radeon_backlight.c

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/*
 * Backlight code for ATI Radeon based graphic cards
 *
 * Copyright (c) 2000 Ani Joshi <[email protected]>
 * Copyright (c) 2003 Benjamin Herrenschmidt <[email protected]>
 * Copyright (c) 2006 Michael Hanselmann <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include "radeonfb.h"
#include <linux/backlight.h>
#include <linux/slab.h>

#ifdef CONFIG_PMAC_BACKLIGHT
#include <asm/backlight.h>
#endif

#define MAX_RADEON_LEVEL 0xFF

struct radeon_bl_privdata {
    struct radeonfb_info *rinfo;
    uint8_t negative;
};

static int radeon_bl_get_level_brightness(struct radeon_bl_privdata *pdata,
        int level)
{
    int rlevel;

    /* Get and convert the value */
    /* No locking of bl_curve since we read a single value */
    rlevel = pdata->rinfo->info->bl_curve[level] *
         FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL;

    if (rlevel < 0)
        rlevel = 0;
    else if (rlevel > MAX_RADEON_LEVEL)
        rlevel = MAX_RADEON_LEVEL;

    if (pdata->negative)
        rlevel = MAX_RADEON_LEVEL - rlevel;

    return rlevel;
}

static int radeon_bl_update_status(struct backlight_device *bd)
{
    struct radeon_bl_privdata *pdata = bl_get_data(bd);
    struct radeonfb_info *rinfo = pdata->rinfo;
    u32 lvds_gen_cntl, tmpPixclksCntl;
    int level;

    if (rinfo->mon1_type != MT_LCD)
        return 0;

    /* We turn off the LCD completely instead of just dimming the
     * backlight. This provides some greater power saving and the display
     * is useless without backlight anyway.
     */
        if (bd->props.power != FB_BLANK_UNBLANK ||
        bd->props.fb_blank != FB_BLANK_UNBLANK)
        level = 0;
    else
        level = bd->props.brightness;

    del_timer_sync(&rinfo->lvds_timer);
    radeon_engine_idle();

    lvds_gen_cntl = INREG(LVDS_GEN_CNTL);
    if (level > 0) {
        lvds_gen_cntl &= ~LVDS_DISPLAY_DIS;
        if (!(lvds_gen_cntl & LVDS_BLON) || !(lvds_gen_cntl & LVDS_ON)) {
            lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_DIGON);
            lvds_gen_cntl |= LVDS_BLON | LVDS_EN;
            OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
            lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
            lvds_gen_cntl |=
                (radeon_bl_get_level_brightness(pdata, level) <<
                 LVDS_BL_MOD_LEVEL_SHIFT);
            lvds_gen_cntl |= LVDS_ON;
            lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_BL_MOD_EN);
            rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
            mod_timer(&rinfo->lvds_timer,
                  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
        } else {
            lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
            lvds_gen_cntl |=
                (radeon_bl_get_level_brightness(pdata, level) <<
                 LVDS_BL_MOD_LEVEL_SHIFT);
            OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
        }
        rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
        rinfo->init_state.lvds_gen_cntl |= rinfo->pending_lvds_gen_cntl
            & LVDS_STATE_MASK;
    } else {
        /* Asic bug, when turning off LVDS_ON, we have to make sure
           RADEON_PIXCLK_LVDS_ALWAYS_ON bit is off
        */
        tmpPixclksCntl = INPLL(PIXCLKS_CNTL);
        if (rinfo->is_mobility || rinfo->is_IGP)
            OUTPLLP(PIXCLKS_CNTL, 0, ~PIXCLK_LVDS_ALWAYS_ONb);
        lvds_gen_cntl &= ~(LVDS_BL_MOD_LEVEL_MASK | LVDS_BL_MOD_EN);
        lvds_gen_cntl |= (radeon_bl_get_level_brightness(pdata, 0) <<
                  LVDS_BL_MOD_LEVEL_SHIFT);
        lvds_gen_cntl |= LVDS_DISPLAY_DIS;
        OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
        udelay(100);
        lvds_gen_cntl &= ~(LVDS_ON | LVDS_EN);
        OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
        lvds_gen_cntl &= ~(LVDS_DIGON);
        rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
        mod_timer(&rinfo->lvds_timer,
              jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
        if (rinfo->is_mobility || rinfo->is_IGP)
            OUTPLL(PIXCLKS_CNTL, tmpPixclksCntl);
    }
    rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
    rinfo->init_state.lvds_gen_cntl |= (lvds_gen_cntl & LVDS_STATE_MASK);

    return 0;
}

static int radeon_bl_get_brightness(struct backlight_device *bd)
{
    return bd->props.brightness;
}

static const struct backlight_ops radeon_bl_data = {
    .get_brightness = radeon_bl_get_brightness,
    .update_status  = radeon_bl_update_status,
};

void radeonfb_bl_init(struct radeonfb_info *rinfo)
{
    struct backlight_properties props;
    struct backlight_device *bd;
    struct radeon_bl_privdata *pdata;
    char name[12];

    if (rinfo->mon1_type != MT_LCD)
        return;

#ifdef CONFIG_PMAC_BACKLIGHT
    if (!pmac_has_backlight_type("ati") &&
        !pmac_has_backlight_type("mnca"))
        return;
#endif

    pdata = kmalloc(sizeof(struct radeon_bl_privdata), GFP_KERNEL);
    if (!pdata) {
        printk("radeonfb: Memory allocation failed\n");
        goto error;
    }

    snprintf(name, sizeof(name), "radeonbl%d", rinfo->info->node);

    memset(&props, 0, sizeof(struct backlight_properties));
    props.type = BACKLIGHT_RAW;
    props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
    bd = backlight_device_register(name, rinfo->info->dev, pdata,
                       &radeon_bl_data, &props);
    if (IS_ERR(bd)) {
        rinfo->info->bl_dev = NULL;
        printk("radeonfb: Backlight registration failed\n");
        goto error;
    }

    pdata->rinfo = rinfo;

    /* Pardon me for that hack... maybe some day we can figure out in what
     * direction backlight should work on a given panel?
     */
    pdata->negative =
        (rinfo->family != CHIP_FAMILY_RV200 &&
         rinfo->family != CHIP_FAMILY_RV250 &&
         rinfo->family != CHIP_FAMILY_RV280 &&
         rinfo->family != CHIP_FAMILY_RV350);

#ifdef CONFIG_PMAC_BACKLIGHT
    pdata->negative = pdata->negative ||
        of_machine_is_compatible("PowerBook4,3") ||
        of_machine_is_compatible("PowerBook6,3") ||
        of_machine_is_compatible("PowerBook6,5");
#endif

    rinfo->info->bl_dev = bd;
    fb_bl_default_curve(rinfo->info, 0,
         63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
        217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);

    bd->props.brightness = bd->props.max_brightness;
    bd->props.power = FB_BLANK_UNBLANK;
    backlight_update_status(bd);

    printk("radeonfb: Backlight initialized (%s)\n", name);

    return;

error:
    kfree(pdata);
    return;
}

void radeonfb_bl_exit(struct radeonfb_info *rinfo)
{
    struct backlight_device *bd = rinfo->info->bl_dev;

    if (bd) {
        struct radeon_bl_privdata *pdata;

        pdata = bl_get_data(bd);
        backlight_device_unregister(bd);
        kfree(pdata);
        rinfo->info->bl_dev = NULL;

        printk("radeonfb: Backlight unloaded\n");
    }
}