@@ -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
@@ -70,6 +70,7 @@ 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
new file mode 100644
@@ -0,0 +1,216 @@
+/*
+ * 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/err.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 acpi_resource_i2c_serialbus *sb;
+ struct i2c_board_info *info = data;
+
+ if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+ return 0;
+
+ sb = &ares->data.i2c_serial_bus;
+ if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+ return 0;
+
+ info->addr = sb->slave_address;
+ if (sb->access_mode == ACPI_I2C_10BIT_MODE)
+ info->flags |= I2C_CLIENT_TEN;
+
+ 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 resource_list_entry *rentry;
+ 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));
+
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list,
+ acpi_i2c_add_resource, &info);
+ if (ret < 0)
+ return AE_OK;
+
+ list_for_each_entry(rentry, &resource_list, node) {
+ struct resource *r = &rentry->res;
+
+ if (resource_type(r) == IORESOURCE_IRQ) {
+ info.irq = r->start;
+ break;
+ }
+ }
+
+ acpi_dev_free_resource_list(&resource_list);
+
+ if (!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 = adapter->dev.acpi_handle;
+ 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);
+
+struct acpi_i2c_find {
+ acpi_handle handle;
+ u16 addr;
+ u8 access_mode;
+ bool found;
+};
+
+static int acpi_i2c_find_child_address(struct acpi_resource *ares, void *data)
+{
+ struct acpi_resource_i2c_serialbus *sb;
+ struct acpi_i2c_find *i2c_find = data;
+
+ if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+ return 1;
+
+ sb = &ares->data.i2c_serial_bus;
+ if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
+ return 1;
+
+ if (sb->slave_address == i2c_find->addr &&
+ sb->access_mode == i2c_find->access_mode)
+ i2c_find->found = true;
+
+ return 1;
+}
+
+static acpi_status acpi_i2c_find_child(acpi_handle handle, u32 level,
+ void *data, void **return_value)
+{
+ struct acpi_i2c_find *i2c_find = data;
+ struct list_head resource_list;
+ 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;
+
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list,
+ acpi_i2c_find_child_address, i2c_find);
+ if (ret < 0)
+ return AE_OK;
+
+ acpi_dev_free_resource_list(&resource_list);
+
+ if (i2c_find->found) {
+ i2c_find->handle = handle;
+ return AE_CTRL_TERMINATE;
+ }
+ return AE_OK;
+}
+
+static int acpi_i2c_find_device(struct device *dev, acpi_handle *handle)
+{
+ struct acpi_i2c_find i2c_find;
+ struct i2c_adapter *adapter;
+ struct i2c_client *client;
+ acpi_handle parent;
+ acpi_status status;
+
+ client = i2c_verify_client(dev);
+ if (!client)
+ return -ENODEV;
+
+ adapter = client->adapter;
+ if (!adapter)
+ return -ENODEV;
+
+ parent = adapter->dev.acpi_handle;
+ if (!parent)
+ return -ENODEV;
+
+ memset(&i2c_find, 0, sizeof(i2c_find));
+ i2c_find.addr = client->addr;
+ if (client->flags & I2C_CLIENT_TEN)
+ i2c_find.access_mode = ACPI_I2C_10BIT_MODE;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1,
+ acpi_i2c_find_child, NULL,
+ &i2c_find, NULL);
+ if (ACPI_FAILURE(status) || !i2c_find.handle)
+ return -ENODEV;
+
+ *handle = i2c_find.handle;
+ return 0;
+}
+
+static struct acpi_bus_type acpi_i2c_bus = {
+ .bus = &i2c_bus_type,
+ .find_device = acpi_i2c_find_device,
+};
+
+void acpi_i2c_bus_register(void)
+{
+ register_acpi_bus_type(&acpi_i2c_bus);
+}
+EXPORT_SYMBOL_GPL(acpi_i2c_bus_register);
+
+void acpi_i2c_bus_unregister(void)
+{
+ unregister_acpi_bus_type(&acpi_i2c_bus);
+}
+EXPORT_SYMBOL_GPL(acpi_i2c_bus_unregister);
@@ -39,6 +39,8 @@
#include <linux/irqflags.h>
#include <linux/rwsem.h>
#include <linux/pm_runtime.h>
+#include <linux/acpi.h>
+#include <linux/acpi_i2c.h>
#include <asm/uaccess.h>
#include "i2c-core.h"
@@ -78,6 +80,10 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
if (of_driver_match_device(dev, drv))
return 1;
+ /* Then ACPI style match */
+ if (acpi_driver_match_device(dev, drv))
+ return 1;
+
driver = to_i2c_driver(drv);
/* match on an id table if there is one */
if (driver->id_table)
@@ -1298,6 +1304,8 @@ static int __init i2c_init(void)
retval = i2c_add_driver(&dummy_driver);
if (retval)
goto class_err;
+
+ acpi_i2c_bus_register();
return 0;
class_err:
@@ -1311,6 +1319,8 @@ bus_err:
static void __exit i2c_exit(void)
{
+ acpi_i2c_bus_unregister();
+
i2c_del_driver(&dummy_driver);
#ifdef CONFIG_I2C_COMPAT
class_compat_unregister(i2c_adapter_compat_class);
new file mode 100644
@@ -0,0 +1,27 @@
+/*
+ * 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.
+ */
+
+#ifndef LINUX_ACPI_I2C_H
+#define LINUX_ACPI_I2C_H
+
+struct i2c_adapter;
+
+#if IS_ENABLED(CONFIG_ACPI_I2C)
+extern void acpi_i2c_register_devices(struct i2c_adapter *adap);
+extern void acpi_i2c_bus_register(void);
+extern void acpi_i2c_bus_unregister(void);
+#else
+static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) {}
+static inline void acpi_i2c_bus_register(void) {}
+static inline void acpi_i2c_bus_unregister(void) {}
+#endif /* IS_ENABLED(CONFIG_ACPI_I2C) */
+
+#endif /* LINUX_ACPI_I2C_H */