diff options
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 100 |
1 files changed, 97 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index fb3f4aaca2c..f1bb2e2ec17 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2675,6 +2675,97 @@ static bool intel_crtc_driving_pch(struct drm_crtc *crtc) return true; } +/* Program iCLKIP clock to the desired frequency */ +static void lpt_program_iclkip(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + struct drm_i915_private *dev_priv = dev->dev_private; + u32 divsel, phaseinc, auxdiv, phasedir = 0; + u32 temp; + + /* It is necessary to ungate the pixclk gate prior to programming + * the divisors, and gate it back when it is done. + */ + I915_WRITE(PIXCLK_GATE, PIXCLK_GATE_GATE); + + /* Disable SSCCTL */ + intel_sbi_write(dev_priv, SBI_SSCCTL6, + intel_sbi_read(dev_priv, SBI_SSCCTL6) | + SBI_SSCCTL_DISABLE); + + /* 20MHz is a corner case which is out of range for the 7-bit divisor */ + if (crtc->mode.clock == 20000) { + auxdiv = 1; + divsel = 0x41; + phaseinc = 0x20; + } else { + /* The iCLK virtual clock root frequency is in MHz, + * but the crtc->mode.clock in in KHz. To get the divisors, + * it is necessary to divide one by another, so we + * convert the virtual clock precision to KHz here for higher + * precision. + */ + u32 iclk_virtual_root_freq = 172800 * 1000; + u32 iclk_pi_range = 64; + u32 desired_divisor, msb_divisor_value, pi_value; + + desired_divisor = (iclk_virtual_root_freq / crtc->mode.clock); + msb_divisor_value = desired_divisor / iclk_pi_range; + pi_value = desired_divisor % iclk_pi_range; + + auxdiv = 0; + divsel = msb_divisor_value - 2; + phaseinc = pi_value; + } + + /* This should not happen with any sane values */ + WARN_ON(SBI_SSCDIVINTPHASE_DIVSEL(divsel) & + ~SBI_SSCDIVINTPHASE_DIVSEL_MASK); + WARN_ON(SBI_SSCDIVINTPHASE_DIR(phasedir) & + ~SBI_SSCDIVINTPHASE_INCVAL_MASK); + + DRM_DEBUG_KMS("iCLKIP clock: found settings for %dKHz refresh rate: auxdiv=%x, divsel=%x, phasedir=%x, phaseinc=%x\n", + crtc->mode.clock, + auxdiv, + divsel, + phasedir, + phaseinc); + + /* Program SSCDIVINTPHASE6 */ + temp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE6); + temp &= ~SBI_SSCDIVINTPHASE_DIVSEL_MASK; + temp |= SBI_SSCDIVINTPHASE_DIVSEL(divsel); + temp &= ~SBI_SSCDIVINTPHASE_INCVAL_MASK; + temp |= SBI_SSCDIVINTPHASE_INCVAL(phaseinc); + temp |= SBI_SSCDIVINTPHASE_DIR(phasedir); + temp |= SBI_SSCDIVINTPHASE_PROPAGATE; + + intel_sbi_write(dev_priv, + SBI_SSCDIVINTPHASE6, + temp); + + /* Program SSCAUXDIV */ + temp = intel_sbi_read(dev_priv, SBI_SSCAUXDIV6); + temp &= ~SBI_SSCAUXDIV_FINALDIV2SEL(1); + temp |= SBI_SSCAUXDIV_FINALDIV2SEL(auxdiv); + intel_sbi_write(dev_priv, + SBI_SSCAUXDIV6, + temp); + + + /* Enable modulator and associated divider */ + temp = intel_sbi_read(dev_priv, SBI_SSCCTL6); + temp &= ~SBI_SSCCTL_DISABLE; + intel_sbi_write(dev_priv, + SBI_SSCCTL6, + temp); + + /* Wait for initialization time */ + udelay(24); + + I915_WRITE(PIXCLK_GATE, PIXCLK_GATE_UNGATE); +} + /* * Enable PCH resources required for PCH ports: * - PCH PLLs @@ -2694,11 +2785,14 @@ static void ironlake_pch_enable(struct drm_crtc *crtc) /* For PCH output, training FDI link */ dev_priv->display.fdi_link_train(crtc); - intel_enable_pch_pll(intel_crtc); - - if (HAS_PCH_CPT(dev)) { + if (HAS_PCH_LPT(dev)) { + DRM_DEBUG_KMS("LPT detected: programming iCLKIP\n"); + lpt_program_iclkip(crtc); + } else if (HAS_PCH_CPT(dev)) { u32 sel; + intel_enable_pch_pll(intel_crtc); + temp = I915_READ(PCH_DPLL_SEL); switch (pipe) { default: |