LXR linux/drivers/nvmem/meson-efuse.c

   1/*
   2 * Amlogic eFuse Driver
   3 *
   4 * Copyright (c) 2016 Endless Computers, Inc.
   5 * Author: Carlo Caione <carlo@endlessm.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify it
   8 * under the terms of version 2 of the GNU General Public License as
   9 * published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but WITHOUT
  12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  14 * more details.
  15 */
  16
  17#include <linux/module.h>
  18#include <linux/nvmem-provider.h>
  19#include <linux/of.h>
  20#include <linux/platform_device.h>
  21
  22#include <linux/firmware/meson/meson_sm.h>
  23
  24static int meson_efuse_read(void *context, unsigned int offset,
  25                            void *val, size_t bytes)
  26{
  27        u8 *buf = val;
  28        int ret;
  29
  30        ret = meson_sm_call_read(buf, SM_EFUSE_READ, offset,
  31                                 bytes, 0, 0, 0);
  32        if (ret < 0)
  33                return ret;
  34
  35        return 0;
  36}
  37
  38static struct nvmem_config econfig = {
  39        .name = "meson-efuse",
  40        .owner = THIS_MODULE,
  41        .stride = 1,
  42        .word_size = 1,
  43        .read_only = true,
  44};
  45
  46static const struct of_device_id meson_efuse_match[] = {
  47        { .compatible = "amlogic,meson-gxbb-efuse", },
  48        { /* sentinel */ },
  49};
  50MODULE_DEVICE_TABLE(of, meson_efuse_match);
  51
  52static int meson_efuse_probe(struct platform_device *pdev)
  53{
  54        struct nvmem_device *nvmem;
  55        unsigned int size;
  56
  57        if (meson_sm_call(SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0)
  58                return -EINVAL;
  59
  60        econfig.dev = &pdev->dev;
  61        econfig.reg_read = meson_efuse_read;
  62        econfig.size = size;
  63
  64        nvmem = nvmem_register(&econfig);
  65        if (IS_ERR(nvmem))
  66                return PTR_ERR(nvmem);
  67
  68        platform_set_drvdata(pdev, nvmem);
  69
  70        return 0;
  71}
  72
  73static int meson_efuse_remove(struct platform_device *pdev)
  74{
  75        struct nvmem_device *nvmem = platform_get_drvdata(pdev);
  76
  77        return nvmem_unregister(nvmem);
  78}
  79
  80static struct platform_driver meson_efuse_driver = {
  81        .probe = meson_efuse_probe,
  82        .remove = meson_efuse_remove,
  83        .driver = {
  84                .name = "meson-efuse",
  85                .of_match_table = meson_efuse_match,
  86        },
  87};
  88
  89module_platform_driver(meson_efuse_driver);
  90
  91MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
  92MODULE_DESCRIPTION("Amlogic Meson NVMEM driver");
  93MODULE_LICENSE("GPL v2");
  94