On 06/29/2017 06:39 AM, Claudiu Beznea wrote:
Add support for reading from different offsets of EEPROM.
The offset is initialized via device tree. If nothing is
given as input the old value, 0x90, is used. In this way
the driver could be used as generic driver for different
vendor memories by only changing the reading offset via
device tree.
Signed-off-by: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
---
drivers/misc/eeprom/at24.c | 5 ++++-
include/linux/platform_data/at24.h | 1 +
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 764ff5df..53c5fb8 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -365,7 +365,7 @@ static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf,
memset(msg, 0, sizeof(msg));
msg[0].addr = client->addr;
msg[0].buf = addrbuf;
- addrbuf[0] = 0x90 + offset;
+ addrbuf[0] = at24->chip.offset + offset;
msg[0].len = 1;
msg[1].addr = client->addr;
msg[1].flags = I2C_M_RD;
@@ -581,6 +581,9 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip)
*/
chip->page_size = 1;
}
+ err = device_property_read_u8(dev, "start-offset", &chip->offset);
Why use u8 here? I have an at24 EEPROM that uses 16-bit addressing where
the MAC address is stored at 0x3F06. Seems like it would be better to
just use u32, then you don't have to mess with /bits/ in the device tree
binding.
+ if (err)
+ chip->offset = 0x90;
}
static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
diff --git a/include/linux/platform_data/at24.h b/include/linux/platform_data/at24.h
index 271a4e2..d55c454 100644
--- a/include/linux/platform_data/at24.h
+++ b/include/linux/platform_data/at24.h
@@ -50,6 +50,7 @@ struct at24_platform_data {
#define AT24_FLAG_TAKE8ADDR BIT(4) /* take always 8 addresses (24c00) */
#define AT24_FLAG_SERIAL BIT(3) /* factory-programmed serial number */
#define AT24_FLAG_MAC BIT(2) /* factory-programmed mac address */
+ u8 offset;
void (*setup)(struct nvmem_device *nvmem, void *context);
void *context;
--
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