diff mbox

[v5,04/10] drm/stm: Add STM32 LTDC driver

Message ID 1490694293-18358-5-git-send-email-yannick.fertre@st.com (mailing list archive)
State New, archived
Headers show

Commit Message

Yannick FERTRE March 28, 2017, 9:44 a.m. UTC
This controller provides output signals to interface directly a variety
of LCD and TFT panels. These output signals are: RGB signals
(up to 24bpp), vertical & horizontal synchronisations, data enable and
the pixel clock.

Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
---
 drivers/gpu/drm/Kconfig      |    3 +-
 drivers/gpu/drm/Makefile     |    1 +
 drivers/gpu/drm/stm/Kconfig  |   16 +
 drivers/gpu/drm/stm/Makefile |    7 +
 drivers/gpu/drm/stm/drv.c    |  221 ++++++++
 drivers/gpu/drm/stm/ltdc.c   | 1210 ++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/stm/ltdc.h   |   40 ++
 7 files changed, 1497 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/stm/Kconfig
 create mode 100644 drivers/gpu/drm/stm/Makefile
 create mode 100644 drivers/gpu/drm/stm/drv.c
 create mode 100644 drivers/gpu/drm/stm/ltdc.c
 create mode 100644 drivers/gpu/drm/stm/ltdc.h

Comments

Eric Anholt April 11, 2017, 8:45 p.m. UTC | #1
Yannick Fertre <yannick.fertre@st.com> writes:

> This controller provides output signals to interface directly a variety
> of LCD and TFT panels. These output signals are: RGB signals
> (up to 24bpp), vertical & horizontal synchronisations, data enable and
> the pixel clock.
>
> Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
> ---
>  drivers/gpu/drm/Kconfig      |    3 +-
>  drivers/gpu/drm/Makefile     |    1 +
>  drivers/gpu/drm/stm/Kconfig  |   16 +
>  drivers/gpu/drm/stm/Makefile |    7 +
>  drivers/gpu/drm/stm/drv.c    |  221 ++++++++
>  drivers/gpu/drm/stm/ltdc.c   | 1210 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/stm/ltdc.h   |   40 ++
>  7 files changed, 1497 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/stm/Kconfig
>  create mode 100644 drivers/gpu/drm/stm/Makefile
>  create mode 100644 drivers/gpu/drm/stm/drv.c
>  create mode 100644 drivers/gpu/drm/stm/ltdc.c
>  create mode 100644 drivers/gpu/drm/stm/ltdc.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 78d7fc0..dd5762a 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -203,7 +203,6 @@ config DRM_VGEM
>  	  as used by Mesa's software renderer for enhanced performance.
>  	  If M is selected the module will be called vgem.
>  
> -

Stray whitespace change.

With this removed, the driver is:

Reviewed-by: Eric Anholt <eric@anholt.net>

Apologies for the delay in the second review offered.  The remainder of
my comments are little cleanups, all of which I think are optional and
fine to do after the code lands.

You should probably update MAINTAINERS for your new driver.  If you'd
like to maintain this driver in the drm-misc small drivers collection
(https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-misc.html),
send a follow-up patch to the list to add the MAINTAINERS entry, and I
can get that and patches 1-4 merged.  Once you have a few more patches
in, we can add you to the drm-misc committers crew so you can merge
directly after getting review.

I'll also take this moment to plug something: Please feel welcome to
review other people's driver patches on the list.  You've built
something nice here, and probably learned a lot of lessons along the way
that you could share with others.  (I just found out about
of_reset_control in reviewing your code, and I wish I had known about it
back when I was landing vc4!)

> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> new file mode 100644
> index 0000000..922f021
> --- /dev/null
> +++ b/drivers/gpu/drm/stm/ltdc.c

> +static void ltdc_crtc_disable(struct drm_crtc *crtc)
> +{
> +	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
> +	struct drm_pending_vblank_event *event = crtc->state->event;
> +
> +	DRM_DEBUG_DRIVER("\n");
> +
> +	if (!crtc->enabled) {
> +		DRM_DEBUG_DRIVER("already disabled\n");
> +		return;
> +	}

I think this crtc->enabled is a given for the disable() being called.

> +
> +	drm_crtc_vblank_off(crtc);
> +
> +	/* disable LTDC */
> +	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
> +
> +	/* disable IRQ */
> +	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
> +
> +	/* immediately commit disable of layers before switching off LTDC */
> +	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
> +
> +	if (event) {
> +		crtc->state->event = NULL;
> +
> +		spin_lock_irq(&crtc->dev->event_lock);
> +		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
> +			drm_crtc_arm_vblank_event(crtc, event);
> +		else
> +			drm_crtc_send_vblank_event(crtc, event);
> +		spin_unlock_irq(&crtc->dev->event_lock);
> +	}

I believe that we're guaranteed that crtc->state->event is NULL in the
disable call, since your atomic_flush() already armed or sent the event
and NULLed out the pointer.

> +struct drm_connector *ltdc_rgb_connector_create(struct drm_device *ddev)
> +{
> +	struct drm_connector *connector;
> +	int err;
> +
> +	connector = devm_kzalloc(ddev->dev, sizeof(*connector), GFP_KERNEL);
> +	if (!connector) {
> +		DRM_ERROR("Failed to allocate connector\n");
> +		return NULL;
> +	}
> +
> +	connector->polled = DRM_CONNECTOR_POLL_HPD;
> +
> +	err = drm_connector_init(ddev, connector, &ltdc_rgb_connector_funcs,
> +				 DRM_MODE_CONNECTOR_LVDS);

I think DRM_MODE_CONNECTOR_DPI (and _ENCODER_DPI) are slightly more
accurate descriptions, if I'm interpreting your pinmux setup right.
It's cosmetic, though.

> +static struct drm_panel *ltdc_get_panel(struct drm_device *ddev)
> +{
> +	struct device *dev = ddev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct device_node *entity, *port = NULL;
> +	struct drm_panel *panel = NULL;
> +
> +	DRM_DEBUG_DRIVER("\n");
> +
> +	/*
> +	 * Parse ltdc node to get remote port and find RGB panel / HDMI slave
> +	 * If a dsi or a bridge (hdmi, lvds...) is connected to ltdc,
> +	 * a remote port & RGB panel will not be found.
> +	 */
> +	for_each_endpoint_of_node(np, entity) {
> +		if (!of_device_is_available(entity))
> +			continue;
> +
> +		port = of_graph_get_remote_port_parent(entity);
> +		if (port) {
> +			panel = of_drm_find_panel(port);
> +			of_node_put(port);
> +			if (panel) {
> +				DRM_DEBUG_DRIVER("remote panel %s\n",
> +						 port->full_name);
> +			} else {
> +				DRM_DEBUG_DRIVER("panel missing\n");
> +				of_node_put(entity);
> +			}
> +		}
> +	}

Future work: You may find the new drm_of_find_panel_or_bridge() useful
to drop this loop.

> +
> +	return panel;
> +}
> +
> +int ltdc_load(struct drm_device *ddev)
> +{
> +	struct platform_device *pdev = to_platform_device(ddev->dev);
> +	struct ltdc_device *ldev = ddev->dev_private;
> +	struct device *dev = ddev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct drm_encoder *encoder;
> +	struct drm_connector *connector = NULL;
> +	struct drm_crtc *crtc;
> +	struct reset_control *rstc;
> +	struct resource res;
> +	int irq, ret, i;
> +
> +	DRM_DEBUG_DRIVER("\n");
> +
> +	ldev->panel = ltdc_get_panel(ddev);
> +	if (!ldev->panel)
> +		return -EPROBE_DEFER;
> +
> +	rstc = of_reset_control_get(np, NULL);
> +
> +	mutex_init(&ldev->err_lock);
> +
> +	ldev->pixel_clk = devm_clk_get(dev, "lcd");
> +	if (IS_ERR(ldev->pixel_clk)) {
> +		DRM_ERROR("Unable to get lcd clock\n");
> +		return -ENODEV;
> +	}
> +
> +	if (clk_prepare_enable(ldev->pixel_clk)) {
> +		DRM_ERROR("Unable to prepare pixel clock\n");
> +		return -ENODEV;
> +	}

Future work: You may want to move the pixel clock enable into the CRTC's
.enable() and disable in .disable().  It sounded in previous versions
like the HW uses that clock for all register accesses, so you'd need to
protect a couple of other places, but that should save power when the
device is off, right?

> +
> +	if (of_address_to_resource(np, 0, &res)) {
> +		DRM_ERROR("Unable to get resource\n");
> +		return -ENODEV;
> +	}
> +
> +	ldev->regs = devm_ioremap_resource(dev, &res);
> +	if (IS_ERR(ldev->regs)) {
> +		DRM_ERROR("Unable to get ltdc registers\n");
> +		return PTR_ERR(ldev->regs);
> +	}
> +
> +	for (i = 0; i < MAX_IRQ; i++) {
> +		irq = platform_get_irq(pdev, i);
> +		if (irq < 0)
> +			continue;
> +
> +		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
> +						ltdc_irq_thread, IRQF_ONESHOT,
> +						dev_name(dev), ddev);
> +		if (ret) {
> +			DRM_ERROR("Failed to register LTDC interrupt\n");
> +			return ret;
> +		}
> +	}
> +
> +	if (!IS_ERR(rstc))
> +		reset_control_deassert(rstc);
> +
> +	/* Disable interrupts */
> +	reg_clear(ldev->regs, LTDC_IER,
> +		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
> +
> +	ret = ltdc_get_caps(ddev);
> +	if (ret) {
> +		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
> +			  ldev->caps.hw_version);
> +		return ret;
> +	}
> +
> +	DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
> +
> +	if (ltdc_create_encoders(ddev)) {
> +		DRM_ERROR("Failed to create encoders\n");
> +		return -EINVAL;
> +	}
> +
> +	if (ldev->panel) {
> +		encoder = ltdc_rgb_encoder_find(ddev);
> +		if (!encoder) {
> +			DRM_ERROR("Failed to find RGB encoder\n");
> +			ret = -EINVAL;
> +			goto err;
> +		}

Given that ltdc_create_encoders() only does work if ldev->panel, its
body could probably be moved in here and then ltdc_rgb_encoder_find
could be dropped.

> +
> +		connector = ltdc_rgb_connector_create(ddev);
> +		if (!connector) {
> +			DRM_ERROR("Failed to create RGB connector\n");
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +
> +		ret = drm_mode_connector_attach_encoder(connector, encoder);
> +		if (ret) {
> +			DRM_ERROR("Failed to attach connector to encoder\n");
> +			goto err;
> +		}
> +
> +		drm_panel_attach(ldev->panel, connector);
> +	}
Daniel Vetter April 11, 2017, 8:51 p.m. UTC | #2
On Tue, Apr 11, 2017 at 01:45:01PM -0700, Eric Anholt wrote:
> Yannick Fertre <yannick.fertre@st.com> writes:
> > +static void ltdc_crtc_disable(struct drm_crtc *crtc)
> > +{
> > +	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
> > +	struct drm_pending_vblank_event *event = crtc->state->event;
> > +
> > +	DRM_DEBUG_DRIVER("\n");
> > +
> > +	if (!crtc->enabled) {
> > +		DRM_DEBUG_DRIVER("already disabled\n");
> > +		return;
> > +	}
> 
> I think this crtc->enabled is a given for the disable() being called.

Yup, one design principle of atomic (compared to the legacy modeset
helpers) is to correctly keep track of hw state and not call a hook when
not needed. If you don't trust them, conver them to WARN_ON, but otherwise
best to remove.

But like Eric said, totally fine in a follow-up patch.
-Daniel
Benjamin Gaignard April 12, 2017, 6:58 p.m. UTC | #3
2017-04-11 22:45 GMT+02:00 Eric Anholt <eric@anholt.net>:
> Yannick Fertre <yannick.fertre@st.com> writes:
>
>> This controller provides output signals to interface directly a variety
>> of LCD and TFT panels. These output signals are: RGB signals
>> (up to 24bpp), vertical & horizontal synchronisations, data enable and
>> the pixel clock.
>>
>> Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
>> ---
>>  drivers/gpu/drm/Kconfig      |    3 +-
>>  drivers/gpu/drm/Makefile     |    1 +
>>  drivers/gpu/drm/stm/Kconfig  |   16 +
>>  drivers/gpu/drm/stm/Makefile |    7 +
>>  drivers/gpu/drm/stm/drv.c    |  221 ++++++++
>>  drivers/gpu/drm/stm/ltdc.c   | 1210 ++++++++++++++++++++++++++++++++++++++++++
>>  drivers/gpu/drm/stm/ltdc.h   |   40 ++
>>  7 files changed, 1497 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/gpu/drm/stm/Kconfig
>>  create mode 100644 drivers/gpu/drm/stm/Makefile
>>  create mode 100644 drivers/gpu/drm/stm/drv.c
>>  create mode 100644 drivers/gpu/drm/stm/ltdc.c
>>  create mode 100644 drivers/gpu/drm/stm/ltdc.h
>>
>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>> index 78d7fc0..dd5762a 100644
>> --- a/drivers/gpu/drm/Kconfig
>> +++ b/drivers/gpu/drm/Kconfig
>> @@ -203,7 +203,6 @@ config DRM_VGEM
>>         as used by Mesa's software renderer for enhanced performance.
>>         If M is selected the module will be called vgem.
>>
>> -
>
> Stray whitespace change.
>
> With this removed, the driver is:
>
> Reviewed-by: Eric Anholt <eric@anholt.net>
>
> Apologies for the delay in the second review offered.  The remainder of
> my comments are little cleanups, all of which I think are optional and
> fine to do after the code lands.
>
> You should probably update MAINTAINERS for your new driver.  If you'd
> like to maintain this driver in the drm-misc small drivers collection
> (https://01.org/linuxgraphics/gfx-docs/maintainer-tools/drm-misc.html),
> send a follow-up patch to the list to add the MAINTAINERS entry, and I
> can get that and patches 1-4 merged.  Once you have a few more patches
> in, we can add you to the drm-misc committers crew so you can merge
> directly after getting review.

Since we are moving sti driver to drm-misc it makes sense to move all
STMicroelectronic SoC display drivers to it.

>
> I'll also take this moment to plug something: Please feel welcome to
> review other people's driver patches on the list.  You've built
> something nice here, and probably learned a lot of lessons along the way
> that you could share with others.  (I just found out about
> of_reset_control in reviewing your code, and I wish I had known about it
> back when I was landing vc4!)
>
>> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
>> new file mode 100644
>> index 0000000..922f021
>> --- /dev/null
>> +++ b/drivers/gpu/drm/stm/ltdc.c
>
>> +static void ltdc_crtc_disable(struct drm_crtc *crtc)
>> +{
>> +     struct ltdc_device *ldev = crtc_to_ltdc(crtc);
>> +     struct drm_pending_vblank_event *event = crtc->state->event;
>> +
>> +     DRM_DEBUG_DRIVER("\n");
>> +
>> +     if (!crtc->enabled) {
>> +             DRM_DEBUG_DRIVER("already disabled\n");
>> +             return;
>> +     }
>
> I think this crtc->enabled is a given for the disable() being called.
>
>> +
>> +     drm_crtc_vblank_off(crtc);
>> +
>> +     /* disable LTDC */
>> +     reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
>> +
>> +     /* disable IRQ */
>> +     reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
>> +
>> +     /* immediately commit disable of layers before switching off LTDC */
>> +     reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
>> +
>> +     if (event) {
>> +             crtc->state->event = NULL;
>> +
>> +             spin_lock_irq(&crtc->dev->event_lock);
>> +             if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
>> +                     drm_crtc_arm_vblank_event(crtc, event);
>> +             else
>> +                     drm_crtc_send_vblank_event(crtc, event);
>> +             spin_unlock_irq(&crtc->dev->event_lock);
>> +     }
>
> I believe that we're guaranteed that crtc->state->event is NULL in the
> disable call, since your atomic_flush() already armed or sent the event
> and NULLed out the pointer.
>
>> +struct drm_connector *ltdc_rgb_connector_create(struct drm_device *ddev)
>> +{
>> +     struct drm_connector *connector;
>> +     int err;
>> +
>> +     connector = devm_kzalloc(ddev->dev, sizeof(*connector), GFP_KERNEL);
>> +     if (!connector) {
>> +             DRM_ERROR("Failed to allocate connector\n");
>> +             return NULL;
>> +     }
>> +
>> +     connector->polled = DRM_CONNECTOR_POLL_HPD;
>> +
>> +     err = drm_connector_init(ddev, connector, &ltdc_rgb_connector_funcs,
>> +                              DRM_MODE_CONNECTOR_LVDS);
>
> I think DRM_MODE_CONNECTOR_DPI (and _ENCODER_DPI) are slightly more
> accurate descriptions, if I'm interpreting your pinmux setup right.
> It's cosmetic, though.
>
>> +static struct drm_panel *ltdc_get_panel(struct drm_device *ddev)
>> +{
>> +     struct device *dev = ddev->dev;
>> +     struct device_node *np = dev->of_node;
>> +     struct device_node *entity, *port = NULL;
>> +     struct drm_panel *panel = NULL;
>> +
>> +     DRM_DEBUG_DRIVER("\n");
>> +
>> +     /*
>> +      * Parse ltdc node to get remote port and find RGB panel / HDMI slave
>> +      * If a dsi or a bridge (hdmi, lvds...) is connected to ltdc,
>> +      * a remote port & RGB panel will not be found.
>> +      */
>> +     for_each_endpoint_of_node(np, entity) {
>> +             if (!of_device_is_available(entity))
>> +                     continue;
>> +
>> +             port = of_graph_get_remote_port_parent(entity);
>> +             if (port) {
>> +                     panel = of_drm_find_panel(port);
>> +                     of_node_put(port);
>> +                     if (panel) {
>> +                             DRM_DEBUG_DRIVER("remote panel %s\n",
>> +                                              port->full_name);
>> +                     } else {
>> +                             DRM_DEBUG_DRIVER("panel missing\n");
>> +                             of_node_put(entity);
>> +                     }
>> +             }
>> +     }
>
> Future work: You may find the new drm_of_find_panel_or_bridge() useful
> to drop this loop.
>
>> +
>> +     return panel;
>> +}
>> +
>> +int ltdc_load(struct drm_device *ddev)
>> +{
>> +     struct platform_device *pdev = to_platform_device(ddev->dev);
>> +     struct ltdc_device *ldev = ddev->dev_private;
>> +     struct device *dev = ddev->dev;
>> +     struct device_node *np = dev->of_node;
>> +     struct drm_encoder *encoder;
>> +     struct drm_connector *connector = NULL;
>> +     struct drm_crtc *crtc;
>> +     struct reset_control *rstc;
>> +     struct resource res;
>> +     int irq, ret, i;
>> +
>> +     DRM_DEBUG_DRIVER("\n");
>> +
>> +     ldev->panel = ltdc_get_panel(ddev);
>> +     if (!ldev->panel)
>> +             return -EPROBE_DEFER;
>> +
>> +     rstc = of_reset_control_get(np, NULL);
>> +
>> +     mutex_init(&ldev->err_lock);
>> +
>> +     ldev->pixel_clk = devm_clk_get(dev, "lcd");
>> +     if (IS_ERR(ldev->pixel_clk)) {
>> +             DRM_ERROR("Unable to get lcd clock\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     if (clk_prepare_enable(ldev->pixel_clk)) {
>> +             DRM_ERROR("Unable to prepare pixel clock\n");
>> +             return -ENODEV;
>> +     }
>
> Future work: You may want to move the pixel clock enable into the CRTC's
> .enable() and disable in .disable().  It sounded in previous versions
> like the HW uses that clock for all register accesses, so you'd need to
> protect a couple of other places, but that should save power when the
> device is off, right?
>
>> +
>> +     if (of_address_to_resource(np, 0, &res)) {
>> +             DRM_ERROR("Unable to get resource\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     ldev->regs = devm_ioremap_resource(dev, &res);
>> +     if (IS_ERR(ldev->regs)) {
>> +             DRM_ERROR("Unable to get ltdc registers\n");
>> +             return PTR_ERR(ldev->regs);
>> +     }
>> +
>> +     for (i = 0; i < MAX_IRQ; i++) {
>> +             irq = platform_get_irq(pdev, i);
>> +             if (irq < 0)
>> +                     continue;
>> +
>> +             ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
>> +                                             ltdc_irq_thread, IRQF_ONESHOT,
>> +                                             dev_name(dev), ddev);
>> +             if (ret) {
>> +                     DRM_ERROR("Failed to register LTDC interrupt\n");
>> +                     return ret;
>> +             }
>> +     }
>> +
>> +     if (!IS_ERR(rstc))
>> +             reset_control_deassert(rstc);
>> +
>> +     /* Disable interrupts */
>> +     reg_clear(ldev->regs, LTDC_IER,
>> +               IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
>> +
>> +     ret = ltdc_get_caps(ddev);
>> +     if (ret) {
>> +             DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
>> +                       ldev->caps.hw_version);
>> +             return ret;
>> +     }
>> +
>> +     DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
>> +
>> +     if (ltdc_create_encoders(ddev)) {
>> +             DRM_ERROR("Failed to create encoders\n");
>> +             return -EINVAL;
>> +     }
>> +
>> +     if (ldev->panel) {
>> +             encoder = ltdc_rgb_encoder_find(ddev);
>> +             if (!encoder) {
>> +                     DRM_ERROR("Failed to find RGB encoder\n");
>> +                     ret = -EINVAL;
>> +                     goto err;
>> +             }
>
> Given that ltdc_create_encoders() only does work if ldev->panel, its
> body could probably be moved in here and then ltdc_rgb_encoder_find
> could be dropped.
>
>> +
>> +             connector = ltdc_rgb_connector_create(ddev);
>> +             if (!connector) {
>> +                     DRM_ERROR("Failed to create RGB connector\n");
>> +                     ret = -EINVAL;
>> +                     goto err;
>> +             }
>> +
>> +             ret = drm_mode_connector_attach_encoder(connector, encoder);
>> +             if (ret) {
>> +                     DRM_ERROR("Failed to attach connector to encoder\n");
>> +                     goto err;
>> +             }
>> +
>> +             drm_panel_attach(ldev->panel, connector);
>> +     }
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 78d7fc0..dd5762a 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -203,7 +203,6 @@  config DRM_VGEM
 	  as used by Mesa's software renderer for enhanced performance.
 	  If M is selected the module will be called vgem.
 
-
 source "drivers/gpu/drm/exynos/Kconfig"
 
 source "drivers/gpu/drm/rockchip/Kconfig"
@@ -246,6 +245,8 @@  source "drivers/gpu/drm/fsl-dcu/Kconfig"
 
 source "drivers/gpu/drm/tegra/Kconfig"
 
+source "drivers/gpu/drm/stm/Kconfig"
+
 source "drivers/gpu/drm/panel/Kconfig"
 
 source "drivers/gpu/drm/bridge/Kconfig"
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 59f0f9b..aa62ded 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -82,6 +82,7 @@  obj-$(CONFIG_DRM_BOCHS) += bochs/
 obj-$(CONFIG_DRM_VIRTIO_GPU) += virtio/
 obj-$(CONFIG_DRM_MSM) += msm/
 obj-$(CONFIG_DRM_TEGRA) += tegra/
+obj-$(CONFIG_DRM_STM) += stm/
 obj-$(CONFIG_DRM_STI) += sti/
 obj-$(CONFIG_DRM_IMX) += imx/
 obj-$(CONFIG_DRM_MEDIATEK) += mediatek/
diff --git a/drivers/gpu/drm/stm/Kconfig b/drivers/gpu/drm/stm/Kconfig
new file mode 100644
index 0000000..2c4817f
--- /dev/null
+++ b/drivers/gpu/drm/stm/Kconfig
@@ -0,0 +1,16 @@ 
+config DRM_STM
+	tristate "DRM Support for STMicroelectronics SoC Series"
+	depends on DRM && (ARCH_STM32 || ARCH_MULTIPLATFORM)
+	select DRM_KMS_HELPER
+	select DRM_GEM_CMA_HELPER
+	select DRM_KMS_CMA_HELPER
+	select DRM_PANEL
+	select VIDEOMODE_HELPERS
+	select FB_PROVIDE_GET_FB_UNMAPPED_AREA
+	default y
+
+	help
+	  Enable support for the on-chip display controller on
+	  STMicroelectronics STM32 MCUs.
+	  To compile this driver as a module, choose M here: the module
+	  will be called stm-drm.
diff --git a/drivers/gpu/drm/stm/Makefile b/drivers/gpu/drm/stm/Makefile
new file mode 100644
index 0000000..e114d45
--- /dev/null
+++ b/drivers/gpu/drm/stm/Makefile
@@ -0,0 +1,7 @@ 
+ccflags-y := -Iinclude/drm
+
+stm-drm-y := \
+	drv.o \
+	ltdc.o
+
+obj-$(CONFIG_DRM_STM) += stm-drm.o
diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
new file mode 100644
index 0000000..83ab48f
--- /dev/null
+++ b/drivers/gpu/drm/stm/drv.c
@@ -0,0 +1,221 @@ 
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * Authors: Philippe Cornu <philippe.cornu@st.com>
+ *          Yannick Fertre <yannick.fertre@st.com>
+ *          Fabien Dessenne <fabien.dessenne@st.com>
+ *          Mickael Reulier <mickael.reulier@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/component.h>
+#include <linux/of_platform.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+
+#include "ltdc.h"
+
+#define DRIVER_NAME		"stm"
+#define DRIVER_DESC		"STMicroelectronics SoC DRM"
+#define DRIVER_DATE		"20170330"
+#define DRIVER_MAJOR		1
+#define DRIVER_MINOR		0
+#define DRIVER_PATCH_LEVEL	0
+
+#define STM_MAX_FB_WIDTH	2048
+#define STM_MAX_FB_HEIGHT	2048 /* same as width to handle orientation */
+
+static void drv_output_poll_changed(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	drm_fbdev_cma_hotplug_event(ldev->fbdev);
+}
+
+static const struct drm_mode_config_funcs drv_mode_config_funcs = {
+	.fb_create = drm_fb_cma_create,
+	.output_poll_changed = drv_output_poll_changed,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static void drv_lastclose(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	drm_fbdev_cma_restore_mode(ldev->fbdev);
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(drv_driver_fops);
+
+static struct drm_driver drv_driver = {
+	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
+			   DRIVER_ATOMIC,
+	.lastclose = drv_lastclose,
+	.name = DRIVER_NAME,
+	.desc = DRIVER_DESC,
+	.date = DRIVER_DATE,
+	.major = DRIVER_MAJOR,
+	.minor = DRIVER_MINOR,
+	.patchlevel = DRIVER_PATCH_LEVEL,
+	.fops = &drv_driver_fops,
+	.dumb_create = drm_gem_cma_dumb_create,
+	.dumb_map_offset = drm_gem_cma_dumb_map_offset,
+	.dumb_destroy = drm_gem_dumb_destroy,
+	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
+	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+	.gem_free_object_unlocked = 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,
+	.enable_vblank = ltdc_crtc_enable_vblank,
+	.disable_vblank = ltdc_crtc_disable_vblank,
+};
+
+static int drv_load(struct drm_device *ddev)
+{
+	struct platform_device *pdev = to_platform_device(ddev->dev);
+	struct drm_fbdev_cma *fbdev;
+	struct ltdc_device *ldev;
+	int ret;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	ldev = devm_kzalloc(ddev->dev, sizeof(*ldev), GFP_KERNEL);
+	if (!ldev)
+		return -ENOMEM;
+
+	ddev->dev_private = (void *)ldev;
+
+	drm_mode_config_init(ddev);
+
+	/*
+	 * set max width and height as default value.
+	 * this value would be used to check framebuffer size limitation
+	 * at drm_mode_addfb().
+	 */
+	ddev->mode_config.min_width = 0;
+	ddev->mode_config.min_height = 0;
+	ddev->mode_config.max_width = STM_MAX_FB_WIDTH;
+	ddev->mode_config.max_height = STM_MAX_FB_HEIGHT;
+	ddev->mode_config.funcs = &drv_mode_config_funcs;
+
+	ret = ltdc_load(ddev);
+	if (ret)
+		goto err;
+
+	drm_mode_config_reset(ddev);
+	drm_kms_helper_poll_init(ddev);
+
+	if (ddev->mode_config.num_connector) {
+		ldev = ddev->dev_private;
+		fbdev = drm_fbdev_cma_init(ddev, 16,
+					   ddev->mode_config.num_connector);
+		if (IS_ERR(fbdev)) {
+			DRM_DEBUG("Warning: fails to create fbdev\n");
+			fbdev = NULL;
+		}
+		ldev->fbdev = fbdev;
+	}
+
+	platform_set_drvdata(pdev, ddev);
+
+	return 0;
+err:
+	drm_mode_config_cleanup(ddev);
+	return ret;
+}
+
+static void drv_unload(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	if (ldev->fbdev) {
+		drm_fbdev_cma_fini(ldev->fbdev);
+		ldev->fbdev = NULL;
+	}
+	drm_kms_helper_poll_fini(ddev);
+	ltdc_unload(ddev);
+	drm_mode_config_cleanup(ddev);
+}
+
+static int stm_drm_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct drm_device *ddev;
+	int ret;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
+
+	ddev = drm_dev_alloc(&drv_driver, dev);
+	if (IS_ERR(ddev))
+		return PTR_ERR(ddev);
+
+	ret = drv_load(ddev);
+	if (ret)
+		goto err_unref;
+
+	ret = drm_dev_register(ddev, 0);
+	if (ret)
+		goto err_unref;
+
+	return 0;
+
+err_unref:
+	drm_dev_unref(ddev);
+
+	return ret;
+}
+
+static int stm_drm_platform_remove(struct platform_device *pdev)
+{
+	struct drm_device *ddev = platform_get_drvdata(pdev);
+
+	DRM_DEBUG("%s\n", __func__);
+
+	drm_dev_unregister(ddev);
+	drv_unload(ddev);
+	drm_dev_unref(ddev);
+
+	return 0;
+}
+
+static const struct of_device_id drv_dt_ids[] = {
+	{ .compatible = "st,stm32-ltdc"},
+	{ /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, drv_dt_ids);
+
+static struct platform_driver stm_drm_platform_driver = {
+	.probe = stm_drm_platform_probe,
+	.remove = stm_drm_platform_remove,
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = drv_dt_ids,
+	},
+};
+
+module_platform_driver(stm_drm_platform_driver);
+
+MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
+MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
+MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
+MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
new file mode 100644
index 0000000..922f021
--- /dev/null
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -0,0 +1,1210 @@ 
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * Authors: Philippe Cornu <philippe.cornu@st.com>
+ *          Yannick Fertre <yannick.fertre@st.com>
+ *          Fabien Dessenne <fabien.dessenne@st.com>
+ *          Mickael Reulier <mickael.reulier@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/of_address.h>
+#include <linux/of_graph.h>
+#include <linux/reset.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_plane_helper.h>
+
+#include <video/videomode.h>
+
+#include "ltdc.h"
+
+#define NB_CRTC 1
+#define CRTC_MASK GENMASK(NB_CRTC - 1, 0)
+
+#define MAX_IRQ 4
+
+#define HWVER_10200 0x010200
+#define HWVER_10300 0x010300
+#define HWVER_20101 0x020101
+
+/*
+ * The address of some registers depends on the HW version: such registers have
+ * an extra offset specified with reg_ofs.
+ */
+#define REG_OFS_NONE	0
+#define REG_OFS_4	4 /* Insertion of "Layer Configuration 2" reg */
+#define REG_OFS		(ldev->caps.reg_ofs)
+#define LAY_OFS		0x80	/* Register Offset between 2 layers */
+
+/* Global register offsets */
+#define LTDC_IDR	0x0000 /* IDentification */
+#define LTDC_LCR	0x0004 /* Layer Count */
+#define LTDC_SSCR	0x0008 /* Synchronization Size Configuration */
+#define LTDC_BPCR	0x000C /* Back Porch Configuration */
+#define LTDC_AWCR	0x0010 /* Active Width Configuration */
+#define LTDC_TWCR	0x0014 /* Total Width Configuration */
+#define LTDC_GCR	0x0018 /* Global Control */
+#define LTDC_GC1R	0x001C /* Global Configuration 1 */
+#define LTDC_GC2R	0x0020 /* Global Configuration 2 */
+#define LTDC_SRCR	0x0024 /* Shadow Reload Configuration */
+#define LTDC_GACR	0x0028 /* GAmma Correction */
+#define LTDC_BCCR	0x002C /* Background Color Configuration */
+#define LTDC_IER	0x0034 /* Interrupt Enable */
+#define LTDC_ISR	0x0038 /* Interrupt Status */
+#define LTDC_ICR	0x003C /* Interrupt Clear */
+#define LTDC_LIPCR	0x0040 /* Line Interrupt Position Configuration */
+#define LTDC_CPSR	0x0044 /* Current Position Status */
+#define LTDC_CDSR	0x0048 /* Current Display Status */
+
+/* Layer register offsets */
+#define LTDC_L1LC1R	(0x0080)	   /* L1 Layer Configuration 1 */
+#define LTDC_L1LC2R	(0x0084)	   /* L1 Layer Configuration 2 */
+#define LTDC_L1CR	(0x0084 + REG_OFS) /* L1 Control */
+#define LTDC_L1WHPCR	(0x0088 + REG_OFS) /* L1 Window Hor Position Config */
+#define LTDC_L1WVPCR	(0x008C + REG_OFS) /* L1 Window Vert Position Config */
+#define LTDC_L1CKCR	(0x0090 + REG_OFS) /* L1 Color Keying Configuration */
+#define LTDC_L1PFCR	(0x0094 + REG_OFS) /* L1 Pixel Format Configuration */
+#define LTDC_L1CACR	(0x0098 + REG_OFS) /* L1 Constant Alpha Config */
+#define LTDC_L1DCCR	(0x009C + REG_OFS) /* L1 Default Color Configuration */
+#define LTDC_L1BFCR	(0x00A0 + REG_OFS) /* L1 Blend Factors Configuration */
+#define LTDC_L1FBBCR	(0x00A4 + REG_OFS) /* L1 FrameBuffer Bus Control */
+#define LTDC_L1AFBCR	(0x00A8 + REG_OFS) /* L1 AuxFB Control */
+#define LTDC_L1CFBAR	(0x00AC + REG_OFS) /* L1 Color FrameBuffer Address */
+#define LTDC_L1CFBLR	(0x00B0 + REG_OFS) /* L1 Color FrameBuffer Length */
+#define LTDC_L1CFBLNR	(0x00B4 + REG_OFS) /* L1 Color FrameBuffer Line Nb */
+#define LTDC_L1AFBAR	(0x00B8 + REG_OFS) /* L1 AuxFB Address */
+#define LTDC_L1AFBLR	(0x00BC + REG_OFS) /* L1 AuxFB Length */
+#define LTDC_L1AFBLNR	(0x00C0 + REG_OFS) /* L1 AuxFB Line Number */
+#define LTDC_L1CLUTWR	(0x00C4 + REG_OFS) /* L1 CLUT Write */
+#define LTDC_L1YS1R	(0x00E0 + REG_OFS) /* L1 YCbCr Scale 1 */
+#define LTDC_L1YS2R	(0x00E4 + REG_OFS) /* L1 YCbCr Scale 2 */
+
+/* Bit definitions */
+#define SSCR_VSH	GENMASK(10, 0)	/* Vertical Synchronization Height */
+#define SSCR_HSW	GENMASK(27, 16)	/* Horizontal Synchronization Width */
+
+#define BPCR_AVBP	GENMASK(10, 0)	/* Accumulated Vertical Back Porch */
+#define BPCR_AHBP	GENMASK(27, 16)	/* Accumulated Horizontal Back Porch */
+
+#define AWCR_AAH	GENMASK(10, 0)	/* Accumulated Active Height */
+#define AWCR_AAW	GENMASK(27, 16)	/* Accumulated Active Width */
+
+#define TWCR_TOTALH	GENMASK(10, 0)	/* TOTAL Height */
+#define TWCR_TOTALW	GENMASK(27, 16)	/* TOTAL Width */
+
+#define GCR_LTDCEN	BIT(0)		/* LTDC ENable */
+#define GCR_DEN		BIT(16)		/* Dither ENable */
+#define GCR_PCPOL	BIT(28)		/* Pixel Clock POLarity */
+#define GCR_DEPOL	BIT(29)		/* Data Enable POLarity */
+#define GCR_VSPOL	BIT(30)		/* Vertical Synchro POLarity */
+#define GCR_HSPOL	BIT(31)		/* Horizontal Synchro POLarity */
+
+#define GC1R_WBCH	GENMASK(3, 0)	/* Width of Blue CHannel output */
+#define GC1R_WGCH	GENMASK(7, 4)	/* Width of Green Channel output */
+#define GC1R_WRCH	GENMASK(11, 8)	/* Width of Red Channel output */
+#define GC1R_PBEN	BIT(12)		/* Precise Blending ENable */
+#define GC1R_DT		GENMASK(15, 14)	/* Dithering Technique */
+#define GC1R_GCT	GENMASK(19, 17)	/* Gamma Correction Technique */
+#define GC1R_SHREN	BIT(21)		/* SHadow Registers ENabled */
+#define GC1R_BCP	BIT(22)		/* Background Colour Programmable */
+#define GC1R_BBEN	BIT(23)		/* Background Blending ENabled */
+#define GC1R_LNIP	BIT(24)		/* Line Number IRQ Position */
+#define GC1R_TP		BIT(25)		/* Timing Programmable */
+#define GC1R_IPP	BIT(26)		/* IRQ Polarity Programmable */
+#define GC1R_SPP	BIT(27)		/* Sync Polarity Programmable */
+#define GC1R_DWP	BIT(28)		/* Dither Width Programmable */
+#define GC1R_STREN	BIT(29)		/* STatus Registers ENabled */
+#define GC1R_BMEN	BIT(31)		/* Blind Mode ENabled */
+
+#define GC2R_EDCA	BIT(0)		/* External Display Control Ability  */
+#define GC2R_STSAEN	BIT(1)		/* Slave Timing Sync Ability ENabled */
+#define GC2R_DVAEN	BIT(2)		/* Dual-View Ability ENabled */
+#define GC2R_DPAEN	BIT(3)		/* Dual-Port Ability ENabled */
+#define GC2R_BW		GENMASK(6, 4)	/* Bus Width (log2 of nb of bytes) */
+#define GC2R_EDCEN	BIT(7)		/* External Display Control ENabled */
+
+#define SRCR_IMR	BIT(0)		/* IMmediate Reload */
+#define SRCR_VBR	BIT(1)		/* Vertical Blanking Reload */
+
+#define BCCR_BCBLACK	0x00		/* Background Color BLACK */
+#define BCCR_BCBLUE	GENMASK(7, 0)	/* Background Color BLUE */
+#define BCCR_BCGREEN	GENMASK(15, 8)	/* Background Color GREEN */
+#define BCCR_BCRED	GENMASK(23, 16)	/* Background Color RED */
+#define BCCR_BCWHITE	GENMASK(23, 0)	/* Background Color WHITE */
+
+#define IER_LIE		BIT(0)		/* Line Interrupt Enable */
+#define IER_FUIE	BIT(1)		/* Fifo Underrun Interrupt Enable */
+#define IER_TERRIE	BIT(2)		/* Transfer ERRor Interrupt Enable */
+#define IER_RRIE	BIT(3)		/* Register Reload Interrupt enable */
+
+#define ISR_LIF		BIT(0)		/* Line Interrupt Flag */
+#define ISR_FUIF	BIT(1)		/* Fifo Underrun Interrupt Flag */
+#define ISR_TERRIF	BIT(2)		/* Transfer ERRor Interrupt Flag */
+#define ISR_RRIF	BIT(3)		/* Register Reload Interrupt Flag */
+
+#define LXCR_LEN	BIT(0)		/* Layer ENable */
+#define LXCR_COLKEN	BIT(1)		/* Color Keying Enable */
+#define LXCR_CLUTEN	BIT(4)		/* Color Look-Up Table ENable */
+
+#define LXWHPCR_WHSTPOS	GENMASK(11, 0)	/* Window Horizontal StarT POSition */
+#define LXWHPCR_WHSPPOS	GENMASK(27, 16)	/* Window Horizontal StoP POSition */
+
+#define LXWVPCR_WVSTPOS	GENMASK(10, 0)	/* Window Vertical StarT POSition */
+#define LXWVPCR_WVSPPOS	GENMASK(26, 16)	/* Window Vertical StoP POSition */
+
+#define LXPFCR_PF	GENMASK(2, 0)	/* Pixel Format */
+
+#define LXCACR_CONSTA	GENMASK(7, 0)	/* CONSTant Alpha */
+
+#define LXBFCR_BF2	GENMASK(2, 0)	/* Blending Factor 2 */
+#define LXBFCR_BF1	GENMASK(10, 8)	/* Blending Factor 1 */
+
+#define LXCFBLR_CFBLL	GENMASK(12, 0)	/* Color Frame Buffer Line Length */
+#define LXCFBLR_CFBP	GENMASK(28, 16)	/* Color Frame Buffer Pitch in bytes */
+
+#define LXCFBLNR_CFBLN	GENMASK(10, 0)	 /* Color Frame Buffer Line Number */
+
+#define HSPOL_AL   0		/* Horizontal Sync POLarity Active Low */
+#define VSPOL_AL   0		/* Vertical Sync POLarity Active Low */
+#define DEPOL_AL   0		/* Data Enable POLarity Active Low */
+#define PCPOL_IPC  0		/* Input Pixel Clock */
+#define HSPOL_AH   GCR_HSPOL	/* Horizontal Sync POLarity Active High */
+#define VSPOL_AH   GCR_VSPOL	/* Vertical Sync POLarity Active High */
+#define DEPOL_AH   GCR_DEPOL	/* Data Enable POLarity Active High */
+#define PCPOL_IIPC GCR_PCPOL	/* Inverted Input Pixel Clock */
+#define CONSTA_MAX 0xFF		/* CONSTant Alpha MAX= 1.0 */
+#define BF1_PAXCA  0x600	/* Pixel Alpha x Constant Alpha */
+#define BF1_CA     0x400	/* Constant Alpha */
+#define BF2_1PAXCA 0x007	/* 1 - (Pixel Alpha x Constant Alpha) */
+#define BF2_1CA	   0x005	/* 1 - Constant Alpha */
+
+#define NB_PF           8       /* Max nb of HW pixel format */
+
+enum ltdc_pix_fmt {
+	PF_NONE,
+	/* RGB formats */
+	PF_ARGB8888,    /* ARGB [32 bits] */
+	PF_RGBA8888,    /* RGBA [32 bits] */
+	PF_RGB888,      /* RGB [24 bits] */
+	PF_RGB565,      /* RGB [16 bits] */
+	PF_ARGB1555,    /* ARGB A:1 bit RGB:15 bits [16 bits] */
+	PF_ARGB4444,    /* ARGB A:4 bits R/G/B: 4 bits each [16 bits] */
+	/* Indexed formats */
+	PF_L8,          /* Indexed 8 bits [8 bits] */
+	PF_AL44,        /* Alpha:4 bits + indexed 4 bits [8 bits] */
+	PF_AL88         /* Alpha:8 bits + indexed 8 bits [16 bits] */
+};
+
+/* The index gives the encoding of the pixel format for an HW version */
+static const enum ltdc_pix_fmt ltdc_pix_fmt_a0[NB_PF] = {
+	PF_ARGB8888,	/* 0x00 */
+	PF_RGB888,	/* 0x01 */
+	PF_RGB565,	/* 0x02 */
+	PF_ARGB1555,	/* 0x03 */
+	PF_ARGB4444,	/* 0x04 */
+	PF_L8,		/* 0x05 */
+	PF_AL44,	/* 0x06 */
+	PF_AL88		/* 0x07 */
+};
+
+static const enum ltdc_pix_fmt ltdc_pix_fmt_a1[NB_PF] = {
+	PF_ARGB8888,	/* 0x00 */
+	PF_RGB888,	/* 0x01 */
+	PF_RGB565,	/* 0x02 */
+	PF_RGBA8888,	/* 0x03 */
+	PF_AL44,	/* 0x04 */
+	PF_L8,		/* 0x05 */
+	PF_ARGB1555,	/* 0x06 */
+	PF_ARGB4444	/* 0x07 */
+};
+
+static inline u32 reg_read(void __iomem *base, u32 reg)
+{
+	return readl_relaxed(base + reg);
+}
+
+static inline void reg_write(void __iomem *base, u32 reg, u32 val)
+{
+	writel_relaxed(val, base + reg);
+}
+
+static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
+{
+	reg_write(base, reg, reg_read(base, reg) | mask);
+}
+
+static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
+{
+	reg_write(base, reg, reg_read(base, reg) & ~mask);
+}
+
+static inline void reg_update_bits(void __iomem *base, u32 reg, u32 mask,
+				   u32 val)
+{
+	reg_write(base, reg, (reg_read(base, reg) & ~mask) | val);
+}
+
+static inline struct ltdc_device *crtc_to_ltdc(struct drm_crtc *crtc)
+{
+	return (struct ltdc_device *)crtc->dev->dev_private;
+}
+
+static inline struct ltdc_device *plane_to_ltdc(struct drm_plane *plane)
+{
+	return (struct ltdc_device *)plane->dev->dev_private;
+}
+
+static inline struct ltdc_device *encoder_to_ltdc(struct drm_encoder *enc)
+{
+	return (struct ltdc_device *)enc->dev->dev_private;
+}
+
+static inline struct ltdc_device *connector_to_ltdc(struct drm_connector *con)
+{
+	return (struct ltdc_device *)con->dev->dev_private;
+}
+
+static inline enum ltdc_pix_fmt to_ltdc_pixelformat(u32 drm_fmt)
+{
+	enum ltdc_pix_fmt pf;
+
+	switch (drm_fmt) {
+	case DRM_FORMAT_ARGB8888:
+	case DRM_FORMAT_XRGB8888:
+		pf = PF_ARGB8888;
+		break;
+	case DRM_FORMAT_RGBA8888:
+	case DRM_FORMAT_RGBX8888:
+		pf = PF_RGBA8888;
+		break;
+	case DRM_FORMAT_RGB888:
+		pf = PF_RGB888;
+		break;
+	case DRM_FORMAT_RGB565:
+		pf = PF_RGB565;
+		break;
+	case DRM_FORMAT_ARGB1555:
+	case DRM_FORMAT_XRGB1555:
+		pf = PF_ARGB1555;
+		break;
+	case DRM_FORMAT_ARGB4444:
+	case DRM_FORMAT_XRGB4444:
+		pf = PF_ARGB4444;
+		break;
+	case DRM_FORMAT_C8:
+		pf = PF_L8;
+		break;
+	default:
+		pf = PF_NONE;
+		break;
+	/* Note: There are no DRM_FORMAT for AL44 and AL88 */
+	}
+
+	return pf;
+}
+
+static inline u32 to_drm_pixelformat(enum ltdc_pix_fmt pf)
+{
+	switch (pf) {
+	case PF_ARGB8888:
+		return DRM_FORMAT_ARGB8888;
+	case PF_RGBA8888:
+		return DRM_FORMAT_RGBA8888;
+	case PF_RGB888:
+		return DRM_FORMAT_RGB888;
+	case PF_RGB565:
+		return DRM_FORMAT_RGB565;
+	case PF_ARGB1555:
+		return DRM_FORMAT_ARGB1555;
+	case PF_ARGB4444:
+		return DRM_FORMAT_ARGB4444;
+	case PF_L8:
+		return DRM_FORMAT_C8;
+	case PF_AL44: /* No DRM support */
+	case PF_AL88: /* No DRM support */
+	case PF_NONE:
+	default:
+		return 0;
+	}
+}
+
+static irqreturn_t ltdc_irq_thread(int irq, void *arg)
+{
+	struct drm_device *ddev = arg;
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct drm_crtc *crtc = drm_crtc_from_index(ddev, 0);
+
+	/* Line IRQ : trigger the vblank event */
+	if (ldev->irq_status & ISR_LIF)
+		drm_crtc_handle_vblank(crtc);
+
+	/* Save FIFO Underrun & Transfer Error status */
+	mutex_lock(&ldev->err_lock);
+	if (ldev->irq_status & ISR_FUIF)
+		ldev->error_status |= ISR_FUIF;
+	if (ldev->irq_status & ISR_TERRIF)
+		ldev->error_status |= ISR_TERRIF;
+	mutex_unlock(&ldev->err_lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ltdc_irq(int irq, void *arg)
+{
+	struct drm_device *ddev = arg;
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	/* Read & Clear the interrupt status */
+	ldev->irq_status = reg_read(ldev->regs, LTDC_ISR);
+	reg_write(ldev->regs, LTDC_ICR, ldev->irq_status);
+
+	return IRQ_WAKE_THREAD;
+}
+
+/*
+ * DRM_CRTC
+ */
+
+static void ltdc_crtc_load_lut(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+	unsigned int i, lay;
+
+	for (lay = 0; lay < ldev->caps.nb_layers; lay++)
+		for (i = 0; i < 256; i++)
+			reg_write(ldev->regs, LTDC_L1CLUTWR + lay * LAY_OFS,
+				  ldev->clut[i]);
+}
+
+static void ltdc_crtc_enable(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+
+	DRM_DEBUG_DRIVER("\n");
+
+	/* Sets the background color value */
+	reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);
+
+	/* Enable IRQ */
+	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
+
+	/* Immediately commit the planes */
+	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
+
+	/* Enable LTDC */
+	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
+
+	drm_crtc_vblank_on(crtc);
+}
+
+static void ltdc_crtc_disable(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+	struct drm_pending_vblank_event *event = crtc->state->event;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (!crtc->enabled) {
+		DRM_DEBUG_DRIVER("already disabled\n");
+		return;
+	}
+
+	drm_crtc_vblank_off(crtc);
+
+	/* disable LTDC */
+	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
+
+	/* disable IRQ */
+	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
+
+	/* immediately commit disable of layers before switching off LTDC */
+	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
+
+	if (event) {
+		crtc->state->event = NULL;
+
+		spin_lock_irq(&crtc->dev->event_lock);
+		if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
+			drm_crtc_arm_vblank_event(crtc, event);
+		else
+			drm_crtc_send_vblank_event(crtc, event);
+		spin_unlock_irq(&crtc->dev->event_lock);
+	}
+}
+
+static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+	struct videomode vm;
+	int rate = mode->clock * 1000;
+	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
+	u32 total_width, total_height;
+	u32 val;
+
+	drm_display_mode_to_videomode(mode, &vm);
+
+	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
+	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
+	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
+			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
+			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
+
+	/* Convert video timings to ltdc timings */
+	hsync = vm.hsync_len - 1;
+	vsync = vm.vsync_len - 1;
+	accum_hbp = hsync + vm.hback_porch;
+	accum_vbp = vsync + vm.vback_porch;
+	accum_act_w = accum_hbp + vm.hactive;
+	accum_act_h = accum_vbp + vm.vactive;
+	total_width = accum_act_w + vm.hfront_porch;
+	total_height = accum_act_h + vm.vfront_porch;
+
+	clk_disable(ldev->pixel_clk);
+
+	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
+		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
+		return;
+	}
+
+	clk_enable(ldev->pixel_clk);
+
+	/* Configures the HS, VS, DE and PC polarities. */
+	val = HSPOL_AL | HSPOL_AL | DEPOL_AL | PCPOL_IPC;
+
+	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
+		val |= HSPOL_AH;
+
+	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
+		val |= VSPOL_AH;
+
+	if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
+		val |= DEPOL_AH;
+
+	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+		val |= PCPOL_IIPC;
+
+	reg_update_bits(ldev->regs, LTDC_GCR,
+			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
+
+	/* Set Synchronization size */
+	val = (hsync << 16) | vsync;
+	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
+
+	/* Set Accumulated Back porch */
+	val = (accum_hbp << 16) | accum_vbp;
+	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
+
+	/* Set Accumulated Active Width */
+	val = (accum_act_w << 16) | accum_act_h;
+	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
+
+	/* Set total width & height */
+	val = (total_width << 16) | total_height;
+	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
+
+	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
+}
+
+static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
+				   struct drm_crtc_state *old_crtc_state)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+	struct drm_pending_vblank_event *event = crtc->state->event;
+
+	DRM_DEBUG_ATOMIC("\n");
+
+	/* Commit shadow registers = update planes at next vblank */
+	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
+
+	if (event) {
+		crtc->state->event = NULL;
+
+		spin_lock_irq(&crtc->dev->event_lock);
+		if (drm_crtc_vblank_get(crtc) == 0)
+			drm_crtc_arm_vblank_event(crtc, event);
+		else
+			drm_crtc_send_vblank_event(crtc, event);
+		spin_unlock_irq(&crtc->dev->event_lock);
+	}
+}
+
+static struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
+	.load_lut = ltdc_crtc_load_lut,
+	.enable = ltdc_crtc_enable,
+	.disable = ltdc_crtc_disable,
+	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
+	.atomic_flush = ltdc_crtc_atomic_flush,
+};
+
+int ltdc_crtc_enable_vblank(struct drm_device *ddev, unsigned int pipe)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG_DRIVER("\n");
+	reg_set(ldev->regs, LTDC_IER, IER_LIE);
+
+	return 0;
+}
+
+void ltdc_crtc_disable_vblank(struct drm_device *ddev, unsigned int pipe)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG_DRIVER("\n");
+	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
+}
+
+static struct drm_crtc_funcs ltdc_crtc_funcs = {
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.reset = drm_atomic_helper_crtc_reset,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+/*
+ * DRM_PLANE
+ */
+
+static int ltdc_plane_atomic_check(struct drm_plane *plane,
+				   struct drm_plane_state *state)
+{
+	struct drm_framebuffer *fb = state->fb;
+	u32 src_x, src_y, src_w, src_h;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (!fb)
+		return 0;
+
+	/* convert src_ from 16:16 format */
+	src_x = state->src_x >> 16;
+	src_y = state->src_y >> 16;
+	src_w = state->src_w >> 16;
+	src_h = state->src_h >> 16;
+
+	/* Reject scaling */
+	if ((src_w != state->crtc_w) || (src_h != state->crtc_h)) {
+		DRM_ERROR("Scaling is not supported");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void ltdc_plane_atomic_update(struct drm_plane *plane,
+				     struct drm_plane_state *oldstate)
+{
+	struct ltdc_device *ldev = plane_to_ltdc(plane);
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	u32 lofs = plane->index * LAY_OFS;
+	u32 x0 = state->crtc_x;
+	u32 x1 = state->crtc_x + state->crtc_w - 1;
+	u32 y0 = state->crtc_y;
+	u32 y1 = state->crtc_y + state->crtc_h - 1;
+	u32 src_x, src_y, src_w, src_h;
+	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
+	enum ltdc_pix_fmt pf;
+
+	if (!state->crtc || !fb) {
+		DRM_DEBUG_DRIVER("fb or crtc NULL");
+		return;
+	}
+
+	/* convert src_ from 16:16 format */
+	src_x = state->src_x >> 16;
+	src_y = state->src_y >> 16;
+	src_w = state->src_w >> 16;
+	src_h = state->src_h >> 16;
+
+	DRM_DEBUG_DRIVER(
+		"plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
+		plane->base.id, fb->base.id,
+		src_w, src_h, src_x, src_y,
+		state->crtc_w, state->crtc_h, state->crtc_x, state->crtc_y);
+
+	bpcr = reg_read(ldev->regs, LTDC_BPCR);
+	ahbp = (bpcr & BPCR_AHBP) >> 16;
+	avbp = bpcr & BPCR_AVBP;
+
+	/* Configures the horizontal start and stop position */
+	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
+	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
+			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
+
+	/* Configures the vertical start and stop position */
+	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
+	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
+			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
+
+	/* Specifies the pixel format */
+	pf = to_ltdc_pixelformat(fb->format->format);
+	for (val = 0; val < NB_PF; val++)
+		if (ldev->caps.pix_fmt_hw[val] == pf)
+			break;
+
+	if (val == NB_PF) {
+		DRM_ERROR("Pixel format %.4s not supported\n",
+			  (char *)&fb->format->format);
+		val = 0; /* set by default ARGB 32 bits */
+	}
+	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
+
+	/* Configures the color frame buffer pitch in bytes & line length */
+	pitch_in_bytes = fb->pitches[0];
+	line_length = drm_format_plane_cpp(fb->format->format, 0) *
+		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
+	val = ((pitch_in_bytes << 16) | line_length);
+	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
+			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
+
+	/* Specifies the constant alpha value */
+	val = CONSTA_MAX;
+	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs,
+			LXCACR_CONSTA, val);
+
+	/* Specifies the blending factors */
+	val = BF1_PAXCA | BF2_1PAXCA;
+	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
+			LXBFCR_BF2 | LXBFCR_BF1, val);
+
+	/* Configures the frame buffer line number */
+	val = y1 - y0 + 1;
+	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs,
+			LXCFBLNR_CFBLN, val);
+
+	/* Sets the FB address */
+	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
+
+	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
+	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
+
+	/* Enable layer and CLUT if needed */
+	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
+	val |= LXCR_LEN;
+	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
+			LXCR_LEN | LXCR_CLUTEN, val);
+
+	mutex_lock(&ldev->err_lock);
+	if (ldev->error_status & ISR_FUIF) {
+		DRM_DEBUG_DRIVER("Fifo underrun\n");
+		ldev->error_status &= ~ISR_FUIF;
+	}
+	if (ldev->error_status & ISR_TERRIF) {
+		DRM_DEBUG_DRIVER("Transfer error\n");
+		ldev->error_status &= ~ISR_TERRIF;
+	}
+	mutex_unlock(&ldev->err_lock);
+}
+
+static void ltdc_plane_atomic_disable(struct drm_plane *plane,
+				      struct drm_plane_state *oldstate)
+{
+	struct ltdc_device *ldev = plane_to_ltdc(plane);
+	u32 lofs = plane->index * LAY_OFS;
+
+	/* disable layer */
+	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
+
+	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
+			 oldstate->crtc->base.id, plane->base.id);
+}
+
+static struct drm_plane_funcs ltdc_plane_funcs = {
+	.update_plane = drm_atomic_helper_update_plane,
+	.disable_plane = drm_atomic_helper_disable_plane,
+	.destroy = drm_plane_cleanup,
+	.set_property = drm_atomic_helper_plane_set_property,
+	.reset = drm_atomic_helper_plane_reset,
+	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
+};
+
+static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
+	.atomic_check = ltdc_plane_atomic_check,
+	.atomic_update = ltdc_plane_atomic_update,
+	.atomic_disable = ltdc_plane_atomic_disable,
+};
+
+static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
+					   enum drm_plane_type type)
+{
+	unsigned long possible_crtcs = CRTC_MASK;
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct device *dev = ddev->dev;
+	struct drm_plane *plane;
+	unsigned int i, nb_fmt = 0;
+	u32 formats[NB_PF];
+	u32 drm_fmt;
+	int ret;
+
+	/* Get supported pixel formats */
+	for (i = 0; i < NB_PF; i++) {
+		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
+		if (!drm_fmt)
+			continue;
+		formats[nb_fmt++] = drm_fmt;
+	}
+
+	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
+	if (!plane)
+		return 0;
+
+	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
+				       &ltdc_plane_funcs, formats, nb_fmt,
+				       type, NULL);
+	if (ret < 0)
+		return 0;
+
+	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
+
+	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
+
+	return plane;
+}
+
+static void ltdc_plane_destroy_all(struct drm_device *ddev)
+{
+	struct drm_plane *plane, *plane_temp;
+
+	list_for_each_entry_safe(plane, plane_temp,
+				 &ddev->mode_config.plane_list, head)
+		drm_plane_cleanup(plane);
+}
+
+static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct drm_plane *primary, *overlay;
+	unsigned int i;
+	int res;
+
+	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
+	if (!primary) {
+		DRM_ERROR("Can not create primary plane\n");
+		return -EINVAL;
+	}
+
+	res = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
+					&ltdc_crtc_funcs, NULL);
+	if (res) {
+		DRM_ERROR("Can not initialize CRTC\n");
+		goto cleanup;
+	}
+
+	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
+
+	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
+
+	/* Add planes. Note : the first layer is used by primary plane */
+	for (i = 1; i < ldev->caps.nb_layers; i++) {
+		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
+		if (!overlay) {
+			res = -ENOMEM;
+			DRM_ERROR("Can not create overlay plane %d\n", i);
+			goto cleanup;
+		}
+	}
+
+	return 0;
+
+cleanup:
+	ltdc_plane_destroy_all(ddev);
+	return res;
+}
+
+/*
+ * DRM_ENCODER
+ */
+
+static void ltdc_rgb_encoder_enable(struct drm_encoder *encoder)
+{
+	struct ltdc_device *ldev = encoder_to_ltdc(encoder);
+
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_panel_prepare(ldev->panel);
+	drm_panel_enable(ldev->panel);
+}
+
+static void ltdc_rgb_encoder_disable(struct drm_encoder *encoder)
+{
+	struct ltdc_device *ldev = encoder_to_ltdc(encoder);
+
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_panel_disable(ldev->panel);
+	drm_panel_unprepare(ldev->panel);
+}
+
+static const struct drm_encoder_helper_funcs ltdc_rgb_encoder_helper_funcs = {
+	.enable = ltdc_rgb_encoder_enable,
+	.disable = ltdc_rgb_encoder_disable,
+};
+
+static const struct drm_encoder_funcs ltdc_rgb_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+static struct drm_encoder *ltdc_rgb_encoder_create(struct drm_device *ddev)
+{
+	struct drm_encoder *encoder;
+
+	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
+	if (!encoder)
+		return NULL;
+
+	encoder->possible_crtcs = CRTC_MASK;
+	encoder->possible_clones = 0; /* No cloning support */
+
+	drm_encoder_init(ddev, encoder, &ltdc_rgb_encoder_funcs,
+			 DRM_MODE_ENCODER_LVDS, NULL);
+
+	drm_encoder_helper_add(encoder, &ltdc_rgb_encoder_helper_funcs);
+
+	DRM_DEBUG_DRIVER("RGB encoder:%d created\n", encoder->base.id);
+
+	return encoder;
+}
+
+static struct drm_encoder *ltdc_rgb_encoder_find(struct drm_device *ddev)
+{
+	struct drm_encoder *encoder;
+
+	list_for_each_entry(encoder, &ddev->mode_config.encoder_list, head) {
+		if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS)
+			return encoder;
+	}
+
+	return NULL;
+}
+
+static int ltdc_create_encoders(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct drm_encoder *encoder;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (ldev->panel) {
+		encoder = ltdc_rgb_encoder_create(ddev);
+		if (!encoder)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * DRM_CONNECTOR
+ */
+
+static int ltdc_rgb_connector_get_modes(struct drm_connector *connector)
+{
+	struct drm_device *ddev = connector->dev;
+	struct ltdc_device *ldev = ddev->dev_private;
+	int ret = 0;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (ldev->panel)
+		ret = drm_panel_get_modes(ldev->panel);
+
+	return ret < 0 ? 0 : ret;
+}
+
+static struct drm_connector_helper_funcs ltdc_rgb_connector_helper_funcs = {
+	.get_modes = ltdc_rgb_connector_get_modes,
+};
+
+static enum drm_connector_status
+ltdc_rgb_connector_detect(struct drm_connector *connector, bool force)
+{
+	struct ltdc_device *ldev = connector_to_ltdc(connector);
+
+	return ldev->panel ? connector_status_connected :
+	       connector_status_disconnected;
+}
+
+static void ltdc_rgb_connector_destroy(struct drm_connector *connector)
+{
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs ltdc_rgb_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ltdc_rgb_connector_detect,
+	.destroy = ltdc_rgb_connector_destroy,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+struct drm_connector *ltdc_rgb_connector_create(struct drm_device *ddev)
+{
+	struct drm_connector *connector;
+	int err;
+
+	connector = devm_kzalloc(ddev->dev, sizeof(*connector), GFP_KERNEL);
+	if (!connector) {
+		DRM_ERROR("Failed to allocate connector\n");
+		return NULL;
+	}
+
+	connector->polled = DRM_CONNECTOR_POLL_HPD;
+
+	err = drm_connector_init(ddev, connector, &ltdc_rgb_connector_funcs,
+				 DRM_MODE_CONNECTOR_LVDS);
+	if (err) {
+		DRM_ERROR("Failed to initialize connector\n");
+		return NULL;
+	}
+
+	drm_connector_helper_add(connector, &ltdc_rgb_connector_helper_funcs);
+
+	DRM_DEBUG_DRIVER("RGB connector:%d created\n", connector->base.id);
+
+	return connector;
+}
+
+static int ltdc_get_caps(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+	u32 bus_width_log2, lcr, gc2r;
+
+	/* at least 1 layer must be managed */
+	lcr = reg_read(ldev->regs, LTDC_LCR);
+
+	ldev->caps.nb_layers = max_t(int, lcr, 1);
+
+	/* set data bus width */
+	gc2r = reg_read(ldev->regs, LTDC_GC2R);
+	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
+	ldev->caps.bus_width = 8 << bus_width_log2;
+	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
+
+	switch (ldev->caps.hw_version) {
+	case HWVER_10200:
+	case HWVER_10300:
+		ldev->caps.reg_ofs = REG_OFS_NONE;
+		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
+		break;
+	case HWVER_20101:
+		ldev->caps.reg_ofs = REG_OFS_4;
+		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static struct drm_panel *ltdc_get_panel(struct drm_device *ddev)
+{
+	struct device *dev = ddev->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *entity, *port = NULL;
+	struct drm_panel *panel = NULL;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	/*
+	 * Parse ltdc node to get remote port and find RGB panel / HDMI slave
+	 * If a dsi or a bridge (hdmi, lvds...) is connected to ltdc,
+	 * a remote port & RGB panel will not be found.
+	 */
+	for_each_endpoint_of_node(np, entity) {
+		if (!of_device_is_available(entity))
+			continue;
+
+		port = of_graph_get_remote_port_parent(entity);
+		if (port) {
+			panel = of_drm_find_panel(port);
+			of_node_put(port);
+			if (panel) {
+				DRM_DEBUG_DRIVER("remote panel %s\n",
+						 port->full_name);
+			} else {
+				DRM_DEBUG_DRIVER("panel missing\n");
+				of_node_put(entity);
+			}
+		}
+	}
+
+	return panel;
+}
+
+int ltdc_load(struct drm_device *ddev)
+{
+	struct platform_device *pdev = to_platform_device(ddev->dev);
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct device *dev = ddev->dev;
+	struct device_node *np = dev->of_node;
+	struct drm_encoder *encoder;
+	struct drm_connector *connector = NULL;
+	struct drm_crtc *crtc;
+	struct reset_control *rstc;
+	struct resource res;
+	int irq, ret, i;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	ldev->panel = ltdc_get_panel(ddev);
+	if (!ldev->panel)
+		return -EPROBE_DEFER;
+
+	rstc = of_reset_control_get(np, NULL);
+
+	mutex_init(&ldev->err_lock);
+
+	ldev->pixel_clk = devm_clk_get(dev, "lcd");
+	if (IS_ERR(ldev->pixel_clk)) {
+		DRM_ERROR("Unable to get lcd clock\n");
+		return -ENODEV;
+	}
+
+	if (clk_prepare_enable(ldev->pixel_clk)) {
+		DRM_ERROR("Unable to prepare pixel clock\n");
+		return -ENODEV;
+	}
+
+	if (of_address_to_resource(np, 0, &res)) {
+		DRM_ERROR("Unable to get resource\n");
+		return -ENODEV;
+	}
+
+	ldev->regs = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(ldev->regs)) {
+		DRM_ERROR("Unable to get ltdc registers\n");
+		return PTR_ERR(ldev->regs);
+	}
+
+	for (i = 0; i < MAX_IRQ; i++) {
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0)
+			continue;
+
+		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
+						ltdc_irq_thread, IRQF_ONESHOT,
+						dev_name(dev), ddev);
+		if (ret) {
+			DRM_ERROR("Failed to register LTDC interrupt\n");
+			return ret;
+		}
+	}
+
+	if (!IS_ERR(rstc))
+		reset_control_deassert(rstc);
+
+	/* Disable interrupts */
+	reg_clear(ldev->regs, LTDC_IER,
+		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
+
+	ret = ltdc_get_caps(ddev);
+	if (ret) {
+		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
+			  ldev->caps.hw_version);
+		return ret;
+	}
+
+	DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
+
+	if (ltdc_create_encoders(ddev)) {
+		DRM_ERROR("Failed to create encoders\n");
+		return -EINVAL;
+	}
+
+	if (ldev->panel) {
+		encoder = ltdc_rgb_encoder_find(ddev);
+		if (!encoder) {
+			DRM_ERROR("Failed to find RGB encoder\n");
+			ret = -EINVAL;
+			goto err;
+		}
+
+		connector = ltdc_rgb_connector_create(ddev);
+		if (!connector) {
+			DRM_ERROR("Failed to create RGB connector\n");
+			ret = -EINVAL;
+			goto err;
+		}
+
+		ret = drm_mode_connector_attach_encoder(connector, encoder);
+		if (ret) {
+			DRM_ERROR("Failed to attach connector to encoder\n");
+			goto err;
+		}
+
+		drm_panel_attach(ldev->panel, connector);
+	}
+
+	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
+	if (!crtc) {
+		DRM_ERROR("Failed to allocate crtc\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	ret = ltdc_crtc_init(ddev, crtc);
+	if (ret) {
+		DRM_ERROR("Failed to init crtc\n");
+		goto err;
+	}
+
+	ret = drm_vblank_init(ddev, NB_CRTC);
+	if (ret) {
+		DRM_ERROR("Failed calling drm_vblank_init()\n");
+		goto err;
+	}
+
+	/* Allow usage of vblank without having to call drm_irq_install */
+	ddev->irq_enabled = 1;
+
+	return 0;
+err:
+	if (ldev->panel)
+		drm_panel_detach(ldev->panel);
+
+	clk_disable_unprepare(ldev->pixel_clk);
+
+	return ret;
+}
+
+void ltdc_unload(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_vblank_cleanup(ddev);
+
+	if (ldev->panel)
+		drm_panel_detach(ldev->panel);
+
+	clk_disable_unprepare(ldev->pixel_clk);
+}
+
+MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
+MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
+MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
+MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
new file mode 100644
index 0000000..d7a9c73
--- /dev/null
+++ b/drivers/gpu/drm/stm/ltdc.h
@@ -0,0 +1,40 @@ 
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * Authors: Philippe Cornu <philippe.cornu@st.com>
+ *          Yannick Fertre <yannick.fertre@st.com>
+ *          Fabien Dessenne <fabien.dessenne@st.com>
+ *          Mickael Reulier <mickael.reulier@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#ifndef _LTDC_H_
+#define _LTDC_H_
+
+struct ltdc_caps {
+	u32 hw_version;		/* hardware version */
+	u32 nb_layers;		/* number of supported layers */
+	u32 reg_ofs;		/* register offset for applicable regs */
+	u32 bus_width;		/* bus width (32 or 64 bits) */
+	const u32 *pix_fmt_hw;	/* supported pixel formats */
+};
+
+struct ltdc_device {
+	struct drm_fbdev_cma *fbdev;
+	void __iomem *regs;
+	struct clk *pixel_clk;	/* lcd pixel clock */
+	struct drm_panel *panel;
+	struct mutex err_lock;	/* protecting error_status */
+	struct ltdc_caps caps;
+	u32 clut[256];		/* color look up table */
+	u32 error_status;
+	u32 irq_status;
+};
+
+int ltdc_crtc_enable_vblank(struct drm_device *dev, unsigned int pipe);
+void ltdc_crtc_disable_vblank(struct drm_device *dev, unsigned int pipe);
+int ltdc_load(struct drm_device *ddev);
+void ltdc_unload(struct drm_device *ddev);
+
+#endif