linux/drivers/video/fbdev/aty/radeon_backlight.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Backlight code for ATI Radeon based graphic cards
   4 *
   5 * Copyright (c) 2000 Ani Joshi <ajoshi@kernel.crashing.org>
   6 * Copyright (c) 2003 Benjamin Herrenschmidt <benh@kernel.crashing.org>
   7 * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
   8 */
   9
  10#include "radeonfb.h"
  11#include <linux/backlight.h>
  12#include <linux/slab.h>
  13
  14#ifdef CONFIG_PMAC_BACKLIGHT
  15#include <asm/backlight.h>
  16#endif
  17
  18#define MAX_RADEON_LEVEL 0xFF
  19
  20struct radeon_bl_privdata {
  21        struct radeonfb_info *rinfo;
  22        uint8_t negative;
  23};
  24
  25static int radeon_bl_get_level_brightness(struct radeon_bl_privdata *pdata,
  26                int level)
  27{
  28        int rlevel;
  29
  30        /* Get and convert the value */
  31        /* No locking of bl_curve since we read a single value */
  32        rlevel = pdata->rinfo->info->bl_curve[level] *
  33                 FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL;
  34
  35        if (rlevel < 0)
  36                rlevel = 0;
  37        else if (rlevel > MAX_RADEON_LEVEL)
  38                rlevel = MAX_RADEON_LEVEL;
  39
  40        if (pdata->negative)
  41                rlevel = MAX_RADEON_LEVEL - rlevel;
  42
  43        return rlevel;
  44}
  45
  46static int radeon_bl_update_status(struct backlight_device *bd)
  47{
  48        struct radeon_bl_privdata *pdata = bl_get_data(bd);
  49        struct radeonfb_info *rinfo = pdata->rinfo;
  50        u32 lvds_gen_cntl, tmpPixclksCntl;
  51        int level;
  52
  53        if (rinfo->mon1_type != MT_LCD)
  54                return 0;
  55
  56        /* We turn off the LCD completely instead of just dimming the
  57         * backlight. This provides some greater power saving and the display
  58         * is useless without backlight anyway.
  59         */
  60        if (bd->props.power != FB_BLANK_UNBLANK ||
  61            bd->props.fb_blank != FB_BLANK_UNBLANK)
  62                level = 0;
  63        else
  64                level = bd->props.brightness;
  65
  66        del_timer_sync(&rinfo->lvds_timer);
  67        radeon_engine_idle();
  68
  69        lvds_gen_cntl = INREG(LVDS_GEN_CNTL);
  70        if (level > 0) {
  71                lvds_gen_cntl &= ~LVDS_DISPLAY_DIS;
  72                if (!(lvds_gen_cntl & LVDS_BLON) || !(lvds_gen_cntl & LVDS_ON)) {
  73                        lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_DIGON);
  74                        lvds_gen_cntl |= LVDS_BLON | LVDS_EN;
  75                        OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
  76                        lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
  77                        lvds_gen_cntl |=
  78                                (radeon_bl_get_level_brightness(pdata, level) <<
  79                                 LVDS_BL_MOD_LEVEL_SHIFT);
  80                        lvds_gen_cntl |= LVDS_ON;
  81                        lvds_gen_cntl |= (rinfo->init_state.lvds_gen_cntl & LVDS_BL_MOD_EN);
  82                        rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
  83                        mod_timer(&rinfo->lvds_timer,
  84                                  jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
  85                } else {
  86                        lvds_gen_cntl &= ~LVDS_BL_MOD_LEVEL_MASK;
  87                        lvds_gen_cntl |=
  88                                (radeon_bl_get_level_brightness(pdata, level) <<
  89                                 LVDS_BL_MOD_LEVEL_SHIFT);
  90                        OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
  91                }
  92                rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
  93                rinfo->init_state.lvds_gen_cntl |= rinfo->pending_lvds_gen_cntl
  94                        & LVDS_STATE_MASK;
  95        } else {
  96                /* Asic bug, when turning off LVDS_ON, we have to make sure
  97                   RADEON_PIXCLK_LVDS_ALWAYS_ON bit is off
  98                */
  99                tmpPixclksCntl = INPLL(PIXCLKS_CNTL);
 100                if (rinfo->is_mobility || rinfo->is_IGP)
 101                        OUTPLLP(PIXCLKS_CNTL, 0, ~PIXCLK_LVDS_ALWAYS_ONb);
 102                lvds_gen_cntl &= ~(LVDS_BL_MOD_LEVEL_MASK | LVDS_BL_MOD_EN);
 103                lvds_gen_cntl |= (radeon_bl_get_level_brightness(pdata, 0) <<
 104                                  LVDS_BL_MOD_LEVEL_SHIFT);
 105                lvds_gen_cntl |= LVDS_DISPLAY_DIS;
 106                OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
 107                udelay(100);
 108                lvds_gen_cntl &= ~(LVDS_ON | LVDS_EN);
 109                OUTREG(LVDS_GEN_CNTL, lvds_gen_cntl);
 110                lvds_gen_cntl &= ~(LVDS_DIGON);
 111                rinfo->pending_lvds_gen_cntl = lvds_gen_cntl;
 112                mod_timer(&rinfo->lvds_timer,
 113                          jiffies + msecs_to_jiffies(rinfo->panel_info.pwr_delay));
 114                if (rinfo->is_mobility || rinfo->is_IGP)
 115                        OUTPLL(PIXCLKS_CNTL, tmpPixclksCntl);
 116        }
 117        rinfo->init_state.lvds_gen_cntl &= ~LVDS_STATE_MASK;
 118        rinfo->init_state.lvds_gen_cntl |= (lvds_gen_cntl & LVDS_STATE_MASK);
 119
 120        return 0;
 121}
 122
 123static const struct backlight_ops radeon_bl_data = {
 124        .update_status  = radeon_bl_update_status,
 125};
 126
 127void radeonfb_bl_init(struct radeonfb_info *rinfo)
 128{
 129        struct backlight_properties props;
 130        struct backlight_device *bd;
 131        struct radeon_bl_privdata *pdata;
 132        char name[12];
 133
 134        if (rinfo->mon1_type != MT_LCD)
 135                return;
 136
 137#ifdef CONFIG_PMAC_BACKLIGHT
 138        if (!pmac_has_backlight_type("ati") &&
 139            !pmac_has_backlight_type("mnca"))
 140                return;
 141#endif
 142
 143        pdata = kmalloc(sizeof(struct radeon_bl_privdata), GFP_KERNEL);
 144        if (!pdata) {
 145                printk("radeonfb: Memory allocation failed\n");
 146                goto error;
 147        }
 148
 149        snprintf(name, sizeof(name), "radeonbl%d", rinfo->info->node);
 150
 151        memset(&props, 0, sizeof(struct backlight_properties));
 152        props.type = BACKLIGHT_RAW;
 153        props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
 154        bd = backlight_device_register(name, rinfo->info->dev, pdata,
 155                                       &radeon_bl_data, &props);
 156        if (IS_ERR(bd)) {
 157                rinfo->info->bl_dev = NULL;
 158                printk("radeonfb: Backlight registration failed\n");
 159                goto error;
 160        }
 161
 162        pdata->rinfo = rinfo;
 163
 164        /* Pardon me for that hack... maybe some day we can figure out in what
 165         * direction backlight should work on a given panel?
 166         */
 167        pdata->negative =
 168                (rinfo->family != CHIP_FAMILY_RV200 &&
 169                 rinfo->family != CHIP_FAMILY_RV250 &&
 170                 rinfo->family != CHIP_FAMILY_RV280 &&
 171                 rinfo->family != CHIP_FAMILY_RV350);
 172
 173#ifdef CONFIG_PMAC_BACKLIGHT
 174        pdata->negative = pdata->negative ||
 175                of_machine_is_compatible("PowerBook4,3") ||
 176                of_machine_is_compatible("PowerBook6,3") ||
 177                of_machine_is_compatible("PowerBook6,5");
 178#endif
 179
 180        rinfo->info->bl_dev = bd;
 181        fb_bl_default_curve(rinfo->info, 0,
 182                 63 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL,
 183                217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
 184
 185        bd->props.brightness = bd->props.max_brightness;
 186        bd->props.power = FB_BLANK_UNBLANK;
 187        backlight_update_status(bd);
 188
 189        printk("radeonfb: Backlight initialized (%s)\n", name);
 190
 191        return;
 192
 193error:
 194        kfree(pdata);
 195        return;
 196}
 197
 198void radeonfb_bl_exit(struct radeonfb_info *rinfo)
 199{
 200        struct backlight_device *bd = rinfo->info->bl_dev;
 201
 202        if (bd) {
 203                struct radeon_bl_privdata *pdata;
 204
 205                pdata = bl_get_data(bd);
 206                backlight_device_unregister(bd);
 207                kfree(pdata);
 208                rinfo->info->bl_dev = NULL;
 209
 210                printk("radeonfb: Backlight unloaded\n");
 211        }
 212}
 213