diff mbox series

[v6,3/3] drm/stm: ltdc: add lvds pixel clock

Message ID 20240226-lvds-v6-3-15e3463fbe70@foss.st.com (mailing list archive)
State New, archived
Headers show
Series Introduce STM32 LVDS driver | expand

Commit Message

Raphael Gallais-Pou Feb. 26, 2024, 10:48 a.m. UTC
The STM32MP25x display subsystem presents a mux which feeds the loopback
pixel clock of the current bridge in use into the LTDC. This mux is only
accessible through sysconfig registers which is not yet available in the
STM32MP25x common clock framework.

While waiting for a complete update of the clock framework, this would
allow to use the LVDS.

Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Signed-off-by: Yannick Fertre <yannick.fertre@foss.st.com>
---
Changes in v2:
	- Fixed my address
	- Fixed smatch warning
---
 drivers/gpu/drm/stm/ltdc.c | 19 +++++++++++++++++++
 drivers/gpu/drm/stm/ltdc.h |  1 +
 2 files changed, 20 insertions(+)

Comments

Yannick FERTRE June 21, 2024, 2:55 p.m. UTC | #1
Hi Raphaël,

Thanks for your patch, it will not merged due to a new clock management.

Philippe,

this patch will be replaced by another which manages all clocks that the 
display controller

  will need (pixel clock, bus clock reference clock).


Best regards


Le 26/02/2024 à 11:48, Raphael Gallais-Pou a écrit :
> The STM32MP25x display subsystem presents a mux which feeds the loopback
> pixel clock of the current bridge in use into the LTDC. This mux is only
> accessible through sysconfig registers which is not yet available in the
> STM32MP25x common clock framework.
>
> While waiting for a complete update of the clock framework, this would
> allow to use the LVDS.
>
> Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
> Signed-off-by: Yannick Fertre <yannick.fertre@foss.st.com>
> ---
> Changes in v2:
> 	- Fixed my address
> 	- Fixed smatch warning
> ---
>   drivers/gpu/drm/stm/ltdc.c | 19 +++++++++++++++++++
>   drivers/gpu/drm/stm/ltdc.h |  1 +
>   2 files changed, 20 insertions(+)
>
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index 5576fdae4962..23011a8913bd 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -838,6 +838,12 @@ ltdc_crtc_mode_valid(struct drm_crtc *crtc,
>   	int target_max = target + CLK_TOLERANCE_HZ;
>   	int result;
>   
> +	if (ldev->lvds_clk) {
> +		result = clk_round_rate(ldev->lvds_clk, target);
> +		DRM_DEBUG_DRIVER("lvds pixclk rate target %d, available %d\n",
> +				 target, result);
> +	}
> +
>   	result = clk_round_rate(ldev->pixel_clk, target);
>   
>   	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
> @@ -1896,6 +1902,8 @@ void ltdc_suspend(struct drm_device *ddev)
>   
>   	DRM_DEBUG_DRIVER("\n");
>   	clk_disable_unprepare(ldev->pixel_clk);
> +	if (ldev->lvds_clk)
> +		clk_disable_unprepare(ldev->lvds_clk);
>   }
>   
>   int ltdc_resume(struct drm_device *ddev)
> @@ -1910,6 +1918,13 @@ int ltdc_resume(struct drm_device *ddev)
>   		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
>   		return ret;
>   	}
> +	if (ldev->lvds_clk) {
> +		if (clk_prepare_enable(ldev->lvds_clk)) {
> +			clk_disable_unprepare(ldev->pixel_clk);
> +			DRM_ERROR("Unable to prepare lvds clock\n");
> +			return -ENODEV;
> +		}
> +	}
>   
>   	return 0;
>   }
> @@ -1981,6 +1996,10 @@ int ltdc_load(struct drm_device *ddev)
>   		}
>   	}
>   
> +	ldev->lvds_clk = devm_clk_get(dev, "lvds");
> +	if (IS_ERR(ldev->lvds_clk))
> +		ldev->lvds_clk = NULL;
> +
>   	rstc = devm_reset_control_get_exclusive(dev, NULL);
>   
>   	mutex_init(&ldev->err_lock);
> diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
> index 9d488043ffdb..4a60ce5b610c 100644
> --- a/drivers/gpu/drm/stm/ltdc.h
> +++ b/drivers/gpu/drm/stm/ltdc.h
> @@ -44,6 +44,7 @@ struct ltdc_device {
>   	void __iomem *regs;
>   	struct regmap *regmap;
>   	struct clk *pixel_clk;	/* lcd pixel clock */
> +	struct clk *lvds_clk;	/* lvds pixel clock */
>   	struct mutex err_lock;	/* protecting error_status */
>   	struct ltdc_caps caps;
>   	u32 irq_status;
>
Philippe CORNU June 28, 2024, 12:45 p.m. UTC | #2
On 6/21/24 16:55, Yannick FERTRE wrote:
> Hi Raphaël,
> 
> Thanks for your patch, it will not merged due to a new clock management.
> 
> Philippe,
> 
> this patch will be replaced by another which manages all clocks that the 
> display controller
> 
>   will need (pixel clock, bus clock reference clock).

Hi Raphaël & Yannick,
I applied 1 & 2 on drm-misc-next.
Many thanks,
Philippe :-)


> 
> 
> Best regards
> 
> 
> Le 26/02/2024 à 11:48, Raphael Gallais-Pou a écrit :
>> The STM32MP25x display subsystem presents a mux which feeds the loopback
>> pixel clock of the current bridge in use into the LTDC. This mux is only
>> accessible through sysconfig registers which is not yet available in the
>> STM32MP25x common clock framework.
>>
>> While waiting for a complete update of the clock framework, this would
>> allow to use the LVDS.
>>
>> Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
>> Signed-off-by: Yannick Fertre <yannick.fertre@foss.st.com>
>> ---
>> Changes in v2:
>>     - Fixed my address
>>     - Fixed smatch warning
>> ---
>>   drivers/gpu/drm/stm/ltdc.c | 19 +++++++++++++++++++
>>   drivers/gpu/drm/stm/ltdc.h |  1 +
>>   2 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
>> index 5576fdae4962..23011a8913bd 100644
>> --- a/drivers/gpu/drm/stm/ltdc.c
>> +++ b/drivers/gpu/drm/stm/ltdc.c
>> @@ -838,6 +838,12 @@ ltdc_crtc_mode_valid(struct drm_crtc *crtc,
>>       int target_max = target + CLK_TOLERANCE_HZ;
>>       int result;
>> +    if (ldev->lvds_clk) {
>> +        result = clk_round_rate(ldev->lvds_clk, target);
>> +        DRM_DEBUG_DRIVER("lvds pixclk rate target %d, available %d\n",
>> +                 target, result);
>> +    }
>> +
>>       result = clk_round_rate(ldev->pixel_clk, target);
>>       DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, 
>> result);
>> @@ -1896,6 +1902,8 @@ void ltdc_suspend(struct drm_device *ddev)
>>       DRM_DEBUG_DRIVER("\n");
>>       clk_disable_unprepare(ldev->pixel_clk);
>> +    if (ldev->lvds_clk)
>> +        clk_disable_unprepare(ldev->lvds_clk);
>>   }
>>   int ltdc_resume(struct drm_device *ddev)
>> @@ -1910,6 +1918,13 @@ int ltdc_resume(struct drm_device *ddev)
>>           DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
>>           return ret;
>>       }
>> +    if (ldev->lvds_clk) {
>> +        if (clk_prepare_enable(ldev->lvds_clk)) {
>> +            clk_disable_unprepare(ldev->pixel_clk);
>> +            DRM_ERROR("Unable to prepare lvds clock\n");
>> +            return -ENODEV;
>> +        }
>> +    }
>>       return 0;
>>   }
>> @@ -1981,6 +1996,10 @@ int ltdc_load(struct drm_device *ddev)
>>           }
>>       }
>> +    ldev->lvds_clk = devm_clk_get(dev, "lvds");
>> +    if (IS_ERR(ldev->lvds_clk))
>> +        ldev->lvds_clk = NULL;
>> +
>>       rstc = devm_reset_control_get_exclusive(dev, NULL);
>>       mutex_init(&ldev->err_lock);
>> diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
>> index 9d488043ffdb..4a60ce5b610c 100644
>> --- a/drivers/gpu/drm/stm/ltdc.h
>> +++ b/drivers/gpu/drm/stm/ltdc.h
>> @@ -44,6 +44,7 @@ struct ltdc_device {
>>       void __iomem *regs;
>>       struct regmap *regmap;
>>       struct clk *pixel_clk;    /* lcd pixel clock */
>> +    struct clk *lvds_clk;    /* lvds pixel clock */
>>       struct mutex err_lock;    /* protecting error_status */
>>       struct ltdc_caps caps;
>>       u32 irq_status;
>>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 5576fdae4962..23011a8913bd 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -838,6 +838,12 @@  ltdc_crtc_mode_valid(struct drm_crtc *crtc,
 	int target_max = target + CLK_TOLERANCE_HZ;
 	int result;
 
+	if (ldev->lvds_clk) {
+		result = clk_round_rate(ldev->lvds_clk, target);
+		DRM_DEBUG_DRIVER("lvds pixclk rate target %d, available %d\n",
+				 target, result);
+	}
+
 	result = clk_round_rate(ldev->pixel_clk, target);
 
 	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);
@@ -1896,6 +1902,8 @@  void ltdc_suspend(struct drm_device *ddev)
 
 	DRM_DEBUG_DRIVER("\n");
 	clk_disable_unprepare(ldev->pixel_clk);
+	if (ldev->lvds_clk)
+		clk_disable_unprepare(ldev->lvds_clk);
 }
 
 int ltdc_resume(struct drm_device *ddev)
@@ -1910,6 +1918,13 @@  int ltdc_resume(struct drm_device *ddev)
 		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
 		return ret;
 	}
+	if (ldev->lvds_clk) {
+		if (clk_prepare_enable(ldev->lvds_clk)) {
+			clk_disable_unprepare(ldev->pixel_clk);
+			DRM_ERROR("Unable to prepare lvds clock\n");
+			return -ENODEV;
+		}
+	}
 
 	return 0;
 }
@@ -1981,6 +1996,10 @@  int ltdc_load(struct drm_device *ddev)
 		}
 	}
 
+	ldev->lvds_clk = devm_clk_get(dev, "lvds");
+	if (IS_ERR(ldev->lvds_clk))
+		ldev->lvds_clk = NULL;
+
 	rstc = devm_reset_control_get_exclusive(dev, NULL);
 
 	mutex_init(&ldev->err_lock);
diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
index 9d488043ffdb..4a60ce5b610c 100644
--- a/drivers/gpu/drm/stm/ltdc.h
+++ b/drivers/gpu/drm/stm/ltdc.h
@@ -44,6 +44,7 @@  struct ltdc_device {
 	void __iomem *regs;
 	struct regmap *regmap;
 	struct clk *pixel_clk;	/* lcd pixel clock */
+	struct clk *lvds_clk;	/* lvds pixel clock */
 	struct mutex err_lock;	/* protecting error_status */
 	struct ltdc_caps caps;
 	u32 irq_status;