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nuttx/drivers/eeprom/i2c_xx24xx.c

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/****************************************************************************
* drivers/eeprom/i2c_xx24xx.c
*
* Copyright (C) 2018 Sebastien Lorquet. 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 I2C EEPROMs that use the same commands as the
* xx24xx.
*
* The following devices should be supported:
*
* Manufacturer Device Bytes PgSize AddrLen DevAddr
* Microchip
* 24xx00 16 1 1 1010000 Special case
* 24xx01 128 8 1 1010000
* 24xx02 256 8 1 1010000
* 24xx04 512 16 1 101000P
* 24xx08 1024 16 1 10100PP
* 24xx16 2048 16 1 1010PPP
* 24xx32 4096 32 2 1010AAA
* 24xx64 8192 32 2 1010AAA
* 24xx128 16384 64 2 1010AAA
* 24xx256 32768 64 2 1010AAA
* 24xx512 65536 128 2 1010AAA
* 24xx1025 131072 128 2 1010PAA Special case: address bit is shifted.
* 24xx1026 131072 128 2 1010AAP
*
* Atmel
* AT24C01 128 8 1 1010AAA
* AT24C02 256 8 1 1010AAA
* AT24C04 512 16 1 1010AAP P bits = word address
* AT24C08 1024 16 1 1010APP
* AT24C16 2048 16 1 1010PPP
* AT24C32 4096 32 2 1010AAA
* AT24C64 8192 32 2 1010AAA
* AT24C128 16384 64 2 10100AA
* AT24C256 32768 64 2 10100AA
* AT24C512 65536 128 2 10100AA
* AT24C1024 131072 256 2 10100AP
*
* ST Microelectronics
* M24C01 128 16 1 1010AAA
* M24C02 256 16 1 1010AAA
* M24C04 512 16 1 1010AAP
* M24C08 1024 16 1 1010APP
* M24C16 2048 16 1 1010PPP
* M24C32 4096 32 2 1010AAA ID pages supported as a separate device
* M24C64 8192 32 2 1010AAA
* M24128 16384 64 2 1010AAA
* M24256 32768 64 2 1010AAA
* M24512 65536 128 2 1010AAA
* M24M01 131072 256 2 1010AAP
* M24M02 262144 256 2 1010APP
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdbool.h>
#include <sys/types.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/fs/fs.h>
#include <nuttx/kmalloc.h>
#include <nuttx/i2c/i2c_master.h>
#include <nuttx/eeprom/i2c_xx24xx.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_EE24XX_FREQUENCY
#define CONFIG_EE24XX_FREQUENCY 100000
#endif
/****************************************************************************
* Types
****************************************************************************/
/* Device geometry description, compact form (2 bytes per entry) */
struct ee24xx_geom_s
{
uint8_t bytes : 4; /* Power of two of 128 bytes (0:128 ... 11:262144) */
uint8_t pagesize : 4; /* Power of two of 8 bytes (0:8 1:16 2:32 3:64 etc) */
uint8_t addrlen : 4; /* Nr of bytes in command address field */
uint8_t abits : 3; /* Nr of Address MSBits in the i2c device address LSBs*/
uint8_t special : 1; /* Special device: uchip 24xx00 (total 16 bytes)
* or 24xx1025 (shifted P bits) */
};
/* Private data attached to the inode */
struct ee24xx_dev_s
{
/* Bus management */
struct i2c_master_s *i2c; /* I2C device where the EEPROM is attached */
uint32_t freq; /* I2C bus speed */
uint8_t addr; /* 7-bit unshifted I2C device address */
/* Driver management */
sem_t sem; /* file write access serialization */
uint8_t refs; /* Nr of times the device has been opened */
bool readonly; /* Flags */
/* Expanded from geometry */
uint32_t size; /* total bytes in device */
uint16_t pgsize; /* write block size, in bytes */
uint16_t addrlen; /* number of bytes in data addresses */
uint16_t haddrbits; /* Number of bits in high address part */
uint16_t haddrshift; /* bit-shift of high address part */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int ee24xx_open(FAR struct file *filep);
static int ee24xx_close(FAR struct file *filep);
static off_t ee24xx_seek(FAR struct file *filep, off_t offset, int whence);
static ssize_t ee24xx_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static ssize_t ee24xx_write(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
static int ee24xx_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/i2c_xx24xx.h
*/
static const struct ee24xx_geom_s g_ee24xx_devices[] =
{
/* Microchip devices */
/* by pg al ab sp device bytes page alen */
{ 0, 1, 1, 0, 1}, /* 24xx00 16 1 1 Ridiculously small device */
{ 0, 0, 1, 0, 0}, /* 24xx01 128 8 1 */
{ 1, 0, 1, 0, 0}, /* 24xx02 256 8 1 */
{ 2, 1, 1, 1, 0}, /* 24xx04 512 16 1 */
{ 3, 1, 1, 2, 0}, /* 24xx08 1024 16 1 */
{ 4, 1, 1, 3, 0}, /* 24xx16 2048 16 1 */
{ 5, 2, 2, 0, 0}, /* 24xx32 4096 32 2 */
{ 6, 2, 2, 0, 0}, /* 24xx64 8192 32 2 */
{ 7, 3, 2, 0, 0}, /* 24xx128 16384 64 2 */
{ 8, 3, 2, 0, 0}, /* 24xx256 32768 64 2 */
{ 9, 4, 2, 0, 0}, /* 24xx512 65536 128 2 */
{10, 4, 2, 1, 1}, /* 24xx1025 131072 128 2 Shifted address, todo */
{10, 4, 2, 1, 0}, /* 24xx1026 131072 128 2 */
/* STM devices */
{ 0, 1, 1, 0, 0}, /* M24C01 128 16 1 */
{ 1, 1, 1, 0, 0}, /* M24C02 256 16 1 */
{11, 5, 2, 2, 0}, /* M24M02 262144 256 2 */
};
/* Driver operations */
static const struct file_operations ee24xx_fops =
{
ee24xx_open, /* open */
ee24xx_close, /* close */
ee24xx_read, /* read */
ee24xx_write, /* write */
ee24xx_seek, /* seek */
ee24xx_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, 0 /* poll */
#endif
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: ee24xx_waitwritecomplete
*
* Use ACK polling to detect the completion of the write operation.
* Returns TRUE if write is complete (device replies to ACK).
* Note: The device always replies an ACK for the control byte, the polling
* shall be done using the ACK for the memory address byte. Read or write does
* not matter.
* Note: We should sleep a bit between retries, the write time is around 5 ms,
* but the bus is slow, so, a few retries at most will happen.
*
****************************************************************************/
static int ee24xx_waitwritecomplete(FAR struct ee24xx_dev_s *eedev,
uint32_t memaddr)
{
struct i2c_msg_s msgs[1];
int ret;
int retries = 100;
uint8_t adr;
uint32_t addr_hi = (memaddr >> (eedev->addrlen << 3));
msgs[0].frequency = eedev->freq;
msgs[0].addr = eedev->addr | (addr_hi & ((1 << eedev->haddrbits) - 1));
msgs[0].flags = I2C_M_READ;
msgs[0].buffer = &adr;
msgs[0].length = 1;
do
{
ret = I2C_TRANSFER(eedev->i2c, msgs, 1);
retries--;
}
while(ret != 0 && retries > 0);
return ret;
}
/****************************************************************************
* Name: ee24xx_writepage
*
* Description: Write data to the EEPROM, NOT crossing page boundaries.
* To avoid allocating a buffer to prepend the address, we are using 2 I2C
* messages while avoiding beginning the second one with a restart condition.
*
****************************************************************************/
static int ee24xx_writepage(FAR struct ee24xx_dev_s *eedev, uint32_t memaddr,
FAR const char *buffer, size_t len)
{
struct i2c_msg_s msgs[2];
uint8_t maddr[2];
uint32_t addr_hi = (memaddr >> (eedev->addrlen << 3));
/* Write data address */
maddr[0] = memaddr >> 8;
maddr[1] = memaddr & 0xFF;
msgs[0].frequency = eedev->freq;
msgs[0].addr = eedev->addr | (addr_hi & ((1 << eedev->haddrbits) - 1));
msgs[0].flags = 0;
msgs[0].buffer = eedev->addrlen==2 ? &maddr[0] : &maddr[1];
msgs[0].length = eedev->addrlen;
/* Write data without a restart nor a control byte */
msgs[1].frequency = msgs[0].frequency;
msgs[1].addr = msgs[0].addr;
msgs[1].flags = I2C_M_NORESTART;
msgs[1].buffer = (uint8_t*)buffer;
msgs[1].length = len;
return I2C_TRANSFER(eedev->i2c, msgs, 2);
}
/****************************************************************************
* Name: ee24xx_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 ee24xx_semtake(FAR struct ee24xx_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.
*/
DEBUGASSERT(errno == EINTR);
}
}
/****************************************************************************
* Name: ee24xx_semgive
*
* Release a resource to access the device.
*
****************************************************************************/
static inline void ee24xx_semgive(FAR struct ee24xx_dev_s *eedev)
{
sem_post(&eedev->sem);
}
/****************************************************************************
* Driver Functions
****************************************************************************/
/****************************************************************************
* Name: ee24xx_open
*
* Description: Open the block device
*
****************************************************************************/
static int ee24xx_open(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ee24xx_dev_s *eedev;
int ret = OK;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee24xx_dev_s *)inode->i_private;
ee24xx_semtake(eedev);
/* Increment the reference count */
if ((eedev->refs + 1) == 0)
{
ret = -EMFILE;
}
else
{
eedev->refs += 1;
}
ee24xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee24xx_close
*
* Description: Close the block device
*
****************************************************************************/
static int ee24xx_close(FAR struct file *filep)
{
FAR struct inode *inode = filep->f_inode;
FAR struct ee24xx_dev_s *eedev;
int ret = OK;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee24xx_dev_s *)inode->i_private;
ee24xx_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;
}
ee24xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee24xx_seek
*
* Remark: Copied from bchlib
*
****************************************************************************/
static off_t ee24xx_seek(FAR struct file *filep, off_t offset, int whence)
{
FAR struct ee24xx_dev_s *eedev;
off_t newpos;
int ret;
FAR struct inode *inode = filep->f_inode;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee24xx_dev_s *)inode->i_private;
ee24xx_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 */
ee24xx_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;
finfo("SEEK newpos %d\n",newpos);
}
else
{
ret = -EINVAL;
}
ee24xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee24xx_read
****************************************************************************/
static ssize_t ee24xx_read(FAR struct file *filep, FAR char *buffer,
size_t len)
{
FAR struct ee24xx_dev_s *eedev;
FAR struct inode *inode = filep->f_inode;
struct i2c_msg_s msgs[2];
uint8_t addr[2];
uint32_t addr_hi;
int ret;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee24xx_dev_s *)inode->i_private;
ee24xx_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;
}
if (len == 0)
{
/* We are at end of file */
ret = 0;
goto done;
}
/* Write data address */
finfo("READ %d bytes at pos %d\n", len, filep->f_pos);
addr_hi = (filep->f_pos >> (eedev->addrlen << 3));
addr[0] = (filep->f_pos) >> 8;
addr[1] = (filep->f_pos) & 0xFF;
msgs[0].frequency = eedev->freq;
msgs[0].addr = eedev->addr | (addr_hi & ((1 << eedev->haddrbits) - 1));
msgs[0].flags = 0;
msgs[0].buffer = eedev->addrlen==2 ? &addr[0] : &addr[1];
msgs[0].length = eedev->addrlen;
/* Read data */
msgs[1].frequency = msgs[0].frequency;
msgs[1].addr = msgs[0].addr;
msgs[1].flags = I2C_M_READ;
msgs[1].buffer = (uint8_t*)buffer;
msgs[1].length = len;
ret = I2C_TRANSFER(eedev->i2c, msgs, 2);
if (ret < 0)
{
goto done;
}
ret = len;
/* Update the file position */
filep->f_pos += len;
done:
ee24xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee24xx_write
****************************************************************************/
static ssize_t ee24xx_write(FAR struct file *filep, FAR const char *buffer,
size_t len)
{
FAR struct ee24xx_dev_s *eedev;
size_t cnt;
int pageoff;
FAR struct inode *inode = filep->f_inode;
int ret = -EACCES;
int savelen;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee24xx_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;
}
finfo("Entering with len=%d\n", len);
/* Clamp len to avoid crossing the end of the memory */
if ((len + filep->f_pos) > eedev->size)
{
len = eedev->size - filep->f_pos;
finfo("Len clamped to %d\n", len);
}
savelen = len; /* save number of bytes written */
ee24xx_semtake(eedev);
/* Writes can't 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, a separate I2C transaction
* required to continue writing.
*/
/* 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)
{
finfo("First %d unaligned bytes at %d (pageoff %d)\n", cnt, filep->f_pos,
pageoff);
ret = ee24xx_writepage(eedev, filep->f_pos, buffer, cnt);
if (ret < 0)
{
ferr("write failed, ret = %d\n", ret);
goto done;
}
ret = ee24xx_waitwritecomplete(eedev, filep->f_pos);
if (ret < 0)
{
ferr("writecomplete failed, ret = %d\n", ret);
goto done;
}
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;
}
finfo("Aligned page write for %d bytes at %d\n", cnt, filep->f_pos);
ret = ee24xx_writepage(eedev, filep->f_pos, buffer, cnt);
if (ret < 0)
{
ferr("write failed, ret = %d\n", ret);
goto done;
}
ret = ee24xx_waitwritecomplete(eedev, filep->f_pos);
if (ret < 0)
{
ferr("writecomplete failed, ret = %d\n", ret);
goto done;
}
len -= cnt;
buffer += cnt;
filep->f_pos += cnt;
}
ret = savelen;
done:
ee24xx_semgive(eedev);
return ret;
}
/****************************************************************************
* Name: ee24xx_ioctl
*
* Description: TODO: Erase a sector/page/device or read device ID / MAC.
* This is completely optional.
*
****************************************************************************/
static int ee24xx_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct ee24xx_dev_s *eedev;
FAR struct inode *inode = filep->f_inode;
int ret = 0;
DEBUGASSERT(inode && inode->i_private);
eedev = (FAR struct ee24xx_dev_s *)inode->i_private;
switch (cmd)
{
default:
(void)eedev;
ret = -EINVAL;
}
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: ee24xx_initialize
*
* Description: Bind a EEPROM driver to an I2C 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 ee24xx_initialize(FAR struct i2c_master_s *bus, uint8_t devaddr,
FAR char *devname, int devtype, int readonly)
{
FAR struct ee24xx_dev_s *eedev;
/* Check device type early */
if ((devtype < 0) ||
(devtype >= sizeof(g_ee24xx_devices) / sizeof(g_ee24xx_devices[0])))
{
return -EINVAL;
}
eedev = kmm_zalloc(sizeof(struct ee24xx_dev_s));
if (!eedev)
{
return -ENOMEM;
}
sem_init(&eedev->sem, 0, 1);
eedev->freq = CONFIG_EE24XX_FREQUENCY;
eedev->i2c = bus;
eedev->addr = devaddr;
eedev->readonly = !!readonly;
/* Expand device geometry from compacted info */
eedev->size = 128 << g_ee24xx_devices[devtype].bytes;
eedev->pgsize = 8 << g_ee24xx_devices[devtype].pagesize;
eedev->addrlen = g_ee24xx_devices[devtype].addrlen;
eedev->haddrbits = g_ee24xx_devices[devtype].abits;
eedev->haddrshift = 0;
/* Apply special properties */
if (g_ee24xx_devices[devtype].special)
{
if (devtype == EEPROM_24xx00)
{
/* Ultra small 16-byte EEPROM */
eedev->size = 16;
/* The device only has BYTE write,
* which is emulated with 1-byte pages
*/
eedev->pgsize = 1;
}
else if (devtype == EEPROM_24xx1025)
{
/* Microchip alien part where the address MSB is << 2 bits */
ferr("Device 24xx1025 is not supported for the moment, TODO.\n");
eedev->haddrshift = 2;
free(eedev);
return -ENODEV;
}
}
finfo("EEPROM device %s, %d bytes, %d per page, addrlen %d, %s\n",
devname, eedev->size, eedev->pgsize, eedev->addrlen,
eedev->readonly ? "readonly" : "");
return register_driver(devname, &ee24xx_fops, 0666, eedev);
}
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