[PATCH v3 06/11] drm/tilcdc: Enable palette loading for revision 2 LCDC too

Bartosz Golaszewski bgolaszewski at baylibre.com
Wed Nov 23 15:12:29 UTC 2016


2016-11-22 17:54 GMT+01:00 Jyri Sarha <jsarha at ti.com>:
> The LCDC revision 2 documentation also mentions the mandatory palette
> for true color modes. Even if the rev 2 LCDC appears to work just fine
> without the palette being loaded loading it helps in testing the
> feature.
>
> Signed-off-by: Jyri Sarha <jsarha at ti.com>
> ---
>  drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 85 +++++++++++++++++-------------------
>  1 file changed, 41 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> index 0f89422..3bdab77 100644
> --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> @@ -28,8 +28,8 @@
>  #include "tilcdc_regs.h"
>
>  #define TILCDC_VBLANK_SAFETY_THRESHOLD_US      1000
> -#define TILCDC_REV1_PALETTE_SIZE               32
> -#define TILCDC_REV1_PALETTE_FIRST_ENTRY                0x4000
> +#define TILCDC_PALETTE_SIZE                    32
> +#define TILCDC_PALETTE_FIRST_ENTRY             0x4000
>
>  struct tilcdc_crtc {
>         struct drm_crtc base;
> @@ -62,7 +62,7 @@ struct tilcdc_crtc {
>         struct work_struct recover_work;
>
>         dma_addr_t palette_dma_handle;
> -       void *palette_base;
> +       u16 *palette_base;
>         struct completion palette_loaded;
>  };
>  #define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
> @@ -114,23 +114,17 @@ static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb)
>  }
>
>  /*
> - * The driver currently only supports the RGB565 format for revision 1. For
> - * 16 bits-per-pixel the palette block is bypassed, but the first 32 bytes of
> - * the framebuffer are still considered palette. The first 16-bit entry must
> - * be 0x4000 while all other entries must be zeroed.
> + * The driver currently only supports only true color formats. For
> + * true color the palette block is bypassed, but a 32 byte palette
> + * should still be loaded. The first 16-bit entry must be 0x4000 while
> + * all other entries must be zeroed.
>   */
>  static void tilcdc_crtc_load_palette(struct drm_crtc *crtc)
>  {
>         u32 dma_fb_base, dma_fb_ceiling, raster_ctl;
> -       struct tilcdc_crtc *tilcdc_crtc;
> -       struct drm_device *dev;
> -       u16 *first_entry;
> -
> -       dev = crtc->dev;
> -       tilcdc_crtc = to_tilcdc_crtc(crtc);
> -       first_entry = tilcdc_crtc->palette_base;
> -
> -       *first_entry = TILCDC_REV1_PALETTE_FIRST_ENTRY;
> +       struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
> +       struct drm_device *dev = crtc->dev;
> +       struct tilcdc_drm_private *priv = dev->dev_private;
>
>         dma_fb_base = tilcdc_read(dev, LCDC_DMA_FB_BASE_ADDR_0_REG);
>         dma_fb_ceiling = tilcdc_read(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG);
> @@ -140,23 +134,34 @@ static void tilcdc_crtc_load_palette(struct drm_crtc *crtc)
>         tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG,
>                      tilcdc_crtc->palette_dma_handle);
>         tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG,
> -                    (u32)tilcdc_crtc->palette_dma_handle
> -                               + TILCDC_REV1_PALETTE_SIZE - 1);
> +                    (u32) tilcdc_crtc->palette_dma_handle +
> +                    TILCDC_PALETTE_SIZE - 1);
>
> -       /* Load it. */
> -       tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
> -                    LCDC_PALETTE_LOAD_MODE(DATA_ONLY));
> -       tilcdc_set(dev, LCDC_RASTER_CTRL_REG,
> -                  LCDC_PALETTE_LOAD_MODE(PALETTE_ONLY));
> +       /* Set dma load mode for palette loading only. */
> +       tilcdc_write_mask(dev, LCDC_RASTER_CTRL_REG,
> +                         LCDC_PALETTE_LOAD_MODE(PALETTE_ONLY),
> +                         LCDC_PALETTE_LOAD_MODE_MASK);
> +
> +       /* Enable DMA Palette Loaded Interrupt */
> +       if (priv->rev == 1)
> +               tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
> +       else
> +               tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_V2_PL_INT_ENA);
>
> -       /* Enable the LCDC and wait for palette to be loaded. */
> -       tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
> +       /* Enable LCDC DMA and wait for palette to be loaded. */
> +       tilcdc_clear_irqstatus(dev, 0xffffffff);
>         tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
>
>         wait_for_completion(&tilcdc_crtc->palette_loaded);
>
> -       /* Restore the registers. */
> +       /* Disable LCDC DMA and DMA Palette Loaded Interrupt. */
>         tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
> +       if (priv->rev == 1)
> +               tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
> +       else
> +               tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG, LCDC_V2_PL_INT_ENA);
> +
> +       /* Restore the registers. */
>         tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, dma_fb_base);
>         tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG, dma_fb_ceiling);
>         tilcdc_write(dev, LCDC_RASTER_CTRL_REG, raster_ctl);
> @@ -217,7 +222,6 @@ static void tilcdc_crtc_enable(struct drm_crtc *crtc)
>  {
>         struct drm_device *dev = crtc->dev;
>         struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
> -       struct tilcdc_drm_private *priv = dev->dev_private;
>
>         WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
>         mutex_lock(&tilcdc_crtc->enable_lock);
> @@ -230,7 +234,7 @@ static void tilcdc_crtc_enable(struct drm_crtc *crtc)
>
>         reset(crtc);
>
> -       if (priv->rev == 1 && !completion_done(&tilcdc_crtc->palette_loaded))
> +       if (!completion_done(&tilcdc_crtc->palette_loaded))
>                 tilcdc_crtc_load_palette(crtc);
>
>         tilcdc_crtc_enable_irqs(dev);
> @@ -280,8 +284,7 @@ static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown)
>          * LCDC will not retain the palette when reset. Make sure it gets
>          * reloaded on tilcdc_crtc_enable().
>          */
> -       if (priv->rev == 1)
> -               reinit_completion(&tilcdc_crtc->palette_loaded);
> +       reinit_completion(&tilcdc_crtc->palette_loaded);
>
>         drm_crtc_vblank_off(crtc);
>
> @@ -916,13 +919,8 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
>                 dev_err_ratelimited(dev->dev, "%s(0x%08x): FIFO underflow",
>                                     __func__, stat);
>
> -       if (priv->rev == 1) {
> -               if (stat & LCDC_PL_LOAD_DONE) {
> -                       complete(&tilcdc_crtc->palette_loaded);
> -                       tilcdc_clear(dev,
> -                                    LCDC_RASTER_CTRL_REG, LCDC_V1_PL_INT_ENA);
> -               }
> -       }
> +       if (stat & LCDC_PL_LOAD_DONE)
> +               complete(&tilcdc_crtc->palette_loaded);
>

The LCDC_V1_PL_INT_ENA bit needs to be cleared here. Otherwise the
system freezes - surprisingly later at register_framebuffer() - in
revision 1.

Thanks,
Bartosz Golaszewski

>         if (stat & LCDC_SYNC_LOST) {
>                 dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost",
> @@ -968,15 +966,14 @@ int tilcdc_crtc_create(struct drm_device *dev)
>                 return -ENOMEM;
>         }
>
> -       if (priv->rev == 1) {
> -               init_completion(&tilcdc_crtc->palette_loaded);
> -               tilcdc_crtc->palette_base = dmam_alloc_coherent(dev->dev,
> -                                       TILCDC_REV1_PALETTE_SIZE,
> +       init_completion(&tilcdc_crtc->palette_loaded);
> +       tilcdc_crtc->palette_base = dmam_alloc_coherent(dev->dev,
> +                                       TILCDC_PALETTE_SIZE,
>                                         &tilcdc_crtc->palette_dma_handle,
>                                         GFP_KERNEL | __GFP_ZERO);
> -               if (!tilcdc_crtc->palette_base)
> -                       return -ENOMEM;
> -       }
> +       if (!tilcdc_crtc->palette_base)
> +               return -ENOMEM;
> +       *tilcdc_crtc->palette_base = TILCDC_PALETTE_FIRST_ENTRY;
>
>         crtc = &tilcdc_crtc->base;
>
> --
> 1.9.1
>


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