1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * i.MX IIM driver
4 *
5 * Copyright (c) 2017 Pengutronix, Michael Grzeschik <m.grzeschik@pengutronix.de>
6 *
7 * Based on the barebox iim driver,
8 * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
9 * Orex Computed Radiography
10 */
11
12 #include <linux/device.h>
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/nvmem-provider.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/clk.h>
21
22 #define IIM_BANK_BASE(n) (0x800 + 0x400 * (n))
23
24 struct imx_iim_drvdata {
25 unsigned int nregs;
26 };
27
28 struct iim_priv {
29 void __iomem *base;
30 struct clk *clk;
31 };
32
imx_iim_read(void * context,unsigned int offset,void * buf,size_t bytes)33 static int imx_iim_read(void *context, unsigned int offset,
34 void *buf, size_t bytes)
35 {
36 struct iim_priv *iim = context;
37 int i, ret;
38 u8 *buf8 = buf;
39
40 ret = clk_prepare_enable(iim->clk);
41 if (ret)
42 return ret;
43
44 for (i = offset; i < offset + bytes; i++) {
45 int bank = i >> 5;
46 int reg = i & 0x1f;
47
48 *buf8++ = readl(iim->base + IIM_BANK_BASE(bank) + reg * 4);
49 }
50
51 clk_disable_unprepare(iim->clk);
52
53 return 0;
54 }
55
56 static struct imx_iim_drvdata imx27_drvdata = {
57 .nregs = 2 * 32,
58 };
59
60 static struct imx_iim_drvdata imx25_imx31_imx35_drvdata = {
61 .nregs = 3 * 32,
62 };
63
64 static struct imx_iim_drvdata imx51_drvdata = {
65 .nregs = 4 * 32,
66 };
67
68 static struct imx_iim_drvdata imx53_drvdata = {
69 .nregs = 4 * 32 + 16,
70 };
71
72 static const struct of_device_id imx_iim_dt_ids[] = {
73 {
74 .compatible = "fsl,imx25-iim",
75 .data = &imx25_imx31_imx35_drvdata,
76 }, {
77 .compatible = "fsl,imx27-iim",
78 .data = &imx27_drvdata,
79 }, {
80 .compatible = "fsl,imx31-iim",
81 .data = &imx25_imx31_imx35_drvdata,
82 }, {
83 .compatible = "fsl,imx35-iim",
84 .data = &imx25_imx31_imx35_drvdata,
85 }, {
86 .compatible = "fsl,imx51-iim",
87 .data = &imx51_drvdata,
88 }, {
89 .compatible = "fsl,imx53-iim",
90 .data = &imx53_drvdata,
91 }, {
92 /* sentinel */
93 },
94 };
95 MODULE_DEVICE_TABLE(of, imx_iim_dt_ids);
96
imx_iim_probe(struct platform_device * pdev)97 static int imx_iim_probe(struct platform_device *pdev)
98 {
99 const struct of_device_id *of_id;
100 struct device *dev = &pdev->dev;
101 struct iim_priv *iim;
102 struct nvmem_device *nvmem;
103 struct nvmem_config cfg = {};
104 const struct imx_iim_drvdata *drvdata = NULL;
105
106 iim = devm_kzalloc(dev, sizeof(*iim), GFP_KERNEL);
107 if (!iim)
108 return -ENOMEM;
109
110 iim->base = devm_platform_ioremap_resource(pdev, 0);
111 if (IS_ERR(iim->base))
112 return PTR_ERR(iim->base);
113
114 of_id = of_match_device(imx_iim_dt_ids, dev);
115 if (!of_id)
116 return -ENODEV;
117
118 drvdata = of_id->data;
119
120 iim->clk = devm_clk_get(dev, NULL);
121 if (IS_ERR(iim->clk))
122 return PTR_ERR(iim->clk);
123
124 cfg.name = "imx-iim",
125 cfg.read_only = true,
126 cfg.word_size = 1,
127 cfg.stride = 1,
128 cfg.reg_read = imx_iim_read,
129 cfg.dev = dev;
130 cfg.size = drvdata->nregs;
131 cfg.priv = iim;
132
133 nvmem = devm_nvmem_register(dev, &cfg);
134
135 return PTR_ERR_OR_ZERO(nvmem);
136 }
137
138 static struct platform_driver imx_iim_driver = {
139 .probe = imx_iim_probe,
140 .driver = {
141 .name = "imx-iim",
142 .of_match_table = imx_iim_dt_ids,
143 },
144 };
145 module_platform_driver(imx_iim_driver);
146
147 MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
148 MODULE_DESCRIPTION("i.MX IIM driver");
149 MODULE_LICENSE("GPL v2");
150