// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright © 2018 Broadcom
 *
 * Authors:
 *      Eric Anholt <eric@anholt.net>
 *      Boris Brezillon <boris.brezillon@bootlin.com>
 */

#include <linux/clk.h>
#include <linux/component.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_edid.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_panel.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_vblank.h>
#include <drm/drm_writeback.h>

#include "vc4_drv.h"
#include "vc4_regs.h"

/* Base address of the output.  Raster formats must be 4-byte aligned,
 * T and LT must be 16-byte aligned or maybe utile-aligned (docs are
 * inconsistent, but probably utile).
 */
#define TXP_DST_PTR             0x00

/* Pitch in bytes for raster images, 16-byte aligned.  For tiled, it's
 * the width in tiles.
 */
#define TXP_DST_PITCH           0x04
/* For T-tiled imgaes, DST_PITCH should be the number of tiles wide,
 * shifted up.
 */
# define TXP_T_TILE_WIDTH_SHIFT         7
/* For LT-tiled images, DST_PITCH should be the number of utiles wide,
 * shifted up.
 */
# define TXP_LT_TILE_WIDTH_SHIFT        4

/* Pre-rotation width/height of the image.  Must match HVS config.
 *
 * If TFORMAT and 32-bit, limit is 1920 for 32-bit and 3840 to 16-bit
 * and width/height must be tile or utile-aligned as appropriate.  If
 * transposing (rotating), width is limited to 1920.
 *
 * Height is limited to various numbers between 4088 and 4095.  I'd
 * just use 4088 to be safe.
 */
#define TXP_DIM                 0x08
# define TXP_HEIGHT_SHIFT               16
# define TXP_HEIGHT_MASK                GENMASK(31, 16)
# define TXP_WIDTH_SHIFT                0
# define TXP_WIDTH_MASK                 GENMASK(15, 0)

#define TXP_DST_CTRL            0x0c
/* These bits are set to 0x54 */
#define TXP_PILOT_SHIFT                 24
#define TXP_PILOT_MASK                  GENMASK(31, 24)
/* Bits 22-23 are set to 0x01 */
#define TXP_VERSION_SHIFT               22
#define TXP_VERSION_MASK                GENMASK(23, 22)

/* Powers down the internal memory. */
# define TXP_POWERDOWN                  BIT(21)

/* Enables storing the alpha component in 8888/4444, instead of
 * filling with ~ALPHA_INVERT.
 */
# define TXP_ALPHA_ENABLE               BIT(20)

/* 4 bits, each enables stores for a channel in each set of 4 bytes.
 * Set to 0xf for normal operation.
 */
# define TXP_BYTE_ENABLE_SHIFT          16
# define TXP_BYTE_ENABLE_MASK           GENMASK(19, 16)

/* Debug: Generate VSTART again at EOF. */
# define TXP_VSTART_AT_EOF              BIT(15)

/* Debug: Terminate the current frame immediately.  Stops AXI
 * writes.
 */
# define TXP_ABORT                      BIT(14)

# define TXP_DITHER                     BIT(13)

/* Inverts alpha if TXP_ALPHA_ENABLE, chooses fill value for
 * !TXP_ALPHA_ENABLE.
 */
# define TXP_ALPHA_INVERT               BIT(12)

/* Note: I've listed the channels here in high bit (in byte 3/2/1) to
 * low bit (in byte 0) order.
 */
# define TXP_FORMAT_SHIFT               8
# define TXP_FORMAT_MASK                GENMASK(11, 8)
# define TXP_FORMAT_ABGR4444            0
# define TXP_FORMAT_ARGB4444            1
# define TXP_FORMAT_BGRA4444            2
# define TXP_FORMAT_RGBA4444            3
# define TXP_FORMAT_BGR565              6
# define TXP_FORMAT_RGB565              7
/* 888s are non-rotated, raster-only */
# define TXP_FORMAT_BGR888              8
# define TXP_FORMAT_RGB888              9
# define TXP_FORMAT_ABGR8888            12
# define TXP_FORMAT_ARGB8888            13
# define TXP_FORMAT_BGRA8888            14
# define TXP_FORMAT_RGBA8888            15

/* If TFORMAT is set, generates LT instead of T format. */
# define TXP_LINEAR_UTILE               BIT(7)

/* Rotate output by 90 degrees. */
# define TXP_TRANSPOSE                  BIT(6)

/* Generate a tiled format for V3D. */
# define TXP_TFORMAT                    BIT(5)

/* Generates some undefined test mode output. */
# define TXP_TEST_MODE                  BIT(4)

/* Request odd field from HVS. */
# define TXP_FIELD                      BIT(3)

/* Raise interrupt when idle. */
# define TXP_EI                         BIT(2)

/* Set when generating a frame, clears when idle. */
# define TXP_BUSY                       BIT(1)

/* Starts a frame.  Self-clearing. */
# define TXP_GO                         BIT(0)

/* Number of lines received and committed to memory. */
#define TXP_PROGRESS            0x10

#define TXP_DST_PTR_HIGH_MOPLET 0x1c
#define TXP_DST_PTR_HIGH_MOP    0x24

#define TXP_READ(offset)                                                                \
        ({                                                                              \
                kunit_fail_current_test("Accessing a register in a unit test!\n");      \
                readl(txp->regs + (offset));                                            \
        })

#define TXP_WRITE(offset, val)                                                          \
        do {                                                                            \
                kunit_fail_current_test("Accessing a register in a unit test!\n");      \
                writel(val, txp->regs + (offset));                                      \
        } while (0)

struct vc4_txp {
        struct vc4_crtc base;
        const struct vc4_txp_data *data;

        struct platform_device *pdev;

        struct vc4_encoder encoder;
        struct drm_writeback_connector connector;

        void __iomem *regs;
};

#define encoder_to_vc4_txp(_encoder)                                    \
        container_of_const(_encoder, struct vc4_txp, encoder.base)

#define connector_to_vc4_txp(_connector)                                \
        container_of_const(_connector, struct vc4_txp, connector.base)

static const struct debugfs_reg32 txp_regs[] = {
        VC4_REG32(TXP_DST_PTR),
        VC4_REG32(TXP_DST_PITCH),
        VC4_REG32(TXP_DIM),
        VC4_REG32(TXP_DST_CTRL),
        VC4_REG32(TXP_PROGRESS),
};

static int vc4_txp_connector_get_modes(struct drm_connector *connector)
{
        struct drm_device *dev = connector->dev;

        return drm_add_modes_noedid(connector, dev->mode_config.max_width,
                                    dev->mode_config.max_height);
}

static enum drm_mode_status
vc4_txp_connector_mode_valid(struct drm_connector *connector,
                             const struct drm_display_mode *mode)
{
        struct drm_device *dev = connector->dev;
        struct drm_mode_config *mode_config = &dev->mode_config;
        int w = mode->hdisplay, h = mode->vdisplay;

        if (w < mode_config->min_width || w > mode_config->max_width)
                return MODE_BAD_HVALUE;

        if (h < mode_config->min_height || h > mode_config->max_height)
                return MODE_BAD_VVALUE;

        return MODE_OK;
}

static const u32 drm_fmts[] = {
        DRM_FORMAT_RGB888,
        DRM_FORMAT_BGR888,
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_XBGR8888,
        DRM_FORMAT_ARGB8888,
        DRM_FORMAT_ABGR8888,
        DRM_FORMAT_RGBX8888,
        DRM_FORMAT_BGRX8888,
        DRM_FORMAT_RGBA8888,
        DRM_FORMAT_BGRA8888,
};

static const u32 txp_fmts[] = {
        TXP_FORMAT_RGB888,
        TXP_FORMAT_BGR888,
        TXP_FORMAT_ARGB8888,
        TXP_FORMAT_ABGR8888,
        TXP_FORMAT_ARGB8888,
        TXP_FORMAT_ABGR8888,
        TXP_FORMAT_RGBA8888,
        TXP_FORMAT_BGRA8888,
        TXP_FORMAT_RGBA8888,
        TXP_FORMAT_BGRA8888,
};

static void vc4_txp_armed(struct drm_crtc_state *state)
{
        struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(state);

        vc4_state->txp_armed = true;
}

static int vc4_txp_connector_atomic_check(struct drm_connector *conn,
                                          struct drm_atomic_state *state)
{
        struct drm_connector_state *conn_state;
        struct drm_crtc_state *crtc_state;
        struct drm_framebuffer *fb;
        int i;

        conn_state = drm_atomic_get_new_connector_state(state, conn);
        if (!conn_state->writeback_job)
                return 0;

        crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);

        fb = conn_state->writeback_job->fb;
        if (fb->width != crtc_state->mode.hdisplay ||
            fb->height != crtc_state->mode.vdisplay) {
                DRM_DEBUG_KMS("Invalid framebuffer size %ux%u\n",
                              fb->width, fb->height);
                return -EINVAL;
        }

        for (i = 0; i < ARRAY_SIZE(drm_fmts); i++) {
                if (fb->format->format == drm_fmts[i])
                        break;
        }

        if (i == ARRAY_SIZE(drm_fmts))
                return -EINVAL;

        /* Pitch must be aligned on 16 bytes. */
        if (fb->pitches[0] & GENMASK(3, 0))
                return -EINVAL;

        vc4_txp_armed(crtc_state);

        return 0;
}

static void vc4_txp_connector_atomic_commit(struct drm_connector *conn,
                                        struct drm_atomic_state *state)
{
        struct drm_device *drm = conn->dev;
        struct drm_connector_state *conn_state = drm_atomic_get_new_connector_state(state,
                                                                                    conn);
        struct vc4_txp *txp = connector_to_vc4_txp(conn);
        const struct vc4_txp_data *txp_data = txp->data;
        struct drm_gem_dma_object *gem;
        struct drm_display_mode *mode;
        struct drm_framebuffer *fb;
        unsigned int hdisplay;
        unsigned int vdisplay;
        dma_addr_t addr;
        u32 ctrl;
        int idx;
        int i;

        if (WARN_ON(!conn_state->writeback_job))
                return;

        mode = &conn_state->crtc->state->adjusted_mode;
        fb = conn_state->writeback_job->fb;

        for (i = 0; i < ARRAY_SIZE(drm_fmts); i++) {
                if (fb->format->format == drm_fmts[i])
                        break;
        }

        if (WARN_ON(i == ARRAY_SIZE(drm_fmts)))
                return;

        ctrl = TXP_GO | TXP_EI |
               VC4_SET_FIELD(txp_fmts[i], TXP_FORMAT);

        if (txp_data->has_byte_enable)
                ctrl |= VC4_SET_FIELD(0xf, TXP_BYTE_ENABLE);

        if (fb->format->has_alpha)
                ctrl |= TXP_ALPHA_ENABLE;
        else
                /*
                 * If TXP_ALPHA_ENABLE isn't set and TXP_ALPHA_INVERT is, the
                 * hardware will force the output padding to be 0xff.
                 */
                ctrl |= TXP_ALPHA_INVERT;

        if (!drm_dev_enter(drm, &idx))
                return;

        gem = drm_fb_dma_get_gem_obj(fb, 0);
        addr = gem->dma_addr + fb->offsets[0];

        TXP_WRITE(TXP_DST_PTR, lower_32_bits(addr));

        if (txp_data->supports_40bit_addresses)
                TXP_WRITE(txp_data->high_addr_ptr_reg, upper_32_bits(addr) & 0xff);

        TXP_WRITE(TXP_DST_PITCH, fb->pitches[0]);

        hdisplay = mode->hdisplay ?: 1;
        vdisplay = mode->vdisplay ?: 1;
        if (txp_data->size_minus_one) {
                hdisplay -= 1;
                vdisplay -= 1;
        }

        TXP_WRITE(TXP_DIM,
                  VC4_SET_FIELD(hdisplay, TXP_WIDTH) |
                  VC4_SET_FIELD(vdisplay, TXP_HEIGHT));

        TXP_WRITE(TXP_DST_CTRL, ctrl);

        drm_writeback_queue_job(&txp->connector, conn_state);

        drm_dev_exit(idx);
}

static const struct drm_connector_helper_funcs vc4_txp_connector_helper_funcs = {
        .get_modes = vc4_txp_connector_get_modes,
        .mode_valid = vc4_txp_connector_mode_valid,
        .atomic_check = vc4_txp_connector_atomic_check,
        .atomic_commit = vc4_txp_connector_atomic_commit,
};

static enum drm_connector_status
vc4_txp_connector_detect(struct drm_connector *connector, bool force)
{
        return connector_status_connected;
}

static const struct drm_connector_funcs vc4_txp_connector_funcs = {
        .detect = vc4_txp_connector_detect,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = drm_connector_cleanup,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static void vc4_txp_encoder_disable(struct drm_encoder *encoder)
{
        struct drm_device *drm = encoder->dev;
        struct vc4_dev *vc4 = to_vc4_dev(drm);
        struct vc4_txp *txp = encoder_to_vc4_txp(encoder);
        int idx;

        if (!drm_dev_enter(drm, &idx))
                return;

        if (TXP_READ(TXP_DST_CTRL) & TXP_BUSY) {
                unsigned long timeout = jiffies + msecs_to_jiffies(1000);

                TXP_WRITE(TXP_DST_CTRL, TXP_ABORT);

                while (TXP_READ(TXP_DST_CTRL) & TXP_BUSY &&
                       time_before(jiffies, timeout))
                        ;

                WARN_ON(TXP_READ(TXP_DST_CTRL) & TXP_BUSY);
        }

        if (vc4->gen < VC4_GEN_6_C)
                TXP_WRITE(TXP_DST_CTRL, TXP_POWERDOWN);

        drm_dev_exit(idx);
}

static const struct drm_encoder_helper_funcs vc4_txp_encoder_helper_funcs = {
        .disable = vc4_txp_encoder_disable,
};

static int vc4_txp_enable_vblank(struct drm_crtc *crtc)
{
        return 0;
}

static void vc4_txp_disable_vblank(struct drm_crtc *crtc) {}

static const struct drm_crtc_funcs vc4_txp_crtc_funcs = {
        .set_config             = drm_atomic_helper_set_config,
        .page_flip              = vc4_page_flip,
        .reset                  = vc4_crtc_reset,
        .atomic_duplicate_state = vc4_crtc_duplicate_state,
        .atomic_destroy_state   = vc4_crtc_destroy_state,
        .enable_vblank          = vc4_txp_enable_vblank,
        .disable_vblank         = vc4_txp_disable_vblank,
        .late_register          = vc4_crtc_late_register,
};

static int vc4_txp_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);
        int ret;

        ret = vc4_hvs_atomic_check(crtc, state);
        if (ret)
                return ret;

        crtc_state->no_vblank = true;

        return 0;
}

static void vc4_txp_atomic_enable(struct drm_crtc *crtc,
                                  struct drm_atomic_state *state)
{
        drm_crtc_vblank_on(crtc);
        vc4_hvs_atomic_enable(crtc, state);
}

static void vc4_txp_atomic_disable(struct drm_crtc *crtc,
                                   struct drm_atomic_state *state)
{
        struct drm_device *dev = crtc->dev;

        /* Disable vblank irq handling before crtc is disabled. */
        drm_crtc_vblank_off(crtc);

        vc4_hvs_atomic_disable(crtc, state);

        /*
         * Make sure we issue a vblank event after disabling the CRTC if
         * someone was waiting it.
         */
        if (crtc->state->event) {
                unsigned long flags;

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

static const struct drm_crtc_helper_funcs vc4_txp_crtc_helper_funcs = {
        .atomic_check   = vc4_txp_atomic_check,
        .atomic_begin   = vc4_hvs_atomic_begin,
        .atomic_flush   = vc4_hvs_atomic_flush,
        .atomic_enable  = vc4_txp_atomic_enable,
        .atomic_disable = vc4_txp_atomic_disable,
};

static irqreturn_t vc4_txp_interrupt(int irq, void *data)
{
        struct vc4_txp *txp = data;
        struct vc4_crtc *vc4_crtc = &txp->base;

        /*
         * We don't need to protect the register access using
         * drm_dev_enter() there because the interrupt handler lifetime
         * is tied to the device itself, and not to the DRM device.
         *
         * So when the device will be gone, one of the first thing we
         * will be doing will be to unregister the interrupt handler,
         * and then unregister the DRM device. drm_dev_enter() would
         * thus always succeed if we are here.
         */
        TXP_WRITE(TXP_DST_CTRL, TXP_READ(TXP_DST_CTRL) & ~TXP_EI);
        vc4_crtc_handle_vblank(vc4_crtc);
        drm_writeback_signal_completion(&txp->connector, 0);

        return IRQ_HANDLED;
}

static const struct vc4_txp_data bcm2712_mop_data = {
        .base = {
                .name = "mop",
                .debugfs_name = "mop_regs",
                .hvs_available_channels = BIT(2),
                .hvs_output = 2,
        },
        .encoder_type = VC4_ENCODER_TYPE_TXP0,
        .high_addr_ptr_reg = TXP_DST_PTR_HIGH_MOP,
        .has_byte_enable = true,
        .size_minus_one = true,
        .supports_40bit_addresses = true,
};

static const struct vc4_txp_data bcm2712_moplet_data = {
        .base = {
                .name = "moplet",
                .debugfs_name = "moplet_regs",
                .hvs_available_channels = BIT(1),
                .hvs_output = 4,
        },
        .encoder_type = VC4_ENCODER_TYPE_TXP1,
        .high_addr_ptr_reg = TXP_DST_PTR_HIGH_MOPLET,
        .size_minus_one = true,
        .supports_40bit_addresses = true,
};

const struct vc4_txp_data bcm2835_txp_data = {
        .base = {
                .name = "txp",
                .debugfs_name = "txp_regs",
                .hvs_available_channels = BIT(2),
                .hvs_output = 2,
        },
        .encoder_type = VC4_ENCODER_TYPE_TXP0,
        .has_byte_enable = true,
};

static int vc4_txp_bind(struct device *dev, struct device *master, void *data)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct drm_device *drm = dev_get_drvdata(master);
        const struct vc4_txp_data *txp_data;
        struct vc4_encoder *vc4_encoder;
        struct drm_encoder *encoder;
        struct vc4_crtc *vc4_crtc;
        struct vc4_txp *txp;
        int ret, irq;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        txp = drmm_kzalloc(drm, sizeof(*txp), GFP_KERNEL);
        if (!txp)
                return -ENOMEM;

        txp_data = of_device_get_match_data(dev);
        if (!txp_data)
                return -ENODEV;

        txp->data = txp_data;
        txp->pdev = pdev;
        txp->regs = vc4_ioremap_regs(pdev, 0);
        if (IS_ERR(txp->regs))
                return PTR_ERR(txp->regs);

        vc4_crtc = &txp->base;
        vc4_crtc->regset.base = txp->regs;
        vc4_crtc->regset.regs = txp_regs;
        vc4_crtc->regset.nregs = ARRAY_SIZE(txp_regs);

        ret = vc4_crtc_init(drm, pdev, vc4_crtc, &txp_data->base,
                            &vc4_txp_crtc_funcs, &vc4_txp_crtc_helper_funcs, true);
        if (ret)
                return ret;

        vc4_encoder = &txp->encoder;
        txp->encoder.type = txp_data->encoder_type;

        encoder = &vc4_encoder->base;
        encoder->possible_crtcs = drm_crtc_mask(&vc4_crtc->base);

        drm_encoder_helper_add(encoder, &vc4_txp_encoder_helper_funcs);

        ret = drmm_encoder_init(drm, encoder, NULL, DRM_MODE_ENCODER_VIRTUAL, NULL);
        if (ret)
                return ret;

        drm_connector_helper_add(&txp->connector.base,
                                 &vc4_txp_connector_helper_funcs);
        ret = drm_writeback_connector_init_with_encoder(drm, &txp->connector,
                                                        encoder,
                                                        &vc4_txp_connector_funcs,
                                                        drm_fmts, ARRAY_SIZE(drm_fmts));
        if (ret)
                return ret;

        ret = devm_request_irq(dev, irq, vc4_txp_interrupt, 0,
                               dev_name(dev), txp);
        if (ret)
                return ret;

        dev_set_drvdata(dev, txp);

        return 0;
}

static void vc4_txp_unbind(struct device *dev, struct device *master,
                           void *data)
{
        struct vc4_txp *txp = dev_get_drvdata(dev);

        drm_connector_cleanup(&txp->connector.base);
}

static const struct component_ops vc4_txp_ops = {
        .bind   = vc4_txp_bind,
        .unbind = vc4_txp_unbind,
};

static int vc4_txp_probe(struct platform_device *pdev)
{
        return component_add(&pdev->dev, &vc4_txp_ops);
}

static void vc4_txp_remove(struct platform_device *pdev)
{
        component_del(&pdev->dev, &vc4_txp_ops);
}

static const struct of_device_id vc4_txp_dt_match[] = {
        { .compatible = "brcm,bcm2712-mop", .data = &bcm2712_mop_data },
        { .compatible = "brcm,bcm2712-moplet", .data = &bcm2712_moplet_data },
        { .compatible = "brcm,bcm2835-txp", .data = &bcm2835_txp_data },
        { /* sentinel */ },
};

struct platform_driver vc4_txp_driver = {
        .probe = vc4_txp_probe,
        .remove = vc4_txp_remove,
        .driver = {
                .name = "vc4_txp",
                .of_match_table = vc4_txp_dt_match,
        },
};