root/drivers/gpu/drm/logicvc/logicvc_layer.c
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2019-2022 Bootlin
 * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 */

#include <linux/of.h>
#include <linux/types.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_blend.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_plane.h>
#include <drm/drm_print.h>

#include "logicvc_crtc.h"
#include "logicvc_drm.h"
#include "logicvc_layer.h"
#include "logicvc_of.h"
#include "logicvc_regs.h"

#define logicvc_layer(p) \
        container_of(p, struct logicvc_layer, drm_plane)

static uint32_t logicvc_layer_formats_rgb16[] = {
        DRM_FORMAT_RGB565,
        DRM_FORMAT_BGR565,
        DRM_FORMAT_INVALID,
};

static uint32_t logicvc_layer_formats_rgb24[] = {
        DRM_FORMAT_XRGB8888,
        DRM_FORMAT_XBGR8888,
        DRM_FORMAT_INVALID,
};

/*
 * What we call depth in this driver only counts color components, not alpha.
 * This allows us to stay compatible with the LogiCVC bistream definitions.
 */
static uint32_t logicvc_layer_formats_rgb24_alpha[] = {
        DRM_FORMAT_ARGB8888,
        DRM_FORMAT_ABGR8888,
        DRM_FORMAT_INVALID,
};

static struct logicvc_layer_formats logicvc_layer_formats[] = {
        {
                .colorspace     = LOGICVC_LAYER_COLORSPACE_RGB,
                .depth          = 16,
                .formats        = logicvc_layer_formats_rgb16,
        },
        {
                .colorspace     = LOGICVC_LAYER_COLORSPACE_RGB,
                .depth          = 24,
                .formats        = logicvc_layer_formats_rgb24,
        },
        {
                .colorspace     = LOGICVC_LAYER_COLORSPACE_RGB,
                .depth          = 24,
                .alpha          = true,
                .formats        = logicvc_layer_formats_rgb24_alpha,
        },
        { }
};

static bool logicvc_layer_format_inverted(uint32_t format)
{
        switch (format) {
        case DRM_FORMAT_BGR565:
        case DRM_FORMAT_BGR888:
        case DRM_FORMAT_XBGR8888:
        case DRM_FORMAT_ABGR8888:
                return true;
        default:
                return false;
        }
}

static int logicvc_plane_atomic_check(struct drm_plane *drm_plane,
                                      struct drm_atomic_state *state)
{
        struct drm_device *drm_dev = drm_plane->dev;
        struct logicvc_layer *layer = logicvc_layer(drm_plane);
        struct logicvc_drm *logicvc = logicvc_drm(drm_dev);
        struct drm_plane_state *new_state =
                drm_atomic_get_new_plane_state(state, drm_plane);
        struct drm_crtc_state *crtc_state;
        int min_scale, max_scale;
        bool can_position;
        int ret;

        if (!new_state->crtc)
                return 0;

        crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
                                                   new_state->crtc);
        if (WARN_ON(!crtc_state))
                return -EINVAL;

        if (new_state->crtc_x < 0 || new_state->crtc_y < 0) {
                drm_err(drm_dev,
                        "Negative on-CRTC positions are not supported.\n");
                return -EINVAL;
        }

        if (!logicvc->caps->layer_address) {
                ret = logicvc_layer_buffer_find_setup(logicvc, layer, new_state,
                                                      NULL);
                if (ret) {
                        drm_err(drm_dev, "No viable setup for buffer found.\n");
                        return ret;
                }
        }

        min_scale = DRM_PLANE_NO_SCALING;
        max_scale = DRM_PLANE_NO_SCALING;

        can_position = (drm_plane->type == DRM_PLANE_TYPE_OVERLAY &&
                        layer->index != (logicvc->config.layers_count - 1) &&
                        logicvc->config.layers_configurable);

        ret = drm_atomic_helper_check_plane_state(new_state, crtc_state,
                                                  min_scale, max_scale,
                                                  can_position, true);
        if (ret) {
                drm_err(drm_dev, "Invalid plane state\n\n");
                return ret;
        }

        return 0;
}

static void logicvc_plane_atomic_update(struct drm_plane *drm_plane,
                                        struct drm_atomic_state *state)
{
        struct logicvc_layer *layer = logicvc_layer(drm_plane);
        struct logicvc_drm *logicvc = logicvc_drm(drm_plane->dev);
        struct drm_device *drm_dev = &logicvc->drm_dev;
        struct drm_plane_state *new_state =
                drm_atomic_get_new_plane_state(state, drm_plane);
        struct drm_crtc *drm_crtc = &logicvc->crtc->drm_crtc;
        struct drm_display_mode *mode = &drm_crtc->state->adjusted_mode;
        struct drm_framebuffer *fb = new_state->fb;
        struct logicvc_layer_buffer_setup setup = {};
        u32 index = layer->index;
        u32 reg;

        /* Layer dimensions */

        regmap_write(logicvc->regmap, LOGICVC_LAYER_WIDTH_REG(index),
                     new_state->crtc_w - 1);
        regmap_write(logicvc->regmap, LOGICVC_LAYER_HEIGHT_REG(index),
                     new_state->crtc_h - 1);

        if (logicvc->caps->layer_address) {
                phys_addr_t fb_addr = drm_fb_dma_get_gem_addr(fb, new_state, 0);

                regmap_write(logicvc->regmap, LOGICVC_LAYER_ADDRESS_REG(index),
                             fb_addr);
        } else {
                /* Rely on offsets to configure the address. */

                logicvc_layer_buffer_find_setup(logicvc, layer, new_state,
                                                &setup);

                /* Layer memory offsets */

                regmap_write(logicvc->regmap, LOGICVC_BUFFER_SEL_REG,
                             LOGICVC_BUFFER_SEL_VALUE(index, setup.buffer_sel));
                regmap_write(logicvc->regmap, LOGICVC_LAYER_HOFFSET_REG(index),
                             setup.hoffset);
                regmap_write(logicvc->regmap, LOGICVC_LAYER_VOFFSET_REG(index),
                             setup.voffset);
        }

        /* Layer position */

        regmap_write(logicvc->regmap, LOGICVC_LAYER_HPOSITION_REG(index),
                     mode->hdisplay - 1 - new_state->crtc_x);

        /* Vertical position must be set last to sync layer register changes. */
        regmap_write(logicvc->regmap, LOGICVC_LAYER_VPOSITION_REG(index),
                     mode->vdisplay - 1 - new_state->crtc_y);

        /* Layer alpha */

        if (layer->config.alpha_mode == LOGICVC_LAYER_ALPHA_LAYER) {
                u32 alpha_bits;
                u32 alpha_max;
                u32 alpha;

                switch (layer->config.depth) {
                case 8:
                        alpha_bits = 3;
                        break;
                case 16:
                        if (layer->config.colorspace ==
                            LOGICVC_LAYER_COLORSPACE_YUV)
                                alpha_bits = 8;
                        else
                                alpha_bits = 6;
                        break;
                default:
                        alpha_bits = 8;
                        break;
                }

                alpha_max = BIT(alpha_bits) - 1;
                alpha = new_state->alpha * alpha_max / DRM_BLEND_ALPHA_OPAQUE;

                drm_dbg_kms(drm_dev, "Setting layer %d alpha to %d/%d\n", index,
                            alpha, alpha_max);

                regmap_write(logicvc->regmap, LOGICVC_LAYER_ALPHA_REG(index),
                             alpha);
        }

        /* Layer control */

        reg = LOGICVC_LAYER_CTRL_ENABLE;

        if (logicvc_layer_format_inverted(fb->format->format))
                reg |= LOGICVC_LAYER_CTRL_PIXEL_FORMAT_INVERT;

        reg |= LOGICVC_LAYER_CTRL_COLOR_KEY_DISABLE;

        regmap_write(logicvc->regmap, LOGICVC_LAYER_CTRL_REG(index), reg);
}

static void logicvc_plane_atomic_disable(struct drm_plane *drm_plane,
                                         struct drm_atomic_state *state)
{
        struct logicvc_layer *layer = logicvc_layer(drm_plane);
        struct logicvc_drm *logicvc = logicvc_drm(drm_plane->dev);
        u32 index = layer->index;

        regmap_write(logicvc->regmap, LOGICVC_LAYER_CTRL_REG(index), 0);
}

static struct drm_plane_helper_funcs logicvc_plane_helper_funcs = {
        .atomic_check           = logicvc_plane_atomic_check,
        .atomic_update          = logicvc_plane_atomic_update,
        .atomic_disable         = logicvc_plane_atomic_disable,
};

static const struct drm_plane_funcs logicvc_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,
};

int logicvc_layer_buffer_find_setup(struct logicvc_drm *logicvc,
                                    struct logicvc_layer *layer,
                                    struct drm_plane_state *state,
                                    struct logicvc_layer_buffer_setup *setup)
{
        struct drm_device *drm_dev = &logicvc->drm_dev;
        struct drm_framebuffer *fb = state->fb;
        /* All the supported formats have a single data plane. */
        u32 layer_bytespp = fb->format->cpp[0];
        u32 layer_stride = layer_bytespp * logicvc->config.row_stride;
        u32 base_offset = layer->config.base_offset * layer_stride;
        u32 buffer_offset = layer->config.buffer_offset * layer_stride;
        u8 buffer_sel = 0;
        u16 voffset = 0;
        u16 hoffset = 0;
        phys_addr_t fb_addr;
        u32 fb_offset;
        u32 gap;

        if (!logicvc->reserved_mem_base) {
                drm_err(drm_dev, "No reserved memory base was registered!\n");
                return -ENOMEM;
        }

        fb_addr = drm_fb_dma_get_gem_addr(fb, state, 0);
        if (fb_addr < logicvc->reserved_mem_base) {
                drm_err(drm_dev,
                        "Framebuffer memory below reserved memory base!\n");
                return -EINVAL;
        }

        fb_offset = (u32) (fb_addr - logicvc->reserved_mem_base);

        if (fb_offset < base_offset) {
                drm_err(drm_dev,
                        "Framebuffer offset below layer base offset!\n");
                return -EINVAL;
        }

        gap = fb_offset - base_offset;

        /* Use the possible video buffers selection. */
        if (gap && buffer_offset) {
                buffer_sel = gap / buffer_offset;
                if (buffer_sel > LOGICVC_BUFFER_SEL_MAX)
                        buffer_sel = LOGICVC_BUFFER_SEL_MAX;

                gap -= buffer_sel * buffer_offset;
        }

        /* Use the vertical offset. */
        if (gap && layer_stride && logicvc->config.layers_configurable) {
                voffset = gap / layer_stride;
                if (voffset > LOGICVC_LAYER_VOFFSET_MAX)
                        voffset = LOGICVC_LAYER_VOFFSET_MAX;

                gap -= voffset * layer_stride;
        }

        /* Use the horizontal offset. */
        if (gap && layer_bytespp && logicvc->config.layers_configurable) {
                hoffset = gap / layer_bytespp;
                if (hoffset > LOGICVC_DIMENSIONS_MAX)
                        hoffset = LOGICVC_DIMENSIONS_MAX;

                gap -= hoffset * layer_bytespp;
        }

        if (gap) {
                drm_err(drm_dev,
                        "Unable to find layer %d buffer setup for 0x%x byte gap\n",
                        layer->index, fb_offset - base_offset);
                return -EINVAL;
        }

        drm_dbg_kms(drm_dev, "Found layer %d buffer setup for 0x%x byte gap:\n",
                    layer->index, fb_offset - base_offset);

        drm_dbg_kms(drm_dev, "- buffer_sel = 0x%x chunks of 0x%x bytes\n",
                    buffer_sel, buffer_offset);
        drm_dbg_kms(drm_dev, "- voffset = 0x%x chunks of 0x%x bytes\n", voffset,
                    layer_stride);
        drm_dbg_kms(drm_dev, "- hoffset = 0x%x chunks of 0x%x bytes\n", hoffset,
                    layer_bytespp);

        if (setup) {
                setup->buffer_sel = buffer_sel;
                setup->voffset = voffset;
                setup->hoffset = hoffset;
        }

        return 0;
}

static struct logicvc_layer_formats *logicvc_layer_formats_lookup(struct logicvc_layer *layer)
{
        bool alpha;
        unsigned int i = 0;

        alpha = (layer->config.alpha_mode == LOGICVC_LAYER_ALPHA_PIXEL);

        while (logicvc_layer_formats[i].formats) {
                if (logicvc_layer_formats[i].colorspace == layer->config.colorspace &&
                    logicvc_layer_formats[i].depth == layer->config.depth &&
                    logicvc_layer_formats[i].alpha == alpha)
                        return &logicvc_layer_formats[i];

                i++;
        }

        return NULL;
}

static unsigned int logicvc_layer_formats_count(struct logicvc_layer_formats *formats)
{
        unsigned int count = 0;

        while (formats->formats[count] != DRM_FORMAT_INVALID)
                count++;

        return count;
}

static int logicvc_layer_config_parse(struct logicvc_drm *logicvc,
                                      struct logicvc_layer *layer)
{
        struct device_node *of_node = layer->of_node;
        struct logicvc_layer_config *config = &layer->config;
        int ret;

        logicvc_of_property_parse_bool(of_node,
                                       LOGICVC_OF_PROPERTY_LAYER_PRIMARY,
                                       &config->primary);

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_LAYER_COLORSPACE,
                                            &config->colorspace);
        if (ret)
                return ret;

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_LAYER_DEPTH,
                                            &config->depth);
        if (ret)
                return ret;

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_LAYER_ALPHA_MODE,
                                            &config->alpha_mode);
        if (ret)
                return ret;

        /*
         * Memory offset is only relevant without layer address configuration.
         */
        if (logicvc->caps->layer_address)
                return 0;

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_LAYER_BASE_OFFSET,
                                            &config->base_offset);
        if (ret)
                return ret;

        ret = logicvc_of_property_parse_u32(of_node,
                                            LOGICVC_OF_PROPERTY_LAYER_BUFFER_OFFSET,
                                            &config->buffer_offset);
        if (ret)
                return ret;

        return 0;
}

struct logicvc_layer *logicvc_layer_get_from_index(struct logicvc_drm *logicvc,
                                                   u32 index)
{
        struct logicvc_layer *layer;

        list_for_each_entry(layer, &logicvc->layers_list, list)
                if (layer->index == index)
                        return layer;

        return NULL;
}

struct logicvc_layer *logicvc_layer_get_from_type(struct logicvc_drm *logicvc,
                                                  enum drm_plane_type type)
{
        struct logicvc_layer *layer;

        list_for_each_entry(layer, &logicvc->layers_list, list)
                if (layer->drm_plane.type == type)
                        return layer;

        return NULL;
}

struct logicvc_layer *logicvc_layer_get_primary(struct logicvc_drm *logicvc)
{
        return logicvc_layer_get_from_type(logicvc, DRM_PLANE_TYPE_PRIMARY);
}

static int logicvc_layer_init(struct logicvc_drm *logicvc,
                              struct device_node *of_node, u32 index)
{
        struct drm_device *drm_dev = &logicvc->drm_dev;
        struct device *dev = drm_dev->dev;
        struct logicvc_layer *layer = NULL;
        struct logicvc_layer_formats *formats;
        unsigned int formats_count;
        enum drm_plane_type type;
        unsigned int zpos;
        int ret;

        layer = devm_kzalloc(dev, sizeof(*layer), GFP_KERNEL);
        if (!layer) {
                ret = -ENOMEM;
                goto error;
        }

        layer->of_node = of_node;
        layer->index = index;

        ret = logicvc_layer_config_parse(logicvc, layer);
        if (ret) {
                drm_err(drm_dev, "Failed to parse config for layer #%d\n",
                        index);
                goto error;
        }

        formats = logicvc_layer_formats_lookup(layer);
        if (!formats) {
                drm_err(drm_dev, "Failed to lookup formats for layer #%d\n",
                        index);
                ret = -EINVAL;
                goto error;
        }

        formats_count = logicvc_layer_formats_count(formats);

        /* The final layer can be configured as a background layer. */
        if (logicvc->config.background_layer &&
            index == (logicvc->config.layers_count - 1)) {
                /*
                 * A zero value for black is only valid for RGB, not for YUV,
                 * so this will need to take the format in account for YUV.
                 */
                u32 background = 0;

                drm_dbg_kms(drm_dev, "Using layer #%d as background layer\n",
                            index);

                regmap_write(logicvc->regmap, LOGICVC_BACKGROUND_COLOR_REG,
                             background);

                devm_kfree(dev, layer);

                return 0;
        }

        if (layer->config.primary)
                type = DRM_PLANE_TYPE_PRIMARY;
        else
                type = DRM_PLANE_TYPE_OVERLAY;

        ret = drm_universal_plane_init(drm_dev, &layer->drm_plane, 0,
                                       &logicvc_plane_funcs, formats->formats,
                                       formats_count, NULL, type, NULL);
        if (ret) {
                drm_err(drm_dev, "Failed to initialize layer plane\n");
                return ret;
        }

        drm_plane_helper_add(&layer->drm_plane, &logicvc_plane_helper_funcs);

        zpos = logicvc->config.layers_count - index - 1;
        drm_dbg_kms(drm_dev, "Giving layer #%d zpos %d\n", index, zpos);

        if (layer->config.alpha_mode == LOGICVC_LAYER_ALPHA_LAYER)
                drm_plane_create_alpha_property(&layer->drm_plane);

        drm_plane_create_zpos_immutable_property(&layer->drm_plane, zpos);

        drm_dbg_kms(drm_dev, "Registering layer #%d\n", index);

        layer->formats = formats;

        list_add_tail(&layer->list, &logicvc->layers_list);

        return 0;

error:
        if (layer)
                devm_kfree(dev, layer);

        return ret;
}

static void logicvc_layer_fini(struct logicvc_drm *logicvc,
                               struct logicvc_layer *layer)
{
        struct device *dev = logicvc->drm_dev.dev;

        list_del(&layer->list);
        devm_kfree(dev, layer);
}

void logicvc_layers_attach_crtc(struct logicvc_drm *logicvc)
{
        uint32_t possible_crtcs = drm_crtc_mask(&logicvc->crtc->drm_crtc);
        struct logicvc_layer *layer;

        list_for_each_entry(layer, &logicvc->layers_list, list) {
                if (layer->drm_plane.type != DRM_PLANE_TYPE_OVERLAY)
                        continue;

                layer->drm_plane.possible_crtcs = possible_crtcs;
        }
}

int logicvc_layers_init(struct logicvc_drm *logicvc)
{
        struct drm_device *drm_dev = &logicvc->drm_dev;
        struct device *dev = drm_dev->dev;
        struct device_node *of_node = dev->of_node;
        struct device_node *layer_node = NULL;
        struct device_node *layers_node;
        struct logicvc_layer *layer;
        struct logicvc_layer *next;
        int ret = 0;

        layers_node = of_get_child_by_name(of_node, "layers");
        if (!layers_node) {
                drm_err(drm_dev, "No layers node found in the description\n");
                ret = -ENODEV;
                goto error;
        }

        for_each_child_of_node(layers_node, layer_node) {
                u32 index = 0;

                if (!logicvc_of_node_is_layer(layer_node))
                        continue;

                ret = of_property_read_u32(layer_node, "reg", &index);
                if (ret)
                        continue;

                layer = logicvc_layer_get_from_index(logicvc, index);
                if (layer) {
                        drm_err(drm_dev, "Duplicated entry for layer #%d\n",
                                index);
                        continue;
                }

                ret = logicvc_layer_init(logicvc, layer_node, index);
                if (ret) {
                        of_node_put(layers_node);
                        goto error;
                }
        }

        of_node_put(layers_node);

        return 0;

error:
        list_for_each_entry_safe(layer, next, &logicvc->layers_list, list)
                logicvc_layer_fini(logicvc, layer);

        return ret;
}