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[PATCH] drm: panel: jd9365da-h3: fix reset signal polarity

Hugo Villeneuve posted 1 patch 2 months ago 
drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
[PATCH] drm: panel: jd9365da-h3: fix reset signal polarity
Posted by Hugo Villeneuve 2 months ago 
From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

In jadard_prepare() a reset pulse is generated with the following
statements (delays ommited for clarity):

    gpiod_set_value(jadard->reset, 1); --> Deassert reset
    gpiod_set_value(jadard->reset, 0); --> Assert reset for 10ms
    gpiod_set_value(jadard->reset, 1); --> Deassert reset

However, specifying second argument of "0" to gpiod_set_value() means to
deassert the GPIO, and "1" means to assert it. If the reset signal is
defined as GPIO_ACTIVE_LOW in the DTS, the above statements will
incorrectly generate the reset pulse (inverted) and leave it asserted
(LOW) at the end of jadard_prepare().

Fix reset behavior by inverting gpiod_set_value() second argument
in jadard_prepare(). Also modify second argument to devm_gpiod_get()
in jadard_dsi_probe() to assert the reset when probing.

Do not modify it in jadard_unprepare() as it is already properly
asserted with "1", which seems to be the intended behavior.

Fixes: 6b818c533dd8 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
Cc: <stable@vger.kernel.org>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
 drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
index 44897e5218a69..6fec99cf4d935 100644
--- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
+++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
@@ -110,13 +110,13 @@ static int jadard_prepare(struct drm_panel *panel)
 	if (jadard->desc->lp11_to_reset_delay_ms)
 		msleep(jadard->desc->lp11_to_reset_delay_ms);
 
-	gpiod_set_value(jadard->reset, 1);
+	gpiod_set_value(jadard->reset, 0);
 	msleep(5);
 
-	gpiod_set_value(jadard->reset, 0);
+	gpiod_set_value(jadard->reset, 1);
 	msleep(10);
 
-	gpiod_set_value(jadard->reset, 1);
+	gpiod_set_value(jadard->reset, 0);
 	msleep(130);
 
 	ret = jadard->desc->init(jadard);
@@ -1131,7 +1131,7 @@ static int jadard_dsi_probe(struct mipi_dsi_device *dsi)
 	dsi->format = desc->format;
 	dsi->lanes = desc->lanes;
 
-	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(jadard->reset)) {
 		DRM_DEV_ERROR(&dsi->dev, "failed to get our reset GPIO\n");
 		return PTR_ERR(jadard->reset);

base-commit: 18ba6034468e7949a9e2c2cf28e2e123b4fe7a50
-- 
2.39.5
Re: [PATCH] drm: panel: jd9365da-h3: fix reset signal polarity
Posted by Neil Armstrong 1 month, 4 weeks ago 
Hi,

On 27/09/2024 15:53, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> 
> In jadard_prepare() a reset pulse is generated with the following
> statements (delays ommited for clarity):
> 
>      gpiod_set_value(jadard->reset, 1); --> Deassert reset
>      gpiod_set_value(jadard->reset, 0); --> Assert reset for 10ms
>      gpiod_set_value(jadard->reset, 1); --> Deassert reset
> 
> However, specifying second argument of "0" to gpiod_set_value() means to
> deassert the GPIO, and "1" means to assert it. If the reset signal is
> defined as GPIO_ACTIVE_LOW in the DTS, the above statements will
> incorrectly generate the reset pulse (inverted) and leave it asserted
> (LOW) at the end of jadard_prepare().

Did you check the polarity in DTS of _all_ users of this driver ?

Neil

> 
> Fix reset behavior by inverting gpiod_set_value() second argument
> in jadard_prepare(). Also modify second argument to devm_gpiod_get()
> in jadard_dsi_probe() to assert the reset when probing.
> 
> Do not modify it in jadard_unprepare() as it is already properly
> asserted with "1", which seems to be the intended behavior.
> 
> Fixes: 6b818c533dd8 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> ---
>   drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> index 44897e5218a69..6fec99cf4d935 100644
> --- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> +++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> @@ -110,13 +110,13 @@ static int jadard_prepare(struct drm_panel *panel)
>   	if (jadard->desc->lp11_to_reset_delay_ms)
>   		msleep(jadard->desc->lp11_to_reset_delay_ms);
>   
> -	gpiod_set_value(jadard->reset, 1);
> +	gpiod_set_value(jadard->reset, 0);
>   	msleep(5);
>   
> -	gpiod_set_value(jadard->reset, 0);
> +	gpiod_set_value(jadard->reset, 1);
>   	msleep(10);
>   
> -	gpiod_set_value(jadard->reset, 1);
> +	gpiod_set_value(jadard->reset, 0);
>   	msleep(130);
>   
>   	ret = jadard->desc->init(jadard);
> @@ -1131,7 +1131,7 @@ static int jadard_dsi_probe(struct mipi_dsi_device *dsi)
>   	dsi->format = desc->format;
>   	dsi->lanes = desc->lanes;
>   
> -	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
>   	if (IS_ERR(jadard->reset)) {
>   		DRM_DEV_ERROR(&dsi->dev, "failed to get our reset GPIO\n");
>   		return PTR_ERR(jadard->reset);
> 
> base-commit: 18ba6034468e7949a9e2c2cf28e2e123b4fe7a50
Re: [PATCH] drm: panel: jd9365da-h3: fix reset signal polarity
Posted by Hugo Villeneuve 1 month, 4 weeks ago 
On Mon, 30 Sep 2024 16:38:14 +0200
Neil Armstrong <neil.armstrong@linaro.org> wrote:

> Hi,
> 
> On 27/09/2024 15:53, Hugo Villeneuve wrote:
> > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> > 
> > In jadard_prepare() a reset pulse is generated with the following
> > statements (delays ommited for clarity):
> > 
> >      gpiod_set_value(jadard->reset, 1); --> Deassert reset
> >      gpiod_set_value(jadard->reset, 0); --> Assert reset for 10ms
> >      gpiod_set_value(jadard->reset, 1); --> Deassert reset
> > 
> > However, specifying second argument of "0" to gpiod_set_value() means to
> > deassert the GPIO, and "1" means to assert it. If the reset signal is
> > defined as GPIO_ACTIVE_LOW in the DTS, the above statements will
> > incorrectly generate the reset pulse (inverted) and leave it asserted
> > (LOW) at the end of jadard_prepare().
> 
> Did you check the polarity in DTS of _all_ users of this driver ?

Hi Neil,
I confirmed that no in-tree DTS is referencing this driver. I did a
search of all the compatible strings defined in the
"jadard,jd9365da-h3.yaml" file. I also did the same on Debian code
search.

Hugo.


> 
> Neil
> 
> > 
> > Fix reset behavior by inverting gpiod_set_value() second argument
> > in jadard_prepare(). Also modify second argument to devm_gpiod_get()
> > in jadard_dsi_probe() to assert the reset when probing.
> > 
> > Do not modify it in jadard_unprepare() as it is already properly
> > asserted with "1", which seems to be the intended behavior.
> > 
> > Fixes: 6b818c533dd8 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> > ---
> >   drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> > index 44897e5218a69..6fec99cf4d935 100644
> > --- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> > +++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> > @@ -110,13 +110,13 @@ static int jadard_prepare(struct drm_panel *panel)
> >   	if (jadard->desc->lp11_to_reset_delay_ms)
> >   		msleep(jadard->desc->lp11_to_reset_delay_ms);
> >   
> > -	gpiod_set_value(jadard->reset, 1);
> > +	gpiod_set_value(jadard->reset, 0);
> >   	msleep(5);
> >   
> > -	gpiod_set_value(jadard->reset, 0);
> > +	gpiod_set_value(jadard->reset, 1);
> >   	msleep(10);
> >   
> > -	gpiod_set_value(jadard->reset, 1);
> > +	gpiod_set_value(jadard->reset, 0);
> >   	msleep(130);
> >   
> >   	ret = jadard->desc->init(jadard);
> > @@ -1131,7 +1131,7 @@ static int jadard_dsi_probe(struct mipi_dsi_device *dsi)
> >   	dsi->format = desc->format;
> >   	dsi->lanes = desc->lanes;
> >   
> > -	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > +	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
> >   	if (IS_ERR(jadard->reset)) {
> >   		DRM_DEV_ERROR(&dsi->dev, "failed to get our reset GPIO\n");
> >   		return PTR_ERR(jadard->reset);
> > 
> > base-commit: 18ba6034468e7949a9e2c2cf28e2e123b4fe7a50
> 
> 


-- 
Hugo Villeneuve
Re: [PATCH] drm: panel: jd9365da-h3: fix reset signal polarity
Posted by neil.armstrong@linaro.org 1 month, 4 weeks ago 
On 30/09/2024 17:05, Hugo Villeneuve wrote:
> On Mon, 30 Sep 2024 16:38:14 +0200
> Neil Armstrong <neil.armstrong@linaro.org> wrote:
> 
>> Hi,
>>
>> On 27/09/2024 15:53, Hugo Villeneuve wrote:
>>> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
>>>
>>> In jadard_prepare() a reset pulse is generated with the following
>>> statements (delays ommited for clarity):
>>>
>>>       gpiod_set_value(jadard->reset, 1); --> Deassert reset
>>>       gpiod_set_value(jadard->reset, 0); --> Assert reset for 10ms
>>>       gpiod_set_value(jadard->reset, 1); --> Deassert reset
>>>
>>> However, specifying second argument of "0" to gpiod_set_value() means to
>>> deassert the GPIO, and "1" means to assert it. If the reset signal is
>>> defined as GPIO_ACTIVE_LOW in the DTS, the above statements will
>>> incorrectly generate the reset pulse (inverted) and leave it asserted
>>> (LOW) at the end of jadard_prepare().
>>
>> Did you check the polarity in DTS of _all_ users of this driver ?
> 
> Hi Neil,
> I confirmed that no in-tree DTS is referencing this driver. I did a
> search of all the compatible strings defined in the
> "jadard,jd9365da-h3.yaml" file. I also did the same on Debian code
> search.


OK then:
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

> 
> Hugo.
> 
> 
>>
>> Neil
>>
>>>
>>> Fix reset behavior by inverting gpiod_set_value() second argument
>>> in jadard_prepare(). Also modify second argument to devm_gpiod_get()
>>> in jadard_dsi_probe() to assert the reset when probing.
>>>
>>> Do not modify it in jadard_unprepare() as it is already properly
>>> asserted with "1", which seems to be the intended behavior.
>>>
>>> Fixes: 6b818c533dd8 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
>>> Cc: <stable@vger.kernel.org>
>>> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
>>> ---
>>>    drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 8 ++++----
>>>    1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
>>> index 44897e5218a69..6fec99cf4d935 100644
>>> --- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
>>> +++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
>>> @@ -110,13 +110,13 @@ static int jadard_prepare(struct drm_panel *panel)
>>>    	if (jadard->desc->lp11_to_reset_delay_ms)
>>>    		msleep(jadard->desc->lp11_to_reset_delay_ms);
>>>    
>>> -	gpiod_set_value(jadard->reset, 1);
>>> +	gpiod_set_value(jadard->reset, 0);
>>>    	msleep(5);
>>>    
>>> -	gpiod_set_value(jadard->reset, 0);
>>> +	gpiod_set_value(jadard->reset, 1);
>>>    	msleep(10);
>>>    
>>> -	gpiod_set_value(jadard->reset, 1);
>>> +	gpiod_set_value(jadard->reset, 0);
>>>    	msleep(130);
>>>    
>>>    	ret = jadard->desc->init(jadard);
>>> @@ -1131,7 +1131,7 @@ static int jadard_dsi_probe(struct mipi_dsi_device *dsi)
>>>    	dsi->format = desc->format;
>>>    	dsi->lanes = desc->lanes;
>>>    
>>> -	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
>>> +	jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
>>>    	if (IS_ERR(jadard->reset)) {
>>>    		DRM_DEV_ERROR(&dsi->dev, "failed to get our reset GPIO\n");
>>>    		return PTR_ERR(jadard->reset);
>>>
>>> base-commit: 18ba6034468e7949a9e2c2cf28e2e123b4fe7a50
>>
>>
> 
>

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