" PRId32 "\n",
geo->blocksize, geo->erasesize, geo->neraseblocks);
}
}
break;
case BIOC_PARTINFO:
{
FAR struct partition_info_s *info =
(FAR struct partition_info_s *)arg;
if (info != NULL)
{
info->numsectors = priv->nsectors <<
(priv->sectorshift - priv->pageshift);
info->sectorsize = 1 << priv->pageshift;
info->startsector = 0;
info->parent[0] = '\0';
ret = OK;
}
}
break;
case MTDIOC_BULKERASE:
{
/* Erase the entire device */
at25_lock(priv->dev);
ret = at25_bulkerase(priv);
at25_unlock(priv->dev);
}
break;
default:
ret = -ENOTTY; /* Bad command */
break;
}
finfo("return %d\n", ret);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: at25_initialize
*
* Description:
* Create an initialize MTD device instance. MTD devices are not registered
* in the file system, but are created as instances that can be bound to
* other functions (such as a block or character driver front end).
*
****************************************************************************/
FAR struct mtd_dev_s *at25_initialize(FAR struct spi_dev_s *dev)
{
FAR struct at25_dev_s *priv;
int ret;
finfo("dev: %p\n", dev);
/* Allocate a state structure (we allocate the structure instead of using
* a fixed, static allocation so that we can handle multiple FLASH devices.
* The current implementation would handle only one FLASH part per SPI
* device (only because of the SPIDEV_FLASH(0) definition) and so would
* have to be extended to handle multiple FLASH parts on the same SPI bus.
*/
priv = kmm_zalloc(sizeof(struct at25_dev_s));
if (priv)
{
/* Initialize the allocated structure (unsupported methods were
* nullified by kmm_zalloc).
*/
priv->mtd.erase = at25_erase;
priv->mtd.bread = at25_bread;
priv->mtd.bwrite = at25_bwrite;
priv->mtd.read = at25_read;
priv->mtd.ioctl = at25_ioctl;
priv->mtd.name = "at25";
priv->dev = dev;
/* Deselect the FLASH */
SPI_SELECT(dev, SPIDEV_FLASH(0), false);
/* Identify the FLASH chip and get its capacity */
ret = at25_readid(priv);
if (ret != OK)
{
/* Unrecognized!
* Discard all of that work we just did and return NULL
*/
ferr("ERROR: Unrecognized\n");
kmm_free(priv);
return NULL;
}
else
{
/* Unprotect all sectors */
at25_writeenable(priv);
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
SPI_SEND(priv->dev, AT25_WRSR);
SPI_SEND(priv->dev, AT25_SR_UNPROT);
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
}
}
/* Return the implementation-specific state structure as the MTD device */
finfo("Return %p\n", priv);
return (FAR struct mtd_dev_s *)priv;
}