[PATCH 1/5] drm/i915/dram: add intel_fsb_freq() and use it

[Rodrigo Vivi]

On Thu, Jul 31, 2025 at 05:21:21PM +0300, Jani Nikula wrote:
> Add a more generic intel_fsb_freq() function instead of platform
> specific ones.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_cdclk.c     |  2 +-
>  drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c |  2 +-
>  drivers/gpu/drm/i915/soc/intel_dram.c          | 14 ++++++++++----
>  drivers/gpu/drm/i915/soc/intel_dram.h          |  2 +-
>  4 files changed, 13 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index 228aa64c1349..50f8e8e7b2a2 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -3569,7 +3569,7 @@ static int i9xx_hrawclk(struct intel_display *display)
>  	struct drm_i915_private *i915 = to_i915(display->drm);
>  
>  	/* hrawclock is 1/4 the FSB frequency */
> -	return DIV_ROUND_CLOSEST(i9xx_fsb_freq(i915), 4);
> +	return DIV_ROUND_CLOSEST(intel_fsb_freq(i915), 4);
>  }
>  
>  /**
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
> index 6c499692d61e..88b147fa5cb1 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_clock_utils.c
> @@ -148,7 +148,7 @@ static u32 gen4_read_clock_frequency(struct intel_uncore *uncore)
>  	 *
>  	 * Testing on actual hardware has shown there is no /16.
>  	 */
> -	return DIV_ROUND_CLOSEST(i9xx_fsb_freq(uncore->i915), 4) * 1000;
> +	return DIV_ROUND_CLOSEST(intel_fsb_freq(uncore->i915), 4) * 1000;
>  }
>  
>  static u32 read_clock_frequency(struct intel_uncore *uncore)
> diff --git a/drivers/gpu/drm/i915/soc/intel_dram.c b/drivers/gpu/drm/i915/soc/intel_dram.c
> index deb159548a09..6be3618d4885 100644
> --- a/drivers/gpu/drm/i915/soc/intel_dram.c
> +++ b/drivers/gpu/drm/i915/soc/intel_dram.c
> @@ -153,7 +153,7 @@ static void detect_mem_freq(struct drm_i915_private *i915)
>  		drm_dbg(&i915->drm, "DDR speed: %d kHz\n", i915->mem_freq);
>  }
>  
> -unsigned int i9xx_fsb_freq(struct drm_i915_private *i915)
> +static unsigned int i9xx_fsb_freq(struct drm_i915_private *i915)
>  {
>  	u32 fsb;
>  
> @@ -235,13 +235,19 @@ static unsigned int ilk_fsb_freq(struct drm_i915_private *dev_priv)
>  	}
>  }
>  
> -static void detect_fsb_freq(struct drm_i915_private *i915)
> +unsigned int intel_fsb_freq(struct drm_i915_private *i915)
>  {
>  	if (GRAPHICS_VER(i915) == 5)
> -		i915->fsb_freq = ilk_fsb_freq(i915);
> +		return ilk_fsb_freq(i915);
>  	else if (GRAPHICS_VER(i915) == 3 || GRAPHICS_VER(i915) == 4)
> -		i915->fsb_freq = i9xx_fsb_freq(i915);
> +		return i9xx_fsb_freq(i915);
> +	else
> +		return 0;
> +}
>  
> +static void detect_fsb_freq(struct drm_i915_private *i915)
> +{
> +	i915->fsb_freq = intel_fsb_freq(i915);
>  	if (i915->fsb_freq)
>  		drm_dbg(&i915->drm, "FSB frequency: %d kHz\n", i915->fsb_freq);
>  }
> diff --git a/drivers/gpu/drm/i915/soc/intel_dram.h b/drivers/gpu/drm/i915/soc/intel_dram.h
> index 2a696e03aad4..09a7a581d949 100644
> --- a/drivers/gpu/drm/i915/soc/intel_dram.h
> +++ b/drivers/gpu/drm/i915/soc/intel_dram.h
> @@ -33,7 +33,7 @@ struct dram_info {
>  
>  void intel_dram_edram_detect(struct drm_i915_private *i915);
>  int intel_dram_detect(struct drm_i915_private *i915);
> -unsigned int i9xx_fsb_freq(struct drm_i915_private *i915);
> +unsigned int intel_fsb_freq(struct drm_i915_private *i915);
>  const struct dram_info *intel_dram_info(struct drm_device *drm);
>  
>  #endif /* __INTEL_DRAM_H__ */
> -- 
> 2.39.5
>