linux/drivers/nvmem/imx-ocotp.c
Daniel Schultz 14ba972842 nvmem: imx-ocotp: Fix wrong register size
All i.MX6 SoCs have an OCOTP Controller with 4kbit fuses. The i.MX6SL is
an exception and has only 2kbit fuses.

In the TRM for the i.MX6DQ (IMX6QDRM - Rev 2, 06/2014) the fuses size is
described in chapter 46.1.1 with:
"32-bit word restricted program and read to 4Kbits of eFuse OTP(512x8)."

In the TRM for the i.MX6SL (IMX6SLRM - Rev 2, 06/2015) the fuses size is
described in chapter 34.1.1 with:
"32-bit word restricted program and read to 2 kbit of eFuse OTP(128x8)."

Since the Freescale Linux kernel OCOTP driver works with a fuses size of
2 kbit for the i.MX6SL, it looks like the TRM is wrong and the formula
to calculate the correct fuses size has to be 256x8.

Signed-off-by: Daniel Schultz <d.schultz@phytec.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-04 18:22:47 +01:00

135 lines
3.3 KiB
C

/*
* i.MX6 OCOTP fusebox driver
*
* Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
*
* Based on the barebox ocotp driver,
* Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
* Orex Computed Radiography
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
struct ocotp_priv {
struct device *dev;
struct clk *clk;
void __iomem *base;
unsigned int nregs;
};
static int imx_ocotp_read(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct ocotp_priv *priv = context;
unsigned int count;
u32 *buf = val;
int i, ret;
u32 index;
index = offset >> 2;
count = bytes >> 2;
if (count > (priv->nregs - index))
count = priv->nregs - index;
ret = clk_prepare_enable(priv->clk);
if (ret < 0) {
dev_err(priv->dev, "failed to prepare/enable ocotp clk\n");
return ret;
}
for (i = index; i < (index + count); i++)
*buf++ = readl(priv->base + 0x400 + i * 0x10);
clk_disable_unprepare(priv->clk);
return 0;
}
static struct nvmem_config imx_ocotp_nvmem_config = {
.name = "imx-ocotp",
.read_only = true,
.word_size = 4,
.stride = 4,
.owner = THIS_MODULE,
.reg_read = imx_ocotp_read,
};
static const struct of_device_id imx_ocotp_dt_ids[] = {
{ .compatible = "fsl,imx6q-ocotp", (void *)128 },
{ .compatible = "fsl,imx6sl-ocotp", (void *)64 },
{ .compatible = "fsl,imx6sx-ocotp", (void *)128 },
{ },
};
MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
static int imx_ocotp_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id;
struct device *dev = &pdev->dev;
struct resource *res;
struct ocotp_priv *priv;
struct nvmem_device *nvmem;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
priv->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(priv->clk))
return PTR_ERR(priv->clk);
of_id = of_match_device(imx_ocotp_dt_ids, dev);
priv->nregs = (unsigned long)of_id->data;
imx_ocotp_nvmem_config.size = 4 * priv->nregs;
imx_ocotp_nvmem_config.dev = dev;
imx_ocotp_nvmem_config.priv = priv;
nvmem = nvmem_register(&imx_ocotp_nvmem_config);
if (IS_ERR(nvmem))
return PTR_ERR(nvmem);
platform_set_drvdata(pdev, nvmem);
return 0;
}
static int imx_ocotp_remove(struct platform_device *pdev)
{
struct nvmem_device *nvmem = platform_get_drvdata(pdev);
return nvmem_unregister(nvmem);
}
static struct platform_driver imx_ocotp_driver = {
.probe = imx_ocotp_probe,
.remove = imx_ocotp_remove,
.driver = {
.name = "imx_ocotp",
.of_match_table = imx_ocotp_dt_ids,
},
};
module_platform_driver(imx_ocotp_driver);
MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
MODULE_DESCRIPTION("i.MX6 OCOTP fuse box driver");
MODULE_LICENSE("GPL v2");