// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) 2007 Advanced Micro Devices, Inc.
 *   Copyright (C) 2008 Andres Salomon <dilinger@debian.org>
 */
#include <linux/fb.h>
#include <asm/io.h>
#include <asm/msr.h>
#include <linux/cs5535.h>
#include <asm/delay.h>

#include "gxfb.h"

static void gx_save_regs(struct gxfb_par *par)
{
        int i;

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

        /* save MSRs */
        rdmsrq(MSR_GX_MSR_PADSEL, par->msr.padsel);
        rdmsrq(MSR_GLCP_DOTPLL, par->msr.dotpll);

        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->vid_regs, sizeof(par->vp));
        memcpy(par->fp, par->vid_regs + VP_FP_START, sizeof(par->fp));

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

static void gx_set_dotpll(uint32_t dotpll_hi)
{
        uint32_t dotpll_lo;
        int i;

        rdmsrq(MSR_GLCP_DOTPLL, dotpll_lo);
        dotpll_lo |= MSR_GLCP_DOTPLL_DOTRESET;
        dotpll_lo &= ~MSR_GLCP_DOTPLL_BYPASS;
        wrmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);

        /* wait for the PLL to lock */
        for (i = 0; i < 200; i++) {
                rdmsrq(MSR_GLCP_DOTPLL, dotpll_lo);
                if (dotpll_lo & MSR_GLCP_DOTPLL_LOCK)
                        break;
                udelay(1);
        }

        /* PLL set, unlock */
        dotpll_lo &= ~MSR_GLCP_DOTPLL_DOTRESET;
        wrmsr(MSR_GLCP_DOTPLL, dotpll_lo, dotpll_hi);
}

static void gx_restore_gfx_proc(struct gxfb_par *par)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(par->gp); i++) {
                switch (i) {
                case GP_VECTOR_MODE:
                case GP_BLT_MODE:
                case GP_BLT_STATUS:
                case GP_HST_SRC:
                        /* don't restore these registers */
                        break;
                default:
                        write_gp(par, i, par->gp[i]);
                }
        }
}

static void gx_restore_display_ctlr(struct gxfb_par *par)
{
        int i;

        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:
                        /* write without the enables */
                        write_dc(par, i, par->dc[i] & ~(DC_GENERAL_CFG_VIDE |
                                        DC_GENERAL_CFG_ICNE |
                                        DC_GENERAL_CFG_CURE |
                                        DC_GENERAL_CFG_DFLE));
                        break;

                case DC_DISPLAY_CFG:
                        /* write without the enables */
                        write_dc(par, i, par->dc[i] & ~(DC_DISPLAY_CFG_VDEN |
                                        DC_DISPLAY_CFG_GDEN |
                                        DC_DISPLAY_CFG_TGEN));
                        break;

                case DC_RSVD_0:
                case DC_RSVD_1:
                case DC_RSVD_2:
                case DC_RSVD_3:
                case DC_RSVD_4:
                case DC_LINE_CNT:
                case DC_PAL_ADDRESS:
                case DC_PAL_DATA:
                case DC_DFIFO_DIAG:
                case DC_CFIFO_DIAG:
                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->pal); i++)
                write_dc(par, DC_PAL_DATA, par->pal[i]);
}

static void gx_restore_video_proc(struct gxfb_par *par)
{
        int i;

        wrmsrq(MSR_GX_MSR_PADSEL, par->msr.padsel);

        for (i = 0; i < ARRAY_SIZE(par->vp); i++) {
                switch (i) {
                case VP_VCFG:
                        /* don't enable video yet */
                        write_vp(par, i, par->vp[i] & ~VP_VCFG_VID_EN);
                        break;

                case VP_DCFG:
                        /* don't enable CRT yet */
                        write_vp(par, i, par->vp[i] &
                                        ~(VP_DCFG_DAC_BL_EN | VP_DCFG_VSYNC_EN |
                                        VP_DCFG_HSYNC_EN | VP_DCFG_CRT_EN));
                        break;

                case VP_GAR:
                case VP_GDR:
                case VP_RSVD_0:
                case VP_RSVD_1:
                case VP_RSVD_2:
                case VP_RSVD_3:
                case VP_CRC32:
                case VP_AWT:
                case VP_VTM:
                        /* don't restore these registers */
                        break;
                default:
                        write_vp(par, i, par->vp[i]);
                }
        }
}

static void gx_restore_regs(struct gxfb_par *par)
{
        int i;

        gx_set_dotpll((uint32_t) (par->msr.dotpll >> 32));
        gx_restore_gfx_proc(par);
        gx_restore_display_ctlr(par);
        gx_restore_video_proc(par);

        /* Flat Panel */
        for (i = 0; i < ARRAY_SIZE(par->fp); i++) {
                if (i != FP_PM && i != FP_RSVD_0)
                        write_fp(par, i, par->fp[i]);
        }
}

static void gx_disable_graphics(struct gxfb_par *par)
{
        /* shut down the engine */
        write_vp(par, VP_VCFG, par->vp[VP_VCFG] & ~VP_VCFG_VID_EN);
        write_vp(par, VP_DCFG, par->vp[VP_DCFG] & ~(VP_DCFG_DAC_BL_EN |
                        VP_DCFG_VSYNC_EN | VP_DCFG_HSYNC_EN | VP_DCFG_CRT_EN));

        /* turn off the flat panel */
        write_fp(par, FP_PM, par->fp[FP_PM] & ~FP_PM_P);


        /* turn off display */
        write_dc(par, DC_UNLOCK, DC_UNLOCK_UNLOCK);
        write_dc(par, DC_GENERAL_CFG, par->dc[DC_GENERAL_CFG] &
                        ~(DC_GENERAL_CFG_VIDE | DC_GENERAL_CFG_ICNE |
                        DC_GENERAL_CFG_CURE | DC_GENERAL_CFG_DFLE));
        write_dc(par, DC_DISPLAY_CFG, par->dc[DC_DISPLAY_CFG] &
                        ~(DC_DISPLAY_CFG_VDEN | DC_DISPLAY_CFG_GDEN |
                        DC_DISPLAY_CFG_TGEN));
        write_dc(par, DC_UNLOCK, DC_UNLOCK_LOCK);
}

static void gx_enable_graphics(struct gxfb_par *par)
{
        uint32_t fp;

        fp = read_fp(par, FP_PM);
        if (par->fp[FP_PM] & FP_PM_P) {
                /* power on the panel if not already power{ed,ing} on */
                if (!(fp & (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 (!(fp & (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 gx_powerdown(struct fb_info *info)
{
        struct gxfb_par *par = info->par;

        if (par->powered_down)
                return 0;

        gx_save_regs(par);
        gx_disable_graphics(par);

        par->powered_down = 1;
        return 0;
}

int gx_powerup(struct fb_info *info)
{
        struct gxfb_par *par = info->par;

        if (!par->powered_down)
                return 0;

        gx_restore_regs(par);
        gx_enable_graphics(par);

        par->powered_down  = 0;
        return 0;
}