xref: /linux/drivers/input/misc/ims-pcu.c (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for IMS Passenger Control Unit Devices
4  *
5  * Copyright (C) 2013 The IMS Company
6  */
7 
8 #include <linux/completion.h>
9 #include <linux/device.h>
10 #include <linux/firmware.h>
11 #include <linux/ihex.h>
12 #include <linux/input.h>
13 #include <linux/kernel.h>
14 #include <linux/leds.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/types.h>
18 #include <linux/usb/input.h>
19 #include <linux/usb/cdc.h>
20 #include <asm/unaligned.h>
21 
22 #define IMS_PCU_KEYMAP_LEN		32
23 
24 struct ims_pcu_buttons {
25 	struct input_dev *input;
26 	char name[32];
27 	char phys[32];
28 	unsigned short keymap[IMS_PCU_KEYMAP_LEN];
29 };
30 
31 struct ims_pcu_gamepad {
32 	struct input_dev *input;
33 	char name[32];
34 	char phys[32];
35 };
36 
37 struct ims_pcu_backlight {
38 	struct led_classdev cdev;
39 	char name[32];
40 };
41 
42 #define IMS_PCU_PART_NUMBER_LEN		15
43 #define IMS_PCU_SERIAL_NUMBER_LEN	8
44 #define IMS_PCU_DOM_LEN			8
45 #define IMS_PCU_FW_VERSION_LEN		(9 + 1)
46 #define IMS_PCU_BL_VERSION_LEN		(9 + 1)
47 #define IMS_PCU_BL_RESET_REASON_LEN	(2 + 1)
48 
49 #define IMS_PCU_PCU_B_DEVICE_ID		5
50 
51 #define IMS_PCU_BUF_SIZE		128
52 
53 struct ims_pcu {
54 	struct usb_device *udev;
55 	struct device *dev; /* control interface's device, used for logging */
56 
57 	unsigned int device_no;
58 
59 	bool bootloader_mode;
60 
61 	char part_number[IMS_PCU_PART_NUMBER_LEN];
62 	char serial_number[IMS_PCU_SERIAL_NUMBER_LEN];
63 	char date_of_manufacturing[IMS_PCU_DOM_LEN];
64 	char fw_version[IMS_PCU_FW_VERSION_LEN];
65 	char bl_version[IMS_PCU_BL_VERSION_LEN];
66 	char reset_reason[IMS_PCU_BL_RESET_REASON_LEN];
67 	int update_firmware_status;
68 	u8 device_id;
69 
70 	u8 ofn_reg_addr;
71 
72 	struct usb_interface *ctrl_intf;
73 
74 	struct usb_endpoint_descriptor *ep_ctrl;
75 	struct urb *urb_ctrl;
76 	u8 *urb_ctrl_buf;
77 	dma_addr_t ctrl_dma;
78 	size_t max_ctrl_size;
79 
80 	struct usb_interface *data_intf;
81 
82 	struct usb_endpoint_descriptor *ep_in;
83 	struct urb *urb_in;
84 	u8 *urb_in_buf;
85 	dma_addr_t read_dma;
86 	size_t max_in_size;
87 
88 	struct usb_endpoint_descriptor *ep_out;
89 	u8 *urb_out_buf;
90 	size_t max_out_size;
91 
92 	u8 read_buf[IMS_PCU_BUF_SIZE];
93 	u8 read_pos;
94 	u8 check_sum;
95 	bool have_stx;
96 	bool have_dle;
97 
98 	u8 cmd_buf[IMS_PCU_BUF_SIZE];
99 	u8 ack_id;
100 	u8 expected_response;
101 	u8 cmd_buf_len;
102 	struct completion cmd_done;
103 	struct mutex cmd_mutex;
104 
105 	u32 fw_start_addr;
106 	u32 fw_end_addr;
107 	struct completion async_firmware_done;
108 
109 	struct ims_pcu_buttons buttons;
110 	struct ims_pcu_gamepad *gamepad;
111 	struct ims_pcu_backlight backlight;
112 
113 	bool setup_complete; /* Input and LED devices have been created */
114 };
115 
116 
117 /*********************************************************************
118  *             Buttons Input device support                          *
119  *********************************************************************/
120 
121 static const unsigned short ims_pcu_keymap_1[] = {
122 	[1] = KEY_ATTENDANT_OFF,
123 	[2] = KEY_ATTENDANT_ON,
124 	[3] = KEY_LIGHTS_TOGGLE,
125 	[4] = KEY_VOLUMEUP,
126 	[5] = KEY_VOLUMEDOWN,
127 	[6] = KEY_INFO,
128 };
129 
130 static const unsigned short ims_pcu_keymap_2[] = {
131 	[4] = KEY_VOLUMEUP,
132 	[5] = KEY_VOLUMEDOWN,
133 	[6] = KEY_INFO,
134 };
135 
136 static const unsigned short ims_pcu_keymap_3[] = {
137 	[1] = KEY_HOMEPAGE,
138 	[2] = KEY_ATTENDANT_TOGGLE,
139 	[3] = KEY_LIGHTS_TOGGLE,
140 	[4] = KEY_VOLUMEUP,
141 	[5] = KEY_VOLUMEDOWN,
142 	[6] = KEY_DISPLAYTOGGLE,
143 	[18] = KEY_PLAYPAUSE,
144 };
145 
146 static const unsigned short ims_pcu_keymap_4[] = {
147 	[1] = KEY_ATTENDANT_OFF,
148 	[2] = KEY_ATTENDANT_ON,
149 	[3] = KEY_LIGHTS_TOGGLE,
150 	[4] = KEY_VOLUMEUP,
151 	[5] = KEY_VOLUMEDOWN,
152 	[6] = KEY_INFO,
153 	[18] = KEY_PLAYPAUSE,
154 };
155 
156 static const unsigned short ims_pcu_keymap_5[] = {
157 	[1] = KEY_ATTENDANT_OFF,
158 	[2] = KEY_ATTENDANT_ON,
159 	[3] = KEY_LIGHTS_TOGGLE,
160 };
161 
162 struct ims_pcu_device_info {
163 	const unsigned short *keymap;
164 	size_t keymap_len;
165 	bool has_gamepad;
166 };
167 
168 #define IMS_PCU_DEVINFO(_n, _gamepad)				\
169 	[_n] = {						\
170 		.keymap = ims_pcu_keymap_##_n,			\
171 		.keymap_len = ARRAY_SIZE(ims_pcu_keymap_##_n),	\
172 		.has_gamepad = _gamepad,			\
173 	}
174 
175 static const struct ims_pcu_device_info ims_pcu_device_info[] = {
176 	IMS_PCU_DEVINFO(1, true),
177 	IMS_PCU_DEVINFO(2, true),
178 	IMS_PCU_DEVINFO(3, true),
179 	IMS_PCU_DEVINFO(4, true),
180 	IMS_PCU_DEVINFO(5, false),
181 };
182 
183 static void ims_pcu_buttons_report(struct ims_pcu *pcu, u32 data)
184 {
185 	struct ims_pcu_buttons *buttons = &pcu->buttons;
186 	struct input_dev *input = buttons->input;
187 	int i;
188 
189 	for (i = 0; i < 32; i++) {
190 		unsigned short keycode = buttons->keymap[i];
191 
192 		if (keycode != KEY_RESERVED)
193 			input_report_key(input, keycode, data & (1UL << i));
194 	}
195 
196 	input_sync(input);
197 }
198 
199 static int ims_pcu_setup_buttons(struct ims_pcu *pcu,
200 				 const unsigned short *keymap,
201 				 size_t keymap_len)
202 {
203 	struct ims_pcu_buttons *buttons = &pcu->buttons;
204 	struct input_dev *input;
205 	int i;
206 	int error;
207 
208 	input = input_allocate_device();
209 	if (!input) {
210 		dev_err(pcu->dev,
211 			"Not enough memory for input input device\n");
212 		return -ENOMEM;
213 	}
214 
215 	snprintf(buttons->name, sizeof(buttons->name),
216 		 "IMS PCU#%d Button Interface", pcu->device_no);
217 
218 	usb_make_path(pcu->udev, buttons->phys, sizeof(buttons->phys));
219 	strlcat(buttons->phys, "/input0", sizeof(buttons->phys));
220 
221 	memcpy(buttons->keymap, keymap, sizeof(*keymap) * keymap_len);
222 
223 	input->name = buttons->name;
224 	input->phys = buttons->phys;
225 	usb_to_input_id(pcu->udev, &input->id);
226 	input->dev.parent = &pcu->ctrl_intf->dev;
227 
228 	input->keycode = buttons->keymap;
229 	input->keycodemax = ARRAY_SIZE(buttons->keymap);
230 	input->keycodesize = sizeof(buttons->keymap[0]);
231 
232 	__set_bit(EV_KEY, input->evbit);
233 	for (i = 0; i < IMS_PCU_KEYMAP_LEN; i++)
234 		__set_bit(buttons->keymap[i], input->keybit);
235 	__clear_bit(KEY_RESERVED, input->keybit);
236 
237 	error = input_register_device(input);
238 	if (error) {
239 		dev_err(pcu->dev,
240 			"Failed to register buttons input device: %d\n",
241 			error);
242 		input_free_device(input);
243 		return error;
244 	}
245 
246 	buttons->input = input;
247 	return 0;
248 }
249 
250 static void ims_pcu_destroy_buttons(struct ims_pcu *pcu)
251 {
252 	struct ims_pcu_buttons *buttons = &pcu->buttons;
253 
254 	input_unregister_device(buttons->input);
255 }
256 
257 
258 /*********************************************************************
259  *             Gamepad Input device support                          *
260  *********************************************************************/
261 
262 static void ims_pcu_gamepad_report(struct ims_pcu *pcu, u32 data)
263 {
264 	struct ims_pcu_gamepad *gamepad = pcu->gamepad;
265 	struct input_dev *input = gamepad->input;
266 	int x, y;
267 
268 	x = !!(data & (1 << 14)) - !!(data & (1 << 13));
269 	y = !!(data & (1 << 12)) - !!(data & (1 << 11));
270 
271 	input_report_abs(input, ABS_X, x);
272 	input_report_abs(input, ABS_Y, y);
273 
274 	input_report_key(input, BTN_A, data & (1 << 7));
275 	input_report_key(input, BTN_B, data & (1 << 8));
276 	input_report_key(input, BTN_X, data & (1 << 9));
277 	input_report_key(input, BTN_Y, data & (1 << 10));
278 	input_report_key(input, BTN_START, data & (1 << 15));
279 	input_report_key(input, BTN_SELECT, data & (1 << 16));
280 
281 	input_sync(input);
282 }
283 
284 static int ims_pcu_setup_gamepad(struct ims_pcu *pcu)
285 {
286 	struct ims_pcu_gamepad *gamepad;
287 	struct input_dev *input;
288 	int error;
289 
290 	gamepad = kzalloc(sizeof(struct ims_pcu_gamepad), GFP_KERNEL);
291 	input = input_allocate_device();
292 	if (!gamepad || !input) {
293 		dev_err(pcu->dev,
294 			"Not enough memory for gamepad device\n");
295 		error = -ENOMEM;
296 		goto err_free_mem;
297 	}
298 
299 	gamepad->input = input;
300 
301 	snprintf(gamepad->name, sizeof(gamepad->name),
302 		 "IMS PCU#%d Gamepad Interface", pcu->device_no);
303 
304 	usb_make_path(pcu->udev, gamepad->phys, sizeof(gamepad->phys));
305 	strlcat(gamepad->phys, "/input1", sizeof(gamepad->phys));
306 
307 	input->name = gamepad->name;
308 	input->phys = gamepad->phys;
309 	usb_to_input_id(pcu->udev, &input->id);
310 	input->dev.parent = &pcu->ctrl_intf->dev;
311 
312 	__set_bit(EV_KEY, input->evbit);
313 	__set_bit(BTN_A, input->keybit);
314 	__set_bit(BTN_B, input->keybit);
315 	__set_bit(BTN_X, input->keybit);
316 	__set_bit(BTN_Y, input->keybit);
317 	__set_bit(BTN_START, input->keybit);
318 	__set_bit(BTN_SELECT, input->keybit);
319 
320 	__set_bit(EV_ABS, input->evbit);
321 	input_set_abs_params(input, ABS_X, -1, 1, 0, 0);
322 	input_set_abs_params(input, ABS_Y, -1, 1, 0, 0);
323 
324 	error = input_register_device(input);
325 	if (error) {
326 		dev_err(pcu->dev,
327 			"Failed to register gamepad input device: %d\n",
328 			error);
329 		goto err_free_mem;
330 	}
331 
332 	pcu->gamepad = gamepad;
333 	return 0;
334 
335 err_free_mem:
336 	input_free_device(input);
337 	kfree(gamepad);
338 	return error;
339 }
340 
341 static void ims_pcu_destroy_gamepad(struct ims_pcu *pcu)
342 {
343 	struct ims_pcu_gamepad *gamepad = pcu->gamepad;
344 
345 	input_unregister_device(gamepad->input);
346 	kfree(gamepad);
347 }
348 
349 
350 /*********************************************************************
351  *             PCU Communication protocol handling                   *
352  *********************************************************************/
353 
354 #define IMS_PCU_PROTOCOL_STX		0x02
355 #define IMS_PCU_PROTOCOL_ETX		0x03
356 #define IMS_PCU_PROTOCOL_DLE		0x10
357 
358 /* PCU commands */
359 #define IMS_PCU_CMD_STATUS		0xa0
360 #define IMS_PCU_CMD_PCU_RESET		0xa1
361 #define IMS_PCU_CMD_RESET_REASON	0xa2
362 #define IMS_PCU_CMD_SEND_BUTTONS	0xa3
363 #define IMS_PCU_CMD_JUMP_TO_BTLDR	0xa4
364 #define IMS_PCU_CMD_GET_INFO		0xa5
365 #define IMS_PCU_CMD_SET_BRIGHTNESS	0xa6
366 #define IMS_PCU_CMD_EEPROM		0xa7
367 #define IMS_PCU_CMD_GET_FW_VERSION	0xa8
368 #define IMS_PCU_CMD_GET_BL_VERSION	0xa9
369 #define IMS_PCU_CMD_SET_INFO		0xab
370 #define IMS_PCU_CMD_GET_BRIGHTNESS	0xac
371 #define IMS_PCU_CMD_GET_DEVICE_ID	0xae
372 #define IMS_PCU_CMD_SPECIAL_INFO	0xb0
373 #define IMS_PCU_CMD_BOOTLOADER		0xb1	/* Pass data to bootloader */
374 #define IMS_PCU_CMD_OFN_SET_CONFIG	0xb3
375 #define IMS_PCU_CMD_OFN_GET_CONFIG	0xb4
376 
377 /* PCU responses */
378 #define IMS_PCU_RSP_STATUS		0xc0
379 #define IMS_PCU_RSP_PCU_RESET		0	/* Originally 0xc1 */
380 #define IMS_PCU_RSP_RESET_REASON	0xc2
381 #define IMS_PCU_RSP_SEND_BUTTONS	0xc3
382 #define IMS_PCU_RSP_JUMP_TO_BTLDR	0	/* Originally 0xc4 */
383 #define IMS_PCU_RSP_GET_INFO		0xc5
384 #define IMS_PCU_RSP_SET_BRIGHTNESS	0xc6
385 #define IMS_PCU_RSP_EEPROM		0xc7
386 #define IMS_PCU_RSP_GET_FW_VERSION	0xc8
387 #define IMS_PCU_RSP_GET_BL_VERSION	0xc9
388 #define IMS_PCU_RSP_SET_INFO		0xcb
389 #define IMS_PCU_RSP_GET_BRIGHTNESS	0xcc
390 #define IMS_PCU_RSP_CMD_INVALID		0xcd
391 #define IMS_PCU_RSP_GET_DEVICE_ID	0xce
392 #define IMS_PCU_RSP_SPECIAL_INFO	0xd0
393 #define IMS_PCU_RSP_BOOTLOADER		0xd1	/* Bootloader response */
394 #define IMS_PCU_RSP_OFN_SET_CONFIG	0xd2
395 #define IMS_PCU_RSP_OFN_GET_CONFIG	0xd3
396 
397 
398 #define IMS_PCU_RSP_EVNT_BUTTONS	0xe0	/* Unsolicited, button state */
399 #define IMS_PCU_GAMEPAD_MASK		0x0001ff80UL	/* Bits 7 through 16 */
400 
401 
402 #define IMS_PCU_MIN_PACKET_LEN		3
403 #define IMS_PCU_DATA_OFFSET		2
404 
405 #define IMS_PCU_CMD_WRITE_TIMEOUT	100 /* msec */
406 #define IMS_PCU_CMD_RESPONSE_TIMEOUT	500 /* msec */
407 
408 static void ims_pcu_report_events(struct ims_pcu *pcu)
409 {
410 	u32 data = get_unaligned_be32(&pcu->read_buf[3]);
411 
412 	ims_pcu_buttons_report(pcu, data & ~IMS_PCU_GAMEPAD_MASK);
413 	if (pcu->gamepad)
414 		ims_pcu_gamepad_report(pcu, data);
415 }
416 
417 static void ims_pcu_handle_response(struct ims_pcu *pcu)
418 {
419 	switch (pcu->read_buf[0]) {
420 	case IMS_PCU_RSP_EVNT_BUTTONS:
421 		if (likely(pcu->setup_complete))
422 			ims_pcu_report_events(pcu);
423 		break;
424 
425 	default:
426 		/*
427 		 * See if we got command completion.
428 		 * If both the sequence and response code match save
429 		 * the data and signal completion.
430 		 */
431 		if (pcu->read_buf[0] == pcu->expected_response &&
432 		    pcu->read_buf[1] == pcu->ack_id - 1) {
433 
434 			memcpy(pcu->cmd_buf, pcu->read_buf, pcu->read_pos);
435 			pcu->cmd_buf_len = pcu->read_pos;
436 			complete(&pcu->cmd_done);
437 		}
438 		break;
439 	}
440 }
441 
442 static void ims_pcu_process_data(struct ims_pcu *pcu, struct urb *urb)
443 {
444 	int i;
445 
446 	for (i = 0; i < urb->actual_length; i++) {
447 		u8 data = pcu->urb_in_buf[i];
448 
449 		/* Skip everything until we get Start Xmit */
450 		if (!pcu->have_stx && data != IMS_PCU_PROTOCOL_STX)
451 			continue;
452 
453 		if (pcu->have_dle) {
454 			pcu->have_dle = false;
455 			pcu->read_buf[pcu->read_pos++] = data;
456 			pcu->check_sum += data;
457 			continue;
458 		}
459 
460 		switch (data) {
461 		case IMS_PCU_PROTOCOL_STX:
462 			if (pcu->have_stx)
463 				dev_warn(pcu->dev,
464 					 "Unexpected STX at byte %d, discarding old data\n",
465 					 pcu->read_pos);
466 			pcu->have_stx = true;
467 			pcu->have_dle = false;
468 			pcu->read_pos = 0;
469 			pcu->check_sum = 0;
470 			break;
471 
472 		case IMS_PCU_PROTOCOL_DLE:
473 			pcu->have_dle = true;
474 			break;
475 
476 		case IMS_PCU_PROTOCOL_ETX:
477 			if (pcu->read_pos < IMS_PCU_MIN_PACKET_LEN) {
478 				dev_warn(pcu->dev,
479 					 "Short packet received (%d bytes), ignoring\n",
480 					 pcu->read_pos);
481 			} else if (pcu->check_sum != 0) {
482 				dev_warn(pcu->dev,
483 					 "Invalid checksum in packet (%d bytes), ignoring\n",
484 					 pcu->read_pos);
485 			} else {
486 				ims_pcu_handle_response(pcu);
487 			}
488 
489 			pcu->have_stx = false;
490 			pcu->have_dle = false;
491 			pcu->read_pos = 0;
492 			break;
493 
494 		default:
495 			pcu->read_buf[pcu->read_pos++] = data;
496 			pcu->check_sum += data;
497 			break;
498 		}
499 	}
500 }
501 
502 static bool ims_pcu_byte_needs_escape(u8 byte)
503 {
504 	return byte == IMS_PCU_PROTOCOL_STX ||
505 	       byte == IMS_PCU_PROTOCOL_ETX ||
506 	       byte == IMS_PCU_PROTOCOL_DLE;
507 }
508 
509 static int ims_pcu_send_cmd_chunk(struct ims_pcu *pcu,
510 				  u8 command, int chunk, int len)
511 {
512 	int error;
513 
514 	error = usb_bulk_msg(pcu->udev,
515 			     usb_sndbulkpipe(pcu->udev,
516 					     pcu->ep_out->bEndpointAddress),
517 			     pcu->urb_out_buf, len,
518 			     NULL, IMS_PCU_CMD_WRITE_TIMEOUT);
519 	if (error < 0) {
520 		dev_dbg(pcu->dev,
521 			"Sending 0x%02x command failed at chunk %d: %d\n",
522 			command, chunk, error);
523 		return error;
524 	}
525 
526 	return 0;
527 }
528 
529 static int ims_pcu_send_command(struct ims_pcu *pcu,
530 				u8 command, const u8 *data, int len)
531 {
532 	int count = 0;
533 	int chunk = 0;
534 	int delta;
535 	int i;
536 	int error;
537 	u8 csum = 0;
538 	u8 ack_id;
539 
540 	pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_STX;
541 
542 	/* We know the command need not be escaped */
543 	pcu->urb_out_buf[count++] = command;
544 	csum += command;
545 
546 	ack_id = pcu->ack_id++;
547 	if (ack_id == 0xff)
548 		ack_id = pcu->ack_id++;
549 
550 	if (ims_pcu_byte_needs_escape(ack_id))
551 		pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
552 
553 	pcu->urb_out_buf[count++] = ack_id;
554 	csum += ack_id;
555 
556 	for (i = 0; i < len; i++) {
557 
558 		delta = ims_pcu_byte_needs_escape(data[i]) ? 2 : 1;
559 		if (count + delta >= pcu->max_out_size) {
560 			error = ims_pcu_send_cmd_chunk(pcu, command,
561 						       ++chunk, count);
562 			if (error)
563 				return error;
564 
565 			count = 0;
566 		}
567 
568 		if (delta == 2)
569 			pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
570 
571 		pcu->urb_out_buf[count++] = data[i];
572 		csum += data[i];
573 	}
574 
575 	csum = 1 + ~csum;
576 
577 	delta = ims_pcu_byte_needs_escape(csum) ? 3 : 2;
578 	if (count + delta >= pcu->max_out_size) {
579 		error = ims_pcu_send_cmd_chunk(pcu, command, ++chunk, count);
580 		if (error)
581 			return error;
582 
583 		count = 0;
584 	}
585 
586 	if (delta == 3)
587 		pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
588 
589 	pcu->urb_out_buf[count++] = csum;
590 	pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_ETX;
591 
592 	return ims_pcu_send_cmd_chunk(pcu, command, ++chunk, count);
593 }
594 
595 static int __ims_pcu_execute_command(struct ims_pcu *pcu,
596 				     u8 command, const void *data, size_t len,
597 				     u8 expected_response, int response_time)
598 {
599 	int error;
600 
601 	pcu->expected_response = expected_response;
602 	init_completion(&pcu->cmd_done);
603 
604 	error = ims_pcu_send_command(pcu, command, data, len);
605 	if (error)
606 		return error;
607 
608 	if (expected_response &&
609 	    !wait_for_completion_timeout(&pcu->cmd_done,
610 					 msecs_to_jiffies(response_time))) {
611 		dev_dbg(pcu->dev, "Command 0x%02x timed out\n", command);
612 		return -ETIMEDOUT;
613 	}
614 
615 	return 0;
616 }
617 
618 #define ims_pcu_execute_command(pcu, code, data, len)			\
619 	__ims_pcu_execute_command(pcu,					\
620 				  IMS_PCU_CMD_##code, data, len,	\
621 				  IMS_PCU_RSP_##code,			\
622 				  IMS_PCU_CMD_RESPONSE_TIMEOUT)
623 
624 #define ims_pcu_execute_query(pcu, code)				\
625 	ims_pcu_execute_command(pcu, code, NULL, 0)
626 
627 /* Bootloader commands */
628 #define IMS_PCU_BL_CMD_QUERY_DEVICE	0xa1
629 #define IMS_PCU_BL_CMD_UNLOCK_CONFIG	0xa2
630 #define IMS_PCU_BL_CMD_ERASE_APP	0xa3
631 #define IMS_PCU_BL_CMD_PROGRAM_DEVICE	0xa4
632 #define IMS_PCU_BL_CMD_PROGRAM_COMPLETE	0xa5
633 #define IMS_PCU_BL_CMD_READ_APP		0xa6
634 #define IMS_PCU_BL_CMD_RESET_DEVICE	0xa7
635 #define IMS_PCU_BL_CMD_LAUNCH_APP	0xa8
636 
637 /* Bootloader commands */
638 #define IMS_PCU_BL_RSP_QUERY_DEVICE	0xc1
639 #define IMS_PCU_BL_RSP_UNLOCK_CONFIG	0xc2
640 #define IMS_PCU_BL_RSP_ERASE_APP	0xc3
641 #define IMS_PCU_BL_RSP_PROGRAM_DEVICE	0xc4
642 #define IMS_PCU_BL_RSP_PROGRAM_COMPLETE	0xc5
643 #define IMS_PCU_BL_RSP_READ_APP		0xc6
644 #define IMS_PCU_BL_RSP_RESET_DEVICE	0	/* originally 0xa7 */
645 #define IMS_PCU_BL_RSP_LAUNCH_APP	0	/* originally 0xa8 */
646 
647 #define IMS_PCU_BL_DATA_OFFSET		3
648 
649 static int __ims_pcu_execute_bl_command(struct ims_pcu *pcu,
650 				        u8 command, const void *data, size_t len,
651 				        u8 expected_response, int response_time)
652 {
653 	int error;
654 
655 	pcu->cmd_buf[0] = command;
656 	if (data)
657 		memcpy(&pcu->cmd_buf[1], data, len);
658 
659 	error = __ims_pcu_execute_command(pcu,
660 				IMS_PCU_CMD_BOOTLOADER, pcu->cmd_buf, len + 1,
661 				expected_response ? IMS_PCU_RSP_BOOTLOADER : 0,
662 				response_time);
663 	if (error) {
664 		dev_err(pcu->dev,
665 			"Failure when sending 0x%02x command to bootloader, error: %d\n",
666 			pcu->cmd_buf[0], error);
667 		return error;
668 	}
669 
670 	if (expected_response && pcu->cmd_buf[2] != expected_response) {
671 		dev_err(pcu->dev,
672 			"Unexpected response from bootloader: 0x%02x, wanted 0x%02x\n",
673 			pcu->cmd_buf[2], expected_response);
674 		return -EINVAL;
675 	}
676 
677 	return 0;
678 }
679 
680 #define ims_pcu_execute_bl_command(pcu, code, data, len, timeout)	\
681 	__ims_pcu_execute_bl_command(pcu,				\
682 				     IMS_PCU_BL_CMD_##code, data, len,	\
683 				     IMS_PCU_BL_RSP_##code, timeout)	\
684 
685 #define IMS_PCU_INFO_PART_OFFSET	2
686 #define IMS_PCU_INFO_DOM_OFFSET		17
687 #define IMS_PCU_INFO_SERIAL_OFFSET	25
688 
689 #define IMS_PCU_SET_INFO_SIZE		31
690 
691 static int ims_pcu_get_info(struct ims_pcu *pcu)
692 {
693 	int error;
694 
695 	error = ims_pcu_execute_query(pcu, GET_INFO);
696 	if (error) {
697 		dev_err(pcu->dev,
698 			"GET_INFO command failed, error: %d\n", error);
699 		return error;
700 	}
701 
702 	memcpy(pcu->part_number,
703 	       &pcu->cmd_buf[IMS_PCU_INFO_PART_OFFSET],
704 	       sizeof(pcu->part_number));
705 	memcpy(pcu->date_of_manufacturing,
706 	       &pcu->cmd_buf[IMS_PCU_INFO_DOM_OFFSET],
707 	       sizeof(pcu->date_of_manufacturing));
708 	memcpy(pcu->serial_number,
709 	       &pcu->cmd_buf[IMS_PCU_INFO_SERIAL_OFFSET],
710 	       sizeof(pcu->serial_number));
711 
712 	return 0;
713 }
714 
715 static int ims_pcu_set_info(struct ims_pcu *pcu)
716 {
717 	int error;
718 
719 	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_PART_OFFSET],
720 	       pcu->part_number, sizeof(pcu->part_number));
721 	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_DOM_OFFSET],
722 	       pcu->date_of_manufacturing, sizeof(pcu->date_of_manufacturing));
723 	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_SERIAL_OFFSET],
724 	       pcu->serial_number, sizeof(pcu->serial_number));
725 
726 	error = ims_pcu_execute_command(pcu, SET_INFO,
727 					&pcu->cmd_buf[IMS_PCU_DATA_OFFSET],
728 					IMS_PCU_SET_INFO_SIZE);
729 	if (error) {
730 		dev_err(pcu->dev,
731 			"Failed to update device information, error: %d\n",
732 			error);
733 		return error;
734 	}
735 
736 	return 0;
737 }
738 
739 static int ims_pcu_switch_to_bootloader(struct ims_pcu *pcu)
740 {
741 	int error;
742 
743 	/* Execute jump to the bootoloader */
744 	error = ims_pcu_execute_command(pcu, JUMP_TO_BTLDR, NULL, 0);
745 	if (error) {
746 		dev_err(pcu->dev,
747 			"Failure when sending JUMP TO BOOLTLOADER command, error: %d\n",
748 			error);
749 		return error;
750 	}
751 
752 	return 0;
753 }
754 
755 /*********************************************************************
756  *             Firmware Update handling                              *
757  *********************************************************************/
758 
759 #define IMS_PCU_FIRMWARE_NAME	"imspcu.fw"
760 
761 struct ims_pcu_flash_fmt {
762 	__le32 addr;
763 	u8 len;
764 	u8 data[];
765 };
766 
767 static unsigned int ims_pcu_count_fw_records(const struct firmware *fw)
768 {
769 	const struct ihex_binrec *rec = (const struct ihex_binrec *)fw->data;
770 	unsigned int count = 0;
771 
772 	while (rec) {
773 		count++;
774 		rec = ihex_next_binrec(rec);
775 	}
776 
777 	return count;
778 }
779 
780 static int ims_pcu_verify_block(struct ims_pcu *pcu,
781 				u32 addr, u8 len, const u8 *data)
782 {
783 	struct ims_pcu_flash_fmt *fragment;
784 	int error;
785 
786 	fragment = (void *)&pcu->cmd_buf[1];
787 	put_unaligned_le32(addr, &fragment->addr);
788 	fragment->len = len;
789 
790 	error = ims_pcu_execute_bl_command(pcu, READ_APP, NULL, 5,
791 					IMS_PCU_CMD_RESPONSE_TIMEOUT);
792 	if (error) {
793 		dev_err(pcu->dev,
794 			"Failed to retrieve block at 0x%08x, len %d, error: %d\n",
795 			addr, len, error);
796 		return error;
797 	}
798 
799 	fragment = (void *)&pcu->cmd_buf[IMS_PCU_BL_DATA_OFFSET];
800 	if (get_unaligned_le32(&fragment->addr) != addr ||
801 	    fragment->len != len) {
802 		dev_err(pcu->dev,
803 			"Wrong block when retrieving 0x%08x (0x%08x), len %d (%d)\n",
804 			addr, get_unaligned_le32(&fragment->addr),
805 			len, fragment->len);
806 		return -EINVAL;
807 	}
808 
809 	if (memcmp(fragment->data, data, len)) {
810 		dev_err(pcu->dev,
811 			"Mismatch in block at 0x%08x, len %d\n",
812 			addr, len);
813 		return -EINVAL;
814 	}
815 
816 	return 0;
817 }
818 
819 static int ims_pcu_flash_firmware(struct ims_pcu *pcu,
820 				  const struct firmware *fw,
821 				  unsigned int n_fw_records)
822 {
823 	const struct ihex_binrec *rec = (const struct ihex_binrec *)fw->data;
824 	struct ims_pcu_flash_fmt *fragment;
825 	unsigned int count = 0;
826 	u32 addr;
827 	u8 len;
828 	int error;
829 
830 	error = ims_pcu_execute_bl_command(pcu, ERASE_APP, NULL, 0, 2000);
831 	if (error) {
832 		dev_err(pcu->dev,
833 			"Failed to erase application image, error: %d\n",
834 			error);
835 		return error;
836 	}
837 
838 	while (rec) {
839 		/*
840 		 * The firmware format is messed up for some reason.
841 		 * The address twice that of what is needed for some
842 		 * reason and we end up overwriting half of the data
843 		 * with the next record.
844 		 */
845 		addr = be32_to_cpu(rec->addr) / 2;
846 		len = be16_to_cpu(rec->len);
847 
848 		fragment = (void *)&pcu->cmd_buf[1];
849 		put_unaligned_le32(addr, &fragment->addr);
850 		fragment->len = len;
851 		memcpy(fragment->data, rec->data, len);
852 
853 		error = ims_pcu_execute_bl_command(pcu, PROGRAM_DEVICE,
854 						NULL, len + 5,
855 						IMS_PCU_CMD_RESPONSE_TIMEOUT);
856 		if (error) {
857 			dev_err(pcu->dev,
858 				"Failed to write block at 0x%08x, len %d, error: %d\n",
859 				addr, len, error);
860 			return error;
861 		}
862 
863 		if (addr >= pcu->fw_start_addr && addr < pcu->fw_end_addr) {
864 			error = ims_pcu_verify_block(pcu, addr, len, rec->data);
865 			if (error)
866 				return error;
867 		}
868 
869 		count++;
870 		pcu->update_firmware_status = (count * 100) / n_fw_records;
871 
872 		rec = ihex_next_binrec(rec);
873 	}
874 
875 	error = ims_pcu_execute_bl_command(pcu, PROGRAM_COMPLETE,
876 					    NULL, 0, 2000);
877 	if (error)
878 		dev_err(pcu->dev,
879 			"Failed to send PROGRAM_COMPLETE, error: %d\n",
880 			error);
881 
882 	return 0;
883 }
884 
885 static int ims_pcu_handle_firmware_update(struct ims_pcu *pcu,
886 					  const struct firmware *fw)
887 {
888 	unsigned int n_fw_records;
889 	int retval;
890 
891 	dev_info(pcu->dev, "Updating firmware %s, size: %zu\n",
892 		 IMS_PCU_FIRMWARE_NAME, fw->size);
893 
894 	n_fw_records = ims_pcu_count_fw_records(fw);
895 
896 	retval = ims_pcu_flash_firmware(pcu, fw, n_fw_records);
897 	if (retval)
898 		goto out;
899 
900 	retval = ims_pcu_execute_bl_command(pcu, LAUNCH_APP, NULL, 0, 0);
901 	if (retval)
902 		dev_err(pcu->dev,
903 			"Failed to start application image, error: %d\n",
904 			retval);
905 
906 out:
907 	pcu->update_firmware_status = retval;
908 	sysfs_notify(&pcu->dev->kobj, NULL, "update_firmware_status");
909 	return retval;
910 }
911 
912 static void ims_pcu_process_async_firmware(const struct firmware *fw,
913 					   void *context)
914 {
915 	struct ims_pcu *pcu = context;
916 	int error;
917 
918 	if (!fw) {
919 		dev_err(pcu->dev, "Failed to get firmware %s\n",
920 			IMS_PCU_FIRMWARE_NAME);
921 		goto out;
922 	}
923 
924 	error = ihex_validate_fw(fw);
925 	if (error) {
926 		dev_err(pcu->dev, "Firmware %s is invalid\n",
927 			IMS_PCU_FIRMWARE_NAME);
928 		goto out;
929 	}
930 
931 	mutex_lock(&pcu->cmd_mutex);
932 	ims_pcu_handle_firmware_update(pcu, fw);
933 	mutex_unlock(&pcu->cmd_mutex);
934 
935 	release_firmware(fw);
936 
937 out:
938 	complete(&pcu->async_firmware_done);
939 }
940 
941 /*********************************************************************
942  *             Backlight LED device support                          *
943  *********************************************************************/
944 
945 #define IMS_PCU_MAX_BRIGHTNESS		31998
946 
947 static int ims_pcu_backlight_set_brightness(struct led_classdev *cdev,
948 					    enum led_brightness value)
949 {
950 	struct ims_pcu_backlight *backlight =
951 			container_of(cdev, struct ims_pcu_backlight, cdev);
952 	struct ims_pcu *pcu =
953 			container_of(backlight, struct ims_pcu, backlight);
954 	__le16 br_val = cpu_to_le16(value);
955 	int error;
956 
957 	mutex_lock(&pcu->cmd_mutex);
958 
959 	error = ims_pcu_execute_command(pcu, SET_BRIGHTNESS,
960 					&br_val, sizeof(br_val));
961 	if (error && error != -ENODEV)
962 		dev_warn(pcu->dev,
963 			 "Failed to set desired brightness %u, error: %d\n",
964 			 value, error);
965 
966 	mutex_unlock(&pcu->cmd_mutex);
967 
968 	return error;
969 }
970 
971 static enum led_brightness
972 ims_pcu_backlight_get_brightness(struct led_classdev *cdev)
973 {
974 	struct ims_pcu_backlight *backlight =
975 			container_of(cdev, struct ims_pcu_backlight, cdev);
976 	struct ims_pcu *pcu =
977 			container_of(backlight, struct ims_pcu, backlight);
978 	int brightness;
979 	int error;
980 
981 	mutex_lock(&pcu->cmd_mutex);
982 
983 	error = ims_pcu_execute_query(pcu, GET_BRIGHTNESS);
984 	if (error) {
985 		dev_warn(pcu->dev,
986 			 "Failed to get current brightness, error: %d\n",
987 			 error);
988 		/* Assume the LED is OFF */
989 		brightness = LED_OFF;
990 	} else {
991 		brightness =
992 			get_unaligned_le16(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET]);
993 	}
994 
995 	mutex_unlock(&pcu->cmd_mutex);
996 
997 	return brightness;
998 }
999 
1000 static int ims_pcu_setup_backlight(struct ims_pcu *pcu)
1001 {
1002 	struct ims_pcu_backlight *backlight = &pcu->backlight;
1003 	int error;
1004 
1005 	snprintf(backlight->name, sizeof(backlight->name),
1006 		 "pcu%d::kbd_backlight", pcu->device_no);
1007 
1008 	backlight->cdev.name = backlight->name;
1009 	backlight->cdev.max_brightness = IMS_PCU_MAX_BRIGHTNESS;
1010 	backlight->cdev.brightness_get = ims_pcu_backlight_get_brightness;
1011 	backlight->cdev.brightness_set_blocking =
1012 					 ims_pcu_backlight_set_brightness;
1013 
1014 	error = led_classdev_register(pcu->dev, &backlight->cdev);
1015 	if (error) {
1016 		dev_err(pcu->dev,
1017 			"Failed to register backlight LED device, error: %d\n",
1018 			error);
1019 		return error;
1020 	}
1021 
1022 	return 0;
1023 }
1024 
1025 static void ims_pcu_destroy_backlight(struct ims_pcu *pcu)
1026 {
1027 	struct ims_pcu_backlight *backlight = &pcu->backlight;
1028 
1029 	led_classdev_unregister(&backlight->cdev);
1030 }
1031 
1032 
1033 /*********************************************************************
1034  *             Sysfs attributes handling                             *
1035  *********************************************************************/
1036 
1037 struct ims_pcu_attribute {
1038 	struct device_attribute dattr;
1039 	size_t field_offset;
1040 	int field_length;
1041 };
1042 
1043 static ssize_t ims_pcu_attribute_show(struct device *dev,
1044 				      struct device_attribute *dattr,
1045 				      char *buf)
1046 {
1047 	struct usb_interface *intf = to_usb_interface(dev);
1048 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1049 	struct ims_pcu_attribute *attr =
1050 			container_of(dattr, struct ims_pcu_attribute, dattr);
1051 	char *field = (char *)pcu + attr->field_offset;
1052 
1053 	return scnprintf(buf, PAGE_SIZE, "%.*s\n", attr->field_length, field);
1054 }
1055 
1056 static ssize_t ims_pcu_attribute_store(struct device *dev,
1057 				       struct device_attribute *dattr,
1058 				       const char *buf, size_t count)
1059 {
1060 
1061 	struct usb_interface *intf = to_usb_interface(dev);
1062 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1063 	struct ims_pcu_attribute *attr =
1064 			container_of(dattr, struct ims_pcu_attribute, dattr);
1065 	char *field = (char *)pcu + attr->field_offset;
1066 	size_t data_len;
1067 	int error;
1068 
1069 	if (count > attr->field_length)
1070 		return -EINVAL;
1071 
1072 	data_len = strnlen(buf, attr->field_length);
1073 	if (data_len > attr->field_length)
1074 		return -EINVAL;
1075 
1076 	error = mutex_lock_interruptible(&pcu->cmd_mutex);
1077 	if (error)
1078 		return error;
1079 
1080 	memset(field, 0, attr->field_length);
1081 	memcpy(field, buf, data_len);
1082 
1083 	error = ims_pcu_set_info(pcu);
1084 
1085 	/*
1086 	 * Even if update failed, let's fetch the info again as we just
1087 	 * clobbered one of the fields.
1088 	 */
1089 	ims_pcu_get_info(pcu);
1090 
1091 	mutex_unlock(&pcu->cmd_mutex);
1092 
1093 	return error < 0 ? error : count;
1094 }
1095 
1096 #define IMS_PCU_ATTR(_field, _mode)					\
1097 struct ims_pcu_attribute ims_pcu_attr_##_field = {			\
1098 	.dattr = __ATTR(_field, _mode,					\
1099 			ims_pcu_attribute_show,				\
1100 			ims_pcu_attribute_store),			\
1101 	.field_offset = offsetof(struct ims_pcu, _field),		\
1102 	.field_length = sizeof(((struct ims_pcu *)NULL)->_field),	\
1103 }
1104 
1105 #define IMS_PCU_RO_ATTR(_field)						\
1106 		IMS_PCU_ATTR(_field, S_IRUGO)
1107 #define IMS_PCU_RW_ATTR(_field)						\
1108 		IMS_PCU_ATTR(_field, S_IRUGO | S_IWUSR)
1109 
1110 static IMS_PCU_RW_ATTR(part_number);
1111 static IMS_PCU_RW_ATTR(serial_number);
1112 static IMS_PCU_RW_ATTR(date_of_manufacturing);
1113 
1114 static IMS_PCU_RO_ATTR(fw_version);
1115 static IMS_PCU_RO_ATTR(bl_version);
1116 static IMS_PCU_RO_ATTR(reset_reason);
1117 
1118 static ssize_t ims_pcu_reset_device(struct device *dev,
1119 				    struct device_attribute *dattr,
1120 				    const char *buf, size_t count)
1121 {
1122 	static const u8 reset_byte = 1;
1123 	struct usb_interface *intf = to_usb_interface(dev);
1124 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1125 	int value;
1126 	int error;
1127 
1128 	error = kstrtoint(buf, 0, &value);
1129 	if (error)
1130 		return error;
1131 
1132 	if (value != 1)
1133 		return -EINVAL;
1134 
1135 	dev_info(pcu->dev, "Attempting to reset device\n");
1136 
1137 	error = ims_pcu_execute_command(pcu, PCU_RESET, &reset_byte, 1);
1138 	if (error) {
1139 		dev_info(pcu->dev,
1140 			 "Failed to reset device, error: %d\n",
1141 			 error);
1142 		return error;
1143 	}
1144 
1145 	return count;
1146 }
1147 
1148 static DEVICE_ATTR(reset_device, S_IWUSR, NULL, ims_pcu_reset_device);
1149 
1150 static ssize_t ims_pcu_update_firmware_store(struct device *dev,
1151 					     struct device_attribute *dattr,
1152 					     const char *buf, size_t count)
1153 {
1154 	struct usb_interface *intf = to_usb_interface(dev);
1155 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1156 	const struct firmware *fw = NULL;
1157 	int value;
1158 	int error;
1159 
1160 	error = kstrtoint(buf, 0, &value);
1161 	if (error)
1162 		return error;
1163 
1164 	if (value != 1)
1165 		return -EINVAL;
1166 
1167 	error = mutex_lock_interruptible(&pcu->cmd_mutex);
1168 	if (error)
1169 		return error;
1170 
1171 	error = request_ihex_firmware(&fw, IMS_PCU_FIRMWARE_NAME, pcu->dev);
1172 	if (error) {
1173 		dev_err(pcu->dev, "Failed to request firmware %s, error: %d\n",
1174 			IMS_PCU_FIRMWARE_NAME, error);
1175 		goto out;
1176 	}
1177 
1178 	/*
1179 	 * If we are already in bootloader mode we can proceed with
1180 	 * flashing the firmware.
1181 	 *
1182 	 * If we are in application mode, then we need to switch into
1183 	 * bootloader mode, which will cause the device to disconnect
1184 	 * and reconnect as different device.
1185 	 */
1186 	if (pcu->bootloader_mode)
1187 		error = ims_pcu_handle_firmware_update(pcu, fw);
1188 	else
1189 		error = ims_pcu_switch_to_bootloader(pcu);
1190 
1191 	release_firmware(fw);
1192 
1193 out:
1194 	mutex_unlock(&pcu->cmd_mutex);
1195 	return error ?: count;
1196 }
1197 
1198 static DEVICE_ATTR(update_firmware, S_IWUSR,
1199 		   NULL, ims_pcu_update_firmware_store);
1200 
1201 static ssize_t
1202 ims_pcu_update_firmware_status_show(struct device *dev,
1203 				    struct device_attribute *dattr,
1204 				    char *buf)
1205 {
1206 	struct usb_interface *intf = to_usb_interface(dev);
1207 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1208 
1209 	return scnprintf(buf, PAGE_SIZE, "%d\n", pcu->update_firmware_status);
1210 }
1211 
1212 static DEVICE_ATTR(update_firmware_status, S_IRUGO,
1213 		   ims_pcu_update_firmware_status_show, NULL);
1214 
1215 static struct attribute *ims_pcu_attrs[] = {
1216 	&ims_pcu_attr_part_number.dattr.attr,
1217 	&ims_pcu_attr_serial_number.dattr.attr,
1218 	&ims_pcu_attr_date_of_manufacturing.dattr.attr,
1219 	&ims_pcu_attr_fw_version.dattr.attr,
1220 	&ims_pcu_attr_bl_version.dattr.attr,
1221 	&ims_pcu_attr_reset_reason.dattr.attr,
1222 	&dev_attr_reset_device.attr,
1223 	&dev_attr_update_firmware.attr,
1224 	&dev_attr_update_firmware_status.attr,
1225 	NULL
1226 };
1227 
1228 static umode_t ims_pcu_is_attr_visible(struct kobject *kobj,
1229 				       struct attribute *attr, int n)
1230 {
1231 	struct device *dev = container_of(kobj, struct device, kobj);
1232 	struct usb_interface *intf = to_usb_interface(dev);
1233 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1234 	umode_t mode = attr->mode;
1235 
1236 	if (pcu->bootloader_mode) {
1237 		if (attr != &dev_attr_update_firmware_status.attr &&
1238 		    attr != &dev_attr_update_firmware.attr &&
1239 		    attr != &dev_attr_reset_device.attr) {
1240 			mode = 0;
1241 		}
1242 	} else {
1243 		if (attr == &dev_attr_update_firmware_status.attr)
1244 			mode = 0;
1245 	}
1246 
1247 	return mode;
1248 }
1249 
1250 static const struct attribute_group ims_pcu_attr_group = {
1251 	.is_visible	= ims_pcu_is_attr_visible,
1252 	.attrs		= ims_pcu_attrs,
1253 };
1254 
1255 /* Support for a separate OFN attribute group */
1256 
1257 #define OFN_REG_RESULT_OFFSET	2
1258 
1259 static int ims_pcu_read_ofn_config(struct ims_pcu *pcu, u8 addr, u8 *data)
1260 {
1261 	int error;
1262 	s16 result;
1263 
1264 	error = ims_pcu_execute_command(pcu, OFN_GET_CONFIG,
1265 					&addr, sizeof(addr));
1266 	if (error)
1267 		return error;
1268 
1269 	result = (s16)get_unaligned_le16(pcu->cmd_buf + OFN_REG_RESULT_OFFSET);
1270 	if (result < 0)
1271 		return -EIO;
1272 
1273 	/* We only need LSB */
1274 	*data = pcu->cmd_buf[OFN_REG_RESULT_OFFSET];
1275 	return 0;
1276 }
1277 
1278 static int ims_pcu_write_ofn_config(struct ims_pcu *pcu, u8 addr, u8 data)
1279 {
1280 	u8 buffer[] = { addr, data };
1281 	int error;
1282 	s16 result;
1283 
1284 	error = ims_pcu_execute_command(pcu, OFN_SET_CONFIG,
1285 					&buffer, sizeof(buffer));
1286 	if (error)
1287 		return error;
1288 
1289 	result = (s16)get_unaligned_le16(pcu->cmd_buf + OFN_REG_RESULT_OFFSET);
1290 	if (result < 0)
1291 		return -EIO;
1292 
1293 	return 0;
1294 }
1295 
1296 static ssize_t ims_pcu_ofn_reg_data_show(struct device *dev,
1297 					 struct device_attribute *dattr,
1298 					 char *buf)
1299 {
1300 	struct usb_interface *intf = to_usb_interface(dev);
1301 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1302 	int error;
1303 	u8 data;
1304 
1305 	mutex_lock(&pcu->cmd_mutex);
1306 	error = ims_pcu_read_ofn_config(pcu, pcu->ofn_reg_addr, &data);
1307 	mutex_unlock(&pcu->cmd_mutex);
1308 
1309 	if (error)
1310 		return error;
1311 
1312 	return scnprintf(buf, PAGE_SIZE, "%x\n", data);
1313 }
1314 
1315 static ssize_t ims_pcu_ofn_reg_data_store(struct device *dev,
1316 					  struct device_attribute *dattr,
1317 					  const char *buf, size_t count)
1318 {
1319 	struct usb_interface *intf = to_usb_interface(dev);
1320 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1321 	int error;
1322 	u8 value;
1323 
1324 	error = kstrtou8(buf, 0, &value);
1325 	if (error)
1326 		return error;
1327 
1328 	mutex_lock(&pcu->cmd_mutex);
1329 	error = ims_pcu_write_ofn_config(pcu, pcu->ofn_reg_addr, value);
1330 	mutex_unlock(&pcu->cmd_mutex);
1331 
1332 	return error ?: count;
1333 }
1334 
1335 static DEVICE_ATTR(reg_data, S_IRUGO | S_IWUSR,
1336 		   ims_pcu_ofn_reg_data_show, ims_pcu_ofn_reg_data_store);
1337 
1338 static ssize_t ims_pcu_ofn_reg_addr_show(struct device *dev,
1339 					 struct device_attribute *dattr,
1340 					 char *buf)
1341 {
1342 	struct usb_interface *intf = to_usb_interface(dev);
1343 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1344 	int error;
1345 
1346 	mutex_lock(&pcu->cmd_mutex);
1347 	error = scnprintf(buf, PAGE_SIZE, "%x\n", pcu->ofn_reg_addr);
1348 	mutex_unlock(&pcu->cmd_mutex);
1349 
1350 	return error;
1351 }
1352 
1353 static ssize_t ims_pcu_ofn_reg_addr_store(struct device *dev,
1354 					  struct device_attribute *dattr,
1355 					  const char *buf, size_t count)
1356 {
1357 	struct usb_interface *intf = to_usb_interface(dev);
1358 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1359 	int error;
1360 	u8 value;
1361 
1362 	error = kstrtou8(buf, 0, &value);
1363 	if (error)
1364 		return error;
1365 
1366 	mutex_lock(&pcu->cmd_mutex);
1367 	pcu->ofn_reg_addr = value;
1368 	mutex_unlock(&pcu->cmd_mutex);
1369 
1370 	return count;
1371 }
1372 
1373 static DEVICE_ATTR(reg_addr, S_IRUGO | S_IWUSR,
1374 		   ims_pcu_ofn_reg_addr_show, ims_pcu_ofn_reg_addr_store);
1375 
1376 struct ims_pcu_ofn_bit_attribute {
1377 	struct device_attribute dattr;
1378 	u8 addr;
1379 	u8 nr;
1380 };
1381 
1382 static ssize_t ims_pcu_ofn_bit_show(struct device *dev,
1383 				    struct device_attribute *dattr,
1384 				    char *buf)
1385 {
1386 	struct usb_interface *intf = to_usb_interface(dev);
1387 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1388 	struct ims_pcu_ofn_bit_attribute *attr =
1389 		container_of(dattr, struct ims_pcu_ofn_bit_attribute, dattr);
1390 	int error;
1391 	u8 data;
1392 
1393 	mutex_lock(&pcu->cmd_mutex);
1394 	error = ims_pcu_read_ofn_config(pcu, attr->addr, &data);
1395 	mutex_unlock(&pcu->cmd_mutex);
1396 
1397 	if (error)
1398 		return error;
1399 
1400 	return scnprintf(buf, PAGE_SIZE, "%d\n", !!(data & (1 << attr->nr)));
1401 }
1402 
1403 static ssize_t ims_pcu_ofn_bit_store(struct device *dev,
1404 				     struct device_attribute *dattr,
1405 				     const char *buf, size_t count)
1406 {
1407 	struct usb_interface *intf = to_usb_interface(dev);
1408 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1409 	struct ims_pcu_ofn_bit_attribute *attr =
1410 		container_of(dattr, struct ims_pcu_ofn_bit_attribute, dattr);
1411 	int error;
1412 	int value;
1413 	u8 data;
1414 
1415 	error = kstrtoint(buf, 0, &value);
1416 	if (error)
1417 		return error;
1418 
1419 	if (value > 1)
1420 		return -EINVAL;
1421 
1422 	mutex_lock(&pcu->cmd_mutex);
1423 
1424 	error = ims_pcu_read_ofn_config(pcu, attr->addr, &data);
1425 	if (!error) {
1426 		if (value)
1427 			data |= 1U << attr->nr;
1428 		else
1429 			data &= ~(1U << attr->nr);
1430 
1431 		error = ims_pcu_write_ofn_config(pcu, attr->addr, data);
1432 	}
1433 
1434 	mutex_unlock(&pcu->cmd_mutex);
1435 
1436 	return error ?: count;
1437 }
1438 
1439 #define IMS_PCU_OFN_BIT_ATTR(_field, _addr, _nr)			\
1440 struct ims_pcu_ofn_bit_attribute ims_pcu_ofn_attr_##_field = {		\
1441 	.dattr = __ATTR(_field, S_IWUSR | S_IRUGO,			\
1442 			ims_pcu_ofn_bit_show, ims_pcu_ofn_bit_store),	\
1443 	.addr = _addr,							\
1444 	.nr = _nr,							\
1445 }
1446 
1447 static IMS_PCU_OFN_BIT_ATTR(engine_enable,   0x60, 7);
1448 static IMS_PCU_OFN_BIT_ATTR(speed_enable,    0x60, 6);
1449 static IMS_PCU_OFN_BIT_ATTR(assert_enable,   0x60, 5);
1450 static IMS_PCU_OFN_BIT_ATTR(xyquant_enable,  0x60, 4);
1451 static IMS_PCU_OFN_BIT_ATTR(xyscale_enable,  0x60, 1);
1452 
1453 static IMS_PCU_OFN_BIT_ATTR(scale_x2,        0x63, 6);
1454 static IMS_PCU_OFN_BIT_ATTR(scale_y2,        0x63, 7);
1455 
1456 static struct attribute *ims_pcu_ofn_attrs[] = {
1457 	&dev_attr_reg_data.attr,
1458 	&dev_attr_reg_addr.attr,
1459 	&ims_pcu_ofn_attr_engine_enable.dattr.attr,
1460 	&ims_pcu_ofn_attr_speed_enable.dattr.attr,
1461 	&ims_pcu_ofn_attr_assert_enable.dattr.attr,
1462 	&ims_pcu_ofn_attr_xyquant_enable.dattr.attr,
1463 	&ims_pcu_ofn_attr_xyscale_enable.dattr.attr,
1464 	&ims_pcu_ofn_attr_scale_x2.dattr.attr,
1465 	&ims_pcu_ofn_attr_scale_y2.dattr.attr,
1466 	NULL
1467 };
1468 
1469 static const struct attribute_group ims_pcu_ofn_attr_group = {
1470 	.name	= "ofn",
1471 	.attrs	= ims_pcu_ofn_attrs,
1472 };
1473 
1474 static void ims_pcu_irq(struct urb *urb)
1475 {
1476 	struct ims_pcu *pcu = urb->context;
1477 	int retval, status;
1478 
1479 	status = urb->status;
1480 
1481 	switch (status) {
1482 	case 0:
1483 		/* success */
1484 		break;
1485 	case -ECONNRESET:
1486 	case -ENOENT:
1487 	case -ESHUTDOWN:
1488 		/* this urb is terminated, clean up */
1489 		dev_dbg(pcu->dev, "%s - urb shutting down with status: %d\n",
1490 			__func__, status);
1491 		return;
1492 	default:
1493 		dev_dbg(pcu->dev, "%s - nonzero urb status received: %d\n",
1494 			__func__, status);
1495 		goto exit;
1496 	}
1497 
1498 	dev_dbg(pcu->dev, "%s: received %d: %*ph\n", __func__,
1499 		urb->actual_length, urb->actual_length, pcu->urb_in_buf);
1500 
1501 	if (urb == pcu->urb_in)
1502 		ims_pcu_process_data(pcu, urb);
1503 
1504 exit:
1505 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1506 	if (retval && retval != -ENODEV)
1507 		dev_err(pcu->dev, "%s - usb_submit_urb failed with result %d\n",
1508 			__func__, retval);
1509 }
1510 
1511 static int ims_pcu_buffers_alloc(struct ims_pcu *pcu)
1512 {
1513 	int error;
1514 
1515 	pcu->urb_in_buf = usb_alloc_coherent(pcu->udev, pcu->max_in_size,
1516 					     GFP_KERNEL, &pcu->read_dma);
1517 	if (!pcu->urb_in_buf) {
1518 		dev_err(pcu->dev,
1519 			"Failed to allocate memory for read buffer\n");
1520 		return -ENOMEM;
1521 	}
1522 
1523 	pcu->urb_in = usb_alloc_urb(0, GFP_KERNEL);
1524 	if (!pcu->urb_in) {
1525 		dev_err(pcu->dev, "Failed to allocate input URB\n");
1526 		error = -ENOMEM;
1527 		goto err_free_urb_in_buf;
1528 	}
1529 
1530 	pcu->urb_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1531 	pcu->urb_in->transfer_dma = pcu->read_dma;
1532 
1533 	usb_fill_bulk_urb(pcu->urb_in, pcu->udev,
1534 			  usb_rcvbulkpipe(pcu->udev,
1535 					  pcu->ep_in->bEndpointAddress),
1536 			  pcu->urb_in_buf, pcu->max_in_size,
1537 			  ims_pcu_irq, pcu);
1538 
1539 	/*
1540 	 * We are using usb_bulk_msg() for sending so there is no point
1541 	 * in allocating memory with usb_alloc_coherent().
1542 	 */
1543 	pcu->urb_out_buf = kmalloc(pcu->max_out_size, GFP_KERNEL);
1544 	if (!pcu->urb_out_buf) {
1545 		dev_err(pcu->dev, "Failed to allocate memory for write buffer\n");
1546 		error = -ENOMEM;
1547 		goto err_free_in_urb;
1548 	}
1549 
1550 	pcu->urb_ctrl_buf = usb_alloc_coherent(pcu->udev, pcu->max_ctrl_size,
1551 					       GFP_KERNEL, &pcu->ctrl_dma);
1552 	if (!pcu->urb_ctrl_buf) {
1553 		dev_err(pcu->dev,
1554 			"Failed to allocate memory for read buffer\n");
1555 		error = -ENOMEM;
1556 		goto err_free_urb_out_buf;
1557 	}
1558 
1559 	pcu->urb_ctrl = usb_alloc_urb(0, GFP_KERNEL);
1560 	if (!pcu->urb_ctrl) {
1561 		dev_err(pcu->dev, "Failed to allocate input URB\n");
1562 		error = -ENOMEM;
1563 		goto err_free_urb_ctrl_buf;
1564 	}
1565 
1566 	pcu->urb_ctrl->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1567 	pcu->urb_ctrl->transfer_dma = pcu->ctrl_dma;
1568 
1569 	usb_fill_int_urb(pcu->urb_ctrl, pcu->udev,
1570 			  usb_rcvintpipe(pcu->udev,
1571 					 pcu->ep_ctrl->bEndpointAddress),
1572 			  pcu->urb_ctrl_buf, pcu->max_ctrl_size,
1573 			  ims_pcu_irq, pcu, pcu->ep_ctrl->bInterval);
1574 
1575 	return 0;
1576 
1577 err_free_urb_ctrl_buf:
1578 	usb_free_coherent(pcu->udev, pcu->max_ctrl_size,
1579 			  pcu->urb_ctrl_buf, pcu->ctrl_dma);
1580 err_free_urb_out_buf:
1581 	kfree(pcu->urb_out_buf);
1582 err_free_in_urb:
1583 	usb_free_urb(pcu->urb_in);
1584 err_free_urb_in_buf:
1585 	usb_free_coherent(pcu->udev, pcu->max_in_size,
1586 			  pcu->urb_in_buf, pcu->read_dma);
1587 	return error;
1588 }
1589 
1590 static void ims_pcu_buffers_free(struct ims_pcu *pcu)
1591 {
1592 	usb_kill_urb(pcu->urb_in);
1593 	usb_free_urb(pcu->urb_in);
1594 
1595 	usb_free_coherent(pcu->udev, pcu->max_out_size,
1596 			  pcu->urb_in_buf, pcu->read_dma);
1597 
1598 	kfree(pcu->urb_out_buf);
1599 
1600 	usb_kill_urb(pcu->urb_ctrl);
1601 	usb_free_urb(pcu->urb_ctrl);
1602 
1603 	usb_free_coherent(pcu->udev, pcu->max_ctrl_size,
1604 			  pcu->urb_ctrl_buf, pcu->ctrl_dma);
1605 }
1606 
1607 static const struct usb_cdc_union_desc *
1608 ims_pcu_get_cdc_union_desc(struct usb_interface *intf)
1609 {
1610 	const void *buf = intf->altsetting->extra;
1611 	size_t buflen = intf->altsetting->extralen;
1612 	struct usb_cdc_union_desc *union_desc;
1613 
1614 	if (!buf) {
1615 		dev_err(&intf->dev, "Missing descriptor data\n");
1616 		return NULL;
1617 	}
1618 
1619 	if (!buflen) {
1620 		dev_err(&intf->dev, "Zero length descriptor\n");
1621 		return NULL;
1622 	}
1623 
1624 	while (buflen >= sizeof(*union_desc)) {
1625 		union_desc = (struct usb_cdc_union_desc *)buf;
1626 
1627 		if (union_desc->bLength > buflen) {
1628 			dev_err(&intf->dev, "Too large descriptor\n");
1629 			return NULL;
1630 		}
1631 
1632 		if (union_desc->bDescriptorType == USB_DT_CS_INTERFACE &&
1633 		    union_desc->bDescriptorSubType == USB_CDC_UNION_TYPE) {
1634 			dev_dbg(&intf->dev, "Found union header\n");
1635 
1636 			if (union_desc->bLength >= sizeof(*union_desc))
1637 				return union_desc;
1638 
1639 			dev_err(&intf->dev,
1640 				"Union descriptor too short (%d vs %zd)\n",
1641 				union_desc->bLength, sizeof(*union_desc));
1642 			return NULL;
1643 		}
1644 
1645 		buflen -= union_desc->bLength;
1646 		buf += union_desc->bLength;
1647 	}
1648 
1649 	dev_err(&intf->dev, "Missing CDC union descriptor\n");
1650 	return NULL;
1651 }
1652 
1653 static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pcu)
1654 {
1655 	const struct usb_cdc_union_desc *union_desc;
1656 	struct usb_host_interface *alt;
1657 
1658 	union_desc = ims_pcu_get_cdc_union_desc(intf);
1659 	if (!union_desc)
1660 		return -EINVAL;
1661 
1662 	pcu->ctrl_intf = usb_ifnum_to_if(pcu->udev,
1663 					 union_desc->bMasterInterface0);
1664 	if (!pcu->ctrl_intf)
1665 		return -EINVAL;
1666 
1667 	alt = pcu->ctrl_intf->cur_altsetting;
1668 
1669 	if (alt->desc.bNumEndpoints < 1)
1670 		return -ENODEV;
1671 
1672 	pcu->ep_ctrl = &alt->endpoint[0].desc;
1673 	pcu->max_ctrl_size = usb_endpoint_maxp(pcu->ep_ctrl);
1674 
1675 	pcu->data_intf = usb_ifnum_to_if(pcu->udev,
1676 					 union_desc->bSlaveInterface0);
1677 	if (!pcu->data_intf)
1678 		return -EINVAL;
1679 
1680 	alt = pcu->data_intf->cur_altsetting;
1681 	if (alt->desc.bNumEndpoints != 2) {
1682 		dev_err(pcu->dev,
1683 			"Incorrect number of endpoints on data interface (%d)\n",
1684 			alt->desc.bNumEndpoints);
1685 		return -EINVAL;
1686 	}
1687 
1688 	pcu->ep_out = &alt->endpoint[0].desc;
1689 	if (!usb_endpoint_is_bulk_out(pcu->ep_out)) {
1690 		dev_err(pcu->dev,
1691 			"First endpoint on data interface is not BULK OUT\n");
1692 		return -EINVAL;
1693 	}
1694 
1695 	pcu->max_out_size = usb_endpoint_maxp(pcu->ep_out);
1696 	if (pcu->max_out_size < 8) {
1697 		dev_err(pcu->dev,
1698 			"Max OUT packet size is too small (%zd)\n",
1699 			pcu->max_out_size);
1700 		return -EINVAL;
1701 	}
1702 
1703 	pcu->ep_in = &alt->endpoint[1].desc;
1704 	if (!usb_endpoint_is_bulk_in(pcu->ep_in)) {
1705 		dev_err(pcu->dev,
1706 			"Second endpoint on data interface is not BULK IN\n");
1707 		return -EINVAL;
1708 	}
1709 
1710 	pcu->max_in_size = usb_endpoint_maxp(pcu->ep_in);
1711 	if (pcu->max_in_size < 8) {
1712 		dev_err(pcu->dev,
1713 			"Max IN packet size is too small (%zd)\n",
1714 			pcu->max_in_size);
1715 		return -EINVAL;
1716 	}
1717 
1718 	return 0;
1719 }
1720 
1721 static int ims_pcu_start_io(struct ims_pcu *pcu)
1722 {
1723 	int error;
1724 
1725 	error = usb_submit_urb(pcu->urb_ctrl, GFP_KERNEL);
1726 	if (error) {
1727 		dev_err(pcu->dev,
1728 			"Failed to start control IO - usb_submit_urb failed with result: %d\n",
1729 			error);
1730 		return -EIO;
1731 	}
1732 
1733 	error = usb_submit_urb(pcu->urb_in, GFP_KERNEL);
1734 	if (error) {
1735 		dev_err(pcu->dev,
1736 			"Failed to start IO - usb_submit_urb failed with result: %d\n",
1737 			error);
1738 		usb_kill_urb(pcu->urb_ctrl);
1739 		return -EIO;
1740 	}
1741 
1742 	return 0;
1743 }
1744 
1745 static void ims_pcu_stop_io(struct ims_pcu *pcu)
1746 {
1747 	usb_kill_urb(pcu->urb_in);
1748 	usb_kill_urb(pcu->urb_ctrl);
1749 }
1750 
1751 static int ims_pcu_line_setup(struct ims_pcu *pcu)
1752 {
1753 	struct usb_host_interface *interface = pcu->ctrl_intf->cur_altsetting;
1754 	struct usb_cdc_line_coding *line = (void *)pcu->cmd_buf;
1755 	int error;
1756 
1757 	memset(line, 0, sizeof(*line));
1758 	line->dwDTERate = cpu_to_le32(57600);
1759 	line->bDataBits = 8;
1760 
1761 	error = usb_control_msg(pcu->udev, usb_sndctrlpipe(pcu->udev, 0),
1762 				USB_CDC_REQ_SET_LINE_CODING,
1763 				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1764 				0, interface->desc.bInterfaceNumber,
1765 				line, sizeof(struct usb_cdc_line_coding),
1766 				5000);
1767 	if (error < 0) {
1768 		dev_err(pcu->dev, "Failed to set line coding, error: %d\n",
1769 			error);
1770 		return error;
1771 	}
1772 
1773 	error = usb_control_msg(pcu->udev, usb_sndctrlpipe(pcu->udev, 0),
1774 				USB_CDC_REQ_SET_CONTROL_LINE_STATE,
1775 				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1776 				0x03, interface->desc.bInterfaceNumber,
1777 				NULL, 0, 5000);
1778 	if (error < 0) {
1779 		dev_err(pcu->dev, "Failed to set line state, error: %d\n",
1780 			error);
1781 		return error;
1782 	}
1783 
1784 	return 0;
1785 }
1786 
1787 static int ims_pcu_get_device_info(struct ims_pcu *pcu)
1788 {
1789 	int error;
1790 
1791 	error = ims_pcu_get_info(pcu);
1792 	if (error)
1793 		return error;
1794 
1795 	error = ims_pcu_execute_query(pcu, GET_FW_VERSION);
1796 	if (error) {
1797 		dev_err(pcu->dev,
1798 			"GET_FW_VERSION command failed, error: %d\n", error);
1799 		return error;
1800 	}
1801 
1802 	snprintf(pcu->fw_version, sizeof(pcu->fw_version),
1803 		 "%02d%02d%02d%02d.%c%c",
1804 		 pcu->cmd_buf[2], pcu->cmd_buf[3], pcu->cmd_buf[4], pcu->cmd_buf[5],
1805 		 pcu->cmd_buf[6], pcu->cmd_buf[7]);
1806 
1807 	error = ims_pcu_execute_query(pcu, GET_BL_VERSION);
1808 	if (error) {
1809 		dev_err(pcu->dev,
1810 			"GET_BL_VERSION command failed, error: %d\n", error);
1811 		return error;
1812 	}
1813 
1814 	snprintf(pcu->bl_version, sizeof(pcu->bl_version),
1815 		 "%02d%02d%02d%02d.%c%c",
1816 		 pcu->cmd_buf[2], pcu->cmd_buf[3], pcu->cmd_buf[4], pcu->cmd_buf[5],
1817 		 pcu->cmd_buf[6], pcu->cmd_buf[7]);
1818 
1819 	error = ims_pcu_execute_query(pcu, RESET_REASON);
1820 	if (error) {
1821 		dev_err(pcu->dev,
1822 			"RESET_REASON command failed, error: %d\n", error);
1823 		return error;
1824 	}
1825 
1826 	snprintf(pcu->reset_reason, sizeof(pcu->reset_reason),
1827 		 "%02x", pcu->cmd_buf[IMS_PCU_DATA_OFFSET]);
1828 
1829 	dev_dbg(pcu->dev,
1830 		"P/N: %s, MD: %s, S/N: %s, FW: %s, BL: %s, RR: %s\n",
1831 		pcu->part_number,
1832 		pcu->date_of_manufacturing,
1833 		pcu->serial_number,
1834 		pcu->fw_version,
1835 		pcu->bl_version,
1836 		pcu->reset_reason);
1837 
1838 	return 0;
1839 }
1840 
1841 static int ims_pcu_identify_type(struct ims_pcu *pcu, u8 *device_id)
1842 {
1843 	int error;
1844 
1845 	error = ims_pcu_execute_query(pcu, GET_DEVICE_ID);
1846 	if (error) {
1847 		dev_err(pcu->dev,
1848 			"GET_DEVICE_ID command failed, error: %d\n", error);
1849 		return error;
1850 	}
1851 
1852 	*device_id = pcu->cmd_buf[IMS_PCU_DATA_OFFSET];
1853 	dev_dbg(pcu->dev, "Detected device ID: %d\n", *device_id);
1854 
1855 	return 0;
1856 }
1857 
1858 static int ims_pcu_init_application_mode(struct ims_pcu *pcu)
1859 {
1860 	static atomic_t device_no = ATOMIC_INIT(-1);
1861 
1862 	const struct ims_pcu_device_info *info;
1863 	int error;
1864 
1865 	error = ims_pcu_get_device_info(pcu);
1866 	if (error) {
1867 		/* Device does not respond to basic queries, hopeless */
1868 		return error;
1869 	}
1870 
1871 	error = ims_pcu_identify_type(pcu, &pcu->device_id);
1872 	if (error) {
1873 		dev_err(pcu->dev,
1874 			"Failed to identify device, error: %d\n", error);
1875 		/*
1876 		 * Do not signal error, but do not create input nor
1877 		 * backlight devices either, let userspace figure this
1878 		 * out (flash a new firmware?).
1879 		 */
1880 		return 0;
1881 	}
1882 
1883 	if (pcu->device_id >= ARRAY_SIZE(ims_pcu_device_info) ||
1884 	    !ims_pcu_device_info[pcu->device_id].keymap) {
1885 		dev_err(pcu->dev, "Device ID %d is not valid\n", pcu->device_id);
1886 		/* Same as above, punt to userspace */
1887 		return 0;
1888 	}
1889 
1890 	/* Device appears to be operable, complete initialization */
1891 	pcu->device_no = atomic_inc_return(&device_no);
1892 
1893 	/*
1894 	 * PCU-B devices, both GEN_1 and GEN_2 do not have OFN sensor
1895 	 */
1896 	if (pcu->device_id != IMS_PCU_PCU_B_DEVICE_ID) {
1897 		error = sysfs_create_group(&pcu->dev->kobj,
1898 					   &ims_pcu_ofn_attr_group);
1899 		if (error)
1900 			return error;
1901 	}
1902 
1903 	error = ims_pcu_setup_backlight(pcu);
1904 	if (error)
1905 		return error;
1906 
1907 	info = &ims_pcu_device_info[pcu->device_id];
1908 	error = ims_pcu_setup_buttons(pcu, info->keymap, info->keymap_len);
1909 	if (error)
1910 		goto err_destroy_backlight;
1911 
1912 	if (info->has_gamepad) {
1913 		error = ims_pcu_setup_gamepad(pcu);
1914 		if (error)
1915 			goto err_destroy_buttons;
1916 	}
1917 
1918 	pcu->setup_complete = true;
1919 
1920 	return 0;
1921 
1922 err_destroy_buttons:
1923 	ims_pcu_destroy_buttons(pcu);
1924 err_destroy_backlight:
1925 	ims_pcu_destroy_backlight(pcu);
1926 	return error;
1927 }
1928 
1929 static void ims_pcu_destroy_application_mode(struct ims_pcu *pcu)
1930 {
1931 	if (pcu->setup_complete) {
1932 		pcu->setup_complete = false;
1933 		mb(); /* make sure flag setting is not reordered */
1934 
1935 		if (pcu->gamepad)
1936 			ims_pcu_destroy_gamepad(pcu);
1937 		ims_pcu_destroy_buttons(pcu);
1938 		ims_pcu_destroy_backlight(pcu);
1939 
1940 		if (pcu->device_id != IMS_PCU_PCU_B_DEVICE_ID)
1941 			sysfs_remove_group(&pcu->dev->kobj,
1942 					   &ims_pcu_ofn_attr_group);
1943 	}
1944 }
1945 
1946 static int ims_pcu_init_bootloader_mode(struct ims_pcu *pcu)
1947 {
1948 	int error;
1949 
1950 	error = ims_pcu_execute_bl_command(pcu, QUERY_DEVICE, NULL, 0,
1951 					   IMS_PCU_CMD_RESPONSE_TIMEOUT);
1952 	if (error) {
1953 		dev_err(pcu->dev, "Bootloader does not respond, aborting\n");
1954 		return error;
1955 	}
1956 
1957 	pcu->fw_start_addr =
1958 		get_unaligned_le32(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET + 11]);
1959 	pcu->fw_end_addr =
1960 		get_unaligned_le32(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET + 15]);
1961 
1962 	dev_info(pcu->dev,
1963 		 "Device is in bootloader mode (addr 0x%08x-0x%08x), requesting firmware\n",
1964 		 pcu->fw_start_addr, pcu->fw_end_addr);
1965 
1966 	error = request_firmware_nowait(THIS_MODULE, true,
1967 					IMS_PCU_FIRMWARE_NAME,
1968 					pcu->dev, GFP_KERNEL, pcu,
1969 					ims_pcu_process_async_firmware);
1970 	if (error) {
1971 		/* This error is not fatal, let userspace have another chance */
1972 		complete(&pcu->async_firmware_done);
1973 	}
1974 
1975 	return 0;
1976 }
1977 
1978 static void ims_pcu_destroy_bootloader_mode(struct ims_pcu *pcu)
1979 {
1980 	/* Make sure our initial firmware request has completed */
1981 	wait_for_completion(&pcu->async_firmware_done);
1982 }
1983 
1984 #define IMS_PCU_APPLICATION_MODE	0
1985 #define IMS_PCU_BOOTLOADER_MODE		1
1986 
1987 static struct usb_driver ims_pcu_driver;
1988 
1989 static int ims_pcu_probe(struct usb_interface *intf,
1990 			 const struct usb_device_id *id)
1991 {
1992 	struct usb_device *udev = interface_to_usbdev(intf);
1993 	struct ims_pcu *pcu;
1994 	int error;
1995 
1996 	pcu = kzalloc(sizeof(struct ims_pcu), GFP_KERNEL);
1997 	if (!pcu)
1998 		return -ENOMEM;
1999 
2000 	pcu->dev = &intf->dev;
2001 	pcu->udev = udev;
2002 	pcu->bootloader_mode = id->driver_info == IMS_PCU_BOOTLOADER_MODE;
2003 	mutex_init(&pcu->cmd_mutex);
2004 	init_completion(&pcu->cmd_done);
2005 	init_completion(&pcu->async_firmware_done);
2006 
2007 	error = ims_pcu_parse_cdc_data(intf, pcu);
2008 	if (error)
2009 		goto err_free_mem;
2010 
2011 	error = usb_driver_claim_interface(&ims_pcu_driver,
2012 					   pcu->data_intf, pcu);
2013 	if (error) {
2014 		dev_err(&intf->dev,
2015 			"Unable to claim corresponding data interface: %d\n",
2016 			error);
2017 		goto err_free_mem;
2018 	}
2019 
2020 	usb_set_intfdata(pcu->ctrl_intf, pcu);
2021 
2022 	error = ims_pcu_buffers_alloc(pcu);
2023 	if (error)
2024 		goto err_unclaim_intf;
2025 
2026 	error = ims_pcu_start_io(pcu);
2027 	if (error)
2028 		goto err_free_buffers;
2029 
2030 	error = ims_pcu_line_setup(pcu);
2031 	if (error)
2032 		goto err_stop_io;
2033 
2034 	error = sysfs_create_group(&intf->dev.kobj, &ims_pcu_attr_group);
2035 	if (error)
2036 		goto err_stop_io;
2037 
2038 	error = pcu->bootloader_mode ?
2039 			ims_pcu_init_bootloader_mode(pcu) :
2040 			ims_pcu_init_application_mode(pcu);
2041 	if (error)
2042 		goto err_remove_sysfs;
2043 
2044 	return 0;
2045 
2046 err_remove_sysfs:
2047 	sysfs_remove_group(&intf->dev.kobj, &ims_pcu_attr_group);
2048 err_stop_io:
2049 	ims_pcu_stop_io(pcu);
2050 err_free_buffers:
2051 	ims_pcu_buffers_free(pcu);
2052 err_unclaim_intf:
2053 	usb_driver_release_interface(&ims_pcu_driver, pcu->data_intf);
2054 err_free_mem:
2055 	kfree(pcu);
2056 	return error;
2057 }
2058 
2059 static void ims_pcu_disconnect(struct usb_interface *intf)
2060 {
2061 	struct ims_pcu *pcu = usb_get_intfdata(intf);
2062 	struct usb_host_interface *alt = intf->cur_altsetting;
2063 
2064 	usb_set_intfdata(intf, NULL);
2065 
2066 	/*
2067 	 * See if we are dealing with control or data interface. The cleanup
2068 	 * happens when we unbind primary (control) interface.
2069 	 */
2070 	if (alt->desc.bInterfaceClass != USB_CLASS_COMM)
2071 		return;
2072 
2073 	sysfs_remove_group(&intf->dev.kobj, &ims_pcu_attr_group);
2074 
2075 	ims_pcu_stop_io(pcu);
2076 
2077 	if (pcu->bootloader_mode)
2078 		ims_pcu_destroy_bootloader_mode(pcu);
2079 	else
2080 		ims_pcu_destroy_application_mode(pcu);
2081 
2082 	ims_pcu_buffers_free(pcu);
2083 	kfree(pcu);
2084 }
2085 
2086 #ifdef CONFIG_PM
2087 static int ims_pcu_suspend(struct usb_interface *intf,
2088 			   pm_message_t message)
2089 {
2090 	struct ims_pcu *pcu = usb_get_intfdata(intf);
2091 	struct usb_host_interface *alt = intf->cur_altsetting;
2092 
2093 	if (alt->desc.bInterfaceClass == USB_CLASS_COMM)
2094 		ims_pcu_stop_io(pcu);
2095 
2096 	return 0;
2097 }
2098 
2099 static int ims_pcu_resume(struct usb_interface *intf)
2100 {
2101 	struct ims_pcu *pcu = usb_get_intfdata(intf);
2102 	struct usb_host_interface *alt = intf->cur_altsetting;
2103 	int retval = 0;
2104 
2105 	if (alt->desc.bInterfaceClass == USB_CLASS_COMM) {
2106 		retval = ims_pcu_start_io(pcu);
2107 		if (retval == 0)
2108 			retval = ims_pcu_line_setup(pcu);
2109 	}
2110 
2111 	return retval;
2112 }
2113 #endif
2114 
2115 static const struct usb_device_id ims_pcu_id_table[] = {
2116 	{
2117 		USB_DEVICE_AND_INTERFACE_INFO(0x04d8, 0x0082,
2118 					USB_CLASS_COMM,
2119 					USB_CDC_SUBCLASS_ACM,
2120 					USB_CDC_ACM_PROTO_AT_V25TER),
2121 		.driver_info = IMS_PCU_APPLICATION_MODE,
2122 	},
2123 	{
2124 		USB_DEVICE_AND_INTERFACE_INFO(0x04d8, 0x0083,
2125 					USB_CLASS_COMM,
2126 					USB_CDC_SUBCLASS_ACM,
2127 					USB_CDC_ACM_PROTO_AT_V25TER),
2128 		.driver_info = IMS_PCU_BOOTLOADER_MODE,
2129 	},
2130 	{ }
2131 };
2132 
2133 static struct usb_driver ims_pcu_driver = {
2134 	.name			= "ims_pcu",
2135 	.id_table		= ims_pcu_id_table,
2136 	.probe			= ims_pcu_probe,
2137 	.disconnect		= ims_pcu_disconnect,
2138 #ifdef CONFIG_PM
2139 	.suspend		= ims_pcu_suspend,
2140 	.resume			= ims_pcu_resume,
2141 	.reset_resume		= ims_pcu_resume,
2142 #endif
2143 };
2144 
2145 module_usb_driver(ims_pcu_driver);
2146 
2147 MODULE_DESCRIPTION("IMS Passenger Control Unit driver");
2148 MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
2149 MODULE_LICENSE("GPL");
2150