From 945f2672ccbb5c92a8a7bf23cba3a68a6b0885e7 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 9 Jun 2017 15:25:58 -0700 Subject: [PATCH] drm/i915/cnl: Implement .get_display_clock_speed() for CNL MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add support for reading out the cdclk frequency from the hardware on CNL. Very similar to BXT, with a few new twists and turns: * the PLL is now called CDCLK PLL, not DE PLL * reference clock can be 24 MHz in addition to the 19.2 MHz BXT had * the ratio now lives in the PLL enable register * Only 1x and 2x CD2X dividers are supported v2: Deal with PLL lock bit the same way as BXT/SKL do now v3: DSSM refclk indicator is bit 31 not 24 (Ander) v4: Rebased by Rodrigo after Ville's cdclk rework. v5: Set cdclk to the ref clock as previous platforms. (Imre) Signed-off-by: Ville Syrjälä Signed-off-by: Rodrigo Vivi Reviewed-by: Imre Deak Signed-off-by: Rodrigo Vivi Link: http://patchwork.freedesktop.org/patch/msgid/1497047175-27250-1-git-send-email-rodrigo.vivi@intel.com --- drivers/gpu/drm/i915/i915_reg.h | 5 +++ drivers/gpu/drm/i915/intel_cdclk.c | 56 +++++++++++++++++++++++++++++- 2 files changed, 60 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index b6d69e289974..ac3df675b4f3 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -6550,6 +6550,9 @@ enum { #define SKL_DFSM_PIPE_B_DISABLE (1 << 21) #define SKL_DFSM_PIPE_C_DISABLE (1 << 28) +#define SKL_DSSM _MMIO(0x51004) +#define CNL_DSSM_CDCLK_PLL_REFCLK_24MHz (1 << 31) + #define GEN7_FF_SLICE_CS_CHICKEN1 _MMIO(0x20e0) #define GEN9_FFSC_PERCTX_PREEMPT_CTRL (1<<14) @@ -8116,6 +8119,8 @@ enum { #define BXT_DE_PLL_ENABLE _MMIO(0x46070) #define BXT_DE_PLL_PLL_ENABLE (1 << 31) #define BXT_DE_PLL_LOCK (1 << 30) +#define CNL_CDCLK_PLL_RATIO(x) (x) +#define CNL_CDCLK_PLL_RATIO_MASK 0xff /* GEN9 DC */ #define DC_STATE_EN _MMIO(0x45504) diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c index 634c89fe6377..1b31d82b2cfe 100644 --- a/drivers/gpu/drm/i915/intel_cdclk.c +++ b/drivers/gpu/drm/i915/intel_cdclk.c @@ -1400,6 +1400,58 @@ void bxt_uninit_cdclk(struct drm_i915_private *dev_priv) bxt_set_cdclk(dev_priv, &cdclk_state); } +static void cnl_cdclk_pll_update(struct drm_i915_private *dev_priv, + struct intel_cdclk_state *cdclk_state) +{ + u32 val; + + if (I915_READ(SKL_DSSM) & CNL_DSSM_CDCLK_PLL_REFCLK_24MHz) + cdclk_state->ref = 24000; + else + cdclk_state->ref = 19200; + + cdclk_state->vco = 0; + + val = I915_READ(BXT_DE_PLL_ENABLE); + if ((val & BXT_DE_PLL_PLL_ENABLE) == 0) + return; + + if (WARN_ON((val & BXT_DE_PLL_LOCK) == 0)) + return; + + cdclk_state->vco = (val & CNL_CDCLK_PLL_RATIO_MASK) * cdclk_state->ref; +} + +static void cnl_get_cdclk(struct drm_i915_private *dev_priv, + struct intel_cdclk_state *cdclk_state) +{ + u32 divider; + int div; + + cnl_cdclk_pll_update(dev_priv, cdclk_state); + + cdclk_state->cdclk = cdclk_state->ref; + + if (cdclk_state->vco == 0) + return; + + divider = I915_READ(CDCLK_CTL) & BXT_CDCLK_CD2X_DIV_SEL_MASK; + + switch (divider) { + case BXT_CDCLK_CD2X_DIV_SEL_1: + div = 2; + break; + case BXT_CDCLK_CD2X_DIV_SEL_2: + div = 4; + break; + default: + MISSING_CASE(divider); + return; + } + + cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco, div); +} + /** * intel_cdclk_state_compare - Determine if two CDCLK states differ * @a: first CDCLK state @@ -1895,7 +1947,9 @@ void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv) skl_modeset_calc_cdclk; } - if (IS_GEN9_BC(dev_priv)) + if (IS_CANNONLAKE(dev_priv)) + dev_priv->display.get_cdclk = cnl_get_cdclk; + else if (IS_GEN9_BC(dev_priv)) dev_priv->display.get_cdclk = skl_get_cdclk; else if (IS_GEN9_LP(dev_priv)) dev_priv->display.get_cdclk = bxt_get_cdclk; -- 2.20.1