drivers/bluetooth/btrtl.c - linux - Git at Google

 /*
  *  Bluetooth support for Realtek devices
  *
  *  Copyright (C) 2015 Endless Mobile, Inc.
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  */

 #include <linux/module.h>
 #include <linux/firmware.h>
 #include <asm/unaligned.h>
 #include <linux/usb.h>

 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>

 #include "btrtl.h"

 #define VERSION "0.1"

 #define RTL_EPATCH_SIGNATURE	"Realtech"
 #define RTL_ROM_LMP_3499	0x3499
 #define RTL_ROM_LMP_8723A	0x1200
 #define RTL_ROM_LMP_8723B	0x8723
 #define RTL_ROM_LMP_8821A	0x8821
 #define RTL_ROM_LMP_8761A	0x8761

 static int rtl_read_rom_version(struct hci_dev *hdev, u8 *version)
 {
 	struct rtl_rom_version_evt *rom_version;
 	struct sk_buff *skb;

 	/* Read RTL ROM version command */
 	skb = __hci_cmd_sync(hdev, 0xfc6d, 0, NULL, HCI_INIT_TIMEOUT);
 	if (IS_ERR(skb)) {
 		BT_ERR("%s: Read ROM version failed (%ld)",
 		       hdev->name, PTR_ERR(skb));
 		return PTR_ERR(skb);
 	}

 	if (skb->len != sizeof(*rom_version)) {
 		BT_ERR("%s: RTL version event length mismatch", hdev->name);
 		kfree_skb(skb);
 		return -EIO;
 	}

 	rom_version = (struct rtl_rom_version_evt *)skb->data;
 	BT_INFO("%s: rom_version status=%x version=%x",
 		hdev->name, rom_version->status, rom_version->version);

 	*version = rom_version->version;

 	kfree_skb(skb);
 	return 0;
 }

 static int rtl8723b_parse_firmware(struct hci_dev *hdev, u16 lmp_subver,
 				   const struct firmware *fw,
 				   unsigned char **_buf)
 {
 	const u8 extension_sig[] = { 0x51, 0x04, 0xfd, 0x77 };
 	struct rtl_epatch_header *epatch_info;
 	unsigned char *buf;
 	int i, ret, len;
 	size_t min_size;
 	u8 opcode, length, data, rom_version = 0;
 	int project_id = -1;
 	const unsigned char *fwptr, *chip_id_base;
 	const unsigned char *patch_length_base, *patch_offset_base;
 	u32 patch_offset = 0;
 	u16 patch_length, num_patches;
 	const u16 project_id_to_lmp_subver[] = {
 		RTL_ROM_LMP_8723A,
 		RTL_ROM_LMP_8723B,
 		RTL_ROM_LMP_8821A,
 		RTL_ROM_LMP_8761A
 	};

 	ret = rtl_read_rom_version(hdev, &rom_version);
 	if (ret)
 		return ret;

 	min_size = sizeof(struct rtl_epatch_header) + sizeof(extension_sig) + 3;
 	if (fw->size < min_size)
 		return -EINVAL;

 	fwptr = fw->data + fw->size - sizeof(extension_sig);
 	if (memcmp(fwptr, extension_sig, sizeof(extension_sig)) != 0) {
 		BT_ERR("%s: extension section signature mismatch", hdev->name);
 		return -EINVAL;
 	}

 	/* Loop from the end of the firmware parsing instructions, until
 	 * we find an instruction that identifies the "project ID" for the
 	 * hardware supported by this firwmare file.
 	 * Once we have that, we double-check that that project_id is suitable
 	 * for the hardware we are working with.
 	 */
 	while (fwptr >= fw->data + (sizeof(struct rtl_epatch_header) + 3)) {
 		opcode = *--fwptr;
 		length = *--fwptr;
 		data = *--fwptr;

 		BT_DBG("check op=%x len=%x data=%x", opcode, length, data);

 		if (opcode == 0xff) /* EOF */
 			break;

 		if (length == 0) {
 			BT_ERR("%s: found instruction with length 0",
 			       hdev->name);
 			return -EINVAL;
 		}

 		if (opcode == 0 && length == 1) {
 			project_id = data;
 			break;
 		}

 		fwptr -= length;
 	}

 	if (project_id < 0) {
 		BT_ERR("%s: failed to find version instruction", hdev->name);
 		return -EINVAL;
 	}

 	if (project_id >= ARRAY_SIZE(project_id_to_lmp_subver)) {
 		BT_ERR("%s: unknown project id %d", hdev->name, project_id);
 		return -EINVAL;
 	}

 	if (lmp_subver != project_id_to_lmp_subver[project_id]) {
 		BT_ERR("%s: firmware is for %x but this is a %x", hdev->name,
 		       project_id_to_lmp_subver[project_id], lmp_subver);
 		return -EINVAL;
 	}

 	epatch_info = (struct rtl_epatch_header *)fw->data;
 	if (memcmp(epatch_info->signature, RTL_EPATCH_SIGNATURE, 8) != 0) {
 		BT_ERR("%s: bad EPATCH signature", hdev->name);
 		return -EINVAL;
 	}

 	num_patches = le16_to_cpu(epatch_info->num_patches);
 	BT_DBG("fw_version=%x, num_patches=%d",
 	       le32_to_cpu(epatch_info->fw_version), num_patches);

 	/* After the rtl_epatch_header there is a funky patch metadata section.
 	 * Assuming 2 patches, the layout is:
 	 * ChipID1 ChipID2 PatchLength1 PatchLength2 PatchOffset1 PatchOffset2
 	 *
 	 * Find the right patch for this chip.
 	 */
 	min_size += 8 * num_patches;
 	if (fw->size < min_size)
 		return -EINVAL;

 	chip_id_base = fw->data + sizeof(struct rtl_epatch_header);
 	patch_length_base = chip_id_base + (sizeof(u16) * num_patches);
 	patch_offset_base = patch_length_base + (sizeof(u16) * num_patches);
 	for (i = 0; i < num_patches; i++) {
 		u16 chip_id = get_unaligned_le16(chip_id_base +
 						 (i * sizeof(u16)));
 		if (chip_id == rom_version + 1) {
 			patch_length = get_unaligned_le16(patch_length_base +
 							  (i * sizeof(u16)));
 			patch_offset = get_unaligned_le32(patch_offset_base +
 							  (i * sizeof(u32)));
 			break;
 		}
 	}

 	if (!patch_offset) {
 		BT_ERR("%s: didn't find patch for chip id %d",
 		       hdev->name, rom_version);
 		return -EINVAL;
 	}

 	BT_DBG("length=%x offset=%x index %d", patch_length, patch_offset, i);
 	min_size = patch_offset + patch_length;
 	if (fw->size < min_size)
 		return -EINVAL;

 	/* Copy the firmware into a new buffer and write the version at
 	 * the end.
 	 */
 	len = patch_length;
 	buf = kmemdup(fw->data + patch_offset, patch_length, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

 	memcpy(buf + patch_length - 4, &epatch_info->fw_version, 4);

 	*_buf = buf;
 	return len;
 }

 static int rtl_download_firmware(struct hci_dev *hdev,
 				 const unsigned char *data, int fw_len)
 {
 	struct rtl_download_cmd *dl_cmd;
 	int frag_num = fw_len / RTL_FRAG_LEN + 1;
 	int frag_len = RTL_FRAG_LEN;
 	int ret = 0;
 	int i;

 	dl_cmd = kmalloc(sizeof(struct rtl_download_cmd), GFP_KERNEL);
 	if (!dl_cmd)
 		return -ENOMEM;

 	for (i = 0; i < frag_num; i++) {
 		struct sk_buff *skb;

 		BT_DBG("download fw (%d/%d)", i, frag_num);

 		dl_cmd->index = i;
 		if (i == (frag_num - 1)) {
 			dl_cmd->index |= 0x80; /* data end */
 			frag_len = fw_len % RTL_FRAG_LEN;
 		}
 		memcpy(dl_cmd->data, data, frag_len);

 		/* Send download command */
 		skb = __hci_cmd_sync(hdev, 0xfc20, frag_len + 1, dl_cmd,
 				     HCI_INIT_TIMEOUT);
 		if (IS_ERR(skb)) {
 			BT_ERR("%s: download fw command failed (%ld)",
 			       hdev->name, PTR_ERR(skb));
 			ret = -PTR_ERR(skb);
 			goto out;
 		}

 		if (skb->len != sizeof(struct rtl_download_response)) {
 			BT_ERR("%s: download fw event length mismatch",
 			       hdev->name);
 			kfree_skb(skb);
 			ret = -EIO;
 			goto out;
 		}

 		kfree_skb(skb);
 		data += RTL_FRAG_LEN;
 	}

 out:
 	kfree(dl_cmd);
 	return ret;
 }

 static int btrtl_setup_rtl8723a(struct hci_dev *hdev)
 {
 	const struct firmware *fw;
 	int ret;

 	BT_INFO("%s: rtl: loading rtl_bt/rtl8723a_fw.bin", hdev->name);
 	ret = request_firmware(&fw, "rtl_bt/rtl8723a_fw.bin", &hdev->dev);
 	if (ret < 0) {
 		BT_ERR("%s: Failed to load rtl_bt/rtl8723a_fw.bin", hdev->name);
 		return ret;
 	}

 	if (fw->size < 8) {
 		ret = -EINVAL;
 		goto out;
 	}

 	/* Check that the firmware doesn't have the epatch signature
 	 * (which is only for RTL8723B and newer).
 	 */
 	if (!memcmp(fw->data, RTL_EPATCH_SIGNATURE, 8)) {
 		BT_ERR("%s: unexpected EPATCH signature!", hdev->name);
 		ret = -EINVAL;
 		goto out;
 	}

 	ret = rtl_download_firmware(hdev, fw->data, fw->size);

 out:
 	release_firmware(fw);
 	return ret;
 }

 static int btrtl_setup_rtl8723b(struct hci_dev *hdev, u16 lmp_subver,
 				const char *fw_name)
 {
 	unsigned char *fw_data = NULL;
 	const struct firmware *fw;
 	int ret;

 	BT_INFO("%s: rtl: loading %s", hdev->name, fw_name);
 	ret = request_firmware(&fw, fw_name, &hdev->dev);
 	if (ret < 0) {
 		BT_ERR("%s: Failed to load %s", hdev->name, fw_name);
 		return ret;
 	}

 	ret = rtl8723b_parse_firmware(hdev, lmp_subver, fw, &fw_data);
 	if (ret < 0)
 		goto out;

 	ret = rtl_download_firmware(hdev, fw_data, ret);
 	kfree(fw_data);
 	if (ret < 0)
 		goto out;

 out:
 	release_firmware(fw);
 	return ret;
 }

 static struct sk_buff *btrtl_read_local_version(struct hci_dev *hdev)
 {
 	struct sk_buff *skb;

 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
 			     HCI_INIT_TIMEOUT);
 	if (IS_ERR(skb)) {
 		BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION failed (%ld)",
 		       hdev->name, PTR_ERR(skb));
 		return skb;
 	}

 	if (skb->len != sizeof(struct hci_rp_read_local_version)) {
 		BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION event length mismatch",
 		       hdev->name);
 		kfree_skb(skb);
 		return ERR_PTR(-EIO);
 	}

 	return skb;
 }

 int btrtl_setup_realtek(struct hci_dev *hdev)
 {
 	struct sk_buff *skb;
 	struct hci_rp_read_local_version *resp;
 	u16 lmp_subver;

 	skb = btrtl_read_local_version(hdev);
 	if (IS_ERR(skb))
 		return -PTR_ERR(skb);

 	resp = (struct hci_rp_read_local_version *)skb->data;
 	BT_INFO("%s: rtl: examining hci_ver=%02x hci_rev=%04x lmp_ver=%02x "
 		"lmp_subver=%04x", hdev->name, resp->hci_ver, resp->hci_rev,
 		resp->lmp_ver, resp->lmp_subver);

 	lmp_subver = le16_to_cpu(resp->lmp_subver);
 	kfree_skb(skb);

 	/* Match a set of subver values that correspond to stock firmware,
 	 * which is not compatible with standard btusb.
 	 * If matched, upload an alternative firmware that does conform to
 	 * standard btusb. Once that firmware is uploaded, the subver changes
 	 * to a different value.
 	 */
 	switch (lmp_subver) {
 	case RTL_ROM_LMP_8723A:
 	case RTL_ROM_LMP_3499:
 		return btrtl_setup_rtl8723a(hdev);
 	case RTL_ROM_LMP_8723B:
 		return btrtl_setup_rtl8723b(hdev, lmp_subver,
 					    "rtl_bt/rtl8723b_fw.bin");
 	case RTL_ROM_LMP_8821A:
 		return btrtl_setup_rtl8723b(hdev, lmp_subver,
 					    "rtl_bt/rtl8821a_fw.bin");
 	case RTL_ROM_LMP_8761A:
 		return btrtl_setup_rtl8723b(hdev, lmp_subver,
 					    "rtl_bt/rtl8761a_fw.bin");
 	default:
 		BT_INFO("rtl: assuming no firmware upload needed.");
 		return 0;
 	}
 }
 EXPORT_SYMBOL_GPL(btrtl_setup_realtek);

 MODULE_AUTHOR("Daniel Drake <drake@endlessm.com>");
 MODULE_DESCRIPTION("Bluetooth support for Realtek devices ver " VERSION);
 MODULE_VERSION(VERSION);
 MODULE_LICENSE("GPL");
	/*
	* Bluetooth support for Realtek devices
	*
	* Copyright (C) 2015 Endless Mobile, Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	*/

	#include <linux/module.h>
	#include <linux/firmware.h>
	#include <asm/unaligned.h>
	#include <linux/usb.h>

	#include <net/bluetooth/bluetooth.h>
	#include <net/bluetooth/hci_core.h>

	#include "btrtl.h"

	#define VERSION "0.1"

	#define RTL_EPATCH_SIGNATURE "Realtech"
	#define RTL_ROM_LMP_3499 0x3499
	#define RTL_ROM_LMP_8723A 0x1200
	#define RTL_ROM_LMP_8723B 0x8723
	#define RTL_ROM_LMP_8821A 0x8821
	#define RTL_ROM_LMP_8761A 0x8761

	static int rtl_read_rom_version(struct hci_dev hdev, u8 version)
	{
	struct rtl_rom_version_evt *rom_version;
	struct sk_buff *skb;

	/* Read RTL ROM version command */
	skb = __hci_cmd_sync(hdev, 0xfc6d, 0, NULL, HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
	BT_ERR("%s: Read ROM version failed (%ld)",
	hdev->name, PTR_ERR(skb));
	return PTR_ERR(skb);
	}

	if (skb->len != sizeof(*rom_version)) {
	BT_ERR("%s: RTL version event length mismatch", hdev->name);
	kfree_skb(skb);
	return -EIO;
	}

	rom_version = (struct rtl_rom_version_evt *)skb->data;
	BT_INFO("%s: rom_version status=%x version=%x",
	hdev->name, rom_version->status, rom_version->version);

	*version = rom_version->version;

	kfree_skb(skb);
	return 0;
	}

	static int rtl8723b_parse_firmware(struct hci_dev *hdev, u16 lmp_subver,
	const struct firmware *fw,
	unsigned char **_buf)
	{
	const u8 extension_sig[] = { 0x51, 0x04, 0xfd, 0x77 };
	struct rtl_epatch_header *epatch_info;
	unsigned char *buf;
	int i, ret, len;
	size_t min_size;
	u8 opcode, length, data, rom_version = 0;
	int project_id = -1;
	const unsigned char fwptr, chip_id_base;
	const unsigned char patch_length_base, patch_offset_base;
	u32 patch_offset = 0;
	u16 patch_length, num_patches;
	const u16 project_id_to_lmp_subver[] = {
	RTL_ROM_LMP_8723A,
	RTL_ROM_LMP_8723B,
	RTL_ROM_LMP_8821A,
	RTL_ROM_LMP_8761A
	};

	ret = rtl_read_rom_version(hdev, &rom_version);
	if (ret)
	return ret;

	min_size = sizeof(struct rtl_epatch_header) + sizeof(extension_sig) + 3;
	if (fw->size < min_size)
	return -EINVAL;

	fwptr = fw->data + fw->size - sizeof(extension_sig);
	if (memcmp(fwptr, extension_sig, sizeof(extension_sig)) != 0) {
	BT_ERR("%s: extension section signature mismatch", hdev->name);
	return -EINVAL;
	}

	/* Loop from the end of the firmware parsing instructions, until
	* we find an instruction that identifies the "project ID" for the
	* hardware supported by this firwmare file.
	* Once we have that, we double-check that that project_id is suitable
	* for the hardware we are working with.
	*/
	while (fwptr >= fw->data + (sizeof(struct rtl_epatch_header) + 3)) {
	opcode = *--fwptr;
	length = *--fwptr;
	data = *--fwptr;

	BT_DBG("check op=%x len=%x data=%x", opcode, length, data);

	if (opcode == 0xff) /* EOF */
	break;

	if (length == 0) {
	BT_ERR("%s: found instruction with length 0",
	hdev->name);
	return -EINVAL;
	}

	if (opcode == 0 && length == 1) {
	project_id = data;
	break;
	}

	fwptr -= length;
	}

	if (project_id < 0) {
	BT_ERR("%s: failed to find version instruction", hdev->name);
	return -EINVAL;
	}

	if (project_id >= ARRAY_SIZE(project_id_to_lmp_subver)) {
	BT_ERR("%s: unknown project id %d", hdev->name, project_id);
	return -EINVAL;
	}

	if (lmp_subver != project_id_to_lmp_subver[project_id]) {
	BT_ERR("%s: firmware is for %x but this is a %x", hdev->name,
	project_id_to_lmp_subver[project_id], lmp_subver);
	return -EINVAL;
	}

	epatch_info = (struct rtl_epatch_header *)fw->data;
	if (memcmp(epatch_info->signature, RTL_EPATCH_SIGNATURE, 8) != 0) {
	BT_ERR("%s: bad EPATCH signature", hdev->name);
	return -EINVAL;
	}

	num_patches = le16_to_cpu(epatch_info->num_patches);
	BT_DBG("fw_version=%x, num_patches=%d",
	le32_to_cpu(epatch_info->fw_version), num_patches);

	/* After the rtl_epatch_header there is a funky patch metadata section.
	* Assuming 2 patches, the layout is:
	* ChipID1 ChipID2 PatchLength1 PatchLength2 PatchOffset1 PatchOffset2
	*
	* Find the right patch for this chip.
	*/
	min_size += 8 * num_patches;
	if (fw->size < min_size)
	return -EINVAL;

	chip_id_base = fw->data + sizeof(struct rtl_epatch_header);
	patch_length_base = chip_id_base + (sizeof(u16) * num_patches);
	patch_offset_base = patch_length_base + (sizeof(u16) * num_patches);
	for (i = 0; i < num_patches; i++) {
	u16 chip_id = get_unaligned_le16(chip_id_base +
	(i * sizeof(u16)));
	if (chip_id == rom_version + 1) {
	patch_length = get_unaligned_le16(patch_length_base +
	(i * sizeof(u16)));
	patch_offset = get_unaligned_le32(patch_offset_base +
	(i * sizeof(u32)));
	break;
	}
	}

	if (!patch_offset) {
	BT_ERR("%s: didn't find patch for chip id %d",
	hdev->name, rom_version);
	return -EINVAL;
	}

	BT_DBG("length=%x offset=%x index %d", patch_length, patch_offset, i);
	min_size = patch_offset + patch_length;
	if (fw->size < min_size)
	return -EINVAL;

	/* Copy the firmware into a new buffer and write the version at
	* the end.
	*/
	len = patch_length;
	buf = kmemdup(fw->data + patch_offset, patch_length, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	memcpy(buf + patch_length - 4, &epatch_info->fw_version, 4);

	*_buf = buf;
	return len;
	}

	static int rtl_download_firmware(struct hci_dev *hdev,
	const unsigned char *data, int fw_len)
	{
	struct rtl_download_cmd *dl_cmd;
	int frag_num = fw_len / RTL_FRAG_LEN + 1;
	int frag_len = RTL_FRAG_LEN;
	int ret = 0;
	int i;

	dl_cmd = kmalloc(sizeof(struct rtl_download_cmd), GFP_KERNEL);
	if (!dl_cmd)
	return -ENOMEM;

	for (i = 0; i < frag_num; i++) {
	struct sk_buff *skb;

	BT_DBG("download fw (%d/%d)", i, frag_num);

	dl_cmd->index = i;
	if (i == (frag_num - 1)) {
	dl_cmd->index \|= 0x80; /* data end */
	frag_len = fw_len % RTL_FRAG_LEN;
	}
	memcpy(dl_cmd->data, data, frag_len);

	/* Send download command */
	skb = __hci_cmd_sync(hdev, 0xfc20, frag_len + 1, dl_cmd,
	HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
	BT_ERR("%s: download fw command failed (%ld)",
	hdev->name, PTR_ERR(skb));
	ret = -PTR_ERR(skb);
	goto out;
	}

	if (skb->len != sizeof(struct rtl_download_response)) {
	BT_ERR("%s: download fw event length mismatch",
	hdev->name);
	kfree_skb(skb);
	ret = -EIO;
	goto out;
	}

	kfree_skb(skb);
	data += RTL_FRAG_LEN;
	}

	out:
	kfree(dl_cmd);
	return ret;
	}

	static int btrtl_setup_rtl8723a(struct hci_dev *hdev)
	{
	const struct firmware *fw;
	int ret;

	BT_INFO("%s: rtl: loading rtl_bt/rtl8723a_fw.bin", hdev->name);
	ret = request_firmware(&fw, "rtl_bt/rtl8723a_fw.bin", &hdev->dev);
	if (ret < 0) {
	BT_ERR("%s: Failed to load rtl_bt/rtl8723a_fw.bin", hdev->name);
	return ret;
	}

	if (fw->size < 8) {
	ret = -EINVAL;
	goto out;
	}

	/* Check that the firmware doesn't have the epatch signature
	* (which is only for RTL8723B and newer).
	*/
	if (!memcmp(fw->data, RTL_EPATCH_SIGNATURE, 8)) {
	BT_ERR("%s: unexpected EPATCH signature!", hdev->name);
	ret = -EINVAL;
	goto out;
	}

	ret = rtl_download_firmware(hdev, fw->data, fw->size);

	out:
	release_firmware(fw);
	return ret;
	}

	static int btrtl_setup_rtl8723b(struct hci_dev *hdev, u16 lmp_subver,
	const char *fw_name)
	{
	unsigned char *fw_data = NULL;
	const struct firmware *fw;
	int ret;

	BT_INFO("%s: rtl: loading %s", hdev->name, fw_name);
	ret = request_firmware(&fw, fw_name, &hdev->dev);
	if (ret < 0) {
	BT_ERR("%s: Failed to load %s", hdev->name, fw_name);
	return ret;
	}

	ret = rtl8723b_parse_firmware(hdev, lmp_subver, fw, &fw_data);
	if (ret < 0)
	goto out;

	ret = rtl_download_firmware(hdev, fw_data, ret);
	kfree(fw_data);
	if (ret < 0)
	goto out;

	out:
	release_firmware(fw);
	return ret;
	}

	static struct sk_buff btrtl_read_local_version(struct hci_dev hdev)
	{
	struct sk_buff *skb;

	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
	HCI_INIT_TIMEOUT);
	if (IS_ERR(skb)) {
	BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION failed (%ld)",
	hdev->name, PTR_ERR(skb));
	return skb;
	}

	if (skb->len != sizeof(struct hci_rp_read_local_version)) {
	BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION event length mismatch",
	hdev->name);
	kfree_skb(skb);
	return ERR_PTR(-EIO);
	}

	return skb;
	}

	int btrtl_setup_realtek(struct hci_dev *hdev)
	{
	struct sk_buff *skb;
	struct hci_rp_read_local_version *resp;
	u16 lmp_subver;

	skb = btrtl_read_local_version(hdev);
	if (IS_ERR(skb))
	return -PTR_ERR(skb);

	resp = (struct hci_rp_read_local_version *)skb->data;
	BT_INFO("%s: rtl: examining hci_ver=%02x hci_rev=%04x lmp_ver=%02x "
	"lmp_subver=%04x", hdev->name, resp->hci_ver, resp->hci_rev,
	resp->lmp_ver, resp->lmp_subver);

	lmp_subver = le16_to_cpu(resp->lmp_subver);
	kfree_skb(skb);

	/* Match a set of subver values that correspond to stock firmware,
	* which is not compatible with standard btusb.
	* If matched, upload an alternative firmware that does conform to
	* standard btusb. Once that firmware is uploaded, the subver changes
	* to a different value.
	*/
	switch (lmp_subver) {
	case RTL_ROM_LMP_8723A:
	case RTL_ROM_LMP_3499:
	return btrtl_setup_rtl8723a(hdev);
	case RTL_ROM_LMP_8723B:
	return btrtl_setup_rtl8723b(hdev, lmp_subver,
	"rtl_bt/rtl8723b_fw.bin");
	case RTL_ROM_LMP_8821A:
	return btrtl_setup_rtl8723b(hdev, lmp_subver,
	"rtl_bt/rtl8821a_fw.bin");
	case RTL_ROM_LMP_8761A:
	return btrtl_setup_rtl8723b(hdev, lmp_subver,
	"rtl_bt/rtl8761a_fw.bin");
	default:
	BT_INFO("rtl: assuming no firmware upload needed.");
	return 0;
	}
	}
	EXPORT_SYMBOL_GPL(btrtl_setup_realtek);

	MODULE_AUTHOR("Daniel Drake <drake@endlessm.com>");
	MODULE_DESCRIPTION("Bluetooth support for Realtek devices ver " VERSION);
	MODULE_VERSION(VERSION);
	MODULE_LICENSE("GPL");