I2C serial bus support
~~~~~~~~~~~~~~~~~~~~~~
The slaves behind I2C bus controller only need to add the ACPI IDs like
-with the platform and SPI drivers. However the I2C bus controller driver
-needs to call acpi_i2c_register_devices() after it has added the adapter.
-
-An I2C bus (controller) driver does:
-
- ...
- ret = i2c_add_numbered_adapter(adapter);
- if (ret)
- /* handle error */
-
- /* Enumerate the slave devices behind this bus via ACPI */
- acpi_i2c_register_devices(adapter);
+with the platform and SPI drivers. The I2C core automatically enumerates
+any slave devices behind the controller device once the adapter is
+registered.
Below is an example of how to add ACPI support to the existing mpu3050
input driver:
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
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
+++ /dev/null
-/*
- * 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.parent);
- 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);
dev_err(&pdev->dev, "failure adding adapter\n");
return r;
}
- acpi_i2c_register_devices(adap);
pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
pm_runtime_use_autosuspend(&pdev->dev);
static void of_i2c_register_devices(struct i2c_adapter *adap) { }
#endif /* CONFIG_OF */
+/* ACPI support code */
+
+#if IS_ENABLED(CONFIG_ACPI)
+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
+ * @adap: 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.
+ */
+static void acpi_i2c_register_devices(struct i2c_adapter *adap)
+{
+ acpi_handle handle;
+ acpi_status status;
+
+ handle = ACPI_HANDLE(adap->dev.parent);
+ if (!handle)
+ return;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+ acpi_i2c_add_device, NULL,
+ adap, NULL);
+ if (ACPI_FAILURE(status))
+ dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
+}
+#else
+static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) {}
+#endif /* CONFIG_ACPI */
+
static int i2c_do_add_adapter(struct i2c_driver *driver,
struct i2c_adapter *adap)
{
exit_recovery:
/* create pre-declared device nodes */
of_i2c_register_devices(adap);
+ acpi_i2c_register_devices(adap);
if (adap->nr < __i2c_first_dynamic_bus_num)
i2c_scan_static_board_info(adap);
}
#endif /* CONFIG_OF */
-#if IS_ENABLED(CONFIG_ACPI_I2C)
-extern void acpi_i2c_register_devices(struct i2c_adapter *adap);
-#else
-static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) {}
-#endif
-
#endif /* _LINUX_I2C_H */
projects / platform / kernel / linux-rpi.git / commitdiff