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incubator-nuttx/drivers/mtd/sst25.c

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/************************************************************************************
* drivers/mtd/sst25.c
* Driver for SPI-based SST25 FLASH.
*
* Copyright (C) 2012-2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Modifications:
*
* - 10/08/2013: David Sidrane <david_s5@nscdg.com>
* - Modified to support SST25VF016B
*
* 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 <string.h>
#include <assert.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 ********************************************************************/
/* Per the data sheet, the SST25 parts can be driven with either SPI mode 0 (CPOL=0
* and CPHA=0) or mode 3 (CPOL=1 and CPHA=1). But I have heard that other devices
* can operate in mode 0 or 1. So you may need to specify CONFIG_SST25_SPIMODE to
* select the best mode for your device. If CONFIG_SST25_SPIMODE is not defined,
* mode 0 will be used.
*/
#ifndef CONFIG_SST25_SPIMODE
# define CONFIG_SST25_SPIMODE SPIDEV_MODE0
#endif
/* SPI Frequency. May be up to 25MHz. */
#ifndef CONFIG_SST25_SPIFREQUENCY
# define CONFIG_SST25_SPIFREQUENCY 20000000
#endif
/* SST25 Instructions ***************************************************************/
/* Command Value Description Addr Data */
/* Dummy */
#define SST25_READ 0x03 /* Read data bytes 3 0 >=1 */
#define SST25_FAST_READ 0x0b /* Higher speed read 3 1 >=1 */
#define SST25_SE 0x20 /* 4Kb Sector erase 3 0 0 */
#define SST25_BE32 0x52 /* 32Kbit block Erase 3 0 0 */
#define SST25_BE64 0xd8 /* 64Kbit block Erase 3 0 0 */
#define SST25_CE 0xc7 /* Chip erase 0 0 0 */
#define SST25_CE_ALT 0x60 /* Chip erase (alternate) 0 0 0 */
#define SST25_BP 0x02 /* Byte program 3 0 1 */
#define SST25_AAI 0xad /* Auto address increment 3 0 >=2 */
#define SST25_RDSR 0x05 /* Read status register 0 0 >=1 */
#define SST25_EWSR 0x50 /* Write enable status 0 0 0 */
#define SST25_WRSR 0x01 /* Write Status Register 0 0 1 */
#define SST25_WREN 0x06 /* Write Enable 0 0 0 */
#define SST25_WRDI 0x04 /* Write Disable 0 0 0 */
#define SST25_RDID 0xab /* Read Identification 0 0 >=1 */
#define SST25_RDID_ALT 0x90 /* Read Identification (alt) 0 0 >=1 */
#define SST25_JEDEC_ID 0x9f /* JEDEC ID read 0 0 >=3 */
#define SST25_EBSY 0x70 /* Enable SO RY/BY# status 0 0 0 */
#define SST25_DBSY 0x80 /* Disable SO RY/BY# status 0 0 0 */
/* SST25 Registers ******************************************************************/
/* Read ID (RDID) register values */
#define SST25_MANUFACTURER 0xbf /* SST manufacturer ID */
#define SST25_VF016_DEVID 0x25 /* SSTVF016B device ID */
#define SST25_VF032_DEVID 0x20 /* SSTVF032B device ID */
/* JEDEC Read ID register values */
#define SST25_JEDEC_MANUFACTURER 0xbf /* SST manufacturer ID */
#define SST25_JEDEC_MEMORY_TYPE 0x25 /* SST25 memory type */
#define SST25_JEDEC_VF032_CAPACITY 0x4a /* SST25VF032B memory capacity */
#define SST25_JEDEC_VF016_CAPACITY 0x41 /* SST25VF016B memory capacity */
/* Status register bit definitions */
#define SST25_SR_BUSY (1 << 0) /* Bit 0: Write in progress */
#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_UPPER64th (1 << SST25_SR_BP_SHIFT) /* Upper 64th */
# define SST25_SR_BP_UPPER32nd (2 << SST25_SR_BP_SHIFT) /* Upper 32nd */
# define SST25_SR_BP_UPPER16th (3 << SST25_SR_BP_SHIFT) /* Upper 16th */
# define SST25_SR_BP_UPPER8th (4 << SST25_SR_BP_SHIFT) /* Upper 8th */
# define SST25_SR_BP_UPPERQTR (5 << SST25_SR_BP_SHIFT) /* Upper quarter */
# define SST25_SR_BP_UPPERHALF (6 << SST25_SR_BP_SHIFT) /* Upper half */
# define SST25_SR_BP_ALL (7 << SST25_SR_BP_SHIFT) /* All sectors */
#define SST25_SR_AAI (1 << 6) /* Bit 6: Auto Address increment programming */
#define SST25_SR_SRWD (1 << 7) /* Bit 7: Status register write protect */
#define SST25_DUMMY 0xa5
/* Chip Geometries ******************************************************************/
/* SST25VF512 capacity is 512Kbit (64Kbit x 8) = 64Kb (8Kb x 8) */
/* SST25VF010 capacity is 1Mbit (128Kbit x 8) = 128Kb (16Kb x 8 */
/* SST25VF520 capacity is 2Mbit (256Kbit x 8) = 256Kb (32Kb x 8) */
/* SST25VF540 capacity is 4Mbit (512Kbit x 8) = 512Kb (64Kb x 8) */
/* SST25VF080 capacity is 8Mbit (1024Kbit x 8) = 1Mb (128Kb x 8) */
/* Not yet supported */
/* SST25VF016 capacity is 16Mbit (2048Kbit x 8) = 2Mb (256Kb x 8) */
#define SST25_VF016_SECTOR_SHIFT 12 /* Sector size 1 << 12 = 4Kb */
#define SST25_VF016_NSECTORS 512 /* 512 sectors x 4096 bytes/sector = 2Mb */
/* SST25VF032 capacity is 32Mbit (4096Kbit x 8) = 4Mb (512kb x 8) */
#define SST25_VF032_SECTOR_SHIFT 12 /* Sector size 1 << 12 = 4Kb */
#define SST25_VF032_NSECTORS 1024 /* 1024 sectors x 4096 bytes/sector = 4Mb */
#ifdef CONFIG_SST25_SECTOR512 /* Simulate a 512 byte sector */
# define SST25_SECTOR_SHIFT 9 /* Sector size 1 << 9 = 512 bytes */
# define SST25_SECTOR_SIZE 512 /* Sector size = 512 bytes */
#endif
#define SST25_ERASED_STATE 0xff /* State of FLASH when erased */
/* Cache flags */
#define SST25_CACHE_VALID (1 << 0) /* 1=Cache has valid data */
#define SST25_CACHE_DIRTY (1 << 1) /* 1=Cache is dirty */
#define SST25_CACHE_ERASED (1 << 2) /* 1=Backing FLASH is erased */
#define IS_VALID(p) ((((p)->flags) & SST25_CACHE_VALID) != 0)
#define IS_DIRTY(p) ((((p)->flags) & SST25_CACHE_DIRTY) != 0)
#define IS_ERASED(p) ((((p)->flags) & SST25_CACHE_ERASED) != 0)
#define SET_VALID(p) do { (p)->flags |= SST25_CACHE_VALID; } while (0)
#define SET_DIRTY(p) do { (p)->flags |= SST25_CACHE_DIRTY; } while (0)
#define SET_ERASED(p) do { (p)->flags |= SST25_CACHE_ERASED; } while (0)
#define CLR_VALID(p) do { (p)->flags &= ~SST25_CACHE_VALID; } while (0)
#define CLR_DIRTY(p) do { (p)->flags &= ~SST25_CACHE_DIRTY; } while (0)
#define CLR_ERASED(p) do { (p)->flags &= ~SST25_CACHE_ERASED; } while (0)
/************************************************************************************
* 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 sst25_dev_s.
*/
struct sst25_dev_s
{
struct mtd_dev_s mtd; /* MTD interface */
FAR struct spi_dev_s *dev; /* Saved SPI interface instance */
uint16_t nsectors; /* Number of erase sectors */
uint8_t sectorshift; /* Log2 of erase sector size */
#if defined(CONFIG_SST25_SECTOR512) && !defined(CONFIG_SST25_READONLY)
uint8_t flags; /* Buffered sector flags */
uint16_t esectno; /* Erase sector number in the cache */
FAR uint8_t *sector; /* Allocated sector data */
#endif
};
/************************************************************************************
* Private Function Prototypes
************************************************************************************/
/* Helpers */
static void sst25_lock(FAR struct spi_dev_s *dev);
static inline void sst25_unlock(FAR struct spi_dev_s *dev);
static inline int sst25_readid(FAR struct sst25_dev_s *priv);
#ifndef CONFIG_SST25_READONLY
static void sst25_unprotect(FAR struct sst25_dev_s *priv);
#endif
static uint8_t sst25_waitwritecomplete(FAR struct sst25_dev_s *priv);
static inline void sst25_cmd(struct sst25_dev_s *priv, uint8_t cmd);
static inline void sst25_wren(FAR struct sst25_dev_s *priv);
#if !defined(CONFIG_SST25_SLOWWRITE) && !defined(CONFIG_SST25_READONLY)
static inline void sst25_wrdi(FAR struct sst25_dev_s *priv);
#endif
static void sst25_sectorerase(FAR struct sst25_dev_s *priv, off_t offset);
static inline int sst25_chiperase(FAR struct sst25_dev_s *priv);
static void sst25_byteread(FAR struct sst25_dev_s *priv, FAR uint8_t *buffer,
off_t address, size_t nbytes);
#ifndef CONFIG_SST25_READONLY
#ifdef CONFIG_SST25_SLOWWRITE
static void sst25_bytewrite(FAR struct sst25_dev_s *priv, FAR const uint8_t *buffer,
off_t address, size_t nbytes);
#else
static void sst25_wordwrite(FAR struct sst25_dev_s *priv, FAR const uint8_t *buffer,
off_t address, size_t nbytes);
#endif
#ifdef CONFIG_SST25_SECTOR512
static void sst25_cacheflush(struct sst25_dev_s *priv);
static FAR uint8_t *sst25_cacheread(struct sst25_dev_s *priv, off_t sector);
static void sst25_cacheerase(struct sst25_dev_s *priv, off_t sector);
static void sst25_cachewrite(FAR struct sst25_dev_s *priv, FAR const uint8_t *buffer,
off_t sector, size_t nsectors);
#endif
#endif
/* MTD driver methods */
static int sst25_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks);
static ssize_t sst25_bread(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR uint8_t *buf);
static ssize_t sst25_bwrite(FAR struct mtd_dev_s *dev, off_t startblock,
size_t nblocks, FAR const uint8_t *buf);
static ssize_t sst25_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR uint8_t *buffer);
static int sst25_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg);
/************************************************************************************
* Private Data
************************************************************************************/
/************************************************************************************
* Private Functions
************************************************************************************/
/************************************************************************************
* Name: sst25_lock
************************************************************************************/
static void sst25_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.
*/
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_SST25_SPIMODE);
SPI_SETBITS(dev, 8);
SPI_HWFEATURES(dev, 0);
SPI_SETFREQUENCY(dev, CONFIG_SST25_SPIFREQUENCY);
}
/************************************************************************************
* Name: sst25_unlock
************************************************************************************/
static inline void sst25_unlock(FAR struct spi_dev_s *dev)
{
SPI_LOCK(dev, false);
}
/************************************************************************************
* Name: sst25_readid
************************************************************************************/
static inline int sst25_readid(struct sst25_dev_s *priv)
{
uint16_t manufacturer;
uint16_t memory;
uint16_t capacity;
finfo("priv: %p\n", priv);
/* Lock the SPI bus, configure the bus, and select this FLASH part. */
sst25_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, SST25_JEDEC_ID);
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(0), false);
sst25_unlock(priv->dev);
finfo("manufacturer: %02x memory: %02x capacity: %02x\n",
manufacturer, memory, capacity);
/* Check for a valid manufacturer and memory type */
if (manufacturer == SST25_JEDEC_MANUFACTURER &&
memory == SST25_JEDEC_MEMORY_TYPE)
{
/* Okay.. is it a FLASH capacity that we understand? This should be
* extended support other members of the SST25 family. If so, save
* the FLASH geometry.
*/
switch (capacity)
{
case SST25_JEDEC_VF032_CAPACITY:
priv->sectorshift = SST25_VF032_SECTOR_SHIFT;
priv->nsectors = SST25_VF032_NSECTORS;
return OK;
case SST25_JEDEC_VF016_CAPACITY:
priv->sectorshift = SST25_VF016_SECTOR_SHIFT;
priv->nsectors = SST25_VF016_NSECTORS;
return OK;
/* Support for this part is not implemented yet */
default:
break;
}
}
return -ENODEV;
}
/************************************************************************************
* Name: sst25_unprotect
************************************************************************************/
#ifndef CONFIG_SST25_READONLY
static void sst25_unprotect(struct sst25_dev_s *priv)
{
/* Send "Write enable status (EWSR)" */
sst25_cmd(priv, SST25_EWSR);
/* Send "Write enable status (WRSR)" */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
SPI_SEND(priv->dev, SST25_WRSR);
/* Followed by the new status value */
SPI_SEND(priv->dev, 0);
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
}
#endif
/************************************************************************************
* Name: sst25_waitwritecomplete
************************************************************************************/
static uint8_t sst25_waitwritecomplete(struct sst25_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, 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(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 0 /* Makes writes too slow */
if ((status & SST25_SR_BUSY) != 0)
{
sst25_unlock(priv->dev);
nxsig_usleep(1000);
sst25_lock(priv->dev);
}
#endif
}
while ((status & SST25_SR_BUSY) != 0);
return status;
}
/************************************************************************************
* Name: sst25_cmd
************************************************************************************/
static inline void sst25_cmd(struct sst25_dev_s *priv, uint8_t cmd)
{
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send command */
SPI_SEND(priv->dev, cmd);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
}
/************************************************************************************
* Name: sst25_wren
************************************************************************************/
static inline void sst25_wren(struct sst25_dev_s *priv)
{
/* Send "Write Enable (WREN)" command */
sst25_cmd(priv, SST25_WREN);
}
/************************************************************************************
* Name: sst25_wrdi
************************************************************************************/
#if !defined(CONFIG_SST25_SLOWWRITE) && !defined(CONFIG_SST25_READONLY)
static inline void sst25_wrdi(struct sst25_dev_s *priv)
{
/* Send "Write Disable (WRDI)" command */
sst25_cmd(priv, SST25_WRDI);
}
#endif
/************************************************************************************
* Name: sst25_sectorerase
************************************************************************************/
static void sst25_sectorerase(struct sst25_dev_s *priv, off_t sector)
{
off_t address = sector << priv->sectorshift;
finfo("sector: %08lx\n", (long)sector);
/* Wait for any preceding write or erase operation to complete. */
sst25_waitwritecomplete(priv);
/* Send write enable instruction */
sst25_wren(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send the "Sector Erase (SE)" instruction */
SPI_SEND(priv->dev, SST25_SE);
/* Send the sector address high byte first. Only the most significant bits (those
* corresponding to the sector) have any meaning.
*/
SPI_SEND(priv->dev, (address >> 16) & 0xff);
SPI_SEND(priv->dev, (address >> 8) & 0xff);
SPI_SEND(priv->dev, address & 0xff);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
}
/************************************************************************************
* Name: sst25_chiperase
************************************************************************************/
static inline int sst25_chiperase(struct sst25_dev_s *priv)
{
finfo("priv: %p\n", priv);
/* Wait for any preceding write or erase operation to complete. */
sst25_waitwritecomplete(priv);
/* Send write enable instruction */
sst25_wren(priv);
/* Send the "Chip Erase (CE)" instruction */
sst25_cmd(priv, SST25_CE);
finfo("Return: OK\n");
return OK;
}
/************************************************************************************
* Name: sst25_byteread
************************************************************************************/
static void sst25_byteread(FAR struct sst25_dev_s *priv, FAR uint8_t *buffer,
off_t address, size_t nbytes)
{
uint8_t status;
finfo("address: %08lx nbytes: %d\n", (long)address, (int)nbytes);
/* Wait for any preceding write or erase operation to complete. */
status = sst25_waitwritecomplete(priv);
DEBUGASSERT((status & (SST25_SR_WEL | SST25_SR_BP_MASK | SST25_SR_AAI)) == 0);
UNUSED(status);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send "Read from Memory " instruction */
#ifdef CONFIG_SST25_SLOWREAD
SPI_SEND(priv->dev, SST25_READ);
#else
SPI_SEND(priv->dev, SST25_FAST_READ);
#endif
/* Send the address high byte first. */
SPI_SEND(priv->dev, (address >> 16) & 0xff);
SPI_SEND(priv->dev, (address >> 8) & 0xff);
SPI_SEND(priv->dev, address & 0xff);
/* Send a dummy byte */
#ifndef CONFIG_SST25_SLOWREAD
SPI_SEND(priv->dev, SST25_DUMMY);
#endif
/* Then read all of the requested bytes */
SPI_RECVBLOCK(priv->dev, buffer, nbytes);
/* Deselect the FLASH */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
}
/************************************************************************************
* Name: sst25_bytewrite
************************************************************************************/
#if defined(CONFIG_SST25_SLOWWRITE) && !defined(CONFIG_SST25_READONLY)
static void sst25_bytewrite(struct sst25_dev_s *priv, FAR const uint8_t *buffer,
off_t address, size_t nbytes)
{
uint8_t status;
finfo("address: %08lx nwords: %d\n", (long)address, (int)nbytes);
DEBUGASSERT(priv && buffer);
/* Write each byte individually */
for (; nbytes > 0; nbytes--)
{
/* Skip over bytes that are begin written to the erased state */
if (*buffer != SST25_ERASED_STATE)
{
/* Wait for any preceding write or erase operation to complete. */
status = sst25_waitwritecomplete(priv);
DEBUGASSERT((status & (SST25_SR_WEL | SST25_SR_BP_MASK | SST25_SR_AAI)) == 0);
/* Enable write access to the FLASH */
sst25_wren(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send "Byte Program (BP)" command */
SPI_SEND(priv->dev, SST25_BP);
/* Send the byte address high byte first. */
SPI_SEND(priv->dev, (address >> 16) & 0xff);
SPI_SEND(priv->dev, (address >> 8) & 0xff);
SPI_SEND(priv->dev, address & 0xff);
/* Then write the single byte */
SPI_SEND(priv->dev, *buffer);
/* Deselect the FLASH and setup for the next pass through the loop */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
}
/* Advance to the next byte */
buffer++;
address++;
}
}
#endif
/************************************************************************************
* Name: sst25_wordwrite
************************************************************************************/
#if !defined(CONFIG_SST25_SLOWWRITE) && !defined(CONFIG_SST25_READONLY)
static void sst25_wordwrite(struct sst25_dev_s *priv, FAR const uint8_t *buffer,
off_t address, size_t nbytes)
{
size_t nwords = (nbytes + 1) >> 1;
uint8_t status;
finfo("address: %08lx nwords: %d\n", (long)address, (int)nwords);
DEBUGASSERT(priv && buffer);
/* Loop until all of the bytes have been written */
while (nwords > 0)
{
/* Skip over any data that is being written to the erased state */
while (nwords > 0 &&
buffer[0] == SST25_ERASED_STATE &&
buffer[1] == SST25_ERASED_STATE)
{
/* Decrement the word count and advance the write position */
nwords--;
buffer += 2;
address += 2;
}
/* If there are no further non-erased bytes in the user buffer, then
* we are finished.
*/
if (nwords < 1)
{
return;
}
/* Wait for any preceding write or erase operation to complete. */
status = sst25_waitwritecomplete(priv);
DEBUGASSERT((status & (SST25_SR_WEL | SST25_SR_BP_MASK | SST25_SR_AAI)) == 0);
UNUSED(status);
/* Enable write access to the FLASH */
sst25_wren(priv);
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send "Auto Address Increment (AAI)" command */
SPI_SEND(priv->dev, SST25_AAI);
/* Send the word address high byte first. */
SPI_SEND(priv->dev, (address >> 16) & 0xff);
SPI_SEND(priv->dev, (address >> 8) & 0xff);
SPI_SEND(priv->dev, address & 0xff);
/* Then write one 16-bit word */
SPI_SNDBLOCK(priv->dev, buffer, 2);
/* Deselect the FLASH: Chip Select high */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
/* Wait for the preceding write to complete. */
status = sst25_waitwritecomplete(priv);
DEBUGASSERT((status & (SST25_SR_WEL | SST25_SR_BP_MASK | SST25_SR_AAI)) ==
(SST25_SR_WEL | SST25_SR_AAI));
UNUSED(status);
/* Decrement the word count and advance the write position */
nwords--;
buffer += 2;
address += 2;
/* Now loop, writing 16-bits of data on each pass through the loop
* until all of the words have been transferred or until we encounter
* data to be written to the erased state.
*/
while (nwords > 0 &&
(buffer[0] != SST25_ERASED_STATE ||
buffer[1] != SST25_ERASED_STATE))
{
/* Select this FLASH part */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), true);
/* Send "Auto Address Increment (AAI)" command with no address */
SPI_SEND(priv->dev, SST25_AAI);
/* Then write one 16-bit word */
SPI_SNDBLOCK(priv->dev, buffer, 2);
/* Deselect the FLASH: Chip Select high */
SPI_SELECT(priv->dev, SPIDEV_FLASH(0), false);
/* Wait for the preceding write to complete. */
status = sst25_waitwritecomplete(priv);
DEBUGASSERT((status & (SST25_SR_WEL | SST25_SR_BP_MASK | SST25_SR_AAI)) ==
(SST25_SR_WEL | SST25_SR_AAI));
UNUSED(status);
/* Decrement the word count and advance the write position */
nwords--;
buffer += 2;
address += 2;
}
/* Disable writing */
sst25_wrdi(priv);
}
}
#endif
/************************************************************************************
* Name: sst25_cacheflush
************************************************************************************/
#if defined(CONFIG_SST25_SECTOR512) && !defined(CONFIG_SST25_READONLY)
static void sst25_cacheflush(struct sst25_dev_s *priv)
{
/* If the cached is dirty (meaning that it no longer matches the old FLASH contents)
* or was erased (with the cache containing the correct FLASH contents), then write
* the cached erase block to FLASH.
*/
if (IS_DIRTY(priv) || IS_ERASED(priv))
{
/* Write entire erase block to FLASH */
#ifdef CONFIG_SST25_SLOWWRITE
sst25_bytewrite(priv, priv->sector, (off_t)priv->esectno << priv->sectorshift,
(1 << priv->sectorshift));
#else
sst25_wordwrite(priv, priv->sector, (off_t)priv->esectno << priv->sectorshift,
(1 << priv->sectorshift));
#endif
/* The case is no long dirty and the FLASH is no longer erased */
CLR_DIRTY(priv);
CLR_ERASED(priv);
}
}
#endif
/************************************************************************************
* Name: sst25_cacheread
************************************************************************************/
#if defined(CONFIG_SST25_SECTOR512) && !defined(CONFIG_SST25_READONLY)
static FAR uint8_t *sst25_cacheread(struct sst25_dev_s *priv, off_t sector)
{
off_t esectno;
int shift;
int index;
/* Convert from the 512 byte sector to the erase sector size of the device. For
* exmample, if the actual erase sector size if 4Kb (1 << 12), then we first
* shift to the right by 3 to get the sector number in 4096 increments.
*/
shift = priv->sectorshift - SST25_SECTOR_SHIFT;
esectno = sector >> shift;
finfo("sector: %ld esectno: %d shift=%d\n", sector, esectno, shift);
/* Check if the requested erase block is already in the cache */
if (!IS_VALID(priv) || esectno != priv->esectno)
{
/* No.. Flush any dirty erase block currently in the cache */
sst25_cacheflush(priv);
/* Read the erase block into the cache */
sst25_byteread(priv, priv->sector, (esectno << priv->sectorshift), 1 << priv->sectorshift);
/* Mark the sector as cached */
priv->esectno = esectno;
SET_VALID(priv); /* The data in the cache is valid */
CLR_DIRTY(priv); /* It should match the FLASH contents */
CLR_ERASED(priv); /* The underlying FLASH has not been erased */
}
/* Get the index to the 512 sector in the erase block that holds the argument */
index = sector & ((1 << shift) - 1);
/* Return the address in the cache that holds this sector */
return &priv->sector[index << SST25_SECTOR_SHIFT];
}
#endif
/************************************************************************************
* Name: sst25_cacheerase
************************************************************************************/
#if defined(CONFIG_SST25_SECTOR512) && !defined(CONFIG_SST25_READONLY)
static void sst25_cacheerase(struct sst25_dev_s *priv, off_t sector)
{
FAR uint8_t *dest;
/* First, make sure that the erase block containing the 512 byte sector is in
* the cache.
*/
dest = sst25_cacheread(priv, sector);
/* Erase the block containing this sector if it is not already erased.
* The erased indicated will be cleared when the data from the erase sector
* is read into the cache and set here when we erase the block.
*/
if (!IS_ERASED(priv))
{
off_t esectno = sector >> (priv->sectorshift - SST25_SECTOR_SHIFT);
finfo("sector: %ld esectno: %d\n", sector, esectno);
sst25_sectorerase(priv, esectno);
SET_ERASED(priv);
}
/* Put the cached sector data into the erase state and mart the cache as dirty
* (but don't update the FLASH yet. The caller will do that at a more optimal
* time).
*/
memset(dest, SST25_ERASED_STATE, SST25_SECTOR_SIZE);
SET_DIRTY(priv);
}
#endif
/************************************************************************************
* Name: sst25_cachewrite
************************************************************************************/
#if defined(CONFIG_SST25_SECTOR512) && !defined(CONFIG_SST25_READONLY)
static void sst25_cachewrite(FAR struct sst25_dev_s *priv, FAR const uint8_t *buffer,
off_t sector, size_t nsectors)
{
FAR uint8_t *dest;
for (; nsectors > 0; nsectors--)
{
/* First, make sure that the erase block containing 512 byte sector is in
* memory.
*/
dest = sst25_cacheread(priv, sector);
/* Erase the block containing this sector if it is not already erased.
* The erased indicated will be cleared when the data from the erase sector
* is read into the cache and set here when we erase the sector.
*/
if (!IS_ERASED(priv))
{
off_t esectno = sector >> (priv->sectorshift - SST25_SECTOR_SHIFT);
finfo("sector: %ld esectno: %d\n", sector, esectno);
sst25_sectorerase(priv, esectno);
SET_ERASED(priv);
}
/* Copy the new sector data into cached erase block */
memcpy(dest, buffer, SST25_SECTOR_SIZE);
SET_DIRTY(priv);
/* Set up for the next 512 byte sector */
buffer += SST25_SECTOR_SIZE;
sector++;
}
/* Flush the last erase block left in the cache */
sst25_cacheflush(priv);
}
#endif
/************************************************************************************
* Name: sst25_erase
************************************************************************************/
static int sst25_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks)
{
#ifdef CONFIG_SST25_READONLY
return -EACESS
#else
FAR struct sst25_dev_s *priv = (FAR struct sst25_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 */
sst25_lock(priv->dev);
while (blocksleft-- > 0)
{
/* Erase each sector */
#ifdef CONFIG_SST25_SECTOR512
sst25_cacheerase(priv, startblock);
#else
sst25_sectorerase(priv, startblock);
#endif
startblock++;
}
#ifdef CONFIG_SST25_SECTOR512
/* Flush the last erase block left in the cache */
sst25_cacheflush(priv);
#endif
sst25_unlock(priv->dev);
return (int)nblocks;
#endif
}
/************************************************************************************
* Name: sst25_bread
************************************************************************************/
static ssize_t sst25_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
FAR uint8_t *buffer)
{
#ifdef CONFIG_SST25_SECTOR512
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 = sst25_read(dev, startblock << SST25_SECTOR_SHIFT, nblocks << SST25_SECTOR_SHIFT, buffer);
if (nbytes > 0)
{
return nbytes >> SST25_SECTOR_SHIFT;
}
return (int)nbytes;
#else
FAR struct sst25_dev_s *priv = (FAR struct sst25_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 = sst25_read(dev, startblock << priv->sectorshift, nblocks << priv->sectorshift, buffer);
if (nbytes > 0)
{
return nbytes >> priv->sectorshift;
}
return (int)nbytes;
#endif
}
/************************************************************************************
* Name: sst25_bwrite
************************************************************************************/
static ssize_t sst25_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
FAR const uint8_t *buffer)
{
#ifdef CONFIG_SST25_READONLY
return -EACCESS;
#else
FAR struct sst25_dev_s *priv = (FAR struct sst25_dev_s *)dev;
finfo("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks);
/* Lock the SPI bus and write all of the pages to FLASH */
sst25_lock(priv->dev);
#if defined(CONFIG_SST25_SECTOR512)
sst25_cachewrite(priv, buffer, startblock, nblocks);
#elif defined(CONFIG_SST25_SLOWWRITE)
sst25_bytewrite(priv, buffer, startblock << priv->sectorshift,
nblocks << priv->sectorshift);
#else
sst25_wordwrite(priv, buffer, startblock << priv->sectorshift,
nblocks << priv->sectorshift);
#endif
sst25_unlock(priv->dev);
return nblocks;
#endif
}
/************************************************************************************
* Name: sst25_read
************************************************************************************/
static ssize_t sst25_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
FAR uint8_t *buffer)
{
FAR struct sst25_dev_s *priv = (FAR struct sst25_dev_s *)dev;
finfo("offset: %08lx nbytes: %d\n", (long)offset, (int)nbytes);
/* Lock the SPI bus and select this FLASH part */
sst25_lock(priv->dev);
sst25_byteread(priv, buffer, offset, nbytes);
sst25_unlock(priv->dev);
finfo("return nbytes: %d\n", (int)nbytes);
return nbytes;
}
/************************************************************************************
* Name: sst25_ioctl
************************************************************************************/
static int sst25_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
{
FAR struct sst25_dev_s *priv = (FAR struct sst25_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)
{
/* 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.
*/
#ifdef CONFIG_SST25_SECTOR512
geo->blocksize = (1 << SST25_SECTOR_SHIFT);
geo->erasesize = (1 << SST25_SECTOR_SHIFT);
geo->neraseblocks = priv->nsectors << (priv->sectorshift - 9);
#else
geo->blocksize = (1 << priv->sectorshift);
geo->erasesize = (1 << priv->sectorshift);
geo->neraseblocks = priv->nsectors;
#endif
ret = OK;
finfo("blocksize: %d erasesize: %d neraseblocks: %d\n",
geo->blocksize, geo->erasesize, geo->neraseblocks);
}
}
break;
case MTDIOC_BULKERASE:
{
/* Erase the entire device */
sst25_lock(priv->dev);
ret = sst25_chiperase(priv);
sst25_unlock(priv->dev);
}
break;
case MTDIOC_XIPBASE:
default:
ret = -ENOTTY; /* Bad command */
break;
}
finfo("return %d\n", ret);
return ret;
}
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: sst25_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 *sst25_initialize(FAR struct spi_dev_s *dev)
{
FAR struct sst25_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 = (FAR struct sst25_dev_s *)kmm_zalloc(sizeof(struct sst25_dev_s));
if (priv)
{
/* Initialize the allocated structure. (unsupported methods were
* nullified by kmm_zalloc).
*/
priv->mtd.erase = sst25_erase;
priv->mtd.bread = sst25_bread;
priv->mtd.bwrite = sst25_bwrite;
priv->mtd.read = sst25_read;
priv->mtd.ioctl = sst25_ioctl;
priv->mtd.name = "sst25";
priv->dev = dev;
/* Deselect the FLASH */
SPI_SELECT(dev, SPIDEV_FLASH(0), false);
/* Identify the FLASH chip and get its capacity */
ret = sst25_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
{
/* Make sure that the FLASH is unprotected so that we can write into it */
#ifndef CONFIG_SST25_READONLY
sst25_unprotect(priv);
#endif
#ifdef CONFIG_SST25_SECTOR512 /* Simulate a 512 byte sector */
/* Allocate a buffer for the erase block cache */
priv->sector = (FAR uint8_t *)kmm_malloc(1 << priv->sectorshift);
if (!priv->sector)
{
/* Allocation failed! Discard all of that work we just did and return NULL */
ferr("ERROR: Allocation failed\n");
kmm_free(priv);
return NULL;
}
#endif
}
}
/* Return the implementation-specific state structure as the MTD device */
finfo("Return %p\n", priv);
return (FAR struct mtd_dev_s *)priv;
}
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