drivers/nvmem/layerscape-sfp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Layerscape SFP driver
   4  *
   5  * Copyright (c) 2022 Michael Walle <michael@walle.cc>
   6  *
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/io.h>
  11 #include <linux/mod_devicetable.h>
  12 #include <linux/module.h>
  13 #include <linux/nvmem-provider.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/property.h>
  16 #include <linux/regmap.h>
  17
  18 #define LAYERSCAPE_SFP_OTP_OFFSET       0x0200
  19
  20 struct layerscape_sfp_priv {
  21         struct regmap *regmap;
  22 };
  23
  24 struct layerscape_sfp_data {
  25         int size;
  26         enum regmap_endian endian;
  27 };
  28
  29 static int layerscape_sfp_read(void *context, unsigned int offset, void *val,
  30                                size_t bytes)
  31 {
  32         struct layerscape_sfp_priv *priv = context;
  33
  34         return regmap_bulk_read(priv->regmap,
  35                                 LAYERSCAPE_SFP_OTP_OFFSET + offset, val,
  36                                 bytes / 4);
  37 }
  38
  39 static struct nvmem_config layerscape_sfp_nvmem_config = {
  40         .name = "fsl-sfp",
  41         .reg_read = layerscape_sfp_read,
  42         .word_size = 4,
  43         .stride = 4,
  44 };
  45
  46 static int layerscape_sfp_probe(struct platform_device *pdev)
  47 {
  48         const struct layerscape_sfp_data *data;
  49         struct layerscape_sfp_priv *priv;
  50         struct nvmem_device *nvmem;
  51         struct regmap_config config = { 0 };
  52         void __iomem *base;
  53
  54         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
  55         if (!priv)
  56                 return -ENOMEM;
  57
  58         base = devm_platform_ioremap_resource(pdev, 0);
  59         if (IS_ERR(base))
  60                 return PTR_ERR(base);
  61
  62         data = device_get_match_data(&pdev->dev);
  63         config.reg_bits = 32;
  64         config.reg_stride = 4;
  65         config.val_bits = 32;
  66         config.val_format_endian = data->endian;
  67         config.max_register = LAYERSCAPE_SFP_OTP_OFFSET + data->size - 4;
  68         priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &config);
  69         if (IS_ERR(priv->regmap))
  70                 return PTR_ERR(priv->regmap);
  71
  72         layerscape_sfp_nvmem_config.size = data->size;
  73         layerscape_sfp_nvmem_config.dev = &pdev->dev;
  74         layerscape_sfp_nvmem_config.priv = priv;
  75
  76         nvmem = devm_nvmem_register(&pdev->dev, &layerscape_sfp_nvmem_config);
  77
  78         return PTR_ERR_OR_ZERO(nvmem);
  79 }
  80
  81 static const struct layerscape_sfp_data ls1021a_data = {
  82         .size = 0x88,
  83         .endian = REGMAP_ENDIAN_BIG,
  84 };
  85
  86 static const struct layerscape_sfp_data ls1028a_data = {
  87         .size = 0x88,
  88         .endian = REGMAP_ENDIAN_LITTLE,
  89 };
  90
  91 static const struct of_device_id layerscape_sfp_dt_ids[] = {
  92         { .compatible = "fsl,ls1021a-sfp", .data = &ls1021a_data },
  93         { .compatible = "fsl,ls1028a-sfp", .data = &ls1028a_data },
  94         {},
  95 };
  96 MODULE_DEVICE_TABLE(of, layerscape_sfp_dt_ids);
  97
  98 static struct platform_driver layerscape_sfp_driver = {
  99         .probe  = layerscape_sfp_probe,
 100         .driver = {
 101                 .name   = "layerscape_sfp",
 102                 .of_match_table = layerscape_sfp_dt_ids,
 103         },
 104 };
 105 module_platform_driver(layerscape_sfp_driver);
 106
 107 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
 108 MODULE_DESCRIPTION("Layerscape Security Fuse Processor driver");
 109 MODULE_LICENSE("GPL");