1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * CE4100 PCI-I2C glue code for PXA's driver
4  * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
5  *
6  * The CE4100's I2C device is more or less the same one as found on PXA.
7  * It does not support target mode, the register slightly moved. This PCI
8  * device provides three bars, every contains a single I2C controller.
9  */
10 #include <linux/init.h>
11 #include <linux/pci.h>
12 #include <linux/platform_device.h>
13 #include <linux/platform_data/i2c-pxa.h>
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 
17 #define CE4100_PCI_I2C_DEVS	3
18 
19 struct ce4100_devices {
20 	struct platform_device *pdev[CE4100_PCI_I2C_DEVS];
21 };
22 
add_i2c_device(struct pci_dev * dev,int bar)23 static struct platform_device *add_i2c_device(struct pci_dev *dev, int bar)
24 {
25 	struct platform_device *pdev;
26 	struct i2c_pxa_platform_data pdata;
27 	struct resource res[2];
28 	struct device_node *child;
29 	static int devnum;
30 	int ret;
31 
32 	memset(&pdata, 0, sizeof(struct i2c_pxa_platform_data));
33 	memset(&res, 0, sizeof(res));
34 
35 	res[0].flags = IORESOURCE_MEM;
36 	res[0].start = pci_resource_start(dev, bar);
37 	res[0].end = pci_resource_end(dev, bar);
38 
39 	res[1].flags = IORESOURCE_IRQ;
40 	res[1].start = dev->irq;
41 	res[1].end = dev->irq;
42 
43 	for_each_child_of_node(dev->dev.of_node, child) {
44 		const void *prop;
45 		struct resource r;
46 		int ret;
47 
48 		ret = of_address_to_resource(child, 0, &r);
49 		if (ret < 0)
50 			continue;
51 		if (r.start != res[0].start)
52 			continue;
53 		if (r.end != res[0].end)
54 			continue;
55 		if (r.flags != res[0].flags)
56 			continue;
57 
58 		prop = of_get_property(child, "fast-mode", NULL);
59 		if (prop)
60 			pdata.fast_mode = 1;
61 
62 		break;
63 	}
64 
65 	if (!child) {
66 		dev_err(&dev->dev, "failed to match a DT node for bar %d.\n",
67 				bar);
68 		ret = -EINVAL;
69 		goto out;
70 	}
71 
72 	pdev = platform_device_alloc("ce4100-i2c", devnum);
73 	if (!pdev) {
74 		of_node_put(child);
75 		ret = -ENOMEM;
76 		goto out;
77 	}
78 	pdev->dev.parent = &dev->dev;
79 	pdev->dev.of_node = child;
80 
81 	ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
82 	if (ret)
83 		goto err;
84 
85 	ret = platform_device_add_data(pdev, &pdata, sizeof(pdata));
86 	if (ret)
87 		goto err;
88 
89 	ret = platform_device_add(pdev);
90 	if (ret)
91 		goto err;
92 	devnum++;
93 	return pdev;
94 err:
95 	platform_device_put(pdev);
96 out:
97 	return ERR_PTR(ret);
98 }
99 
ce4100_i2c_probe(struct pci_dev * dev,const struct pci_device_id * ent)100 static int ce4100_i2c_probe(struct pci_dev *dev,
101 		const struct pci_device_id *ent)
102 {
103 	int ret;
104 	int i;
105 	struct ce4100_devices *sds;
106 
107 	ret = pcim_enable_device(dev);
108 	if (ret)
109 		return ret;
110 
111 	if (!dev->dev.of_node) {
112 		dev_err(&dev->dev, "Missing device tree node.\n");
113 		return -EINVAL;
114 	}
115 	sds = kzalloc(sizeof(*sds), GFP_KERNEL);
116 	if (!sds)
117 		return -ENOMEM;
118 
119 	for (i = 0; i < ARRAY_SIZE(sds->pdev); i++) {
120 		sds->pdev[i] = add_i2c_device(dev, i);
121 		if (IS_ERR(sds->pdev[i])) {
122 			ret = PTR_ERR(sds->pdev[i]);
123 			while (--i >= 0)
124 				platform_device_unregister(sds->pdev[i]);
125 			goto err_dev_add;
126 		}
127 	}
128 	pci_set_drvdata(dev, sds);
129 	return 0;
130 
131 err_dev_add:
132 	kfree(sds);
133 	return ret;
134 }
135 
136 static const struct pci_device_id ce4100_i2c_devices[] = {
137 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2e68)},
138 	{ }
139 };
140 
141 static struct pci_driver ce4100_i2c_driver = {
142 	.driver = {
143 		.suppress_bind_attrs = true,
144 	},
145 	.name           = "ce4100_i2c",
146 	.id_table       = ce4100_i2c_devices,
147 	.probe          = ce4100_i2c_probe,
148 };
149 builtin_pci_driver(ce4100_i2c_driver);
150