[PATCH v2 0/2] drm/msm/dsi: support CPHY mode for 7nm pll/phy

[PATCH v2 0/2] drm/msm/dsi: support CPHY mode for 7nm pll/phy

[Jonathan Marek]

Add the required changes to support 7nm pll/phy in CPHY mode.

This adds a "qcom,dsi-phy-cphy-mode" property for the PHY node to enable
the CPHY mode.

v2:
 - rebased on DSI PHY reworks
 - reworked getting cphy_mode in dsi_host.c
 - documentation change in separate patch

Jonathan Marek (2):
  drm/msm/dsi: support CPHY mode for 7nm pll/phy
  dt-bindings: display: msm/dsi: add qcom,dsi-phy-cphy-mode option

 .../devicetree/bindings/display/msm/dsi.txt   |   1 +
 drivers/gpu/drm/msm/dsi/dsi.xml.h             |   2 +
 drivers/gpu/drm/msm/dsi/dsi_host.c            |  34 +++-
 drivers/gpu/drm/msm/dsi/phy/dsi_phy.c         |  47 ++++++
 drivers/gpu/drm/msm/dsi/phy/dsi_phy.h         |   3 +
 drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c     | 147 ++++++++++++------
 6 files changed, 186 insertions(+), 48 deletions(-)

-- 
2.26.1

[PATCH v2 2/2] dt-bindings: display: msm/dsi: add qcom,dsi-phy-cphy-mode option

[Jonathan Marek]

Document qcom,dsi-phy-cphy-mode option, which can be used to control
whether DSI will operate in D-PHY (default) or C-PHY mode.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
---
 Documentation/devicetree/bindings/display/msm/dsi.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/display/msm/dsi.txt b/Documentation/devicetree/bindings/display/msm/dsi.txt
index b9a64d3ff184..7ffc86a9816b 100644
--- a/Documentation/devicetree/bindings/display/msm/dsi.txt
+++ b/Documentation/devicetree/bindings/display/msm/dsi.txt
@@ -124,6 +124,7 @@ Required properties:
 Optional properties:
 - qcom,dsi-phy-regulator-ldo-mode: Boolean value indicating if the LDO mode PHY
   regulator is wanted.
+- qcom,dsi-phy-cphy-mode: Boolean value indicating if CPHY mode is wanted.
 - qcom,mdss-mdp-transfer-time-us:	Specifies the dsi transfer time for command mode
 					panels in microseconds. Driver uses this number to adjust
 					the clock rate according to the expected transfer time.
-- 
2.26.1

Re: [PATCH v2 2/2] dt-bindings: display: msm/dsi: add qcom,dsi-phy-cphy-mode option

[Rob Herring]

On Fri, Apr 23, 2021 at 01:24:40PM -0400, Jonathan Marek wrote:
> Document qcom,dsi-phy-cphy-mode option, which can be used to control
> whether DSI will operate in D-PHY (default) or C-PHY mode.

Given this is a standard MIPI thing, I think this needs to be a common 
property. We already have phy bindings that use the phy cells to set the 
phy type which I think you should use here. See 
include/dt-bindings/phy/phy.h.

> 
> Signed-off-by: Jonathan Marek <jonathan@marek.ca>
> ---
>  Documentation/devicetree/bindings/display/msm/dsi.txt | 1 +
>  1 file changed, 1 insertion(+)

Note that this file is in the process of being converted to schema. 
That's been going on for at least the last year... :(

Re: [Freedreno] [PATCH v2 2/2] dt-bindings: display: msm/dsi: add qcom, dsi-phy-cphy-mode option

[Jonathan Marek]

On 5/3/21 1:11 PM, Rob Herring wrote:
> On Fri, Apr 23, 2021 at 01:24:40PM -0400, Jonathan Marek wrote:
>> Document qcom,dsi-phy-cphy-mode option, which can be used to control
>> whether DSI will operate in D-PHY (default) or C-PHY mode.
> 
> Given this is a standard MIPI thing, I think this needs to be a common
> property. We already have phy bindings that use the phy cells to set the
> phy type which I think you should use here. See
> include/dt-bindings/phy/phy.h.
> 

Is it OK to simply change the option to something like "phy-mode = 
<PHY_TYPE_DSI_CPHY>;"?

(using phy-cells would be annoying to implement, with no benefit IMO)

Re: [Freedreno] [PATCH v2 2/2] dt-bindings: display: msm/dsi: add qcom, dsi-phy-cphy-mode option

[Dmitry Baryshkov]

On 28/05/2021 15:57, Jonathan Marek wrote:
> On 5/3/21 1:11 PM, Rob Herring wrote:
>> On Fri, Apr 23, 2021 at 01:24:40PM -0400, Jonathan Marek wrote:
>>> Document qcom,dsi-phy-cphy-mode option, which can be used to control
>>> whether DSI will operate in D-PHY (default) or C-PHY mode.
>>
>> Given this is a standard MIPI thing, I think this needs to be a common
>> property. We already have phy bindings that use the phy cells to set the
>> phy type which I think you should use here. See
>> include/dt-bindings/phy/phy.h.
>>
> 
> Is it OK to simply change the option to something like "phy-mode = 
> <PHY_TYPE_DSI_CPHY>;"?
> 
> (using phy-cells would be annoying to implement, with no benefit IMO)


To add another feather to the balance scales:

- `phys = <&dsi0_phy PHY_TYPE_DSI_CPHY>;` would bring knowledge about 
PHY mode to the DSI host (which does not really care about PHY mode)

- `phy-mode = <PHY_TYPE_DSI_CPHY>;` would stay in the PHY node, where 
this information belongs.

-- 
With best wishes
Dmitry