drivers/nvmem/sec-qfprom.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
   4  */
   5
   6 #include <linux/firmware/qcom/qcom_scm.h>
   7 #include <linux/mod_devicetable.h>
   8 #include <linux/nvmem-provider.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/pm_runtime.h>
  11
  12 /**
  13  * struct sec_qfprom - structure holding secure qfprom attributes
  14  *
  15  * @base: starting physical address for secure qfprom corrected address space.
  16  * @dev: qfprom device structure.
  17  */
  18 struct sec_qfprom {
  19         phys_addr_t base;
  20         struct device *dev;
  21 };
  22
  23 static int sec_qfprom_reg_read(void *context, unsigned int reg, void *_val, size_t bytes)
  24 {
  25         struct sec_qfprom *priv = context;
  26         unsigned int i;
  27         u8 *val = _val;
  28         u32 read_val;
  29         u8 *tmp;
  30
  31         for (i = 0; i < bytes; i++, reg++) {
  32                 if (i == 0 || reg % 4 == 0) {
  33                         if (qcom_scm_io_readl(priv->base + (reg & ~3), &read_val)) {
  34                                 dev_err(priv->dev, "Couldn't access fuse register\n");
  35                                 return -EINVAL;
  36                         }
  37                         tmp = (u8 *)&read_val;
  38                 }
  39
  40                 val[i] = tmp[reg & 3];
  41         }
  42
  43         return 0;
  44 }
  45
  46 static int sec_qfprom_probe(struct platform_device *pdev)
  47 {
  48         struct nvmem_config econfig = {
  49                 .name = "sec-qfprom",
  50                 .add_legacy_fixed_of_cells = true,
  51                 .stride = 1,
  52                 .word_size = 1,
  53                 .id = NVMEM_DEVID_AUTO,
  54                 .reg_read = sec_qfprom_reg_read,
  55         };
  56         struct device *dev = &pdev->dev;
  57         struct nvmem_device *nvmem;
  58         struct sec_qfprom *priv;
  59         struct resource *res;
  60
  61         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  62         if (!priv)
  63                 return -ENOMEM;
  64
  65         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  66         if (!res)
  67                 return -EINVAL;
  68
  69         priv->base = res->start;
  70
  71         econfig.size = resource_size(res);
  72         econfig.dev = dev;
  73         econfig.priv = priv;
  74
  75         priv->dev = dev;
  76
  77         nvmem = devm_nvmem_register(dev, &econfig);
  78
  79         return PTR_ERR_OR_ZERO(nvmem);
  80 }
  81
  82 static const struct of_device_id sec_qfprom_of_match[] = {
  83         { .compatible = "qcom,sec-qfprom" },
  84         {/* sentinel */},
  85 };
  86 MODULE_DEVICE_TABLE(of, sec_qfprom_of_match);
  87
  88 static struct platform_driver qfprom_driver = {
  89         .probe = sec_qfprom_probe,
  90         .driver = {
  91                 .name = "qcom_sec_qfprom",
  92                 .of_match_table = sec_qfprom_of_match,
  93         },
  94 };
  95 module_platform_driver(qfprom_driver);
  96 MODULE_DESCRIPTION("Qualcomm Secure QFPROM driver");
  97 MODULE_LICENSE("GPL");