drivers/nvmem/zynqmp_nvmem.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Copyright (C) 2019 Xilinx, Inc.
0004  */
0005
0006 #include <linux/module.h>
0007 #include <linux/nvmem-provider.h>
0008 #include <linux/of.h>
0009 #include <linux/platform_device.h>
0010 #include <linux/firmware/xlnx-zynqmp.h>
0011
0012 #define SILICON_REVISION_MASK 0xF
0013
0014 struct zynqmp_nvmem_data {
0015     struct device *dev;
0016     struct nvmem_device *nvmem;
0017 };
0018
0019 static int zynqmp_nvmem_read(void *context, unsigned int offset,
0020                  void *val, size_t bytes)
0021 {
0022     int ret;
0023     int idcode, version;
0024     struct zynqmp_nvmem_data *priv = context;
0025
0026     ret = zynqmp_pm_get_chipid(&idcode, &version);
0027     if (ret < 0)
0028         return ret;
0029
0030     dev_dbg(priv->dev, "Read chipid val %x %x\n", idcode, version);
0031     *(int *)val = version & SILICON_REVISION_MASK;
0032
0033     return 0;
0034 }
0035
0036 static struct nvmem_config econfig = {
0037     .name = "zynqmp-nvmem",
0038     .owner = THIS_MODULE,
0039     .word_size = 1,
0040     .size = 1,
0041     .read_only = true,
0042 };
0043
0044 static const struct of_device_id zynqmp_nvmem_match[] = {
0045     { .compatible = "xlnx,zynqmp-nvmem-fw", },
0046     { /* sentinel */ },
0047 };
0048 MODULE_DEVICE_TABLE(of, zynqmp_nvmem_match);
0049
0050 static int zynqmp_nvmem_probe(struct platform_device *pdev)
0051 {
0052     struct device *dev = &pdev->dev;
0053     struct zynqmp_nvmem_data *priv;
0054
0055     priv = devm_kzalloc(dev, sizeof(struct zynqmp_nvmem_data), GFP_KERNEL);
0056     if (!priv)
0057         return -ENOMEM;
0058
0059     priv->dev = dev;
0060     econfig.dev = dev;
0061     econfig.reg_read = zynqmp_nvmem_read;
0062     econfig.priv = priv;
0063
0064     priv->nvmem = devm_nvmem_register(dev, &econfig);
0065
0066     return PTR_ERR_OR_ZERO(priv->nvmem);
0067 }
0068
0069 static struct platform_driver zynqmp_nvmem_driver = {
0070     .probe = zynqmp_nvmem_probe,
0071     .driver = {
0072         .name = "zynqmp-nvmem",
0073         .of_match_table = zynqmp_nvmem_match,
0074     },
0075 };
0076
0077 module_platform_driver(zynqmp_nvmem_driver);
0078
0079 MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>, Nava kishore Manne <navam@xilinx.com>");
0080 MODULE_DESCRIPTION("ZynqMP NVMEM driver");
0081 MODULE_LICENSE("GPL");