[PATCH 1/2] drm: Add drm driver for OpenCores VGA/LCD display controller

Daniel Vetter daniel at ffwll.ch
Tue Jul 12 10:20:32 UTC 2016


On Mon, Jun 27, 2016 at 01:33:24PM +0200, Andrea Merello wrote:
> On Fri, Jun 10, 2016 at 4:27 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
> > On Thu, Jun 09, 2016 at 03:32:55PM +0200, Andrea Merello wrote:
> >> This driver supports the VGA/LCD core available from OpenCores:
> >> http://opencores.org/project,vga_lcd
> >>
> >> It's intended as a replacement for the "ocfb" framebuffer driver
> >>
> >> Signed-off-by: Andrea Merello <andrea.merello at gmail.com>
> >> Cc: Stefan Kristiansson <stefan.kristiansson at saunalahti.fi>
> >> Cc: Tomi Valkeinen <tomi.valkeinen at ti.com>
> >> Cc: Francesco Diotalevi <francesco.diotalevi at iit.it>
> >> Cc: Claudio Lorini <claudio.lorini at iit.it>
> >
> > Bunch of comments below, but this driver might be a good candidate for the
> > drm_simple_display_pipe helpers that Noralf Tronnes is working on. Would
> > allow you to cut down a pile more boilerplate I think. Please take a look.
> > I think the only thing you'd need is a new small function to set the
> > drm_bridge for the encoder in struct drm_simple_display_pipe
> 
> Yes, it seems a good option. I'll look into it.
> 
> Beside this, OK for all your comments below.
> 
> BTW I forgot to mention that, beside we are using it with a HDMI
> bridge, it would need something like the "RGB to VGA bridge" patch
> from Maxime Ripard [1] to actually replace the old "ocfb" driver. Is
> it likely to be accepted for merge sooner or later ?
> 
> [1] https://patchwork.kernel.org/patch/9102271/

Sure, just needs review/testing and then it can be merged. But 4.8 is
getting awefully close (drm subsystem starts closing down after -rc5), so
probably 4.9 material all.
-Daniel
> 
> 
> > -Daniel
> >
> >> ---
> >>  drivers/gpu/drm/Kconfig               |   2 +
> >>  drivers/gpu/drm/Makefile              |   1 +
> >>  drivers/gpu/drm/ocdrm/Kconfig         |   7 +
> >>  drivers/gpu/drm/ocdrm/Makefile        |   7 +
> >>  drivers/gpu/drm/ocdrm/ocdrm_crtc.c    | 336 ++++++++++++++++++++++++++++++++++
> >>  drivers/gpu/drm/ocdrm/ocdrm_crtc.h    |  48 +++++
> >>  drivers/gpu/drm/ocdrm/ocdrm_drv.c     | 312 +++++++++++++++++++++++++++++++
> >>  drivers/gpu/drm/ocdrm/ocdrm_drv.h     |  89 +++++++++
> >>  drivers/gpu/drm/ocdrm/ocdrm_encoder.c |  95 ++++++++++
> >>  drivers/gpu/drm/ocdrm/ocdrm_encoder.h |  48 +++++
> >>  10 files changed, 945 insertions(+)
> >>  create mode 100644 drivers/gpu/drm/ocdrm/Kconfig
> >>  create mode 100644 drivers/gpu/drm/ocdrm/Makefile
> >>  create mode 100644 drivers/gpu/drm/ocdrm/ocdrm_crtc.c
> >>  create mode 100644 drivers/gpu/drm/ocdrm/ocdrm_crtc.h
> >>  create mode 100644 drivers/gpu/drm/ocdrm/ocdrm_drv.c
> >>  create mode 100644 drivers/gpu/drm/ocdrm/ocdrm_drv.h
> >>  create mode 100644 drivers/gpu/drm/ocdrm/ocdrm_encoder.c
> >>  create mode 100644 drivers/gpu/drm/ocdrm/ocdrm_encoder.h
> >>
> >> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> >> index fc35731..48f56e4 100644
> >> --- a/drivers/gpu/drm/Kconfig
> >> +++ b/drivers/gpu/drm/Kconfig
> >> @@ -290,3 +290,5 @@ source "drivers/gpu/drm/arc/Kconfig"
> >>  source "drivers/gpu/drm/hisilicon/Kconfig"
> >>
> >>  source "drivers/gpu/drm/mediatek/Kconfig"
> >> +
> >> +source "drivers/gpu/drm/ocdrm/Kconfig"
> >> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> >> index be43afb..871da6a 100644
> >> --- a/drivers/gpu/drm/Makefile
> >> +++ b/drivers/gpu/drm/Makefile
> >> @@ -82,3 +82,4 @@ obj-$(CONFIG_DRM_FSL_DCU) += fsl-dcu/
> >>  obj-$(CONFIG_DRM_ETNAVIV) += etnaviv/
> >>  obj-$(CONFIG_DRM_ARCPGU)+= arc/
> >>  obj-y                        += hisilicon/
> >> +obj-$(CONFIG_DRM_OCDRM) += ocdrm/
> >> diff --git a/drivers/gpu/drm/ocdrm/Kconfig b/drivers/gpu/drm/ocdrm/Kconfig
> >> new file mode 100644
> >> index 0000000..a918503
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/Kconfig
> >> @@ -0,0 +1,7 @@
> >> +config DRM_OCDRM
> >> +     tristate "DRM Support for opencores OCFB"
> >> +     depends on DRM
> >> +     default n
> >> +     select DRM_KMS_HELPER
> >> +     select DRM_KMS_CMA_HELPER
> >> +     select VT_HW_CONSOLE_BINDING if FRAMEBUFFER_CONSOLE
> >> diff --git a/drivers/gpu/drm/ocdrm/Makefile b/drivers/gpu/drm/ocdrm/Makefile
> >> new file mode 100644
> >> index 0000000..4ea17d2
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/Makefile
> >> @@ -0,0 +1,7 @@
> >> +#
> >> +# Makefile for the drm device driver.  This driver provides support for the
> >> +# Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
> >> +
> >> +ocdrm-y := ocdrm_crtc.o ocdrm_drv.o ocdrm_encoder.o
> >> +
> >> +obj-$(CONFIG_DRM_OCDRM) += ocdrm.o
> >> diff --git a/drivers/gpu/drm/ocdrm/ocdrm_crtc.c b/drivers/gpu/drm/ocdrm/ocdrm_crtc.c
> >> new file mode 100644
> >> index 0000000..ebfe03e
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/ocdrm_crtc.c
> >> @@ -0,0 +1,336 @@
> >> +/*
> >> + * Open cores VGA/LCD 2.0 core DRM driver
> >> + * Copyright (c) 2016 Istituto Italiano di Tecnologia
> >> + * Electronic Design Lab.
> >> + *
> >> + * Author: Andrea Merello <andrea.merello at gmail.com>
> >> + *
> >> + * Based on the following drivers:
> >> + *   - Analog Devices AXI HDMI DRM driver, which is
> >> + *     Copyright 2012 Analog Devices Inc.
> >> + *
> >> + *   - ARC PGU DRM driver.
> >> + *     Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> >> + *
> >> + *   - ARM HDLCD Driver
> >> + *     Copyright (C) 2013-2015 ARM Limited
> >> + *
> >> + *   - Atmel atmel-hlcdc driver, which is
> >> + *     Copyright (C) 2014 Traphandler
> >> + *     Copyright (C) 2014 Free Electrons
> >> + *
> >> + *   - OpenCores VGA/LCD 2.0 core frame buffer driver
> >> + *     Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson at saunalahti.fi
> >> + *
> >> + *   - R-Car Display Unit DRM driver
> >> + *     Copyright (C) 2013-2015 Renesas Electronics Corporation
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify it
> >> + * under the terms of the GNU General Public License version 2 as published by
> >> + * the Free Software Foundation.
> >> + *
> >> + * 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.
> >> + *
> >> + * You should have received a copy of the GNU General Public License along with
> >> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#include <linux/slab.h>
> >> +
> >> +#include <drm/drmP.h>
> >> +#include <drm/drm_crtc_helper.h>
> >> +#include <drm/drm_gem_cma_helper.h>
> >> +#include <drm/drm_plane_helper.h>
> >> +#include <drm/drm_crtc_helper.h>
> >> +#include <drm/drm_atomic_helper.h>
> >> +
> >> +#include "ocdrm_crtc.h"
> >> +
> >> +
> >> +static inline struct ocdrm_priv *crtc_to_ocdrm(struct drm_crtc *crtc)
> >> +{
> >> +     return container_of(crtc, struct ocdrm_priv, crtc);
> >> +}
> >> +
> >> +static inline struct ocdrm_priv *plane_to_ocdrm(struct drm_plane *plane)
> >> +{
> >> +     return container_of(plane, struct ocdrm_priv, plane);
> >> +}
> >> +
> >> +static void ocdrm_plane_atomic_update(struct drm_plane *plane,
> >> +                             struct drm_plane_state *old_state)
> >> +{
> >> +     struct drm_gem_cma_object *obj;
> >> +     u32 val;
> >> +     uint32_t pixel_format;
> >> +     int hgate;
> >> +     struct ocdrm_priv *priv = plane_to_ocdrm(plane);
> >> +
> >> +     if (!plane->state->crtc || !plane->state->fb)
> >> +             return;
> >> +
> >> +     pixel_format = plane->state->fb->pixel_format;
> >> +     hgate = plane->state->crtc->state->adjusted_mode.crtc_hdisplay;
> >> +
> >> +     val = ocdrm_readreg(priv, OCFB_CTRL);
> >> +     ocdrm_writereg(priv, OCFB_CTRL, val & ~OCFB_CTRL_VEN);
> >> +
> >> +     if (!drm_atomic_plane_disabling(plane, plane->state)) {
> >> +             obj = drm_fb_cma_get_gem_obj(plane->state->fb, 0);
> >> +             ocdrm_writereg(priv, OCFB_VBARA, obj->paddr);
> >> +
> >> +             val &= ~(OCFB_CTRL_CD8 | OCFB_CTRL_CD16 |
> >> +                     OCFB_CTRL_CD24 | OCFB_CTRL_CD32);
> >> +             val &= ~(OCFB_CTRL_VBL8 | OCFB_CTRL_VBL4 |
> >> +                     OCFB_CTRL_VBL2 | OCFB_CTRL_VBL1);
> >> +
> >> +             switch (pixel_format) {
> >> +             /* TODO
> >> +              *case DRM_FORMAT_RGB332:
> >> +              *      hgate /= 4;
> >> +              *      val |= OCFB_CTRL_CD8;
> >> +              *      val |= OCFB_CTRL_PC;
> >> +              *      break;
> >> +              */
> >> +
> >> +             case DRM_FORMAT_RGB565:
> >> +                     dev_dbg(priv->drm_dev->dev, "16 bpp\n");
> >> +                     hgate /= 2;
> >> +                     val |= OCFB_CTRL_CD16;
> >> +                     break;
> >> +
> >> +             case DRM_FORMAT_RGB888:
> >> +                     dev_dbg(priv->drm_dev->dev, "24 bpp\n");
> >> +                     hgate = hgate * 3 / 4;
> >> +                     val |= OCFB_CTRL_CD24;
> >> +                     break;
> >> +
> >> +             case DRM_FORMAT_XRGB8888:
> >> +                     dev_dbg(priv->drm_dev->dev, "32 bpp\n");
> >> +                     val |= OCFB_CTRL_CD32;
> >> +                     break;
> >> +
> >> +             default:
> >> +                     dev_err(priv->drm_dev->dev, "Invalid pixelformat specified\n");
> >> +                     return;
> >> +             }
> >> +
> >> +             if ((0 == (obj->paddr & 0x1f)) && (0 == (hgate % 8))) {
> >> +                     dev_dbg(priv->drm_dev->dev, "dma burst 8 cycles\n");
> >> +                     val |= OCFB_CTRL_VBL8;
> >> +             } else if ((0 == (obj->paddr & 0xf)) && (0 == (hgate % 4))) {
> >> +                     dev_dbg(priv->drm_dev->dev, "dma burst 4 cycles\n");
> >> +                     val |= OCFB_CTRL_VBL4;
> >> +             } else if ((0 == (obj->paddr & 0x7)) && (0 == (hgate % 2))) {
> >> +                     dev_dbg(priv->drm_dev->dev, "dma burst 2 cycles\n");
> >> +                     val |= OCFB_CTRL_VBL2;
> >> +             } else {
> >> +                     dev_dbg(priv->drm_dev->dev, "dma burst 1 cycle\n");
> >> +                     val |= OCFB_CTRL_VBL1;
> >> +             }
> >> +
> >> +             ocdrm_writereg(priv, OCFB_CTRL, val | OCFB_CTRL_VEN);
> >> +     }
> >> +}
> >> +
> >> +static void ocdrm_crtc_enable(struct drm_crtc *crtc)
> >> +{
> >> +
> >> +     struct ocdrm_priv *priv = crtc_to_ocdrm(crtc);
> >> +
> >> +     if (!priv->clk_enabled)
> >> +             clk_prepare_enable(priv->pixel_clock);
> >> +     priv->clk_enabled = true;
> >> +}
> >> +
> >> +static void ocdrm_crtc_disable(struct drm_crtc *crtc)
> >> +{
> >> +     struct ocdrm_priv *priv = crtc_to_ocdrm(crtc);
> >> +
> >> +     /* why the plane has been not disabled ? .. we get here from destroy  */
> >> +     ocdrm_writereg(priv, OCFB_CTRL, 0);
> >> +
> >> +     if (priv->clk_enabled)
> >> +             clk_disable_unprepare(priv->pixel_clock);
> >> +     priv->clk_enabled = false;
> >> +}
> >> +
> >> +static void ocdrm_crtc_mode_set_nofb(struct drm_crtc *crtc)
> >> +{
> >> +     u32 ctrl;
> >> +     int ret;
> >> +     struct ocdrm_priv *priv = crtc_to_ocdrm(crtc);
> >> +     struct drm_display_mode *m = &crtc->state->adjusted_mode;
> >> +     uint32_t hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
> >> +     uint32_t vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
> >> +     uint32_t vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
> >> +     uint32_t hback_porch = m->crtc_htotal - m->crtc_hsync_end;
> >> +
> >> +     ctrl = ocdrm_readreg(priv, OCFB_CTRL);
> >> +     ocdrm_writereg(priv, OCFB_CTRL, ctrl & ~OCFB_CTRL_VEN);
> >> +
> >> +     /* Horizontal timings */
> >> +     ocdrm_writereg(priv, OCFB_HTIM, (hsync_len - 1) << 24 |
> >> +                   (hback_porch - 1) << 16 | (m->crtc_hdisplay - 1));
> >> +
> >> +     /* Vertical timings */
> >> +     ocdrm_writereg(priv, OCFB_VTIM, (vsync_len - 1) << 24 |
> >> +                   (vback_porch - 1) << 16 | (m->crtc_vdisplay - 1));
> >> +
> >> +     ocdrm_writereg(priv, OCFB_HVLEN, ((uint32_t)m->crtc_htotal - 1) << 16 |
> >> +             (m->crtc_vtotal - 1));
> >> +
> >> +     dev_dbg(priv->drm_dev->dev, "set mode H slen %u, bporch %u, tot %u\n",
> >> +             hsync_len, hback_porch, m->crtc_htotal);
> >> +     dev_dbg(priv->drm_dev->dev, "set mode V slen %u, bporch %u, tot %u\n",
> >> +             vsync_len, vback_porch, m->crtc_vtotal);
> >> +
> >> +     if (m->flags & DRM_MODE_FLAG_NHSYNC)
> >> +             ctrl |= OCFB_CTRL_HSL;
> >> +     else
> >> +             ctrl &= ~OCFB_CTRL_HSL;
> >> +
> >> +     if (m->flags & DRM_MODE_FLAG_NVSYNC)
> >> +             ctrl |= OCFB_CTRL_VSL;
> >> +     else
> >> +             ctrl &= ~OCFB_CTRL_VSL;
> >> +
> >> +     dev_dbg(priv->drm_dev->dev, "VPOL %d, HPOL %d\n",
> >> +             m->flags & DRM_MODE_FLAG_NVSYNC,
> >> +             m->flags & DRM_MODE_FLAG_NHSYNC);
> >> +
> >> +
> >> +     /* Set sync polarity. */
> >> +     ocdrm_writereg(priv, OCFB_CTRL, ctrl);
> >> +
> >> +     if (priv->clk_enabled)
> >> +             clk_disable_unprepare(priv->pixel_clock);
> >> +
> >> +     ret = clk_set_rate(priv->pixel_clock, m->crtc_clock * 1000);
> >> +     if (ret) {
> >> +             dev_err(priv->drm_dev->dev, "failed to set pixclk %d\n", ret);
> >> +             return;
> >> +     }
> >> +
> >> +     if (priv->clk_enabled)
> >> +             clk_prepare_enable(priv->pixel_clock);
> >> +
> >> +     dev_dbg(priv->drm_dev->dev, "pixel clock: %d\n", m->crtc_clock);
> >> +
> >> +     /* if video was enabled, then enable it */
> >> +     ocdrm_writereg(priv, OCFB_CTRL, ctrl);
> >> +}
> >> +
> >> +static bool ocdrm_crtc_mode_fixup(struct drm_crtc *crtc,
> >> +                             const struct drm_display_mode *mode,
> >> +                             struct drm_display_mode *adjusted_mode)
> >> +{
> >> +     struct ocdrm_priv *priv = crtc_to_ocdrm(crtc);
> >> +
> >> +     if (mode->clock < 16000 || mode->clock > 165000)
> >> +             return false;
> >> +
> >> +     adjusted_mode->clock = clk_round_rate(priv->pixel_clock,
> >> +                                     mode->clock * 1000) / 1000;
> >> +     return true;
> >> +}
> >> +
> >> +static int ocdrm_crtc_atomic_check(struct drm_crtc *crtc,
> >> +                             struct drm_crtc_state *state)
> >> +{
> >> +     struct ocdrm_priv *priv = crtc_to_ocdrm(crtc);
> >> +     struct drm_display_mode *m = &state->adjusted_mode;
> >> +     uint32_t hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
> >> +     uint32_t vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
> >> +     uint32_t vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
> >> +     uint32_t hback_porch = m->crtc_htotal - m->crtc_hsync_end;
> >> +     int rate;
> >> +
> >> +     if (m->clock < 16000 || m->clock > 165000)
> >> +             return false;
> >> +
> >> +     rate = clk_round_rate(priv->pixel_clock, m->clock * 1000) / 1000;
> >> +
> >> +     if (m->clock != rate)
> >> +             return -EINVAL;
> >> +
> >> +     if (hsync_len > 255 || vsync_len > 255 ||
> >> +             vback_porch > 255 || hback_porch > 255)
> >> +             return -EINVAL;
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static struct drm_crtc_helper_funcs ocdrm_crtc_helper_funcs = {
> >> +     .mode_fixup     = ocdrm_crtc_mode_fixup,
> >> +     .mode_set       = drm_helper_crtc_mode_set,
> >> +     .mode_set_base  = drm_helper_crtc_mode_set_base,
> >
> > You don't need the above 2 callbacks when exlusively using atomic.
> >
> >> +     .mode_set_nofb  = ocdrm_crtc_mode_set_nofb,
> >> +     .disable        = ocdrm_crtc_disable,
> >> +     .enable         = ocdrm_crtc_enable,
> >> +     .atomic_check   = ocdrm_crtc_atomic_check,
> >> +};
> >> +
> >> +static void ocdrm_crtc_destroy(struct drm_crtc *crtc)
> >> +{
> >> +     ocdrm_crtc_disable(crtc);
> >> +     drm_crtc_cleanup(crtc);
> >> +}
> >> +
> >> +static struct drm_crtc_funcs ocdrm_crtc_funcs = {
> >> +     .page_flip              = drm_atomic_helper_page_flip,
> >> +     .set_config             = drm_atomic_helper_set_config,
> >> +     .destroy                = ocdrm_crtc_destroy,
> >> +     .reset                  = drm_atomic_helper_crtc_reset,
> >> +     .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
> >> +     .atomic_destroy_state   = drm_atomic_helper_crtc_destroy_state
> >> +};
> >> +
> >> +static const struct drm_plane_helper_funcs ocdrm_plane_helper_funcs = {
> >> +     .atomic_update  = ocdrm_plane_atomic_update,
> >> +     .atomic_disable = NULL,
> >> +     .prepare_fb     = NULL,
> >> +     .cleanup_fb     = NULL
> >
> > Don't set to NULL, that's always the case for global data.
> >
> >> +};
> >> +
> >> +static const struct drm_plane_funcs ocdrm_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 ocdrm_crtc_create(struct ocdrm_priv *priv)
> >> +{
> >> +     int ret;
> >> +     uint32_t format[] = { DRM_FORMAT_RGB565,
> >> +                           DRM_FORMAT_RGB888,
> >> +                           DRM_FORMAT_XRGB8888,
> >> +     };
> >> +
> >> +     drm_plane_helper_add(&priv->plane, &ocdrm_plane_helper_funcs);
> >> +
> >> +     ret = drm_universal_plane_init(priv->drm_dev, &priv->plane, 0,
> >> +                             &ocdrm_plane_funcs,
> >> +                             format, ARRAY_SIZE(format),
> >> +                             DRM_PLANE_TYPE_PRIMARY, NULL);
> >> +     if (ret) {
> >> +             dev_err(priv->drm_dev->dev, "cannot initialize plane");
> >> +             return ret;
> >> +     }
> >> +
> >> +     drm_crtc_helper_add(&priv->crtc, &ocdrm_crtc_helper_funcs);
> >> +     ret = drm_crtc_init_with_planes(priv->drm_dev, &priv->crtc,
> >> +                                     &priv->plane, NULL,
> >> +                                     &ocdrm_crtc_funcs, NULL);
> >> +     if (ret)
> >> +             dev_err(priv->drm_dev->dev, "cannot initialize crtc");
> >> +             return ret;
> >> +
> >> +     return 0;
> >> +}
> >> diff --git a/drivers/gpu/drm/ocdrm/ocdrm_crtc.h b/drivers/gpu/drm/ocdrm/ocdrm_crtc.h
> >> new file mode 100644
> >> index 0000000..778327e
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/ocdrm_crtc.h
> >> @@ -0,0 +1,48 @@
> >> +/*
> >> + * Open cores VGA/LCD 2.0 core DRM driver
> >> + * Copyright (c) 2016 Istituto Italiano di Tecnologia
> >> + * Electronic Design Lab.
> >> + *
> >> + * Author: Andrea Merello <andrea.merello at gmail.com>
> >> + *
> >> + * Based on the following drivers:
> >> + *   - Analog Devices AXI HDMI DRM driver, which is
> >> + *     Copyright 2012 Analog Devices Inc.
> >> + *
> >> + *   - ARC PGU DRM driver.
> >> + *     Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> >> + *
> >> + *   - ARM HDLCD Driver
> >> + *     Copyright (C) 2013-2015 ARM Limited
> >> + *
> >> + *   - Atmel atmel-hlcdc driver, which is
> >> + *     Copyright (C) 2014 Traphandler
> >> + *     Copyright (C) 2014 Free Electrons
> >> + *
> >> + *   - OpenCores VGA/LCD 2.0 core frame buffer driver
> >> + *     Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson at saunalahti.fi
> >> + *
> >> + *   - R-Car Display Unit DRM driver
> >> + *     Copyright (C) 2013-2015 Renesas Electronics Corporation
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify it
> >> + * under the terms of the GNU General Public License version 2 as published by
> >> + * the Free Software Foundation.
> >> + *
> >> + * 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.
> >> + *
> >> + * You should have received a copy of the GNU General Public License along with
> >> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#ifndef _OCDRM_CRTC_H_
> >> +#define _OCDRM_CRTC_H_
> >> +
> >> +#include "ocdrm_drv.h"
> >> +
> >> +int ocdrm_crtc_create(struct ocdrm_priv *priv);
> >> +
> >> +#endif
> >> diff --git a/drivers/gpu/drm/ocdrm/ocdrm_drv.c b/drivers/gpu/drm/ocdrm/ocdrm_drv.c
> >> new file mode 100644
> >> index 0000000..4b335dc
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/ocdrm_drv.c
> >> @@ -0,0 +1,312 @@
> >> +/*
> >> + * Open cores VGA/LCD 2.0 core DRM driver
> >> + * Copyright (c) 2016 Istituto Italiano di Tecnologia
> >> + * Electronic Design Lab.
> >> + *
> >> + * Author: Andrea Merello <andrea.merello at gmail.com>
> >> + *
> >> + * Based on the following drivers:
> >> + *   - Analog Devices AXI HDMI DRM driver, which is
> >> + *     Copyright 2012 Analog Devices Inc.
> >> + *
> >> + *   - ARC PGU DRM driver.
> >> + *     Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> >> + *
> >> + *   - ARM HDLCD Driver
> >> + *     Copyright (C) 2013-2015 ARM Limited
> >> + *
> >> + *   - Atmel atmel-hlcdc driver, which is
> >> + *     Copyright (C) 2014 Traphandler
> >> + *     Copyright (C) 2014 Free Electrons
> >> + *
> >> + *   - OpenCores VGA/LCD 2.0 core frame buffer driver
> >> + *     Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson at saunalahti.fi
> >> + *
> >> + *   - R-Car Display Unit DRM driver
> >> + *     Copyright (C) 2013-2015 Renesas Electronics Corporation
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify it
> >> + * under the terms of the GNU General Public License version 2 as published by
> >> + * the Free Software Foundation.
> >> + *
> >> + * 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.
> >> + *
> >> + * You should have received a copy of the GNU General Public License along with
> >> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/platform_device.h>
> >> +#include <linux/of.h>
> >> +#include <linux/i2c.h>
> >> +#include <linux/of_address.h>
> >> +#include <linux/of_dma.h>
> >> +#include <linux/clk.h>
> >> +
> >> +#include <drm/drmP.h>
> >> +#include <drm/drm.h>
> >> +#include <drm/drm_atomic.h>
> >> +#include <drm/drm_atomic_helper.h>
> >> +#include <drm/drm_crtc_helper.h>
> >> +#include <drm/drm_gem_cma_helper.h>
> >> +
> >> +#include "ocdrm_drv.h"
> >> +#include "ocdrm_crtc.h"
> >> +#include "ocdrm_encoder.h"
> >> +
> >> +#define DRIVER_NAME  "ocdrm"
> >> +#define DRIVER_DESC  "OpenCores DRM"
> >> +#define DRIVER_DATE  "20160527"
> >> +#define DRIVER_MAJOR 1
> >> +#define DRIVER_MINOR 0
> >> +
> >> +static void ocdrm_output_poll_changed(struct drm_device *drm)
> >> +{
> >> +     struct ocdrm_priv *priv = drm->dev_private;
> >> +
> >> +     drm_fbdev_cma_hotplug_event(priv->fbdev);
> >> +}
> >> +
> >> +static int ocdrm_atomic_commit(struct drm_device *dev,
> >> +                                 struct drm_atomic_state *state, bool async)
> >> +{
> >> +     return drm_atomic_helper_commit(dev, state, false);
> >> +}
> >> +
> >> +static struct drm_mode_config_funcs ocdrm_mode_config_funcs = {
> >> +     .output_poll_changed = ocdrm_output_poll_changed,
> >> +     .fb_create = drm_fb_cma_create,
> >> +     .atomic_check = drm_atomic_helper_check,
> >> +     .atomic_commit = ocdrm_atomic_commit,
> >
> > Just use drm_atomic_helper_commit please, there's patches in-flight to
> > give you nonblocking atomic for free. Cheating with the above trick (like
> > arcpgu does) needs to stop.
> >
> >> +};
> >> +
> >> +u32 ocdrm_readreg(struct ocdrm_priv *priv, loff_t offset)
> >> +{
> >> +     if (priv->little_endian)
> >> +             return ioread32(priv->regs + offset);
> >> +     else
> >> +             return ioread32be(priv->regs + offset);
> >> +}
> >> +
> >> +void ocdrm_writereg(struct ocdrm_priv *priv, loff_t offset, u32 data)
> >> +{
> >> +     if (priv->little_endian)
> >> +             iowrite32(data, priv->regs + offset);
> >> +     else
> >> +             iowrite32be(data, priv->regs + offset);
> >> +}
> >> +
> >> +static void ocdrm_mode_config_init(struct ocdrm_priv *priv)
> >> +{
> >> +     struct drm_device *dev = priv->drm_dev;
> >> +
> >> +     dev->mode_config.min_width = 0;
> >> +     dev->mode_config.min_height = 0;
> >> +
> >> +     dev->mode_config.max_width = 1500;
> >> +     dev->mode_config.max_height = 1500;
> >> +
> >> +     dev->mode_config.funcs = &ocdrm_mode_config_funcs;
> >> +}
> >> +
> >> +static void ocdrm_detect_endian(struct ocdrm_priv *priv)
> >> +{
> >> +     priv->little_endian = false;
> >> +     ocdrm_writereg(priv, OCFB_VBARA, 0xfffffff0);
> >> +     if (ocdrm_readreg(priv, OCFB_VBARA) != 0xfffffff0)
> >> +             priv->little_endian = true;
> >> +
> >> +     ocdrm_writereg(priv, OCFB_VBARA, 0x0);
> >> +}
> >> +
> >> +static int ocdrm_load(struct drm_device *dev)
> >> +{
> >> +     struct ocdrm_priv *priv;
> >> +     int ret;
> >> +     struct resource *res;
> >> +     struct platform_device *pdev = to_platform_device(dev->dev);
> >> +
> >> +     priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> >> +     if (!priv)
> >> +             return -ENOMEM;
> >> +     dev->dev_private = priv;
> >> +     priv->drm_dev = dev;
> >> +
> >> +     priv->pixel_clock = devm_clk_get(&pdev->dev, NULL);
> >> +     if (IS_ERR(priv->pixel_clock))
> >> +             return -EPROBE_DEFER;
> >> +
> >> +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> +     priv->regs = devm_ioremap_resource(&pdev->dev, res);
> >> +     if (IS_ERR(priv->regs))
> >> +             return PTR_ERR(priv->regs);
> >> +
> >> +     if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)))
> >> +             return -ENOMEM;
> >> +
> >> +     ocdrm_detect_endian(priv);
> >> +
> >> +     drm_mode_config_init(dev);
> >> +     ocdrm_mode_config_init(priv);
> >> +
> >> +     ret = ocdrm_crtc_create(priv);
> >> +     if (ret)
> >> +             goto err_crtc;
> >> +
> >> +     ret = ocdrm_encoder_create(priv);
> >> +     if (ret)
> >> +             goto err_crtc;
> >> +
> >> +     drm_mode_config_reset(dev);
> >> +     drm_kms_helper_poll_init(dev);
> >> +
> >> +     priv->fbdev = drm_fbdev_cma_init(dev, 16, dev->mode_config.num_crtc,
> >> +                                     dev->mode_config.num_connector);
> >> +
> >> +     if (IS_ERR(priv->fbdev)) {
> >> +             DRM_ERROR("failed to initialize drm fbdev\n");
> >> +             ret = PTR_ERR(priv->fbdev);
> >> +             goto err_crtc;
> >> +     }
> >> +
> >> +     platform_set_drvdata(pdev, priv);
> >> +     return 0;
> >> +
> >> +err_crtc:
> >> +     drm_mode_config_cleanup(dev);
> >> +     return ret;
> >> +}
> >> +
> >> +static int ocdrm_unload(struct drm_device *dev)
> >> +{
> >> +     struct ocdrm_priv *priv = dev->dev_private;
> >> +
> >> +     if (priv->fbdev) {
> >> +             drm_fbdev_cma_fini(priv->fbdev);
> >> +             priv->fbdev = NULL;
> >> +     }
> >> +     drm_kms_helper_poll_fini(dev);
> >> +     drm_vblank_cleanup(dev);
> >> +     drm_mode_config_cleanup(dev);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static void ocdrm_lastclose(struct drm_device *dev)
> >> +{
> >> +     struct ocdrm_priv *priv = dev->dev_private;
> >> +
> >> +     drm_fbdev_cma_restore_mode(priv->fbdev);
> >> +}
> >> +
> >> +static const struct file_operations ocdrm_driver_fops = {
> >> +     .owner          = THIS_MODULE,
> >> +     .open           = drm_open,
> >> +     .mmap           = drm_gem_cma_mmap,
> >> +     .poll           = drm_poll,
> >> +     .read           = drm_read,
> >> +     .unlocked_ioctl = drm_ioctl,
> >> +#ifdef CONFIG_COMPAT
> >> +     .compat_ioctl   = drm_compat_ioctl,
> >> +#endif
> >> +     .llseek         = no_llseek,
> >> +     .release        = drm_release,
> >> +};
> >> +
> >> +static struct drm_driver ocdrm_drm_driver = {
> >> +     .driver_features        = DRIVER_MODESET | DRIVER_GEM |
> >> +             DRIVER_ATOMIC | DRIVER_PRIME,
> >> +     .lastclose              = ocdrm_lastclose,
> >> +     .fops                   = &ocdrm_driver_fops,
> >> +     .name                   = DRIVER_NAME,
> >> +     .desc                   = DRIVER_DESC,
> >> +     .date                   = DRIVER_DATE,
> >> +     .major                  = DRIVER_MAJOR,
> >> +     .minor                  = DRIVER_MINOR,
> >> +     .dumb_create            = drm_gem_cma_dumb_create,
> >> +     .dumb_map_offset        = drm_gem_cma_dumb_map_offset,
> >> +     .dumb_destroy           = drm_gem_dumb_destroy,
> >> +     .get_vblank_counter     = drm_vblank_no_hw_counter,
> >> +     .prime_handle_to_fd     = drm_gem_prime_handle_to_fd,
> >> +     .prime_fd_to_handle     = drm_gem_prime_fd_to_handle,
> >> +     .gem_free_object        = drm_gem_cma_free_object,
> >> +     .gem_vm_ops             = &drm_gem_cma_vm_ops,
> >> +     .gem_prime_export       = drm_gem_prime_export,
> >> +     .gem_prime_import       = drm_gem_prime_import,
> >> +     .gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
> >> +     .gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
> >> +     .gem_prime_vmap         = drm_gem_cma_prime_vmap,
> >> +     .gem_prime_vunmap       = drm_gem_cma_prime_vunmap,
> >> +     .gem_prime_mmap         = drm_gem_cma_prime_mmap,
> >> +
> >> +};
> >> +
> >> +static const struct of_device_id ocdrm_of_match[] = {
> >> +     { .compatible = "opencores,ocfb-drm", },
> >> +     {},
> >> +};
> >> +MODULE_DEVICE_TABLE(of, ocdrm_of_match);
> >> +
> >> +static int ocdrm_probe(struct platform_device *pdev)
> >> +{
> >> +     int ret;
> >> +     struct drm_device *drm;
> >> +
> >> +     drm = drm_dev_alloc(&ocdrm_drm_driver, &pdev->dev);
> >> +     if (!drm)
> >> +             return -ENOMEM;
> >> +
> >> +     ret = ocdrm_load(drm);
> >> +     if (ret)
> >> +             goto err_unref;
> >> +
> >> +     ret = drm_dev_register(drm, 0);
> >> +     if (ret)
> >> +             goto err_unload;
> >> +
> >> +     ret = drm_connector_register_all(drm);
> >> +     if (ret)
> >> +             goto err_unregister;
> >> +     return 0;
> >> +
> >> +err_unregister:
> >> +     drm_dev_unregister(drm);
> >> +err_unload:
> >> +     ocdrm_unload(drm);
> >> +err_unref:
> >> +     drm_dev_unref(drm);
> >> +
> >> +     return ret;
> >> +}
> >> +
> >> +static int ocdrm_remove(struct platform_device *pdev)
> >> +{
> >> +     struct ocdrm_priv *priv = platform_get_drvdata(pdev);
> >> +     struct drm_device *drm = priv->drm_dev;
> >> +
> >> +     drm_connector_unregister_all(priv->drm_dev);
> >> +     drm_dev_unregister(drm);
> >> +     ocdrm_unload(drm);
> >> +     drm_dev_unref(drm);
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static struct platform_driver ocdrm_platform_driver = {
> >> +     .driver = {
> >> +             .name = "oc-drm",
> >> +             .owner = THIS_MODULE,
> >> +             .of_match_table = ocdrm_of_match,
> >> +     },
> >> +     .probe = ocdrm_probe,
> >> +     .remove = ocdrm_remove,
> >> +};
> >> +module_platform_driver(ocdrm_platform_driver);
> >> +
> >> +MODULE_LICENSE("GPL v2");
> >> +MODULE_AUTHOR("Andrea Merello <andrea.merello at gmail.com>");
> >> +MODULE_DESCRIPTION("OpenCores DRM driver");
> >> diff --git a/drivers/gpu/drm/ocdrm/ocdrm_drv.h b/drivers/gpu/drm/ocdrm/ocdrm_drv.h
> >> new file mode 100644
> >> index 0000000..14e5539
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/ocdrm_drv.h
> >> @@ -0,0 +1,89 @@
> >> +/*
> >> + * Open cores VGA/LCD 2.0 core DRM driver
> >> + * Copyright (c) 2016 Istituto Italiano di Tecnologia
> >> + * Electronic Design Lab.
> >> + *
> >> + * Author: Andrea Merello <andrea.merello at gmail.com>
> >> + *
> >> + * Based on the following drivers:
> >> + *   - Analog Devices AXI HDMI DRM driver, which is
> >> + *     Copyright 2012 Analog Devices Inc.
> >> + *
> >> + *   - ARC PGU DRM driver.
> >> + *     Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> >> + *
> >> + *   - ARM HDLCD Driver
> >> + *     Copyright (C) 2013-2015 ARM Limited
> >> + *
> >> + *   - Atmel atmel-hlcdc driver, which is
> >> + *     Copyright (C) 2014 Traphandler
> >> + *     Copyright (C) 2014 Free Electrons
> >> + *
> >> + *   - OpenCores VGA/LCD 2.0 core frame buffer driver
> >> + *     Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson at saunalahti.fi
> >> + *
> >> + *   - R-Car Display Unit DRM driver
> >> + *     Copyright (C) 2013-2015 Renesas Electronics Corporation
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify it
> >> + * under the terms of the GNU General Public License version 2 as published by
> >> + * the Free Software Foundation.
> >> + *
> >> + * 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.
> >> + *
> >> + * You should have received a copy of the GNU General Public License along with
> >> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#ifndef _OCDRM_DRV_H_
> >> +#define _OCDRM_DRV_H_
> >> +
> >> +#include <drm/drm.h>
> >> +#include <drm/drm_fb_cma_helper.h>
> >> +#include <linux/of.h>
> >> +#include <linux/clk.h>
> >> +
> >> +/* OCFB register defines */
> >> +#define OCFB_CTRL    0x000
> >> +#define OCFB_STAT    0x004
> >> +#define OCFB_HTIM    0x008
> >> +#define OCFB_VTIM    0x00c
> >> +#define OCFB_HVLEN   0x010
> >> +#define OCFB_VBARA   0x014
> >> +#define OCFB_PALETTE 0x800
> >> +
> >> +#define OCFB_CTRL_VEN        0x00000001 /* Video Enable */
> >> +#define OCFB_CTRL_HIE        0x00000002 /* HSync Interrupt Enable */
> >> +#define OCFB_CTRL_PC 0x00000800 /* 8-bit Pseudo Color Enable*/
> >> +#define OCFB_CTRL_CD8        0x00000000 /* Color Depth 8 */
> >> +#define OCFB_CTRL_CD16       0x00000200 /* Color Depth 16 */
> >> +#define OCFB_CTRL_CD24       0x00000400 /* Color Depth 24 */
> >> +#define OCFB_CTRL_CD32       0x00000600 /* Color Depth 32 */
> >> +#define OCFB_CTRL_VBL1       0x00000000 /* Burst Length 1 */
> >> +#define OCFB_CTRL_VBL2       0x00000080 /* Burst Length 2 */
> >> +#define OCFB_CTRL_VBL4       0x00000100 /* Burst Length 4 */
> >> +#define OCFB_CTRL_VBL8       0x00000180 /* Burst Length 8 */
> >> +#define OCFB_CTRL_HSL        0x00001000 /* HSync active low */
> >> +#define OCFB_CTRL_VSL        0x00002000 /* VSync active low */
> >> +
> >> +#define PALETTE_SIZE 256
> >> +
> >> +struct ocdrm_priv {
> >> +     struct drm_device *drm_dev;
> >> +     struct drm_fbdev_cma *fbdev;
> >> +     struct drm_crtc crtc;
> >> +     struct drm_plane plane;
> >> +     struct drm_encoder encoder;
> >> +     struct clk *pixel_clock;
> >> +     bool clk_enabled;
> >> +     void __iomem *regs;
> >> +     bool little_endian;
> >> +};
> >> +
> >> +extern void ocdrm_writereg(struct ocdrm_priv *priv, loff_t offset, u32 data);
> >> +extern u32 ocdrm_readreg(struct ocdrm_priv *priv, loff_t offset);
> >> +
> >> +#endif
> >> diff --git a/drivers/gpu/drm/ocdrm/ocdrm_encoder.c b/drivers/gpu/drm/ocdrm/ocdrm_encoder.c
> >> new file mode 100644
> >> index 0000000..f157bb5
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/ocdrm_encoder.c
> >> @@ -0,0 +1,95 @@
> >> +/*
> >> + * Open cores VGA/LCD 2.0 core DRM driver
> >> + * Copyright (c) 2016 Istituto Italiano di Tecnologia
> >> + * Electronic Design Lab.
> >> + *
> >> + * Author: Andrea Merello <andrea.merello at gmail.com>
> >> + *
> >> + * Based on the following drivers:
> >> + *   - Analog Devices AXI HDMI DRM driver, which is
> >> + *     Copyright 2012 Analog Devices Inc.
> >> + *
> >> + *   - ARC PGU DRM driver.
> >> + *     Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> >> + *
> >> + *   - ARM HDLCD Driver
> >> + *     Copyright (C) 2013-2015 ARM Limited
> >> + *
> >> + *   - Atmel atmel-hlcdc driver, which is
> >> + *     Copyright (C) 2014 Traphandler
> >> + *     Copyright (C) 2014 Free Electrons
> >> + *
> >> + *   - OpenCores VGA/LCD 2.0 core frame buffer driver
> >> + *     Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson at saunalahti.fi
> >> + *
> >> + *   - R-Car Display Unit DRM driver
> >> + *     Copyright (C) 2013-2015 Renesas Electronics Corporation
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify it
> >> + * under the terms of the GNU General Public License version 2 as published by
> >> + * the Free Software Foundation.
> >> + *
> >> + * 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.
> >> + *
> >> + * You should have received a copy of the GNU General Public License along with
> >> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#include <linux/of.h>
> >> +#include <linux/of_graph.h>
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/platform_device.h>
> >> +#include <drm/drmP.h>
> >> +#include <drm/drm_crtc_helper.h>
> >> +#include "ocdrm_encoder.h"
> >> +
> >> +static void ocdrm_encoder_nop(struct drm_encoder *encoder)
> >> +{
> >> +}
> >> +
> >> +static const struct drm_encoder_funcs ocdrm_encoder_funcs = {
> >> +     .destroy = drm_encoder_cleanup
> >> +};
> >> +
> >> +static struct drm_encoder_helper_funcs ocdrm_encoder_helper_funcs = {
> >> +     .commit = ocdrm_encoder_nop,
> >> +     .enable  = ocdrm_encoder_nop,
> >> +     .disable = ocdrm_encoder_nop
> >> +};
> >
> > Please nuke all these no-op functions. Even more so, just nuke the entire
> > helper struct, it can be NULL.
> >> +
> >> +int ocdrm_encoder_create(struct ocdrm_priv *priv)
> >> +{
> >> +     struct drm_encoder *encoder;
> >> +     struct drm_bridge *bridge;
> >> +     struct device_node *ep, *bridge_node;
> >> +     int ret;
> >> +
> >> +     encoder = &priv->encoder;
> >> +     encoder->possible_crtcs = 1 << drm_crtc_index(&priv->crtc);
> >> +
> >> +     drm_encoder_helper_add(encoder, &ocdrm_encoder_helper_funcs);
> >> +     ret = drm_encoder_init(priv->drm_dev, encoder, &ocdrm_encoder_funcs,
> >> +                     DRM_MODE_ENCODER_NONE, NULL);
> >> +     if (ret)
> >> +             return ret;
> >> +     ep = of_graph_get_next_endpoint(priv->drm_dev->dev->of_node, NULL);
> >> +     if (!ep)
> >> +             return -ENODEV;
> >> +
> >> +     bridge_node = of_graph_get_remote_port_parent(ep);
> >> +     if (!bridge_node)
> >> +             return -ENODEV;
> >> +
> >> +     bridge = of_drm_find_bridge(bridge_node);
> >> +     if (!bridge)
> >> +             return -EPROBE_DEFER;
> >> +
> >> +     bridge->encoder = encoder;
> >> +     encoder->bridge = bridge;
> >> +     drm_bridge_attach(priv->drm_dev, bridge);
> >> +     return 0;
> >> +}
> >> diff --git a/drivers/gpu/drm/ocdrm/ocdrm_encoder.h b/drivers/gpu/drm/ocdrm/ocdrm_encoder.h
> >> new file mode 100644
> >> index 0000000..a5ee5f6
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/ocdrm/ocdrm_encoder.h
> >> @@ -0,0 +1,48 @@
> >> +/*
> >> + * Open cores VGA/LCD 2.0 core DRM driver
> >> + * Copyright (c) 2016 Istituto Italiano di Tecnologia
> >> + * Electronic Design Lab.
> >> + *
> >> + * Author: Andrea Merello <andrea.merello at gmail.com>
> >> + *
> >> + * Based on the following drivers:
> >> + *   - Analog Devices AXI HDMI DRM driver, which is
> >> + *     Copyright 2012 Analog Devices Inc.
> >> + *
> >> + *   - ARC PGU DRM driver.
> >> + *     Copyright (C) 2016 Synopsys, Inc. (www.synopsys.com)
> >> + *
> >> + *   - ARM HDLCD Driver
> >> + *     Copyright (C) 2013-2015 ARM Limited
> >> + *
> >> + *   - Atmel atmel-hlcdc driver, which is
> >> + *     Copyright (C) 2014 Traphandler
> >> + *     Copyright (C) 2014 Free Electrons
> >> + *
> >> + *   - OpenCores VGA/LCD 2.0 core frame buffer driver
> >> + *     Copyright (C) 2013 Stefan Kristiansson, stefan.kristiansson at saunalahti.fi
> >> + *
> >> + *   - R-Car Display Unit DRM driver
> >> + *     Copyright (C) 2013-2015 Renesas Electronics Corporation
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify it
> >> + * under the terms of the GNU General Public License version 2 as published by
> >> + * the Free Software Foundation.
> >> + *
> >> + * 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.
> >> + *
> >> + * You should have received a copy of the GNU General Public License along with
> >> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> >> + */
> >> +
> >> +#ifndef _OCDRM_ENCODER_H_
> >> +#define _OCDRM_ENCODER_H_
> >> +
> >> +#include "ocdrm_drv.h"
> >> +
> >> +int ocdrm_encoder_create(struct ocdrm_priv *priv);
> >> +
> >> +#endif
> >> --
> >> 1.9.1
> >>
> >> _______________________________________________
> >> dri-devel mailing list
> >> dri-devel at lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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