[Intel-gfx] [PATCH 27/27] drm/i915/gen11: add support for reading the timestamp frequency

[Lionel Landwerlin]

On 09/01/18 23:28, Paulo Zanoni wrote:
> The only thing that differs here is that the crystal clock freq now
> has four possible values.
>
> This patch gets rid of the "Unknown gen, unable to compute..." message
> at boot for gen11.
>
> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

Still

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_reg.h          |  6 +++
>   drivers/gpu/drm/i915/intel_device_info.c | 71 +++++++++++++++++++++++++-------
>   2 files changed, 61 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index eb6c7dcd4db0..fde88cd91ef1 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -1138,6 +1138,12 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
>   #define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK	(1 << GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT)
>   #define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ	0
>   #define  GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ	1
> +#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT	3
> +#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK	(0x7 << GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT)
> +#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ	0
> +#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ	1
> +#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_38_4_MHZ	2
> +#define  GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_25_MHZ	3
>   #define  GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT	1
>   #define  GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK	(0x3 << GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT)
>   
> diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
> index 895c41ef4abf..168f6ba83ddd 100644
> --- a/drivers/gpu/drm/i915/intel_device_info.c
> +++ b/drivers/gpu/drm/i915/intel_device_info.c
> @@ -395,6 +395,52 @@ static u32 read_reference_ts_freq(struct drm_i915_private *dev_priv)
>   	return base_freq + frac_freq;
>   }
>   
> +static u32 gen10_get_crystal_clock_freq(struct drm_i915_private *dev_priv,
> +					u32 rpm_config_reg)
> +{
> +	u32 f19_2_mhz = 19200;
> +	u32 f24_mhz = 24000;
> +	u32 crystal_clock = (rpm_config_reg &
> +			     GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
> +			    GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
> +
> +	switch (crystal_clock) {
> +	case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
> +		return f19_2_mhz;
> +	case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
> +		return f24_mhz;
> +	default:
> +		MISSING_CASE(crystal_clock);
> +		return 0;
> +	}
> +}
> +
> +static u32 gen11_get_crystal_clock_freq(struct drm_i915_private *dev_priv,
> +					u32 rpm_config_reg)
> +{
> +	u32 f19_2_mhz = 19200;
> +	u32 f24_mhz = 24000;
> +	u32 f25_mhz = 25000;
> +	u32 f38_4_mhz = 38400;
> +	u32 crystal_clock = (rpm_config_reg &
> +			     GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
> +			    GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
> +
> +	switch (crystal_clock) {
> +	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
> +		return f24_mhz;
> +	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
> +		return f19_2_mhz;
> +	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_38_4_MHZ:
> +		return f38_4_mhz;
> +	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_25_MHZ:
> +		return f25_mhz;
> +	default:
> +		MISSING_CASE(crystal_clock);
> +		return 0;
> +	}
> +}
> +
>   static u32 read_timestamp_frequency(struct drm_i915_private *dev_priv)
>   {
>   	u32 f12_5_mhz = 12500;
> @@ -435,10 +481,9 @@ static u32 read_timestamp_frequency(struct drm_i915_private *dev_priv)
>   		}
>   
>   		return freq;
> -	} else if (INTEL_GEN(dev_priv) <= 10) {
> +	} else if (INTEL_GEN(dev_priv) <= 11) {
>   		u32 ctc_reg = I915_READ(CTC_MODE);
>   		u32 freq = 0;
> -		u32 rpm_config_reg = 0;
>   
>   		/* First figure out the reference frequency. There are 2 ways
>   		 * we can compute the frequency, either through the
> @@ -448,20 +493,14 @@ static u32 read_timestamp_frequency(struct drm_i915_private *dev_priv)
>   		if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
>   			freq = read_reference_ts_freq(dev_priv);
>   		} else {
> -			u32 crystal_clock;
> -
> -			rpm_config_reg = I915_READ(RPM_CONFIG0);
> -			crystal_clock = (rpm_config_reg &
> -					 GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
> -				GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
> -			switch (crystal_clock) {
> -			case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
> -				freq = f19_2_mhz;
> -				break;
> -			case GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
> -				freq = f24_mhz;
> -				break;
> -			}
> +			u32 rpm_config_reg = I915_READ(RPM_CONFIG0);
> +
> +			if (INTEL_GEN(dev_priv) <= 10)
> +				freq = gen10_get_crystal_clock_freq(dev_priv,
> +								rpm_config_reg);
> +			else
> +				freq = gen11_get_crystal_clock_freq(dev_priv,
> +								rpm_config_reg);
>   
>   			/* Now figure out how the command stream's timestamp
>   			 * register increments from this frequency (it might