[PATCH V4 0/6] drm: bridge: samsung-dsim: Support variable clocking

From: Adam Ford
Date: Fri May 05 2023 - 21:09:53 EST


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.


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 | 145 +++++++++++++++++++++++---
include/drm/bridge/samsung-dsim.h | 5 +
3 files changed, 134 insertions(+), 17 deletions(-)

---
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 backwords 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.

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2.39.2