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/types.h>
17
18#define IRQ_RESOURCE_TYPE GENMASK(1, 0)
19#define IRQ_RESOURCE_NONE 0
20#define IRQ_RESOURCE_GPIO 1
21#define IRQ_RESOURCE_APIC 2
22
23struct i2c_inst_data {
24 const char *type;
25 unsigned int flags;
26 int irq_idx;
27};
28
29struct i2c_multi_inst_data {
30 int num_clients;
31 struct i2c_client *clients[0];
32};
33
34static int i2c_multi_inst_count(struct acpi_resource *ares, void *data)
35{
36 struct acpi_resource_i2c_serialbus *sb;
37 int *count = data;
38
39 if (i2c_acpi_get_i2c_resource(ares, &sb))
40 *count = *count + 1;
41
42 return 1;
43}
44
45static int i2c_multi_inst_count_resources(struct acpi_device *adev)
46{
47 LIST_HEAD(r);
48 int count = 0;
49 int ret;
50
51 ret = acpi_dev_get_resources(adev, &r, i2c_multi_inst_count, &count);
52 if (ret < 0)
53 return ret;
54
55 acpi_dev_free_resource_list(&r);
56 return count;
57}
58
59static int i2c_multi_inst_probe(struct platform_device *pdev)
60{
61 struct i2c_multi_inst_data *multi;
62 const struct acpi_device_id *match;
63 const struct i2c_inst_data *inst_data;
64 struct i2c_board_info board_info = {};
65 struct device *dev = &pdev->dev;
66 struct acpi_device *adev;
67 char name[32];
68 int i, ret;
69
70 match = acpi_match_device(dev->driver->acpi_match_table, dev);
71 if (!match) {
72 dev_err(dev, "Error ACPI match data is missing\n");
73 return -ENODEV;
74 }
75 inst_data = (const struct i2c_inst_data *)match->driver_data;
76
77 adev = ACPI_COMPANION(dev);
78
79 /* Count number of clients to instantiate */
80 ret = i2c_multi_inst_count_resources(adev);
81 if (ret < 0)
82 return ret;
83
84 multi = devm_kmalloc(dev,
85 offsetof(struct i2c_multi_inst_data, clients[ret]),
86 GFP_KERNEL);
87 if (!multi)
88 return -ENOMEM;
89
90 multi->num_clients = ret;
91
92 for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
93 memset(&board_info, 0, sizeof(board_info));
94 strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
95 snprintf(name, sizeof(name), "%s-%s.%d", match->id,
96 inst_data[i].type, i);
97 board_info.dev_name = name;
98 switch (inst_data[i].flags & IRQ_RESOURCE_TYPE) {
99 case IRQ_RESOURCE_GPIO:
100 ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx);
101 if (ret < 0) {
102 dev_err(dev, "Error requesting irq at index %d: %d\n",
103 inst_data[i].irq_idx, ret);
104 goto error;
105 }
106 board_info.irq = ret;
107 break;
108 case IRQ_RESOURCE_APIC:
109 ret = platform_get_irq(pdev, inst_data[i].irq_idx);
110 if (ret < 0) {
111 dev_dbg(dev, "Error requesting irq at index %d: %d\n",
112 inst_data[i].irq_idx, ret);
113 }
114 board_info.irq = ret;
115 break;
116 default:
117 board_info.irq = 0;
118 break;
119 }
120 multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
121 if (IS_ERR(multi->clients[i])) {
122 ret = PTR_ERR(multi->clients[i]);
123 if (ret != -EPROBE_DEFER)
124 dev_err(dev, "Error creating i2c-client, idx %d\n", i);
125 goto error;
126 }
127 }
128 if (i < multi->num_clients) {
129 dev_err(dev, "Error finding driver, idx %d\n", i);
130 ret = -ENODEV;
131 goto error;
132 }
133
134 platform_set_drvdata(pdev, multi);
135 return 0;
136
137error:
138 while (--i >= 0)
139 i2c_unregister_device(multi->clients[i]);
140
141 return ret;
142}
143
144static int i2c_multi_inst_remove(struct platform_device *pdev)
145{
146 struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
147 int i;
148
149 for (i = 0; i < multi->num_clients; i++)
150 i2c_unregister_device(multi->clients[i]);
151
152 return 0;
153}
154
155static const struct i2c_inst_data bsg1160_data[] = {
156 { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
157 { "bmc150_magn" },
158 { "bmg160" },
159 {}
160};
161
162static const struct i2c_inst_data bsg2150_data[] = {
163 { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
164 { "bmc150_magn" },
165 /* The resources describe a 3th client, but it is not really there. */
166 { "bsg2150_dummy_dev" },
167 {}
168};
169
170static const struct i2c_inst_data int3515_data[] = {
171 { "tps6598x", IRQ_RESOURCE_APIC, 0 },
172 { "tps6598x", IRQ_RESOURCE_APIC, 1 },
173 { "tps6598x", IRQ_RESOURCE_APIC, 2 },
174 { "tps6598x", IRQ_RESOURCE_APIC, 3 },
175 {}
176};
177
178/*
179 * Note new device-ids must also be added to i2c_multi_instantiate_ids in
180 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
181 */
182static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
183 { "BSG1160", (unsigned long)bsg1160_data },
184 { "BSG2150", (unsigned long)bsg2150_data },
185 { "INT3515", (unsigned long)int3515_data },
186 { }
187};
188MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
189
190static struct platform_driver i2c_multi_inst_driver = {
191 .driver = {
192 .name = "I2C multi instantiate pseudo device driver",
193 .acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
194 },
195 .probe = i2c_multi_inst_probe,
196 .remove = i2c_multi_inst_remove,
197};
198module_platform_driver(i2c_multi_inst_driver);
199
200MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
201MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
202MODULE_LICENSE("GPL");