[PATCH] drm/exynos: Add exynos drm specific fb_mmap function

[Rahul Sharma]

Hi All,

Please review the following patch.

regards,
Rahul Sharma

On Wed, Nov 7, 2012 at 4:38 PM, Rahul Sharma <rahul.sharma at samsung.com> wrote:
> From: Prathyush K <prathyush.k at samsung.com>
>
> This patch adds a exynos drm specific implementation of fb_mmap
> which supports mapping a non-contiguous buffer to user space.
>
> This new function does not assume that the frame buffer is contiguous
> and calls dma_mmap_writecombine for mapping the buffer to user space.
> dma_mmap_writecombine will be able to map a contiguous buffer as well
> as non-contig buffer depending on whether an IOMMU mapping is created
> for drm or not.
>
> Signed-off-by: Prathyush K <prathyush.k at samsung.com>
> Signed-off-by: Rahul Sharma <rahul.sharma at samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c |   26 ++++++++++++++++++++++++++
>  1 files changed, 26 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index 67eb6ba..3939f7f 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -46,8 +46,34 @@ struct exynos_drm_fbdev {
>         struct exynos_drm_gem_obj       *exynos_gem_obj;
>  };
>
> +static int exynos_drm_fb_mmap(struct fb_info *info,
> +                             struct vm_area_struct *vma)
> +{
> +       DRM_DEBUG_KMS("%s\n", __func__);
> +
> +       if (!vma || !info) {
> +               DRM_ERROR("invalid arguments vma 0x%x, info 0x%x.\n",
> +                               (unsigned int)vma, (unsigned int)info);
> +               return -EINVAL;
> +       }
> +
> +       if (!info->screen_base || info->screen_size == 0) {
> +               DRM_ERROR("invalid screen information.\n");
> +               return -EINVAL;
> +       }
> +
> +       vma->vm_pgoff = 0;
> +       vma->vm_flags |= VM_IO;
> +       if (dma_mmap_writecombine(info->device, vma, info->screen_base,
> +                       info->fix.smem_start, vma->vm_end - vma->vm_start))
> +               return -EAGAIN;
> +
> +       return 0;
> +}
> +
>  static struct fb_ops exynos_drm_fb_ops = {
>         .owner          = THIS_MODULE,
> +       .fb_mmap        = exynos_drm_fb_mmap,
>         .fb_fillrect    = cfb_fillrect,
>         .fb_copyarea    = cfb_copyarea,
>         .fb_imageblit   = cfb_imageblit,
> --
> 1.7.0.4
>