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