[PATCH v4 00/17] drm/bridge: cdns-dsi: Make it work a bit better

Tomi Valkeinen posted 17 patches 3 months, 3 weeks ago
There is a newer version of this series
drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 211 +++++++++++--------------
drivers/gpu/drm/tidss/tidss_crtc.c             |   2 +-
drivers/gpu/drm/tidss/tidss_dispc.c            |  16 +-
drivers/gpu/drm/tidss/tidss_dispc.h            |   3 +
drivers/gpu/drm/tidss/tidss_drv.h              |   2 +
drivers/gpu/drm/tidss/tidss_plane.h            |   2 +
drivers/gpu/drm/tidss/tidss_scale_coefs.h      |   2 +
drivers/phy/cadence/cdns-dphy.c                |  24 ++-
8 files changed, 115 insertions(+), 147 deletions(-)
[PATCH v4 00/17] drm/bridge: cdns-dsi: Make it work a bit better
Posted by Tomi Valkeinen 3 months, 3 weeks ago
While trying to get the cdns-dsi to work on Toradex's AM69 Aquila
platform, I hit multiple issues in the driver. Basicaly nothing worked
for with the board.

This series fixes those issues. While I itch to make much larger changes
to the cdns-dsi driver, I opted to keep this series relatively simple to
make the fixes more clear and possibly help with backporting.

The series also touches tidss, but those changes are not strictly
needed, and can be merged separately. And the series also touches
cdns-dphy, and those changes are needed.

This has been tested on Toradex AM69 Aquila (upstream) and AM62P Verdin
(Toradex's BSP), with:
- HDMI output using lontium lt8912b
- LVDS panel (sn65dsi84 + panel-lvds)

 Tomi

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
Changes in v4:
- Rebased on top of drm-misc-next, which has most of the dependencies
  merged
- Moved one dependency, "drm/bridge: cdns-dsi: Fix the _atomic_check()"
  into this series
- Dropped "drm/tidss: Adjust the pclk based on the HW capabilities".
  This causes a regression with OLDI outputs, and is not strictly
  required. Fixing this needs restructuring tidss clock handling.
- Link to v3: https://lore.kernel.org/r/20250414-cdns-dsi-impro-v3-0-4e52551d4f07@ideasonboard.com

Changes in v3:
- Add Aradhya's "drm/bridge: cdns-dsi: Fix the _atomic_check()" to the
  dependencies
- The above patch from Aradhya allowed adding "drm/bridge: cdns-dsi:
  Drop crtc_* code", which resulted in quite large changes in the
  commits, even if the end result doesn't really differ.
- Reordered commits to decrease back-and-forth (e.g. fixing something in
  a a code that will be removed in the next commits)
- The reordering caused quite big changes in the commits (even if the
  final end result is more or less the same), so I chose not to add
  tested-by tags.
- Rename 'cdns_get_dphy_pll_cfg' to 'cdns_dphy_get_pll_cfg'
- Use div_u64() instead of div64_u64()
- Drop "Fail if HS rate changed when validating PHY config". This was
  too strict, as clock rounding (especially with DRM's 1kHz
  resolution...) leads to clock rates that do not match exactly.
  However, the rate mismatch should be fine as the commits adjust the
  pixel clock, and the resulting differences should be so small that we
  can't even improve the timings match by adjusting the DSI HFP, as the
  adjustment rounds to 0.
- Link to v2: https://lore.kernel.org/r/20250402-cdns-dsi-impro-v2-0-4a093eaa5e27@ideasonboard.com

Changes in v2:
- Change the tidss clock adjustment from mode_fixup() to atomic_check()
- Link to v1: https://lore.kernel.org/r/20250320-cdns-dsi-impro-v1-0-725277c5f43b@ideasonboard.com

---
Aradhya Bhatia (1):
      drm/bridge: cdns-dsi: Fix the _atomic_check()

Tomi Valkeinen (16):
      drm/tidss: Fix missing includes and struct decls
      drm/tidss: Use the crtc_* timings when programming the HW
      phy: cdns-dphy: Store hs_clk_rate and return it
      phy: cdns-dphy: Remove leftover code
      drm/bridge: cdns-dsi: Remove extra line at the end of the file
      drm/bridge: cdns-dsi: Drop crtc_* code
      drm/bridge: cdns-dsi: Remove broken fifo emptying check
      drm/bridge: cdns-dsi: Drop checks that shouldn't be in .mode_valid()
      drm/bridge: cdns-dsi: Update htotal in cdns_dsi_mode2cfg()
      drm/bridge: cdns-dsi: Drop cdns_dsi_adjust_phy_config()
      drm/bridge: cdns-dsi: Adjust mode to negative syncs
      drm/bridge: cdns-dsi: Fix REG_WAKEUP_TIME value
      drm/bridge: cdns-dsi: Use video mode and clean up cdns_dsi_mode2cfg()
      drm/bridge: cdns-dsi: Fix event mode
      drm/bridge: cdns-dsi: Tune adjusted_mode->clock according to dsi needs
      drm/bridge: cdns-dsi: Don't fail on MIPI_DSI_MODE_VIDEO_BURST

 drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 211 +++++++++++--------------
 drivers/gpu/drm/tidss/tidss_crtc.c             |   2 +-
 drivers/gpu/drm/tidss/tidss_dispc.c            |  16 +-
 drivers/gpu/drm/tidss/tidss_dispc.h            |   3 +
 drivers/gpu/drm/tidss/tidss_drv.h              |   2 +
 drivers/gpu/drm/tidss/tidss_plane.h            |   2 +
 drivers/gpu/drm/tidss/tidss_scale_coefs.h      |   2 +
 drivers/phy/cadence/cdns-dphy.c                |  24 ++-
 8 files changed, 115 insertions(+), 147 deletions(-)
---
base-commit: 261a603062a87bad0b54904c76dacb15fa126c74
change-id: 20250320-cdns-dsi-impro-3d8fbd7848d1

Best regards,
-- 
Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Re: [PATCH v4 00/17] drm/bridge: cdns-dsi: Make it work a bit better
Posted by Jayesh Choudhary 3 months, 2 weeks ago
Hello Tomi,

On 18/06/25 15:29, Tomi Valkeinen wrote:
> While trying to get the cdns-dsi to work on Toradex's AM69 Aquila
> platform, I hit multiple issues in the driver. Basicaly nothing worked
> for with the board.
> 
> This series fixes those issues. While I itch to make much larger changes
> to the cdns-dsi driver, I opted to keep this series relatively simple to
> make the fixes more clear and possibly help with backporting.
> 
> The series also touches tidss, but those changes are not strictly
> needed, and can be merged separately. And the series also touches
> cdns-dphy, and those changes are needed.
> 
> This has been tested on Toradex AM69 Aquila (upstream) and AM62P Verdin
> (Toradex's BSP), with:
> - HDMI output using lontium lt8912b
> - LVDS panel (sn65dsi84 + panel-lvds)
> 
>   Tomi
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
> Changes in v4:
> - Rebased on top of drm-misc-next, which has most of the dependencies
>    merged
> - Moved one dependency, "drm/bridge: cdns-dsi: Fix the _atomic_check()"
>    into this series
> - Dropped "drm/tidss: Adjust the pclk based on the HW capabilities".
>    This causes a regression with OLDI outputs, and is not strictly
>    required. Fixing this needs restructuring tidss clock handling.

Here upon further investigating the issue for OLDI, that caused this
patch to be dropped, I saw that it was due to the VP clock owned by
OLDI driver. It does not actually go into the determine_rate() call
like we would expect it to.

Tested on J784S4-EVM platform (along with the DSI support as posted in
https://lore.kernel.org/all/20250624082619.324851-1-j-choudhary@ti.com/)
I can see that display comes up for 800x600 and 1280x1024 resolution.


Tested-by: Jayesh Choudhary <j-choudhary@ti.com>


I observed that we still need something like drm_mode_set_crtcinfo()
to propagate correct crtc_* fields even when we do not call round_rate()
Since mode_fixup() is not preferred now, we need it in atomic_check()
like you had it in v3:[3/17]

I have posted a delta patch on top of this series:
https://lore.kernel.org/all/20250624080402.302526-1-j-choudhary@ti.com/
that doe sit and helps in further enabling other modes.

Warm Regards,
Jayesh



> - Link to v3: https://lore.kernel.org/r/20250414-cdns-dsi-impro-v3-0-4e52551d4f07@ideasonboard.com
> 
> Changes in v3:
> - Add Aradhya's "drm/bridge: cdns-dsi: Fix the _atomic_check()" to the
>    dependencies
> - The above patch from Aradhya allowed adding "drm/bridge: cdns-dsi:
>    Drop crtc_* code", which resulted in quite large changes in the
>    commits, even if the end result doesn't really differ.
> - Reordered commits to decrease back-and-forth (e.g. fixing something in
>    a a code that will be removed in the next commits)
> - The reordering caused quite big changes in the commits (even if the
>    final end result is more or less the same), so I chose not to add
>    tested-by tags.
> - Rename 'cdns_get_dphy_pll_cfg' to 'cdns_dphy_get_pll_cfg'
> - Use div_u64() instead of div64_u64()
> - Drop "Fail if HS rate changed when validating PHY config". This was
>    too strict, as clock rounding (especially with DRM's 1kHz
>    resolution...) leads to clock rates that do not match exactly.
>    However, the rate mismatch should be fine as the commits adjust the
>    pixel clock, and the resulting differences should be so small that we
>    can't even improve the timings match by adjusting the DSI HFP, as the
>    adjustment rounds to 0.
> - Link to v2: https://lore.kernel.org/r/20250402-cdns-dsi-impro-v2-0-4a093eaa5e27@ideasonboard.com
> 
> Changes in v2:
> - Change the tidss clock adjustment from mode_fixup() to atomic_check()
> - Link to v1: https://lore.kernel.org/r/20250320-cdns-dsi-impro-v1-0-725277c5f43b@ideasonboard.com
> 
> ---
> Aradhya Bhatia (1):
>        drm/bridge: cdns-dsi: Fix the _atomic_check()
> 
> Tomi Valkeinen (16):
>        drm/tidss: Fix missing includes and struct decls
>        drm/tidss: Use the crtc_* timings when programming the HW
>        phy: cdns-dphy: Store hs_clk_rate and return it
>        phy: cdns-dphy: Remove leftover code
>        drm/bridge: cdns-dsi: Remove extra line at the end of the file
>        drm/bridge: cdns-dsi: Drop crtc_* code
>        drm/bridge: cdns-dsi: Remove broken fifo emptying check
>        drm/bridge: cdns-dsi: Drop checks that shouldn't be in .mode_valid()
>        drm/bridge: cdns-dsi: Update htotal in cdns_dsi_mode2cfg()
>        drm/bridge: cdns-dsi: Drop cdns_dsi_adjust_phy_config()
>        drm/bridge: cdns-dsi: Adjust mode to negative syncs
>        drm/bridge: cdns-dsi: Fix REG_WAKEUP_TIME value
>        drm/bridge: cdns-dsi: Use video mode and clean up cdns_dsi_mode2cfg()
>        drm/bridge: cdns-dsi: Fix event mode
>        drm/bridge: cdns-dsi: Tune adjusted_mode->clock according to dsi needs
>        drm/bridge: cdns-dsi: Don't fail on MIPI_DSI_MODE_VIDEO_BURST
> 
>   drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 211 +++++++++++--------------
>   drivers/gpu/drm/tidss/tidss_crtc.c             |   2 +-
>   drivers/gpu/drm/tidss/tidss_dispc.c            |  16 +-
>   drivers/gpu/drm/tidss/tidss_dispc.h            |   3 +
>   drivers/gpu/drm/tidss/tidss_drv.h              |   2 +
>   drivers/gpu/drm/tidss/tidss_plane.h            |   2 +
>   drivers/gpu/drm/tidss/tidss_scale_coefs.h      |   2 +
>   drivers/phy/cadence/cdns-dphy.c                |  24 ++-
>   8 files changed, 115 insertions(+), 147 deletions(-)
> ---
> base-commit: 261a603062a87bad0b54904c76dacb15fa126c74
> change-id: 20250320-cdns-dsi-impro-3d8fbd7848d1
> 
> Best regards,