[01/14] phy: Distinguish between Rx and Tx for MIPI D-PHY with submodes
diff mbox series

Message ID 20201023174546.504028-2-paul.kocialkowski@bootlin.com
State New, archived
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Series
  • Allwinner MIPI CSI-2 support for A31/V3s/A83T
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Commit Message

Paul Kocialkowski Oct. 23, 2020, 5:45 p.m. UTC
As some D-PHY controllers support both Rx and Tx mode, we need a way for
users to explicitly request one or the other. For instance, Rx mode can
be used along with MIPI CSI-2 while Tx mode can be used with MIPI DSI.

Introduce new MIPI D-PHY PHY submodes to use with PHY_MODE_MIPI_DPHY.
The default (zero value) is kept to Tx so only the rkisp1 driver, which
uses D-PHY in Rx mode, needs to be adapted.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 drivers/staging/media/rkisp1/rkisp1-isp.c |  3 ++-
 include/linux/phy/phy-mipi-dphy.h         | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

Comments

Jernej Škrabec Oct. 23, 2020, 6:18 p.m. UTC | #1
Hi!

Dne petek, 23. oktober 2020 ob 19:45:33 CEST je Paul Kocialkowski napisal(a):
> As some D-PHY controllers support both Rx and Tx mode, we need a way for
> users to explicitly request one or the other. For instance, Rx mode can
> be used along with MIPI CSI-2 while Tx mode can be used with MIPI DSI.
> 
> Introduce new MIPI D-PHY PHY submodes to use with PHY_MODE_MIPI_DPHY.
> The default (zero value) is kept to Tx so only the rkisp1 driver, which
> uses D-PHY in Rx mode, needs to be adapted.
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
>  drivers/staging/media/rkisp1/rkisp1-isp.c |  3 ++-
>  include/linux/phy/phy-mipi-dphy.h         | 13 +++++++++++++

I think some changes are missing in this patch. For example, 
phy_set_mode_ext() must be modified to take another argument, otherwise change 
of rkisp1-isp driver doesn't make much sense.

Best regards,
Jernej

>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/rkisp1/rkisp1-isp.c b/drivers/staging/
media/rkisp1/rkisp1-isp.c
> index 6ec1e9816e9f..0afbce00121e 100644
> --- a/drivers/staging/media/rkisp1/rkisp1-isp.c
> +++ b/drivers/staging/media/rkisp1/rkisp1-isp.c
> @@ -902,7 +902,8 @@ static int rkisp1_mipi_csi2_start(struct rkisp1_isp 
*isp,
>  
>  	phy_mipi_dphy_get_default_config(pixel_clock, isp->sink_fmt-
>bus_width,
>  					 sensor->lanes, cfg);
> -	phy_set_mode(sensor->dphy, PHY_MODE_MIPI_DPHY);
> +	phy_set_mode_ext(cdev->dphy, PHY_MODE_MIPI_DPHY,
> +			 PHY_MIPI_DPHY_SUBMODE_RX);
>  	phy_configure(sensor->dphy, &opts);
>  	phy_power_on(sensor->dphy);
>  
> diff --git a/include/linux/phy/phy-mipi-dphy.h b/include/linux/phy/phy-mipi-
dphy.h
> index a877ffee845d..0f57ef46a8b5 100644
> --- a/include/linux/phy/phy-mipi-dphy.h
> +++ b/include/linux/phy/phy-mipi-dphy.h
> @@ -6,6 +6,19 @@
>  #ifndef __PHY_MIPI_DPHY_H_
>  #define __PHY_MIPI_DPHY_H_
>  
> +/**
> + * enum phy_mipi_dphy_submode - MIPI D-PHY sub-mode
> + *
> + * A MIPI D-PHY can be used to transmit or receive data.
> + * Since some controllers can support both, the direction to enable is 
specified
> + * with the PHY sub-mode. Transmit is assumed by default with phy_set_mode.
> + */
> +
> +enum phy_mipi_dphy_submode {
> +	PHY_MIPI_DPHY_SUBMODE_TX = 0,
> +	PHY_MIPI_DPHY_SUBMODE_RX,
> +};
> +
>  /**
>   * struct phy_configure_opts_mipi_dphy - MIPI D-PHY configuration set
>   *
> -- 
> 2.28.0
> 
> -- 
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linux-sunxi/20201023174546.504028-2-paul.kocialkowski%40bootlin.com.
>
Paul Kocialkowski Oct. 24, 2020, 8:31 a.m. UTC | #2
Hi Jernej,

On Fri 23 Oct 20, 20:18, Jernej Škrabec wrote:
> Dne petek, 23. oktober 2020 ob 19:45:33 CEST je Paul Kocialkowski napisal(a):
> > As some D-PHY controllers support both Rx and Tx mode, we need a way for
> > users to explicitly request one or the other. For instance, Rx mode can
> > be used along with MIPI CSI-2 while Tx mode can be used with MIPI DSI.
> > 
> > Introduce new MIPI D-PHY PHY submodes to use with PHY_MODE_MIPI_DPHY.
> > The default (zero value) is kept to Tx so only the rkisp1 driver, which
> > uses D-PHY in Rx mode, needs to be adapted.
> > 
> > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> > ---
> >  drivers/staging/media/rkisp1/rkisp1-isp.c |  3 ++-
> >  include/linux/phy/phy-mipi-dphy.h         | 13 +++++++++++++
> 
> I think some changes are missing in this patch. For example, 
> phy_set_mode_ext() must be modified to take another argument, otherwise change 
> of rkisp1-isp driver doesn't make much sense.

Thanks for looking into this! As you can see in:
https://elixir.bootlin.com/linux/latest/source/include/linux/phy/phy.h#L213

phy_set_mode_ext already takes a submode argument (which is already used for
USB mode selection, for instance) and phy_set_mode is just a macro which calls
phy_set_mode_ext with submode set to 0.

In our case, that means that most current users of phy_set_mode with
PHY_MODE_MIPI_DPHY will select Tx mode by default, so there is no particular
need for adaptation. Only the rkisp1 driver uses PHY_MODE_MIPI_DPHY for Rx,
so this one was changed to use phy_set_mode_ext with PHY_MIPI_DPHY_SUBMODE_RX
instead.

As a result, there should be no missing changes. Do you agree?

Cheers,

Paul

> Best regards,
> Jernej
> 
> >  2 files changed, 15 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/staging/media/rkisp1/rkisp1-isp.c b/drivers/staging/
> media/rkisp1/rkisp1-isp.c
> > index 6ec1e9816e9f..0afbce00121e 100644
> > --- a/drivers/staging/media/rkisp1/rkisp1-isp.c
> > +++ b/drivers/staging/media/rkisp1/rkisp1-isp.c
> > @@ -902,7 +902,8 @@ static int rkisp1_mipi_csi2_start(struct rkisp1_isp 
> *isp,
> >  
> >  	phy_mipi_dphy_get_default_config(pixel_clock, isp->sink_fmt-
> >bus_width,
> >  					 sensor->lanes, cfg);
> > -	phy_set_mode(sensor->dphy, PHY_MODE_MIPI_DPHY);
> > +	phy_set_mode_ext(cdev->dphy, PHY_MODE_MIPI_DPHY,
> > +			 PHY_MIPI_DPHY_SUBMODE_RX);
> >  	phy_configure(sensor->dphy, &opts);
> >  	phy_power_on(sensor->dphy);
> >  
> > diff --git a/include/linux/phy/phy-mipi-dphy.h b/include/linux/phy/phy-mipi-
> dphy.h
> > index a877ffee845d..0f57ef46a8b5 100644
> > --- a/include/linux/phy/phy-mipi-dphy.h
> > +++ b/include/linux/phy/phy-mipi-dphy.h
> > @@ -6,6 +6,19 @@
> >  #ifndef __PHY_MIPI_DPHY_H_
> >  #define __PHY_MIPI_DPHY_H_
> >  
> > +/**
> > + * enum phy_mipi_dphy_submode - MIPI D-PHY sub-mode
> > + *
> > + * A MIPI D-PHY can be used to transmit or receive data.
> > + * Since some controllers can support both, the direction to enable is 
> specified
> > + * with the PHY sub-mode. Transmit is assumed by default with phy_set_mode.
> > + */
> > +
> > +enum phy_mipi_dphy_submode {
> > +	PHY_MIPI_DPHY_SUBMODE_TX = 0,
> > +	PHY_MIPI_DPHY_SUBMODE_RX,
> > +};
> > +
> >  /**
> >   * struct phy_configure_opts_mipi_dphy - MIPI D-PHY configuration set
> >   *
> > -- 
> > 2.28.0
> > 
> > -- 
> > You received this message because you are subscribed to the Google Groups 
> "linux-sunxi" group.
> > To unsubscribe from this group and stop receiving emails from it, send an 
> email to linux-sunxi+unsubscribe@googlegroups.com.
> > To view this discussion on the web, visit https://groups.google.com/d/msgid/
> linux-sunxi/20201023174546.504028-2-paul.kocialkowski%40bootlin.com.
> > 
> 
>
Helen Koike Oct. 30, 2020, 10:44 p.m. UTC | #3
Hi Paul,

On 10/23/20 2:45 PM, Paul Kocialkowski wrote:
> As some D-PHY controllers support both Rx and Tx mode, we need a way for
> users to explicitly request one or the other. For instance, Rx mode can
> be used along with MIPI CSI-2 while Tx mode can be used with MIPI DSI.
> 
> Introduce new MIPI D-PHY PHY submodes to use with PHY_MODE_MIPI_DPHY.
> The default (zero value) is kept to Tx so only the rkisp1 driver, which
> uses D-PHY in Rx mode, needs to be adapted.
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
>  drivers/staging/media/rkisp1/rkisp1-isp.c |  3 ++-
>  include/linux/phy/phy-mipi-dphy.h         | 13 +++++++++++++
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/rkisp1/rkisp1-isp.c b/drivers/staging/media/rkisp1/rkisp1-isp.c
> index 6ec1e9816e9f..0afbce00121e 100644
> --- a/drivers/staging/media/rkisp1/rkisp1-isp.c
> +++ b/drivers/staging/media/rkisp1/rkisp1-isp.c
> @@ -902,7 +902,8 @@ static int rkisp1_mipi_csi2_start(struct rkisp1_isp *isp,
>  
>  	phy_mipi_dphy_get_default_config(pixel_clock, isp->sink_fmt->bus_width,
>  					 sensor->lanes, cfg);
> -	phy_set_mode(sensor->dphy, PHY_MODE_MIPI_DPHY);
> +	phy_set_mode_ext(cdev->dphy, PHY_MODE_MIPI_DPHY,
> +			 PHY_MIPI_DPHY_SUBMODE_RX);

From rkisp1 pov, looks good to me

Acked-by: Helen Koike <helen.koike@collabora.com>

Regards,
Helen

>  	phy_configure(sensor->dphy, &opts);
>  	phy_power_on(sensor->dphy);
>  
> diff --git a/include/linux/phy/phy-mipi-dphy.h b/include/linux/phy/phy-mipi-dphy.h
> index a877ffee845d..0f57ef46a8b5 100644
> --- a/include/linux/phy/phy-mipi-dphy.h
> +++ b/include/linux/phy/phy-mipi-dphy.h
> @@ -6,6 +6,19 @@
>  #ifndef __PHY_MIPI_DPHY_H_
>  #define __PHY_MIPI_DPHY_H_
>  
> +/**
> + * enum phy_mipi_dphy_submode - MIPI D-PHY sub-mode
> + *
> + * A MIPI D-PHY can be used to transmit or receive data.
> + * Since some controllers can support both, the direction to enable is specified
> + * with the PHY sub-mode. Transmit is assumed by default with phy_set_mode.
> + */
> +
> +enum phy_mipi_dphy_submode {
> +	PHY_MIPI_DPHY_SUBMODE_TX = 0,
> +	PHY_MIPI_DPHY_SUBMODE_RX,
> +};
> +
>  /**
>   * struct phy_configure_opts_mipi_dphy - MIPI D-PHY configuration set
>   *
>

Patch
diff mbox series

diff --git a/drivers/staging/media/rkisp1/rkisp1-isp.c b/drivers/staging/media/rkisp1/rkisp1-isp.c
index 6ec1e9816e9f..0afbce00121e 100644
--- a/drivers/staging/media/rkisp1/rkisp1-isp.c
+++ b/drivers/staging/media/rkisp1/rkisp1-isp.c
@@ -902,7 +902,8 @@  static int rkisp1_mipi_csi2_start(struct rkisp1_isp *isp,
 
 	phy_mipi_dphy_get_default_config(pixel_clock, isp->sink_fmt->bus_width,
 					 sensor->lanes, cfg);
-	phy_set_mode(sensor->dphy, PHY_MODE_MIPI_DPHY);
+	phy_set_mode_ext(cdev->dphy, PHY_MODE_MIPI_DPHY,
+			 PHY_MIPI_DPHY_SUBMODE_RX);
 	phy_configure(sensor->dphy, &opts);
 	phy_power_on(sensor->dphy);
 
diff --git a/include/linux/phy/phy-mipi-dphy.h b/include/linux/phy/phy-mipi-dphy.h
index a877ffee845d..0f57ef46a8b5 100644
--- a/include/linux/phy/phy-mipi-dphy.h
+++ b/include/linux/phy/phy-mipi-dphy.h
@@ -6,6 +6,19 @@ 
 #ifndef __PHY_MIPI_DPHY_H_
 #define __PHY_MIPI_DPHY_H_
 
+/**
+ * enum phy_mipi_dphy_submode - MIPI D-PHY sub-mode
+ *
+ * A MIPI D-PHY can be used to transmit or receive data.
+ * Since some controllers can support both, the direction to enable is specified
+ * with the PHY sub-mode. Transmit is assumed by default with phy_set_mode.
+ */
+
+enum phy_mipi_dphy_submode {
+	PHY_MIPI_DPHY_SUBMODE_TX = 0,
+	PHY_MIPI_DPHY_SUBMODE_RX,
+};
+
 /**
  * struct phy_configure_opts_mipi_dphy - MIPI D-PHY configuration set
  *