// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 - 2018 Intel Corporation
 * Copyright 2017 Google LLC
 *
 * Based on Intel IPU4 driver.
 *
 */

#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>

#include "ipu3.h"
#include "ipu3-dmamap.h"
#include "ipu3-mmu.h"

#define IMGU_PCI_ID			0x1919
#define IMGU_PCI_BAR			0
#define IMGU_DMA_MASK			DMA_BIT_MASK(39)
#define IMGU_MAX_QUEUE_DEPTH		(2 + 2)

/*
 * pre-allocated buffer size for IMGU dummy buffers. Those
 * values should be tuned to big enough to avoid buffer
 * re-allocation when streaming to lower streaming latency.
 */
#define CSS_QUEUE_IN_BUF_SIZE		0
#define CSS_QUEUE_PARAMS_BUF_SIZE	0
#define CSS_QUEUE_OUT_BUF_SIZE		(4160 * 3120 * 12 / 8)
#define CSS_QUEUE_VF_BUF_SIZE		(1920 * 1080 * 12 / 8)
#define CSS_QUEUE_STAT_3A_BUF_SIZE	sizeof(struct ipu3_uapi_stats_3a)

static const size_t css_queue_buf_size_map[IPU3_CSS_QUEUES] = {
	[IPU3_CSS_QUEUE_IN] = CSS_QUEUE_IN_BUF_SIZE,
	[IPU3_CSS_QUEUE_PARAMS] = CSS_QUEUE_PARAMS_BUF_SIZE,
	[IPU3_CSS_QUEUE_OUT] = CSS_QUEUE_OUT_BUF_SIZE,
	[IPU3_CSS_QUEUE_VF] = CSS_QUEUE_VF_BUF_SIZE,
	[IPU3_CSS_QUEUE_STAT_3A] = CSS_QUEUE_STAT_3A_BUF_SIZE,
};

static const struct imgu_node_mapping imgu_node_map[IMGU_NODE_NUM] = {
	[IMGU_NODE_IN] = {IPU3_CSS_QUEUE_IN, "input"},
	[IMGU_NODE_PARAMS] = {IPU3_CSS_QUEUE_PARAMS, "parameters"},
	[IMGU_NODE_OUT] = {IPU3_CSS_QUEUE_OUT, "output"},
	[IMGU_NODE_VF] = {IPU3_CSS_QUEUE_VF, "viewfinder"},
	[IMGU_NODE_STAT_3A] = {IPU3_CSS_QUEUE_STAT_3A, "3a stat"},
};

unsigned int imgu_node_to_queue(unsigned int node)
{
	return imgu_node_map[node].css_queue;
}

unsigned int imgu_map_node(struct imgu_device *imgu, unsigned int css_queue)
{
	unsigned int i;

	for (i = 0; i < IMGU_NODE_NUM; i++)
		if (imgu_node_map[i].css_queue == css_queue)
			break;

	return i;
}

/**************** Dummy buffers ****************/

static void imgu_dummybufs_cleanup(struct imgu_device *imgu, unsigned int pipe)
{
	unsigned int i;
	struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[pipe];

	for (i = 0; i < IPU3_CSS_QUEUES; i++)
		imgu_dmamap_free(imgu,
				 &imgu_pipe->queues[i].dmap);
}

static int imgu_dummybufs_preallocate(struct imgu_device *imgu,
				      unsigned int pipe)
{
	unsigned int i;
	size_t size;
	struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[pipe];

	for (i = 0; i < IPU3_CSS_QUEUES; i++) {
		size = css_queue_buf_size_map[i];
		/*
		 * Do not enable dummy buffers for master queue,
		 * always require that real buffers from user are
		 * available.
		 */
		if (i == IMGU_QUEUE_MASTER || size == 0)
			continue;

		if (!imgu_dmamap_alloc(imgu,
				       &imgu_pipe->queues[i].dmap, size)) {
			imgu_dummybufs_cleanup(imgu, pipe);
			return -ENOMEM;
		}
	}

	return 0;
}

static int imgu_dummybufs_init(struct imgu_device *imgu, unsigned int pipe)
{
	const struct v4l2_pix_format_mplane *mpix;
	const struct v4l2_meta_format	*meta;
	unsigned int i, k, node;
	size_t size;
	struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[pipe];

	/* Allocate a dummy buffer for each queue where buffer is optional */
	for (i = 0; i < IPU3_CSS_QUEUES; i++) {
		node = imgu_map_node(imgu, i);
		if (!imgu_pipe->queue_enabled[node] || i == IMGU_QUEUE_MASTER)
			continue;

		if (!imgu_pipe->nodes[IMGU_NODE_VF].enabled &&
		    i == IPU3_CSS_QUEUE_VF)
			/*
			 * Do not enable dummy buffers for VF if it is not
			 * requested by the user.
			 */
			continue;

		meta = &imgu_pipe->nodes[node].vdev_fmt.fmt.meta;
		mpix = &imgu_pipe->nodes[node].vdev_fmt.fmt.pix_mp;

		if (node == IMGU_NODE_STAT_3A || node == IMGU_NODE_PARAMS)
			size = meta->buffersize;
		else
			size = mpix->plane_fmt[0].sizeimage;

		if (imgu_css_dma_buffer_resize(imgu,
					       &imgu_pipe->queues[i].dmap,
					       size)) {
			imgu_dummybufs_cleanup(imgu, pipe);
			return -ENOMEM;
		}

		for (k = 0; k < IMGU_MAX_QUEUE_DEPTH; k++)
			imgu_css_buf_init(&imgu_pipe->queues[i].dummybufs[k], i,
					  imgu_pipe->queues[i].dmap.daddr);
	}

	return 0;
}

/* May be called from atomic context */
static struct imgu_css_buffer *imgu_dummybufs_get(struct imgu_device *imgu,
						   int queue, unsigned int pipe)
{
	unsigned int i;
	struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[pipe];

	/* dummybufs are not allocated for master q */
	if (queue == IPU3_CSS_QUEUE_IN)
		return NULL;

	if (WARN_ON(!imgu_pipe->queues[queue].dmap.vaddr))
		/* Buffer should not be allocated here */
		return NULL;

	for (i = 0; i < IMGU_MAX_QUEUE_DEPTH; i++)
		if (imgu_css_buf_state(&imgu_pipe->queues[queue].dummybufs[i]) !=
			IPU3_CSS_BUFFER_QUEUED)
			break;

	if (i == IMGU_MAX_QUEUE_DEPTH)
		return NULL;

	imgu_css_buf_init(&imgu_pipe->queues[queue].dummybufs[i], queue,
			  imgu_pipe->queues[queue].dmap.daddr);

	return &imgu_pipe->queues[queue].dummybufs[i];
}

/* Check if given buffer is a dummy buffer */
static bool imgu_dummybufs_check(struct imgu_device *imgu,
				 struct imgu_css_buffer *buf,
				 unsigned int pipe)
{
	unsigned int i;
	struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[pipe];

	for (i = 0; i < IMGU_MAX_QUEUE_DEPTH; i++)
		if (buf == &imgu_pipe->queues[buf->queue].dummybufs[i])
			break;

	return i < IMGU_MAX_QUEUE_DEPTH;
}

static void imgu_buffer_done(struct imgu_device *imgu, struct vb2_buffer *vb,
			     enum vb2_buffer_state state)
{
	mutex_lock(&imgu->lock);
	imgu_v4l2_buffer_done(vb, state);
	mutex_unlock(&imgu->lock);
}

static struct imgu_css_buffer *imgu_queue_getbuf(struct imgu_device *imgu,
						 unsigned int node,
						 unsigned int pipe)
{
	struct imgu_buffer *buf;
	struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[pipe];

	if (WARN_ON(node >= IMGU_NODE_NUM))
		return NULL;

	/* Find first free buffer from the node */
	list_for_each_entry(buf, &imgu_pipe->nodes[node].buffers, vid_buf.list) {
		if (imgu_css_buf_state(&buf->css_buf) == IPU3_CSS_BUFFER_NEW)
			return &buf->css_buf;
	}

	/* There were no free buffers, try to return a dummy buffer */
	return imgu_dummybufs_get(imgu, imgu_node_map[node].css_queue, pipe);
}

/*
 * Queue as many buffers to CSS as possible. If all buffers don't fit into
 * CSS buffer queues, they remain unqueued and will be queued later.
 */
int imgu_queue_buffers(struct imgu_device *imgu, bool initial, unsigned int pipe)
{
	unsigned int node;
	int r = 0;
	struct imgu_media_pipe *imgu_pipe = &imgu->imgu_pipe[pipe];

	if (!imgu_css_is_streaming(&imgu->css))
		return 0;

	dev_dbg(&imgu->pci_dev->dev, "Queue buffers to pipe %d", pipe);
	mutex_lock(&imgu->lock);

	if (!imgu_css_pipe_queue_empty(&imgu->css, pipe)) {
		mutex_unlock(&imgu->lock);
		return 0;
	}

	/* Buffer set is queued to FW only when input buffer is ready */
	for (node = IMGU_NODE_NUM - 1;
	     imgu_queue_getbuf(imgu, IMGU_NODE_IN, pipe);
	     node = node ? node - 1 : IMGU_NODE_NUM - 1) {
		if (node == IMGU_NODE_VF &&
		    !imgu_pipe->nodes[IMGU_NODE_VF].enabled) {
			dev_warn(&imgu->pci_dev->dev,
				 "Vf not enabled, ignore queue");
			continue;
		} else if (node == IMGU_NODE_PARAMS &&
			   imgu_pipe->nodes[node].enabled) {
			struct vb2_buffer *vb;
			struct imgu_vb2_buffer *ivb;

			/* No parameters for this frame */
			if (list_empty(&imgu_pipe->nodes[node].buffers))
				continue;

			ivb = list_first_entry(&imgu_pipe->nodes[node].buffers,
					       struct imgu_vb2_buffer, list);
			list_del(&ivb->list);
			vb = &ivb->vbb.vb2_buf;
			r = imgu_css_set_parameters(&imgu->css, pipe,
						    vb2_plane_vaddr(vb, 0));
			if (r) {
				vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
				dev_warn(&imgu->pci_dev->dev,
					 "set parameters failed.");
				continue;
			}

			vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
			dev_dbg(&imgu->pci_dev->dev,
				"queue user parameters %d to css.", vb->index);
		} else if (imgu_pipe->queue_enabled[node]) {
			struct imgu_css_buffer *buf =
				imgu_queue_getbuf(imgu, node, pipe);
			struct imgu_buffer *ibuf = NULL;
			bool dummy;

			if (!buf)
				break;

			r = imgu_css_buf_queue(&imgu->css, pipe, buf);
			if (r)
				break;
			dummy = imgu_dummybufs_check(imgu, buf, pipe);
			if (!dummy)
				ibuf = container_of(buf, struct imgu_buffer,
						    css_buf);
			dev_dbg(&imgu->pci_dev->dev,
				"queue %s %s buffer %u to css da: 0x%08x\n",
				dummy ? "dummy" : "user",
				imgu_node_map[node].name,
				dummy ? 0 : ibuf->vid_buf.vbb.vb2_buf.index,
				(u32)buf->daddr);
		}
	}
	mutex_unlock(&imgu->lock);

	if (r && r != -EBUSY)
		goto failed;

	return 0;

failed:
	/*
	 * On error, mark all buffers as failed which are not
	 * yet queued to CSS
	 */
	dev_err(&imgu->pci_dev->dev,
		"failed to queue buffer to CSS on queue %i (%d)\n",
		node, r);

	if (initial)
		/* If we were called from streamon(), no need to finish bufs */
		return r;

	for (node = 0; node < IMGU_NODE_NUM; node++) {
		struct imgu_buffer *buf, *buf0;

		if (!imgu_pipe->queue_enabled[node])
			continue;	/* Skip disabled queues */

		mutex_lock(&imgu->lock);
		list_for_each_entry_safe(buf, buf0,
					 &imgu_pipe->nodes[node].buffers,
					 vid_buf.list) {
			if (imgu_css_buf_state(&buf->css_buf) ==
			    IPU3_CSS_BUFFER_QUEUED)
				continue;	/* Was already queued, skip */

			imgu_v4l2_buffer_done(&buf->vid_buf.vbb.vb2_buf,
					      VB2_BUF_STATE_ERROR);
		}
		mutex_unlock(&imgu->lock);
	}

	return r;
}

static int imgu_powerup(struct imgu_device *imgu)
{
	int r;
	unsigned int pipe;
	unsigned int freq = 200;
	struct v4l2_mbus_framefmt *fmt;

	/* input larger than 2048*1152, ask imgu to work on high freq */
	for_each_set_bit(pipe, imgu->css.enabled_pipes, IMGU_MAX_PIPE_NUM) {
		fmt = &imgu->imgu_pipe[pipe].nodes[IMGU_NODE_IN].pad_fmt;
		dev_dbg(&imgu->pci_dev->dev, "pipe %u input format = %ux%u",
			pipe, fmt->width, fmt->height);
		if ((fmt->width * fmt->height) >= (2048 * 1152))
			freq = 450;
	}

	r = imgu_css_set_powerup(&imgu->pci_dev->dev, imgu->base, freq);
	if (r)
		return r;

	imgu_mmu_resume(imgu->mmu);
	return 0;
}

static void imgu_powerdown(struct imgu_device *imgu)
{
	imgu_mmu_suspend(imgu->mmu);
	imgu_css_set_powerdown(&imgu->pci_dev->dev, imgu->base);
}

int imgu_s_stream(struct imgu_device *imgu, int enable)
{
	struct device *dev = &imgu->pci_dev->dev;
	int r, pipe;

	if (!enable) {
		/* Stop streaming */
		dev_dbg(dev, "stream off\n");
		/* Block new buffers to be queued to CSS. */
		atomic_set(&imgu->qbuf_barrier, 1);
		imgu_css_stop_streaming(&imgu->css);
		synchronize_irq(imgu->pci_dev->irq);
		atomic_set(&imgu->qbuf_barrier, 0);
		imgu_powerdown(imgu);
		pm_runtime_put(&imgu->pci_dev->dev);

		return 0;
	}

	/* Set Power */
	r = pm_runtime_resume_and_get(dev);
	if (r < 0) {
		dev_err(dev, "failed to set imgu power\n");
		return r;
	}

	r = imgu_powerup(imgu);
	if (r) {
		dev_err(dev, "failed to power up imgu\n");
		pm_runtime_put(dev);
		return r;
	}

	/* Start CSS streaming */
	r = imgu_css_start_streaming(&imgu->css);
	if (r) {
		dev_err(dev, "failed to start css streaming (%d)", r);
		goto fail_start_streaming;
	}

	for_each_set_bit(pipe, imgu->css.enabled_pipes, IMGU_MAX_PIPE_NUM) {
		/* Initialize dummy buffers */
		r = imgu_dummybufs_init(imgu, pipe);
		if (r) {
			dev_err(dev, "failed to initialize dummy buffers (%d)", r);
			goto fail_dummybufs;
		}

		/* Queue as many buffers from queue as possible */
		r = imgu_queue_buffers(imgu, true, pipe);
		if (r) {
			dev_err(dev, "failed to queue initial buffers (%d)", r);
			goto fail_queueing;
		}
	}

	return 0;
fail_queueing:
	for_each_set_bit(pipe, imgu->css.enabled_pipes, IMGU_MAX_PIPE_NUM)
		imgu_dummybufs_cleanup(imgu, pipe);
fail_dummybufs:
	imgu_css_stop_streaming(&imgu->css);
fail_start_streaming:
	pm_runtime_put(dev);

	return r;
}

static int imgu_video_nodes_init(struct imgu_device *imgu)
{
	struct v4l2_pix_format_mplane *fmts[IPU3_CSS_QUEUES] = { NULL };
	struct v4l2_rect *rects[IPU3_CSS_RECTS] = { NULL };
	struct imgu_media_pipe *imgu_pipe;
	unsigned int i, j;
	int r;

	imgu->buf_struct_size = sizeof(struct imgu_buffer);

	for (j = 0; j < IMGU_MAX_PIPE_NUM; j++) {
		imgu_pipe = &imgu->imgu_pipe[j];

		for (i = 0; i < IMGU_NODE_NUM; i++) {
			imgu_pipe->nodes[i].name = imgu_node_map[i].name;
			imgu_pipe->nodes[i].output = i < IMGU_QUEUE_FIRST_INPUT;
			imgu_pipe->nodes[i].enabled = false;

			if (i != IMGU_NODE_PARAMS && i != IMGU_NODE_STAT_3A)
				fmts[imgu_node_map[i].css_queue] =
					&imgu_pipe->nodes[i].vdev_fmt.fmt.pix_mp;
			atomic_set(&imgu_pipe->nodes[i].sequence, 0);
		}
	}

	r = imgu_v4l2_register(imgu);
	if (r)
		return r;

	/* Set initial formats and initialize formats of video nodes */
	for (j = 0; j < IMGU_MAX_PIPE_NUM; j++) {
		imgu_pipe = &imgu->imgu_pipe[j];

		rects[IPU3_CSS_RECT_EFFECTIVE] = &imgu_pipe->imgu_sd.rect.eff;
		rects[IPU3_CSS_RECT_BDS] = &imgu_pipe->imgu_sd.rect.bds;
		imgu_css_fmt_set(&imgu->css, fmts, rects, j);

		/* Pre-allocate dummy buffers */
		r = imgu_dummybufs_preallocate(imgu, j);
		if (r) {
			dev_err(&imgu->pci_dev->dev,
				"failed to pre-allocate dummy buffers (%d)", r);
			goto out_cleanup;
		}
	}

	return 0;

out_cleanup:
	for (j = 0; j < IMGU_MAX_PIPE_NUM; j++)
		imgu_dummybufs_cleanup(imgu, j);

	imgu_v4l2_unregister(imgu);

	return r;
}

static void imgu_video_nodes_exit(struct imgu_device *imgu)
{
	int i;

	for (i = 0; i < IMGU_MAX_PIPE_NUM; i++)
		imgu_dummybufs_cleanup(imgu, i);

	imgu_v4l2_unregister(imgu);
}

/**************** PCI interface ****************/

static irqreturn_t imgu_isr_threaded(int irq, void *imgu_ptr)
{
	struct imgu_device *imgu = imgu_ptr;
	struct imgu_media_pipe *imgu_pipe;
	int p;

	/* Dequeue / queue buffers */
	do {
		u64 ns = ktime_get_ns();
		struct imgu_css_buffer *b;
		struct imgu_buffer *buf = NULL;
		unsigned int node, pipe;
		bool dummy;

		do {
			mutex_lock(&imgu->lock);
			b = imgu_css_buf_dequeue(&imgu->css);
			mutex_unlock(&imgu->lock);
		} while (PTR_ERR(b) == -EAGAIN);

		if (IS_ERR(b)) {
			if (PTR_ERR(b) != -EBUSY)	/* All done */
				dev_err(&imgu->pci_dev->dev,
					"failed to dequeue buffers (%ld)\n",
					PTR_ERR(b));
			break;
		}

		node = imgu_map_node(imgu, b->queue);
		pipe = b->pipe;
		dummy = imgu_dummybufs_check(imgu, b, pipe);
		if (!dummy)
			buf = container_of(b, struct imgu_buffer, css_buf);
		dev_dbg(&imgu->pci_dev->dev,
			"dequeue %s %s buffer %d daddr 0x%x from css\n",
			dummy ? "dummy" : "user",
			imgu_node_map[node].name,
			dummy ? 0 : buf->vid_buf.vbb.vb2_buf.index,
			(u32)b->daddr);

		if (dummy)
			/* It was a dummy buffer, skip it */
			continue;

		/* Fill vb2 buffer entries and tell it's ready */
		imgu_pipe = &imgu->imgu_pipe[pipe];
		if (!imgu_pipe->nodes[node].output) {
			buf->vid_buf.vbb.vb2_buf.timestamp = ns;
			buf->vid_buf.vbb.field = V4L2_FIELD_NONE;
			buf->vid_buf.vbb.sequence =
				atomic_inc_return(
				&imgu_pipe->nodes[node].sequence);
			dev_dbg(&imgu->pci_dev->dev, "vb2 buffer sequence %d",
				buf->vid_buf.vbb.sequence);
		}
		imgu_buffer_done(imgu, &buf->vid_buf.vbb.vb2_buf,
				 imgu_css_buf_state(&buf->css_buf) ==
						    IPU3_CSS_BUFFER_DONE ?
						    VB2_BUF_STATE_DONE :
						    VB2_BUF_STATE_ERROR);
		mutex_lock(&imgu->lock);
		if (imgu_css_queue_empty(&imgu->css))
			wake_up_all(&imgu->buf_drain_wq);
		mutex_unlock(&imgu->lock);
	} while (1);

	/*
	 * Try to queue more buffers for CSS.
	 * qbuf_barrier is used to disable new buffers
	 * to be queued to CSS.
	 */
	if (!atomic_read(&imgu->qbuf_barrier))
		for_each_set_bit(p, imgu->css.enabled_pipes, IMGU_MAX_PIPE_NUM)
			imgu_queue_buffers(imgu, false, p);

	return IRQ_HANDLED;
}

static irqreturn_t imgu_isr(int irq, void *imgu_ptr)
{
	struct imgu_device *imgu = imgu_ptr;

	/* acknowledge interruption */
	if (imgu_css_irq_ack(&imgu->css) < 0)
		return IRQ_NONE;

	return IRQ_WAKE_THREAD;
}

static int imgu_pci_config_setup(struct pci_dev *dev)
{
	u16 pci_command;
	int r = pci_enable_msi(dev);

	if (r) {
		dev_err(&dev->dev, "failed to enable MSI (%d)\n", r);
		return r;
	}

	pci_read_config_word(dev, PCI_COMMAND, &pci_command);
	pci_command |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
			PCI_COMMAND_INTX_DISABLE;
	pci_write_config_word(dev, PCI_COMMAND, pci_command);

	return 0;
}

static int imgu_pci_probe(struct pci_dev *pci_dev,
			  const struct pci_device_id *id)
{
	struct imgu_device *imgu;
	phys_addr_t phys;
	unsigned long phys_len;
	void __iomem *const *iomap;
	int r;

	imgu = devm_kzalloc(&pci_dev->dev, sizeof(*imgu), GFP_KERNEL);
	if (!imgu)
		return -ENOMEM;

	imgu->pci_dev = pci_dev;

	r = pcim_enable_device(pci_dev);
	if (r) {
		dev_err(&pci_dev->dev, "failed to enable device (%d)\n", r);
		return r;
	}

	dev_info(&pci_dev->dev, "device 0x%x (rev: 0x%x)\n",
		 pci_dev->device, pci_dev->revision);

	phys = pci_resource_start(pci_dev, IMGU_PCI_BAR);
	phys_len = pci_resource_len(pci_dev, IMGU_PCI_BAR);

	r = pcim_iomap_regions(pci_dev, 1 << IMGU_PCI_BAR, pci_name(pci_dev));
	if (r) {
		dev_err(&pci_dev->dev, "failed to remap I/O memory (%d)\n", r);
		return r;
	}
	dev_info(&pci_dev->dev, "physical base address %pap, %lu bytes\n",
		 &phys, phys_len);

	iomap = pcim_iomap_table(pci_dev);
	if (!iomap) {
		dev_err(&pci_dev->dev, "failed to iomap table\n");
		return -ENODEV;
	}

	imgu->base = iomap[IMGU_PCI_BAR];

	pci_set_drvdata(pci_dev, imgu);

	pci_set_master(pci_dev);

	r = dma_coerce_mask_and_coherent(&pci_dev->dev, IMGU_DMA_MASK);
	if (r) {
		dev_err(&pci_dev->dev, "failed to set DMA mask (%d)\n", r);
		return -ENODEV;
	}

	r = imgu_pci_config_setup(pci_dev);
	if (r)
		return r;

	mutex_init(&imgu->lock);
	mutex_init(&imgu->streaming_lock);
	atomic_set(&imgu->qbuf_barrier, 0);
	init_waitqueue_head(&imgu->buf_drain_wq);

	r = imgu_css_set_powerup(&pci_dev->dev, imgu->base, 200);
	if (r) {
		dev_err(&pci_dev->dev,
			"failed to power up CSS (%d)\n", r);
		goto out_mutex_destroy;
	}

	imgu->mmu = imgu_mmu_init(&pci_dev->dev, imgu->base);
	if (IS_ERR(imgu->mmu)) {
		r = PTR_ERR(imgu->mmu);
		dev_err(&pci_dev->dev, "failed to initialize MMU (%d)\n", r);
		goto out_css_powerdown;
	}

	r = imgu_dmamap_init(imgu);
	if (r) {
		dev_err(&pci_dev->dev,
			"failed to initialize DMA mapping (%d)\n", r);
		goto out_mmu_exit;
	}

	/* ISP programming */
	r = imgu_css_init(&pci_dev->dev, &imgu->css, imgu->base, phys_len);
	if (r) {
		dev_err(&pci_dev->dev, "failed to initialize CSS (%d)\n", r);
		goto out_dmamap_exit;
	}

	/* v4l2 sub-device registration */
	r = imgu_video_nodes_init(imgu);
	if (r) {
		dev_err(&pci_dev->dev, "failed to create V4L2 devices (%d)\n",
			r);
		goto out_css_cleanup;
	}

	r = devm_request_threaded_irq(&pci_dev->dev, pci_dev->irq,
				      imgu_isr, imgu_isr_threaded,
				      IRQF_SHARED, IMGU_NAME, imgu);
	if (r) {
		dev_err(&pci_dev->dev, "failed to request IRQ (%d)\n", r);
		goto out_video_exit;
	}

	pm_runtime_put_noidle(&pci_dev->dev);
	pm_runtime_allow(&pci_dev->dev);

	return 0;

out_video_exit:
	imgu_video_nodes_exit(imgu);
out_css_cleanup:
	imgu_css_cleanup(&imgu->css);
out_dmamap_exit:
	imgu_dmamap_exit(imgu);
out_mmu_exit:
	imgu_mmu_exit(imgu->mmu);
out_css_powerdown:
	imgu_css_set_powerdown(&pci_dev->dev, imgu->base);
out_mutex_destroy:
	mutex_destroy(&imgu->streaming_lock);
	mutex_destroy(&imgu->lock);

	return r;
}

static void imgu_pci_remove(struct pci_dev *pci_dev)
{
	struct imgu_device *imgu = pci_get_drvdata(pci_dev);

	pm_runtime_forbid(&pci_dev->dev);
	pm_runtime_get_noresume(&pci_dev->dev);

	imgu_video_nodes_exit(imgu);
	imgu_css_cleanup(&imgu->css);
	imgu_css_set_powerdown(&pci_dev->dev, imgu->base);
	imgu_dmamap_exit(imgu);
	imgu_mmu_exit(imgu->mmu);
	mutex_destroy(&imgu->streaming_lock);
	mutex_destroy(&imgu->lock);
}

static int __maybe_unused imgu_suspend(struct device *dev)
{
	struct pci_dev *pci_dev = to_pci_dev(dev);
	struct imgu_device *imgu = pci_get_drvdata(pci_dev);

	dev_dbg(dev, "enter %s\n", __func__);
	imgu->suspend_in_stream = imgu_css_is_streaming(&imgu->css);
	if (!imgu->suspend_in_stream)
		goto out;
	/* Block new buffers to be queued to CSS. */
	atomic_set(&imgu->qbuf_barrier, 1);
	/*
	 * Wait for currently running irq handler to be done so that
	 * no new buffers will be queued to fw later.
	 */
	synchronize_irq(pci_dev->irq);
	/* Wait until all buffers in CSS are done. */
	if (!wait_event_timeout(imgu->buf_drain_wq,
	    imgu_css_queue_empty(&imgu->css), msecs_to_jiffies(1000)))
		dev_err(dev, "wait buffer drain timeout.\n");

	imgu_css_stop_streaming(&imgu->css);
	atomic_set(&imgu->qbuf_barrier, 0);
	imgu_powerdown(imgu);
	pm_runtime_force_suspend(dev);
out:
	dev_dbg(dev, "leave %s\n", __func__);
	return 0;
}

static int __maybe_unused imgu_resume(struct device *dev)
{
	struct imgu_device *imgu = dev_get_drvdata(dev);
	int r = 0;
	unsigned int pipe;

	dev_dbg(dev, "enter %s\n", __func__);

	if (!imgu->suspend_in_stream)
		goto out;

	pm_runtime_force_resume(dev);

	r = imgu_powerup(imgu);
	if (r) {
		dev_err(dev, "failed to power up imgu\n");
		goto out;
	}

	/* Start CSS streaming */
	r = imgu_css_start_streaming(&imgu->css);
	if (r) {
		dev_err(dev, "failed to resume css streaming (%d)", r);
		goto out;
	}

	for_each_set_bit(pipe, imgu->css.enabled_pipes, IMGU_MAX_PIPE_NUM) {
		r = imgu_queue_buffers(imgu, true, pipe);
		if (r)
			dev_err(dev, "failed to queue buffers to pipe %d (%d)",
				pipe, r);
	}

out:
	dev_dbg(dev, "leave %s\n", __func__);

	return r;
}

/*
 * PCI rpm framework checks the existence of driver rpm callbacks.
 * Place a dummy callback here to avoid rpm going into error state.
 */
static __maybe_unused int imgu_rpm_dummy_cb(struct device *dev)
{
	return 0;
}

static const struct dev_pm_ops imgu_pm_ops = {
	SET_RUNTIME_PM_OPS(&imgu_rpm_dummy_cb, &imgu_rpm_dummy_cb, NULL)
	SET_SYSTEM_SLEEP_PM_OPS(&imgu_suspend, &imgu_resume)
};

static const struct pci_device_id imgu_pci_tbl[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, IMGU_PCI_ID) },
	{ 0, }
};

MODULE_DEVICE_TABLE(pci, imgu_pci_tbl);

static struct pci_driver imgu_pci_driver = {
	.name = IMGU_NAME,
	.id_table = imgu_pci_tbl,
	.probe = imgu_pci_probe,
	.remove = imgu_pci_remove,
	.driver = {
		.pm = &imgu_pm_ops,
	},
};

module_pci_driver(imgu_pci_driver);

MODULE_AUTHOR("Tuukka Toivonen <tuukka.toivonen@intel.com>");
MODULE_AUTHOR("Tianshu Qiu <tian.shu.qiu@intel.com>");
MODULE_AUTHOR("Jian Xu Zheng <jian.xu.zheng@intel.com>");
MODULE_AUTHOR("Yuning Pu <yuning.pu@intel.com>");
MODULE_AUTHOR("Yong Zhi <yong.zhi@intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Intel ipu3_imgu PCI driver");