nes-proj/cpu/x86/drivers/legacy_pc/pci.c

80 lines
3.2 KiB
C

/*
* Copyright (C) 2015, Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "pci.h"
#include "helpers.h"
/* I/O port for PCI configuration address */
#define PCI_CONFIG_ADDR_PORT 0xCF8
/* I/O port for PCI configuration data */
#define PCI_CONFIG_DATA_PORT 0xCFC
/*---------------------------------------------------------------------------*/
/* Initialize PCI configuration register address in preparation for accessing
* the specified register.
*/
static void
set_addr(pci_config_addr_t addr)
{
addr.en_mapping = 1;
outl(PCI_CONFIG_ADDR_PORT, addr.raw);
}
/*---------------------------------------------------------------------------*/
/**
* \brief Read from the specified PCI configuration register.
* \param addr Address of PCI configuration register.
* \return Value read from PCI configuration register.
*/
uint32_t
pci_config_read(pci_config_addr_t addr)
{
set_addr(addr);
return inl(PCI_CONFIG_DATA_PORT);
}
/*---------------------------------------------------------------------------*/
/**
* \brief Initialize a structure for a PCI device driver that performs
* MMIO to address range 0. Assumes that device has already
* been configured with an MMIO address range 0, e.g. by
* firmware.
* \param c_this Structure that will be initialized to represent the driver.
* \param pci_addr PCI base address of device.
*/
void
pci_init_bar0(pci_driver_t *c_this, pci_config_addr_t pci_addr)
{
pci_addr.reg_off = PCI_CONFIG_REG_BAR0;
/* The BAR0 value is masked to clear non-address bits. */
c_this->mmio = pci_config_read(pci_addr) & ~0xFFF;
}
/*---------------------------------------------------------------------------*/