zircon/kernel/lib/kpci/include/lib/pci/pio.h

// Copyright 2017 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#ifndef ZIRCON_KERNEL_LIB_PCI_INCLUDE_LIB_PCI_PIO_H_
#define ZIRCON_KERNEL_LIB_PCI_INCLUDE_LIB_PCI_PIO_H_

#include <stdint.h>
#include <zircon/types.h>

namespace Pci {
// Returns the BDF address without the bottom two bits masked off.
constexpr uint32_t PciBdfRawAddr(uint8_t bus, uint8_t dev, uint8_t func, uint8_t off) {
  return (((bus & 0xFF) << 16) |  // bits 23-16 bus
          ((dev & 0x1F) << 11) |  // bits 15-11 device
          ((func & 0x7) << 8) |   // bifs 10-8 func
          (off & 0xFF));          // bits 7-2 register, WITH bottom two bits as well
}

// Return BDF address with bottom two bits masked off.
constexpr uint32_t PciBdfAddr(uint8_t bus, uint8_t dev, uint8_t func, uint8_t off) {
  // Bits 1 & 0 must be zero
  return PciBdfRawAddr(bus, dev, func, off) & ~0x3;
}

// |addr| is expected to NOT have the bottom to bits masked off
zx_status_t PioCfgRead(uint32_t addr, uint32_t* val, size_t width);
zx_status_t PioCfgRead(uint8_t bus, uint8_t dev, uint8_t func, uint8_t offset, uint32_t* val,
                       size_t width);

// |addr| is expected to NOT have the bottom to bits masked off
zx_status_t PioCfgWrite(uint32_t addr, uint32_t val, size_t width);
zx_status_t PioCfgWrite(uint8_t bus, uint8_t dev, uint8_t func, uint8_t offset, uint32_t val,
                        size_t width);
}  // namespace Pci

#endif  // ZIRCON_KERNEL_LIB_PCI_INCLUDE_LIB_PCI_PIO_H_