eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
/*
|
|
|
|
* at24.c - handle most I2C EEPROMs
|
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*
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* Copyright (C) 2005-2007 David Brownell
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* Copyright (C) 2008 Wolfram Sang, Pengutronix
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*
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|
* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <common.h>
|
|
|
|
#include <init.h>
|
|
|
|
#include <malloc.h>
|
|
|
|
#include <clock.h>
|
|
|
|
#include <driver.h>
|
|
|
|
#include <xfuncs.h>
|
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|
|
#include <errno.h>
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|
|
#include <linux/math64.h>
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|
|
#include <linux/log2.h>
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|
#include <i2c/i2c.h>
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#include <i2c/at24.h>
|
2015-07-30 15:38:29 +00:00
|
|
|
#include <gpio.h>
|
|
|
|
#include <of_gpio.h>
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
|
|
|
|
/*
|
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|
* I2C EEPROMs from most vendors are inexpensive and mostly interchangeable.
|
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* Differences between different vendor product lines (like Atmel AT24C or
|
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|
|
* MicroChip 24LC, etc) won't much matter for typical read/write access.
|
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|
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* There are also I2C RAM chips, likewise interchangeable. One example
|
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|
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* would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes).
|
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*
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* However, misconfiguration can lose data. "Set 16-bit memory address"
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* to a part with 8-bit addressing will overwrite data. Writing with too
|
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* big a page size also loses data. And it's not safe to assume that the
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* conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC
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* uses 0x51, for just one example.
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*
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* So this driver uses "new style" I2C driver binding, expecting to be
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* told what devices exist. That may be in arch/X/mach-Y/board-Z.c or
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* similar kernel-resident tables; or, configuration data coming from
|
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|
|
* a bootloader.
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*
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* Other than binding model, current differences from "eeprom" driver are
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* that this one handles write access and isn't restricted to 24c02 devices.
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* It also handles larger devices (32 kbit and up) with two-byte addresses,
|
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* which won't work on pure SMBus systems.
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|
|
*/
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struct at24_data {
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struct at24_platform_data chip;
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struct cdev cdev;
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|
|
struct file_operations fops;
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|
|
u8 *writebuf;
|
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|
|
unsigned write_max;
|
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|
|
unsigned num_addresses;
|
2015-07-30 15:38:29 +00:00
|
|
|
int wp_gpio;
|
|
|
|
int wp_active_low;
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Some chips tie up multiple I2C addresses; dummy devices reserve
|
|
|
|
* them for us.
|
|
|
|
*/
|
|
|
|
struct i2c_client *client[];
|
|
|
|
};
|
|
|
|
|
|
|
|
/*
|
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|
|
* This parameter is to help this driver avoid blocking other drivers out
|
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|
|
* of I2C for potentially troublesome amounts of time. With a 100 kHz I2C
|
|
|
|
* clock, one 256 byte read takes about 1/43 second which is excessive;
|
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|
|
* but the 1/170 second it takes at 400 kHz may be quite reasonable; and
|
|
|
|
* at 1 MHz (Fm+) a 1/430 second delay could easily be invisible.
|
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|
|
*
|
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|
|
* This value is forced to be a power of two so that writes align on pages.
|
|
|
|
*/
|
|
|
|
static unsigned io_limit = 128;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Specs often allow 5 msec for a page write, sometimes 20 msec;
|
|
|
|
* it's important to recover from write timeouts.
|
|
|
|
*/
|
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|
|
static unsigned write_timeout = 25;
|
|
|
|
|
2015-11-23 23:40:53 +00:00
|
|
|
/* number of bits in driver_data reserved for eeprom byte length */
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
#define AT24_SIZE_BYTELEN 5
|
2015-11-23 23:40:53 +00:00
|
|
|
/* number of bits in driver_data reserved for flags */
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
#define AT24_SIZE_FLAGS 8
|
|
|
|
|
|
|
|
#define AT24_BITMASK(x) (BIT(x) - 1)
|
|
|
|
|
|
|
|
/* create non-zero magic value for given eeprom parameters */
|
|
|
|
#define AT24_DEVICE_MAGIC(_len, _flags) \
|
|
|
|
((1 << AT24_SIZE_FLAGS | (_flags)) \
|
|
|
|
<< AT24_SIZE_BYTELEN | ilog2(_len))
|
|
|
|
|
|
|
|
static struct platform_device_id at24_ids[] = {
|
|
|
|
/* needs 8 addresses as A0-A2 are ignored */
|
|
|
|
{ "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) },
|
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|
|
/* old variants can't be handled with this generic entry! */
|
|
|
|
{ "24c01", AT24_DEVICE_MAGIC(1024 / 8, 0) },
|
|
|
|
{ "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) },
|
|
|
|
/* spd is a 24c02 in memory DIMMs */
|
|
|
|
{ "spd", AT24_DEVICE_MAGIC(2048 / 8,
|
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|
|
AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
|
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|
|
{ "24c04", AT24_DEVICE_MAGIC(4096 / 8, 0) },
|
|
|
|
/* 24rf08 quirk is handled at i2c-core */
|
|
|
|
{ "24c08", AT24_DEVICE_MAGIC(8192 / 8, 0) },
|
|
|
|
{ "24c16", AT24_DEVICE_MAGIC(16384 / 8, 0) },
|
|
|
|
{ "24c32", AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16) },
|
|
|
|
{ "24c64", AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16) },
|
|
|
|
{ "24c128", AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16) },
|
|
|
|
{ "24c256", AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16) },
|
|
|
|
{ "24c512", AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16) },
|
|
|
|
{ "24c1024", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16) },
|
2015-11-23 23:40:53 +00:00
|
|
|
{ "24c1025", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16 | AT24_FLAG_BANK_BIT_2) },
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
{ "at24", 0 },
|
|
|
|
{ /* END OF LIST */ }
|
|
|
|
};
|
|
|
|
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* This routine supports chips which consume multiple I2C addresses. It
|
|
|
|
* computes the addressing information to be used for a given r/w request.
|
|
|
|
* Assumes that sanity checks for offset happened at sysfs-layer.
|
|
|
|
*/
|
|
|
|
static struct i2c_client *at24_translate_offset(struct at24_data *at24,
|
|
|
|
unsigned *offset)
|
|
|
|
{
|
|
|
|
unsigned i;
|
|
|
|
|
|
|
|
if (at24->chip.flags & AT24_FLAG_ADDR16) {
|
|
|
|
i = *offset >> 16;
|
|
|
|
*offset &= 0xffff;
|
|
|
|
} else {
|
|
|
|
i = *offset >> 8;
|
|
|
|
*offset &= 0xff;
|
|
|
|
}
|
|
|
|
|
|
|
|
return at24->client[i];
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf,
|
|
|
|
unsigned offset, size_t count)
|
|
|
|
{
|
|
|
|
struct i2c_msg msg[2];
|
|
|
|
u8 msgbuf[2];
|
|
|
|
struct i2c_client *client;
|
|
|
|
int status, i;
|
|
|
|
uint64_t start, read_time;
|
|
|
|
|
|
|
|
memset(msg, 0, sizeof(msg));
|
|
|
|
|
|
|
|
/*
|
|
|
|
* REVISIT some multi-address chips don't rollover page reads to
|
|
|
|
* the next slave address, so we may need to truncate the count.
|
|
|
|
* Those chips might need another quirk flag.
|
|
|
|
*
|
|
|
|
* If the real hardware used four adjacent 24c02 chips and that
|
|
|
|
* were misconfigured as one 24c08, that would be a similar effect:
|
|
|
|
* one "eeprom" file not four, but larger reads would fail when
|
|
|
|
* they crossed certain pages.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Slave address and byte offset derive from the offset. Always
|
|
|
|
* set the byte address; on a multi-master board, another master
|
|
|
|
* may have changed the chip's "current" address pointer.
|
|
|
|
*/
|
|
|
|
client = at24_translate_offset(at24, &offset);
|
|
|
|
|
|
|
|
if (count > io_limit)
|
|
|
|
count = io_limit;
|
|
|
|
|
|
|
|
i = 0;
|
|
|
|
if (at24->chip.flags & AT24_FLAG_ADDR16)
|
|
|
|
msgbuf[i++] = offset >> 8;
|
|
|
|
msgbuf[i++] = offset;
|
|
|
|
|
|
|
|
msg[0].addr = client->addr;
|
|
|
|
msg[0].buf = msgbuf;
|
|
|
|
msg[0].len = i;
|
|
|
|
|
|
|
|
msg[1].addr = client->addr;
|
|
|
|
msg[1].flags = I2C_M_RD;
|
|
|
|
msg[1].buf = buf;
|
|
|
|
msg[1].len = count;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Reads fail if the previous write didn't complete yet. We may
|
|
|
|
* loop a few times until this one succeeds, waiting at least
|
|
|
|
* long enough for one entire page write to work.
|
|
|
|
*/
|
|
|
|
start = get_time_ns();
|
|
|
|
do {
|
|
|
|
read_time = get_time_ns();
|
|
|
|
status = i2c_transfer(client->adapter, msg, 2);
|
|
|
|
if (status == 2)
|
|
|
|
status = count;
|
|
|
|
dev_dbg(&client->dev, "read %zu@%d --> %d (%llu)\n",
|
|
|
|
count, offset, status, read_time);
|
|
|
|
|
|
|
|
if (status == count)
|
|
|
|
return count;
|
|
|
|
|
|
|
|
/* REVISIT: at HZ=100, this is sloooow */
|
|
|
|
mdelay(1);
|
|
|
|
} while (!is_timeout(start, write_timeout * MSECOND));
|
|
|
|
|
|
|
|
return -ETIMEDOUT;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t at24_read(struct at24_data *at24,
|
|
|
|
char *buf, loff_t off, size_t count)
|
|
|
|
{
|
|
|
|
ssize_t retval = 0;
|
|
|
|
|
|
|
|
if (unlikely(!count))
|
|
|
|
return count;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Read data from chip, protecting against concurrent updates
|
|
|
|
* from this host, but not from other I2C masters.
|
|
|
|
*/
|
|
|
|
while (count) {
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
status = at24_eeprom_read(at24, buf, off, count);
|
|
|
|
if (status <= 0) {
|
|
|
|
if (retval == 0)
|
|
|
|
retval = status;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
buf += status;
|
|
|
|
off += status;
|
|
|
|
count -= status;
|
|
|
|
retval += status;
|
|
|
|
}
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t at24_cdev_read(struct cdev *cdev, void *buf, size_t count,
|
|
|
|
loff_t off, ulong flags)
|
|
|
|
{
|
|
|
|
struct at24_data *at24 = cdev->priv;
|
|
|
|
|
|
|
|
return at24_read(at24, buf, off, count);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Note that if the hardware write-protect pin is pulled high, the whole
|
|
|
|
* chip is normally write protected. But there are plenty of product
|
|
|
|
* variants here, including OTP fuses and partial chip protect.
|
|
|
|
*
|
|
|
|
* We only use page mode writes; the alternative is sloooow. This routine
|
|
|
|
* writes at most one page.
|
|
|
|
*/
|
|
|
|
static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
|
|
|
|
unsigned offset, size_t count)
|
|
|
|
{
|
|
|
|
struct i2c_client *client;
|
|
|
|
struct i2c_msg msg;
|
|
|
|
ssize_t status;
|
|
|
|
uint64_t start, write_time;
|
|
|
|
unsigned next_page;
|
|
|
|
int i = 0;
|
|
|
|
|
|
|
|
/* Get corresponding I2C address and adjust offset */
|
|
|
|
client = at24_translate_offset(at24, &offset);
|
|
|
|
|
|
|
|
/* write_max is at most a page */
|
|
|
|
if (count > at24->write_max)
|
|
|
|
count = at24->write_max;
|
|
|
|
|
|
|
|
/* Never roll over backwards, to the start of this page */
|
|
|
|
next_page = roundup(offset + 1, at24->chip.page_size);
|
|
|
|
if (offset + count > next_page)
|
|
|
|
count = next_page - offset;
|
|
|
|
|
|
|
|
|
|
|
|
msg.addr = client->addr;
|
|
|
|
msg.flags = 0;
|
|
|
|
|
|
|
|
/* msg.buf is u8 and casts will mask the values */
|
|
|
|
msg.buf = at24->writebuf;
|
|
|
|
if (at24->chip.flags & AT24_FLAG_ADDR16)
|
|
|
|
msg.buf[i++] = offset >> 8;
|
|
|
|
|
|
|
|
msg.buf[i++] = offset;
|
|
|
|
memcpy(&msg.buf[i], buf, count);
|
|
|
|
msg.len = i + count;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Writes fail if the previous one didn't complete yet. We may
|
|
|
|
* loop a few times until this one succeeds, waiting at least
|
|
|
|
* long enough for one entire page write to work.
|
|
|
|
*/
|
|
|
|
start = get_time_ns();
|
|
|
|
do {
|
|
|
|
write_time = get_time_ns();
|
|
|
|
status = i2c_transfer(client->adapter, &msg, 1);
|
|
|
|
if (status == 1)
|
|
|
|
status = count;
|
|
|
|
dev_dbg(&client->dev, "write %zu@%d --> %zd (%llu)\n",
|
|
|
|
count, offset, status, write_time);
|
|
|
|
|
|
|
|
if (status == count)
|
|
|
|
return count;
|
|
|
|
|
|
|
|
/* REVISIT: at HZ=100, this is sloooow */
|
|
|
|
mdelay(1);
|
|
|
|
} while (!is_timeout(start, write_timeout * MSECOND));
|
|
|
|
|
|
|
|
return -ETIMEDOUT;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t at24_write(struct at24_data *at24, const char *buf, loff_t off,
|
|
|
|
size_t count)
|
|
|
|
{
|
|
|
|
ssize_t retval = 0;
|
|
|
|
|
|
|
|
if (unlikely(!count))
|
|
|
|
return count;
|
|
|
|
|
|
|
|
while (count) {
|
|
|
|
ssize_t status;
|
|
|
|
|
|
|
|
status = at24_eeprom_write(at24, buf, off, count);
|
|
|
|
if (status <= 0) {
|
|
|
|
if (retval == 0)
|
|
|
|
retval = status;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
buf += status;
|
|
|
|
off += status;
|
|
|
|
count -= status;
|
|
|
|
retval += status;
|
|
|
|
}
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t at24_cdev_write(struct cdev *cdev, const void *buf, size_t count,
|
|
|
|
loff_t off, ulong flags)
|
|
|
|
{
|
|
|
|
struct at24_data *at24 = cdev->priv;
|
|
|
|
|
|
|
|
return at24_write(at24, buf, off, count);
|
|
|
|
}
|
|
|
|
|
2015-07-30 15:38:29 +00:00
|
|
|
static ssize_t at24_cdev_protect(struct cdev *cdev, size_t count, loff_t offset,
|
|
|
|
int prot)
|
|
|
|
{
|
|
|
|
struct at24_data *at24 = cdev->priv;
|
|
|
|
|
|
|
|
if (!gpio_is_valid(at24->wp_gpio))
|
|
|
|
return -EOPNOTSUPP;
|
|
|
|
|
|
|
|
prot = !!prot;
|
|
|
|
if (at24->wp_active_low)
|
|
|
|
prot = !prot;
|
|
|
|
|
|
|
|
gpio_set_value(at24->wp_gpio, prot);
|
|
|
|
|
|
|
|
udelay(50);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
static int at24_probe(struct device_d *dev)
|
|
|
|
{
|
|
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
|
|
struct at24_platform_data chip;
|
|
|
|
bool writable;
|
|
|
|
struct at24_data *at24;
|
|
|
|
int err;
|
|
|
|
unsigned i, num_addresses;
|
|
|
|
|
|
|
|
if (dev->platform_data) {
|
|
|
|
chip = *(struct at24_platform_data *)dev->platform_data;
|
|
|
|
} else {
|
|
|
|
unsigned long magic;
|
2015-11-24 19:53:56 +00:00
|
|
|
u32 page_size;
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
|
2015-04-29 08:56:58 +00:00
|
|
|
err = dev_get_drvdata(dev, (const void **)&magic);
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
if (err)
|
|
|
|
return err;
|
|
|
|
|
|
|
|
chip.byte_len = BIT(magic & AT24_BITMASK(AT24_SIZE_BYTELEN));
|
|
|
|
magic >>= AT24_SIZE_BYTELEN;
|
|
|
|
chip.flags = magic & AT24_BITMASK(AT24_SIZE_FLAGS);
|
2015-11-24 19:53:56 +00:00
|
|
|
if (dev->device_node &&
|
|
|
|
!of_property_read_u32(dev->device_node, "pagesize", &page_size))
|
|
|
|
chip.page_size = page_size;
|
|
|
|
else {
|
|
|
|
/*
|
|
|
|
* This is slow, but we can't know all eeproms, so we better
|
|
|
|
* play safe. Specifying custom eeprom-types via platform_data
|
|
|
|
* is recommended anyhow.
|
|
|
|
*/
|
|
|
|
chip.page_size = 1;
|
|
|
|
}
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
if (!is_power_of_2(chip.byte_len))
|
|
|
|
dev_warn(&client->dev,
|
|
|
|
"byte_len looks suspicious (no power of 2)!\n");
|
|
|
|
if (!chip.page_size) {
|
|
|
|
dev_err(&client->dev, "page_size must not be 0!\n");
|
|
|
|
err = -EINVAL;
|
|
|
|
goto err_out;
|
|
|
|
}
|
|
|
|
if (!is_power_of_2(chip.page_size))
|
|
|
|
dev_warn(&client->dev,
|
|
|
|
"page_size looks suspicious (no power of 2)!\n");
|
|
|
|
|
|
|
|
if (chip.flags & AT24_FLAG_TAKE8ADDR)
|
|
|
|
num_addresses = 8;
|
|
|
|
else
|
|
|
|
num_addresses = DIV_ROUND_UP(chip.byte_len,
|
|
|
|
(chip.flags & AT24_FLAG_ADDR16) ? 65536 : 256);
|
|
|
|
|
|
|
|
at24 = xzalloc(sizeof(struct at24_data) +
|
|
|
|
num_addresses * sizeof(struct i2c_client *));
|
|
|
|
|
|
|
|
at24->chip = chip;
|
|
|
|
at24->num_addresses = num_addresses;
|
|
|
|
at24->cdev.name = asprintf("eeprom%d", dev->id);
|
|
|
|
at24->cdev.priv = at24;
|
|
|
|
at24->cdev.dev = dev;
|
|
|
|
at24->cdev.ops = &at24->fops;
|
|
|
|
at24->fops.lseek = dev_lseek_default;
|
|
|
|
at24->fops.read = at24_cdev_read,
|
2015-07-30 15:38:29 +00:00
|
|
|
at24->fops.protect = at24_cdev_protect,
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
at24->cdev.size = chip.byte_len;
|
|
|
|
|
|
|
|
writable = !(chip.flags & AT24_FLAG_READONLY);
|
|
|
|
if (writable) {
|
|
|
|
unsigned write_max = chip.page_size;
|
|
|
|
|
|
|
|
at24->fops.write = at24_cdev_write;
|
|
|
|
|
|
|
|
if (write_max > io_limit)
|
|
|
|
write_max = io_limit;
|
|
|
|
at24->write_max = write_max;
|
|
|
|
|
|
|
|
/* buffer (data + address at the beginning) */
|
|
|
|
at24->writebuf = xmalloc(write_max + 2);
|
|
|
|
}
|
|
|
|
|
2015-07-30 15:38:29 +00:00
|
|
|
at24->wp_gpio = -1;
|
|
|
|
if (dev->device_node) {
|
|
|
|
enum of_gpio_flags flags;
|
|
|
|
at24->wp_gpio = of_get_named_gpio_flags(dev->device_node,
|
|
|
|
"wp-gpios", 0, &flags);
|
|
|
|
if (gpio_is_valid(at24->wp_gpio)) {
|
|
|
|
at24->wp_active_low = flags & OF_GPIO_ACTIVE_LOW;
|
|
|
|
gpio_request(at24->wp_gpio, "eeprom-wp");
|
|
|
|
gpio_direction_output(at24->wp_gpio,
|
|
|
|
!at24->wp_active_low);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
at24->client[0] = client;
|
|
|
|
|
|
|
|
/* use dummy devices for multiple-address chips */
|
|
|
|
for (i = 1; i < num_addresses; i++) {
|
2015-11-23 23:40:53 +00:00
|
|
|
const int shift = (chip.flags & AT24_FLAG_BANK_BIT_2) ? 2 : 0;
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
at24->client[i] = i2c_new_dummy(client->adapter,
|
2015-11-23 23:40:53 +00:00
|
|
|
client->addr + (i << shift));
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
if (!at24->client[i]) {
|
|
|
|
dev_err(&client->dev, "address 0x%02x unavailable\n",
|
2015-11-23 23:40:53 +00:00
|
|
|
client->addr + (i << shift));
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
err = -EADDRINUSE;
|
|
|
|
goto err_clients;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
devfs_create(&at24->cdev);
|
|
|
|
|
2013-11-07 13:31:50 +00:00
|
|
|
of_parse_partitions(&at24->cdev, dev->device_node);
|
|
|
|
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
err_clients:
|
2015-07-30 15:38:29 +00:00
|
|
|
gpio_free(at24->wp_gpio);
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
kfree(at24->writebuf);
|
|
|
|
kfree(at24);
|
|
|
|
err_out:
|
|
|
|
dev_dbg(&client->dev, "probe error %d\n", err);
|
|
|
|
return err;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct driver_d at24_driver = {
|
|
|
|
.name = "at24",
|
|
|
|
.probe = at24_probe,
|
|
|
|
.id_table = at24_ids,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int at24_init(void)
|
|
|
|
{
|
2013-03-10 06:41:34 +00:00
|
|
|
i2c_driver_register(&at24_driver);
|
eeprom: add at24 support
This driver to get read/write support to most I2C EEPROMs,
after you configure the driver to know about each EEPROM on
your target board. Use these generic chip names, instead of
vendor-specific ones like at24c64 or 24lc02:
24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08,
24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024
Unless you like data loss puzzles, always be sure that any chip
you configure as a 24c32 (32 kbit) or larger is NOT really a
24c16 (16 kbit) or smaller, and vice versa. Marking the chip
as read-only won't help recover from this. Also, if your chip
has any software write-protect mechanism you may want to review the
code to make sure this driver won't turn it on by accident.
Based on linux 3.6
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2012-11-03 20:58:30 +00:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
device_initcall(at24_init);
|