xref: /linux/drivers/hid/intel-ish-hid/ipc/ipc.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
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 == CHV_DEVICE_ID) {
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 == CHV_DEVICE_ID) {
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  * @unused: not used
550  *
551  * Call ish_fw_reset_handler to complete FW reset
552  */
553 static void fw_reset_work_fn(struct work_struct *unused)
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 		ishtp_reset_compl_handler(ishtp_dev);
566 	} else
567 		dev_err(ishtp_dev->devc, "[ishtp-ish]: FW reset failed (%d)\n",
568 			rv);
569 }
570 
571 /**
572  * _ish_sync_fw_clock() -Sync FW clock with the OS clock
573  * @dev: ishtp device pointer
574  *
575  * Sync FW and OS time
576  */
577 static void _ish_sync_fw_clock(struct ishtp_device *dev)
578 {
579 	static unsigned long	prev_sync;
580 	uint64_t	usec;
581 
582 	if (prev_sync && time_before(jiffies, prev_sync + 20 * HZ))
583 		return;
584 
585 	prev_sync = jiffies;
586 	usec = ktime_to_us(ktime_get_boottime());
587 	ipc_send_mng_msg(dev, MNG_SYNC_FW_CLOCK, &usec, sizeof(uint64_t));
588 }
589 
590 /**
591  * recv_ipc() - Receive and process IPC management messages
592  * @dev: ishtp device instance
593  * @doorbell_val: doorbell value
594  *
595  * This function runs in ISR context.
596  * NOTE: Any other mng command than reset_notify and reset_notify_ack
597  * won't wake BH handler
598  */
599 static void	recv_ipc(struct ishtp_device *dev, uint32_t doorbell_val)
600 {
601 	uint32_t	mng_cmd;
602 
603 	mng_cmd = IPC_HEADER_GET_MNG_CMD(doorbell_val);
604 
605 	switch (mng_cmd) {
606 	default:
607 		break;
608 
609 	case MNG_RX_CMPL_INDICATION:
610 		if (dev->suspend_flag) {
611 			dev->suspend_flag = 0;
612 			wake_up_interruptible(&dev->suspend_wait);
613 		}
614 		if (dev->resume_flag) {
615 			dev->resume_flag = 0;
616 			wake_up_interruptible(&dev->resume_wait);
617 		}
618 
619 		write_ipc_from_queue(dev);
620 		break;
621 
622 	case MNG_RESET_NOTIFY:
623 		if (!ishtp_dev) {
624 			ishtp_dev = dev;
625 		}
626 		schedule_work(&fw_reset_work);
627 		break;
628 
629 	case MNG_RESET_NOTIFY_ACK:
630 		dev->recvd_hw_ready = 1;
631 		wake_up_interruptible(&dev->wait_hw_ready);
632 		break;
633 	}
634 }
635 
636 /**
637  * ish_irq_handler() - ISH IRQ handler
638  * @irq: irq number
639  * @dev_id: ishtp device pointer
640  *
641  * ISH IRQ handler. If interrupt is generated and is for ISH it will process
642  * the interrupt.
643  */
644 irqreturn_t ish_irq_handler(int irq, void *dev_id)
645 {
646 	struct ishtp_device	*dev = dev_id;
647 	uint32_t	doorbell_val;
648 	bool	interrupt_generated;
649 
650 	/* Check that it's interrupt from ISH (may be shared) */
651 	interrupt_generated = check_generated_interrupt(dev);
652 
653 	if (!interrupt_generated)
654 		return IRQ_NONE;
655 
656 	doorbell_val = ish_reg_read(dev, IPC_REG_ISH2HOST_DRBL);
657 	if (!IPC_IS_BUSY(doorbell_val))
658 		return IRQ_HANDLED;
659 
660 	if (dev->dev_state == ISHTP_DEV_DISABLED)
661 		return	IRQ_HANDLED;
662 
663 	/* Sanity check: IPC dgram length in header */
664 	if (IPC_HEADER_GET_LENGTH(doorbell_val) > IPC_PAYLOAD_SIZE) {
665 		dev_err(dev->devc,
666 			"IPC hdr - bad length: %u; dropped\n",
667 			(unsigned int)IPC_HEADER_GET_LENGTH(doorbell_val));
668 		goto	eoi;
669 	}
670 
671 	switch (IPC_HEADER_GET_PROTOCOL(doorbell_val)) {
672 	default:
673 		break;
674 	case IPC_PROTOCOL_MNG:
675 		recv_ipc(dev, doorbell_val);
676 		break;
677 	case IPC_PROTOCOL_ISHTP:
678 		ishtp_recv(dev);
679 		break;
680 	}
681 
682 eoi:
683 	/* Update IPC counters */
684 	++dev->ipc_rx_cnt;
685 	dev->ipc_rx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
686 
687 	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
688 	/* Flush write to doorbell */
689 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
690 
691 	return	IRQ_HANDLED;
692 }
693 
694 /**
695  * ish_disable_dma() - disable dma communication between host and ISHFW
696  * @dev: ishtp device pointer
697  *
698  * Clear the dma enable bit and wait for dma inactive.
699  *
700  * Return: 0 for success else error code.
701  */
702 int ish_disable_dma(struct ishtp_device *dev)
703 {
704 	unsigned int	dma_delay;
705 
706 	/* Clear the dma enable bit */
707 	ish_reg_write(dev, IPC_REG_ISH_RMP2, 0);
708 
709 	/* wait for dma inactive */
710 	for (dma_delay = 0; dma_delay < MAX_DMA_DELAY &&
711 		_ish_read_fw_sts_reg(dev) & (IPC_ISH_IN_DMA);
712 		dma_delay += 5)
713 		mdelay(5);
714 
715 	if (dma_delay >= MAX_DMA_DELAY) {
716 		dev_err(dev->devc,
717 			"Wait for DMA inactive timeout\n");
718 		return	-EBUSY;
719 	}
720 
721 	return 0;
722 }
723 
724 /**
725  * ish_wakeup() - wakeup ishfw from waiting-for-host state
726  * @dev: ishtp device pointer
727  *
728  * Set the dma enable bit and send a void message to FW,
729  * it wil wakeup FW from waiting-for-host state.
730  */
731 static void ish_wakeup(struct ishtp_device *dev)
732 {
733 	/* Set dma enable bit */
734 	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
735 
736 	/*
737 	 * Send 0 IPC message so that ISH FW wakes up if it was already
738 	 * asleep.
739 	 */
740 	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
741 
742 	/* Flush writes to doorbell and REMAP2 */
743 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
744 }
745 
746 /**
747  * _ish_hw_reset() - HW reset
748  * @dev: ishtp device pointer
749  *
750  * Reset ISH HW to recover if any error
751  *
752  * Return: 0 for success else error fault code
753  */
754 static int _ish_hw_reset(struct ishtp_device *dev)
755 {
756 	struct pci_dev *pdev = dev->pdev;
757 	int	rv;
758 	uint16_t csr;
759 
760 	if (!pdev)
761 		return	-ENODEV;
762 
763 	rv = pci_reset_function(pdev);
764 	if (!rv)
765 		dev->dev_state = ISHTP_DEV_RESETTING;
766 
767 	if (!pdev->pm_cap) {
768 		dev_err(&pdev->dev, "Can't reset - no PM caps\n");
769 		return	-EINVAL;
770 	}
771 
772 	/* Disable dma communication between FW and host */
773 	if (ish_disable_dma(dev)) {
774 		dev_err(&pdev->dev,
775 			"Can't reset - stuck with DMA in-progress\n");
776 		return	-EBUSY;
777 	}
778 
779 	pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &csr);
780 
781 	csr &= ~PCI_PM_CTRL_STATE_MASK;
782 	csr |= PCI_D3hot;
783 	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
784 
785 	mdelay(pdev->d3hot_delay);
786 
787 	csr &= ~PCI_PM_CTRL_STATE_MASK;
788 	csr |= PCI_D0;
789 	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
790 
791 	/* Now we can enable ISH DMA operation and wakeup ISHFW */
792 	ish_wakeup(dev);
793 
794 	return	0;
795 }
796 
797 /**
798  * _ish_ipc_reset() - IPC reset
799  * @dev: ishtp device pointer
800  *
801  * Resets host and fw IPC and upper layers
802  *
803  * Return: 0 for success else error fault code
804  */
805 static int _ish_ipc_reset(struct ishtp_device *dev)
806 {
807 	struct ipc_rst_payload_type ipc_mng_msg;
808 	int	rv = 0;
809 
810 	ipc_mng_msg.reset_id = 1;
811 	ipc_mng_msg.reserved = 0;
812 
813 	set_host_ready(dev);
814 
815 	/* Clear the incoming doorbell */
816 	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
817 	/* Flush write to doorbell */
818 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
819 
820 	dev->recvd_hw_ready = 0;
821 
822 	/* send message */
823 	rv = ipc_send_mng_msg(dev, MNG_RESET_NOTIFY, &ipc_mng_msg,
824 		sizeof(struct ipc_rst_payload_type));
825 	if (rv) {
826 		dev_err(dev->devc, "Failed to send IPC MNG_RESET_NOTIFY\n");
827 		return	rv;
828 	}
829 
830 	wait_event_interruptible_timeout(dev->wait_hw_ready,
831 					 dev->recvd_hw_ready, 2 * HZ);
832 	if (!dev->recvd_hw_ready) {
833 		dev_err(dev->devc, "Timed out waiting for HW ready\n");
834 		rv = -ENODEV;
835 	}
836 
837 	return rv;
838 }
839 
840 /**
841  * ish_hw_start() -Start ISH HW
842  * @dev: ishtp device pointer
843  *
844  * Set host to ready state and wait for FW reset
845  *
846  * Return: 0 for success else error fault code
847  */
848 int ish_hw_start(struct ishtp_device *dev)
849 {
850 	ish_set_host_rdy(dev);
851 
852 	set_host_ready(dev);
853 
854 	/* After that we can enable ISH DMA operation and wakeup ISHFW */
855 	ish_wakeup(dev);
856 
857 	/* wait for FW-initiated reset flow */
858 	if (!dev->recvd_hw_ready)
859 		wait_event_interruptible_timeout(dev->wait_hw_ready,
860 						 dev->recvd_hw_ready,
861 						 10 * HZ);
862 
863 	if (!dev->recvd_hw_ready) {
864 		dev_err(dev->devc,
865 			"[ishtp-ish]: Timed out waiting for FW-initiated reset\n");
866 		return	-ENODEV;
867 	}
868 
869 	return 0;
870 }
871 
872 /**
873  * ish_ipc_get_header() -Get doorbell value
874  * @dev: ishtp device pointer
875  * @length: length of message
876  * @busy: busy status
877  *
878  * Get door bell value from message header
879  *
880  * Return: door bell value
881  */
882 static uint32_t ish_ipc_get_header(struct ishtp_device *dev, int length,
883 				   int busy)
884 {
885 	uint32_t drbl_val;
886 
887 	drbl_val = IPC_BUILD_HEADER(length, IPC_PROTOCOL_ISHTP, busy);
888 
889 	return drbl_val;
890 }
891 
892 /**
893  * _dma_no_cache_snooping()
894  *
895  * Check on current platform, DMA supports cache snooping or not.
896  * This callback is used to notify uplayer driver if manully cache
897  * flush is needed when do DMA operation.
898  *
899  * Please pay attention to this callback implementation, if declare
900  * having cache snooping on a cache snooping not supported platform
901  * will cause uplayer driver receiving mismatched data; and if
902  * declare no cache snooping on a cache snooping supported platform
903  * will cause cache be flushed twice and performance hit.
904  *
905  * @dev: ishtp device pointer
906  *
907  * Return: false - has cache snooping capability
908  *         true - no cache snooping, need manually cache flush
909  */
910 static bool _dma_no_cache_snooping(struct ishtp_device *dev)
911 {
912 	return (dev->pdev->device == EHL_Ax_DEVICE_ID ||
913 		dev->pdev->device == TGL_LP_DEVICE_ID ||
914 		dev->pdev->device == TGL_H_DEVICE_ID ||
915 		dev->pdev->device == ADL_S_DEVICE_ID ||
916 		dev->pdev->device == ADL_P_DEVICE_ID);
917 }
918 
919 static const struct ishtp_hw_ops ish_hw_ops = {
920 	.hw_reset = _ish_hw_reset,
921 	.ipc_reset = _ish_ipc_reset,
922 	.ipc_get_header = ish_ipc_get_header,
923 	.ishtp_read = _ishtp_read,
924 	.write = write_ipc_to_queue,
925 	.get_fw_status = _ish_read_fw_sts_reg,
926 	.sync_fw_clock = _ish_sync_fw_clock,
927 	.ishtp_read_hdr = _ishtp_read_hdr,
928 	.dma_no_cache_snooping = _dma_no_cache_snooping
929 };
930 
931 /**
932  * ish_dev_init() -Initialize ISH devoce
933  * @pdev: PCI device
934  *
935  * Allocate ISHTP device and initialize IPC processing
936  *
937  * Return: ISHTP device instance on success else NULL
938  */
939 struct ishtp_device *ish_dev_init(struct pci_dev *pdev)
940 {
941 	struct ishtp_device *dev;
942 	int	i;
943 	int	ret;
944 
945 	dev = devm_kzalloc(&pdev->dev,
946 			   sizeof(struct ishtp_device) + sizeof(struct ish_hw),
947 			   GFP_KERNEL);
948 	if (!dev)
949 		return NULL;
950 
951 	ishtp_device_init(dev);
952 
953 	init_waitqueue_head(&dev->wait_hw_ready);
954 
955 	spin_lock_init(&dev->wr_processing_spinlock);
956 
957 	/* Init IPC processing and free lists */
958 	INIT_LIST_HEAD(&dev->wr_processing_list);
959 	INIT_LIST_HEAD(&dev->wr_free_list);
960 	for (i = 0; i < IPC_TX_FIFO_SIZE; i++) {
961 		struct wr_msg_ctl_info	*tx_buf;
962 
963 		tx_buf = devm_kzalloc(&pdev->dev,
964 				      sizeof(struct wr_msg_ctl_info),
965 				      GFP_KERNEL);
966 		if (!tx_buf) {
967 			/*
968 			 * IPC buffers may be limited or not available
969 			 * at all - although this shouldn't happen
970 			 */
971 			dev_err(dev->devc,
972 				"[ishtp-ish]: failure in Tx FIFO allocations (%d)\n",
973 				i);
974 			break;
975 		}
976 		list_add_tail(&tx_buf->link, &dev->wr_free_list);
977 	}
978 
979 	ret = devm_work_autocancel(&pdev->dev, &fw_reset_work, fw_reset_work_fn);
980 	if (ret) {
981 		dev_err(dev->devc, "Failed to initialise FW reset work\n");
982 		return NULL;
983 	}
984 
985 	dev->ops = &ish_hw_ops;
986 	dev->devc = &pdev->dev;
987 	dev->mtu = IPC_PAYLOAD_SIZE - sizeof(struct ishtp_msg_hdr);
988 	return dev;
989 }
990 
991 /**
992  * ish_device_disable() - Disable ISH device
993  * @dev: ISHTP device pointer
994  *
995  * Disable ISH by clearing host ready to inform firmware.
996  */
997 void	ish_device_disable(struct ishtp_device *dev)
998 {
999 	struct pci_dev *pdev = dev->pdev;
1000 
1001 	if (!pdev)
1002 		return;
1003 
1004 	/* Disable dma communication between FW and host */
1005 	if (ish_disable_dma(dev)) {
1006 		dev_err(&pdev->dev,
1007 			"Can't reset - stuck with DMA in-progress\n");
1008 		return;
1009 	}
1010 
1011 	/* Put ISH to D3hot state for power saving */
1012 	pci_set_power_state(pdev, PCI_D3hot);
1013 
1014 	dev->dev_state = ISHTP_DEV_DISABLED;
1015 	ish_clr_host_rdy(dev);
1016 }
1017