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

commit 3c9e2cb6cecf65f7501004038c5d1ed85fb7db84 upstream.

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: 22e9e6fcfb50 ("nvmem: imx: support i.MX93 OCOTP")
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: stable <stable@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230141901.263976-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/imx-ocotp-ele.c b/drivers/nvmem/imx-ocotp-ele.c
index 2d00a07b4222ee324fbe56721b66b254d66b6498..422a6d53b10efaacc1d63019fc54eef8bcc387e9 100644 (file)
--- a/drivers/nvmem/imx-ocotp-ele.c
+++ b/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);