nvmem: imx-ocotp-ele: fix reading from non zero offset

In imx_ocotp_reg_read() the offset comes in as bytes and not as words.
This means we have to divide offset by 4 to get to the correct word
offset.

Also the incoming offset might not be word aligned. In order to read
from the OCOTP the driver aligns down the previous word boundary and
reads from there. This means we have to skip this alignment offset from
the temporary buffer when copying the data to the output buffer.

Fixes: 22e9e6f ("nvmem: imx: support i.MX93 OCOTP")
Signed-off-by: Sascha Hauer <[email protected]>
Cc: stable <[email protected]>
Reviewed-by: Peng Fan <[email protected]>
Signed-off-by: Srinivas Kandagatla <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: saschahauer

drivers/nvmem/imx-ocotp-ele.c

@@ -71,12 +71,14 @@ static int imx_ocotp_reg_read(void *context, unsigned int offset, void *val, siz
 	u32 *buf;
 	void *p;
 	int i;
+	u8 skipbytes;
 
 	if (offset + bytes > priv->data->size)
 		bytes = priv->data->size - offset;
 
-	index = offset;
-	num_bytes = round_up(bytes, 4);
+	index = offset >> 2;
+	skipbytes = offset - (index << 2);
+	num_bytes = round_up(bytes + skipbytes, 4);
 	count = num_bytes >> 2;
 
 	p = kzalloc(num_bytes, GFP_KERNEL);
@@ -100,7 +102,7 @@ static int imx_ocotp_reg_read(void *context, unsigned int offset, void *val, siz
 			*buf++ = readl_relaxed(reg + (i << 2));
 	}
 
-	memcpy(val, (u8 *)p, bytes);
+	memcpy(val, ((u8 *)p) + skipbytes, bytes);
 
 	mutex_unlock(&priv->lock);