// SPDX-License-Identifier: GPL-2.0+

#include <linux/io.h>
#include "ipmi_si.h"

static unsigned char port_inb(const struct si_sm_io *io, unsigned int offset)
{
        unsigned int addr = io->addr_data;

        return inb(addr + (offset * io->regspacing));
}

static void port_outb(const struct si_sm_io *io, unsigned int offset,
                      unsigned char b)
{
        unsigned int addr = io->addr_data;

        outb(b, addr + (offset * io->regspacing));
}

static unsigned char port_inw(const struct si_sm_io *io, unsigned int offset)
{
        unsigned int addr = io->addr_data;

        return (inw(addr + (offset * io->regspacing)) >> io->regshift) & 0xff;
}

static void port_outw(const struct si_sm_io *io, unsigned int offset,
                      unsigned char b)
{
        unsigned int addr = io->addr_data;

        outw(b << io->regshift, addr + (offset * io->regspacing));
}

static unsigned char port_inl(const struct si_sm_io *io, unsigned int offset)
{
        unsigned int addr = io->addr_data;

        return (inl(addr + (offset * io->regspacing)) >> io->regshift) & 0xff;
}

static void port_outl(const struct si_sm_io *io, unsigned int offset,
                      unsigned char b)
{
        unsigned int addr = io->addr_data;

        outl(b << io->regshift, addr+(offset * io->regspacing));
}

static void port_cleanup(struct si_sm_io *io)
{
        unsigned int addr = io->addr_data;
        int          idx;

        if (addr) {
                for (idx = 0; idx < io->io_size; idx++)
                        release_region(addr + idx * io->regspacing,
                                       io->regsize);
        }
}

int ipmi_si_port_setup(struct si_sm_io *io)
{
        unsigned int addr = io->addr_data;
        int          idx;

        if (!addr)
                return -ENODEV;

        /*
         * Figure out the actual inb/inw/inl/etc routine to use based
         * upon the register size.
         */
        switch (io->regsize) {
        case 1:
                io->inputb = port_inb;
                io->outputb = port_outb;
                break;
        case 2:
                io->inputb = port_inw;
                io->outputb = port_outw;
                break;
        case 4:
                io->inputb = port_inl;
                io->outputb = port_outl;
                break;
        default:
                dev_warn(io->dev, "Invalid register size: %d\n",
                         io->regsize);
                return -EINVAL;
        }

        /*
         * Some BIOSes reserve disjoint I/O regions in their ACPI
         * tables.  This causes problems when trying to register the
         * entire I/O region.  Therefore we must register each I/O
         * port separately.
         */
        for (idx = 0; idx < io->io_size; idx++) {
                if (request_region(addr + idx * io->regspacing,
                                   io->regsize, SI_DEVICE_NAME) == NULL) {
                        /* Undo allocations */
                        while (idx--)
                                release_region(addr + idx * io->regspacing,
                                               io->regsize);
                        return -EIO;
                }
        }

        io->io_cleanup = port_cleanup;

        return 0;
}