[Intel-gfx] [PATCH 1/2] drm/i915: Allow /2 CD2X divider on gen11+
Ville Syrjälä
ville.syrjala at linux.intel.com
Tue Aug 27 13:52:50 UTC 2019
On Mon, Aug 26, 2019 at 03:55:39PM -0700, Matt Roper wrote:
> The bspec has just recently been updated with new cdclk values that
> require the use of a /2 CD2X divider rather than a /1 divider. Once we
> add the divider selection logic to ICL+ cdclk programming, we have
> pretty much the same logic we were already using on CNL, so it's simpler
> to drop icl_set_cdclk() completely and reuse cnl_set_cdclk() on gen11+
> platforms as well.
>
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_cdclk.c | 90 +++++++++-------------
> drivers/gpu/drm/i915/i915_reg.h | 1 +
> 2 files changed, 36 insertions(+), 55 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index 939088c7d814..a56ccd0930e0 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -1659,10 +1659,23 @@ static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
> cnl_cdclk_pll_enable(dev_priv, vco);
>
> val = divider | skl_cdclk_decimal(cdclk);
> - if (pipe == INVALID_PIPE)
> - val |= BXT_CDCLK_CD2X_PIPE_NONE;
> - else
> - val |= BXT_CDCLK_CD2X_PIPE(pipe);
> +
> + if (INTEL_GEN(dev_priv) >= 12) {
> + if (pipe == INVALID_PIPE)
> + val |= ICL_CDCLK_CD2X_PIPE_NONE;
> + else
> + val |= BXT_CDCLK_CD2X_PIPE(pipe);
Hmm. So the mess made here with icl is now fixed. Cool. Sad they
didn't fix it on icl as well.
However I have a feeling this may end up confusing people, so maybe we
should just add TGL_CDCLK_CD2X_PIPE()?
> + } else if (INTEL_GEN(dev_priv) >= 11) {
> + if (pipe == INVALID_PIPE)
> + val |= ICL_CDCLK_CD2X_PIPE_NONE;
> + else
> + val |= ICL_CDCLK_CD2X_PIPE(pipe);
> + } else {
> + if (pipe == INVALID_PIPE)
> + val |= BXT_CDCLK_CD2X_PIPE_NONE;
> + else
> + val |= BXT_CDCLK_CD2X_PIPE(pipe);
> + }
> I915_WRITE(CDCLK_CTL, val);
>
> if (pipe != INVALID_PIPE)
> @@ -1813,51 +1826,6 @@ static int icl_calc_cdclk_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
> return dev_priv->cdclk.hw.ref * ratio;
> }
>
> -static void icl_set_cdclk(struct drm_i915_private *dev_priv,
> - const struct intel_cdclk_state *cdclk_state,
> - enum pipe pipe)
> -{
> - unsigned int cdclk = cdclk_state->cdclk;
> - unsigned int vco = cdclk_state->vco;
> - int ret;
> -
> - ret = skl_pcode_request(dev_priv, SKL_PCODE_CDCLK_CONTROL,
> - SKL_CDCLK_PREPARE_FOR_CHANGE,
> - SKL_CDCLK_READY_FOR_CHANGE,
> - SKL_CDCLK_READY_FOR_CHANGE, 3);
> - if (ret) {
> - DRM_ERROR("Failed to inform PCU about cdclk change (%d)\n",
> - ret);
> - return;
> - }
> -
> - if (dev_priv->cdclk.hw.vco != 0 &&
> - dev_priv->cdclk.hw.vco != vco)
> - cnl_cdclk_pll_disable(dev_priv);
> -
> - if (dev_priv->cdclk.hw.vco != vco)
> - cnl_cdclk_pll_enable(dev_priv, vco);
> -
> - /*
> - * On ICL CD2X_DIV can only be 1, so we'll never end up changing the
> - * divider here synchronized to a pipe while CDCLK is on, nor will we
> - * need the corresponding vblank wait.
> - */
> - I915_WRITE(CDCLK_CTL, ICL_CDCLK_CD2X_PIPE_NONE |
> - skl_cdclk_decimal(cdclk));
> -
> - sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL,
> - cdclk_state->voltage_level);
> -
> - intel_update_cdclk(dev_priv);
> -
> - /*
> - * Can't read out the voltage level :(
> - * Let's just assume everything is as expected.
> - */
> - dev_priv->cdclk.hw.voltage_level = cdclk_state->voltage_level;
> -}
> -
> static u8 icl_calc_voltage_level(struct drm_i915_private *dev_priv, int cdclk)
> {
> if (IS_ELKHARTLAKE(dev_priv)) {
> @@ -1881,6 +1849,7 @@ static void icl_get_cdclk(struct drm_i915_private *dev_priv,
> struct intel_cdclk_state *cdclk_state)
> {
> u32 val;
> + int div;
>
> cdclk_state->bypass = 50000;
>
> @@ -1914,10 +1883,21 @@ static void icl_get_cdclk(struct drm_i915_private *dev_priv,
>
> cdclk_state->vco = (val & BXT_DE_PLL_RATIO_MASK) * cdclk_state->ref;
>
> - val = I915_READ(CDCLK_CTL);
> - WARN_ON((val & BXT_CDCLK_CD2X_DIV_SEL_MASK) != 0);
> + val = I915_READ(CDCLK_CTL) & BXT_CDCLK_CD2X_DIV_SEL_MASK;
> + switch (val) {
> + case BXT_CDCLK_CD2X_DIV_SEL_1:
> + div = 2;
> + break;
> + case BXT_CDCLK_CD2X_DIV_SEL_2:
> + div = 4;
> + break;
> + default:
> + MISSING_CASE(val);
> + div = 2;
> + break;
> + }
>
> - cdclk_state->cdclk = cdclk_state->vco / 2;
> + cdclk_state->cdclk = cdclk_state->vco / div;
cnl uses DIV_ROUND_CLOSEST(). In general this function looks rather
different to cnl_get_cdclk() even though the actual differences are
minimal. Some unification of style might be nice. Not sure if reusing
the cnl function on icl might actually make sense. Would require
a few ifs.
>
> out:
> /*
> @@ -1963,7 +1943,7 @@ static void icl_init_cdclk(struct drm_i915_private *dev_priv)
> icl_calc_voltage_level(dev_priv,
> sanitized_state.cdclk);
>
> - icl_set_cdclk(dev_priv, &sanitized_state, INVALID_PIPE);
> + cnl_set_cdclk(dev_priv, &sanitized_state, INVALID_PIPE);
> }
>
> static void icl_uninit_cdclk(struct drm_i915_private *dev_priv)
> @@ -1975,7 +1955,7 @@ static void icl_uninit_cdclk(struct drm_i915_private *dev_priv)
> cdclk_state.voltage_level = icl_calc_voltage_level(dev_priv,
> cdclk_state.cdclk);
>
> - icl_set_cdclk(dev_priv, &cdclk_state, INVALID_PIPE);
> + cnl_set_cdclk(dev_priv, &cdclk_state, INVALID_PIPE);
> }
>
> static void cnl_init_cdclk(struct drm_i915_private *dev_priv)
> @@ -2810,7 +2790,7 @@ void intel_update_rawclk(struct drm_i915_private *dev_priv)
> void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv)
> {
> if (INTEL_GEN(dev_priv) >= 11) {
> - dev_priv->display.set_cdclk = icl_set_cdclk;
> + dev_priv->display.set_cdclk = cnl_set_cdclk;
> dev_priv->display.modeset_calc_cdclk = icl_modeset_calc_cdclk;
> } else if (IS_CANNONLAKE(dev_priv)) {
> dev_priv->display.set_cdclk = cnl_set_cdclk;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index a142aa3d74e3..958dfdfb4e10 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -9671,6 +9671,7 @@ enum skl_power_gate {
> #define BXT_CDCLK_CD2X_PIPE(pipe) ((pipe) << 20)
> #define CDCLK_DIVMUX_CD_OVERRIDE (1 << 19)
> #define BXT_CDCLK_CD2X_PIPE_NONE BXT_CDCLK_CD2X_PIPE(3)
> +#define ICL_CDCLK_CD2X_PIPE(pipe) (_PICK(pipe, 0, 2, 6) << 19)
Could also do eg.
((((pipe) << 1) | ((pipe) & ~1)) << 19)
if we want to avoid the _PICK(). Doesn't really matter I suppose.
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> #define ICL_CDCLK_CD2X_PIPE_NONE (7 << 19)
> #define BXT_CDCLK_SSA_PRECHARGE_ENABLE (1 << 16)
> #define CDCLK_FREQ_DECIMAL_MASK (0x7ff)
> --
> 2.20.1
>
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--
Ville Syrjälä
Intel
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