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authorKevin Hilman <khilman@deeprootsystems.com>2009-04-02 16:56:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-02 19:04:50 -0700
commit7274ec8bd71e99018642f474528ea7de4bb3ae25 (patch)
tree3c2e719f696292afa0717f7111d174bdfc073f27
parent06c421ee0d5af95c8c6749ca0ba620cd5010707f (diff)
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 <khilman@deeprootsystems.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/misc/eeprom/at24.c67
-rw-r--r--include/linux/i2c/at24.h4
2 files changed, 58 insertions, 13 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index d4775528abc..d184dfab963 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 f6edd522a92..8ace93024d6 100644
--- a/include/linux/i2c/at24.h
+++ b/include/linux/i2c/at24.h
@@ -2,6 +2,7 @@
#define _LINUX_AT24_H
#include <linux/types.h>
+#include <linux/memory.h>
/*
* 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 */