path: root/drivers/media/platform/vsp1/vsp1_dl.c

/*
 * vsp1_dl.h  --  R-Car VSP1 Display List
 *
 * Copyright (C) 2015 Renesas Corporation
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/workqueue.h>

#include "vsp1.h"
#include "vsp1_dl.h"

#define VSP1_DL_NUM_ENTRIES		256

#define VSP1_DLH_INT_ENABLE		(1 << 1)
#define VSP1_DLH_AUTO_START		(1 << 0)

struct vsp1_dl_header_list {
	u32 num_bytes;
	u32 addr;
} __attribute__((__packed__));

struct vsp1_dl_header {
	u32 num_lists;
	struct vsp1_dl_header_list lists[8];
	u32 next_header;
	u32 flags;
} __attribute__((__packed__));

struct vsp1_dl_entry {
	u32 addr;
	u32 data;
} __attribute__((__packed__));

/**
 * struct vsp1_dl_body - Display list body
 * @list: entry in the display list list of bodies
 * @vsp1: the VSP1 device
 * @entries: array of entries
 * @dma: DMA address of the entries
 * @size: size of the DMA memory in bytes
 * @num_entries: number of stored entries
 */
struct vsp1_dl_body {
	struct list_head list;
	struct vsp1_device *vsp1;

	struct vsp1_dl_entry *entries;
	dma_addr_t dma;
	size_t size;

	unsigned int num_entries;
};

/**
 * struct vsp1_dl_list - Display list
 * @list: entry in the display list manager lists
 * @dlm: the display list manager
 * @header: display list header, NULL for headerless lists
 * @dma: DMA address for the header
 * @body0: first display list body
 * @fragments: list of extra display list bodies
 * @chain: entry in the display list partition chain
 */
struct vsp1_dl_list {
	struct list_head list;
	struct vsp1_dl_manager *dlm;

	struct vsp1_dl_header *header;
	dma_addr_t dma;

	struct vsp1_dl_body body0;
	struct list_head fragments;

	bool has_chain;
	struct list_head chain;
};

enum vsp1_dl_mode {
	VSP1_DL_MODE_HEADER,
	VSP1_DL_MODE_HEADERLESS,
};

/**
 * struct vsp1_dl_manager - Display List manager
 * @index: index of the related WPF
 * @mode: display list operation mode (header or headerless)
 * @vsp1: the VSP1 device
 * @lock: protects the free, active, queued, pending and gc_fragments lists
 * @free: array of all free display lists
 * @active: list currently being processed (loaded) by hardware
 * @queued: list queued to the hardware (written to the DL registers)
 * @pending: list waiting to be queued to the hardware
 * @gc_work: fragments garbage collector work struct
 * @gc_fragments: array of display list fragments waiting to be freed
 */
struct vsp1_dl_manager {
	unsigned int index;
	enum vsp1_dl_mode mode;
	struct vsp1_device *vsp1;

	spinlock_t lock;
	struct list_head free;
	struct vsp1_dl_list *active;
	struct vsp1_dl_list *queued;
	struct vsp1_dl_list *pending;

	struct work_struct gc_work;
	struct list_head gc_fragments;
};

/* -----------------------------------------------------------------------------
 * Display List Body Management
 */

/*
 * Initialize a display list body object and allocate DMA memory for the body
 * data. The display list body object is expected to have been initialized to
 * 0 when allocated.
 */
static int vsp1_dl_body_init(struct vsp1_device *vsp1,
			     struct vsp1_dl_body *dlb, unsigned int num_entries,
			     size_t extra_size)
{
	size_t size = num_entries * sizeof(*dlb->entries) + extra_size;

	dlb->vsp1 = vsp1;
	dlb->size = size;

	dlb->entries = dma_alloc_wc(vsp1->bus_master, dlb->size, &dlb->dma,
				    GFP_KERNEL);
	if (!dlb->entries)
		return -ENOMEM;

	return 0;
}

/*
 * Cleanup a display list body and free allocated DMA memory allocated.
 */
static void vsp1_dl_body_cleanup(struct vsp1_dl_body *dlb)
{
	dma_free_wc(dlb->vsp1->bus_master, dlb->size, dlb->entries, dlb->dma);
}

/**
 * vsp1_dl_fragment_alloc - Allocate a display list fragment
 * @vsp1: The VSP1 device
 * @num_entries: The maximum number of entries that the fragment can contain
 *
 * Allocate a display list fragment with enough memory to contain the requested
 * number of entries.
 *
 * Return a pointer to a fragment on success or NULL if memory can't be
 * allocated.
 */
struct vsp1_dl_body *vsp1_dl_fragment_alloc(struct vsp1_device *vsp1,
					    unsigned int num_entries)
{
	struct vsp1_dl_body *dlb;
	int ret;

	dlb = kzalloc(sizeof(*dlb), GFP_KERNEL);
	if (!dlb)
		return NULL;

	ret = vsp1_dl_body_init(vsp1, dlb, num_entries, 0);
	if (ret < 0) {
		kfree(dlb);
		return NULL;
	}

	return dlb;
}

/**
 * vsp1_dl_fragment_free - Free a display list fragment
 * @dlb: The fragment
 *
 * Free the given display list fragment and the associated DMA memory.
 *
 * Fragments must only be freed explicitly if they are not added to a display
 * list, as the display list will take ownership of them and free them
 * otherwise. Manual free typically happens at cleanup time for fragments that
 * have been allocated but not used.
 *
 * Passing a NULL pointer to this function is safe, in that case no operation
 * will be performed.
 */
void vsp1_dl_fragment_free(struct vsp1_dl_body *dlb)
{
	if (!dlb)
		return;

	vsp1_dl_body_cleanup(dlb);
	kfree(dlb);
}

/**
 * vsp1_dl_fragment_write - Write a register to a display list fragment
 * @dlb: The fragment
 * @reg: The register address
 * @data: The register value
 *
 * Write the given register and value to the display list fragment. The maximum
 * number of entries that can be written in a fragment is specified when the
 * fragment is allocated by vsp1_dl_fragment_alloc().
 */
void vsp1_dl_fragment_write(struct vsp1_dl_body *dlb, u32 reg, u32 data)
{
	dlb->entries[dlb->num_entries].addr = reg;
	dlb->entries[dlb->num_entries].data = data;
	dlb->num_entries++;
}

/* -----------------------------------------------------------------------------
 * Display List Transaction Management
 */

static struct vsp1_dl_list *vsp1_dl_list_alloc(struct vsp1_dl_manager *dlm)
{
	struct vsp1_dl_list *dl;
	size_t header_size;
	int ret;

	dl = kzalloc(sizeof(*dl), GFP_KERNEL);
	if (!dl)
		return NULL;

	INIT_LIST_HEAD(&dl->fragments);
	dl->dlm = dlm;

	/*
	 * Initialize the display list body and allocate DMA memory for the body
	 * and the optional header. Both are allocated together to avoid memory
	 * fragmentation, with the header located right after the body in
	 * memory.
	 */
	header_size = dlm->mode == VSP1_DL_MODE_HEADER
		    ? ALIGN(sizeof(struct vsp1_dl_header), 8)
		    : 0;

	ret = vsp1_dl_body_init(dlm->vsp1, &dl->body0, VSP1_DL_NUM_ENTRIES,
				header_size);
	if (ret < 0) {
		kfree(dl);
		return NULL;
	}

	if (dlm->mode == VSP1_DL_MODE_HEADER) {
		size_t header_offset = VSP1_DL_NUM_ENTRIES
				     * sizeof(*dl->body0.entries);

		dl->header = ((void *)dl->body0.entries) + header_offset;
		dl->dma = dl->body0.dma + header_offset;

		memset(dl->header, 0, sizeof(*dl->header));
		dl->header->lists[0].addr = dl->body0.dma;