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