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
24struct imx_iim_drvdata {
25	unsigned int nregs;
26};
27
28struct iim_priv {
29	void __iomem *base;
30	struct clk *clk;
31};
32
33static 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
56static struct imx_iim_drvdata imx27_drvdata = {
57	.nregs = 2 * 32,
58};
59
60static struct imx_iim_drvdata imx25_imx31_imx35_drvdata = {
61	.nregs = 3 * 32,
62};
63
64static struct imx_iim_drvdata imx51_drvdata = {
65	.nregs = 4 * 32,
66};
67
68static struct imx_iim_drvdata imx53_drvdata = {
69	.nregs = 4 * 32 + 16,
70};
71
72static 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};
95MODULE_DEVICE_TABLE(of, imx_iim_dt_ids);
96
97static 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
138static 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};
145module_platform_driver(imx_iim_driver);
146
147MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
148MODULE_DESCRIPTION("i.MX IIM driver");
149MODULE_LICENSE("GPL v2");
150