linux/drivers/nvmem/imx-ocotp-ele.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * i.MX9 OCOTP fusebox driver
 *
 * Copyright 2023 NXP
 */

#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

enum fuse_type { … };

struct ocotp_map_entry { … };

struct ocotp_devtype_data { … };

struct imx_ocotp_priv { … };

static enum fuse_type imx_ocotp_fuse_type(void *context, u32 index)
{ … }

static int imx_ocotp_reg_read(void *context, unsigned int offset, void *val, size_t bytes)
{
	struct imx_ocotp_priv *priv = context;
	void __iomem *reg = priv->base + priv->data->reg_off;
	u32 count, index, num_bytes;
	enum fuse_type type;
	u32 *buf;
	void *p;
	int i;

	index = offset;
	num_bytes = round_up(bytes, 4);
	count = num_bytes >> 2;

	if (count > ((priv->data->size >> 2) - index))
		count = (priv->data->size >> 2) - index;

	p = kzalloc(num_bytes, GFP_KERNEL);
	if (!p)
		return -ENOMEM;

	mutex_lock(&priv->lock);

	buf = p;

	for (i = index; i < (index + count); i++) {
		type = imx_ocotp_fuse_type(context, i);
		if (type == FUSE_INVALID || type == FUSE_ELE) {
			*buf++ = 0;
			continue;
		}

		*buf++ = readl_relaxed(reg + (i << 2));
	}

	memcpy(val, (u8 *)p, bytes);

	mutex_unlock(&priv->lock);

	kfree(p);

	return 0;
};

static int imx_ele_ocotp_probe(struct platform_device *pdev)
{ … }

static const struct ocotp_devtype_data imx93_ocotp_data = …;

static const struct of_device_id imx_ele_ocotp_dt_ids[] = …;
MODULE_DEVICE_TABLE(of, imx_ele_ocotp_dt_ids);

static struct platform_driver imx_ele_ocotp_driver = …;
module_platform_driver(…) …;

MODULE_DESCRIPTION(…) …;
MODULE_AUTHOR(…) …;
MODULE_LICENSE(…) …;