xref: /linux/drivers/hid/intel-ish-hid/ipc/ipc.c (revision afeea2758b4f1210361ce2a91d8fa3e7df606ad2)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * H/W layer of ISHTP provider device (ISH)
4  *
5  * Copyright (c) 2014-2016, Intel Corporation.
6  */
7 
8 #include <linux/devm-helpers.h>
9 #include <linux/sched.h>
10 #include <linux/spinlock.h>
11 #include <linux/delay.h>
12 #include <linux/jiffies.h>
13 #include "client.h"
14 #include "hw-ish.h"
15 #include "hbm.h"
16 
17 /* For FW reset flow */
18 static struct work_struct fw_reset_work;
19 static struct ishtp_device *ishtp_dev;
20 
21 /**
22  * ish_reg_read() - Read register
23  * @dev: ISHTP device pointer
24  * @offset: Register offset
25  *
26  * Read 32 bit register at a given offset
27  *
28  * Return: Read register value
29  */
30 static inline uint32_t ish_reg_read(const struct ishtp_device *dev,
31 	unsigned long offset)
32 {
33 	struct ish_hw *hw = to_ish_hw(dev);
34 
35 	return readl(hw->mem_addr + offset);
36 }
37 
38 /**
39  * ish_reg_write() - Write register
40  * @dev: ISHTP device pointer
41  * @offset: Register offset
42  * @value: Value to write
43  *
44  * Writes 32 bit register at a give offset
45  */
46 static inline void ish_reg_write(struct ishtp_device *dev,
47 				 unsigned long offset,
48 				 uint32_t value)
49 {
50 	struct ish_hw *hw = to_ish_hw(dev);
51 
52 	writel(value, hw->mem_addr + offset);
53 }
54 
55 /**
56  * _ish_read_fw_sts_reg() - Read FW status register
57  * @dev: ISHTP device pointer
58  *
59  * Read FW status register
60  *
61  * Return: Read register value
62  */
63 static inline uint32_t _ish_read_fw_sts_reg(struct ishtp_device *dev)
64 {
65 	return ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
66 }
67 
68 /**
69  * check_generated_interrupt() - Check if ISH interrupt
70  * @dev: ISHTP device pointer
71  *
72  * Check if an interrupt was generated for ISH
73  *
74  * Return: Read true or false
75  */
76 static bool check_generated_interrupt(struct ishtp_device *dev)
77 {
78 	bool interrupt_generated = true;
79 	uint32_t pisr_val = 0;
80 
81 	if (dev->pdev->device == PCI_DEVICE_ID_INTEL_ISH_CHV) {
82 		pisr_val = ish_reg_read(dev, IPC_REG_PISR_CHV_AB);
83 		interrupt_generated =
84 			IPC_INT_FROM_ISH_TO_HOST_CHV_AB(pisr_val);
85 	} else {
86 		pisr_val = ish_reg_read(dev, IPC_REG_PISR_BXT);
87 		interrupt_generated = !!pisr_val;
88 		/* only busy-clear bit is RW, others are RO */
89 		if (pisr_val)
90 			ish_reg_write(dev, IPC_REG_PISR_BXT, pisr_val);
91 	}
92 
93 	return interrupt_generated;
94 }
95 
96 /**
97  * ish_is_input_ready() - Check if FW ready for RX
98  * @dev: ISHTP device pointer
99  *
100  * Check if ISH FW is ready for receiving data
101  *
102  * Return: Read true or false
103  */
104 static bool ish_is_input_ready(struct ishtp_device *dev)
105 {
106 	uint32_t doorbell_val;
107 
108 	doorbell_val = ish_reg_read(dev, IPC_REG_HOST2ISH_DRBL);
109 	return !IPC_IS_BUSY(doorbell_val);
110 }
111 
112 /**
113  * set_host_ready() - Indicate host ready
114  * @dev: ISHTP device pointer
115  *
116  * Set host ready indication to FW
117  */
118 static void set_host_ready(struct ishtp_device *dev)
119 {
120 	if (dev->pdev->device == PCI_DEVICE_ID_INTEL_ISH_CHV) {
121 		if (dev->pdev->revision == REVISION_ID_CHT_A0 ||
122 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
123 				REVISION_ID_CHT_Ax_SI)
124 			ish_reg_write(dev, IPC_REG_HOST_COMM, 0x81);
125 		else if (dev->pdev->revision == REVISION_ID_CHT_B0 ||
126 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
127 				REVISION_ID_CHT_Bx_SI ||
128 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
129 				REVISION_ID_CHT_Kx_SI ||
130 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
131 				REVISION_ID_CHT_Dx_SI) {
132 			uint32_t host_comm_val;
133 
134 			host_comm_val = ish_reg_read(dev, IPC_REG_HOST_COMM);
135 			host_comm_val |= IPC_HOSTCOMM_INT_EN_BIT_CHV_AB | 0x81;
136 			ish_reg_write(dev, IPC_REG_HOST_COMM, host_comm_val);
137 		}
138 	} else {
139 			uint32_t host_pimr_val;
140 
141 			host_pimr_val = ish_reg_read(dev, IPC_REG_PIMR_BXT);
142 			host_pimr_val |= IPC_PIMR_INT_EN_BIT_BXT;
143 			/*
144 			 * disable interrupt generated instead of
145 			 * RX_complete_msg
146 			 */
147 			host_pimr_val &= ~IPC_HOST2ISH_BUSYCLEAR_MASK_BIT;
148 
149 			ish_reg_write(dev, IPC_REG_PIMR_BXT, host_pimr_val);
150 	}
151 }
152 
153 /**
154  * ishtp_fw_is_ready() - Check if FW ready
155  * @dev: ISHTP device pointer
156  *
157  * Check if ISH FW is ready
158  *
159  * Return: Read true or false
160  */
161 static bool ishtp_fw_is_ready(struct ishtp_device *dev)
162 {
163 	uint32_t ish_status = _ish_read_fw_sts_reg(dev);
164 
165 	return IPC_IS_ISH_ILUP(ish_status) &&
166 		IPC_IS_ISH_ISHTP_READY(ish_status);
167 }
168 
169 /**
170  * ish_set_host_rdy() - Indicate host ready
171  * @dev: ISHTP device pointer
172  *
173  * Set host ready indication to FW
174  */
175 static void ish_set_host_rdy(struct ishtp_device *dev)
176 {
177 	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
178 
179 	IPC_SET_HOST_READY(host_status);
180 	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
181 }
182 
183 /**
184  * ish_clr_host_rdy() - Indicate host not ready
185  * @dev: ISHTP device pointer
186  *
187  * Send host not ready indication to FW
188  */
189 static void ish_clr_host_rdy(struct ishtp_device *dev)
190 {
191 	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
192 
193 	IPC_CLEAR_HOST_READY(host_status);
194 	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
195 }
196 
197 static bool ish_chk_host_rdy(struct ishtp_device *dev)
198 {
199 	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
200 
201 	return (host_status & IPC_HOSTCOMM_READY_BIT);
202 }
203 
204 /**
205  * ish_set_host_ready() - reconfig ipc host registers
206  * @dev: ishtp device pointer
207  *
208  * Set host to ready state
209  * This API is called in some case:
210  *    fw is still on, but ipc is powered down.
211  *    such as OOB case.
212  *
213  * Return: 0 for success else error fault code
214  */
215 void ish_set_host_ready(struct ishtp_device *dev)
216 {
217 	if (ish_chk_host_rdy(dev))
218 		return;
219 
220 	ish_set_host_rdy(dev);
221 	set_host_ready(dev);
222 }
223 
224 /**
225  * _ishtp_read_hdr() - Read message header
226  * @dev: ISHTP device pointer
227  *
228  * Read header of 32bit length
229  *
230  * Return: Read register value
231  */
232 static uint32_t _ishtp_read_hdr(const struct ishtp_device *dev)
233 {
234 	return ish_reg_read(dev, IPC_REG_ISH2HOST_MSG);
235 }
236 
237 /**
238  * _ishtp_read - Read message
239  * @dev: ISHTP device pointer
240  * @buffer: message buffer
241  * @buffer_length: length of message buffer
242  *
243  * Read message from FW
244  *
245  * Return: Always 0
246  */
247 static int _ishtp_read(struct ishtp_device *dev, unsigned char *buffer,
248 	unsigned long buffer_length)
249 {
250 	uint32_t	i;
251 	uint32_t	*r_buf = (uint32_t *)buffer;
252 	uint32_t	msg_offs;
253 
254 	msg_offs = IPC_REG_ISH2HOST_MSG + sizeof(struct ishtp_msg_hdr);
255 	for (i = 0; i < buffer_length; i += sizeof(uint32_t))
256 		*r_buf++ = ish_reg_read(dev, msg_offs + i);
257 
258 	return 0;
259 }
260 
261 /**
262  * write_ipc_from_queue() - try to write ipc msg from Tx queue to device
263  * @dev: ishtp device pointer
264  *
265  * Check if DRBL is cleared. if it is - write the first IPC msg,  then call
266  * the callback function (unless it's NULL)
267  *
268  * Return: 0 for success else failure code
269  */
270 static int write_ipc_from_queue(struct ishtp_device *dev)
271 {
272 	struct wr_msg_ctl_info	*ipc_link;
273 	unsigned long	length;
274 	unsigned long	rem;
275 	unsigned long	flags;
276 	uint32_t	doorbell_val;
277 	uint32_t	*r_buf;
278 	uint32_t	reg_addr;
279 	int	i;
280 	void	(*ipc_send_compl)(void *);
281 	void	*ipc_send_compl_prm;
282 
283 	if (dev->dev_state == ISHTP_DEV_DISABLED)
284 		return -EINVAL;
285 
286 	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
287 	if (!ish_is_input_ready(dev)) {
288 		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
289 		return -EBUSY;
290 	}
291 
292 	/*
293 	 * if tx send list is empty - return 0;
294 	 * may happen, as RX_COMPLETE handler doesn't check list emptiness.
295 	 */
296 	if (list_empty(&dev->wr_processing_list)) {
297 		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
298 		return	0;
299 	}
300 
301 	ipc_link = list_first_entry(&dev->wr_processing_list,
302 				    struct wr_msg_ctl_info, link);
303 	/* first 4 bytes of the data is the doorbell value (IPC header) */
304 	length = ipc_link->length - sizeof(uint32_t);
305 	doorbell_val = *(uint32_t *)ipc_link->inline_data;
306 	r_buf = (uint32_t *)(ipc_link->inline_data + sizeof(uint32_t));
307 
308 	/* If sending MNG_SYNC_FW_CLOCK, update clock again */
309 	if (IPC_HEADER_GET_PROTOCOL(doorbell_val) == IPC_PROTOCOL_MNG &&
310 		IPC_HEADER_GET_MNG_CMD(doorbell_val) == MNG_SYNC_FW_CLOCK) {
311 		uint64_t usec_system, usec_utc;
312 		struct ipc_time_update_msg time_update;
313 		struct time_sync_format ts_format;
314 
315 		usec_system = ktime_to_us(ktime_get_boottime());
316 		usec_utc = ktime_to_us(ktime_get_real());
317 		ts_format.ts1_source = HOST_SYSTEM_TIME_USEC;
318 		ts_format.ts2_source = HOST_UTC_TIME_USEC;
319 		ts_format.reserved = 0;
320 
321 		time_update.primary_host_time = usec_system;
322 		time_update.secondary_host_time = usec_utc;
323 		time_update.sync_info = ts_format;
324 
325 		memcpy(r_buf, &time_update,
326 		       sizeof(struct ipc_time_update_msg));
327 	}
328 
329 	for (i = 0, reg_addr = IPC_REG_HOST2ISH_MSG; i < length >> 2; i++,
330 			reg_addr += 4)
331 		ish_reg_write(dev, reg_addr, r_buf[i]);
332 
333 	rem = length & 0x3;
334 	if (rem > 0) {
335 		uint32_t reg = 0;
336 
337 		memcpy(&reg, &r_buf[length >> 2], rem);
338 		ish_reg_write(dev, reg_addr, reg);
339 	}
340 	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, doorbell_val);
341 
342 	/* Flush writes to msg registers and doorbell */
343 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
344 
345 	/* Update IPC counters */
346 	++dev->ipc_tx_cnt;
347 	dev->ipc_tx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
348 
349 	ipc_send_compl = ipc_link->ipc_send_compl;
350 	ipc_send_compl_prm = ipc_link->ipc_send_compl_prm;
351 	list_del_init(&ipc_link->link);
352 	list_add(&ipc_link->link, &dev->wr_free_list);
353 	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
354 
355 	/*
356 	 * callback will be called out of spinlock,
357 	 * after ipc_link returned to free list
358 	 */
359 	if (ipc_send_compl)
360 		ipc_send_compl(ipc_send_compl_prm);
361 
362 	return 0;
363 }
364 
365 /**
366  * write_ipc_to_queue() - write ipc msg to Tx queue
367  * @dev: ishtp device instance
368  * @ipc_send_compl: Send complete callback
369  * @ipc_send_compl_prm:	Parameter to send in complete callback
370  * @msg: Pointer to message
371  * @length: Length of message
372  *
373  * Recived msg with IPC (and upper protocol) header  and add it to the device
374  *  Tx-to-write list then try to send the first IPC waiting msg
375  *  (if DRBL is cleared)
376  * This function returns negative value for failure (means free list
377  *  is empty, or msg too long) and 0 for success.
378  *
379  * Return: 0 for success else failure code
380  */
381 static int write_ipc_to_queue(struct ishtp_device *dev,
382 	void (*ipc_send_compl)(void *), void *ipc_send_compl_prm,
383 	unsigned char *msg, int length)
384 {
385 	struct wr_msg_ctl_info *ipc_link;
386 	unsigned long flags;
387 
388 	if (length > IPC_FULL_MSG_SIZE)
389 		return -EMSGSIZE;
390 
391 	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
392 	if (list_empty(&dev->wr_free_list)) {
393 		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
394 		return -ENOMEM;
395 	}
396 	ipc_link = list_first_entry(&dev->wr_free_list,
397 				    struct wr_msg_ctl_info, link);
398 	list_del_init(&ipc_link->link);
399 
400 	ipc_link->ipc_send_compl = ipc_send_compl;
401 	ipc_link->ipc_send_compl_prm = ipc_send_compl_prm;
402 	ipc_link->length = length;
403 	memcpy(ipc_link->inline_data, msg, length);
404 
405 	list_add_tail(&ipc_link->link, &dev->wr_processing_list);
406 	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
407 
408 	write_ipc_from_queue(dev);
409 
410 	return 0;
411 }
412 
413 /**
414  * ipc_send_mng_msg() - Send management message
415  * @dev: ishtp device instance
416  * @msg_code: Message code
417  * @msg: Pointer to message
418  * @size: Length of message
419  *
420  * Send management message to FW
421  *
422  * Return: 0 for success else failure code
423  */
424 static int ipc_send_mng_msg(struct ishtp_device *dev, uint32_t msg_code,
425 	void *msg, size_t size)
426 {
427 	unsigned char	ipc_msg[IPC_FULL_MSG_SIZE];
428 	uint32_t	drbl_val = IPC_BUILD_MNG_MSG(msg_code, size);
429 
430 	memcpy(ipc_msg, &drbl_val, sizeof(uint32_t));
431 	memcpy(ipc_msg + sizeof(uint32_t), msg, size);
432 	return	write_ipc_to_queue(dev, NULL, NULL, ipc_msg,
433 		sizeof(uint32_t) + size);
434 }
435 
436 #define WAIT_FOR_FW_RDY			0x1
437 #define WAIT_FOR_INPUT_RDY		0x2
438 
439 /**
440  * timed_wait_for_timeout() - wait special event with timeout
441  * @dev: ISHTP device pointer
442  * @condition: indicate the condition for waiting
443  * @timeinc: time slice for every wait cycle, in ms
444  * @timeout: time in ms for timeout
445  *
446  * This function will check special event to be ready in a loop, the loop
447  * period is specificd in timeinc. Wait timeout will causes failure.
448  *
449  * Return: 0 for success else failure code
450  */
451 static int timed_wait_for_timeout(struct ishtp_device *dev, int condition,
452 				unsigned int timeinc, unsigned int timeout)
453 {
454 	bool complete = false;
455 	int ret;
456 
457 	do {
458 		if (condition == WAIT_FOR_FW_RDY) {
459 			complete = ishtp_fw_is_ready(dev);
460 		} else if (condition == WAIT_FOR_INPUT_RDY) {
461 			complete = ish_is_input_ready(dev);
462 		} else {
463 			ret = -EINVAL;
464 			goto out;
465 		}
466 
467 		if (!complete) {
468 			unsigned long left_time;
469 
470 			left_time = msleep_interruptible(timeinc);
471 			timeout -= (timeinc - left_time);
472 		}
473 	} while (!complete && timeout > 0);
474 
475 	if (complete)
476 		ret = 0;
477 	else
478 		ret = -EBUSY;
479 
480 out:
481 	return ret;
482 }
483 
484 #define TIME_SLICE_FOR_FW_RDY_MS		100
485 #define TIME_SLICE_FOR_INPUT_RDY_MS		100
486 #define TIMEOUT_FOR_FW_RDY_MS			2000
487 #define TIMEOUT_FOR_INPUT_RDY_MS		2000
488 
489 /**
490  * ish_fw_reset_handler() - FW reset handler
491  * @dev: ishtp device pointer
492  *
493  * Handle FW reset
494  *
495  * Return: 0 for success else failure code
496  */
497 static int ish_fw_reset_handler(struct ishtp_device *dev)
498 {
499 	uint32_t	reset_id;
500 	unsigned long	flags;
501 
502 	/* Read reset ID */
503 	reset_id = ish_reg_read(dev, IPC_REG_ISH2HOST_MSG) & 0xFFFF;
504 
505 	/* Clear IPC output queue */
506 	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
507 	list_splice_init(&dev->wr_processing_list, &dev->wr_free_list);
508 	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
509 
510 	/* ISHTP notification in IPC_RESET */
511 	ishtp_reset_handler(dev);
512 
513 	if (!ish_is_input_ready(dev))
514 		timed_wait_for_timeout(dev, WAIT_FOR_INPUT_RDY,
515 			TIME_SLICE_FOR_INPUT_RDY_MS, TIMEOUT_FOR_INPUT_RDY_MS);
516 
517 	/* ISH FW is dead */
518 	if (!ish_is_input_ready(dev))
519 		return	-EPIPE;
520 	/*
521 	 * Set HOST2ISH.ILUP. Apparently we need this BEFORE sending
522 	 * RESET_NOTIFY_ACK - FW will be checking for it
523 	 */
524 	ish_set_host_rdy(dev);
525 	/* Send RESET_NOTIFY_ACK (with reset_id) */
526 	ipc_send_mng_msg(dev, MNG_RESET_NOTIFY_ACK, &reset_id,
527 			 sizeof(uint32_t));
528 
529 	/* Wait for ISH FW'es ILUP and ISHTP_READY */
530 	timed_wait_for_timeout(dev, WAIT_FOR_FW_RDY,
531 			TIME_SLICE_FOR_FW_RDY_MS, TIMEOUT_FOR_FW_RDY_MS);
532 	if (!ishtp_fw_is_ready(dev)) {
533 		/* ISH FW is dead */
534 		uint32_t	ish_status;
535 
536 		ish_status = _ish_read_fw_sts_reg(dev);
537 		dev_err(dev->devc,
538 			"[ishtp-ish]: completed reset, ISH is dead (FWSTS = %08X)\n",
539 			ish_status);
540 		return -ENODEV;
541 	}
542 	return	0;
543 }
544 
545 #define TIMEOUT_FOR_HW_RDY_MS			300
546 
547 /**
548  * fw_reset_work_fn() - FW reset worker function
549  * @work: Work item
550  *
551  * Call ish_fw_reset_handler to complete FW reset
552  */
553 static void fw_reset_work_fn(struct work_struct *work)
554 {
555 	int	rv;
556 
557 	rv = ish_fw_reset_handler(ishtp_dev);
558 	if (!rv) {
559 		/* ISH is ILUP & ISHTP-ready. Restart ISHTP */
560 		msleep_interruptible(TIMEOUT_FOR_HW_RDY_MS);
561 		ishtp_dev->recvd_hw_ready = 1;
562 		wake_up_interruptible(&ishtp_dev->wait_hw_ready);
563 
564 		/* ISHTP notification in IPC_RESET sequence completion */
565 		if (!work_pending(work))
566 			ishtp_reset_compl_handler(ishtp_dev);
567 	} else
568 		dev_err(ishtp_dev->devc, "[ishtp-ish]: FW reset failed (%d)\n",
569 			rv);
570 }
571 
572 /**
573  * _ish_sync_fw_clock() -Sync FW clock with the OS clock
574  * @dev: ishtp device pointer
575  *
576  * Sync FW and OS time
577  */
578 static void _ish_sync_fw_clock(struct ishtp_device *dev)
579 {
580 	static unsigned long	prev_sync;
581 	uint64_t	usec;
582 
583 	if (prev_sync && time_before(jiffies, prev_sync + 20 * HZ))
584 		return;
585 
586 	prev_sync = jiffies;
587 	usec = ktime_to_us(ktime_get_boottime());
588 	ipc_send_mng_msg(dev, MNG_SYNC_FW_CLOCK, &usec, sizeof(uint64_t));
589 }
590 
591 /**
592  * recv_ipc() - Receive and process IPC management messages
593  * @dev: ishtp device instance
594  * @doorbell_val: doorbell value
595  *
596  * This function runs in ISR context.
597  * NOTE: Any other mng command than reset_notify and reset_notify_ack
598  * won't wake BH handler
599  */
600 static void	recv_ipc(struct ishtp_device *dev, uint32_t doorbell_val)
601 {
602 	uint32_t	mng_cmd;
603 
604 	mng_cmd = IPC_HEADER_GET_MNG_CMD(doorbell_val);
605 
606 	switch (mng_cmd) {
607 	default:
608 		break;
609 
610 	case MNG_RX_CMPL_INDICATION:
611 		if (dev->suspend_flag) {
612 			dev->suspend_flag = 0;
613 			wake_up_interruptible(&dev->suspend_wait);
614 		}
615 		if (dev->resume_flag) {
616 			dev->resume_flag = 0;
617 			wake_up_interruptible(&dev->resume_wait);
618 		}
619 
620 		write_ipc_from_queue(dev);
621 		break;
622 
623 	case MNG_RESET_NOTIFY:
624 		if (!ishtp_dev) {
625 			ishtp_dev = dev;
626 		}
627 		schedule_work(&fw_reset_work);
628 		break;
629 
630 	case MNG_RESET_NOTIFY_ACK:
631 		dev->recvd_hw_ready = 1;
632 		wake_up_interruptible(&dev->wait_hw_ready);
633 		break;
634 	}
635 }
636 
637 /**
638  * ish_irq_handler() - ISH IRQ handler
639  * @irq: irq number
640  * @dev_id: ishtp device pointer
641  *
642  * ISH IRQ handler. If interrupt is generated and is for ISH it will process
643  * the interrupt.
644  */
645 irqreturn_t ish_irq_handler(int irq, void *dev_id)
646 {
647 	struct ishtp_device	*dev = dev_id;
648 	uint32_t	doorbell_val;
649 	bool	interrupt_generated;
650 
651 	/* Check that it's interrupt from ISH (may be shared) */
652 	interrupt_generated = check_generated_interrupt(dev);
653 
654 	if (!interrupt_generated)
655 		return IRQ_NONE;
656 
657 	doorbell_val = ish_reg_read(dev, IPC_REG_ISH2HOST_DRBL);
658 	if (!IPC_IS_BUSY(doorbell_val))
659 		return IRQ_HANDLED;
660 
661 	if (dev->dev_state == ISHTP_DEV_DISABLED)
662 		return	IRQ_HANDLED;
663 
664 	/* Sanity check: IPC dgram length in header */
665 	if (IPC_HEADER_GET_LENGTH(doorbell_val) > IPC_PAYLOAD_SIZE) {
666 		dev_err(dev->devc,
667 			"IPC hdr - bad length: %u; dropped\n",
668 			(unsigned int)IPC_HEADER_GET_LENGTH(doorbell_val));
669 		goto	eoi;
670 	}
671 
672 	switch (IPC_HEADER_GET_PROTOCOL(doorbell_val)) {
673 	default:
674 		break;
675 	case IPC_PROTOCOL_MNG:
676 		recv_ipc(dev, doorbell_val);
677 		break;
678 	case IPC_PROTOCOL_ISHTP:
679 		ishtp_recv(dev);
680 		break;
681 	}
682 
683 eoi:
684 	/* Update IPC counters */
685 	++dev->ipc_rx_cnt;
686 	dev->ipc_rx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
687 
688 	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
689 	/* Flush write to doorbell */
690 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
691 
692 	return	IRQ_HANDLED;
693 }
694 
695 /**
696  * ish_disable_dma() - disable dma communication between host and ISHFW
697  * @dev: ishtp device pointer
698  *
699  * Clear the dma enable bit and wait for dma inactive.
700  *
701  * Return: 0 for success else error code.
702  */
703 int ish_disable_dma(struct ishtp_device *dev)
704 {
705 	unsigned int	dma_delay;
706 
707 	/* Clear the dma enable bit */
708 	ish_reg_write(dev, IPC_REG_ISH_RMP2, 0);
709 
710 	/* wait for dma inactive */
711 	for (dma_delay = 0; dma_delay < MAX_DMA_DELAY &&
712 		_ish_read_fw_sts_reg(dev) & (IPC_ISH_IN_DMA);
713 		dma_delay += 5)
714 		mdelay(5);
715 
716 	if (dma_delay >= MAX_DMA_DELAY) {
717 		dev_err(dev->devc,
718 			"Wait for DMA inactive timeout\n");
719 		return	-EBUSY;
720 	}
721 
722 	return 0;
723 }
724 
725 /**
726  * ish_wakeup() - wakeup ishfw from waiting-for-host state
727  * @dev: ishtp device pointer
728  *
729  * Set the dma enable bit and send a void message to FW,
730  * it wil wakeup FW from waiting-for-host state.
731  */
732 static void ish_wakeup(struct ishtp_device *dev)
733 {
734 	/* Set dma enable bit */
735 	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
736 
737 	/*
738 	 * Send 0 IPC message so that ISH FW wakes up if it was already
739 	 * asleep.
740 	 */
741 	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
742 
743 	/* Flush writes to doorbell and REMAP2 */
744 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
745 }
746 
747 /**
748  * _ish_hw_reset() - HW reset
749  * @dev: ishtp device pointer
750  *
751  * Reset ISH HW to recover if any error
752  *
753  * Return: 0 for success else error fault code
754  */
755 static int _ish_hw_reset(struct ishtp_device *dev)
756 {
757 	struct pci_dev *pdev = dev->pdev;
758 	int	rv;
759 	uint16_t csr;
760 
761 	if (!pdev)
762 		return	-ENODEV;
763 
764 	rv = pci_reset_function(pdev);
765 	if (!rv)
766 		dev->dev_state = ISHTP_DEV_RESETTING;
767 
768 	if (!pdev->pm_cap) {
769 		dev_err(&pdev->dev, "Can't reset - no PM caps\n");
770 		return	-EINVAL;
771 	}
772 
773 	/* Disable dma communication between FW and host */
774 	if (ish_disable_dma(dev)) {
775 		dev_err(&pdev->dev,
776 			"Can't reset - stuck with DMA in-progress\n");
777 		return	-EBUSY;
778 	}
779 
780 	pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &csr);
781 
782 	csr &= ~PCI_PM_CTRL_STATE_MASK;
783 	csr |= PCI_D3hot;
784 	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
785 
786 	mdelay(pdev->d3hot_delay);
787 
788 	csr &= ~PCI_PM_CTRL_STATE_MASK;
789 	csr |= PCI_D0;
790 	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
791 
792 	/* Now we can enable ISH DMA operation and wakeup ISHFW */
793 	ish_wakeup(dev);
794 
795 	return	0;
796 }
797 
798 /**
799  * _ish_ipc_reset() - IPC reset
800  * @dev: ishtp device pointer
801  *
802  * Resets host and fw IPC and upper layers
803  *
804  * Return: 0 for success else error fault code
805  */
806 static int _ish_ipc_reset(struct ishtp_device *dev)
807 {
808 	struct ipc_rst_payload_type ipc_mng_msg;
809 	int	rv = 0;
810 
811 	ipc_mng_msg.reset_id = 1;
812 	ipc_mng_msg.reserved = 0;
813 
814 	set_host_ready(dev);
815 
816 	/* Clear the incoming doorbell */
817 	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
818 	/* Flush write to doorbell */
819 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
820 
821 	dev->recvd_hw_ready = 0;
822 
823 	/* send message */
824 	rv = ipc_send_mng_msg(dev, MNG_RESET_NOTIFY, &ipc_mng_msg,
825 		sizeof(struct ipc_rst_payload_type));
826 	if (rv) {
827 		dev_err(dev->devc, "Failed to send IPC MNG_RESET_NOTIFY\n");
828 		return	rv;
829 	}
830 
831 	wait_event_interruptible_timeout(dev->wait_hw_ready,
832 					 dev->recvd_hw_ready, 2 * HZ);
833 	if (!dev->recvd_hw_ready) {
834 		dev_err(dev->devc, "Timed out waiting for HW ready\n");
835 		rv = -ENODEV;
836 	}
837 
838 	return rv;
839 }
840 
841 /**
842  * ish_hw_start() -Start ISH HW
843  * @dev: ishtp device pointer
844  *
845  * Set host to ready state and wait for FW reset
846  *
847  * Return: 0 for success else error fault code
848  */
849 int ish_hw_start(struct ishtp_device *dev)
850 {
851 	ish_set_host_rdy(dev);
852 
853 	set_host_ready(dev);
854 
855 	/* After that we can enable ISH DMA operation and wakeup ISHFW */
856 	ish_wakeup(dev);
857 
858 	/* wait for FW-initiated reset flow */
859 	if (!dev->recvd_hw_ready)
860 		wait_event_interruptible_timeout(dev->wait_hw_ready,
861 						 dev->recvd_hw_ready,
862 						 10 * HZ);
863 
864 	if (!dev->recvd_hw_ready) {
865 		dev_err(dev->devc,
866 			"[ishtp-ish]: Timed out waiting for FW-initiated reset\n");
867 		return	-ENODEV;
868 	}
869 
870 	return 0;
871 }
872 
873 /**
874  * ish_ipc_get_header() -Get doorbell value
875  * @dev: ishtp device pointer
876  * @length: length of message
877  * @busy: busy status
878  *
879  * Get door bell value from message header
880  *
881  * Return: door bell value
882  */
883 static uint32_t ish_ipc_get_header(struct ishtp_device *dev, int length,
884 				   int busy)
885 {
886 	uint32_t drbl_val;
887 
888 	drbl_val = IPC_BUILD_HEADER(length, IPC_PROTOCOL_ISHTP, busy);
889 
890 	return drbl_val;
891 }
892 
893 /**
894  * _dma_no_cache_snooping()
895  *
896  * Check on current platform, DMA supports cache snooping or not.
897  * This callback is used to notify uplayer driver if manully cache
898  * flush is needed when do DMA operation.
899  *
900  * Please pay attention to this callback implementation, if declare
901  * having cache snooping on a cache snooping not supported platform
902  * will cause uplayer driver receiving mismatched data; and if
903  * declare no cache snooping on a cache snooping supported platform
904  * will cause cache be flushed twice and performance hit.
905  *
906  * @dev: ishtp device pointer
907  *
908  * Return: false - has cache snooping capability
909  *         true - no cache snooping, need manually cache flush
910  */
911 static bool _dma_no_cache_snooping(struct ishtp_device *dev)
912 {
913 	return (dev->pdev->device == PCI_DEVICE_ID_INTEL_ISH_EHL_Ax ||
914 		dev->pdev->device == PCI_DEVICE_ID_INTEL_ISH_TGL_LP ||
915 		dev->pdev->device == PCI_DEVICE_ID_INTEL_ISH_TGL_H ||
916 		dev->pdev->device == PCI_DEVICE_ID_INTEL_ISH_ADL_S ||
917 		dev->pdev->device == PCI_DEVICE_ID_INTEL_ISH_ADL_P);
918 }
919 
920 static const struct ishtp_hw_ops ish_hw_ops = {
921 	.hw_reset = _ish_hw_reset,
922 	.ipc_reset = _ish_ipc_reset,
923 	.ipc_get_header = ish_ipc_get_header,
924 	.ishtp_read = _ishtp_read,
925 	.write = write_ipc_to_queue,
926 	.get_fw_status = _ish_read_fw_sts_reg,
927 	.sync_fw_clock = _ish_sync_fw_clock,
928 	.ishtp_read_hdr = _ishtp_read_hdr,
929 	.dma_no_cache_snooping = _dma_no_cache_snooping
930 };
931 
932 /**
933  * ish_dev_init() -Initialize ISH devoce
934  * @pdev: PCI device
935  *
936  * Allocate ISHTP device and initialize IPC processing
937  *
938  * Return: ISHTP device instance on success else NULL
939  */
940 struct ishtp_device *ish_dev_init(struct pci_dev *pdev)
941 {
942 	struct ishtp_device *dev;
943 	int	i;
944 	int	ret;
945 
946 	dev = devm_kzalloc(&pdev->dev,
947 			   sizeof(struct ishtp_device) + sizeof(struct ish_hw),
948 			   GFP_KERNEL);
949 	if (!dev)
950 		return NULL;
951 
952 	dev->devc = &pdev->dev;
953 	ishtp_device_init(dev);
954 
955 	init_waitqueue_head(&dev->wait_hw_ready);
956 
957 	spin_lock_init(&dev->wr_processing_spinlock);
958 
959 	/* Init IPC processing and free lists */
960 	INIT_LIST_HEAD(&dev->wr_processing_list);
961 	INIT_LIST_HEAD(&dev->wr_free_list);
962 	for (i = 0; i < IPC_TX_FIFO_SIZE; i++) {
963 		struct wr_msg_ctl_info	*tx_buf;
964 
965 		tx_buf = devm_kzalloc(&pdev->dev,
966 				      sizeof(struct wr_msg_ctl_info),
967 				      GFP_KERNEL);
968 		if (!tx_buf) {
969 			/*
970 			 * IPC buffers may be limited or not available
971 			 * at all - although this shouldn't happen
972 			 */
973 			dev_err(dev->devc,
974 				"[ishtp-ish]: failure in Tx FIFO allocations (%d)\n",
975 				i);
976 			break;
977 		}
978 		list_add_tail(&tx_buf->link, &dev->wr_free_list);
979 	}
980 
981 	ret = devm_work_autocancel(&pdev->dev, &fw_reset_work, fw_reset_work_fn);
982 	if (ret) {
983 		dev_err(dev->devc, "Failed to initialise FW reset work\n");
984 		return NULL;
985 	}
986 
987 	dev->ops = &ish_hw_ops;
988 	dev->mtu = IPC_PAYLOAD_SIZE - sizeof(struct ishtp_msg_hdr);
989 	return dev;
990 }
991 
992 /**
993  * ish_device_disable() - Disable ISH device
994  * @dev: ISHTP device pointer
995  *
996  * Disable ISH by clearing host ready to inform firmware.
997  */
998 void	ish_device_disable(struct ishtp_device *dev)
999 {
1000 	struct pci_dev *pdev = dev->pdev;
1001 
1002 	if (!pdev)
1003 		return;
1004 
1005 	/* Disable dma communication between FW and host */
1006 	if (ish_disable_dma(dev)) {
1007 		dev_err(&pdev->dev,
1008 			"Can't reset - stuck with DMA in-progress\n");
1009 		return;
1010 	}
1011 
1012 	/* Put ISH to D3hot state for power saving */
1013 	pci_set_power_state(pdev, PCI_D3hot);
1014 
1015 	dev->dev_state = ISHTP_DEV_DISABLED;
1016 	ish_clr_host_rdy(dev);
1017 }
1018