// SPDX-License-Identifier: GPL-2.0+
/*
 * i.MX IPUv3 Graphics driver
 *
 * Copyright (C) 2011 Sascha Hauer, Pengutronix
 */

#include <linux/clk.h>
#include <linux/component.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#include <video/imx-ipu-v3.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_vblank.h>

#include "imx-drm.h"
#include "ipuv3-plane.h"

#define DRIVER_DESC             "i.MX IPUv3 Graphics"

struct ipu_crtc {
        struct device           *dev;
        struct drm_crtc         base;

        /* plane[0] is the full plane, plane[1] is the partial plane */
        struct ipu_plane        *plane[2];

        struct ipu_dc           *dc;
        struct ipu_di           *di;
        int                     irq;
        struct drm_pending_vblank_event *event;
};

static inline struct ipu_crtc *to_ipu_crtc(struct drm_crtc *crtc)
{
        return container_of(crtc, struct ipu_crtc, base);
}

static void ipu_crtc_atomic_enable(struct drm_crtc *crtc,
                                   struct drm_atomic_state *state)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
        struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);

        ipu_prg_enable(ipu);
        ipu_dc_enable(ipu);
        ipu_dc_enable_channel(ipu_crtc->dc);
        ipu_di_enable(ipu_crtc->di);
}

static void ipu_crtc_disable_planes(struct ipu_crtc *ipu_crtc,
                                    struct drm_crtc_state *old_crtc_state)
{
        bool disable_partial = false;
        bool disable_full = false;
        struct drm_plane *plane;

        drm_atomic_crtc_state_for_each_plane(plane, old_crtc_state) {
                if (plane == &ipu_crtc->plane[0]->base)
                        disable_full = true;
                if (&ipu_crtc->plane[1] && plane == &ipu_crtc->plane[1]->base)
                        disable_partial = true;
        }

        if (disable_partial)
                ipu_plane_disable(ipu_crtc->plane[1], true);
        if (disable_full)
                ipu_plane_disable(ipu_crtc->plane[0], true);
}

static void ipu_crtc_atomic_disable(struct drm_crtc *crtc,
                                    struct drm_atomic_state *state)
{
        struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(state,
                                                                              crtc);
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
        struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);

        ipu_dc_disable_channel(ipu_crtc->dc);
        ipu_di_disable(ipu_crtc->di);
        /*
         * Planes must be disabled before DC clock is removed, as otherwise the
         * attached IDMACs will be left in undefined state, possibly hanging
         * the IPU or even system.
         */
        ipu_crtc_disable_planes(ipu_crtc, old_crtc_state);
        ipu_dc_disable(ipu);
        ipu_prg_disable(ipu);

        drm_crtc_vblank_off(crtc);

        spin_lock_irq(&crtc->dev->event_lock);
        if (crtc->state->event && !crtc->state->active) {
                drm_crtc_send_vblank_event(crtc, crtc->state->event);
                crtc->state->event = NULL;
        }
        spin_unlock_irq(&crtc->dev->event_lock);
}

static void imx_drm_crtc_reset(struct drm_crtc *crtc)
{
        struct imx_crtc_state *state;

        if (crtc->state)
                __drm_atomic_helper_crtc_destroy_state(crtc->state);

        kfree(to_imx_crtc_state(crtc->state));
        crtc->state = NULL;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (state)
                __drm_atomic_helper_crtc_reset(crtc, &state->base);
}

static struct drm_crtc_state *imx_drm_crtc_duplicate_state(struct drm_crtc *crtc)
{
        struct imx_crtc_state *state;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (!state)
                return NULL;

        __drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);

        WARN_ON(state->base.crtc != crtc);
        state->base.crtc = crtc;

        return &state->base;
}

static void imx_drm_crtc_destroy_state(struct drm_crtc *crtc,
                                       struct drm_crtc_state *state)
{
        __drm_atomic_helper_crtc_destroy_state(state);
        kfree(to_imx_crtc_state(state));
}

static int ipu_enable_vblank(struct drm_crtc *crtc)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        enable_irq(ipu_crtc->irq);

        return 0;
}

static void ipu_disable_vblank(struct drm_crtc *crtc)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

        disable_irq_nosync(ipu_crtc->irq);
}

static const struct drm_crtc_funcs ipu_crtc_funcs = {
        .set_config = drm_atomic_helper_set_config,
        .page_flip = drm_atomic_helper_page_flip,
        .reset = imx_drm_crtc_reset,
        .atomic_duplicate_state = imx_drm_crtc_duplicate_state,
        .atomic_destroy_state = imx_drm_crtc_destroy_state,
        .enable_vblank = ipu_enable_vblank,
        .disable_vblank = ipu_disable_vblank,
};

static irqreturn_t ipu_irq_handler(int irq, void *dev_id)
{
        struct ipu_crtc *ipu_crtc = dev_id;
        struct drm_crtc *crtc = &ipu_crtc->base;
        unsigned long flags;
        int i;

        drm_crtc_handle_vblank(crtc);

        if (ipu_crtc->event) {
                for (i = 0; i < ARRAY_SIZE(ipu_crtc->plane); i++) {
                        struct ipu_plane *plane = ipu_crtc->plane[i];

                        if (!plane)
                                continue;

                        if (ipu_plane_atomic_update_pending(&plane->base))
                                break;
                }

                if (i == ARRAY_SIZE(ipu_crtc->plane)) {
                        spin_lock_irqsave(&crtc->dev->event_lock, flags);
                        drm_crtc_send_vblank_event(crtc, ipu_crtc->event);
                        ipu_crtc->event = NULL;
                        drm_crtc_vblank_put(crtc);
                        spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
                }
        }

        return IRQ_HANDLED;
}

static bool ipu_crtc_mode_fixup(struct drm_crtc *crtc,
                                  const struct drm_display_mode *mode,
                                  struct drm_display_mode *adjusted_mode)
{
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
        struct videomode vm;
        int ret;

        drm_display_mode_to_videomode(adjusted_mode, &vm);

        ret = ipu_di_adjust_videomode(ipu_crtc->di, &vm);
        if (ret)
                return false;

        if ((vm.vsync_len == 0) || (vm.hsync_len == 0))
                return false;

        drm_display_mode_from_videomode(&vm, adjusted_mode);

        return true;
}

static int ipu_crtc_atomic_check(struct drm_crtc *crtc,
                                 struct drm_atomic_state *state)
{
        struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
                                                                          crtc);
        u32 primary_plane_mask = drm_plane_mask(crtc->primary);

        if (crtc_state->active && (primary_plane_mask & crtc_state->plane_mask) == 0)
                return -EINVAL;

        return 0;
}

static void ipu_crtc_atomic_begin(struct drm_crtc *crtc,
                                  struct drm_atomic_state *state)
{
        drm_crtc_vblank_on(crtc);
}

static void ipu_crtc_atomic_flush(struct drm_crtc *crtc,
                                  struct drm_atomic_state *state)
{
        spin_lock_irq(&crtc->dev->event_lock);
        if (crtc->state->event) {
                struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);

                WARN_ON(drm_crtc_vblank_get(crtc));
                ipu_crtc->event = crtc->state->event;
                crtc->state->event = NULL;
        }
        spin_unlock_irq(&crtc->dev->event_lock);
}

static void ipu_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
        struct drm_device *dev = crtc->dev;
        struct drm_encoder *encoder;
        struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
        struct drm_display_mode *mode = &crtc->state->adjusted_mode;
        struct imx_crtc_state *imx_crtc_state = to_imx_crtc_state(crtc->state);
        struct ipu_di_signal_cfg sig_cfg = {};
        unsigned long encoder_types = 0;

        dev_dbg(ipu_crtc->dev, "%s: mode->hdisplay: %d\n", __func__,
                        mode->hdisplay);
        dev_dbg(ipu_crtc->dev, "%s: mode->vdisplay: %d\n", __func__,
                        mode->vdisplay);

        list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
                if (encoder->crtc == crtc)
                        encoder_types |= BIT(encoder->encoder_type);
        }

        dev_dbg(ipu_crtc->dev, "%s: attached to encoder types 0x%lx\n",
                __func__, encoder_types);

        /*
         * If we have DAC or LDB, then we need the IPU DI clock to be
         * the same as the LDB DI clock. For TVDAC, derive the IPU DI
         * clock from 27 MHz TVE_DI clock, but allow to divide it.
         */
        if (encoder_types & (BIT(DRM_MODE_ENCODER_DAC) |
                             BIT(DRM_MODE_ENCODER_LVDS)))
                sig_cfg.clkflags = IPU_DI_CLKMODE_SYNC | IPU_DI_CLKMODE_EXT;
        else if (encoder_types & BIT(DRM_MODE_ENCODER_TVDAC))
                sig_cfg.clkflags = IPU_DI_CLKMODE_EXT;
        else
                sig_cfg.clkflags = 0;

        sig_cfg.enable_pol = !(imx_crtc_state->bus_flags & DRM_BUS_FLAG_DE_LOW);
        /* Default to driving pixel data on negative clock edges */
        sig_cfg.clk_pol = !!(imx_crtc_state->bus_flags &
                             DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE);
        sig_cfg.bus_format = imx_crtc_state->bus_format;
        sig_cfg.v_to_h_sync = 0;
        sig_cfg.hsync_pin = imx_crtc_state->di_hsync_pin;
        sig_cfg.vsync_pin = imx_crtc_state->di_vsync_pin;

        drm_display_mode_to_videomode(mode, &sig_cfg.mode);
        if (!IS_ALIGNED(sig_cfg.mode.hactive, 8)) {
                unsigned int new_hactive = ALIGN(sig_cfg.mode.hactive, 8);

                dev_warn(ipu_crtc->dev, "8-pixel align hactive %d -> %d\n",
                         sig_cfg.mode.hactive, new_hactive);

                sig_cfg.mode.hfront_porch = new_hactive - sig_cfg.mode.hactive;
                sig_cfg.mode.hactive = new_hactive;
        }

        ipu_dc_init_sync(ipu_crtc->dc, ipu_crtc->di,
                         mode->flags & DRM_MODE_FLAG_INTERLACE,
                         imx_crtc_state->bus_format, sig_cfg.mode.hactive);
        ipu_di_init_sync_panel(ipu_crtc->di, &sig_cfg);
}

static const struct drm_crtc_helper_funcs ipu_helper_funcs = {
        .mode_fixup = ipu_crtc_mode_fixup,
        .mode_set_nofb = ipu_crtc_mode_set_nofb,
        .atomic_check = ipu_crtc_atomic_check,
        .atomic_begin = ipu_crtc_atomic_begin,
        .atomic_flush = ipu_crtc_atomic_flush,
        .atomic_disable = ipu_crtc_atomic_disable,
        .atomic_enable = ipu_crtc_atomic_enable,
};

static void ipu_put_resources(struct drm_device *dev, void *ptr)
{
        struct ipu_crtc *ipu_crtc = ptr;

        if (!IS_ERR_OR_NULL(ipu_crtc->dc))
                ipu_dc_put(ipu_crtc->dc);
        if (!IS_ERR_OR_NULL(ipu_crtc->di))
                ipu_di_put(ipu_crtc->di);
}

static int ipu_get_resources(struct drm_device *dev, struct ipu_crtc *ipu_crtc,
                             struct ipu_client_platformdata *pdata)
{
        struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent);
        int ret;

        ipu_crtc->dc = ipu_dc_get(ipu, pdata->dc);
        if (IS_ERR(ipu_crtc->dc))
                return PTR_ERR(ipu_crtc->dc);

        ret = drmm_add_action_or_reset(dev, ipu_put_resources, ipu_crtc);
        if (ret)
                return ret;

        ipu_crtc->di = ipu_di_get(ipu, pdata->di);
        if (IS_ERR(ipu_crtc->di))
                return PTR_ERR(ipu_crtc->di);

        return 0;
}

static int ipu_drm_bind(struct device *dev, struct device *master, void *data)
{
        struct ipu_client_platformdata *pdata = dev->platform_data;
        struct ipu_soc *ipu = dev_get_drvdata(dev->parent);
        struct drm_device *drm = data;
        struct ipu_plane *primary_plane;
        struct ipu_crtc *ipu_crtc;
        struct drm_crtc *crtc;
        int dp = -EINVAL;
        int ret;

        if (pdata->dp >= 0)
                dp = IPU_DP_FLOW_SYNC_BG;
        primary_plane = ipu_plane_init(drm, ipu, pdata->dma[0], dp, 0,
                                       DRM_PLANE_TYPE_PRIMARY);
        if (IS_ERR(primary_plane))
                return PTR_ERR(primary_plane);

        ipu_crtc = drmm_crtc_alloc_with_planes(drm, struct ipu_crtc, base,
                                               &primary_plane->base, NULL,
                                               &ipu_crtc_funcs, NULL);
        if (IS_ERR(ipu_crtc))
                return PTR_ERR(ipu_crtc);

        ipu_crtc->dev = dev;
        ipu_crtc->plane[0] = primary_plane;

        crtc = &ipu_crtc->base;
        crtc->port = pdata->of_node;
        drm_crtc_helper_add(crtc, &ipu_helper_funcs);

        ret = ipu_get_resources(drm, ipu_crtc, pdata);
        if (ret) {
                dev_err(ipu_crtc->dev, "getting resources failed with %d.\n",
                        ret);
                return ret;
        }

        /* If this crtc is using the DP, add an overlay plane */
        if (pdata->dp >= 0 && pdata->dma[1] > 0) {
                ipu_crtc->plane[1] = ipu_plane_init(drm, ipu, pdata->dma[1],
                                                IPU_DP_FLOW_SYNC_FG,
                                                drm_crtc_mask(&ipu_crtc->base),
                                                DRM_PLANE_TYPE_OVERLAY);
                if (IS_ERR(ipu_crtc->plane[1]))
                        ipu_crtc->plane[1] = NULL;
        }

        ipu_crtc->irq = ipu_plane_irq(ipu_crtc->plane[0]);
        ret = devm_request_irq(ipu_crtc->dev, ipu_crtc->irq, ipu_irq_handler, 0,
                        "imx_drm", ipu_crtc);
        if (ret < 0) {
                dev_err(ipu_crtc->dev, "irq request failed with %d.\n", ret);
                return ret;
        }
        /* Only enable IRQ when we actually need it to trigger work. */
        disable_irq(ipu_crtc->irq);

        return 0;
}

static const struct component_ops ipu_crtc_ops = {
        .bind = ipu_drm_bind,
};

static int ipu_drm_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        int ret;

        if (!dev->platform_data)
                return -EINVAL;

        ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

        return component_add(dev, &ipu_crtc_ops);
}

static int ipu_drm_remove(struct platform_device *pdev)
{
        component_del(&pdev->dev, &ipu_crtc_ops);
        return 0;
}

struct platform_driver ipu_drm_driver = {
        .driver = {
                .name = "imx-ipuv3-crtc",
        },
        .probe = ipu_drm_probe,
        .remove = ipu_drm_remove,
};