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_count(struct acpi_resource *ares, void *data)
 36{
 37	struct acpi_resource_i2c_serialbus *sb;
 38	int *count = data;
 39
 40	if (i2c_acpi_get_i2c_resource(ares, &sb))
 41		*count = *count + 1;
 42
 43	return 1;
 44}
 45
 46static int i2c_multi_inst_count_resources(struct acpi_device *adev)
 47{
 48	LIST_HEAD(r);
 49	int count = 0;
 50	int ret;
 51
 52	ret = acpi_dev_get_resources(adev, &r, i2c_multi_inst_count, &count);
 53	if (ret < 0)
 54		return ret;
 55
 56	acpi_dev_free_resource_list(&r);
 57	return count;
 58}
 59
 60static int i2c_multi_inst_probe(struct platform_device *pdev)
 61{
 62	struct i2c_multi_inst_data *multi;
 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	inst_data = device_get_match_data(dev);
 71	if (!inst_data) {
 72		dev_err(dev, "Error ACPI match data is missing\n");
 73		return -ENODEV;
 74	}
 75
 76	adev = ACPI_COMPANION(dev);
 77
 78	/* Count number of clients to instantiate */
 79	ret = i2c_multi_inst_count_resources(adev);
 80	if (ret < 0)
 81		return ret;
 82
 83	multi = devm_kmalloc(dev, struct_size(multi, clients, ret), GFP_KERNEL);
 84	if (!multi)
 85		return -ENOMEM;
 86
 87	multi->num_clients = ret;
 88
 89	for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
 90		memset(&board_info, 0, sizeof(board_info));
 91		strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
 92		snprintf(name, sizeof(name), "%s-%s.%d", dev_name(dev),
 93			 inst_data[i].type, i);
 94		board_info.dev_name = name;
 95		switch (inst_data[i].flags & IRQ_RESOURCE_TYPE) {
 96		case IRQ_RESOURCE_GPIO:
 97			ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx);
 98			if (ret < 0) {
 99				dev_err(dev, "Error requesting irq at index %d: %d\n",
100					inst_data[i].irq_idx, ret);
101				goto error;
102			}
103			board_info.irq = ret;
104			break;
105		case IRQ_RESOURCE_APIC:
106			ret = platform_get_irq(pdev, inst_data[i].irq_idx);
107			if (ret < 0) {
108				dev_dbg(dev, "Error requesting irq at index %d: %d\n",
109					inst_data[i].irq_idx, ret);
110				goto error;
111			}
112			board_info.irq = ret;
113			break;
114		default:
115			board_info.irq = 0;
116			break;
117		}
118		multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
119		if (IS_ERR(multi->clients[i])) {
120			ret = dev_err_probe(dev, PTR_ERR(multi->clients[i]),
121					    "Error creating i2c-client, idx %d\n", i);
122			goto error;
123		}
124	}
125	if (i < multi->num_clients) {
126		dev_err(dev, "Error finding driver, idx %d\n", i);
127		ret = -ENODEV;
128		goto error;
129	}
130
131	platform_set_drvdata(pdev, multi);
132	return 0;
133
134error:
135	while (--i >= 0)
136		i2c_unregister_device(multi->clients[i]);
137
138	return ret;
139}
140
141static int i2c_multi_inst_remove(struct platform_device *pdev)
142{
143	struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
144	int i;
145
146	for (i = 0; i < multi->num_clients; i++)
147		i2c_unregister_device(multi->clients[i]);
148
149	return 0;
150}
151
152static const struct i2c_inst_data bsg1160_data[]  = {
153	{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
154	{ "bmc150_magn" },
155	{ "bmg160" },
156	{}
157};
158
159static const struct i2c_inst_data bsg2150_data[]  = {
160	{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
161	{ "bmc150_magn" },
162	/* The resources describe a 3th client, but it is not really there. */
163	{ "bsg2150_dummy_dev" },
164	{}
165};
166
167/*
168 * Device with _HID INT3515 (TI PD controllers) has some unresolved interrupt
169 * issues. The most common problem seen is interrupt flood.
170 *
171 * There are at least two known causes. Firstly, on some boards, the
172 * I2CSerialBus resource index does not match the Interrupt resource, i.e. they
173 * are not one-to-one mapped like in the array below. Secondly, on some boards
174 * the IRQ line from the PD controller is not actually connected at all. But the
175 * interrupt flood is also seen on some boards where those are not a problem, so
176 * there are some other problems as well.
177 *
178 * Because of the issues with the interrupt, the device is disabled for now. If
179 * you wish to debug the issues, uncomment the below, and add an entry for the
180 * INT3515 device to the i2c_multi_instance_ids table.
181 *
182 * static const struct i2c_inst_data int3515_data[]  = {
183 *	{ "tps6598x", IRQ_RESOURCE_APIC, 0 },
184 *	{ "tps6598x", IRQ_RESOURCE_APIC, 1 },
185 *	{ "tps6598x", IRQ_RESOURCE_APIC, 2 },
186 *	{ "tps6598x", IRQ_RESOURCE_APIC, 3 },
187 *	{ }
188 * };
189 */
190
191/*
192 * Note new device-ids must also be added to i2c_multi_instantiate_ids in
193 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
194 */
195static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
196	{ "BSG1160", (unsigned long)bsg1160_data },
197	{ "BSG2150", (unsigned long)bsg2150_data },
198	{ }
199};
200MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
201
202static struct platform_driver i2c_multi_inst_driver = {
203	.driver	= {
204		.name = "I2C multi instantiate pseudo device driver",
205		.acpi_match_table = i2c_multi_inst_acpi_ids,
206	},
207	.probe = i2c_multi_inst_probe,
208	.remove = i2c_multi_inst_remove,
209};
210module_platform_driver(i2c_multi_inst_driver);
211
212MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
213MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
214MODULE_LICENSE("GPL");