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	struct device *dev = &pdev->dev;
100	struct iim_priv *iim;
101	struct nvmem_device *nvmem;
102	struct nvmem_config cfg = {};
103	const struct imx_iim_drvdata *drvdata = NULL;
104
105	iim = devm_kzalloc(dev, sizeof(*iim), GFP_KERNEL);
106	if (!iim)
107		return -ENOMEM;
108
109	iim->base = devm_platform_ioremap_resource(pdev, 0);
110	if (IS_ERR(iim->base))
111		return PTR_ERR(iim->base);
112
113	drvdata = of_device_get_match_data(&pdev->dev);
114
115	iim->clk = devm_clk_get(dev, NULL);
116	if (IS_ERR(iim->clk))
117		return PTR_ERR(iim->clk);
118
119	cfg.name = "imx-iim",
120	cfg.read_only = true,
121	cfg.word_size = 1,
122	cfg.stride = 1,
123	cfg.reg_read = imx_iim_read,
124	cfg.dev = dev;
125	cfg.size = drvdata->nregs;
126	cfg.priv = iim;
127
128	nvmem = devm_nvmem_register(dev, &cfg);
129
130	return PTR_ERR_OR_ZERO(nvmem);
131}
132
133static struct platform_driver imx_iim_driver = {
134	.probe	= imx_iim_probe,
135	.driver = {
136		.name	= "imx-iim",
137		.of_match_table = imx_iim_dt_ids,
138	},
139};
140module_platform_driver(imx_iim_driver);
141
142MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
143MODULE_DESCRIPTION("i.MX IIM driver");
144MODULE_LICENSE("GPL v2");