root/drivers/video/fbdev/geode/lxfb_ops.c
// SPDX-License-Identifier: GPL-2.0-or-later
/* Geode LX framebuffer driver
 *
 * Copyright (C) 2006-2007, Advanced Micro Devices,Inc.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/cs5535.h>

#include <asm/msr.h>
#include "lxfb.h"

/* TODO
 * Support panel scaling
 * Add acceleration
 * Add support for interlacing (TV out)
 * Support compression
 */

/* This is the complete list of PLL frequencies that we can set -
 * we will choose the closest match to the incoming clock.
 * freq is the frequency of the dotclock * 1000 (for example,
 * 24823 = 24.983 Mhz).
 * pllval is the corresponding PLL value
*/

static const struct {
  unsigned int pllval;
  unsigned int freq;
} pll_table[] = {
  { 0x000131AC,   6231 },
  { 0x0001215D,   6294 },
  { 0x00011087,   6750 },
  { 0x0001216C,   7081 },
  { 0x0001218D,   7140 },
  { 0x000110C9,   7800 },
  { 0x00013147,   7875 },
  { 0x000110A7,   8258 },
  { 0x00012159,   8778 },
  { 0x00014249,   8875 },
  { 0x00010057,   9000 },
  { 0x0001219A,   9472 },
  { 0x00012158,   9792 },
  { 0x00010045,  10000 },
  { 0x00010089,  10791 },
  { 0x000110E7,  11225 },
  { 0x00012136,  11430 },
  { 0x00013207,  12375 },
  { 0x00012187,  12500 },
  { 0x00014286,  14063 },
  { 0x000110E5,  15016 },
  { 0x00014214,  16250 },
  { 0x00011105,  17045 },
  { 0x000131E4,  18563 },
  { 0x00013183,  18750 },
  { 0x00014284,  19688 },
  { 0x00011104,  20400 },
  { 0x00016363,  23625 },
  { 0x000031AC,  24923 },
  { 0x0000215D,  25175 },
  { 0x00001087,  27000 },
  { 0x0000216C,  28322 },
  { 0x0000218D,  28560 },
  { 0x000010C9,  31200 },
  { 0x00003147,  31500 },
  { 0x000010A7,  33032 },
  { 0x00002159,  35112 },
  { 0x00004249,  35500 },
  { 0x00000057,  36000 },
  { 0x0000219A,  37889 },
  { 0x00002158,  39168 },
  { 0x00000045,  40000 },
  { 0x00000089,  43163 },
  { 0x000010E7,  44900 },
  { 0x00002136,  45720 },
  { 0x00003207,  49500 },
  { 0x00002187,  50000 },
  { 0x00004286,  56250 },
  { 0x000010E5,  60065 },
  { 0x00004214,  65000 },
  { 0x00001105,  68179 },
  { 0x000031E4,  74250 },
  { 0x00003183,  75000 },
  { 0x00004284,  78750 },
  { 0x00001104,  81600 },
  { 0x00006363,  94500 },
  { 0x00005303,  97520 },
  { 0x00002183, 100187 },
  { 0x00002122, 101420 },
  { 0x00001081, 108000 },
  { 0x00006201, 113310 },
  { 0x00000041, 119650 },
  { 0x000041A1, 129600 },
  { 0x00002182, 133500 },
  { 0x000041B1, 135000 },
  { 0x00000051, 144000 },
  { 0x000041E1, 148500 },
  { 0x000062D1, 157500 },
  { 0x000031A1, 162000 },
  { 0x00000061, 169203 },
  { 0x00004231, 172800 },
  { 0x00002151, 175500 },
  { 0x000052E1, 189000 },
  { 0x00000071, 192000 },
  { 0x00003201, 198000 },
  { 0x00004291, 202500 },
  { 0x00001101, 204750 },
  { 0x00007481, 218250 },
  { 0x00004170, 229500 },
  { 0x00006210, 234000 },
  { 0x00003140, 251182 },
  { 0x00006250, 261000 },
  { 0x000041C0, 278400 },
  { 0x00005220, 280640 },
  { 0x00000050, 288000 },
  { 0x000041E0, 297000 },
  { 0x00002130, 320207 }
};


static void lx_set_dotpll(u32 pllval)
{
        u32 dotpll_lo, dotpll_hi;
        int i;

        rdmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);

        if ((dotpll_lo & MSR_GLCP_DOTPLL_LOCK) && (dotpll_hi == pllval))
                return;

        dotpll_hi = pllval;
        dotpll_lo &= ~(MSR_GLCP_DOTPLL_BYPASS | MSR_GLCP_DOTPLL_HALFPIX);
        dotpll_lo |= MSR_GLCP_DOTPLL_DOTRESET;

        wrmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);

        /* Wait 100us for the PLL to lock */

        udelay(100);

        /* Now, loop for the lock bit */

        for (i = 0; i < 1000; i++) {
                rdmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);
                if (dotpll_lo & MSR_GLCP_DOTPLL_LOCK)
                        break;
        }

        /* Clear the reset bit */

        dotpll_lo &= ~MSR_GLCP_DOTPLL_DOTRESET;
        wrmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);
}

/* Set the clock based on the frequency specified by the current mode */

static void lx_set_clock(struct fb_info *info)
{
        unsigned int diff, min, best = 0;
        unsigned int freq, i;

        freq = (unsigned int) (1000000000 / info->var.pixclock);

        min = abs(pll_table[0].freq - freq);

        for (i = 0; i < ARRAY_SIZE(pll_table); i++) {
                diff = abs(pll_table[i].freq - freq);
                if (diff < min) {
                        min = diff;
                        best = i;
                }
        }

        lx_set_dotpll(pll_table[best].pllval & 0x00017FFF);
}

static void lx_graphics_disable(struct fb_info *info)
{
        struct lxfb_par *par = info->par;
        unsigned int val, gcfg;

        /* Note:  This assumes that the video is in a quitet state */

        write_vp(par, VP_A1T, 0);
        write_vp(par, VP_A2T, 0);
        write_vp(par, VP_A3T, 0);

        /* Turn off the VGA and video enable */
        val = read_dc(par, DC_GENERAL_CFG) & ~(DC_GENERAL_CFG_VGAE |
                        DC_GENERAL_CFG_VIDE);

        write_dc(par, DC_GENERAL_CFG, val);

        val = read_vp(par, VP_VCFG) & ~VP_VCFG_VID_EN;
        write_vp(par, VP_VCFG, val);

        write_dc(par, DC_IRQ, DC_IRQ_MASK | DC_IRQ_VIP_VSYNC_LOSS_IRQ_MASK |
                        DC_IRQ_STATUS | DC_IRQ_VIP_VSYNC_IRQ_STATUS);

        val = read_dc(par, DC_GENLK_CTL) & ~DC_GENLK_CTL_GENLK_EN;
        write_dc(par, DC_GENLK_CTL, val);

        val = read_dc(par, DC_CLR_KEY);
        write_dc(par, DC_CLR_KEY, val & ~DC_CLR_KEY_CLR_KEY_EN);

        /* turn off the panel */
        write_fp(par, FP_PM, read_fp(par, FP_PM) & ~FP_PM_P);

        val = read_vp(par, VP_MISC) | VP_MISC_DACPWRDN;
        write_vp(par, VP_MISC, val);

        /* Turn off the display */

        val = read_vp(par, VP_DCFG);
        write_vp(par, VP_DCFG, val & ~(VP_DCFG_CRT_EN | VP_DCFG_HSYNC_EN |
                        VP_DCFG_VSYNC_EN | VP_DCFG_DAC_BL_EN));

        gcfg = read_dc(par, DC_GENERAL_CFG);
        gcfg &= ~(DC_GENERAL_CFG_CMPE | DC_GENERAL_CFG_DECE);
        write_dc(par, DC_GENERAL_CFG, gcfg);

        /* Turn off the TGEN */
        val = read_dc(par, DC_DISPLAY_CFG);
        val &= ~DC_DISPLAY_CFG_TGEN;
        write_dc(par, DC_DISPLAY_CFG, val);

        /* Wait 1000 usecs to ensure that the TGEN is clear */
        udelay(1000);

        /* Turn off the FIFO loader */

        gcfg &= ~DC_GENERAL_CFG_DFLE;
        write_dc(par, DC_GENERAL_CFG, gcfg);

        /* Lastly, wait for the GP to go idle */

        do {
                val = read_gp(par, GP_BLT_STATUS);
        } while ((val & GP_BLT_STATUS_PB) || !(val & GP_BLT_STATUS_CE));
}

static void lx_graphics_enable(struct fb_info *info)
{
        struct lxfb_par *par = info->par;
        u32 temp, config;

        /* Set the video request register */
        write_vp(par, VP_VRR, 0);

        /* Set up the polarities */

        config = read_vp(par, VP_DCFG);

        config &= ~(VP_DCFG_CRT_SYNC_SKW | VP_DCFG_PWR_SEQ_DELAY |
                        VP_DCFG_CRT_HSYNC_POL | VP_DCFG_CRT_VSYNC_POL);

        config |= (VP_DCFG_CRT_SYNC_SKW_DEFAULT | VP_DCFG_PWR_SEQ_DELAY_DEFAULT
                        | VP_DCFG_GV_GAM);

        if (info->var.sync & FB_SYNC_HOR_HIGH_ACT)
                config |= VP_DCFG_CRT_HSYNC_POL;

        if (info->var.sync & FB_SYNC_VERT_HIGH_ACT)
                config |= VP_DCFG_CRT_VSYNC_POL;

        if (par->output & OUTPUT_PANEL) {
                u32 msrlo, msrhi;

                write_fp(par, FP_PT1, 0);
                temp = FP_PT2_SCRC;

                if (!(info->var.sync & FB_SYNC_HOR_HIGH_ACT))
                        temp |= FP_PT2_HSP;

                if (!(info->var.sync & FB_SYNC_VERT_HIGH_ACT))
                        temp |= FP_PT2_VSP;

                write_fp(par, FP_PT2, temp);
                write_fp(par, FP_DFC, FP_DFC_BC);

                msrlo = MSR_LX_MSR_PADSEL_TFT_SEL_LOW;
                msrhi = MSR_LX_MSR_PADSEL_TFT_SEL_HIGH;

                wrmsr(MSR_LX_MSR_PADSEL, msrlo, msrhi);
        }

        if (par->output & OUTPUT_CRT) {
                config |= VP_DCFG_CRT_EN | VP_DCFG_HSYNC_EN |
                                VP_DCFG_VSYNC_EN | VP_DCFG_DAC_BL_EN;
        }

        write_vp(par, VP_DCFG, config);

        /* Turn the CRT dacs back on */

        if (par->output & OUTPUT_CRT) {
                temp = read_vp(par, VP_MISC);
                temp &= ~(VP_MISC_DACPWRDN | VP_MISC_APWRDN);
                write_vp(par, VP_MISC, temp);
        }

        /* Turn the panel on (if it isn't already) */
        if (par->output & OUTPUT_PANEL)
                write_fp(par, FP_PM, read_fp(par, FP_PM) | FP_PM_P);
}

unsigned int lx_framebuffer_size(void)
{
        unsigned int val;

        if (!cs5535_has_vsa2()) {
                uint32_t hi, lo;

                /* The number of pages is (PMAX - PMIN)+1 */
                rdmsr(MSR_GLIU_P2D_RO0, lo, hi);

                /* PMAX */
                val = ((hi & 0xff) << 12) | ((lo & 0xfff00000) >> 20);
                /* PMIN */
                val -= (lo & 0x000fffff);
                val += 1;

                /* The page size is 4k */
                return (val << 12);
        }

        /* The frame buffer size is reported by a VSM in VSA II */
        /* Virtual Register Class    = 0x02                     */
        /* VG_MEM_SIZE (1MB units)   = 0x00                     */

        outw(VSA_VR_UNLOCK, VSA_VRC_INDEX);
        outw(VSA_VR_MEM_SIZE, VSA_VRC_INDEX);

        val = (unsigned int)(inw(VSA_VRC_DATA)) & 0xFE;
        return (val << 20);
}

void lx_set_mode(struct fb_info *info)
{
        struct lxfb_par *par = info->par;
        u64 msrval;

        unsigned int max, dv, val, size;

        unsigned int gcfg, dcfg;
        int hactive, hblankstart, hsyncstart, hsyncend, hblankend, htotal;
        int vactive, vblankstart, vsyncstart, vsyncend, vblankend, vtotal;

        /* Unlock the DC registers */
        write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);

        lx_graphics_disable(info);

        lx_set_clock(info);

        /* Set output mode */

        rdmsrq(MSR_LX_GLD_MSR_CONFIG, msrval);
        msrval &= ~MSR_LX_GLD_MSR_CONFIG_FMT;

        if (par->output & OUTPUT_PANEL) {
                msrval |= MSR_LX_GLD_MSR_CONFIG_FMT_FP;

                if (par->output & OUTPUT_CRT)
                        msrval |= MSR_LX_GLD_MSR_CONFIG_FPC;
                else
                        msrval &= ~MSR_LX_GLD_MSR_CONFIG_FPC;
        } else
                msrval |= MSR_LX_GLD_MSR_CONFIG_FMT_CRT;

        wrmsrq(MSR_LX_GLD_MSR_CONFIG, msrval);

        /* Clear the various buffers */
        /* FIXME:  Adjust for panning here */

        write_dc(par, DC_FB_ST_OFFSET, 0);
        write_dc(par, DC_CB_ST_OFFSET, 0);
        write_dc(par, DC_CURS_ST_OFFSET, 0);

        /* FIXME: Add support for interlacing */
        /* FIXME: Add support for scaling */

        val = read_dc(par, DC_GENLK_CTL);
        val &= ~(DC_GENLK_CTL_ALPHA_FLICK_EN | DC_GENLK_CTL_FLICK_EN |
                        DC_GENLK_CTL_FLICK_SEL_MASK);

        /* Default scaling params */

        write_dc(par, DC_GFX_SCALE, (0x4000 << 16) | 0x4000);
        write_dc(par, DC_IRQ_FILT_CTL, 0);
        write_dc(par, DC_GENLK_CTL, val);

        /* FIXME:  Support compression */

        if (info->fix.line_length > 4096)
                dv = DC_DV_CTL_DV_LINE_SIZE_8K;
        else if (info->fix.line_length > 2048)
                dv = DC_DV_CTL_DV_LINE_SIZE_4K;
        else if (info->fix.line_length > 1024)
                dv = DC_DV_CTL_DV_LINE_SIZE_2K;
        else
                dv = DC_DV_CTL_DV_LINE_SIZE_1K;

        max = info->fix.line_length * info->var.yres;
        max = (max + 0x3FF) & 0xFFFFFC00;

        write_dc(par, DC_DV_TOP, max | DC_DV_TOP_DV_TOP_EN);

        val = read_dc(par, DC_DV_CTL) & ~DC_DV_CTL_DV_LINE_SIZE;
        write_dc(par, DC_DV_CTL, val | dv);

        size = info->var.xres * (info->var.bits_per_pixel >> 3);

        write_dc(par, DC_GFX_PITCH, info->fix.line_length >> 3);
        write_dc(par, DC_LINE_SIZE, (size + 7) >> 3);

        /* Set default watermark values */

        rdmsrq(MSR_LX_SPARE_MSR, msrval);

        msrval &= ~(MSR_LX_SPARE_MSR_DIS_CFIFO_HGO
                        | MSR_LX_SPARE_MSR_VFIFO_ARB_SEL
                        | MSR_LX_SPARE_MSR_LOAD_WM_LPEN_M
                        | MSR_LX_SPARE_MSR_WM_LPEN_OVRD);
        msrval |= MSR_LX_SPARE_MSR_DIS_VIFO_WM |
                        MSR_LX_SPARE_MSR_DIS_INIT_V_PRI;
        wrmsrq(MSR_LX_SPARE_MSR, msrval);

        gcfg = DC_GENERAL_CFG_DFLE;   /* Display fifo enable */
        gcfg |= (0x6 << DC_GENERAL_CFG_DFHPSL_SHIFT) | /* default priority */
                        (0xb << DC_GENERAL_CFG_DFHPEL_SHIFT);
        gcfg |= DC_GENERAL_CFG_FDTY;  /* Set the frame dirty mode */

        dcfg  = DC_DISPLAY_CFG_VDEN;  /* Enable video data */
        dcfg |= DC_DISPLAY_CFG_GDEN;  /* Enable graphics */
        dcfg |= DC_DISPLAY_CFG_TGEN;  /* Turn on the timing generator */
        dcfg |= DC_DISPLAY_CFG_TRUP;  /* Update timings immediately */
        dcfg |= DC_DISPLAY_CFG_PALB;  /* Palette bypass in > 8 bpp modes */
        dcfg |= DC_DISPLAY_CFG_VISL;
        dcfg |= DC_DISPLAY_CFG_DCEN;  /* Always center the display */

        /* Set the current BPP mode */

        switch (info->var.bits_per_pixel) {
        case 8:
                dcfg |= DC_DISPLAY_CFG_DISP_MODE_8BPP;
                break;

        case 16:
                dcfg |= DC_DISPLAY_CFG_DISP_MODE_16BPP;
                break;

        case 32:
        case 24:
                dcfg |= DC_DISPLAY_CFG_DISP_MODE_24BPP;
                break;
        }

        /* Now - set up the timings */

        hactive = info->var.xres;
        hblankstart = hactive;
        hsyncstart = hblankstart + info->var.right_margin;
        hsyncend =  hsyncstart + info->var.hsync_len;
        hblankend = hsyncend + info->var.left_margin;
        htotal = hblankend;

        vactive = info->var.yres;
        vblankstart = vactive;
        vsyncstart = vblankstart + info->var.lower_margin;
        vsyncend =  vsyncstart + info->var.vsync_len;
        vblankend = vsyncend + info->var.upper_margin;
        vtotal = vblankend;

        write_dc(par, DC_H_ACTIVE_TIMING, (hactive - 1) | ((htotal - 1) << 16));
        write_dc(par, DC_H_BLANK_TIMING,
                        (hblankstart - 1) | ((hblankend - 1) << 16));
        write_dc(par, DC_H_SYNC_TIMING,
                        (hsyncstart - 1) | ((hsyncend - 1) << 16));

        write_dc(par, DC_V_ACTIVE_TIMING, (vactive - 1) | ((vtotal - 1) << 16));
        write_dc(par, DC_V_BLANK_TIMING,
                        (vblankstart - 1) | ((vblankend - 1) << 16));
        write_dc(par, DC_V_SYNC_TIMING,
                        (vsyncstart - 1) | ((vsyncend - 1) << 16));

        write_dc(par, DC_FB_ACTIVE,
                        (info->var.xres - 1) << 16 | (info->var.yres - 1));

        /* And re-enable the graphics output */
        lx_graphics_enable(info);

        /* Write the two main configuration registers */
        write_dc(par, DC_DISPLAY_CFG, dcfg);
        write_dc(par, DC_ARB_CFG, 0);
        write_dc(par, DC_GENERAL_CFG, gcfg);

        /* Lock the DC registers */
        write_dc(par, DC_UNLOCK, DC_UNLOCK_LOCK);
}

void lx_set_palette_reg(struct fb_info *info, unsigned regno,
                        unsigned red, unsigned green, unsigned blue)
{
        struct lxfb_par *par = info->par;
        int val;

        /* Hardware palette is in RGB 8-8-8 format. */

        val  = (red   << 8) & 0xff0000;
        val |= (green)      & 0x00ff00;
        val |= (blue  >> 8) & 0x0000ff;

        write_dc(par, DC_PAL_ADDRESS, regno);
        write_dc(par, DC_PAL_DATA, val);
}

int lx_blank_display(struct fb_info *info, int blank_mode)
{
        struct lxfb_par *par = info->par;
        u32 dcfg, misc, fp_pm;
        int blank, hsync, vsync;

        /* CRT power saving modes. */
        switch (blank_mode) {
        case FB_BLANK_UNBLANK:
                blank = 0; hsync = 1; vsync = 1;
                break;
        case FB_BLANK_NORMAL:
                blank = 1; hsync = 1; vsync = 1;
                break;
        case FB_BLANK_VSYNC_SUSPEND:
                blank = 1; hsync = 1; vsync = 0;
                break;
        case FB_BLANK_HSYNC_SUSPEND:
                blank = 1; hsync = 0; vsync = 1;
                break;
        case FB_BLANK_POWERDOWN:
                blank = 1; hsync = 0; vsync = 0;
                break;
        default:
                return -EINVAL;
        }

        dcfg = read_vp(par, VP_DCFG);
        dcfg &= ~(VP_DCFG_DAC_BL_EN | VP_DCFG_HSYNC_EN | VP_DCFG_VSYNC_EN |
                        VP_DCFG_CRT_EN);
        if (!blank)
                dcfg |= VP_DCFG_DAC_BL_EN | VP_DCFG_CRT_EN;
        if (hsync)
                dcfg |= VP_DCFG_HSYNC_EN;
        if (vsync)
                dcfg |= VP_DCFG_VSYNC_EN;

        write_vp(par, VP_DCFG, dcfg);

        misc = read_vp(par, VP_MISC);

        if (vsync && hsync)
                misc &= ~VP_MISC_DACPWRDN;
        else
                misc |= VP_MISC_DACPWRDN;

        write_vp(par, VP_MISC, misc);

        /* Power on/off flat panel */

        if (par->output & OUTPUT_PANEL) {
                fp_pm = read_fp(par, FP_PM);
                if (blank_mode == FB_BLANK_POWERDOWN)
                        fp_pm &= ~FP_PM_P;
                else
                        fp_pm |= FP_PM_P;
                write_fp(par, FP_PM, fp_pm);
        }

        return 0;
}

static void lx_save_regs(struct lxfb_par *par)
{
        uint32_t filt;
        int i;

        /* wait for the BLT engine to stop being busy */
        do {
                i = read_gp(par, GP_BLT_STATUS);
        } while ((i & GP_BLT_STATUS_PB) || !(i & GP_BLT_STATUS_CE));

        /* save MSRs */
        rdmsrq(MSR_LX_MSR_PADSEL, par->msr.padsel);
        rdmsrq(MSR_GLCP_DOTPLL, par->msr.dotpll);
        rdmsrq(MSR_LX_GLD_MSR_CONFIG, par->msr.dfglcfg);
        rdmsrq(MSR_LX_SPARE_MSR, par->msr.dcspare);

        write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);

        /* save registers */
        memcpy(par->gp, par->gp_regs, sizeof(par->gp));
        memcpy(par->dc, par->dc_regs, sizeof(par->dc));
        memcpy(par->vp, par->vp_regs, sizeof(par->vp));
        memcpy(par->fp, par->vp_regs + VP_FP_START, sizeof(par->fp));

        /* save the display controller palette */
        write_dc(par, DC_PAL_ADDRESS, 0);
        for (i = 0; i < ARRAY_SIZE(par->dc_pal); i++)
                par->dc_pal[i] = read_dc(par, DC_PAL_DATA);

        /* save the video processor palette */
        write_vp(par, VP_PAR, 0);
        for (i = 0; i < ARRAY_SIZE(par->vp_pal); i++)
                par->vp_pal[i] = read_vp(par, VP_PDR);

        /* save the horizontal filter coefficients */
        filt = par->dc[DC_IRQ_FILT_CTL] | DC_IRQ_FILT_CTL_H_FILT_SEL;
        for (i = 0; i < ARRAY_SIZE(par->hcoeff); i += 2) {
                write_dc(par, DC_IRQ_FILT_CTL, (filt & 0xffffff00) | i);
                par->hcoeff[i] = read_dc(par, DC_FILT_COEFF1);
                par->hcoeff[i + 1] = read_dc(par, DC_FILT_COEFF2);
        }

        /* save the vertical filter coefficients */
        filt &= ~DC_IRQ_FILT_CTL_H_FILT_SEL;
        for (i = 0; i < ARRAY_SIZE(par->vcoeff); i++) {
                write_dc(par, DC_IRQ_FILT_CTL, (filt & 0xffffff00) | i);
                par->vcoeff[i] = read_dc(par, DC_FILT_COEFF1);
        }

        /* save video coeff ram */
        memcpy(par->vp_coeff, par->vp_regs + VP_VCR, sizeof(par->vp_coeff));
}

static void lx_restore_gfx_proc(struct lxfb_par *par)
{
        int i;

        /* a bunch of registers require GP_RASTER_MODE to be set first */
        write_gp(par, GP_RASTER_MODE, par->gp[GP_RASTER_MODE]);

        for (i = 0; i < ARRAY_SIZE(par->gp); i++) {
                switch (i) {
                case GP_RASTER_MODE:
                case GP_VECTOR_MODE:
                case GP_BLT_MODE:
                case GP_BLT_STATUS:
                case GP_HST_SRC:
                        /* FIXME: restore LUT data */
                case GP_LUT_INDEX:
                case GP_LUT_DATA:
                        /* don't restore these registers */
                        break;

                default:
                        write_gp(par, i, par->gp[i]);
                }
        }
}

static void lx_restore_display_ctlr(struct lxfb_par *par)
{
        uint32_t filt;
        int i;

        wrmsrq(MSR_LX_SPARE_MSR, par->msr.dcspare);

        for (i = 0; i < ARRAY_SIZE(par->dc); i++) {
                switch (i) {
                case DC_UNLOCK:
                        /* unlock the DC; runs first */
                        write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);
                        break;

                case DC_GENERAL_CFG:
                case DC_DISPLAY_CFG:
                        /* disable all while restoring */
                        write_dc(par, i, 0);
                        break;

                case DC_DV_CTL:
                        /* set all ram to dirty */
                        write_dc(par, i, par->dc[i] | DC_DV_CTL_CLEAR_DV_RAM);
                        break;

                case DC_RSVD_1:
                case DC_RSVD_2:
                case DC_RSVD_3:
                case DC_LINE_CNT:
                case DC_PAL_ADDRESS:
                case DC_PAL_DATA:
                case DC_DFIFO_DIAG:
                case DC_CFIFO_DIAG:
                case DC_FILT_COEFF1:
                case DC_FILT_COEFF2:
                case DC_RSVD_4:
                case DC_RSVD_5:
                        /* don't restore these registers */
                        break;

                default:
                        write_dc(par, i, par->dc[i]);
                }
        }

        /* restore the palette */
        write_dc(par, DC_PAL_ADDRESS, 0);
        for (i = 0; i < ARRAY_SIZE(par->dc_pal); i++)
                write_dc(par, DC_PAL_DATA, par->dc_pal[i]);

        /* restore the horizontal filter coefficients */
        filt = par->dc[DC_IRQ_FILT_CTL] | DC_IRQ_FILT_CTL_H_FILT_SEL;
        for (i = 0; i < ARRAY_SIZE(par->hcoeff); i += 2) {
                write_dc(par, DC_IRQ_FILT_CTL, (filt & 0xffffff00) | i);
                write_dc(par, DC_FILT_COEFF1, par->hcoeff[i]);
                write_dc(par, DC_FILT_COEFF2, par->hcoeff[i + 1]);
        }

        /* restore the vertical filter coefficients */
        filt &= ~DC_IRQ_FILT_CTL_H_FILT_SEL;
        for (i = 0; i < ARRAY_SIZE(par->vcoeff); i++) {
                write_dc(par, DC_IRQ_FILT_CTL, (filt & 0xffffff00) | i);
                write_dc(par, DC_FILT_COEFF1, par->vcoeff[i]);
        }
}

static void lx_restore_video_proc(struct lxfb_par *par)
{
        int i;

        wrmsrq(MSR_LX_GLD_MSR_CONFIG, par->msr.dfglcfg);
        wrmsrq(MSR_LX_MSR_PADSEL, par->msr.padsel);

        for (i = 0; i < ARRAY_SIZE(par->vp); i++) {
                switch (i) {
                case VP_VCFG:
                case VP_DCFG:
                case VP_PAR:
                case VP_PDR:
                case VP_CCS:
                case VP_RSVD_0:
                /* case VP_VDC: */ /* why should this not be restored? */
                case VP_RSVD_1:
                case VP_CRC32:
                        /* don't restore these registers */
                        break;

                default:
                        write_vp(par, i, par->vp[i]);
                }
        }

        /* restore video processor palette */
        write_vp(par, VP_PAR, 0);
        for (i = 0; i < ARRAY_SIZE(par->vp_pal); i++)
                write_vp(par, VP_PDR, par->vp_pal[i]);

        /* restore video coeff ram */
        memcpy(par->vp_regs + VP_VCR, par->vp_coeff, sizeof(par->vp_coeff));
}

static void lx_restore_regs(struct lxfb_par *par)
{
        int i;

        lx_set_dotpll((u32) (par->msr.dotpll >> 32));
        lx_restore_gfx_proc(par);
        lx_restore_display_ctlr(par);
        lx_restore_video_proc(par);

        /* Flat Panel */
        for (i = 0; i < ARRAY_SIZE(par->fp); i++) {
                switch (i) {
                case FP_PM:
                case FP_RSVD_0:
                case FP_RSVD_1:
                case FP_RSVD_2:
                case FP_RSVD_3:
                case FP_RSVD_4:
                        /* don't restore these registers */
                        break;

                default:
                        write_fp(par, i, par->fp[i]);
                }
        }

        /* control the panel */
        if (par->fp[FP_PM] & FP_PM_P) {
                /* power on the panel if not already power{ed,ing} on */
                if (!(read_fp(par, FP_PM) &
                                (FP_PM_PANEL_ON|FP_PM_PANEL_PWR_UP)))
                        write_fp(par, FP_PM, par->fp[FP_PM]);
        } else {
                /* power down the panel if not already power{ed,ing} down */
                if (!(read_fp(par, FP_PM) &
                                (FP_PM_PANEL_OFF|FP_PM_PANEL_PWR_DOWN)))
                        write_fp(par, FP_PM, par->fp[FP_PM]);
        }

        /* turn everything on */
        write_vp(par, VP_VCFG, par->vp[VP_VCFG]);
        write_vp(par, VP_DCFG, par->vp[VP_DCFG]);
        write_dc(par, DC_DISPLAY_CFG, par->dc[DC_DISPLAY_CFG]);
        /* do this last; it will enable the FIFO load */
        write_dc(par, DC_GENERAL_CFG, par->dc[DC_GENERAL_CFG]);

        /* lock the door behind us */
        write_dc(par, DC_UNLOCK, DC_UNLOCK_LOCK);
}

int lx_powerdown(struct fb_info *info)
{
        struct lxfb_par *par = info->par;

        if (par->powered_down)
                return 0;

        lx_save_regs(par);
        lx_graphics_disable(info);

        par->powered_down = 1;
        return 0;
}

int lx_powerup(struct fb_info *info)
{
        struct lxfb_par *par = info->par;

        if (!par->powered_down)
                return 0;

        lx_restore_regs(par);

        par->powered_down = 0;
        return 0;
}