system/ulib/ddk/include/ddk/protocol/pci-lib.h

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#pragma once

#include <ddk/protocol/pci.h>

__BEGIN_CDECLS;

static inline zx_status_t pci_config_read8(const pci_protocol_t* pci,
                                           uint16_t offset, uint8_t* value) {
    uint32_t value_;
    zx_status_t st = pci->ops->config_read(pci->ctx, offset, sizeof(uint8_t), &value_);
    *value = value_ & UINT8_MAX;
    return st;
}

static inline zx_status_t pci_config_read16(const pci_protocol_t* pci,
                                            uint16_t offset, uint16_t* value) {
    uint32_t value_;
    zx_status_t st = pci->ops->config_read(pci->ctx, offset, sizeof(uint16_t), &value_);
    *value = value_ & UINT16_MAX;
    return st;
}

static inline zx_status_t pci_config_read32(const pci_protocol_t* pci,
                                            uint16_t offset, uint32_t* value) {
    return pci->ops->config_read(pci->ctx, offset, sizeof(uint32_t), value);
}

static inline zx_status_t pci_config_write8(const pci_protocol_t* pci,
                                            uint16_t offset, uint8_t value) {
    return pci->ops->config_write(pci->ctx, offset, sizeof(uint8_t), value);
}

static inline zx_status_t pci_config_write16(const pci_protocol_t* pci,
                                             uint16_t offset, uint16_t value) {
    return pci->ops->config_write(pci->ctx, offset, sizeof(uint16_t), value);
}

static inline zx_status_t pci_config_write32(const pci_protocol_t* pci,
                                             uint16_t offset, uint32_t value) {
    return pci->ops->config_write(pci->ctx, offset, sizeof(uint32_t), value);
}

static inline uint8_t pci_get_first_capability(const pci_protocol_t* pci, uint8_t type) {
    // the next_capability method will always look at the second byte next
    // pointer to fetch the next capability. By offsetting the CapPtr field
    // by -1 we can pretend we're working with a normal capability entry
    return pci_get_next_capability(pci, PCI_CFG_CAPABILITIES_PTR - 1u, type);
}

__END_CDECLS;