1 // SPDX-License-Identifier: GPL-2.0+
2 
3 #define pr_fmt(fmt) "of_pmem: " fmt
4 
5 #include <linux/of.h>
6 #include <linux/libnvdimm.h>
7 #include <linux/module.h>
8 #include <linux/ioport.h>
9 #include <linux/platform_device.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 = devm_kstrdup(&pdev->dev, pdev->name,
34 							GFP_KERNEL);
35 	if (!priv->bus_desc.provider_name) {
36 		kfree(priv);
37 		return -ENOMEM;
38 	}
39 
40 	priv->bus_desc.module = THIS_MODULE;
41 	priv->bus_desc.of_node = np;
42 
43 	priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
44 	if (!bus) {
45 		kfree(priv);
46 		return -ENODEV;
47 	}
48 	platform_set_drvdata(pdev, priv);
49 
50 	is_volatile = of_property_read_bool(np, "volatile");
51 	dev_dbg(&pdev->dev, "Registering %s regions from %pOF\n",
52 			is_volatile ? "volatile" : "non-volatile",  np);
53 
54 	for (i = 0; i < pdev->num_resources; i++) {
55 		struct nd_region_desc ndr_desc;
56 		struct nd_region *region;
57 
58 		/*
59 		 * NB: libnvdimm copies the data from ndr_desc into it's own
60 		 * structures so passing a stack pointer is fine.
61 		 */
62 		memset(&ndr_desc, 0, sizeof(ndr_desc));
63 		ndr_desc.numa_node = dev_to_node(&pdev->dev);
64 		ndr_desc.target_node = ndr_desc.numa_node;
65 		ndr_desc.res = &pdev->resource[i];
66 		ndr_desc.of_node = np;
67 		set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
68 
69 		if (is_volatile)
70 			region = nvdimm_volatile_region_create(bus, &ndr_desc);
71 		else {
72 			set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
73 			region = nvdimm_pmem_region_create(bus, &ndr_desc);
74 		}
75 
76 		if (!region)
77 			dev_warn(&pdev->dev, "Unable to register region %pR from %pOF\n",
78 					ndr_desc.res, np);
79 		else
80 			dev_dbg(&pdev->dev, "Registered region %pR from %pOF\n",
81 					ndr_desc.res, np);
82 	}
83 
84 	return 0;
85 }
86 
of_pmem_region_remove(struct platform_device * pdev)87 static void of_pmem_region_remove(struct platform_device *pdev)
88 {
89 	struct of_pmem_private *priv = platform_get_drvdata(pdev);
90 
91 	nvdimm_bus_unregister(priv->bus);
92 	kfree(priv);
93 }
94 
95 static const struct of_device_id of_pmem_region_match[] = {
96 	{ .compatible = "pmem-region" },
97 	{ .compatible = "pmem-region-v2" },
98 	{ },
99 };
100 
101 static struct platform_driver of_pmem_region_driver = {
102 	.probe = of_pmem_region_probe,
103 	.remove_new = of_pmem_region_remove,
104 	.driver = {
105 		.name = "of_pmem",
106 		.of_match_table = of_pmem_region_match,
107 	},
108 };
109 
110 module_platform_driver(of_pmem_region_driver);
111 MODULE_DEVICE_TABLE(of, of_pmem_region_match);
112 MODULE_DESCRIPTION("NVDIMM Device Tree support");
113 MODULE_LICENSE("GPL");
114 MODULE_AUTHOR("IBM Corporation");
115