imx-ocotp.c
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/*
* 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/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/regmap.h>
#include <linux/slab.h>
struct ocotp_priv {
struct device *dev;
void __iomem *base;
unsigned int nregs;
};
static int imx_ocotp_read(void *context, const void *reg, size_t reg_size,
void *val, size_t val_size)
{
struct ocotp_priv *priv = context;
unsigned int offset = *(u32 *)reg;
unsigned int count;
int i;
u32 index;
index = offset >> 2;
count = val_size >> 2;
if (count > (priv->nregs - index))
count = priv->nregs - index;
for (i = index; i < (index + count); i++) {
*(u32 *)val = readl(priv->base + 0x400 + i * 0x10);
val += 4;
}
return (i - index) * 4;
}
static int imx_ocotp_write(void *context, const void *data, size_t count)
{
/* Not implemented */
return 0;
}
static struct regmap_bus imx_ocotp_bus = {
.read = imx_ocotp_read,
.write = imx_ocotp_write,
.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
};
static bool imx_ocotp_writeable_reg(struct device *dev, unsigned int reg)
{
return false;
}
static struct regmap_config imx_ocotp_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
.writeable_reg = imx_ocotp_writeable_reg,
.name = "imx-ocotp",
};
static struct nvmem_config imx_ocotp_nvmem_config = {
.name = "imx-ocotp",
.read_only = true,
.owner = THIS_MODULE,
};
static const struct of_device_id imx_ocotp_dt_ids[] = {
{ .compatible = "fsl,imx6q-ocotp", (void *)128 },
{ .compatible = "fsl,imx6sl-ocotp", (void *)32 },
{ .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 regmap *regmap;
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);
of_id = of_match_device(imx_ocotp_dt_ids, dev);
priv->nregs = (unsigned int)of_id->data;
imx_ocotp_regmap_config.max_register = 4 * priv->nregs - 4;
regmap = devm_regmap_init(dev, &imx_ocotp_bus, priv,
&imx_ocotp_regmap_config);
if (IS_ERR(regmap)) {
dev_err(dev, "regmap init failed\n");
return PTR_ERR(regmap);
}
imx_ocotp_nvmem_config.dev = dev;
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");