summaryrefslogtreecommitdiffstats
path: root/drivers/nvmem/imx-ocotp.c
blob: 8e7b120696fa91da63a44bc7f4f8422b5d24bc7e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 * 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");
OpenPOWER on IntegriCloud