On systems with ACPI instantiated i2c-clients, normally there is 1 fw_node per i2c-device and that fw-node contains 1 I2cSerialBus resource for that 1 i2c-device. But in some rare cases the manufacturer has decided to describe multiple i2c-devices in a single ACPI fwnode with multiple I2cSerialBus resources. An earlier attempt to fix this in the i2c-core resulted in a lot of extra code to support this corner-case. This commit introduces a new i2c-multi-instantiate driver which fixes this in a different way. This new driver can be built as a module which will only loaded on affected systems. This driver will instantiate a new i2c-client per I2cSerialBus resource, using the driver_data from the acpi_device_id it is binding to to tell it which chip-type (and optional irq-resource) to use when instantiating. Note this driver depends on a platform device being instantiated for the ACPI fwnode, see the i2c_multi_instantiate_ids list of ACPI device-ids in drivers/acpi/scan.c: acpi_device_enumeration_by_parent(). Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Acked-by: Wolfram Sang <wsa@xxxxxxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- Changes in v2: -Rebase on top of 4.18-rc2 Changes in v3: -Change from an i2c-driver using a hack to allow having multiple i2c clients at the same address to a platform-driver Changes in v4: -Tweak MAINTAINERS entry a bit Changes in v5: -s/no_clients/num_clients/ -Change patch Subject prefix to platform/x86 Changes in v6: -s/irq_idx/gpio_irq_idx/ --- MAINTAINERS | 6 + drivers/platform/x86/Kconfig | 11 ++ drivers/platform/x86/Makefile | 1 + drivers/platform/x86/i2c-multi-instantiate.c | 132 +++++++++++++++++++ 4 files changed, 150 insertions(+) create mode 100644 drivers/platform/x86/i2c-multi-instantiate.c diff --git a/MAINTAINERS b/MAINTAINERS index 9b377508f24f..dbe7836e4f6b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -367,6 +367,12 @@ L: linux-acpi@xxxxxxxxxxxxxxx S: Maintained F: drivers/acpi/arm64 +ACPI I2C MULTI INSTANTIATE DRIVER +M: Hans de Goede <hdegoede@xxxxxxxxxx> +L: platform-driver-x86@xxxxxxxxxxxxxxx +S: Maintained +F: drivers/platform/x86/i2c-multi-instantiate.c + ACPI PMIC DRIVERS M: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> M: Len Brown <lenb@xxxxxxxxxx> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index 85a93453237c..64c82592d4b6 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -1219,6 +1219,17 @@ config INTEL_CHTDC_TI_PWRBTN To compile this driver as a module, choose M here: the module will be called intel_chtdc_ti_pwrbtn. +config I2C_MULTI_INSTANTIATE + tristate "I2C multi instantiate pseudo device driver" + depends on I2C && ACPI + help + Some ACPI-based systems list multiple i2c-devices in a single ACPI + firmware-node. This driver will instantiate separate i2c-clients + for each device in the firmware-node. + + To compile this driver as a module, choose M here: the module + will be called i2c-multi-instantiate. + endif # X86_PLATFORM_DEVICES config PMC_ATOM diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 8d9477114fb5..e6d1becf81ce 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -91,3 +91,4 @@ obj-$(CONFIG_PMC_ATOM) += pmc_atom.o obj-$(CONFIG_MLX_PLATFORM) += mlx-platform.o obj-$(CONFIG_INTEL_TURBO_MAX_3) += intel_turbo_max_3.o obj-$(CONFIG_INTEL_CHTDC_TI_PWRBTN) += intel_chtdc_ti_pwrbtn.o +obj-$(CONFIG_I2C_MULTI_INSTANTIATE) += i2c-multi-instantiate.o diff --git a/drivers/platform/x86/i2c-multi-instantiate.c b/drivers/platform/x86/i2c-multi-instantiate.c new file mode 100644 index 000000000000..5456581b473c --- /dev/null +++ b/drivers/platform/x86/i2c-multi-instantiate.c @@ -0,0 +1,132 @@ +// 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@xxxxxxxxxx> + */ + +#include <linux/acpi.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +struct i2c_inst_data { + const char *type; + int gpio_irq_idx; +}; + +struct i2c_multi_inst_data { + int num_clients; + struct i2c_client *clients[0]; +}; + +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 */ + for (i = 0; inst_data[i].type; i++) {} + + multi = devm_kmalloc(dev, + offsetof(struct i2c_multi_inst_data, clients[i]), + GFP_KERNEL); + if (!multi) + return -ENOMEM; + + multi->num_clients = i; + + for (i = 0; i < multi->num_clients; 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", match->id, + inst_data[i].type); + board_info.dev_name = name; + board_info.irq = 0; + if (inst_data[i].gpio_irq_idx != -1) { + ret = acpi_dev_gpio_irq_get(adev, + inst_data[i].gpio_irq_idx); + if (ret < 0) { + dev_err(dev, "Error requesting irq at index %d: %d\n", + inst_data[i].gpio_irq_idx, ret); + goto error; + } + board_info.irq = ret; + } + multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info); + if (!multi->clients[i]) { + dev_err(dev, "Error creating i2c-client, 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", 0 }, + { "bmc150_magn", -1 }, + { "bmg160", -1 }, + {} +}; + +/* + * 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 }, + { } +}; +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@xxxxxxxxxx>"); +MODULE_LICENSE("GPL"); -- 2.18.0