xref: /linux/drivers/hid/intel-ish-hid/ipc/ipc.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * H/W layer of ISHTP provider device (ISH)
3  *
4  * Copyright (c) 2014-2016, Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13  * more details.
14  */
15 
16 #include <linux/sched.h>
17 #include <linux/spinlock.h>
18 #include <linux/delay.h>
19 #include <linux/jiffies.h>
20 #include "client.h"
21 #include "hw-ish.h"
22 #include "hbm.h"
23 
24 /* For FW reset flow */
25 static struct work_struct fw_reset_work;
26 static struct ishtp_device *ishtp_dev;
27 
28 /**
29  * ish_reg_read() - Read register
30  * @dev: ISHTP device pointer
31  * @offset: Register offset
32  *
33  * Read 32 bit register at a given offset
34  *
35  * Return: Read register value
36  */
37 static inline uint32_t ish_reg_read(const struct ishtp_device *dev,
38 	unsigned long offset)
39 {
40 	struct ish_hw *hw = to_ish_hw(dev);
41 
42 	return readl(hw->mem_addr + offset);
43 }
44 
45 /**
46  * ish_reg_write() - Write register
47  * @dev: ISHTP device pointer
48  * @offset: Register offset
49  * @value: Value to write
50  *
51  * Writes 32 bit register at a give offset
52  */
53 static inline void ish_reg_write(struct ishtp_device *dev,
54 				 unsigned long offset,
55 				 uint32_t value)
56 {
57 	struct ish_hw *hw = to_ish_hw(dev);
58 
59 	writel(value, hw->mem_addr + offset);
60 }
61 
62 /**
63  * _ish_read_fw_sts_reg() - Read FW status register
64  * @dev: ISHTP device pointer
65  *
66  * Read FW status register
67  *
68  * Return: Read register value
69  */
70 static inline uint32_t _ish_read_fw_sts_reg(struct ishtp_device *dev)
71 {
72 	return ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
73 }
74 
75 /**
76  * check_generated_interrupt() - Check if ISH interrupt
77  * @dev: ISHTP device pointer
78  *
79  * Check if an interrupt was generated for ISH
80  *
81  * Return: Read true or false
82  */
83 static bool check_generated_interrupt(struct ishtp_device *dev)
84 {
85 	bool interrupt_generated = true;
86 	uint32_t pisr_val = 0;
87 
88 	if (dev->pdev->device == CHV_DEVICE_ID) {
89 		pisr_val = ish_reg_read(dev, IPC_REG_PISR_CHV_AB);
90 		interrupt_generated =
91 			IPC_INT_FROM_ISH_TO_HOST_CHV_AB(pisr_val);
92 	} else {
93 		pisr_val = ish_reg_read(dev, IPC_REG_PISR_BXT);
94 		interrupt_generated = IPC_INT_FROM_ISH_TO_HOST_BXT(pisr_val);
95 	}
96 
97 	return interrupt_generated;
98 }
99 
100 /**
101  * ish_is_input_ready() - Check if FW ready for RX
102  * @dev: ISHTP device pointer
103  *
104  * Check if ISH FW is ready for receiving data
105  *
106  * Return: Read true or false
107  */
108 static bool ish_is_input_ready(struct ishtp_device *dev)
109 {
110 	uint32_t doorbell_val;
111 
112 	doorbell_val = ish_reg_read(dev, IPC_REG_HOST2ISH_DRBL);
113 	return !IPC_IS_BUSY(doorbell_val);
114 }
115 
116 /**
117  * set_host_ready() - Indicate host ready
118  * @dev: ISHTP device pointer
119  *
120  * Set host ready indication to FW
121  */
122 static void set_host_ready(struct ishtp_device *dev)
123 {
124 	if (dev->pdev->device == CHV_DEVICE_ID) {
125 		if (dev->pdev->revision == REVISION_ID_CHT_A0 ||
126 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
127 				REVISION_ID_CHT_Ax_SI)
128 			ish_reg_write(dev, IPC_REG_HOST_COMM, 0x81);
129 		else if (dev->pdev->revision == REVISION_ID_CHT_B0 ||
130 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
131 				REVISION_ID_CHT_Bx_SI ||
132 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
133 				REVISION_ID_CHT_Kx_SI ||
134 				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
135 				REVISION_ID_CHT_Dx_SI) {
136 			uint32_t host_comm_val;
137 
138 			host_comm_val = ish_reg_read(dev, IPC_REG_HOST_COMM);
139 			host_comm_val |= IPC_HOSTCOMM_INT_EN_BIT_CHV_AB | 0x81;
140 			ish_reg_write(dev, IPC_REG_HOST_COMM, host_comm_val);
141 		}
142 	} else {
143 			uint32_t host_pimr_val;
144 
145 			host_pimr_val = ish_reg_read(dev, IPC_REG_PIMR_BXT);
146 			host_pimr_val |= IPC_PIMR_INT_EN_BIT_BXT;
147 			/*
148 			 * disable interrupt generated instead of
149 			 * RX_complete_msg
150 			 */
151 			host_pimr_val &= ~IPC_HOST2ISH_BUSYCLEAR_MASK_BIT;
152 
153 			ish_reg_write(dev, IPC_REG_PIMR_BXT, host_pimr_val);
154 	}
155 }
156 
157 /**
158  * ishtp_fw_is_ready() - Check if FW ready
159  * @dev: ISHTP device pointer
160  *
161  * Check if ISH FW is ready
162  *
163  * Return: Read true or false
164  */
165 static bool ishtp_fw_is_ready(struct ishtp_device *dev)
166 {
167 	uint32_t ish_status = _ish_read_fw_sts_reg(dev);
168 
169 	return IPC_IS_ISH_ILUP(ish_status) &&
170 		IPC_IS_ISH_ISHTP_READY(ish_status);
171 }
172 
173 /**
174  * ish_set_host_rdy() - Indicate host ready
175  * @dev: ISHTP device pointer
176  *
177  * Set host ready indication to FW
178  */
179 static void ish_set_host_rdy(struct ishtp_device *dev)
180 {
181 	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
182 
183 	IPC_SET_HOST_READY(host_status);
184 	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
185 }
186 
187 /**
188  * ish_clr_host_rdy() - Indicate host not ready
189  * @dev: ISHTP device pointer
190  *
191  * Send host not ready indication to FW
192  */
193 static void ish_clr_host_rdy(struct ishtp_device *dev)
194 {
195 	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
196 
197 	IPC_CLEAR_HOST_READY(host_status);
198 	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
199 }
200 
201 /**
202  * _ishtp_read_hdr() - Read message header
203  * @dev: ISHTP device pointer
204  *
205  * Read header of 32bit length
206  *
207  * Return: Read register value
208  */
209 static uint32_t _ishtp_read_hdr(const struct ishtp_device *dev)
210 {
211 	return ish_reg_read(dev, IPC_REG_ISH2HOST_MSG);
212 }
213 
214 /**
215  * _ishtp_read - Read message
216  * @dev: ISHTP device pointer
217  * @buffer: message buffer
218  * @buffer_length: length of message buffer
219  *
220  * Read message from FW
221  *
222  * Return: Always 0
223  */
224 static int _ishtp_read(struct ishtp_device *dev, unsigned char *buffer,
225 	unsigned long buffer_length)
226 {
227 	uint32_t	i;
228 	uint32_t	*r_buf = (uint32_t *)buffer;
229 	uint32_t	msg_offs;
230 
231 	msg_offs = IPC_REG_ISH2HOST_MSG + sizeof(struct ishtp_msg_hdr);
232 	for (i = 0; i < buffer_length; i += sizeof(uint32_t))
233 		*r_buf++ = ish_reg_read(dev, msg_offs + i);
234 
235 	return 0;
236 }
237 
238 /**
239  * write_ipc_from_queue() - try to write ipc msg from Tx queue to device
240  * @dev: ishtp device pointer
241  *
242  * Check if DRBL is cleared. if it is - write the first IPC msg,  then call
243  * the callback function (unless it's NULL)
244  *
245  * Return: 0 for success else failure code
246  */
247 static int write_ipc_from_queue(struct ishtp_device *dev)
248 {
249 	struct wr_msg_ctl_info	*ipc_link;
250 	unsigned long	length;
251 	unsigned long	rem;
252 	unsigned long	flags;
253 	uint32_t	doorbell_val;
254 	uint32_t	*r_buf;
255 	uint32_t	reg_addr;
256 	int	i;
257 	void	(*ipc_send_compl)(void *);
258 	void	*ipc_send_compl_prm;
259 	static int	out_ipc_locked;
260 	unsigned long	out_ipc_flags;
261 
262 	if (dev->dev_state == ISHTP_DEV_DISABLED)
263 		return	-EINVAL;
264 
265 	spin_lock_irqsave(&dev->out_ipc_spinlock, out_ipc_flags);
266 	if (out_ipc_locked) {
267 		spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
268 		return -EBUSY;
269 	}
270 	out_ipc_locked = 1;
271 	if (!ish_is_input_ready(dev)) {
272 		out_ipc_locked = 0;
273 		spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
274 		return -EBUSY;
275 	}
276 	spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
277 
278 	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
279 	/*
280 	 * if tx send list is empty - return 0;
281 	 * may happen, as RX_COMPLETE handler doesn't check list emptiness.
282 	 */
283 	if (list_empty(&dev->wr_processing_list_head.link)) {
284 		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
285 		out_ipc_locked = 0;
286 		return	0;
287 	}
288 
289 	ipc_link = list_entry(dev->wr_processing_list_head.link.next,
290 			      struct wr_msg_ctl_info, link);
291 	/* first 4 bytes of the data is the doorbell value (IPC header) */
292 	length = ipc_link->length - sizeof(uint32_t);
293 	doorbell_val = *(uint32_t *)ipc_link->inline_data;
294 	r_buf = (uint32_t *)(ipc_link->inline_data + sizeof(uint32_t));
295 
296 	/* If sending MNG_SYNC_FW_CLOCK, update clock again */
297 	if (IPC_HEADER_GET_PROTOCOL(doorbell_val) == IPC_PROTOCOL_MNG &&
298 		IPC_HEADER_GET_MNG_CMD(doorbell_val) == MNG_SYNC_FW_CLOCK) {
299 		struct timespec ts_system;
300 		struct timeval tv_utc;
301 		uint64_t        usec_system, usec_utc;
302 		struct ipc_time_update_msg time_update;
303 		struct time_sync_format ts_format;
304 
305 		get_monotonic_boottime(&ts_system);
306 		do_gettimeofday(&tv_utc);
307 		usec_system = (timespec_to_ns(&ts_system)) / NSEC_PER_USEC;
308 		usec_utc = (uint64_t)tv_utc.tv_sec * 1000000 +
309 						((uint32_t)tv_utc.tv_usec);
310 		ts_format.ts1_source = HOST_SYSTEM_TIME_USEC;
311 		ts_format.ts2_source = HOST_UTC_TIME_USEC;
312 		ts_format.reserved = 0;
313 
314 		time_update.primary_host_time = usec_system;
315 		time_update.secondary_host_time = usec_utc;
316 		time_update.sync_info = ts_format;
317 
318 		memcpy(r_buf, &time_update,
319 		       sizeof(struct ipc_time_update_msg));
320 	}
321 
322 	for (i = 0, reg_addr = IPC_REG_HOST2ISH_MSG; i < length >> 2; i++,
323 			reg_addr += 4)
324 		ish_reg_write(dev, reg_addr, r_buf[i]);
325 
326 	rem = length & 0x3;
327 	if (rem > 0) {
328 		uint32_t reg = 0;
329 
330 		memcpy(&reg, &r_buf[length >> 2], rem);
331 		ish_reg_write(dev, reg_addr, reg);
332 	}
333 	/* Flush writes to msg registers and doorbell */
334 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
335 
336 	/* Update IPC counters */
337 	++dev->ipc_tx_cnt;
338 	dev->ipc_tx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
339 
340 	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, doorbell_val);
341 	out_ipc_locked = 0;
342 
343 	ipc_send_compl = ipc_link->ipc_send_compl;
344 	ipc_send_compl_prm = ipc_link->ipc_send_compl_prm;
345 	list_del_init(&ipc_link->link);
346 	list_add_tail(&ipc_link->link, &dev->wr_free_list_head.link);
347 	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
348 
349 	/*
350 	 * callback will be called out of spinlock,
351 	 * after ipc_link returned to free list
352 	 */
353 	if (ipc_send_compl)
354 		ipc_send_compl(ipc_send_compl_prm);
355 
356 	return 0;
357 }
358 
359 /**
360  * write_ipc_to_queue() - write ipc msg to Tx queue
361  * @dev: ishtp device instance
362  * @ipc_send_compl: Send complete callback
363  * @ipc_send_compl_prm:	Parameter to send in complete callback
364  * @msg: Pointer to message
365  * @length: Length of message
366  *
367  * Recived msg with IPC (and upper protocol) header  and add it to the device
368  *  Tx-to-write list then try to send the first IPC waiting msg
369  *  (if DRBL is cleared)
370  * This function returns negative value for failure (means free list
371  *  is empty, or msg too long) and 0 for success.
372  *
373  * Return: 0 for success else failure code
374  */
375 static int write_ipc_to_queue(struct ishtp_device *dev,
376 	void (*ipc_send_compl)(void *), void *ipc_send_compl_prm,
377 	unsigned char *msg, int length)
378 {
379 	struct wr_msg_ctl_info *ipc_link;
380 	unsigned long	flags;
381 
382 	if (length > IPC_FULL_MSG_SIZE)
383 		return -EMSGSIZE;
384 
385 	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
386 	if (list_empty(&dev->wr_free_list_head.link)) {
387 		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
388 		return -ENOMEM;
389 	}
390 	ipc_link = list_entry(dev->wr_free_list_head.link.next,
391 		struct wr_msg_ctl_info, link);
392 	list_del_init(&ipc_link->link);
393 
394 	ipc_link->ipc_send_compl = ipc_send_compl;
395 	ipc_link->ipc_send_compl_prm = ipc_send_compl_prm;
396 	ipc_link->length = length;
397 	memcpy(ipc_link->inline_data, msg, length);
398 
399 	list_add_tail(&ipc_link->link, &dev->wr_processing_list_head.link);
400 	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
401 
402 	write_ipc_from_queue(dev);
403 
404 	return 0;
405 }
406 
407 /**
408  * ipc_send_mng_msg() - Send management message
409  * @dev: ishtp device instance
410  * @msg_code: Message code
411  * @msg: Pointer to message
412  * @size: Length of message
413  *
414  * Send management message to FW
415  *
416  * Return: 0 for success else failure code
417  */
418 static int ipc_send_mng_msg(struct ishtp_device *dev, uint32_t msg_code,
419 	void *msg, size_t size)
420 {
421 	unsigned char	ipc_msg[IPC_FULL_MSG_SIZE];
422 	uint32_t	drbl_val = IPC_BUILD_MNG_MSG(msg_code, size);
423 
424 	memcpy(ipc_msg, &drbl_val, sizeof(uint32_t));
425 	memcpy(ipc_msg + sizeof(uint32_t), msg, size);
426 	return	write_ipc_to_queue(dev, NULL, NULL, ipc_msg,
427 		sizeof(uint32_t) + size);
428 }
429 
430 #define WAIT_FOR_FW_RDY			0x1
431 #define WAIT_FOR_INPUT_RDY		0x2
432 
433 /**
434  * timed_wait_for_timeout() - wait special event with timeout
435  * @dev: ISHTP device pointer
436  * @condition: indicate the condition for waiting
437  * @timeinc: time slice for every wait cycle, in ms
438  * @timeout: time in ms for timeout
439  *
440  * This function will check special event to be ready in a loop, the loop
441  * period is specificd in timeinc. Wait timeout will causes failure.
442  *
443  * Return: 0 for success else failure code
444  */
445 static int timed_wait_for_timeout(struct ishtp_device *dev, int condition,
446 				unsigned int timeinc, unsigned int timeout)
447 {
448 	bool complete = false;
449 	int ret;
450 
451 	do {
452 		if (condition == WAIT_FOR_FW_RDY) {
453 			complete = ishtp_fw_is_ready(dev);
454 		} else if (condition == WAIT_FOR_INPUT_RDY) {
455 			complete = ish_is_input_ready(dev);
456 		} else {
457 			ret = -EINVAL;
458 			goto out;
459 		}
460 
461 		if (!complete) {
462 			unsigned long left_time;
463 
464 			left_time = msleep_interruptible(timeinc);
465 			timeout -= (timeinc - left_time);
466 		}
467 	} while (!complete && timeout > 0);
468 
469 	if (complete)
470 		ret = 0;
471 	else
472 		ret = -EBUSY;
473 
474 out:
475 	return ret;
476 }
477 
478 #define TIME_SLICE_FOR_FW_RDY_MS		100
479 #define TIME_SLICE_FOR_INPUT_RDY_MS		100
480 #define TIMEOUT_FOR_FW_RDY_MS			2000
481 #define TIMEOUT_FOR_INPUT_RDY_MS		2000
482 
483 /**
484  * ish_fw_reset_handler() - FW reset handler
485  * @dev: ishtp device pointer
486  *
487  * Handle FW reset
488  *
489  * Return: 0 for success else failure code
490  */
491 static int ish_fw_reset_handler(struct ishtp_device *dev)
492 {
493 	uint32_t	reset_id;
494 	unsigned long	flags;
495 	struct wr_msg_ctl_info *processing, *next;
496 
497 	/* Read reset ID */
498 	reset_id = ish_reg_read(dev, IPC_REG_ISH2HOST_MSG) & 0xFFFF;
499 
500 	/* Clear IPC output queue */
501 	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
502 	list_for_each_entry_safe(processing, next,
503 			&dev->wr_processing_list_head.link, link) {
504 		list_move_tail(&processing->link, &dev->wr_free_list_head.link);
505 	}
506 	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
507 
508 	/* ISHTP notification in IPC_RESET */
509 	ishtp_reset_handler(dev);
510 
511 	if (!ish_is_input_ready(dev))
512 		timed_wait_for_timeout(dev, WAIT_FOR_INPUT_RDY,
513 			TIME_SLICE_FOR_INPUT_RDY_MS, TIMEOUT_FOR_INPUT_RDY_MS);
514 
515 	/* ISH FW is dead */
516 	if (!ish_is_input_ready(dev))
517 		return	-EPIPE;
518 	/*
519 	 * Set HOST2ISH.ILUP. Apparently we need this BEFORE sending
520 	 * RESET_NOTIFY_ACK - FW will be checking for it
521 	 */
522 	ish_set_host_rdy(dev);
523 	/* Send RESET_NOTIFY_ACK (with reset_id) */
524 	ipc_send_mng_msg(dev, MNG_RESET_NOTIFY_ACK, &reset_id,
525 			 sizeof(uint32_t));
526 
527 	/* Wait for ISH FW'es ILUP and ISHTP_READY */
528 	timed_wait_for_timeout(dev, WAIT_FOR_FW_RDY,
529 			TIME_SLICE_FOR_FW_RDY_MS, TIMEOUT_FOR_FW_RDY_MS);
530 	if (!ishtp_fw_is_ready(dev)) {
531 		/* ISH FW is dead */
532 		uint32_t	ish_status;
533 
534 		ish_status = _ish_read_fw_sts_reg(dev);
535 		dev_err(dev->devc,
536 			"[ishtp-ish]: completed reset, ISH is dead (FWSTS = %08X)\n",
537 			ish_status);
538 		return -ENODEV;
539 	}
540 	return	0;
541 }
542 
543 #define TIMEOUT_FOR_HW_RDY_MS			300
544 
545 /**
546  * ish_fw_reset_work_fn() - FW reset worker function
547  * @unused: not used
548  *
549  * Call ish_fw_reset_handler to complete FW reset
550  */
551 static void fw_reset_work_fn(struct work_struct *unused)
552 {
553 	int	rv;
554 
555 	rv = ish_fw_reset_handler(ishtp_dev);
556 	if (!rv) {
557 		/* ISH is ILUP & ISHTP-ready. Restart ISHTP */
558 		msleep_interruptible(TIMEOUT_FOR_HW_RDY_MS);
559 		ishtp_dev->recvd_hw_ready = 1;
560 		wake_up_interruptible(&ishtp_dev->wait_hw_ready);
561 
562 		/* ISHTP notification in IPC_RESET sequence completion */
563 		ishtp_reset_compl_handler(ishtp_dev);
564 	} else
565 		dev_err(ishtp_dev->devc, "[ishtp-ish]: FW reset failed (%d)\n",
566 			rv);
567 }
568 
569 /**
570  * _ish_sync_fw_clock() -Sync FW clock with the OS clock
571  * @dev: ishtp device pointer
572  *
573  * Sync FW and OS time
574  */
575 static void _ish_sync_fw_clock(struct ishtp_device *dev)
576 {
577 	static unsigned long	prev_sync;
578 	struct timespec	ts;
579 	uint64_t	usec;
580 
581 	if (prev_sync && jiffies - prev_sync < 20 * HZ)
582 		return;
583 
584 	prev_sync = jiffies;
585 	get_monotonic_boottime(&ts);
586 	usec = (timespec_to_ns(&ts)) / NSEC_PER_USEC;
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 			INIT_WORK(&fw_reset_work, fw_reset_work_fn);
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 static 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->d3_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 	/* After that we can enable ISH DMA operation and wakeup ISHFW */
854 	ish_wakeup(dev);
855 
856 	set_host_ready(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 static const struct ishtp_hw_ops ish_hw_ops = {
894 	.hw_reset = _ish_hw_reset,
895 	.ipc_reset = _ish_ipc_reset,
896 	.ipc_get_header = ish_ipc_get_header,
897 	.ishtp_read = _ishtp_read,
898 	.write = write_ipc_to_queue,
899 	.get_fw_status = _ish_read_fw_sts_reg,
900 	.sync_fw_clock = _ish_sync_fw_clock,
901 	.ishtp_read_hdr = _ishtp_read_hdr
902 };
903 
904 /**
905  * ish_dev_init() -Initialize ISH devoce
906  * @pdev: PCI device
907  *
908  * Allocate ISHTP device and initialize IPC processing
909  *
910  * Return: ISHTP device instance on success else NULL
911  */
912 struct ishtp_device *ish_dev_init(struct pci_dev *pdev)
913 {
914 	struct ishtp_device *dev;
915 	int	i;
916 
917 	dev = kzalloc(sizeof(struct ishtp_device) + sizeof(struct ish_hw),
918 		GFP_KERNEL);
919 	if (!dev)
920 		return NULL;
921 
922 	ishtp_device_init(dev);
923 
924 	init_waitqueue_head(&dev->wait_hw_ready);
925 
926 	spin_lock_init(&dev->wr_processing_spinlock);
927 	spin_lock_init(&dev->out_ipc_spinlock);
928 
929 	/* Init IPC processing and free lists */
930 	INIT_LIST_HEAD(&dev->wr_processing_list_head.link);
931 	INIT_LIST_HEAD(&dev->wr_free_list_head.link);
932 	for (i = 0; i < IPC_TX_FIFO_SIZE; ++i) {
933 		struct wr_msg_ctl_info	*tx_buf;
934 
935 		tx_buf = kzalloc(sizeof(struct wr_msg_ctl_info), GFP_KERNEL);
936 		if (!tx_buf) {
937 			/*
938 			 * IPC buffers may be limited or not available
939 			 * at all - although this shouldn't happen
940 			 */
941 			dev_err(dev->devc,
942 				"[ishtp-ish]: failure in Tx FIFO allocations (%d)\n",
943 				i);
944 			break;
945 		}
946 		list_add_tail(&tx_buf->link, &dev->wr_free_list_head.link);
947 	}
948 
949 	dev->ops = &ish_hw_ops;
950 	dev->devc = &pdev->dev;
951 	dev->mtu = IPC_PAYLOAD_SIZE - sizeof(struct ishtp_msg_hdr);
952 	return dev;
953 }
954 
955 /**
956  * ish_device_disable() - Disable ISH device
957  * @dev: ISHTP device pointer
958  *
959  * Disable ISH by clearing host ready to inform firmware.
960  */
961 void	ish_device_disable(struct ishtp_device *dev)
962 {
963 	struct pci_dev *pdev = dev->pdev;
964 
965 	if (!pdev)
966 		return;
967 
968 	/* Disable dma communication between FW and host */
969 	if (ish_disable_dma(dev)) {
970 		dev_err(&pdev->dev,
971 			"Can't reset - stuck with DMA in-progress\n");
972 		return;
973 	}
974 
975 	/* Put ISH to D3hot state for power saving */
976 	pci_set_power_state(pdev, PCI_D3hot);
977 
978 	dev->dev_state = ISHTP_DEV_DISABLED;
979 	ish_clr_host_rdy(dev);
980 }
981