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

   1/*
   2 * i.MX IIM driver
   3 *
   4 * Copyright (c) 2017 Pengutronix, Michael Grzeschik <m.grzeschik@pengutronix.de>
   5 *
   6 * Based on the barebox iim driver,
   7 * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>,
   8 *      Orex Computed Radiography
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License version 2
  12 * as published by the Free Software Foundation.
  13 *
  14 * http://www.opensource.org/licenses/gpl-license.html
  15 * http://www.gnu.org/copyleft/gpl.html
  16 */
  17
  18#include <linux/device.h>
  19#include <linux/io.h>
  20#include <linux/module.h>
  21#include <linux/nvmem-provider.h>
  22#include <linux/of.h>
  23#include <linux/of_device.h>
  24#include <linux/platform_device.h>
  25#include <linux/slab.h>
  26#include <linux/clk.h>
  27
  28#define IIM_BANK_BASE(n)        (0x800 + 0x400 * (n))
  29
  30struct imx_iim_drvdata {
  31        unsigned int nregs;
  32};
  33
  34struct iim_priv {
  35        void __iomem *base;
  36        struct clk *clk;
  37};
  38
  39static int imx_iim_read(void *context, unsigned int offset,
  40                          void *buf, size_t bytes)
  41{
  42        struct iim_priv *iim = context;
  43        int i, ret;
  44        u8 *buf8 = buf;
  45
  46        ret = clk_prepare_enable(iim->clk);
  47        if (ret)
  48                return ret;
  49
  50        for (i = offset; i < offset + bytes; i++) {
  51                int bank = i >> 5;
  52                int reg = i & 0x1f;
  53
  54                *buf8++ = readl(iim->base + IIM_BANK_BASE(bank) + reg * 4);
  55        }
  56
  57        clk_disable_unprepare(iim->clk);
  58
  59        return 0;
  60}
  61
  62static struct imx_iim_drvdata imx27_drvdata = {
  63        .nregs = 2 * 32,
  64};
  65
  66static struct imx_iim_drvdata imx25_imx31_imx35_drvdata = {
  67        .nregs = 3 * 32,
  68};
  69
  70static struct imx_iim_drvdata imx51_drvdata = {
  71        .nregs = 4 * 32,
  72};
  73
  74static struct imx_iim_drvdata imx53_drvdata = {
  75        .nregs = 4 * 32 + 16,
  76};
  77
  78static const struct of_device_id imx_iim_dt_ids[] = {
  79        {
  80                .compatible = "fsl,imx25-iim",
  81                .data = &imx25_imx31_imx35_drvdata,
  82        }, {
  83                .compatible = "fsl,imx27-iim",
  84                .data = &imx27_drvdata,
  85        }, {
  86                .compatible = "fsl,imx31-iim",
  87                .data = &imx25_imx31_imx35_drvdata,
  88        }, {
  89                .compatible = "fsl,imx35-iim",
  90                .data = &imx25_imx31_imx35_drvdata,
  91        }, {
  92                .compatible = "fsl,imx51-iim",
  93                .data = &imx51_drvdata,
  94        }, {
  95                .compatible = "fsl,imx53-iim",
  96                .data = &imx53_drvdata,
  97        }, {
  98                /* sentinel */
  99        },
 100};
 101MODULE_DEVICE_TABLE(of, imx_iim_dt_ids);
 102
 103static int imx_iim_probe(struct platform_device *pdev)
 104{
 105        const struct of_device_id *of_id;
 106        struct device *dev = &pdev->dev;
 107        struct resource *res;
 108        struct iim_priv *iim;
 109        struct nvmem_device *nvmem;
 110        struct nvmem_config cfg = {};
 111        const struct imx_iim_drvdata *drvdata = NULL;
 112
 113        iim = devm_kzalloc(dev, sizeof(*iim), GFP_KERNEL);
 114        if (!iim)
 115                return -ENOMEM;
 116
 117        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 118        iim->base = devm_ioremap_resource(dev, res);
 119        if (IS_ERR(iim->base))
 120                return PTR_ERR(iim->base);
 121
 122        of_id = of_match_device(imx_iim_dt_ids, dev);
 123        if (!of_id)
 124                return -ENODEV;
 125
 126        drvdata = of_id->data;
 127
 128        iim->clk = devm_clk_get(dev, NULL);
 129        if (IS_ERR(iim->clk))
 130                return PTR_ERR(iim->clk);
 131
 132        cfg.name = "imx-iim",
 133        cfg.read_only = true,
 134        cfg.word_size = 1,
 135        cfg.stride = 1,
 136        cfg.reg_read = imx_iim_read,
 137        cfg.dev = dev;
 138        cfg.size = drvdata->nregs;
 139        cfg.priv = iim;
 140
 141        nvmem = devm_nvmem_register(dev, &cfg);
 142
 143        return PTR_ERR_OR_ZERO(nvmem);
 144}
 145
 146static struct platform_driver imx_iim_driver = {
 147        .probe  = imx_iim_probe,
 148        .driver = {
 149                .name   = "imx-iim",
 150                .of_match_table = imx_iim_dt_ids,
 151        },
 152};
 153module_platform_driver(imx_iim_driver);
 154
 155MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>");
 156MODULE_DESCRIPTION("i.MX IIM driver");
 157MODULE_LICENSE("GPL v2");
 158