drivers/nvmem/zynqmp_nvmem.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2019 Xilinx, Inc.
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/nvmem-provider.h>
   8 #include <linux/of.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/firmware/xlnx-zynqmp.h>
  11
  12 #define SILICON_REVISION_MASK 0xF
  13
  14 struct zynqmp_nvmem_data {
  15         struct device *dev;
  16         struct nvmem_device *nvmem;
  17 };
  18
  19 static int zynqmp_nvmem_read(void *context, unsigned int offset,
  20                              void *val, size_t bytes)
  21 {
  22         int ret;
  23         int idcode, version;
  24         struct zynqmp_nvmem_data *priv = context;
  25
  26         const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
  27
  28         if (!eemi_ops || !eemi_ops->get_chipid)
  29                 return -ENXIO;
  30
  31         ret = eemi_ops->get_chipid(&idcode, &version);
  32         if (ret < 0)
  33                 return ret;
  34
  35         dev_dbg(priv->dev, "Read chipid val %x %x\n", idcode, version);
  36         *(int *)val = version & SILICON_REVISION_MASK;
  37
  38         return 0;
  39 }
  40
  41 static struct nvmem_config econfig = {
  42         .name = "zynqmp-nvmem",
  43         .owner = THIS_MODULE,
  44         .word_size = 1,
  45         .size = 1,
  46         .read_only = true,
  47 };
  48
  49 static const struct of_device_id zynqmp_nvmem_match[] = {
  50         { .compatible = "xlnx,zynqmp-nvmem-fw", },
  51         { /* sentinel */ },
  52 };
  53 MODULE_DEVICE_TABLE(of, zynqmp_nvmem_match);
  54
  55 static int zynqmp_nvmem_probe(struct platform_device *pdev)
  56 {
  57         struct device *dev = &pdev->dev;
  58         struct zynqmp_nvmem_data *priv;
  59
  60         priv = devm_kzalloc(dev, sizeof(struct zynqmp_nvmem_data), GFP_KERNEL);
  61         if (!priv)
  62                 return -ENOMEM;
  63
  64         priv->dev = dev;
  65         econfig.dev = dev;
  66         econfig.reg_read = zynqmp_nvmem_read;
  67         econfig.priv = priv;
  68
  69         priv->nvmem = devm_nvmem_register(dev, &econfig);
  70
  71         return PTR_ERR_OR_ZERO(priv->nvmem);
  72 }
  73
  74 static struct platform_driver zynqmp_nvmem_driver = {
  75         .probe = zynqmp_nvmem_probe,
  76         .driver = {
  77                 .name = "zynqmp-nvmem",
  78                 .of_match_table = zynqmp_nvmem_match,
  79         },
  80 };
  81
  82 module_platform_driver(zynqmp_nvmem_driver);
  83
  84 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>, Nava kishore Manne <navam@xilinx.com>");
  85 MODULE_DESCRIPTION("ZynqMP NVMEM driver");
  86 MODULE_LICENSE("GPL");