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[V6,0/6] drm: bridge: samsung-dsim: Support variable clocking

Message ID 20230515235713.232939-1-aford173@gmail.com (mailing list archive)
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Series drm: bridge: samsung-dsim: Support variable clocking | expand

Message

Adam Ford May 15, 2023, 11:57 p.m. UTC
This series fixes the blanking pack size and the PMS calculation.  It then
adds support to allows the DSIM to dynamically DPHY clocks, and support
non-burst mode while allowing the removal of the hard-coded clock values
for the PLL for imx8m mini/nano/plus, and it allows the removal of the
burst-clock device tree entry when burst-mode isn't supported by connected
devices like an HDMI brige.  In that event, the HS clock is set to the
value requested by the bridge chip.

This has been tested on both an i.MX8M Nano and i.MX8M Plus, and should
work on i.MX8M Mini as well. Marek Szyprowski has tested it on various
Exynos boards.

Adam Ford (5):
  drm: bridge: samsung-dsim: Fix PMS Calculator on imx8m[mnp]
  drm: bridge: samsung-dsim: Fetch pll-clock-frequency automatically
  drm: bridge: samsung-dsim: Select GENERIC_PHY_MIPI_DPHY
  drm: bridge: samsung-dsim: Dynamically configure DPHY timing
  drm: bridge: samsung-dsim: Support non-burst mode

Lucas Stach (1):
  drm: bridge: samsung-dsim: fix blanking packet size calculation

 drivers/gpu/drm/bridge/Kconfig        |   1 +
 drivers/gpu/drm/bridge/samsung-dsim.c | 143 +++++++++++++++++++++-----
 include/drm/bridge/samsung-dsim.h     |   4 +
 3 files changed, 125 insertions(+), 23 deletions(-)


V6:  Squash-in an additional error fix from Lucas Stach regarding the
     DPHY calcuations.  Remove the dynamic_dphy variable and let
     everyone use the new calculations.  Move the hs_clock caching
     from patch 6 to patch 5 to go along with the DPHY calcuations
     since they are now based on the recorded hs_clock rate.
     
V5:  Update error message to dev_info and change them to indicate
     what is happening without sounding like an error when optional
     device tree entries are missing.

V4:  Undo some accidental whitespace changes, rename PS_TO_CYCLE
     variables to ps and hz from PS and MHz. Remove if check
     before the samsung_dsim_set_phy_ctrl call since it's
     unnecessary.
     Added additional tested-by and reviewed-by comments.
     Squash patches 6 and 7 together since the supporting
     non-burst (patch 6) mode doesn't really work until
     patch 7 was applied.

V3:  When checking if the bust-clock is present, only check for it
     in the device tree, and don't check the presence of the
     MIPI_DSI_MODE_VIDEO_BURST flag as it breaks an existing Exynos
     board.

     Add a new patch to the series to select GENERIC_PHY_MIPI_DPHY in
     Kconfig otherwise the build breaks on the 32-bit Exynos.

     Change vco_min variable name to min_freq

     Added tested-by from Chen-Yu Tsai

V2:  Instead of using my packet blanking calculation, this integrates
     on from Lucas Stach which gets modified later in the series to
     cache the value of the HS-clock instead of having to do the
     calucations again.

     Instead of completely eliminating the PLL clock frequency from
     the device tree, this makes it optional to avoid breaking some
     Samsung devices.  When the samsung,pll-clock-frequency is not
     found, it reads the value of the clock named "sclk_mipi"
     This also maintains backwards compatibility with older device
     trees.

     This also changes the DPHY calcuation from a Look-up table,
     a reverse engineered algorithm which uses
     phy_mipi_dphy_get_default_config to determine the standard
     nominal values and calculates the cycles necessary to update
     the DPHY timings accordingly.

Comments

Marek Szyprowski May 16, 2023, 10:57 p.m. UTC | #1
On 16.05.2023 01:57, Adam Ford wrote:
> This series fixes the blanking pack size and the PMS calculation.  It then
> adds support to allows the DSIM to dynamically DPHY clocks, and support
> non-burst mode while allowing the removal of the hard-coded clock values
> for the PLL for imx8m mini/nano/plus, and it allows the removal of the
> burst-clock device tree entry when burst-mode isn't supported by connected
> devices like an HDMI brige.  In that event, the HS clock is set to the
> value requested by the bridge chip.
>
> This has been tested on both an i.MX8M Nano and i.MX8M Plus, and should
> work on i.MX8M Mini as well. Marek Szyprowski has tested it on various
> Exynos boards.
>
> Adam Ford (5):
>    drm: bridge: samsung-dsim: Fix PMS Calculator on imx8m[mnp]
>    drm: bridge: samsung-dsim: Fetch pll-clock-frequency automatically
>    drm: bridge: samsung-dsim: Select GENERIC_PHY_MIPI_DPHY
>    drm: bridge: samsung-dsim: Dynamically configure DPHY timing
>    drm: bridge: samsung-dsim: Support non-burst mode
>
> Lucas Stach (1):
>    drm: bridge: samsung-dsim: fix blanking packet size calculation
>
>   drivers/gpu/drm/bridge/Kconfig        |   1 +
>   drivers/gpu/drm/bridge/samsung-dsim.c | 143 +++++++++++++++++++++-----
>   include/drm/bridge/samsung-dsim.h     |   4 +
>   3 files changed, 125 insertions(+), 23 deletions(-)

Feel free to add to all patches:

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>


> V6:  Squash-in an additional error fix from Lucas Stach regarding the
>       DPHY calcuations.  Remove the dynamic_dphy variable and let
>       everyone use the new calculations.  Move the hs_clock caching
>       from patch 6 to patch 5 to go along with the DPHY calcuations
>       since they are now based on the recorded hs_clock rate.
>       
> V5:  Update error message to dev_info and change them to indicate
>       what is happening without sounding like an error when optional
>       device tree entries are missing.
>
> V4:  Undo some accidental whitespace changes, rename PS_TO_CYCLE
>       variables to ps and hz from PS and MHz. Remove if check
>       before the samsung_dsim_set_phy_ctrl call since it's
>       unnecessary.
>       Added additional tested-by and reviewed-by comments.
>       Squash patches 6 and 7 together since the supporting
>       non-burst (patch 6) mode doesn't really work until
>       patch 7 was applied.
>
> V3:  When checking if the bust-clock is present, only check for it
>       in the device tree, and don't check the presence of the
>       MIPI_DSI_MODE_VIDEO_BURST flag as it breaks an existing Exynos
>       board.
>
>       Add a new patch to the series to select GENERIC_PHY_MIPI_DPHY in
>       Kconfig otherwise the build breaks on the 32-bit Exynos.
>
>       Change vco_min variable name to min_freq
>
>       Added tested-by from Chen-Yu Tsai
>
> V2:  Instead of using my packet blanking calculation, this integrates
>       on from Lucas Stach which gets modified later in the series to
>       cache the value of the HS-clock instead of having to do the
>       calucations again.
>
>       Instead of completely eliminating the PLL clock frequency from
>       the device tree, this makes it optional to avoid breaking some
>       Samsung devices.  When the samsung,pll-clock-frequency is not
>       found, it reads the value of the clock named "sclk_mipi"
>       This also maintains backwards compatibility with older device
>       trees.
>
>       This also changes the DPHY calcuation from a Look-up table,
>       a reverse engineered algorithm which uses
>       phy_mipi_dphy_get_default_config to determine the standard
>       nominal values and calculates the cycles necessary to update
>       the DPHY timings accordingly.
>       

Best regards
Adam Ford May 17, 2023, 2:57 a.m. UTC | #2
On Tue, May 16, 2023 at 5:57 PM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> On 16.05.2023 01:57, Adam Ford wrote:
> > This series fixes the blanking pack size and the PMS calculation.  It then
> > adds support to allows the DSIM to dynamically DPHY clocks, and support
> > non-burst mode while allowing the removal of the hard-coded clock values
> > for the PLL for imx8m mini/nano/plus, and it allows the removal of the
> > burst-clock device tree entry when burst-mode isn't supported by connected
> > devices like an HDMI brige.  In that event, the HS clock is set to the
> > value requested by the bridge chip.
> >
> > This has been tested on both an i.MX8M Nano and i.MX8M Plus, and should
> > work on i.MX8M Mini as well. Marek Szyprowski has tested it on various
> > Exynos boards.
> >
> > Adam Ford (5):
> >    drm: bridge: samsung-dsim: Fix PMS Calculator on imx8m[mnp]
> >    drm: bridge: samsung-dsim: Fetch pll-clock-frequency automatically
> >    drm: bridge: samsung-dsim: Select GENERIC_PHY_MIPI_DPHY
> >    drm: bridge: samsung-dsim: Dynamically configure DPHY timing
> >    drm: bridge: samsung-dsim: Support non-burst mode
> >
> > Lucas Stach (1):
> >    drm: bridge: samsung-dsim: fix blanking packet size calculation
> >
> >   drivers/gpu/drm/bridge/Kconfig        |   1 +
> >   drivers/gpu/drm/bridge/samsung-dsim.c | 143 +++++++++++++++++++++-----
> >   include/drm/bridge/samsung-dsim.h     |   4 +
> >   3 files changed, 125 insertions(+), 23 deletions(-)
>
> Feel free to add to all patches:
>
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

Thanks for all your help testing.  I hope the V7 will be the last
attempt.  I've fixed the repeated declaration in patch 6, and added
your t-b statements to each of the patches with code changes.

I'm hoping to push V7 in a day or two pending any more feedback.

adam
>
>
> > V6:  Squash-in an additional error fix from Lucas Stach regarding the
> >       DPHY calcuations.  Remove the dynamic_dphy variable and let
> >       everyone use the new calculations.  Move the hs_clock caching
> >       from patch 6 to patch 5 to go along with the DPHY calcuations
> >       since they are now based on the recorded hs_clock rate.
> >
> > V5:  Update error message to dev_info and change them to indicate
> >       what is happening without sounding like an error when optional
> >       device tree entries are missing.
> >
> > V4:  Undo some accidental whitespace changes, rename PS_TO_CYCLE
> >       variables to ps and hz from PS and MHz. Remove if check
> >       before the samsung_dsim_set_phy_ctrl call since it's
> >       unnecessary.
> >       Added additional tested-by and reviewed-by comments.
> >       Squash patches 6 and 7 together since the supporting
> >       non-burst (patch 6) mode doesn't really work until
> >       patch 7 was applied.
> >
> > V3:  When checking if the bust-clock is present, only check for it
> >       in the device tree, and don't check the presence of the
> >       MIPI_DSI_MODE_VIDEO_BURST flag as it breaks an existing Exynos
> >       board.
> >
> >       Add a new patch to the series to select GENERIC_PHY_MIPI_DPHY in
> >       Kconfig otherwise the build breaks on the 32-bit Exynos.
> >
> >       Change vco_min variable name to min_freq
> >
> >       Added tested-by from Chen-Yu Tsai
> >
> > V2:  Instead of using my packet blanking calculation, this integrates
> >       on from Lucas Stach which gets modified later in the series to
> >       cache the value of the HS-clock instead of having to do the
> >       calucations again.
> >
> >       Instead of completely eliminating the PLL clock frequency from
> >       the device tree, this makes it optional to avoid breaking some
> >       Samsung devices.  When the samsung,pll-clock-frequency is not
> >       found, it reads the value of the clock named "sclk_mipi"
> >       This also maintains backwards compatibility with older device
> >       trees.
> >
> >       This also changes the DPHY calcuation from a Look-up table,
> >       a reverse engineered algorithm which uses
> >       phy_mipi_dphy_get_default_config to determine the standard
> >       nominal values and calculates the cycles necessary to update
> >       the DPHY timings accordingly.
> >
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>