barebox/include/i2c/at24.h
Jean-Christophe PLAGNIOL-VILLARD 7f8547648c 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>
2012-11-15 20:18:50 +01:00

36 lines
1.1 KiB
C

/*
* at24.h - platform_data for the at24 (generic eeprom) driver
* (C) Copyright 2008 by Pengutronix
* (C) Copyright 2012 by Wolfram Sang
* same license as the driver
*/
#ifndef _LINUX_AT24_H
#define _LINUX_AT24_H
#include <linux/types.h>
/**
* struct at24_platform_data - data to set up at24 (generic eeprom) driver
* @byte_len: size of eeprom in byte
* @page_size: number of byte which can be written in one go
* @flags: tunable options, check AT24_FLAG_* defines
*
* If you set up a custom eeprom type, please double-check the parameters.
* Especially page_size needs extra care, as you risk data loss if your value
* is bigger than what the chip actually supports!
*
*/
struct at24_platform_data {
u32 byte_len; /* size (sum of all addr) */
u16 page_size; /* for writes */
u8 flags;
#define AT24_FLAG_ADDR16 0x80 /* address pointer is 16 bit */
#define AT24_FLAG_READONLY 0x40 /* sysfs-entry will be read-only */
#define AT24_FLAG_IRUGO 0x20 /* sysfs-entry will be world-readable */
#define AT24_FLAG_TAKE8ADDR 0x10 /* take always 8 addresses (24c00) */
};
#endif /* _LINUX_AT24_H */