Commit 3311bf18 authored by Peng Fan's avatar Peng Fan Committed by Greg Kroah-Hartman
Browse files

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



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: default avatarPeng Fan <peng.fan@nxp.com>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20201127102837.19366-6-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 044ee8f8

drivers/nvmem/imx-ocotp.c

+24 −6
Original line number Diff line number Diff line
@@ -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,

};