diff mbox series

[2/2] drm/i915/icl: Get DDI clock for ICL for MG PLL and TBT PLL

Message ID 20180727200457.16560-2-paulo.r.zanoni@intel.com (mailing list archive)
State New, archived
Headers show
Series [1/2] drm/i915/icl: Implement HSDIV_RATIO of MG_CLKTOP2_HSCLKCTL_PORT reg as separate divider value defines | expand

Commit Message

Zanoni, Paulo R July 27, 2018, 8:04 p.m. UTC
From: Manasi Navare <manasi.d.navare@intel.com>

PLLs are the source clocks for the DDIs so in order to determine the
ddi clock we need to check the PLL configuration.

For MG PHy Ports (C - F), depending on whether it is a TBT PLL or MG
PLL the link lock can be obtained from the the PLL divisors based on
the specification.

v2 (from Paulo):
 * Make the algorithm look more like what's in the spec, also document
   where we differ form the spec and why.
 * Make the code a little more consistent with our coding style.

Cc: James Ausmus <james.ausmus@intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  |  5 ++
 drivers/gpu/drm/i915/intel_ddi.c | 81 +++++++++++++++++++++++++++++++-
 2 files changed, 84 insertions(+), 2 deletions(-)

Comments

Souza, Jose Aug. 13, 2018, 10:19 p.m. UTC | #1
On Fri, 2018-07-27 at 13:04 -0700, Paulo Zanoni wrote:
> From: Manasi Navare <manasi.d.navare@intel.com>
> 
> PLLs are the source clocks for the DDIs so in order to determine the
> ddi clock we need to check the PLL configuration.
> 
> For MG PHy Ports (C - F), depending on whether it is a TBT PLL or MG
> PLL the link lock can be obtained from the the PLL divisors based on
> the specification.
> 
> v2 (from Paulo):
>  * Make the algorithm look more like what's in the spec, also
> document
>    where we differ form the spec and why.
>  * Make the code a little more consistent with our coding style.
> 
> Cc: James Ausmus <james.ausmus@intel.com>
> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h  |  5 ++
>  drivers/gpu/drm/i915/intel_ddi.c | 81
> +++++++++++++++++++++++++++++++-
>  2 files changed, 84 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h
> index e04ac47d53db..cd37e76d4d19 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9458,6 +9458,7 @@ enum skl_power_gate {
>  #define   MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_5		(2 << 12)
>  #define   MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_7		(3 << 12)
>  #define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO(x)		((x) << 8)
> +#define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_SHIFT		8
>  #define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK		(0xf <<
> 8)
>  #define MG_CLKTOP2_HSCLKCTL(port) _MMIO_PORT((port) - PORT_C, \
>  					     _MG_CLKTOP2_HSCLKCTL_PORT1
> , \
> @@ -9468,7 +9469,10 @@ enum skl_power_gate {
>  #define _MG_PLL_DIV0_PORT3				0x16AA00
>  #define _MG_PLL_DIV0_PORT4				0x16BA00
>  #define   MG_PLL_DIV0_FRACNEN_H				(1 <<
> 30)
> +#define   MG_PLL_DIV0_FBDIV_FRAC_MASK			(0x3fff
> ff << 8)
> +#define   MG_PLL_DIV0_FBDIV_FRAC_SHIFT			8
>  #define   MG_PLL_DIV0_FBDIV_FRAC(x)			((x) << 8)
> +#define   MG_PLL_DIV0_FBDIV_INT_MASK			(0xff << 0)
>  #define   MG_PLL_DIV0_FBDIV_INT(x)			((x) << 0)
>  #define MG_PLL_DIV0(port) _MMIO_PORT((port) - PORT_C,
> _MG_PLL_DIV0_PORT1, \
>  				     _MG_PLL_DIV0_PORT2)
> @@ -9483,6 +9487,7 @@ enum skl_power_gate {
>  #define   MG_PLL_DIV1_DITHER_DIV_4			(2 << 12)
>  #define   MG_PLL_DIV1_DITHER_DIV_8			(3 << 12)
>  #define   MG_PLL_DIV1_NDIVRATIO(x)			((x) << 4)
> +#define   MG_PLL_DIV1_FBPREDIV_MASK			(0xf << 0)
>  #define   MG_PLL_DIV1_FBPREDIV(x)			((x) << 0)
>  #define MG_PLL_DIV1(port) _MMIO_PORT((port) - PORT_C,
> _MG_PLL_DIV1_PORT1, \
>  				     _MG_PLL_DIV1_PORT2)
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> b/drivers/gpu/drm/i915/intel_ddi.c
> index 0adc043529f2..a18d57046bcc 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1427,6 +1427,81 @@ static int cnl_calc_wrpll_link(struct
> drm_i915_private *dev_priv,
>  	return dco_freq / (p0 * p1 * p2 * 5);
>  }
>  
> +static int icl_calc_tbt_pll_link(struct drm_i915_private *dev_priv,
> +				 enum port port)
> +{
> +	u32 val = I915_READ(DDI_CLK_SEL(port)) & DDI_CLK_SEL_MASK;
> +
> +	switch (val) {
> +	case DDI_CLK_SEL_NONE:
> +		return 0;
> +	case DDI_CLK_SEL_TBT_162:
> +		return 162000;
> +	case DDI_CLK_SEL_TBT_270:
> +		return 270000;
> +	case DDI_CLK_SEL_TBT_540:
> +		return 540000;
> +	case DDI_CLK_SEL_TBT_810:
> +		return 810000;
> +	default:
> +		MISSING_CASE(val);
> +		return 0;
> +	}
> +}
> +
> +static int icl_calc_mg_pll_link(struct drm_i915_private *dev_priv,
> +				enum port port)
> +{
> +	u32 mg_pll_div0, mg_clktop_hsclkctl;
> +	u32 m1, m2_int, m2_frac, div1, div2, refclk;
> +	u64 tmp;
> +
> +	refclk = dev_priv->cdclk.hw.ref;
> +
> +	mg_pll_div0 = I915_READ(MG_PLL_DIV0(port));
> +	mg_clktop_hsclkctl = I915_READ(MG_CLKTOP2_HSCLKCTL(port));
> +
> +	m1 = I915_READ(MG_PLL_DIV1(port)) & MG_PLL_DIV1_FBPREDIV_MASK;
> +	m2_int = mg_pll_div0 & MG_PLL_DIV0_FBDIV_INT_MASK;
> +	m2_frac = (mg_pll_div0 & MG_PLL_DIV0_FRACNEN_H) ?
> +		  (mg_pll_div0 & MG_PLL_DIV0_FBDIV_FRAC_MASK) >>
> +		  MG_PLL_DIV0_FBDIV_FRAC_SHIFT : 0;
> +
> +	switch (mg_clktop_hsclkctl &
> MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_MASK) {
> +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_2:
> +		div1 = 2;
> +		break;
> +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_3:
> +		div1 = 3;
> +		break;
> +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_5:
> +		div1 = 5;
> +		break;
> +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_7:
> +		div1 = 7;
> +		break;
> +	default:
> +		MISSING_CASE(mg_clktop_hsclkctl);
> +		return 0;
> +	}
> +
> +	div2 = (mg_clktop_hsclkctl &
> MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK) >>
> +		MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_SHIFT;
> +	/* div2 value of 0 is same as 1 means no div */
> +	if (div2 == 0)
> +		div2 = 1;
> +
> +	/*
> +	 * Adjust the original formula to delay the division by 2^22 in
> order to
> +	 * minimize possible rounding errors.
> +	 */
> +	tmp = (u64)m1 * m2_int * refclk +
> +	      (((u64)m1 * m2_frac * refclk) >> 22);

In my calculations this is not the same as: M1 * M2 * refclk

As M2 is = m2_int + (m2_frac/2^22)

Other than that everything else looks good.


> +	tmp = div_u64(tmp, 5 * div1 * div2);
> +
> +	return tmp;
> +}
> +
>  static void ddi_dotclock_get(struct intel_crtc_state *pipe_config)
>  {
>  	int dotclock;
> @@ -1467,8 +1542,10 @@ static void icl_ddi_clock_get(struct
> intel_encoder *encoder,
>  			link_clock =
> icl_calc_dp_combo_pll_link(dev_priv,
>  								pll_id)
> ;
>  	} else {
> -		/* FIXME - Add for MG PLL */
> -		WARN(1, "MG PLL clock_get code not implemented yet\n");
> +		if (pll_id == DPLL_ID_ICL_TBTPLL)
> +			link_clock = icl_calc_tbt_pll_link(dev_priv,
> port);
> +		else
> +			link_clock = icl_calc_mg_pll_link(dev_priv,
> port);
>  	}
>  
>  	pipe_config->port_clock = link_clock;
Souza, Jose Aug. 14, 2018, 8:06 p.m. UTC | #2
On Mon, 2018-08-13 at 22:19 +0000, Souza, Jose wrote:
> On Fri, 2018-07-27 at 13:04 -0700, Paulo Zanoni wrote:
> > From: Manasi Navare <manasi.d.navare@intel.com>
> > 
> > PLLs are the source clocks for the DDIs so in order to determine
> > the
> > ddi clock we need to check the PLL configuration.
> > 
> > For MG PHy Ports (C - F), depending on whether it is a TBT PLL or
> > MG
> > PLL the link lock can be obtained from the the PLL divisors based
> > on
> > the specification.
> > 
> > v2 (from Paulo):
> >  * Make the algorithm look more like what's in the spec, also
> > document
> >    where we differ form the spec and why.
> >  * Make the code a little more consistent with our coding style.
> > 
> > Cc: James Ausmus <james.ausmus@intel.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h  |  5 ++
> >  drivers/gpu/drm/i915/intel_ddi.c | 81
> > +++++++++++++++++++++++++++++++-
> >  2 files changed, 84 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h
> > index e04ac47d53db..cd37e76d4d19 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -9458,6 +9458,7 @@ enum skl_power_gate {
> >  #define   MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_5		(2 <<
> > 12)
> >  #define   MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_7		(3 <<
> > 12)
> >  #define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO(x)		((x) <<
> > 8)
> > +#define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_SHIFT		8
> >  #define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK		(0xf <<
> > 8)
> >  #define MG_CLKTOP2_HSCLKCTL(port) _MMIO_PORT((port) - PORT_C, \
> >  					     _MG_CLKTOP2_HSCLKCTL_PORT1
> > , \
> > @@ -9468,7 +9469,10 @@ enum skl_power_gate {
> >  #define _MG_PLL_DIV0_PORT3				0x16AA00
> >  #define _MG_PLL_DIV0_PORT4				0x16BA00
> >  #define   MG_PLL_DIV0_FRACNEN_H				(1 <<
> > 30)
> > +#define   MG_PLL_DIV0_FBDIV_FRAC_MASK			(0x3fff
> > ff << 8)
> > +#define   MG_PLL_DIV0_FBDIV_FRAC_SHIFT			8
> >  #define   MG_PLL_DIV0_FBDIV_FRAC(x)			((x) <<
> > 8)
> > +#define   MG_PLL_DIV0_FBDIV_INT_MASK			(0xff
> > << 0)
> >  #define   MG_PLL_DIV0_FBDIV_INT(x)			((x) << 0)
> >  #define MG_PLL_DIV0(port) _MMIO_PORT((port) - PORT_C,
> > _MG_PLL_DIV0_PORT1, \
> >  				     _MG_PLL_DIV0_PORT2)
> > @@ -9483,6 +9487,7 @@ enum skl_power_gate {
> >  #define   MG_PLL_DIV1_DITHER_DIV_4			(2 << 12)
> >  #define   MG_PLL_DIV1_DITHER_DIV_8			(3 << 12)
> >  #define   MG_PLL_DIV1_NDIVRATIO(x)			((x) << 4)
> > +#define   MG_PLL_DIV1_FBPREDIV_MASK			(0xf <<
> > 0)
> >  #define   MG_PLL_DIV1_FBPREDIV(x)			((x) << 0)
> >  #define MG_PLL_DIV1(port) _MMIO_PORT((port) - PORT_C,
> > _MG_PLL_DIV1_PORT1, \
> >  				     _MG_PLL_DIV1_PORT2)
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> > b/drivers/gpu/drm/i915/intel_ddi.c
> > index 0adc043529f2..a18d57046bcc 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -1427,6 +1427,81 @@ static int cnl_calc_wrpll_link(struct
> > drm_i915_private *dev_priv,
> >  	return dco_freq / (p0 * p1 * p2 * 5);
> >  }
> >  
> > +static int icl_calc_tbt_pll_link(struct drm_i915_private
> > *dev_priv,
> > +				 enum port port)
> > +{
> > +	u32 val = I915_READ(DDI_CLK_SEL(port)) & DDI_CLK_SEL_MASK;
> > +
> > +	switch (val) {
> > +	case DDI_CLK_SEL_NONE:
> > +		return 0;
> > +	case DDI_CLK_SEL_TBT_162:
> > +		return 162000;
> > +	case DDI_CLK_SEL_TBT_270:
> > +		return 270000;
> > +	case DDI_CLK_SEL_TBT_540:
> > +		return 540000;
> > +	case DDI_CLK_SEL_TBT_810:
> > +		return 810000;
> > +	default:
> > +		MISSING_CASE(val);
> > +		return 0;
> > +	}
> > +}
> > +
> > +static int icl_calc_mg_pll_link(struct drm_i915_private *dev_priv,
> > +				enum port port)
> > +{
> > +	u32 mg_pll_div0, mg_clktop_hsclkctl;
> > +	u32 m1, m2_int, m2_frac, div1, div2, refclk;
> > +	u64 tmp;
> > +
> > +	refclk = dev_priv->cdclk.hw.ref;
> > +
> > +	mg_pll_div0 = I915_READ(MG_PLL_DIV0(port));
> > +	mg_clktop_hsclkctl = I915_READ(MG_CLKTOP2_HSCLKCTL(port));
> > +
> > +	m1 = I915_READ(MG_PLL_DIV1(port)) & MG_PLL_DIV1_FBPREDIV_MASK;
> > +	m2_int = mg_pll_div0 & MG_PLL_DIV0_FBDIV_INT_MASK;
> > +	m2_frac = (mg_pll_div0 & MG_PLL_DIV0_FRACNEN_H) ?
> > +		  (mg_pll_div0 & MG_PLL_DIV0_FBDIV_FRAC_MASK) >>
> > +		  MG_PLL_DIV0_FBDIV_FRAC_SHIFT : 0;
> > +
> > +	switch (mg_clktop_hsclkctl &
> > MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_MASK) {
> > +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_2:
> > +		div1 = 2;
> > +		break;
> > +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_3:
> > +		div1 = 3;
> > +		break;
> > +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_5:
> > +		div1 = 5;
> > +		break;
> > +	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_7:
> > +		div1 = 7;
> > +		break;
> > +	default:
> > +		MISSING_CASE(mg_clktop_hsclkctl);
> > +		return 0;
> > +	}
> > +
> > +	div2 = (mg_clktop_hsclkctl &
> > MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK) >>
> > +		MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_SHIFT;
> > +	/* div2 value of 0 is same as 1 means no div */
> > +	if (div2 == 0)
> > +		div2 = 1;
> > +
> > +	/*
> > +	 * Adjust the original formula to delay the division by 2^22 in
> > order to
> > +	 * minimize possible rounding errors.
> > +	 */
> > +	tmp = (u64)m1 * m2_int * refclk +
> > +	      (((u64)m1 * m2_frac * refclk) >> 22);
> 
> In my calculations this is not the same as: M1 * M2 * refclk
> 
> As M2 is = m2_int + (m2_frac/2^22)
> 
> Other than that everything else looks good.

Please disconsider that, I did the calculations again and this new
formula matches spec.

Reviewed-by: José Roberto de Souza <jose.souza@intel.com>


> 
> 
> > +	tmp = div_u64(tmp, 5 * div1 * div2);
> > +
> > +	return tmp;
> > +}
> > +
> >  static void ddi_dotclock_get(struct intel_crtc_state *pipe_config)
> >  {
> >  	int dotclock;
> > @@ -1467,8 +1542,10 @@ static void icl_ddi_clock_get(struct
> > intel_encoder *encoder,
> >  			link_clock =
> > icl_calc_dp_combo_pll_link(dev_priv,
> >  								pll_id)
> > ;
> >  	} else {
> > -		/* FIXME - Add for MG PLL */
> > -		WARN(1, "MG PLL clock_get code not implemented yet\n");
> > +		if (pll_id == DPLL_ID_ICL_TBTPLL)
> > +			link_clock = icl_calc_tbt_pll_link(dev_priv,
> > port);
> > +		else
> > +			link_clock = icl_calc_mg_pll_link(dev_priv,
> > port);
> >  	}
> >  
> >  	pipe_config->port_clock = link_clock;
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index e04ac47d53db..cd37e76d4d19 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -9458,6 +9458,7 @@  enum skl_power_gate {
 #define   MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_5		(2 << 12)
 #define   MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_7		(3 << 12)
 #define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO(x)		((x) << 8)
+#define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_SHIFT		8
 #define   MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK		(0xf << 8)
 #define MG_CLKTOP2_HSCLKCTL(port) _MMIO_PORT((port) - PORT_C, \
 					     _MG_CLKTOP2_HSCLKCTL_PORT1, \
@@ -9468,7 +9469,10 @@  enum skl_power_gate {
 #define _MG_PLL_DIV0_PORT3				0x16AA00
 #define _MG_PLL_DIV0_PORT4				0x16BA00
 #define   MG_PLL_DIV0_FRACNEN_H				(1 << 30)
+#define   MG_PLL_DIV0_FBDIV_FRAC_MASK			(0x3fffff << 8)
+#define   MG_PLL_DIV0_FBDIV_FRAC_SHIFT			8
 #define   MG_PLL_DIV0_FBDIV_FRAC(x)			((x) << 8)
+#define   MG_PLL_DIV0_FBDIV_INT_MASK			(0xff << 0)
 #define   MG_PLL_DIV0_FBDIV_INT(x)			((x) << 0)
 #define MG_PLL_DIV0(port) _MMIO_PORT((port) - PORT_C, _MG_PLL_DIV0_PORT1, \
 				     _MG_PLL_DIV0_PORT2)
@@ -9483,6 +9487,7 @@  enum skl_power_gate {
 #define   MG_PLL_DIV1_DITHER_DIV_4			(2 << 12)
 #define   MG_PLL_DIV1_DITHER_DIV_8			(3 << 12)
 #define   MG_PLL_DIV1_NDIVRATIO(x)			((x) << 4)
+#define   MG_PLL_DIV1_FBPREDIV_MASK			(0xf << 0)
 #define   MG_PLL_DIV1_FBPREDIV(x)			((x) << 0)
 #define MG_PLL_DIV1(port) _MMIO_PORT((port) - PORT_C, _MG_PLL_DIV1_PORT1, \
 				     _MG_PLL_DIV1_PORT2)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 0adc043529f2..a18d57046bcc 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1427,6 +1427,81 @@  static int cnl_calc_wrpll_link(struct drm_i915_private *dev_priv,
 	return dco_freq / (p0 * p1 * p2 * 5);
 }
 
+static int icl_calc_tbt_pll_link(struct drm_i915_private *dev_priv,
+				 enum port port)
+{
+	u32 val = I915_READ(DDI_CLK_SEL(port)) & DDI_CLK_SEL_MASK;
+
+	switch (val) {
+	case DDI_CLK_SEL_NONE:
+		return 0;
+	case DDI_CLK_SEL_TBT_162:
+		return 162000;
+	case DDI_CLK_SEL_TBT_270:
+		return 270000;
+	case DDI_CLK_SEL_TBT_540:
+		return 540000;
+	case DDI_CLK_SEL_TBT_810:
+		return 810000;
+	default:
+		MISSING_CASE(val);
+		return 0;
+	}
+}
+
+static int icl_calc_mg_pll_link(struct drm_i915_private *dev_priv,
+				enum port port)
+{
+	u32 mg_pll_div0, mg_clktop_hsclkctl;
+	u32 m1, m2_int, m2_frac, div1, div2, refclk;
+	u64 tmp;
+
+	refclk = dev_priv->cdclk.hw.ref;
+
+	mg_pll_div0 = I915_READ(MG_PLL_DIV0(port));
+	mg_clktop_hsclkctl = I915_READ(MG_CLKTOP2_HSCLKCTL(port));
+
+	m1 = I915_READ(MG_PLL_DIV1(port)) & MG_PLL_DIV1_FBPREDIV_MASK;
+	m2_int = mg_pll_div0 & MG_PLL_DIV0_FBDIV_INT_MASK;
+	m2_frac = (mg_pll_div0 & MG_PLL_DIV0_FRACNEN_H) ?
+		  (mg_pll_div0 & MG_PLL_DIV0_FBDIV_FRAC_MASK) >>
+		  MG_PLL_DIV0_FBDIV_FRAC_SHIFT : 0;
+
+	switch (mg_clktop_hsclkctl & MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_MASK) {
+	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_2:
+		div1 = 2;
+		break;
+	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_3:
+		div1 = 3;
+		break;
+	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_5:
+		div1 = 5;
+		break;
+	case MG_CLKTOP2_HSCLKCTL_HSDIV_RATIO_7:
+		div1 = 7;
+		break;
+	default:
+		MISSING_CASE(mg_clktop_hsclkctl);
+		return 0;
+	}
+
+	div2 = (mg_clktop_hsclkctl & MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_MASK) >>
+		MG_CLKTOP2_HSCLKCTL_DSDIV_RATIO_SHIFT;
+	/* div2 value of 0 is same as 1 means no div */
+	if (div2 == 0)
+		div2 = 1;
+
+	/*
+	 * Adjust the original formula to delay the division by 2^22 in order to
+	 * minimize possible rounding errors.
+	 */
+	tmp = (u64)m1 * m2_int * refclk +
+	      (((u64)m1 * m2_frac * refclk) >> 22);
+	tmp = div_u64(tmp, 5 * div1 * div2);
+
+	return tmp;
+}
+
 static void ddi_dotclock_get(struct intel_crtc_state *pipe_config)
 {
 	int dotclock;
@@ -1467,8 +1542,10 @@  static void icl_ddi_clock_get(struct intel_encoder *encoder,
 			link_clock = icl_calc_dp_combo_pll_link(dev_priv,
 								pll_id);
 	} else {
-		/* FIXME - Add for MG PLL */
-		WARN(1, "MG PLL clock_get code not implemented yet\n");
+		if (pll_id == DPLL_ID_ICL_TBTPLL)
+			link_clock = icl_calc_tbt_pll_link(dev_priv, port);
+		else
+			link_clock = icl_calc_mg_pll_link(dev_priv, port);
 	}
 
 	pipe_config->port_clock = link_clock;