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