sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
f2603866e0
nuttx/drivers/eeprom/spi_xx25xx.c
Gregory Nutt bc3212d70e EEPROM: Add a README file
2014-11-27 09:14:00 -06:00

796 lines
24 KiB
C
Raw Blame History

/****************************************************************************
* drivers/eeprom/spi_xx25xx.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Sebastien Lorquet <sebastien@lorquet.fr>
*
* 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.
*
****************************************************************************/
/* This is a driver for SPI EEPROMs that use the same commands as the
* 25AA160.
*
* Write time 5ms, 6ms for 25xx1025 (determined automatically with polling)
* Max SPI speed is :
* 10 MHz for -A/B/C/D/E/UID versions
* 1 MHz for 25AA versions
* 2 MHz for 25LC versions
* 3 MHz for 25C versions
* 10 MHz for 25xxN versions where N=128 and more
* 20 MHz for 25AA512, 25LC512, 25xx1024
* 20 MHz for Atmel devices (>4.5V)
* 10 MHz for Atmel devices (>2.5V)
* All devices have the same instruction set.
*
* The following devices should be supported:
*
* Manufacturer Device Bytes PgSize AddrLen
* Microchip
* 25xx010A 128 16 1
* 25xx020A 256 16 1
* 25AA02UID 256 16 1
* 25AA02E48 256 16 1
* 25AA02E64 256 16 1
* 25xx040 512 16 1+bit
* 25xx040A 512 16 1+bit
* 25xx080 1024 16 1
* 25xx080A 1024 16 2
* 25xx080B 1024 32 2
* 25xx080C 1024 16 x
* 25xx080D 1024 32 x
* 25xx160 2048 16 2
* 25xx160A/C 2048 16 2 TESTED
* 25xx160B/D 2048 32 2
* 25xx160C 2048 16 2
* 25xx160D 2048 32 2
* 25xx320 4096 32 2
* 25xx320A 4096 32 2
* 25xx640 8192 32 2
* 25xx640A 8192 32 2
* 25xx128 16384 64 2
* 25xx256 32768 64 2
* 25xx512 65536 128 2
* 25xx1024 131072 256 3
* Atmel
* AT25010B 128 8 1
* AT25020B 256 8 1
* AT25040B 512 8 1+bit
* AT25080B 1024 32 2
* AT25160B 2048 32 2
* AT25320B 4096 32 2
* AT25640B 8192 32 2
* AT25128B 16384 64 2
* AT25256B 32768 64 2
* AT25512 65536 128 2
* AT25M01 131072 256 3
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/kmalloc.h>
#include <nuttx/spi/spi.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_EE25XX_SPIMODE
# define CONFIG_EE25XX_SPIMODE 0
#endif
/* EEPROM commands
* High bit of low nibble used for A8 in 25xx040/at25040 products
*/
#define EE25XX_CMD_WRSR 0x01
#define EE25XX_CMD_WRITE 0x02
#define EE25XX_CMD_READ 0x03
#define EE25XX_CMD_WRDIS 0x04
#define EE25XX_CMD_RDSR 0x05
#define EE25XX_CMD_WREN 0x06
/* Following commands will be available some day via IOCTLs
* PE 0x42 Page erase (25xx512/1024)
* SE 0xD8 Sector erase (25xx512/1024)
* CE 0xC7 Chip erase (25xx512/1024)
* RDID 0xAB Wake up and read electronic signature (25xx512/1024)
* DPD 0xB9 Sleep (25xx512/1024)
*/
/* SR bits definitions */
#define EE25XX_SR_WIP 0x01 /* Write in Progress */
#define EE25XX_SR_WEL 0x02 /* Write Enable Latch */
#define EE25XX_SR_BP0 0x04 /* First Block Protect bit */
#define EE25XX_SR_BP1 0x08 /* Second Block Protect bit */
#define EE25XX_SR_WPEN 0x80 /* Write Protect Enable */
#define EE25XX_DUMMY 0xFF
/****************************************************************************
* Types
****************************************************************************/
/* Device geometry description, compact form (2 bytes per entry) */
struct ee25xx_geom_s
{
uint8_t bytes : 4; /*power of two of 128 bytes (0:128 1:256 2:512 etc) */
uint8_t pagesize : 4; /*power of two of 8 bytes (0:8 1:16 2:32 3:64 etc)*/
uint8_t addrlen : 4; /*number of bytes in command address field */
uint8_t flags : 4; /*special address management for 25xx040, 1=A8 in inst*/
};
/* Private data attached to the inode */
struct ee25xx_dev_s
{
struct spi_dev_s *spi; /* spi device where the EEPROM is attached */
uint32_t size; /* in bytes, expanded from geometry */
uint16_t pgsize; /* write block size, in bytes, expanded from geometry */
uint16_t addrlen; /* number of BITS in data addresses */
sem_t sem; /* file access serialization */
uint8_t refs; /* The number of times the device has been opened */
uint8_t readonly; /* Flags */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int ee25xx_open(FAR struct file *filep);
static int ee25xx_close(FAR struct file *filep);
static off_t ee25xx_seek(FAR struct file *filep, off_t offset, int whence);
static ssize_t ee25xx_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t ee25xx_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int ee25xx_ioctl(FAR struct file *filep, int cmd,
unsigned long arg);
/****************************************************************************
* Private Data
****************************************************************************/
/* Supported device geometries.
* One geometry can fit more than one device.
* The user will use an enum'ed index from include/eeprom/spi_xx25xx.h
*/
static const struct ee25xx_geom_s g_ee25xx_devices[] =
{
/* Microchip devices */
{ 0, 1, 1, 0}, /*25xx010A 128 16 1*/
{ 1, 1, 1, 0}, /*25xx020A 256 16 1*/
{ 2, 1, 1, 1}, /*25xx040 512 16 1+bit*/
{ 3, 1, 1, 0}, /*25xx080 1024 16 1*/
{ 3, 2, 2, 0}, /*25xx080B 1024 32 2*/
{ 4, 1, 2, 0}, /*25xx160 2048 16 2*/
{ 4, 2, 2, 0}, /*25xx160B/D 2048 32 2*/
{ 5, 2, 2, 0}, /*25xx320 4096 32 2*/
{ 6, 2, 2, 0}, /*25xx640 8192 32 2*/
{ 7, 3, 2, 0}, /*25xx128 16384 64 2*/
{ 8, 3, 2, 0}, /*25xx256 32768 64 2*/
{ 9, 4, 2, 0}, /*25xx512 65536 128 2*/
{10, 5, 3, 0}, /*25xx1024 131072 256 3*/
/* Atmel devices */
{ 0, 0, 1, 0}, /*AT25010B 128 8 1*/
{ 1, 0, 1, 0}, /*AT25020B 256 8 1*/
{ 2, 0, 1, 1}, /*AT25040B 512 8 1+bit*/
};
/* Driver operations */
static const struct file_operations ee25xx_fops =
{
ee25xx_open, /* open */
ee25xx_close, /* close */
ee25xx_read, /* read */
ee25xx_write, /* write */
ee25xx_seek, /* seek */
ee25xx_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, 0 /* poll */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: ee25xx_lock
****************************************************************************/
static void ee25xx_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.
*/
(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 bus is being shared, then it may
* have been left in an incompatible state.
*/
SPI_SETMODE(dev, CONFIG_EE25XX_SPIMODE);
SPI_SETBITS(dev, 8);
(void)SPI_SETFREQUENCY(dev, 10000000); /* This is the default speed */
}
/****************************************************************************
* Name: ee25xx_unlock
****************************************************************************/
static inline void ee25xx_unlock(FAR struct spi_dev_s *dev)
{
(void)SPI_LOCK(dev, false);
}
/****************************************************************************
* Name: ee25xx_sendcmd
*
* Description: Send command and address as one transaction to take advantage
* of possible faster DMA transfers. Sending byte per byte is FAR FAR slower.
*
****************************************************************************/
static void ee25xx_sendcmd(FAR struct spi_dev_s *spi, uint8_t cmd,
uint8_t addrlen, uint32_t addr)
{
uint8_t buf[4];
int cmdlen = 1;
/* Store command */
buf[0] = cmd;
/* Store address according to its length */
if (addrlen == 9)
{
buf[0] |= (((addr >> 8) & 1) << 3);
}
if (addrlen > 16)
{
buf[cmdlen++] = (addr >> 16) & 0xff;
}
if (addrlen > 9)
{
buf[cmdlen++] = (addr >> 8) & 0xff;
}
buf[cmdlen++] = addr & 0xff;
SPI_SNDBLOCK(spi,buf,cmdlen);
}
/****************************************************************************
* Name: ee25xx_waitwritecomplete
*
* Description: loop until the write operation is done.
*
****************************************************************************/
static void ee25xx_waitwritecomplete(struct ee25xx_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->spi, SPIDEV_EEPROM, true);
/* Send "Read Status Register (RDSR)" command */
(void)SPI_SEND(priv->spi, EE25XX_CMD_RDSR);
/* Send a dummy byte to generate the clock needed to shift out the
* status
*/
status = SPI_SEND(priv->spi, EE25XX_DUMMY);
/* Deselect the FLASH */
SPI_SELECT(priv->spi, SPIDEV_EEPROM, false);
/* Given that writing could take up to a few milliseconds,
* the following short delay in the "busy" case will allow
* other peripherals to access the SPI bus.
*/
if ((status & EE25XX_SR_WIP) != 0)
{
ee25xx_unlock(priv->spi);
usleep(1000);
ee25xx_lock(priv->spi);
}
}
while ((status & EE25XX_SR_WIP) != 0);
fvdbg("Complete\n");
}
/****************************************************************************
* Name: ee25xx_writeenable
*
* Description: Enable or disable write operations.
* This is required before any write, since a lot of operations automatically
* disables the write latch.
*
****************************************************************************/
static void ee25xx_writeenable(FAR struct spi_dev_s *spi, int enable)
{
ee25xx_lock(spi);
SPI_SELECT(spi, SPIDEV_EEPROM, true);
SPI_SEND(spi, enable ? EE25XX_CMD_WREN : EE25XX_CMD_WRDIS);
SPI_SELECT(spi, SPIDEV_EEPROM, false);
ee25xx_unlock(spi);
}
/****************************************************************************
* Name: ee25xx_writepage
*
* Description: Write data to the EEPROM, NOT crossing page boundaries.
*
****************************************************************************/
static void ee25xx_writepage(FAR struct ee25xx_dev_s *eedev, uint32_t devaddr,
FAR const char *data, size_t len)
{
ee25xx_lock(eedev->spi);
SPI_SELECT(eedev->spi, SPIDEV_EEPROM, true);
ee25xx_sendcmd(eedev->spi, EE25XX_CMD_WRITE, eedev->addrlen, devaddr);
SPI_SNDBLOCK(eedev->spi, data, len);
SPI_SELECT(eedev->spi, SPIDEV_EEPROM, false);
ee25xx_unlock(eedev->spi);
}
/****************************************************************************
* Name: ee25xx_semtake
*
* Acquire a resource to access the device.
* The purpose of the semaphore is to block tasks that try to access the
* EEPROM while another task is actively using it.
*
****************************************************************************/
static void ee25xx_semtake(FAR struct ee25xx_dev_s *eedev)
{
/* Take the semaphore (perhaps waiting) */
while (sem_wait(&eedev->sem) != 0)
{
/* The only case that an error should occur here is if
* the wait was awakened by a signal.
*/
ASSERT(errno == EINTR);
}
}
/****************************************************************************
* Name: ee25xx_semgive
*
* Release a resource to access the device.
*
****************************************************************************/
static inline void ee25xx_semgive(FAR struct ee25xx_dev_s *eedev)
{
sem_post(&eedev->sem);
}
/****************************************************************************
* Driver Functions
****************************************************************************/
/****************************************************************************
* Name: ee25xx_open
*
* Description: Open the block device
*
****************************************************************************/
static int ee25xx_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ee25xx_dev_s *eedev;
int ret = OK;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee25xx_dev_s *)inode->i_private;
ee25xx_semtake(eedev);
/* Increment the reference count */
if ( (eedev->refs + 1) == 0)
{
ret = -EMFILE;
}
else
{
eedev->refs += 1;
}
ee25xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee25xx_close
*
* Description: Close the block device
*
****************************************************************************/
static int ee25xx_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ee25xx_dev_s *eedev;
int ret = OK;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee25xx_dev_s *)inode->i_private;
ee25xx_semtake(eedev);
/* Decrement the reference count. I want the entire close operation
* to be atomic wrt other driver operations.
*/
if (eedev->refs == 0)
{
ret = -EIO;
}
else
{
eedev->refs -= 1;
}
ee25xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee25xx_seek
*
* Remark: Copied from bchlib
*
****************************************************************************/
static off_t ee25xx_seek(FAR struct file *filep, off_t offset, int whence)
{
FAR struct ee25xx_dev_s *eedev;
off_t newpos;
int ret;
FAR struct inode *inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee25xx_dev_s *)inode->i_private;
ee25xx_semtake(eedev);
/* Determine the new, requested file position */
switch (whence)
{
case SEEK_CUR:
newpos = filep->f_pos + offset;
break;
case SEEK_SET:
newpos = offset;
break;
case SEEK_END:
newpos = eedev->size + offset;
break;
default:
/* Return EINVAL if the whence argument is invalid */
ee25xx_semgive(eedev);
return -EINVAL;
}
/* Opengroup.org:
*
* "The lseek() function shall allow the file offset to be set beyond the end
* of the existing data in the file. If data is later written at this point,
* subsequent reads of data in the gap shall return bytes with the value 0
* until data is actually written into the gap."
*
* We can conform to the first part, but not the second. But return EINVAL if
*
* "...the resulting file offset would be negative for a regular file, block
* special file, or directory."
*/
if (newpos >= 0)
{
filep->f_pos = newpos;
ret = newpos;
}
else
{
ret = -EINVAL;
}
ee25xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee25xx_read
****************************************************************************/
static ssize_t ee25xx_read(FAR struct file *filep, FAR char *buffer,
size_t len)
{
FAR struct ee25xx_dev_s *eedev;
FAR struct inode *inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee25xx_dev_s *)inode->i_private;
ee25xx_semtake(eedev);
/* trim len if read would go beyond end of device */
if ((filep->f_pos + len) > eedev->size)
{
len = eedev->size - filep->f_pos;
}
ee25xx_lock(eedev->spi);
SPI_SELECT(eedev->spi, SPIDEV_EEPROM, true);
/* STM32F4Disco: There is a 25 us delay here */
ee25xx_sendcmd(eedev->spi, EE25XX_CMD_READ, eedev->addrlen, filep->f_pos);
/* STM32F4Disco: There is a 42 us delay here */
SPI_RECVBLOCK(eedev->spi, buffer, len);
/* STM32F4Disco: There is a 20 us delay here */
SPI_SELECT(eedev->spi, SPIDEV_EEPROM, false);
ee25xx_unlock(eedev->spi);
/* Update the file position */
filep->f_pos += len;
ee25xx_semgive(eedev);
return len;
}
/****************************************************************************
* Name: ee25xx_write
****************************************************************************/
static ssize_t ee25xx_write(FAR struct file *filep, FAR const char *buffer,
size_t len)
{
FAR struct ee25xx_dev_s *eedev;
size_t cnt;
int pageoff;
FAR struct inode *inode = filep->f_inode;
int ret = -EACCES;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee25xx_dev_s *)inode->i_private;
if (eedev->readonly)
{
return ret;
}
/* Forbid writes past the end of the device */
if (filep->f_pos >= eedev->size)
{
return -EFBIG;
}
/* Clamp len to avoid crossing the end of the memory */
if ( (len + filep->f_pos) > eedev->size)
{
len = eedev->size - filep->f_pos;
}
/* From this point no failure cannot be detected anymore.
* The user should verify the write by rereading memory.
*/
ret = len; /* save number of bytes written */
ee25xx_semtake(eedev);
/* Writes cant happen in a row like the read does.
* The EEPROM is made of pages, and write sequences
* cannot cross page boundaries. So every time the last
* byte of a page is programmed, the SPI transaction is
* stopped, and the status register is read until the
* write operation has completed.
*/
/* First, write some page-unaligned data */
pageoff = filep->f_pos & (eedev->pgsize - 1);
cnt = eedev->pgsize - pageoff;
if (cnt > len)
{
cnt = len;
}
if (pageoff > 0)
{
ee25xx_writeenable(eedev->spi, true);
ee25xx_writepage(eedev, filep->f_pos, buffer, cnt);
ee25xx_waitwritecomplete(eedev);
len -= cnt;
buffer += cnt;
filep->f_pos += cnt;
}
/* Then, write remaining bytes at page-aligned addresses */
while (len > 0)
{
cnt = len;
if (cnt > eedev->pgsize)
{
cnt = eedev->pgsize;
}
ee25xx_writeenable(eedev->spi, true);
ee25xx_writepage(eedev, filep->f_pos, buffer, cnt);
ee25xx_waitwritecomplete(eedev);
len -= cnt;
buffer += cnt;
filep->f_pos += cnt;
}
ee25xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee25xx_ioctl
*
* Description: TODO: Erase a sector/page/device or read device ID.
* This is completely optional and only applies to bigger devices.
*
****************************************************************************/
static int ee25xx_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct ee25xx_dev_s *eedev;
FAR struct inode *inode = filep->f_inode;
int ret = 0;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee25xx_dev_s *)inode->i_private;
switch (cmd)
{
default:
(void)eedev;
ret = -EINVAL;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ee25xx_initialize
*
* Description: Bind a EEPROM driver to an SPI bus. The user MUST provide
* a description of the device geometry, since it is not possible to read
* this information from the device (contrary to the SPI flash devices).
*
****************************************************************************/
int ee25xx_initialize(FAR struct spi_dev_s *dev, FAR char *devname,
int devtype, int readonly)
{
FAR struct ee25xx_dev_s *eedev;
/* Check device type early */
if ((devtype < 0) ||
(devtype >= sizeof(g_ee25xx_devices) / sizeof(g_ee25xx_devices[0])))
{
return -EINVAL;
}
eedev = kmm_zalloc(sizeof(struct ee25xx_dev_s));
if (!eedev)
{
return -ENOMEM;
}
sem_init(&eedev->sem, 0, 1);
eedev->spi = dev;
eedev->size = 128 << g_ee25xx_devices[devtype].bytes;
eedev->pgsize = 8 << g_ee25xx_devices[devtype].pagesize;
eedev->addrlen = g_ee25xx_devices[devtype].addrlen << 3;
if ( (g_ee25xx_devices[devtype].flags & 1))
{
eedev->addrlen = 9;
}
eedev->readonly = !!readonly;
lowsyslog(LOG_NOTICE,
"EEPROM device %s, %d bytes, %d per page, addrlen %d, readonly %d\n",
devname, eedev->size, eedev->pgsize, eedev->addrlen, eedev->readonly);
return register_driver(devname, &ee25xx_fops, 0666, eedev);
}
Reference in New Issue View Git Blame Copy Permalink