> On 06/18/2021 10:05 AM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> On Tue, Sep 25, 2018 at 6:34 PM Laurent Pinchart
> <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> wrote:
> > From: Ulrich Hecht <uli+renesas@xxxxxxxx>
> >
> > Adds LVDS decoder, HDMI encoder and connector for the Draak board.
> >
> > The LVDS0 and LVDS1 encoders can use the DU_DOTCLKIN0, DU_DOTCLKIN1 and
> > EXTAL externals clocks. Two of them are provided to the SoC on the Draak
> > board, hook them up in DT.
> >
> > Signed-off-by: Ulrich Hecht <uli+renesas@xxxxxxxx>
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> > Tested-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
>
> > --- a/arch/arm64/boot/dts/renesas/r8a77995-draak.dts
> > +++ b/arch/arm64/boot/dts/renesas/r8a77995-draak.dts
>
> > @@ -190,6 +225,43 @@
> >
> > };
> >
> > + hdmi-encoder@39 {
> > + compatible = "adi,adv7511w";
> > + reg = <0x39>, <0x3f>, <0x38>, <0x3c>;
> > + reg-names = "main", "edid", "packet", "cec";
> > + interrupt-parent = <&gpio1>;
> > + interrupts = <28 IRQ_TYPE_LEVEL_LOW>;
> > +
> > + /* Depends on LVDS */
> > + max-clock = <135000000>;
> > + min-vrefresh = <50>;
>
> Where do these two come from? They fail to validate with commit
> cfe34bb7a770c5d8 ("dt-bindings: drm: bridge: adi,adv7511.txt: convert
> to yaml").
> I can't find where it is used in the driver, nor in the driver history.
I have found a prototype patch in my archives that uses these properties. I guess the patch itself didn't make it into the final series, but the properties inadvertently did. I vaguely remember this was supposed to work around an issue with modes that use a higher clock than supported by one of the parts in the display pipeline.
I would say that if there are no issues with HDMI output, both the patch and the properties are obsolete.
For reference, this is the patch:
===snip===
>From 8502e09a87a02216a195a985243e3e6567848154 Mon Sep 17 00:00:00 2001
From: Koji Matsuoka <koji.matsuoka.xm@xxxxxxxxxxx>
Date: Thu, 7 Dec 2017 20:10:39 +0900
Subject: [PROTO][PATCH 05/10] drm/bridge: adv7511: Add max-clock, min-vrefresh
options
This patch adds the option to specify a maximal clock and a minimal vertical
refresh rate.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@xxxxxxxxxxx>
[uli: renamed properties, fixed transposed parsing]
Signed-off-by: Ulrich Hecht <uli+renesas@xxxxxxxx>
---
drivers/gpu/drm/bridge/adv7511/adv7511.h | 7 +++++++
drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 22 ++++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h b/drivers/gpu/drm/bridge/adv7511/adv7511.h
index 73d8ccb..7f29d4f 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511.h
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h
@@ -271,6 +271,8 @@ enum adv7511_sync_polarity {
* @sync_pulse: Select the sync pulse
* @vsync_polarity: vsync input signal configuration
* @hsync_polarity: hsync input signal configuration
+ * @min_vrefresh_option: min vrefresh option
+ * @max_freq_option: max frequency option
*/
struct adv7511_link_config {
unsigned int input_color_depth;
@@ -285,6 +287,9 @@ struct adv7511_link_config {
enum adv7511_input_sync_pulse sync_pulse;
enum adv7511_sync_polarity vsync_polarity;
enum adv7511_sync_polarity hsync_polarity;
+
+ unsigned int min_vrefresh_option;
+ unsigned int max_freq_option;
};
/**
@@ -354,6 +359,8 @@ struct adv7511 {
enum adv7511_sync_polarity vsync_polarity;
enum adv7511_sync_polarity hsync_polarity;
bool rgb;
+ unsigned int min_vref;
+ unsigned int max_freq;
struct gpio_desc *gpio_pd;
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index 6437b87..2938b02 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -323,6 +323,8 @@ static void adv7511_set_link_config(struct adv7511 *adv7511,
adv7511->hsync_polarity = config->hsync_polarity;
adv7511->vsync_polarity = config->vsync_polarity;
adv7511->rgb = config->input_colorspace == HDMI_COLORSPACE_RGB;
+ adv7511->min_vref = config->min_vrefresh_option;
+ adv7511->max_freq = config->max_freq_option;
}
static void __adv7511_power_on(struct adv7511 *adv7511)
@@ -660,6 +662,16 @@ static enum drm_mode_status adv7511_mode_valid(struct adv7511 *adv7511,
if (mode->clock > 165000)
return MODE_CLOCK_HIGH;
+ if (adv7511->max_freq) {
+ if (mode->clock > (adv7511->max_freq / 1000))
+ return MODE_CLOCK_HIGH;
+ }
+
+ if (adv7511->min_vref) {
+ if (drm_mode_vrefresh(mode) < adv7511->min_vref)
+ return MODE_BAD;
+ }
+
return MODE_OK;
}
@@ -1074,6 +1086,16 @@ static int adv7511_parse_dt(struct device_node *np,
config->vsync_polarity = ADV7511_SYNC_POLARITY_PASSTHROUGH;
config->hsync_polarity = ADV7511_SYNC_POLARITY_PASSTHROUGH;
+ ret = of_property_read_u32(np, "max-clock",
+ &config->max_freq_option);
+ if (ret < 0)
+ config->max_freq_option = 0;
+
+ ret = of_property_read_u32(np, "min-vrefresh",
+ &config->min_vrefresh_option);
+ if (ret < 0)
+ config->min_vrefresh_option = 0;
+
return 0;
}
--
2.7.4
===snip===
CU
Uli
