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         ret = zynqmp_pm_get_chipid(&idcode, &version);
  27         if (ret < 0)
  28                 return ret;
  29
  30         dev_dbg(priv->dev, "Read chipid val %x %x\n", idcode, version);
  31         *(int *)val = version & SILICON_REVISION_MASK;
  32
  33         return 0;
  34 }
  35
  36 static struct nvmem_config econfig = {
  37         .name = "zynqmp-nvmem",
  38         .owner = THIS_MODULE,
  39         .word_size = 1,
  40         .size = 1,
  41         .read_only = true,
  42 };
  43
  44 static const struct of_device_id zynqmp_nvmem_match[] = {
  45         { .compatible = "xlnx,zynqmp-nvmem-fw", },
  46         { /* sentinel */ },
  47 };
  48 MODULE_DEVICE_TABLE(of, zynqmp_nvmem_match);
  49
  50 static int zynqmp_nvmem_probe(struct platform_device *pdev)
  51 {
  52         struct device *dev = &pdev->dev;
  53         struct zynqmp_nvmem_data *priv;
  54
  55         priv = devm_kzalloc(dev, sizeof(struct zynqmp_nvmem_data), GFP_KERNEL);
  56         if (!priv)
  57                 return -ENOMEM;
  58
  59         priv->dev = dev;
  60         econfig.dev = dev;
  61         econfig.reg_read = zynqmp_nvmem_read;
  62         econfig.priv = priv;
  63
  64         priv->nvmem = devm_nvmem_register(dev, &econfig);
  65
  66         return PTR_ERR_OR_ZERO(priv->nvmem);
  67 }
  68
  69 static struct platform_driver zynqmp_nvmem_driver = {
  70         .probe = zynqmp_nvmem_probe,
  71         .driver = {
  72                 .name = "zynqmp-nvmem",
  73                 .of_match_table = zynqmp_nvmem_match,
  74         },
  75 };
  76
  77 module_platform_driver(zynqmp_nvmem_driver);
  78
  79 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>, Nava kishore Manne <navam@xilinx.com>");
  80 MODULE_DESCRIPTION("ZynqMP NVMEM driver");
  81 MODULE_LICENSE("GPL");