LXR linux/drivers/nvmem/imx-iim.c

   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