linux/drivers/platform/x86/i2c-multi-instantiate.c

203 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* I2C multi-instantiate driver, pseudo driver to instantiate multiple
* i2c-clients from a single fwnode.
*
* Copyright 2018 Hans de Goede <hdegoede@redhat.com>
*/
#include <linux/acpi.h>
#include <linux/bits.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#define IRQ_RESOURCE_TYPE GENMASK(1, 0)
#define IRQ_RESOURCE_NONE 0
#define IRQ_RESOURCE_GPIO 1
#define IRQ_RESOURCE_APIC 2
struct i2c_inst_data {
const char *type;
unsigned int flags;
int irq_idx;
};
struct i2c_multi_inst_data {
int num_clients;
struct i2c_client *clients[0];
};
static int i2c_multi_inst_count(struct acpi_resource *ares, void *data)
{
struct acpi_resource_i2c_serialbus *sb;
int *count = data;
if (i2c_acpi_get_i2c_resource(ares, &sb))
*count = *count + 1;
return 1;
}
static int i2c_multi_inst_count_resources(struct acpi_device *adev)
{
LIST_HEAD(r);
int count = 0;
int ret;
ret = acpi_dev_get_resources(adev, &r, i2c_multi_inst_count, &count);
if (ret < 0)
return ret;
acpi_dev_free_resource_list(&r);
return count;
}
static int i2c_multi_inst_probe(struct platform_device *pdev)
{
struct i2c_multi_inst_data *multi;
const struct acpi_device_id *match;
const struct i2c_inst_data *inst_data;
struct i2c_board_info board_info = {};
struct device *dev = &pdev->dev;
struct acpi_device *adev;
char name[32];
int i, ret;
match = acpi_match_device(dev->driver->acpi_match_table, dev);
if (!match) {
dev_err(dev, "Error ACPI match data is missing\n");
return -ENODEV;
}
inst_data = (const struct i2c_inst_data *)match->driver_data;
adev = ACPI_COMPANION(dev);
/* Count number of clients to instantiate */
ret = i2c_multi_inst_count_resources(adev);
if (ret < 0)
return ret;
multi = devm_kmalloc(dev,
offsetof(struct i2c_multi_inst_data, clients[ret]),
GFP_KERNEL);
if (!multi)
return -ENOMEM;
multi->num_clients = ret;
for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
memset(&board_info, 0, sizeof(board_info));
strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
snprintf(name, sizeof(name), "%s-%s.%d", match->id,
inst_data[i].type, i);
board_info.dev_name = name;
switch (inst_data[i].flags & IRQ_RESOURCE_TYPE) {
case IRQ_RESOURCE_GPIO:
ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx);
if (ret < 0) {
dev_err(dev, "Error requesting irq at index %d: %d\n",
inst_data[i].irq_idx, ret);
goto error;
}
board_info.irq = ret;
break;
case IRQ_RESOURCE_APIC:
ret = platform_get_irq(pdev, inst_data[i].irq_idx);
if (ret < 0) {
dev_dbg(dev, "Error requesting irq at index %d: %d\n",
inst_data[i].irq_idx, ret);
}
board_info.irq = ret;
break;
default:
board_info.irq = 0;
break;
}
multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
if (IS_ERR(multi->clients[i])) {
ret = PTR_ERR(multi->clients[i]);
if (ret != -EPROBE_DEFER)
dev_err(dev, "Error creating i2c-client, idx %d\n", i);
goto error;
}
}
if (i < multi->num_clients) {
dev_err(dev, "Error finding driver, idx %d\n", i);
ret = -ENODEV;
goto error;
}
platform_set_drvdata(pdev, multi);
return 0;
error:
while (--i >= 0)
i2c_unregister_device(multi->clients[i]);
return ret;
}
static int i2c_multi_inst_remove(struct platform_device *pdev)
{
struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
int i;
for (i = 0; i < multi->num_clients; i++)
i2c_unregister_device(multi->clients[i]);
return 0;
}
static const struct i2c_inst_data bsg1160_data[] = {
{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
{ "bmc150_magn" },
{ "bmg160" },
{}
};
static const struct i2c_inst_data bsg2150_data[] = {
{ "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
{ "bmc150_magn" },
/* The resources describe a 3th client, but it is not really there. */
{ "bsg2150_dummy_dev" },
{}
};
static const struct i2c_inst_data int3515_data[] = {
{ "tps6598x", IRQ_RESOURCE_APIC, 0 },
{ "tps6598x", IRQ_RESOURCE_APIC, 1 },
{ "tps6598x", IRQ_RESOURCE_APIC, 2 },
{ "tps6598x", IRQ_RESOURCE_APIC, 3 },
{}
};
/*
* Note new device-ids must also be added to i2c_multi_instantiate_ids in
* drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
*/
static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
{ "BSG1160", (unsigned long)bsg1160_data },
{ "BSG2150", (unsigned long)bsg2150_data },
{ "INT3515", (unsigned long)int3515_data },
{ }
};
MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
static struct platform_driver i2c_multi_inst_driver = {
.driver = {
.name = "I2C multi instantiate pseudo device driver",
.acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
},
.probe = i2c_multi_inst_probe,
.remove = i2c_multi_inst_remove,
};
module_platform_driver(i2c_multi_inst_driver);
MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_LICENSE("GPL");