1// SPDX-License-Identifier: GPL-2.0-only
2
3/* Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved. */
4
5#include <linux/firmware.h>
6#include <linux/limits.h>
7#include <linux/mhi.h>
8#include <linux/minmax.h>
9#include <linux/mod_devicetable.h>
10#include <linux/overflow.h>
11#include <linux/types.h>
12#include <linux/workqueue.h>
13
14#include "sahara.h"
15
16#define SAHARA_HELLO_CMD		0x1  /* Min protocol version 1.0 */
17#define SAHARA_HELLO_RESP_CMD		0x2  /* Min protocol version 1.0 */
18#define SAHARA_READ_DATA_CMD		0x3  /* Min protocol version 1.0 */
19#define SAHARA_END_OF_IMAGE_CMD		0x4  /* Min protocol version 1.0 */
20#define SAHARA_DONE_CMD			0x5  /* Min protocol version 1.0 */
21#define SAHARA_DONE_RESP_CMD		0x6  /* Min protocol version 1.0 */
22#define SAHARA_RESET_CMD		0x7  /* Min protocol version 1.0 */
23#define SAHARA_RESET_RESP_CMD		0x8  /* Min protocol version 1.0 */
24#define SAHARA_MEM_DEBUG_CMD		0x9  /* Min protocol version 2.0 */
25#define SAHARA_MEM_READ_CMD		0xa  /* Min protocol version 2.0 */
26#define SAHARA_CMD_READY_CMD		0xb  /* Min protocol version 2.1 */
27#define SAHARA_SWITCH_MODE_CMD		0xc  /* Min protocol version 2.1 */
28#define SAHARA_EXECUTE_CMD		0xd  /* Min protocol version 2.1 */
29#define SAHARA_EXECUTE_RESP_CMD		0xe  /* Min protocol version 2.1 */
30#define SAHARA_EXECUTE_DATA_CMD		0xf  /* Min protocol version 2.1 */
31#define SAHARA_MEM_DEBUG64_CMD		0x10 /* Min protocol version 2.5 */
32#define SAHARA_MEM_READ64_CMD		0x11 /* Min protocol version 2.5 */
33#define SAHARA_READ_DATA64_CMD		0x12 /* Min protocol version 2.8 */
34#define SAHARA_RESET_STATE_CMD		0x13 /* Min protocol version 2.9 */
35#define SAHARA_WRITE_DATA_CMD		0x14 /* Min protocol version 3.0 */
36
37#define SAHARA_PACKET_MAX_SIZE		0xffffU /* MHI_MAX_MTU */
38#define SAHARA_TRANSFER_MAX_SIZE	0x80000
39#define SAHARA_NUM_TX_BUF		DIV_ROUND_UP(SAHARA_TRANSFER_MAX_SIZE,\
40							SAHARA_PACKET_MAX_SIZE)
41#define SAHARA_IMAGE_ID_NONE		U32_MAX
42
43#define SAHARA_VERSION			2
44#define SAHARA_SUCCESS			0
45
46#define SAHARA_MODE_IMAGE_TX_PENDING	0x0
47#define SAHARA_MODE_IMAGE_TX_COMPLETE	0x1
48#define SAHARA_MODE_MEMORY_DEBUG	0x2
49#define SAHARA_MODE_COMMAND		0x3
50
51#define SAHARA_HELLO_LENGTH		0x30
52#define SAHARA_READ_DATA_LENGTH		0x14
53#define SAHARA_END_OF_IMAGE_LENGTH	0x10
54#define SAHARA_DONE_LENGTH		0x8
55#define SAHARA_RESET_LENGTH		0x8
56
57struct sahara_packet {
58	__le32 cmd;
59	__le32 length;
60
61	union {
62		struct {
63			__le32 version;
64			__le32 version_compat;
65			__le32 max_length;
66			__le32 mode;
67		} hello;
68		struct {
69			__le32 version;
70			__le32 version_compat;
71			__le32 status;
72			__le32 mode;
73		} hello_resp;
74		struct {
75			__le32 image;
76			__le32 offset;
77			__le32 length;
78		} read_data;
79		struct {
80			__le32 image;
81			__le32 status;
82		} end_of_image;
83	};
84};
85
86struct sahara_context {
87	struct sahara_packet		*tx[SAHARA_NUM_TX_BUF];
88	struct sahara_packet		*rx;
89	struct work_struct		work;
90	struct mhi_device		*mhi_dev;
91	const char			**image_table;
92	u32				table_size;
93	u32				active_image_id;
94	const struct firmware		*firmware;
95};
96
97static const char *aic100_image_table[] = {
98	[1]  = "qcom/aic100/fw1.bin",
99	[2]  = "qcom/aic100/fw2.bin",
100	[4]  = "qcom/aic100/fw4.bin",
101	[5]  = "qcom/aic100/fw5.bin",
102	[6]  = "qcom/aic100/fw6.bin",
103	[8]  = "qcom/aic100/fw8.bin",
104	[9]  = "qcom/aic100/fw9.bin",
105	[10] = "qcom/aic100/fw10.bin",
106};
107
108static int sahara_find_image(struct sahara_context *context, u32 image_id)
109{
110	int ret;
111
112	if (image_id == context->active_image_id)
113		return 0;
114
115	if (context->active_image_id != SAHARA_IMAGE_ID_NONE) {
116		dev_err(&context->mhi_dev->dev, "image id %d is not valid as %d is active\n",
117			image_id, context->active_image_id);
118		return -EINVAL;
119	}
120
121	if (image_id >= context->table_size || !context->image_table[image_id]) {
122		dev_err(&context->mhi_dev->dev, "request for unknown image: %d\n", image_id);
123		return -EINVAL;
124	}
125
126	/*
127	 * This image might be optional. The device may continue without it.
128	 * Only the device knows. Suppress error messages that could suggest an
129	 * a problem when we were actually able to continue.
130	 */
131	ret = firmware_request_nowarn(&context->firmware,
132				      context->image_table[image_id],
133				      &context->mhi_dev->dev);
134	if (ret) {
135		dev_dbg(&context->mhi_dev->dev, "request for image id %d / file %s failed %d\n",
136			image_id, context->image_table[image_id], ret);
137		return ret;
138	}
139
140	context->active_image_id = image_id;
141
142	return 0;
143}
144
145static void sahara_release_image(struct sahara_context *context)
146{
147	if (context->active_image_id != SAHARA_IMAGE_ID_NONE)
148		release_firmware(context->firmware);
149	context->active_image_id = SAHARA_IMAGE_ID_NONE;
150}
151
152static void sahara_send_reset(struct sahara_context *context)
153{
154	int ret;
155
156	context->tx[0]->cmd = cpu_to_le32(SAHARA_RESET_CMD);
157	context->tx[0]->length = cpu_to_le32(SAHARA_RESET_LENGTH);
158
159	ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE, context->tx[0],
160			    SAHARA_RESET_LENGTH, MHI_EOT);
161	if (ret)
162		dev_err(&context->mhi_dev->dev, "Unable to send reset response %d\n", ret);
163}
164
165static void sahara_hello(struct sahara_context *context)
166{
167	int ret;
168
169	dev_dbg(&context->mhi_dev->dev,
170		"HELLO cmd received. length:%d version:%d version_compat:%d max_length:%d mode:%d\n",
171		le32_to_cpu(context->rx->length),
172		le32_to_cpu(context->rx->hello.version),
173		le32_to_cpu(context->rx->hello.version_compat),
174		le32_to_cpu(context->rx->hello.max_length),
175		le32_to_cpu(context->rx->hello.mode));
176
177	if (le32_to_cpu(context->rx->length) != SAHARA_HELLO_LENGTH) {
178		dev_err(&context->mhi_dev->dev, "Malformed hello packet - length %d\n",
179			le32_to_cpu(context->rx->length));
180		return;
181	}
182	if (le32_to_cpu(context->rx->hello.version) != SAHARA_VERSION) {
183		dev_err(&context->mhi_dev->dev, "Unsupported hello packet - version %d\n",
184			le32_to_cpu(context->rx->hello.version));
185		return;
186	}
187
188	if (le32_to_cpu(context->rx->hello.mode) != SAHARA_MODE_IMAGE_TX_PENDING &&
189	    le32_to_cpu(context->rx->hello.mode) != SAHARA_MODE_IMAGE_TX_COMPLETE) {
190		dev_err(&context->mhi_dev->dev, "Unsupported hello packet - mode %d\n",
191			le32_to_cpu(context->rx->hello.mode));
192		return;
193	}
194
195	context->tx[0]->cmd = cpu_to_le32(SAHARA_HELLO_RESP_CMD);
196	context->tx[0]->length = cpu_to_le32(SAHARA_HELLO_LENGTH);
197	context->tx[0]->hello_resp.version = cpu_to_le32(SAHARA_VERSION);
198	context->tx[0]->hello_resp.version_compat = cpu_to_le32(SAHARA_VERSION);
199	context->tx[0]->hello_resp.status = cpu_to_le32(SAHARA_SUCCESS);
200	context->tx[0]->hello_resp.mode = context->rx->hello_resp.mode;
201
202	ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE, context->tx[0],
203			    SAHARA_HELLO_LENGTH, MHI_EOT);
204	if (ret)
205		dev_err(&context->mhi_dev->dev, "Unable to send hello response %d\n", ret);
206}
207
208static void sahara_read_data(struct sahara_context *context)
209{
210	u32 image_id, data_offset, data_len, pkt_data_len;
211	int ret;
212	int i;
213
214	dev_dbg(&context->mhi_dev->dev,
215		"READ_DATA cmd received. length:%d image:%d offset:%d data_length:%d\n",
216		le32_to_cpu(context->rx->length),
217		le32_to_cpu(context->rx->read_data.image),
218		le32_to_cpu(context->rx->read_data.offset),
219		le32_to_cpu(context->rx->read_data.length));
220
221	if (le32_to_cpu(context->rx->length) != SAHARA_READ_DATA_LENGTH) {
222		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - length %d\n",
223			le32_to_cpu(context->rx->length));
224		return;
225	}
226
227	image_id = le32_to_cpu(context->rx->read_data.image);
228	data_offset = le32_to_cpu(context->rx->read_data.offset);
229	data_len = le32_to_cpu(context->rx->read_data.length);
230
231	ret = sahara_find_image(context, image_id);
232	if (ret) {
233		sahara_send_reset(context);
234		return;
235	}
236
237	/*
238	 * Image is released when the device is done with it via
239	 * SAHARA_END_OF_IMAGE_CMD. sahara_send_reset() will either cause the
240	 * device to retry the operation with a modification, or decide to be
241	 * done with the image and trigger SAHARA_END_OF_IMAGE_CMD.
242	 * release_image() is called from SAHARA_END_OF_IMAGE_CMD. processing
243	 * and is not needed here on error.
244	 */
245
246	if (data_len > SAHARA_TRANSFER_MAX_SIZE) {
247		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - data len %d exceeds max xfer size %d\n",
248			data_len, SAHARA_TRANSFER_MAX_SIZE);
249		sahara_send_reset(context);
250		return;
251	}
252
253	if (data_offset >= context->firmware->size) {
254		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - data offset %d exceeds file size %zu\n",
255			data_offset, context->firmware->size);
256		sahara_send_reset(context);
257		return;
258	}
259
260	if (size_add(data_offset, data_len) > context->firmware->size) {
261		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - data offset %d and length %d exceeds file size %zu\n",
262			data_offset, data_len, context->firmware->size);
263		sahara_send_reset(context);
264		return;
265	}
266
267	for (i = 0; i < SAHARA_NUM_TX_BUF && data_len; ++i) {
268		pkt_data_len = min(data_len, SAHARA_PACKET_MAX_SIZE);
269
270		memcpy(context->tx[i], &context->firmware->data[data_offset], pkt_data_len);
271
272		data_offset += pkt_data_len;
273		data_len -= pkt_data_len;
274
275		ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE,
276				    context->tx[i], pkt_data_len,
277				    !data_len ? MHI_EOT : MHI_CHAIN);
278		if (ret) {
279			dev_err(&context->mhi_dev->dev, "Unable to send read_data response %d\n",
280				ret);
281			return;
282		}
283	}
284}
285
286static void sahara_end_of_image(struct sahara_context *context)
287{
288	int ret;
289
290	dev_dbg(&context->mhi_dev->dev,
291		"END_OF_IMAGE cmd received. length:%d image:%d status:%d\n",
292		le32_to_cpu(context->rx->length),
293		le32_to_cpu(context->rx->end_of_image.image),
294		le32_to_cpu(context->rx->end_of_image.status));
295
296	if (le32_to_cpu(context->rx->length) != SAHARA_END_OF_IMAGE_LENGTH) {
297		dev_err(&context->mhi_dev->dev, "Malformed end_of_image packet - length %d\n",
298			le32_to_cpu(context->rx->length));
299		return;
300	}
301
302	if (context->active_image_id != SAHARA_IMAGE_ID_NONE &&
303	    le32_to_cpu(context->rx->end_of_image.image) != context->active_image_id) {
304		dev_err(&context->mhi_dev->dev, "Malformed end_of_image packet - image %d is not the active image\n",
305			le32_to_cpu(context->rx->end_of_image.image));
306		return;
307	}
308
309	sahara_release_image(context);
310
311	if (le32_to_cpu(context->rx->end_of_image.status))
312		return;
313
314	context->tx[0]->cmd = cpu_to_le32(SAHARA_DONE_CMD);
315	context->tx[0]->length = cpu_to_le32(SAHARA_DONE_LENGTH);
316
317	ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE, context->tx[0],
318			    SAHARA_DONE_LENGTH, MHI_EOT);
319	if (ret)
320		dev_dbg(&context->mhi_dev->dev, "Unable to send done response %d\n", ret);
321}
322
323static void sahara_processing(struct work_struct *work)
324{
325	struct sahara_context *context = container_of(work, struct sahara_context, work);
326	int ret;
327
328	switch (le32_to_cpu(context->rx->cmd)) {
329	case SAHARA_HELLO_CMD:
330		sahara_hello(context);
331		break;
332	case SAHARA_READ_DATA_CMD:
333		sahara_read_data(context);
334		break;
335	case SAHARA_END_OF_IMAGE_CMD:
336		sahara_end_of_image(context);
337		break;
338	case SAHARA_DONE_RESP_CMD:
339		/* Intentional do nothing as we don't need to exit an app */
340		break;
341	default:
342		dev_err(&context->mhi_dev->dev, "Unknown command %d\n",
343			le32_to_cpu(context->rx->cmd));
344		break;
345	}
346
347	ret = mhi_queue_buf(context->mhi_dev, DMA_FROM_DEVICE, context->rx,
348			    SAHARA_PACKET_MAX_SIZE, MHI_EOT);
349	if (ret)
350		dev_err(&context->mhi_dev->dev, "Unable to requeue rx buf %d\n", ret);
351}
352
353static int sahara_mhi_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id)
354{
355	struct sahara_context *context;
356	int ret;
357	int i;
358
359	context = devm_kzalloc(&mhi_dev->dev, sizeof(*context), GFP_KERNEL);
360	if (!context)
361		return -ENOMEM;
362
363	context->rx = devm_kzalloc(&mhi_dev->dev, SAHARA_PACKET_MAX_SIZE, GFP_KERNEL);
364	if (!context->rx)
365		return -ENOMEM;
366
367	/*
368	 * AIC100 defines SAHARA_TRANSFER_MAX_SIZE as the largest value it
369	 * will request for READ_DATA. This is larger than
370	 * SAHARA_PACKET_MAX_SIZE, and we need 9x SAHARA_PACKET_MAX_SIZE to
371	 * cover SAHARA_TRANSFER_MAX_SIZE. When the remote side issues a
372	 * READ_DATA, it requires a transfer of the exact size requested. We
373	 * can use MHI_CHAIN to link multiple buffers into a single transfer
374	 * but the remote side will not consume the buffers until it sees an
375	 * EOT, thus we need to allocate enough buffers to put in the tx fifo
376	 * to cover an entire READ_DATA request of the max size.
377	 */
378	for (i = 0; i < SAHARA_NUM_TX_BUF; ++i) {
379		context->tx[i] = devm_kzalloc(&mhi_dev->dev, SAHARA_PACKET_MAX_SIZE, GFP_KERNEL);
380		if (!context->tx[i])
381			return -ENOMEM;
382	}
383
384	context->mhi_dev = mhi_dev;
385	INIT_WORK(&context->work, sahara_processing);
386	context->image_table = aic100_image_table;
387	context->table_size = ARRAY_SIZE(aic100_image_table);
388	context->active_image_id = SAHARA_IMAGE_ID_NONE;
389	dev_set_drvdata(&mhi_dev->dev, context);
390
391	ret = mhi_prepare_for_transfer(mhi_dev);
392	if (ret)
393		return ret;
394
395	ret = mhi_queue_buf(mhi_dev, DMA_FROM_DEVICE, context->rx, SAHARA_PACKET_MAX_SIZE, MHI_EOT);
396	if (ret) {
397		mhi_unprepare_from_transfer(mhi_dev);
398		return ret;
399	}
400
401	return 0;
402}
403
404static void sahara_mhi_remove(struct mhi_device *mhi_dev)
405{
406	struct sahara_context *context = dev_get_drvdata(&mhi_dev->dev);
407
408	cancel_work_sync(&context->work);
409	sahara_release_image(context);
410	mhi_unprepare_from_transfer(mhi_dev);
411}
412
413static void sahara_mhi_ul_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
414{
415}
416
417static void sahara_mhi_dl_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
418{
419	struct sahara_context *context = dev_get_drvdata(&mhi_dev->dev);
420
421	if (!mhi_result->transaction_status)
422		schedule_work(&context->work);
423}
424
425static const struct mhi_device_id sahara_mhi_match_table[] = {
426	{ .chan = "QAIC_SAHARA", },
427	{},
428};
429
430static struct mhi_driver sahara_mhi_driver = {
431	.id_table = sahara_mhi_match_table,
432	.remove = sahara_mhi_remove,
433	.probe = sahara_mhi_probe,
434	.ul_xfer_cb = sahara_mhi_ul_xfer_cb,
435	.dl_xfer_cb = sahara_mhi_dl_xfer_cb,
436	.driver = {
437		.name = "sahara",
438	},
439};
440
441int sahara_register(void)
442{
443	return mhi_driver_register(&sahara_mhi_driver);
444}
445
446void sahara_unregister(void)
447{
448	mhi_driver_unregister(&sahara_mhi_driver);
449}
450