// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
 * Parts of this file were based on sources as follows:
 *
 * Copyright (C) 2006-2008 Intel Corporation
 * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
 * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
 * Copyright (C) 2011 Texas Instruments
 * Copyright (C) 2017 Eric Anholt
 */

#include <linux/clk.h>
#include <linux/dma-buf.h>
#include <linux/of_graph.h>
#include <linux/delay.h>

#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_vblank.h>

#include "tve200_drm.h"

irqreturn_t tve200_irq(int irq, void *data)
{
        struct tve200_drm_dev_private *priv = data;
        u32 stat;
        u32 val;

        stat = readl(priv->regs + TVE200_INT_STAT);

        if (!stat)
                return IRQ_NONE;

        /*
         * Vblank IRQ
         *
         * The hardware is a bit tilted: the line stays high after clearing
         * the vblank IRQ, firing many more interrupts. We counter this
         * by toggling the IRQ back and forth from firing at vblank and
         * firing at start of active image, which works around the problem
         * since those occur strictly in sequence, and we get two IRQs for each
         * frame, one at start of Vblank (that we make call into the CRTC) and
         * another one at the start of the image (that we discard).
         */
        if (stat & TVE200_INT_V_STATUS) {
                val = readl(priv->regs + TVE200_CTRL);
                /* We have an actual start of vsync */
                if (!(val & TVE200_VSTSTYPE_BITS)) {
                        drm_crtc_handle_vblank(&priv->pipe.crtc);
                        /* Toggle trigger to start of active image */
                        val |= TVE200_VSTSTYPE_VAI;
                } else {
                        /* Toggle trigger back to start of vsync */
                        val &= ~TVE200_VSTSTYPE_BITS;
                }
                writel(val, priv->regs + TVE200_CTRL);
        } else
                dev_err(priv->drm->dev, "stray IRQ %08x\n", stat);

        /* Clear the interrupt once done */
        writel(stat, priv->regs + TVE200_INT_CLR);

        return IRQ_HANDLED;
}

static int tve200_display_check(struct drm_simple_display_pipe *pipe,
                               struct drm_plane_state *pstate,
                               struct drm_crtc_state *cstate)
{
        const struct drm_display_mode *mode = &cstate->mode;
        struct drm_framebuffer *old_fb = pipe->plane.state->fb;
        struct drm_framebuffer *fb = pstate->fb;

        /*
         * We support these specific resolutions and nothing else.
         */
        if (!(mode->hdisplay == 352 && mode->vdisplay == 240) && /* SIF(525) */
            !(mode->hdisplay == 352 && mode->vdisplay == 288) && /* CIF(625) */
            !(mode->hdisplay == 640 && mode->vdisplay == 480) && /* VGA */
            !(mode->hdisplay == 720 && mode->vdisplay == 480) && /* D1 */
            !(mode->hdisplay == 720 && mode->vdisplay == 576)) { /* D1 */
                DRM_DEBUG_KMS("unsupported display mode (%u x %u)\n",
                        mode->hdisplay, mode->vdisplay);
                return -EINVAL;
        }

        if (fb) {
                u32 offset = drm_fb_dma_get_gem_addr(fb, pstate, 0);

                /* FB base address must be dword aligned. */
                if (offset & 3) {
                        DRM_DEBUG_KMS("FB not 32-bit aligned\n");
                        return -EINVAL;
                }

                /*
                 * There's no pitch register, the mode's hdisplay
                 * controls this.
                 */
                if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0]) {
                        DRM_DEBUG_KMS("can't handle pitches\n");
                        return -EINVAL;
                }

                /*
                 * We can't change the FB format in a flicker-free
                 * manner (and only update it during CRTC enable).
                 */
                if (old_fb && old_fb->format != fb->format)
                        cstate->mode_changed = true;
        }

        return 0;
}

static void tve200_display_enable(struct drm_simple_display_pipe *pipe,
                                 struct drm_crtc_state *cstate,
                                 struct drm_plane_state *plane_state)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_plane *plane = &pipe->plane;
        struct drm_device *drm = crtc->dev;
        struct tve200_drm_dev_private *priv = drm->dev_private;
        const struct drm_display_mode *mode = &cstate->mode;
        struct drm_framebuffer *fb = plane->state->fb;
        struct drm_connector *connector = priv->connector;
        u32 format = fb->format->format;
        u32 ctrl1 = 0;
        int retries;

        clk_prepare_enable(priv->clk);

        /* Reset the TVE200 and wait for it to come back online */
        writel(TVE200_CTRL_4_RESET, priv->regs + TVE200_CTRL_4);
        for (retries = 0; retries < 5; retries++) {
                usleep_range(30000, 50000);
                if (readl(priv->regs + TVE200_CTRL_4) & TVE200_CTRL_4_RESET)
                        continue;
                else
                        break;
        }
        if (retries == 5 &&
            readl(priv->regs + TVE200_CTRL_4) & TVE200_CTRL_4_RESET) {
                dev_err(drm->dev, "can't get hardware out of reset\n");
                return;
        }

        /* Function 1 */
        ctrl1 |= TVE200_CTRL_CSMODE;
        /* Interlace mode for CCIR656: parameterize? */
        ctrl1 |= TVE200_CTRL_NONINTERLACE;
        /* 32 words per burst */
        ctrl1 |= TVE200_CTRL_BURST_32_WORDS;
        /* 16 retries */
        ctrl1 |= TVE200_CTRL_RETRYCNT_16;
        /* NTSC mode: parametrize? */
        ctrl1 |= TVE200_CTRL_NTSC;

        /* Vsync IRQ at start of Vsync at first */
        ctrl1 |= TVE200_VSTSTYPE_VSYNC;

        if (connector->display_info.bus_flags &
            DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
                ctrl1 |= TVE200_CTRL_TVCLKP;

        if ((mode->hdisplay == 352 && mode->vdisplay == 240) || /* SIF(525) */
            (mode->hdisplay == 352 && mode->vdisplay == 288)) { /* CIF(625) */
                ctrl1 |= TVE200_CTRL_IPRESOL_CIF;
                dev_info(drm->dev, "CIF mode\n");
        } else if (mode->hdisplay == 640 && mode->vdisplay == 480) {
                ctrl1 |= TVE200_CTRL_IPRESOL_VGA;
                dev_info(drm->dev, "VGA mode\n");
        } else if ((mode->hdisplay == 720 && mode->vdisplay == 480) ||
                   (mode->hdisplay == 720 && mode->vdisplay == 576)) {
                ctrl1 |= TVE200_CTRL_IPRESOL_D1;
                dev_info(drm->dev, "D1 mode\n");
        }

        if (format & DRM_FORMAT_BIG_ENDIAN) {
                ctrl1 |= TVE200_CTRL_BBBP;
                format &= ~DRM_FORMAT_BIG_ENDIAN;
        }

        switch (format) {
        case DRM_FORMAT_XRGB8888:
                ctrl1 |= TVE200_IPDMOD_RGB888;
                break;
        case DRM_FORMAT_RGB565:
                ctrl1 |= TVE200_IPDMOD_RGB565;
                break;
        case DRM_FORMAT_XRGB1555:
                ctrl1 |= TVE200_IPDMOD_RGB555;
                break;
        case DRM_FORMAT_XBGR8888:
                ctrl1 |= TVE200_IPDMOD_RGB888 | TVE200_BGR;
                break;
        case DRM_FORMAT_BGR565:
                ctrl1 |= TVE200_IPDMOD_RGB565 | TVE200_BGR;
                break;
        case DRM_FORMAT_XBGR1555:
                ctrl1 |= TVE200_IPDMOD_RGB555 | TVE200_BGR;
                break;
        case DRM_FORMAT_YUYV:
                ctrl1 |= TVE200_IPDMOD_YUV422;
                ctrl1 |= TVE200_CTRL_YCBCRODR_CR0Y1CB0Y0;
                break;
        case DRM_FORMAT_YVYU:
                ctrl1 |= TVE200_IPDMOD_YUV422;
                ctrl1 |= TVE200_CTRL_YCBCRODR_CB0Y1CR0Y0;
                break;
        case DRM_FORMAT_UYVY:
                ctrl1 |= TVE200_IPDMOD_YUV422;
                ctrl1 |= TVE200_CTRL_YCBCRODR_Y1CR0Y0CB0;
                break;
        case DRM_FORMAT_VYUY:
                ctrl1 |= TVE200_IPDMOD_YUV422;
                ctrl1 |= TVE200_CTRL_YCBCRODR_Y1CB0Y0CR0;
                break;
        case DRM_FORMAT_YUV420:
                ctrl1 |= TVE200_CTRL_YUV420;
                ctrl1 |= TVE200_IPDMOD_YUV420;
                break;
        default:
                dev_err(drm->dev, "Unknown FB format 0x%08x\n",
                        fb->format->format);
                break;
        }

        ctrl1 |= TVE200_TVEEN;

        /* Turn it on */
        writel(ctrl1, priv->regs + TVE200_CTRL);

        drm_crtc_vblank_on(crtc);
}

static void tve200_display_disable(struct drm_simple_display_pipe *pipe)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct tve200_drm_dev_private *priv = drm->dev_private;

        drm_crtc_vblank_off(crtc);

        /* Disable put into reset and Power Down */
        writel(0, priv->regs + TVE200_CTRL);
        writel(TVE200_CTRL_4_RESET, priv->regs + TVE200_CTRL_4);

        clk_disable_unprepare(priv->clk);
}

static void tve200_display_update(struct drm_simple_display_pipe *pipe,
                                 struct drm_plane_state *old_pstate)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct tve200_drm_dev_private *priv = drm->dev_private;
        struct drm_pending_vblank_event *event = crtc->state->event;
        struct drm_plane *plane = &pipe->plane;
        struct drm_plane_state *pstate = plane->state;
        struct drm_framebuffer *fb = pstate->fb;

        if (fb) {
                /* For RGB, the Y component is used as base address */
                writel(drm_fb_dma_get_gem_addr(fb, pstate, 0),
                       priv->regs + TVE200_Y_FRAME_BASE_ADDR);

                /* For three plane YUV we need two more addresses */
                if (fb->format->format == DRM_FORMAT_YUV420) {
                        writel(drm_fb_dma_get_gem_addr(fb, pstate, 1),
                               priv->regs + TVE200_U_FRAME_BASE_ADDR);
                        writel(drm_fb_dma_get_gem_addr(fb, pstate, 2),
                               priv->regs + TVE200_V_FRAME_BASE_ADDR);
                }
        }

        if (event) {
                crtc->state->event = NULL;

                spin_lock_irq(&crtc->dev->event_lock);
                if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
                        drm_crtc_arm_vblank_event(crtc, event);
                else
                        drm_crtc_send_vblank_event(crtc, event);
                spin_unlock_irq(&crtc->dev->event_lock);
        }
}

static int tve200_display_enable_vblank(struct drm_simple_display_pipe *pipe)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct tve200_drm_dev_private *priv = drm->dev_private;

        /* Clear any IRQs and enable */
        writel(0xFF, priv->regs + TVE200_INT_CLR);
        writel(TVE200_INT_V_STATUS, priv->regs + TVE200_INT_EN);
        return 0;
}

static void tve200_display_disable_vblank(struct drm_simple_display_pipe *pipe)
{
        struct drm_crtc *crtc = &pipe->crtc;
        struct drm_device *drm = crtc->dev;
        struct tve200_drm_dev_private *priv = drm->dev_private;

        writel(0, priv->regs + TVE200_INT_EN);
}

static const struct drm_simple_display_pipe_funcs tve200_display_funcs = {
        .check = tve200_display_check,
        .enable = tve200_display_enable,
        .disable = tve200_display_disable,
        .update = tve200_display_update,
        .enable_vblank = tve200_display_enable_vblank,
        .disable_vblank = tve200_display_disable_vblank,
};

int tve200_display_init(struct drm_device *drm)
{
        struct tve200_drm_dev_private *priv = drm->dev_private;
        int ret;
        static const u32 formats[] = {
                DRM_FORMAT_XRGB8888,
                DRM_FORMAT_XBGR8888,
                DRM_FORMAT_RGB565,
                DRM_FORMAT_BGR565,
                DRM_FORMAT_XRGB1555,
                DRM_FORMAT_XBGR1555,
                /*
                 * The controller actually supports any YCbCr ordering,
                 * for packed YCbCr. This just lists the orderings that
                 * DRM supports.
                 */
                DRM_FORMAT_YUYV,
                DRM_FORMAT_YVYU,
                DRM_FORMAT_UYVY,
                DRM_FORMAT_VYUY,
                /* This uses three planes */
                DRM_FORMAT_YUV420,
        };

        ret = drm_simple_display_pipe_init(drm, &priv->pipe,
                                           &tve200_display_funcs,
                                           formats, ARRAY_SIZE(formats),
                                           NULL,
                                           priv->connector);
        if (ret)
                return ret;

        return 0;
}