Merge branch 'topic/simple' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...
[linux-2.6-block.git] / drivers / nvmem / imx-ocotp.c
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
28 struct ocotp_priv {
29         struct device *dev;
30         struct clk *clk;
31         void __iomem *base;
32         unsigned int nregs;
33 };
34
35 static 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
63 static 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
72 static const struct of_device_id imx_ocotp_dt_ids[] = {
73         { .compatible = "fsl,imx6q-ocotp",  (void *)128 },
74         { .compatible = "fsl,imx6sl-ocotp", (void *)32 },
75         { .compatible = "fsl,imx6sx-ocotp", (void *)128 },
76         { },
77 };
78 MODULE_DEVICE_TABLE(of, imx_ocotp_dt_ids);
79
80 static int imx_ocotp_probe(struct platform_device *pdev)
81 {
82         const struct of_device_id *of_id;
83         struct device *dev = &pdev->dev;
84         struct resource *res;
85         struct ocotp_priv *priv;
86         struct nvmem_device *nvmem;
87
88         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
89         if (!priv)
90                 return -ENOMEM;
91
92         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
93         priv->base = devm_ioremap_resource(dev, res);
94         if (IS_ERR(priv->base))
95                 return PTR_ERR(priv->base);
96
97         priv->clk = devm_clk_get(&pdev->dev, NULL);
98         if (IS_ERR(priv->clk))
99                 return PTR_ERR(priv->clk);
100
101         of_id = of_match_device(imx_ocotp_dt_ids, dev);
102         priv->nregs = (unsigned long)of_id->data;
103         imx_ocotp_nvmem_config.size = 4 * priv->nregs;
104         imx_ocotp_nvmem_config.dev = dev;
105         imx_ocotp_nvmem_config.priv = priv;
106         nvmem = nvmem_register(&imx_ocotp_nvmem_config);
107         if (IS_ERR(nvmem))
108                 return PTR_ERR(nvmem);
109
110         platform_set_drvdata(pdev, nvmem);
111
112         return 0;
113 }
114
115 static int imx_ocotp_remove(struct platform_device *pdev)
116 {
117         struct nvmem_device *nvmem = platform_get_drvdata(pdev);
118
119         return nvmem_unregister(nvmem);
120 }
121
122 static struct platform_driver imx_ocotp_driver = {
123         .probe  = imx_ocotp_probe,
124         .remove = imx_ocotp_remove,
125         .driver = {
126                 .name   = "imx_ocotp",
127                 .of_match_table = imx_ocotp_dt_ids,
128         },
129 };
130 module_platform_driver(imx_ocotp_driver);
131
132 MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
133 MODULE_DESCRIPTION("i.MX6 OCOTP fuse box driver");
134 MODULE_LICENSE("GPL v2");