1 /* 2 * at24.h - platform_data for the at24 (generic eeprom) driver 3 * (C) Copyright 2008 by Pengutronix 4 * (C) Copyright 2012 by Wolfram Sang 5 * same license as the driver 6 */ 7 8 #ifndef _LINUX_AT24_H 9 #define _LINUX_AT24_H 10 11 #include <linux/types.h> 12 #include <linux/nvmem-consumer.h> 13 #include <linux/bitops.h> 14 15 /** 16 * struct at24_platform_data - data to set up at24 (generic eeprom) driver 17 * @byte_len: size of eeprom in byte 18 * @page_size: number of byte which can be written in one go 19 * @flags: tunable options, check AT24_FLAG_* defines 20 * @setup: an optional callback invoked after eeprom is probed; enables kernel 21 code to access eeprom via nvmem, see example 22 * @context: optional parameter passed to setup() 23 * 24 * If you set up a custom eeprom type, please double-check the parameters. 25 * Especially page_size needs extra care, as you risk data loss if your value 26 * is bigger than what the chip actually supports! 27 * 28 * An example in pseudo code for a setup() callback: 29 * 30 * void get_mac_addr(struct nvmem_device *nvmem, void *context) 31 * { 32 * u8 *mac_addr = ethernet_pdata->mac_addr; 33 * off_t offset = context; 34 * 35 * // Read MAC addr from EEPROM 36 * if (nvmem_device_read(nvmem, offset, ETH_ALEN, mac_addr) == ETH_ALEN) 37 * pr_info("Read MAC addr from EEPROM: %pM\n", mac_addr); 38 * } 39 * 40 * This function pointer and context can now be set up in at24_platform_data. 41 */ 42 43 struct at24_platform_data { 44 u32 byte_len; /* size (sum of all addr) */ 45 u16 page_size; /* for writes */ 46 u8 flags; 47 #define AT24_FLAG_ADDR16 BIT(7) /* address pointer is 16 bit */ 48 #define AT24_FLAG_READONLY BIT(6) /* sysfs-entry will be read-only */ 49 #define AT24_FLAG_IRUGO BIT(5) /* sysfs-entry will be world-readable */ 50 #define AT24_FLAG_TAKE8ADDR BIT(4) /* take always 8 addresses (24c00) */ 51 #define AT24_FLAG_SERIAL BIT(3) /* factory-programmed serial number */ 52 #define AT24_FLAG_MAC BIT(2) /* factory-programmed mac address */ 53 #define AT24_FLAG_NO_RDROL BIT(1) /* does not auto-rollover reads to */ 54 /* the next slave address */ 55 56 void (*setup)(struct nvmem_device *nvmem, void *context); 57 void *context; 58 }; 59 60 #endif /* _LINUX_AT24_H */ 61