/*
 * Allwinner DW HDMI bridge
 *
 * (C) Copyright 2017 Jernej Skrabec <jernej.skrabec@siol.net>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <display.h>
#include <dm.h>
#include <dw_hdmi.h>
#include <edid.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/lcdc.h>

struct sunxi_dw_hdmi_priv {
        struct dw_hdmi hdmi;
        int mux;
};

struct sunxi_hdmi_phy {
        u32 pol;
        u32 res1[3];
        u32 read_en;
        u32 unscramble;
        u32 res2[2];
        u32 ctrl;
        u32 unk1;
        u32 unk2;
        u32 pll;
        u32 clk;
        u32 unk3;
        u32 status;
};

#define HDMI_PHY_OFFS 0x10000

static int sunxi_dw_hdmi_get_divider(uint clock)
{
        /*
         * Due to missing documentaion of HDMI PHY, we know correct
         * settings only for following four PHY dividers. Select one
         * based on clock speed.
         */
        if (clock <= 27000000)
                return 11;
        else if (clock <= 74250000)
                return 4;
        else if (clock <= 148500000)
                return 2;
        else
                return 1;
}

static void sunxi_dw_hdmi_phy_init(void)
{
        struct sunxi_hdmi_phy * const phy =
                (struct sunxi_hdmi_phy *)(SUNXI_HDMI_BASE + HDMI_PHY_OFFS);
        unsigned long tmo;
        u32 tmp;

        /*
         * HDMI PHY settings are taken as-is from Allwinner BSP code.
         * There is no documentation.
         */
        writel(0, &phy->ctrl);
        setbits_le32(&phy->ctrl, BIT(0));
        udelay(5);
        setbits_le32(&phy->ctrl, BIT(16));
        setbits_le32(&phy->ctrl, BIT(1));
        udelay(10);
        setbits_le32(&phy->ctrl, BIT(2));
        udelay(5);
        setbits_le32(&phy->ctrl, BIT(3));
        udelay(40);
        setbits_le32(&phy->ctrl, BIT(19));
        udelay(100);
        setbits_le32(&phy->ctrl, BIT(18));
        setbits_le32(&phy->ctrl, 7 << 4);

        /* Note that Allwinner code doesn't fail in case of timeout */
        tmo = timer_get_us() + 2000;
        while ((readl(&phy->status) & 0x80) == 0) {
                if (timer_get_us() > tmo) {
                        printf("Warning: HDMI PHY init timeout!\n");
                        break;
                }
        }

        setbits_le32(&phy->ctrl, 0xf << 8);
        setbits_le32(&phy->ctrl, BIT(7));

        writel(0x39dc5040, &phy->pll);
        writel(0x80084343, &phy->clk);
        udelay(10000);
        writel(1, &phy->unk3);
        setbits_le32(&phy->pll, BIT(25));
        udelay(100000);
        tmp = (readl(&phy->status) & 0x1f800) >> 11;
        setbits_le32(&phy->pll, BIT(31) | BIT(30));
        setbits_le32(&phy->pll, tmp);
        writel(0x01FF0F7F, &phy->ctrl);
        writel(0x80639000, &phy->unk1);
        writel(0x0F81C405, &phy->unk2);

        /* enable read access to HDMI controller */
        writel(0x54524545, &phy->read_en);
        /* descramble register offsets */
        writel(0x42494E47, &phy->unscramble);
}

static int sunxi_dw_hdmi_get_plug_in_status(void)
{
        struct sunxi_hdmi_phy * const phy =
                (struct sunxi_hdmi_phy *)(SUNXI_HDMI_BASE + HDMI_PHY_OFFS);

        return !!(readl(&phy->status) & (1 << 19));
}

static int sunxi_dw_hdmi_wait_for_hpd(void)
{
        ulong start;

        start = get_timer(0);
        do {
                if (sunxi_dw_hdmi_get_plug_in_status())
                        return 0;
                udelay(100);
        } while (get_timer(start) < 300);

        return -1;
}

static void sunxi_dw_hdmi_phy_set(uint clock)
{
        struct sunxi_hdmi_phy * const phy =
                (struct sunxi_hdmi_phy *)(SUNXI_HDMI_BASE + HDMI_PHY_OFFS);
        int div = sunxi_dw_hdmi_get_divider(clock);
        u32 tmp;

        /*
         * Unfortunately, we don't know much about those magic
         * numbers. They are taken from Allwinner BSP driver.
         */
        switch (div) {
        case 1:
                writel(0x30dc5fc0, &phy->pll);
                writel(0x800863C0, &phy->clk);
                mdelay(10);
                writel(0x00000001, &phy->unk3);
                setbits_le32(&phy->pll, BIT(25));
                mdelay(200);
                tmp = (readl(&phy->status) & 0x1f800) >> 11;
                setbits_le32(&phy->pll, BIT(31) | BIT(30));
                if (tmp < 0x3d)
                        setbits_le32(&phy->pll, tmp + 2);
                else
                        setbits_le32(&phy->pll, 0x3f);
                mdelay(100);
                writel(0x01FFFF7F, &phy->ctrl);
                writel(0x8063b000, &phy->unk1);
                writel(0x0F8246B5, &phy->unk2);
                break;
        case 2:
                writel(0x39dc5040, &phy->pll);
                writel(0x80084381, &phy->clk);
                mdelay(10);
                writel(0x00000001, &phy->unk3);
                setbits_le32(&phy->pll, BIT(25));
                mdelay(100);
                tmp = (readl(&phy->status) & 0x1f800) >> 11;
                setbits_le32(&phy->pll, BIT(31) | BIT(30));
                setbits_le32(&phy->pll, tmp);
                writel(0x01FFFF7F, &phy->ctrl);
                writel(0x8063a800, &phy->unk1);
                writel(0x0F81C485, &phy->unk2);
                break;
        case 4:
                writel(0x39dc5040, &phy->pll);
                writel(0x80084343, &phy->clk);
                mdelay(10);
                writel(0x00000001, &phy->unk3);
                setbits_le32(&phy->pll, BIT(25));
                mdelay(100);
                tmp = (readl(&phy->status) & 0x1f800) >> 11;
                setbits_le32(&phy->pll, BIT(31) | BIT(30));
                setbits_le32(&phy->pll, tmp);
                writel(0x01FFFF7F, &phy->ctrl);
                writel(0x8063b000, &phy->unk1);
                writel(0x0F81C405, &phy->unk2);
                break;
        case 11:
                writel(0x39dc5040, &phy->pll);
                writel(0x8008430a, &phy->clk);
                mdelay(10);
                writel(0x00000001, &phy->unk3);
                setbits_le32(&phy->pll, BIT(25));
                mdelay(100);
                tmp = (readl(&phy->status) & 0x1f800) >> 11;
                setbits_le32(&phy->pll, BIT(31) | BIT(30));
                setbits_le32(&phy->pll, tmp);
                writel(0x01FFFF7F, &phy->ctrl);
                writel(0x8063b000, &phy->unk1);
                writel(0x0F81C405, &phy->unk2);
                break;
        }
}

static void sunxi_dw_hdmi_pll_set(uint clk_khz)
{
        int value, n, m, div = 0, diff;
        int best_n = 0, best_m = 0, best_diff = 0x0FFFFFFF;

        div = sunxi_dw_hdmi_get_divider(clk_khz * 1000);

        /*
         * Find the lowest divider resulting in a matching clock. If there
         * is no match, pick the closest lower clock, as monitors tend to
         * not sync to higher frequencies.
         */
        for (m = 1; m <= 16; m++) {
                n = (m * div * clk_khz) / 24000;

                if ((n >= 1) && (n <= 128)) {
                        value = (24000 * n) / m / div;
                        diff = clk_khz - value;
                        if (diff < best_diff) {
                                best_diff = diff;
                                best_m = m;
                                best_n = n;
                        }
                }
        }

        clock_set_pll3_factors(best_m, best_n);
        debug("dotclock: %dkHz = %dkHz: (24MHz * %d) / %d / %d\n",
              clk_khz, (clock_get_pll3() / 1000) / div,
              best_n, best_m, div);
}

static void sunxi_dw_hdmi_lcdc_init(int mux, const struct display_timing *edid,
                                    int bpp)
{
        struct sunxi_ccm_reg * const ccm =
                (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
        int div = sunxi_dw_hdmi_get_divider(edid->pixelclock.typ);
        struct sunxi_lcdc_reg *lcdc;

        if (mux == 0) {
                lcdc = (struct sunxi_lcdc_reg *)SUNXI_LCD0_BASE;

                /* Reset off */
                setbits_le32(&ccm->ahb_reset1_cfg, 1 << AHB_RESET_OFFSET_LCD0);

                /* Clock on */
                setbits_le32(&ccm->ahb_gate1, 1 << AHB_GATE_OFFSET_LCD0);
                writel(CCM_LCD0_CTRL_GATE | CCM_LCD0_CTRL_M(div),
                       &ccm->lcd0_clk_cfg);
        } else {
                lcdc = (struct sunxi_lcdc_reg *)SUNXI_LCD1_BASE;

                /* Reset off */
                setbits_le32(&ccm->ahb_reset1_cfg, 1 << AHB_RESET_OFFSET_LCD1);

                /* Clock on */
                setbits_le32(&ccm->ahb_gate1, 1 << AHB_GATE_OFFSET_LCD1);
                writel(CCM_LCD1_CTRL_GATE | CCM_LCD1_CTRL_M(div),
                       &ccm->lcd1_clk_cfg);
        }

        lcdc_init(lcdc);
        lcdc_tcon1_mode_set(lcdc, edid, false, false);
        lcdc_enable(lcdc, bpp);
}

static int sunxi_dw_hdmi_phy_cfg(struct dw_hdmi *hdmi, uint mpixelclock)
{
        sunxi_dw_hdmi_pll_set(mpixelclock/1000);
        sunxi_dw_hdmi_phy_set(mpixelclock);

        return 0;
}

static int sunxi_dw_hdmi_read_edid(struct udevice *dev, u8 *buf, int buf_size)
{
        struct sunxi_dw_hdmi_priv *priv = dev_get_priv(dev);

        return dw_hdmi_read_edid(&priv->hdmi, buf, buf_size);
}

static int sunxi_dw_hdmi_enable(struct udevice *dev, int panel_bpp,
                                const struct display_timing *edid)
{
        struct sunxi_hdmi_phy * const phy =
                (struct sunxi_hdmi_phy *)(SUNXI_HDMI_BASE + HDMI_PHY_OFFS);
        struct sunxi_dw_hdmi_priv *priv = dev_get_priv(dev);
        int ret;

        ret = dw_hdmi_enable(&priv->hdmi, edid);
        if (ret)
                return ret;

        sunxi_dw_hdmi_lcdc_init(priv->mux, edid, panel_bpp);

        if (edid->flags & DISPLAY_FLAGS_HSYNC_LOW)
                setbits_le32(&phy->pol, 0x200);

        if (edid->flags & DISPLAY_FLAGS_VSYNC_LOW)
                setbits_le32(&phy->pol, 0x100);

        setbits_le32(&phy->ctrl, 0xf << 12);

        /*
         * This is last hdmi access before boot, so scramble addresses
         * again or othwerwise BSP driver won't work. Dummy read is
         * needed or otherwise last write doesn't get written correctly.
         */
        (void)readb(SUNXI_HDMI_BASE);
        writel(0, &phy->unscramble);

        return 0;
}

static int sunxi_dw_hdmi_probe(struct udevice *dev)
{
        struct display_plat *uc_plat = dev_get_uclass_platdata(dev);
        struct sunxi_dw_hdmi_priv *priv = dev_get_priv(dev);
        struct sunxi_ccm_reg * const ccm =
                (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
        int ret;

        /* Set pll3 to 297 MHz */
        clock_set_pll3(297000000);

        /* Set hdmi parent to pll3 */
        clrsetbits_le32(&ccm->hdmi_clk_cfg, CCM_HDMI_CTRL_PLL_MASK,
                        CCM_HDMI_CTRL_PLL3);

        /* Set ahb gating to pass */
        setbits_le32(&ccm->ahb_reset1_cfg, 1 << AHB_RESET_OFFSET_HDMI);
        setbits_le32(&ccm->ahb_reset1_cfg, 1 << AHB_RESET_OFFSET_HDMI2);
        setbits_le32(&ccm->ahb_gate1, 1 << AHB_GATE_OFFSET_HDMI);
        setbits_le32(&ccm->hdmi_slow_clk_cfg, CCM_HDMI_SLOW_CTRL_DDC_GATE);

        /* Clock on */
        setbits_le32(&ccm->hdmi_clk_cfg, CCM_HDMI_CTRL_GATE);

        sunxi_dw_hdmi_phy_init();

        ret = sunxi_dw_hdmi_wait_for_hpd();
        if (ret < 0) {
                debug("hdmi can not get hpd signal\n");
                return -1;
        }

        priv->hdmi.ioaddr = SUNXI_HDMI_BASE;
        priv->hdmi.i2c_clk_high = 0xd8;
        priv->hdmi.i2c_clk_low = 0xfe;
        priv->hdmi.reg_io_width = 1;
        priv->hdmi.phy_set = sunxi_dw_hdmi_phy_cfg;
        priv->mux = uc_plat->source_id;

        dw_hdmi_init(&priv->hdmi);

        return 0;
}

static const struct dm_display_ops sunxi_dw_hdmi_ops = {
        .read_edid = sunxi_dw_hdmi_read_edid,
        .enable = sunxi_dw_hdmi_enable,
};

U_BOOT_DRIVER(sunxi_dw_hdmi) = {
        .name   = "sunxi_dw_hdmi",
        .id     = UCLASS_DISPLAY,
        .ops    = &sunxi_dw_hdmi_ops,
        .probe  = sunxi_dw_hdmi_probe,
        .priv_auto_alloc_size = sizeof(struct sunxi_dw_hdmi_priv),
};

U_BOOT_DEVICE(sunxi_dw_hdmi) = {
        .name = "sunxi_dw_hdmi"
};