nouveau_volt.c

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/*
 * Copyright 2010 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 <drm/drmP.h>

#include "nouveau_drm.h"
#include "nouveau_pm.h"

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

static const enum dcb_gpio_func_name vidtag[] = { 0x04, 0x05, 0x06, 0x1a, 0x73 };
static int nr_vidtag = sizeof(vidtag) / sizeof(vidtag[0]);

int
nouveau_voltage_gpio_get(struct drm_device *dev)
{
    struct nouveau_pm_voltage *volt = &nouveau_pm(dev)->voltage;
    struct nouveau_device *device = nouveau_dev(dev);
    struct nouveau_gpio *gpio = nouveau_gpio(device);
    u8 vid = 0;
    int i;

    for (i = 0; i < nr_vidtag; i++) {
        if (!(volt->vid_mask & (1 << i)))
            continue;

        vid |= gpio->get(gpio, 0, vidtag[i], 0xff) << i;
    }

    return nouveau_volt_lvl_lookup(dev, vid);
}

int
nouveau_voltage_gpio_set(struct drm_device *dev, int voltage)
{
    struct nouveau_device *device = nouveau_dev(dev);
    struct nouveau_gpio *gpio = nouveau_gpio(device);
    struct nouveau_pm_voltage *volt = &nouveau_pm(dev)->voltage;
    int vid, i;

    vid = nouveau_volt_vid_lookup(dev, voltage);
    if (vid < 0)
        return vid;

    for (i = 0; i < nr_vidtag; i++) {
        if (!(volt->vid_mask & (1 << i)))
            continue;

        gpio->set(gpio, 0, vidtag[i], 0xff, !!(vid & (1 << i)));
    }

    return 0;
}

int
nouveau_volt_vid_lookup(struct drm_device *dev, int voltage)
{
    struct nouveau_pm_voltage *volt = &nouveau_pm(dev)->voltage;
    int i;

    for (i = 0; i < volt->nr_level; i++) {
        if (volt->level[i].voltage == voltage)
            return volt->level[i].vid;
    }

    return -ENOENT;
}

int
nouveau_volt_lvl_lookup(struct drm_device *dev, int vid)
{
    struct nouveau_pm_voltage *volt = &nouveau_pm(dev)->voltage;
    int i;

    for (i = 0; i < volt->nr_level; i++) {
        if (volt->level[i].vid == vid)
            return volt->level[i].voltage;
    }

    return -ENOENT;
}

void
nouveau_volt_init(struct drm_device *dev)
{
    struct nouveau_drm *drm = nouveau_drm(dev);
    struct nouveau_gpio *gpio = nouveau_gpio(drm->device);
    struct nouveau_pm *pm = nouveau_pm(dev);
    struct nouveau_pm_voltage *voltage = &pm->voltage;
    struct nvbios *bios = &drm->vbios;
    struct dcb_gpio_func func;
    struct bit_entry P;
    u8 *volt = NULL, *entry;
    int i, headerlen, recordlen, entries, vidmask, vidshift;

    if (bios->type == NVBIOS_BIT) {
        if (bit_table(dev, 'P', &P))
            return;

        if (P.version == 1)
            volt = ROMPTR(dev, P.data[16]);
        else
        if (P.version == 2)
            volt = ROMPTR(dev, P.data[12]);
        else {
            NV_WARN(drm, "unknown volt for BIT P %d\n", P.version);
        }
    } else {
        if (bios->data[bios->offset + 6] < 0x27) {
            NV_DEBUG(drm, "BMP version too old for voltage\n");
            return;
        }

        volt = ROMPTR(dev, bios->data[bios->offset + 0x98]);
    }

    if (!volt) {
        NV_DEBUG(drm, "voltage table pointer invalid\n");
        return;
    }

    switch (volt[0]) {
    case 0x10:
    case 0x11:
    case 0x12:
        headerlen = 5;
        recordlen = volt[1];
        entries   = volt[2];
        vidshift  = 0;
        vidmask   = volt[4];
        break;
    case 0x20:
        headerlen = volt[1];
        recordlen = volt[3];
        entries   = volt[2];
        vidshift  = 0; /* could be vidshift like 0x30? */
        vidmask   = volt[5];
        break;
    case 0x30:
        headerlen = volt[1];
        recordlen = volt[2];
        entries   = volt[3];
        vidmask   = volt[4];
        /* no longer certain what volt[5] is, if it's related to
         * the vid shift then it's definitely not a function of
         * how many bits are set.
         *
         * after looking at a number of nva3+ vbios images, they
         * all seem likely to have a static shift of 2.. lets
         * go with that for now until proven otherwise.
         */
        vidshift  = 2;
        break;
    case 0x40:
        headerlen = volt[1];
        recordlen = volt[2];
        entries   = volt[3]; /* not a clue what the entries are for.. */
        vidmask   = volt[11]; /* guess.. */
        vidshift  = 0;
        break;
    default:
        NV_WARN(drm, "voltage table 0x%02x unknown\n", volt[0]);
        return;
    }

    /* validate vid mask */
    voltage->vid_mask = vidmask;
    if (!voltage->vid_mask)
        return;

    i = 0;
    while (vidmask) {
        if (i > nr_vidtag) {
            NV_DEBUG(drm, "vid bit %d unknown\n", i);
            return;
        }

        if (gpio && gpio->find(gpio, 0, vidtag[i], 0xff, &func)) {
            NV_DEBUG(drm, "vid bit %d has no gpio tag\n", i);
            return;
        }

        vidmask >>= 1;
        i++;
    }

    /* parse vbios entries into common format */
    voltage->version = volt[0];
    if (voltage->version < 0x40) {
        voltage->nr_level = entries;
        voltage->level =
            kcalloc(entries, sizeof(*voltage->level), GFP_KERNEL);
        if (!voltage->level)
            return;

        entry = volt + headerlen;
        for (i = 0; i < entries; i++, entry += recordlen) {
            voltage->level[i].voltage = entry[0] * 10000;
            voltage->level[i].vid     = entry[1] >> vidshift;
        }
    } else {
        u32 volt_uv = ROM32(volt[4]);
        s16 step_uv = ROM16(volt[8]);
        u8 vid;

        voltage->nr_level = voltage->vid_mask + 1;
        voltage->level = kcalloc(voltage->nr_level,
                     sizeof(*voltage->level), GFP_KERNEL);
        if (!voltage->level)
            return;

        for (vid = 0; vid <= voltage->vid_mask; vid++) {
            voltage->level[vid].voltage = volt_uv;
            voltage->level[vid].vid = vid;
            volt_uv += step_uv;
        }
    }

    voltage->supported = true;
}

void
nouveau_volt_fini(struct drm_device *dev)
{
    struct nouveau_pm_voltage *volt = &nouveau_pm(dev)->voltage;

    kfree(volt->level);
}