gpio.c

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/*
 * Copyright 2012 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Ben Skeggs
 */

#include <subdev/bios.h>
#include <subdev/bios/dcb.h>
#include <subdev/bios/gpio.h>

u16
dcb_gpio_table(struct nouveau_bios *bios)
{
    u8  ver, hdr, cnt, len;
    u16 dcb = dcb_table(bios, &ver, &hdr, &cnt, &len);
    if (dcb) {
        if (ver >= 0x30 && hdr >= 0x0c)
            return nv_ro16(bios, dcb + 0x0a);
        if (ver >= 0x22 && nv_ro08(bios, dcb - 1) >= 0x13)
            return nv_ro16(bios, dcb - 0x0f);
    }
    return 0x0000;
}

u16
dcb_gpio_entry(struct nouveau_bios *bios, int idx, int ent, u8 *ver)
{
    u16 gpio = dcb_gpio_table(bios);
    if (gpio) {
        *ver = nv_ro08(bios, gpio);
        if (*ver < 0x30 && ent < nv_ro08(bios, gpio + 2))
            return gpio + 3 + (ent * nv_ro08(bios, gpio + 1));
        else if (ent < nv_ro08(bios, gpio + 2))
            return gpio + nv_ro08(bios, gpio + 1) +
                   (ent * nv_ro08(bios, gpio + 3));
    }
    return 0x0000;
}

int
dcb_gpio_parse(struct nouveau_bios *bios, int idx, u8 func, u8 line,
           struct dcb_gpio_func *gpio)
{
    u8  ver, hdr, cnt, len;
    u16 entry;
    int i = -1;

    while ((entry = dcb_gpio_entry(bios, idx, ++i, &ver))) {
        if (ver < 0x40) {
            u16 data = nv_ro16(bios, entry);
            *gpio = (struct dcb_gpio_func) {
                .line = (data & 0x001f) >> 0,
                .func = (data & 0x07e0) >> 5,
                .log[0] = (data & 0x1800) >> 11,
                .log[1] = (data & 0x6000) >> 13,
                .param = !!(data & 0x8000),
            };
        } else
        if (ver < 0x41) {
            u32 data = nv_ro32(bios, entry);
            *gpio = (struct dcb_gpio_func) {
                .line = (data & 0x0000001f) >> 0,
                .func = (data & 0x0000ff00) >> 8,
                .log[0] = (data & 0x18000000) >> 27,
                .log[1] = (data & 0x60000000) >> 29,
                .param = !!(data & 0x80000000),
            };
        } else {
            u32 data = nv_ro32(bios, entry + 0);
            u8 data1 = nv_ro32(bios, entry + 4);
            *gpio = (struct dcb_gpio_func) {
                .line = (data & 0x0000003f) >> 0,
                .func = (data & 0x0000ff00) >> 8,
                .log[0] = (data1 & 0x30) >> 4,
                .log[1] = (data1 & 0xc0) >> 6,
                .param = !!(data & 0x80000000),
            };
        }

        if ((line == 0xff || line == gpio->line) &&
            (func == 0xff || func == gpio->func))
            return 0;
    }

    /* DCB 2.2, fixed TVDAC GPIO data */
    if ((entry = dcb_table(bios, &ver, &hdr, &cnt, &len)) && ver >= 0x22) {
        if (func == DCB_GPIO_TVDAC0) {
            u8 conf = nv_ro08(bios, entry - 5);
            u8 addr = nv_ro08(bios, entry - 4);
            if (conf & 0x01) {
                *gpio = (struct dcb_gpio_func) {
                    .func = DCB_GPIO_TVDAC0,
                    .line = addr >> 4,
                    .log[0] = !!(conf & 0x02),
                    .log[1] =  !(conf & 0x02),
                };
                return 0;
            }
        }
    }

    return -EINVAL;
}