From: Roman Beranek <romanberanek@icloud.com>
To: Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
Jernej Skrabec <jernej.skrabec@gmail.com>,
Samuel Holland <samuel@sholland.org>
Cc: dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org,
linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH] drm/sun4i: uncouple DSI dotclock divider from TCON0_DCLK_REG
Date: Mon, 20 Mar 2023 17:16:36 +0100 [thread overview]
Message-ID: <20230320161636.24411-1-romanberanek@icloud.com> (raw)
In the case of DSI output, the value of SUN4I_TCON0_DCLK_DIV (4) does
not represent the actual dotclock divider, PLL_MIPI instead runs at
(bpp / lanes )-multiple [1] of the dotclock. [2] Setting 4 as dotclock
divder thus leads to reduced frame rate, specifically by 1/3 on 4-lane
panels, and by 2/3 on 2-lane panels respectively.
As sun4i_dotclock driver stores its calculated divider directly in
the register, conditional handling of the DSI output scenario is needed.
Instead of reading the divider from SUN4I_TCON0_DCLK_REG, retrieve
the value from tcon->dclk_min_div.
[1] bits per pixel / number of DSI lanes
[2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp-4.4/blob/66bef0f2f30b367eb93b1cbad21ce85e0361f7ae/linux-sunxi/drivers/video/fbdev/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L322
Signed-off-by: Roman Beranek <romanberanek@icloud.com>
---
drivers/gpu/drm/sun4i/sun4i_dotclock.c | 6 +++++-
drivers/gpu/drm/sun4i/sun4i_tcon.c | 5 +++--
drivers/gpu/drm/sun4i/sun4i_tcon.h | 1 +
3 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 417ade3d2565..26fa99aff590 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -11,6 +11,7 @@
#include "sun4i_tcon.h"
#include "sun4i_dotclock.h"
+#include "sun6i_mipi_dsi.h"
struct sun4i_dclk {
struct clk_hw hw;
@@ -56,6 +57,9 @@ static unsigned long sun4i_dclk_recalc_rate(struct clk_hw *hw,
struct sun4i_dclk *dclk = hw_to_dclk(hw);
u32 val;
+ if (dclk->tcon->is_dsi)
+ return parent_rate / dclk->tcon->dclk_min_div;
+
regmap_read(dclk->regmap, SUN4I_TCON0_DCLK_REG, &val);
val >>= SUN4I_TCON0_DCLK_DIV_SHIFT;
@@ -116,7 +120,7 @@ static int sun4i_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct sun4i_dclk *dclk = hw_to_dclk(hw);
- u8 div = parent_rate / rate;
+ u8 div = dclk->tcon->is_dsi ? SUN6I_DSI_TCON_DIV : parent_rate / rate;
return regmap_update_bits(dclk->regmap, SUN4I_TCON0_DCLK_REG,
GENMASK(6, 0), div);
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 523a6d787921..7f5d3c135058 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -367,8 +367,9 @@ static void sun4i_tcon0_mode_set_cpu(struct sun4i_tcon *tcon,
u32 block_space, start_delay;
u32 tcon_div;
- tcon->dclk_min_div = SUN6I_DSI_TCON_DIV;
- tcon->dclk_max_div = SUN6I_DSI_TCON_DIV;
+ tcon->is_dsi = true;
+ tcon->dclk_min_div = bpp / lanes;
+ tcon->dclk_max_div = bpp / lanes;
sun4i_tcon0_mode_set_common(tcon, mode);
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index fa23aa23fe4a..d8150ba2f319 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -271,6 +271,7 @@ struct sun4i_tcon {
struct clk *dclk;
u8 dclk_max_div;
u8 dclk_min_div;
+ bool is_dsi;
/* Reset control */
struct reset_control *lcd_rst;
--
2.32.0 (Apple Git-132)
next reply other threads:[~2023-03-20 16:31 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-20 16:16 Roman Beranek [this message]
2023-03-21 14:56 ` [PATCH] drm/sun4i: uncouple DSI dotclock divider from TCON0_DCLK_REG Maxime Ripard
2023-03-21 16:50 ` Roman Beranek
2023-03-21 20:53 ` Roman Beranek
2023-03-27 20:21 ` Maxime Ripard
2023-03-25 11:40 ` Frank Oltmanns
2023-03-27 20:20 ` Maxime Ripard
2023-03-27 23:48 ` Roman Beranek
2023-03-29 19:58 ` Maxime Ripard
2023-03-30 4:45 ` Frank Oltmanns
2023-03-31 5:36 ` Roman Beranek
2023-04-05 12:34 ` Roman Beranek
2023-04-05 15:03 ` Maxime Ripard
2023-04-12 7:14 ` Roman Beranek
2023-04-12 14:09 ` Maxime Ripard
2023-04-08 7:07 ` Jernej Škrabec
2023-04-12 1:22 ` Roman Beranek
2023-03-28 19:28 ` Frank Oltmanns
2023-03-29 19:56 ` Maxime Ripard
2023-03-30 4:41 ` Frank Oltmanns
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