xref: /openbmc/linux/drivers/bluetooth/btrtl.c (revision 293d5b43)
1 /*
2  *  Bluetooth support for Realtek devices
3  *
4  *  Copyright (C) 2015 Endless Mobile, Inc.
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  */
17 
18 #include <linux/module.h>
19 #include <linux/firmware.h>
20 #include <asm/unaligned.h>
21 #include <linux/usb.h>
22 
23 #include <net/bluetooth/bluetooth.h>
24 #include <net/bluetooth/hci_core.h>
25 
26 #include "btrtl.h"
27 
28 #define VERSION "0.1"
29 
30 #define RTL_EPATCH_SIGNATURE	"Realtech"
31 #define RTL_ROM_LMP_3499	0x3499
32 #define RTL_ROM_LMP_8723A	0x1200
33 #define RTL_ROM_LMP_8723B	0x8723
34 #define RTL_ROM_LMP_8821A	0x8821
35 #define RTL_ROM_LMP_8761A	0x8761
36 
37 static int rtl_read_rom_version(struct hci_dev *hdev, u8 *version)
38 {
39 	struct rtl_rom_version_evt *rom_version;
40 	struct sk_buff *skb;
41 
42 	/* Read RTL ROM version command */
43 	skb = __hci_cmd_sync(hdev, 0xfc6d, 0, NULL, HCI_INIT_TIMEOUT);
44 	if (IS_ERR(skb)) {
45 		BT_ERR("%s: Read ROM version failed (%ld)",
46 		       hdev->name, PTR_ERR(skb));
47 		return PTR_ERR(skb);
48 	}
49 
50 	if (skb->len != sizeof(*rom_version)) {
51 		BT_ERR("%s: RTL version event length mismatch", hdev->name);
52 		kfree_skb(skb);
53 		return -EIO;
54 	}
55 
56 	rom_version = (struct rtl_rom_version_evt *)skb->data;
57 	BT_INFO("%s: rom_version status=%x version=%x",
58 		hdev->name, rom_version->status, rom_version->version);
59 
60 	*version = rom_version->version;
61 
62 	kfree_skb(skb);
63 	return 0;
64 }
65 
66 static int rtl8723b_parse_firmware(struct hci_dev *hdev, u16 lmp_subver,
67 				   const struct firmware *fw,
68 				   unsigned char **_buf)
69 {
70 	const u8 extension_sig[] = { 0x51, 0x04, 0xfd, 0x77 };
71 	struct rtl_epatch_header *epatch_info;
72 	unsigned char *buf;
73 	int i, ret, len;
74 	size_t min_size;
75 	u8 opcode, length, data, rom_version = 0;
76 	int project_id = -1;
77 	const unsigned char *fwptr, *chip_id_base;
78 	const unsigned char *patch_length_base, *patch_offset_base;
79 	u32 patch_offset = 0;
80 	u16 patch_length, num_patches;
81 	const u16 project_id_to_lmp_subver[] = {
82 		RTL_ROM_LMP_8723A,
83 		RTL_ROM_LMP_8723B,
84 		RTL_ROM_LMP_8821A,
85 		RTL_ROM_LMP_8761A
86 	};
87 
88 	ret = rtl_read_rom_version(hdev, &rom_version);
89 	if (ret)
90 		return ret;
91 
92 	min_size = sizeof(struct rtl_epatch_header) + sizeof(extension_sig) + 3;
93 	if (fw->size < min_size)
94 		return -EINVAL;
95 
96 	fwptr = fw->data + fw->size - sizeof(extension_sig);
97 	if (memcmp(fwptr, extension_sig, sizeof(extension_sig)) != 0) {
98 		BT_ERR("%s: extension section signature mismatch", hdev->name);
99 		return -EINVAL;
100 	}
101 
102 	/* Loop from the end of the firmware parsing instructions, until
103 	 * we find an instruction that identifies the "project ID" for the
104 	 * hardware supported by this firwmare file.
105 	 * Once we have that, we double-check that that project_id is suitable
106 	 * for the hardware we are working with.
107 	 */
108 	while (fwptr >= fw->data + (sizeof(struct rtl_epatch_header) + 3)) {
109 		opcode = *--fwptr;
110 		length = *--fwptr;
111 		data = *--fwptr;
112 
113 		BT_DBG("check op=%x len=%x data=%x", opcode, length, data);
114 
115 		if (opcode == 0xff) /* EOF */
116 			break;
117 
118 		if (length == 0) {
119 			BT_ERR("%s: found instruction with length 0",
120 			       hdev->name);
121 			return -EINVAL;
122 		}
123 
124 		if (opcode == 0 && length == 1) {
125 			project_id = data;
126 			break;
127 		}
128 
129 		fwptr -= length;
130 	}
131 
132 	if (project_id < 0) {
133 		BT_ERR("%s: failed to find version instruction", hdev->name);
134 		return -EINVAL;
135 	}
136 
137 	if (project_id >= ARRAY_SIZE(project_id_to_lmp_subver)) {
138 		BT_ERR("%s: unknown project id %d", hdev->name, project_id);
139 		return -EINVAL;
140 	}
141 
142 	if (lmp_subver != project_id_to_lmp_subver[project_id]) {
143 		BT_ERR("%s: firmware is for %x but this is a %x", hdev->name,
144 		       project_id_to_lmp_subver[project_id], lmp_subver);
145 		return -EINVAL;
146 	}
147 
148 	epatch_info = (struct rtl_epatch_header *)fw->data;
149 	if (memcmp(epatch_info->signature, RTL_EPATCH_SIGNATURE, 8) != 0) {
150 		BT_ERR("%s: bad EPATCH signature", hdev->name);
151 		return -EINVAL;
152 	}
153 
154 	num_patches = le16_to_cpu(epatch_info->num_patches);
155 	BT_DBG("fw_version=%x, num_patches=%d",
156 	       le32_to_cpu(epatch_info->fw_version), num_patches);
157 
158 	/* After the rtl_epatch_header there is a funky patch metadata section.
159 	 * Assuming 2 patches, the layout is:
160 	 * ChipID1 ChipID2 PatchLength1 PatchLength2 PatchOffset1 PatchOffset2
161 	 *
162 	 * Find the right patch for this chip.
163 	 */
164 	min_size += 8 * num_patches;
165 	if (fw->size < min_size)
166 		return -EINVAL;
167 
168 	chip_id_base = fw->data + sizeof(struct rtl_epatch_header);
169 	patch_length_base = chip_id_base + (sizeof(u16) * num_patches);
170 	patch_offset_base = patch_length_base + (sizeof(u16) * num_patches);
171 	for (i = 0; i < num_patches; i++) {
172 		u16 chip_id = get_unaligned_le16(chip_id_base +
173 						 (i * sizeof(u16)));
174 		if (chip_id == rom_version + 1) {
175 			patch_length = get_unaligned_le16(patch_length_base +
176 							  (i * sizeof(u16)));
177 			patch_offset = get_unaligned_le32(patch_offset_base +
178 							  (i * sizeof(u32)));
179 			break;
180 		}
181 	}
182 
183 	if (!patch_offset) {
184 		BT_ERR("%s: didn't find patch for chip id %d",
185 		       hdev->name, rom_version);
186 		return -EINVAL;
187 	}
188 
189 	BT_DBG("length=%x offset=%x index %d", patch_length, patch_offset, i);
190 	min_size = patch_offset + patch_length;
191 	if (fw->size < min_size)
192 		return -EINVAL;
193 
194 	/* Copy the firmware into a new buffer and write the version at
195 	 * the end.
196 	 */
197 	len = patch_length;
198 	buf = kmemdup(fw->data + patch_offset, patch_length, GFP_KERNEL);
199 	if (!buf)
200 		return -ENOMEM;
201 
202 	memcpy(buf + patch_length - 4, &epatch_info->fw_version, 4);
203 
204 	*_buf = buf;
205 	return len;
206 }
207 
208 static int rtl_download_firmware(struct hci_dev *hdev,
209 				 const unsigned char *data, int fw_len)
210 {
211 	struct rtl_download_cmd *dl_cmd;
212 	int frag_num = fw_len / RTL_FRAG_LEN + 1;
213 	int frag_len = RTL_FRAG_LEN;
214 	int ret = 0;
215 	int i;
216 
217 	dl_cmd = kmalloc(sizeof(struct rtl_download_cmd), GFP_KERNEL);
218 	if (!dl_cmd)
219 		return -ENOMEM;
220 
221 	for (i = 0; i < frag_num; i++) {
222 		struct sk_buff *skb;
223 
224 		BT_DBG("download fw (%d/%d)", i, frag_num);
225 
226 		dl_cmd->index = i;
227 		if (i == (frag_num - 1)) {
228 			dl_cmd->index |= 0x80; /* data end */
229 			frag_len = fw_len % RTL_FRAG_LEN;
230 		}
231 		memcpy(dl_cmd->data, data, frag_len);
232 
233 		/* Send download command */
234 		skb = __hci_cmd_sync(hdev, 0xfc20, frag_len + 1, dl_cmd,
235 				     HCI_INIT_TIMEOUT);
236 		if (IS_ERR(skb)) {
237 			BT_ERR("%s: download fw command failed (%ld)",
238 			       hdev->name, PTR_ERR(skb));
239 			ret = -PTR_ERR(skb);
240 			goto out;
241 		}
242 
243 		if (skb->len != sizeof(struct rtl_download_response)) {
244 			BT_ERR("%s: download fw event length mismatch",
245 			       hdev->name);
246 			kfree_skb(skb);
247 			ret = -EIO;
248 			goto out;
249 		}
250 
251 		kfree_skb(skb);
252 		data += RTL_FRAG_LEN;
253 	}
254 
255 out:
256 	kfree(dl_cmd);
257 	return ret;
258 }
259 
260 static int btrtl_setup_rtl8723a(struct hci_dev *hdev)
261 {
262 	const struct firmware *fw;
263 	int ret;
264 
265 	BT_INFO("%s: rtl: loading rtl_bt/rtl8723a_fw.bin", hdev->name);
266 	ret = request_firmware(&fw, "rtl_bt/rtl8723a_fw.bin", &hdev->dev);
267 	if (ret < 0) {
268 		BT_ERR("%s: Failed to load rtl_bt/rtl8723a_fw.bin", hdev->name);
269 		return ret;
270 	}
271 
272 	if (fw->size < 8) {
273 		ret = -EINVAL;
274 		goto out;
275 	}
276 
277 	/* Check that the firmware doesn't have the epatch signature
278 	 * (which is only for RTL8723B and newer).
279 	 */
280 	if (!memcmp(fw->data, RTL_EPATCH_SIGNATURE, 8)) {
281 		BT_ERR("%s: unexpected EPATCH signature!", hdev->name);
282 		ret = -EINVAL;
283 		goto out;
284 	}
285 
286 	ret = rtl_download_firmware(hdev, fw->data, fw->size);
287 
288 out:
289 	release_firmware(fw);
290 	return ret;
291 }
292 
293 static int btrtl_setup_rtl8723b(struct hci_dev *hdev, u16 lmp_subver,
294 				const char *fw_name)
295 {
296 	unsigned char *fw_data = NULL;
297 	const struct firmware *fw;
298 	int ret;
299 
300 	BT_INFO("%s: rtl: loading %s", hdev->name, fw_name);
301 	ret = request_firmware(&fw, fw_name, &hdev->dev);
302 	if (ret < 0) {
303 		BT_ERR("%s: Failed to load %s", hdev->name, fw_name);
304 		return ret;
305 	}
306 
307 	ret = rtl8723b_parse_firmware(hdev, lmp_subver, fw, &fw_data);
308 	if (ret < 0)
309 		goto out;
310 
311 	ret = rtl_download_firmware(hdev, fw_data, ret);
312 	kfree(fw_data);
313 	if (ret < 0)
314 		goto out;
315 
316 out:
317 	release_firmware(fw);
318 	return ret;
319 }
320 
321 static struct sk_buff *btrtl_read_local_version(struct hci_dev *hdev)
322 {
323 	struct sk_buff *skb;
324 
325 	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL,
326 			     HCI_INIT_TIMEOUT);
327 	if (IS_ERR(skb)) {
328 		BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION failed (%ld)",
329 		       hdev->name, PTR_ERR(skb));
330 		return skb;
331 	}
332 
333 	if (skb->len != sizeof(struct hci_rp_read_local_version)) {
334 		BT_ERR("%s: HCI_OP_READ_LOCAL_VERSION event length mismatch",
335 		       hdev->name);
336 		kfree_skb(skb);
337 		return ERR_PTR(-EIO);
338 	}
339 
340 	return skb;
341 }
342 
343 int btrtl_setup_realtek(struct hci_dev *hdev)
344 {
345 	struct sk_buff *skb;
346 	struct hci_rp_read_local_version *resp;
347 	u16 lmp_subver;
348 
349 	skb = btrtl_read_local_version(hdev);
350 	if (IS_ERR(skb))
351 		return -PTR_ERR(skb);
352 
353 	resp = (struct hci_rp_read_local_version *)skb->data;
354 	BT_INFO("%s: rtl: examining hci_ver=%02x hci_rev=%04x lmp_ver=%02x "
355 		"lmp_subver=%04x", hdev->name, resp->hci_ver, resp->hci_rev,
356 		resp->lmp_ver, resp->lmp_subver);
357 
358 	lmp_subver = le16_to_cpu(resp->lmp_subver);
359 	kfree_skb(skb);
360 
361 	/* Match a set of subver values that correspond to stock firmware,
362 	 * which is not compatible with standard btusb.
363 	 * If matched, upload an alternative firmware that does conform to
364 	 * standard btusb. Once that firmware is uploaded, the subver changes
365 	 * to a different value.
366 	 */
367 	switch (lmp_subver) {
368 	case RTL_ROM_LMP_8723A:
369 	case RTL_ROM_LMP_3499:
370 		return btrtl_setup_rtl8723a(hdev);
371 	case RTL_ROM_LMP_8723B:
372 		return btrtl_setup_rtl8723b(hdev, lmp_subver,
373 					    "rtl_bt/rtl8723b_fw.bin");
374 	case RTL_ROM_LMP_8821A:
375 		return btrtl_setup_rtl8723b(hdev, lmp_subver,
376 					    "rtl_bt/rtl8821a_fw.bin");
377 	case RTL_ROM_LMP_8761A:
378 		return btrtl_setup_rtl8723b(hdev, lmp_subver,
379 					    "rtl_bt/rtl8761a_fw.bin");
380 	default:
381 		BT_INFO("rtl: assuming no firmware upload needed.");
382 		return 0;
383 	}
384 }
385 EXPORT_SYMBOL_GPL(btrtl_setup_realtek);
386 
387 MODULE_AUTHOR("Daniel Drake <drake@endlessm.com>");
388 MODULE_DESCRIPTION("Bluetooth support for Realtek devices ver " VERSION);
389 MODULE_VERSION(VERSION);
390 MODULE_LICENSE("GPL");
391