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authorMika Westerberg <mika.westerberg@linux.intel.com>2013-08-21 17:28:23 +0300
committerWolfram Sang <wsa@the-dreams.de>2013-08-23 10:22:29 +0200
commit55e71edb81b2b45273e7b284cce13ff24bde846f (patch)
tree6a9a473f7865779bf4a5cf3036711f0356ebae75 /drivers/i2c/i2c-core.c
parent687b81d083c082bc1e853032e3a2a54f8c251d27 (diff)
downloadlinux-55e71edb81b2b45273e7b284cce13ff24bde846f.tar.bz2
i2c: move ACPI helpers into the core
This follows what has already been done for the DeviceTree helpers. Move the ACPI helpers from drivers/acpi/acpi_i2c.c to the I2C core and update documentation accordingly. This also solves a problem reported by Jerry Snitselaar that we can't build the ACPI I2C helpers as a module. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r--drivers/i2c/i2c-core.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index e874b052b4f8..29d3f045a2bf 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1058,6 +1058,96 @@ EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
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)
{
@@ -1163,6 +1253,7 @@ static int i2c_register_adapter(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);