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nvmem: imx-ocotp: add support for the unaliged word count

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When offset is not 4 bytes aligned, directly shift righty by 2 bits
will cause reading out wrong data. Since imx ocotp only supports
4 bytes reading once, we need handle offset is not 4 bytes aligned
and enlarge the bytes to 4 bytes aligned. After reading finished,
copy the needed data from buffer to caller and free buffer.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20201127102837.19366-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peng Fan 2020-11-27 10:28:37 +00:00 committed by Greg Kroah-Hartman
parent 044ee8f852
commit 3311bf1846
1 changed files with 24 additions and 6 deletions
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30
drivers/nvmem/imx-ocotp.c
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@ -4,6 +4,8 @@
*
* Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
*
* Copyright 2019 NXP
*
* Based on the barebox ocotp driver,
* Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
* Orex Computed Radiography
@ -158,22 +160,30 @@ static int imx_ocotp_read(void *context, unsigned int offset,
{
struct ocotp_priv *priv = context;
unsigned int count;
u32 *buf = val;
u8 *buf, *p;
int i, ret;
u32 index;
u32 index, num_bytes;
index = offset >> 2;
count = bytes >> 2;
num_bytes = round_up((offset % 4) + bytes, 4);
count = num_bytes >> 2;
if (count > (priv->params->nregs - index))
count = priv->params->nregs - index;
p = kzalloc(num_bytes, GFP_KERNEL);
if (!p)
return -ENOMEM;
mutex_lock(&ocotp_mutex);
buf = p;
ret = clk_prepare_enable(priv->clk);
if (ret < 0) {
mutex_unlock(&ocotp_mutex);
dev_err(priv->dev, "failed to prepare/enable ocotp clk\n");
kfree(p);
return ret;
}
@ -184,7 +194,7 @@ static int imx_ocotp_read(void *context, unsigned int offset,
}
for (i = index; i < (index + count); i++) {
*buf++ = readl(priv->base + IMX_OCOTP_OFFSET_B0W0 +
*(u32 *)buf = readl(priv->base + IMX_OCOTP_OFFSET_B0W0 +
i * IMX_OCOTP_OFFSET_PER_WORD);
/* 47.3.1.2
@ -193,13 +203,21 @@ static int imx_ocotp_read(void *context, unsigned int offset,
* software before any new write, read or reload access can be
* issued
*/
if (*(buf - 1) == IMX_OCOTP_READ_LOCKED_VAL)
if (*((u32 *)buf) == IMX_OCOTP_READ_LOCKED_VAL)
imx_ocotp_clr_err_if_set(priv);
buf += 4;
}
index = offset % 4;
memcpy(val, &p[index], bytes);
read_end:
clk_disable_unprepare(priv->clk);
mutex_unlock(&ocotp_mutex);
kfree(p);
return ret;
}
@ -447,7 +465,7 @@ static struct nvmem_config imx_ocotp_nvmem_config = {
.name = "imx-ocotp",
.read_only = false,
.word_size = 4,
.stride = 4,
.stride = 1,
.reg_read = imx_ocotp_read,
.reg_write = imx_ocotp_write,
};