// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Marek Vasut <marex@denx.de>
 *
 * This code is based on drivers/video/fbdev/mxsfb.c :
 * Copyright (C) 2010 Juergen Beisert, Pengutronix
 * Copyright (C) 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright (C) 2008 Embedded Alley Solutions, Inc All Rights Reserved.
 */

#include <linux/aperture.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/pm_runtime.h>

#include <drm/clients/drm_client_setup.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_drv.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_mode_config.h>
#include <drm/drm_module.h>
#include <drm/drm_of.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_vblank.h>

#include "mxsfb_drv.h"
#include "mxsfb_regs.h"

enum mxsfb_devtype {
        MXSFB_V3,
        MXSFB_V4,
        /*
         * Starting at i.MX6 the hardware version register is gone, use the
         * i.MX family number as the version.
         */
        MXSFB_V6,
};

static const struct mxsfb_devdata mxsfb_devdata[] = {
        [MXSFB_V3] = {
                .transfer_count = LCDC_V3_TRANSFER_COUNT,
                .cur_buf        = LCDC_V3_CUR_BUF,
                .next_buf       = LCDC_V3_NEXT_BUF,
                .hs_wdth_mask   = 0xff,
                .hs_wdth_shift  = 24,
                .has_overlay    = false,
                .has_ctrl2      = false,
                .has_crc32      = false,
        },
        [MXSFB_V4] = {
                .transfer_count = LCDC_V4_TRANSFER_COUNT,
                .cur_buf        = LCDC_V4_CUR_BUF,
                .next_buf       = LCDC_V4_NEXT_BUF,
                .hs_wdth_mask   = 0x3fff,
                .hs_wdth_shift  = 18,
                .has_overlay    = false,
                .has_ctrl2      = true,
                .has_crc32      = true,
        },
        [MXSFB_V6] = {
                .transfer_count = LCDC_V4_TRANSFER_COUNT,
                .cur_buf        = LCDC_V4_CUR_BUF,
                .next_buf       = LCDC_V4_NEXT_BUF,
                .hs_wdth_mask   = 0x3fff,
                .hs_wdth_shift  = 18,
                .has_overlay    = true,
                .has_ctrl2      = true,
                .has_crc32      = true,
        },
};

void mxsfb_enable_axi_clk(struct mxsfb_drm_private *mxsfb)
{
        clk_prepare_enable(mxsfb->clk_axi);
}

void mxsfb_disable_axi_clk(struct mxsfb_drm_private *mxsfb)
{
        clk_disable_unprepare(mxsfb->clk_axi);
}

static struct drm_framebuffer *
mxsfb_fb_create(struct drm_device *dev, struct drm_file *file_priv,
                const struct drm_format_info *info,
                const struct drm_mode_fb_cmd2 *mode_cmd)
{
        if (mode_cmd->width * info->cpp[0] != mode_cmd->pitches[0]) {
                dev_dbg(dev->dev, "Invalid pitch: fb width must match pitch\n");
                return ERR_PTR(-EINVAL);
        }

        return drm_gem_fb_create(dev, file_priv, info, mode_cmd);
}

static const struct drm_mode_config_funcs mxsfb_mode_config_funcs = {
        .fb_create              = mxsfb_fb_create,
        .atomic_check           = drm_atomic_helper_check,
        .atomic_commit          = drm_atomic_helper_commit,
};

static const struct drm_mode_config_helper_funcs mxsfb_mode_config_helpers = {
        .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
};

static int mxsfb_attach_bridge(struct mxsfb_drm_private *mxsfb)
{
        struct drm_device *drm = mxsfb->drm;
        struct drm_connector_list_iter iter;
        struct drm_panel *panel;
        struct drm_bridge *bridge;
        int ret;

        ret = drm_of_find_panel_or_bridge(drm->dev->of_node, 0, 0, &panel,
                                          &bridge);
        if (ret)
                return ret;

        if (panel) {
                bridge = devm_drm_panel_bridge_add_typed(drm->dev, panel,
                                                         DRM_MODE_CONNECTOR_DPI);
                if (IS_ERR(bridge))
                        return PTR_ERR(bridge);
        }

        if (!bridge)
                return -ENODEV;

        ret = drm_bridge_attach(&mxsfb->encoder, bridge, NULL, 0);
        if (ret)
                return dev_err_probe(drm->dev, ret, "Failed to attach bridge\n");

        mxsfb->bridge = bridge;

        /*
         * Get hold of the connector. This is a bit of a hack, until the bridge
         * API gives us bus flags and formats.
         */
        drm_connector_list_iter_begin(drm, &iter);
        mxsfb->connector = drm_connector_list_iter_next(&iter);
        drm_connector_list_iter_end(&iter);

        return 0;
}

static irqreturn_t mxsfb_irq_handler(int irq, void *data)
{
        struct drm_device *drm = data;
        struct mxsfb_drm_private *mxsfb = drm->dev_private;
        u32 reg, crc;
        u64 vbc;

        reg = readl(mxsfb->base + LCDC_CTRL1);

        if (reg & CTRL1_CUR_FRAME_DONE_IRQ) {
                drm_crtc_handle_vblank(&mxsfb->crtc);
                if (mxsfb->crc_active) {
                        crc = readl(mxsfb->base + LCDC_V4_CRC_STAT);
                        vbc = drm_crtc_accurate_vblank_count(&mxsfb->crtc);
                        drm_crtc_add_crc_entry(&mxsfb->crtc, true, vbc, &crc);
                }
        }

        writel(CTRL1_CUR_FRAME_DONE_IRQ, mxsfb->base + LCDC_CTRL1 + REG_CLR);

        return IRQ_HANDLED;
}

static void mxsfb_irq_disable(struct drm_device *drm)
{
        struct mxsfb_drm_private *mxsfb = drm->dev_private;

        mxsfb_enable_axi_clk(mxsfb);

        /* Disable and clear VBLANK IRQ */
        writel(CTRL1_CUR_FRAME_DONE_IRQ_EN, mxsfb->base + LCDC_CTRL1 + REG_CLR);
        writel(CTRL1_CUR_FRAME_DONE_IRQ, mxsfb->base + LCDC_CTRL1 + REG_CLR);

        mxsfb_disable_axi_clk(mxsfb);
}

static int mxsfb_irq_install(struct drm_device *dev, int irq)
{
        if (irq == IRQ_NOTCONNECTED)
                return -ENOTCONN;

        mxsfb_irq_disable(dev);

        return request_irq(irq, mxsfb_irq_handler, 0,  dev->driver->name, dev);
}

static void mxsfb_irq_uninstall(struct drm_device *dev)
{
        struct mxsfb_drm_private *mxsfb = dev->dev_private;

        mxsfb_irq_disable(dev);
        free_irq(mxsfb->irq, dev);
}

static int mxsfb_load(struct drm_device *drm,
                      const struct mxsfb_devdata *devdata)
{
        struct platform_device *pdev = to_platform_device(drm->dev);
        struct mxsfb_drm_private *mxsfb;
        int ret;

        mxsfb = devm_kzalloc(&pdev->dev, sizeof(*mxsfb), GFP_KERNEL);
        if (!mxsfb)
                return -ENOMEM;

        mxsfb->drm = drm;
        drm->dev_private = mxsfb;
        mxsfb->devdata = devdata;

        mxsfb->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(mxsfb->base))
                return PTR_ERR(mxsfb->base);

        mxsfb->clk = devm_clk_get(drm->dev, NULL);
        if (IS_ERR(mxsfb->clk))
                return PTR_ERR(mxsfb->clk);

        mxsfb->clk_axi = devm_clk_get_optional(drm->dev, "axi");
        if (IS_ERR(mxsfb->clk_axi))
                return PTR_ERR(mxsfb->clk_axi);

        mxsfb->clk_disp_axi = devm_clk_get(drm->dev, "disp_axi");
        if (IS_ERR(mxsfb->clk_disp_axi))
                mxsfb->clk_disp_axi = NULL;

        ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

        pm_runtime_enable(drm->dev);

        /* Modeset init */
        ret = drmm_mode_config_init(drm);
        if (ret) {
                dev_err(drm->dev, "Failed to initialize mode config\n");
                goto err_vblank;
        }

        ret = mxsfb_kms_init(mxsfb);
        if (ret < 0) {
                dev_err(drm->dev, "Failed to initialize KMS pipeline\n");
                goto err_vblank;
        }

        ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
        if (ret < 0) {
                dev_err(drm->dev, "Failed to initialise vblank\n");
                goto err_vblank;
        }

        /* Start with vertical blanking interrupt reporting disabled. */
        drm_crtc_vblank_off(&mxsfb->crtc);

        ret = mxsfb_attach_bridge(mxsfb);
        if (ret) {
                dev_err_probe(drm->dev, ret, "Cannot connect bridge\n");
                goto err_vblank;
        }

        drm->mode_config.min_width      = MXSFB_MIN_XRES;
        drm->mode_config.min_height     = MXSFB_MIN_YRES;
        drm->mode_config.max_width      = MXSFB_MAX_XRES;
        drm->mode_config.max_height     = MXSFB_MAX_YRES;
        drm->mode_config.funcs          = &mxsfb_mode_config_funcs;
        drm->mode_config.helper_private = &mxsfb_mode_config_helpers;

        drm_mode_config_reset(drm);

        ret = platform_get_irq(pdev, 0);
        if (ret < 0)
                goto err_vblank;
        mxsfb->irq = ret;

        pm_runtime_get_sync(drm->dev);
        ret = mxsfb_irq_install(drm, mxsfb->irq);
        pm_runtime_put_sync(drm->dev);

        if (ret < 0) {
                dev_err(drm->dev, "Failed to install IRQ handler\n");
                goto err_vblank;
        }

        drm_kms_helper_poll_init(drm);

        platform_set_drvdata(pdev, drm);

        drm_helper_hpd_irq_event(drm);

        return 0;

err_vblank:
        pm_runtime_disable(drm->dev);

        return ret;
}

static void mxsfb_unload(struct drm_device *drm)
{
        drm_kms_helper_poll_fini(drm);

        pm_runtime_get_sync(drm->dev);
        mxsfb_irq_uninstall(drm);
        pm_runtime_put_sync(drm->dev);

        drm->dev_private = NULL;

        pm_runtime_disable(drm->dev);
}

DEFINE_DRM_GEM_DMA_FOPS(fops);

static const struct drm_driver mxsfb_driver = {
        .driver_features        = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
        DRM_GEM_DMA_DRIVER_OPS,
        DRM_FBDEV_DMA_DRIVER_OPS,
        .fops   = &fops,
        .name   = "mxsfb-drm",
        .desc   = "MXSFB Controller DRM",
        .major  = 1,
        .minor  = 0,
};

static const struct of_device_id mxsfb_dt_ids[] = {
        { .compatible = "fsl,imx23-lcdif", .data = &mxsfb_devdata[MXSFB_V3], },
        { .compatible = "fsl,imx28-lcdif", .data = &mxsfb_devdata[MXSFB_V4], },
        { .compatible = "fsl,imx6sx-lcdif", .data = &mxsfb_devdata[MXSFB_V6], },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mxsfb_dt_ids);

static int mxsfb_probe(struct platform_device *pdev)
{
        struct drm_device *drm;
        int ret;

        drm = drm_dev_alloc(&mxsfb_driver, &pdev->dev);
        if (IS_ERR(drm))
                return PTR_ERR(drm);

        ret = mxsfb_load(drm, device_get_match_data(&pdev->dev));
        if (ret)
                goto err_free;

        /*
         * Remove early framebuffers (ie. simplefb). The framebuffer can be
         * located anywhere in RAM
         */
        ret = aperture_remove_all_conflicting_devices(mxsfb_driver.name);
        if (ret)
                return dev_err_probe(&pdev->dev, ret,
                                     "can't kick out existing framebuffers\n");

        ret = drm_dev_register(drm, 0);
        if (ret)
                goto err_unload;

        drm_client_setup(drm, NULL);

        return 0;

err_unload:
        mxsfb_unload(drm);
err_free:
        drm_dev_put(drm);

        return ret;
}

static void mxsfb_remove(struct platform_device *pdev)
{
        struct drm_device *drm = platform_get_drvdata(pdev);

        drm_dev_unregister(drm);
        drm_atomic_helper_shutdown(drm);
        mxsfb_unload(drm);
        drm_dev_put(drm);
}

static void mxsfb_shutdown(struct platform_device *pdev)
{
        struct drm_device *drm = platform_get_drvdata(pdev);

        drm_atomic_helper_shutdown(drm);
}

#ifdef CONFIG_PM_SLEEP
static int mxsfb_suspend(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);

        return drm_mode_config_helper_suspend(drm);
}

static int mxsfb_resume(struct device *dev)
{
        struct drm_device *drm = dev_get_drvdata(dev);

        return drm_mode_config_helper_resume(drm);
}
#endif

static const struct dev_pm_ops mxsfb_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(mxsfb_suspend, mxsfb_resume)
};

static struct platform_driver mxsfb_platform_driver = {
        .probe          = mxsfb_probe,
        .remove         = mxsfb_remove,
        .shutdown       = mxsfb_shutdown,
        .driver = {
                .name           = "mxsfb",
                .of_match_table = mxsfb_dt_ids,
                .pm             = &mxsfb_pm_ops,
        },
};

drm_module_platform_driver(mxsfb_platform_driver);

MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
MODULE_DESCRIPTION("Freescale MXS DRM/KMS driver");
MODULE_LICENSE("GPL");