tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * I2C multi-instantiate driver, pseudo driver to instantiate multiple
4 * i2c-clients from a single fwnode.
5 *
6 * Copyright 2018 Hans de Goede <hdegoede@redhat.com>
7 */
8
9#include <linux/acpi.h>
10#include <linux/bits.h>
11#include <linux/i2c.h>
12#include <linux/interrupt.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/property.h>
17#include <linux/types.h>
18
19#define IRQ_RESOURCE_TYPE GENMASK(1, 0)
20#define IRQ_RESOURCE_NONE 0
21#define IRQ_RESOURCE_GPIO 1
22#define IRQ_RESOURCE_APIC 2
23
24struct i2c_inst_data {
25 const char *type;
26 unsigned int flags;
27 int irq_idx;
28};
29
30struct i2c_multi_inst_data {
31 int num_clients;
32 struct i2c_client *clients[];
33};
34
35static int i2c_multi_inst_probe(struct platform_device *pdev)
36{
37 struct i2c_multi_inst_data *multi;
38 const struct i2c_inst_data *inst_data;
39 struct i2c_board_info board_info = {};
40 struct device *dev = &pdev->dev;
41 struct acpi_device *adev;
42 char name[32];
43 int i, ret;
44
45 inst_data = device_get_match_data(dev);
46 if (!inst_data) {
47 dev_err(dev, "Error ACPI match data is missing\n");
48 return -ENODEV;
49 }
50
51 adev = ACPI_COMPANION(dev);
52
53 /* Count number of clients to instantiate */
54 ret = i2c_acpi_client_count(adev);
55 if (ret < 0)
56 return ret;
57
58 multi = devm_kmalloc(dev, struct_size(multi, clients, ret), GFP_KERNEL);
59 if (!multi)
60 return -ENOMEM;
61
62 multi->num_clients = ret;
63
64 for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
65 memset(&board_info, 0, sizeof(board_info));
66 strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
67 snprintf(name, sizeof(name), "%s-%s.%d", dev_name(dev),
68 inst_data[i].type, i);
69 board_info.dev_name = name;
70 switch (inst_data[i].flags & IRQ_RESOURCE_TYPE) {
71 case IRQ_RESOURCE_GPIO:
72 ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx);
73 if (ret < 0) {
74 dev_err(dev, "Error requesting irq at index %d: %d\n",
75 inst_data[i].irq_idx, ret);
76 goto error;
77 }
78 board_info.irq = ret;
79 break;
80 case IRQ_RESOURCE_APIC:
81 ret = platform_get_irq(pdev, inst_data[i].irq_idx);
82 if (ret < 0) {
83 dev_dbg(dev, "Error requesting irq at index %d: %d\n",
84 inst_data[i].irq_idx, ret);
85 goto error;
86 }
87 board_info.irq = ret;
88 break;
89 default:
90 board_info.irq = 0;
91 break;
92 }
93 multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
94 if (IS_ERR(multi->clients[i])) {
95 ret = dev_err_probe(dev, PTR_ERR(multi->clients[i]),
96 "Error creating i2c-client, idx %d\n", i);
97 goto error;
98 }
99 }
100 if (i < multi->num_clients) {
101 dev_err(dev, "Error finding driver, idx %d\n", i);
102 ret = -ENODEV;
103 goto error;
104 }
105
106 platform_set_drvdata(pdev, multi);
107 return 0;
108
109error:
110 while (--i >= 0)
111 i2c_unregister_device(multi->clients[i]);
112
113 return ret;
114}
115
116static int i2c_multi_inst_remove(struct platform_device *pdev)
117{
118 struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
119 int i;
120
121 for (i = 0; i < multi->num_clients; i++)
122 i2c_unregister_device(multi->clients[i]);
123
124 return 0;
125}
126
127static const struct i2c_inst_data bsg1160_data[] = {
128 { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
129 { "bmc150_magn" },
130 { "bmg160" },
131 {}
132};
133
134static const struct i2c_inst_data bsg2150_data[] = {
135 { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
136 { "bmc150_magn" },
137 /* The resources describe a 3th client, but it is not really there. */
138 { "bsg2150_dummy_dev" },
139 {}
140};
141
142static const struct i2c_inst_data int3515_data[] = {
143 { "tps6598x", IRQ_RESOURCE_APIC, 0 },
144 { "tps6598x", IRQ_RESOURCE_APIC, 1 },
145 { "tps6598x", IRQ_RESOURCE_APIC, 2 },
146 { "tps6598x", IRQ_RESOURCE_APIC, 3 },
147 {}
148};
149
150/*
151 * Note new device-ids must also be added to i2c_multi_instantiate_ids in
152 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
153 */
154static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
155 { "BSG1160", (unsigned long)bsg1160_data },
156 { "BSG2150", (unsigned long)bsg2150_data },
157 { "INT3515", (unsigned long)int3515_data },
158 { }
159};
160MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
161
162static struct platform_driver i2c_multi_inst_driver = {
163 .driver = {
164 .name = "I2C multi instantiate pseudo device driver",
165 .acpi_match_table = i2c_multi_inst_acpi_ids,
166 },
167 .probe = i2c_multi_inst_probe,
168 .remove = i2c_multi_inst_remove,
169};
170module_platform_driver(i2c_multi_inst_driver);
171
172MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
173MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
174MODULE_LICENSE("GPL");