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
zynqmp_nvmem_read(void * context,unsigned int offset,void * val,size_t bytes)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
zynqmp_nvmem_probe(struct platform_device * pdev)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");
82