source: mainline/uspace/drv/bus/usb/ehci/res.c@ d967aa1

/*
 * Copyright (c) 2011 Jan Vesely
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/**
 * @addtogroup drvusbehci
 * @{
 */
/**
 * @file
 * PCI related functions needed by the EHCI driver.
 */

#include <errno.h>
#include <str_error.h>
#include <assert.h>
#include <devman.h>
#include <ddi.h>
#include <usb/debug.h>
#include <device/hw_res_parsed.h>
#include <pci_dev_iface.h>

#include "res.h"
#include "ehci_regs.h"

#define USBLEGSUP_OFFSET 0
#define USBLEGSUP_BIOS_CONTROL (1 << 16)
#define USBLEGSUP_OS_CONTROL (1 << 24)
#define USBLEGCTLSTS_OFFSET 4

#define DEFAULT_WAIT 1000
#define WAIT_STEP 10

/** Implements BIOS hands-off routine as described in EHCI spec
 *
 * @param device EHCI device
 * @param eecp Value of EHCI Extended Capabilities pointer.
 * @return Error code.
 */
static int disable_extended_caps(async_sess_t *parent_sess, unsigned eecp)
{
        /* nothing to do */
        if (eecp == 0)
                return EOK;

        /* Read the first EEC. i.e. Legacy Support register */
        uint32_t usblegsup;
        int ret = pci_config_space_read_32(parent_sess,
            eecp + USBLEGSUP_OFFSET, &usblegsup);
        if (ret != EOK) {
                usb_log_error("Failed to read USBLEGSUP: %s.\n", str_error(ret));
                return ret;
        }
        usb_log_debug2("USBLEGSUP: %" PRIx32 ".\n", usblegsup);

        /* Request control from firmware/BIOS by writing 1 to highest
         * byte. (OS Control semaphore)*/
        usb_log_debug("Requesting OS control.\n");
        ret = pci_config_space_write_8(parent_sess,
            eecp + USBLEGSUP_OFFSET + 3, 1);
        if (ret != EOK) {
                usb_log_error("Failed to request OS EHCI control: %s.\n",
                    str_error(ret));
                return ret;
        }

        size_t wait = 0;
        /* Wait for BIOS to release control. */
        ret = pci_config_space_read_32(
            parent_sess, eecp + USBLEGSUP_OFFSET, &usblegsup);
        while ((ret == EOK) && (wait < DEFAULT_WAIT)
            && (usblegsup & USBLEGSUP_BIOS_CONTROL)) {
                async_usleep(WAIT_STEP);
                ret = pci_config_space_read_32(parent_sess,
                    eecp + USBLEGSUP_OFFSET, &usblegsup);
                wait += WAIT_STEP;
        }

        if ((usblegsup & USBLEGSUP_BIOS_CONTROL) == 0) {
                usb_log_info("BIOS released control after %zu usec.\n", wait);
                return EOK;
        }

        /* BIOS failed to hand over control, this should not happen. */
        usb_log_warning( "BIOS failed to release control after "
            "%zu usecs, force it.\n", wait);
        ret = pci_config_space_write_32(parent_sess,
            eecp + USBLEGSUP_OFFSET, USBLEGSUP_OS_CONTROL);
        if (ret != EOK) {
                usb_log_error("Failed to force OS control: %s.\n",
                    str_error(ret));
                return ret;
        }

        /*
         * Check capability type here, value of 01h identifies the capability
         * as Legacy Support. This extended capability requires one additional
         * 32-bit register for control/status information and this register is
         * located at offset EECP+04h
         */
        if ((usblegsup & 0xff) == 1) {
                /* Read the second EEC Legacy Support and Control register */
                uint32_t usblegctlsts;
                ret = pci_config_space_read_32(parent_sess,
                    eecp + USBLEGCTLSTS_OFFSET, &usblegctlsts);
                if (ret != EOK) {
                        usb_log_error("Failed to get USBLEGCTLSTS: %s.\n",
                            str_error(ret));
                        return ret;
                }
                usb_log_debug2("USBLEGCTLSTS: %" PRIx32 ".\n", usblegctlsts);
                /*
                 * Zero SMI enables in legacy control register.
                 * It should prevent pre-OS code from
                 * interfering. NOTE: Three upper bits are WC
                 */
                ret = pci_config_space_write_32(parent_sess,
                    eecp + USBLEGCTLSTS_OFFSET, 0xe0000000);
                if (ret != EOK) {
                        usb_log_error("Failed to zero USBLEGCTLSTS: %s\n",
                            str_error(ret));
                        return ret;
                }

                udelay(10);
                /* read again to amke sure it's zeroed */
                ret = pci_config_space_read_32(parent_sess,
                    eecp + USBLEGCTLSTS_OFFSET, &usblegctlsts);
                if (ret != EOK) {
                        usb_log_error("Failed to get USBLEGCTLSTS 2: %s.\n",
                            str_error(ret));
                        return ret;
                }
                usb_log_debug2("Zeroed USBLEGCTLSTS: %" PRIx32 ".\n",
                    usblegctlsts);
        }

        /* Read again Legacy Support register */
        ret = pci_config_space_read_32(parent_sess,
            eecp + USBLEGSUP_OFFSET, &usblegsup);
        if (ret != EOK) {
                usb_log_error("Failed to read USBLEGSUP: %s.\n",
                    str_error(ret));
                return ret;
        }
        usb_log_debug2("USBLEGSUP: %" PRIx32 ".\n", usblegsup);
        return ret;
}

int disable_legacy(hc_t *hc, ddf_dev_t *device)
{
        assert(device);

        async_sess_t *parent_sess = devman_parent_device_connect(
            ddf_dev_get_handle(device), IPC_FLAG_BLOCKING);
        if (!parent_sess)
                return ENOMEM;

        usb_log_debug("Disabling EHCI legacy support.\n");


        const uint32_t hcc_params = EHCI_RD(hc->caps->hccparams);
        usb_log_debug2("Value of hcc params register: %x.\n", hcc_params);

        /* Read value of EHCI Extended Capabilities Pointer
         * position of EEC registers (points to PCI config space) */
        const uint32_t eecp =
            (hcc_params >> EHCI_CAPS_HCC_EECP_SHIFT) & EHCI_CAPS_HCC_EECP_MASK;
        usb_log_debug2("Value of EECP: %x.\n", eecp);

        int ret = disable_extended_caps(parent_sess, eecp);
        if (ret != EOK) {
                usb_log_error("Failed to disable extended capabilities: %s.\n",
                    str_error(ret));
                    goto clean;
        }
clean:
        async_hangup(parent_sess);
        return ret;
}

/**
 * @}
 */