xref: /openbmc/linux/drivers/input/misc/ims-pcu.c (revision be709d48)
1 /*
2  * Driver for IMS Passenger Control Unit Devices
3  *
4  * Copyright (C) 2013 The IMS Company
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 version 2
8  * as published by the Free Software Foundation.
9  */
10 
11 #include <linux/completion.h>
12 #include <linux/device.h>
13 #include <linux/firmware.h>
14 #include <linux/ihex.h>
15 #include <linux/input.h>
16 #include <linux/kernel.h>
17 #include <linux/leds.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21 #include <linux/usb/input.h>
22 #include <linux/usb/cdc.h>
23 #include <asm/unaligned.h>
24 
25 #define IMS_PCU_KEYMAP_LEN		32
26 
27 struct ims_pcu_buttons {
28 	struct input_dev *input;
29 	char name[32];
30 	char phys[32];
31 	unsigned short keymap[IMS_PCU_KEYMAP_LEN];
32 };
33 
34 struct ims_pcu_gamepad {
35 	struct input_dev *input;
36 	char name[32];
37 	char phys[32];
38 };
39 
40 struct ims_pcu_backlight {
41 	struct led_classdev cdev;
42 	char name[32];
43 };
44 
45 #define IMS_PCU_PART_NUMBER_LEN		15
46 #define IMS_PCU_SERIAL_NUMBER_LEN	8
47 #define IMS_PCU_DOM_LEN			8
48 #define IMS_PCU_FW_VERSION_LEN		(9 + 1)
49 #define IMS_PCU_BL_VERSION_LEN		(9 + 1)
50 #define IMS_PCU_BL_RESET_REASON_LEN	(2 + 1)
51 
52 #define IMS_PCU_PCU_B_DEVICE_ID		5
53 
54 #define IMS_PCU_BUF_SIZE		128
55 
56 struct ims_pcu {
57 	struct usb_device *udev;
58 	struct device *dev; /* control interface's device, used for logging */
59 
60 	unsigned int device_no;
61 
62 	bool bootloader_mode;
63 
64 	char part_number[IMS_PCU_PART_NUMBER_LEN];
65 	char serial_number[IMS_PCU_SERIAL_NUMBER_LEN];
66 	char date_of_manufacturing[IMS_PCU_DOM_LEN];
67 	char fw_version[IMS_PCU_FW_VERSION_LEN];
68 	char bl_version[IMS_PCU_BL_VERSION_LEN];
69 	char reset_reason[IMS_PCU_BL_RESET_REASON_LEN];
70 	int update_firmware_status;
71 	u8 device_id;
72 
73 	u8 ofn_reg_addr;
74 
75 	struct usb_interface *ctrl_intf;
76 
77 	struct usb_endpoint_descriptor *ep_ctrl;
78 	struct urb *urb_ctrl;
79 	u8 *urb_ctrl_buf;
80 	dma_addr_t ctrl_dma;
81 	size_t max_ctrl_size;
82 
83 	struct usb_interface *data_intf;
84 
85 	struct usb_endpoint_descriptor *ep_in;
86 	struct urb *urb_in;
87 	u8 *urb_in_buf;
88 	dma_addr_t read_dma;
89 	size_t max_in_size;
90 
91 	struct usb_endpoint_descriptor *ep_out;
92 	u8 *urb_out_buf;
93 	size_t max_out_size;
94 
95 	u8 read_buf[IMS_PCU_BUF_SIZE];
96 	u8 read_pos;
97 	u8 check_sum;
98 	bool have_stx;
99 	bool have_dle;
100 
101 	u8 cmd_buf[IMS_PCU_BUF_SIZE];
102 	u8 ack_id;
103 	u8 expected_response;
104 	u8 cmd_buf_len;
105 	struct completion cmd_done;
106 	struct mutex cmd_mutex;
107 
108 	u32 fw_start_addr;
109 	u32 fw_end_addr;
110 	struct completion async_firmware_done;
111 
112 	struct ims_pcu_buttons buttons;
113 	struct ims_pcu_gamepad *gamepad;
114 	struct ims_pcu_backlight backlight;
115 
116 	bool setup_complete; /* Input and LED devices have been created */
117 };
118 
119 
120 /*********************************************************************
121  *             Buttons Input device support                          *
122  *********************************************************************/
123 
124 static const unsigned short ims_pcu_keymap_1[] = {
125 	[1] = KEY_ATTENDANT_OFF,
126 	[2] = KEY_ATTENDANT_ON,
127 	[3] = KEY_LIGHTS_TOGGLE,
128 	[4] = KEY_VOLUMEUP,
129 	[5] = KEY_VOLUMEDOWN,
130 	[6] = KEY_INFO,
131 };
132 
133 static const unsigned short ims_pcu_keymap_2[] = {
134 	[4] = KEY_VOLUMEUP,
135 	[5] = KEY_VOLUMEDOWN,
136 	[6] = KEY_INFO,
137 };
138 
139 static const unsigned short ims_pcu_keymap_3[] = {
140 	[1] = KEY_HOMEPAGE,
141 	[2] = KEY_ATTENDANT_TOGGLE,
142 	[3] = KEY_LIGHTS_TOGGLE,
143 	[4] = KEY_VOLUMEUP,
144 	[5] = KEY_VOLUMEDOWN,
145 	[6] = KEY_DISPLAYTOGGLE,
146 	[18] = KEY_PLAYPAUSE,
147 };
148 
149 static const unsigned short ims_pcu_keymap_4[] = {
150 	[1] = KEY_ATTENDANT_OFF,
151 	[2] = KEY_ATTENDANT_ON,
152 	[3] = KEY_LIGHTS_TOGGLE,
153 	[4] = KEY_VOLUMEUP,
154 	[5] = KEY_VOLUMEDOWN,
155 	[6] = KEY_INFO,
156 	[18] = KEY_PLAYPAUSE,
157 };
158 
159 static const unsigned short ims_pcu_keymap_5[] = {
160 	[1] = KEY_ATTENDANT_OFF,
161 	[2] = KEY_ATTENDANT_ON,
162 	[3] = KEY_LIGHTS_TOGGLE,
163 };
164 
165 struct ims_pcu_device_info {
166 	const unsigned short *keymap;
167 	size_t keymap_len;
168 	bool has_gamepad;
169 };
170 
171 #define IMS_PCU_DEVINFO(_n, _gamepad)				\
172 	[_n] = {						\
173 		.keymap = ims_pcu_keymap_##_n,			\
174 		.keymap_len = ARRAY_SIZE(ims_pcu_keymap_##_n),	\
175 		.has_gamepad = _gamepad,			\
176 	}
177 
178 static const struct ims_pcu_device_info ims_pcu_device_info[] = {
179 	IMS_PCU_DEVINFO(1, true),
180 	IMS_PCU_DEVINFO(2, true),
181 	IMS_PCU_DEVINFO(3, true),
182 	IMS_PCU_DEVINFO(4, true),
183 	IMS_PCU_DEVINFO(5, false),
184 };
185 
186 static void ims_pcu_buttons_report(struct ims_pcu *pcu, u32 data)
187 {
188 	struct ims_pcu_buttons *buttons = &pcu->buttons;
189 	struct input_dev *input = buttons->input;
190 	int i;
191 
192 	for (i = 0; i < 32; i++) {
193 		unsigned short keycode = buttons->keymap[i];
194 
195 		if (keycode != KEY_RESERVED)
196 			input_report_key(input, keycode, data & (1UL << i));
197 	}
198 
199 	input_sync(input);
200 }
201 
202 static int ims_pcu_setup_buttons(struct ims_pcu *pcu,
203 				 const unsigned short *keymap,
204 				 size_t keymap_len)
205 {
206 	struct ims_pcu_buttons *buttons = &pcu->buttons;
207 	struct input_dev *input;
208 	int i;
209 	int error;
210 
211 	input = input_allocate_device();
212 	if (!input) {
213 		dev_err(pcu->dev,
214 			"Not enough memory for input input device\n");
215 		return -ENOMEM;
216 	}
217 
218 	snprintf(buttons->name, sizeof(buttons->name),
219 		 "IMS PCU#%d Button Interface", pcu->device_no);
220 
221 	usb_make_path(pcu->udev, buttons->phys, sizeof(buttons->phys));
222 	strlcat(buttons->phys, "/input0", sizeof(buttons->phys));
223 
224 	memcpy(buttons->keymap, keymap, sizeof(*keymap) * keymap_len);
225 
226 	input->name = buttons->name;
227 	input->phys = buttons->phys;
228 	usb_to_input_id(pcu->udev, &input->id);
229 	input->dev.parent = &pcu->ctrl_intf->dev;
230 
231 	input->keycode = buttons->keymap;
232 	input->keycodemax = ARRAY_SIZE(buttons->keymap);
233 	input->keycodesize = sizeof(buttons->keymap[0]);
234 
235 	__set_bit(EV_KEY, input->evbit);
236 	for (i = 0; i < IMS_PCU_KEYMAP_LEN; i++)
237 		__set_bit(buttons->keymap[i], input->keybit);
238 	__clear_bit(KEY_RESERVED, input->keybit);
239 
240 	error = input_register_device(input);
241 	if (error) {
242 		dev_err(pcu->dev,
243 			"Failed to register buttons input device: %d\n",
244 			error);
245 		input_free_device(input);
246 		return error;
247 	}
248 
249 	buttons->input = input;
250 	return 0;
251 }
252 
253 static void ims_pcu_destroy_buttons(struct ims_pcu *pcu)
254 {
255 	struct ims_pcu_buttons *buttons = &pcu->buttons;
256 
257 	input_unregister_device(buttons->input);
258 }
259 
260 
261 /*********************************************************************
262  *             Gamepad Input device support                          *
263  *********************************************************************/
264 
265 static void ims_pcu_gamepad_report(struct ims_pcu *pcu, u32 data)
266 {
267 	struct ims_pcu_gamepad *gamepad = pcu->gamepad;
268 	struct input_dev *input = gamepad->input;
269 	int x, y;
270 
271 	x = !!(data & (1 << 14)) - !!(data & (1 << 13));
272 	y = !!(data & (1 << 12)) - !!(data & (1 << 11));
273 
274 	input_report_abs(input, ABS_X, x);
275 	input_report_abs(input, ABS_Y, y);
276 
277 	input_report_key(input, BTN_A, data & (1 << 7));
278 	input_report_key(input, BTN_B, data & (1 << 8));
279 	input_report_key(input, BTN_X, data & (1 << 9));
280 	input_report_key(input, BTN_Y, data & (1 << 10));
281 	input_report_key(input, BTN_START, data & (1 << 15));
282 	input_report_key(input, BTN_SELECT, data & (1 << 16));
283 
284 	input_sync(input);
285 }
286 
287 static int ims_pcu_setup_gamepad(struct ims_pcu *pcu)
288 {
289 	struct ims_pcu_gamepad *gamepad;
290 	struct input_dev *input;
291 	int error;
292 
293 	gamepad = kzalloc(sizeof(struct ims_pcu_gamepad), GFP_KERNEL);
294 	input = input_allocate_device();
295 	if (!gamepad || !input) {
296 		dev_err(pcu->dev,
297 			"Not enough memory for gamepad device\n");
298 		error = -ENOMEM;
299 		goto err_free_mem;
300 	}
301 
302 	gamepad->input = input;
303 
304 	snprintf(gamepad->name, sizeof(gamepad->name),
305 		 "IMS PCU#%d Gamepad Interface", pcu->device_no);
306 
307 	usb_make_path(pcu->udev, gamepad->phys, sizeof(gamepad->phys));
308 	strlcat(gamepad->phys, "/input1", sizeof(gamepad->phys));
309 
310 	input->name = gamepad->name;
311 	input->phys = gamepad->phys;
312 	usb_to_input_id(pcu->udev, &input->id);
313 	input->dev.parent = &pcu->ctrl_intf->dev;
314 
315 	__set_bit(EV_KEY, input->evbit);
316 	__set_bit(BTN_A, input->keybit);
317 	__set_bit(BTN_B, input->keybit);
318 	__set_bit(BTN_X, input->keybit);
319 	__set_bit(BTN_Y, input->keybit);
320 	__set_bit(BTN_START, input->keybit);
321 	__set_bit(BTN_SELECT, input->keybit);
322 
323 	__set_bit(EV_ABS, input->evbit);
324 	input_set_abs_params(input, ABS_X, -1, 1, 0, 0);
325 	input_set_abs_params(input, ABS_Y, -1, 1, 0, 0);
326 
327 	error = input_register_device(input);
328 	if (error) {
329 		dev_err(pcu->dev,
330 			"Failed to register gamepad input device: %d\n",
331 			error);
332 		goto err_free_mem;
333 	}
334 
335 	pcu->gamepad = gamepad;
336 	return 0;
337 
338 err_free_mem:
339 	input_free_device(input);
340 	kfree(gamepad);
341 	return -ENOMEM;
342 }
343 
344 static void ims_pcu_destroy_gamepad(struct ims_pcu *pcu)
345 {
346 	struct ims_pcu_gamepad *gamepad = pcu->gamepad;
347 
348 	input_unregister_device(gamepad->input);
349 	kfree(gamepad);
350 }
351 
352 
353 /*********************************************************************
354  *             PCU Communication protocol handling                   *
355  *********************************************************************/
356 
357 #define IMS_PCU_PROTOCOL_STX		0x02
358 #define IMS_PCU_PROTOCOL_ETX		0x03
359 #define IMS_PCU_PROTOCOL_DLE		0x10
360 
361 /* PCU commands */
362 #define IMS_PCU_CMD_STATUS		0xa0
363 #define IMS_PCU_CMD_PCU_RESET		0xa1
364 #define IMS_PCU_CMD_RESET_REASON	0xa2
365 #define IMS_PCU_CMD_SEND_BUTTONS	0xa3
366 #define IMS_PCU_CMD_JUMP_TO_BTLDR	0xa4
367 #define IMS_PCU_CMD_GET_INFO		0xa5
368 #define IMS_PCU_CMD_SET_BRIGHTNESS	0xa6
369 #define IMS_PCU_CMD_EEPROM		0xa7
370 #define IMS_PCU_CMD_GET_FW_VERSION	0xa8
371 #define IMS_PCU_CMD_GET_BL_VERSION	0xa9
372 #define IMS_PCU_CMD_SET_INFO		0xab
373 #define IMS_PCU_CMD_GET_BRIGHTNESS	0xac
374 #define IMS_PCU_CMD_GET_DEVICE_ID	0xae
375 #define IMS_PCU_CMD_SPECIAL_INFO	0xb0
376 #define IMS_PCU_CMD_BOOTLOADER		0xb1	/* Pass data to bootloader */
377 #define IMS_PCU_CMD_OFN_SET_CONFIG	0xb3
378 #define IMS_PCU_CMD_OFN_GET_CONFIG	0xb4
379 
380 /* PCU responses */
381 #define IMS_PCU_RSP_STATUS		0xc0
382 #define IMS_PCU_RSP_PCU_RESET		0	/* Originally 0xc1 */
383 #define IMS_PCU_RSP_RESET_REASON	0xc2
384 #define IMS_PCU_RSP_SEND_BUTTONS	0xc3
385 #define IMS_PCU_RSP_JUMP_TO_BTLDR	0	/* Originally 0xc4 */
386 #define IMS_PCU_RSP_GET_INFO		0xc5
387 #define IMS_PCU_RSP_SET_BRIGHTNESS	0xc6
388 #define IMS_PCU_RSP_EEPROM		0xc7
389 #define IMS_PCU_RSP_GET_FW_VERSION	0xc8
390 #define IMS_PCU_RSP_GET_BL_VERSION	0xc9
391 #define IMS_PCU_RSP_SET_INFO		0xcb
392 #define IMS_PCU_RSP_GET_BRIGHTNESS	0xcc
393 #define IMS_PCU_RSP_CMD_INVALID		0xcd
394 #define IMS_PCU_RSP_GET_DEVICE_ID	0xce
395 #define IMS_PCU_RSP_SPECIAL_INFO	0xd0
396 #define IMS_PCU_RSP_BOOTLOADER		0xd1	/* Bootloader response */
397 #define IMS_PCU_RSP_OFN_SET_CONFIG	0xd2
398 #define IMS_PCU_RSP_OFN_GET_CONFIG	0xd3
399 
400 
401 #define IMS_PCU_RSP_EVNT_BUTTONS	0xe0	/* Unsolicited, button state */
402 #define IMS_PCU_GAMEPAD_MASK		0x0001ff80UL	/* Bits 7 through 16 */
403 
404 
405 #define IMS_PCU_MIN_PACKET_LEN		3
406 #define IMS_PCU_DATA_OFFSET		2
407 
408 #define IMS_PCU_CMD_WRITE_TIMEOUT	100 /* msec */
409 #define IMS_PCU_CMD_RESPONSE_TIMEOUT	500 /* msec */
410 
411 static void ims_pcu_report_events(struct ims_pcu *pcu)
412 {
413 	u32 data = get_unaligned_be32(&pcu->read_buf[3]);
414 
415 	ims_pcu_buttons_report(pcu, data & ~IMS_PCU_GAMEPAD_MASK);
416 	if (pcu->gamepad)
417 		ims_pcu_gamepad_report(pcu, data);
418 }
419 
420 static void ims_pcu_handle_response(struct ims_pcu *pcu)
421 {
422 	switch (pcu->read_buf[0]) {
423 	case IMS_PCU_RSP_EVNT_BUTTONS:
424 		if (likely(pcu->setup_complete))
425 			ims_pcu_report_events(pcu);
426 		break;
427 
428 	default:
429 		/*
430 		 * See if we got command completion.
431 		 * If both the sequence and response code match save
432 		 * the data and signal completion.
433 		 */
434 		if (pcu->read_buf[0] == pcu->expected_response &&
435 		    pcu->read_buf[1] == pcu->ack_id - 1) {
436 
437 			memcpy(pcu->cmd_buf, pcu->read_buf, pcu->read_pos);
438 			pcu->cmd_buf_len = pcu->read_pos;
439 			complete(&pcu->cmd_done);
440 		}
441 		break;
442 	}
443 }
444 
445 static void ims_pcu_process_data(struct ims_pcu *pcu, struct urb *urb)
446 {
447 	int i;
448 
449 	for (i = 0; i < urb->actual_length; i++) {
450 		u8 data = pcu->urb_in_buf[i];
451 
452 		/* Skip everything until we get Start Xmit */
453 		if (!pcu->have_stx && data != IMS_PCU_PROTOCOL_STX)
454 			continue;
455 
456 		if (pcu->have_dle) {
457 			pcu->have_dle = false;
458 			pcu->read_buf[pcu->read_pos++] = data;
459 			pcu->check_sum += data;
460 			continue;
461 		}
462 
463 		switch (data) {
464 		case IMS_PCU_PROTOCOL_STX:
465 			if (pcu->have_stx)
466 				dev_warn(pcu->dev,
467 					 "Unexpected STX at byte %d, discarding old data\n",
468 					 pcu->read_pos);
469 			pcu->have_stx = true;
470 			pcu->have_dle = false;
471 			pcu->read_pos = 0;
472 			pcu->check_sum = 0;
473 			break;
474 
475 		case IMS_PCU_PROTOCOL_DLE:
476 			pcu->have_dle = true;
477 			break;
478 
479 		case IMS_PCU_PROTOCOL_ETX:
480 			if (pcu->read_pos < IMS_PCU_MIN_PACKET_LEN) {
481 				dev_warn(pcu->dev,
482 					 "Short packet received (%d bytes), ignoring\n",
483 					 pcu->read_pos);
484 			} else if (pcu->check_sum != 0) {
485 				dev_warn(pcu->dev,
486 					 "Invalid checksum in packet (%d bytes), ignoring\n",
487 					 pcu->read_pos);
488 			} else {
489 				ims_pcu_handle_response(pcu);
490 			}
491 
492 			pcu->have_stx = false;
493 			pcu->have_dle = false;
494 			pcu->read_pos = 0;
495 			break;
496 
497 		default:
498 			pcu->read_buf[pcu->read_pos++] = data;
499 			pcu->check_sum += data;
500 			break;
501 		}
502 	}
503 }
504 
505 static bool ims_pcu_byte_needs_escape(u8 byte)
506 {
507 	return byte == IMS_PCU_PROTOCOL_STX ||
508 	       byte == IMS_PCU_PROTOCOL_ETX ||
509 	       byte == IMS_PCU_PROTOCOL_DLE;
510 }
511 
512 static int ims_pcu_send_cmd_chunk(struct ims_pcu *pcu,
513 				  u8 command, int chunk, int len)
514 {
515 	int error;
516 
517 	error = usb_bulk_msg(pcu->udev,
518 			     usb_sndbulkpipe(pcu->udev,
519 					     pcu->ep_out->bEndpointAddress),
520 			     pcu->urb_out_buf, len,
521 			     NULL, IMS_PCU_CMD_WRITE_TIMEOUT);
522 	if (error < 0) {
523 		dev_dbg(pcu->dev,
524 			"Sending 0x%02x command failed at chunk %d: %d\n",
525 			command, chunk, error);
526 		return error;
527 	}
528 
529 	return 0;
530 }
531 
532 static int ims_pcu_send_command(struct ims_pcu *pcu,
533 				u8 command, const u8 *data, int len)
534 {
535 	int count = 0;
536 	int chunk = 0;
537 	int delta;
538 	int i;
539 	int error;
540 	u8 csum = 0;
541 	u8 ack_id;
542 
543 	pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_STX;
544 
545 	/* We know the command need not be escaped */
546 	pcu->urb_out_buf[count++] = command;
547 	csum += command;
548 
549 	ack_id = pcu->ack_id++;
550 	if (ack_id == 0xff)
551 		ack_id = pcu->ack_id++;
552 
553 	if (ims_pcu_byte_needs_escape(ack_id))
554 		pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
555 
556 	pcu->urb_out_buf[count++] = ack_id;
557 	csum += ack_id;
558 
559 	for (i = 0; i < len; i++) {
560 
561 		delta = ims_pcu_byte_needs_escape(data[i]) ? 2 : 1;
562 		if (count + delta >= pcu->max_out_size) {
563 			error = ims_pcu_send_cmd_chunk(pcu, command,
564 						       ++chunk, count);
565 			if (error)
566 				return error;
567 
568 			count = 0;
569 		}
570 
571 		if (delta == 2)
572 			pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
573 
574 		pcu->urb_out_buf[count++] = data[i];
575 		csum += data[i];
576 	}
577 
578 	csum = 1 + ~csum;
579 
580 	delta = ims_pcu_byte_needs_escape(csum) ? 3 : 2;
581 	if (count + delta >= pcu->max_out_size) {
582 		error = ims_pcu_send_cmd_chunk(pcu, command, ++chunk, count);
583 		if (error)
584 			return error;
585 
586 		count = 0;
587 	}
588 
589 	if (delta == 3)
590 		pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
591 
592 	pcu->urb_out_buf[count++] = csum;
593 	pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_ETX;
594 
595 	return ims_pcu_send_cmd_chunk(pcu, command, ++chunk, count);
596 }
597 
598 static int __ims_pcu_execute_command(struct ims_pcu *pcu,
599 				     u8 command, const void *data, size_t len,
600 				     u8 expected_response, int response_time)
601 {
602 	int error;
603 
604 	pcu->expected_response = expected_response;
605 	init_completion(&pcu->cmd_done);
606 
607 	error = ims_pcu_send_command(pcu, command, data, len);
608 	if (error)
609 		return error;
610 
611 	if (expected_response &&
612 	    !wait_for_completion_timeout(&pcu->cmd_done,
613 					 msecs_to_jiffies(response_time))) {
614 		dev_dbg(pcu->dev, "Command 0x%02x timed out\n", command);
615 		return -ETIMEDOUT;
616 	}
617 
618 	return 0;
619 }
620 
621 #define ims_pcu_execute_command(pcu, code, data, len)			\
622 	__ims_pcu_execute_command(pcu,					\
623 				  IMS_PCU_CMD_##code, data, len,	\
624 				  IMS_PCU_RSP_##code,			\
625 				  IMS_PCU_CMD_RESPONSE_TIMEOUT)
626 
627 #define ims_pcu_execute_query(pcu, code)				\
628 	ims_pcu_execute_command(pcu, code, NULL, 0)
629 
630 /* Bootloader commands */
631 #define IMS_PCU_BL_CMD_QUERY_DEVICE	0xa1
632 #define IMS_PCU_BL_CMD_UNLOCK_CONFIG	0xa2
633 #define IMS_PCU_BL_CMD_ERASE_APP	0xa3
634 #define IMS_PCU_BL_CMD_PROGRAM_DEVICE	0xa4
635 #define IMS_PCU_BL_CMD_PROGRAM_COMPLETE	0xa5
636 #define IMS_PCU_BL_CMD_READ_APP		0xa6
637 #define IMS_PCU_BL_CMD_RESET_DEVICE	0xa7
638 #define IMS_PCU_BL_CMD_LAUNCH_APP	0xa8
639 
640 /* Bootloader commands */
641 #define IMS_PCU_BL_RSP_QUERY_DEVICE	0xc1
642 #define IMS_PCU_BL_RSP_UNLOCK_CONFIG	0xc2
643 #define IMS_PCU_BL_RSP_ERASE_APP	0xc3
644 #define IMS_PCU_BL_RSP_PROGRAM_DEVICE	0xc4
645 #define IMS_PCU_BL_RSP_PROGRAM_COMPLETE	0xc5
646 #define IMS_PCU_BL_RSP_READ_APP		0xc6
647 #define IMS_PCU_BL_RSP_RESET_DEVICE	0	/* originally 0xa7 */
648 #define IMS_PCU_BL_RSP_LAUNCH_APP	0	/* originally 0xa8 */
649 
650 #define IMS_PCU_BL_DATA_OFFSET		3
651 
652 static int __ims_pcu_execute_bl_command(struct ims_pcu *pcu,
653 				        u8 command, const void *data, size_t len,
654 				        u8 expected_response, int response_time)
655 {
656 	int error;
657 
658 	pcu->cmd_buf[0] = command;
659 	if (data)
660 		memcpy(&pcu->cmd_buf[1], data, len);
661 
662 	error = __ims_pcu_execute_command(pcu,
663 				IMS_PCU_CMD_BOOTLOADER, pcu->cmd_buf, len + 1,
664 				expected_response ? IMS_PCU_RSP_BOOTLOADER : 0,
665 				response_time);
666 	if (error) {
667 		dev_err(pcu->dev,
668 			"Failure when sending 0x%02x command to bootloader, error: %d\n",
669 			pcu->cmd_buf[0], error);
670 		return error;
671 	}
672 
673 	if (expected_response && pcu->cmd_buf[2] != expected_response) {
674 		dev_err(pcu->dev,
675 			"Unexpected response from bootloader: 0x%02x, wanted 0x%02x\n",
676 			pcu->cmd_buf[2], expected_response);
677 		return -EINVAL;
678 	}
679 
680 	return 0;
681 }
682 
683 #define ims_pcu_execute_bl_command(pcu, code, data, len, timeout)	\
684 	__ims_pcu_execute_bl_command(pcu,				\
685 				     IMS_PCU_BL_CMD_##code, data, len,	\
686 				     IMS_PCU_BL_RSP_##code, timeout)	\
687 
688 #define IMS_PCU_INFO_PART_OFFSET	2
689 #define IMS_PCU_INFO_DOM_OFFSET		17
690 #define IMS_PCU_INFO_SERIAL_OFFSET	25
691 
692 #define IMS_PCU_SET_INFO_SIZE		31
693 
694 static int ims_pcu_get_info(struct ims_pcu *pcu)
695 {
696 	int error;
697 
698 	error = ims_pcu_execute_query(pcu, GET_INFO);
699 	if (error) {
700 		dev_err(pcu->dev,
701 			"GET_INFO command failed, error: %d\n", error);
702 		return error;
703 	}
704 
705 	memcpy(pcu->part_number,
706 	       &pcu->cmd_buf[IMS_PCU_INFO_PART_OFFSET],
707 	       sizeof(pcu->part_number));
708 	memcpy(pcu->date_of_manufacturing,
709 	       &pcu->cmd_buf[IMS_PCU_INFO_DOM_OFFSET],
710 	       sizeof(pcu->date_of_manufacturing));
711 	memcpy(pcu->serial_number,
712 	       &pcu->cmd_buf[IMS_PCU_INFO_SERIAL_OFFSET],
713 	       sizeof(pcu->serial_number));
714 
715 	return 0;
716 }
717 
718 static int ims_pcu_set_info(struct ims_pcu *pcu)
719 {
720 	int error;
721 
722 	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_PART_OFFSET],
723 	       pcu->part_number, sizeof(pcu->part_number));
724 	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_DOM_OFFSET],
725 	       pcu->date_of_manufacturing, sizeof(pcu->date_of_manufacturing));
726 	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_SERIAL_OFFSET],
727 	       pcu->serial_number, sizeof(pcu->serial_number));
728 
729 	error = ims_pcu_execute_command(pcu, SET_INFO,
730 					&pcu->cmd_buf[IMS_PCU_DATA_OFFSET],
731 					IMS_PCU_SET_INFO_SIZE);
732 	if (error) {
733 		dev_err(pcu->dev,
734 			"Failed to update device information, error: %d\n",
735 			error);
736 		return error;
737 	}
738 
739 	return 0;
740 }
741 
742 static int ims_pcu_switch_to_bootloader(struct ims_pcu *pcu)
743 {
744 	int error;
745 
746 	/* Execute jump to the bootoloader */
747 	error = ims_pcu_execute_command(pcu, JUMP_TO_BTLDR, NULL, 0);
748 	if (error) {
749 		dev_err(pcu->dev,
750 			"Failure when sending JUMP TO BOOLTLOADER command, error: %d\n",
751 			error);
752 		return error;
753 	}
754 
755 	return 0;
756 }
757 
758 /*********************************************************************
759  *             Firmware Update handling                              *
760  *********************************************************************/
761 
762 #define IMS_PCU_FIRMWARE_NAME	"imspcu.fw"
763 
764 struct ims_pcu_flash_fmt {
765 	__le32 addr;
766 	u8 len;
767 	u8 data[];
768 };
769 
770 static unsigned int ims_pcu_count_fw_records(const struct firmware *fw)
771 {
772 	const struct ihex_binrec *rec = (const struct ihex_binrec *)fw->data;
773 	unsigned int count = 0;
774 
775 	while (rec) {
776 		count++;
777 		rec = ihex_next_binrec(rec);
778 	}
779 
780 	return count;
781 }
782 
783 static int ims_pcu_verify_block(struct ims_pcu *pcu,
784 				u32 addr, u8 len, const u8 *data)
785 {
786 	struct ims_pcu_flash_fmt *fragment;
787 	int error;
788 
789 	fragment = (void *)&pcu->cmd_buf[1];
790 	put_unaligned_le32(addr, &fragment->addr);
791 	fragment->len = len;
792 
793 	error = ims_pcu_execute_bl_command(pcu, READ_APP, NULL, 5,
794 					IMS_PCU_CMD_RESPONSE_TIMEOUT);
795 	if (error) {
796 		dev_err(pcu->dev,
797 			"Failed to retrieve block at 0x%08x, len %d, error: %d\n",
798 			addr, len, error);
799 		return error;
800 	}
801 
802 	fragment = (void *)&pcu->cmd_buf[IMS_PCU_BL_DATA_OFFSET];
803 	if (get_unaligned_le32(&fragment->addr) != addr ||
804 	    fragment->len != len) {
805 		dev_err(pcu->dev,
806 			"Wrong block when retrieving 0x%08x (0x%08x), len %d (%d)\n",
807 			addr, get_unaligned_le32(&fragment->addr),
808 			len, fragment->len);
809 		return -EINVAL;
810 	}
811 
812 	if (memcmp(fragment->data, data, len)) {
813 		dev_err(pcu->dev,
814 			"Mismatch in block at 0x%08x, len %d\n",
815 			addr, len);
816 		return -EINVAL;
817 	}
818 
819 	return 0;
820 }
821 
822 static int ims_pcu_flash_firmware(struct ims_pcu *pcu,
823 				  const struct firmware *fw,
824 				  unsigned int n_fw_records)
825 {
826 	const struct ihex_binrec *rec = (const struct ihex_binrec *)fw->data;
827 	struct ims_pcu_flash_fmt *fragment;
828 	unsigned int count = 0;
829 	u32 addr;
830 	u8 len;
831 	int error;
832 
833 	error = ims_pcu_execute_bl_command(pcu, ERASE_APP, NULL, 0, 2000);
834 	if (error) {
835 		dev_err(pcu->dev,
836 			"Failed to erase application image, error: %d\n",
837 			error);
838 		return error;
839 	}
840 
841 	while (rec) {
842 		/*
843 		 * The firmware format is messed up for some reason.
844 		 * The address twice that of what is needed for some
845 		 * reason and we end up overwriting half of the data
846 		 * with the next record.
847 		 */
848 		addr = be32_to_cpu(rec->addr) / 2;
849 		len = be16_to_cpu(rec->len);
850 
851 		fragment = (void *)&pcu->cmd_buf[1];
852 		put_unaligned_le32(addr, &fragment->addr);
853 		fragment->len = len;
854 		memcpy(fragment->data, rec->data, len);
855 
856 		error = ims_pcu_execute_bl_command(pcu, PROGRAM_DEVICE,
857 						NULL, len + 5,
858 						IMS_PCU_CMD_RESPONSE_TIMEOUT);
859 		if (error) {
860 			dev_err(pcu->dev,
861 				"Failed to write block at 0x%08x, len %d, error: %d\n",
862 				addr, len, error);
863 			return error;
864 		}
865 
866 		if (addr >= pcu->fw_start_addr && addr < pcu->fw_end_addr) {
867 			error = ims_pcu_verify_block(pcu, addr, len, rec->data);
868 			if (error)
869 				return error;
870 		}
871 
872 		count++;
873 		pcu->update_firmware_status = (count * 100) / n_fw_records;
874 
875 		rec = ihex_next_binrec(rec);
876 	}
877 
878 	error = ims_pcu_execute_bl_command(pcu, PROGRAM_COMPLETE,
879 					    NULL, 0, 2000);
880 	if (error)
881 		dev_err(pcu->dev,
882 			"Failed to send PROGRAM_COMPLETE, error: %d\n",
883 			error);
884 
885 	return 0;
886 }
887 
888 static int ims_pcu_handle_firmware_update(struct ims_pcu *pcu,
889 					  const struct firmware *fw)
890 {
891 	unsigned int n_fw_records;
892 	int retval;
893 
894 	dev_info(pcu->dev, "Updating firmware %s, size: %zu\n",
895 		 IMS_PCU_FIRMWARE_NAME, fw->size);
896 
897 	n_fw_records = ims_pcu_count_fw_records(fw);
898 
899 	retval = ims_pcu_flash_firmware(pcu, fw, n_fw_records);
900 	if (retval)
901 		goto out;
902 
903 	retval = ims_pcu_execute_bl_command(pcu, LAUNCH_APP, NULL, 0, 0);
904 	if (retval)
905 		dev_err(pcu->dev,
906 			"Failed to start application image, error: %d\n",
907 			retval);
908 
909 out:
910 	pcu->update_firmware_status = retval;
911 	sysfs_notify(&pcu->dev->kobj, NULL, "update_firmware_status");
912 	return retval;
913 }
914 
915 static void ims_pcu_process_async_firmware(const struct firmware *fw,
916 					   void *context)
917 {
918 	struct ims_pcu *pcu = context;
919 	int error;
920 
921 	if (!fw) {
922 		dev_err(pcu->dev, "Failed to get firmware %s\n",
923 			IMS_PCU_FIRMWARE_NAME);
924 		goto out;
925 	}
926 
927 	error = ihex_validate_fw(fw);
928 	if (error) {
929 		dev_err(pcu->dev, "Firmware %s is invalid\n",
930 			IMS_PCU_FIRMWARE_NAME);
931 		goto out;
932 	}
933 
934 	mutex_lock(&pcu->cmd_mutex);
935 	ims_pcu_handle_firmware_update(pcu, fw);
936 	mutex_unlock(&pcu->cmd_mutex);
937 
938 	release_firmware(fw);
939 
940 out:
941 	complete(&pcu->async_firmware_done);
942 }
943 
944 /*********************************************************************
945  *             Backlight LED device support                          *
946  *********************************************************************/
947 
948 #define IMS_PCU_MAX_BRIGHTNESS		31998
949 
950 static int ims_pcu_backlight_set_brightness(struct led_classdev *cdev,
951 					    enum led_brightness value)
952 {
953 	struct ims_pcu_backlight *backlight =
954 			container_of(cdev, struct ims_pcu_backlight, cdev);
955 	struct ims_pcu *pcu =
956 			container_of(backlight, struct ims_pcu, backlight);
957 	__le16 br_val = cpu_to_le16(value);
958 	int error;
959 
960 	mutex_lock(&pcu->cmd_mutex);
961 
962 	error = ims_pcu_execute_command(pcu, SET_BRIGHTNESS,
963 					&br_val, sizeof(br_val));
964 	if (error && error != -ENODEV)
965 		dev_warn(pcu->dev,
966 			 "Failed to set desired brightness %u, error: %d\n",
967 			 value, error);
968 
969 	mutex_unlock(&pcu->cmd_mutex);
970 
971 	return error;
972 }
973 
974 static enum led_brightness
975 ims_pcu_backlight_get_brightness(struct led_classdev *cdev)
976 {
977 	struct ims_pcu_backlight *backlight =
978 			container_of(cdev, struct ims_pcu_backlight, cdev);
979 	struct ims_pcu *pcu =
980 			container_of(backlight, struct ims_pcu, backlight);
981 	int brightness;
982 	int error;
983 
984 	mutex_lock(&pcu->cmd_mutex);
985 
986 	error = ims_pcu_execute_query(pcu, GET_BRIGHTNESS);
987 	if (error) {
988 		dev_warn(pcu->dev,
989 			 "Failed to get current brightness, error: %d\n",
990 			 error);
991 		/* Assume the LED is OFF */
992 		brightness = LED_OFF;
993 	} else {
994 		brightness =
995 			get_unaligned_le16(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET]);
996 	}
997 
998 	mutex_unlock(&pcu->cmd_mutex);
999 
1000 	return brightness;
1001 }
1002 
1003 static int ims_pcu_setup_backlight(struct ims_pcu *pcu)
1004 {
1005 	struct ims_pcu_backlight *backlight = &pcu->backlight;
1006 	int error;
1007 
1008 	snprintf(backlight->name, sizeof(backlight->name),
1009 		 "pcu%d::kbd_backlight", pcu->device_no);
1010 
1011 	backlight->cdev.name = backlight->name;
1012 	backlight->cdev.max_brightness = IMS_PCU_MAX_BRIGHTNESS;
1013 	backlight->cdev.brightness_get = ims_pcu_backlight_get_brightness;
1014 	backlight->cdev.brightness_set_blocking =
1015 					 ims_pcu_backlight_set_brightness;
1016 
1017 	error = led_classdev_register(pcu->dev, &backlight->cdev);
1018 	if (error) {
1019 		dev_err(pcu->dev,
1020 			"Failed to register backlight LED device, error: %d\n",
1021 			error);
1022 		return error;
1023 	}
1024 
1025 	return 0;
1026 }
1027 
1028 static void ims_pcu_destroy_backlight(struct ims_pcu *pcu)
1029 {
1030 	struct ims_pcu_backlight *backlight = &pcu->backlight;
1031 
1032 	led_classdev_unregister(&backlight->cdev);
1033 }
1034 
1035 
1036 /*********************************************************************
1037  *             Sysfs attributes handling                             *
1038  *********************************************************************/
1039 
1040 struct ims_pcu_attribute {
1041 	struct device_attribute dattr;
1042 	size_t field_offset;
1043 	int field_length;
1044 };
1045 
1046 static ssize_t ims_pcu_attribute_show(struct device *dev,
1047 				      struct device_attribute *dattr,
1048 				      char *buf)
1049 {
1050 	struct usb_interface *intf = to_usb_interface(dev);
1051 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1052 	struct ims_pcu_attribute *attr =
1053 			container_of(dattr, struct ims_pcu_attribute, dattr);
1054 	char *field = (char *)pcu + attr->field_offset;
1055 
1056 	return scnprintf(buf, PAGE_SIZE, "%.*s\n", attr->field_length, field);
1057 }
1058 
1059 static ssize_t ims_pcu_attribute_store(struct device *dev,
1060 				       struct device_attribute *dattr,
1061 				       const char *buf, size_t count)
1062 {
1063 
1064 	struct usb_interface *intf = to_usb_interface(dev);
1065 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1066 	struct ims_pcu_attribute *attr =
1067 			container_of(dattr, struct ims_pcu_attribute, dattr);
1068 	char *field = (char *)pcu + attr->field_offset;
1069 	size_t data_len;
1070 	int error;
1071 
1072 	if (count > attr->field_length)
1073 		return -EINVAL;
1074 
1075 	data_len = strnlen(buf, attr->field_length);
1076 	if (data_len > attr->field_length)
1077 		return -EINVAL;
1078 
1079 	error = mutex_lock_interruptible(&pcu->cmd_mutex);
1080 	if (error)
1081 		return error;
1082 
1083 	memset(field, 0, attr->field_length);
1084 	memcpy(field, buf, data_len);
1085 
1086 	error = ims_pcu_set_info(pcu);
1087 
1088 	/*
1089 	 * Even if update failed, let's fetch the info again as we just
1090 	 * clobbered one of the fields.
1091 	 */
1092 	ims_pcu_get_info(pcu);
1093 
1094 	mutex_unlock(&pcu->cmd_mutex);
1095 
1096 	return error < 0 ? error : count;
1097 }
1098 
1099 #define IMS_PCU_ATTR(_field, _mode)					\
1100 struct ims_pcu_attribute ims_pcu_attr_##_field = {			\
1101 	.dattr = __ATTR(_field, _mode,					\
1102 			ims_pcu_attribute_show,				\
1103 			ims_pcu_attribute_store),			\
1104 	.field_offset = offsetof(struct ims_pcu, _field),		\
1105 	.field_length = sizeof(((struct ims_pcu *)NULL)->_field),	\
1106 }
1107 
1108 #define IMS_PCU_RO_ATTR(_field)						\
1109 		IMS_PCU_ATTR(_field, S_IRUGO)
1110 #define IMS_PCU_RW_ATTR(_field)						\
1111 		IMS_PCU_ATTR(_field, S_IRUGO | S_IWUSR)
1112 
1113 static IMS_PCU_RW_ATTR(part_number);
1114 static IMS_PCU_RW_ATTR(serial_number);
1115 static IMS_PCU_RW_ATTR(date_of_manufacturing);
1116 
1117 static IMS_PCU_RO_ATTR(fw_version);
1118 static IMS_PCU_RO_ATTR(bl_version);
1119 static IMS_PCU_RO_ATTR(reset_reason);
1120 
1121 static ssize_t ims_pcu_reset_device(struct device *dev,
1122 				    struct device_attribute *dattr,
1123 				    const char *buf, size_t count)
1124 {
1125 	static const u8 reset_byte = 1;
1126 	struct usb_interface *intf = to_usb_interface(dev);
1127 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1128 	int value;
1129 	int error;
1130 
1131 	error = kstrtoint(buf, 0, &value);
1132 	if (error)
1133 		return error;
1134 
1135 	if (value != 1)
1136 		return -EINVAL;
1137 
1138 	dev_info(pcu->dev, "Attempting to reset device\n");
1139 
1140 	error = ims_pcu_execute_command(pcu, PCU_RESET, &reset_byte, 1);
1141 	if (error) {
1142 		dev_info(pcu->dev,
1143 			 "Failed to reset device, error: %d\n",
1144 			 error);
1145 		return error;
1146 	}
1147 
1148 	return count;
1149 }
1150 
1151 static DEVICE_ATTR(reset_device, S_IWUSR, NULL, ims_pcu_reset_device);
1152 
1153 static ssize_t ims_pcu_update_firmware_store(struct device *dev,
1154 					     struct device_attribute *dattr,
1155 					     const char *buf, size_t count)
1156 {
1157 	struct usb_interface *intf = to_usb_interface(dev);
1158 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1159 	const struct firmware *fw = NULL;
1160 	int value;
1161 	int error;
1162 
1163 	error = kstrtoint(buf, 0, &value);
1164 	if (error)
1165 		return error;
1166 
1167 	if (value != 1)
1168 		return -EINVAL;
1169 
1170 	error = mutex_lock_interruptible(&pcu->cmd_mutex);
1171 	if (error)
1172 		return error;
1173 
1174 	error = request_ihex_firmware(&fw, IMS_PCU_FIRMWARE_NAME, pcu->dev);
1175 	if (error) {
1176 		dev_err(pcu->dev, "Failed to request firmware %s, error: %d\n",
1177 			IMS_PCU_FIRMWARE_NAME, error);
1178 		goto out;
1179 	}
1180 
1181 	/*
1182 	 * If we are already in bootloader mode we can proceed with
1183 	 * flashing the firmware.
1184 	 *
1185 	 * If we are in application mode, then we need to switch into
1186 	 * bootloader mode, which will cause the device to disconnect
1187 	 * and reconnect as different device.
1188 	 */
1189 	if (pcu->bootloader_mode)
1190 		error = ims_pcu_handle_firmware_update(pcu, fw);
1191 	else
1192 		error = ims_pcu_switch_to_bootloader(pcu);
1193 
1194 	release_firmware(fw);
1195 
1196 out:
1197 	mutex_unlock(&pcu->cmd_mutex);
1198 	return error ?: count;
1199 }
1200 
1201 static DEVICE_ATTR(update_firmware, S_IWUSR,
1202 		   NULL, ims_pcu_update_firmware_store);
1203 
1204 static ssize_t
1205 ims_pcu_update_firmware_status_show(struct device *dev,
1206 				    struct device_attribute *dattr,
1207 				    char *buf)
1208 {
1209 	struct usb_interface *intf = to_usb_interface(dev);
1210 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1211 
1212 	return scnprintf(buf, PAGE_SIZE, "%d\n", pcu->update_firmware_status);
1213 }
1214 
1215 static DEVICE_ATTR(update_firmware_status, S_IRUGO,
1216 		   ims_pcu_update_firmware_status_show, NULL);
1217 
1218 static struct attribute *ims_pcu_attrs[] = {
1219 	&ims_pcu_attr_part_number.dattr.attr,
1220 	&ims_pcu_attr_serial_number.dattr.attr,
1221 	&ims_pcu_attr_date_of_manufacturing.dattr.attr,
1222 	&ims_pcu_attr_fw_version.dattr.attr,
1223 	&ims_pcu_attr_bl_version.dattr.attr,
1224 	&ims_pcu_attr_reset_reason.dattr.attr,
1225 	&dev_attr_reset_device.attr,
1226 	&dev_attr_update_firmware.attr,
1227 	&dev_attr_update_firmware_status.attr,
1228 	NULL
1229 };
1230 
1231 static umode_t ims_pcu_is_attr_visible(struct kobject *kobj,
1232 				       struct attribute *attr, int n)
1233 {
1234 	struct device *dev = container_of(kobj, struct device, kobj);
1235 	struct usb_interface *intf = to_usb_interface(dev);
1236 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1237 	umode_t mode = attr->mode;
1238 
1239 	if (pcu->bootloader_mode) {
1240 		if (attr != &dev_attr_update_firmware_status.attr &&
1241 		    attr != &dev_attr_update_firmware.attr &&
1242 		    attr != &dev_attr_reset_device.attr) {
1243 			mode = 0;
1244 		}
1245 	} else {
1246 		if (attr == &dev_attr_update_firmware_status.attr)
1247 			mode = 0;
1248 	}
1249 
1250 	return mode;
1251 }
1252 
1253 static const struct attribute_group ims_pcu_attr_group = {
1254 	.is_visible	= ims_pcu_is_attr_visible,
1255 	.attrs		= ims_pcu_attrs,
1256 };
1257 
1258 /* Support for a separate OFN attribute group */
1259 
1260 #define OFN_REG_RESULT_OFFSET	2
1261 
1262 static int ims_pcu_read_ofn_config(struct ims_pcu *pcu, u8 addr, u8 *data)
1263 {
1264 	int error;
1265 	s16 result;
1266 
1267 	error = ims_pcu_execute_command(pcu, OFN_GET_CONFIG,
1268 					&addr, sizeof(addr));
1269 	if (error)
1270 		return error;
1271 
1272 	result = (s16)get_unaligned_le16(pcu->cmd_buf + OFN_REG_RESULT_OFFSET);
1273 	if (result < 0)
1274 		return -EIO;
1275 
1276 	/* We only need LSB */
1277 	*data = pcu->cmd_buf[OFN_REG_RESULT_OFFSET];
1278 	return 0;
1279 }
1280 
1281 static int ims_pcu_write_ofn_config(struct ims_pcu *pcu, u8 addr, u8 data)
1282 {
1283 	u8 buffer[] = { addr, data };
1284 	int error;
1285 	s16 result;
1286 
1287 	error = ims_pcu_execute_command(pcu, OFN_SET_CONFIG,
1288 					&buffer, sizeof(buffer));
1289 	if (error)
1290 		return error;
1291 
1292 	result = (s16)get_unaligned_le16(pcu->cmd_buf + OFN_REG_RESULT_OFFSET);
1293 	if (result < 0)
1294 		return -EIO;
1295 
1296 	return 0;
1297 }
1298 
1299 static ssize_t ims_pcu_ofn_reg_data_show(struct device *dev,
1300 					 struct device_attribute *dattr,
1301 					 char *buf)
1302 {
1303 	struct usb_interface *intf = to_usb_interface(dev);
1304 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1305 	int error;
1306 	u8 data;
1307 
1308 	mutex_lock(&pcu->cmd_mutex);
1309 	error = ims_pcu_read_ofn_config(pcu, pcu->ofn_reg_addr, &data);
1310 	mutex_unlock(&pcu->cmd_mutex);
1311 
1312 	if (error)
1313 		return error;
1314 
1315 	return scnprintf(buf, PAGE_SIZE, "%x\n", data);
1316 }
1317 
1318 static ssize_t ims_pcu_ofn_reg_data_store(struct device *dev,
1319 					  struct device_attribute *dattr,
1320 					  const char *buf, size_t count)
1321 {
1322 	struct usb_interface *intf = to_usb_interface(dev);
1323 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1324 	int error;
1325 	u8 value;
1326 
1327 	error = kstrtou8(buf, 0, &value);
1328 	if (error)
1329 		return error;
1330 
1331 	mutex_lock(&pcu->cmd_mutex);
1332 	error = ims_pcu_write_ofn_config(pcu, pcu->ofn_reg_addr, value);
1333 	mutex_unlock(&pcu->cmd_mutex);
1334 
1335 	return error ?: count;
1336 }
1337 
1338 static DEVICE_ATTR(reg_data, S_IRUGO | S_IWUSR,
1339 		   ims_pcu_ofn_reg_data_show, ims_pcu_ofn_reg_data_store);
1340 
1341 static ssize_t ims_pcu_ofn_reg_addr_show(struct device *dev,
1342 					 struct device_attribute *dattr,
1343 					 char *buf)
1344 {
1345 	struct usb_interface *intf = to_usb_interface(dev);
1346 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1347 	int error;
1348 
1349 	mutex_lock(&pcu->cmd_mutex);
1350 	error = scnprintf(buf, PAGE_SIZE, "%x\n", pcu->ofn_reg_addr);
1351 	mutex_unlock(&pcu->cmd_mutex);
1352 
1353 	return error;
1354 }
1355 
1356 static ssize_t ims_pcu_ofn_reg_addr_store(struct device *dev,
1357 					  struct device_attribute *dattr,
1358 					  const char *buf, size_t count)
1359 {
1360 	struct usb_interface *intf = to_usb_interface(dev);
1361 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1362 	int error;
1363 	u8 value;
1364 
1365 	error = kstrtou8(buf, 0, &value);
1366 	if (error)
1367 		return error;
1368 
1369 	mutex_lock(&pcu->cmd_mutex);
1370 	pcu->ofn_reg_addr = value;
1371 	mutex_unlock(&pcu->cmd_mutex);
1372 
1373 	return count;
1374 }
1375 
1376 static DEVICE_ATTR(reg_addr, S_IRUGO | S_IWUSR,
1377 		   ims_pcu_ofn_reg_addr_show, ims_pcu_ofn_reg_addr_store);
1378 
1379 struct ims_pcu_ofn_bit_attribute {
1380 	struct device_attribute dattr;
1381 	u8 addr;
1382 	u8 nr;
1383 };
1384 
1385 static ssize_t ims_pcu_ofn_bit_show(struct device *dev,
1386 				    struct device_attribute *dattr,
1387 				    char *buf)
1388 {
1389 	struct usb_interface *intf = to_usb_interface(dev);
1390 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1391 	struct ims_pcu_ofn_bit_attribute *attr =
1392 		container_of(dattr, struct ims_pcu_ofn_bit_attribute, dattr);
1393 	int error;
1394 	u8 data;
1395 
1396 	mutex_lock(&pcu->cmd_mutex);
1397 	error = ims_pcu_read_ofn_config(pcu, attr->addr, &data);
1398 	mutex_unlock(&pcu->cmd_mutex);
1399 
1400 	if (error)
1401 		return error;
1402 
1403 	return scnprintf(buf, PAGE_SIZE, "%d\n", !!(data & (1 << attr->nr)));
1404 }
1405 
1406 static ssize_t ims_pcu_ofn_bit_store(struct device *dev,
1407 				     struct device_attribute *dattr,
1408 				     const char *buf, size_t count)
1409 {
1410 	struct usb_interface *intf = to_usb_interface(dev);
1411 	struct ims_pcu *pcu = usb_get_intfdata(intf);
1412 	struct ims_pcu_ofn_bit_attribute *attr =
1413 		container_of(dattr, struct ims_pcu_ofn_bit_attribute, dattr);
1414 	int error;
1415 	int value;
1416 	u8 data;
1417 
1418 	error = kstrtoint(buf, 0, &value);
1419 	if (error)
1420 		return error;
1421 
1422 	if (value > 1)
1423 		return -EINVAL;
1424 
1425 	mutex_lock(&pcu->cmd_mutex);
1426 
1427 	error = ims_pcu_read_ofn_config(pcu, attr->addr, &data);
1428 	if (!error) {
1429 		if (value)
1430 			data |= 1U << attr->nr;
1431 		else
1432 			data &= ~(1U << attr->nr);
1433 
1434 		error = ims_pcu_write_ofn_config(pcu, attr->addr, data);
1435 	}
1436 
1437 	mutex_unlock(&pcu->cmd_mutex);
1438 
1439 	return error ?: count;
1440 }
1441 
1442 #define IMS_PCU_OFN_BIT_ATTR(_field, _addr, _nr)			\
1443 struct ims_pcu_ofn_bit_attribute ims_pcu_ofn_attr_##_field = {		\
1444 	.dattr = __ATTR(_field, S_IWUSR | S_IRUGO,			\
1445 			ims_pcu_ofn_bit_show, ims_pcu_ofn_bit_store),	\
1446 	.addr = _addr,							\
1447 	.nr = _nr,							\
1448 }
1449 
1450 static IMS_PCU_OFN_BIT_ATTR(engine_enable,   0x60, 7);
1451 static IMS_PCU_OFN_BIT_ATTR(speed_enable,    0x60, 6);
1452 static IMS_PCU_OFN_BIT_ATTR(assert_enable,   0x60, 5);
1453 static IMS_PCU_OFN_BIT_ATTR(xyquant_enable,  0x60, 4);
1454 static IMS_PCU_OFN_BIT_ATTR(xyscale_enable,  0x60, 1);
1455 
1456 static IMS_PCU_OFN_BIT_ATTR(scale_x2,        0x63, 6);
1457 static IMS_PCU_OFN_BIT_ATTR(scale_y2,        0x63, 7);
1458 
1459 static struct attribute *ims_pcu_ofn_attrs[] = {
1460 	&dev_attr_reg_data.attr,
1461 	&dev_attr_reg_addr.attr,
1462 	&ims_pcu_ofn_attr_engine_enable.dattr.attr,
1463 	&ims_pcu_ofn_attr_speed_enable.dattr.attr,
1464 	&ims_pcu_ofn_attr_assert_enable.dattr.attr,
1465 	&ims_pcu_ofn_attr_xyquant_enable.dattr.attr,
1466 	&ims_pcu_ofn_attr_xyscale_enable.dattr.attr,
1467 	&ims_pcu_ofn_attr_scale_x2.dattr.attr,
1468 	&ims_pcu_ofn_attr_scale_y2.dattr.attr,
1469 	NULL
1470 };
1471 
1472 static const struct attribute_group ims_pcu_ofn_attr_group = {
1473 	.name	= "ofn",
1474 	.attrs	= ims_pcu_ofn_attrs,
1475 };
1476 
1477 static void ims_pcu_irq(struct urb *urb)
1478 {
1479 	struct ims_pcu *pcu = urb->context;
1480 	int retval, status;
1481 
1482 	status = urb->status;
1483 
1484 	switch (status) {
1485 	case 0:
1486 		/* success */
1487 		break;
1488 	case -ECONNRESET:
1489 	case -ENOENT:
1490 	case -ESHUTDOWN:
1491 		/* this urb is terminated, clean up */
1492 		dev_dbg(pcu->dev, "%s - urb shutting down with status: %d\n",
1493 			__func__, status);
1494 		return;
1495 	default:
1496 		dev_dbg(pcu->dev, "%s - nonzero urb status received: %d\n",
1497 			__func__, status);
1498 		goto exit;
1499 	}
1500 
1501 	dev_dbg(pcu->dev, "%s: received %d: %*ph\n", __func__,
1502 		urb->actual_length, urb->actual_length, pcu->urb_in_buf);
1503 
1504 	if (urb == pcu->urb_in)
1505 		ims_pcu_process_data(pcu, urb);
1506 
1507 exit:
1508 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1509 	if (retval && retval != -ENODEV)
1510 		dev_err(pcu->dev, "%s - usb_submit_urb failed with result %d\n",
1511 			__func__, retval);
1512 }
1513 
1514 static int ims_pcu_buffers_alloc(struct ims_pcu *pcu)
1515 {
1516 	int error;
1517 
1518 	pcu->urb_in_buf = usb_alloc_coherent(pcu->udev, pcu->max_in_size,
1519 					     GFP_KERNEL, &pcu->read_dma);
1520 	if (!pcu->urb_in_buf) {
1521 		dev_err(pcu->dev,
1522 			"Failed to allocate memory for read buffer\n");
1523 		return -ENOMEM;
1524 	}
1525 
1526 	pcu->urb_in = usb_alloc_urb(0, GFP_KERNEL);
1527 	if (!pcu->urb_in) {
1528 		dev_err(pcu->dev, "Failed to allocate input URB\n");
1529 		error = -ENOMEM;
1530 		goto err_free_urb_in_buf;
1531 	}
1532 
1533 	pcu->urb_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1534 	pcu->urb_in->transfer_dma = pcu->read_dma;
1535 
1536 	usb_fill_bulk_urb(pcu->urb_in, pcu->udev,
1537 			  usb_rcvbulkpipe(pcu->udev,
1538 					  pcu->ep_in->bEndpointAddress),
1539 			  pcu->urb_in_buf, pcu->max_in_size,
1540 			  ims_pcu_irq, pcu);
1541 
1542 	/*
1543 	 * We are using usb_bulk_msg() for sending so there is no point
1544 	 * in allocating memory with usb_alloc_coherent().
1545 	 */
1546 	pcu->urb_out_buf = kmalloc(pcu->max_out_size, GFP_KERNEL);
1547 	if (!pcu->urb_out_buf) {
1548 		dev_err(pcu->dev, "Failed to allocate memory for write buffer\n");
1549 		error = -ENOMEM;
1550 		goto err_free_in_urb;
1551 	}
1552 
1553 	pcu->urb_ctrl_buf = usb_alloc_coherent(pcu->udev, pcu->max_ctrl_size,
1554 					       GFP_KERNEL, &pcu->ctrl_dma);
1555 	if (!pcu->urb_ctrl_buf) {
1556 		dev_err(pcu->dev,
1557 			"Failed to allocate memory for read buffer\n");
1558 		error = -ENOMEM;
1559 		goto err_free_urb_out_buf;
1560 	}
1561 
1562 	pcu->urb_ctrl = usb_alloc_urb(0, GFP_KERNEL);
1563 	if (!pcu->urb_ctrl) {
1564 		dev_err(pcu->dev, "Failed to allocate input URB\n");
1565 		error = -ENOMEM;
1566 		goto err_free_urb_ctrl_buf;
1567 	}
1568 
1569 	pcu->urb_ctrl->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1570 	pcu->urb_ctrl->transfer_dma = pcu->ctrl_dma;
1571 
1572 	usb_fill_int_urb(pcu->urb_ctrl, pcu->udev,
1573 			  usb_rcvintpipe(pcu->udev,
1574 					 pcu->ep_ctrl->bEndpointAddress),
1575 			  pcu->urb_ctrl_buf, pcu->max_ctrl_size,
1576 			  ims_pcu_irq, pcu, pcu->ep_ctrl->bInterval);
1577 
1578 	return 0;
1579 
1580 err_free_urb_ctrl_buf:
1581 	usb_free_coherent(pcu->udev, pcu->max_ctrl_size,
1582 			  pcu->urb_ctrl_buf, pcu->ctrl_dma);
1583 err_free_urb_out_buf:
1584 	kfree(pcu->urb_out_buf);
1585 err_free_in_urb:
1586 	usb_free_urb(pcu->urb_in);
1587 err_free_urb_in_buf:
1588 	usb_free_coherent(pcu->udev, pcu->max_in_size,
1589 			  pcu->urb_in_buf, pcu->read_dma);
1590 	return error;
1591 }
1592 
1593 static void ims_pcu_buffers_free(struct ims_pcu *pcu)
1594 {
1595 	usb_kill_urb(pcu->urb_in);
1596 	usb_free_urb(pcu->urb_in);
1597 
1598 	usb_free_coherent(pcu->udev, pcu->max_out_size,
1599 			  pcu->urb_in_buf, pcu->read_dma);
1600 
1601 	kfree(pcu->urb_out_buf);
1602 
1603 	usb_kill_urb(pcu->urb_ctrl);
1604 	usb_free_urb(pcu->urb_ctrl);
1605 
1606 	usb_free_coherent(pcu->udev, pcu->max_ctrl_size,
1607 			  pcu->urb_ctrl_buf, pcu->ctrl_dma);
1608 }
1609 
1610 static const struct usb_cdc_union_desc *
1611 ims_pcu_get_cdc_union_desc(struct usb_interface *intf)
1612 {
1613 	const void *buf = intf->altsetting->extra;
1614 	size_t buflen = intf->altsetting->extralen;
1615 	struct usb_cdc_union_desc *union_desc;
1616 
1617 	if (!buf) {
1618 		dev_err(&intf->dev, "Missing descriptor data\n");
1619 		return NULL;
1620 	}
1621 
1622 	if (!buflen) {
1623 		dev_err(&intf->dev, "Zero length descriptor\n");
1624 		return NULL;
1625 	}
1626 
1627 	while (buflen >= sizeof(*union_desc)) {
1628 		union_desc = (struct usb_cdc_union_desc *)buf;
1629 
1630 		if (union_desc->bLength > buflen) {
1631 			dev_err(&intf->dev, "Too large descriptor\n");
1632 			return NULL;
1633 		}
1634 
1635 		if (union_desc->bDescriptorType == USB_DT_CS_INTERFACE &&
1636 		    union_desc->bDescriptorSubType == USB_CDC_UNION_TYPE) {
1637 			dev_dbg(&intf->dev, "Found union header\n");
1638 
1639 			if (union_desc->bLength >= sizeof(*union_desc))
1640 				return union_desc;
1641 
1642 			dev_err(&intf->dev,
1643 				"Union descriptor too short (%d vs %zd)\n",
1644 				union_desc->bLength, sizeof(*union_desc));
1645 			return NULL;
1646 		}
1647 
1648 		buflen -= union_desc->bLength;
1649 		buf += union_desc->bLength;
1650 	}
1651 
1652 	dev_err(&intf->dev, "Missing CDC union descriptor\n");
1653 	return NULL;
1654 }
1655 
1656 static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pcu)
1657 {
1658 	const struct usb_cdc_union_desc *union_desc;
1659 	struct usb_host_interface *alt;
1660 
1661 	union_desc = ims_pcu_get_cdc_union_desc(intf);
1662 	if (!union_desc)
1663 		return -EINVAL;
1664 
1665 	pcu->ctrl_intf = usb_ifnum_to_if(pcu->udev,
1666 					 union_desc->bMasterInterface0);
1667 	if (!pcu->ctrl_intf)
1668 		return -EINVAL;
1669 
1670 	alt = pcu->ctrl_intf->cur_altsetting;
1671 
1672 	if (alt->desc.bNumEndpoints < 1)
1673 		return -ENODEV;
1674 
1675 	pcu->ep_ctrl = &alt->endpoint[0].desc;
1676 	pcu->max_ctrl_size = usb_endpoint_maxp(pcu->ep_ctrl);
1677 
1678 	pcu->data_intf = usb_ifnum_to_if(pcu->udev,
1679 					 union_desc->bSlaveInterface0);
1680 	if (!pcu->data_intf)
1681 		return -EINVAL;
1682 
1683 	alt = pcu->data_intf->cur_altsetting;
1684 	if (alt->desc.bNumEndpoints != 2) {
1685 		dev_err(pcu->dev,
1686 			"Incorrect number of endpoints on data interface (%d)\n",
1687 			alt->desc.bNumEndpoints);
1688 		return -EINVAL;
1689 	}
1690 
1691 	pcu->ep_out = &alt->endpoint[0].desc;
1692 	if (!usb_endpoint_is_bulk_out(pcu->ep_out)) {
1693 		dev_err(pcu->dev,
1694 			"First endpoint on data interface is not BULK OUT\n");
1695 		return -EINVAL;
1696 	}
1697 
1698 	pcu->max_out_size = usb_endpoint_maxp(pcu->ep_out);
1699 	if (pcu->max_out_size < 8) {
1700 		dev_err(pcu->dev,
1701 			"Max OUT packet size is too small (%zd)\n",
1702 			pcu->max_out_size);
1703 		return -EINVAL;
1704 	}
1705 
1706 	pcu->ep_in = &alt->endpoint[1].desc;
1707 	if (!usb_endpoint_is_bulk_in(pcu->ep_in)) {
1708 		dev_err(pcu->dev,
1709 			"Second endpoint on data interface is not BULK IN\n");
1710 		return -EINVAL;
1711 	}
1712 
1713 	pcu->max_in_size = usb_endpoint_maxp(pcu->ep_in);
1714 	if (pcu->max_in_size < 8) {
1715 		dev_err(pcu->dev,
1716 			"Max IN packet size is too small (%zd)\n",
1717 			pcu->max_in_size);
1718 		return -EINVAL;
1719 	}
1720 
1721 	return 0;
1722 }
1723 
1724 static int ims_pcu_start_io(struct ims_pcu *pcu)
1725 {
1726 	int error;
1727 
1728 	error = usb_submit_urb(pcu->urb_ctrl, GFP_KERNEL);
1729 	if (error) {
1730 		dev_err(pcu->dev,
1731 			"Failed to start control IO - usb_submit_urb failed with result: %d\n",
1732 			error);
1733 		return -EIO;
1734 	}
1735 
1736 	error = usb_submit_urb(pcu->urb_in, GFP_KERNEL);
1737 	if (error) {
1738 		dev_err(pcu->dev,
1739 			"Failed to start IO - usb_submit_urb failed with result: %d\n",
1740 			error);
1741 		usb_kill_urb(pcu->urb_ctrl);
1742 		return -EIO;
1743 	}
1744 
1745 	return 0;
1746 }
1747 
1748 static void ims_pcu_stop_io(struct ims_pcu *pcu)
1749 {
1750 	usb_kill_urb(pcu->urb_in);
1751 	usb_kill_urb(pcu->urb_ctrl);
1752 }
1753 
1754 static int ims_pcu_line_setup(struct ims_pcu *pcu)
1755 {
1756 	struct usb_host_interface *interface = pcu->ctrl_intf->cur_altsetting;
1757 	struct usb_cdc_line_coding *line = (void *)pcu->cmd_buf;
1758 	int error;
1759 
1760 	memset(line, 0, sizeof(*line));
1761 	line->dwDTERate = cpu_to_le32(57600);
1762 	line->bDataBits = 8;
1763 
1764 	error = usb_control_msg(pcu->udev, usb_sndctrlpipe(pcu->udev, 0),
1765 				USB_CDC_REQ_SET_LINE_CODING,
1766 				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1767 				0, interface->desc.bInterfaceNumber,
1768 				line, sizeof(struct usb_cdc_line_coding),
1769 				5000);
1770 	if (error < 0) {
1771 		dev_err(pcu->dev, "Failed to set line coding, error: %d\n",
1772 			error);
1773 		return error;
1774 	}
1775 
1776 	error = usb_control_msg(pcu->udev, usb_sndctrlpipe(pcu->udev, 0),
1777 				USB_CDC_REQ_SET_CONTROL_LINE_STATE,
1778 				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1779 				0x03, interface->desc.bInterfaceNumber,
1780 				NULL, 0, 5000);
1781 	if (error < 0) {
1782 		dev_err(pcu->dev, "Failed to set line state, error: %d\n",
1783 			error);
1784 		return error;
1785 	}
1786 
1787 	return 0;
1788 }
1789 
1790 static int ims_pcu_get_device_info(struct ims_pcu *pcu)
1791 {
1792 	int error;
1793 
1794 	error = ims_pcu_get_info(pcu);
1795 	if (error)
1796 		return error;
1797 
1798 	error = ims_pcu_execute_query(pcu, GET_FW_VERSION);
1799 	if (error) {
1800 		dev_err(pcu->dev,
1801 			"GET_FW_VERSION command failed, error: %d\n", error);
1802 		return error;
1803 	}
1804 
1805 	snprintf(pcu->fw_version, sizeof(pcu->fw_version),
1806 		 "%02d%02d%02d%02d.%c%c",
1807 		 pcu->cmd_buf[2], pcu->cmd_buf[3], pcu->cmd_buf[4], pcu->cmd_buf[5],
1808 		 pcu->cmd_buf[6], pcu->cmd_buf[7]);
1809 
1810 	error = ims_pcu_execute_query(pcu, GET_BL_VERSION);
1811 	if (error) {
1812 		dev_err(pcu->dev,
1813 			"GET_BL_VERSION command failed, error: %d\n", error);
1814 		return error;
1815 	}
1816 
1817 	snprintf(pcu->bl_version, sizeof(pcu->bl_version),
1818 		 "%02d%02d%02d%02d.%c%c",
1819 		 pcu->cmd_buf[2], pcu->cmd_buf[3], pcu->cmd_buf[4], pcu->cmd_buf[5],
1820 		 pcu->cmd_buf[6], pcu->cmd_buf[7]);
1821 
1822 	error = ims_pcu_execute_query(pcu, RESET_REASON);
1823 	if (error) {
1824 		dev_err(pcu->dev,
1825 			"RESET_REASON command failed, error: %d\n", error);
1826 		return error;
1827 	}
1828 
1829 	snprintf(pcu->reset_reason, sizeof(pcu->reset_reason),
1830 		 "%02x", pcu->cmd_buf[IMS_PCU_DATA_OFFSET]);
1831 
1832 	dev_dbg(pcu->dev,
1833 		"P/N: %s, MD: %s, S/N: %s, FW: %s, BL: %s, RR: %s\n",
1834 		pcu->part_number,
1835 		pcu->date_of_manufacturing,
1836 		pcu->serial_number,
1837 		pcu->fw_version,
1838 		pcu->bl_version,
1839 		pcu->reset_reason);
1840 
1841 	return 0;
1842 }
1843 
1844 static int ims_pcu_identify_type(struct ims_pcu *pcu, u8 *device_id)
1845 {
1846 	int error;
1847 
1848 	error = ims_pcu_execute_query(pcu, GET_DEVICE_ID);
1849 	if (error) {
1850 		dev_err(pcu->dev,
1851 			"GET_DEVICE_ID command failed, error: %d\n", error);
1852 		return error;
1853 	}
1854 
1855 	*device_id = pcu->cmd_buf[IMS_PCU_DATA_OFFSET];
1856 	dev_dbg(pcu->dev, "Detected device ID: %d\n", *device_id);
1857 
1858 	return 0;
1859 }
1860 
1861 static int ims_pcu_init_application_mode(struct ims_pcu *pcu)
1862 {
1863 	static atomic_t device_no = ATOMIC_INIT(-1);
1864 
1865 	const struct ims_pcu_device_info *info;
1866 	int error;
1867 
1868 	error = ims_pcu_get_device_info(pcu);
1869 	if (error) {
1870 		/* Device does not respond to basic queries, hopeless */
1871 		return error;
1872 	}
1873 
1874 	error = ims_pcu_identify_type(pcu, &pcu->device_id);
1875 	if (error) {
1876 		dev_err(pcu->dev,
1877 			"Failed to identify device, error: %d\n", error);
1878 		/*
1879 		 * Do not signal error, but do not create input nor
1880 		 * backlight devices either, let userspace figure this
1881 		 * out (flash a new firmware?).
1882 		 */
1883 		return 0;
1884 	}
1885 
1886 	if (pcu->device_id >= ARRAY_SIZE(ims_pcu_device_info) ||
1887 	    !ims_pcu_device_info[pcu->device_id].keymap) {
1888 		dev_err(pcu->dev, "Device ID %d is not valid\n", pcu->device_id);
1889 		/* Same as above, punt to userspace */
1890 		return 0;
1891 	}
1892 
1893 	/* Device appears to be operable, complete initialization */
1894 	pcu->device_no = atomic_inc_return(&device_no);
1895 
1896 	/*
1897 	 * PCU-B devices, both GEN_1 and GEN_2 do not have OFN sensor
1898 	 */
1899 	if (pcu->device_id != IMS_PCU_PCU_B_DEVICE_ID) {
1900 		error = sysfs_create_group(&pcu->dev->kobj,
1901 					   &ims_pcu_ofn_attr_group);
1902 		if (error)
1903 			return error;
1904 	}
1905 
1906 	error = ims_pcu_setup_backlight(pcu);
1907 	if (error)
1908 		return error;
1909 
1910 	info = &ims_pcu_device_info[pcu->device_id];
1911 	error = ims_pcu_setup_buttons(pcu, info->keymap, info->keymap_len);
1912 	if (error)
1913 		goto err_destroy_backlight;
1914 
1915 	if (info->has_gamepad) {
1916 		error = ims_pcu_setup_gamepad(pcu);
1917 		if (error)
1918 			goto err_destroy_buttons;
1919 	}
1920 
1921 	pcu->setup_complete = true;
1922 
1923 	return 0;
1924 
1925 err_destroy_buttons:
1926 	ims_pcu_destroy_buttons(pcu);
1927 err_destroy_backlight:
1928 	ims_pcu_destroy_backlight(pcu);
1929 	return error;
1930 }
1931 
1932 static void ims_pcu_destroy_application_mode(struct ims_pcu *pcu)
1933 {
1934 	if (pcu->setup_complete) {
1935 		pcu->setup_complete = false;
1936 		mb(); /* make sure flag setting is not reordered */
1937 
1938 		if (pcu->gamepad)
1939 			ims_pcu_destroy_gamepad(pcu);
1940 		ims_pcu_destroy_buttons(pcu);
1941 		ims_pcu_destroy_backlight(pcu);
1942 
1943 		if (pcu->device_id != IMS_PCU_PCU_B_DEVICE_ID)
1944 			sysfs_remove_group(&pcu->dev->kobj,
1945 					   &ims_pcu_ofn_attr_group);
1946 	}
1947 }
1948 
1949 static int ims_pcu_init_bootloader_mode(struct ims_pcu *pcu)
1950 {
1951 	int error;
1952 
1953 	error = ims_pcu_execute_bl_command(pcu, QUERY_DEVICE, NULL, 0,
1954 					   IMS_PCU_CMD_RESPONSE_TIMEOUT);
1955 	if (error) {
1956 		dev_err(pcu->dev, "Bootloader does not respond, aborting\n");
1957 		return error;
1958 	}
1959 
1960 	pcu->fw_start_addr =
1961 		get_unaligned_le32(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET + 11]);
1962 	pcu->fw_end_addr =
1963 		get_unaligned_le32(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET + 15]);
1964 
1965 	dev_info(pcu->dev,
1966 		 "Device is in bootloader mode (addr 0x%08x-0x%08x), requesting firmware\n",
1967 		 pcu->fw_start_addr, pcu->fw_end_addr);
1968 
1969 	error = request_firmware_nowait(THIS_MODULE, true,
1970 					IMS_PCU_FIRMWARE_NAME,
1971 					pcu->dev, GFP_KERNEL, pcu,
1972 					ims_pcu_process_async_firmware);
1973 	if (error) {
1974 		/* This error is not fatal, let userspace have another chance */
1975 		complete(&pcu->async_firmware_done);
1976 	}
1977 
1978 	return 0;
1979 }
1980 
1981 static void ims_pcu_destroy_bootloader_mode(struct ims_pcu *pcu)
1982 {
1983 	/* Make sure our initial firmware request has completed */
1984 	wait_for_completion(&pcu->async_firmware_done);
1985 }
1986 
1987 #define IMS_PCU_APPLICATION_MODE	0
1988 #define IMS_PCU_BOOTLOADER_MODE		1
1989 
1990 static struct usb_driver ims_pcu_driver;
1991 
1992 static int ims_pcu_probe(struct usb_interface *intf,
1993 			 const struct usb_device_id *id)
1994 {
1995 	struct usb_device *udev = interface_to_usbdev(intf);
1996 	struct ims_pcu *pcu;
1997 	int error;
1998 
1999 	pcu = kzalloc(sizeof(struct ims_pcu), GFP_KERNEL);
2000 	if (!pcu)
2001 		return -ENOMEM;
2002 
2003 	pcu->dev = &intf->dev;
2004 	pcu->udev = udev;
2005 	pcu->bootloader_mode = id->driver_info == IMS_PCU_BOOTLOADER_MODE;
2006 	mutex_init(&pcu->cmd_mutex);
2007 	init_completion(&pcu->cmd_done);
2008 	init_completion(&pcu->async_firmware_done);
2009 
2010 	error = ims_pcu_parse_cdc_data(intf, pcu);
2011 	if (error)
2012 		goto err_free_mem;
2013 
2014 	error = usb_driver_claim_interface(&ims_pcu_driver,
2015 					   pcu->data_intf, pcu);
2016 	if (error) {
2017 		dev_err(&intf->dev,
2018 			"Unable to claim corresponding data interface: %d\n",
2019 			error);
2020 		goto err_free_mem;
2021 	}
2022 
2023 	usb_set_intfdata(pcu->ctrl_intf, pcu);
2024 	usb_set_intfdata(pcu->data_intf, pcu);
2025 
2026 	error = ims_pcu_buffers_alloc(pcu);
2027 	if (error)
2028 		goto err_unclaim_intf;
2029 
2030 	error = ims_pcu_start_io(pcu);
2031 	if (error)
2032 		goto err_free_buffers;
2033 
2034 	error = ims_pcu_line_setup(pcu);
2035 	if (error)
2036 		goto err_stop_io;
2037 
2038 	error = sysfs_create_group(&intf->dev.kobj, &ims_pcu_attr_group);
2039 	if (error)
2040 		goto err_stop_io;
2041 
2042 	error = pcu->bootloader_mode ?
2043 			ims_pcu_init_bootloader_mode(pcu) :
2044 			ims_pcu_init_application_mode(pcu);
2045 	if (error)
2046 		goto err_remove_sysfs;
2047 
2048 	return 0;
2049 
2050 err_remove_sysfs:
2051 	sysfs_remove_group(&intf->dev.kobj, &ims_pcu_attr_group);
2052 err_stop_io:
2053 	ims_pcu_stop_io(pcu);
2054 err_free_buffers:
2055 	ims_pcu_buffers_free(pcu);
2056 err_unclaim_intf:
2057 	usb_driver_release_interface(&ims_pcu_driver, pcu->data_intf);
2058 err_free_mem:
2059 	kfree(pcu);
2060 	return error;
2061 }
2062 
2063 static void ims_pcu_disconnect(struct usb_interface *intf)
2064 {
2065 	struct ims_pcu *pcu = usb_get_intfdata(intf);
2066 	struct usb_host_interface *alt = intf->cur_altsetting;
2067 
2068 	usb_set_intfdata(intf, NULL);
2069 
2070 	/*
2071 	 * See if we are dealing with control or data interface. The cleanup
2072 	 * happens when we unbind primary (control) interface.
2073 	 */
2074 	if (alt->desc.bInterfaceClass != USB_CLASS_COMM)
2075 		return;
2076 
2077 	sysfs_remove_group(&intf->dev.kobj, &ims_pcu_attr_group);
2078 
2079 	ims_pcu_stop_io(pcu);
2080 
2081 	if (pcu->bootloader_mode)
2082 		ims_pcu_destroy_bootloader_mode(pcu);
2083 	else
2084 		ims_pcu_destroy_application_mode(pcu);
2085 
2086 	ims_pcu_buffers_free(pcu);
2087 	kfree(pcu);
2088 }
2089 
2090 #ifdef CONFIG_PM
2091 static int ims_pcu_suspend(struct usb_interface *intf,
2092 			   pm_message_t message)
2093 {
2094 	struct ims_pcu *pcu = usb_get_intfdata(intf);
2095 	struct usb_host_interface *alt = intf->cur_altsetting;
2096 
2097 	if (alt->desc.bInterfaceClass == USB_CLASS_COMM)
2098 		ims_pcu_stop_io(pcu);
2099 
2100 	return 0;
2101 }
2102 
2103 static int ims_pcu_resume(struct usb_interface *intf)
2104 {
2105 	struct ims_pcu *pcu = usb_get_intfdata(intf);
2106 	struct usb_host_interface *alt = intf->cur_altsetting;
2107 	int retval = 0;
2108 
2109 	if (alt->desc.bInterfaceClass == USB_CLASS_COMM) {
2110 		retval = ims_pcu_start_io(pcu);
2111 		if (retval == 0)
2112 			retval = ims_pcu_line_setup(pcu);
2113 	}
2114 
2115 	return retval;
2116 }
2117 #endif
2118 
2119 static const struct usb_device_id ims_pcu_id_table[] = {
2120 	{
2121 		USB_DEVICE_AND_INTERFACE_INFO(0x04d8, 0x0082,
2122 					USB_CLASS_COMM,
2123 					USB_CDC_SUBCLASS_ACM,
2124 					USB_CDC_ACM_PROTO_AT_V25TER),
2125 		.driver_info = IMS_PCU_APPLICATION_MODE,
2126 	},
2127 	{
2128 		USB_DEVICE_AND_INTERFACE_INFO(0x04d8, 0x0083,
2129 					USB_CLASS_COMM,
2130 					USB_CDC_SUBCLASS_ACM,
2131 					USB_CDC_ACM_PROTO_AT_V25TER),
2132 		.driver_info = IMS_PCU_BOOTLOADER_MODE,
2133 	},
2134 	{ }
2135 };
2136 
2137 static struct usb_driver ims_pcu_driver = {
2138 	.name			= "ims_pcu",
2139 	.id_table		= ims_pcu_id_table,
2140 	.probe			= ims_pcu_probe,
2141 	.disconnect		= ims_pcu_disconnect,
2142 #ifdef CONFIG_PM
2143 	.suspend		= ims_pcu_suspend,
2144 	.resume			= ims_pcu_resume,
2145 	.reset_resume		= ims_pcu_resume,
2146 #endif
2147 };
2148 
2149 module_usb_driver(ims_pcu_driver);
2150 
2151 MODULE_DESCRIPTION("IMS Passenger Control Unit driver");
2152 MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
2153 MODULE_LICENSE("GPL");
2154