[v3,16/25] drm/sun4i: sun6i_mipi_dsi: Add support for VCC-DSI voltage regulator
diff mbox series

Message ID 20181026144344.27778-17-jagan@amarulasolutions.com
State Superseded
Headers show
Series
  • drm/sun4i: Allwinner A64 MIPI-DSI support
Related show

Commit Message

Jagan Teki Oct. 26, 2018, 2:43 p.m. UTC
Some boards have VCC-DSI pin connected to voltage regulator which may
not be turned on by default.

Add support for such boards by adding voltage regulator handling code to
MIPI DSI driver.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com>
---
Changes for v3:
- new patch
Changes for v2:
- none

 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 14 ++++++++++++++
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |  3 +++
 2 files changed, 17 insertions(+)

Comments

Maxime Ripard Oct. 29, 2018, 9:31 a.m. UTC | #1
On Fri, Oct 26, 2018 at 08:13:35PM +0530, Jagan Teki wrote:
> Some boards have VCC-DSI pin connected to voltage regulator which may
> not be turned on by default.
> 
> Add support for such boards by adding voltage regulator handling code to
> MIPI DSI driver.
> 
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> Tested-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
> Changes for v3:
> - new patch
> Changes for v2:
> - none
> 
>  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 14 ++++++++++++++
>  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |  3 +++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> index 42bd7506abaf..bc57343592e0 100644
> --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> @@ -949,6 +949,12 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
>  
>  	dsi->drv = drv;
>  
> +	ret = regulator_enable(dsi->regulator);
> +	if (ret) {
> +		dev_err(dev, "Failed to enable regulator\n");
> +		return ret;
> +	}
> +

The regulator should be enabled only when the device is in use.

>  	drm_encoder_helper_add(&dsi->encoder,
>  			       &sun6i_dsi_enc_helper_funcs);
>  	ret = drm_encoder_init(drm,
> @@ -980,6 +986,7 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
>  
>  err_cleanup_connector:
>  	drm_encoder_cleanup(&dsi->encoder);
> +	regulator_disable(dsi->regulator);
>  	return ret;
>  }
>  
> @@ -989,6 +996,7 @@ static void sun6i_dsi_unbind(struct device *dev, struct device *master,
>  	struct sun6i_dsi *dsi = dev_get_drvdata(dev);
>  
>  	drm_panel_detach(dsi->panel);
> +	regulator_disable(dsi->regulator);
>  }
>  
>  static const struct component_ops sun6i_dsi_ops = {
> @@ -1022,6 +1030,12 @@ static int sun6i_dsi_probe(struct platform_device *pdev)
>  		return PTR_ERR(base);
>  	}
>  
> +	dsi->regulator = devm_regulator_get(dev, "vcc-dsi");
> +	if (IS_ERR(dsi->regulator)) {
> +		dev_err(dev, "Couldn't get regulator\n");
> +		return PTR_ERR(dsi->regulator);
> +	}
> +

You haven't updated the DT bindings accordingly.

Maxime
Jagan Teki Oct. 29, 2018, 2:48 p.m. UTC | #2
On Mon, Oct 29, 2018 at 3:01 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Fri, Oct 26, 2018 at 08:13:35PM +0530, Jagan Teki wrote:
> > Some boards have VCC-DSI pin connected to voltage regulator which may
> > not be turned on by default.
> >
> > Add support for such boards by adding voltage regulator handling code to
> > MIPI DSI driver.
> >
> > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > Tested-by: Jagan Teki <jagan@amarulasolutions.com>
> > ---
> > Changes for v3:
> > - new patch
> > Changes for v2:
> > - none
> >
> >  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 14 ++++++++++++++
> >  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |  3 +++
> >  2 files changed, 17 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > index 42bd7506abaf..bc57343592e0 100644
> > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > @@ -949,6 +949,12 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
> >
> >       dsi->drv = drv;
> >
> > +     ret = regulator_enable(dsi->regulator);
> > +     if (ret) {
> > +             dev_err(dev, "Failed to enable regulator\n");
> > +             return ret;
> > +     }
> > +
>
> The regulator should be enabled only when the device is in use.

True, but there is no device specific quirk needed because who ever
not needed simply use dummy regulator
[    0.245821] sun6i-mipi-dsi 1ca0000.dsi: 1ca0000.dsi supply vcc-dsi
not found, using dummy regulato
r

even like HVCC in hdmi driver [1]

[1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c?id=633ba1e086e1abbeef1ffd899911de8cf3987d9f
Maxime Ripard Nov. 5, 2018, 8:34 a.m. UTC | #3
On Mon, Oct 29, 2018 at 08:18:05PM +0530, Jagan Teki wrote:
> On Mon, Oct 29, 2018 at 3:01 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> >
> > On Fri, Oct 26, 2018 at 08:13:35PM +0530, Jagan Teki wrote:
> > > Some boards have VCC-DSI pin connected to voltage regulator which may
> > > not be turned on by default.
> > >
> > > Add support for such boards by adding voltage regulator handling code to
> > > MIPI DSI driver.
> > >
> > > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > > Tested-by: Jagan Teki <jagan@amarulasolutions.com>
> > > ---
> > > Changes for v3:
> > > - new patch
> > > Changes for v2:
> > > - none
> > >
> > >  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 14 ++++++++++++++
> > >  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |  3 +++
> > >  2 files changed, 17 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > index 42bd7506abaf..bc57343592e0 100644
> > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
> > > @@ -949,6 +949,12 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
> > >
> > >       dsi->drv = drv;
> > >
> > > +     ret = regulator_enable(dsi->regulator);
> > > +     if (ret) {
> > > +             dev_err(dev, "Failed to enable regulator\n");
> > > +             return ret;
> > > +     }
> > > +
> >
> > The regulator should be enabled only when the device is in use.
> 
> True, but there is no device specific quirk needed because who ever
> not needed simply use dummy regulator
> [    0.245821] sun6i-mipi-dsi 1ca0000.dsi: 1ca0000.dsi supply vcc-dsi
> not found, using dummy regulato
> r
> 
> even like HVCC in hdmi driver [1]
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c?id=633ba1e086e1abbeef1ffd899911de8cf3987d9f

That's not my point. You should enable the regulator only when the DSI
bridge is being enabled, not when the driver has probed.

Maxime

Patch
diff mbox series

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 42bd7506abaf..bc57343592e0 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -949,6 +949,12 @@  static int sun6i_dsi_bind(struct device *dev, struct device *master,
 
 	dsi->drv = drv;
 
+	ret = regulator_enable(dsi->regulator);
+	if (ret) {
+		dev_err(dev, "Failed to enable regulator\n");
+		return ret;
+	}
+
 	drm_encoder_helper_add(&dsi->encoder,
 			       &sun6i_dsi_enc_helper_funcs);
 	ret = drm_encoder_init(drm,
@@ -980,6 +986,7 @@  static int sun6i_dsi_bind(struct device *dev, struct device *master,
 
 err_cleanup_connector:
 	drm_encoder_cleanup(&dsi->encoder);
+	regulator_disable(dsi->regulator);
 	return ret;
 }
 
@@ -989,6 +996,7 @@  static void sun6i_dsi_unbind(struct device *dev, struct device *master,
 	struct sun6i_dsi *dsi = dev_get_drvdata(dev);
 
 	drm_panel_detach(dsi->panel);
+	regulator_disable(dsi->regulator);
 }
 
 static const struct component_ops sun6i_dsi_ops = {
@@ -1022,6 +1030,12 @@  static int sun6i_dsi_probe(struct platform_device *pdev)
 		return PTR_ERR(base);
 	}
 
+	dsi->regulator = devm_regulator_get(dev, "vcc-dsi");
+	if (IS_ERR(dsi->regulator)) {
+		dev_err(dev, "Couldn't get regulator\n");
+		return PTR_ERR(dsi->regulator);
+	}
+
 	dsi->regs = devm_regmap_init_mmio_clk(dev, "bus", base,
 					      &sun6i_dsi_regmap_config);
 	if (IS_ERR(dsi->regs)) {
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
index 597b62227019..0df60f84bab3 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
@@ -13,6 +13,8 @@ 
 #include <drm/drm_encoder.h>
 #include <drm/drm_mipi_dsi.h>
 
+#include <linux/regulator/consumer.h>
+
 struct sun6i_dphy {
 	struct clk		*bus_clk;
 	struct clk		*mod_clk;
@@ -32,6 +34,7 @@  struct sun6i_dsi {
 	struct clk		*bus_clk;
 	struct clk		*mod_clk;
 	struct regmap		*regs;
+	struct regulator	*regulator;
 	struct reset_control	*reset;
 	struct sun6i_dphy	*dphy;