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, 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
136error:
137	while (--i >= 0)
138		i2c_unregister_device(multi->clients[i]);
139
140	return ret;
141}
142
143static 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
154static const struct i2c_inst_data bsg1160_data[]  = {
155	{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
156	{ "bmc150_magn" },
157	{ "bmg160" },
158	{}
159};
160
161static 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
169static const struct i2c_inst_data int3515_data[]  = {
170	{ "tps6598x", IRQ_RESOURCE_APIC, 0 },
171	{ "tps6598x", IRQ_RESOURCE_APIC, 1 },
172	{ "tps6598x", IRQ_RESOURCE_APIC, 2 },
173	{ "tps6598x", IRQ_RESOURCE_APIC, 3 },
174	{}
175};
176
177/*
178 * Note new device-ids must also be added to i2c_multi_instantiate_ids in
179 * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
180 */
181static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
182	{ "BSG1160", (unsigned long)bsg1160_data },
183	{ "BSG2150", (unsigned long)bsg2150_data },
184	{ "INT3515", (unsigned long)int3515_data },
185	{ }
186};
187MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
188
189static struct platform_driver i2c_multi_inst_driver = {
190	.driver	= {
191		.name = "I2C multi instantiate pseudo device driver",
192		.acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
193	},
194	.probe = i2c_multi_inst_probe,
195	.remove = i2c_multi_inst_remove,
196};
197module_platform_driver(i2c_multi_inst_driver);
198
199MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
200MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
201MODULE_LICENSE("GPL");