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nuttx/drivers/mtd/sst25xx.c

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/************************************************************************************
* drivers/mtd/sst25xx.c
* Driver for SPI-based SST25VF parts 64MBit and larger.
*
* For smaller SST25 parts, use the sst25.c driver instead as support
* a different program mechanism (byte or word writing vs page writing
* supported in this driver).
*
* Copyright (C) 2009-2011, 2013 Gregory Nutt. All rights reserved.
* Author: Ken Pettit <pettitkd@gmail.com>
*
* Copied from / based on m25px.c and sst25.c drivers written by
* Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <sys/types.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/fs/ioctl.h>
#include <nuttx/spi/spi.h>
#include <nuttx/mtd/mtd.h>
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/* Configuration ********************************************************************/
/* Per the data sheet, SST25 parts can be driven with either SPI mode 0 (CPOL=0 and
* CPHA=0) or mode 3 (CPOL=1 and CPHA=1). So you may need to specify
* CONFIG_SST25XX_SPIMODE to select the best mode for your device. If
* CONFIG_SST25XX_SPIMODE is not defined, mode 0 will be used.
*/
#ifndef CONFIG_SST25XX_SPIMODE
# define CONFIG_SST25XX_SPIMODE SPIDEV_MODE0
#endif
/* SPI Frequency. May be up to 25MHz. */
#ifndef CONFIG_SST25XX_SPIFREQUENCY
# define CONFIG_SST25XX_SPIFREQUENCY 20000000
#endif
/* Various manufacturers may have produced the parts. 0xBF is the manufacturer ID
* for the SST serial FLASH.
*/
#ifndef CONFIG_SST25XX_MANUFACTURER
# define CONFIG_SST25XX_MANUFACTURER 0xBF
#endif
#ifndef CONFIG_SST25XX_MEMORY_TYPE
# define CONFIG_SST25XX_MEMORY_TYPE 0x25
#endif
/* SST25 Registers *******************************************************************/
/* Indentification register values */
#define SST25_MANUFACTURER CONFIG_SST25XX_MANUFACTURER
#define SST25_MEMORY_TYPE CONFIG_SST25XX_MEMORY_TYPE
#define SST25_SST25064_CAPACITY 0x4b /* 64 M-bit */
/* SST25064 capacity is 8,388,608 bytes:
* (2,0548 sectors) * (4,096 bytes per sector)
* (32,768 pages) * (256 bytes per page)
*/
#define SST25_SST25064_SECTOR_SHIFT 12 /* Sector size 1 << 15 = 65,536 */
#define SST25_SST25064_NSECTORS 2048
#define SST25_SST25064_PAGE_SHIFT 8 /* Page size 1 << 8 = 256 */
#define SST25_SST25064_NPAGES 32768
/* Instructions */
/* Command Value N Description Addr Dummy Data */
#define SST25_WREN 0x06 /* 1 Write Enable 0 0 0 */
#define SST25_WRDI 0x04 /* 1 Write Disable 0 0 0 */
#define SST25_RDID 0x9f /* 1 Read Identification 0 0 1-3 */
#define SST25_RDSR 0x05 /* 1 Read Status Register 0 0 >=1 */
#define SST25_EWSR 0x50 /* 1 Write enable status 0 0 0 */
#define SST25_WRSR 0x01 /* 1 Write Status Register 0 0 1 */
#define SST25_READ 0x03 /* 1 Read Data Bytes 3 0 >=1 */
#define SST25_FAST_READ 0x0b /* 1 Higher speed read 3 1 >=1 */
#define SST25_PP 0x02 /* 1 Page Program 3 0 1-256 */
#define SST25_SE 0x20 /* 1 Sector Erase 3 0 0 */
#define SST25_BE32 0x52 /* 2 32K Block Erase 3 0 0 */
#define SST25_BE64 0xD8 /* 2 64K Block Erase 3 0 0 */
#define SST25_BE 0xc7 /* 1 Bulk Erase 0 0 0 */
#define SST25_RES 0xab /* 1 Read Electronic Signature 0 3 >=1 */
/* NOTE 1: All parts.
* NOTE 2: In SST25064 terminology, 0x52 and 0xd8 are block erase and 0x20
* is a sector erase. Block erase provides a faster way to erase
* multiple 4K sectors at once.
*/
/* Status register bit definitions */
#define SST25_SR_WIP (1 << 0) /* Bit 0: Write in progress bit */
#define SST25_SR_WEL (1 << 1) /* Bit 1: Write enable latch bit */
#define SST25_SR_BP_SHIFT (2) /* Bits 2-5: Block protect bits */
#define SST25_SR_BP_MASK (15 << SST25_SR_BP_SHIFT)
# define SST25_SR_BP_NONE (0 << SST25_SR_BP_SHIFT) /* Unprotected */
# define SST25_SR_BP_UPPER128th (1 << SST25_SR_BP_SHIFT) /* Upper 128th */
# define SST25_SR_BP_UPPER64th (2 << SST25_SR_BP_SHIFT) /* Upper 64th */
# define SST25_SR_BP_UPPER32nd (3 << SST25_SR_BP_SHIFT) /* Upper 32nd */
# define SST25_SR_BP_UPPER16th (4 << SST25_SR_BP_SHIFT) /* Upper 16th */
# define SST25_SR_BP_UPPER8th (5 << SST25_SR_BP_SHIFT) /* Upper 8th */
# define SST25_SR_BP_UPPERQTR (6 << SST25_SR_BP_SHIFT) /* Upper quarter */
# define SST25_SR_BP_UPPERHALF (7 << SST25_SR_BP_SHIFT) /* Upper half */
# define SST25_SR_BP_ALL (8 << SST25_SR_BP_SHIFT) /* All sectors */
#define SST_SR_SEC (1 << 6) /* Security ID status */
#define SST25_SR_SRWD (1 << 7) /* Bit 7: Status register write protect */
#define SST25_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 sst25xx_dev_s.
*/
struct sst25xx_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 */
uint8_t lastwaswrite; /* Indicates if last operation was write */
};
/************************************************************************************
* Private Function Prototypes
************************************************************************************/
/* Helpers */
static void sst25xx_lock(FAR struct spi_dev_s *dev);
static inline void sst25xx_unlock(FAR struct spi_dev_s *dev);
static inline int sst25xx_readid(struct sst25xx_dev_s *priv);
static void sst25xx_waitwritecomplete(struct sst25xx_dev_s *priv);
static void sst25xx_writeenable(struct sst25xx_dev_s *priv);
static inline void sst25xx_sectorerase(struct sst25xx_dev_s *priv, off_t offset, uint8_t type);
static inline int sst25xx_bulkerase(struct sst25xx_dev_s *priv);
static inline void sst25xx_pagewrite(struct sst25xx_dev_s *priv, FAR const uint8_t *buffer,
off_t offset);
/* MTD driver methods */
static int sst25xx_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks);
static ssize_t sst25xx_bread(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR uint8_t *buf);
static ssize_t sst25xx_bwrite(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR const uint8_t *buf);
static ssize_t sst25xx_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR uint8_t *buffer);
#ifdef CONFIG_MTD_BYTE_WRITE
static ssize_t sst25xx_write(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR const uint8_t *buffer);
#endif
static int sst25xx_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg);
/************************************************************************************
* Private Data
************************************************************************************/
/************************************************************************************
* Private Functions
************************************************************************************/
/************************************************************************************
* Name: sst25xx_lock
************************************************************************************/
static void sst25xx_lock(FAR struct spi_dev_s *dev)
{
/* On SPI busses where there are multiple devices, it will be necessary to
* lock SPI to have exclusive access to the busses 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 exclusiv access to
* the SPI buss. We will retain that exclusive access until the bus is unlocked.
*/
(void)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 buss is being shared, then it may have been left in an incompatible
* state.
*/
SPI_SETMODE(dev, CONFIG_SST25XX_SPIMODE);
SPI_SETBITS(dev, 8);
(void)SPI_HWFEATURES(dev, 0);
(void)SPI_SETFREQUENCY(dev, CONFIG_SST25XX_SPIFREQUENCY);
}
/************************************************************************************
* Name: sst25xx_unlock
************************************************************************************/
static inline void sst25xx_unlock(FAR struct spi_dev_s *dev)
{
(void)SPI_LOCK(dev, false);
}
/************************************************************************************
* Name: sst25xx_readid
************************************************************************************/
static inline int sst25xx_readid(struct sst25xx_dev_s *priv)
{
uint16_t manufacturer;
uint16_t memory;
uint16_t capacity;
fvdbg("priv: %p\n", priv);
/* Lock the SPI bus, configure the bus, and select this FLASH part. */
sst25xx_lock(priv->dev);
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send the "Read ID (RDID)" command and read the first three ID bytes */
(void)SPI_SEND(priv->dev, SST25_RDID);
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
manufacturer = SPI_SEND(priv->dev, SST25_DUMMY);
memory = SPI_SEND(priv->dev, SST25_DUMMY);
capacity = SPI_SEND(priv->dev, SST25_DUMMY);
/* Deselect the FLASH and unlock the bus */
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
sst25xx_unlock(priv->dev);
fvdbg("manufacturer: %02x memory: %02x capacity: %02x\n",
manufacturer, memory, capacity);
/* Check for a valid manufacturer and memory type */
if (manufacturer == SST25_MANUFACTURER && memory == SST25_MEMORY_TYPE)
{
/* Okay.. is it a FLASH capacity that we understand? */
if (capacity == SST25_SST25064_CAPACITY)
{
/* Save the FLASH geometry */
priv->sectorshift = SST25_SST25064_SECTOR_SHIFT;
priv->nsectors = SST25_SST25064_NSECTORS;
priv->pageshift = SST25_SST25064_PAGE_SHIFT;
priv->npages = SST25_SST25064_NPAGES;
return OK;
}
}
return -ENODEV;
}
/************************************************************************************
* Name: sst25xx_waitwritecomplete
************************************************************************************/
static void sst25xx_waitwritecomplete(struct sst25xx_dev_s *priv)
{
uint8_t status;
/* No need to check if no write / erase was done */
#if 0
if (!priv->lastwaswrite)
{
return;
}
#endif
/* Loop as long as the memory is busy with a write cycle */
do
{
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send "Read Status Register (RDSR)" command */
(void)SPI_SEND(priv->dev, SST25_RDSR);
/* Send a dummy byte to generate the clock needed to shift out the status */
status = SPI_SEND(priv->dev, SST25_DUMMY);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH, 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 & SST25_SR_WIP) != 0)
{
sst25xx_unlock(priv->dev);
usleep(1000);
sst25xx_lock(priv->dev);
}
}
while ((status & SST25_SR_WIP) != 0);
priv->lastwaswrite = false;
fvdbg("Complete\n");
}
/************************************************************************************
* Name: sst25xx_writeenable
************************************************************************************/
static void sst25xx_writeenable(struct sst25xx_dev_s *priv)
{
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send "Write Enable (WREN)" command */
(void)SPI_SEND(priv->dev, SST25_WREN);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
fvdbg("Enabled\n");
}
/************************************************************************************
* Name: sst25xx_unprotect
************************************************************************************/
static void sst25xx_unprotect(struct sst25xx_dev_s *priv)
{
/* Send "Write enable status (EWSR)" */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
(void)SPI_SEND(priv->dev, SST25_EWSR);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
/* Send "Write status (WRSR)" */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
SPI_SEND(priv->dev, SST25_WRSR);
/* Followed by the new status value */
SPI_SEND(priv->dev, 0);
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
}
/************************************************************************************
* Name: sst25xx_sectorerase
************************************************************************************/
static void sst25xx_sectorerase(struct sst25xx_dev_s *priv, off_t sector, uint8_t type)
{
off_t offset;
offset = sector << priv->sectorshift;
fvdbg("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.
*/
sst25xx_waitwritecomplete(priv);
/* Send write enable instruction */
sst25xx_writeenable(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send the "Sector Erase (SE)" or Sub-Sector Erase (SSE) instruction
* that was passed in as the erase type.
*/
(void)SPI_SEND(priv->dev, type);
/* 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.
*/
(void)SPI_SEND(priv->dev, (offset >> 16) & 0xff);
(void)SPI_SEND(priv->dev, (offset >> 8) & 0xff);
(void)SPI_SEND(priv->dev, offset & 0xff);
priv->lastwaswrite = true;
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
fvdbg("Erased\n");
}
/************************************************************************************
* Name: sst25xx_bulkerase
************************************************************************************/
static inline int sst25xx_bulkerase(struct sst25xx_dev_s *priv)
{
fvdbg("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.
*/
sst25xx_waitwritecomplete(priv);
/* Send write enable instruction */
sst25xx_writeenable(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send the "Bulk Erase (BE)" instruction */
(void)SPI_SEND(priv->dev, SST25_BE);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
sst25xx_waitwritecomplete(priv);
fvdbg("Return: OK\n");
return OK;
}
/************************************************************************************
* Name: sst25xx_pagewrite
************************************************************************************/
static inline void sst25xx_pagewrite(struct sst25xx_dev_s *priv, FAR const uint8_t *buffer,
off_t page)
{
off_t offset = page << priv->pageshift;
fvdbg("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.
*/
sst25xx_waitwritecomplete(priv);
/* Enable the write access to the FLASH */
sst25xx_writeenable(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send "Page Program (PP)" command */
(void)SPI_SEND(priv->dev, SST25_PP);
/* Send the page offset high byte first. */
(void)SPI_SEND(priv->dev, (offset >> 16) & 0xff);
(void)SPI_SEND(priv->dev, (offset >> 8) & 0xff);
(void)SPI_SEND(priv->dev, offset & 0xff);
/* Then write the specified number of bytes */
SPI_SNDBLOCK(priv->dev, buffer, 1 << priv->pageshift);
priv->lastwaswrite = true;
/* Deselect the FLASH: Chip Select high */
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
fvdbg("Written\n");
}
/************************************************************************************
* Name: sst25xx_bytewrite
************************************************************************************/
#ifdef CONFIG_MTD_BYTE_WRITE
static inline void sst25xx_bytewrite(struct sst25xx_dev_s *priv, FAR const uint8_t *buffer,
off_t offset, uint16_t count)
{
fvdbg("offset: %08lx count:%d\n", (long)offset, count);
/* 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.
*/
sst25xx_waitwritecomplete(priv);
/* Enable the write access to the FLASH */
sst25xx_writeenable(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send "Page Program (PP)" command */
(void)SPI_SEND(priv->dev, SST25_PP);
/* Send the page offset high byte first. */
(void)SPI_SEND(priv->dev, (offset >> 16) & 0xff);
(void)SPI_SEND(priv->dev, (offset >> 8) & 0xff);
(void)SPI_SEND(priv->dev, offset & 0xff);
/* Then write the specified number of bytes */
SPI_SNDBLOCK(priv->dev, buffer, count);
priv->lastwaswrite = true;
/* Deselect the FLASH: Chip Select high */
SPI_SELECT(priv->dev, SPIDEV_FLASH, false);
fvdbg("Written\n");
}
#endif
/************************************************************************************
* Name: sst25xx_erase
************************************************************************************/
static int sst25xx_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks)
{
FAR struct sst25xx_dev_s *priv = (FAR struct sst25xx_dev_s *)dev;
size_t blocksleft = nblocks;
fvdbg("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks);
/* Lock access to the SPI bus until we complete the erase */
sst25xx_lock(priv->dev);
while (blocksleft > 0)
{
size_t sectorboundry;
size_t blkper;
/* We will erase in either 4K sectors or 32K or 64K blocks depending
* on the largest unit we can use given the startblock and nblocks.
* This will reduce erase time (in the event we have partitions
* enabled and are doing a bulk erase which is translated into
* a block erase operation).
*/
/* Test for 64K alignment */
blkper = 64 / 4;
sectorboundry = (startblock + blkper - 1) / blkper;
sectorboundry *= blkper;
/* If we are on a sector boundry and have at least a full sector
* of blocks left to erase, then we can do a full sector erase.
*/
if (startblock == sectorboundry && blocksleft >= blkper)
{
/* Do a 64k block erase */
sst25xx_sectorerase(priv, startblock, SST25_BE64);
startblock += blkper;
blocksleft -= blkper;
continue;
}
/* Test for 32K block alignment */
blkper = 32 / 4;
sectorboundry = (startblock + blkper - 1) / blkper;
sectorboundry *= blkper;
if (startblock == sectorboundry && blocksleft >= blkper)
{
/* Do a 32k block erase */
sst25xx_sectorerase(priv, startblock, SST25_BE32);
startblock += blkper;
blocksleft -= blkper;
continue;
}
else
{
/* Just do a sector erase */
sst25xx_sectorerase(priv, startblock, SST25_SE);
startblock++;
blocksleft--;
continue;
}
}
sst25xx_unlock(priv->dev);
return (int)nblocks;
}
/************************************************************************************
* Name: sst25xx_bread
************************************************************************************/
static ssize_t sst25xx_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
FAR uint8_t *buffer)
{
FAR struct sst25xx_dev_s *priv = (FAR struct sst25xx_dev_s *)dev;
ssize_t nbytes;
fvdbg("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 = sst25xx_read(dev, startblock << priv->pageshift, nblocks << priv->pageshift, buffer);
if (nbytes > 0)
{
return nbytes >> priv->pageshift;
}
return (int)nbytes;
}
/************************************************************************************
* Name: sst25xx_bwrite
************************************************************************************/
static ssize_t sst25xx_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
FAR const uint8_t *buffer)
{
FAR struct sst25xx_dev_s *priv = (FAR struct sst25xx_dev_s *)dev;
size_t blocksleft = nblocks;
size_t pagesize = 1 << priv->pageshift;
fvdbg("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks);
/* Lock the SPI bus and write each page to FLASH */
sst25xx_lock(priv->dev);
while (blocksleft-- > 0)
{
sst25xx_pagewrite(priv, buffer, startblock);
buffer += pagesize;
startblock++;
}
sst25xx_unlock(priv->dev);
return nblocks;
}
/************************************************************************************
* Name: sst25xx_read
************************************************************************************/
static ssize_t sst25xx_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR uint8_t *buffer)
{
FAR struct sst25xx_dev_s *priv = (FAR struct sst25xx_dev_s *)dev;
fvdbg("offset: %08lx nbytes: %d\n", (long)offset, (int)nbytes);
/* 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.
*/
if (priv->lastwaswrite)
{
sst25xx_waitwritecomplete(priv);
}
/* Lock the SPI bus and select this FLASH part */
sst25xx_lock(priv->dev);
SPI_SELECT(priv->dev, SPIDEV_FLASH, true);
/* Send "Read from Memory " instruction */
(void)SPI_SEND(priv->dev, SST25_READ);
/* Send the page offset high byte first. */
(void)SPI_SEND(priv->dev, (offset >> 16) & 0xff);
(void)SPI_SEND(priv->dev, (offset >> 8) & 0xff);
(void)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, false);
sst25xx_unlock(priv->dev);
fvdbg("return nbytes: %d\n", (int)nbytes);
return nbytes;
}
/************************************************************************************
* Name: sst25xx_write
************************************************************************************/
#ifdef CONFIG_MTD_BYTE_WRITE
static ssize_t sst25xx_write(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR const uint8_t *buffer)
{
FAR struct sst25xx_dev_s *priv = (FAR struct sst25xx_dev_s *)dev;
int startpage;
int endpage;
int count;
int index;
int pagesize;
int bytestowrite;
fvdbg("offset: %08lx nbytes: %d\n", (long)offset, (int)nbytes);
/* We must test if the offset + count crosses one or more pages
* and perform individual writes. The devices can only write in
* page increments.
*/
startpage = offset / (1 << priv->pageshift);
endpage = (offset + nbytes) / (1 << priv->pageshift);
if (startpage == endpage)
{
/* All bytes within one programmable page. Just do the write. */
sst25xx_bytewrite(priv, buffer, offset, nbytes);
}
else
{
/* Write the 1st partial-page */
count = nbytes;
pagesize = (1 << priv->pageshift);
bytestowrite = pagesize - (offset & (pagesize-1));
sst25xx_bytewrite(priv, buffer, offset, bytestowrite);
/* Update offset and count */
offset += bytestowrite;
count -= bytestowrite;
index = bytestowrite;
/* Write full pages */
while (count >= pagesize)
{
sst25xx_bytewrite(priv, &buffer[index], offset, pagesize);
/* Update offset and count */
offset += pagesize;
count -= pagesize;
index += pagesize;
}
/* Now write any partial page at the end */
if (count > 0)
{
sst25xx_bytewrite(priv, &buffer[index], offset, count);
}
priv->lastwaswrite = true;
}
return nbytes;
}
#endif /* CONFIG_MTD_BYTE_WRITE */
/************************************************************************************
* Name: sst25xx_ioctl
************************************************************************************/
static int sst25xx_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
{
FAR struct sst25xx_dev_s *priv = (FAR struct sst25xx_dev_s *)dev;
int ret = -EINVAL; /* Assume good command with bad parameters */
fvdbg("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)
{
/* 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;
fvdbg("blocksize: %d erasesize: %d neraseblocks: %d\n",
geo->blocksize, geo->erasesize, geo->neraseblocks);
}
}
break;
case MTDIOC_BULKERASE:
{
/* Erase the entire device */
sst25xx_lock(priv->dev);
ret = sst25xx_bulkerase(priv);
sst25xx_unlock(priv->dev);
}
break;
case MTDIOC_XIPBASE:
default:
ret = -ENOTTY; /* Bad command */
break;
}
fvdbg("return %d\n", ret);
return ret;
}
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: sst25xx_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 *sst25xx_initialize(FAR struct spi_dev_s *dev)
{
FAR struct sst25xx_dev_s *priv;
int ret;
fvdbg("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 definition) and so would have
* to be extended to handle multiple FLASH parts on the same SPI bus.
*/
priv = (FAR struct sst25xx_dev_s *)kmm_zalloc(sizeof(struct sst25xx_dev_s));
if (priv)
{
/* Initialize the allocated structure. (unsupported methods were
* nullified by kmm_zalloc).
*/
priv->mtd.erase = sst25xx_erase;
priv->mtd.bread = sst25xx_bread;
priv->mtd.bwrite = sst25xx_bwrite;
priv->mtd.read = sst25xx_read;
#ifdef CONFIG_MTD_BYTE_WRITE
priv->mtd.write = sst25xx_write;
#endif
priv->mtd.ioctl = sst25xx_ioctl;
priv->dev = dev;
priv->lastwaswrite = false;
/* Deselect the FLASH */
SPI_SELECT(dev, SPIDEV_FLASH, false);
/* Identify the FLASH chip and get its capacity */
ret = sst25xx_readid(priv);
if (ret != OK)
{
/* Unrecognized! Discard all of that work we just did and return NULL */
fdbg("Unrecognized\n");
kmm_free(priv);
priv = NULL;
}
else
{
/* Make sure that the FLASH is unprotected so that we can write into it */
sst25xx_unprotect(priv);
}
}
/* Register the MTD with the procfs system if enabled */
#ifdef CONFIG_MTD_REGISTRATION
mtd_register(&priv->mtd, "sst25xx");
#endif
/* Return the implementation-specific state structure as the MTD device */
fvdbg("Return %p\n", priv);
return (FAR struct mtd_dev_s *)priv;
}
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