M7350/kernel/include/linux/i2c/at24.h
2024-09-09 08:52:07 +00:00

56 lines
1.8 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>
#include <linux/memory.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
* @setup: an optional callback invoked after eeprom is probed; enables kernel
code to access eeprom via memory_accessor, see example
* @context: optional parameter passed to setup()
*
* 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!
*
* An example in pseudo code for a setup() callback:
*
* void get_mac_addr(struct memory_accessor *mem_acc, void *context)
* {
* u8 *mac_addr = ethernet_pdata->mac_addr;
* off_t offset = context;
*
* // Read MAC addr from EEPROM
* if (mem_acc->read(mem_acc, mac_addr, offset, ETH_ALEN) == ETH_ALEN)
* pr_info("Read MAC addr from EEPROM: %pM\n", mac_addr);
* }
*
* This function pointer and context can now be set up in at24_platform_data.
*/
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) */
void (*setup)(struct memory_accessor *, void *context);
void *context;
};
#endif /* _LINUX_AT24_H */