[PATCH v4 0/4] ti-sn65dsi83 patches

[PATCH v4 0/4] ti-sn65dsi83 patches

[Alexander Stein]

Changes in V4 of this set:
* Rebased to next-20211118 (due to merge-conflict in linux-next)
* Added Rob Herring's Ack on Patch 1 & 3
* Reworked patch 4 due to other changes in linux-next
* Removed Sam Ravnborg's Reviewed-by for patch4 due to rework

Changes in V3 of this set:
* Do not require vcc-supply in bindings, making it purely optional
* Move regulator enable/disable to sn65dsi83_atomic_pre_enable and
  sn65dsi83_atomic_disable

Changes in V2 of this set:
* Add patch from Laurent for fixing the binding regarding optional GPIO
* Reorder patches so bindings are changed beforehand
* Add small fixes from Sam's review

Alexander Stein (3):
  drm/bridge: ti-sn65dsi83: Make enable GPIO optional
  dt-bindings: drm/bridge: ti-sn65dsi83: Add vcc supply bindings
  drm/bridge: ti-sn65dsi83: Add vcc supply regulator support

Laurent Pinchart (1):
  dt-bindings: display: bridge: sn65dsi83: Make enable GPIO optional

 .../bindings/display/bridge/ti,sn65dsi83.yaml |  5 ++++-
 drivers/gpu/drm/bridge/ti-sn65dsi83.c         | 22 ++++++++++++++++++-
 2 files changed, 25 insertions(+), 2 deletions(-)

-- 
2.25.1

[PATCH v4 1/4] dt-bindings: display: bridge: sn65dsi83: Make enable GPIO optional

[Alexander Stein]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The SN65DSI8x EN signal may be tied to VCC, or otherwise controlled by
means not available to the kernel. Make the GPIO optional.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
 .../devicetree/bindings/display/bridge/ti,sn65dsi83.yaml         | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
index b446d0f0f1b4..c3f3e73f740a 100644
--- a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
@@ -91,7 +91,6 @@ properties:
 required:
   - compatible
   - reg
-  - enable-gpios
   - ports
 
 allOf:
-- 
2.25.1

[PATCH v4 2/4] drm/bridge: ti-sn65dsi83: Make enable GPIO optional

[Alexander Stein]

The enable signal may not be controllable by the kernel. Make it
optional.
This is a similar to commit bbda1704fc15 ("drm/bridge: ti-sn65dsi86: Make
enable GPIO optional")

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
 drivers/gpu/drm/bridge/ti-sn65dsi83.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
index 945f08de45f1..065610edc37a 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
@@ -662,7 +662,8 @@ static int sn65dsi83_probe(struct i2c_client *client,
 	}
 
 	/* Put the chip in reset, pull EN line low, and assure 10ms reset low timing. */
-	ctx->enable_gpio = devm_gpiod_get(ctx->dev, "enable", GPIOD_OUT_LOW);
+	ctx->enable_gpio = devm_gpiod_get_optional(ctx->dev, "enable",
+						   GPIOD_OUT_LOW);
 	if (IS_ERR(ctx->enable_gpio))
 		return PTR_ERR(ctx->enable_gpio);
 
-- 
2.25.1

[PATCH v4 3/4] dt-bindings: drm/bridge: ti-sn65dsi83: Add vcc supply bindings

[Alexander Stein]

Add a VCC regulator which needs to be enabled before the EN pin is
released.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
 .../devicetree/bindings/display/bridge/ti,sn65dsi83.yaml      | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
index c3f3e73f740a..48a97bb3e2e0 100644
--- a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
@@ -32,6 +32,9 @@ properties:
     maxItems: 1
     description: GPIO specifier for bridge_en pin (active high).
 
+  vcc-supply:
+    description: A 1.8V power supply (see regulator/regulator.yaml).
+
   ports:
     $ref: /schemas/graph.yaml#/properties/ports
 
@@ -132,6 +135,7 @@ examples:
             reg = <0x2d>;
 
             enable-gpios = <&gpio2 1 GPIO_ACTIVE_HIGH>;
+            vcc-supply = <&reg_sn65dsi83_1v8>;
 
             ports {
                 #address-cells = <1>;
-- 
2.25.1

[PATCH v4 4/4] drm/bridge: ti-sn65dsi83: Add vcc supply regulator support

[Alexander Stein]

VCC needs to be enabled before releasing the enable GPIO.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
---
 drivers/gpu/drm/bridge/ti-sn65dsi83.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
index 065610edc37a..54d18e82ed74 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
@@ -33,6 +33,7 @@
 #include <linux/of_device.h>
 #include <linux/of_graph.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
@@ -143,6 +144,7 @@ struct sn65dsi83 {
 	struct mipi_dsi_device		*dsi;
 	struct drm_bridge		*panel_bridge;
 	struct gpio_desc		*enable_gpio;
+	struct regulator		*vcc;
 	int				dsi_lanes;
 	bool				lvds_dual_link;
 	bool				lvds_dual_link_even_odd_swap;
@@ -337,6 +339,12 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
 	u16 val;
 	int ret;
 
+	ret = regulator_enable(ctx->vcc);
+	if (ret) {
+		dev_err(ctx->dev, "Failed to enable vcc\n");
+		return;
+	}
+
 	/* Deassert reset */
 	gpiod_set_value(ctx->enable_gpio, 1);
 	usleep_range(1000, 1100);
@@ -486,11 +494,16 @@ static void sn65dsi83_atomic_disable(struct drm_bridge *bridge,
 				     struct drm_bridge_state *old_bridge_state)
 {
 	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
+	int ret;
 
 	/* Put the chip in reset, pull EN line low, and assure 10ms reset low timing. */
 	gpiod_set_value(ctx->enable_gpio, 0);
 	usleep_range(10000, 11000);
 
+	ret = regulator_disable(ctx->vcc);
+	if (ret)
+		dev_err(ctx->dev, "Failed to disable vcc: %i\n", ret);
+
 	regcache_mark_dirty(ctx->regmap);
 }
 
@@ -599,6 +612,12 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
 
 	ctx->panel_bridge = panel_bridge;
 
+	ctx->vcc = devm_regulator_get(dev, "vcc");
+	if (IS_ERR(ctx->vcc))
+		return dev_err_probe(dev, PTR_ERR(ctx->vcc),
+				     "Failed to get supply 'vcc': %pe\n",
+				     ERR_PTR(ret));
+
 	return 0;
 }
 
-- 
2.25.1

Re: [PATCH v4 4/4] drm/bridge: ti-sn65dsi83: Add vcc supply regulator support

[Jagan Teki]

On Thu, Nov 18, 2021 at 2:50 PM Alexander Stein
<alexander.stein@ew.tq-group.com> wrote:
>
> VCC needs to be enabled before releasing the enable GPIO.
>
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> ---
>  drivers/gpu/drm/bridge/ti-sn65dsi83.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> index 065610edc37a..54d18e82ed74 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> @@ -33,6 +33,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_graph.h>
>  #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
> @@ -143,6 +144,7 @@ struct sn65dsi83 {
>         struct mipi_dsi_device          *dsi;
>         struct drm_bridge               *panel_bridge;
>         struct gpio_desc                *enable_gpio;
> +       struct regulator                *vcc;
>         int                             dsi_lanes;
>         bool                            lvds_dual_link;
>         bool                            lvds_dual_link_even_odd_swap;
> @@ -337,6 +339,12 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
>         u16 val;
>         int ret;
>
> +       ret = regulator_enable(ctx->vcc);
> +       if (ret) {
> +               dev_err(ctx->dev, "Failed to enable vcc\n");
> +               return;
> +       }

Better check the vcc and enable it since it is an optional one.

Jagan.

Re: [PATCH v4 1/4] dt-bindings: display: bridge: sn65dsi83: Make enable GPIO optional

[Jagan Teki]

On Thu, Nov 18, 2021 at 2:50 PM Alexander Stein
<alexander.stein@ew.tq-group.com> wrote:
>
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>
> The SN65DSI8x EN signal may be tied to VCC, or otherwise controlled by
> means not available to the kernel. Make the GPIO optional.

Sorry, I couldn't understand what it means. Does it mean VCC enabled
designs no need to enable GPIO? I've a design that do support both EN
and VCC.

Jagan.

Re: [PATCH v4 3/4] dt-bindings: drm/bridge: ti-sn65dsi83: Add vcc supply bindings

[Jagan Teki]

On Thu, Nov 18, 2021 at 2:50 PM Alexander Stein
<alexander.stein@ew.tq-group.com> wrote:
>
> Add a VCC regulator which needs to be enabled before the EN pin is
> released.
>
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> Acked-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> ---
>  .../devicetree/bindings/display/bridge/ti,sn65dsi83.yaml      | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
> index c3f3e73f740a..48a97bb3e2e0 100644
> --- a/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/ti,sn65dsi83.yaml
> @@ -32,6 +32,9 @@ properties:
>      maxItems: 1
>      description: GPIO specifier for bridge_en pin (active high).
>
> +  vcc-supply:
> +    description: A 1.8V power supply (see regulator/regulator.yaml).

Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>

Re: (EXT) Re: [PATCH v4 1/4] dt-bindings: display: bridge: sn65dsi83: Make enable GPIO optional

[Alexander Stein]

Am Donnerstag, dem 09.12.2021 um 12:37 +0530 schrieb Jagan Teki:
> On Thu, Nov 18, 2021 at 2:50 PM Alexander Stein
> <
> alexander.stein@ew.tq-group.com
> > wrote:
> > From: Laurent Pinchart <
> > laurent.pinchart@ideasonboard.com
> > >
> > 
> > The SN65DSI8x EN signal may be tied to VCC, or otherwise controlled
> > by
> > means not available to the kernel. Make the GPIO optional.
> 
> Sorry, I couldn't understand what it means. Does it mean VCC enabled
> designs no need to enable GPIO? I've a design that do support both EN
> and VCC.

The patches 1 & 2 are only about the "enable" gpio for the bridge, it's
unrelated to the VCC regulator introduced in patch 3 & 4.
Maybe the commit message should say:
> The SN65DSI8x EN signal may be hard-wired to VCC, or otherwise
controlled[...]
But I copied the message from bbda1704fc15 ("drm/bridge: ti-sn65dsi86:
Make enable GPIO optional").

This is for use-cases where there is no GPIO the kernel can use, to
control the EN pad of the bridge. Thus make this gpio optional in
bindings and driver.

HTH
Alexander

Re: [PATCH v4 4/4] drm/bridge: ti-sn65dsi83: Add vcc supply regulator support

[Laurent Pinchart]

Hi Alexander,

Thank you for the patch.

On Thu, Nov 18, 2021 at 10:19:55AM +0100, Alexander Stein wrote:
> VCC needs to be enabled before releasing the enable GPIO.
> 
> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> ---
>  drivers/gpu/drm/bridge/ti-sn65dsi83.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> index 065610edc37a..54d18e82ed74 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> @@ -33,6 +33,7 @@
>  #include <linux/of_device.h>
>  #include <linux/of_graph.h>
>  #include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
>  
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
> @@ -143,6 +144,7 @@ struct sn65dsi83 {
>  	struct mipi_dsi_device		*dsi;
>  	struct drm_bridge		*panel_bridge;
>  	struct gpio_desc		*enable_gpio;
> +	struct regulator		*vcc;
>  	int				dsi_lanes;
>  	bool				lvds_dual_link;
>  	bool				lvds_dual_link_even_odd_swap;
> @@ -337,6 +339,12 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
>  	u16 val;
>  	int ret;
>  
> +	ret = regulator_enable(ctx->vcc);
> +	if (ret) {
> +		dev_err(ctx->dev, "Failed to enable vcc\n");

I'd print the error code here as you do so in
sn65dsi83_atomic_disable().

> +		return;
> +	}
> +
>  	/* Deassert reset */
>  	gpiod_set_value(ctx->enable_gpio, 1);
>  	usleep_range(1000, 1100);
> @@ -486,11 +494,16 @@ static void sn65dsi83_atomic_disable(struct drm_bridge *bridge,
>  				     struct drm_bridge_state *old_bridge_state)
>  {
>  	struct sn65dsi83 *ctx = bridge_to_sn65dsi83(bridge);
> +	int ret;
>  
>  	/* Put the chip in reset, pull EN line low, and assure 10ms reset low timing. */
>  	gpiod_set_value(ctx->enable_gpio, 0);
>  	usleep_range(10000, 11000);
>  
> +	ret = regulator_disable(ctx->vcc);
> +	if (ret)
> +		dev_err(ctx->dev, "Failed to disable vcc: %i\n", ret);

I wish printf didn't have identical %i and %d specifiers :-)

> +
>  	regcache_mark_dirty(ctx->regmap);
>  }
>  
> @@ -599,6 +612,12 @@ static int sn65dsi83_parse_dt(struct sn65dsi83 *ctx, enum sn65dsi83_model model)
>  
>  	ctx->panel_bridge = panel_bridge;
>  
> +	ctx->vcc = devm_regulator_get(dev, "vcc");
> +	if (IS_ERR(ctx->vcc))
> +		return dev_err_probe(dev, PTR_ERR(ctx->vcc),
> +				     "Failed to get supply 'vcc': %pe\n",
> +				     ERR_PTR(ret));

This doesn't seem right, ret doesn't contain any useful error code at
this point.

		return dev_err_probe(dev, PTR_ERR(ctx->vcc),
				     "Failed to get supply 'vcc'\n");

should be enough, as dev_err_probe() adds the error to the message
internally.

With those small fixes,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +
>  	return 0;
>  }
>  

-- 
Regards,

Laurent Pinchart

Re: [PATCH v4 4/4] drm/bridge: ti-sn65dsi83: Add vcc supply regulator support

[Laurent Pinchart]

Hi Jagan,

On Thu, Dec 09, 2021 at 12:34:49PM +0530, Jagan Teki wrote:
> On Thu, Nov 18, 2021 at 2:50 PM Alexander Stein wrote:
> >
> > VCC needs to be enabled before releasing the enable GPIO.
> >
> > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > ---
> >  drivers/gpu/drm/bridge/ti-sn65dsi83.c | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > index 065610edc37a..54d18e82ed74 100644
> > --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > @@ -33,6 +33,7 @@
> >  #include <linux/of_device.h>
> >  #include <linux/of_graph.h>
> >  #include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> >
> >  #include <drm/drm_atomic_helper.h>
> >  #include <drm/drm_bridge.h>
> > @@ -143,6 +144,7 @@ struct sn65dsi83 {
> >         struct mipi_dsi_device          *dsi;
> >         struct drm_bridge               *panel_bridge;
> >         struct gpio_desc                *enable_gpio;
> > +       struct regulator                *vcc;
> >         int                             dsi_lanes;
> >         bool                            lvds_dual_link;
> >         bool                            lvds_dual_link_even_odd_swap;
> > @@ -337,6 +339,12 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
> >         u16 val;
> >         int ret;
> >
> > +       ret = regulator_enable(ctx->vcc);
> > +       if (ret) {
> > +               dev_err(ctx->dev, "Failed to enable vcc\n");
> > +               return;
> > +       }
> 
> Better check the vcc and enable it since it is an optional one.

Won't the regulator core create a dummy regulator if none is specified
in DT ?

-- 
Regards,

Laurent Pinchart

Re: [PATCH v4 4/4] drm/bridge: ti-sn65dsi83: Add vcc supply regulator support

[Jagan Teki]

Hi Laurent,

On Thu, Dec 9, 2021 at 10:09 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Jagan,
>
> On Thu, Dec 09, 2021 at 12:34:49PM +0530, Jagan Teki wrote:
> > On Thu, Nov 18, 2021 at 2:50 PM Alexander Stein wrote:
> > >
> > > VCC needs to be enabled before releasing the enable GPIO.
> > >
> > > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > > ---
> > >  drivers/gpu/drm/bridge/ti-sn65dsi83.c | 19 +++++++++++++++++++
> > >  1 file changed, 19 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > > index 065610edc37a..54d18e82ed74 100644
> > > --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > > +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
> > > @@ -33,6 +33,7 @@
> > >  #include <linux/of_device.h>
> > >  #include <linux/of_graph.h>
> > >  #include <linux/regmap.h>
> > > +#include <linux/regulator/consumer.h>
> > >
> > >  #include <drm/drm_atomic_helper.h>
> > >  #include <drm/drm_bridge.h>
> > > @@ -143,6 +144,7 @@ struct sn65dsi83 {
> > >         struct mipi_dsi_device          *dsi;
> > >         struct drm_bridge               *panel_bridge;
> > >         struct gpio_desc                *enable_gpio;
> > > +       struct regulator                *vcc;
> > >         int                             dsi_lanes;
> > >         bool                            lvds_dual_link;
> > >         bool                            lvds_dual_link_even_odd_swap;
> > > @@ -337,6 +339,12 @@ static void sn65dsi83_atomic_enable(struct drm_bridge *bridge,
> > >         u16 val;
> > >         int ret;
> > >
> > > +       ret = regulator_enable(ctx->vcc);
> > > +       if (ret) {
> > > +               dev_err(ctx->dev, "Failed to enable vcc\n");
> > > +               return;
> > > +       }
> >
> > Better check the vcc and enable it since it is an optional one.
>
> Won't the regulator core create a dummy regulator if none is specified
> in DT ?

Agreed, thanks (Usually I do check to avoid NULL pointer if any).

Jagan.