i82801dx.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <device/device.h>
#include <device/pci.h>
#include <device/pci_ops.h>
#include "i82801dx.h"
 
void i82801dx_enable(struct device *dev)
{
        unsigned int index = 0;
        uint8_t bHasDisableBit = 0;
        uint16_t cur_disable_mask, new_disable_mask;
 
//      all 82801dbm devices are in bus 0
        unsigned int devfn = PCI_DEVFN(0x1f, 0);        // lpc
        struct device *lpc_dev = pcidev_path_on_root(devfn);    // 0
        if (!lpc_dev)
                return;
 
        // Calculate disable bit position for specified device:function
        // NOTE: For ICH-4, only the following devices can be disabled:
        //               D31: F0, F1, F3, F5, F6,
        //               D29: F0, F1, F2, F7
 
        if (PCI_SLOT(dev->path.pci.devfn) == 31) {
                index = PCI_FUNC(dev->path.pci.devfn);
 
                switch (index) {
                case 0:
                case 1:
                case 3:
                case 5:
                case 6:
                        bHasDisableBit = 1;
                        break;
 
                default:
                        break;
                };
 
                if (index == 0)
                        index = 14;     // D31:F0 bit is an exception
 
        } else if (PCI_SLOT(dev->path.pci.devfn) == 29) {
                index = 8 + PCI_FUNC(dev->path.pci.devfn);
 
                if ((PCI_FUNC(dev->path.pci.devfn) < 3)
                    || (PCI_FUNC(dev->path.pci.devfn) == 7))
                        bHasDisableBit = 1;
        }
 
        if (bHasDisableBit) {
                cur_disable_mask = pci_read_config16(lpc_dev, FUNC_DIS);
                new_disable_mask = cur_disable_mask & ~(1 << index);    // enable it
                if (!dev->enabled) {
                        new_disable_mask |= (1 << index);       // disable it
                }
                if (new_disable_mask != cur_disable_mask) {
                        pci_write_config16(lpc_dev, FUNC_DIS, new_disable_mask);
                }
        }
}
 
struct chip_operations southbridge_intel_i82801dx_ops = {
        CHIP_NAME("Intel ICH4/ICH4-M (82801Dx) Series Southbridge")
            .enable_dev = i82801dx_enable,
};