[PATCH v6 1/5] drm/vc4: Move the DSI clock divider workaround closer to the clock call.

[PATCH v6 1/5] drm/vc4: Move the DSI clock divider workaround closer to the clock call.

[Eric Anholt]

We want the adjusted_mode->clock to be the actual clock we're
expecting to program, so that consumers see the right values for clock
and vrefresh.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index d1e0dc908048..eb787eed8abe 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -859,11 +859,7 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
 	pll_clock = parent_rate / divider;
 	pixel_clock_hz = pll_clock / dsi->divider;
 
-	/* Round up the clk_set_rate() request slightly, since
-	 * PLLD_DSI1 is an integer divider and its rate selection will
-	 * never round up.
-	 */
-	adjusted_mode->clock = pixel_clock_hz / 1000 + 1;
+	adjusted_mode->clock = pixel_clock_hz / 1000;
 
 	/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
 	adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal);
@@ -900,7 +896,11 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
 		vc4_dsi_dump_regs(dsi);
 	}
 
-	phy_clock = pixel_clock_hz * dsi->divider;
+	/* Round up the clk_set_rate() request slightly, since
+	 * PLLD_DSI1 is an integer divider and its rate selection will
+	 * never round up.
+	 */
+	phy_clock = (pixel_clock_hz + 1000) * dsi->divider;
 	ret = clk_set_rate(dsi->pll_phy_clock, phy_clock);
 	if (ret) {
 		dev_err(&dsi->pdev->dev,
-- 
2.14.1

[PATCH v6 2/5] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math.

[Eric Anholt]

The incoming mode might have a missing vrefresh field if it came from
drmModeSetCrtc(), which the kernel is supposed to calculate using
drm_mode_vrefresh().  We could either use that or the adjusted_mode's
original vrefresh value.

However, we can maintain a more exact vrefresh value (not just the
integer approximation), by scaling by the ratio of our clocks.

v2: Use math suggested by Andrzej Hajda instead.
v3: Simplify math now that adjusted_mode->clock isn't padded.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index eb787eed8abe..2516cd3a1d87 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -862,7 +862,8 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
 	adjusted_mode->clock = pixel_clock_hz / 1000;
 
 	/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
-	adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal);
+	adjusted_mode->htotal = (adjusted_mode->clock * mode->htotal /
+				 mode->clock);
 	adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal;
 	adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal;
 
-- 
2.14.1

Re: [PATCH v6 2/5] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math.

[Andrzej Hajda]

On 16.08.2017 01:47, Eric Anholt wrote:
> The incoming mode might have a missing vrefresh field if it came from
> drmModeSetCrtc(), which the kernel is supposed to calculate using
> drm_mode_vrefresh().  We could either use that or the adjusted_mode's
> original vrefresh value.
>
> However, we can maintain a more exact vrefresh value (not just the
> integer approximation), by scaling by the ratio of our clocks.
>
> v2: Use math suggested by Andrzej Hajda instead.
> v3: Simplify math now that adjusted_mode->clock isn't padded.
>
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>  drivers/gpu/drm/vc4/vc4_dsi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index eb787eed8abe..2516cd3a1d87 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -862,7 +862,8 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
>  	adjusted_mode->clock = pixel_clock_hz / 1000;
>  
>  	/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
> -	adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal);
> +	adjusted_mode->htotal = (adjusted_mode->clock * mode->htotal /
> +				 mode->clock);

Parentheses can be removed.
Beside this:

Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

 --
Regards
Andrzej

>  	adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal;
>  	adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal;
>  

Re: [PATCH v6 2/5] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math.

[Boris Brezillon]

On Tue, 15 Aug 2017 16:47:19 -0700
Eric Anholt <eric@anholt.net> wrote:

> The incoming mode might have a missing vrefresh field if it came from
> drmModeSetCrtc(), which the kernel is supposed to calculate using
> drm_mode_vrefresh().  We could either use that or the adjusted_mode's
> original vrefresh value.
> 
> However, we can maintain a more exact vrefresh value (not just the
> integer approximation), by scaling by the ratio of our clocks.
> 
> v2: Use math suggested by Andrzej Hajda instead.
> v3: Simplify math now that adjusted_mode->clock isn't padded.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>

Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

> ---
>  drivers/gpu/drm/vc4/vc4_dsi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index eb787eed8abe..2516cd3a1d87 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -862,7 +862,8 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
>  	adjusted_mode->clock = pixel_clock_hz / 1000;
>  
>  	/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
> -	adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal);
> +	adjusted_mode->htotal = (adjusted_mode->clock * mode->htotal /
> +				 mode->clock);
>  	adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal;
>  	adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal;
>  

[PATCH v6 3/5] drm/vc4: Set up the DSI host at pdev probe time, not component bind.

[Eric Anholt]

We need the following things to happen in sequence:

DSI host creation
DSI device creation in the panel driver (needs DSI host)
DSI device attach from panel to host.
DSI drm_panel_add()
DSI encoder creation
DSI encoder's DRM panel/bridge attach

Unless we allow device creation while the host isn't up yet, we need
to break the -EPROBE_DEFER deadlock between the panel driver looking
up the host and the host driver looking up the panel.  We can do so by
moving the DSI host creation outside of the component bind loop, and
the panel/bridge lookup/attach into the component bind process.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 97 +++++++++++++++++++++++++------------------
 1 file changed, 57 insertions(+), 40 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index 2516cd3a1d87..ec1d646b3151 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -33,6 +33,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_mipi_dsi.h>
+#include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
@@ -504,7 +505,6 @@ struct vc4_dsi {
 	struct mipi_dsi_host dsi_host;
 	struct drm_encoder *encoder;
 	struct drm_bridge *bridge;
-	bool is_panel_bridge;
 
 	void __iomem *regs;
 
@@ -1289,7 +1289,6 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
 			       struct mipi_dsi_device *device)
 {
 	struct vc4_dsi *dsi = host_to_dsi(host);
-	int ret = 0;
 
 	dsi->lanes = device->lanes;
 	dsi->channel = device->channel;
@@ -1324,34 +1323,12 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
 		return 0;
 	}
 
-	dsi->bridge = of_drm_find_bridge(device->dev.of_node);
-	if (!dsi->bridge) {
-		struct drm_panel *panel =
-			of_drm_find_panel(device->dev.of_node);
-
-		dsi->bridge = drm_panel_bridge_add(panel,
-						   DRM_MODE_CONNECTOR_DSI);
-		if (IS_ERR(dsi->bridge)) {
-			ret = PTR_ERR(dsi->bridge);
-			dsi->bridge = NULL;
-			return ret;
-		}
-		dsi->is_panel_bridge = true;
-	}
-
-	return drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
+	return 0;
 }
 
 static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
 			       struct mipi_dsi_device *device)
 {
-	struct vc4_dsi *dsi = host_to_dsi(host);
-
-	if (dsi->is_panel_bridge) {
-		drm_panel_bridge_remove(dsi->bridge);
-		dsi->bridge = NULL;
-	}
-
 	return 0;
 }
 
@@ -1493,16 +1470,13 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct drm_device *drm = dev_get_drvdata(master);
 	struct vc4_dev *vc4 = to_vc4_dev(drm);
-	struct vc4_dsi *dsi;
+	struct vc4_dsi *dsi = dev_get_drvdata(dev);
 	struct vc4_dsi_encoder *vc4_dsi_encoder;
+	struct drm_panel *panel;
 	const struct of_device_id *match;
 	dma_cap_mask_t dma_mask;
 	int ret;
 
-	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
-	if (!dsi)
-		return -ENOMEM;
-
 	match = of_match_device(vc4_dsi_dt_match, dev);
 	if (!match)
 		return -ENODEV;
@@ -1517,7 +1491,6 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 	vc4_dsi_encoder->dsi = dsi;
 	dsi->encoder = &vc4_dsi_encoder->base.base;
 
-	dsi->pdev = pdev;
 	dsi->regs = vc4_ioremap_regs(pdev, 0);
 	if (IS_ERR(dsi->regs))
 		return PTR_ERR(dsi->regs);
@@ -1598,6 +1571,18 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 	}
 
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
+					  &panel, &dsi->bridge);
+	if (ret)
+		return ret;
+
+	if (panel) {
+		dsi->bridge = devm_drm_panel_bridge_add(dev, panel,
+							DRM_MODE_CONNECTOR_DSI);
+		if (IS_ERR(dsi->bridge))
+			return PTR_ERR(dsi->bridge);
+	}
+
 	/* The esc clock rate is supposed to always be 100Mhz. */
 	ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
 	if (ret) {
@@ -1616,12 +1601,11 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 			 DRM_MODE_ENCODER_DSI, NULL);
 	drm_encoder_helper_add(dsi->encoder, &vc4_dsi_encoder_helper_funcs);
 
-	dsi->dsi_host.ops = &vc4_dsi_host_ops;
-	dsi->dsi_host.dev = dev;
-
-	mipi_dsi_host_register(&dsi->dsi_host);
-
-	dev_set_drvdata(dev, dsi);
+	ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
+	if (ret) {
+		dev_err(dev, "bridge attach failed: %d\n", ret);
+		return ret;
+	}
 
 	pm_runtime_enable(dev);
 
@@ -1639,8 +1623,6 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master,
 
 	vc4_dsi_encoder_destroy(dsi->encoder);
 
-	mipi_dsi_host_unregister(&dsi->dsi_host);
-
 	if (dsi->port == 1)
 		vc4->dsi1 = NULL;
 }
@@ -1652,12 +1634,47 @@ static const struct component_ops vc4_dsi_ops = {
 
 static int vc4_dsi_dev_probe(struct platform_device *pdev)
 {
-	return component_add(&pdev->dev, &vc4_dsi_ops);
+	struct device *dev = &pdev->dev;
+	struct vc4_dsi *dsi;
+	int ret;
+
+	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
+	if (!dsi)
+		return -ENOMEM;
+	dev_set_drvdata(dev, dsi);
+
+	dsi->pdev = pdev;
+
+	/* Note, the initialization sequence for DSI and panels is
+	 * tricky.  The component bind above won't get past its
+	 * -EPROBE_DEFER until the panel/bridge probes.  The
+	 * panel/bridge will return -EPROBE_DEFER until it has a
+	 * mipi_dsi_host to register its device to.  So, we register
+	 * the host during pdev probe time, so vc4 as a whole can then
+	 * -EPROBE_DEFER its component bind process until the panel
+	 * successfully attaches.
+	 */
+	dsi->dsi_host.ops = &vc4_dsi_host_ops;
+	dsi->dsi_host.dev = dev;
+	mipi_dsi_host_register(&dsi->dsi_host);
+
+	ret = component_add(&pdev->dev, &vc4_dsi_ops);
+	if (ret) {
+		mipi_dsi_host_unregister(&dsi->dsi_host);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int vc4_dsi_dev_remove(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
+	struct vc4_dsi *dsi = dev_get_drvdata(dev);
+
 	component_del(&pdev->dev, &vc4_dsi_ops);
+	mipi_dsi_host_unregister(&dsi->dsi_host);
+
 	return 0;
 }
 
-- 
2.14.1

Re: [PATCH v6 3/5] drm/vc4: Set up the DSI host at pdev probe time, not component bind.

[Archit Taneja]

On 08/16/2017 05:17 AM, Eric Anholt wrote:
> We need the following things to happen in sequence:
> 
> DSI host creation
> DSI device creation in the panel driver (needs DSI host)
> DSI device attach from panel to host.
> DSI drm_panel_add()
> DSI encoder creation
> DSI encoder's DRM panel/bridge attach
> 
> Unless we allow device creation while the host isn't up yet, we need
> to break the -EPROBE_DEFER deadlock between the panel driver looking
> up the host and the host driver looking up the panel.  We can do so by
> moving the DSI host creation outside of the component bind loop, and
> the panel/bridge lookup/attach into the component bind process.

Reviewed-by: Archit Taneja <architt@codeaurora.org>

> 
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>   drivers/gpu/drm/vc4/vc4_dsi.c | 97 +++++++++++++++++++++++++------------------
>   1 file changed, 57 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index 2516cd3a1d87..ec1d646b3151 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -33,6 +33,7 @@
>   #include <drm/drm_crtc_helper.h>
>   #include <drm/drm_edid.h>
>   #include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_of.h>
>   #include <drm/drm_panel.h>
>   #include <linux/clk.h>
>   #include <linux/clk-provider.h>
> @@ -504,7 +505,6 @@ struct vc4_dsi {
>   	struct mipi_dsi_host dsi_host;
>   	struct drm_encoder *encoder;
>   	struct drm_bridge *bridge;
> -	bool is_panel_bridge;
>   
>   	void __iomem *regs;
>   
> @@ -1289,7 +1289,6 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
>   			       struct mipi_dsi_device *device)
>   {
>   	struct vc4_dsi *dsi = host_to_dsi(host);
> -	int ret = 0;
>   
>   	dsi->lanes = device->lanes;
>   	dsi->channel = device->channel;
> @@ -1324,34 +1323,12 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
>   		return 0;
>   	}
>   
> -	dsi->bridge = of_drm_find_bridge(device->dev.of_node);
> -	if (!dsi->bridge) {
> -		struct drm_panel *panel =
> -			of_drm_find_panel(device->dev.of_node);
> -
> -		dsi->bridge = drm_panel_bridge_add(panel,
> -						   DRM_MODE_CONNECTOR_DSI);
> -		if (IS_ERR(dsi->bridge)) {
> -			ret = PTR_ERR(dsi->bridge);
> -			dsi->bridge = NULL;
> -			return ret;
> -		}
> -		dsi->is_panel_bridge = true;
> -	}
> -
> -	return drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
> +	return 0;
>   }
>   
>   static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
>   			       struct mipi_dsi_device *device)
>   {
> -	struct vc4_dsi *dsi = host_to_dsi(host);
> -
> -	if (dsi->is_panel_bridge) {
> -		drm_panel_bridge_remove(dsi->bridge);
> -		dsi->bridge = NULL;
> -	}
> -
>   	return 0;
>   }
>   
> @@ -1493,16 +1470,13 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>   	struct platform_device *pdev = to_platform_device(dev);
>   	struct drm_device *drm = dev_get_drvdata(master);
>   	struct vc4_dev *vc4 = to_vc4_dev(drm);
> -	struct vc4_dsi *dsi;
> +	struct vc4_dsi *dsi = dev_get_drvdata(dev);
>   	struct vc4_dsi_encoder *vc4_dsi_encoder;
> +	struct drm_panel *panel;
>   	const struct of_device_id *match;
>   	dma_cap_mask_t dma_mask;
>   	int ret;
>   
> -	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> -	if (!dsi)
> -		return -ENOMEM;
> -
>   	match = of_match_device(vc4_dsi_dt_match, dev);
>   	if (!match)
>   		return -ENODEV;
> @@ -1517,7 +1491,6 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>   	vc4_dsi_encoder->dsi = dsi;
>   	dsi->encoder = &vc4_dsi_encoder->base.base;
>   
> -	dsi->pdev = pdev;
>   	dsi->regs = vc4_ioremap_regs(pdev, 0);
>   	if (IS_ERR(dsi->regs))
>   		return PTR_ERR(dsi->regs);
> @@ -1598,6 +1571,18 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>   		return ret;
>   	}
>   
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> +					  &panel, &dsi->bridge);
> +	if (ret)
> +		return ret;
> +
> +	if (panel) {
> +		dsi->bridge = devm_drm_panel_bridge_add(dev, panel,
> +							DRM_MODE_CONNECTOR_DSI);
> +		if (IS_ERR(dsi->bridge))
> +			return PTR_ERR(dsi->bridge);
> +	}
> +
>   	/* The esc clock rate is supposed to always be 100Mhz. */
>   	ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
>   	if (ret) {
> @@ -1616,12 +1601,11 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>   			 DRM_MODE_ENCODER_DSI, NULL);
>   	drm_encoder_helper_add(dsi->encoder, &vc4_dsi_encoder_helper_funcs);
>   
> -	dsi->dsi_host.ops = &vc4_dsi_host_ops;
> -	dsi->dsi_host.dev = dev;
> -
> -	mipi_dsi_host_register(&dsi->dsi_host);
> -
> -	dev_set_drvdata(dev, dsi);
> +	ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
> +	if (ret) {
> +		dev_err(dev, "bridge attach failed: %d\n", ret);
> +		return ret;
> +	}
>   
>   	pm_runtime_enable(dev);
>   
> @@ -1639,8 +1623,6 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master,
>   
>   	vc4_dsi_encoder_destroy(dsi->encoder);
>   
> -	mipi_dsi_host_unregister(&dsi->dsi_host);
> -
>   	if (dsi->port == 1)
>   		vc4->dsi1 = NULL;
>   }
> @@ -1652,12 +1634,47 @@ static const struct component_ops vc4_dsi_ops = {
>   
>   static int vc4_dsi_dev_probe(struct platform_device *pdev)
>   {
> -	return component_add(&pdev->dev, &vc4_dsi_ops);
> +	struct device *dev = &pdev->dev;
> +	struct vc4_dsi *dsi;
> +	int ret;
> +
> +	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> +	if (!dsi)
> +		return -ENOMEM;
> +	dev_set_drvdata(dev, dsi);
> +
> +	dsi->pdev = pdev;
> +
> +	/* Note, the initialization sequence for DSI and panels is
> +	 * tricky.  The component bind above won't get past its
> +	 * -EPROBE_DEFER until the panel/bridge probes.  The
> +	 * panel/bridge will return -EPROBE_DEFER until it has a
> +	 * mipi_dsi_host to register its device to.  So, we register
> +	 * the host during pdev probe time, so vc4 as a whole can then
> +	 * -EPROBE_DEFER its component bind process until the panel
> +	 * successfully attaches.
> +	 */
> +	dsi->dsi_host.ops = &vc4_dsi_host_ops;
> +	dsi->dsi_host.dev = dev;
> +	mipi_dsi_host_register(&dsi->dsi_host);
> +
> +	ret = component_add(&pdev->dev, &vc4_dsi_ops);
> +	if (ret) {
> +		mipi_dsi_host_unregister(&dsi->dsi_host);
> +		return ret;
> +	}
> +
> +	return 0;
>   }
>   
>   static int vc4_dsi_dev_remove(struct platform_device *pdev)
>   {
> +	struct device *dev = &pdev->dev;
> +	struct vc4_dsi *dsi = dev_get_drvdata(dev);
> +
>   	component_del(&pdev->dev, &vc4_dsi_ops);
> +	mipi_dsi_host_unregister(&dsi->dsi_host);
> +
>   	return 0;
>   }
>   
> 

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v6 3/5] drm/vc4: Set up the DSI host at pdev probe time, not component bind.

[Boris Brezillon]

On Tue, 15 Aug 2017 16:47:20 -0700
Eric Anholt <eric@anholt.net> wrote:

> We need the following things to happen in sequence:
> 
> DSI host creation
> DSI device creation in the panel driver (needs DSI host)
> DSI device attach from panel to host.
> DSI drm_panel_add()
> DSI encoder creation
> DSI encoder's DRM panel/bridge attach
> 
> Unless we allow device creation while the host isn't up yet, we need
> to break the -EPROBE_DEFER deadlock between the panel driver looking
> up the host and the host driver looking up the panel.  We can do so by
> moving the DSI host creation outside of the component bind loop, and
> the panel/bridge lookup/attach into the component bind process.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>

Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

> ---
>  drivers/gpu/drm/vc4/vc4_dsi.c | 97 +++++++++++++++++++++++++------------------
>  1 file changed, 57 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index 2516cd3a1d87..ec1d646b3151 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -33,6 +33,7 @@
>  #include <drm/drm_crtc_helper.h>
>  #include <drm/drm_edid.h>
>  #include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_of.h>
>  #include <drm/drm_panel.h>
>  #include <linux/clk.h>
>  #include <linux/clk-provider.h>
> @@ -504,7 +505,6 @@ struct vc4_dsi {
>  	struct mipi_dsi_host dsi_host;
>  	struct drm_encoder *encoder;
>  	struct drm_bridge *bridge;
> -	bool is_panel_bridge;
>  
>  	void __iomem *regs;
>  
> @@ -1289,7 +1289,6 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
>  			       struct mipi_dsi_device *device)
>  {
>  	struct vc4_dsi *dsi = host_to_dsi(host);
> -	int ret = 0;
>  
>  	dsi->lanes = device->lanes;
>  	dsi->channel = device->channel;
> @@ -1324,34 +1323,12 @@ static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
>  		return 0;
>  	}
>  
> -	dsi->bridge = of_drm_find_bridge(device->dev.of_node);
> -	if (!dsi->bridge) {
> -		struct drm_panel *panel =
> -			of_drm_find_panel(device->dev.of_node);
> -
> -		dsi->bridge = drm_panel_bridge_add(panel,
> -						   DRM_MODE_CONNECTOR_DSI);
> -		if (IS_ERR(dsi->bridge)) {
> -			ret = PTR_ERR(dsi->bridge);
> -			dsi->bridge = NULL;
> -			return ret;
> -		}
> -		dsi->is_panel_bridge = true;
> -	}
> -
> -	return drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
> +	return 0;
>  }
>  
>  static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
>  			       struct mipi_dsi_device *device)
>  {
> -	struct vc4_dsi *dsi = host_to_dsi(host);
> -
> -	if (dsi->is_panel_bridge) {
> -		drm_panel_bridge_remove(dsi->bridge);
> -		dsi->bridge = NULL;
> -	}
> -
>  	return 0;
>  }
>  
> @@ -1493,16 +1470,13 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>  	struct platform_device *pdev = to_platform_device(dev);
>  	struct drm_device *drm = dev_get_drvdata(master);
>  	struct vc4_dev *vc4 = to_vc4_dev(drm);
> -	struct vc4_dsi *dsi;
> +	struct vc4_dsi *dsi = dev_get_drvdata(dev);
>  	struct vc4_dsi_encoder *vc4_dsi_encoder;
> +	struct drm_panel *panel;
>  	const struct of_device_id *match;
>  	dma_cap_mask_t dma_mask;
>  	int ret;
>  
> -	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> -	if (!dsi)
> -		return -ENOMEM;
> -
>  	match = of_match_device(vc4_dsi_dt_match, dev);
>  	if (!match)
>  		return -ENODEV;
> @@ -1517,7 +1491,6 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>  	vc4_dsi_encoder->dsi = dsi;
>  	dsi->encoder = &vc4_dsi_encoder->base.base;
>  
> -	dsi->pdev = pdev;
>  	dsi->regs = vc4_ioremap_regs(pdev, 0);
>  	if (IS_ERR(dsi->regs))
>  		return PTR_ERR(dsi->regs);
> @@ -1598,6 +1571,18 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>  		return ret;
>  	}
>  
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> +					  &panel, &dsi->bridge);
> +	if (ret)
> +		return ret;
> +
> +	if (panel) {
> +		dsi->bridge = devm_drm_panel_bridge_add(dev, panel,
> +							DRM_MODE_CONNECTOR_DSI);
> +		if (IS_ERR(dsi->bridge))
> +			return PTR_ERR(dsi->bridge);
> +	}
> +
>  	/* The esc clock rate is supposed to always be 100Mhz. */
>  	ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
>  	if (ret) {
> @@ -1616,12 +1601,11 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>  			 DRM_MODE_ENCODER_DSI, NULL);
>  	drm_encoder_helper_add(dsi->encoder, &vc4_dsi_encoder_helper_funcs);
>  
> -	dsi->dsi_host.ops = &vc4_dsi_host_ops;
> -	dsi->dsi_host.dev = dev;
> -
> -	mipi_dsi_host_register(&dsi->dsi_host);
> -
> -	dev_set_drvdata(dev, dsi);
> +	ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
> +	if (ret) {
> +		dev_err(dev, "bridge attach failed: %d\n", ret);
> +		return ret;
> +	}
>  
>  	pm_runtime_enable(dev);
>  
> @@ -1639,8 +1623,6 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master,
>  
>  	vc4_dsi_encoder_destroy(dsi->encoder);
>  
> -	mipi_dsi_host_unregister(&dsi->dsi_host);
> -
>  	if (dsi->port == 1)
>  		vc4->dsi1 = NULL;
>  }
> @@ -1652,12 +1634,47 @@ static const struct component_ops vc4_dsi_ops = {
>  
>  static int vc4_dsi_dev_probe(struct platform_device *pdev)
>  {
> -	return component_add(&pdev->dev, &vc4_dsi_ops);
> +	struct device *dev = &pdev->dev;
> +	struct vc4_dsi *dsi;
> +	int ret;
> +
> +	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> +	if (!dsi)
> +		return -ENOMEM;
> +	dev_set_drvdata(dev, dsi);
> +
> +	dsi->pdev = pdev;
> +
> +	/* Note, the initialization sequence for DSI and panels is
> +	 * tricky.  The component bind above won't get past its
> +	 * -EPROBE_DEFER until the panel/bridge probes.  The
> +	 * panel/bridge will return -EPROBE_DEFER until it has a
> +	 * mipi_dsi_host to register its device to.  So, we register
> +	 * the host during pdev probe time, so vc4 as a whole can then
> +	 * -EPROBE_DEFER its component bind process until the panel
> +	 * successfully attaches.
> +	 */
> +	dsi->dsi_host.ops = &vc4_dsi_host_ops;
> +	dsi->dsi_host.dev = dev;
> +	mipi_dsi_host_register(&dsi->dsi_host);
> +
> +	ret = component_add(&pdev->dev, &vc4_dsi_ops);
> +	if (ret) {
> +		mipi_dsi_host_unregister(&dsi->dsi_host);
> +		return ret;
> +	}
> +
> +	return 0;
>  }
>  
>  static int vc4_dsi_dev_remove(struct platform_device *pdev)
>  {
> +	struct device *dev = &pdev->dev;
> +	struct vc4_dsi *dsi = dev_get_drvdata(dev);
> +
>  	component_del(&pdev->dev, &vc4_dsi_ops);
> +	mipi_dsi_host_unregister(&dsi->dsi_host);
> +
>  	return 0;
>  }
>  

[PATCH v6 4/5] dt-bindings: Document the Raspberry Pi Touchscreen nodes.

[Eric Anholt]

This doesn't yet cover input, but the driver does get the display
working when the firmware is disabled from talking to our I2C lines.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../panel/raspberrypi,7inch-touchscreen.txt        | 49 ++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/raspberrypi,7inch-touchscreen.txt

diff --git a/Documentation/devicetree/bindings/display/panel/raspberrypi,7inch-touchscreen.txt b/Documentation/devicetree/bindings/display/panel/raspberrypi,7inch-touchscreen.txt
new file mode 100644
index 000000000000..e9e19c059260
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/raspberrypi,7inch-touchscreen.txt
@@ -0,0 +1,49 @@
+This binding covers the official 7" (800x480) Raspberry Pi touchscreen
+panel.
+
+This DSI panel contains:
+
+- TC358762 DSI->DPI bridge
+- Atmel microcontroller on I2C for power sequencing the DSI bridge and
+  controlling backlight
+- Touchscreen controller on I2C for touch input
+
+and this binding covers the DSI display parts but not its touch input.
+
+Required properties:
+- compatible:	Must be "raspberrypi,7inch-touchscreen-panel"
+- reg:		Must be "45"
+- port:		See panel-common.txt
+
+Example:
+
+dsi1: dsi@7e700000 {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	<...>
+
+	port {
+		dsi_out_port: endpoint {
+			remote-endpoint = <&panel_dsi_port>;
+		};
+	};
+};
+
+i2c_dsi: i2c {
+	compatible = "i2c-gpio";
+	#address-cells = <1>;
+	#size-cells = <0>;
+	gpios = <&gpio 28 0
+		 &gpio 29 0>;
+
+	lcd@45 {
+		compatible = "raspberrypi,7inch-touchscreen-panel";
+		reg = <0x45>;
+
+		port {
+			panel_dsi_port: endpoint {
+				remote-endpoint = <&dsi_out_port>;
+			};
+		};
+	};
+};
-- 
2.14.1

[PATCH v6 5/5] drm/panel: Add support for the Raspberry Pi 7" Touchscreen.

[Eric Anholt]

This driver communicates with the Atmel microcontroller for sequencing
the poweron of the TC358762 DSI-DPI bridge and controlling the
backlight PWM.

v2: Set the same default orientation as the closed source firmware
    used, which is the best for viewing angle.
v3: Rewrite as an i2c client driver after bridge driver rejection.
v4: Finish probe without the DSI host, using the new delayed
    registration, and attach to the host during mipi_dsi_driver probe.
v5: Rework to drop the "probe without DSI host" mode again, now that
    vc4 will create the host early on.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/panel/Kconfig                      |   8 +
 drivers/gpu/drm/panel/Makefile                     |   1 +
 .../gpu/drm/panel/panel-raspberrypi-touchscreen.c  | 517 +++++++++++++++++++++
 3 files changed, 526 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index d84a031fae24..d6f1969b8a3b 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -73,6 +73,14 @@ config DRM_PANEL_PANASONIC_VVX10F034N00
 	  WUXGA (1920x1200) Novatek NT1397-based DSI panel as found in some
 	  Xperia Z2 tablets
 
+config DRM_PANEL_RASPBERRYPI_TOUCHSCREEN
+	tristate "Raspberry Pi 7-inch touchscreen panel"
+	depends on DRM_MIPI_DSI
+	help
+	  Say Y here if you want to enable support for the Raspberry
+	  Pi 7" Touchscreen.  To compile this driver as a module,
+	  choose M here.
+
 config DRM_PANEL_SAMSUNG_S6E3HA2
 	tristate "Samsung S6E3HA2 DSI video mode panel"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 9f6610d08b00..bd17fac21c7b 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(CONFIG_DRM_PANEL_PANASONIC_VVX10F034N00) += panel-panasonic-vvx10f034n00.o
+obj-$(CONFIG_DRM_PANEL_RASPBERRYPI_TOUCHSCREEN) += panel-raspberrypi-touchscreen.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E3HA2) += panel-samsung-s6e3ha2.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
new file mode 100644
index 000000000000..4237a0cbcdcc
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -0,0 +1,517 @@
+/*
+ * Copyright © 2016-2017 Broadcom
+ *
+ * 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.
+ *
+ * Portions of this file (derived from panel-simple.c) are:
+ *
+ * Copyright (C) 2013, NVIDIA Corporation.  All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * Raspberry Pi 7" touchscreen panel driver.
+ *
+ * The 7" touchscreen consists of a DPI LCD panel, a Toshiba
+ * TC358762XBG DSI-DPI bridge, and an I2C-connected Atmel ATTINY88-MUR
+ * controlling power management, the LCD PWM, and initial register
+ * setup of the Tohsiba.
+ *
+ * This driver controls the TC358762 and ATTINY88, presenting a DSI
+ * device with a drm_panel.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/pm.h>
+
+#include <drm/drm_panel.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#define RPI_DSI_DRIVER_NAME "rpi-ts-dsi"
+
+/* I2C registers of the Atmel microcontroller. */
+enum REG_ADDR {
+	REG_ID = 0x80,
+	REG_PORTA, /* BIT(2) for horizontal flip, BIT(3) for vertical flip */
+	REG_PORTB,
+	REG_PORTC,
+	REG_PORTD,
+	REG_POWERON,
+	REG_PWM,
+	REG_DDRA,
+	REG_DDRB,
+	REG_DDRC,
+	REG_DDRD,
+	REG_TEST,
+	REG_WR_ADDRL,
+	REG_WR_ADDRH,
+	REG_READH,
+	REG_READL,
+	REG_WRITEH,
+	REG_WRITEL,
+	REG_ID2,
+};
+
+/* We only turn the PWM on or off, without varying values. */
+#define RPI_TOUCHSCREEN_MAX_BRIGHTNESS 1
+
+/* DSI D-PHY Layer Registers */
+#define D0W_DPHYCONTTX		0x0004
+#define CLW_DPHYCONTRX		0x0020
+#define D0W_DPHYCONTRX		0x0024
+#define D1W_DPHYCONTRX		0x0028
+#define COM_DPHYCONTRX		0x0038
+#define CLW_CNTRL		0x0040
+#define D0W_CNTRL		0x0044
+#define D1W_CNTRL		0x0048
+#define DFTMODE_CNTRL		0x0054
+
+/* DSI PPI Layer Registers */
+#define PPI_STARTPPI		0x0104
+#define PPI_BUSYPPI		0x0108
+#define PPI_LINEINITCNT		0x0110
+#define PPI_LPTXTIMECNT		0x0114
+#define PPI_CLS_ATMR		0x0140
+#define PPI_D0S_ATMR		0x0144
+#define PPI_D1S_ATMR		0x0148
+#define PPI_D0S_CLRSIPOCOUNT	0x0164
+#define PPI_D1S_CLRSIPOCOUNT	0x0168
+#define CLS_PRE			0x0180
+#define D0S_PRE			0x0184
+#define D1S_PRE			0x0188
+#define CLS_PREP		0x01A0
+#define D0S_PREP		0x01A4
+#define D1S_PREP		0x01A8
+#define CLS_ZERO		0x01C0
+#define D0S_ZERO		0x01C4
+#define D1S_ZERO		0x01C8
+#define PPI_CLRFLG		0x01E0
+#define PPI_CLRSIPO		0x01E4
+#define HSTIMEOUT		0x01F0
+#define HSTIMEOUTENABLE		0x01F4
+
+/* DSI Protocol Layer Registers */
+#define DSI_STARTDSI		0x0204
+#define DSI_BUSYDSI		0x0208
+#define DSI_LANEENABLE		0x0210
+# define DSI_LANEENABLE_CLOCK		BIT(0)
+# define DSI_LANEENABLE_D0		BIT(1)
+# define DSI_LANEENABLE_D1		BIT(2)
+
+#define DSI_LANESTATUS0		0x0214
+#define DSI_LANESTATUS1		0x0218
+#define DSI_INTSTATUS		0x0220
+#define DSI_INTMASK		0x0224
+#define DSI_INTCLR		0x0228
+#define DSI_LPTXTO		0x0230
+#define DSI_MODE		0x0260
+#define DSI_PAYLOAD0		0x0268
+#define DSI_PAYLOAD1		0x026C
+#define DSI_SHORTPKTDAT		0x0270
+#define DSI_SHORTPKTREQ		0x0274
+#define DSI_BTASTA		0x0278
+#define DSI_BTACLR		0x027C
+
+/* DSI General Registers */
+#define DSIERRCNT		0x0300
+#define DSISIGMOD		0x0304
+
+/* DSI Application Layer Registers */
+#define APLCTRL			0x0400
+#define APLSTAT			0x0404
+#define APLERR			0x0408
+#define PWRMOD			0x040C
+#define RDPKTLN			0x0410
+#define PXLFMT			0x0414
+#define MEMWRCMD		0x0418
+
+/* LCDC/DPI Host Registers */
+#define LCDCTRL			0x0420
+#define HSR			0x0424
+#define HDISPR			0x0428
+#define VSR			0x042C
+#define VDISPR			0x0430
+#define VFUEN			0x0434
+
+/* DBI-B Host Registers */
+#define DBIBCTRL		0x0440
+
+/* SPI Master Registers */
+#define SPICMR			0x0450
+#define SPITCR			0x0454
+
+/* System Controller Registers */
+#define SYSSTAT			0x0460
+#define SYSCTRL			0x0464
+#define SYSPLL1			0x0468
+#define SYSPLL2			0x046C
+#define SYSPLL3			0x0470
+#define SYSPMCTRL		0x047C
+
+/* GPIO Registers */
+#define GPIOC			0x0480
+#define GPIOO			0x0484
+#define GPIOI			0x0488
+
+/* I2C Registers */
+#define I2CCLKCTRL		0x0490
+
+/* Chip/Rev Registers */
+#define IDREG			0x04A0
+
+/* Debug Registers */
+#define WCMDQUEUE		0x0500
+#define RCMDQUEUE		0x0504
+
+struct rpi_touchscreen {
+	struct drm_panel base;
+	struct mipi_dsi_device *dsi;
+	struct i2c_client *i2c;
+};
+
+static const struct drm_display_mode rpi_touchscreen_modes[] = {
+	{
+		/* Modeline comes from the Raspberry Pi firmware, with HFP=1
+		 * plugged in and clock re-computed from that.
+		 */
+		.clock = 25979400 / 1000,
+		.hdisplay = 800,
+		.hsync_start = 800 + 1,
+		.hsync_end = 800 + 1 + 2,
+		.htotal = 800 + 1 + 2 + 46,
+		.vdisplay = 480,
+		.vsync_start = 480 + 7,
+		.vsync_end = 480 + 7 + 2,
+		.vtotal = 480 + 7 + 2 + 21,
+		.vrefresh = 60,
+	},
+};
+
+static struct rpi_touchscreen *panel_to_ts(struct drm_panel *panel)
+{
+	return container_of(panel, struct rpi_touchscreen, base);
+}
+
+static u8 rpi_touchscreen_i2c_read(struct rpi_touchscreen *ts, u8 reg)
+{
+	return i2c_smbus_read_byte_data(ts->i2c, reg);
+}
+
+static void rpi_touchscreen_i2c_write(struct rpi_touchscreen *ts,
+				      u8 reg, u8 val)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(ts->i2c, reg, val);
+	if (ret)
+		dev_err(&ts->dsi->dev, "I2C write failed: %d\n", ret);
+}
+
+static int rpi_touchscreen_write(struct rpi_touchscreen *ts, u16 reg, u32 val)
+{
+#if 0
+	/* The firmware uses LP DSI transactions like this to bring up
+	 * the hardware, which should be faster than using I2C to then
+	 * pass to the Toshiba.  However, I was unable to get it to
+	 * work.
+	 */
+	u8 msg[] = {
+		reg,
+		reg >> 8,
+		val,
+		val >> 8,
+		val >> 16,
+		val >> 24,
+	};
+
+	mipi_dsi_dcs_write_buffer(ts->dsi, msg, sizeof(msg));
+#else
+	rpi_touchscreen_i2c_write(ts, REG_WR_ADDRH, reg >> 8);
+	rpi_touchscreen_i2c_write(ts, REG_WR_ADDRL, reg);
+	rpi_touchscreen_i2c_write(ts, REG_WRITEH, val >> 8);
+	rpi_touchscreen_i2c_write(ts, REG_WRITEL, val);
+#endif
+
+	return 0;
+}
+
+static int rpi_touchscreen_disable(struct drm_panel *panel)
+{
+	struct rpi_touchscreen *ts = panel_to_ts(panel);
+
+	rpi_touchscreen_i2c_write(ts, REG_PWM, 0);
+
+	rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
+	udelay(1);
+
+	return 0;
+}
+
+static int rpi_touchscreen_noop(struct drm_panel *panel)
+{
+	return 0;
+}
+
+static int rpi_touchscreen_enable(struct drm_panel *panel)
+{
+	struct rpi_touchscreen *ts = panel_to_ts(panel);
+	int i;
+
+	rpi_touchscreen_i2c_write(ts, REG_POWERON, 1);
+	/* Wait for nPWRDWN to go low to indicate poweron is done. */
+	for (i = 0; i < 100; i++) {
+		if (rpi_touchscreen_i2c_read(ts, REG_PORTB) & 1)
+			break;
+	}
+
+	rpi_touchscreen_write(ts, DSI_LANEENABLE,
+			      DSI_LANEENABLE_CLOCK |
+			      DSI_LANEENABLE_D0);
+	rpi_touchscreen_write(ts, PPI_D0S_CLRSIPOCOUNT, 0x05);
+	rpi_touchscreen_write(ts, PPI_D1S_CLRSIPOCOUNT, 0x05);
+	rpi_touchscreen_write(ts, PPI_D0S_ATMR, 0x00);
+	rpi_touchscreen_write(ts, PPI_D1S_ATMR, 0x00);
+	rpi_touchscreen_write(ts, PPI_LPTXTIMECNT, 0x03);
+
+	rpi_touchscreen_write(ts, SPICMR, 0x00);
+	rpi_touchscreen_write(ts, LCDCTRL, 0x00100150);
+	rpi_touchscreen_write(ts, SYSCTRL, 0x040f);
+	msleep(100);
+
+	rpi_touchscreen_write(ts, PPI_STARTPPI, 0x01);
+	rpi_touchscreen_write(ts, DSI_STARTDSI, 0x01);
+	msleep(100);
+
+	/* Turn on the backlight. */
+	rpi_touchscreen_i2c_write(ts, REG_PWM, 255);
+
+	/* Default to the same orientation as the closed source
+	 * firmware used for the panel.  Runtime rotation
+	 * configuration will be supported using VC4's plane
+	 * orientation bits.
+	 */
+	rpi_touchscreen_i2c_write(ts, REG_PORTA, BIT(2));
+
+	return 0;
+}
+
+static int rpi_touchscreen_get_modes(struct drm_panel *panel)
+{
+	struct drm_connector *connector = panel->connector;
+	struct drm_device *drm = panel->drm;
+	unsigned int i, num = 0;
+	static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+
+	for (i = 0; i < ARRAY_SIZE(rpi_touchscreen_modes); i++) {
+		const struct drm_display_mode *m = &rpi_touchscreen_modes[i];
+		struct drm_display_mode *mode;
+
+		mode = drm_mode_duplicate(drm, m);
+		if (!mode) {
+			dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
+				m->hdisplay, m->vdisplay, m->vrefresh);
+			continue;
+		}
+
+		mode->type |= DRM_MODE_TYPE_DRIVER;
+
+		if (i == 0)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+		drm_mode_set_name(mode);
+
+		drm_mode_probed_add(connector, mode);
+		num++;
+	}
+
+	connector->display_info.bpc = 8;
+	connector->display_info.width_mm = 154;
+	connector->display_info.height_mm = 86;
+	drm_display_info_set_bus_formats(&connector->display_info,
+					 &bus_format, 1);
+
+	return num;
+}
+
+static const struct drm_panel_funcs rpi_touchscreen_funcs = {
+	.disable = rpi_touchscreen_disable,
+	.unprepare = rpi_touchscreen_noop,
+	.prepare = rpi_touchscreen_noop,
+	.enable = rpi_touchscreen_enable,
+	.get_modes = rpi_touchscreen_get_modes,
+};
+
+static int rpi_touchscreen_probe(struct i2c_client *i2c,
+				 const struct i2c_device_id *id)
+{
+	struct device *dev = &i2c->dev;
+	struct rpi_touchscreen *ts;
+	struct device_node *endpoint, *dsi_host_node;
+	struct mipi_dsi_host *host;
+	int ret, ver;
+	struct mipi_dsi_device_info info = {
+		.type = RPI_DSI_DRIVER_NAME,
+		.channel = 0,
+		.node = NULL,
+	};
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, ts);
+
+	ts->i2c = i2c;
+
+	ver = rpi_touchscreen_i2c_read(ts, REG_ID);
+	if (ver < 0) {
+		dev_err(dev, "Atmel I2C read failed: %d\n", ver);
+		return -ENODEV;
+	}
+
+	switch (ver) {
+	case 0xde: /* ver 1 */
+	case 0xc3: /* ver 2 */
+		break;
+	default:
+		dev_err(dev, "Unknown Atmel firmware revision: 0x%02x\n", ver);
+		return -ENODEV;
+	}
+
+	/* Turn off at boot, so we can cleanly sequence powering on. */
+	rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
+
+	/* Look up the DSI host.  It needs to probe before we do. */
+	endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
+	dsi_host_node = of_graph_get_remote_port_parent(endpoint);
+	host = of_find_mipi_dsi_host_by_node(dsi_host_node);
+	of_node_put(dsi_host_node);
+	if (!host) {
+		of_node_put(endpoint);
+		return -EPROBE_DEFER;
+	}
+
+	info.node = of_graph_get_remote_port(endpoint);
+	of_node_put(endpoint);
+
+	ts->dsi = mipi_dsi_device_register_full(host, &info);
+	if (IS_ERR(ts->dsi)) {
+		dev_err(dev, "DSI device registration failed: %ld\n",
+			PTR_ERR(ts->dsi));
+		return PTR_ERR(ts->dsi);
+	}
+
+	ts->base.dev = dev;
+	ts->base.funcs = &rpi_touchscreen_funcs;
+
+	/* This appears last, as it's what will unblock the DSI host
+	 * driver's component bind function.
+	 */
+	ret = drm_panel_add(&ts->base);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int rpi_touchscreen_remove(struct i2c_client *i2c)
+{
+	struct rpi_touchscreen *ts = i2c_get_clientdata(i2c);
+
+	mipi_dsi_detach(ts->dsi);
+
+	drm_panel_remove(&ts->base);
+
+	mipi_dsi_device_unregister(ts->dsi);
+	kfree(ts->dsi);
+
+	return 0;
+}
+
+static int rpi_touchscreen_dsi_probe(struct mipi_dsi_device *dsi)
+{
+	int ret;
+
+	dsi->mode_flags = (MIPI_DSI_MODE_VIDEO |
+			   MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+			   MIPI_DSI_MODE_LPM);
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = 1;
+
+	ret = mipi_dsi_attach(dsi);
+
+	if (ret)
+		dev_err(&dsi->dev, "failed to attach dsi to host: %d\n", ret);
+
+	return ret;
+}
+
+static struct mipi_dsi_driver rpi_touchscreen_dsi_driver = {
+	.driver.name = RPI_DSI_DRIVER_NAME,
+	.probe = rpi_touchscreen_dsi_probe,
+};
+
+static const struct of_device_id rpi_touchscreen_of_ids[] = {
+	{ .compatible = "raspberrypi,7inch-touchscreen-panel" },
+	{ } /* sentinel */
+};
+MODULE_DEVICE_TABLE(of, rpi_touchscreen_of_ids);
+
+static struct i2c_driver rpi_touchscreen_driver = {
+	.driver = {
+		.name = "rpi_touchscreen",
+		.of_match_table = rpi_touchscreen_of_ids,
+	},
+	.probe = rpi_touchscreen_probe,
+	.remove = rpi_touchscreen_remove,
+};
+
+static int __init rpi_touchscreen_init(void)
+{
+	mipi_dsi_driver_register(&rpi_touchscreen_dsi_driver);
+	return i2c_add_driver(&rpi_touchscreen_driver);
+}
+module_init(rpi_touchscreen_init);
+
+static void __exit rpi_touchscreen_exit(void)
+{
+	i2c_del_driver(&rpi_touchscreen_driver);
+	mipi_dsi_driver_unregister(&rpi_touchscreen_dsi_driver);
+}
+module_exit(rpi_touchscreen_exit);
+
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Raspberry Pi 7-inch touchscreen driver");
+MODULE_LICENSE("GPL v2");
-- 
2.14.1

Re: [PATCH v6 1/5] drm/vc4: Move the DSI clock divider workaround closer to the clock call.

[Boris Brezillon]

On Tue, 15 Aug 2017 16:47:18 -0700
Eric Anholt <eric@anholt.net> wrote:

> We want the adjusted_mode->clock to be the actual clock we're
> expecting to program, so that consumers see the right values for clock
> and vrefresh.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>

Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>

> ---
>  drivers/gpu/drm/vc4/vc4_dsi.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index d1e0dc908048..eb787eed8abe 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -859,11 +859,7 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
>  	pll_clock = parent_rate / divider;
>  	pixel_clock_hz = pll_clock / dsi->divider;
>  
> -	/* Round up the clk_set_rate() request slightly, since
> -	 * PLLD_DSI1 is an integer divider and its rate selection will
> -	 * never round up.
> -	 */
> -	adjusted_mode->clock = pixel_clock_hz / 1000 + 1;
> +	adjusted_mode->clock = pixel_clock_hz / 1000;
>  
>  	/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
>  	adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal);
> @@ -900,7 +896,11 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
>  		vc4_dsi_dump_regs(dsi);
>  	}
>  
> -	phy_clock = pixel_clock_hz * dsi->divider;
> +	/* Round up the clk_set_rate() request slightly, since
> +	 * PLLD_DSI1 is an integer divider and its rate selection will
> +	 * never round up.
> +	 */
> +	phy_clock = (pixel_clock_hz + 1000) * dsi->divider;
>  	ret = clk_set_rate(dsi->pll_phy_clock, phy_clock);
>  	if (ret) {
>  		dev_err(&dsi->pdev->dev,