From 7274ec8bd71e99018642f474528ea7de4bb3ae25 Mon Sep 17 00:00:00 2001 From: Kevin Hilman Date: Thu, 2 Apr 2009 16:56:57 -0700 Subject: [PATCH] memory_accessor: implement the new memory_accessor interface for I2C EEPROM In the case of at24, the platform code registers a 'setup' callback with the at24_platform_data. When the at24 driver detects an EEPROM, it fills out the read and write functions of the memory_accessor and calls the setup callback passing the memory_accessor struct. The platform code can then use the read/write functions in the memory_accessor struct for reading and writing the EEPROM. Signed-off-by: Kevin Hilman Cc: David Brownell Cc: Jean Delvare Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/misc/eeprom/at24.c | 67 ++++++++++++++++++++++++++++++-------- include/linux/i2c/at24.h | 4 +++ 2 files changed, 58 insertions(+), 13 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index d4775528abc6..d184dfab9631 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -53,6 +53,7 @@ struct at24_data { struct at24_platform_data chip; + struct memory_accessor macc; bool use_smbus; /* @@ -225,14 +226,11 @@ static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf, return status; } -static ssize_t at24_bin_read(struct kobject *kobj, struct bin_attribute *attr, +static ssize_t at24_read(struct at24_data *at24, char *buf, loff_t off, size_t count) { - struct at24_data *at24; ssize_t retval = 0; - at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); - if (unlikely(!count)) return count; @@ -262,12 +260,14 @@ static ssize_t at24_bin_read(struct kobject *kobj, struct bin_attribute *attr, return retval; } +static ssize_t at24_bin_read(struct kobject *kobj, struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct at24_data *at24; -/* - * REVISIT: export at24_bin{read,write}() to let other kernel code use - * eeprom data. For example, it might hold a board's Ethernet address, or - * board-specific calibration data generated on the manufacturing floor. - */ + at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); + return at24_read(at24, buf, off, count); +} /* @@ -347,14 +347,11 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, char *buf, return -ETIMEDOUT; } -static ssize_t at24_bin_write(struct kobject *kobj, struct bin_attribute *attr, +static ssize_t at24_write(struct at24_data *at24, char *buf, loff_t off, size_t count) { - struct at24_data *at24; ssize_t retval = 0; - at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); - if (unlikely(!count)) return count; @@ -384,6 +381,39 @@ static ssize_t at24_bin_write(struct kobject *kobj, struct bin_attribute *attr, return retval; } +static ssize_t at24_bin_write(struct kobject *kobj, struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct at24_data *at24; + + at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); + return at24_write(at24, buf, off, count); +} + +/*-------------------------------------------------------------------------*/ + +/* + * This lets other kernel code access the eeprom data. For example, it + * might hold a board's Ethernet address, or board-specific calibration + * data generated on the manufacturing floor. + */ + +static ssize_t at24_macc_read(struct memory_accessor *macc, char *buf, + off_t offset, size_t count) +{ + struct at24_data *at24 = container_of(macc, struct at24_data, macc); + + return at24_read(at24, buf, offset, count); +} + +static ssize_t at24_macc_write(struct memory_accessor *macc, char *buf, + off_t offset, size_t count) +{ + struct at24_data *at24 = container_of(macc, struct at24_data, macc); + + return at24_write(at24, buf, offset, count); +} + /*-------------------------------------------------------------------------*/ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) @@ -413,6 +443,9 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) * is recommended anyhow. */ chip.page_size = 1; + + chip.setup = NULL; + chip.context = NULL; } if (!is_power_of_2(chip.byte_len)) @@ -463,6 +496,8 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) at24->bin.read = at24_bin_read; at24->bin.size = chip.byte_len; + at24->macc.read = at24_macc_read; + writable = !(chip.flags & AT24_FLAG_READONLY); if (writable) { if (!use_smbus || i2c_check_functionality(client->adapter, @@ -470,6 +505,8 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) unsigned write_max = chip.page_size; + at24->macc.write = at24_macc_write; + at24->bin.write = at24_bin_write; at24->bin.attr.mode |= S_IWUSR; @@ -520,6 +557,10 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) at24->write_max, use_smbus ? ", use_smbus" : ""); + /* export data to kernel code */ + if (chip.setup) + chip.setup(&at24->macc, chip.context); + return 0; err_clients: diff --git a/include/linux/i2c/at24.h b/include/linux/i2c/at24.h index f6edd522a929..8ace93024d60 100644 --- a/include/linux/i2c/at24.h +++ b/include/linux/i2c/at24.h @@ -2,6 +2,7 @@ #define _LINUX_AT24_H #include +#include /* * As seen through Linux I2C, differences between the most common types of I2C @@ -23,6 +24,9 @@ struct at24_platform_data { #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 */ -- 2.30.2