diff options
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/acpi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/acpi/acpi_i2c.c | 103 |
3 files changed, 110 insertions, 0 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 119d58db8342..0300bf612946 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -181,6 +181,12 @@ config ACPI_DOCK This driver supports ACPI-controlled docking stations and removable drive bays such as the IBM Ultrabay and the Dell Module Bay. +config ACPI_I2C + def_tristate I2C + depends on I2C + help + ACPI I2C enumeration support. + config ACPI_PROCESSOR tristate "Processor" select THERMAL diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index 3223edfb23b6..7198b6d6b763 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -69,6 +69,7 @@ obj-$(CONFIG_ACPI_HED) += hed.o obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o obj-$(CONFIG_ACPI_BGRT) += bgrt.o +obj-$(CONFIG_ACPI_I2C) += acpi_i2c.o # processor has its own "processor." module_param namespace processor-y := processor_driver.o processor_throttling.o diff --git a/drivers/acpi/acpi_i2c.c b/drivers/acpi/acpi_i2c.c new file mode 100644 index 000000000000..82045e3f5cac --- /dev/null +++ b/drivers/acpi/acpi_i2c.c @@ -0,0 +1,103 @@ +/* + * ACPI I2C enumeration support + * + * Copyright (C) 2012, Intel Corporation + * Author: Mika Westerberg <mika.westerberg@linux.intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/acpi.h> +#include <linux/device.h> +#include <linux/export.h> +#include <linux/i2c.h> +#include <linux/ioport.h> + +ACPI_MODULE_NAME("i2c"); + +static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data) +{ + struct i2c_board_info *info = data; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_i2c_serialbus *sb; + + sb = &ares->data.i2c_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) { + info->addr = sb->slave_address; + if (sb->access_mode == ACPI_I2C_10BIT_MODE) + info->flags |= I2C_CLIENT_TEN; + } + } else if (info->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + info->irq = r.start; + } + + /* Tell the ACPI core to skip this resource */ + return 1; +} + +static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct i2c_adapter *adapter = data; + struct list_head resource_list; + struct i2c_board_info info; + struct acpi_device *adev; + int ret; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + if (acpi_bus_get_status(adev) || !adev->status.present) + return AE_OK; + + memset(&info, 0, sizeof(info)); + info.acpi_node.handle = handle; + info.irq = -1; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_i2c_add_resource, &info); + acpi_dev_free_resource_list(&resource_list); + + if (ret < 0 || !info.addr) + return AE_OK; + + strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type)); + if (!i2c_new_device(adapter, &info)) { + dev_err(&adapter->dev, + "failed to add I2C device %s from ACPI\n", + dev_name(&adev->dev)); + } + + return AE_OK; +} + +/** + * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter + * @adapter: pointer to adapter + * + * Enumerate all I2C slave devices behind this adapter by walking the ACPI + * namespace. When a device is found it will be added to the Linux device + * model and bound to the corresponding ACPI handle. + */ +void acpi_i2c_register_devices(struct i2c_adapter *adapter) +{ + acpi_handle handle; + acpi_status status; + + handle = ACPI_HANDLE(&adapter->dev); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_i2c_add_device, NULL, + adapter, NULL); + if (ACPI_FAILURE(status)) + dev_warn(&adapter->dev, "failed to enumerate I2C slaves\n"); +} +EXPORT_SYMBOL_GPL(acpi_i2c_register_devices); |