diff options
Diffstat (limited to 'drivers/platform/x86/i2c-multi-instantiate.c')
| -rw-r--r-- | drivers/platform/x86/i2c-multi-instantiate.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/platform/x86/i2c-multi-instantiate.c b/drivers/platform/x86/i2c-multi-instantiate.c new file mode 100644 index 000000000..d3b5afbe4 --- /dev/null +++ b/drivers/platform/x86/i2c-multi-instantiate.c @@ -0,0 +1,216 @@ +// 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[]; +}; + +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, struct_size(multi, 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", dev_name(dev), + 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); + goto error; + } + 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" }, + {} +}; + +/* + * Device with _HID INT3515 (TI PD controllers) has some unresolved interrupt + * issues. The most common problem seen is interrupt flood. + * + * There are at least two known causes. Firstly, on some boards, the + * I2CSerialBus resource index does not match the Interrupt resource, i.e. they + * are not one-to-one mapped like in the array below. Secondly, on some boards + * the IRQ line from the PD controller is not actually connected at all. But the + * interrupt flood is also seen on some boards where those are not a problem, so + * there are some other problems as well. + * + * Because of the issues with the interrupt, the device is disabled for now. If + * you wish to debug the issues, uncomment the below, and add an entry for the + * INT3515 device to the i2c_multi_instance_ids table. + * + * 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 }, + { } +}; +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"); |