summaryrefslogtreecommitdiffstats
path: root/drivers/platform/x86/i2c-multi-instantiate.c
blob: d99bbaed0ca28233593b58f15ca74c7c09aa4f06 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
// SPDX-License-Identifier: GPL-2.0+
/*
 * I2C multi-instantiate driver, pseudo driver to instantiate multiple
 * i2c-clients from a single fwnode.
 *
 * Copyright 2018 Hans de Goede <hdegoede@redhat.com>
 */

#include <linux/acpi.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>

struct i2c_inst_data {
	const char *type;
	int gpio_irq_idx;
};

struct i2c_multi_inst_data {
	int num_clients;
	struct i2c_client *clients[0];
};

static int i2c_multi_inst_count(struct acpi_resource *ares, void *data)
{
	struct acpi_resource_i2c_serialbus *sb;
	int *count = data;

	if (i2c_acpi_get_i2c_resource(ares, &sb))
		*count = *count + 1;

	return 1;
}

static int i2c_multi_inst_count_resources(struct acpi_device *adev)
{
	LIST_HEAD(r);
	int count = 0;
	int ret;

	ret = acpi_dev_get_resources(adev, &r, i2c_multi_inst_count, &count);
	if (ret < 0)
		return ret;

	acpi_dev_free_resource_list(&r);
	return count;
}

static int i2c_multi_inst_probe(struct platform_device *pdev)
{
	struct i2c_multi_inst_data *multi;
	const struct acpi_device_id *match;
	const struct i2c_inst_data *inst_data;
	struct i2c_board_info board_info = {};
	struct device *dev = &pdev->dev;
	struct acpi_device *adev;
	char name[32];
	int i, ret;

	match = acpi_match_device(dev->driver->acpi_match_table, dev);
	if (!match) {
		dev_err(dev, "Error ACPI match data is missing\n");
		return -ENODEV;
	}
	inst_data = (const struct i2c_inst_data *)match->driver_data;

	adev = ACPI_COMPANION(dev);

	/* Count number of clients to instantiate */
	ret = i2c_multi_inst_count_resources(adev);
	if (ret < 0)
		return ret;

	multi = devm_kmalloc(dev,
			offsetof(struct i2c_multi_inst_data, clients[ret]),
			GFP_KERNEL);
	if (!multi)
		return -ENOMEM;

	multi->num_clients = ret;

	for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
		memset(&board_info, 0, sizeof(board_info));
		strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
		snprintf(name, sizeof(name), "%s-%s", match->id,
			 inst_data[i].type);
		board_info.dev_name = name;
		board_info.irq = 0;
		if (inst_data[i].gpio_irq_idx != -1) {
			ret = acpi_dev_gpio_irq_get(adev,
						    inst_data[i].gpio_irq_idx);
			if (ret < 0) {
				dev_err(dev, "Error requesting irq at index %d: %d\n",
					inst_data[i].gpio_irq_idx, ret);
				goto error;
			}
			board_info.irq = ret;
		}
		multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
		if (IS_ERR(multi->clients[i])) {
			ret = PTR_ERR(multi->clients[i]);
			if (ret != -EPROBE_DEFER)
				dev_err(dev, "Error creating i2c-client, idx %d\n", i);
			goto error;
		}
	}
	if (i < multi->num_clients) {
		dev_err(dev, "Error finding driver, idx %d\n", i);
		ret = -ENODEV;
		goto error;
	}

	platform_set_drvdata(pdev, multi);
	return 0;

error:
	while (--i >= 0)
		i2c_unregister_device(multi->clients[i]);

	return ret;
}

static int i2c_multi_inst_remove(struct platform_device *pdev)
{
	struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < multi->num_clients; i++)
		i2c_unregister_device(multi->clients[i]);

	return 0;
}

static const struct i2c_inst_data bsg1160_data[]  = {
	{ "bmc150_accel", 0 },
	{ "bmc150_magn", -1 },
	{ "bmg160", -1 },
	{}
};

/*
 * Note new device-ids must also be added to i2c_multi_instantiate_ids in
 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
 */
static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
	{ "BSG1160", (unsigned long)bsg1160_data },
	{ }
};
MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);

static struct platform_driver i2c_multi_inst_driver = {
	.driver	= {
		.name = "I2C multi instantiate pseudo device driver",
		.acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
	},
	.probe = i2c_multi_inst_probe,
	.remove = i2c_multi_inst_remove,
};
module_platform_driver(i2c_multi_inst_driver);

MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_LICENSE("GPL");