/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
 *
 * From Linux kernel include/uapi/linux/virtio_mmio.h
 */

#ifndef _LINUX_VIRTIO_MMIO_H
#define _LINUX_VIRTIO_MMIO_H

/* Control registers */

/* Magic value ("virt" string) - Read Only */
#include <linux/bitops.h>
#define VIRTIO_MMIO_MAGIC_VALUE		0x000

/* Virtio device version - Read Only */
#define VIRTIO_MMIO_VERSION		0x004

/* Virtio device ID - Read Only */
#define VIRTIO_MMIO_DEVICE_ID		0x008

/* Virtio vendor ID - Read Only */
#define VIRTIO_MMIO_VENDOR_ID		0x00c

/*
 * Bitmask of the features supported by the device (host)
 * (32 bits per set) - Read Only
 */
#define VIRTIO_MMIO_DEVICE_FEATURES	0x010

/* Device (host) features set selector - Write Only */
#define VIRTIO_MMIO_DEVICE_FEATURES_SEL	0x014

/*
 * Bitmask of features activated by the driver (guest)
 * (32 bits per set) - Write Only
 */
#define VIRTIO_MMIO_DRIVER_FEATURES	0x020

/* Activated features set selector - Write Only */
#define VIRTIO_MMIO_DRIVER_FEATURES_SEL	0x024

#ifndef VIRTIO_MMIO_NO_LEGACY /* LEGACY DEVICES ONLY! */

/* Guest's memory page size in bytes - Write Only */
#define VIRTIO_MMIO_GUEST_PAGE_SIZE	0x028

#endif

/* Queue selector - Write Only */
#define VIRTIO_MMIO_QUEUE_SEL		0x030

/* Maximum size of the currently selected queue - Read Only */
#define VIRTIO_MMIO_QUEUE_NUM_MAX	0x034

/* Queue size for the currently selected queue - Write Only */
#define VIRTIO_MMIO_QUEUE_NUM		0x038

#ifndef VIRTIO_MMIO_NO_LEGACY /* LEGACY DEVICES ONLY! */

/* Used Ring alignment for the currently selected queue - Write Only */
#define VIRTIO_MMIO_QUEUE_ALIGN		0x03c

/* Guest's PFN for the currently selected queue - Read Write */
#define VIRTIO_MMIO_QUEUE_PFN		0x040

#endif

/* Ready bit for the currently selected queue - Read Write */
#define VIRTIO_MMIO_QUEUE_READY		0x044

/* Queue notifier - Write Only */
#define VIRTIO_MMIO_QUEUE_NOTIFY	0x050

/* Interrupt status - Read Only */
#define VIRTIO_MMIO_INTERRUPT_STATUS	0x060

/* Interrupt acknowledge - Write Only */
#define VIRTIO_MMIO_INTERRUPT_ACK	0x064

/* Device status register - Read Write */
#define VIRTIO_MMIO_STATUS		0x070

/* Selected queue's Descriptor Table address, 64 bits in two halves */
#define VIRTIO_MMIO_QUEUE_DESC_LOW	0x080
#define VIRTIO_MMIO_QUEUE_DESC_HIGH	0x084

/* Selected queue's Available Ring address, 64 bits in two halves */
#define VIRTIO_MMIO_QUEUE_AVAIL_LOW	0x090
#define VIRTIO_MMIO_QUEUE_AVAIL_HIGH	0x094

/* Selected queue's Used Ring address, 64 bits in two halves */
#define VIRTIO_MMIO_QUEUE_USED_LOW	0x0a0
#define VIRTIO_MMIO_QUEUE_USED_HIGH	0x0a4

/* Configuration atomicity value */
#define VIRTIO_MMIO_CONFIG_GENERATION	0x0fc

/*
 * The config space is defined by each driver as
 * the per-driver configuration space - Read Write
 */
#define VIRTIO_MMIO_CONFIG		0x100

/* Interrupt flags (re: interrupt status & acknowledge registers) */

#define VIRTIO_MMIO_INT_VRING		BIT(0)
#define VIRTIO_MMIO_INT_CONFIG		BIT(1)

/*
 * The alignment to use between consumer and producer parts of vring.
 * Currently hardcoded to the page size.
 */
#define PAGE_SHIFT			12
#define VIRTIO_MMIO_VRING_ALIGN		PAGE_SIZE

/**
 * virtio mmio transport driver private data
 *
 * @base:		mmio transport device register base
 * @version:		mmio transport device version
 */
struct virtio_mmio_priv {
	void __iomem *base;
	u32 version;
};

#endif /* _LINUX_VIRTIO_MMIO_H */