/* Hisilicon Hibmc SoC drm driver
 *
 * Based on the bochs drm driver.
 *
 * Copyright (c) 2016 Huawei Limited.
 *
 * Author:
 *      Rongrong Zou <zourongrong@huawei.com>
 *      Rongrong Zou <zourongrong@gmail.com>
 *      Jianhua Li <lijianhua@huawei.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_plane_helper.h>

#include "hibmc_drm_drv.h"
#include "hibmc_drm_regs.h"

struct hibmc_display_panel_pll {
        unsigned long M;
        unsigned long N;
        unsigned long OD;
        unsigned long POD;
};

struct hibmc_dislay_pll_config {
        unsigned long hdisplay;
        unsigned long vdisplay;
        u32 pll1_config_value;
        u32 pll2_config_value;
};

static const struct hibmc_dislay_pll_config hibmc_pll_table[] = {
        {800, 600, CRT_PLL1_HS_40MHZ, CRT_PLL2_HS_40MHZ},
        {1024, 768, CRT_PLL1_HS_65MHZ, CRT_PLL2_HS_65MHZ},
        {1152, 864, CRT_PLL1_HS_80MHZ_1152, CRT_PLL2_HS_80MHZ},
        {1280, 768, CRT_PLL1_HS_80MHZ, CRT_PLL2_HS_80MHZ},
        {1280, 720, CRT_PLL1_HS_74MHZ, CRT_PLL2_HS_74MHZ},
        {1280, 960, CRT_PLL1_HS_108MHZ, CRT_PLL2_HS_108MHZ},
        {1280, 1024, CRT_PLL1_HS_108MHZ, CRT_PLL2_HS_108MHZ},
        {1600, 1200, CRT_PLL1_HS_162MHZ, CRT_PLL2_HS_162MHZ},
        {1920, 1080, CRT_PLL1_HS_148MHZ, CRT_PLL2_HS_148MHZ},
        {1920, 1200, CRT_PLL1_HS_193MHZ, CRT_PLL2_HS_193MHZ},
};

#define PADDING(align, data) (((data) + (align) - 1) & (~((align) - 1)))

static int hibmc_plane_atomic_check(struct drm_plane *plane,
                                    struct drm_plane_state *state)
{
        struct drm_framebuffer *fb = state->fb;
        struct drm_crtc *crtc = state->crtc;
        struct drm_crtc_state *crtc_state;
        u32 src_w = state->src_w >> 16;
        u32 src_h = state->src_h >> 16;

        if (!crtc || !fb)
                return 0;

        crtc_state = drm_atomic_get_crtc_state(state->state, crtc);
        if (IS_ERR(crtc_state))
                return PTR_ERR(crtc_state);

        if (src_w != state->crtc_w || src_h != state->crtc_h) {
                DRM_DEBUG_ATOMIC("scale not support\n");
                return -EINVAL;
        }

        if (state->crtc_x < 0 || state->crtc_y < 0) {
                DRM_DEBUG_ATOMIC("crtc_x/y of drm_plane state is invalid\n");
                return -EINVAL;
        }

        if (state->crtc_x + state->crtc_w >
            crtc_state->adjusted_mode.hdisplay ||
            state->crtc_y + state->crtc_h >
            crtc_state->adjusted_mode.vdisplay) {
                DRM_DEBUG_ATOMIC("visible portion of plane is invalid\n");
                return -EINVAL;
        }

        return 0;
}

static void hibmc_plane_atomic_update(struct drm_plane *plane,
                                      struct drm_plane_state *old_state)
{
        struct drm_plane_state  *state  = plane->state;
        u32 reg;
        int ret;
        u64 gpu_addr = 0;
        unsigned int line_l;
        struct hibmc_drm_private *priv = plane->dev->dev_private;
        struct hibmc_framebuffer *hibmc_fb;
        struct hibmc_bo *bo;

        if (!state->fb)
                return;

        hibmc_fb = to_hibmc_framebuffer(state->fb);
        bo = gem_to_hibmc_bo(hibmc_fb->obj);
        ret = ttm_bo_reserve(&bo->bo, true, false, NULL);
        if (ret) {
                DRM_ERROR("failed to reserve ttm_bo: %d", ret);
                return;
        }

        ret = hibmc_bo_pin(bo, TTM_PL_FLAG_VRAM, &gpu_addr);
        ttm_bo_unreserve(&bo->bo);
        if (ret) {
                DRM_ERROR("failed to pin hibmc_bo: %d", ret);
                return;
        }

        writel(gpu_addr, priv->mmio + HIBMC_CRT_FB_ADDRESS);

        reg = state->fb->width * (state->fb->format->cpp[0]);
        /* now line_pad is 16 */
        reg = PADDING(16, reg);

        line_l = state->fb->width * state->fb->format->cpp[0];
        line_l = PADDING(16, line_l);
        writel(HIBMC_FIELD(HIBMC_CRT_FB_WIDTH_WIDTH, reg) |
               HIBMC_FIELD(HIBMC_CRT_FB_WIDTH_OFFS, line_l),
               priv->mmio + HIBMC_CRT_FB_WIDTH);

        /* SET PIXEL FORMAT */
        reg = readl(priv->mmio + HIBMC_CRT_DISP_CTL);
        reg &= ~HIBMC_CRT_DISP_CTL_FORMAT_MASK;
        reg |= HIBMC_FIELD(HIBMC_CRT_DISP_CTL_FORMAT,
                           state->fb->format->cpp[0] * 8 / 16);
        writel(reg, priv->mmio + HIBMC_CRT_DISP_CTL);
}

static const u32 channel_formats1[] = {
        DRM_FORMAT_RGB565, DRM_FORMAT_BGR565, DRM_FORMAT_RGB888,
        DRM_FORMAT_BGR888, DRM_FORMAT_XRGB8888, DRM_FORMAT_XBGR8888,
        DRM_FORMAT_RGBA8888, DRM_FORMAT_BGRA8888, DRM_FORMAT_ARGB8888,
        DRM_FORMAT_ABGR8888
};

static struct drm_plane_funcs hibmc_plane_funcs = {
        .update_plane   = drm_atomic_helper_update_plane,
        .disable_plane  = drm_atomic_helper_disable_plane,
        .destroy = drm_plane_cleanup,
        .reset = drm_atomic_helper_plane_reset,
        .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
};

static const struct drm_plane_helper_funcs hibmc_plane_helper_funcs = {
        .atomic_check = hibmc_plane_atomic_check,
        .atomic_update = hibmc_plane_atomic_update,
};

static struct drm_plane *hibmc_plane_init(struct hibmc_drm_private *priv)
{
        struct drm_device *dev = priv->dev;
        struct drm_plane *plane;
        int ret = 0;

        plane = devm_kzalloc(dev->dev, sizeof(*plane), GFP_KERNEL);
        if (!plane) {
                DRM_ERROR("failed to alloc memory when init plane\n");
                return ERR_PTR(-ENOMEM);
        }
        /*
         * plane init
         * TODO: Now only support primary plane, overlay planes
         * need to do.
         */
        ret = drm_universal_plane_init(dev, plane, 1, &hibmc_plane_funcs,
                                       channel_formats1,
                                       ARRAY_SIZE(channel_formats1),
                                       NULL,
                                       DRM_PLANE_TYPE_PRIMARY,
                                       NULL);
        if (ret) {
                DRM_ERROR("failed to init plane: %d\n", ret);
                return ERR_PTR(ret);
        }

        drm_plane_helper_add(plane, &hibmc_plane_helper_funcs);
        return plane;
}

static void hibmc_crtc_atomic_enable(struct drm_crtc *crtc,
                                     struct drm_crtc_state *old_state)
{
        unsigned int reg;
        struct hibmc_drm_private *priv = crtc->dev->dev_private;

        hibmc_set_power_mode(priv, HIBMC_PW_MODE_CTL_MODE_MODE0);

        /* Enable display power gate & LOCALMEM power gate*/
        reg = readl(priv->mmio + HIBMC_CURRENT_GATE);
        reg &= ~HIBMC_CURR_GATE_LOCALMEM_MASK;
        reg &= ~HIBMC_CURR_GATE_DISPLAY_MASK;
        reg |= HIBMC_CURR_GATE_LOCALMEM(1);
        reg |= HIBMC_CURR_GATE_DISPLAY(1);
        hibmc_set_current_gate(priv, reg);
        drm_crtc_vblank_on(crtc);
}

static void hibmc_crtc_atomic_disable(struct drm_crtc *crtc,
                                      struct drm_crtc_state *old_state)
{
        unsigned int reg;
        struct hibmc_drm_private *priv = crtc->dev->dev_private;

        drm_crtc_vblank_off(crtc);

        hibmc_set_power_mode(priv, HIBMC_PW_MODE_CTL_MODE_SLEEP);

        /* Enable display power gate & LOCALMEM power gate*/
        reg = readl(priv->mmio + HIBMC_CURRENT_GATE);
        reg &= ~HIBMC_CURR_GATE_LOCALMEM_MASK;
        reg &= ~HIBMC_CURR_GATE_DISPLAY_MASK;
        reg |= HIBMC_CURR_GATE_LOCALMEM(0);
        reg |= HIBMC_CURR_GATE_DISPLAY(0);
        hibmc_set_current_gate(priv, reg);
}

static unsigned int format_pll_reg(void)
{
        unsigned int pllreg = 0;
        struct hibmc_display_panel_pll pll = {0};

        /*
         * Note that all PLL's have the same format. Here,
         * we just use Panel PLL parameter to work out the bit
         * fields in the register.On returning a 32 bit number, the value can
         * be applied to any PLL in the calling function.
         */
        pllreg |= HIBMC_FIELD(HIBMC_PLL_CTRL_BYPASS, 0);
        pllreg |= HIBMC_FIELD(HIBMC_PLL_CTRL_POWER, 1);
        pllreg |= HIBMC_FIELD(HIBMC_PLL_CTRL_INPUT, 0);
        pllreg |= HIBMC_FIELD(HIBMC_PLL_CTRL_POD, pll.POD);
        pllreg |= HIBMC_FIELD(HIBMC_PLL_CTRL_OD, pll.OD);
        pllreg |= HIBMC_FIELD(HIBMC_PLL_CTRL_N, pll.N);
        pllreg |= HIBMC_FIELD(HIBMC_PLL_CTRL_M, pll.M);

        return pllreg;
}

static void set_vclock_hisilicon(struct drm_device *dev, unsigned long pll)
{
        u32 val;
        struct hibmc_drm_private *priv = dev->dev_private;

        val = readl(priv->mmio + CRT_PLL1_HS);
        val &= ~(CRT_PLL1_HS_OUTER_BYPASS(1));
        writel(val, priv->mmio + CRT_PLL1_HS);

        val = CRT_PLL1_HS_INTER_BYPASS(1) | CRT_PLL1_HS_POWERON(1);
        writel(val, priv->mmio + CRT_PLL1_HS);

        writel(pll, priv->mmio + CRT_PLL1_HS);

        usleep_range(1000, 2000);

        val = pll & ~(CRT_PLL1_HS_POWERON(1));
        writel(val, priv->mmio + CRT_PLL1_HS);

        usleep_range(1000, 2000);

        val &= ~(CRT_PLL1_HS_INTER_BYPASS(1));
        writel(val, priv->mmio + CRT_PLL1_HS);

        usleep_range(1000, 2000);

        val |= CRT_PLL1_HS_OUTER_BYPASS(1);
        writel(val, priv->mmio + CRT_PLL1_HS);
}

static void get_pll_config(unsigned long x, unsigned long y,
                           u32 *pll1, u32 *pll2)
{
        int i;
        int count = ARRAY_SIZE(hibmc_pll_table);

        for (i = 0; i < count; i++) {
                if (hibmc_pll_table[i].hdisplay == x &&
                    hibmc_pll_table[i].vdisplay == y) {
                        *pll1 = hibmc_pll_table[i].pll1_config_value;
                        *pll2 = hibmc_pll_table[i].pll2_config_value;
                        return;
                }
        }

        /* if found none, we use default value */
        *pll1 = CRT_PLL1_HS_25MHZ;
        *pll2 = CRT_PLL2_HS_25MHZ;
}

/*
 * This function takes care the extra registers and bit fields required to
 * setup a mode in board.
 * Explanation about Display Control register:
 * FPGA only supports 7 predefined pixel clocks, and clock select is
 * in bit 4:0 of new register 0x802a8.
 */
static unsigned int display_ctrl_adjust(struct drm_device *dev,
                                        struct drm_display_mode *mode,
                                        unsigned int ctrl)
{
        unsigned long x, y;
        u32 pll1; /* bit[31:0] of PLL */
        u32 pll2; /* bit[63:32] of PLL */
        struct hibmc_drm_private *priv = dev->dev_private;

        x = mode->hdisplay;
        y = mode->vdisplay;

        get_pll_config(x, y, &pll1, &pll2);
        writel(pll2, priv->mmio + CRT_PLL2_HS);
        set_vclock_hisilicon(dev, pll1);

        /*
         * Hisilicon has to set up the top-left and bottom-right
         * registers as well.
         * Note that normal chip only use those two register for
         * auto-centering mode.
         */
        writel(HIBMC_FIELD(HIBMC_CRT_AUTO_CENTERING_TL_TOP, 0) |
               HIBMC_FIELD(HIBMC_CRT_AUTO_CENTERING_TL_LEFT, 0),
               priv->mmio + HIBMC_CRT_AUTO_CENTERING_TL);

        writel(HIBMC_FIELD(HIBMC_CRT_AUTO_CENTERING_BR_BOTTOM, y - 1) |
               HIBMC_FIELD(HIBMC_CRT_AUTO_CENTERING_BR_RIGHT, x - 1),
               priv->mmio + HIBMC_CRT_AUTO_CENTERING_BR);

        /*
         * Assume common fields in ctrl have been properly set before
         * calling this function.
         * This function only sets the extra fields in ctrl.
         */

        /* Set bit 25 of display controller: Select CRT or VGA clock */
        ctrl &= ~HIBMC_CRT_DISP_CTL_CRTSELECT_MASK;
        ctrl &= ~HIBMC_CRT_DISP_CTL_CLOCK_PHASE_MASK;

        ctrl |= HIBMC_CRT_DISP_CTL_CRTSELECT(HIBMC_CRTSELECT_CRT);

        /* clock_phase_polarity is 0 */
        ctrl |= HIBMC_CRT_DISP_CTL_CLOCK_PHASE(0);

        writel(ctrl, priv->mmio + HIBMC_CRT_DISP_CTL);

        return ctrl;
}

static void hibmc_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
        unsigned int val;
        struct drm_display_mode *mode = &crtc->state->mode;
        struct drm_device *dev = crtc->dev;
        struct hibmc_drm_private *priv = dev->dev_private;
        int width = mode->hsync_end - mode->hsync_start;
        int height = mode->vsync_end - mode->vsync_start;

        writel(format_pll_reg(), priv->mmio + HIBMC_CRT_PLL_CTRL);
        writel(HIBMC_FIELD(HIBMC_CRT_HORZ_TOTAL_TOTAL, mode->htotal - 1) |
               HIBMC_FIELD(HIBMC_CRT_HORZ_TOTAL_DISP_END, mode->hdisplay - 1),
               priv->mmio + HIBMC_CRT_HORZ_TOTAL);

        writel(HIBMC_FIELD(HIBMC_CRT_HORZ_SYNC_WIDTH, width) |
               HIBMC_FIELD(HIBMC_CRT_HORZ_SYNC_START, mode->hsync_start - 1),
               priv->mmio + HIBMC_CRT_HORZ_SYNC);

        writel(HIBMC_FIELD(HIBMC_CRT_VERT_TOTAL_TOTAL, mode->vtotal - 1) |
               HIBMC_FIELD(HIBMC_CRT_VERT_TOTAL_DISP_END, mode->vdisplay - 1),
               priv->mmio + HIBMC_CRT_VERT_TOTAL);

        writel(HIBMC_FIELD(HIBMC_CRT_VERT_SYNC_HEIGHT, height) |
               HIBMC_FIELD(HIBMC_CRT_VERT_SYNC_START, mode->vsync_start - 1),
               priv->mmio + HIBMC_CRT_VERT_SYNC);

        val = HIBMC_FIELD(HIBMC_CRT_DISP_CTL_VSYNC_PHASE, 0);
        val |= HIBMC_FIELD(HIBMC_CRT_DISP_CTL_HSYNC_PHASE, 0);
        val |= HIBMC_CRT_DISP_CTL_TIMING(1);
        val |= HIBMC_CRT_DISP_CTL_PLANE(1);

        display_ctrl_adjust(dev, mode, val);
}

static void hibmc_crtc_atomic_begin(struct drm_crtc *crtc,
                                    struct drm_crtc_state *old_state)
{
        unsigned int reg;
        struct drm_device *dev = crtc->dev;
        struct hibmc_drm_private *priv = dev->dev_private;

        hibmc_set_power_mode(priv, HIBMC_PW_MODE_CTL_MODE_MODE0);

        /* Enable display power gate & LOCALMEM power gate*/
        reg = readl(priv->mmio + HIBMC_CURRENT_GATE);
        reg &= ~HIBMC_CURR_GATE_DISPLAY_MASK;
        reg &= ~HIBMC_CURR_GATE_LOCALMEM_MASK;
        reg |= HIBMC_CURR_GATE_DISPLAY(1);
        reg |= HIBMC_CURR_GATE_LOCALMEM(1);
        hibmc_set_current_gate(priv, reg);

        /* We can add more initialization as needed. */
}

static void hibmc_crtc_atomic_flush(struct drm_crtc *crtc,
                                    struct drm_crtc_state *old_state)

{
        unsigned long flags;

        spin_lock_irqsave(&crtc->dev->event_lock, flags);
        if (crtc->state->event)
                drm_crtc_send_vblank_event(crtc, crtc->state->event);
        crtc->state->event = NULL;
        spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
}

static int hibmc_crtc_enable_vblank(struct drm_crtc *crtc)
{
        struct hibmc_drm_private *priv = crtc->dev->dev_private;

        writel(HIBMC_RAW_INTERRUPT_EN_VBLANK(1),
               priv->mmio + HIBMC_RAW_INTERRUPT_EN);

        return 0;
}

static void hibmc_crtc_disable_vblank(struct drm_crtc *crtc)
{
        struct hibmc_drm_private *priv = crtc->dev->dev_private;

        writel(HIBMC_RAW_INTERRUPT_EN_VBLANK(0),
               priv->mmio + HIBMC_RAW_INTERRUPT_EN);
}

static const struct drm_crtc_funcs hibmc_crtc_funcs = {
        .page_flip = drm_atomic_helper_page_flip,
        .set_config = drm_atomic_helper_set_config,
        .destroy = drm_crtc_cleanup,
        .reset = drm_atomic_helper_crtc_reset,
        .atomic_duplicate_state =  drm_atomic_helper_crtc_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
        .enable_vblank = hibmc_crtc_enable_vblank,
        .disable_vblank = hibmc_crtc_disable_vblank,
};

static const struct drm_crtc_helper_funcs hibmc_crtc_helper_funcs = {
        .mode_set_nofb  = hibmc_crtc_mode_set_nofb,
        .atomic_begin   = hibmc_crtc_atomic_begin,
        .atomic_flush   = hibmc_crtc_atomic_flush,
        .atomic_enable  = hibmc_crtc_atomic_enable,
        .atomic_disable = hibmc_crtc_atomic_disable,
};

int hibmc_de_init(struct hibmc_drm_private *priv)
{
        struct drm_device *dev = priv->dev;
        struct drm_crtc *crtc;
        struct drm_plane *plane;
        int ret;

        plane = hibmc_plane_init(priv);
        if (IS_ERR(plane)) {
                DRM_ERROR("failed to create plane: %ld\n", PTR_ERR(plane));
                return PTR_ERR(plane);
        }

        crtc = devm_kzalloc(dev->dev, sizeof(*crtc), GFP_KERNEL);
        if (!crtc) {
                DRM_ERROR("failed to alloc memory when init crtc\n");
                return -ENOMEM;
        }

        ret = drm_crtc_init_with_planes(dev, crtc, plane,
                                        NULL, &hibmc_crtc_funcs, NULL);
        if (ret) {
                DRM_ERROR("failed to init crtc: %d\n", ret);
                return ret;
        }

        ret = drm_mode_crtc_set_gamma_size(crtc, 256);
        if (ret) {
                DRM_ERROR("failed to set gamma size: %d\n", ret);
                return ret;
        }
        drm_crtc_helper_add(crtc, &hibmc_crtc_helper_funcs);

        return 0;
}