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/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
  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
  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");