Hi Giulio,
You did a typo
Il 13/01/2021 17:05, Giulio Benetti ha scritto:
From: Giulio Benetti giulio.benetti@micronovasrl.com
During commit 88bc4178568b ("drm: Use new DRM_BUS_FLAG_*_(DRIVE|SAMPLE)_(POS|NEG)EDGE flags") DRM_BUS_FLAG_* macros have been changed to avoid ambiguity but just because of this ambiguity previous DRM_BUS_FLAG_PIXDATA_(POS/NEG)EDGE were used meaning _SAMPLE_ not _DRIVE_. This leads to DLCK inversion and need to fix but instead of swapping phase values, let's adopt an easier approach Maxime suggested: It turned out that bit 26 of SUN4I_TCON0_IO_POL_REG is dedicated to invert DCLK polarity and this makes things really easier than before. So let's handle DCLK polarity by adding SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGEDGE as bit 26 and activating according to bus_flags the same way it is done for all the other signals polarity.
Fixes: 88bc4178568b ("drm: Use new DRM_BUS_FLAG_*_(DRIVE|SAMPLE)_(POS|NEG)EDGE flags") Suggested-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Giulio Benetti giulio.benetti@micronovasrl.com
V2->V3:
- squash 2 patches into 1
V3->V4:
- add SUN4I_TCON0_IO_POL_DCLK_POSITIVE to regmap_update_bits()
V4->V5: polarity is still wrong so:
- let's use SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGEDGE macro instead of _DCLK_POSITIVE(that would make sense only in realtion with DCLK)
- invert condition using _NEGEDGE instead of _POSEDGE and then matching with register bit SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGEDGE
- correct commit log according to V4->V5 changes
drivers/gpu/drm/sun4i/sun4i_tcon.c | 21 ++------------------- drivers/gpu/drm/sun4i/sun4i_tcon.h | 1 + 2 files changed, 3 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index eaaf5d70e352..c172ccfff7e5 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -569,30 +569,13 @@ static void sun4i_tcon0_mode_set_rgb(struct sun4i_tcon *tcon, if (info->bus_flags & DRM_BUS_FLAG_DE_LOW) val |= SUN4I_TCON0_IO_POL_DE_NEGATIVE;
- /*
* On A20 and similar SoCs, the only way to achieve Positive Edge* (Rising Edge), is setting dclk clock phase to 2/3(240°).* By default TCON works in Negative Edge(Falling Edge),* this is why phase is set to 0 in that case.* Unfortunately there's no way to logically invert dclk through* IO_POL register.* The only acceptable way to work, triple checked with scope,* is using clock phase set to 0° for Negative Edge and set to 240°* for Positive Edge.* On A33 and similar SoCs there would be a 90° phase option,* but it divides also dclk by 2.* Following code is a way to avoid quirks all around TCON* and DOTCLOCK drivers.*/- if (info->bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE)
clk_set_phase(tcon->dclk, 240);- if (info->bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
clk_set_phase(tcon->dclk, 0);
val |= SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGEDGE;regmap_update_bits(tcon->regs, SUN4I_TCON0_IO_POL_REG, SUN4I_TCON0_IO_POL_HSYNC_POSITIVE | SUN4I_TCON0_IO_POL_VSYNC_POSITIVE |
Here Below you missed an 'E'
SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGDGE | SUN4I_TCON0_IO_POL_DE_NEGATIVE, val);diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h index cfbf4e6c1679..c5ac1b02482c 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h @@ -113,6 +113,7 @@ #define SUN4I_TCON0_IO_POL_REG 0x88 #define SUN4I_TCON0_IO_POL_DCLK_PHASE(phase) ((phase & 3) << 28) #define SUN4I_TCON0_IO_POL_DE_NEGATIVE BIT(27) +#define SUN4I_TCON0_IO_POL_DCLK_DRIVE_NEGEDGE BIT(26) #define SUN4I_TCON0_IO_POL_HSYNC_POSITIVE BIT(25) #define SUN4I_TCON0_IO_POL_VSYNC_POSITIVE BIT(24)