drm_fb_cma_helper.c

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/*
 * drm kms/fb cma (contiguous memory allocator) helper functions
 *
 * Copyright (C) 2012 Analog Device Inc.
 *   Author: Lars-Peter Clausen <[email protected]>
 *
 * Based on udl_fbdev.c
 *  Copyright (C) 2012 Red Hat
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_fb_cma_helper.h>
#include <linux/module.h>

struct drm_fb_cma {
    struct drm_framebuffer      fb;
    struct drm_gem_cma_object   *obj[4];
};

struct drm_fbdev_cma {
    struct drm_fb_helper    fb_helper;
    struct drm_fb_cma   *fb;
};

static inline struct drm_fbdev_cma *to_fbdev_cma(struct drm_fb_helper *helper)
{
    return container_of(helper, struct drm_fbdev_cma, fb_helper);
}

static inline struct drm_fb_cma *to_fb_cma(struct drm_framebuffer *fb)
{
    return container_of(fb, struct drm_fb_cma, fb);
}

static void drm_fb_cma_destroy(struct drm_framebuffer *fb)
{
    struct drm_fb_cma *fb_cma = to_fb_cma(fb);
    int i;

    for (i = 0; i < 4; i++) {
        if (fb_cma->obj[i])
            drm_gem_object_unreference_unlocked(&fb_cma->obj[i]->base);
    }

    drm_framebuffer_cleanup(fb);
    kfree(fb_cma);
}

static int drm_fb_cma_create_handle(struct drm_framebuffer *fb,
    struct drm_file *file_priv, unsigned int *handle)
{
    struct drm_fb_cma *fb_cma = to_fb_cma(fb);

    return drm_gem_handle_create(file_priv,
            &fb_cma->obj[0]->base, handle);
}

static struct drm_framebuffer_funcs drm_fb_cma_funcs = {
    .destroy    = drm_fb_cma_destroy,
    .create_handle  = drm_fb_cma_create_handle,
};

static struct drm_fb_cma *drm_fb_cma_alloc(struct drm_device *dev,
    struct drm_mode_fb_cmd2 *mode_cmd, struct drm_gem_cma_object **obj,
    unsigned int num_planes)
{
    struct drm_fb_cma *fb_cma;
    int ret;
    int i;

    fb_cma = kzalloc(sizeof(*fb_cma), GFP_KERNEL);
    if (!fb_cma)
        return ERR_PTR(-ENOMEM);

    ret = drm_framebuffer_init(dev, &fb_cma->fb, &drm_fb_cma_funcs);
    if (ret) {
        dev_err(dev->dev, "Failed to initalize framebuffer: %d\n", ret);
        kfree(fb_cma);
        return ERR_PTR(ret);
    }

    drm_helper_mode_fill_fb_struct(&fb_cma->fb, mode_cmd);

    for (i = 0; i < num_planes; i++)
        fb_cma->obj[i] = obj[i];

    return fb_cma;
}

struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev,
    struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd)
{
    struct drm_fb_cma *fb_cma;
    struct drm_gem_cma_object *objs[4];
    struct drm_gem_object *obj;
    unsigned int hsub;
    unsigned int vsub;
    int ret;
    int i;

    hsub = drm_format_horz_chroma_subsampling(mode_cmd->pixel_format);
    vsub = drm_format_vert_chroma_subsampling(mode_cmd->pixel_format);

    for (i = 0; i < drm_format_num_planes(mode_cmd->pixel_format); i++) {
        unsigned int width = mode_cmd->width / (i ? hsub : 1);
        unsigned int height = mode_cmd->height / (i ? vsub : 1);
        unsigned int min_size;

        obj = drm_gem_object_lookup(dev, file_priv, mode_cmd->handles[i]);
        if (!obj) {
            dev_err(dev->dev, "Failed to lookup GEM object\n");
            ret = -ENXIO;
            goto err_gem_object_unreference;
        }

        min_size = (height - 1) * mode_cmd->pitches[i]
             + width * drm_format_plane_cpp(mode_cmd->pixel_format, i)
             + mode_cmd->offsets[i];

        if (obj->size < min_size) {
            drm_gem_object_unreference_unlocked(obj);
            ret = -EINVAL;
            goto err_gem_object_unreference;
        }
        objs[i] = to_drm_gem_cma_obj(obj);
    }

    fb_cma = drm_fb_cma_alloc(dev, mode_cmd, objs, i);
    if (IS_ERR(fb_cma)) {
        ret = PTR_ERR(fb_cma);
        goto err_gem_object_unreference;
    }

    return &fb_cma->fb;

err_gem_object_unreference:
    for (i--; i >= 0; i--)
        drm_gem_object_unreference_unlocked(&objs[i]->base);
    return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(drm_fb_cma_create);

struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
    unsigned int plane)
{
    struct drm_fb_cma *fb_cma = to_fb_cma(fb);

    if (plane >= 4)
        return NULL;

    return fb_cma->obj[plane];
}
EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);

static struct fb_ops drm_fbdev_cma_ops = {
    .owner      = THIS_MODULE,
    .fb_fillrect    = sys_fillrect,
    .fb_copyarea    = sys_copyarea,
    .fb_imageblit   = sys_imageblit,
    .fb_check_var   = drm_fb_helper_check_var,
    .fb_set_par = drm_fb_helper_set_par,
    .fb_blank   = drm_fb_helper_blank,
    .fb_pan_display = drm_fb_helper_pan_display,
    .fb_setcmap = drm_fb_helper_setcmap,
};

static int drm_fbdev_cma_create(struct drm_fb_helper *helper,
    struct drm_fb_helper_surface_size *sizes)
{
    struct drm_fbdev_cma *fbdev_cma = to_fbdev_cma(helper);
    struct drm_mode_fb_cmd2 mode_cmd = { 0 };
    struct drm_device *dev = helper->dev;
    struct drm_gem_cma_object *obj;
    struct drm_framebuffer *fb;
    unsigned int bytes_per_pixel;
    unsigned long offset;
    struct fb_info *fbi;
    size_t size;
    int ret;

    DRM_DEBUG_KMS("surface width(%d), height(%d) and bpp(%d)\n",
            sizes->surface_width, sizes->surface_height,
            sizes->surface_bpp);

    bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);

    mode_cmd.width = sizes->surface_width;
    mode_cmd.height = sizes->surface_height;
    mode_cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
    mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
        sizes->surface_depth);

    size = mode_cmd.pitches[0] * mode_cmd.height;
    obj = drm_gem_cma_create(dev, size);
    if (IS_ERR(obj))
        return -ENOMEM;

    fbi = framebuffer_alloc(0, dev->dev);
    if (!fbi) {
        dev_err(dev->dev, "Failed to allocate framebuffer info.\n");
        ret = -ENOMEM;
        goto err_drm_gem_cma_free_object;
    }

    fbdev_cma->fb = drm_fb_cma_alloc(dev, &mode_cmd, &obj, 1);
    if (IS_ERR(fbdev_cma->fb)) {
        dev_err(dev->dev, "Failed to allocate DRM framebuffer.\n");
        ret = PTR_ERR(fbdev_cma->fb);
        goto err_framebuffer_release;
    }

    fb = &fbdev_cma->fb->fb;
    helper->fb = fb;
    helper->fbdev = fbi;

    fbi->par = helper;
    fbi->flags = FBINFO_FLAG_DEFAULT;
    fbi->fbops = &drm_fbdev_cma_ops;

    ret = fb_alloc_cmap(&fbi->cmap, 256, 0);
    if (ret) {
        dev_err(dev->dev, "Failed to allocate color map.\n");
        goto err_drm_fb_cma_destroy;
    }

    drm_fb_helper_fill_fix(fbi, fb->pitches[0], fb->depth);
    drm_fb_helper_fill_var(fbi, helper, fb->width, fb->height);

    offset = fbi->var.xoffset * bytes_per_pixel;
    offset += fbi->var.yoffset * fb->pitches[0];

    dev->mode_config.fb_base = (resource_size_t)obj->paddr;
    fbi->screen_base = obj->vaddr + offset;
    fbi->fix.smem_start = (unsigned long)(obj->paddr + offset);
    fbi->screen_size = size;
    fbi->fix.smem_len = size;

    return 0;

err_drm_fb_cma_destroy:
    drm_fb_cma_destroy(fb);
err_framebuffer_release:
    framebuffer_release(fbi);
err_drm_gem_cma_free_object:
    drm_gem_cma_free_object(&obj->base);
    return ret;
}

static int drm_fbdev_cma_probe(struct drm_fb_helper *helper,
    struct drm_fb_helper_surface_size *sizes)
{
    int ret = 0;

    if (!helper->fb) {
        ret = drm_fbdev_cma_create(helper, sizes);
        if (ret < 0)
            return ret;
        ret = 1;
    }

    return ret;
}

static struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
    .fb_probe = drm_fbdev_cma_probe,
};

struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev,
    unsigned int preferred_bpp, unsigned int num_crtc,
    unsigned int max_conn_count)
{
    struct drm_fbdev_cma *fbdev_cma;
    struct drm_fb_helper *helper;
    int ret;

    fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
    if (!fbdev_cma) {
        dev_err(dev->dev, "Failed to allocate drm fbdev.\n");
        return ERR_PTR(-ENOMEM);
    }

    fbdev_cma->fb_helper.funcs = &drm_fb_cma_helper_funcs;
    helper = &fbdev_cma->fb_helper;

    ret = drm_fb_helper_init(dev, helper, num_crtc, max_conn_count);
    if (ret < 0) {
        dev_err(dev->dev, "Failed to initialize drm fb helper.\n");
        goto err_free;
    }

    ret = drm_fb_helper_single_add_all_connectors(helper);
    if (ret < 0) {
        dev_err(dev->dev, "Failed to add connectors.\n");
        goto err_drm_fb_helper_fini;

    }

    ret = drm_fb_helper_initial_config(helper, preferred_bpp);
    if (ret < 0) {
        dev_err(dev->dev, "Failed to set inital hw configuration.\n");
        goto err_drm_fb_helper_fini;
    }

    return fbdev_cma;

err_drm_fb_helper_fini:
    drm_fb_helper_fini(helper);
err_free:
    kfree(fbdev_cma);

    return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);

void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
{
    if (fbdev_cma->fb_helper.fbdev) {
        struct fb_info *info;
        int ret;

        info = fbdev_cma->fb_helper.fbdev;
        ret = unregister_framebuffer(info);
        if (ret < 0)
            DRM_DEBUG_KMS("failed unregister_framebuffer()\n");

        if (info->cmap.len)
            fb_dealloc_cmap(&info->cmap);

        framebuffer_release(info);
    }

    if (fbdev_cma->fb)
        drm_fb_cma_destroy(&fbdev_cma->fb->fb);

    drm_fb_helper_fini(&fbdev_cma->fb_helper);
    kfree(fbdev_cma);
}
EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);

void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma)
{
    if (fbdev_cma)
        drm_fb_helper_restore_fbdev_mode(&fbdev_cma->fb_helper);
}
EXPORT_SYMBOL_GPL(drm_fbdev_cma_restore_mode);

void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma)
{
    if (fbdev_cma)
        drm_fb_helper_hotplug_event(&fbdev_cma->fb_helper);
}
EXPORT_SYMBOL_GPL(drm_fbdev_cma_hotplug_event);