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
23 struct i2c_inst_data {
24 const char *type;
25 unsigned int flags;
26 int irq_idx;
27 };
28
29 struct i2c_multi_inst_data {
30 int num_clients;
31 struct i2c_client *clients[];
32 };
33
i2c_multi_inst_count(struct acpi_resource * ares,void * data)34 static 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
i2c_multi_inst_count_resources(struct acpi_device * adev)45 static 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
i2c_multi_inst_probe(struct platform_device * pdev)59 static 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, struct_size(multi, clients, ret), GFP_KERNEL);
85 if (!multi)
86 return -ENOMEM;
87
88 multi->num_clients = ret;
89
90 for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
91 memset(&board_info, 0, sizeof(board_info));
92 strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
93 snprintf(name, sizeof(name), "%s-%s.%d", dev_name(dev),
94 inst_data[i].type, i);
95 board_info.dev_name = name;
96 switch (inst_data[i].flags & IRQ_RESOURCE_TYPE) {
97 case IRQ_RESOURCE_GPIO:
98 ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx);
99 if (ret < 0) {
100 dev_err(dev, "Error requesting irq at index %d: %d\n",
101 inst_data[i].irq_idx, ret);
102 goto error;
103 }
104 board_info.irq = ret;
105 break;
106 case IRQ_RESOURCE_APIC:
107 ret = platform_get_irq(pdev, inst_data[i].irq_idx);
108 if (ret < 0) {
109 dev_dbg(dev, "Error requesting irq at index %d: %d\n",
110 inst_data[i].irq_idx, ret);
111 goto error;
112 }
113 board_info.irq = ret;
114 break;
115 default:
116 board_info.irq = 0;
117 break;
118 }
119 multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
120 if (IS_ERR(multi->clients[i])) {
121 ret = PTR_ERR(multi->clients[i]);
122 if (ret != -EPROBE_DEFER)
123 dev_err(dev, "Error creating i2c-client, idx %d\n", i);
124 goto error;
125 }
126 }
127 if (i < multi->num_clients) {
128 dev_err(dev, "Error finding driver, idx %d\n", i);
129 ret = -ENODEV;
130 goto error;
131 }
132
133 platform_set_drvdata(pdev, multi);
134 return 0;
135
136 error:
137 while (--i >= 0)
138 i2c_unregister_device(multi->clients[i]);
139
140 return ret;
141 }
142
i2c_multi_inst_remove(struct platform_device * pdev)143 static int i2c_multi_inst_remove(struct platform_device *pdev)
144 {
145 struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
146 int i;
147
148 for (i = 0; i < multi->num_clients; i++)
149 i2c_unregister_device(multi->clients[i]);
150
151 return 0;
152 }
153
154 static const struct i2c_inst_data bsg1160_data[] = {
155 { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
156 { "bmc150_magn" },
157 { "bmg160" },
158 {}
159 };
160
161 static const struct i2c_inst_data bsg2150_data[] = {
162 { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
163 { "bmc150_magn" },
164 /* The resources describe a 3th client, but it is not really there. */
165 { "bsg2150_dummy_dev" },
166 {}
167 };
168
169 /*
170 * Device with _HID INT3515 (TI PD controllers) has some unresolved interrupt
171 * issues. The most common problem seen is interrupt flood.
172 *
173 * There are at least two known causes. Firstly, on some boards, the
174 * I2CSerialBus resource index does not match the Interrupt resource, i.e. they
175 * are not one-to-one mapped like in the array below. Secondly, on some boards
176 * the IRQ line from the PD controller is not actually connected at all. But the
177 * interrupt flood is also seen on some boards where those are not a problem, so
178 * there are some other problems as well.
179 *
180 * Because of the issues with the interrupt, the device is disabled for now. If
181 * you wish to debug the issues, uncomment the below, and add an entry for the
182 * INT3515 device to the i2c_multi_instance_ids table.
183 *
184 * static const struct i2c_inst_data int3515_data[] = {
185 * { "tps6598x", IRQ_RESOURCE_APIC, 0 },
186 * { "tps6598x", IRQ_RESOURCE_APIC, 1 },
187 * { "tps6598x", IRQ_RESOURCE_APIC, 2 },
188 * { "tps6598x", IRQ_RESOURCE_APIC, 3 },
189 * { }
190 * };
191 */
192
193 /*
194 * Note new device-ids must also be added to i2c_multi_instantiate_ids in
195 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
196 */
197 static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
198 { "BSG1160", (unsigned long)bsg1160_data },
199 { "BSG2150", (unsigned long)bsg2150_data },
200 { }
201 };
202 MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
203
204 static struct platform_driver i2c_multi_inst_driver = {
205 .driver = {
206 .name = "I2C multi instantiate pseudo device driver",
207 .acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
208 },
209 .probe = i2c_multi_inst_probe,
210 .remove = i2c_multi_inst_remove,
211 };
212 module_platform_driver(i2c_multi_inst_driver);
213
214 MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
215 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
216 MODULE_LICENSE("GPL");
217