diff mbox series

[v6,resend,2/5] phy: Add LVDS configuration options

Message ID 20220402052451.2517469-3-victor.liu@nxp.com (mailing list archive)
State New, archived
Headers show
Series phy: phy-fsl-imx8-mipi-dphy: Add i.MX8qxp LVDS PHY mode support | expand

Commit Message

Liu Ying April 2, 2022, 5:24 a.m. UTC
This patch allows LVDS PHYs to be configured through
the generic functions and through a custom structure
added to the generic union.

The parameters added here are based on common LVDS PHY
implementation practices.  The set of parameters
should cover all potential users.

Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: NXP Linux Team <linux-imx@nxp.com>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
v5->v6:
* Rebase upon v5.17-rc1.

v4->v5:
* Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
* Trivial tweaks.
* Drop Robert's R-b tag.

v3->v4:
* Add Robert's R-b tag.

v2->v3:
* No change.

v1->v2:
* No change.

 include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
 include/linux/phy/phy.h      |  4 ++++
 2 files changed, 36 insertions(+)
 create mode 100644 include/linux/phy/phy-lvds.h

Comments

Vinod Koul April 13, 2022, 6:11 a.m. UTC | #1
On 02-04-22, 13:24, Liu Ying wrote:
> This patch allows LVDS PHYs to be configured through
> the generic functions and through a custom structure
> added to the generic union.
> 
> The parameters added here are based on common LVDS PHY
> implementation practices.  The set of parameters
> should cover all potential users.
> 
> Cc: Kishon Vijay Abraham I <kishon@ti.com>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: NXP Linux Team <linux-imx@nxp.com>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v5->v6:
> * Rebase upon v5.17-rc1.
> 
> v4->v5:
> * Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
> * Trivial tweaks.
> * Drop Robert's R-b tag.
> 
> v3->v4:
> * Add Robert's R-b tag.
> 
> v2->v3:
> * No change.
> 
> v1->v2:
> * No change.
> 
>  include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
>  include/linux/phy/phy.h      |  4 ++++
>  2 files changed, 36 insertions(+)
>  create mode 100644 include/linux/phy/phy-lvds.h
> 
> diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-lvds.h
> new file mode 100644
> index 000000000000..7a2f4747f624
> --- /dev/null
> +++ b/include/linux/phy/phy-lvds.h
> @@ -0,0 +1,32 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright 2020 NXP

2022 now

> + */
> +
> +#ifndef __PHY_LVDS_H_
> +#define __PHY_LVDS_H_
> +
> +/**
> + * struct phy_configure_opts_lvds - LVDS configuration set
> + * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane and
> + *					differential clock cycle.

What does it mean by bits per data lane and differential clock cycle?

> + * @differential_clk_rate:		Clock rate, in Hertz, of the LVDS
> + *					differential clock.
> + * @lanes:				Number of active, consecutive,
> + *					data lanes, starting from lane 0,
> + *					used for the transmissions.
> + * @is_slave:				Boolean, true if the phy is a slave
> + *					which works together with a master
> + *					phy to support dual link transmission,
> + *					otherwise a regular phy or a master phy.
> + *
> + * This structure is used to represent the configuration state of a LVDS phy.
> + */
> +struct phy_configure_opts_lvds {
> +	unsigned int	bits_per_lane_and_dclk_cycle;
> +	unsigned long	differential_clk_rate;
> +	unsigned int	lanes;
> +	bool		is_slave;
> +};

Where is the user of this new configuration? Can you post that patch for
reference as well please
Liu Ying April 13, 2022, 10:04 a.m. UTC | #2
Hi Vinod,

On Wed, 2022-04-13 at 11:41 +0530, Vinod Koul wrote:
> On 02-04-22, 13:24, Liu Ying wrote:
> > This patch allows LVDS PHYs to be configured through
> > the generic functions and through a custom structure
> > added to the generic union.
> > 
> > The parameters added here are based on common LVDS PHY
> > implementation practices.  The set of parameters
> > should cover all potential users.
> > 
> > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > Cc: Vinod Koul <vkoul@kernel.org>
> > Cc: NXP Linux Team <linux-imx@nxp.com>
> > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > ---
> > v5->v6:
> > * Rebase upon v5.17-rc1.
> > 
> > v4->v5:
> > * Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
> > * Trivial tweaks.
> > * Drop Robert's R-b tag.
> > 
> > v3->v4:
> > * Add Robert's R-b tag.
> > 
> > v2->v3:
> > * No change.
> > 
> > v1->v2:
> > * No change.
> > 
> >  include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
> >  include/linux/phy/phy.h      |  4 ++++
> >  2 files changed, 36 insertions(+)
> >  create mode 100644 include/linux/phy/phy-lvds.h
> > 
> > diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-
> > lvds.h
> > new file mode 100644
> > index 000000000000..7a2f4747f624
> > --- /dev/null
> > +++ b/include/linux/phy/phy-lvds.h
> > @@ -0,0 +1,32 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright 2020 NXP
> 
> 2022 now

I may change it to 'Copyright 2020,2022 NXP'.

> 
> > + */
> > +
> > +#ifndef __PHY_LVDS_H_
> > +#define __PHY_LVDS_H_
> > +
> > +/**
> > + * struct phy_configure_opts_lvds - LVDS configuration set
> > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane
> > and
> > + *					differential clock cycle.
> 
> What does it mean by bits per data lane and differential clock cycle?

Please check Documentation/devicetree/bindings/display/panel/lvds.yaml.
lvds.yaml metions slot.  'bits_per_lane_and_dclk_cycle' means the
number of slots.  But, I don't find the word 'slot' in my lvds relevant
specs which mentioned in lvds.yaml, so 'slots' is probably not a
generic name(lvds.yaml is for display panel).  So, I use
'bits_per_lane_and_dclk_cycle' as the name tells what it means.

> 
> > + * @differential_clk_rate:		Clock rate, in Hertz, of the
> > LVDS
> > + *					differential clock.
> > + * @lanes:				Number of active, consecutive,
> > + *					data lanes, starting from lane
> > 0,
> > + *					used for the transmissions.
> > + * @is_slave:				Boolean, true if the
> > phy is a slave
> > + *					which works together with a
> > master
> > + *					phy to support dual link
> > transmission,
> > + *					otherwise a regular phy or a
> > master phy.
> > + *
> > + * This structure is used to represent the configuration state of
> > a LVDS phy.
> > + */
> > +struct phy_configure_opts_lvds {
> > +	unsigned int	bits_per_lane_and_dclk_cycle;
> > +	unsigned long	differential_clk_rate;
> > +	unsigned int	lanes;
> > +	bool		is_slave;
> > +};
> 
> Where is the user of this new configuration? Can you post that patch
> for
> reference as well please

Patch 5/5 uses it. Also, I posted two drm bridge drivers[1][2] which
use it.

[1] 
https://patchwork.kernel.org/project/dri-devel/patch/1617172405-12962-13-git-send-email-victor.liu@nxp.com/
[2] 
https://patchwork.kernel.org/project/dri-devel/patch/1617172405-12962-14-git-send-email-victor.liu@nxp.com/

Regards,
Liu Ying
Vinod Koul April 13, 2022, 10:49 a.m. UTC | #3
On 13-04-22, 18:04, Liu Ying wrote:
> Hi Vinod,
> 
> On Wed, 2022-04-13 at 11:41 +0530, Vinod Koul wrote:
> > On 02-04-22, 13:24, Liu Ying wrote:
> > > This patch allows LVDS PHYs to be configured through
> > > the generic functions and through a custom structure
> > > added to the generic union.
> > > 
> > > The parameters added here are based on common LVDS PHY
> > > implementation practices.  The set of parameters
> > > should cover all potential users.
> > > 
> > > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > > Cc: Vinod Koul <vkoul@kernel.org>
> > > Cc: NXP Linux Team <linux-imx@nxp.com>
> > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > ---
> > > v5->v6:
> > > * Rebase upon v5.17-rc1.
> > > 
> > > v4->v5:
> > > * Align kernel-doc style to include/linux/phy/phy.h. (Vinod)
> > > * Trivial tweaks.
> > > * Drop Robert's R-b tag.
> > > 
> > > v3->v4:
> > > * Add Robert's R-b tag.
> > > 
> > > v2->v3:
> > > * No change.
> > > 
> > > v1->v2:
> > > * No change.
> > > 
> > >  include/linux/phy/phy-lvds.h | 32 ++++++++++++++++++++++++++++++++
> > >  include/linux/phy/phy.h      |  4 ++++
> > >  2 files changed, 36 insertions(+)
> > >  create mode 100644 include/linux/phy/phy-lvds.h
> > > 
> > > diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-
> > > lvds.h
> > > new file mode 100644
> > > index 000000000000..7a2f4747f624
> > > --- /dev/null
> > > +++ b/include/linux/phy/phy-lvds.h
> > > @@ -0,0 +1,32 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +/*
> > > + * Copyright 2020 NXP
> > 
> > 2022 now
> 
> I may change it to 'Copyright 2020,2022 NXP'.
> 
> > 
> > > + */
> > > +
> > > +#ifndef __PHY_LVDS_H_
> > > +#define __PHY_LVDS_H_
> > > +
> > > +/**
> > > + * struct phy_configure_opts_lvds - LVDS configuration set
> > > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane
> > > and
> > > + *					differential clock cycle.
> > 
> > What does it mean by bits per data lane and differential clock cycle?
> 
> Please check Documentation/devicetree/bindings/display/panel/lvds.yaml.
> lvds.yaml metions slot.  'bits_per_lane_and_dclk_cycle' means the
> number of slots.  But, I don't find the word 'slot' in my lvds relevant
> specs which mentioned in lvds.yaml, so 'slots' is probably not a
> generic name(lvds.yaml is for display panel).  So, I use
> 'bits_per_lane_and_dclk_cycle' as the name tells what it means.

variable name is fine, explanation for bit per lane and differential
clock cycle didnt help, maybe add better explanation of what this
variable means

> 
> > 
> > > + * @differential_clk_rate:		Clock rate, in Hertz, of the
> > > LVDS
> > > + *					differential clock.
> > > + * @lanes:				Number of active, consecutive,
> > > + *					data lanes, starting from lane
> > > 0,
> > > + *					used for the transmissions.
> > > + * @is_slave:				Boolean, true if the
> > > phy is a slave
> > > + *					which works together with a
> > > master
> > > + *					phy to support dual link
> > > transmission,
> > > + *					otherwise a regular phy or a
> > > master phy.
> > > + *
> > > + * This structure is used to represent the configuration state of
> > > a LVDS phy.
> > > + */
> > > +struct phy_configure_opts_lvds {
> > > +	unsigned int	bits_per_lane_and_dclk_cycle;
> > > +	unsigned long	differential_clk_rate;
> > > +	unsigned int	lanes;
> > > +	bool		is_slave;
> > > +};
> > 
> > Where is the user of this new configuration? Can you post that patch
> > for
> > reference as well please
> 
> Patch 5/5 uses it. Also, I posted two drm bridge drivers[1][2] which
> use it.

That is phy driver not the user
> 
> [1] 
> https://patchwork.kernel.org/project/dri-devel/patch/1617172405-12962-13-git-send-email-victor.liu@nxp.com/
> [2] 
> https://patchwork.kernel.org/project/dri-devel/patch/1617172405-12962-14-git-send-email-victor.liu@nxp.com/

this is helpful, thanks
Liu Ying April 13, 2022, 12:39 p.m. UTC | #4
On Wed, 2022-04-13 at 16:19 +0530, Vinod Koul wrote:
> On 13-04-22, 18:04, Liu Ying wrote:
> > Hi Vinod,
> > 
> > On Wed, 2022-04-13 at 11:41 +0530, Vinod Koul wrote:
> > > On 02-04-22, 13:24, Liu Ying wrote:
> > > > This patch allows LVDS PHYs to be configured through
> > > > the generic functions and through a custom structure
> > > > added to the generic union.
> > > > 
> > > > The parameters added here are based on common LVDS PHY
> > > > implementation practices.  The set of parameters
> > > > should cover all potential users.
> > > > 
> > > > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > > > Cc: Vinod Koul <vkoul@kernel.org>
> > > > Cc: NXP Linux Team <linux-imx@nxp.com>
> > > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > > ---

[...]

> > > > + */
> > > > +
> > > > +#ifndef __PHY_LVDS_H_
> > > > +#define __PHY_LVDS_H_
> > > > +
> > > > +/**
> > > > + * struct phy_configure_opts_lvds - LVDS configuration set
> > > > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data
> > > > lane
> > > > and
> > > > + *					differential clock
> > > > cycle.
> > > 
> > > What does it mean by bits per data lane and differential clock
> > > cycle?
> > 
> > Please check
> > Documentation/devicetree/bindings/display/panel/lvds.yaml.
> > lvds.yaml metions slot.  'bits_per_lane_and_dclk_cycle' means the
> > number of slots.  But, I don't find the word 'slot' in my lvds
> > relevant
> > specs which mentioned in lvds.yaml, so 'slots' is probably not a
> > generic name(lvds.yaml is for display panel).  So, I use
> > 'bits_per_lane_and_dclk_cycle' as the name tells what it means.
> 
> variable name is fine, explanation for bit per lane and differential
> clock cycle didnt help, maybe add better explanation of what this
> variable means

I may add an example diagram as below...

> 
> > 
> > > 
> > > > + * @differential_clk_rate:		Clock rate, in Hertz,
> > > > of the
> > > > LVDS
> > > > + *					differential clock.
> > > > + * @lanes:				Number of active,
> > > > consecutive,
> > > > + *					data lanes, starting
> > > > from lane
> > > > 0,
> > > > + *					used for the
> > > > transmissions.
> > > > + * @is_slave:				Boolean, true if the
> > > > phy is a slave
> > > > + *					which works together
> > > > with a
> > > > master
> > > > + *					phy to support dual
> > > > link
> > > > transmission,
> > > > + *					otherwise a regular phy
> > > > or a
> > > > master phy.

---------------------------------8<------------------------------------
+ * This is an example with 4 lanes and 7 bits per data lane and
differential
+ * clock cycle:
+ *
+ * ::
+ *               |<------------- one differential clock cycle --------
----->|
+
*                ________________                         ____________
Vinod Koul April 14, 2022, 5:37 a.m. UTC | #5
On 13-04-22, 20:39, Liu Ying wrote:
> On Wed, 2022-04-13 at 16:19 +0530, Vinod Koul wrote:
> > On 13-04-22, 18:04, Liu Ying wrote:
> > > Hi Vinod,
> > > 
> > > On Wed, 2022-04-13 at 11:41 +0530, Vinod Koul wrote:
> > > > On 02-04-22, 13:24, Liu Ying wrote:
> > > > > This patch allows LVDS PHYs to be configured through
> > > > > the generic functions and through a custom structure
> > > > > added to the generic union.
> > > > > 
> > > > > The parameters added here are based on common LVDS PHY
> > > > > implementation practices.  The set of parameters
> > > > > should cover all potential users.
> > > > > 
> > > > > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > > > > Cc: Vinod Koul <vkoul@kernel.org>
> > > > > Cc: NXP Linux Team <linux-imx@nxp.com>
> > > > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > > > ---
> 
> [...]
> 
> > > > > + */
> > > > > +
> > > > > +#ifndef __PHY_LVDS_H_
> > > > > +#define __PHY_LVDS_H_
> > > > > +
> > > > > +/**
> > > > > + * struct phy_configure_opts_lvds - LVDS configuration set
> > > > > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data
> > > > > lane
> > > > > and
> > > > > + *					differential clock
> > > > > cycle.
> > > > 
> > > > What does it mean by bits per data lane and differential clock
> > > > cycle?
> > > 
> > > Please check
> > > Documentation/devicetree/bindings/display/panel/lvds.yaml.
> > > lvds.yaml metions slot.  'bits_per_lane_and_dclk_cycle' means the
> > > number of slots.  But, I don't find the word 'slot' in my lvds
> > > relevant
> > > specs which mentioned in lvds.yaml, so 'slots' is probably not a
> > > generic name(lvds.yaml is for display panel).  So, I use
> > > 'bits_per_lane_and_dclk_cycle' as the name tells what it means.
> > 
> > variable name is fine, explanation for bit per lane and differential
> > clock cycle didnt help, maybe add better explanation of what this
> > variable means
> 
> I may add an example diagram as below...

Not really a diagram, you can add if you like.. But something which
explains in a sentence or few about the variable.

bits per lane per differential clock cycle ?
Liu Ying April 14, 2022, 6:35 a.m. UTC | #6
On Thu, 2022-04-14 at 11:07 +0530, Vinod Koul wrote:
> On 13-04-22, 20:39, Liu Ying wrote:
> > On Wed, 2022-04-13 at 16:19 +0530, Vinod Koul wrote:
> > > On 13-04-22, 18:04, Liu Ying wrote:
> > > > Hi Vinod,
> > > > 
> > > > On Wed, 2022-04-13 at 11:41 +0530, Vinod Koul wrote:
> > > > > On 02-04-22, 13:24, Liu Ying wrote:
> > > > > > This patch allows LVDS PHYs to be configured through
> > > > > > the generic functions and through a custom structure
> > > > > > added to the generic union.
> > > > > > 
> > > > > > The parameters added here are based on common LVDS PHY
> > > > > > implementation practices.  The set of parameters
> > > > > > should cover all potential users.
> > > > > > 
> > > > > > Cc: Kishon Vijay Abraham I <kishon@ti.com>
> > > > > > Cc: Vinod Koul <vkoul@kernel.org>
> > > > > > Cc: NXP Linux Team <linux-imx@nxp.com>
> > > > > > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > > > > > ---
> > 
> > [...]
> > 
> > > > > > + */
> > > > > > +
> > > > > > +#ifndef __PHY_LVDS_H_
> > > > > > +#define __PHY_LVDS_H_
> > > > > > +
> > > > > > +/**
> > > > > > + * struct phy_configure_opts_lvds - LVDS configuration set
> > > > > > + * @bits_per_lane_and_dclk_cycle:	Number of bits per data
> > > > > > lane
> > > > > > and
> > > > > > + *					differential clock
> > > > > > cycle.
> > > > > 
> > > > > What does it mean by bits per data lane and differential
> > > > > clock
> > > > > cycle?
> > > > 
> > > > Please check
> > > > Documentation/devicetree/bindings/display/panel/lvds.yaml.
> > > > lvds.yaml metions slot.  'bits_per_lane_and_dclk_cycle' means
> > > > the
> > > > number of slots.  But, I don't find the word 'slot' in my lvds
> > > > relevant
> > > > specs which mentioned in lvds.yaml, so 'slots' is probably not
> > > > a
> > > > generic name(lvds.yaml is for display panel).  So, I use
> > > > 'bits_per_lane_and_dclk_cycle' as the name tells what it means.
> > > 
> > > variable name is fine, explanation for bit per lane and
> > > differential
> > > clock cycle didnt help, maybe add better explanation of what this
> > > variable means
> > 
> > I may add an example diagram as below...
> 
> Not really a diagram, you can add if you like.. But something which
> explains in a sentence or few about the variable.

Ok, no diagram.

> 
> bits per lane per differential clock cycle ?

Ok, will use this explaination.

Regards,
Liu Ying
diff mbox series

Patch

diff --git a/include/linux/phy/phy-lvds.h b/include/linux/phy/phy-lvds.h
new file mode 100644
index 000000000000..7a2f4747f624
--- /dev/null
+++ b/include/linux/phy/phy-lvds.h
@@ -0,0 +1,32 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2020 NXP
+ */
+
+#ifndef __PHY_LVDS_H_
+#define __PHY_LVDS_H_
+
+/**
+ * struct phy_configure_opts_lvds - LVDS configuration set
+ * @bits_per_lane_and_dclk_cycle:	Number of bits per data lane and
+ *					differential clock cycle.
+ * @differential_clk_rate:		Clock rate, in Hertz, of the LVDS
+ *					differential clock.
+ * @lanes:				Number of active, consecutive,
+ *					data lanes, starting from lane 0,
+ *					used for the transmissions.
+ * @is_slave:				Boolean, true if the phy is a slave
+ *					which works together with a master
+ *					phy to support dual link transmission,
+ *					otherwise a regular phy or a master phy.
+ *
+ * This structure is used to represent the configuration state of a LVDS phy.
+ */
+struct phy_configure_opts_lvds {
+	unsigned int	bits_per_lane_and_dclk_cycle;
+	unsigned long	differential_clk_rate;
+	unsigned int	lanes;
+	bool		is_slave;
+};
+
+#endif /* __PHY_LVDS_H_ */
diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
index f3286f4cd306..b1413757fcc3 100644
--- a/include/linux/phy/phy.h
+++ b/include/linux/phy/phy.h
@@ -17,6 +17,7 @@ 
 #include <linux/regulator/consumer.h>
 
 #include <linux/phy/phy-dp.h>
+#include <linux/phy/phy-lvds.h>
 #include <linux/phy/phy-mipi-dphy.h>
 
 struct phy;
@@ -57,10 +58,13 @@  enum phy_media {
  *		the MIPI_DPHY phy mode.
  * @dp:		Configuration set applicable for phys supporting
  *		the DisplayPort protocol.
+ * @lvds:	Configuration set applicable for phys supporting
+ *		the LVDS phy mode.
  */
 union phy_configure_opts {
 	struct phy_configure_opts_mipi_dphy	mipi_dphy;
 	struct phy_configure_opts_dp		dp;
+	struct phy_configure_opts_lvds		lvds;
 };
 
 /**