[PATCH] at24: add kernel side usage description

[yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org]

From: Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>

Add EEPROM usage instructions and example for kernel side.
dm644x-evm was taken as example.

Signed-off-by: Yegor Yefremov <yegorslists-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
---
 drivers/misc/eeprom/at24.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index ab1ad41..49494ad 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -438,6 +438,15 @@ static ssize_t at24_bin_write(struct file *filp, struct kobject *kobj,
  * 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.
+ *
+ * struct at24_platform_data provides special hook .setup, that can
+ * invoke at24_macc_read()/at24_macc_write() through memory_accessor:
+ * 
+ * void		(*setup)(struct memory_accessor *, void *context);
+ *
+ * setup hook (if provided) will be executed at the end of at24_probe().
+ *
+ * See arch/arm/mach-davinci/board-dm644x-evm.c for details.
  */
 
 static ssize_t at24_macc_read(struct memory_accessor *macc, char *buf,
-- 
1.7.1.1