1 // SPDX-License-Identifier: GPL-2.0+
2 
3 #define pr_fmt(fmt) "of_pmem: " fmt
4 
5 #include <linux/of_platform.h>
6 #include <linux/of_address.h>
7 #include <linux/libnvdimm.h>
8 #include <linux/module.h>
9 #include <linux/ioport.h>
10 #include <linux/slab.h>
11 
12 struct of_pmem_private {
13 	struct nvdimm_bus_descriptor bus_desc;
14 	struct nvdimm_bus *bus;
15 };
16 
of_pmem_region_probe(struct platform_device * pdev)17 static int of_pmem_region_probe(struct platform_device *pdev)
18 {
19 	struct of_pmem_private *priv;
20 	struct device_node *np;
21 	struct nvdimm_bus *bus;
22 	bool is_volatile;
23 	int i;
24 
25 	np = dev_of_node(&pdev->dev);
26 	if (!np)
27 		return -ENXIO;
28 
29 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
30 	if (!priv)
31 		return -ENOMEM;
32 
33 	priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
34 	priv->bus_desc.module = THIS_MODULE;
35 	priv->bus_desc.of_node = np;
36 
37 	priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
38 	if (!bus) {
39 		kfree(priv);
40 		return -ENODEV;
41 	}
42 	platform_set_drvdata(pdev, priv);
43 
44 	is_volatile = !!of_find_property(np, "volatile", NULL);
45 	dev_dbg(&pdev->dev, "Registering %s regions from %pOF\n",
46 			is_volatile ? "volatile" : "non-volatile",  np);
47 
48 	for (i = 0; i < pdev->num_resources; i++) {
49 		struct nd_region_desc ndr_desc;
50 		struct nd_region *region;
51 
52 		/*
53 		 * NB: libnvdimm copies the data from ndr_desc into it's own
54 		 * structures so passing a stack pointer is fine.
55 		 */
56 		memset(&ndr_desc, 0, sizeof(ndr_desc));
57 		ndr_desc.numa_node = dev_to_node(&pdev->dev);
58 		ndr_desc.target_node = ndr_desc.numa_node;
59 		ndr_desc.res = &pdev->resource[i];
60 		ndr_desc.of_node = np;
61 		set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
62 
63 		if (is_volatile)
64 			region = nvdimm_volatile_region_create(bus, &ndr_desc);
65 		else {
66 			set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
67 			region = nvdimm_pmem_region_create(bus, &ndr_desc);
68 		}
69 
70 		if (!region)
71 			dev_warn(&pdev->dev, "Unable to register region %pR from %pOF\n",
72 					ndr_desc.res, np);
73 		else
74 			dev_dbg(&pdev->dev, "Registered region %pR from %pOF\n",
75 					ndr_desc.res, np);
76 	}
77 
78 	return 0;
79 }
80 
of_pmem_region_remove(struct platform_device * pdev)81 static int of_pmem_region_remove(struct platform_device *pdev)
82 {
83 	struct of_pmem_private *priv = platform_get_drvdata(pdev);
84 
85 	nvdimm_bus_unregister(priv->bus);
86 	kfree(priv);
87 
88 	return 0;
89 }
90 
91 static const struct of_device_id of_pmem_region_match[] = {
92 	{ .compatible = "pmem-region" },
93 	{ .compatible = "pmem-region-v2" },
94 	{ },
95 };
96 
97 static struct platform_driver of_pmem_region_driver = {
98 	.probe = of_pmem_region_probe,
99 	.remove = of_pmem_region_remove,
100 	.driver = {
101 		.name = "of_pmem",
102 		.of_match_table = of_pmem_region_match,
103 	},
104 };
105 
106 module_platform_driver(of_pmem_region_driver);
107 MODULE_DEVICE_TABLE(of, of_pmem_region_match);
108 MODULE_LICENSE("GPL");
109 MODULE_AUTHOR("IBM Corporation");
110