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 slave 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_device.h>
16 #include <linux/of_address.h>
17 
18 #define CE4100_PCI_I2C_DEVS	3
19 
20 struct ce4100_devices {
21 	struct platform_device *pdev[CE4100_PCI_I2C_DEVS];
22 };
23 
add_i2c_device(struct pci_dev * dev,int bar)24 static struct platform_device *add_i2c_device(struct pci_dev *dev, int bar)
25 {
26 	struct platform_device *pdev;
27 	struct i2c_pxa_platform_data pdata;
28 	struct resource res[2];
29 	struct device_node *child;
30 	static int devnum;
31 	int ret;
32 
33 	memset(&pdata, 0, sizeof(struct i2c_pxa_platform_data));
34 	memset(&res, 0, sizeof(res));
35 
36 	res[0].flags = IORESOURCE_MEM;
37 	res[0].start = pci_resource_start(dev, bar);
38 	res[0].end = pci_resource_end(dev, bar);
39 
40 	res[1].flags = IORESOURCE_IRQ;
41 	res[1].start = dev->irq;
42 	res[1].end = dev->irq;
43 
44 	for_each_child_of_node(dev->dev.of_node, child) {
45 		const void *prop;
46 		struct resource r;
47 		int ret;
48 
49 		ret = of_address_to_resource(child, 0, &r);
50 		if (ret < 0)
51 			continue;
52 		if (r.start != res[0].start)
53 			continue;
54 		if (r.end != res[0].end)
55 			continue;
56 		if (r.flags != res[0].flags)
57 			continue;
58 
59 		prop = of_get_property(child, "fast-mode", NULL);
60 		if (prop)
61 			pdata.fast_mode = 1;
62 
63 		break;
64 	}
65 
66 	if (!child) {
67 		dev_err(&dev->dev, "failed to match a DT node for bar %d.\n",
68 				bar);
69 		ret = -EINVAL;
70 		goto out;
71 	}
72 
73 	pdev = platform_device_alloc("ce4100-i2c", devnum);
74 	if (!pdev) {
75 		of_node_put(child);
76 		ret = -ENOMEM;
77 		goto out;
78 	}
79 	pdev->dev.parent = &dev->dev;
80 	pdev->dev.of_node = child;
81 
82 	ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
83 	if (ret)
84 		goto err;
85 
86 	ret = platform_device_add_data(pdev, &pdata, sizeof(pdata));
87 	if (ret)
88 		goto err;
89 
90 	ret = platform_device_add(pdev);
91 	if (ret)
92 		goto err;
93 	devnum++;
94 	return pdev;
95 err:
96 	platform_device_put(pdev);
97 out:
98 	return ERR_PTR(ret);
99 }
100 
ce4100_i2c_probe(struct pci_dev * dev,const struct pci_device_id * ent)101 static int ce4100_i2c_probe(struct pci_dev *dev,
102 		const struct pci_device_id *ent)
103 {
104 	int ret;
105 	int i;
106 	struct ce4100_devices *sds;
107 
108 	ret = pci_enable_device_mem(dev);
109 	if (ret)
110 		return ret;
111 
112 	if (!dev->dev.of_node) {
113 		dev_err(&dev->dev, "Missing device tree node.\n");
114 		return -EINVAL;
115 	}
116 	sds = kzalloc(sizeof(*sds), GFP_KERNEL);
117 	if (!sds) {
118 		ret = -ENOMEM;
119 		goto err_mem;
120 	}
121 
122 	for (i = 0; i < ARRAY_SIZE(sds->pdev); i++) {
123 		sds->pdev[i] = add_i2c_device(dev, i);
124 		if (IS_ERR(sds->pdev[i])) {
125 			ret = PTR_ERR(sds->pdev[i]);
126 			while (--i >= 0)
127 				platform_device_unregister(sds->pdev[i]);
128 			goto err_dev_add;
129 		}
130 	}
131 	pci_set_drvdata(dev, sds);
132 	return 0;
133 
134 err_dev_add:
135 	kfree(sds);
136 err_mem:
137 	pci_disable_device(dev);
138 	return ret;
139 }
140 
141 static const struct pci_device_id ce4100_i2c_devices[] = {
142 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2e68)},
143 	{ },
144 };
145 
146 static struct pci_driver ce4100_i2c_driver = {
147 	.driver = {
148 		.suppress_bind_attrs = true,
149 	},
150 	.name           = "ce4100_i2c",
151 	.id_table       = ce4100_i2c_devices,
152 	.probe          = ce4100_i2c_probe,
153 };
154 builtin_pci_driver(ce4100_i2c_driver);
155