Bluetooth: btintel: Add Device Configuration support

btintel_load_ddc_config retrieves the ddc file and sends its content
via DDC commands (opcode 0xfc8b).

The ddc file should contain one or more DDC structures.
A DDC structure is composed of the folowing fields:
field: | DDC LEN |    DDC ID    |   DDC VALUE   |
size:  | 1 byte  |    2 bytes   |  DDC LEN - 2  |

Signed-off-by: Loic Poulain <loic.poulain@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btintel.c

@@ -22,6 +22,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/firmware.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
@@ -169,6 +170,51 @@ int btintel_secure_send(struct hci_dev *hdev, u8 fragment_type, u32 plen,
 }
 EXPORT_SYMBOL_GPL(btintel_secure_send);
 
+int btintel_load_ddc_config(struct hci_dev *hdev, const char *ddc_name)
+{
+	const struct firmware *fw;
+	struct sk_buff *skb;
+	const u8 *fw_ptr;
+	int err;
+
+	err = request_firmware_direct(&fw, ddc_name, &hdev->dev);
+	if (err < 0) {
+		bt_dev_err(hdev, "Failed to load Intel DDC file %s (%d)",
+			   ddc_name, err);
+		return err;
+	}
+
+	bt_dev_info(hdev, "Found Intel DDC parameters: %s", ddc_name);
+
+	fw_ptr = fw->data;
+
+	/* DDC file contains one or more DDC structure which has
+	 * Length (1 byte), DDC ID (2 bytes), and DDC value (Length - 2).
+	 */
+	while (fw->size > fw_ptr - fw->data) {
+		u8 cmd_plen = fw_ptr[0] + sizeof(u8);
+
+		skb = __hci_cmd_sync(hdev, 0xfc8b, cmd_plen, fw_ptr,
+				     HCI_INIT_TIMEOUT);
+		if (IS_ERR(skb)) {
+			bt_dev_err(hdev, "Failed to send Intel_Write_DDC (%ld)",
+				   PTR_ERR(skb));
+			release_firmware(fw);
+			return PTR_ERR(skb);
+		}
+
+		fw_ptr += cmd_plen;
+		kfree_skb(skb);
+	}
+
+	release_firmware(fw);
+
+	bt_dev_info(hdev, "Applying Intel DDC parameters completed");
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(btintel_load_ddc_config);
+
 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 MODULE_DESCRIPTION("Bluetooth support for Intel devices ver " VERSION);
 MODULE_VERSION(VERSION);

drivers/bluetooth/btintel.h

@@ -78,6 +78,7 @@ void btintel_hw_error(struct hci_dev *hdev, u8 code);
 void btintel_version_info(struct hci_dev *hdev, struct intel_version *ver);
 int btintel_secure_send(struct hci_dev *hdev, u8 fragment_type, u32 plen,
 			const void *param);
+int btintel_load_ddc_config(struct hci_dev *hdev, const char *ddc_name);
 
 #else
 
@@ -106,4 +107,10 @@ static inline int btintel_secure_send(struct hci_dev *hdev, u8 fragment_type,
 	return -EOPNOTSUPP;
 }
 
+static inline int btintel_load_ddc_config(struct hci_dev *hdev,
+					  const char *ddc_name)
+{
+	return -EOPNOTSUPP;
+}
+
 #endif