tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * i.MX6 OCOTP fusebox driver
3 *
4 * Copyright (c) 2015 Pengutronix, Philipp Zabel <p.zabel@pengutronix.de>
5 *
6 * Based on the barebox ocotp driver,
7 * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
8 * Orex Computed Radiography
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation.
13 *
14 * http://www.opensource.org/licenses/gpl-license.html
15 * http://www.gnu.org/copyleft/gpl.html
16 */
17
18#include <linux/clk.h>
19#include <linux/device.h>
20#include <linux/io.h>
21#include <linux/module.h>
22#include <linux/nvmem-provider.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/platform_device.h>
26#include <linux/slab.h>
27
28struct ocotp_priv {
29 struct device *dev;
30 struct clk *clk;
31 void __iomem *base;
32 unsigned int nregs;
33};
34
35static int imx_ocotp_read(void *context, unsigned int offset,
36 void *val, size_t bytes)
37{
38 struct ocotp_priv *priv = context;
39 unsigned int count;
40 u32 *buf = val;
41 int i, ret;
42 u32 index;
43
44 index = offset >> 2;
45 count = bytes >> 2;
46
47 if (count > (priv->nregs - index))
48 count = priv->nregs - index;
49
50 ret = clk_prepare_enable(priv->clk);
51 if (ret < 0) {
52 dev_err(priv->dev, "failed to prepare/enable ocotp clk\n");
53 return ret;
54 }
55 for (i = index; i < (index + count); i++)
56 *buf++ = readl(priv->base + 0x400 + i * 0x10);
57
58 clk_disable_unprepare(priv->clk);
59
60 return 0;
61}
62
63static struct nvmem_config imx_ocotp_nvmem_config = {
64 .name = "imx-ocotp",
65 .read_only = true,
66 .word_size = 4,
67 .stride = 4,
68 .owner = THIS_MODULE,
69 .reg_read = imx_ocotp_read,
70};
71
72static const struct of_device_id imx_ocotp_dt_ids[] = {
73 { .compatible = "fsl,imx6q-ocotp", (void *)128 },
74 { .compatible = "fsl,imx6sl-ocotp", (void *)64 },
75 { .compatible = "fsl,imx6sx-ocotp", (void *)128 },
76 { .compatible = "fsl,imx6ul-ocotp", (void *)128 },
77 { },
78};
79MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
80
81static int imx_ocotp_probe(struct platform_device *pdev)
82{
83 const struct of_device_id *of_id;
84 struct device *dev = &pdev->dev;
85 struct resource *res;
86 struct ocotp_priv *priv;
87 struct nvmem_device *nvmem;
88
89 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
90 if (!priv)
91 return -ENOMEM;
92
93 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
94 priv->base = devm_ioremap_resource(dev, res);
95 if (IS_ERR(priv->base))
96 return PTR_ERR(priv->base);
97
98 priv->clk = devm_clk_get(&pdev->dev, NULL);
99 if (IS_ERR(priv->clk))
100 return PTR_ERR(priv->clk);
101
102 of_id = of_match_device(imx_ocotp_dt_ids, dev);
103 priv->nregs = (unsigned long)of_id->data;
104 imx_ocotp_nvmem_config.size = 4 * priv->nregs;
105 imx_ocotp_nvmem_config.dev = dev;
106 imx_ocotp_nvmem_config.priv = priv;
107 nvmem = nvmem_register(&imx_ocotp_nvmem_config);
108 if (IS_ERR(nvmem))
109 return PTR_ERR(nvmem);
110
111 platform_set_drvdata(pdev, nvmem);
112
113 return 0;
114}
115
116static int imx_ocotp_remove(struct platform_device *pdev)
117{
118 struct nvmem_device *nvmem = platform_get_drvdata(pdev);
119
120 return nvmem_unregister(nvmem);
121}
122
123static struct platform_driver imx_ocotp_driver = {
124 .probe = imx_ocotp_probe,
125 .remove = imx_ocotp_remove,
126 .driver = {
127 .name = "imx_ocotp",
128 .of_match_table = imx_ocotp_dt_ids,
129 },
130};
131module_platform_driver(imx_ocotp_driver);
132
133MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
134MODULE_DESCRIPTION("i.MX6 OCOTP fuse box driver");
135MODULE_LICENSE("GPL v2");